lib/scanner: Less strict validation (fixes #6827 ) (#6828 )

This fixes the change in #6674 where the weak hash became a deciding factor. Now we again just use it to accept a block, but don't take a negative as meaning the block is bad.
gui: Fix auto dismissing auth notification (ref #6536 )
2025-12-24 06:28:10 -05:00 · 2020-07-11 20:17:41 +02:00 · 2020-06-08 08:29:55 +02:00 · 2020-06-08 08:14:50 +02:00 · 2020-06-08 08:12:06 +02:00 · 2020-06-07 20:29:53 +02:00
2649 changed files with 109720 additions and 1093752 deletions
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -0,0 +1,5 @@
+coverage:
+  range: "40...100"
+
+ignore:
+  - "**.pb.go"
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -0,0 +1,2 @@
+/AUTHORS    @calmh
+/*.md       @calmh
--- a/.github/ISSUE_TEMPLATE/01-feature.md
+++ b/.github/ISSUE_TEMPLATE/01-feature.md
@@ -0,0 +1,13 @@
+---
+name: Feature request
+about: If you're just not sure how to do something, see "ask a question".
+labels: enhancement, needs-triage
+---
+
+### Include required information
+
+Please be sure to include at least:
+
+ - what problem your new feature would solve
+ - how or why you think it is generally useful (i.e., not just for you)
+ - what alternatives or workarounds you considered
--- a/.github/ISSUE_TEMPLATE/02-bug.md
+++ b/.github/ISSUE_TEMPLATE/02-bug.md
@@ -0,0 +1,23 @@
+---
+name: Bug report
+about: If you're actually looking for support, see "ask a question".
+labels: bug, needs-triage
+---
+
+### 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`.
+
+### Include required information
+
+Please be sure to include at least:
+
+ - which version of Syncthing and what operating system you are using
+ - browser and version, if applicable
+ - what happened,
+ - what you expected to happen instead, and
+ - any steps to reproduce the problem.
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Ask a question
+    url: https://forum.syncthing.net/
+    about: Ask questions, get support, and discuss with other community members.
+  - name: Android issues
+    url: https://github.com/syncthing/syncthing-android/issues/
+    about: The Android app has its own issue tracker.
--- 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/.github/SECURITY.md
+++ b/.github/SECURITY.md
@@ -0,0 +1,10 @@
+## Reporting a Vulnerability
+
+If you believe that you've found a Syncthing-related security vulnerability,
+please report it by sending email to the address security@syncthing.net. The
+[PGP key for security@syncthing.net
+(B683AD7B76CAB013)](https://syncthing.net/security-key.txt) can be used to
+send encrypted mail or to verify responses received from that address.
+
+You can read more about Syncthing security at
+https://syncthing.net/security/.
--- a/.gitignore
+++ b/.gitignore
@@ -15,5 +15,5 @@ coverage.xml
 syncthing.sig
 RELEASE
 deb
-lib/auto/gui.files.go
-snapcraft.yaml
+*.bz2
+/repos
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -0,0 +1,26 @@
+linters-settings:
+  maligned:
+    suggest-new: true
+
+linters:
+  enable-all: true
+  disable:
+    - goimports
+    - depguard
+    - lll
+    - gochecknoinits
+    - gochecknoglobals
+    - gofmt
+    - scopelint
+    - gocyclo
+    - funlen
+    - wsl
+    - gocognit
+    - godox
+
+service:
+  golangci-lint-version: 1.21.x
+  prepare:
+    - rm -f go.sum # 1.12 -> 1.13 issues with QUIC-go
+    - GO111MODULE=on go mod vendor
+    - go run build.go assets
--- a/.mailmap
+++ b/.mailmap
@@ -1 +0,0 @@
-NICKS
--- a/160
+++ b/160
@@ -1,111 +1,249 @@
 # 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 (ProactiveServices) <aD@simplypeachy.co.uk> <simplypeachy@users.noreply.github.com> <ProactiveServices@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>
+Alan Pope <alan@popey.com>
+Alberto Donato <albertodonato@users.noreply.github.com>
 Alessandro G. (alessandro.g89) <alessandro.g89@gmail.com>
+Alex Xu <alex.hello71@gmail.com>
 Alexander Graf (alex2108) <register-github@alex-graf.de>
 Alexandre Viau (aviau) <alexandre@alexandreviau.net> <aviau@debian.org>
+Aman Gupta <aman@tmm1.net>
 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>
+André Colomb (acolomb) <src@andre.colomb.de> <github.com@andre.colomb.de>
+andyleap <andyleap@gmail.com>
+Anjan Momi <anjan@momi.ca>
 Antoine Lamielle (0x010C) <antoine.lamielle@0x010c.fr> <gh@0x010c.fr>
 Antony Male (canton7) <antony.male@gmail.com>
+Aranjedeath <Aranjedeath@users.noreply.github.com>
+Arkadiusz Tymiński <gevleeog@gmail.com>
 Arthur Axel fREW Schmidt (frioux) <frew@afoolishmanifesto.com> <frioux@gmail.com>
-Audrius Butkevicius (AudriusButkevicius) <audrius.butkevicius@gmail.com>
+Artur Zubilewicz <AkaZecik@users.noreply.github.com>
+Audrius Butkevicius (AudriusButkevicius) <audrius.butkevicius@gmail.com> <github@audrius.rocks>
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+Carsten Hagemann (carstenhag) <moter8@gmail.com> <carsten@chagemann.de>
+Cathryne Linenweaver (Cathryne) <cathryne.linenweaver@gmail.com> <Cathryne@users.noreply.github.com> <katrinleinweber@MAC.local>
 Cedric Staniewski (xduugu) <cedric@gmx.ca>
+chenrui <rui@meetup.com>
 Chris Howie (cdhowie) <me@chrishowie.com>
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+Chris Tonkinson <chris@masterbran.ch>
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+Dale Visser <dale.visser@live.com>
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 Jaakko Hannikainen (jgke) <jgke@jgke.fi>
 Jacek Szafarkiewicz (hadogenes) <szafar@linux.pl>
+Jacob <jyundt@gmail.com>
 Jake Peterson (acogdev) <jake@acogdev.com>
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+jelle van der Waa <jelle@vdwaa.nl>
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 Jochen Voss (seehuhn) <voss@seehuhn.de>
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 Johan Vromans (sciurius) <jvromans@squirrel.nl>
+John Rinehart (fuzzybear3965) <johnrichardrinehart@gmail.com>
+Jonas Thelemann <e-mail@jonas-thelemann.de>
+Jonathan <artback@protonmail.com>
+Jonathan Cross <jcross@gmail.com>
