cmd/syncthing: Updated code name

lib/events: Become a service (fixes #5372 ) (#5373 )
Here the event Logger is rewritten as a service with a main loop instead of mutexes. This loop has a select with essentially two legs: incoming events, and subscription changes. When both are possible select will chose one randomly, thus ensuring that in practice unsubscribes will happen timely and not block the system.
2026-01-03 03:19:04 -05:00 · 2018-12-26 17:23:05 +01:00 · 2018-12-13 13:42:28 +01:00 · 2018-12-13 08:11:51 +01:00 · 2018-12-12 12:09:39 +01:00 · 2018-12-12 07:45:23 +01:00
2997 changed files with 765874 additions and 398067 deletions
--- a/.gitattributes
+++ b/.gitattributes
@@ -6,4 +6,3 @@ vendor/**   -text=auto

 # Diffs on these files are meaningless
 *.svg           -diff
-*.pb.go         -diff
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -0,0 +1,2 @@
+/AUTHORS    @calmh
+/*.md       @calmh
--- a/.github/ISSUE_TEMPLATE.md
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,42 @@
+### DO NOT REPORT SECURITY ISSUES IN THIS ISSUE TRACKER
+
+Instead, contact security@syncthing.net directly - see
+https://syncthing.net/security.html for more information.
+
+### DO NOT POST SUPPORT REQUESTS OR GENERAL QUESTIONS IN THIS ISSUE TRACKER
+
+Please use the forum at https://forum.syncthing.net/ where a large number of
+helpful people hang out. This issue tracker is for reporting bugs or feature
+requests directly to the developers. Worst case you might get a short
+"that's a bug, please report it on GitHub" response on the forum, in which
+case we thank you for your patience and following our advice. :)
+
+### Please use the correct issue tracker
+
+If your problem relates to a Syncthing wrapper or [sub-project](https://github.com/syncthing) such as [Syncthing for Android](https://github.com/syncthing/syncthing-android/issues), [SyncTrayzor](https://github.com/canton7/synctrayzor) or the [documentation](https://github.com/syncthing/docs/issues), please use their respective issue trackers.
+
+### Does your log mention database corruption?
+
+If your Syncthing log reports panics because of database corruption it is most likely a fault with your system's storage or memory. Affected log entries will contain lines starting with `panic: leveldb`. You will need to delete the index database to clear this, by running `syncthing -reset-database`.
+
+### Please do post actual bug reports and feature requests.
+
+If your issue is a bug report, replace this boilerplate with a description
+of the problem, being sure to include at least:
+
+ - what happened,
+ - what you expected to happen instead, and
+ - any steps to reproduce the problem.
+
+Also fill out the version information below and add log output or
+screenshots as appropriate.
+
+If your issue is a feature request, simply replace this template text in
+its entirety.
+
+### Version Information
+
+Syncthing Version: v0.x.y
+OS Version: Windows 7 / Ubuntu 14.04 / ...
+Browser Version: (if applicable, for GUI issues)
+
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -20,13 +20,8 @@ If this is a user visible change (including API and protocol changes), add a lin
 to the corresponding pull request on https://github.com/syncthing/docs or describe
 the documentation changes necessary.

-### Authorship
+## Authorship
+
+Your name and email will be added automatically to the AUTHORS file
+based on the commit metadata.

-Every author of a code contribution (Go, Javascript, HTML, CSS etc, with the
-possible exception of minor typo corrections and similar) is recorded in the
-AUTHORS and NICKS files and the in-GUI credits. If this is your first
-contribution, a maintainer will add you properly before accepting the
-contribution. You need not do so yourself or worry about the fact that the
-"authors" automated test fails. However, if your name (such as you want it
-presented in the credits) is not visible on your Github profile or in your
-commit messages, please assist by providing it here.
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ stdiscosrv.exe
 *.tar.gz
 *.zip
 *.asc
+*.deb
 .jshintrc
 coverage.out
 files/pidx
@@ -15,3 +16,10 @@ syncthing.sig
 RELEASE
 deb
 lib/auto/gui.files.go
+snapcraft.yaml
+prime/
+snap/
+parts/
+stage/
+*.snap
+*.bz2
--- a/.mailmap
+++ b/.mailmap
@@ -1 +0,0 @@
-NICKS
--- a/106
+++ b/106
@@ -1,45 +1,73 @@
 # This is the official list of Syncthing authors for copyright purposes.
-# The format is:
+#
+# THIS FILE IS MOSTLY AUTO GENERATED. IF YOU'VE MADE A COMMIT TO THE
+# REPOSITORY YOU WILL BE ADDED HERE AUTOMATICALLY WITHOUT THE NEED FOR
+# ANY MANUAL ACTION.
+#
+# That said, you are welcome to correct your name or add a nickname / GitHub
+# user name as appropriate. The format is:
 #
 #    Name Name Name (nickname) <email1@example.com> <email2@example.com>
 #
-# The NICKS list is auto generated from this file.
+# The in-GUI authors list is periodically automatically updated from the
+# contents of this file.
+#

 Aaron Bieber (qbit) <qbit@deftly.net>
-Adam Piggott (simplypeachy) <aD@simplypeachy.co.uk> <simplypeachy@users.noreply.github.com>
+Adam Piggott (ProactiveServices) <aD@simplypeachy.co.uk> <simplypeachy@users.noreply.github.com> <ProactiveServices@users.noreply.github.com> <adam@proactiveservices.co.uk>
+Adel Qalieh (adelq) <aqalieh95@gmail.com> <adelq@users.noreply.github.com>
 Alessandro G. (alessandro.g89) <alessandro.g89@gmail.com>
 Alexander Graf (alex2108) <register-github@alex-graf.de>
 Alexandre Viau (aviau) <alexandre@alexandreviau.net> <aviau@debian.org>
 Anderson Mesquita (andersonvom) <andersonvom@gmail.com>
+andresvia <andres.via@gmail.com>
 Andrew Dunham (andrew-d) <andrew@du.nham.ca>
-Andrey D (scienmind) <scintertech@cryptolab.net>
+Andrew Rabert (nvllsvm) <ar@nullsum.net> <6550543+nvllsvm@users.noreply.github.com>
+Andrey D (scienmind) <scintertech@cryptolab.net> <scienmind@users.noreply.github.com>
+andyleap <andyleap@gmail.com>
 Antoine Lamielle (0x010C) <antoine.lamielle@0x010c.fr> <gh@0x010c.fr>
 Antony Male (canton7) <antony.male@gmail.com>
+Aranjedeath <Aranjedeath@users.noreply.github.com>
 Arthur Axel fREW Schmidt (frioux) <frew@afoolishmanifesto.com> <frioux@gmail.com>
 Audrius Butkevicius (AudriusButkevicius) <audrius.butkevicius@gmail.com>
+BAHADIR YILMAZ <bahadiryilmaz32@gmail.com>
 Bart De Vries (mogwa1) <devriesb@gmail.com>
 Ben Curthoys (bencurthoys) <ben@bencurthoys.com>
 Ben Schulz (uok) <ueomkail@gmail.com> <uok@users.noreply.github.com>
+Ben Shepherd (benshep) <bjashepherd@gmail.com>
 Ben Sidhom (bsidhom) <bsidhom@gmail.com>
+Benedikt Heine (bebehei) <bebe@bebehei.de>
+Benedikt Morbach <benedikt.morbach@googlemail.com>
+Benno Fünfstück <benno.fuenfstueck@gmail.com>
 Benny Ng (tpng) <benny.tpng@gmail.com>
+Boris Rybalkin <ribalkin@gmail.com>
 Brandon Philips (philips) <brandon@ifup.org>
 Brendan Long (brendanlong) <self@brendanlong.com>
 Brian R. Becker (brbecker) <brbecker@gmail.com>
 Caleb Callaway (cqcallaw) <enlightened.despot@gmail.com>
 Carsten Hagemann (Moter8) <moter8@gmail.com>
-Cathryne Linenweaver (Cathryne) <cathryne.linenweaver@gmail.com> <Cathryne@users.noreply.github.com>
+Cathryne Linenweaver (Cathryne) <cathryne.linenweaver@gmail.com> <Cathryne@users.noreply.github.com> <katrinleinweber@MAC.local>
 Cedric Staniewski (xduugu) <cedric@gmx.ca>
 Chris Howie (cdhowie) <me@chrishowie.com>
 Chris Joel (cdata) <chris@scriptolo.gy>
+Chris Tonkinson <chris@masterbran.ch>
+chucic <chucic@seznam.cz>
 Colin Kennedy (moshen) <moshen.colin@gmail.com>
+Cromefire_ <tim.l@nghorst.net>
+Dale Visser <dale.visser@live.com>
 Daniel Bergmann (brgmnn) <dan.arne.bergmann@gmail.com> <brgmnn@users.noreply.github.com>
 Daniel Harte (norgeous) <daniel@harte.me> <daniel@danielharte.co.uk> <norgeous@users.noreply.github.com>
 Daniel Martí (mvdan) <mvdan@mvdan.cc>
+Darshil Chanpura (dtchanpura) <dtchanpura@gmail.com> <dcprime314@gmail.com>
 David Rimmer (dinosore) <dinosore@dbrsoftware.co.uk>
 Denis A. (dva) <denisva@gmail.com>
 Dennis Wilson (snnd) <dw@risu.io>
+derekriemer <derek.riemer@colorado.edu>
+desbma <desbma@users.noreply.github.com>
+Dmitry Saveliev (dsaveliev) <d.e.saveliev@gmail.com>
 Dominik Heidler (asdil12) <dominik@heidler.eu>
 Elias Jarlebring (jarlebring) <jarlebring@gmail.com>
+Elliot Huffman <thelich2@gmail.com>
 Emil Hessman (ceh) <emil@hessman.se>
 Erik Meitner (WSGCSysadmin) <e.meitner@willystreet.coop>
 Federico Castagnini (facastagnini) <federico.castagnini@gmail.com>
@@ -48,52 +76,118 @@ Felix Unterpaintner (bigbear2nd) <bigbear2nd@gmail.com>
 Francois-Xavier Gsell (zukoo) <fxgsell@gmail.com>
 Frank Isemann (fti7) <frank@isemann.name>
 Gilli Sigurdsson (gillisig) <gilli@vx.is>
+Graham Miln (grahammiln) <graham.miln@dssw.co.uk> <graham.miln@miln.eu>
+Han Boetes <han@boetes.org>
+Harrison Jones (harrisonhjones) <harrisonhjones@users.noreply.github.com>
+Heiko Zuerker (Smiley73) <heiko@zuerker.org>
+Iain Barnett <iainspeed@gmail.com>
+Ian Johnson (anonymouse64) <ian.johnson@canonical.com> <person.uwsome@gmail.com>
 Jaakko Hannikainen (jgke) <jgke@jgke.fi>
 Jacek Szafarkiewicz (hadogenes) <szafar@linux.pl>
 Jake Peterson (acogdev) <jake@acogdev.com>
 Jakob Borg (calmh) <jakob@nym.se> <jakob@kastelo.net>
 James Patterson (jpjp) <jamespatterson@operamail.com> <jpjp@users.noreply.github.com>
+janost <janost@tuta.io>
 Jaroslav Malec (dzarda) <dzardacz@gmail.com>
+jaseg <githubaccount@jaseg.net>
+Jaya Chithra (jayachithra) <s.k.jayachithra@gmail.com>
 Jens Diemer (jedie) <github.com@jensdiemer.de> <git@jensdiemer.de>
+Jerry Jacobs (xor-gate) <jerry.jacobs@xor-gate.org> <xor-gate@users.noreply.github.com>
 Jochen Voss (seehuhn) <voss@seehuhn.de>
+Johan Andersson <j@i19.se>
 Johan Vromans (sciurius) <jvromans@squirrel.nl>
+John Rinehart (fuzzybear3965) <johnrichardrinehart@gmail.com>
+Jonathan Cross <jcross@gmail.com>
+Jose Manuel Delicado (jmdaweb) <jmdaweb@hotmail.com> <jmdaweb@users.noreply.github.com>
+Jörg Thalheim <Mic92@users.noreply.github.com>
 Karol Różycki (krozycki) <rozycki.karol@gmail.com>
+Keith Turner <kturner@apache.org>
 Kelong Cong (kc1212) <kc04bc@gmx.com> <kc1212@users.noreply.github.com>
 Ken'ichi Kamada (kamadak) <kamada@nanohz.org>
 Kevin Allen (ironmig) <kma1660@gmail.com>
+Kevin White, Jr. (kwhite17) <kevinwhite1710@gmail.com>
+klemens <ka7@github.com>
+Kurt Fitzner (Kudalufi) <kurt@va1der.ca> <kurt.fitzner@gmail.com>
 Lars K.W. Gohlke (lkwg82) <lkwg82@gmx.de>
+Laurent Arnoud <laurent@spkdev.net>
 Laurent Etiemble (letiemble) <laurent.etiemble@gmail.com> <laurent.etiemble@monobjc.net>
+Leo Arias (elopio) <yo@elopio.net>
+Liu Siyuan (liusy182) <liusy182@gmail.com> <liusy182@hotmail.com>
 Lode Hoste (Zillode) <zillode@zillode.be>
 Lord Landon Agahnim (LordLandon) <lordlandon@gmail.com>
 Majed Abdulaziz (majedev) <majed.alhajry@gmail.com>
 Marc Laporte (marclaporte) <marc@marclaporte.com> <marc@laporte.name>
 Marc Pujol (kilburn) <kilburn@la3.org>
 Marcin Dziadus (marcindziadus) <dziadus.marcin@gmail.com>
+marco-m <marco.molteni@laposte.net>
+Mark Pulford (mpx) <mark@kyne.com.au>
 Mateusz Naściszewski (mateon1) <matin1111@wp.pl>
+Matic Potočnik <hairyfotr@gmail.com>
 Matt Burke (burkemw3) <mburke@amplify.com> <burkemw3@gmail.com>
+Matteo Ruina <matteo.ruina@gmail.com>
 Max Schulze (kralo) <max.schulze@online.de> <kralo@users.noreply.github.com>
+MaximAL <almaximal@ya.ru>
+Maxime Thirouin <m@moox.io>
 Michael Jephcote (Rewt0r) <rewt0r@gmx.com> <Rewt0r@users.noreply.github.com>
 Michael Ploujnikov (plouj) <ploujj@gmail.com>
 Michael Tilli (pyfisch) <pyfisch@gmail.com>
+Mike Boone <mike@boonedocks.net>
+MikeLund <MikeLund@users.noreply.github.com>
 Nate Morrison (nrm21) <natemorrison@gmail.com>
+Nicholas Rishel (PrototypeNM1) <rishel.nick@gmail.com> <PrototypeNM1@users.noreply.github.com>
+Nico Stapelbroek <3368018+nstapelbroek@users.noreply.github.com>
+Nicolas Braud-Santoni <nicolas@braud-santoni.eu>
+Niels Peter Roest (Niller303) <nielsproest@hotmail.com> <seje.niels@hotmail.com>
+Nils Jakobi (thunderstorm99) <jakobi.nils@gmail.com>
+NoLooseEnds <jon.koslung@gmail.com>
+Oyebanji Jacob Mayowa <oyebanji05@gmail.com>
 Pascal Jungblut (pascalj) <github@pascalj.com> <mail@pascal-jungblut.com>
+Pawel Palenica (qepasa) <pawelpalenica11@gmail.com>
+Paweł Rozlach <vespian@users.noreply.github.com>
+perewa <cavalcante.ten@gmail.com>
+Peter Badida <KeyWeeUsr@users.noreply.github.com>
+Peter Dave Hello <hsu@peterdavehello.org>
 Peter Hoeg (peterhoeg) <peter@speartail.com>
+Peter Marquardt (wwwutz) <wwwutz@gmail.com> <wwwutz@googlemail.com>
+Phil Davis <phil.davis@inf.org>
 Philippe Schommers (filoozoom) <philippe@schommers.be>
 Phill Luby (pluby) <phill.luby@newredo.com>
+Pier Paolo Ramon <ramonpierre@gmail.com>
 Piotr Bejda (piobpl) <piotrb10@gmail.com>
+Pramodh KP (pramodhkp) <pramodh.p@directi.com> <1507241+pramodhkp@users.noreply.github.com>
+Richard Hartmann <RichiH@users.noreply.github.com>
+Robert Carosi (nov1n) <robert@carosi.nl>
+Roman Zaynetdinov (zaynetro) <romanznet@gmail.com>
+Ross Smith II (rasa) <ross@smithii.com>
+rubenbe <github-com-00ff86@vandamme.email>
 Ryan Sullivan (KayoticSully) <kayoticsully@gmail.com>
+Sacheendra Talluri (sacheendra) <sacheendra.t@gmail.com>
 Scott Klupfel (kluppy) <kluppy@going2blue.com>
 Sergey Mishin (ralder) <ralder@yandex.ru>
+Simon Frei (imsodin) <freisim93@gmail.com>
+Sly_tom_cat <slytomcat@mail.ru>
 Stefan Kuntz (Stefan-Code) <stefan.github@gmail.com> <Stefan.github@gmail.com>
 Stefan Tatschner (rumpelsepp) <stefan@sevenbyte.org> <rumpelsepp@sevenbyte.org>
+Suhas Gundimeda (snugghash) <suhas.gundimeda@gmail.com> <snugghash@gmail.com>
+Taylor Khan (nelsonkhan) <nelsonkhan@gmail.com>
+Thomas Hipp <thomashipp@gmail.com>
 Tim Abell (timabell) <tim@timwise.co.uk>
+Tim Howes (timhowes) <timhowes@berkeley.edu>
 Tobias Nygren (tnn2) <tnn@nygren.pp.se>
+Tobias Tom (tobiastom) <t.tom@succont.de>
 Tomas Cerveny (kozec) <kozec@kozec.com>
+Tommy Thorn <tommy-github-email@thorn.ws>
 Tully Robinson (tojrobinson) <tully@tojr.org>
 Tyler Brazier (tylerbrazier) <tyler@tylerbrazier.com>
+Unrud (Unrud) <unrud@openaliasbox.org> <Unrud@users.noreply.github.com>
 Veeti Paananen (veeti) <veeti.paananen@rojekti.fi>
 Victor Buinsky (buinsky) <vix_booja@tut.by>
 Vil Brekin (Vilbrekin) <vilbrekin@gmail.com>
+Vladimir Rusinov <vrusinov@google.com>
+wangguoliang <liangcszzu@163.com>
 William A. Kennington III (wkennington) <william@wkennington.com>
-Wulf Weich (wweich) <wweich@users.noreply.github.com> <wweich@gmx.de>
+Wulf Weich (wweich) <wweich@users.noreply.github.com> <wweich@gmx.de> <wulf@weich-kr.de>
+Xavier O. (damajor) <damajor@gmail.com>
+xjtdy888 (xjtdy888) <xjtdy888@163.com>
 Yannic A. (eipiminus1) <eipiminusone+github@gmail.com> <eipiminus1@users.noreply.github.com>
+佛跳墙 <daoquan@qq.com>
--- a/CONDUCT.md
+++ b/CONDUCT.md
@@ -1,92 +1,73 @@
-## Conduct
+# Contributor Covenant Code of Conduct

-* We are committed to providing a friendly, safe and welcoming
-  environment for all, regardless of gender, sexual orientation,
-  disability, ethnicity, religion, or similar personal characteristic.
+## Our Pledge

-* On IRC, please avoid using overtly sexual nicknames or other nicknames
-  that might detract from a friendly, safe and welcoming environment for
-  all.
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+education, socio-economic status, nationality, personal appearance, race,
+religion, or sexual identity and orientation.

-* Please be kind and courteous. There's no need to be mean or rude.
+## Our Standards

-* Respect that people have differences of opinion and that every design
-  or implementation choice carries a trade-off and numerous costs. There
-  is seldom a right answer.
+Examples of behavior that contributes to creating a positive environment
+include:

-* Please keep unstructured critique to a minimum. If you have solid
-  ideas you want to experiment with, make a fork and see how it works.
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members

-* We will exclude you from interaction if you insult, demean or harass
-  anyone. That is not welcome behaviour. We interpret the term
-  "harassment" as including the definition in the <a
-  href="http://citizencodeofconduct.org/">Citizen Code of Conduct</a>;
-  if you have any lack of clarity about what might be included in that
-  concept, please read their definition. In particular, we don't
-  tolerate behavior that excludes people in socially marginalized
-  groups.
+Examples of unacceptable behavior by participants include:

-* Private harassment is also unacceptable. No matter who you are, if you
-  feel you have been or are being harassed or made uncomfortable by a
-  community member, please contact one of the channel ops or any of the
-  Syncthing core team immediately. Whether you're a regular  contributor
-  or a newcomer, we care about making this community a safe place for
-  you and we've got your back.
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting

-* Likewise any spamming, trolling, flaming, baiting or other
-  attention-stealing behaviour is not welcome.
+## Our Responsibilities

-## Moderation
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.

-These are the policies for upholding our community's standards of
-conduct in our communication channels, most notably in Syncthing-related
-IRC channels and on the web forum.
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.

-1. Remarks that violate the Syncthing standards of conduct, including
-   hateful, hurtful, oppressive, or exclusionary remarks, are not
-   allowed. (Cursing is allowed, but never targeting another user, and
-   never in a hateful manner.)
+## Scope

-2. Remarks that moderators find inappropriate, whether listed in the
-   code of conduct or not, are also not allowed.
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.

-3. Moderators will first respond to such remarks with a warning.
+## Enforcement

-4. If the warning is unheeded, the user will be "kicked," i.e., kicked
-   out of the communication channel to cool off.
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at security@syncthing.net. All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. The project team is
+obligated to maintain confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.

-5. If the user comes back and continues to make trouble, they will be
-   banned, i.e., indefinitely excluded.
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.

-6. Moderators may choose at their discretion to un-ban the user if it
-   was a first offense and they offer the offended party a genuine
-   apology.
+## Attribution

-7. If a moderator bans someone and you think it was unjustified, please
-   take it up with that moderator, or with a different moderator, **in
-   private**. Complaints about bans in-channel are not allowed.
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html

-8. Moderators are held to a higher standard than other community
-   members. If a moderator creates an inappropriate situation, they
-   should expect less leeway than others.
-
-In the Syncthing community we strive to go the extra step to look out
-for each other. Don't just aim to be technically unimpeachable, try to
-be your best self. In particular, avoid flirting with offensive or
-sensitive issues, particularly if they're off-topic; this all too
-often leads to unnecessary fights, hurt feelings, and damaged trust;
-worse, it can drive people away from the community entirely.
-
-And if someone takes issue with something you said or did, resist the
-urge to be defensive. Just stop doing what it was they complained about
-and apologize. Even if you feel you were misinterpreted or unfairly
-accused, chances are good there was something you could've communicated
-better — remember that it's your responsibility to make your fellow
-community members comfortable. Everyone wants to get along and we are
-all here first and foremost because we want to talk about cool
-technology. You will find that people will be eager to assume good
-intent and forgive as long as you earn their trust.
-
-*Adapted from the [Rust Code of Conduct](https://github.com/rust-lang/rust/wiki/Note-development-policy#conduct)*
-
-*Adapted from the [Node.js Policy on Trolling](http://blog.izs.me/post/30036893703/policy-on-trolling)*
+[homepage]: https://www.contributor-covenant.org
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -33,12 +33,12 @@ latest info on Transifex.

 Every contribution is welcome. If you want to contribute but are unsure
 where to start, any open issues are fair game! See the [Contribution
-Guidelines](http://docs.syncthing.net/dev/contributing.html) for the full
+Guidelines](https://docs.syncthing.net/dev/contributing.html) for the full
 story on committing code.

 ## Contributing Documentation

-Updates to the [documentation site](http://docs.syncthing.net/) can be
+Updates to the [documentation site](https://docs.syncthing.net/) can be
 made as pull requests on the [documentation
 repository](https://github.com/syncthing/docs).

--- a/32
+++ b/32
@@ -0,0 +1,32 @@
+FROM golang:1.11 AS builder
+
+WORKDIR /go/src/github.com/syncthing/syncthing
+COPY . .
+
+ENV CGO_ENABLED=0
+ENV BUILD_HOST=syncthing.net
+ENV BUILD_USER=docker
+RUN rm -f syncthing && go run build.go -no-upgrade build syncthing
+
+FROM alpine
+
+EXPOSE 8384 22000 21027/udp
+
+VOLUME ["/var/syncthing"]
+
+RUN apk add --no-cache ca-certificates su-exec
+
+COPY --from=builder /go/src/github.com/syncthing/syncthing/syncthing /bin/syncthing
+
+ENV PUID=1000 PGID=1000
+
+HEALTHCHECK --interval=1m --timeout=10s \
+  CMD nc -z localhost 8384 || exit 1
+
+ENTRYPOINT \
+  chown "${PUID}:${PGID}" /var/syncthing \
+  && su-exec "${PUID}:${PGID}" \
+     env HOME=/var/syncthing \
+     /bin/syncthing \
+       -home /var/syncthing/config \
+       -gui-address 0.0.0.0:8384
--- a/GOALS.md
+++ b/GOALS.md
@@ -0,0 +1,83 @@
+# The Syncthing Goals
+
+Syncthing is a **continuous file synchronization program**. It synchronizes
+files between two or more computers. We strive to fulfill the goals below.
+The goals are listed in order of importance, the most important one being
+the first.
+
+> "Syncing files" here is precise. It means we specifically exclude things
+> that are not files - calendar items, instant messages, and so on. If those
+> are in fact stored as files on disk, they can of course be synced as
+> files.
+
+Syncthing should be:
+
+### 1. Safe From Data Loss
+
+Protecting the user's data is paramount. We take every reasonable precaution
+to avoid corrupting the user's files.
+
+> This is the overriding goal, without which synchronizing files becomes
+> pointless. This means that we do not make unsafe trade offs for the sake
+> of performance or, in some cases, even usability.
+
+### 2. Secure Against Attackers
+
+Again, protecting the user's data is paramount. Regardless of our other
+goals we must never allow the user's data to be susceptible to eavesdropping
+or modification by unauthorized parties.
+
+> This should be understood in context. It is not necessarily reasonable to
+> expect Syncthing to be resistant against well equipped state level
+> attackers. We will however do our best. Note also that this is different
+> from anonymity which is not, currently, a goal.
+
+### 3. Easy to Use
+
+Syncthing should be approachable, understandable and inclusive.
+
+> Complex concepts and maths form the base of Syncthing's functionality.
+> This should nonetheless be abstracted or hidden to a degree where
+> Syncthing is usable by the general public.
+
+### 4. Automatic
+
+User interaction should be required only when absolutely necessary.
+
+> Specifically this means that changes to files are picked up without
+> prompting, conflicts are resolved without prompting and connections are
+> maintained without prompting. We only prompt the user when it is required
+> to fulfill one of the (overriding) Secure, Safe or Easy goals.
+
+### 5. Universally Available
+
+Syncthing should run on every common computer. We are mindful that the
+latest technology is not always available to any given individual.
+
+> Computers include desktops, laptops, servers, virtual machines, small
+> general purpose computers such as Raspberry Pis and, *where possible*,
+> tablets and phones. NAS appliances, toasters, cars, firearms, thermostats
+> and so on may include computing capabitilies but it is not our goal for
+> Syncthing to run smoothly on these devices.
+
+### 6. For Individuals
+
+Syncthing is primarily about empowering the individual user with safe,
+secure and easy to use file synchronization.
+
+> We acknowledge that it's also useful in an enterprise setting and include
+> functionality to support that. If this is in conflict with the
+> requirements of the individual, those will however take priority.
+
+### 7. Everything Else
+
+There are many things we care about that don't make it on to the list. It is
+fine to optimize for these values as well, as long as they are not in
+conflict with the stated goals above.
+
+> For example, performance is a thing we care about. We just don't care more
+> about it than safety, security, etc. Maintainability of the code base and
+> providing entertainment value for the maintainers are also things that
+> matter. It is understood that there are aspects of Syncthing that are
+> suboptimal or even in opposition with the goals above. However, we
+> continuously strive to align Syncthing more and more with these goals.
--- a/ISSUE_TEMPLATE.md
+++ b/ISSUE_TEMPLATE.md
@@ -1,28 +0,0 @@
-Do not report security issues in this bug tracker. Instead, contact
-security@syncthing.net directly - see https://syncthing.net/security.html
-for more information.
-
-If your issue is a support request ("How do I get my devices to connect?"
-or similar), please use the support forum at https://forum.syncthing.net/
-where a large number of helpful people hang out. This issue tracker is for
-reporting bugs or feature requests directly to the developers.
-
-If your issue is a bug report, replace this boilerplate with a description
-of the problem, being sure to include at least:
-
- - what happened,
- - what you expected to happen instead, and
- - any steps to reproduce the problem.
-
-Also fill out the version information below and add log output or
-screenshots as appropriate.
-
-If your issue is a feature request, simply replace this template text in
-its entirety.
-
-### Version Information
-
-Syncthing Version: v0.x.y
-OS Version: Windows 7 / Ubuntu 14.04 / ...
-Browser Version: (if applicable, for GUI issues)
-
--- a/2
+++ b/2
@@ -357,7 +357,7 @@ Exhibit A - Source Code Form License Notice

  This Source Code Form is subject to the terms of the Mozilla Public
  License, v. 2.0. If a copy of the MPL was not distributed with this
-  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+  file, You can obtain one at https://mozilla.org/MPL/2.0/.

 If it is not possible or desirable to put the notice in a particular
 file, then You may include the notice in a location (such as a LICENSE
--- a/118
+++ b/118
@@ -1,118 +0,0 @@
-# This file maps email addresses used in commits to nicks used the changelog.
-# It is auto generated from the AUTHORS file by script/authors.go.
-
-0x010C <antoine.lamielle@0x010c.fr>
-0x010C <gh@0x010c.fr>
-acogdev <jake@acogdev.com>
-alessandro.g89 <alessandro.g89@gmail.com>
-alex2108 <register-github@alex-graf.de>
-andersonvom <andersonvom@gmail.com>
-andrew-d <andrew@du.nham.ca>
-asdil12 <dominik@heidler.eu>
-AudriusButkevicius <audrius.butkevicius@gmail.com>
-aviau <alexandre@alexandreviau.net>
-aviau <aviau@debian.org>
-bencurthoys <ben@bencurthoys.com>
-bigbear2nd <bigbear2nd@gmail.com>
-brbecker <brbecker@gmail.com>
-brendanlong <self@brendanlong.com>
-brgmnn <dan.arne.bergmann@gmail.com>
-brgmnn <brgmnn@users.noreply.github.com>
-bsidhom <bsidhom@gmail.com>
-buinsky <vix_booja@tut.by>
-burkemw3 <mburke@amplify.com>
-burkemw3 <burkemw3@gmail.com>
-calmh <jakob@nym.se>
-calmh <jakob@kastelo.net>
-canton7 <antony.male@gmail.com>
-Cathryne <cathryne.linenweaver@gmail.com>
-Cathryne <Cathryne@users.noreply.github.com>
-cdata <chris@scriptolo.gy>
-cdhowie <me@chrishowie.com>
-ceh <emil@hessman.se>
-cqcallaw <enlightened.despot@gmail.com>
-dinosore <dinosore@dbrsoftware.co.uk>
-dva <denisva@gmail.com>
-dzarda <dzardacz@gmail.com>
-eipiminus1 <eipiminusone+github@gmail.com>
-eipiminus1 <eipiminus1@users.noreply.github.com>
-facastagnini <federico.castagnini@gmail.com>
-filoozoom <philippe@schommers.be>
-frioux <frew@afoolishmanifesto.com>
-frioux <frioux@gmail.com>
-fti7 <frank@isemann.name>
-gillisig <gilli@vx.is>
-hadogenes <szafar@linux.pl>
-ironmig <kma1660@gmail.com>
-jarlebring <jarlebring@gmail.com>
-jedie <github.com@jensdiemer.de>
-jedie <git@jensdiemer.de>
-jgke <jgke@jgke.fi>
-jpjp <jamespatterson@operamail.com>
-jpjp <jpjp@users.noreply.github.com>
-kamadak <kamada@nanohz.org>
-KayoticSully <kayoticsully@gmail.com>
-kc1212 <kc04bc@gmx.com>
-kc1212 <kc1212@users.noreply.github.com>
-kilburn <kilburn@la3.org>
-kluppy <kluppy@going2blue.com>
-kozec <kozec@kozec.com>
-kralo <max.schulze@online.de>
-kralo <kralo@users.noreply.github.com>
-krozycki <rozycki.karol@gmail.com>
-letiemble <laurent.etiemble@gmail.com>
-letiemble <laurent.etiemble@monobjc.net>
-lkwg82 <lkwg82@gmx.de>
-LordLandon <lordlandon@gmail.com>
-majedev <majed.alhajry@gmail.com>
-marcindziadus <dziadus.marcin@gmail.com>
-marclaporte <marc@marclaporte.com>
-marclaporte <marc@laporte.name>
-mateon1 <matin1111@wp.pl>
-mogwa1 <devriesb@gmail.com>
-moshen <moshen.colin@gmail.com>
-Moter8 <moter8@gmail.com>
-mvdan <mvdan@mvdan.cc>
-norgeous <daniel@harte.me>
-norgeous <daniel@danielharte.co.uk>
-norgeous <norgeous@users.noreply.github.com>
-nrm21 <natemorrison@gmail.com>
-Nutomic <me@nutomic.com>
-pascalj <github@pascalj.com>
-pascalj <mail@pascal-jungblut.com>
-peterhoeg <peter@speartail.com>
-philips <brandon@ifup.org>
-piobpl <piotrb10@gmail.com>
-plouj <ploujj@gmail.com>
-pluby <phill.luby@newredo.com>
-pyfisch <pyfisch@gmail.com>
-qbit <qbit@deftly.net>
-ralder <ralder@yandex.ru>
-Rewt0r <rewt0r@gmx.com>
-Rewt0r <Rewt0r@users.noreply.github.com>
-rumpelsepp <stefan@sevenbyte.org>
-rumpelsepp <rumpelsepp@sevenbyte.org>
-scienmind <scintertech@cryptolab.net>
-sciurius <jvromans@squirrel.nl>
-seehuhn <voss@seehuhn.de>
-simplypeachy <aD@simplypeachy.co.uk>
-simplypeachy <simplypeachy@users.noreply.github.com>
-snnd <dw@risu.io>
-Stefan-Code <stefan.github@gmail.com>
-Stefan-Code <Stefan.github@gmail.com>
-timabell <tim@timwise.co.uk>
-tnn2 <tnn@nygren.pp.se>
-tojrobinson <tully@tojr.org>
-tpng <benny.tpng@gmail.com>
-tylerbrazier <tyler@tylerbrazier.com>
-uok <ueomkail@gmail.com>
-uok <uok@users.noreply.github.com>
-veeti <veeti.paananen@rojekti.fi>
-Vilbrekin <vilbrekin@gmail.com>
-wkennington <william@wkennington.com>
-WSGCSysadmin <e.meitner@willystreet.coop>
-wweich <wweich@users.noreply.github.com>
-wweich <wweich@gmx.de>
-xduugu <cedric@gmx.ca>
-Zillode <zillode@zillode.be>
-zukoo <fxgsell@gmail.com>
--- a/README-Docker.md
+++ b/README-Docker.md
@@ -0,0 +1,43 @@
+# Docker Container for Syncthing
+
+Use the Dockerfile in this repo, or pull the `syncthing/syncthing` image
+from Docker Hub. Use volumes to have the synchronized files available on the
+host.
+
+The exposed volumes are by default:
+
+    /var/syncthing/config   - the configuration and index directory into the Container
+    /var/syncthing          - the default sync folder into the Container
+
+You can add more folders and map them as you prefer.
+
+Note that Syncthing runs as UID 1000 and GID 1000 by default. These may be
+altered with the ``PUID`` and ``PGID`` environment variables.
+
+Example usage:
+
+```
+$ docker pull syncthing/syncthing
+$ docker run -p 8384:8384 -p 22000:22000 \
+    -v /wherever/st-cfg:/var/syncthing/config \
+    -v /wherever/st-sync:/var/syncthing \
+    syncthing/syncthing:latest
+```
+
+Note that local device discovery will not work with the above command resulting
+in poor local transfer rates if local device addresses are not manually
+configured.
+
+To allow local discovery, the docker host network can be used instead:
+
+```
+$ docker pull syncthing/syncthing
+$ docker run --network=host \
+    -v /wherever/st-cfg:/var/syncthing/config \
+    -v /wherever/st-sync:/var/syncthing \
+    syncthing/syncthing:latest
+```
+
+Be aware that syncthing alone is now in control of what interfaces and ports it
+listens on. You can edit the syncthing configuration to change the defaults if
+there are conflicts.
--- a/README.md
+++ b/README.md
@@ -1,23 +1,59 @@
-# Syncthing
+[![Syncthing][14]][15]

-[![Latest Build (Official)](https://img.shields.io/jenkins/s/http/build.syncthing.net/syncthing.svg?style=flat-square&label=unix%20build)](http://build.syncthing.net/job/syncthing/lastBuild/)
-[![API Documentation](https://img.shields.io/badge/api-Godoc-blue.svg?style=flat-square)](http://godoc.org/github.com/syncthing/syncthing)
+---
+
+[![Latest Downloads](https://img.shields.io/badge/latest-downloads-brightgreen.svg?style=flat-square)](https://build.syncthing.net/latest/)
+[![Latest Linux & Cross Build](https://img.shields.io/teamcity/https/build.syncthing.net/s/Syncthing_BuildLinuxCross.svg?style=flat-square&label=linux+%26+cross+build)](https://build.syncthing.net/viewType.html?buildTypeId=Syncthing_BuildLinuxCross&guest=1)
+[![Latest Windows Build](https://img.shields.io/teamcity/https/build.syncthing.net/s/Syncthing_BuildWindows.svg?style=flat-square&label=windows+build)](https://build.syncthing.net/viewType.html?buildTypeId=Syncthing_BuildWindows&guest=1)
+[![Latest Mac Build](https://img.shields.io/teamcity/https/build.syncthing.net/s/Syncthing_BuildMac.svg?style=flat-square&label=mac+build)](https://build.syncthing.net/viewType.html?buildTypeId=Syncthing_BuildMac&guest=1)
 [![MPLv2 License](https://img.shields.io/badge/license-MPLv2-blue.svg?style=flat-square)](https://www.mozilla.org/MPL/2.0/)
+[![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/88/badge)](https://bestpractices.coreinfrastructure.org/projects/88)
+[![Go Report Card](https://goreportcard.com/badge/github.com/syncthing/syncthing)](https://goreportcard.com/report/github.com/syncthing/syncthing)

-This is the Syncthing project which pursues the following goals:
+## Goals

- 1. Define a protocol for synchronization of a folder between a number of
-    collaborating devices. This protocol should be well defined, unambiguous,
-    easily understood, free to use, efficient, secure and language neutral.
-    This is called the [Block Exchange Protocol][1].
+Syncthing is a **continuous file synchronization program**. It synchronizes
+files between two or more computers. We strive to fulfill the goals below.
+The goals are listed in order of importance, the most important one being
+the first. This is the summary version of the goal list - for more
+commentary, see the full [Goals document][13].