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 Karol Różycki (krozycki) <rozycki.karol@gmail.com>
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 Ken'ichi Kamada (kamadak) <kamada@nanohz.org>
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+Kevin Bushiri (keevBush) <keevbush@gmail.com> <36192217+keevBush@users.noreply.github.com>
 Kevin White, Jr. (kwhite17) <kevinwhite1710@gmail.com>
-Kurt Fitzner (Kudalufi) <kurt@va1der.ca>
+klemens <ka7@github.com>
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 Lars K.W. Gohlke (lkwg82) <lkwg82@gmx.de>
+Laurent Arnoud <laurent@spkdev.net>
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+Liu Siyuan (liusy182) <liusy182@gmail.com> <liusy182@hotmail.com>
 Lode Hoste (Zillode) <zillode@zillode.be>
 Lord Landon Agahnim (LordLandon) <lordlandon@gmail.com>
+Lukas Lihotzki <lukas@lihotzki.de>
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 Mark Pulford (mpx) <mark@kyne.com.au>
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+Mateusz Ż <thedead4fun@live.com>
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 Matt Burke (burkemw3) <mburke@amplify.com> <burkemw3@gmail.com>
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 Max Schulze (kralo) <max.schulze@online.de> <kralo@users.noreply.github.com>
+MaximAL <almaximal@ya.ru>
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 Michael Jephcote (Rewt0r) <rewt0r@gmx.com> <Rewt0r@users.noreply.github.com>
 Michael Ploujnikov (plouj) <ploujj@gmail.com>
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 Michael Tilli (pyfisch) <pyfisch@gmail.com>
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 Pascal Jungblut (pascalj) <github@pascalj.com> <mail@pascal-jungblut.com>
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+Phil Davis <phil.davis@inf.org>
 Philippe Schommers (filoozoom) <philippe@schommers.be>
 Phill Luby (pluby) <phill.luby@newredo.com>
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 Roman Zaynetdinov (zaynetro) <romanznet@gmail.com>
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+Sacheendra Talluri (sacheendra) <sacheendra.t@gmail.com>
 Scott Klupfel (kluppy) <kluppy@going2blue.com>
 Sergey Mishin (ralder) <ralder@yandex.ru>
+Shaarad Dalvi <60266155+shaaraddalvi@users.noreply.github.com>
 Simon Frei (imsodin) <freisim93@gmail.com>
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 Stefan Kuntz (Stefan-Code) <stefan.github@gmail.com> <Stefan.github@gmail.com>
-Stefan Tatschner (rumpelsepp) <stefan@sevenbyte.org> <rumpelsepp@sevenbyte.org>
+Stefan Tatschner (rumpelsepp) <stefan@sevenbyte.org> <rumpelsepp@sevenbyte.org> <stefan@rumpelsepp.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>
-Tomas Cerveny (kozec) <kozec@kozec.com>
+Tobias Tom (tobiastom) <t.tom@succont.de>
+Tom Jakubowski <tom@crystae.net>
+Tomasz Wilczyński <5626656+tomasz1986@users.noreply.github.com>
+Tommy Thorn <tommy-github-email@thorn.ws>
 Tully Robinson (tojrobinson) <tully@tojr.org>
 Tyler Brazier (tylerbrazier) <tyler@tylerbrazier.com>
+Tyler Kropp <kropptyler@gmail.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>
+xarx00 <xarx00@users.noreply.github.com>
 Xavier O. (damajor) <damajor@gmail.com>
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 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/29
+++ b/29
@@ -0,0 +1,29 @@
+ARG GOVERSION=latest
+FROM golang:$GOVERSION AS builder
+
+WORKDIR /src
+COPY . .
+
+ENV CGO_ENABLED=0
+ENV BUILD_HOST=syncthing.net
+ENV BUILD_USER=docker
+RUN rm -f syncthing && go run build.go -no-upgrade build syncthing
+
+FROM alpine
+
+EXPOSE 8384 22000 21027/udp
+
+VOLUME ["/var/syncthing"]
+
+RUN apk add --no-cache ca-certificates su-exec tzdata
+
+COPY --from=builder /src/syncthing /bin/syncthing
+COPY --from=builder /src/script/docker-entrypoint.sh /bin/entrypoint.sh
+
+ENV PUID=1000 PGID=1000 HOME=/var/syncthing
+
+HEALTHCHECK --interval=1m --timeout=10s \
+  CMD nc -z 127.0.0.1 8384 || exit 1
+
+ENV STGUIADDRESS=0.0.0.0:8384
+ENTRYPOINT ["/bin/entrypoint.sh", "/bin/syncthing", "-home", "/var/syncthing/config"]
--- a/Dockerfile.builder
+++ b/Dockerfile.builder
@@ -0,0 +1,9 @@
+ARG GOVERSION=latest
+FROM golang:$GOVERSION
+
+# FPM to build Debian packages
+RUN apt-get update && apt-get install -y --no-install-recommends \
+	locales rubygems ruby-dev build-essential git \
+	&& apt-get clean \
+	&& rm -rf /var/lib/apt/lists/* \
+	&& gem install --no-ri --no-rdoc fpm
--- a/Dockerfile.stdiscosrv
+++ b/Dockerfile.stdiscosrv
@@ -0,0 +1,29 @@
+ARG GOVERSION=latest
+FROM golang:$GOVERSION AS builder
+
+WORKDIR /src
+COPY . .
+
+ENV CGO_ENABLED=0
+ENV BUILD_HOST=syncthing.net
+ENV BUILD_USER=docker
+RUN rm -f stdiscosrv && go run build.go -no-upgrade build stdiscosrv
+
+FROM alpine
+
+EXPOSE 19200 8443
+
+VOLUME ["/var/stdiscosrv"]
+
+RUN apk add --no-cache ca-certificates su-exec
+
+COPY --from=builder /src/stdiscosrv /bin/stdiscosrv
+COPY --from=builder /src/script/docker-entrypoint.sh /bin/entrypoint.sh
+
+ENV PUID=1000 PGID=1000 HOME=/var/stdiscosrv
+
+HEALTHCHECK --interval=1m --timeout=10s \
+  CMD nc -z localhost 8443 || exit 1
+
+WORKDIR /var/stdiscosrv
+ENTRYPOINT ["/bin/entrypoint.sh", "/bin/stdiscosrv"]
--- a/Dockerfile.strelaysrv
+++ b/Dockerfile.strelaysrv
@@ -0,0 +1,29 @@
+ARG GOVERSION=latest
+FROM golang:$GOVERSION AS builder
+
+WORKDIR /src
+COPY . .
+
+ENV CGO_ENABLED=0
+ENV BUILD_HOST=syncthing.net
+ENV BUILD_USER=docker
+RUN rm -f strelaysrv && go run build.go -no-upgrade build strelaysrv
+
+FROM alpine
+
+EXPOSE 22067 22070
+
+VOLUME ["/var/strelaysrv"]
+
+RUN apk add --no-cache ca-certificates su-exec
+
+COPY --from=builder /src/strelaysrv /bin/strelaysrv
+COPY --from=builder /src/script/docker-entrypoint.sh /bin/entrypoint.sh
+
+ENV PUID=1000 PGID=1000 HOME=/var/strelaysrv
+
+HEALTHCHECK --interval=1m --timeout=10s \
+  CMD nc -z localhost 22067 || exit 1
+
+WORKDIR /var/strelaysrv
+ENTRYPOINT ["/bin/entrypoint.sh", "/bin/strelaysrv"]
--- a/GOALS.md
+++ b/GOALS.md
@@ -1,6 +1,6 @@
 # The Syncthing Goals