- 2. Provide the reference implementation to demonstrate the usability of
-    said protocol. This is the `syncthing` utility. We hope that
-    alternative, compatible implementations of the protocol will arise.
+Syncthing should be:

-The two are evolving together; the protocol is not to be considered
-stable until Syncthing 1.0 is released, at which point it is locked down
-for incompatible changes.
+1. **Safe From Data Loss**
+
+   Protecting the user's data is paramount. We take every reasonable
+   precaution to avoid corrupting the user's files.
+
+2. **Secure Against Attackers**
+
+   Again, protecting the user's data is paramount. Regardless of our other
+   goals we must never allow the user's data to be susceptible to
+   eavesdropping or modification by unauthorized parties.
+
+3. **Easy to Use**
+
+   Syncthing should be approachable, understandable and inclusive.
+
+4. **Automatic**
+
+   User interaction should be required only when absolutely necessary.
+
+5. **Universally Available**
+
+   Syncthing should run on every common computer. We are mindful that the
+   latest technology is not always available to any given individual.
+
+6. **For Individuals**
+
+   Syncthing is primarily about empowering the individual user with safe,
+   secure and easy to use file synchronization.
+
+7. **Everything Else**
+
+   There are many things we care about that don't make it on to the list. It
+   is fine to optimize for these values, as long as they are not in conflict
+   with the stated goals above.

 ## Getting Started

@@ -51,8 +87,8 @@ D26E6ED000654A3E, available from https://syncthing.net/security.html and
 most key servers.

 There is also a built in automatic upgrade mechanism (disabled in some
-distribution channels) which uses a compiled in ECDSA signature. Mac OS
-X binaries are also properly code signed.
+distribution channels) which uses a compiled in ECDSA signature. macOS
+binaries are also properly code signed.

 ## Documentation

@@ -60,15 +96,19 @@ Please see the [Syncthing documentation site][6].

 All code is licensed under the [MPLv2 License][7].

-[1]: http://docs.syncthing.net/specs/bep-v1.html
-[2]: http://docs.syncthing.net/intro/getting-started.html
+[1]: https://docs.syncthing.net/specs/bep-v1.html
+[2]: https://docs.syncthing.net/intro/getting-started.html
 [3]: https://github.com/syncthing/syncthing/blob/master/etc
-[4]: http://www.freenode.net/irc_servers.shtml
-[5]: http://docs.syncthing.net/dev/building.html
-[6]: http://docs.syncthing.net/
+[4]: https://www.freenode.net/
+[5]: https://docs.syncthing.net/dev/building.html
+[6]: https://docs.syncthing.net/
 [7]: https://github.com/syncthing/syncthing/blob/master/LICENSE
 [8]: https://forum.syncthing.net/
 [9]: https://kiwiirc.com/client/irc.freenode.net/#syncthing
 [10]: https://github.com/syncthing/syncthing/issues
-[11]: http://docs.syncthing.net/users/contrib.html#gui-wrappers
+[11]: https://docs.syncthing.net/users/contrib.html#gui-wrappers
 [12]: https://www.bountysource.com/teams/syncthing/issues
+[13]: https://github.com/syncthing/syncthing/blob/master/GOALS.md
+[14]: assets/logo-text-128.png
+[15]: https://syncthing.net/
+
--- a/assets/logo.ico
+++ b/assets/logo.ico
--- a/assets/syncthing_folder_icon.icns
+++ b/assets/syncthing_folder_icon.icns
--- a/build.go
+++ b/build.go
--- a/build.sh
+++ b/build.sh
@@ -48,9 +48,6 @@ case "${1:-default}" in
 		;;

 	test)
-		ulimit -t 600 &>/dev/null || true
-		ulimit -d 512000 &>/dev/null || true
-		ulimit -m 512000 &>/dev/null || true
 		LOGGER_DISCARD=1 build test
 		;;

@@ -61,9 +58,9 @@ case "${1:-default}" in
 	prerelease)
 		go run script/authors.go
 		build transifex
-		git add -A gui/default/assets/ lib/auto/
 		pushd man ; ./refresh.sh ; popd
-		git add -A man
+		git add -A gui man AUTHORS
+		git commit -m 'gui, man, authors: Update docs, translations, and contributors'
 		;;

 	noupgrade)
@@ -93,44 +90,7 @@ case "${1:-default}" in
 		done
 		;;

-	test-cov)
-		ulimit -t 600 &>/dev/null || true
-		ulimit -d 512000 &>/dev/null || true
-		ulimit -m 512000 &>/dev/null || true
-
-		echo "mode: set" > coverage.out
-		fail=0
-
-		# For every package in the repo
-		for dir in $(go list ./lib/... ./cmd/...) ; do
-			# run the tests
-			GOPATH="$(pwd)/Godeps/_workspace:$GOPATH" go test -coverprofile=profile.out $dir
-			if [ -f profile.out ] ; then
-				# and if there was test output, append it to coverage.out
-				grep -v "mode: " profile.out >> coverage.out
-				rm profile.out
-			fi
-		done
-
-		notCovered=$(egrep -c '\s0$' coverage.out)
-		total=$(wc -l coverage.out | awk '{print $1}')
-		coverPct=$(awk "BEGIN{print (1 - $notCovered / $total) * 100}")
-		echo "Total coverage is $coverPct%"
-
-		gocov convert coverage.out | gocov-xml > coverage.xml
-
-		# This is usually run from within Jenkins. If it is, we need to
-		# tweak the paths in coverage.xml so cobertura finds the
-		# source.
-		if [[ "${WORKSPACE:-default}" != "default" ]] ; then
-			sed "s#$WORKSPACE##g" < coverage.xml > coverage.xml.new && mv coverage.xml.new coverage.xml
-		fi
-		;;
-
 	test-xunit)
-		ulimit -t 600 &>/dev/null || true
-		ulimit -d 512000 &>/dev/null || true
-		ulimit -m 512000 &>/dev/null || true

 		(GOPATH="$(pwd)/Godeps/_workspace:$GOPATH" go test -v -race ./lib/... ./cmd/... || true) > tests.out
 		go2xunit -output tests.xml -fail < tests.out
--- a/cmd/stbench/main.go
+++ b/cmd/stbench/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 // This doesn't build on Windows due to the Rusage stuff.

@@ -92,7 +92,7 @@ loop:
 	return t1.Sub(t0)
 }

-// report stops the given process and reports on it's resource usage in two
+// report stops the given process and reports on its resource usage in two
 // ways: human readable to stderr, and CSV to stdout.
 func report(p *rc.Process, wallTime time.Duration) {
 	sv, err := p.SystemVersion()
--- a/vendor/github.com/calmh/luhn/LICENSE
+++ b/vendor/github.com/calmh/luhn/LICENSE
@@ -1,4 +1,4 @@
-Copyright (C) 2014 Jakob Borg
+Copyright (C) 2014 Audrius Butkevičius

 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in
--- a/cmd/stcli/client.go
+++ b/cmd/stcli/client.go
@@ -0,0 +1,115 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"bytes"
+	"crypto/tls"
+	"net/http"
+	"strings"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+type APIClient struct {
+	httpClient http.Client
+	endpoint   string
+	apikey     string
+	username   string
+	password   string
+	id         string
+	csrf       string
+}
+
+var instance *APIClient
+
+func getClient(c *cli.Context) *APIClient {
+	if instance != nil {
+		return instance
+	}
+	endpoint := c.GlobalString("endpoint")
+	if !strings.HasPrefix(endpoint, "http") {
+		endpoint = "http://" + endpoint
+	}
+	httpClient := http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: c.GlobalBool("insecure"),
+			},
+		},
+	}
+	client := APIClient{
+		httpClient: httpClient,
+		endpoint:   endpoint,
+		apikey:     c.GlobalString("apikey"),
+		username:   c.GlobalString("username"),
+		password:   c.GlobalString("password"),
+	}
+
+	if client.apikey == "" {
+		request, err := http.NewRequest("GET", client.endpoint, nil)
+		die(err)
+		response := client.handleRequest(request)
+		client.id = response.Header.Get("X-Syncthing-ID")
+		if client.id == "" {
+			die("Failed to get device ID")
+		}
+		for _, item := range response.Cookies() {
+			if item.Name == "CSRF-Token-"+client.id[:5] {
+				client.csrf = item.Value
+				goto csrffound
+			}
+		}
+		die("Failed to get CSRF token")
+	csrffound:
+	}
+	instance = &client
+	return &client
+}
+
+func (client *APIClient) handleRequest(request *http.Request) *http.Response {
+	if client.apikey != "" {
+		request.Header.Set("X-API-Key", client.apikey)
+	}
+	if client.username != "" || client.password != "" {
+		request.SetBasicAuth(client.username, client.password)
+	}
+	if client.csrf != "" {
+		request.Header.Set("X-CSRF-Token-"+client.id[:5], client.csrf)
+	}
+
+	response, err := client.httpClient.Do(request)
+	die(err)
+
+	if response.StatusCode == 404 {
+		die("Invalid endpoint or API call")
+	} else if response.StatusCode == 401 {
+		die("Invalid username or password")
+	} else if response.StatusCode == 403 {
+		if client.apikey == "" {
+			die("Invalid CSRF token")
+		}
+		die("Invalid API key")
+	} else if response.StatusCode != 200 {
+		body := strings.TrimSpace(string(responseToBArray(response)))
+		if body != "" {
+			die(body)
+		}
+		die("Unknown HTTP status returned: " + response.Status)
+	}
+	return response
+}
+
+func httpGet(c *cli.Context, url string) *http.Response {
+	client := getClient(c)
+	request, err := http.NewRequest("GET", client.endpoint+"/rest/"+url, nil)
+	die(err)
+	return client.handleRequest(request)
+}
+
+func httpPost(c *cli.Context, url string, body string) *http.Response {
+	client := getClient(c)
+	request, err := http.NewRequest("POST", client.endpoint+"/rest/"+url, bytes.NewBufferString(body))
+	die(err)
+	return client.handleRequest(request)
+}
--- a/cmd/stcli/cmd_devices.go
+++ b/cmd/stcli/cmd_devices.go
@@ -0,0 +1,188 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/AudriusButkevicius/cli"
+	"github.com/syncthing/syncthing/lib/config"
+)
+
+func init() {
+	cliCommands = append(cliCommands, cli.Command{
+		Name:     "devices",
+		HideHelp: true,
+		Usage:    "Device command group",
+		Subcommands: []cli.Command{
+			{
+				Name:     "list",
+				Usage:    "List registered devices",
+				Requires: &cli.Requires{},
+				Action:   devicesList,
+			},
+			{
+				Name:     "add",
+				Usage:    "Add a new device",
+				Requires: &cli.Requires{"device id", "device name?"},
+				Action:   devicesAdd,
+			},
+			{
+				Name:     "remove",
+				Usage:    "Remove an existing device",
+				Requires: &cli.Requires{"device id"},
+				Action:   devicesRemove,
+			},
+			{
+				Name:     "get",
+				Usage:    "Get a property of a device",
+				Requires: &cli.Requires{"device id", "property"},
+				Action:   devicesGet,
+			},
+			{
+				Name:     "set",
+				Usage:    "Set a property of a device",
+				Requires: &cli.Requires{"device id", "property", "value..."},
+				Action:   devicesSet,
+			},
+		},
+	})
+}
+
+func devicesList(c *cli.Context) {
+	cfg := getConfig(c)
+	first := true
+	writer := newTableWriter()
+	for _, device := range cfg.Devices {
+		if !first {
+			fmt.Fprintln(writer)
+		}
+		fmt.Fprintln(writer, "ID:\t", device.DeviceID, "\t")
+		fmt.Fprintln(writer, "Name:\t", device.Name, "\t(name)")
+		fmt.Fprintln(writer, "Address:\t", strings.Join(device.Addresses, " "), "\t(address)")
+		fmt.Fprintln(writer, "Compression:\t", device.Compression, "\t(compression)")
+		fmt.Fprintln(writer, "Certificate name:\t", device.CertName, "\t(certname)")
+		fmt.Fprintln(writer, "Introducer:\t", device.Introducer, "\t(introducer)")
+		first = false
+	}
+	writer.Flush()
+}
+
+func devicesAdd(c *cli.Context) {
+	nid := c.Args()[0]
+	id := parseDeviceID(nid)
+
+	newDevice := config.DeviceConfiguration{
+		DeviceID:  id,
+		Name:      nid,
+		Addresses: []string{"dynamic"},
+	}
+
+	if len(c.Args()) > 1 {
+		newDevice.Name = c.Args()[1]
+	}
+
+	if len(c.Args()) > 2 {
+		addresses := c.Args()[2:]
+		for _, item := range addresses {
+			if item == "dynamic" {
+				continue
+			}
+			validAddress(item)
+		}
+		newDevice.Addresses = addresses
+	}
+
+	cfg := getConfig(c)
+	for _, device := range cfg.Devices {
+		if device.DeviceID == id {
+			die("Device " + nid + " already exists")
+		}
+	}
+	cfg.Devices = append(cfg.Devices, newDevice)
+	setConfig(c, cfg)
+}
+
+func devicesRemove(c *cli.Context) {
+	nid := c.Args()[0]
+	id := parseDeviceID(nid)
+	if nid == getMyID(c) {
+		die("Cannot remove yourself")
+	}
+	cfg := getConfig(c)
+	for i, device := range cfg.Devices {
+		if device.DeviceID == id {
+			last := len(cfg.Devices) - 1
+			cfg.Devices[i] = cfg.Devices[last]
+			cfg.Devices = cfg.Devices[:last]
+			setConfig(c, cfg)
+			return
+		}
+	}
+	die("Device " + nid + " not found")
+}
+
+func devicesGet(c *cli.Context) {
+	nid := c.Args()[0]
+	id := parseDeviceID(nid)
+	arg := c.Args()[1]
+	cfg := getConfig(c)
+	for _, device := range cfg.Devices {
+		if device.DeviceID != id {
+			continue
+		}
+		switch strings.ToLower(arg) {
+		case "name":
+			fmt.Println(device.Name)
+		case "address":
+			fmt.Println(strings.Join(device.Addresses, "\n"))
+		case "compression":
+			fmt.Println(device.Compression.String())
+		case "certname":
+			fmt.Println(device.CertName)
+		case "introducer":
+			fmt.Println(device.Introducer)
+		default:
+			die("Invalid property: " + arg + "\nAvailable properties: name, address, compression, certname, introducer")
+		}
+		return
+	}
+	die("Device " + nid + " not found")
+}
+
+func devicesSet(c *cli.Context) {
+	nid := c.Args()[0]
+	id := parseDeviceID(nid)
+	arg := c.Args()[1]
+	config := getConfig(c)
+	for i, device := range config.Devices {
+		if device.DeviceID != id {
+			continue
+		}
+		switch strings.ToLower(arg) {
+		case "name":
+			config.Devices[i].Name = strings.Join(c.Args()[2:], " ")
+		case "address":
+			for _, item := range c.Args()[2:] {
+				if item == "dynamic" {
+					continue
+				}
+				validAddress(item)
+			}
+			config.Devices[i].Addresses = c.Args()[2:]
+		case "compression":
+			err := config.Devices[i].Compression.UnmarshalText([]byte(c.Args()[2]))
+			die(err)
+		case "certname":
+			config.Devices[i].CertName = strings.Join(c.Args()[2:], " ")
+		case "introducer":
+			config.Devices[i].Introducer = parseBool(c.Args()[2])
+		default:
+			die("Invalid property: " + arg + "\nAvailable properties: name, address, compression, certname, introducer")
+		}
+		setConfig(c, config)
+		return
+	}
+	die("Device " + nid + " not found")
+}
--- a/cmd/stcli/cmd_errors.go
+++ b/cmd/stcli/cmd_errors.go
@@ -0,0 +1,67 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+func init() {
+	cliCommands = append(cliCommands, cli.Command{
+		Name:     "errors",
+		HideHelp: true,
+		Usage:    "Error command group",
+		Subcommands: []cli.Command{
+			{
+				Name:     "show",
+				Usage:    "Show pending errors",
+				Requires: &cli.Requires{},
+				Action:   errorsShow,
+			},
+			{
+				Name:     "push",
+				Usage:    "Push an error to active clients",
+				Requires: &cli.Requires{"error message..."},
+				Action:   errorsPush,
+			},
+			{
+				Name:     "clear",
+				Usage:    "Clear pending errors",
+				Requires: &cli.Requires{},
+				Action:   wrappedHTTPPost("system/error/clear"),
+			},
+		},
+	})
+}
+
+func errorsShow(c *cli.Context) {
+	response := httpGet(c, "system/error")
+	var data map[string][]map[string]interface{}
+	json.Unmarshal(responseToBArray(response), &data)
+	writer := newTableWriter()
+	for _, item := range data["errors"] {
+		time := item["when"].(string)[:19]
+		time = strings.Replace(time, "T", " ", 1)
+		err := item["message"].(string)
+		err = strings.TrimSpace(err)
+		fmt.Fprintln(writer, time+":\t"+err)
+	}
+	writer.Flush()
+}
+
+func errorsPush(c *cli.Context) {
+	err := strings.Join(c.Args(), " ")
+	response := httpPost(c, "system/error", strings.TrimSpace(err))
+	if response.StatusCode != 200 {
+		err = fmt.Sprint("Failed to push error\nStatus code: ", response.StatusCode)
+		body := string(responseToBArray(response))
+		if body != "" {
+			err += "\nBody: " + body
+		}
+		die(err)
+	}
+}
--- a/cmd/stcli/cmd_folders.go
+++ b/cmd/stcli/cmd_folders.go
@@ -0,0 +1,361 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"github.com/AudriusButkevicius/cli"
+	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/fs"
+)
+
+func init() {
+	cliCommands = append(cliCommands, cli.Command{
+		Name:     "folders",
+		HideHelp: true,
+		Usage:    "Folder command group",
+		Subcommands: []cli.Command{
+			{
+				Name:     "list",
+				Usage:    "List available folders",
+				Requires: &cli.Requires{},
+				Action:   foldersList,
+			},
+			{
+				Name:     "add",
+				Usage:    "Add a new folder",
+				Requires: &cli.Requires{"folder id", "directory"},
+				Action:   foldersAdd,
+			},
+			{
+				Name:     "remove",
+				Usage:    "Remove an existing folder",
+				Requires: &cli.Requires{"folder id"},
+				Action:   foldersRemove,
+			},
+			{
+				Name:     "override",
+				Usage:    "Override changes from other nodes for a master folder",
+				Requires: &cli.Requires{"folder id"},
+				Action:   foldersOverride,
+			},
+			{
+				Name:     "get",
+				Usage:    "Get a property of a folder",
+				Requires: &cli.Requires{"folder id", "property"},
+				Action:   foldersGet,
+			},
+			{
+				Name:     "set",
+				Usage:    "Set a property of a folder",
+				Requires: &cli.Requires{"folder id", "property", "value..."},
+				Action:   foldersSet,
+			},
+			{
+				Name:     "unset",
+				Usage:    "Unset a property of a folder",
+				Requires: &cli.Requires{"folder id", "property"},
+				Action:   foldersUnset,
+			},
+			{
+				Name:     "devices",
+				Usage:    "Folder devices command group",
+				HideHelp: true,
+				Subcommands: []cli.Command{
+					{
+						Name:     "list",
+						Usage:    "List of devices which the folder is shared with",
+						Requires: &cli.Requires{"folder id"},
+						Action:   foldersDevicesList,
+					},
+					{
+						Name:     "add",
+						Usage:    "Share a folder with a device",
+						Requires: &cli.Requires{"folder id", "device id"},
+						Action:   foldersDevicesAdd,
+					},
+					{
+						Name:     "remove",
+						Usage:    "Unshare a folder with a device",
+						Requires: &cli.Requires{"folder id", "device id"},
+						Action:   foldersDevicesRemove,
+					},
+					{
+						Name:     "clear",
+						Usage:    "Unshare a folder with all devices",
+						Requires: &cli.Requires{"folder id"},
+						Action:   foldersDevicesClear,
+					},
+				},
+			},
+		},
+	})
+}
+
+func foldersList(c *cli.Context) {
+	cfg := getConfig(c)
+	first := true
+	writer := newTableWriter()
+	for _, folder := range cfg.Folders {
+		if !first {
+			fmt.Fprintln(writer)
+		}
+		fs := folder.Filesystem()
+		fmt.Fprintln(writer, "ID:\t", folder.ID, "\t")
+		fmt.Fprintln(writer, "Path:\t", fs.URI(), "\t(directory)")
+		fmt.Fprintln(writer, "Path type:\t", fs.Type(), "\t(directory-type)")
+		fmt.Fprintln(writer, "Folder type:\t", folder.Type, "\t(type)")
+		fmt.Fprintln(writer, "Ignore permissions:\t", folder.IgnorePerms, "\t(permissions)")
+		fmt.Fprintln(writer, "Rescan interval in seconds:\t", folder.RescanIntervalS, "\t(rescan)")
+
+		if folder.Versioning.Type != "" {
+			fmt.Fprintln(writer, "Versioning:\t", folder.Versioning.Type, "\t(versioning)")
+			for key, value := range folder.Versioning.Params {
+				fmt.Fprintf(writer, "Versioning %s:\t %s \t(versioning-%s)\n", key, value, key)
+			}
+		}
+		first = false
+	}
+	writer.Flush()
+}
+
+func foldersAdd(c *cli.Context) {
+	cfg := getConfig(c)
+	abs, err := filepath.Abs(c.Args()[1])
+	die(err)
+	folder := config.FolderConfiguration{
+		ID:             c.Args()[0],
+		Path:           filepath.Clean(abs),
+		FilesystemType: fs.FilesystemTypeBasic,
+	}
+	cfg.Folders = append(cfg.Folders, folder)
+	setConfig(c, cfg)
+}
+
+func foldersRemove(c *cli.Context) {
+	cfg := getConfig(c)
+	rid := c.Args()[0]
+	for i, folder := range cfg.Folders {
+		if folder.ID == rid {
+			last := len(cfg.Folders) - 1
+			cfg.Folders[i] = cfg.Folders[last]
+			cfg.Folders = cfg.Folders[:last]
+			setConfig(c, cfg)
+			return
+		}
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersOverride(c *cli.Context) {
+	cfg := getConfig(c)
+	rid := c.Args()[0]
+	for _, folder := range cfg.Folders {
+		if folder.ID == rid && folder.Type == config.FolderTypeSendOnly {
+			response := httpPost(c, "db/override", "")
+			if response.StatusCode != 200 {
+				err := fmt.Sprint("Failed to override changes\nStatus code: ", response.StatusCode)
+				body := string(responseToBArray(response))
+				if body != "" {
+					err += "\nBody: " + body
+				}
+				die(err)
+			}
+			return
+		}
+	}
+	die("Folder " + rid + " not found or folder not master")
+}
+
+func foldersGet(c *cli.Context) {
+	cfg := getConfig(c)
+	rid := c.Args()[0]
+	arg := strings.ToLower(c.Args()[1])
+	for _, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		if strings.HasPrefix(arg, "versioning-") {
+			arg = arg[11:]
+			value, ok := folder.Versioning.Params[arg]
+			if ok {
+				fmt.Println(value)
+				return
+			}
+			die("Versioning property " + c.Args()[1][11:] + " not found")
+		}
+		switch arg {
+		case "directory":
+			fmt.Println(folder.Filesystem().URI())
+		case "directory-type":
+			fmt.Println(folder.Filesystem().Type())
+		case "type":
+			fmt.Println(folder.Type)
+		case "permissions":
+			fmt.Println(folder.IgnorePerms)
+		case "rescan":
+			fmt.Println(folder.RescanIntervalS)
+		case "versioning":
+			if folder.Versioning.Type != "" {
+				fmt.Println(folder.Versioning.Type)
+			}
+		default:
+			die("Invalid property: " + c.Args()[1] + "\nAvailable properties: directory, directory-type, type, permissions, versioning, versioning-<key>")
+		}
+		return
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersSet(c *cli.Context) {
+	rid := c.Args()[0]
+	arg := strings.ToLower(c.Args()[1])
+	val := strings.Join(c.Args()[2:], " ")
+	cfg := getConfig(c)
+	for i, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		if strings.HasPrefix(arg, "versioning-") {
+			cfg.Folders[i].Versioning.Params[arg[11:]] = val
+			setConfig(c, cfg)
+			return
+		}
+		switch arg {
+		case "directory":
+			cfg.Folders[i].Path = val
+		case "directory-type":
+			var fsType fs.FilesystemType
+			fsType.UnmarshalText([]byte(val))
+			cfg.Folders[i].FilesystemType = fsType
+		case "type":
+			var t config.FolderType
+			if err := t.UnmarshalText([]byte(val)); err != nil {
+				die("Invalid folder type: " + err.Error())
+			}
+			cfg.Folders[i].Type = t
+		case "permissions":
+			cfg.Folders[i].IgnorePerms = parseBool(val)
+		case "rescan":
+			cfg.Folders[i].RescanIntervalS = parseInt(val)
+		case "versioning":
+			cfg.Folders[i].Versioning.Type = val
+		default:
+			die("Invalid property: " + c.Args()[1] + "\nAvailable properties: directory, master, permissions, versioning, versioning-<key>")
+		}
+		setConfig(c, cfg)
+		return
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersUnset(c *cli.Context) {
+	rid := c.Args()[0]
+	arg := strings.ToLower(c.Args()[1])
+	cfg := getConfig(c)
+	for i, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		if strings.HasPrefix(arg, "versioning-") {
+			arg = arg[11:]
+			if _, ok := folder.Versioning.Params[arg]; ok {
+				delete(cfg.Folders[i].Versioning.Params, arg)
+				setConfig(c, cfg)
+				return
+			}
+			die("Versioning property " + c.Args()[1][11:] + " not found")
+		}
+		switch arg {
+		case "versioning":
+			cfg.Folders[i].Versioning.Type = ""
+			cfg.Folders[i].Versioning.Params = make(map[string]string)
+		default:
+			die("Invalid property: " + c.Args()[1] + "\nAvailable properties: versioning, versioning-<key>")
+		}
+		setConfig(c, cfg)
+		return
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersDevicesList(c *cli.Context) {
+	rid := c.Args()[0]
+	cfg := getConfig(c)
+	for _, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		for _, device := range folder.Devices {
+			fmt.Println(device.DeviceID)
+		}
+		return
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersDevicesAdd(c *cli.Context) {
+	rid := c.Args()[0]
+	nid := parseDeviceID(c.Args()[1])
+	cfg := getConfig(c)
+	for i, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		for _, device := range folder.Devices {
+			if device.DeviceID == nid {
+				die("Device " + c.Args()[1] + " is already part of this folder")
+			}
+		}
+		for _, device := range cfg.Devices {
+			if device.DeviceID == nid {
+				cfg.Folders[i].Devices = append(folder.Devices, config.FolderDeviceConfiguration{
+					DeviceID: device.DeviceID,
+				})
+				setConfig(c, cfg)
+				return
+			}
+		}
+		die("Device " + c.Args()[1] + " not found in device list")
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersDevicesRemove(c *cli.Context) {
+	rid := c.Args()[0]
+	nid := parseDeviceID(c.Args()[1])
+	cfg := getConfig(c)
+	for ri, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		for ni, device := range folder.Devices {
+			if device.DeviceID == nid {
+				last := len(folder.Devices) - 1
+				cfg.Folders[ri].Devices[ni] = folder.Devices[last]
+				cfg.Folders[ri].Devices = cfg.Folders[ri].Devices[:last]
+				setConfig(c, cfg)
+				return
+			}
+		}
+		die("Device " + c.Args()[1] + " not found")
+	}
+	die("Folder " + rid + " not found")
+}
+
+func foldersDevicesClear(c *cli.Context) {
+	rid := c.Args()[0]
+	cfg := getConfig(c)
+	for i, folder := range cfg.Folders {
+		if folder.ID != rid {
+			continue
+		}
+		cfg.Folders[i].Devices = []config.FolderDeviceConfiguration{}
+		setConfig(c, cfg)
+		return
+	}
+	die("Folder " + rid + " not found")
+}
--- a/cmd/stcli/cmd_general.go
+++ b/cmd/stcli/cmd_general.go
@@ -0,0 +1,94 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+func init() {
+	cliCommands = append(cliCommands, []cli.Command{
+		{
+			Name:     "id",
+			Usage:    "Get ID of the Syncthing client",
+			Requires: &cli.Requires{},
+			Action:   generalID,
+		},
+		{
+			Name:     "status",
+			Usage:    "Configuration status, whether or not a restart is required for changes to take effect",
+			Requires: &cli.Requires{},
+			Action:   generalStatus,
+		},
+		{
+			Name:     "config",
+			Usage:    "Configuration",
+			Requires: &cli.Requires{},
+			Action:   generalConfiguration,
+		},
+		{
+			Name:     "restart",
+			Usage:    "Restart syncthing",
+			Requires: &cli.Requires{},
+			Action:   wrappedHTTPPost("system/restart"),
+		},
+		{
+			Name:     "shutdown",
+			Usage:    "Shutdown syncthing",
+			Requires: &cli.Requires{},
+			Action:   wrappedHTTPPost("system/shutdown"),
+		},
+		{
+			Name:     "reset",
+			Usage:    "Reset syncthing deleting all folders and devices",
+			Requires: &cli.Requires{},
+			Action:   wrappedHTTPPost("system/reset"),
+		},
+		{
+			Name:     "upgrade",
+			Usage:    "Upgrade syncthing (if a newer version is available)",
+			Requires: &cli.Requires{},
+			Action:   wrappedHTTPPost("system/upgrade"),
+		},
+		{
+			Name:     "version",
+			Usage:    "Syncthing client version",
+			Requires: &cli.Requires{},
+			Action:   generalVersion,
+		},
+	}...)
+}
+
+func generalID(c *cli.Context) {
+	fmt.Println(getMyID(c))
+}
+
+func generalStatus(c *cli.Context) {
+	response := httpGet(c, "system/config/insync")
+	var status struct{ ConfigInSync bool }
+	json.Unmarshal(responseToBArray(response), &status)
+	if !status.ConfigInSync {
+		die("Config out of sync")
+	}
+	fmt.Println("Config in sync")
+}
+
+func generalConfiguration(c *cli.Context) {
+	response := httpGet(c, "system/config")
+	var jsResponse interface{}
+	json.Unmarshal(responseToBArray(response), &jsResponse)
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetIndent("", "  ")
+	enc.Encode(jsResponse)
+}
+
+func generalVersion(c *cli.Context) {
+	response := httpGet(c, "system/version")
+	version := make(map[string]interface{})
+	json.Unmarshal(responseToBArray(response), &version)
+	prettyPrintJSON(version)
+}
--- a/cmd/stcli/cmd_gui.go
+++ b/cmd/stcli/cmd_gui.go
@@ -0,0 +1,127 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+func init() {
+	cliCommands = append(cliCommands, cli.Command{
+		Name:     "gui",
+		HideHelp: true,
+		Usage:    "GUI command group",
+		Subcommands: []cli.Command{
+			{
+				Name:     "dump",
+				Usage:    "Show all GUI configuration settings",
+				Requires: &cli.Requires{},
+				Action:   guiDump,
+			},
+			{
+				Name:     "get",
+				Usage:    "Get a GUI configuration setting",
+				Requires: &cli.Requires{"setting"},
+				Action:   guiGet,
+			},
+			{
+				Name:     "set",
+				Usage:    "Set a GUI configuration setting",
+				Requires: &cli.Requires{"setting", "value"},
+				Action:   guiSet,
+			},
+			{
+				Name:     "unset",
+				Usage:    "Unset a GUI configuration setting",
+				Requires: &cli.Requires{"setting"},
+				Action:   guiUnset,
+			},
+		},
+	})
+}
+
+func guiDump(c *cli.Context) {
+	cfg := getConfig(c).GUI
+	writer := newTableWriter()
+	fmt.Fprintln(writer, "Enabled:\t", cfg.Enabled, "\t(enabled)")
+	fmt.Fprintln(writer, "Use HTTPS:\t", cfg.UseTLS(), "\t(tls)")
+	fmt.Fprintln(writer, "Listen Addresses:\t", cfg.Address(), "\t(address)")
+	if cfg.User != "" {
+		fmt.Fprintln(writer, "Authentication User:\t", cfg.User, "\t(username)")
+		fmt.Fprintln(writer, "Authentication Password:\t", cfg.Password, "\t(password)")
+	}
+	if cfg.APIKey != "" {
+		fmt.Fprintln(writer, "API Key:\t", cfg.APIKey, "\t(apikey)")
+	}
+	writer.Flush()
+}
+
+func guiGet(c *cli.Context) {
+	cfg := getConfig(c).GUI
+	arg := c.Args()[0]
+	switch strings.ToLower(arg) {
+	case "enabled":
+		fmt.Println(cfg.Enabled)
+	case "tls":
+		fmt.Println(cfg.UseTLS())
+	case "address":
+		fmt.Println(cfg.Address())
+	case "user":
+		if cfg.User != "" {
+			fmt.Println(cfg.User)
+		}
+	case "password":
+		if cfg.User != "" {
+			fmt.Println(cfg.Password)
+		}
+	case "apikey":
+		if cfg.APIKey != "" {
+			fmt.Println(cfg.APIKey)
+		}
+	default:
+		die("Invalid setting: " + arg + "\nAvailable settings: enabled, tls, address, user, password, apikey")
+	}
+}
+
+func guiSet(c *cli.Context) {
+	cfg := getConfig(c)
+	arg := c.Args()[0]
+	val := c.Args()[1]
+	switch strings.ToLower(arg) {
+	case "enabled":
+		cfg.GUI.Enabled = parseBool(val)
+	case "tls":
+		cfg.GUI.RawUseTLS = parseBool(val)
+	case "address":
+		validAddress(val)
+		cfg.GUI.RawAddress = val
+	case "user":
+		cfg.GUI.User = val
+	case "password":
+		cfg.GUI.Password = val
+	case "apikey":
+		cfg.GUI.APIKey = val
+	default:
+		die("Invalid setting: " + arg + "\nAvailable settings: enabled, tls, address, user, password, apikey")
+	}
+	setConfig(c, cfg)
+}
+
+func guiUnset(c *cli.Context) {
+	cfg := getConfig(c)
+	arg := c.Args()[0]
+	switch strings.ToLower(arg) {
+	case "user":
+		cfg.GUI.User = ""
+	case "password":
+		cfg.GUI.Password = ""
+	case "apikey":
+		cfg.GUI.APIKey = ""
+	default:
+		die("Invalid setting: " + arg + "\nAvailable settings: user, password, apikey")
+	}
+	setConfig(c, cfg)
+}
--- a/cmd/stcli/cmd_options.go
+++ b/cmd/stcli/cmd_options.go
@@ -0,0 +1,173 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+func init() {
+	cliCommands = append(cliCommands, cli.Command{
+		Name:     "options",
+		HideHelp: true,
+		Usage:    "Options command group",
+		Subcommands: []cli.Command{
+			{
+				Name:     "dump",
+				Usage:    "Show all Syncthing option settings",
+				Requires: &cli.Requires{},
+				Action:   optionsDump,
+			},
+			{
+				Name:     "get",
+				Usage:    "Get a Syncthing option setting",
+				Requires: &cli.Requires{"setting"},
+				Action:   optionsGet,
+			},
+			{
+				Name:     "set",
+				Usage:    "Set a Syncthing option setting",
+				Requires: &cli.Requires{"setting", "value..."},
+				Action:   optionsSet,
+			},
+		},
+	})
+}
+
+func optionsDump(c *cli.Context) {
+	cfg := getConfig(c).Options
+	writer := newTableWriter()
+
+	fmt.Fprintln(writer, "Sync protocol listen addresses:\t", strings.Join(cfg.ListenAddresses, " "), "\t(addresses)")
+	fmt.Fprintln(writer, "Global discovery enabled:\t", cfg.GlobalAnnEnabled, "\t(globalannenabled)")
+	fmt.Fprintln(writer, "Global discovery servers:\t", strings.Join(cfg.GlobalAnnServers, " "), "\t(globalannserver)")
+
+	fmt.Fprintln(writer, "Local discovery enabled:\t", cfg.LocalAnnEnabled, "\t(localannenabled)")
+	fmt.Fprintln(writer, "Local discovery port:\t", cfg.LocalAnnPort, "\t(localannport)")
+
+	fmt.Fprintln(writer, "Outgoing rate limit in KiB/s:\t", cfg.MaxSendKbps, "\t(maxsend)")
+	fmt.Fprintln(writer, "Incoming rate limit in KiB/s:\t", cfg.MaxRecvKbps, "\t(maxrecv)")
+	fmt.Fprintln(writer, "Reconnect interval in seconds:\t", cfg.ReconnectIntervalS, "\t(reconnect)")
+	fmt.Fprintln(writer, "Start browser:\t", cfg.StartBrowser, "\t(browser)")
+	fmt.Fprintln(writer, "Enable UPnP:\t", cfg.NATEnabled, "\t(nat)")
+	fmt.Fprintln(writer, "UPnP Lease in minutes:\t", cfg.NATLeaseM, "\t(natlease)")
+	fmt.Fprintln(writer, "UPnP Renewal period in minutes:\t", cfg.NATRenewalM, "\t(natrenew)")
+	fmt.Fprintln(writer, "Restart on Wake Up:\t", cfg.RestartOnWakeup, "\t(wake)")
+
+	reporting := "unrecognized value"
+	switch cfg.URAccepted {
+	case -1:
+		reporting = "false"
+	case 0:
+		reporting = "undecided/false"
+	case 1:
+		reporting = "true"
+	}
+	fmt.Fprintln(writer, "Anonymous usage reporting:\t", reporting, "\t(reporting)")
+
+	writer.Flush()
+}
+
+func optionsGet(c *cli.Context) {
+	cfg := getConfig(c).Options
+	arg := c.Args()[0]
+	switch strings.ToLower(arg) {
+	case "address":
+		fmt.Println(strings.Join(cfg.ListenAddresses, "\n"))
+	case "globalannenabled":
+		fmt.Println(cfg.GlobalAnnEnabled)
+	case "globalannservers":
+		fmt.Println(strings.Join(cfg.GlobalAnnServers, "\n"))
+	case "localannenabled":
+		fmt.Println(cfg.LocalAnnEnabled)
+	case "localannport":
+		fmt.Println(cfg.LocalAnnPort)
+	case "maxsend":
+		fmt.Println(cfg.MaxSendKbps)
+	case "maxrecv":
+		fmt.Println(cfg.MaxRecvKbps)
+	case "reconnect":
+		fmt.Println(cfg.ReconnectIntervalS)
+	case "browser":
+		fmt.Println(cfg.StartBrowser)
+	case "nat":
+		fmt.Println(cfg.NATEnabled)
+	case "natlease":
+		fmt.Println(cfg.NATLeaseM)
+	case "natrenew":
+		fmt.Println(cfg.NATRenewalM)
+	case "reporting":
+		switch cfg.URAccepted {
+		case -1:
+			fmt.Println("false")
+		case 0:
+			fmt.Println("undecided/false")
+		case 1:
+			fmt.Println("true")
+		default:
+			fmt.Println("unknown")
+		}
+	case "wake":
+		fmt.Println(cfg.RestartOnWakeup)
+	default:
+		die("Invalid setting: " + arg + "\nAvailable settings: address, globalannenabled, globalannserver, localannenabled, localannport, maxsend, maxrecv, reconnect, browser, upnp, upnplease, upnprenew, reporting, wake")
+	}
+}
+
+func optionsSet(c *cli.Context) {
+	config := getConfig(c)
+	arg := c.Args()[0]
+	val := c.Args()[1]
+	switch strings.ToLower(arg) {
+	case "address":
+		for _, item := range c.Args().Tail() {
+			validAddress(item)
+		}
+		config.Options.ListenAddresses = c.Args().Tail()
+	case "globalannenabled":
+		config.Options.GlobalAnnEnabled = parseBool(val)
+	case "globalannserver":
+		for _, item := range c.Args().Tail() {
+			validAddress(item)
+		}
+		config.Options.GlobalAnnServers = c.Args().Tail()
+	case "localannenabled":
+		config.Options.LocalAnnEnabled = parseBool(val)
+	case "localannport":
+		config.Options.LocalAnnPort = parsePort(val)
+	case "maxsend":
+		config.Options.MaxSendKbps = parseUint(val)
+	case "maxrecv":
+		config.Options.MaxRecvKbps = parseUint(val)
+	case "reconnect":
+		config.Options.ReconnectIntervalS = parseUint(val)
+	case "browser":
+		config.Options.StartBrowser = parseBool(val)
+	case "nat":
+		config.Options.NATEnabled = parseBool(val)
+	case "natlease":
+		config.Options.NATLeaseM = parseUint(val)
+	case "natrenew":
+		config.Options.NATRenewalM = parseUint(val)
+	case "reporting":
+		switch strings.ToLower(val) {
+		case "u", "undecided", "unset":
+			config.Options.URAccepted = 0
+		default:
+			boolvalue := parseBool(val)
+			if boolvalue {
+				config.Options.URAccepted = 1
+			} else {
+				config.Options.URAccepted = -1
+			}
+		}
+	case "wake":
+		config.Options.RestartOnWakeup = parseBool(val)
+	default:
+		die("Invalid setting: " + arg + "\nAvailable settings: address, globalannenabled, globalannserver, localannenabled, localannport, maxsend, maxrecv, reconnect, browser, upnp, upnplease, upnprenew, reporting, wake")
+	}
+	setConfig(c, config)
+}
--- a/cmd/stcli/cmd_report.go
+++ b/cmd/stcli/cmd_report.go
@@ -0,0 +1,72 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+func init() {
+	cliCommands = append(cliCommands, cli.Command{
+		Name:     "report",
+		HideHelp: true,
+		Usage:    "Reporting command group",
+		Subcommands: []cli.Command{
+			{
+				Name:     "system",
+				Usage:    "Report system state",
+				Requires: &cli.Requires{},
+				Action:   reportSystem,
+			},
+			{
+				Name:     "connections",
+				Usage:    "Report about connections to other devices",
+				Requires: &cli.Requires{},
+				Action:   reportConnections,
+			},
+			{
+				Name:     "usage",
+				Usage:    "Usage report",
+				Requires: &cli.Requires{},
+				Action:   reportUsage,
+			},
+		},
+	})
+}
+
+func reportSystem(c *cli.Context) {
+	response := httpGet(c, "system/status")
+	data := make(map[string]interface{})
+	json.Unmarshal(responseToBArray(response), &data)
+	prettyPrintJSON(data)
+}
+
+func reportConnections(c *cli.Context) {
+	response := httpGet(c, "system/connections")
+	data := make(map[string]map[string]interface{})
+	json.Unmarshal(responseToBArray(response), &data)
+	var overall map[string]interface{}
+	for key, value := range data {
+		if key == "total" {
+			overall = value
+			continue
+		}
+		value["Device ID"] = key
+		prettyPrintJSON(value)
+		fmt.Println()
+	}
+	if overall != nil {
+		fmt.Println("=== Overall statistics ===")
+		prettyPrintJSON(overall)
+	}
+}
+
+func reportUsage(c *cli.Context) {
+	response := httpGet(c, "svc/report")
+	report := make(map[string]interface{})
+	json.Unmarshal(responseToBArray(response), &report)
+	prettyPrintJSON(report)
+}
--- a/cmd/stcli/labels.go
+++ b/cmd/stcli/labels.go
@@ -0,0 +1,31 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+var jsonAttributeLabels = map[string]string{
+	"folderMaxMiB":   "Largest folder size in MiB",
+	"folderMaxFiles": "Largest folder file count",
+	"longVersion":    "Long version",
+	"totMiB":         "Total size in MiB",
+	"totFiles":       "Total files",
+	"uniqueID":       "Unique ID",
+	"numFolders":     "Folder count",
+	"numDevices":     "Device count",
+	"memoryUsageMiB": "Memory usage in MiB",
+	"memorySize":     "Total memory in MiB",
+	"sha256Perf":     "SHA256 Benchmark",
+	"At":             "Last contacted",
+	"Completion":     "Percent complete",
+	"InBytesTotal":   "Total bytes received",
+	"OutBytesTotal":  "Total bytes sent",
+	"ClientVersion":  "Client version",
+	"alloc":          "Memory allocated in bytes",
+	"sys":            "Memory using in bytes",
+	"cpuPercent":     "CPU load in percent",
+	"extAnnounceOK":  "External announcments working",
+	"goroutines":     "Number of Go routines",
+	"myID":           "Client ID",
+	"tilde":          "Tilde expands to",
+	"arch":           "Architecture",
+	"os":             "OS",
+}
--- a/cmd/stcli/main.go
+++ b/cmd/stcli/main.go
@@ -0,0 +1,63 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"sort"
+
+	"github.com/AudriusButkevicius/cli"
+)
+
+type ByAlphabet []cli.Command
+
+func (a ByAlphabet) Len() int           { return len(a) }
+func (a ByAlphabet) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a ByAlphabet) Less(i, j int) bool { return a[i].Name < a[j].Name }
+
+var cliCommands []cli.Command
+
+func main() {
+	app := cli.NewApp()
+	app.Name = "syncthing-cli"
+	app.Author = "Audrius Butkevičius"
+	app.Email = "audrius.butkevicius@gmail.com"
+	app.Usage = "Syncthing command line interface"
+	app.Version = "0.1"
+	app.HideHelp = true
+
+	app.Flags = []cli.Flag{
+		cli.StringFlag{
+			Name:   "endpoint, e",
+			Value:  "http://127.0.0.1:8384",
+			Usage:  "End point to connect to",
+			EnvVar: "STENDPOINT",
+		},
+		cli.StringFlag{
+			Name:   "apikey, k",
+			Value:  "",
+			Usage:  "API Key",
+			EnvVar: "STAPIKEY",
+		},
+		cli.StringFlag{
+			Name:   "username, u",
+			Value:  "",
+			Usage:  "Username",
+			EnvVar: "STUSERNAME",
+		},
+		cli.StringFlag{
+			Name:   "password, p",
+			Value:  "",
+			Usage:  "Password",
+			EnvVar: "STPASSWORD",
+		},
+		cli.BoolFlag{
+			Name:   "insecure, i",
+			Usage:  "Do not verify SSL certificate",
+			EnvVar: "STINSECURE",
+		},
+	}
+
+	sort.Sort(ByAlphabet(cliCommands))
+	app.Commands = cliCommands
+	app.RunAndExitOnError()
+}
--- a/cmd/stcli/utils.go
+++ b/cmd/stcli/utils.go
@@ -0,0 +1,165 @@
+// Copyright (C) 2014 Audrius Butkevičius
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"text/tabwriter"
+	"unicode"
+
+	"github.com/AudriusButkevicius/cli"
+	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+func responseToBArray(response *http.Response) []byte {
+	defer response.Body.Close()
+	bytes, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		die(err)
+	}
+	return bytes
+}
+
+func die(vals ...interface{}) {
+	if len(vals) > 1 || vals[0] != nil {
+		os.Stderr.WriteString(fmt.Sprintln(vals...))
+		os.Exit(1)
+	}
+}
+
+func wrappedHTTPPost(url string) func(c *cli.Context) {
+	return func(c *cli.Context) {
+		httpPost(c, url, "")
+	}
+}
+
+func prettyPrintJSON(json map[string]interface{}) {
+	writer := newTableWriter()
+	remap := make(map[string]interface{})
+	for k, v := range json {
+		key, ok := jsonAttributeLabels[k]
+		if !ok {
+			key = firstUpper(k)
+		}
+		remap[key] = v
+	}
+
+	jsonKeys := make([]string, 0, len(remap))
+	for key := range remap {
+		jsonKeys = append(jsonKeys, key)
+	}
+	sort.Strings(jsonKeys)
+	for _, k := range jsonKeys {
+		var value string
+		rvalue := remap[k]
+		switch rvalue.(type) {
+		case int, int16, int32, int64, uint, uint16, uint32, uint64, float32, float64:
+			value = fmt.Sprintf("%.0f", rvalue)
+		default:
+			value = fmt.Sprint(rvalue)
+		}
+		if value == "" {
+			continue
+		}
+		fmt.Fprintln(writer, k+":\t"+value)
+	}
+	writer.Flush()
+}
+
+func firstUpper(str string) string {
+	for i, v := range str {
+		return string(unicode.ToUpper(v)) + str[i+1:]
+	}
+	return ""
+}
+
+func newTableWriter() *tabwriter.Writer {
+	writer := new(tabwriter.Writer)
+	writer.Init(os.Stdout, 0, 8, 0, '\t', 0)
+	return writer
+}
+
+func getMyID(c *cli.Context) string {
+	response := httpGet(c, "system/status")
+	data := make(map[string]interface{})
+	json.Unmarshal(responseToBArray(response), &data)
+	return data["myID"].(string)
+}
+
+func getConfig(c *cli.Context) config.Configuration {
+	response := httpGet(c, "system/config")
+	config := config.Configuration{}
+	json.Unmarshal(responseToBArray(response), &config)
+	return config
+}
+
+func setConfig(c *cli.Context, cfg config.Configuration) {
+	body, err := json.Marshal(cfg)
+	die(err)
+	response := httpPost(c, "system/config", string(body))
+	if response.StatusCode != 200 {
+		die("Unexpected status code", response.StatusCode)
+	}
+}
+
+func parseBool(input string) bool {
+	val, err := strconv.ParseBool(input)
+	if err != nil {
+		die(input + " is not a valid value for a boolean")
+	}
+	return val
+}
+
+func parseInt(input string) int {
+	val, err := strconv.ParseInt(input, 0, 64)
+	if err != nil {
+		die(input + " is not a valid value for an integer")
+	}
+	return int(val)
+}
+
+func parseUint(input string) int {
+	val, err := strconv.ParseUint(input, 0, 64)
+	if err != nil {
+		die(input + " is not a valid value for an unsigned integer")
+	}
+	return int(val)
+}
+
+func parsePort(input string) int {
+	port := parseUint(input)
+	if port < 1 || port > 65535 {
+		die(input + " is not a valid port\nExpected value between 1 and 65535")
+	}
+	return port
+}
+
+func validAddress(input string) {
+	tokens := strings.Split(input, ":")
+	if len(tokens) != 2 {
+		die(input + " is not a valid value for an address\nExpected format <ip or hostname>:<port>")
+	}
+	matched, err := regexp.MatchString("^[a-zA-Z0-9]+([-a-zA-Z0-9.]+[-a-zA-Z0-9]+)?$", tokens[0])
+	die(err)
+	if !matched {
+		die(input + " is not a valid value for an address\nExpected format <ip or hostname>:<port>")
+	}
+	parsePort(tokens[1])
+}
+
+func parseDeviceID(input string) protocol.DeviceID {
+	device, err := protocol.DeviceIDFromString(input)
+	if err != nil {
+		die(input + " is not a valid device id")
+	}
+	return device
+}
--- a/cmd/stcompdirs/main.go
+++ b/cmd/stcompdirs/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -15,8 +15,6 @@ import (
 	"log"
 	"os"
 	"path/filepath"
-
-	"github.com/syncthing/syncthing/lib/symlinks"
 )

 func main() {
@@ -90,10 +88,10 @@ func startWalker(dir string, res chan<- fileInfo, abort <-chan struct{}) chan er
 		}

 		rn, _ := filepath.Rel(dir, path)
-		if rn == "." || rn == ".stfolder" {
+		if rn == "." {
 			return nil
 		}
-		if rn == ".stversions" {
+		if rn == ".stversions" || rn == ".stfolder" {
 			return filepath.SkipDir
 		}

@@ -104,7 +102,7 @@ func startWalker(dir string, res chan<- fileInfo, abort <-chan struct{}) chan er
 				mode: os.ModeSymlink,
 			}

-			tgt, _, err := symlinks.Read(path)
+			tgt, err := os.Readlink(path)
 			if err != nil {
 				return err
 			}
--- a/cmd/stdisco/main.go
+++ b/cmd/stdisco/main.go
@@ -2,12 +2,11 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

 import (
-	"bytes"
 	"crypto/rand"
 	"encoding/binary"
 	"flag"
@@ -45,7 +44,7 @@ func main() {
 	flag.Parse()

 	if fake {
-		log.Println("My ID:", protocol.DeviceIDFromBytes(myID))
+		log.Println("My ID:", myID)
 	}

 	runbeacon(beacon.NewMulticast(mc), fake)
@@ -75,17 +74,17 @@ func recv(bc beacon.Interface) {
 		var ann discover.Announce
 		ann.Unmarshal(data[4:])

-		if bytes.Equal(ann.ID, myID) {
+		if ann.ID == myID {
 			// This is one of our own fake packets, don't print it.
 			continue
 		}

 		// Print announcement details for the first packet from a given
 		// device ID and source address, or if -all was given.
-		key := string(ann.ID) + src.String()
+		key := ann.ID.String() + src.String()
 		if all || !seen[key] {
 			log.Printf("Announcement from %v\n", src)
-			log.Printf(" %v at %s\n", protocol.DeviceIDFromBytes(ann.ID), strings.Join(ann.Addresses, ", "))
+			log.Printf(" %v at %s\n", ann.ID, strings.Join(ann.Addresses, ", "))
 			seen[key] = true
 		}
 	}
@@ -106,9 +105,9 @@ func send(bc beacon.Interface) {
 }

 // returns a random but recognizable device ID
-func randomDeviceID() []byte {
-	var id [32]byte
+func randomDeviceID() protocol.DeviceID {
+	var id protocol.DeviceID
 	copy(id[:], randomPrefix)
 	rand.Read(id[len(randomPrefix):])
-	return id[:]
+	return id
 }
--- a/cmd/stdiscosrv/LICENSE
+++ b/cmd/stdiscosrv/LICENSE
@@ -1,19 +0,0 @@
-Copyright (C) 2014-2015 The Discosrv Authors
-
-Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the "Software"), to deal in
-the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-of the Software, and to permit persons to whom the Software is furnished to do
-so, subject to the following conditions:
-
- The above copyright notice and this permission notice shall be included in
-  all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
--- a/cmd/stdiscosrv/README.md
+++ b/cmd/stdiscosrv/README.md
@@ -1,40 +1,10 @@
 stdiscosrv
 ==========

-[![Latest Build](http://img.shields.io/jenkins/s/http/build.syncthing.net/stdiscosrv.svg?style=flat-square)](http://build.syncthing.net/job/stdiscosrv/lastBuild/)
-
 This is the global discovery server for the `syncthing` project.

-To get it, run `go get github.com/syncthing/stdiscosrv` or download the
-[latest build](http://build.syncthing.net/job/stdiscosrv/lastSuccessfulBuild/artifact/)
-from the build server.
-
 Usage
 -----

-The discovery server supports `ql` and `postgres` backends.
-Specify the backend via `-db-backend` and the database DSN via `-db-dsn`.
+https://docs.syncthing.net/users/stdiscosrv.html