-Syncthing is a **continous file synchronization program**. It synchronizes
+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.
@@ -36,7 +36,7 @@ or modification by unauthorized parties.

 Syncthing should be approachable, understandable and inclusive.

-> Complex concepts and maths form the base of Synchting's functionality.
+> 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.

@@ -80,4 +80,4 @@ conflict with the stated goals above.
 > 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
-> continously strive to align Syncthing more and more with these goals.
+> 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/133
+++ b/133
@@ -1,133 +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>
-adelq <aqalieh95@gmail.com>
-adelq <adelq@users.noreply.github.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>
-benshep <bjashepherd@gmail.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>
-damajor <damajor@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>
-elopio <yo@elopio.net>
-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>
-imsodin <freisim93@gmail.com>
-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>
-Kudalufi <kurt@va1der.ca>
-kwhite17 <kevinwhite1710@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>
-mpx <mark@kyne.com.au>
-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>
-ProactiveServices <aD@simplypeachy.co.uk>
-ProactiveServices <simplypeachy@users.noreply.github.com>
-ProactiveServices <ProactiveServices@users.noreply.github.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>
-Smiley73 <heiko@zuerker.org>
-snnd <dw@risu.io>
-Stefan-Code <stefan.github@gmail.com>
-Stefan-Code <Stefan.github@gmail.com>
-timabell <tim@timwise.co.uk>
-timhowes <timhowes@berkeley.edu>
-tnn2 <tnn@nygren.pp.se>
-tojrobinson <tully@tojr.org>
-tpng <benny.tpng@gmail.com>
-tylerbrazier <tyler@tylerbrazier.com>
-Unrud <unrud@openaliasbox.org>
-Unrud <Unrud@users.noreply.github.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>
-zaynetro <romanznet@gmail.com>
-Zillode <zillode@zillode.be>
-zukoo <fxgsell@gmail.com>
--- a/README-Docker.md
+++ b/README-Docker.md
@@ -0,0 +1,59 @@
+# Docker Container for Syncthing
+
+Use the Dockerfile in this repo, or pull the `syncthing/syncthing` image
+from Docker Hub.
+
+Use the `/var/syncthing` volume to have the synchronized files available on the
+host. 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-sync:/var/syncthing \
+    syncthing/syncthing:latest
+```
+
+## Discovery
+
+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-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.
+
+## GUI Security
+
+By default Syncthing inside the Docker image listens on 0.0.0.0:8384 to
+allow GUI connections via the Docker proxy. This is set by the
+`STGUIADDRESS` environment variable in the Dockerfile, as it differs from
+what Syncthing would otherwise use by default. This means you should set up
+authentication in the GUI, like for any other externally reachable Syncthing
+instance. If you do not require the GUI, or you use host networking, you can
+unset the `STGUIADDRESS` variable to have Syncthing fall back to listening
+on 127.0.0.1:
+
+```
+$ docker pull syncthing/syncthing
+$ docker run -e STGUIADDRESS= \
+    -v /wherever/st-sync:/var/syncthing \
+    syncthing/syncthing:latest
+```
+
+With the environment variable unset Syncthing will follow what is set in the
+configuration file / GUI settings dialog.
--- a/README.md
+++ b/README.md
@@ -1,10 +1,10 @@
-# Syncthing
+[![Syncthing][14]][15]

-[![Latest Linux & Cross Build](https://img.shields.io/jenkins/s/http/build.syncthing.net/syncthing.svg?style=flat-square&label=linux+%26+cross)](http://build.syncthing.net/job/syncthing/lastBuild/)
-[![Latest Windows Build](https://img.shields.io/jenkins/s/http/build.syncthing.net/syncthing-windows.svg?style=flat-square&label=windows)](http://build.syncthing.net/job/syncthing/lastBuild/)
-[![Latest Mac Build](https://img.shields.io/jenkins/s/http/build.syncthing.net/syncthing-mac.svg?style=flat-square&label=mac)](http://build.syncthing.net/job/syncthing/lastBuild/)
-[![Latest Solaris Build](https://img.shields.io/jenkins/s/http/build.syncthing.net/syncthing-solaris.svg?style=flat-square&label=solaris)](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 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)
@@ -19,36 +19,36 @@ commentary, see the full [Goals document][13].

 Syncthing should be:

-1. Safe From Data Loss
+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
+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
+3. **Easy to Use**

   Syncthing should be approachable, understandable and inclusive.

-4. Automatic
+4. **Automatic**

   User interaction should be required only when absolutely necessary.

-5. Universally Available
+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
+6. **For Individuals**

   Syncthing is primarily about empowering the individual user with safe,
   secure and easy to use file synchronization.

-7. Everything Else
+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
@@ -62,6 +62,10 @@ There are a few examples for keeping Syncthing running in the background
 on your system in [the etc directory][3]. There are also several [GUI
 implementations][11] for Windows, Mac and Linux.