-By default it will use in-memory `ql` backend. If you wish to persist the
-information on disk between restarts in `ql`, specify a file DSN:
-
-```bash
-$ stdiscosrv -db-dsn="file:///var/run/stdiscosrv.db"
-```
-
-For `postgres`, you will need to create a database and a user with permissions
-to create tables in it, then start the stdiscosrv as follows:
-
-```bash
-$ export STDISCOSRV_DB_DSN="postgres://user:password@localhost/databasename"
-$ stdiscosrv -db-backend="postgres"
-```
-
-You can pass the DSN as command line option, but the value what you pass in will
-be visible in most process managers, potentially exposing the database password
-to other users.
-
-In all cases, the appropriate tables and indexes will be created at first
-startup. If it doesn't exit with an error, you're fine.
-
-See `stdiscosrv -help` for other options.
--- a/cmd/stdiscosrv/apisrv.go
+++ b/cmd/stdiscosrv/apisrv.go
@@ -0,0 +1,411 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"encoding/json"
+	"encoding/pem"
+	"fmt"
+	"log"
+	"math/rand"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+// announcement is the format received from and sent to clients
+type announcement struct {
+	Seen      time.Time `json:"seen"`
+	Addresses []string  `json:"addresses"`
+}
+
+type apiSrv struct {
+	addr     string
+	cert     tls.Certificate
+	db       database
+	listener net.Listener
+	repl     replicator // optional
+	useHTTP  bool
+
+	mapsMut sync.Mutex
+	misses  map[string]int32
+}
+
+type requestID int64
+
+func (i requestID) String() string {
+	return fmt.Sprintf("%016x", int64(i))
+}
+
+type contextKey int
+
+const idKey contextKey = iota
+
+func newAPISrv(addr string, cert tls.Certificate, db database, repl replicator, useHTTP bool) *apiSrv {
+	return &apiSrv{
+		addr:    addr,
+		cert:    cert,
+		db:      db,
+		repl:    repl,
+		useHTTP: useHTTP,
+		misses:  make(map[string]int32),
+	}
+}
+
+func (s *apiSrv) Serve() {
+	if s.useHTTP {
+		listener, err := net.Listen("tcp", s.addr)
+		if err != nil {
+			log.Println("Listen:", err)
+			return
+		}
+		s.listener = listener
+	} else {
+		tlsCfg := &tls.Config{
+			Certificates:           []tls.Certificate{s.cert},
+			ClientAuth:             tls.RequestClientCert,
+			SessionTicketsDisabled: true,
+			MinVersion:             tls.VersionTLS12,
+			CipherSuites: []uint16{
+				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+				tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+				tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+				tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+				tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+			},
+		}
+
+		tlsListener, err := tls.Listen("tcp", s.addr, tlsCfg)
+		if err != nil {
+			log.Println("Listen:", err)
+			return
+		}
+		s.listener = tlsListener
+	}
+
+	http.HandleFunc("/", s.handler)
+	http.HandleFunc("/ping", handlePing)
+
+	srv := &http.Server{
+		ReadTimeout:    httpReadTimeout,
+		WriteTimeout:   httpWriteTimeout,
+		MaxHeaderBytes: httpMaxHeaderBytes,
+	}
+
+	if err := srv.Serve(s.listener); err != nil {
+		log.Println("Serve:", err)
+	}
+}
+
+var topCtx = context.Background()
+
+func (s *apiSrv) handler(w http.ResponseWriter, req *http.Request) {
+	t0 := time.Now()
+
+	lw := NewLoggingResponseWriter(w)
+
+	defer func() {
+		diff := time.Since(t0)
+		apiRequestsSeconds.WithLabelValues(req.Method).Observe(diff.Seconds())
+		apiRequestsTotal.WithLabelValues(req.Method, strconv.Itoa(lw.statusCode)).Inc()
+	}()
+
+	reqID := requestID(rand.Int63())
+	ctx := context.WithValue(topCtx, idKey, reqID)
+
+	if debug {
+		log.Println(reqID, req.Method, req.URL)
+	}
+
+	var remoteIP net.IP
+	if s.useHTTP {
+		remoteIP = net.ParseIP(req.Header.Get("X-Forwarded-For"))
+	} else {
+		addr, err := net.ResolveTCPAddr("tcp", req.RemoteAddr)
+		if err != nil {
+			log.Println("remoteAddr:", err)
+			lw.Header().Set("Retry-After", errorRetryAfterString())
+			http.Error(lw, "Internal Server Error", http.StatusInternalServerError)
+			apiRequestsTotal.WithLabelValues("no_remote_addr").Inc()
+			return
+		}
+		remoteIP = addr.IP
+	}
+
+	switch req.Method {
+	case "GET":
+		s.handleGET(ctx, lw, req)
+	case "POST":
+		s.handlePOST(ctx, remoteIP, lw, req)
+	default:
+		http.Error(lw, "Method Not Allowed", http.StatusMethodNotAllowed)
+	}
+}
+
+func (s *apiSrv) handleGET(ctx context.Context, w http.ResponseWriter, req *http.Request) {
+	reqID := ctx.Value(idKey).(requestID)
+
+	deviceID, err := protocol.DeviceIDFromString(req.URL.Query().Get("device"))
+	if err != nil {
+		if debug {
+			log.Println(reqID, "bad device param")
+		}
+		lookupRequestsTotal.WithLabelValues("bad_request").Inc()
+		w.Header().Set("Retry-After", errorRetryAfterString())
+		http.Error(w, "Bad Request", http.StatusBadRequest)
+		return
+	}
+
+	key := deviceID.String()
+	rec, err := s.db.get(key)
+	if err != nil {
+		// some sort of internal error
+		lookupRequestsTotal.WithLabelValues("internal_error").Inc()
+		w.Header().Set("Retry-After", errorRetryAfterString())
+		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		return
+	}
+
+	if len(rec.Addresses) == 0 {
+		lookupRequestsTotal.WithLabelValues("not_found").Inc()
+
+		s.mapsMut.Lock()
+		misses := s.misses[key]
+		if misses < rec.Misses {
+			misses = rec.Misses + 1
+		} else {
+			misses++
+		}
+		s.misses[key] = misses
+		s.mapsMut.Unlock()
+
+		if misses%notFoundMissesWriteInterval == 0 {
+			rec.Misses = misses
+			rec.Missed = time.Now().UnixNano()
+			rec.Addresses = nil
+			// rec.Seen retained from get
+			s.db.put(key, rec)
+		}
+
+		w.Header().Set("Retry-After", notFoundRetryAfterString(int(misses)))
+		http.Error(w, "Not Found", http.StatusNotFound)
+		return
+	}
+
+	lookupRequestsTotal.WithLabelValues("success").Inc()
+
+	bs, _ := json.Marshal(announcement{
+		Seen:      time.Unix(0, rec.Seen),
+		Addresses: addressStrs(rec.Addresses),
+	})
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(bs)
+}
+
+func (s *apiSrv) handlePOST(ctx context.Context, remoteIP net.IP, w http.ResponseWriter, req *http.Request) {
+	reqID := ctx.Value(idKey).(requestID)
+
+	rawCert := certificateBytes(req)
+	if rawCert == nil {
+		if debug {
+			log.Println(reqID, "no certificates")
+		}
+		announceRequestsTotal.WithLabelValues("no_certificate").Inc()
+		w.Header().Set("Retry-After", errorRetryAfterString())
+		http.Error(w, "Forbidden", http.StatusForbidden)
+		return
+	}
+
+	var ann announcement
+	if err := json.NewDecoder(req.Body).Decode(&ann); err != nil {
+		if debug {
+			log.Println(reqID, "decode:", err)
+		}
+		announceRequestsTotal.WithLabelValues("bad_request").Inc()
+		w.Header().Set("Retry-After", errorRetryAfterString())
+		http.Error(w, "Bad Request", http.StatusBadRequest)
+		return
+	}
+
+	deviceID := protocol.NewDeviceID(rawCert)
+
+	addresses := fixupAddresses(remoteIP, ann.Addresses)
+	if len(addresses) == 0 {
+		announceRequestsTotal.WithLabelValues("bad_request").Inc()
+		w.Header().Set("Retry-After", errorRetryAfterString())
+		http.Error(w, "Bad Request", http.StatusBadRequest)
+		return
+	}
+
+	if err := s.handleAnnounce(remoteIP, deviceID, addresses); err != nil {
+		announceRequestsTotal.WithLabelValues("internal_error").Inc()
+		w.Header().Set("Retry-After", errorRetryAfterString())
+		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		return
+	}
+
+	announceRequestsTotal.WithLabelValues("success").Inc()
+
+	w.Header().Set("Reannounce-After", reannounceAfterString())
+	w.WriteHeader(http.StatusNoContent)
+}
+
+func (s *apiSrv) Stop() {
+	s.listener.Close()
+}
+
+func (s *apiSrv) handleAnnounce(remote net.IP, deviceID protocol.DeviceID, addresses []string) error {
+	key := deviceID.String()
+	now := time.Now()
+	expire := now.Add(addressExpiryTime).UnixNano()
+
+	dbAddrs := make([]DatabaseAddress, len(addresses))
+	for i := range addresses {
+		dbAddrs[i].Address = addresses[i]
+		dbAddrs[i].Expires = expire
+	}
+
+	seen := now.UnixNano()
+	if s.repl != nil {
+		s.repl.send(key, dbAddrs, seen)
+	}
+	return s.db.merge(key, dbAddrs, seen)
+}
+
+func handlePing(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(204)
+}
+
+func certificateBytes(req *http.Request) []byte {
+	if req.TLS != nil && len(req.TLS.PeerCertificates) > 0 {
+		return req.TLS.PeerCertificates[0].Raw
+	}
+
+	if hdr := req.Header.Get("X-SSL-Cert"); hdr != "" {
+		bs := []byte(hdr)
+		// The certificate is in PEM format but with spaces for newlines. We
+		// need to reinstate the newlines for the PEM decoder. But we need to
+		// leave the spaces in the BEGIN and END lines - the first and last
+		// space - alone.
+		firstSpace := bytes.Index(bs, []byte(" "))
+		lastSpace := bytes.LastIndex(bs, []byte(" "))
+		for i := firstSpace + 1; i < lastSpace; i++ {
+			if bs[i] == ' ' {
+				bs[i] = '\n'
+			}
+		}
+		block, _ := pem.Decode(bs)
+		if block == nil {
+			// Decoding failed
+			return nil
+		}
+		return block.Bytes
+	}
+
+	return nil
+}
+
+// fixupAddresses checks the list of addresses, removing invalid ones and
+// replacing unspecified IPs with the given remote IP.
+func fixupAddresses(remote net.IP, addresses []string) []string {
+	fixed := make([]string, 0, len(addresses))
+	for _, annAddr := range addresses {
+		uri, err := url.Parse(annAddr)
+		if err != nil {
+			continue
+		}
+
+		host, port, err := net.SplitHostPort(uri.Host)
+		if err != nil {
+			continue
+		}
+
+		ip := net.ParseIP(host)
+
+		// Some classes of IP are no-go.
+		if ip.IsLoopback() || ip.IsMulticast() {
+			continue
+		}
+
+		if host == "" || ip.IsUnspecified() {
+			// Replace the unspecified IP with the request source.
+
+			// ... unless the request source is the loopback address or
+			// multicast/unspecified (can't happen, really).
+			if remote.IsLoopback() || remote.IsMulticast() || remote.IsUnspecified() {
+				continue
+			}
+
+			// Do not use IPv6 remote address if requested scheme is ...4
+			// (i.e., tcp4, etc.)
+			if strings.HasSuffix(uri.Scheme, "4") && remote.To4() == nil {
+				continue
+			}
+
+			// Do not use IPv4 remote address if requested scheme is ...6
+			if strings.HasSuffix(uri.Scheme, "6") && remote.To4() != nil {
+				continue
+			}
+
+			host = remote.String()
+		}
+
+		uri.Host = net.JoinHostPort(host, port)
+		fixed = append(fixed, uri.String())
+	}
+
+	return fixed
+}
+
+type loggingResponseWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func NewLoggingResponseWriter(w http.ResponseWriter) *loggingResponseWriter {
+	return &loggingResponseWriter{w, http.StatusOK}
+}
+
+func (lrw *loggingResponseWriter) WriteHeader(code int) {
+	lrw.statusCode = code
+	lrw.ResponseWriter.WriteHeader(code)
+}
+
+func addressStrs(dbAddrs []DatabaseAddress) []string {
+	res := make([]string, len(dbAddrs))
+	for i, a := range dbAddrs {
+		res[i] = a.Address
+	}
+	return res
+}
+
+func errorRetryAfterString() string {
+	return strconv.Itoa(errorRetryAfterSeconds + rand.Intn(errorRetryFuzzSeconds))
+}
+
+func notFoundRetryAfterString(misses int) string {
+	retryAfterS := notFoundRetryMinSeconds + notFoundRetryIncSeconds*misses
+	if retryAfterS > notFoundRetryMaxSeconds {
+		retryAfterS = notFoundRetryMaxSeconds
+	}
+	retryAfterS += rand.Intn(notFoundRetryFuzzSeconds)
+	return strconv.Itoa(retryAfterS)
+}
+
+func reannounceAfterString() string {
+	return strconv.Itoa(reannounceAfterSeconds + rand.Intn(reannounzeFuzzSeconds))
+}
--- a/cmd/stdiscosrv/apisrv_test.go
+++ b/cmd/stdiscosrv/apisrv_test.go
@@ -0,0 +1,65 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"fmt"
+	"net"
+	"testing"
+)
+
+func TestFixupAddresses(t *testing.T) {
+	cases := []struct {
+		remote net.IP
+		in     []string
+		out    []string
+	}{
+		{ // verbatim passthrough
+			in:  []string{"tcp://1.2.3.4:22000"},
+			out: []string{"tcp://1.2.3.4:22000"},
+		}, { // unspecified replaced by remote
+			remote: net.ParseIP("1.2.3.4"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://1.2.3.4:22000", "tcp://192.0.2.42:22000"},
+		}, { // unspecified not used as replacement
+			remote: net.ParseIP("0.0.0.0"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		}, { // unspecified not used as replacement
+			remote: net.ParseIP("::"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		}, { // localhost not used as replacement
+			remote: net.ParseIP("127.0.0.1"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		}, { // localhost not used as replacement
+			remote: net.ParseIP("::1"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		}, { // multicast not used as replacement
+			remote: net.ParseIP("224.0.0.1"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		}, { // multicast not used as replacement
+			remote: net.ParseIP("ff80::42"),
+			in:     []string{"tcp://:22000", "tcp://192.0.2.42:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		}, { // explicitly announced weirdness is also filtered
+			remote: net.ParseIP("192.0.2.42"),
+			in:     []string{"tcp://:22000", "tcp://127.1.2.3:22000", "tcp://[::1]:22000", "tcp://[ff80::42]:22000"},
+			out:    []string{"tcp://192.0.2.42:22000"},
+		},
+	}
+
+	for _, tc := range cases {
+		out := fixupAddresses(tc.remote, tc.in)
+		if fmt.Sprint(out) != fmt.Sprint(tc.out) {
+			t.Errorf("fixupAddresses(%v, %v) => %v, expected %v", tc.remote, tc.in, out, tc.out)
+		}
+	}
+}
--- a/cmd/stdiscosrv/clean.go
+++ b/cmd/stdiscosrv/clean.go
@@ -1,75 +0,0 @@
-// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
-
-package main
-
-import (
-	"database/sql"
-	"log"
-	"time"
-)
-
-type cleansrv struct {
-	intv time.Duration
-	db   *sql.DB
-	prep map[string]*sql.Stmt
-}
-
-func (s *cleansrv) Serve() {
-	for {
-		time.Sleep(next(s.intv))
-
-		err := s.cleanOldEntries()
-		if err != nil {
-			log.Println("Clean:", err)
-		}
-	}
-}
-
-func (s *cleansrv) Stop() {
-	panic("stop unimplemented")
-}
-
-func (s *cleansrv) cleanOldEntries() (err error) {
-	var tx *sql.Tx
-	tx, err = s.db.Begin()
-	if err != nil {
-		return err
-	}
-
-	defer func() {
-		if err == nil {
-			err = tx.Commit()
-		} else {
-			tx.Rollback()
-		}
-	}()
-
-	res, err := tx.Stmt(s.prep["cleanAddress"]).Exec()
-	if err != nil {
-		return err
-	}
-	if rows, _ := res.RowsAffected(); rows > 0 {
-		log.Printf("Clean: %d old addresses", rows)
-	}
-
-	res, err = tx.Stmt(s.prep["cleanDevice"]).Exec()
-	if err != nil {
-		return err
-	}
-	if rows, _ := res.RowsAffected(); rows > 0 {
-		log.Printf("Clean: %d old devices", rows)
-	}
-
-	var devs, addrs int
-	row := tx.Stmt(s.prep["countDevice"]).QueryRow()
-	if err = row.Scan(&devs); err != nil {
-		return err
-	}
-	row = tx.Stmt(s.prep["countAddress"]).QueryRow()
-	if err = row.Scan(&addrs); err != nil {
-		return err
-	}
-
-	log.Printf("Database: %d devices, %d addresses", devs, addrs)
-	return nil
-}
--- a/cmd/stdiscosrv/database.go
+++ b/cmd/stdiscosrv/database.go
@@ -0,0 +1,354 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//go:generate go run ../../script/protofmt.go database.proto
+//go:generate protoc -I ../../../../../ -I ../../vendor/ -I ../../vendor/github.com/gogo/protobuf/protobuf -I . --gogofast_out=. database.proto
+
+package main
+
+import (
+	"sort"
+	"time"
+
+	"github.com/syndtr/goleveldb/leveldb"
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+type clock interface {
+	Now() time.Time
+}
+
+type defaultClock struct{}
+
+func (defaultClock) Now() time.Time {
+	return time.Now()
+}
+
+type database interface {
+	put(key string, rec DatabaseRecord) error
+	merge(key string, addrs []DatabaseAddress, seen int64) error
+	get(key string) (DatabaseRecord, error)
+}
+
+type levelDBStore struct {
+	db         *leveldb.DB
+	inbox      chan func()
+	stop       chan struct{}
+	clock      clock
+	marshalBuf []byte
+}
+
+func newLevelDBStore(dir string) (*levelDBStore, error) {
+	db, err := leveldb.OpenFile(dir, levelDBOptions)
+	if err != nil {
+		return nil, err
+	}
+	return &levelDBStore{
+		db:    db,
+		inbox: make(chan func(), 16),
+		stop:  make(chan struct{}),
+		clock: defaultClock{},
+	}, nil
+}
+
+func (s *levelDBStore) put(key string, rec DatabaseRecord) error {
+	t0 := time.Now()
+	defer func() {
+		databaseOperationSeconds.WithLabelValues(dbOpPut).Observe(time.Since(t0).Seconds())
+	}()
+
+	rc := make(chan error)
+
+	s.inbox <- func() {
+		size := rec.Size()
+		if len(s.marshalBuf) < size {
+			s.marshalBuf = make([]byte, size)
+		}
+		n, _ := rec.MarshalTo(s.marshalBuf)
+		rc <- s.db.Put([]byte(key), s.marshalBuf[:n], nil)
+	}
+
+	err := <-rc
+	if err != nil {
+		databaseOperations.WithLabelValues(dbOpPut, dbResError).Inc()
+	} else {
+		databaseOperations.WithLabelValues(dbOpPut, dbResSuccess).Inc()
+	}
+
+	return err
+}
+
+func (s *levelDBStore) merge(key string, addrs []DatabaseAddress, seen int64) error {
+	t0 := time.Now()
+	defer func() {
+		databaseOperationSeconds.WithLabelValues(dbOpMerge).Observe(time.Since(t0).Seconds())
+	}()
+
+	rc := make(chan error)
+	newRec := DatabaseRecord{
+		Addresses: addrs,
+		Seen:      seen,
+	}
+
+	s.inbox <- func() {
+		// grab the existing record
+		oldRec, err := s.get(key)
+		if err != nil {
+			// "not found" is not an error from get, so this is serious
+			// stuff only
+			rc <- err
+			return
+		}
+		newRec = merge(newRec, oldRec)
+
+		// We replicate s.put() functionality here ourselves instead of
+		// calling it because we want to serialize our get above together
+		// with the put in the same function.
+		size := newRec.Size()
+		if len(s.marshalBuf) < size {
+			s.marshalBuf = make([]byte, size)
+		}
+		n, _ := newRec.MarshalTo(s.marshalBuf)
+		rc <- s.db.Put([]byte(key), s.marshalBuf[:n], nil)
+	}
+
+	err := <-rc
+	if err != nil {
+		databaseOperations.WithLabelValues(dbOpMerge, dbResError).Inc()
+	} else {
+		databaseOperations.WithLabelValues(dbOpMerge, dbResSuccess).Inc()
+	}
+
+	return err
+}
+
+func (s *levelDBStore) get(key string) (DatabaseRecord, error) {
+	t0 := time.Now()
+	defer func() {
+		databaseOperationSeconds.WithLabelValues(dbOpGet).Observe(time.Since(t0).Seconds())
+	}()
+
+	keyBs := []byte(key)
+	val, err := s.db.Get(keyBs, nil)
+	if err == leveldb.ErrNotFound {
+		databaseOperations.WithLabelValues(dbOpGet, dbResNotFound).Inc()
+		return DatabaseRecord{}, nil
+	}
+	if err != nil {
+		databaseOperations.WithLabelValues(dbOpGet, dbResError).Inc()
+		return DatabaseRecord{}, err
+	}
+
+	var rec DatabaseRecord
+
+	if err := rec.Unmarshal(val); err != nil {
+		databaseOperations.WithLabelValues(dbOpGet, dbResUnmarshalError).Inc()
+		return DatabaseRecord{}, nil
+	}
+
+	rec.Addresses = expire(rec.Addresses, s.clock.Now().UnixNano())
+	databaseOperations.WithLabelValues(dbOpGet, dbResSuccess).Inc()
+	return rec, nil
+}
+
+func (s *levelDBStore) Serve() {
+	t := time.NewTimer(0)
+	defer t.Stop()
+	defer s.db.Close()
+
+	// Start the statistics serve routine. It will exit with us when
+	// statisticsTrigger is closed.
+	statisticsTrigger := make(chan struct{})
+	statisticsDone := make(chan struct{})
+	go s.statisticsServe(statisticsTrigger, statisticsDone)
+
+loop:
+	for {
+		select {
+		case fn := <-s.inbox:
+			// Run function in serialized order.
+			fn()
+
+		case <-t.C:
+			// Trigger the statistics routine to do its thing in the
+			// background.
+			statisticsTrigger <- struct{}{}
+
+		case <-statisticsDone:
+			// The statistics routine is done with one iteratation, schedule
+			// the next.
+			t.Reset(databaseStatisticsInterval)
+
+		case <-s.stop:
+			// We're done.
+			close(statisticsTrigger)
+			break loop
+		}
+	}
+
+	// Also wait for statisticsServe to return
+	<-statisticsDone
+}
+
+func (s *levelDBStore) statisticsServe(trigger <-chan struct{}, done chan<- struct{}) {
+	defer close(done)
+
+	for range trigger {
+		t0 := time.Now()
+		nowNanos := t0.UnixNano()
+		cutoff24h := t0.Add(-24 * time.Hour).UnixNano()
+		cutoff1w := t0.Add(-7 * 24 * time.Hour).UnixNano()
+		cutoff2Mon := t0.Add(-60 * 24 * time.Hour).UnixNano()
+		current, last24h, last1w, inactive, errors := 0, 0, 0, 0, 0
+
+		iter := s.db.NewIterator(&util.Range{}, nil)
+		for iter.Next() {
+			// Attempt to unmarshal the record and count the
+			// failure if there's something wrong with it.
+			var rec DatabaseRecord
+			if err := rec.Unmarshal(iter.Value()); err != nil {
+				errors++
+				continue
+			}
+
+			// If there are addresses that have not expired it's a current
+			// record, otherwise account it based on when it was last seen
+			// (last 24 hours or last week) or finally as inactice.
+			switch {
+			case len(expire(rec.Addresses, nowNanos)) > 0:
+				current++
+			case rec.Seen > cutoff24h:
+				last24h++
+			case rec.Seen > cutoff1w:
+				last1w++
+			case rec.Seen > cutoff2Mon:
+				inactive++
+			case rec.Missed < cutoff2Mon:
+				// It hasn't been seen lately and we haven't recorded
+				// someone asking for this device in a long time either;
+				// delete the record.
+				if err := s.db.Delete(iter.Key(), nil); err != nil {
+					databaseOperations.WithLabelValues(dbOpDelete, dbResError).Inc()
+				} else {
+					databaseOperations.WithLabelValues(dbOpDelete, dbResSuccess).Inc()
+				}
+			default:
+				inactive++
+			}
+		}
+
+		iter.Release()
+
+		databaseKeys.WithLabelValues("current").Set(float64(current))
+		databaseKeys.WithLabelValues("last24h").Set(float64(last24h))
+		databaseKeys.WithLabelValues("last1w").Set(float64(last1w))
+		databaseKeys.WithLabelValues("inactive").Set(float64(inactive))
+		databaseKeys.WithLabelValues("error").Set(float64(errors))
+		databaseStatisticsSeconds.Set(time.Since(t0).Seconds())
+
+		// Signal that we are done and can be scheduled again.
+		done <- struct{}{}
+	}
+}
+
+func (s *levelDBStore) Stop() {
+	close(s.stop)
+}
+
+// merge returns the merged result of the two database records a and b. The
+// result is the union of the two address sets, with the newer expiry time
+// chosen for any duplicates.
+func merge(a, b DatabaseRecord) DatabaseRecord {
+	// Both lists must be sorted for this to work.
+	sort.Slice(a.Addresses, func(i, j int) bool {
+		return a.Addresses[i].Address < a.Addresses[j].Address
+	})
+	sort.Slice(b.Addresses, func(i, j int) bool {
+		return b.Addresses[i].Address < b.Addresses[j].Address
+	})
+
+	res := DatabaseRecord{
+		Addresses: make([]DatabaseAddress, 0, len(a.Addresses)+len(b.Addresses)),
+		Seen:      a.Seen,
+	}
+	if b.Seen > a.Seen {
+		res.Seen = b.Seen
+	}
+
+	aIdx := 0
+	bIdx := 0
+	aAddrs := a.Addresses
+	bAddrs := b.Addresses
+loop:
+	for {
+		switch {
+		case aIdx == len(aAddrs) && bIdx == len(bAddrs):
+			// both lists are exhausted, we are done
+			break loop
+
+		case aIdx == len(aAddrs):
+			// a is exhausted, pick from b and continue
+			res.Addresses = append(res.Addresses, bAddrs[bIdx])
+			bIdx++
+			continue
+
+		case bIdx == len(bAddrs):
+			// b is exhausted, pick from a and continue
+			res.Addresses = append(res.Addresses, aAddrs[aIdx])
+			aIdx++
+			continue
+		}
+
+		// We have values left on both sides.
+		aVal := aAddrs[aIdx]
+		bVal := bAddrs[bIdx]
+
+		switch {
+		case aVal.Address == bVal.Address:
+			// update for same address, pick newer
+			if aVal.Expires > bVal.Expires {
+				res.Addresses = append(res.Addresses, aVal)
+			} else {
+				res.Addresses = append(res.Addresses, bVal)
+			}
+			aIdx++
+			bIdx++
+
+		case aVal.Address < bVal.Address:
+			// a is smallest, pick it and continue
+			res.Addresses = append(res.Addresses, aVal)
+			aIdx++
+
+		default:
+			// b is smallest, pick it and continue
+			res.Addresses = append(res.Addresses, bVal)
+			bIdx++
+		}
+	}
+	return res
+}
+
+// expire returns the list of addresses after removing expired entries.
+// Expiration happen in place, so the slice given as the parameter is
+// destroyed. Internal order is not preserved.
+func expire(addrs []DatabaseAddress, now int64) []DatabaseAddress {
+	i := 0
+	for i < len(addrs) {
+		if addrs[i].Expires < now {
+			// This item is expired. Replace it with the last in the list
+			// (noop if we are at the last item).
+			addrs[i] = addrs[len(addrs)-1]
+			// Wipe the last item of the list to release references to
+			// strings and stuff.
+			addrs[len(addrs)-1] = DatabaseAddress{}
+			// Shorten the slice.
+			addrs = addrs[:len(addrs)-1]
+			continue
+		}
+		i++
+	}
+	return addrs
+}
--- a/cmd/stdiscosrv/database.pb.go
+++ b/cmd/stdiscosrv/database.pb.go
@@ -0,0 +1,772 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: database.proto
+
+/*
+	Package main is a generated protocol buffer package.
+
+	It is generated from these files:
+		database.proto
+
+	It has these top-level messages:
+		DatabaseRecord
+		ReplicationRecord
+		DatabaseAddress
+*/
+package main
+
+import proto "github.com/gogo/protobuf/proto"
+import fmt "fmt"
+import math "math"
+import _ "github.com/gogo/protobuf/gogoproto"
+
+import io "io"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.GoGoProtoPackageIsVersion2 // please upgrade the proto package
+
+type DatabaseRecord struct {
+	Addresses []DatabaseAddress `protobuf:"bytes,1,rep,name=addresses" json:"addresses"`
+	Misses    int32             `protobuf:"varint,2,opt,name=misses,proto3" json:"misses,omitempty"`
+	Seen      int64             `protobuf:"varint,3,opt,name=seen,proto3" json:"seen,omitempty"`
+	Missed    int64             `protobuf:"varint,4,opt,name=missed,proto3" json:"missed,omitempty"`
+}
+
+func (m *DatabaseRecord) Reset()                    { *m = DatabaseRecord{} }
+func (m *DatabaseRecord) String() string            { return proto.CompactTextString(m) }
+func (*DatabaseRecord) ProtoMessage()               {}
+func (*DatabaseRecord) Descriptor() ([]byte, []int) { return fileDescriptorDatabase, []int{0} }
+
+type ReplicationRecord struct {
+	Key       string            `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+	Addresses []DatabaseAddress `protobuf:"bytes,2,rep,name=addresses" json:"addresses"`
+	Seen      int64             `protobuf:"varint,3,opt,name=seen,proto3" json:"seen,omitempty"`
+}
+
+func (m *ReplicationRecord) Reset()                    { *m = ReplicationRecord{} }
+func (m *ReplicationRecord) String() string            { return proto.CompactTextString(m) }
+func (*ReplicationRecord) ProtoMessage()               {}
+func (*ReplicationRecord) Descriptor() ([]byte, []int) { return fileDescriptorDatabase, []int{1} }
+
+type DatabaseAddress struct {
+	Address string `protobuf:"bytes,1,opt,name=address,proto3" json:"address,omitempty"`
+	Expires int64  `protobuf:"varint,2,opt,name=expires,proto3" json:"expires,omitempty"`
+}
+
+func (m *DatabaseAddress) Reset()                    { *m = DatabaseAddress{} }
+func (m *DatabaseAddress) String() string            { return proto.CompactTextString(m) }
+func (*DatabaseAddress) ProtoMessage()               {}
+func (*DatabaseAddress) Descriptor() ([]byte, []int) { return fileDescriptorDatabase, []int{2} }
+
+func init() {
+	proto.RegisterType((*DatabaseRecord)(nil), "main.DatabaseRecord")
+	proto.RegisterType((*ReplicationRecord)(nil), "main.ReplicationRecord")
+	proto.RegisterType((*DatabaseAddress)(nil), "main.DatabaseAddress")
+}
+func (m *DatabaseRecord) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *DatabaseRecord) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Addresses) > 0 {
+		for _, msg := range m.Addresses {
+			dAtA[i] = 0xa
+			i++
+			i = encodeVarintDatabase(dAtA, i, uint64(msg.Size()))
+			n, err := msg.MarshalTo(dAtA[i:])
+			if err != nil {
+				return 0, err
+			}
+			i += n
+		}
+	}
+	if m.Misses != 0 {
+		dAtA[i] = 0x10
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Misses))
+	}
+	if m.Seen != 0 {
+		dAtA[i] = 0x18
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Seen))
+	}
+	if m.Missed != 0 {
+		dAtA[i] = 0x20
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Missed))
+	}
+	return i, nil
+}
+
+func (m *ReplicationRecord) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ReplicationRecord) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Key) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(len(m.Key)))
+		i += copy(dAtA[i:], m.Key)
+	}
+	if len(m.Addresses) > 0 {
+		for _, msg := range m.Addresses {
+			dAtA[i] = 0x12
+			i++
+			i = encodeVarintDatabase(dAtA, i, uint64(msg.Size()))
+			n, err := msg.MarshalTo(dAtA[i:])
+			if err != nil {
+				return 0, err
+			}
+			i += n
+		}
+	}
+	if m.Seen != 0 {
+		dAtA[i] = 0x18
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Seen))
+	}
+	return i, nil
+}
+
+func (m *DatabaseAddress) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *DatabaseAddress) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Address) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(len(m.Address)))
+		i += copy(dAtA[i:], m.Address)
+	}
+	if m.Expires != 0 {
+		dAtA[i] = 0x10
+		i++
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Expires))
+	}
+	return i, nil
+}
+
+func encodeFixed64Database(dAtA []byte, offset int, v uint64) int {
+	dAtA[offset] = uint8(v)
+	dAtA[offset+1] = uint8(v >> 8)
+	dAtA[offset+2] = uint8(v >> 16)
+	dAtA[offset+3] = uint8(v >> 24)
+	dAtA[offset+4] = uint8(v >> 32)
+	dAtA[offset+5] = uint8(v >> 40)
+	dAtA[offset+6] = uint8(v >> 48)
+	dAtA[offset+7] = uint8(v >> 56)
+	return offset + 8
+}
+func encodeFixed32Database(dAtA []byte, offset int, v uint32) int {
+	dAtA[offset] = uint8(v)
+	dAtA[offset+1] = uint8(v >> 8)
+	dAtA[offset+2] = uint8(v >> 16)
+	dAtA[offset+3] = uint8(v >> 24)
+	return offset + 4
+}
+func encodeVarintDatabase(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *DatabaseRecord) Size() (n int) {
+	var l int
+	_ = l
+	if len(m.Addresses) > 0 {
+		for _, e := range m.Addresses {
+			l = e.Size()
+			n += 1 + l + sovDatabase(uint64(l))
+		}
+	}
+	if m.Misses != 0 {
+		n += 1 + sovDatabase(uint64(m.Misses))
+	}
+	if m.Seen != 0 {
+		n += 1 + sovDatabase(uint64(m.Seen))
+	}
+	if m.Missed != 0 {
+		n += 1 + sovDatabase(uint64(m.Missed))
+	}
+	return n
+}
+
+func (m *ReplicationRecord) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Key)
+	if l > 0 {
+		n += 1 + l + sovDatabase(uint64(l))
+	}
+	if len(m.Addresses) > 0 {
+		for _, e := range m.Addresses {
+			l = e.Size()
+			n += 1 + l + sovDatabase(uint64(l))
+		}
+	}
+	if m.Seen != 0 {
+		n += 1 + sovDatabase(uint64(m.Seen))
+	}
+	return n
+}
+
+func (m *DatabaseAddress) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Address)
+	if l > 0 {
+		n += 1 + l + sovDatabase(uint64(l))
+	}
+	if m.Expires != 0 {
+		n += 1 + sovDatabase(uint64(m.Expires))
+	}
+	return n
+}
+
+func sovDatabase(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozDatabase(x uint64) (n int) {
+	return sovDatabase(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *DatabaseRecord) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowDatabase
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: DatabaseRecord: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: DatabaseRecord: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Addresses", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Addresses = append(m.Addresses, DatabaseAddress{})
+			if err := m.Addresses[len(m.Addresses)-1].Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Misses", wireType)
+			}
+			m.Misses = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Misses |= (int32(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Seen", wireType)
+			}
+			m.Seen = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Seen |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 4:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Missed", wireType)
+			}
+			m.Missed = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Missed |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipDatabase(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *ReplicationRecord) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowDatabase
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ReplicationRecord: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ReplicationRecord: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Key", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= (uint64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Key = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Addresses", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Addresses = append(m.Addresses, DatabaseAddress{})
+			if err := m.Addresses[len(m.Addresses)-1].Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Seen", wireType)
+			}
+			m.Seen = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Seen |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipDatabase(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *DatabaseAddress) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowDatabase
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: DatabaseAddress: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: DatabaseAddress: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Address", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= (uint64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Address = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Expires", wireType)
+			}
+			m.Expires = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Expires |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipDatabase(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipDatabase(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowDatabase
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowDatabase
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthDatabase
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowDatabase
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipDatabase(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthDatabase = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowDatabase   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("database.proto", fileDescriptorDatabase) }
+
+var fileDescriptorDatabase = []byte{
+	// 264 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x4b, 0x49, 0x2c, 0x49,
+	0x4c, 0x4a, 0x2c, 0x4e, 0xd5, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0xc9, 0x4d, 0xcc, 0xcc,
+	0x93, 0xd2, 0x4d, 0xcf, 0x2c, 0xc9, 0x28, 0x4d, 0xd2, 0x4b, 0xce, 0xcf, 0xd5, 0x4f, 0xcf, 0x4f,
+	0xcf, 0xd7, 0x07, 0x4b, 0x26, 0x95, 0xa6, 0x81, 0x79, 0x60, 0x0e, 0x98, 0x05, 0xd1, 0xa4, 0xd4,
+	0xcf, 0xc8, 0xc5, 0xe7, 0x02, 0x35, 0x27, 0x28, 0x35, 0x39, 0xbf, 0x28, 0x45, 0xc8, 0x92, 0x8b,
+	0x33, 0x31, 0x25, 0xa5, 0x28, 0xb5, 0xb8, 0x38, 0xb5, 0x58, 0x82, 0x51, 0x81, 0x59, 0x83, 0xdb,
+	0x48, 0x54, 0x0f, 0x64, 0xb6, 0x1e, 0x4c, 0xa1, 0x23, 0x44, 0xda, 0x89, 0xe5, 0xc4, 0x3d, 0x79,
+	0x86, 0x20, 0x84, 0x6a, 0x21, 0x31, 0x2e, 0xb6, 0xdc, 0x4c, 0xb0, 0x3e, 0x26, 0x05, 0x46, 0x0d,
+	0xd6, 0x20, 0x28, 0x4f, 0x48, 0x88, 0x8b, 0xa5, 0x38, 0x35, 0x35, 0x4f, 0x82, 0x59, 0x81, 0x51,
+	0x83, 0x39, 0x08, 0xcc, 0x86, 0xab, 0x4d, 0x91, 0x60, 0x01, 0x8b, 0x42, 0x79, 0x4a, 0x25, 0x5c,
+	0x82, 0x41, 0xa9, 0x05, 0x39, 0x99, 0xc9, 0x89, 0x25, 0x99, 0xf9, 0x79, 0x50, 0x37, 0x09, 0x70,
+	0x31, 0x67, 0xa7, 0x56, 0x4a, 0x30, 0x2a, 0x30, 0x6a, 0x70, 0x06, 0x81, 0x98, 0xa8, 0xae, 0x64,
+	0x22, 0xc9, 0x95, 0x58, 0x5c, 0xa3, 0xe4, 0xca, 0xc5, 0x8f, 0xa6, 0x4f, 0x48, 0x82, 0x8b, 0x1d,
+	0xaa, 0x07, 0x6a, 0x2f, 0x8c, 0x0b, 0x92, 0x49, 0xad, 0x28, 0xc8, 0x2c, 0x82, 0xfa, 0x93, 0x39,
+	0x08, 0xc6, 0x75, 0x12, 0x38, 0xf1, 0x50, 0x8e, 0xe1, 0xc4, 0x23, 0x39, 0xc6, 0x0b, 0x8f, 0xe4,
+	0x18, 0x1f, 0x3c, 0x92, 0x63, 0x4c, 0x62, 0x03, 0x87, 0xb3, 0x31, 0x20, 0x00, 0x00, 0xff, 0xff,
+	0x6a, 0x22, 0xa2, 0x85, 0xae, 0x01, 0x00, 0x00,
+}
--- a/cmd/stdiscosrv/database.proto
+++ b/cmd/stdiscosrv/database.proto
@@ -0,0 +1,33 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+syntax = "proto3";
+
+package main;
+
+import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+
+option (gogoproto.goproto_getters_all) = false;
+
+message DatabaseRecord {
+    repeated DatabaseAddress addresses = 1 [(gogoproto.nullable) = false];
+    int32                    misses    = 2; // Number of lookups* without hits
+    int64                    seen      = 3; // Unix nanos, last device announce
+    int64                    missed    = 4; // Unix nanos, last* failed lookup
+}
+
+// *) Not every lookup results in a write, so may not be completely accurate
+
+message ReplicationRecord {
+    string                   key       = 1;
+    repeated DatabaseAddress addresses = 2 [(gogoproto.nullable) = false];
+    int64                    seen      = 3; // Unix nanos, last device announce
+}
+
+message DatabaseAddress {
+    string address = 1;
+    int64  expires = 2; // Unix nanos
+}
--- a/cmd/stdiscosrv/database_test.go
+++ b/cmd/stdiscosrv/database_test.go
@@ -0,0 +1,211 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"testing"
+	"time"
+)
+
+func TestDatabaseGetSet(t *testing.T) {
+	os.RemoveAll("_database")
+	defer os.RemoveAll("_database")
+	db, err := newLevelDBStore("_database")
+	if err != nil {
+		t.Fatal(err)
+	}
+	go db.Serve()
+	defer db.Stop()
+
+	// Check missing record
+
+	rec, err := db.get("abcd")
+	if err != nil {
+		t.Error("not found should not be an error")
+	}
+	if len(rec.Addresses) != 0 {
+		t.Error("addresses should be empty")
+	}
+	if rec.Misses != 0 {
+		t.Error("missing should be zero")
+	}
+
+	// Set up a clock
+
+	now := time.Now()
+	tc := &testClock{now}
+	db.clock = tc
+
+	// Put a record
+
+	rec.Addresses = []DatabaseAddress{
+		{Address: "tcp://1.2.3.4:5", Expires: tc.Now().Add(time.Minute).UnixNano()},
+	}
+	if err := db.put("abcd", rec); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify it
+
+	rec, err = db.get("abcd")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rec.Addresses) != 1 {
+		t.Log(rec.Addresses)
+		t.Fatal("should have one address")
+	}
+	if rec.Addresses[0].Address != "tcp://1.2.3.4:5" {
+		t.Log(rec.Addresses)
+		t.Error("incorrect address")
+	}
+
+	// Wind the clock one half expiry, and merge in a new address
+
+	tc.wind(30 * time.Second)
+
+	addrs := []DatabaseAddress{
+		{Address: "tcp://6.7.8.9:0", Expires: tc.Now().Add(time.Minute).UnixNano()},
+	}
+	if err := db.merge("abcd", addrs, tc.Now().UnixNano()); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify it
+
+	rec, err = db.get("abcd")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rec.Addresses) != 2 {
+		t.Log(rec.Addresses)
+		t.Fatal("should have two addresses")
+	}
+	if rec.Addresses[0].Address != "tcp://1.2.3.4:5" {
+		t.Log(rec.Addresses)
+		t.Error("incorrect address[0]")
+	}
+	if rec.Addresses[1].Address != "tcp://6.7.8.9:0" {
+		t.Log(rec.Addresses)
+		t.Error("incorrect address[1]")
+	}
+
+	// Pass the first expiry time
+
+	tc.wind(45 * time.Second)
+
+	// Verify it
+
+	rec, err = db.get("abcd")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rec.Addresses) != 1 {
+		t.Log(rec.Addresses)
+		t.Fatal("should have one address")
+	}
+	if rec.Addresses[0].Address != "tcp://6.7.8.9:0" {
+		t.Log(rec.Addresses)
+		t.Error("incorrect address")
+	}
+
+	// Put a record with misses
+
+	rec = DatabaseRecord{Misses: 42}
+	if err := db.put("efgh", rec); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify it
+
+	rec, err = db.get("efgh")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rec.Addresses) != 0 {
+		t.Log(rec.Addresses)
+		t.Fatal("should have no addresses")
+	}
+	if rec.Misses != 42 {
+		t.Log(rec.Misses)
+		t.Error("incorrect misses")
+	}
+
+	// Set an address
+
+	addrs = []DatabaseAddress{
+		{Address: "tcp://6.7.8.9:0", Expires: tc.Now().Add(time.Minute).UnixNano()},
+	}
+	if err := db.merge("efgh", addrs, tc.Now().UnixNano()); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify it
+
+	rec, err = db.get("efgh")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(rec.Addresses) != 1 {
+		t.Log(rec.Addresses)
+		t.Fatal("should have one address")
+	}
+	if rec.Misses != 0 {
+		t.Log(rec.Misses)
+		t.Error("should have no misses")
+	}
+}
+
+func TestFilter(t *testing.T) {
+	// all cases are expired with t=10
+	cases := []struct {
+		a []DatabaseAddress
+		b []DatabaseAddress
+	}{
+		{
+			a: nil,
+			b: nil,
+		},
+		{
+			a: []DatabaseAddress{{Address: "a", Expires: 9}, {Address: "b", Expires: 9}, {Address: "c", Expires: 9}},
+			b: []DatabaseAddress{},
+		},
+		{
+			a: []DatabaseAddress{{Address: "a", Expires: 10}},
+			b: []DatabaseAddress{{Address: "a", Expires: 10}},
+		},
+		{
+			a: []DatabaseAddress{{Address: "a", Expires: 10}, {Address: "b", Expires: 10}, {Address: "c", Expires: 10}},
+			b: []DatabaseAddress{{Address: "a", Expires: 10}, {Address: "b", Expires: 10}, {Address: "c", Expires: 10}},
+		},
+		{
+			a: []DatabaseAddress{{Address: "a", Expires: 5}, {Address: "b", Expires: 15}, {Address: "c", Expires: 5}, {Address: "d", Expires: 15}, {Address: "e", Expires: 5}},
+			b: []DatabaseAddress{{Address: "d", Expires: 15}, {Address: "b", Expires: 15}}, // gets reordered
+		},
+	}
+
+	for _, tc := range cases {
+		res := expire(tc.a, 10)
+		if fmt.Sprint(res) != fmt.Sprint(tc.b) {
+			t.Errorf("Incorrect result %v, expected %v", res, tc.b)
+		}
+	}
+}
+
+type testClock struct {
+	now time.Time
+}
+
+func (t *testClock) wind(d time.Duration) {
+	t.now = t.now.Add(d)
+}
+
+func (t *testClock) Now() time.Time {
+	return t.now
+}
--- a/cmd/stdiscosrv/db.go
+++ b/cmd/stdiscosrv/db.go
@@ -1,32 +0,0 @@
-// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
-
-package main
-
-import (
-	"database/sql"
-	"fmt"
-)
-
-type setupFunc func(db *sql.DB) error
-type compileFunc func(db *sql.DB) (map[string]*sql.Stmt, error)
-
-var (
-	setupFuncs   = make(map[string]setupFunc)
-	compileFuncs = make(map[string]compileFunc)
-)
-
-func register(name string, setup setupFunc, compile compileFunc) {
-	setupFuncs[name] = setup
-	compileFuncs[name] = compile
-}
-
-func setup(backend string, db *sql.DB) (map[string]*sql.Stmt, error) {
-	setup, ok := setupFuncs[backend]
-	if !ok {
-		return nil, fmt.Errorf("Unsupported backend")
-	}
-	if err := setup(db); err != nil {
-		return nil, err
-	}
-	return compileFuncs[backend](db)
-}
--- a/cmd/stdiscosrv/main.go
+++ b/cmd/stdiscosrv/main.go
@@ -1,29 +1,70 @@
-// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

 import (
 	"crypto/tls"
-	"database/sql"
 	"flag"
 	"fmt"
 	"log"
+	"net"
+	"net/http"
 	"os"
 	"runtime"
 	"strconv"
+	"strings"
 	"time"

+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/tlsutil"
+	"github.com/syndtr/goleveldb/leveldb/opt"
 	"github.com/thejerf/suture"
 )

 const (
-	minNegCache  = 60        // seconds
-	maxNegCache  = 3600      // seconds
-	maxDeviceAge = 7 * 86400 // one week, in seconds
+	addressExpiryTime          = 2 * time.Hour
+	databaseStatisticsInterval = 5 * time.Minute
+
+	// Reannounce-After is set to reannounceAfterSeconds +
+	// random(reannounzeFuzzSeconds), similar for Retry-After
+	reannounceAfterSeconds = 3300
+	reannounzeFuzzSeconds  = 300
+	errorRetryAfterSeconds = 1500
+	errorRetryFuzzSeconds  = 300
+
+	// Retry for not found is minSeconds + failures * incSeconds +
+	// random(fuzz), where failures is the number of consecutive lookups
+	// with no answer, up to maxSeconds. The fuzz is applied after capping
+	// to maxSeconds.
+	notFoundRetryMinSeconds  = 60
+	notFoundRetryMaxSeconds  = 3540
+	notFoundRetryIncSeconds  = 10
+	notFoundRetryFuzzSeconds = 60
+
+	// How often (in requests) we serialize the missed counter to database.
+	notFoundMissesWriteInterval = 10
+
+	httpReadTimeout    = 5 * time.Second
+	httpWriteTimeout   = 5 * time.Second
+	httpMaxHeaderBytes = 1 << 10
+
+	// Size of the replication outbox channel
+	replicationOutboxSize = 10000
 )

+// These options make the database a little more optimized for writes, at
+// the expense of some memory usage and risk of losing writes in a (system)
+// crash.
+var levelDBOptions = &opt.Options{
+	NoSync:      true,
+	WriteBuffer: 32 << 20, // default 4<<20
+}
+
 var (
 	Version    string
 	BuildStamp string
@@ -43,17 +84,7 @@ func init() {
 }

 var (
-	lruSize     = 10240
-	limitAvg    = 5
-	limitBurst  = 20
-	globalStats stats
-	statsFile   string
-	backend     = "ql"
-	dsn         = getEnvDefault("STDISCOSRV_DB_DSN", "memory://stdiscosrv")
-	certFile    = "cert.pem"
-	keyFile     = "key.pem"
-	debug       = false
-	useHTTP     = false
+	debug = false
 )

 func main() {
@@ -63,84 +94,114 @@ func main() {
 	)

 	var listen string
+	var dir string
+	var metricsListen string
+	var replicationListen string
+	var replicationPeers string
+	var certFile string
+	var keyFile string
+	var useHTTP bool

 	log.SetOutput(os.Stdout)
 	log.SetFlags(0)

+	flag.StringVar(&certFile, "cert", "./cert.pem", "Certificate file")
+	flag.StringVar(&dir, "db-dir", "./discovery.db", "Database directory")
+	flag.BoolVar(&debug, "debug", false, "Print debug output")
+	flag.BoolVar(&useHTTP, "http", false, "Listen on HTTP (behind an HTTPS proxy)")
 	flag.StringVar(&listen, "listen", ":8443", "Listen address")
-	flag.IntVar(&lruSize, "limit-cache", lruSize, "Limiter cache entries")
-	flag.IntVar(&limitAvg, "limit-avg", limitAvg, "Allowed average package rate, per 10 s")
-	flag.IntVar(&limitBurst, "limit-burst", limitBurst, "Allowed burst size, packets")
-	flag.StringVar(&statsFile, "stats-file", statsFile, "File to write periodic operation stats to")
-	flag.StringVar(&backend, "db-backend", backend, "Database backend to use")
-	flag.StringVar(&dsn, "db-dsn", dsn, "Database DSN")
-	flag.StringVar(&certFile, "cert", certFile, "Certificate file")
-	flag.StringVar(&keyFile, "key", keyFile, "Key file")
-	flag.BoolVar(&debug, "debug", debug, "Debug")
-	flag.BoolVar(&useHTTP, "http", useHTTP, "Listen on HTTP (behind an HTTPS proxy)")
+	flag.StringVar(&keyFile, "key", "./key.pem", "Key file")
+	flag.StringVar(&metricsListen, "metrics-listen", "", "Metrics listen address")
+	flag.StringVar(&replicationPeers, "replicate", "", "Replication peers, id@address, comma separated")
+	flag.StringVar(&replicationListen, "replication-listen", ":19200", "Replication listen address")
 	flag.Parse()

 	log.Println(LongVersion)

-	var cert tls.Certificate
-	var err error
-	if !useHTTP {
-		cert, err = tls.LoadX509KeyPair(certFile, keyFile)
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		log.Println("Failed to load keypair. Generating one, this might take a while...")
+		cert, err = tlsutil.NewCertificate(certFile, keyFile, "stdiscosrv")
 		if err != nil {
-			log.Println("Failed to load keypair. Generating one, this might take a while...")
-			cert, err = tlsutil.NewCertificate(certFile, keyFile, "stdiscosrv", 3072)
-			if err != nil {
-				log.Fatalln("Failed to generate X509 key pair:", err)
-			}
+			log.Fatalln("Failed to generate X509 key pair:", err)
 		}
-
-		devID := protocol.NewDeviceID(cert.Certificate[0])
-		log.Println("Server device ID is", devID)
 	}

-	db, err := sql.Open(backend, dsn)
+	devID := protocol.NewDeviceID(cert.Certificate[0])
+	log.Println("Server device ID is", devID)
+
+	// Parse the replication specs, if any.
+	var allowedReplicationPeers []protocol.DeviceID
+	var replicationDestinations []string
+	parts := strings.Split(replicationPeers, ",")
+	for _, part := range parts {
+		fields := strings.Split(part, "@")
+
+		switch len(fields) {
+		case 2:
+			// This is an id@address specification. Grab the address for the
+			// destination list. Try to resolve it once to catch obvious
+			// syntax errors here rather than having the sender service fail
+			// repeatedly later.
+			_, err := net.ResolveTCPAddr("tcp", fields[1])
+			if err != nil {
+				log.Fatalln("Resolving address:", err)
+			}
+			replicationDestinations = append(replicationDestinations, fields[1])
+			fallthrough // N.B.
+
+		case 1:
+			// The first part is always a device ID.
+			id, err := protocol.DeviceIDFromString(fields[0])
+			if err != nil {
+				log.Fatalln("Parsing device ID:", err)
+			}
+			allowedReplicationPeers = append(allowedReplicationPeers, id)
+
+		default:
+			log.Fatalln("Unrecognized replication spec:", part)
+		}
+	}
+
+	// Root of the service tree.
+	main := suture.New("main", suture.Spec{
+		PassThroughPanics: true,
+	})
+
+	// Start the database.
+	db, err := newLevelDBStore(dir)
 	if err != nil {
-		log.Fatalln("sql.Open:", err)
+		log.Fatalln("Open database:", err)
 	}
-	prep, err := setup(backend, db)
-	if err != nil {
-		log.Fatalln("Setup:", err)
+	main.Add(db)
+
+	// Start any replication senders.
+	var repl replicationMultiplexer
+	for _, dst := range replicationDestinations {
+		rs := newReplicationSender(dst, cert, allowedReplicationPeers)
+		main.Add(rs)
+		repl = append(repl, rs)
 	}

-	main := suture.NewSimple("main")
+	// If we have replication configured, start the replication listener.
+	if len(allowedReplicationPeers) > 0 {
+		rl := newReplicationListener(replicationListen, cert, allowedReplicationPeers, db)
+		main.Add(rl)
+	}

-	main.Add(&querysrv{
-		addr: listen,
-		cert: cert,
-		db:   db,
-		prep: prep,
-	})
+	// Start the main API server.
+	qs := newAPISrv(listen, cert, db, repl, useHTTP)
+	main.Add(qs)

-	main.Add(&cleansrv{
-		intv: cleanIntv,
-		db:   db,
-		prep: prep,
-	})
+	// If we have a metrics port configured, start a metrics handler.
+	if metricsListen != "" {
+		go func() {
+			mux := http.NewServeMux()
+			mux.Handle("/metrics", promhttp.Handler())
+			log.Fatal(http.ListenAndServe(metricsListen, mux))
+		}()
+	}