+## Docker
+
+To run Syncthing in Docker, see [the Docker README][16].
+
 ## Vote on features/bugs

 We'd like to encourage you to [vote][12] on issues that matter to you.
@@ -86,8 +90,8 @@ 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

@@ -98,7 +102,7 @@ All code is licensed under the [MPLv2 License][7].
 [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
+[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
@@ -108,3 +112,7 @@ All code is licensed under the [MPLv2 License][7].
 [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/
+[16]: https://github.com/syncthing/syncthing/blob/master/README-Docker.md
+
--- a/assets/logo-128.png
+++ b/assets/logo-128.png
--- a/assets/logo-256.png
+++ b/assets/logo-256.png
--- a/assets/logo-32.png
+++ b/assets/logo-32.png
--- a/assets/logo-512.png
+++ b/assets/logo-512.png
--- a/assets/logo-64.png
+++ b/assets/logo-64.png
--- a/assets/logo-text-128.png
+++ b/assets/logo-text-128.png
--- a/assets/logo-text-256.png
+++ b/assets/logo-text-256.png
--- a/assets/logo-text-64.png
+++ b/assets/logo-text-64.png
--- a/assets/logo-wtext.png
+++ b/assets/logo-wtext.png
--- a/assets/logo.ico
+++ b/assets/logo.ico
--- a/assets/logo.pdf
+++ b/assets/logo.pdf
--- a/assets/syncthing_folder_icon.icns
+++ b/assets/syncthing_folder_icon.icns
--- a/build.go
+++ b/build.go
--- a/build.ps1
+++ b/build.ps1
@@ -0,0 +1,20 @@
+function build {
+    go run build.go @args
+}
+
+$cmd, $rest = $args
+switch ($cmd) {
+    "test" {
+        $env:LOGGER_DISCARD=1
+        build test
+    }
+
+    "bench" {
+        $env:LOGGER_DISCARD=1
+        build bench
+    }
+
+    default {
+        build @rest
+    }
+}
--- a/build.sh
+++ b/build.sh
@@ -2,8 +2,6 @@
 set -euo pipefail
 IFS=$'\n\t'

-STTRACE=${STTRACE:-}
-
 script() {
 	name="$1"
 	shift
@@ -15,128 +13,23 @@ build() {
 }

 case "${1:-default}" in
-	default)
-		build
-		;;
-
-	clean)
-		build "$@"
-		;;
-
-	tar)
-		build "$@"
-		;;
-
-	assets)
-		build "$@"
-		;;
-
-	xdr)
-		build "$@"
-		;;
-
-	translate)
-		build "$@"
-		;;
-
-	deb)
-		build "$@"
-		;;
-
-	setup)
-		build "$@"
-		;;
-
 	test)
-		ulimit -t 600 &>/dev/null || true
-		ulimit -d 512000 &>/dev/null || true
-		ulimit -m 512000 &>/dev/null || true
 		LOGGER_DISCARD=1 build test
 		;;

 	bench)
-		LOGGER_DISCARD=1 build bench | script benchfilter
+		LOGGER_DISCARD=1 build bench
 		;;

 	prerelease)
-		go run script/authors.go
+		script authors
 		build transifex
-		git add -A gui/default/assets/ lib/auto/
 		pushd man ; ./refresh.sh ; popd
-		git add -A man
-		;;
-
-	noupgrade)
-		build -no-upgrade tar
-		;;
-
-	all)
-		platforms=(
-			darwin-amd64 dragonfly-amd64 freebsd-amd64 linux-amd64 netbsd-amd64 openbsd-amd64 solaris-amd64 windows-amd64
-			freebsd-386 linux-386 netbsd-386 openbsd-386 windows-386
-			linux-arm linux-arm64 linux-ppc64 linux-ppc64le
-		)
-
-		for plat in "${platforms[@]}"; do
-			echo Building "$plat"
-
-			goos="${plat%-*}"
-			goarch="${plat#*-}"
-			dist="tar"
-
-			if [[ $goos == "windows" ]]; then
-				dist="zip"
-			fi
-
-			build -goos "$goos" -goarch "$goarch" "$dist"
-			echo
-		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
+		git add -A gui man AUTHORS
+		git commit -m 'gui, man, authors: Update docs, translations, and contributors'
 		;;

 	*)
-		echo "Unknown build command $1"
+		build "$@"
 		;;
 esac
--- a/cmd/stbench/main.go
+++ b/cmd/stbench/main.go
@@ -1,143 +0,0 @@
-// Copyright (C) 2016 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/.
-
-// This doesn't build on Windows due to the Rusage stuff.
-
-// +build !windows
-
-package main
-
-import (
-	"flag"
-	"fmt"
-	"log"
-	"runtime"
-	"syscall"
-	"time"
-
-	"github.com/syncthing/syncthing/lib/rc"
-)
-
-var homeDir = "h1"
-var syncthingBin = "./bin/syncthing"
-var test = "scan"
-
-func main() {
-	flag.StringVar(&homeDir, "home", homeDir, "Home directory location")
-	flag.StringVar(&syncthingBin, "bin", syncthingBin, "Binary location")
-	flag.StringVar(&test, "test", test, "Test to run")
-	flag.Parse()
-
-	switch test {
-	case "scan":
-		// scan measures the resource usage required to perform the initial
-		// scan, without cleaning away the database first.
-		testScan()
-	}
-}
-
-// testScan starts a process and reports on the resource usage required to
-// perform the initial scan.
-func testScan() {
-	log.Println("Starting...")
-	p := rc.NewProcess("127.0.0.1:8081")
-	if err := p.Start(syncthingBin, "-home", homeDir, "-no-browser"); err != nil {
-		log.Println(err)
-		return
-	}
-	defer p.Stop()
-
-	wallTime := awaitScanComplete(p)
-
-	report(p, wallTime)
-}
-
-// awaitScanComplete waits for a folder to transition idle->scanning and
-// then scanning->idle and returns the time taken for the scan.
-func awaitScanComplete(p *rc.Process) time.Duration {
-	log.Println("Awaiting scan completion...")
-	var t0, t1 time.Time
-	lastEvent := 0
-loop:
-	for {
-		evs, err := p.Events(lastEvent)
-		if err != nil {
-			continue
-		}
-
-		for _, ev := range evs {
-			if ev.Type == "StateChanged" {
-				data := ev.Data.(map[string]interface{})
-				log.Println(ev)
-
-				if data["to"].(string) == "scanning" {
-					t0 = ev.Time
-					continue
-				}
-
-				if !t0.IsZero() && data["to"].(string) == "idle" {
-					t1 = ev.Time
-					break loop
-				}
-			}
-			lastEvent = ev.ID
-		}
-
-		time.Sleep(250 * time.Millisecond)
-	}
-
-	return t1.Sub(t0)
-}
-
-// report stops the given process and reports on it's 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()
-	if err != nil {
-		log.Println(err)
-		return
-	}
-
-	ss, err := p.SystemStatus()
-	if err != nil {
-		log.Println(err)
-		return
-	}
-
-	proc, err := p.Stop()
-	if err != nil {
-		return
-	}
-
-	rusage, ok := proc.SysUsage().(*syscall.Rusage)
-	if !ok {
-		return
-	}
-
-	log.Println("Version:", sv.Version)
-	log.Println("Alloc:", ss.Alloc/1024, "KiB")
-	log.Println("Sys:", ss.Sys/1024, "KiB")
-	log.Println("Goroutines:", ss.Goroutines)
-	log.Println("Wall time:", wallTime)
-	log.Println("Utime:", time.Duration(rusage.Utime.Nano()))
-	log.Println("Stime:", time.Duration(rusage.Stime.Nano()))
-	if runtime.GOOS == "darwin" {
-		// Darwin reports in bytes, Linux seems to report in KiB even
-		// though the manpage says otherwise.
-		rusage.Maxrss /= 1024
-	}
-	log.Println("MaxRSS:", rusage.Maxrss, "KiB")
-
-	fmt.Printf("%s,%d,%d,%d,%.02f,%.02f,%.02f,%d\n",
-		sv.Version,
-		ss.Alloc/1024,
-		ss.Sys/1024,
-		ss.Goroutines,
-		wallTime.Seconds(),
-		time.Duration(rusage.Utime.Nano()).Seconds(),
-		time.Duration(rusage.Stime.Nano()).Seconds(),
-		rusage.Maxrss)
-}
--- a/cmd/stcli/LICENSE
+++ b/cmd/stcli/LICENSE
@@ -1,19 +0,0 @@
-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
-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/stcli/README.md
+++ b/cmd/stcli/README.md
@@ -1,10 +0,0 @@
-syncthing-cli
-=============
-
-[![Latest Build](http://img.shields.io/jenkins/s/http/build.syncthing.net/syncthing-cli.svg?style=flat-square)](http://build.syncthing.net/job/syncthing-cli/lastBuild/)
-
-A CLI that talks to the Syncthing REST interface.
-
-`go get github.com/syncthing/syncthing-cli`
-
-Or download the [latest build](http://build.syncthing.net/job/syncthing-cli/lastSuccessfulBuild/artifact/).
--- a/cmd/stcli/client.go
+++ b/cmd/stcli/client.go
@@ -1,115 +1,96 @@
-// Copyright (C) 2014 Audrius Butkevičius
+// Copyright (C) 2019 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"
+	"errors"
+	"fmt"
+	"net"
 	"net/http"
 	"strings"