-	main.Add(&statssrv{
-		intv: statsIntv,
-		file: statsFile,
-		db:   db,
-	})
-
-	globalStats.Reset()
+	// Engage!
 	main.Serve()
 }
-
-func getEnvDefault(key, def string) string {
-	if val := os.Getenv(key); val != "" {
-		return val
-	}
-	return def
-}
-
-func next(intv time.Duration) time.Duration {
-	t0 := time.Now()
-	t1 := t0.Add(intv).Truncate(intv)
-	return t1.Sub(t0)
-}
--- a/cmd/stdiscosrv/psql.go
+++ b/cmd/stdiscosrv/psql.go
@@ -1,98 +0,0 @@
-// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
-
-package main
-
-import (
-	"database/sql"
-	"fmt"
-
-	_ "github.com/lib/pq"
-)
-
-func init() {
-	register("postgres", postgresSetup, postgresCompile)
-}
-
-func postgresSetup(db *sql.DB) error {
-	var err error
-
-	db.SetMaxIdleConns(4)
-	db.SetMaxOpenConns(8)
-
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS Devices (
-		DeviceID CHAR(63) NOT NULL PRIMARY KEY,
-		Seen TIMESTAMP NOT NULL
-	)`)
-	if err != nil {
-		return err
-	}
-
-	var tmp string
-	row := db.QueryRow(`SELECT 'DevicesDeviceIDIndex'::regclass`)
-	if err = row.Scan(&tmp); err != nil {
-		_, err = db.Exec(`CREATE INDEX DevicesDeviceIDIndex ON Devices (DeviceID)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	row = db.QueryRow(`SELECT 'DevicesSeenIndex'::regclass`)
-	if err = row.Scan(&tmp); err != nil {
-		_, err = db.Exec(`CREATE INDEX DevicesSeenIndex ON Devices (Seen)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS Addresses (
-		DeviceID CHAR(63) NOT NULL,
-		Seen TIMESTAMP NOT NULL,
-		Address VARCHAR(2048) NOT NULL
-	)`)
-	if err != nil {
-		return err
-	}
-
-	row = db.QueryRow(`SELECT 'AddressesDeviceIDSeenIndex'::regclass`)
-	if err = row.Scan(&tmp); err != nil {
-		_, err = db.Exec(`CREATE INDEX AddressesDeviceIDSeenIndex ON Addresses (DeviceID, Seen)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	row = db.QueryRow(`SELECT 'AddressesDeviceIDAddressIndex'::regclass`)
-	if err = row.Scan(&tmp); err != nil {
-		_, err = db.Exec(`CREATE INDEX AddressesDeviceIDAddressIndex ON Addresses (DeviceID, Address)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	return nil
-}
-
-func postgresCompile(db *sql.DB) (map[string]*sql.Stmt, error) {
-	stmts := map[string]string{
-		"cleanAddress":  "DELETE FROM Addresses WHERE Seen < now() - '2 hour'::INTERVAL",
-		"cleanDevice":   fmt.Sprintf("DELETE FROM Devices WHERE Seen < now() - '%d hour'::INTERVAL", maxDeviceAge/3600),
-		"countAddress":  "SELECT count(*) FROM Addresses",
-		"countDevice":   "SELECT count(*) FROM Devices",
-		"insertAddress": "INSERT INTO Addresses (DeviceID, Seen, Address) VALUES ($1, now(), $2)",
-		"insertDevice":  "INSERT INTO Devices (DeviceID, Seen) VALUES ($1, now())",
-		"selectAddress": "SELECT Address FROM Addresses WHERE DeviceID=$1 AND Seen > now() - '1 hour'::INTERVAL ORDER BY random() LIMIT 16",
-		"selectDevice":  "SELECT Seen FROM Devices WHERE DeviceID=$1",
-		"updateAddress": "UPDATE Addresses SET Seen=now() WHERE DeviceID=$1 AND Address=$2",
-		"updateDevice":  "UPDATE Devices SET Seen=now() WHERE DeviceID=$1",
-	}
-
-	res := make(map[string]*sql.Stmt, len(stmts))
-	for key, stmt := range stmts {
-		prep, err := db.Prepare(stmt)
-		if err != nil {
-			return nil, err
-		}
-		res[key] = prep
-	}
-	return res, nil
-}
--- a/cmd/stdiscosrv/ql.go
+++ b/cmd/stdiscosrv/ql.go
@@ -1,81 +0,0 @@
-// Copyright (C) 2015 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).
-
-package main
-
-import (
-	"database/sql"
-	"fmt"
-	"log"
-
-	"github.com/cznic/ql"
-)
-
-func init() {
-	ql.RegisterDriver()
-	register("ql", qlSetup, qlCompile)
-}
-
-func qlSetup(db *sql.DB) (err error) {
-	tx, err := db.Begin()
-	if err != nil {
-		return
-	}
-
-	defer func() {
-		if err == nil {
-			err = tx.Commit()
-		} else {
-			tx.Rollback()
-		}
-	}()
-
-	_, err = tx.Exec(`CREATE TABLE IF NOT EXISTS Devices (
-		DeviceID STRING NOT NULL,
-		Seen TIME NOT NULL
-	)`)
-	if err != nil {
-		return
-	}
-
-	if _, err = tx.Exec(`CREATE INDEX IF NOT EXISTS DevicesDeviceIDIndex ON Devices (DeviceID)`); err != nil {
-		return
-	}
-
-	_, err = tx.Exec(`CREATE TABLE IF NOT EXISTS Addresses (
-		DeviceID STRING NOT NULL,
-		Seen TIME NOT NULL,
-		Address STRING NOT NULL,
-	)`)
-	if err != nil {
-		return
-	}
-
-	_, err = tx.Exec(`CREATE INDEX IF NOT EXISTS AddressesDeviceIDAddressIndex ON Addresses (DeviceID, Address)`)
-	return
-}
-
-func qlCompile(db *sql.DB) (map[string]*sql.Stmt, error) {
-	stmts := map[string]string{
-		"cleanAddress":  `DELETE FROM Addresses WHERE Seen < now() - duration("2h")`,
-		"cleanDevice":   fmt.Sprintf(`DELETE FROM Devices WHERE Seen < now() - duration("%dh")`, maxDeviceAge/3600),
-		"countAddress":  "SELECT count(*) FROM Addresses",
-		"countDevice":   "SELECT count(*) FROM Devices",
-		"insertAddress": "INSERT INTO Addresses (DeviceID, Seen, Address) VALUES ($1, now(), $2)",
-		"insertDevice":  "INSERT INTO Devices (DeviceID, Seen) VALUES ($1, now())",
-		"selectAddress": `SELECT Address from Addresses WHERE DeviceID==$1 AND Seen > now() - duration("1h") LIMIT 16`,
-		"selectDevice":  "SELECT Seen FROM Devices WHERE DeviceID==$1",
-		"updateAddress": "UPDATE Addresses Seen=now() WHERE DeviceID==$1 AND Address==$2",
-		"updateDevice":  "UPDATE Devices Seen=now() WHERE DeviceID==$1",
-	}
-
-	res := make(map[string]*sql.Stmt, len(stmts))
-	for key, stmt := range stmts {
-		prep, err := db.Prepare(stmt)
-		if err != nil {
-			log.Println("Failed to compile", stmt)
-			return nil, err
-		}
-		res[key] = prep
-	}
-	return res, nil
-}
--- a/cmd/stdiscosrv/querysrv.go
+++ b/cmd/stdiscosrv/querysrv.go
@@ -1,488 +0,0 @@
-// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
-
-package main
-
-import (
-	"bytes"
-	"crypto/tls"
-	"database/sql"
-	"encoding/json"
-	"encoding/pem"
-	"fmt"
-	"log"
-	"math/rand"
-	"net"
-	"net/http"
-	"net/url"
-	"strconv"
-	"sync"
-	"time"
-
-	"github.com/golang/groupcache/lru"
-	"github.com/juju/ratelimit"
-	"github.com/syncthing/syncthing/lib/protocol"
-	"golang.org/x/net/context"
-)
-
-type querysrv struct {
-	addr     string
-	db       *sql.DB
-	prep     map[string]*sql.Stmt
-	limiter  *safeCache
-	cert     tls.Certificate
-	listener net.Listener
-}
-
-type announcement struct {
-	Seen      time.Time `json:"seen"`
-	Addresses []string  `json:"addresses"`
-}
-
-type safeCache struct {
-	*lru.Cache
-	mut sync.Mutex
-}
-
-func (s *safeCache) Get(key string) (val interface{}, ok bool) {
-	s.mut.Lock()
-	val, ok = s.Cache.Get(key)
-	s.mut.Unlock()
-	return
-}
-
-func (s *safeCache) Add(key string, val interface{}) {
-	s.mut.Lock()
-	s.Cache.Add(key, val)
-	s.mut.Unlock()
-}
-
-type requestID int64
-
-func (i requestID) String() string {
-	return fmt.Sprintf("%016x", int64(i))
-}
-
-func negCacheFor(lastSeen time.Time) int {
-	since := time.Since(lastSeen).Seconds()
-	if since >= maxDeviceAge {
-		return maxNegCache
-	}
-	if since < 0 {
-		// That's weird
-		return minNegCache
-	}
-
-	// Return a value linearly scaled from minNegCache (at zero seconds ago)
-	// to maxNegCache (at maxDeviceAge seconds ago).
-	r := since / maxDeviceAge
-	return int(minNegCache + r*(maxNegCache-minNegCache))
-}
-
-func (s *querysrv) Serve() {
-	s.limiter = &safeCache{
-		Cache: lru.New(lruSize),
-	}
-
-	if useHTTP {
-		listener, err := net.Listen("tcp", s.addr)
-		if err != nil {
-			log.Println("Listen:", err)
-			return
-		}
-		s.listener = listener
-	} else {
-		tlsCfg := &tls.Config{
-			Certificates:           []tls.Certificate{s.cert},
-			ClientAuth:             tls.RequestClientCert,
-			SessionTicketsDisabled: true,
-			MinVersion:             tls.VersionTLS12,
-			CipherSuites: []uint16{
-				tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
-				tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
-				tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
-				tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
-			},
-		}
-
-		tlsListener, err := tls.Listen("tcp", s.addr, tlsCfg)
-		if err != nil {
-			log.Println("Listen:", err)
-			return
-		}
-		s.listener = tlsListener
-	}
-
-	http.HandleFunc("/v2/", s.handler)
-	http.HandleFunc("/ping", handlePing)
-
-	srv := &http.Server{
-		ReadTimeout:    5 * time.Second,
-		WriteTimeout:   5 * time.Second,
-		MaxHeaderBytes: 1 << 10,
-	}
-
-	if err := srv.Serve(s.listener); err != nil {
-		log.Println("Serve:", err)
-	}
-}
-
-var topCtx = context.Background()
-
-func (s *querysrv) handler(w http.ResponseWriter, req *http.Request) {
-	reqID := requestID(rand.Int63())
-	ctx := context.WithValue(topCtx, "id", reqID)
-
-	if debug {
-		log.Println(reqID, req.Method, req.URL)
-	}
-
-	t0 := time.Now()
-	defer func() {
-		diff := time.Since(t0)
-		var comment string
-		if diff > time.Second {
-			comment = "(very slow request)"
-		} else if diff > 100*time.Millisecond {
-			comment = "(slow request)"
-		}
-		if comment != "" || debug {
-			log.Println(reqID, req.Method, req.URL, "completed in", diff, comment)
-		}
-	}()
-
-	var remoteIP net.IP
-	if useHTTP {
-		remoteIP = net.ParseIP(req.Header.Get("X-Forwarded-For"))
-	} else {
-		addr, err := net.ResolveTCPAddr("tcp", req.RemoteAddr)
-		if err != nil {
-			log.Println("remoteAddr:", err)
-			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
-			return
-		}
-		remoteIP = addr.IP
-	}
-
-	if s.limit(remoteIP) {
-		if debug {
-			log.Println(remoteIP, "is limited")
-		}
-		w.Header().Set("Retry-After", "60")
-		http.Error(w, "Too Many Requests", 429)
-		return
-	}
-
-	switch req.Method {
-	case "GET":
-		s.handleGET(ctx, w, req)
-	case "POST":
-		s.handlePOST(ctx, remoteIP, w, req)
-	default:
-		globalStats.Error()
-		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
-	}
-}
-
-func (s *querysrv) handleGET(ctx context.Context, w http.ResponseWriter, req *http.Request) {
-	reqID := ctx.Value("id").(requestID)
-
-	deviceID, err := protocol.DeviceIDFromString(req.URL.Query().Get("device"))
-	if err != nil {
-		if debug {
-			log.Println(reqID, "bad device param")
-		}
-		globalStats.Error()
-		http.Error(w, "Bad Request", http.StatusBadRequest)
-		return
-	}
-
-	var ann announcement
-
-	ann.Seen, err = s.getDeviceSeen(deviceID)
-	negCache := strconv.Itoa(negCacheFor(ann.Seen))
-	w.Header().Set("Retry-After", negCache)
-	w.Header().Set("Cache-Control", "public, max-age="+negCache)
-
-	if err != nil {
-		// The device is not in the database.
-		globalStats.Query()
-		http.Error(w, "Not Found", http.StatusNotFound)
-		return
-	}
-
-	t0 := time.Now()
-	ann.Addresses, err = s.getAddresses(ctx, deviceID)
-	if err != nil {
-		log.Println(reqID, "getAddresses:", err)
-		globalStats.Error()
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
-		return
-	}
-	if debug {
-		log.Println(reqID, "getAddresses in", time.Since(t0))
-	}
-
-	globalStats.Query()
-
-	if len(ann.Addresses) == 0 {
-		http.Error(w, "Not Found", http.StatusNotFound)
-		return
-	}
-
-	globalStats.Answer()
-
-	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(ann)
-}
-
-func (s *querysrv) handlePOST(ctx context.Context, remoteIP net.IP, w http.ResponseWriter, req *http.Request) {
-	reqID := ctx.Value("id").(requestID)
-
-	rawCert := certificateBytes(req)
-	if rawCert == nil {
-		if debug {
-			log.Println(reqID, "no certificates")
-		}
-		globalStats.Error()
-		http.Error(w, "Forbidden", http.StatusForbidden)
-		return
-	}
-
-	var ann announcement
-	if err := json.NewDecoder(req.Body).Decode(&ann); err != nil {
-		if debug {
-			log.Println(reqID, "decode:", err)
-		}
-		globalStats.Error()
-		http.Error(w, "Bad Request", http.StatusBadRequest)
-		return
-	}
-
-	deviceID := protocol.NewDeviceID(rawCert)
-
-	// handleAnnounce returns *two* errors. The first indicates a problem with
-	// something the client posted to us. We should return a 400 Bad Request
-	// and not worry about it. The second indicates that the request was fine,
-	// but something internal messed up. We should log it and respond with a
-	// more apologetic 500 Internal Server Error.
-	userErr, internalErr := s.handleAnnounce(ctx, remoteIP, deviceID, ann.Addresses)
-	if userErr != nil {
-		if debug {
-			log.Println(reqID, "handleAnnounce:", userErr)
-		}
-		globalStats.Error()
-		http.Error(w, "Bad Request", http.StatusBadRequest)
-		return
-	}
-	if internalErr != nil {
-		log.Println(reqID, "handleAnnounce:", internalErr)
-		globalStats.Error()
-		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
-		return
-	}
-
-	globalStats.Announce()
-
-	// TODO: Slowly increase this for stable clients
-	w.Header().Set("Reannounce-After", "1800")
-
-	// We could return the lookup result here, but it's kind of unnecessarily
-	// expensive to go query the database again so we let the client decide to
-	// do a lookup if they really care.
-	w.WriteHeader(http.StatusNoContent)
-}
-
-func (s *querysrv) Stop() {
-	s.listener.Close()
-}
-
-func (s *querysrv) handleAnnounce(ctx context.Context, remote net.IP, deviceID protocol.DeviceID, addresses []string) (userErr, internalErr error) {
-	reqID := ctx.Value("id").(requestID)
-
-	tx, err := s.db.Begin()
-	if err != nil {
-		internalErr = err
-		return
-	}
-
-	defer func() {
-		// Since we return from a bunch of different places, we handle
-		// rollback in the defer.
-		if internalErr != nil || userErr != nil {
-			tx.Rollback()
-		}
-	}()
-
-	for _, annAddr := range addresses {
-		uri, err := url.Parse(annAddr)
-		if err != nil {
-			userErr = err
-			return
-		}
-
-		host, port, err := net.SplitHostPort(uri.Host)
-		if err != nil {
-			userErr = err
-			return
-		}
-
-		ip := net.ParseIP(host)
-		if host == "" || ip.IsUnspecified() {
-			// Do not use IPv6 remote address if requested scheme is tcp4
-			if uri.Scheme == "tcp4" && remote.To4() == nil {
-				continue
-			}
-
-			// Do not use IPv4 remote address if requested scheme is tcp6
-			if uri.Scheme == "tcp6" && remote.To4() != nil {
-				continue
-			}
-
-			host = remote.String()
-		}
-
-		uri.Host = net.JoinHostPort(host, port)
-
-		if err := s.updateAddress(ctx, tx, deviceID, uri.String()); err != nil {
-			internalErr = err
-			return
-		}
-	}
-
-	if err := s.updateDevice(ctx, tx, deviceID); err != nil {
-		internalErr = err
-		return
-	}
-
-	t0 := time.Now()
-	internalErr = tx.Commit()
-	if debug {
-		log.Println(reqID, "commit in", time.Since(t0))
-	}
-	return
-}
-
-func (s *querysrv) limit(remote net.IP) bool {
-	key := remote.String()
-
-	bkt, ok := s.limiter.Get(key)
-	if ok {
-		bkt := bkt.(*ratelimit.Bucket)
-		if bkt.TakeAvailable(1) != 1 {
-			// Rate limit exceeded; ignore packet
-			return true
-		}
-	} else {
-		// One packet per ten seconds average rate, burst ten packets
-		s.limiter.Add(key, ratelimit.NewBucket(10*time.Second/time.Duration(limitAvg), int64(limitBurst)))
-	}
-
-	return false
-}
-
-func (s *querysrv) updateDevice(ctx context.Context, tx *sql.Tx, device protocol.DeviceID) error {
-	reqID := ctx.Value("id").(requestID)
-	t0 := time.Now()
-	res, err := tx.Stmt(s.prep["updateDevice"]).Exec(device.String())
-	if err != nil {
-		return err
-	}
-	if debug {
-		log.Println(reqID, "updateDevice in", time.Since(t0))
-	}
-
-	if rows, _ := res.RowsAffected(); rows == 0 {
-		t0 = time.Now()
-		_, err := tx.Stmt(s.prep["insertDevice"]).Exec(device.String())
-		if err != nil {
-			return err
-		}
-		if debug {
-			log.Println(reqID, "insertDevice in", time.Since(t0))
-		}
-	}
-
-	return nil
-}
-
-func (s *querysrv) updateAddress(ctx context.Context, tx *sql.Tx, device protocol.DeviceID, uri string) error {
-	res, err := tx.Stmt(s.prep["updateAddress"]).Exec(device.String(), uri)
-	if err != nil {
-		return err
-	}
-
-	if rows, _ := res.RowsAffected(); rows == 0 {
-		_, err := tx.Stmt(s.prep["insertAddress"]).Exec(device.String(), uri)
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (s *querysrv) getAddresses(ctx context.Context, device protocol.DeviceID) ([]string, error) {
-	rows, err := s.prep["selectAddress"].Query(device.String())
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
-
-	var res []string
-	for rows.Next() {
-		var addr string
-
-		err := rows.Scan(&addr)
-		if err != nil {
-			log.Println("Scan:", err)
-			continue
-		}
-		res = append(res, addr)
-	}
-
-	return res, nil
-}
-
-func (s *querysrv) getDeviceSeen(device protocol.DeviceID) (time.Time, error) {
-	row := s.prep["selectDevice"].QueryRow(device.String())
-	var seen time.Time
-	if err := row.Scan(&seen); err != nil {
-		return time.Time{}, err
-	}
-	return seen.In(time.UTC), nil
-}
-
-func handlePing(w http.ResponseWriter, r *http.Request) {
-	w.WriteHeader(204)
-}
-
-func certificateBytes(req *http.Request) []byte {
-	if req.TLS != nil && len(req.TLS.PeerCertificates) > 0 {
-		return req.TLS.PeerCertificates[0].Raw
-	}
-
-	if hdr := req.Header.Get("X-SSL-Cert"); hdr != "" {
-		bs := []byte(hdr)
-		// The certificate is in PEM format but with spaces for newlines. We
-		// need to reinstate the newlines for the PEM decoder. But we need to
-		// leave the spaces in the BEGIN and END lines - the first and last
-		// space - alone.
-		firstSpace := bytes.Index(bs, []byte(" "))
-		lastSpace := bytes.LastIndex(bs, []byte(" "))
-		for i := firstSpace + 1; i < lastSpace; i++ {
-			if bs[i] == ' ' {
-				bs[i] = '\n'
-			}
-		}
-		block, _ := pem.Decode(bs)
-		if block == nil {
-			// Decoding failed
-			return nil
-		}
-		return block.Bytes
-	}
-
-	return nil
-}
--- a/cmd/stdiscosrv/replication.go
+++ b/cmd/stdiscosrv/replication.go
@@ -0,0 +1,326 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"crypto/tls"
+	"encoding/binary"
+	"fmt"
+	io "io"
+	"log"
+	"net"
+	"time"
+
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+const replicationReadTimeout = time.Minute
+const replicationHeartbeatInterval = time.Second * 30
+
+type replicator interface {
+	send(key string, addrs []DatabaseAddress, seen int64)
+}
+
+// a replicationSender tries to connect to the remote address and provide
+// them with a feed of replication updates.
+type replicationSender struct {
+	dst        string
+	cert       tls.Certificate // our certificate
+	allowedIDs []protocol.DeviceID
+	outbox     chan ReplicationRecord
+	stop       chan struct{}
+}
+
+func newReplicationSender(dst string, cert tls.Certificate, allowedIDs []protocol.DeviceID) *replicationSender {
+	return &replicationSender{
+		dst:        dst,
+		cert:       cert,
+		allowedIDs: allowedIDs,
+		outbox:     make(chan ReplicationRecord, replicationOutboxSize),
+		stop:       make(chan struct{}),
+	}
+}
+
+func (s *replicationSender) Serve() {
+	// Sleep a little at startup. Peers often restart at the same time, and
+	// this avoid the service failing and entering backoff state
+	// unnecessarily, while also reducing the reconnect rate to something
+	// reasonable by default.
+	time.Sleep(2 * time.Second)
+
+	tlsCfg := &tls.Config{
+		Certificates:       []tls.Certificate{s.cert},
+		MinVersion:         tls.VersionTLS12,
+		InsecureSkipVerify: true,
+	}
+
+	// Dial the TLS connection.
+	conn, err := tls.Dial("tcp", s.dst, tlsCfg)
+	if err != nil {
+		log.Println("Replication connect:", err)
+		return
+	}
+	defer func() {
+		conn.SetWriteDeadline(time.Now().Add(time.Second))
+		conn.Close()
+	}()
+
+	// Get the other side device ID.
+	remoteID, err := deviceID(conn)
+	if err != nil {
+		log.Println("Replication connect:", err)
+		return
+	}
+
+	// Verify it's in the set of allowed device IDs.
+	if !deviceIDIn(remoteID, s.allowedIDs) {
+		log.Println("Replication connect: unexpected device ID:", remoteID)
+		return
+	}
+
+	heartBeatTicker := time.NewTicker(replicationHeartbeatInterval)
+	defer heartBeatTicker.Stop()
+
+	// Send records.
+	buf := make([]byte, 1024)
+	for {
+		select {
+		case <-heartBeatTicker.C:
+			if len(s.outbox) > 0 {
+				// No need to send heartbeats if there are events/prevrious
+				// heartbeats to send, they will keep the connection alive.
+				continue
+			}
+			// Empty replication message is the heartbeat:
+			s.outbox <- ReplicationRecord{}
+
+		case rec := <-s.outbox:
+			// Buffer must hold record plus four bytes for size
+			size := rec.Size()
+			if len(buf) < size+4 {
+				buf = make([]byte, size+4)
+			}
+
+			// Record comes after the four bytes size
+			n, err := rec.MarshalTo(buf[4:])
+			if err != nil {
+				// odd to get an error here, but we haven't sent anything
+				// yet so it's not fatal
+				replicationSendsTotal.WithLabelValues("error").Inc()
+				log.Println("Replication marshal:", err)
+				continue
+			}
+			binary.BigEndian.PutUint32(buf, uint32(n))
+
+			// Send
+			conn.SetWriteDeadline(time.Now().Add(5 * time.Second))
+			if _, err := conn.Write(buf[:4+n]); err != nil {
+				replicationSendsTotal.WithLabelValues("error").Inc()
+				log.Println("Replication write:", err)
+				// Yes, we are loosing the replication event here.
+				return
+			}
+			replicationSendsTotal.WithLabelValues("success").Inc()
+
+		case <-s.stop:
+			return
+		}
+	}
+}
+
+func (s *replicationSender) Stop() {
+	close(s.stop)
+}
+
+func (s *replicationSender) String() string {
+	return fmt.Sprintf("replicationSender(%q)", s.dst)
+}
+
+func (s *replicationSender) send(key string, ps []DatabaseAddress, seen int64) {
+	item := ReplicationRecord{
+		Key:       key,
+		Addresses: ps,
+	}
+
+	// The send should never block. The inbox is suitably buffered for at
+	// least a few seconds of stalls, which shouldn't happen in practice.
+	select {
+	case s.outbox <- item:
+	default:
+		replicationSendsTotal.WithLabelValues("drop").Inc()
+	}
+}
+
+// a replicationMultiplexer sends to multiple replicators
+type replicationMultiplexer []replicator
+
+func (m replicationMultiplexer) send(key string, ps []DatabaseAddress, seen int64) {
+	for _, s := range m {
+		// each send is nonblocking
+		s.send(key, ps, seen)
+	}
+}
+
+// replicationListener accepts incoming connections and reads replication
+// items from them. Incoming items are applied to the KV store.
+type replicationListener struct {
+	addr       string
+	cert       tls.Certificate
+	allowedIDs []protocol.DeviceID
+	db         database
+	stop       chan struct{}
+}
+
+func newReplicationListener(addr string, cert tls.Certificate, allowedIDs []protocol.DeviceID, db database) *replicationListener {
+	return &replicationListener{
+		addr:       addr,
+		cert:       cert,
+		allowedIDs: allowedIDs,
+		db:         db,
+		stop:       make(chan struct{}),
+	}
+}
+
+func (l *replicationListener) Serve() {
+	tlsCfg := &tls.Config{
+		Certificates:       []tls.Certificate{l.cert},
+		ClientAuth:         tls.RequestClientCert,
+		MinVersion:         tls.VersionTLS12,
+		InsecureSkipVerify: true,
+	}
+
+	lst, err := tls.Listen("tcp", l.addr, tlsCfg)
+	if err != nil {
+		log.Println("Replication listen:", err)
+		return
+	}
+	defer lst.Close()
+
+	for {
+		select {
+		case <-l.stop:
+			return
+		default:
+		}
+
+		// Accept a connection
+		conn, err := lst.Accept()
+		if err != nil {
+			log.Println("Replication accept:", err)
+			return
+		}
+
+		// Figure out the other side device ID
+		remoteID, err := deviceID(conn.(*tls.Conn))
+		if err != nil {
+			log.Println("Replication accept:", err)
+			conn.SetWriteDeadline(time.Now().Add(time.Second))
+			conn.Close()
+			continue
+		}
+
+		// Verify it is in the set of allowed device IDs
+		if !deviceIDIn(remoteID, l.allowedIDs) {
+			log.Println("Replication accept: unexpected device ID:", remoteID)
+			conn.SetWriteDeadline(time.Now().Add(time.Second))
+			conn.Close()
+			continue
+		}
+
+		go l.handle(conn)
+	}
+}
+
+func (l *replicationListener) Stop() {
+	close(l.stop)
+}
+
+func (l *replicationListener) String() string {
+	return fmt.Sprintf("replicationListener(%q)", l.addr)
+}
+
+func (l *replicationListener) handle(conn net.Conn) {
+	defer func() {
+		conn.SetWriteDeadline(time.Now().Add(time.Second))
+		conn.Close()
+	}()
+
+	buf := make([]byte, 1024)
+
+	for {
+		select {
+		case <-l.stop:
+			return
+		default:
+		}
+
+		conn.SetReadDeadline(time.Now().Add(replicationReadTimeout))
+
+		// First four bytes are the size
+		if _, err := io.ReadFull(conn, buf[:4]); err != nil {
+			log.Println("Replication read size:", err)
+			replicationRecvsTotal.WithLabelValues("error").Inc()
+			return
+		}
+
+		// Read the rest of the record
+		size := int(binary.BigEndian.Uint32(buf[:4]))
+		if len(buf) < size {
+			buf = make([]byte, size)
+		}
+
+		if size == 0 {
+			// Heartbeat, ignore
+			continue
+		}
+
+		if _, err := io.ReadFull(conn, buf[:size]); err != nil {
+			log.Println("Replication read record:", err)
+			replicationRecvsTotal.WithLabelValues("error").Inc()
+			return
+		}
+
+		// Unmarshal
+		var rec ReplicationRecord
+		if err := rec.Unmarshal(buf[:size]); err != nil {
+			log.Println("Replication unmarshal:", err)
+			replicationRecvsTotal.WithLabelValues("error").Inc()
+			continue
+		}
+
+		// Store
+		l.db.merge(rec.Key, rec.Addresses, rec.Seen)
+		replicationRecvsTotal.WithLabelValues("success").Inc()
+	}
+}
+
+func deviceID(conn *tls.Conn) (protocol.DeviceID, error) {
+	// Handshake may not be complete on the server side yet, which we need
+	// to get the client certificate.
+	if !conn.ConnectionState().HandshakeComplete {
+		if err := conn.Handshake(); err != nil {
+			return protocol.DeviceID{}, err
+		}
+	}
+
+	// We expect exactly one certificate.
+	certs := conn.ConnectionState().PeerCertificates
+	if len(certs) != 1 {
+		return protocol.DeviceID{}, fmt.Errorf("unexpected number of certificates (%d != 1)", len(certs))
+	}
+
+	return protocol.NewDeviceID(certs[0].Raw), nil
+}
+
+func deviceIDIn(id protocol.DeviceID, ids []protocol.DeviceID) bool {
+	for _, candidate := range ids {
+		if id == candidate {
+			return true
+		}
+	}
+	return false
+}
--- a/cmd/stdiscosrv/stats.go
+++ b/cmd/stdiscosrv/stats.go
@@ -1,141 +1,123 @@
-// Copyright (C) 2014-2015 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

 import (
-	"bytes"
-	"database/sql"
-	"fmt"
-	"io/ioutil"
-	"log"
 	"os"
-	"sync/atomic"
-	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
 )

-type stats struct {
-	// Incremented atomically
-	announces int64
-	queries   int64
-	answers   int64
-	errors    int64
-}
+var (
+	apiRequestsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "api_requests_total",
+			Help:      "Number of API requests.",
+		}, []string{"type", "result"})
+	apiRequestsSeconds = prometheus.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Namespace:  "syncthing",
+			Subsystem:  "discovery",
+			Name:       "api_requests_seconds",
+			Help:       "Latency of API requests.",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+		}, []string{"type"})

-func (s *stats) Announce() {
-	atomic.AddInt64(&s.announces, 1)
-}
+	lookupRequestsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "lookup_requests_total",
+			Help:      "Number of lookup requests.",
+		}, []string{"result"})
+	announceRequestsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "announcement_requests_total",
+			Help:      "Number of announcement requests.",
+		}, []string{"result"})

-func (s *stats) Query() {
-	atomic.AddInt64(&s.queries, 1)
-}
+	replicationSendsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "replication_sends_total",
+			Help:      "Number of replication sends.",
+		}, []string{"result"})
+	replicationRecvsTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "replication_recvs_total",
+			Help:      "Number of replication receives.",
+		}, []string{"result"})

-func (s *stats) Answer() {
-	atomic.AddInt64(&s.answers, 1)
-}
+	databaseKeys = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "database_keys",
+			Help:      "Number of database keys at last count.",
+		}, []string{"category"})
+	databaseStatisticsSeconds = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "database_statistics_seconds",
+			Help:      "Time spent running the statistics routine.",
+		})

-func (s *stats) Error() {
-	atomic.AddInt64(&s.errors, 1)
-}
+	databaseOperations = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "discovery",
+			Name:      "database_operations_total",
+			Help:      "Number of database operations.",
+		}, []string{"operation", "result"})
+	databaseOperationSeconds = prometheus.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Namespace:  "syncthing",
+			Subsystem:  "discovery",
+			Name:       "database_operation_seconds",
+			Help:       "Latency of database operations.",
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+		}, []string{"operation"})
+)

-// Reset returns a copy of the current stats and resets the counters to
-// zero.
-func (s *stats) Reset() stats {
-	// Create a copy of the stats using atomic reads
-	copy := stats{
-		announces: atomic.LoadInt64(&s.announces),
-		queries:   atomic.LoadInt64(&s.queries),
-		answers:   atomic.LoadInt64(&s.answers),
-		errors:    atomic.LoadInt64(&s.errors),
+const (
+	dbOpGet             = "get"
+	dbOpPut             = "put"
+	dbOpMerge           = "merge"
+	dbOpDelete          = "delete"
+	dbResSuccess        = "success"
+	dbResNotFound       = "not_found"
+	dbResError          = "error"
+	dbResUnmarshalError = "unmarsh_err"
+)
+
+func init() {
+	prometheus.MustRegister(apiRequestsTotal, apiRequestsSeconds,
+		lookupRequestsTotal, announceRequestsTotal,
+		replicationSendsTotal, replicationRecvsTotal,
+		databaseKeys, databaseStatisticsSeconds,
+		databaseOperations, databaseOperationSeconds)
+
+	processCollectorOpts := prometheus.ProcessCollectorOpts{
+		Namespace: "syncthing_discovery",
+		PidFn: func() (int, error) {
+			return os.Getpid(), nil
+		},
 	}

-	// Reset the stats by subtracting the values that we copied
-	atomic.AddInt64(&s.announces, -copy.announces)
-	atomic.AddInt64(&s.queries, -copy.queries)
-	atomic.AddInt64(&s.answers, -copy.answers)
-	atomic.AddInt64(&s.errors, -copy.errors)
+	prometheus.MustRegister(
+		prometheus.NewProcessCollector(processCollectorOpts),
+	)

-	return copy
-}
-
-type statssrv struct {
-	intv time.Duration
-	file string
-	db   *sql.DB
-}
-
-func (s *statssrv) Serve() {
-	lastReset := time.Now()
-	for {
-		time.Sleep(next(s.intv))
-
-		stats := globalStats.Reset()
-		d := time.Since(lastReset).Seconds()
-		lastReset = time.Now()
-
-		log.Printf("Stats: %.02f announces/s, %.02f queries/s, %.02f answers/s, %.02f errors/s",
-			float64(stats.announces)/d, float64(stats.queries)/d, float64(stats.answers)/d, float64(stats.errors)/d)
-
-		if s.file != "" {
-			s.writeToFile(stats, d)
-		}
-	}
-}
-
-func (s *statssrv) Stop() {
-	panic("stop unimplemented")
-}
-
-func (s *statssrv) writeToFile(stats stats, secs float64) {
-	newLine := []byte("\n")
-
-	var addrs int
-	row := s.db.QueryRow("SELECT COUNT(*) FROM Addresses")
-	if err := row.Scan(&addrs); err != nil {
-		log.Println("stats query:", err)
-		return
-	}
-
-	fd, err := os.OpenFile(s.file, os.O_RDWR|os.O_CREATE, 0666)
-	if err != nil {
-		log.Println("stats file:", err)
-		return
-	}
-	defer func() {
-		err = fd.Close()
-		if err != nil {
-			log.Println("stats file:", err)
-		}
-	}()
-
-	bs, err := ioutil.ReadAll(fd)
-	if err != nil {
-		log.Println("stats file:", err)
-		return
-	}
-	lines := bytes.Split(bytes.TrimSpace(bs), newLine)
-	if len(lines) > 12 {
-		lines = lines[len(lines)-12:]
-	}
-
-	latest := fmt.Sprintf("%v: %6d addresses, %8.02f announces/s, %8.02f queries/s, %8.02f answers/s, %8.02f errors/s\n",
-		time.Now().UTC().Format(time.RFC3339), addrs,
-		float64(stats.announces)/secs, float64(stats.queries)/secs, float64(stats.answers)/secs, float64(stats.errors)/secs)
-	lines = append(lines, []byte(latest))
-
-	_, err = fd.Seek(0, 0)
-	if err != nil {
-		log.Println("stats file:", err)
-		return
-	}
-	err = fd.Truncate(0)
-	if err != nil {
-		log.Println("stats file:", err)
-		return
-	}
-
-	_, err = fd.Write(bytes.Join(lines, newLine))
-	if err != nil {
-		log.Println("stats file:", err)
-		return
-	}
 }
--- a/cmd/stevents/main.go
+++ b/cmd/stevents/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/stfileinfo/main.go
+++ b/cmd/stfileinfo/main.go
@@ -2,11 +2,12 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

 import (
+	"context"
 	"flag"
 	"log"
 	"os"
@@ -67,10 +68,10 @@ func main() {
 		}

 		blockSize := int(fi.Size())
-		if *standardBlocks || blockSize < protocol.BlockSize {
-			blockSize = protocol.BlockSize
+		if *standardBlocks || blockSize < protocol.MinBlockSize {
+			blockSize = protocol.BlockSize(fi.Size())
 		}
-		bs, err := scanner.Blocks(fd, blockSize, fi.Size(), nil)
+		bs, err := scanner.Blocks(context.TODO(), fd, blockSize, fi.Size(), nil, true)
 		if err != nil {
 			log.Fatal(err)
 		}
--- a/cmd/stfinddevice/main.go
+++ b/cmd/stfinddevice/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/stfindignored/main.go
+++ b/cmd/stfindignored/main.go
@@ -0,0 +1,44 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+// Commmand stfindignored lists ignored files under a given folder root.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/syncthing/syncthing/lib/fs"
+	"github.com/syncthing/syncthing/lib/ignore"
+)
+
+func main() {
+	flag.Parse()
+	root := flag.Arg(0)
+	if root == "" {
+		root = "."
+	}
+
+	vfs := fs.NewWalkFilesystem(fs.NewFilesystem(fs.FilesystemTypeBasic, root))
+
+	ign := ignore.New(vfs)
+	if err := ign.Load(".stignore"); err != nil {
+		fmt.Fprintf(os.Stderr, "Fatal: loading ignores: %v\n", err)
+		os.Exit(1)
+	}
+
+	vfs.Walk(".", func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Warning: %s: %v\n", path, err)
+			return fs.SkipDir
+		}
+		if ign.Match(path).IsIgnored() {
+			fmt.Println(path)
+		}
+		return nil
+	})
+}
--- a/cmd/stgenfiles/main.go
+++ b/cmd/stgenfiles/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -66,7 +66,7 @@ func generateFiles(dir string, files, maxexp int, srcname string) error {
 }

 func generateOneFile(fd io.ReadSeeker, p1 string, s int64) error {
-	src := io.LimitReader(&inifiteReader{fd}, int64(s))
+	src := io.LimitReader(&inifiteReader{fd}, s)
 	dst, err := os.Create(p1)
 	if err != nil {
 		return err
@@ -85,12 +85,7 @@ func generateOneFile(fd io.ReadSeeker, p1 string, s int64) error {
 	_ = os.Chmod(p1, os.FileMode(rand.Intn(0777)|0400))

 	t := time.Now().Add(-time.Duration(rand.Intn(30*86400)) * time.Second)
-	err = os.Chtimes(p1, t, t)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return os.Chtimes(p1, t, t)
 }

 func randomName() string {
--- a/cmd/stindex/dump.go
+++ b/cmd/stindex/dump.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -16,7 +16,7 @@ import (
 	"github.com/syncthing/syncthing/lib/protocol"
 )

-func dump(ldb *db.Instance) {
+func dump(ldb *db.Lowlevel) {
 	it := ldb.NewIterator(nil, nil)
 	for it.Next() {
 		key := it.Key()
--- a/cmd/stindex/dumpsize.go
+++ b/cmd/stindex/dumpsize.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -37,7 +37,7 @@ func (h *ElementHeap) Pop() interface{} {
 	return x
 }

-func dumpsize(ldb *db.Instance) {
+func dumpsize(ldb *db.Lowlevel) {
 	h := &ElementHeap{}
 	heap.Init(h)