-	"github.com/AudriusButkevicius/cli"
+	"github.com/syncthing/syncthing/lib/config"
 )

 type APIClient struct {
-	httpClient http.Client
-	endpoint   string
-	apikey     string
-	username   string
-	password   string
-	id         string
-	csrf       string
+	http.Client
+	cfg    config.GUIConfiguration
+	apikey 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
-	}
+func getClient(cfg config.GUIConfiguration) *APIClient {
 	httpClient := http.Client{
 		Transport: &http.Transport{
 			TLSClientConfig: &tls.Config{
-				InsecureSkipVerify: c.GlobalBool("insecure"),
+				InsecureSkipVerify: true,
+			},
+			DialContext: func(_ context.Context, _, _ string) (net.Conn, error) {
+				return net.Dial(cfg.Network(), cfg.Address())
 			},
 		},
 	}
-	client := APIClient{
-		httpClient: httpClient,
-		endpoint:   endpoint,
-		apikey:     c.GlobalString("apikey"),
-		username:   c.GlobalString("username"),
-		password:   c.GlobalString("password"),
+	return &APIClient{
+		Client: httpClient,
+		cfg:    cfg,
+		apikey: cfg.APIKey,
 	}
-
-	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)
+func (c *APIClient) Endpoint() string {
+	if c.cfg.Network() == "unix" {
+		return "http://unix/"
 	}
-	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)
+	url := c.cfg.URL()
+	if !strings.HasSuffix(url, "/") {
+		url += "/"
 	}
+	return url
+}

-	response, err := client.httpClient.Do(request)
-	die(err)
+func (c *APIClient) Do(req *http.Request) (*http.Response, error) {
+	req.Header.Set("X-API-Key", c.apikey)
+	resp, err := c.Client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	return resp, checkResponse(resp)
+}

+func (c *APIClient) Get(url string) (*http.Response, error) {
+	request, err := http.NewRequest("GET", c.Endpoint()+"rest/"+url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return c.Do(request)
+}
+
+func (c *APIClient) Post(url, body string) (*http.Response, error) {
+	request, err := http.NewRequest("POST", c.Endpoint()+"rest/"+url, bytes.NewBufferString(body))
+	if err != nil {
+		return nil, err
+	}
+	return c.Do(request)
+}
+
+func checkResponse(response *http.Response) error {
 	if response.StatusCode == 404 {
-		die("Invalid endpoint or API call")
-	} else if response.StatusCode == 401 {
-		die("Invalid username or password")
+		return errors.New("invalid endpoint or API call")
 	} else if response.StatusCode == 403 {
-		if client.apikey == "" {
-			die("Invalid CSRF token")
-		}
-		die("Invalid API key")
+		return errors.New("invalid API key")
 	} else if response.StatusCode != 200 {
-		body := strings.TrimSpace(string(responseToBArray(response)))
-		if body != "" {
-			die(body)
+		data, err := responseToBArray(response)
+		if err != nil {
+			return err
 		}
-		die("Unknown HTTP status returned: " + response.Status)
+		body := strings.TrimSpace(string(data))
+		return fmt.Errorf("unexpected HTTP status returned: %s\n%s", response.Status, body)
 	}
-	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)
+	return nil
 }
--- a/cmd/stcli/cmd_devices.go
+++ b/cmd/stcli/cmd_devices.go
@@ -1,188 +0,0 @@
-// 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
@@ -1,67 +0,0 @@
-// 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["time"].(string)[:19]
-		time = strings.Replace(time, "T", " ", 1)
-		err := item["error"].(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
@@ -1,351 +0,0 @@
-// Copyright (C) 2014 Audrius Butkevičius
-
-package main
-
-import (
-	"fmt"
-	"path/filepath"
-	"strings"
-
-	"github.com/AudriusButkevicius/cli"
-	"github.com/syncthing/syncthing/lib/config"
-)
-
-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)
-		}
-		fmt.Fprintln(writer, "ID:\t", folder.ID, "\t")
-		fmt.Fprintln(writer, "Path:\t", folder.RawPath, "\t(directory)")
-		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],
-		RawPath: filepath.Clean(abs),
-	}
-	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.RawPath)
-		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, 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].RawPath = val
-		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
@@ -1,78 +0,0 @@
-// Copyright (C) 2014 Audrius Butkevičius
-
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-
-	"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:     "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 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
@@ -1,127 +0,0 @@
-// 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
@@ -1,173 +0,0 @@
-// 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
@@ -1,72 +0,0 @@
-// 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/errors.go
+++ b/cmd/stcli/errors.go
@@ -0,0 +1,61 @@
+// Copyright (C) 2019 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 (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/urfave/cli"
+)
+
+var errorsCommand = cli.Command{
+	Name:     "errors",
+	HideHelp: true,
+	Usage:    "Error command group",
+	Subcommands: []cli.Command{
+		{
+			Name:   "show",
+			Usage:  "Show pending errors",
+			Action: expects(0, dumpOutput("system/error")),
+		},
+		{
+			Name:      "push",
+			Usage:     "Push an error to active clients",
+			ArgsUsage: "[error message]",
+			Action:    expects(1, errorsPush),
+		},
+		{
+			Name:   "clear",
+			Usage:  "Clear pending errors",
+			Action: expects(0, emptyPost("system/error/clear")),
+		},
+	},
+}
+
+func errorsPush(c *cli.Context) error {
+	client := c.App.Metadata["client"].(*APIClient)
+	errStr := strings.Join(c.Args(), " ")
+	response, err := client.Post("system/error", strings.TrimSpace(errStr))
+	if err != nil {
+		return err
+	}
+	if response.StatusCode != 200 {
+		errStr = fmt.Sprint("Failed to push error\nStatus code: ", response.StatusCode)
+		bytes, err := responseToBArray(response)
+		if err != nil {
+			return err
+		}
+		body := string(bytes)
+		if body != "" {
+			errStr += "\nBody: " + body
+		}
+		return errors.New(errStr)
+	}
+	return nil
+}
--- a/cmd/stcli/labels.go
+++ b/cmd/stcli/labels.go
@@ -1,31 +0,0 @@
-// 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
@@ -1,63 +1,192 @@
-// Copyright (C) 2014 Audrius Butkevičius
+// Copyright (C) 2019 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 (
-	"sort"
+	"bufio"
+	"crypto/tls"
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"reflect"