--- a/cmd/stindex/idxck.go
+++ b/cmd/stindex/idxck.go
@@ -0,0 +1,242 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+
+	"github.com/syncthing/syncthing/lib/db"
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+type fileInfoKey struct {
+	folder uint32
+	device uint32
+	name   string
+}
+
+type globalKey struct {
+	folder uint32
+	name   string
+}
+
+type sequenceKey struct {
+	folder   uint32
+	sequence uint64
+}
+
+func idxck(ldb *db.Lowlevel) (success bool) {
+	folders := make(map[uint32]string)
+	devices := make(map[uint32]string)
+	deviceToIDs := make(map[string]uint32)
+	fileInfos := make(map[fileInfoKey]protocol.FileInfo)
+	globals := make(map[globalKey]db.VersionList)
+	sequences := make(map[sequenceKey]string)
+	needs := make(map[globalKey]struct{})
+	var localDeviceKey uint32
+	success = true
+
+	it := ldb.NewIterator(nil, nil)
+	for it.Next() {
+		key := it.Key()
+		switch key[0] {
+		case db.KeyTypeDevice:
+			folder := binary.BigEndian.Uint32(key[1:])
+			device := binary.BigEndian.Uint32(key[1+4:])
+			name := nulString(key[1+4+4:])
+
+			var f protocol.FileInfo
+			err := f.Unmarshal(it.Value())
+			if err != nil {
+				fmt.Println("Unable to unmarshal FileInfo:", err)
+				success = false
+				continue
+			}
+
+			fileInfos[fileInfoKey{folder, device, name}] = f
+
+		case db.KeyTypeGlobal:
+			folder := binary.BigEndian.Uint32(key[1:])
+			name := nulString(key[1+4:])
+			var flv db.VersionList
+			if err := flv.Unmarshal(it.Value()); err != nil {
+				fmt.Println("Unable to unmarshal VersionList:", err)
+				success = false
+				continue
+			}
+			globals[globalKey{folder, name}] = flv
+
+		case db.KeyTypeFolderIdx:
+			key := binary.BigEndian.Uint32(it.Key()[1:])
+			folders[key] = string(it.Value())
+
+		case db.KeyTypeDeviceIdx:
+			key := binary.BigEndian.Uint32(it.Key()[1:])
+			devices[key] = string(it.Value())
+			deviceToIDs[string(it.Value())] = key
+			if bytes.Equal(it.Value(), protocol.LocalDeviceID[:]) {
+				localDeviceKey = key
+			}
+
+		case db.KeyTypeSequence:
+			folder := binary.BigEndian.Uint32(key[1:])
+			seq := binary.BigEndian.Uint64(key[5:])
+			val := it.Value()
+			sequences[sequenceKey{folder, seq}] = string(val[9:])
+
+		case db.KeyTypeNeed:
+			folder := binary.BigEndian.Uint32(key[1:])
+			name := nulString(key[1+4:])
+			needs[globalKey{folder, name}] = struct{}{}
+		}
+	}
+
+	if localDeviceKey == 0 {
+		fmt.Println("Missing key for local device in device index (bailing out)")
+		success = false
+		return
+	}
+
+	for fk, fi := range fileInfos {
+		if fk.name != fi.Name {
+			fmt.Printf("Mismatching FileInfo name, %q (key) != %q (actual)\n", fk.name, fi.Name)
+			success = false
+		}
+
+		folder := folders[fk.folder]
+		if folder == "" {
+			fmt.Printf("Unknown folder ID %d for FileInfo %q\n", fk.folder, fk.name)
+			success = false
+			continue
+		}
+		if devices[fk.device] == "" {
+			fmt.Printf("Unknown device ID %d for FileInfo %q, folder %q\n", fk.folder, fk.name, folder)
+			success = false
+		}
+
+		if fk.device == localDeviceKey {
+			name, ok := sequences[sequenceKey{fk.folder, uint64(fi.Sequence)}]
+			if !ok {
+				fmt.Printf("Sequence entry missing for FileInfo %q, folder %q, seq %d\n", fi.Name, folder, fi.Sequence)
+				success = false
+				continue
+			}
+			if name != fi.Name {
+				fmt.Printf("Sequence entry refers to wrong name, %q (seq) != %q (FileInfo), folder %q, seq %d\n", name, fi.Name, folder, fi.Sequence)
+				success = false
+			}
+		}
+	}
+
+	for gk, vl := range globals {
+		folder := folders[gk.folder]
+		if folder == "" {
+			fmt.Printf("Unknown folder ID %d for VersionList %q\n", gk.folder, gk.name)
+			success = false
+		}
+		for i, fv := range vl.Versions {
+			dev, ok := deviceToIDs[string(fv.Device)]
+			if !ok {
+				fmt.Printf("VersionList %q, folder %q refers to unknown device %q\n", gk.name, folder, fv.Device)
+				success = false
+			}
+			fi, ok := fileInfos[fileInfoKey{gk.folder, dev, gk.name}]
+			if !ok {
+				fmt.Printf("VersionList %q, folder %q, entry %d refers to unknown FileInfo\n", gk.name, folder, i)
+				success = false
+			}
+			if !fi.Version.Equal(fv.Version) {
+				fmt.Printf("VersionList %q, folder %q, entry %d, FileInfo version mismatch, %v (VersionList) != %v (FileInfo)\n", gk.name, folder, i, fv.Version, fi.Version)
+				success = false
+			}
+			if fi.IsInvalid() != fv.Invalid {
+				fmt.Printf("VersionList %q, folder %q, entry %d, FileInfo invalid mismatch, %v (VersionList) != %v (FileInfo)\n", gk.name, folder, i, fv.Invalid, fi.IsInvalid())
+				success = false
+			}
+		}
+
+		// If we need this file we should have a need entry for it. False
+		// positives from needsLocally for deleted files, where we might
+		// legitimately lack an entry if we never had it, and ignored files.
+		if needsLocally(vl) {
+			_, ok := needs[gk]
+			if !ok {
+				dev, _ := deviceToIDs[string(vl.Versions[0].Device)]
+				fi, _ := fileInfos[fileInfoKey{gk.folder, dev, gk.name}]
+				if !fi.IsDeleted() && !fi.IsIgnored() {
+					fmt.Printf("Missing need entry for needed file %q, folder %q\n", gk.name, folder)
+				}
+			}
+		}
+	}
+
+	seenSeq := make(map[fileInfoKey]uint64)
+	for sk, name := range sequences {
+		folder := folders[sk.folder]
+		if folder == "" {
+			fmt.Printf("Unknown folder ID %d for sequence entry %d, %q\n", sk.folder, sk.sequence, name)
+			success = false
+			continue
+		}
+
+		if prev, ok := seenSeq[fileInfoKey{folder: sk.folder, name: name}]; ok {
+			fmt.Printf("Duplicate sequence entry for %q, folder %q, seq %d (prev %d)\n", name, folder, sk.sequence, prev)
+			success = false
+		}
+		seenSeq[fileInfoKey{folder: sk.folder, name: name}] = sk.sequence
+
+		fi, ok := fileInfos[fileInfoKey{sk.folder, localDeviceKey, name}]
+		if !ok {
+			fmt.Printf("Missing FileInfo for sequence entry %d, folder %q, %q\n", sk.sequence, folder, name)
+			success = false
+			continue
+		}
+		if fi.Sequence != int64(sk.sequence) {
+			fmt.Printf("Sequence mismatch for %q, folder %q, %d (key) != %d (FileInfo)\n", name, folder, sk.sequence, fi.Sequence)
+			success = false
+		}
+	}
+
+	for nk := range needs {
+		folder := folders[nk.folder]
+		if folder == "" {
+			fmt.Printf("Unknown folder ID %d for need entry %q\n", nk.folder, nk.name)
+			success = false
+			continue
+		}
+
+		vl, ok := globals[nk]
+		if !ok {
+			fmt.Printf("Missing global for need entry %q, folder %q\n", nk.name, folder)
+			success = false
+			continue
+		}
+
+		if !needsLocally(vl) {
+			fmt.Printf("Need entry for file we don't need, %q, folder %q\n", nk.name, folder)
+			success = false
+		}
+	}
+
+	return
+}
+
+func needsLocally(vl db.VersionList) bool {
+	var lv *protocol.Vector
+	for _, fv := range vl.Versions {
+		if bytes.Equal(fv.Device, protocol.LocalDeviceID[:]) {
+			lv = &fv.Version
+			break
+		}
+	}
+	if lv == nil {
+		return true // proviosinally, it looks like we need the file
+	}
+	return !lv.GreaterEqual(vl.Versions[0].Version)
+}
--- a/cmd/stindex/main.go
+++ b/cmd/stindex/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -21,7 +21,7 @@ func main() {
 	log.SetFlags(0)
 	log.SetOutput(os.Stdout)

-	flag.StringVar(&mode, "mode", "dump", "Mode of operation: dump, dumpsize")
+	flag.StringVar(&mode, "mode", "dump", "Mode of operation: dump, dumpsize, idxck")

 	flag.Parse()

@@ -30,9 +30,7 @@ func main() {
 		path = filepath.Join(defaultConfigDir(), "index-v0.14.0.db")
 	}

-	fmt.Println("Path:", path)
-
-	ldb, err := db.Open(path)
+	ldb, err := db.OpenRO(path)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -41,6 +39,10 @@ func main() {
 		dump(ldb)
 	} else if mode == "dumpsize" {
 		dumpsize(ldb)
+	} else if mode == "idxck" {
+		if !idxck(ldb) {
+			os.Exit(1)
+		}
 	} else {
 		fmt.Println("Unknown mode")
 	}
--- a/cmd/stindex/util.go
+++ b/cmd/stindex/util.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -12,7 +12,7 @@ import (
 	"path/filepath"
 	"runtime"

-	"github.com/syncthing/syncthing/lib/osutil"
+	"github.com/syncthing/syncthing/lib/fs"
 )

 func nulString(bs []byte) string {
@@ -33,7 +33,7 @@ func defaultConfigDir() string {
 		return filepath.Join(os.Getenv("AppData"), "Syncthing")

 	case "darwin":
-		dir, err := osutil.ExpandTilde("~/Library/Application Support/Syncthing")
+		dir, err := fs.ExpandTilde("~/Library/Application Support/Syncthing")
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -43,7 +43,7 @@ func defaultConfigDir() string {
 		if xdgCfg := os.Getenv("XDG_CONFIG_HOME"); xdgCfg != "" {
 			return filepath.Join(xdgCfg, "syncthing")
 		}
-		dir, err := osutil.ExpandTilde("~/.config/syncthing")
+		dir, err := fs.ExpandTilde("~/.config/syncthing")
 		if err != nil {
 			log.Fatal(err)
 		}
--- a/cmd/strelaypoolsrv/README.md
+++ b/cmd/strelaypoolsrv/README.md
@@ -1,15 +1,24 @@
 # relaypoolsrv

-[![Latest Build](http://img.shields.io/jenkins/s/http/build.syncthing.net/relaypoolsrv.svg?style=flat-square)](http://build.syncthing.net/job/relaypoolsrv/lastBuild/)
+This is the relay pool server for the `syncthing` project, which allows
+community hosted [relaysrv](https://github.com/syncthing/relaysrv)'s to join
+the public pool.

-This is the relay pool server for the `syncthing` project, which allows community hosted [relaysrv](https://github.com/syncthing/relaysrv)'s to join the public pool.
+Servers that join the pool are then advertised to users of `syncthing` as
+potential connection points for those who are unable to connect directly due
+to NAT or firewall issues.

-Servers that join the pool are then advertised to users of `syncthing` as potential connection points for those who are unable to connect directly due to NAT or firewall issues.
-
-There is very little reason why you'd want to run this yourself, as `relaypoolsrv` is just used for announcement and lookup of public relay servers. If you are looking to setup a private or a public relay, please check the documentation for [relaysrv](https://github.com/syncthing/relaysrv), which also explains how to join the default public pool.
-
-If you still want to run it, you can run `go get github.com/syncthing/relaypoolsrv` download it or download the
-[latest build](http://build.syncthing.net/job/relaypoolsrv/lastSuccessfulBuild/artifact/)
-from the build server.
+There is very little reason why you'd want to run this yourself, as
+`relaypoolsrv` is just used for announcement and lookup of public relay
+servers. If you are looking to setup a private or a public relay, please
+check the documentation for
+[relaysrv](https://github.com/syncthing/relaysrv), which also explains how
+to join the default public pool.

 See `relaypoolsrv -help` for configuration options.
+
+##### Third-party attributions
+
+[oschwald/geoip2-golang](https://github.com/oschwald/geoip2-golang), [oschwald/maxminddb-golang](https://github.com/oschwald/maxminddb-golang), Copyright (C) 2015 [Gregory J. Oschwald](mailto:oschwald@gmail.com).
+
+[lib/pq](https://github.com/lib/pq)</a>, Copyright (C) 2011-2013 'pq' Contributors Portions Copyright (C) 2011 Blake Mizerany.
--- a/cmd/strelaypoolsrv/auto/.gitignore
+++ b/cmd/strelaypoolsrv/auto/.gitignore
@@ -1 +1 @@
-gui.go
+gui.files.go
--- a/cmd/strelaypoolsrv/auto/doc.go
+++ b/cmd/strelaypoolsrv/auto/doc.go
@@ -0,0 +1,10 @@
+// Copyright (C) 2018 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//go:generate go run ../../../script/genassets.go -o gui.files.go ../gui
+
+// Package auto contains auto generated files for web assets.
+package auto
--- a/cmd/strelaypoolsrv/gui/index.html
+++ b/cmd/strelaypoolsrv/gui/index.html
@@ -2,15 +2,15 @@

 <html lang="en" ng-app="syncthing" ng-controller="relayDataController">
  <head>
-    <meta charset="utf-8">
-    <meta http-equiv="X-UA-Compatible" content="IE=edge">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <meta name="description" content="">
-    <meta name="author" content="">
+    <meta charset="utf-8"/>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+    <meta name="description" content=""/>
+    <meta name="author" content=""/>

    <title>Relay stats</title>
-    <link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet">
-    <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.6.1/css/font-awesome.min.css">
+    <link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet"/>
+    <link rel="stylesheet" href="//use.fontawesome.com/releases/v5.0.13/css/all.css"/>

    <style>
      #map {
@@ -36,9 +36,9 @@

  <body class="ng-cloak">
    <div class="container">
-      <h1>Relay Pool Data</h2>
+      <h1>Relay Pool Data</h1>
      <div ng-if="relays === undefined" class="text-center">
-        <img src="//cdnjs.cloudflare.com/ajax/libs/galleriffic/2.0.1/css/loader.gif"/>
+        <img src="//cdnjs.cloudflare.com/ajax/libs/galleriffic/2.0.1/css/loader.gif" alt=""/>
        <p>Please wait while we gather data</p>
      </div>
      <div>
@@ -48,7 +48,7 @@
          </p>
        </div>
        <div id="map"></div> <!-- Can't hide the map, otherwise it freaks out -->
-        <p>The circle size represents how much bytes the relay transfered relative to other relays</p>
+        <p>The circle size represents how much bytes the relay transferred relative to other relays</p>
      </div>
      <div>
        <table class="table table-striped table-condensed table">
@@ -56,105 +56,105 @@
            <tr>
              <th rowspan="2">Address</td>
              <th rowspan="2">
-                <a ng-click="sortType = 'status.numActiveSessions || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.numActiveSessions'; sortReverse = !sortReverse">
                  Sessions
-                  <span ng-show="sortType == 'status.numActiveSessions || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.numActiveSessions || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.numActiveSessions' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.numActiveSessions' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th rowspan="2">
-                <a ng-click="sortType = 'status.numConnections || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.numConnections'; sortReverse = !sortReverse">
                  Connections
-                  <span ng-show="sortType == 'status.numConnections || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.numConnections || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.numConnections' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.numConnections' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th rowspan="2">
-                <a ng-click="sortType = 'status.bytesProxied || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.bytesProxied'; sortReverse = !sortReverse">
                  Data relayed
-                  <span ng-show="sortType == 'status.bytesProxied || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.bytesProxied || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.bytesProxied' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.bytesProxied' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th colspan="6" class="text-center">Transfer rate in the last period</th>
              <th rowspan="2">
-                <a ng-click="sortType = 'status.uptimeSeconds || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.uptimeSeconds'; sortReverse = !sortReverse">
                  Uptime hours
-                  <span ng-show="sortType == 'status.uptimeSeconds || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.uptimeSeconds || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.uptimeSeconds' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'status.uptimeSeconds' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th rowspan="2">
-                <a ng-click="sortType = 'status.options[\'provided-by\'] || \'\''; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.options[\'provided-by\'] || \'\''; sortReverse = !sortReverse">
                  Provided by
-                  <span ng-show="sortType == 'status.options[\'provided-by\'] || \'\'' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.options[\'provided-by\'] || \'\'' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.options[\'provided-by\'] || \'\'' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.options[\'provided-by\'] || \'\'' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
            </tr>
            <tr>
              <th>
-                <a ng-click="sortType = 'status.kbps10s1m5m15m30m60m[0] || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[0]'; sortReverse = !sortReverse">
                  10s
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[0] || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[0] || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[0]' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[0]' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th>
-                <a ng-click="sortType = 'status.kbps10s1m5m15m30m60m[1] || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[1]'; sortReverse = !sortReverse">
                  1m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[1] || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[1] || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[1]' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[1]' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th>
-                <a ng-click="sortType = 'status.kbps10s1m5m15m30m60m[2] || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[2]'; sortReverse = !sortReverse">
                  5m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[2] || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[2] || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[2]' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[2]' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th>
-                <a ng-click="sortType = 'status.kbps10s1m5m15m30m60m[3] || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[3]'; sortReverse = !sortReverse">
                  15m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[3] || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[3] || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[3]' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[3]' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th>
-                <a ng-click="sortType = 'status.kbps10s1m5m15m30m60m[4] || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[4]'; sortReverse = !sortReverse">
                  30m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[4] || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[4] || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[4]' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[4]' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
              <th>
-                <a ng-click="sortType = 'status.kbps10s1m5m15m30m60m[5] || -1'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[5]'; sortReverse = !sortReverse">
                  60m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[5] || -1' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[5] || -1' && sortReverse" class="fa fa-caret-up"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[5]' && !sortReverse" class="fas fa-caret-down"></span>
+                  <span ng-show="sortType == 'stats.kbps10s1m5m15m30m60m[5]' && sortReverse" class="fas fa-caret-up"></span>
                </a>
              </th>
            </tr>
          </thead>
          <tbody>
-            <tr ng-repeat="relay in relays | orderBy:sortType:sortReverse ">
+            <tr ng-repeat="relay in relays | orderBy:sortType:sortReverse:sortCompare" ng-mouseover="relay.showMarker()" ng-mouseleave="relay.hideMarker()">
              <td>{{ relay.address }}</td>
-              <td ng-if="relay.status === undefined" colspan="11" class="text-center">Looking up...</td>
-              <td ng-if-start="relay.status !== undefined">{{ relay.status.numActiveSessions }}</td>
-              <td>{{ relay.status.numConnections }}</td>
-              <td>{{ relay.status.bytesProxied | bytes }}</td>
-              <td>{{ relay.status.kbps10s1m5m15m30m60m[0] * 128 | bytes }}/s</td>
-              <td>{{ relay.status.kbps10s1m5m15m30m60m[1] * 128 | bytes }}/s</td>
-              <td>{{ relay.status.kbps10s1m5m15m30m60m[2] * 128 | bytes }}/s</td>
-              <td>{{ relay.status.kbps10s1m5m15m30m60m[3] * 128 | bytes }}/s</td>
-              <td>{{ relay.status.kbps10s1m5m15m30m60m[4] * 128 | bytes }}/s</td>
-              <td>{{ relay.status.kbps10s1m5m15m30m60m[5] * 128 | bytes }}/s</td>
-              <td ng-if="relay.status.uptimeSeconds != undefined">{{ relay.status.uptimeSeconds/60/60 | number:0 }}</td>
-              <td ng-if="relay.status.uptimeSeconds == undefined"></td>
-              <td title="{{ relay.status.options['provided-by'] || '' }}" ng-if-end>
-                {{ relay.status.options['provided-by'] || '' | limitTo:50 }}
-                <span ng-if="(relay.status.options['provided-by'] || '').length > 50">&hellip;
+              <td ng-if="!relay.stats" colspan="11"></td>
+              <td ng-if-start="relay.stats">{{ relay.stats.numActiveSessions }}</td>
+              <td>{{ relay.stats.numConnections }}</td>
+              <td>{{ relay.stats.bytesProxied | bytes }}</td>
+              <td>{{ relay.stats.kbps10s1m5m15m30m60m[0] * 128 | bytes }}/s</td>
+              <td>{{ relay.stats.kbps10s1m5m15m30m60m[1] * 128 | bytes }}/s</td>
+              <td>{{ relay.stats.kbps10s1m5m15m30m60m[2] * 128 | bytes }}/s</td>
+              <td>{{ relay.stats.kbps10s1m5m15m30m60m[3] * 128 | bytes }}/s</td>
+              <td>{{ relay.stats.kbps10s1m5m15m30m60m[4] * 128 | bytes }}/s</td>
+              <td>{{ relay.stats.kbps10s1m5m15m30m60m[5] * 128 | bytes }}/s</td>
+              <td ng-if="relay.stats.uptimeSeconds != undefined">{{ relay.stats.uptimeSeconds/60/60 | number:0 }}</td>
+              <td ng-if="relay.stats.uptimeSeconds == undefined"></td>
+              <td title="{{ relay.stats.options['provided-by'] || '' }}" ng-if-end>
+                {{ relay.stats.options['provided-by'] || '' | limitTo:50 }}
+                <span ng-if="(relay.stats.options['provided-by'] || '').length > 50">&hellip;
              </td>
            </tr>
          </tbody>
@@ -184,10 +184,10 @@
    </div>


-    <script src="//code.jquery.com/jquery-2.1.4.min.js"></script>
-    <script src="//cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.7/angular.min.js"></script>
-    <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
-    <script src="//maps.googleapis.com/maps/api/js"></script>
+    <script type="text/javascript" src="//code.jquery.com/jquery-2.1.4.min.js"></script>
+    <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/angular.min.js"></script>
+    <script type="text/javascript" src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
+    <script type="text/javascript" src="//maps.googleapis.com/maps/api/js?key=AIzaSyDk5WJ8s7ueLKb99X5DbQ-vkWtPDAKqYs0"></script>
  </body>

  <script>
@@ -235,30 +235,48 @@
    $scope.mapBounds = new google.maps.LatLngBounds();
    $scope.tooltipTemplate = $('#infoTemplate').html();
    $scope.usedLocations = {};
-    $scope.sortType = 'status.numActiveSessions || -1';
+    $scope.sortType = 'stats.numActiveSessions';
    $scope.sortReverse = true;
+    $scope.sortCompare = function(a, b) {
+      if (a.value == b.value) {
+        return 0;
+      }
+      if (a.type == "undefined" || a.type == "null") {
+        return -1;
+      }
+      if (b.type == "undefined" || b.type == "null") {
+        return 1;
+      }
+      return a.value > b.value ? 1 : -1;
+    }

    $http.get("/endpoint").then(function(response) {
      $scope.relays = response.data.relays;
-      var promises = [];
-      angular.forEach($scope.relays, function(relay) {

+      angular.forEach($scope.relays, function(relay) {
        relay.uri = constructURI(relay.url);
        relay.address = relay.url.split('/')[2];

        addMarkerToMap(relay);

-        promises.push(getRelayStatus(relay));
+        if (relay.stats) {
+          angular.forEach($scope.totals, function(value, key) {
+            if (typeof $scope.totals[key] == 'number') {
+              $scope.totals[key] += relay.stats[key];
+            } else if (typeof $scope.totals[key] == 'object' && $scope.totals[key] instanceof Array) {
+              angular.forEach($scope.totals[key], function(value, index) {
+                $scope.totals[key][index] += relay.stats[key][index];
+              });
+            }
+          });
+        }
      });

-      // Can only add circles once we know the totals for transfers, which means
-      // we need to resolve all statuses.
-      $q.all(promises).then(function() {
-        angular.forEach($scope.relays, function(relay) {
-          if (relay.status) {
-            addCircleToMap(relay);
-          }
-        });
+      // After the totals were calculated, add circles.
+      angular.forEach($scope.relays, function(relay) {
+        if (relay.stats) {
+          addCircleToMap(relay);
+        }
      });

      $scope.map.fitBounds($scope.mapBounds);
@@ -295,13 +313,16 @@
          content: $compile($scope.tooltipTemplate)(scope)[0],
        });

-        relay.marker.addListener('mouseover', function() {
+        relay.showMarker = function() {
          relay.marker.info.open($scope.map, relay.marker);
-        });
+        }

-        relay.marker.addListener('mouseout', function() {
+        relay.hideMarker = function() {
          relay.marker.info.close();
-        });
+        }
+
+        relay.marker.addListener('mouseover', relay.showMarker);
+        relay.marker.addListener('mouseout', relay.hideMarker);

        $scope.mapBounds.extend(relay.marker.position);
    }
@@ -315,40 +336,10 @@
        fillOpacity: 0.35,
        map: $scope.map,
        center: relay.marker.position,
-        radius: ((relay.status.bytesProxied * 100) / $scope.totals.bytesProxied) * 10000
+        radius: ((relay.stats.bytesProxied * 100) / $scope.totals.bytesProxied) * 10000
      });
    }

-    function getRelayStatus(relay) {
-      // Normal timeout doesn't deal with relays which accept the TCP connection
-      // but don't respond (some firewalls do that), so deal with it this way.
-      var timeoutRequest = $q.defer();
-      var resolveStatus = $q.defer();
-
-      $http.get("http://" + relay.uri.hostname + (relay.uri.args.statusAddr || ":22070") + "/status", { timeout: timeoutRequest.promise }).then(function (response) {
-        relay.status = response.data;
-        resolveStatus.resolve();
-        angular.forEach($scope.totals, function(value, key) {
-          if (typeof $scope.totals[key] == 'number') {
-            $scope.totals[key] += response.data[key];
-          } else if (typeof $scope.totals[key] == 'object' && $scope.totals[key] instanceof Array) {
-            angular.forEach($scope.totals[key], function(value, index) {
-              $scope.totals[key][index] += response.data[key][index];
-            });
-          }
-        });
-      }, function() {
-        relay.status = null;
-        resolveStatus.resolve();
-      });
-
-      $timeout(function() {
-        timeoutRequest.resolve();
-      }, 5000);
-
-      return resolveStatus.promise;
-    }
-
    function constructURI(url) {
      var uri = document.createElement('a');

@@ -369,25 +360,25 @@

  <script type="text/template" id="infoTemplate">
    <div>
-      <p><b>{{ relay.uri.hostname }}</b> <span ng-if="relay.status.options['provided-by']">provided by <u>{{ relay.status.options['provided-by'] }}</u></span></p>
-      <div ng-if="relay.status">
-        <span ng-if="relay.status.startTime">Start time: {{ relay.status.startTime | date:"medium" }}</br></span>
-        <span ng-if="relay.status.bytesProxied != undefined">Proxied: {{ relay.status.bytesProxied | bytes }}</br></span>
-        <span ng-if="relay.status.numActiveSessions != undefined">Sessions: {{ relay.status.numActiveSessions }}</br></span>
-        <span ng-if="relay.status.numConnections != undefined">Clients: {{ relay.status.numConnections }}</br></span>
-        <span ng-if="relay.status.options.pools">Pools: {{ relay.status.options.pools.join(', ') }}</br></span>
-        <span ng-if="relay.status.options['global-rate'] != undefined">
-          <span ng-if="relay.status.options['global-rate'] > 0">Global rate limit: {{ relay.status.options['global-rate'] | bytes }}/s</span>
-          <span ng-if="relay.status.options['global-rate'] == 0">Global rate limit: unlimited</span>
-          </br>
+      <p><b>{{ relay.uri.hostname }}</b> <span ng-if="relay.stats.options['provided-by']">provided by <u>{{ relay.stats.options['provided-by'] }}</u></span></p>
+      <div ng-if="relay.stats">
+        <span ng-if="relay.stats.startTime">Start time: {{ relay.stats.startTime | date:"medium" }}</br></span>
+        <span ng-if="relay.stats.bytesProxied != undefined">Proxied: {{ relay.stats.bytesProxied | bytes }}</br></span>
+        <span ng-if="relay.stats.numActiveSessions != undefined">Sessions: {{ relay.stats.numActiveSessions }}</br></span>
+        <span ng-if="relay.stats.numConnections != undefined">Clients: {{ relay.stats.numConnections }}</br></span>
+        <span ng-if="relay.stats.options.pools">Pools: {{ relay.stats.options.pools.join(', ') }}</br></span>
+        <span ng-if="relay.stats.options['global-rate'] != undefined">
+          <span ng-if="relay.stats.options['global-rate'] > 0">Global rate limit: {{ relay.stats.options['global-rate'] | bytes }}/s</span>
+          <span ng-if="relay.stats.options['global-rate'] == 0">Global rate limit: unlimited</span>
+          <br/>
        </span>
-        <span ng-if="relay.status.options['per-session-rate'] != undefined">
-          <span ng-if="relay.status.options['per-session-rate'] > 0">Session rate limit: {{ relay.status.options['per-session-rate'] | bytes }}/s</span>
-          <span ng-if="relay.status.options['per-session-rate'] == 0">Session rate limit: unlimited</span>
-          </br>
+        <span ng-if="relay.stats.options['per-session-rate'] != undefined">
+          <span ng-if="relay.stats.options['per-session-rate'] > 0">Session rate limit: {{ relay.stats.options['per-session-rate'] | bytes }}/s</span>
+          <span ng-if="relay.stats.options['per-session-rate'] == 0">Session rate limit: unlimited</span>
+          <br/>
        </span>
      </div>
-      <div ng-if="!relay.status">
+      <div ng-if="!relay.stats">
        Data unavailable.
      <div>
    </div>
--- a/cmd/strelaypoolsrv/main.go
+++ b/cmd/strelaypoolsrv/main.go
@@ -1,6 +1,6 @@
 // Copyright (C) 2015 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).

-//go:generate go run genassets.go gui auto/gui.go
+//go:generate go run ../../script/genassets.go gui >auto/gui.go

 package main

@@ -18,30 +18,62 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"time"

 	"github.com/golang/groupcache/lru"
-	"github.com/juju/ratelimit"
-
 	"github.com/oschwald/geoip2-golang"
-
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/syncthing/syncthing/cmd/strelaypoolsrv/auto"
 	"github.com/syncthing/syncthing/lib/relay/client"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/tlsutil"
+	"golang.org/x/time/rate"
 )

 type location struct {
 	Latitude  float64 `json:"latitude"`
 	Longitude float64 `json:"longitude"`
+	City      string  `json:"city"`
+	Country   string  `json:"country"`
+	Continent string  `json:"continent"`
 }

 type relay struct {
-	URL      string   `json:"url"`
-	Location location `json:"location"`
-	uri      *url.URL
+	URL            string   `json:"url"`
+	Location       location `json:"location"`
+	uri            *url.URL
+	Stats          *stats    `json:"stats"`
+	StatsRetrieved time.Time `json:"statsRetrieved"`
+}
+
+type stats struct {
+	StartTime          time.Time `json:"startTime"`
+	UptimeSeconds      int       `json:"uptimeSeconds"`
+	PendingSessionKeys int       `json:"numPendingSessionKeys"`
+	ActiveSessions     int       `json:"numActiveSessions"`
+	Connections        int       `json:"numConnections"`
+	Proxies            int       `json:"numProxies"`
+	BytesProxied       int       `json:"bytesProxied"`
+	GoVersion          string    `json:"goVersion"`
+	GoOS               string    `json:"goOS"`
+	GoArch             string    `json:"goArch"`
+	GoMaxProcs         int       `json:"goMaxProcs"`
+	GoRoutines         int       `json:"goNumRoutine"`
+	Rates              []int64   `json:"kbps10s1m5m15m30m60m"`
+	Options            struct {
+		NetworkTimeout int      `json:"network-timeout"`
+		PintInterval   int      `json:"ping-interval"`
+		MessageTimeout int      `json:"message-timeout"`
+		SessionRate    int      `json:"per-session-rate"`
+		GlobalRate     int      `json:"global-rate"`
+		Pools          []string `json:"pools"`
+		ProvidedBy     string   `json:"provided-by"`
+	} `json:"options"`
 }

 func (r relay) String() string {
@@ -49,9 +81,9 @@ func (r relay) String() string {
 }

 type request struct {
-	relay  relay
-	uri    *url.URL
-	result chan result
+	relay      *relay
+	result     chan result
+	queueTimer *prometheus.Timer
 }

 type result struct {
@@ -60,23 +92,25 @@ type result struct {
 }

 var (
-	testCert       tls.Certificate
-	listen         = ":80"
-	dir            string
-	evictionTime   = time.Hour
-	debug          bool
-	getLRUSize           = 10 << 10
-	getLimitBurst  int64 = 10
-	getLimitAvg          = 1
-	postLRUSize          = 1 << 10
-	postLimitBurst int64 = 2
-	postLimitAvg         = 1
-	getLimit       time.Duration
-	postLimit      time.Duration
-	permRelaysFile string
-	ipHeader       string
-	geoipPath      string
-	proto          string
+	testCert        tls.Certificate
+	knownRelaysFile = filepath.Join(os.TempDir(), "strelaypoolsrv_known_relays")
+	listen          = ":80"
+	dir             string
+	evictionTime    = time.Hour
+	debug           bool
+	getLRUSize      = 10 << 10
+	getLimitBurst   = 10
+	getLimitAvg     = 2
+	postLRUSize     = 1 << 10
+	postLimitBurst  = 2
+	postLimitAvg    = 2
+	getLimit        time.Duration
+	postLimit       time.Duration
+	permRelaysFile  string
+	ipHeader        string
+	geoipPath       string
+	proto           string
+	statsRefresh    = time.Minute / 2

 	getMut      = sync.NewRWMutex()
 	getLRUCache *lru.Cache
@@ -87,26 +121,31 @@ var (
 	requests = make(chan request, 10)

 	mut             = sync.NewRWMutex()
-	knownRelays     = make([]relay, 0)
-	permanentRelays = make([]relay, 0)
+	knownRelays     = make([]*relay, 0)
+	permanentRelays = make([]*relay, 0)
 	evictionTimers  = make(map[string]*time.Timer)
 )

+const (
+	httpStatusEnhanceYourCalm = 429
+)
+
 func main() {
 	flag.StringVar(&listen, "listen", listen, "Listen address")
 	flag.StringVar(&dir, "keys", dir, "Directory where http-cert.pem and http-key.pem is stored for TLS listening")
 	flag.BoolVar(&debug, "debug", debug, "Enable debug output")
 	flag.DurationVar(&evictionTime, "eviction", evictionTime, "After how long the relay is evicted")
 	flag.IntVar(&getLRUSize, "get-limit-cache", getLRUSize, "Get request limiter cache size")
-	flag.IntVar(&getLimitAvg, "get-limit-avg", 2, "Allowed average get request rate, per 10 s")
-	flag.Int64Var(&getLimitBurst, "get-limit-burst", getLimitBurst, "Allowed burst get requests")
+	flag.IntVar(&getLimitAvg, "get-limit-avg", getLimitAvg, "Allowed average get request rate, per 10 s")
+	flag.IntVar(&getLimitBurst, "get-limit-burst", getLimitBurst, "Allowed burst get requests")
 	flag.IntVar(&postLRUSize, "post-limit-cache", postLRUSize, "Post request limiter cache size")
-	flag.IntVar(&postLimitAvg, "post-limit-avg", 2, "Allowed average post request rate, per minute")
-	flag.Int64Var(&postLimitBurst, "post-limit-burst", postLimitBurst, "Allowed burst post requests")
+	flag.IntVar(&postLimitAvg, "post-limit-avg", postLimitAvg, "Allowed average post request rate, per minute")
+	flag.IntVar(&postLimitBurst, "post-limit-burst", postLimitBurst, "Allowed burst post requests")
 	flag.StringVar(&permRelaysFile, "perm-relays", "", "Path to list of permanent relays")
 	flag.StringVar(&ipHeader, "ip-header", "", "Name of header which holds clients ip:port. Only meaningful when running behind a reverse proxy.")
 	flag.StringVar(&geoipPath, "geoip", "GeoLite2-City.mmdb", "Path to GeoLite2-City database")
 	flag.StringVar(&proto, "protocol", "tcp", "Protocol used for listening. 'tcp' for IPv4 and IPv6, 'tcp4' for IPv4, 'tcp6' for IPv6")
+	flag.DurationVar(&statsRefresh, "stats-refresh", statsRefresh, "Interval at which to refresh relay stats")

 	flag.Parse()

@@ -120,13 +159,31 @@ func main() {
 	var err error

 	if permRelaysFile != "" {
-		loadPermanentRelays(permRelaysFile)
+		permanentRelays = loadRelays(permRelaysFile)
 	}

 	testCert = createTestCertificate()

 	go requestProcessor()

+	// Load relays from cache in the background.
+	// Load them in a serial fashion to make sure any genuine requests
+	// are not dropped.
+	go func() {
+		for _, relay := range loadRelays(knownRelaysFile) {
+			resultChan := make(chan result)
+			requests <- request{relay, resultChan, nil}
+			result := <-resultChan
+			if result.err != nil {
+				relayTestsTotal.WithLabelValues("failed").Inc()
+			} else {
+				relayTestsTotal.WithLabelValues("success").Inc()
+			}
+		}
+		// Run the the stats refresher once the relays are loaded.
+		statsRefresher(statsRefresh)
+	}()
+
 	if dir != "" {
 		if debug {
 			log.Println("Starting TLS listener on", listen)
@@ -171,6 +228,7 @@ func main() {
 	handler := http.NewServeMux()
 	handler.HandleFunc("/", handleAssets)
 	handler.HandleFunc("/endpoint", handleRequest)
+	handler.HandleFunc("/metrics", handleMetrics)

 	srv := http.Server{
 		Handler:     handler,
@@ -183,7 +241,18 @@ func main() {
 	}
 }

+func handleMetrics(w http.ResponseWriter, r *http.Request) {
+	timer := prometheus.NewTimer(metricsRequestsSeconds)
+	// Acquire the mutex just to make sure we're not caught mid-way stats collection
+	mut.RLock()
+	promhttp.Handler().ServeHTTP(w, r)
+	mut.RUnlock()
+	timer.ObserveDuration()
+}
+
 func handleAssets(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+
 	assets := auto.Assets()
 	path := r.URL.Path[1:]
 	if path == "" {
@@ -196,11 +265,28 @@ func handleAssets(w http.ResponseWriter, r *http.Request) {
 		return
 	}

+	etag := fmt.Sprintf("%d", auto.Generated)
+	modified := time.Unix(auto.Generated, 0).UTC()
+
+	w.Header().Set("Last-Modified", modified.Format(http.TimeFormat))
+	w.Header().Set("Etag", etag)
+
 	mtype := mimeTypeForFile(path)
 	if len(mtype) != 0 {
 		w.Header().Set("Content-Type", mtype)
 	}

+	if t, err := time.Parse(http.TimeFormat, r.Header.Get("If-Modified-Since")); err == nil && modified.Add(time.Second).After(t) {
+		w.WriteHeader(http.StatusNotModified)
+		return
+	}
+
+	if match := r.Header.Get("If-None-Match"); match != "" {
+		if strings.Contains(match, etag) {
+			w.WriteHeader(http.StatusNotModified)
+			return
+		}
+	}
 	if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
 		w.Header().Set("Content-Encoding", "gzip")
 	} else {
@@ -243,20 +329,29 @@ func mimeTypeForFile(file string) string {
 }

 func handleRequest(w http.ResponseWriter, r *http.Request) {
+	timer := prometheus.NewTimer(apiRequestsSeconds.WithLabelValues(r.Method))
+
+	lw := NewLoggingResponseWriter(w)
+
+	defer func() {
+		timer.ObserveDuration()
+		apiRequestsTotal.WithLabelValues(r.Method, strconv.Itoa(lw.statusCode)).Inc()
+	}()
+
 	if ipHeader != "" {
 		r.RemoteAddr = r.Header.Get(ipHeader)
 	}
 	w.Header().Set("Access-Control-Allow-Origin", "*")
 	switch r.Method {
 	case "GET":
-		if limit(r.RemoteAddr, getLRUCache, getMut, getLimit, int64(getLimitBurst)) {
-			w.WriteHeader(429)
+		if limit(r.RemoteAddr, getLRUCache, getMut, getLimit, getLimitBurst) {
+			w.WriteHeader(httpStatusEnhanceYourCalm)
 			return
 		}
 		handleGetRequest(w, r)
 	case "POST":
-		if limit(r.RemoteAddr, postLRUCache, postMut, postLimit, int64(postLimitBurst)) {
-			w.WriteHeader(429)
+		if limit(r.RemoteAddr, postLRUCache, postMut, postLimit, postLimitBurst) {
+			w.WriteHeader(httpStatusEnhanceYourCalm)
 			return
 		}
 		handlePostRequest(w, r)
@@ -280,7 +375,7 @@ func handleGetRequest(w http.ResponseWriter, r *http.Request) {
 		relays[i], relays[j] = relays[j], relays[i]
 	}

-	json.NewEncoder(w).Encode(map[string][]relay{
+	json.NewEncoder(w).Encode(map[string][]*relay{
 		"relays": relays,
 	})
 }
@@ -317,35 +412,32 @@ func handlePostRequest(w http.ResponseWriter, r *http.Request) {
 	}

 	// Get the IP address of the client
-	rhost, _, err := net.SplitHostPort(r.RemoteAddr)
-	if err != nil {
-		if debug {
-			log.Println("Failed to split remote address", r.RemoteAddr)
-		}
-		http.Error(w, err.Error(), 500)
-		return
+	rhost := r.RemoteAddr
+	if host, _, err := net.SplitHostPort(rhost); err == nil {
+		rhost = host
 	}

+	ip := net.ParseIP(host)
 	// The client did not provide an IP address, use the IP address of the client.
-	if host == "" {
+	if ip == nil || ip.IsUnspecified() {
 		uri.Host = net.JoinHostPort(rhost, port)
 		newRelay.URL = uri.String()
 	} else if host != rhost {
 		if debug {
 			log.Println("IP address advertised does not match client IP address", r.RemoteAddr, uri)
 		}
-		http.Error(w, "IP address does not match client IP", http.StatusUnauthorized)
+		http.Error(w, fmt.Sprintf("IP advertised %s does not match client IP %s", host, rhost), http.StatusUnauthorized)
 		return
 	}
+
 	newRelay.uri = uri
-	newRelay.Location = getLocation(uri.Host)

 	for _, current := range permanentRelays {
 		if current.uri.Host == newRelay.uri.Host {
 			if debug {
 				log.Println("Asked to add a relay", newRelay, "which exists in permanent list")
 			}
-			http.Error(w, "Invalid request", 500)
+			http.Error(w, "Invalid request", http.StatusBadRequest)
 			return
 		}
 	}
@@ -353,78 +445,105 @@ func handlePostRequest(w http.ResponseWriter, r *http.Request) {
 	reschan := make(chan result)

 	select {
-	case requests <- request{newRelay, uri, reschan}:
+	case requests <- request{&newRelay, reschan, prometheus.NewTimer(relayTestActionsSeconds.WithLabelValues("queue"))}:
 		result := <-reschan
 		if result.err != nil {
-			http.Error(w, result.err.Error(), 500)
+			relayTestsTotal.WithLabelValues("failed").Inc()
+			http.Error(w, result.err.Error(), http.StatusBadRequest)
 			return
 		}
+		relayTestsTotal.WithLabelValues("success").Inc()
 		w.Header().Set("Content-Type", "application/json; charset=utf-8")
 		json.NewEncoder(w).Encode(map[string]time.Duration{
 			"evictionIn": result.eviction,
 		})

 	default:
+		relayTestsTotal.WithLabelValues("dropped").Inc()
 		if debug {
 			log.Println("Dropping request")
 		}
-		w.WriteHeader(429)
+		w.WriteHeader(httpStatusEnhanceYourCalm)
 	}
 }

 func requestProcessor() {
 	for request := range requests {
-		if debug {
-			log.Println("Request for", request.relay)
-		}
-		if !client.TestRelay(request.uri, []tls.Certificate{testCert}, time.Second, 2*time.Second, 3) {
-			if debug {
-				log.Println("Test for relay", request.relay, "failed")
-			}
-			request.result <- result{fmt.Errorf("test failed"), 0}
-			continue
+		if request.queueTimer != nil {
+			request.queueTimer.ObserveDuration()
 		}

-		mut.Lock()
-		timer, ok := evictionTimers[request.relay.uri.Host]
-		if ok {
-			if debug {
-				log.Println("Stopping existing timer for", request.relay)
-			}
-			timer.Stop()
-		}
-
-		for i, current := range knownRelays {
-			if current.uri.Host == request.relay.uri.Host {
-				if debug {
-					log.Println("Relay", request.relay, "already exists")
-				}
-
-				// Evict the old entry anyway, as configuration might have changed.
-				last := len(knownRelays) - 1
-				knownRelays[i] = knownRelays[last]
-				knownRelays = knownRelays[:last]
-
-				goto found
-			}
-		}
-
-		if debug {
-			log.Println("Adding new relay", request.relay)
-		}
-
-	found:
-
-		knownRelays = append(knownRelays, request.relay)
-
-		evictionTimers[request.relay.uri.Host] = time.AfterFunc(evictionTime, evict(request.relay))
-		mut.Unlock()
-		request.result <- result{nil, evictionTime}
+		timer := prometheus.NewTimer(relayTestActionsSeconds.WithLabelValues("test"))
+		handleRelayTest(request)
+		timer.ObserveDuration()
 	}
-
 }

-func evict(relay relay) func() {
+func handleRelayTest(request request) {
+	if debug {
+		log.Println("Request for", request.relay)
+	}
+	if !client.TestRelay(request.relay.uri, []tls.Certificate{testCert}, time.Second, 2*time.Second, 3) {
+		if debug {
+			log.Println("Test for relay", request.relay, "failed")
+		}
+		request.result <- result{fmt.Errorf("connection test failed"), 0}
+		return
+	}
+
+	stats := fetchStats(request.relay)
+	location := getLocation(request.relay.uri.Host)
+
+	mut.Lock()
+	if stats != nil {
+		updateMetrics(request.relay.uri.Host, *stats, location)
+	}
+	request.relay.Stats = stats
+	request.relay.StatsRetrieved = time.Now()
+	request.relay.Location = location
+
+	timer, ok := evictionTimers[request.relay.uri.Host]
+	if ok {
+		if debug {
+			log.Println("Stopping existing timer for", request.relay)
+		}
+		timer.Stop()
+	}
+
+	for i, current := range knownRelays {
+		if current.uri.Host == request.relay.uri.Host {
+			if debug {
+				log.Println("Relay", request.relay, "already exists")
+			}
+
+			// Evict the old entry anyway, as configuration might have changed.
+			last := len(knownRelays) - 1
+			knownRelays[i] = knownRelays[last]
+			knownRelays = knownRelays[:last]
+
+			goto found
+		}
+	}
+
+	if debug {
+		log.Println("Adding new relay", request.relay)
+	}
+
+found:
+
+	knownRelays = append(knownRelays, request.relay)
+	evictionTimers[request.relay.uri.Host] = time.AfterFunc(evictionTime, evict(request.relay))
+
+	mut.Unlock()
+
+	if err := saveRelays(knownRelaysFile, knownRelays); err != nil {
+		log.Println("Failed to write known relays: " + err.Error())
+	}
+
+	request.result <- result{nil, evictionTime}
+}
+
+func evict(relay *relay) func() {
 	return func() {
 		mut.Lock()
 		defer mut.Unlock()
@@ -439,41 +558,43 @@ func evict(relay relay) func() {
 				last := len(knownRelays) - 1
 				knownRelays[i] = knownRelays[last]
 				knownRelays = knownRelays[:last]
+				deleteMetrics(current.uri.Host)
 			}
 		}
 		delete(evictionTimers, relay.uri.Host)
 	}
 }

-func limit(addr string, cache *lru.Cache, lock sync.RWMutex, rate time.Duration, burst int64) bool {
-	host, _, err := net.SplitHostPort(addr)
-	if err != nil {
-		return false
+func limit(addr string, cache *lru.Cache, lock sync.RWMutex, intv time.Duration, burst int) bool {
+	if host, _, err := net.SplitHostPort(addr); err == nil {
+		addr = host
 	}

 	lock.RLock()
-	bkt, ok := cache.Get(host)
+	bkt, ok := cache.Get(addr)
 	lock.RUnlock()
 	if ok {
-		bkt := bkt.(*ratelimit.Bucket)
-		if bkt.TakeAvailable(1) != 1 {
+		bkt := bkt.(*rate.Limiter)
+		if !bkt.Allow() {
 			// Rate limit
 			return true
 		}
 	} else {
 		lock.Lock()
-		cache.Add(host, ratelimit.NewBucket(rate, burst))
+		cache.Add(addr, rate.NewLimiter(rate.Every(intv), burst))
 		lock.Unlock()
 	}
 	return false
 }

-func loadPermanentRelays(file string) {
+func loadRelays(file string) []*relay {
 	content, err := ioutil.ReadFile(file)
 	if err != nil {
-		log.Fatal(err)
+		log.Println("Failed to load relays: " + err.Error())
+		return nil
 	}

+	var relays []*relay
 	for _, line := range strings.Split(string(content), "\n") {
 		if len(line) == 0 {
 			continue
@@ -482,21 +603,30 @@ func loadPermanentRelays(file string) {
 		uri, err := url.Parse(line)
 		if err != nil {
 			if debug {
-				log.Println("Skipping permanent relay", line, "due to parse error", err)
+				log.Println("Skipping relay", line, "due to parse error", err)
 			}
 			continue

 		}

-		permanentRelays = append(permanentRelays, relay{
+		relays = append(relays, &relay{
 			URL:      line,
 			Location: getLocation(uri.Host),
 			uri:      uri,
 		})
 		if debug {
-			log.Println("Adding permanent relay", line)
+			log.Println("Adding relay", line)
 		}
 	}
+	return relays
+}
+
+func saveRelays(file string, relays []*relay) error {
+	var content string
+	for _, relay := range relays {
+		content += relay.uri.String() + "\n"
+	}
+	return ioutil.WriteFile(file, []byte(content), 0777)
 }

 func createTestCertificate() tls.Certificate {
@@ -506,7 +636,7 @@ func createTestCertificate() tls.Certificate {
 	}

 	certFile, keyFile := filepath.Join(tmpDir, "cert.pem"), filepath.Join(tmpDir, "key.pem")
-	cert, err := tlsutil.NewCertificate(certFile, keyFile, "relaypoolsrv", 3072)
+	cert, err := tlsutil.NewCertificate(certFile, keyFile, "relaypoolsrv")
 	if err != nil {
 		log.Fatalln("Failed to create test X509 key pair:", err)
 	}
@@ -515,6 +645,8 @@ func createTestCertificate() tls.Certificate {
 }

 func getLocation(host string) location {
+	timer := prometheus.NewTimer(locationLookupSeconds)
+	defer timer.ObserveDuration()
 	db, err := geoip2.Open(geoipPath)
 	if err != nil {
 		return location{}
@@ -532,7 +664,24 @@ func getLocation(host string) location {
 	}

 	return location{
-		Latitude:  city.Location.Latitude,
 		Longitude: city.Location.Longitude,
+		Latitude:  city.Location.Latitude,
+		City:      city.City.Names["en"],
+		Country:   city.Country.IsoCode,
+		Continent: city.Continent.Code,
 	}
 }
+
+type loggingResponseWriter struct {
+	http.ResponseWriter
+	statusCode int
+}
+
+func NewLoggingResponseWriter(w http.ResponseWriter) *loggingResponseWriter {
+	return &loggingResponseWriter{w, http.StatusOK}
+}
+
+func (lrw *loggingResponseWriter) WriteHeader(code int) {
+	lrw.statusCode = code
+	lrw.ResponseWriter.WriteHeader(code)
+}
--- a/cmd/strelaypoolsrv/stats.go
+++ b/cmd/strelaypoolsrv/stats.go
@@ -0,0 +1,259 @@
+// Copyright (C) 2018 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).
+
+package main
+
+import (
+	"encoding/json"
+	"net"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/syncthing/syncthing/lib/sync"
+)
+
+func init() {
+	processCollectorOpts := prometheus.ProcessCollectorOpts{
+		Namespace: "syncthing_relaypoolsrv",
+		PidFn: func() (int, error) {
+			return os.Getpid(), nil
+		},
+	}
+
+	prometheus.MustRegister(
+		prometheus.NewProcessCollector(processCollectorOpts),
+	)
+}
+
+var (
+	statusClient = http.Client{
+		Timeout: 5 * time.Second,
+	}
+
+	apiRequestsTotal   = makeCounter("api_requests_total", "Number of API requests.", "type", "result")
+	apiRequestsSeconds = makeSummary("api_requests_seconds", "Latency of API requests.", "type")
+
+	relayTestsTotal         = makeCounter("tests_total", "Number of relay tests.", "result")
+	relayTestActionsSeconds = makeSummary("test_actions_seconds", "Latency of relay test actions.", "type")
+
+	locationLookupSeconds = makeSummary("location_lookup_seconds", "Latency of location lookups.").WithLabelValues()
+
+	metricsRequestsSeconds = makeSummary("metrics_requests_seconds", "Latency of metric requests.").WithLabelValues()
+	scrapeSeconds          = makeSummary("relay_scrape_seconds", "Latency of metric scrapes from remote relays.", "result")
+
+	relayUptime             = makeGauge("relay_uptime", "Uptime of relay", "relay")
+	relayPendingSessionKeys = makeGauge("relay_pending_session_keys", "Number of pending session keys (two keys per session, one per each side of the connection)", "relay")
+	relayActiveSessions     = makeGauge("relay_active_sessions", "Number of sessions that are happening, a session contains two parties", "relay")
+	relayConnections        = makeGauge("relay_connections", "Number of devices connected to the relay", "relay")
+	relayProxies            = makeGauge("relay_proxies", "Number of active proxy routines sending data between peers (two proxies per session, one for each way)", "relay")
+	relayBytesProxied       = makeGauge("relay_bytes_proxied", "Number of bytes proxied by the relay", "relay")
+	relayGoRoutines         = makeGauge("relay_go_routines", "Number of Go routines in the process", "relay")
+	relaySessionRate        = makeGauge("relay_session_rate", "Rate applied per session", "relay")
+	relayGlobalRate         = makeGauge("relay_global_rate", "Global rate applied on the whole relay", "relay")
+	relayBuildInfo          = makeGauge("relay_build_info", "Build information about a relay", "relay", "go_version", "go_os", "go_arch")
+	relayLocationInfo       = makeGauge("relay_location_info", "Location information about a relay", "relay", "city", "country", "continent")
+
+	lastStats = make(map[string]stats)
+)
+
+func makeGauge(name string, help string, labels ...string) *prometheus.GaugeVec {
+	gauge := prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: "syncthing",
+			Subsystem: "relaypoolsrv",
+			Name:      name,
+			Help:      help,
+		},
+		labels,
+	)
+	prometheus.MustRegister(gauge)
+	return gauge
+}
+
+func makeSummary(name string, help string, labels ...string) *prometheus.SummaryVec {
+	summary := prometheus.NewSummaryVec(
+		prometheus.SummaryOpts{
+			Namespace:  "syncthing",
+			Subsystem:  "relaypoolsrv",
+			Name:       name,
+			Help:       help,
+			Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+		},
+		labels,
+	)
+	prometheus.MustRegister(summary)
+	return summary
+}
+
+func makeCounter(name string, help string, labels ...string) *prometheus.CounterVec {
+	counter := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "syncthing",
+			Subsystem: "relaypoolsrv",
+			Name:      name,
+			Help:      help,
+		},
+		labels,
+	)
+	prometheus.MustRegister(counter)
+	return counter
+}
+
+func statsRefresher(interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	for range ticker.C {
+		refreshStats()
+	}
+}
+
+type statsFetchResult struct {
+	relay *relay
+	stats *stats
+}
+
+func refreshStats() {
+	mut.RLock()
+	relays := append(permanentRelays, knownRelays...)
+	mut.RUnlock()
+
+	now := time.Now()
+	wg := sync.NewWaitGroup()
+
+	results := make(chan statsFetchResult, len(relays))
+	for _, rel := range relays {
+		wg.Add(1)
+		go func(rel *relay) {
+			t0 := time.Now()
+			stats := fetchStats(rel)
+			duration := time.Now().Sub(t0).Seconds()
+			result := "success"
+			if stats == nil {
+				result = "failed"
+			}
+			scrapeSeconds.WithLabelValues(result).Observe(duration)
+
+			results <- statsFetchResult{
+				relay: rel,
+				stats: fetchStats(rel),
+			}
+			wg.Done()
+		}(rel)
+	}
+
+	wg.Wait()
+	close(results)
+
+	mut.Lock()
+	relayBuildInfo.Reset()
+	relayLocationInfo.Reset()
+	for result := range results {
+		result.relay.StatsRetrieved = now
+		result.relay.Stats = result.stats
+		if result.stats == nil {
+			deleteMetrics(result.relay.uri.Host)
+		} else {
+			updateMetrics(result.relay.uri.Host, *result.stats, result.relay.Location)
+		}
+	}
+	mut.Unlock()
+}
+
+func fetchStats(relay *relay) *stats {
+	statusAddr := relay.uri.Query().Get("statusAddr")
+	if statusAddr == "" {
+		statusAddr = ":22070"
+	}
+
+	statusHost, statusPort, err := net.SplitHostPort(statusAddr)
+	if err != nil {
+		return nil
+	}
+
+	if statusHost == "" {
+		if host, _, err := net.SplitHostPort(relay.uri.Host); err != nil {
+			return nil
+		} else {
+			statusHost = host
+		}
+	}
+
+	url := "http://" + net.JoinHostPort(statusHost, statusPort) + "/status"
+
+	response, err := statusClient.Get(url)
+	if err != nil {
+		return nil
+	}
+
+	var stats stats
+
+	if json.NewDecoder(response.Body).Decode(&stats); err != nil {
+		return nil
+	}
+	return &stats
+}
+
+func updateMetrics(host string, stats stats, location location) {
+	if stats.GoVersion != "" || stats.GoOS != "" || stats.GoArch != "" {
+		relayBuildInfo.WithLabelValues(host, stats.GoVersion, stats.GoOS, stats.GoArch).Add(1)
+	}
+	if location.City != "" || location.Country != "" || location.Continent != "" {
+		relayLocationInfo.WithLabelValues(host, location.City, location.Country, location.Continent).Add(1)
+	}
+
+	if lastStat, ok := lastStats[host]; ok {
+		stats = mergeStats(stats, lastStat)
+	}
+
+	relayUptime.WithLabelValues(host).Set(float64(stats.UptimeSeconds))
+	relayPendingSessionKeys.WithLabelValues(host).Set(float64(stats.PendingSessionKeys))
+	relayActiveSessions.WithLabelValues(host).Set(float64(stats.ActiveSessions))
+	relayConnections.WithLabelValues(host).Set(float64(stats.Connections))
+	relayProxies.WithLabelValues(host).Set(float64(stats.Proxies))
+	relayBytesProxied.WithLabelValues(host).Set(float64(stats.BytesProxied))
+	relayGoRoutines.WithLabelValues(host).Set(float64(stats.GoRoutines))
+	relaySessionRate.WithLabelValues(host).Set(float64(stats.Options.SessionRate))
+	relayGlobalRate.WithLabelValues(host).Set(float64(stats.Options.GlobalRate))
+	lastStats[host] = stats
+}
+
+func deleteMetrics(host string) {
+	relayUptime.DeleteLabelValues(host)
+	relayPendingSessionKeys.DeleteLabelValues(host)
+	relayActiveSessions.DeleteLabelValues(host)
+	relayConnections.DeleteLabelValues(host)
+	relayProxies.DeleteLabelValues(host)
+	relayBytesProxied.DeleteLabelValues(host)
+	relayGoRoutines.DeleteLabelValues(host)
+	relaySessionRate.DeleteLabelValues(host)
+	relayGlobalRate.DeleteLabelValues(host)
+	delete(lastStats, host)
+}
+
+// Due to some unexplainable behaviour, some of the numbers sometimes travel slightly backwards (by less than 1%)
+// This happens between scrapes, which is 30s, so this can't be a race.
+// This causes prometheus to assume a "rate reset", hence causes phenomenal spikes.
+// One of the number that moves backwards is BytesProxied, which atomically increments a counter with numeric value
+// returned by net.Conn.Read(). I don't think that can return a negative value, so I have no idea what's going on.
+func mergeStats(new stats, old stats) stats {
+	new.UptimeSeconds = mergeValue(new.UptimeSeconds, old.UptimeSeconds)
+	new.PendingSessionKeys = mergeValue(new.PendingSessionKeys, old.PendingSessionKeys)
+	new.ActiveSessions = mergeValue(new.ActiveSessions, old.ActiveSessions)
+	new.Connections = mergeValue(new.Connections, old.Connections)
+	new.Proxies = mergeValue(new.Proxies, old.Proxies)
+	new.BytesProxied = mergeValue(new.BytesProxied, old.BytesProxied)
+	new.GoRoutines = mergeValue(new.GoRoutines, old.GoRoutines)
+	new.Options.SessionRate = mergeValue(new.Options.SessionRate, old.Options.SessionRate)
+	new.Options.GlobalRate = mergeValue(new.Options.GlobalRate, old.Options.GlobalRate)
+	return new
+}
+
+func mergeValue(new, old int) int {
+	if new >= old {
+		return new // normal increase
+	}
+	if float64(new) > 0.99*float64(old) {
+		return old // slight backward movement
+	}
+	return new // reset (relay restart)
+}
--- a/cmd/strelaypoolsrv/stats_test.go
+++ b/cmd/strelaypoolsrv/stats_test.go
@@ -0,0 +1,21 @@
+// Copyright (C) 2015 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).
+
+package main
+
+import (
+	"testing"
+)
+
+func TestMerge(t *testing.T) {
+	if mergeValue(1001, 1000) != 1001 {
+		t.Error("the computer says no")
+	}
+
+	if mergeValue(999, 1000) != 1000 {
+		t.Error("the computer says no")
+	}
+
+	if mergeValue(1, 1000) != 1 {
+		t.Error("the computer says no")
+	}
+}
--- a/cmd/strelaysrv/README.md
+++ b/cmd/strelaysrv/README.md
@@ -1,28 +1,20 @@
 strelaysrv
 ==========

-[![Latest Build](http://img.shields.io/jenkins/s/http/build.syncthing.net/strelaysrv.svg?style=flat-square)](http://build.syncthing.net/job/strelaysrv/lastBuild/)
-
 This is the relay server for the `syncthing` project.

-To get it, run `go get github.com/syncthing/syncthing/cmd/strelaysrv` or download the
-[latest build](http://build.syncthing.net/job/strelaysrv/lastSuccessfulBuild/artifact/)
-from the build server.
-
 :exclamation:Warnings:exclamation: - Read or regret
 -----

-By default, all relay servers will join the default public relay pool, which means that the relay server will be availble for public use, and **will consume your bandwidth** helping others to connect.
+By default, all relay servers will join to the default public relay pool, which means that the relay server will be available for public use, and **will consume your bandwidth** helping others to connect.

-If you wish to disable this behaviour, please specify `-pools=""` argument.
+If you wish to disable this behaviour, please specify the `-pools=""` argument.

 Please note that `strelaysrv` is only usable by `syncthing` **version v0.12 and onwards**.

-To run `strelaysrv` you need to have port 22067 available to the internet, which means you might need to allow it through your firewall if you **have a public IP, or setup a port-forwarding** (22067 to 22067) if you are behind a router.
+To run `strelaysrv` you need to have port 22067 available to the internet, which means you might need to port forward it and/or allow it through your firewall.

-Furthermore, **by default strelaysrv will also expose a /status HTTP endpoint on port 22070**, which is used by the pool servers to peek at metrics of the strelaysrv, such as what are the current transfer rates, how many clients are connected, etc, etc. If you wish this information to be available, similarlly you might want to allow it through your firewall, or port-forward it (22070 to 22070) on your NAT device.
-
-This is **not mandatory** for the strelaysrv to function, and is used only to gather metrics and present them in the overview page of the pool server, displaying stats about the specific relay.
+Furthermore, by default `strelaysrv` will also expose a /status HTTP endpoint on port 22070, which is used by the pool servers to read metrics of the `strelaysrv`, such as  the current transfer rates, how many clients are connected, etc. If you wish this information to be available you may need to port forward and allow it through your firewall. This is not mandatory for the `strelaysrv` to function, and is used only to gather metrics and present them in the overview page of the pool server.

 At the point of writing the endpoint output looks as follows:

@@ -66,7 +58,7 @@ If you wish to disable the /status endpoint, provide `-status-srv=""` as one of

 Running for public use
 ----
-Make sure you have a public IP with port 22067 open, or make sure you have port-forwarding (22067 to 22067) if you are behind a router.
+Make sure you have a public IP with port 22067 open, or have forwarded port 22067 if you are behind a NAT.

 Run the `strelaysrv` with no arguments (or `-debug` if you want more output), and that should be enough for the server to join the public relay pool.
 You should see a message saying:
@@ -79,37 +71,37 @@ See `strelaysrv -help` for other options, such as rate limits, timeout intervals
 Running for private use
 -----

-Once you've started the `strelaysrv`, it will generate a key pair and print an URI:
+Once you've started the `strelaysrv`, it will generate a key pair and print a URI:
 ```bash
 relay://:22067/?id=EZQOIDM-6DDD4ZI-DJ65NSM-4OQWRAT-EIKSMJO-OZ552BO-WQZEGYY-STS5RQM&pingInterval=1m0s&networkTimeout=2m0s&sessionLimitBps=0&globalLimitBps=0&statusAddr=:22070
 ```

-This URI contains partial address of the relay server, as well as it's options which in the future may be taken into account when choosing the best suitable relay out of multiple available.
+This URI contains a partial address of the relay server, as well as its options which in the future may be taken into account when choosing the most suitable relay.

-Because `-listen` option was not used, the `strelaysrv` does not know it's external IP, therefore you should replace the host part of the URI with your public IP address on which the `strelaysrv` will be available:
+Because the `-listen` option was not used `strelaysrv` does not know its external IP, therefore you should replace the host part of the URI with your public IP address on which the `strelaysrv` will be available:

 ```bash
-relay://123.123.123.123:22067/?id=EZQOIDM-6DDD4ZI-DJ65NSM-4OQWRAT-EIKSMJO-OZ552BO-WQZEGYY-STS5RQM&pingInterval=1m0s&networkTimeout=2m0s&sessionLimitBps=0&globalLimitBps=0&statusAddr=:22070
+relay://192.0.2.1:22067/?id=EZQOIDM-6DDD4ZI-DJ65NSM-4OQWRAT-EIKSMJO-OZ552BO-WQZEGYY-STS5RQM&pingInterval=1m0s&networkTimeout=2m0s&sessionLimitBps=0&globalLimitBps=0&statusAddr=:22070
 ```

 If you do not care about certificate pinning (improved security) or do not care about passing verbose settings to the clients, you can shorten the URL to just the host part:

 ```bash
-relay://123.123.123.123:22067
+relay://192.0.2.1:22067
 ```

-This URI can then be used in `syncthing` as one of the relay servers.
+This URI can then be used in `syncthing` clients as one of the relay servers by adding the URI to the "Sync Protocol Listen Address" field, under Actions and Settings.

 See `strelaysrv -help` for other options, such as rate limits, timeout intervals, etc.

 Other items available in this repo
 ----
 ##### testutil
-A test utility which can be used to test connectivity of a relay server.
-You need to generate two x509 key pairs (key.pem and cert.pem), one for the client, another one for the server, in separate directories.
+A test utility which can be used to test the connectivity of a relay server.
+You need to generate two x509 key pairs (key.pem and cert.pem), one for the client and one for the server, in separate directories.
 Afterwards, start the client:
 ```bash
-./testutil -relay="relay://uri.of.relay" -keys=certs/client/ -join
+./testutil -relay="relay://192.0.2.1:22067" -keys=certs/client/ -join
 ```

 This prints out the client ID:
@@ -120,7 +112,7 @@ This prints out the client ID:
 In the other terminal run the following:

 ```bash
- ./testutil -relay="relay://uri.of.relay" -keys=certs/server/ -connect=BG2C5ZA-W7XPFDO-LH222Z6-65F3HJX-ADFTGRT-3SBFIGM-KV26O2Q-E5RMRQ2
+ ./testutil -relay="relay://192.0.2.1:22067" -keys=certs/server/ -connect=BG2C5ZA-W7XPFDO-LH222Z6-65F3HJX-ADFTGRT-3SBFIGM-KV26O2Q-E5RMRQ2
 ```

 Which should then give you an interactive prompt, where you can type things in one terminal, and they get relayed to the other terminal.
@@ -137,5 +129,3 @@ Relay related libraries used by this repo
 Only used by the testutil.

 [Available here](https://github.com/syncthing/syncthing/tree/master/lib/relay/client)
-
-
--- a/cmd/strelaysrv/listener.go
+++ b/cmd/strelaysrv/listener.go
@@ -59,6 +59,13 @@ func listener(proto, addr string, config *tls.Config) {

 func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
 	conn := tls.Server(tcpConn, config)
+	if err := conn.SetDeadline(time.Now().Add(messageTimeout)); err != nil {
+		if debug {
+			log.Println("Weird error setting deadline:", err, "on", conn.RemoteAddr())
+		}
+		conn.Close()
+		return
+	}
 	err := conn.Handshake()
 	if err != nil {
 		if debug {
@@ -81,6 +88,7 @@ func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
 		conn.Close()
 		return
 	}
+	conn.SetDeadline(time.Time{})

 	id := syncthingprotocol.NewDeviceID(certs[0].Raw)

@@ -96,7 +104,9 @@ func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
 	go messageReader(conn, messages, errors)

 	pingTicker := time.NewTicker(pingInterval)
+	defer pingTicker.Stop()
 	timeoutTicker := time.NewTimer(networkTimeout)
+	defer timeoutTicker.Stop()
 	joined := false

 	for {
@@ -172,7 +182,7 @@ func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
 					if debug {
 						log.Println("Sent invitation from", id, "to", requestedPeer)
 					}
-				default:
+				case <-time.After(time.Second):
 					if debug {
 						log.Println("Could not send invitation from", id, "to", requestedPeer, "as peer disconnected")
 					}
@@ -204,7 +214,6 @@ func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
 			if debug {
 				log.Printf("Closing connection %s: %s", id, err)
 			}
-			close(outbox)

 			// Potentially closing a second time.
 			conn.Close()
@@ -260,10 +269,6 @@ func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
 			conn.Close()

 		case msg := <-outbox:
-			if msg == nil {
-				conn.Close()
-				return
-			}
 			if debug {
 				log.Printf("Sending message %T to %s", msg, id)
 			}
@@ -282,6 +287,7 @@ func sessionConnectionHandler(conn net.Conn) {
 		if debug {
 			log.Println("Weird error setting deadline:", err, "on", conn.RemoteAddr())
 		}
+		conn.Close()
 		return
 	}

--- a/cmd/strelaysrv/main.go
+++ b/cmd/strelaysrv/main.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"net/http"
 	"net/url"
 	"os"
 	"os/signal"
@@ -19,10 +20,10 @@ import (
 	"syscall"
 	"time"

-	"github.com/juju/ratelimit"
 	"github.com/syncthing/syncthing/lib/osutil"
 	"github.com/syncthing/syncthing/lib/relay/protocol"
 	"github.com/syncthing/syncthing/lib/tlsutil"
+	"golang.org/x/time/rate"

 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/nat"
@@ -53,7 +54,6 @@ func init() {
 var (
 	listen string
 	debug  bool
-	proto  string

 	sessionAddress []byte
 	sessionPort    uint16
@@ -64,12 +64,13 @@ var (

 	limitCheckTimer *time.Timer

-	sessionLimitBps int
-	globalLimitBps  int
-	overLimit       int32
-	descriptorLimit int64
-	sessionLimiter  *ratelimit.Bucket
-	globalLimiter   *ratelimit.Bucket
+	sessionLimitBps   int
+	globalLimitBps    int
+	overLimit         int32
+	descriptorLimit   int64
+	sessionLimiter    *rate.Limiter
+	globalLimiter     *rate.Limiter
+	networkBufferSize int

 	statusAddr       string
 	poolAddrs        string
@@ -81,8 +82,16 @@ var (
 	natLease   int
 	natRenewal int
 	natTimeout int
+
+	pprofEnabled bool
 )

+// httpClient is the HTTP client we use for outbound requests. It has a
+// timeout and may get further options set during initialization.
+var httpClient = &http.Client{
+	Timeout: 30 * time.Second,
+}
+
 func main() {
 	log.SetFlags(log.Lshortfile | log.LstdFlags)

@@ -105,6 +114,8 @@ func main() {
 	flag.IntVar(&natLease, "nat-lease", 60, "NAT lease length in minutes")
 	flag.IntVar(&natRenewal, "nat-renewal", 30, "NAT renewal frequency in minutes")
 	flag.IntVar(&natTimeout, "nat-timeout", 10, "NAT discovery timeout in seconds")
+	flag.BoolVar(&pprofEnabled, "pprof", false, "Enable the built in profiling on the status server")
+	flag.IntVar(&networkBufferSize, "network-buffer", 2048, "Network buffer size (two of these per proxied connection)")
 	flag.Parse()

 	if extAddress == "" {
@@ -120,6 +131,21 @@ func main() {
 		log.Fatal(err)
 	}

+	laddr, err := net.ResolveTCPAddr(proto, listen)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if laddr.IP != nil && !laddr.IP.IsUnspecified() {
+		// We bind to a specific address. Our outgoing HTTP requests should
+		// also come from that address.
+		laddr.Port = 0
+		boundDialer := &net.Dialer{LocalAddr: laddr}
+		httpClient.Transport = &http.Transport{
+			DialContext: boundDialer.DialContext,
+		}
+	}
+
 	log.Println(LongVersion)

 	maxDescriptors, err := osutil.MaximizeOpenFileLimit()
@@ -140,7 +166,7 @@ func main() {
 	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
 	if err != nil {
 		log.Println("Failed to load keypair. Generating one, this might take a while...")
-		cert, err = tlsutil.NewCertificate(certFile, keyFile, "strelaysrv", 3072)
+		cert, err = tlsutil.NewCertificate(certFile, keyFile, "strelaysrv")
 		if err != nil {
 			log.Fatalln("Failed to generate X509 key pair:", err)
 		}
@@ -200,10 +226,10 @@ func main() {
 	}

 	if sessionLimitBps > 0 {
-		sessionLimiter = ratelimit.NewBucketWithRate(float64(sessionLimitBps), int64(2*sessionLimitBps))
+		sessionLimiter = rate.NewLimiter(rate.Limit(sessionLimitBps), 2*sessionLimitBps)
 	}
 	if globalLimitBps > 0 {
-		globalLimiter = ratelimit.NewBucketWithRate(float64(globalLimitBps), int64(2*globalLimitBps))
+		globalLimiter = rate.NewLimiter(rate.Limit(globalLimitBps), 2*globalLimitBps)
 	}

 	if statusAddr != "" {
--- a/cmd/strelaysrv/pool.go
+++ b/cmd/strelaysrv/pool.go
@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"io/ioutil"
 	"log"
-	"net/http"
 	"net/url"
 	"time"
 )
@@ -27,7 +26,7 @@ func poolHandler(pool string, uri *url.URL, mapping mapping) {
 			uriCopy.String(),
 		})

-		resp, err := http.Post(pool, "application/json", &b)
+		resp, err := httpClient.Post(pool, "application/json", &b)
 		if err != nil {
 			log.Println("Error joining pool", pool, err)
 		} else if resp.StatusCode == 500 {
--- a/cmd/strelaysrv/session.go
+++ b/cmd/strelaysrv/session.go
@@ -7,15 +7,16 @@ import (
 	"encoding/hex"
 	"fmt"
 	"log"
+	"math"
 	"net"
 	"sync"
 	"sync/atomic"
 	"time"

-	"github.com/juju/ratelimit"
-	"github.com/syncthing/syncthing/lib/relay/protocol"
+	"golang.org/x/time/rate"

 	syncthingprotocol "github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/lib/relay/protocol"
 )

 var (
@@ -26,7 +27,7 @@ var (
 	bytesProxied    int64
 )

-func newSession(serverid, clientid syncthingprotocol.DeviceID, sessionRateLimit, globalRateLimit *ratelimit.Bucket) *session {
+func newSession(serverid, clientid syncthingprotocol.DeviceID, sessionRateLimit, globalRateLimit *rate.Limiter) *session {
 	serverkey := make([]byte, 32)
 	_, err := rand.Read(serverkey)
 	if err != nil {
@@ -108,7 +109,7 @@ type session struct {
 	clientkey []byte
 	clientid  syncthingprotocol.DeviceID

-	rateLimit func(bytes int64)
+	rateLimit func(bytes int)

 	connsChan chan net.Conn
 	conns     []net.Conn
@@ -188,7 +189,7 @@ done:
 	// We can end up here in 3 cases:
 	// 1. Timeout joining, in which case there are potentially entries in pendingSessions
 	// 2. General session end/timeout, in which case there are entries in activeSessions
-	// 3. Protocol handler calls dropSession as one of it's clients disconnects.
+	// 3. Protocol handler calls dropSession as one of its clients disconnects.

 	sessionMut.Lock()
 	delete(pendingSessions, string(s.serverkey))
@@ -216,7 +217,7 @@ done:
 func (s *session) GetClientInvitationMessage() protocol.SessionInvitation {
 	return protocol.SessionInvitation{
 		From:         s.serverid[:],
-		Key:          []byte(s.clientkey),
+		Key:          s.clientkey,
 		Address:      sessionAddress,
 		Port:         sessionPort,
 		ServerSocket: false,
@@ -226,7 +227,7 @@ func (s *session) GetClientInvitationMessage() protocol.SessionInvitation {
 func (s *session) GetServerInvitationMessage() protocol.SessionInvitation {
 	return protocol.SessionInvitation{
 		From:         s.clientid[:],
-		Key:          []byte(s.serverkey),
+		Key:          s.serverkey,
 		Address:      sessionAddress,
 		Port:         sessionPort,
 		ServerSocket: true,
@@ -253,7 +254,7 @@ func (s *session) proxy(c1, c2 net.Conn) error {
 	atomic.AddInt64(&numProxies, 1)
 	defer atomic.AddInt64(&numProxies, -1)