-	"github.com/AudriusButkevicius/cli"
+	"github.com/AudriusButkevicius/recli"
+	"github.com/flynn-archive/go-shlex"
+	"github.com/mattn/go-isatty"
+	"github.com/pkg/errors"
+	"github.com/syncthing/syncthing/lib/build"
+	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/events"
+	"github.com/syncthing/syncthing/lib/locations"
+	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/urfave/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
+	// This is somewhat a hack around a chicken and egg problem.
+	// We need to set the home directory and potentially other flags to know where the syncthing instance is running
+	// in order to get it's config ... which we then use to construct the actual CLI ... at which point it's too late
+	// to add flags there...
+	homeBaseDir := locations.GetBaseDir(locations.ConfigBaseDir)
+	guiCfg := config.GUIConfiguration{}

-	app.Flags = []cli.Flag{
+	flags := flag.NewFlagSet("", flag.ContinueOnError)
+	flags.StringVar(&guiCfg.RawAddress, "gui-address", guiCfg.RawAddress, "Override GUI address (e.g. \"http://192.0.2.42:8443\")")
+	flags.StringVar(&guiCfg.APIKey, "gui-apikey", guiCfg.APIKey, "Override GUI API key")
+	flags.StringVar(&homeBaseDir, "home", homeBaseDir, "Set configuration directory")
+
+	// Implement the same flags at the lower CLI, with the same default values (pre-parse), but do nothing with them.
+	// This is so that we could reuse os.Args
+	fakeFlags := []cli.Flag{
 		cli.StringFlag{
-			Name:   "endpoint, e",
-			Value:  "http://127.0.0.1:8384",
-			Usage:  "End point to connect to",
-			EnvVar: "STENDPOINT",
+			Name:  "gui-address",
+			Value: guiCfg.RawAddress,
+			Usage: "Override GUI address (e.g. \"http://192.0.2.42:8443\")",
 		},
 		cli.StringFlag{
-			Name:   "apikey, k",
-			Value:  "",
-			Usage:  "API Key",
-			EnvVar: "STAPIKEY",
+			Name:  "gui-apikey",
+			Value: guiCfg.APIKey,
+			Usage: "Override GUI API key",
 		},
 		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",
+			Name:  "home",
+			Value: homeBaseDir,
+			Usage: "Set configuration directory",
 		},
 	}

-	sort.Sort(ByAlphabet(cliCommands))
-	app.Commands = cliCommands
-	app.RunAndExitOnError()
+	// Do not print usage of these flags, and ignore errors as this can't understand plenty of things
+	flags.Usage = func() {}
+	_ = flags.Parse(os.Args[1:])
+
+	// Now if the API key and address is not provided (we are not connecting to a remote instance),
+	// try to rip it out of the config.
+	if guiCfg.RawAddress == "" && guiCfg.APIKey == "" {
+		// Update the base directory
+		err := locations.SetBaseDir(locations.ConfigBaseDir, homeBaseDir)
+		if err != nil {
+			log.Fatal(errors.Wrap(err, "setting home"))
+		}
+
+		// Load the certs and get the ID
+		cert, err := tls.LoadX509KeyPair(
+			locations.Get(locations.CertFile),
+			locations.Get(locations.KeyFile),
+		)
+		if err != nil {
+			log.Fatal(errors.Wrap(err, "reading device ID"))
+		}
+
+		myID := protocol.NewDeviceID(cert.Certificate[0])
+
+		// Load the config
+		cfg, err := config.Load(locations.Get(locations.ConfigFile), myID, events.NoopLogger)
+		if err != nil {
+			log.Fatalln(errors.Wrap(err, "loading config"))
+		}
+
+		guiCfg = cfg.GUI()
+	} else if guiCfg.Address() == "" || guiCfg.APIKey == "" {
+		log.Fatalln("Both -gui-address and -gui-apikey should be specified")
+	}
+
+	if guiCfg.Address() == "" {
+		log.Fatalln("Could not find GUI Address")
+	}
+
+	if guiCfg.APIKey == "" {
+		log.Fatalln("Could not find GUI API key")
+	}
+
+	client := getClient(guiCfg)
+
+	cfg, err := getConfig(client)
+	original := cfg.Copy()
+	if err != nil {
+		log.Fatalln(errors.Wrap(err, "getting config"))
+	}
+
+	// Copy the config and set the default flags
+	recliCfg := recli.DefaultConfig
+	recliCfg.IDTag.Name = "xml"
+	recliCfg.SkipTag.Name = "json"
+
+	commands, err := recli.New(recliCfg).Construct(&cfg)
+	if err != nil {
+		log.Fatalln(errors.Wrap(err, "config reflect"))
+	}
+
+	// Construct the actual CLI
+	app := cli.NewApp()
+	app.Name = "stcli"
+	app.HelpName = app.Name
+	app.Author = "The Syncthing Authors"
+	app.Usage = "Syncthing command line interface"
+	app.Version = build.Version
+	app.Flags = fakeFlags
+	app.Metadata = map[string]interface{}{
+		"client": client,
+	}
+	app.Commands = []cli.Command{
+		{
+			Name:        "config",
+			HideHelp:    true,
+			Usage:       "Configuration modification command group",
+			Subcommands: commands,
+		},
+		showCommand,
+		operationCommand,
+		errorsCommand,
+	}
+
+	tty := isatty.IsTerminal(os.Stdin.Fd()) || isatty.IsCygwinTerminal(os.Stdin.Fd())
+	if !tty {
+		// Not a TTY, consume from stdin
+		scanner := bufio.NewScanner(os.Stdin)
+		for scanner.Scan() {
+			input, err := shlex.Split(scanner.Text())
+			if err != nil {
+				log.Fatalln(errors.Wrap(err, "parsing input"))
+			}
+			if len(input) == 0 {
+				continue
+			}
+			err = app.Run(append(os.Args, input...))
+			if err != nil {
+				log.Fatalln(err)
+			}
+		}
+		err = scanner.Err()
+		if err != nil {
+			log.Fatalln(err)
+		}
+	} else {
+		err = app.Run(os.Args)
+		if err != nil {
+			log.Fatalln(err)
+		}
+	}
+
+	if !reflect.DeepEqual(cfg, original) {
+		body, err := json.MarshalIndent(cfg, "", "  ")
+		if err != nil {
+			log.Fatalln(err)
+		}
+		resp, err := client.Post("system/config", string(body))
+		if err != nil {
+			log.Fatalln(err)
+		}
+		if resp.StatusCode != 200 {
+			body, err := responseToBArray(resp)
+			if err != nil {
+				log.Fatalln(err)
+			}
+			log.Fatalln(string(body))
+		}
+	}
 }
--- a/cmd/stcli/operations.go
+++ b/cmd/stcli/operations.go
@@ -0,0 +1,78 @@
+// Copyright (C) 2019 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"
+
+	"github.com/urfave/cli"
+)
+
+var operationCommand = cli.Command{
+	Name:     "operations",
+	HideHelp: true,
+	Usage:    "Operation command group",
+	Subcommands: []cli.Command{
+		{
+			Name:   "restart",
+			Usage:  "Restart syncthing",
+			Action: expects(0, emptyPost("system/restart")),
+		},
+		{
+			Name:   "shutdown",
+			Usage:  "Shutdown syncthing",
+			Action: expects(0, emptyPost("system/shutdown")),
+		},
+		{
+			Name:   "reset",
+			Usage:  "Reset syncthing deleting all folders and devices",
+			Action: expects(0, emptyPost("system/reset")),
+		},
+		{
+			Name:   "upgrade",
+			Usage:  "Upgrade syncthing (if a newer version is available)",
+			Action: expects(0, emptyPost("system/upgrade")),
+		},
+		{
+			Name:      "folder-override",
+			Usage:     "Override changes on folder (remote for sendonly, local for receiveonly)",
+			ArgsUsage: "[folder id]",
+			Action:    expects(1, foldersOverride),
+		},
+	},
+}
+
+func foldersOverride(c *cli.Context) error {
+	client := c.App.Metadata["client"].(*APIClient)
+	cfg, err := getConfig(client)
+	if err != nil {
+		return err
+	}
+	rid := c.Args()[0]
+	for _, folder := range cfg.Folders {
+		if folder.ID == rid {
+			response, err := client.Post("db/override", "")
+			if err != nil {
+				return err
+			}
+			if response.StatusCode != 200 {
+				errStr := fmt.Sprint("Failed to override changes\nStatus code: ", response.StatusCode)
+				bytes, err := responseToBArray(response)
+				if err != nil {
+					return err
+				}
+				body := string(bytes)
+				if body != "" {
+					errStr += "\nBody: " + body
+				}
+				return fmt.Errorf(errStr)
+			}
+			return nil
+		}
+	}
+	return fmt.Errorf("Folder " + rid + " not found")
+}
--- a/cmd/stcli/show.go
+++ b/cmd/stcli/show.go
@@ -0,0 +1,44 @@
+// Copyright (C) 2019 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 (
+	"github.com/urfave/cli"
+)
+
+var showCommand = cli.Command{
+	Name:     "show",
+	HideHelp: true,
+	Usage:    "Show command group",
+	Subcommands: []cli.Command{
+		{
+			Name:   "version",
+			Usage:  "Show syncthing client version",
+			Action: expects(0, dumpOutput("system/version")),
+		},
+		{
+			Name:   "config-status",
+			Usage:  "Show configuration status, whether or not a restart is required for changes to take effect",
+			Action: expects(0, dumpOutput("system/config/insync")),
+		},
+		{
+			Name:   "system",
+			Usage:  "Show system status",
+			Action: expects(0, dumpOutput("system/status")),
+		},
+		{
+			Name:   "connections",
+			Usage:  "Report about connections to other devices",
+			Action: expects(0, dumpOutput("system/connections")),
+		},
+		{
+			Name:   "usage",
+			Usage:  "Show usage report",
+			Action: expects(0, dumpOutput("svc/report")),
+		},
+	},
+}
--- a/cmd/stcli/utils.go
+++ b/cmd/stcli/utils.go
@@ -1,4 +1,8 @@
-// Copyright (C) 2014 Audrius Butkevičius
+// Copyright (C) 2019 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

@@ -8,158 +12,83 @@ import (
 	"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"
+	"github.com/urfave/cli"
 )

-func responseToBArray(response *http.Response) []byte {
-	defer response.Body.Close()
+func responseToBArray(response *http.Response) ([]byte, error) {
 	bytes, err := ioutil.ReadAll(response.Body)
 	if err != nil {
-		die(err)
+		return nil, err
 	}
-	return bytes
+	return bytes, response.Body.Close()
 }