-	buf := make([]byte, 65536)
+	buf := make([]byte, networkBufferSize)
 	for {
 		c1.SetReadDeadline(time.Now().Add(networkTimeout))
 		n, err := c1.Read(buf)
@@ -268,7 +269,7 @@ func (s *session) proxy(c1, c2 net.Conn) error {
 		}

 		if s.rateLimit != nil {
-			s.rateLimit(int64(n))
+			s.rateLimit(n)
 		}

 		c2.SetWriteDeadline(time.Now().Add(networkTimeout))
@@ -283,7 +284,7 @@ func (s *session) String() string {
 	return fmt.Sprintf("<%s/%s>", hex.EncodeToString(s.clientkey)[:5], hex.EncodeToString(s.serverkey)[:5])
 }

-func makeRateLimitFunc(sessionRateLimit, globalRateLimit *ratelimit.Bucket) func(int64) {
+func makeRateLimitFunc(sessionRateLimit, globalRateLimit *rate.Limiter) func(int) {
 	// This may be a case of super duper premature optimization... We build an
 	// optimized function to do the rate limiting here based on what we need
 	// to do and then use it in the loop.
@@ -298,29 +299,55 @@ func makeRateLimitFunc(sessionRateLimit, globalRateLimit *ratelimit.Bucket) func

 	if sessionRateLimit == nil {
 		// We only have a global limiter
-		return func(bytes int64) {
-			globalRateLimit.Wait(bytes)
+		return func(bytes int) {
+			take(bytes, globalRateLimit)
 		}
 	}

 	if globalRateLimit == nil {
 		// We only have a session limiter
-		return func(bytes int64) {
-			sessionRateLimit.Wait(bytes)
+		return func(bytes int) {
+			take(bytes, sessionRateLimit)
 		}
 	}

 	// We have both. Queue the bytes on both the global and session specific
-	// rate limiters. Wait for both in parallell, so that the actual send
-	// happens when both conditions are satisfied. In practice this just means
-	// wait the longer of the two times.
-	return func(bytes int64) {
-		t0 := sessionRateLimit.Take(bytes)
-		t1 := globalRateLimit.Take(bytes)
-		if t0 > t1 {
-			time.Sleep(t0)
-		} else {
-			time.Sleep(t1)
-		}
+	// rate limiters.
+	return func(bytes int) {
+		take(bytes, sessionRateLimit, globalRateLimit)
+	}
+}
+
+// take is a utility function to consume tokens from a set of rate.Limiters.
+// Tokens are consumed in parallel on all limiters, respecting their
+// individual burst sizes.
+func take(tokens int, ls ...*rate.Limiter) {
+	// minBurst is the smallest burst size supported by all limiters.
+	minBurst := int(math.MaxInt32)
+	for _, l := range ls {
+		if burst := l.Burst(); burst < minBurst {
+			minBurst = burst
+		}
+	}
+
+	for tokens > 0 {
+		// chunk is how many tokens we can consume at a time
+		chunk := tokens
+		if chunk > minBurst {
+			chunk = minBurst
+		}
+
+		// maxDelay is the longest delay mandated by any of the limiters for
+		// the chosen chunk size.
+		var maxDelay time.Duration
+		for _, l := range ls {
+			res := l.ReserveN(time.Now(), chunk)
+			if del := res.Delay(); del > maxDelay {
+				maxDelay = del
+			}
+		}
+
+		time.Sleep(maxDelay)
+		tokens -= chunk
 	}
 }
--- a/cmd/strelaysrv/status.go
+++ b/cmd/strelaysrv/status.go
@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"log"
 	"net/http"
+	"net/http/pprof"
 	"runtime"
 	"sync/atomic"
 	"time"
@@ -16,8 +17,19 @@ var rc *rateCalculator
 func statusService(addr string) {
 	rc = newRateCalculator(360, 10*time.Second, &bytesProxied)

-	http.HandleFunc("/status", getStatus)
-	if err := http.ListenAndServe(addr, nil); err != nil {
+	handler := http.NewServeMux()
+	handler.HandleFunc("/status", getStatus)
+	if pprofEnabled {
+		handler.HandleFunc("/debug/pprof/", pprof.Index)
+	}
+
+	srv := http.Server{
+		Addr:        addr,
+		Handler:     handler,
+		ReadTimeout: 15 * time.Second,
+	}
+	srv.SetKeepAlivesEnabled(false)
+	if err := srv.ListenAndServe(); err != nil {
 		log.Fatal(err)
 	}
 }
@@ -28,6 +40,10 @@ func getStatus(w http.ResponseWriter, r *http.Request) {

 	sessionMut.Lock()
 	// This can potentially be double the number of pending sessions, as each session has two keys, one for each side.
+	status["version"] = Version
+	status["buildHost"] = BuildHost
+	status["buildUser"] = BuildUser
+	status["buildDate"] = BuildDate
 	status["startTime"] = rc.startTime
 	status["uptimeSeconds"] = time.Since(rc.startTime) / time.Second
 	status["numPendingSessionKeys"] = len(pendingSessions)
@@ -42,7 +58,7 @@ func getStatus(w http.ResponseWriter, r *http.Request) {
 	status["goMaxProcs"] = runtime.GOMAXPROCS(-1)
 	status["goNumRoutine"] = runtime.NumGoroutine()
 	status["kbps10s1m5m15m30m60m"] = []int64{
-		rc.rate(10/10) * 8 / 1000,
+		rc.rate(1) * 8 / 1000, // each interval is 10s
 		rc.rate(60/10) * 8 / 1000,
 		rc.rate(5*60/10) * 8 / 1000,
 		rc.rate(15*60/10) * 8 / 1000,
--- a/cmd/stsigtool/main.go
+++ b/cmd/stsigtool/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -24,7 +24,7 @@ func main() {
 	flag.Parse()

 	if flag.NArg() < 1 {
-		log.Println(`Usage:
+		log.Print(`Usage:
 	stsigtool <command>

 Where command is one of:
@@ -40,6 +40,7 @@ Where command is one of:

 	verify <signaturefile> <datafile> <pubkeyfile>
 		- verify a signature, using the specified public key file
+
 `)
 	}

--- a/cmd/stvanity/main.go
+++ b/cmd/stvanity/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/stwatchfile/main.go
+++ b/cmd/stwatchfile/main.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/syncthing/auditservice.go
+++ b/cmd/syncthing/auditservice.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/syncthing/auditservice_test.go
+++ b/cmd/syncthing/auditservice_test.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -20,13 +20,13 @@ func TestAuditService(t *testing.T) {
 	service := newAuditService(buf)

 	// Event sent before start, will not be logged
-	events.Default.Log(events.Ping, "the first event")
+	events.Default.Log(events.ConfigSaved, "the first event")

 	go service.Serve()
 	service.WaitForStart()

 	// Event that should end up in the audit log
-	events.Default.Log(events.Ping, "the second event")
+	events.Default.Log(events.ConfigSaved, "the second event")

 	// We need to give the events time to arrive, since the channels are buffered etc.
 	time.Sleep(10 * time.Millisecond)
@@ -35,7 +35,7 @@ func TestAuditService(t *testing.T) {
 	service.WaitForStop()

 	// This event should not be logged, since we have stopped.
-	events.Default.Log(events.Ping, "the third event")
+	events.Default.Log(events.ConfigSaved, "the third event")

 	result := string(buf.Bytes())
 	t.Log(result)
--- a/cmd/syncthing/blockprof.go
+++ b/cmd/syncthing/blockprof.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/syncthing/buildtag_noupgrade.go
+++ b/cmd/syncthing/buildtag_noupgrade.go
@@ -0,0 +1,13 @@
+// Copyright (C) 2017 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//+build noupgrade
+
+package main
+
+func init() {
+	BuildTags = append(BuildTags, "noupgrade")
+}
--- a/cmd/syncthing/buildtag_race.go
+++ b/cmd/syncthing/buildtag_race.go
@@ -0,0 +1,13 @@
+// Copyright (C) 2017 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//+build race
+
+package main
+
+func init() {
+	BuildTags = append(BuildTags, "race")
+}
--- a/cmd/syncthing/cpuusage.go
+++ b/cmd/syncthing/cpuusage.go
@@ -0,0 +1,59 @@
+// Copyright (C) 2017 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"math"
+	"time"
+
+	metrics "github.com/rcrowley/go-metrics"
+)
+
+const cpuTickRate = 5 * time.Second
+
+type cpuService struct {
+	avg  metrics.EWMA
+	stop chan struct{}
+}
+
+func newCPUService() *cpuService {
+	return &cpuService{
+		// 10 second average. Magic alpha value comes from looking at EWMA package
+		// definitions of EWMA1, EWMA5. The tick rate *must* be five seconds (hard
+		// coded in the EWMA package).
+		avg:  metrics.NewEWMA(1 - math.Exp(-float64(cpuTickRate)/float64(time.Second)/10.0)),
+		stop: make(chan struct{}),
+	}
+}
+
+func (s *cpuService) Serve() {
+	// Initialize prevUsage to an actual value returned by cpuUsage
+	// instead of zero, because at least Windows returns a huge negative
+	// number here that then slowly increments...
+	prevUsage := cpuUsage()
+	ticker := time.NewTicker(cpuTickRate)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			curUsage := cpuUsage()
+			s.avg.Update(int64((curUsage - prevUsage) / time.Millisecond))
+			prevUsage = curUsage
+			s.avg.Tick()
+		case <-s.stop:
+			return
+		}
+	}
+}
+
+func (s *cpuService) Stop() {
+	close(s.stop)
+}
+
+func (s *cpuService) Rate() float64 {
+	return s.avg.Rate()
+}
--- a/cmd/syncthing/cpuusage_solaris.go
+++ b/cmd/syncthing/cpuusage_solaris.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 //+build solaris

@@ -59,40 +59,20 @@ type prusage_t struct {

 }

-func solarisPrusage(pid int, rusage *prusage_t) error {
-	fd, err := os.Open(fmt.Sprintf("/proc/%d/usage", pid))
+var procFile = fmt.Sprintf("/proc/%d/usage", os.Getpid())
+
+func cpuUsage() time.Duration {
+	fd, err := os.Open(procFile)
 	if err != nil {
-		return err
+		return 0
 	}
+
+	var rusage prusage_t
 	err = binary.Read(fd, binary.LittleEndian, rusage)
 	fd.Close()
-	return err
-}
-
-func init() {
-	go trackCPUUsage()
-}
-
-func trackCPUUsage() {
-	var prevUsage int64
-	var prevTime = time.Now().UnixNano()
-	var rusage prusage_t
-	var pid = os.Getpid()
-	for range time.NewTicker(time.Second).C {
-		err := solarisPrusage(pid, &rusage)
-		if err != nil {
-			l.Warnln("getting prusage:", err)
-			continue
-		}
-		curTime := time.Now().UnixNano()
-		timeDiff := curTime - prevTime
-		curUsage := rusage.Pr_utime.Nano() + rusage.Pr_stime.Nano()
-		usageDiff := curUsage - prevUsage
-		cpuUsageLock.Lock()
-		copy(cpuUsagePercent[1:], cpuUsagePercent[0:])
-		cpuUsagePercent[0] = 100 * float64(usageDiff) / float64(timeDiff)
-		cpuUsageLock.Unlock()
-		prevTime = curTime
-		prevUsage = curUsage
+	if err != nil {
+		return 0
 	}
+
+	return time.Duration(rusage.Pr_utime.Nano() + rusage.Pr_stime.Nano())
 }
--- a/cmd/syncthing/cpuusage_unix.go
+++ b/cmd/syncthing/cpuusage_unix.go
@@ -0,0 +1,18 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//+build !windows,!solaris
+
+package main
+
+import "syscall"
+import "time"
+
+func cpuUsage() time.Duration {
+	var rusage syscall.Rusage
+	syscall.Getrusage(syscall.RUSAGE_SELF, &rusage)
+	return time.Duration(rusage.Utime.Nano() + rusage.Stime.Nano())
+}
--- a/cmd/syncthing/cpuusage_windows.go
+++ b/cmd/syncthing/cpuusage_windows.go
@@ -0,0 +1,27 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+//+build windows
+
+package main
+
+import "syscall"
+import "time"
+
+func cpuUsage() time.Duration {
+	handle, err := syscall.GetCurrentProcess()
+	if err != nil {
+		return 0
+	}
+	defer syscall.CloseHandle(handle)
+
+	var ctime, etime, ktime, utime syscall.Filetime
+	if err := syscall.GetProcessTimes(handle, &ctime, &etime, &ktime, &utime); err != nil {
+		return 0
+	}
+
+	return time.Duration(ktime.Nanoseconds() + utime.Nanoseconds())
+}
--- a/cmd/syncthing/debug.go
+++ b/cmd/syncthing/debug.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/syncthing/gui.go
+++ b/cmd/syncthing/gui.go
--- a/cmd/syncthing/gui_auth.go
+++ b/cmd/syncthing/gui_auth.go
@@ -2,13 +2,15 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

 import (
 	"bytes"
+	"crypto/tls"
 	"encoding/base64"
+	"fmt"
 	"net/http"
 	"strings"
 	"time"
@@ -18,6 +20,7 @@ import (
 	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/sync"
 	"golang.org/x/crypto/bcrypt"
+	"gopkg.in/ldap.v2"
 )

 var (
@@ -32,9 +35,9 @@ func emitLoginAttempt(success bool, username string) {
 	})
 }

-func basicAuthAndSessionMiddleware(cookieName string, cfg config.GUIConfiguration, next http.Handler) http.Handler {
+func basicAuthAndSessionMiddleware(cookieName string, guiCfg config.GUIConfiguration, ldapCfg config.LDAPConfiguration, next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if cfg.IsValidAPIKey(r.Header.Get("X-API-Key")) {
+		if guiCfg.IsValidAPIKey(r.Header.Get("X-API-Key")) {
 			next.ServeHTTP(w, r)
 			return
 		}
@@ -77,42 +80,26 @@ func basicAuthAndSessionMiddleware(cookieName string, cfg config.GUIConfiguratio
 			return
 		}

-		// Check if the username is correct, assuming it was sent as UTF-8
+		authOk := false
 		username := string(fields[0])
-		if username == cfg.User {
-			goto usernameOK
+		password := string(fields[1])
+
+		authOk = auth(username, password, guiCfg, ldapCfg)
+		if !authOk {
+			usernameIso := string(iso88591ToUTF8([]byte(username)))
+			passwordIso := string(iso88591ToUTF8([]byte(password)))
+			authOk = auth(usernameIso, passwordIso, guiCfg, ldapCfg)
+			if authOk {
+				username = usernameIso
+			}
 		}

-		// ... check it again, converting it from assumed ISO-8859-1 to UTF-8
-		username = string(iso88591ToUTF8(fields[0]))
-		if username == cfg.User {
-			goto usernameOK
+		if !authOk {
+			emitLoginAttempt(false, username)
+			error()
+			return
 		}

-		// Neither of the possible interpretations match the configured username
-		emitLoginAttempt(false, username)
-		error()
-		return
-
-	usernameOK:
-		// Check password as given (assumes UTF-8 encoding)
-		password := fields[1]
-		if err := bcrypt.CompareHashAndPassword([]byte(cfg.Password), password); err == nil {
-			goto passwordOK
-		}
-
-		// ... check it again, converting it from assumed ISO-8859-1 to UTF-8
-		password = iso88591ToUTF8(password)
-		if err := bcrypt.CompareHashAndPassword([]byte(cfg.Password), password); err == nil {
-			goto passwordOK
-		}
-
-		// Neither of the attempts to verify the password checked out
-		emitLoginAttempt(false, username)
-		error()
-		return
-
-	passwordOK:
 		sessionid := rand.String(32)
 		sessionsMut.Lock()
 		sessions[sessionid] = true
@@ -128,6 +115,54 @@ func basicAuthAndSessionMiddleware(cookieName string, cfg config.GUIConfiguratio
 	})
 }

+func auth(username string, password string, guiCfg config.GUIConfiguration, ldapCfg config.LDAPConfiguration) bool {
+	if guiCfg.AuthMode == config.AuthModeLDAP {
+		return authLDAP(username, password, ldapCfg)
+	} else {
+		return authStatic(username, password, guiCfg.User, guiCfg.Password)
+	}
+}
+
+func authStatic(username string, password string, configUser string, configPassword string) bool {
+	configPasswordBytes := []byte(configPassword)
+	passwordBytes := []byte(password)
+	return bcrypt.CompareHashAndPassword(configPasswordBytes, passwordBytes) == nil && username == configUser
+}
+
+func authLDAP(username string, password string, cfg config.LDAPConfiguration) bool {
+	address := cfg.Address
+	var connection *ldap.Conn
+	var err error
+	if cfg.Transport == config.LDAPTransportTLS {
+		connection, err = ldap.DialTLS("tcp", address, &tls.Config{InsecureSkipVerify: cfg.InsecureSkipVerify})
+	} else {
+		connection, err = ldap.Dial("tcp", address)
+	}
+
+	if err != nil {
+		l.Warnln("LDAP Dial:", err)
+		return false
+	}
+
+	if cfg.Transport == config.LDAPTransportStartTLS {
+		err = connection.StartTLS(&tls.Config{InsecureSkipVerify: cfg.InsecureSkipVerify})
+		if err != nil {
+			l.Warnln("LDAP Start TLS:", err)
+			return false
+		}
+	}
+
+	defer connection.Close()
+
+	err = connection.Bind(fmt.Sprintf(cfg.BindDN, username), password)
+	if err != nil {
+		l.Warnln("LDAP Bind:", err)
+		return false
+	}
+
+	return true
+}
+
 // Convert an ISO-8859-1 encoded byte string to UTF-8. Works by the
 // principle that ISO-8859-1 bytes are equivalent to unicode code points,
 // that a rune slice is a list of code points, and that stringifying a slice
--- a/cmd/syncthing/gui_auth_test.go
+++ b/cmd/syncthing/gui_auth_test.go
@@ -0,0 +1,40 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"testing"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+var passwordHashBytes []byte
+
+func init() {
+	passwordHashBytes, _ = bcrypt.GenerateFromPassword([]byte("pass"), 0)
+}
+
+func TestStaticAuthOK(t *testing.T) {
+	ok := authStatic("user", "pass", "user", string(passwordHashBytes))
+	if !ok {
+		t.Fatalf("should pass auth")
+	}
+}
+
+func TestSimpleAuthUsernameFail(t *testing.T) {
+	ok := authStatic("userWRONG", "pass", "user", string(passwordHashBytes))
+	if ok {
+		t.Fatalf("should fail auth")
+	}
+}
+
+func TestStaticAuthPasswordFail(t *testing.T) {
+	ok := authStatic("user", "passWRONG", "user", string(passwordHashBytes))
+	if ok {
+		t.Fatalf("should fail auth")
+	}
+}
--- a/cmd/syncthing/gui_csrf.go
+++ b/cmd/syncthing/gui_csrf.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -37,6 +37,9 @@ func csrfMiddleware(unique string, prefix string, cfg config.GUIConfiguration, n
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		// Allow requests carrying a valid API key
 		if cfg.IsValidAPIKey(r.Header.Get("X-API-Key")) {
+			// Set the access-control-allow-origin header for CORS requests
+			// since a valid API key has been provided
+			w.Header().Add("Access-Control-Allow-Origin", "*")
 			next.ServeHTTP(w, r)
 			return
 		}
@@ -113,7 +116,7 @@ func saveCsrfTokens() {
 	// nothing relevant we can do about them anyway...

 	name := locations[locCsrfTokens]
-	f, err := osutil.CreateAtomic(name, 0600)
+	f, err := osutil.CreateAtomic(name)
 	if err != nil {
 		return
 	}
--- a/cmd/syncthing/gui_statics.go
+++ b/cmd/syncthing/gui_statics.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -16,6 +16,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"

 	"github.com/syncthing/syncthing/lib/auto"
 	"github.com/syncthing/syncthing/lib/config"
@@ -71,6 +72,8 @@ func (s *staticsServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }

 func (s *staticsServer) serveAsset(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+
 	file := r.URL.Path

 	if file[0] == '/' {
@@ -89,6 +92,10 @@ func (s *staticsServer) serveAsset(w http.ResponseWriter, r *http.Request) {
 	if s.assetDir != "" {
 		p := filepath.Join(s.assetDir, theme, filepath.FromSlash(file))
 		if _, err := os.Stat(p); err == nil {
+			mtype := s.mimeTypeForFile(file)
+			if len(mtype) != 0 {
+				w.Header().Set("Content-Type", mtype)
+			}
 			http.ServeFile(w, r, p)
 			return
 		}
@@ -101,6 +108,10 @@ func (s *staticsServer) serveAsset(w http.ResponseWriter, r *http.Request) {
 		if s.assetDir != "" {
 			p := filepath.Join(s.assetDir, config.DefaultTheme, filepath.FromSlash(file))
 			if _, err := os.Stat(p); err == nil {
+				mtype := s.mimeTypeForFile(file)
+				if len(mtype) != 0 {
+					w.Header().Set("Content-Type", mtype)
+				}
 				http.ServeFile(w, r, p)
 				return
 			}
@@ -114,6 +125,26 @@ func (s *staticsServer) serveAsset(w http.ResponseWriter, r *http.Request) {
 		}
 	}

+	etag := fmt.Sprintf("%d", auto.Generated)
+	modified := time.Unix(auto.Generated, 0).UTC()
+
+	w.Header().Set("Last-Modified", modified.Format(http.TimeFormat))
+	w.Header().Set("Etag", etag)
+
+	if t, err := time.Parse(http.TimeFormat, r.Header.Get("If-Modified-Since")); err == nil {
+		if modified.Equal(t) || modified.Before(t) {
+			w.WriteHeader(http.StatusNotModified)
+			return
+		}
+	}
+
+	if match := r.Header.Get("If-None-Match"); match != "" {
+		if strings.Contains(match, etag) {
+			w.WriteHeader(http.StatusNotModified)
+			return
+		}
+	}
+
 	mtype := s.mimeTypeForFile(file)
 	if len(mtype) != 0 {
 		w.Header().Set("Content-Type", mtype)
@@ -141,17 +172,17 @@ func (s *staticsServer) serveThemes(w http.ResponseWriter, r *http.Request) {
 func (s *staticsServer) mimeTypeForFile(file string) string {
 	// We use a built in table of the common types since the system
 	// TypeByExtension might be unreliable. But if we don't know, we delegate
-	// to the system.
+	// to the system. All our files are UTF-8.
 	ext := filepath.Ext(file)
 	switch ext {
 	case ".htm", ".html":
-		return "text/html"
+		return "text/html; charset=utf-8"
 	case ".css":
-		return "text/css"
+		return "text/css; charset=utf-8"
 	case ".js":
-		return "application/javascript"
+		return "application/javascript; charset=utf-8"
 	case ".json":
-		return "application/json"
+		return "application/json; charset=utf-8"
 	case ".png":
 		return "image/png"
 	case ".ttf":
@@ -159,7 +190,7 @@ func (s *staticsServer) mimeTypeForFile(file string) string {
 	case ".woff":
 		return "application/x-font-woff"
 	case ".svg":
-		return "image/svg+xml"
+		return "image/svg+xml; charset=utf-8"
 	default:
 		return mime.TypeByExtension(ext)
 	}
--- a/cmd/syncthing/gui_test.go
+++ b/cmd/syncthing/gui_test.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -16,6 +16,8 @@ import (
 	"net"
 	"net/http"
 	"net/http/httptest"
+	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"testing"
@@ -23,6 +25,8 @@ import (

 	"github.com/d4l3k/messagediff"
 	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/events"
+	"github.com/syncthing/syncthing/lib/fs"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/thejerf/suture"
@@ -70,10 +74,12 @@ func TestStopAfterBrokenConfig(t *testing.T) {
 	}
 	w := config.Wrap("/dev/null", cfg)

-	srv := newAPIService(protocol.LocalDeviceID, w, "../../test/h1/https-cert.pem", "../../test/h1/https-key.pem", "", nil, nil, nil, nil, nil, nil)
+	srv := newAPIService(protocol.LocalDeviceID, w, "../../test/h1/https-cert.pem", "../../test/h1/https-key.pem", "", nil, nil, nil, nil, nil, nil, nil, nil)
 	srv.started = make(chan string)

-	sup := suture.NewSimple("test")
+	sup := suture.New("test", suture.Spec{
+		PassThroughPanics: true,
+	})
 	sup.Add(srv)
 	sup.ServeBackground()

@@ -469,19 +475,23 @@ func startHTTP(cfg *mockedConfig) (string, error) {
 	httpsKeyFile := "../../test/h1/https-key.pem"
 	assetDir := "../../gui"
 	eventSub := new(mockedEventSub)
+	diskEventSub := new(mockedEventSub)
 	discoverer := new(mockedCachingMux)
 	connections := new(mockedConnections)
 	errorLog := new(mockedLoggerRecorder)
 	systemLog := new(mockedLoggerRecorder)
+	cpu := new(mockedCPUService)
 	addrChan := make(chan string)

 	// Instantiate the API service
 	svc := newAPIService(protocol.LocalDeviceID, cfg, httpsCertFile, httpsKeyFile, assetDir, model,
-		eventSub, discoverer, connections, errorLog, systemLog)
+		eventSub, diskEventSub, discoverer, connections, errorLog, systemLog, cpu)
 	svc.started = addrChan

 	// Actually start the API service
-	supervisor := suture.NewSimple("API test")
+	supervisor := suture.New("API test", suture.Spec{
+		PassThroughPanics: true,
+	})
 	supervisor.Add(svc)
 	supervisor.ServeBackground()

@@ -506,6 +516,9 @@ func TestCSRFRequired(t *testing.T) {
 	cfg := new(mockedConfig)
 	cfg.gui.APIKey = testAPIKey
 	baseURL, err := startHTTP(cfg)
+	if err != nil {
+		t.Fatal("Unexpected error from getting base URL:", err)
+	}

 	cli := &http.Client{
 		Timeout: time.Second,
@@ -832,15 +845,25 @@ func TestAddressIsLocalhost(t *testing.T) {
 	}{
 		// These are all valid localhost addresses
 		{"localhost", true},
+		{"LOCALHOST", true},
+		{"localhost.", true},
 		{"::1", true},
 		{"127.0.0.1", true},
+		{"127.23.45.56", true},
 		{"localhost:8080", true},
+		{"LOCALHOST:8000", true},
+		{"localhost.:8080", true},
 		{"[::1]:8080", true},
 		{"127.0.0.1:8080", true},
+		{"127.23.45.56:8080", true},

 		// These are all non-localhost addresses
 		{"example.com", false},
 		{"example.com:8080", false},
+		{"localhost.com", false},
+		{"localhost.com:8080", false},
+		{"www.localhost", false},
+		{"www.localhost:8080", false},
 		{"192.0.2.10", false},
 		{"192.0.2.10:8080", false},
 		{"0.0.0.0", false},
@@ -857,3 +880,179 @@ func TestAddressIsLocalhost(t *testing.T) {
 		}
 	}
 }
+
+func TestAccessControlAllowOriginHeader(t *testing.T) {
+	const testAPIKey = "foobarbaz"
+	cfg := new(mockedConfig)
+	cfg.gui.APIKey = testAPIKey
+	baseURL, err := startHTTP(cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cli := &http.Client{
+		Timeout: time.Second,
+	}
+
+	req, _ := http.NewRequest("GET", baseURL+"/rest/system/status", nil)
+	req.Header.Set("X-API-Key", testAPIKey)
+	resp, err := cli.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		t.Fatal("GET on /rest/system/status should succeed, not", resp.Status)
+	}
+	if resp.Header.Get("Access-Control-Allow-Origin") != "*" {
+		t.Fatal("GET on /rest/system/status should return a 'Access-Control-Allow-Origin: *' header")
+	}
+}
+
+func TestOptionsRequest(t *testing.T) {
+	const testAPIKey = "foobarbaz"
+	cfg := new(mockedConfig)
+	cfg.gui.APIKey = testAPIKey
+	baseURL, err := startHTTP(cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cli := &http.Client{
+		Timeout: time.Second,
+	}
+
+	req, _ := http.NewRequest("OPTIONS", baseURL+"/rest/system/status", nil)
+	resp, err := cli.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	resp.Body.Close()
+	if resp.StatusCode != http.StatusNoContent {
+		t.Fatal("OPTIONS on /rest/system/status should succeed, not", resp.Status)
+	}
+	if resp.Header.Get("Access-Control-Allow-Origin") != "*" {
+		t.Fatal("OPTIONS on /rest/system/status should return a 'Access-Control-Allow-Origin: *' header")
+	}
+	if resp.Header.Get("Access-Control-Allow-Methods") != "GET, POST" {
+		t.Fatal("OPTIONS on /rest/system/status should return a 'Access-Control-Allow-Methods: GET, POST' header")
+	}
+	if resp.Header.Get("Access-Control-Allow-Headers") != "Content-Type, X-API-Key" {
+		t.Fatal("OPTIONS on /rest/system/status should return a 'Access-Control-Allow-Headers: Content-Type, X-API-KEY' header")
+	}
+}
+
+func TestEventMasks(t *testing.T) {
+	cfg := new(mockedConfig)
+	defSub := new(mockedEventSub)
+	diskSub := new(mockedEventSub)
+	svc := newAPIService(protocol.LocalDeviceID, cfg, "", "", "", nil, defSub, diskSub, nil, nil, nil, nil, nil)
+
+	if mask := svc.getEventMask(""); mask != defaultEventMask {
+		t.Errorf("incorrect default mask %x != %x", int64(mask), int64(defaultEventMask))
+	}
+
+	expected := events.FolderSummary | events.LocalChangeDetected
+	if mask := svc.getEventMask("FolderSummary,LocalChangeDetected"); mask != expected {
+		t.Errorf("incorrect parsed mask %x != %x", int64(mask), int64(expected))
+	}
+
+	expected = 0
+	if mask := svc.getEventMask("WeirdEvent,something else that doesn't exist"); mask != expected {
+		t.Errorf("incorrect parsed mask %x != %x", int64(mask), int64(expected))
+	}
+
+	if res := svc.getEventSub(defaultEventMask); res != defSub {
+		t.Errorf("should have returned the given default event sub")
+	}
+	if res := svc.getEventSub(diskEventMask); res != diskSub {
+		t.Errorf("should have returned the given disk event sub")
+	}
+	if res := svc.getEventSub(events.LocalIndexUpdated); res == nil || res == defSub || res == diskSub {
+		t.Errorf("should have returned a valid, non-default event sub")
+	}
+}
+
+func TestBrowse(t *testing.T) {
+	pathSep := string(os.PathSeparator)
+
+	tmpDir, err := ioutil.TempDir("", "syncthing")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	if err := os.Mkdir(filepath.Join(tmpDir, "dir"), 0755); err != nil {
+		t.Fatal(err)
+	}
+	if err := ioutil.WriteFile(filepath.Join(tmpDir, "file"), []byte("hello"), 0644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(filepath.Join(tmpDir, "MiXEDCase"), 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	// We expect completion to return the full path to the completed
+	// directory, with an ending slash.
+	dirPath := filepath.Join(tmpDir, "dir") + pathSep
+	mixedCaseDirPath := filepath.Join(tmpDir, "MiXEDCase") + pathSep
+
+	cases := []struct {
+		current string
+		returns []string
+	}{
+		// The direcotory without slash is completed to one with slash.
+		{tmpDir, []string{tmpDir + pathSep}},
+		// With slash it's completed to its contents.
+		// Dirs are given pathSeps.
+		// Files are not returned.
+		{tmpDir + pathSep, []string{mixedCaseDirPath, dirPath}},
+		// Globbing is automatic based on prefix.
+		{tmpDir + pathSep + "d", []string{dirPath}},
+		{tmpDir + pathSep + "di", []string{dirPath}},
+		{tmpDir + pathSep + "dir", []string{dirPath}},
+		{tmpDir + pathSep + "f", nil},
+		{tmpDir + pathSep + "q", nil},
+		// Globbing is case-insensitve
+		{tmpDir + pathSep + "mixed", []string{mixedCaseDirPath}},
+	}
+
+	for _, tc := range cases {
+		ret := browseFiles(tc.current, fs.FilesystemTypeBasic)
+		if !equalStrings(ret, tc.returns) {
+			t.Errorf("browseFiles(%q) => %q, expected %q", tc.current, ret, tc.returns)
+		}
+	}
+}
+
+func TestPrefixMatch(t *testing.T) {
+	cases := []struct {
+		s        string
+		prefix   string
+		expected int
+	}{
+		{"aaaA", "aaa", matchExact},
+		{"AAAX", "BBB", noMatch},
+		{"AAAX", "aAa", matchCaseIns},
+		{"äÜX", "äü", matchCaseIns},
+	}
+
+	for _, tc := range cases {
+		ret := checkPrefixMatch(tc.s, tc.prefix)
+		if ret != tc.expected {
+			t.Errorf("checkPrefixMatch(%q, %q) => %v, expected %v", tc.s, tc.prefix, ret, tc.expected)
+		}
+	}
+}
+
+func equalStrings(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}
--- a/cmd/syncthing/gui_unix.go
+++ b/cmd/syncthing/gui_unix.go
@@ -1,37 +0,0 @@
-// Copyright (C) 2014 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
-
-//+build !windows,!solaris
-
-package main
-
-import (
-	"syscall"
-	"time"
-)
-
-func init() {
-	go trackCPUUsage()
-}
-
-func trackCPUUsage() {
-	var prevUsage int64
-	var prevTime = time.Now().UnixNano()
-	var rusage syscall.Rusage
-	for range time.NewTicker(time.Second).C {
-		syscall.Getrusage(syscall.RUSAGE_SELF, &rusage)
-		curTime := time.Now().UnixNano()
-		timeDiff := curTime - prevTime
-		curUsage := rusage.Utime.Nano() + rusage.Stime.Nano()
-		usageDiff := curUsage - prevUsage
-		cpuUsageLock.Lock()
-		copy(cpuUsagePercent[1:], cpuUsagePercent[0:])
-		cpuUsagePercent[0] = 100 * float64(usageDiff) / float64(timeDiff)
-		cpuUsageLock.Unlock()
-		prevTime = curTime
-		prevUsage = curUsage
-	}
-}
--- a/cmd/syncthing/gui_windows.go
+++ b/cmd/syncthing/gui_windows.go
@@ -1,58 +0,0 @@
-// Copyright (C) 2014 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
-
-//+build windows
-
-package main
-
-import (
-	"syscall"
-	"time"
-)
-
-func init() {
-	go trackCPUUsage()
-}
-
-func trackCPUUsage() {
-	handle, err := syscall.GetCurrentProcess()
-	if err != nil {
-		l.Warnln("Cannot track CPU usage:", err)
-		return
-	}
-
-	var ctime, etime, ktime, utime syscall.Filetime
-	err = syscall.GetProcessTimes(handle, &ctime, &etime, &ktime, &utime)
-	if err != nil {
-		l.Warnln("Cannot track CPU usage:", err)
-		return
-	}
-
-	prevTime := ctime.Nanoseconds()
-	prevUsage := ktime.Nanoseconds() + utime.Nanoseconds() // Always overflows
-
-	for range time.NewTicker(time.Second).C {
-		err := syscall.GetProcessTimes(handle, &ctime, &etime, &ktime, &utime)
-		if err != nil {
-			continue
-		}
-
-		curTime := time.Now().UnixNano()
-		timeDiff := curTime - prevTime
-		// This is sometimes 0, no clue why.
-		if timeDiff == 0 {
-			continue
-		}
-		curUsage := ktime.Nanoseconds() + utime.Nanoseconds()
-		usageDiff := curUsage - prevUsage
-		cpuUsageLock.Lock()
-		copy(cpuUsagePercent[1:], cpuUsagePercent[0:])
-		cpuUsagePercent[0] = 100 * float64(usageDiff) / float64(timeDiff)
-		cpuUsageLock.Unlock()
-		prevTime = curTime
-		prevUsage = curUsage
-	}
-}
--- a/cmd/syncthing/heapprof.go
+++ b/cmd/syncthing/heapprof.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/syncthing/locations.go
+++ b/cmd/syncthing/locations.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

@@ -13,7 +13,7 @@ import (
 	"strings"
 	"time"

-	"github.com/syncthing/syncthing/lib/osutil"
+	"github.com/syncthing/syncthing/lib/fs"
 )

 type locationEnum string
@@ -65,7 +65,7 @@ func expandLocations() error {
 			dir = strings.Replace(dir, "${"+varName+"}", value, -1)
 		}
 		var err error
-		dir, err = osutil.ExpandTilde(dir)
+		dir, err = fs.ExpandTilde(dir)
 		if err != nil {
 			return err
 		}
@@ -86,7 +86,7 @@ func defaultConfigDir() string {
 		return filepath.Join(os.Getenv("AppData"), "Syncthing")

 	case "darwin":
-		dir, err := osutil.ExpandTilde("~/Library/Application Support/Syncthing")
+		dir, err := fs.ExpandTilde("~/Library/Application Support/Syncthing")
 		if err != nil {
 			l.Fatalln(err)
 		}
@@ -96,7 +96,7 @@ func defaultConfigDir() string {
 		if xdgCfg := os.Getenv("XDG_CONFIG_HOME"); xdgCfg != "" {
 			return filepath.Join(xdgCfg, "syncthing")
 		}
-		dir, err := osutil.ExpandTilde("~/.config/syncthing")
+		dir, err := fs.ExpandTilde("~/.config/syncthing")
 		if err != nil {
 			l.Fatalln(err)
 		}
@@ -106,7 +106,7 @@ func defaultConfigDir() string {

 // homeDir returns the user's home directory, or dies trying.
 func homeDir() string {
-	home, err := osutil.ExpandTilde("~")
+	home, err := fs.ExpandTilde("~")
 	if err != nil {
 		l.Fatalln(err)
 	}
--- a/cmd/syncthing/main.go
+++ b/cmd/syncthing/main.go
--- a/cmd/syncthing/main_test.go
+++ b/cmd/syncthing/main_test.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/cmd/syncthing/memsize_darwin.go
+++ b/cmd/syncthing/memsize_darwin.go
@@ -2,7 +2,7 @@
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at http://mozilla.org/MPL/2.0/.
+// You can obtain one at https://mozilla.org/MPL/2.0/.

 package main

--- a/Show More
+++ b/Show More