-func die(vals ...interface{}) {
-	if len(vals) > 1 || vals[0] != nil {
-		os.Stderr.WriteString(fmt.Sprintln(vals...))
-		os.Exit(1)
+func emptyPost(url string) cli.ActionFunc {
+	return func(c *cli.Context) error {
+		client := c.App.Metadata["client"].(*APIClient)
+		_, err := client.Post(url, "")
+		return err
 	}
 }

-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)
+func dumpOutput(url string) cli.ActionFunc {
+	return func(c *cli.Context) error {
+		client := c.App.Metadata["client"].(*APIClient)
+		response, err := client.Get(url)
+		if err != nil {
+			return err
 		}
-		remap[key] = v
+		return prettyPrintResponse(c, response)
 	}
+}

-	jsonKeys := make([]string, 0, len(remap))
-	for key := range remap {
-		jsonKeys = append(jsonKeys, key)
+func getConfig(c *APIClient) (config.Configuration, error) {
+	cfg := config.Configuration{}
+	response, err := c.Get("system/config")
+	if err != nil {
+		return cfg, err
 	}
-	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)
+	bytes, err := responseToBArray(response)
+	if err != nil {
+		return cfg, err
+	}
+	err = json.Unmarshal(bytes, &cfg)
+	if err == nil {
+		return cfg, err
+	}
+	return cfg, nil
+}
+
+func expects(n int, actionFunc cli.ActionFunc) cli.ActionFunc {
+	return func(ctx *cli.Context) error {
+		if ctx.NArg() != n {
+			plural := ""
+			if n != 1 {
+				plural = "s"
+			}
+			return fmt.Errorf("expected %d argument%s, got %d", n, plural, ctx.NArg())
 		}
-		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)
+		return actionFunc(ctx)
 	}
 }

-func parseBool(input string) bool {
-	val, err := strconv.ParseBool(input)
+func prettyPrintJSON(data interface{}) error {
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetIndent("", "  ")
+	return enc.Encode(data)
+}
+
+func prettyPrintResponse(c *cli.Context, response *http.Response) error {
+	bytes, err := responseToBArray(response)
 	if err != nil {
-		die(input + " is not a valid value for a boolean")
+		return err
 	}
-	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
+	var data interface{}
+	if err := json.Unmarshal(bytes, &data); err != nil {
+		return err
+	}
+	// TODO: Check flag for pretty print format
+	return prettyPrintJSON(data)
 }
--- 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() {
@@ -62,7 +60,7 @@ func compareDirectories(dirs ...string) error {
 				} else if res[i].name > res[0].name {
 					return fmt.Errorf("%s missing %v (present in %s)", dirs[i], res[0], dirs[0])
 				}
-				return fmt.Errorf("Mismatch; %v (%s) != %v (%s)", res[i], dirs[i], res[0], dirs[0])
+				return fmt.Errorf("mismatch; %v (%s) != %v (%s)", res[i], dirs[i], res[0], dirs[0])
 			}
 		}

@@ -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/stcrashreceiver/_testdata/panic.log
+++ b/cmd/stcrashreceiver/_testdata/panic.log
--- a/cmd/stcrashreceiver/sentry.go
+++ b/cmd/stcrashreceiver/sentry.go
@@ -0,0 +1,219 @@
+// Copyright (C) 2019 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"
+	"errors"
+	"io/ioutil"
+	"regexp"
+	"strings"
+	"sync"
+
+	raven "github.com/getsentry/raven-go"
+	"github.com/maruel/panicparse/stack"
+)
+
+const reportServer = "https://crash.syncthing.net/report/"
+
+var loader = newGithubSourceCodeLoader()
+
+func init() {
+	raven.SetSourceCodeLoader(loader)
+}
+
+var (
+	clients    = make(map[string]*raven.Client)
+	clientsMut sync.Mutex
+)
+
+func sendReport(dsn, path string, report []byte, userID string) error {
+	pkt, err := parseReport(path, report)
+	if err != nil {
+		return err
+	}
+
+	pkt.Interfaces = append(pkt.Interfaces, &raven.User{ID: userID})
+
+	clientsMut.Lock()
+	defer clientsMut.Unlock()
+
+	cli, ok := clients[dsn]
+	if !ok {
+		cli, err = raven.New(dsn)
+		if err != nil {
+			return err
+		}
+		clients[dsn] = cli
+	}
+
+	// The client sets release and such on the packet before sending, in the
+	// misguided idea that it knows this better than than the packet we give
+	// it. So we copy the values from the packet to the client first...
+	cli.SetRelease(pkt.Release)
+	cli.SetEnvironment(pkt.Environment)
+
+	defer cli.Wait()
+	_, errC := cli.Capture(pkt, nil)
+	return <-errC
+}
+
+func parseReport(path string, report []byte) (*raven.Packet, error) {
+	parts := bytes.SplitN(report, []byte("\n"), 2)
+	if len(parts) != 2 {
+		return nil, errors.New("no first line")
+	}
+
+	version, err := parseVersion(string(parts[0]))
+	if err != nil {
+		return nil, err
+	}
+	report = parts[1]
+
+	foundPanic := false
+	var subjectLine []byte
+	for {
+		parts = bytes.SplitN(report, []byte("\n"), 2)
+		if len(parts) != 2 {
+			return nil, errors.New("no panic line found")
+		}
+
+		line := parts[0]
+		report = parts[1]
+
+		if foundPanic {
+			// The previous line was our "Panic at ..." header. We are now
+			// at the beginning of the real panic trace and this is our
+			// subject line.
+			subjectLine = line
+			break
+		} else if bytes.HasPrefix(line, []byte("Panic at")) {
+			foundPanic = true
+		}
+	}
+
+	r := bytes.NewReader(report)
+	ctx, err := stack.ParseDump(r, ioutil.Discard, false)
+	if err != nil {
+		return nil, err
+	}
+
+	// Lock the source code loader to the version we are processing here.
+	if version.commit != "" {
+		// We have a commit hash, so we know exactly which source to use
+		loader.LockWithVersion(version.commit)
+	} else if strings.HasPrefix(version.tag, "v") {
+		// Lets hope the tag is close enough
+		loader.LockWithVersion(version.tag)
+	} else {
+		// Last resort
+		loader.LockWithVersion("master")
+	}
+	defer loader.Unlock()
+
+	var trace raven.Stacktrace
+	for _, gr := range ctx.Goroutines {
+		if gr.First {
+			trace.Frames = make([]*raven.StacktraceFrame, len(gr.Stack.Calls))
+			for i, sc := range gr.Stack.Calls {
+				trace.Frames[len(trace.Frames)-1-i] = raven.NewStacktraceFrame(0, sc.Func.Name(), sc.SrcPath, sc.Line, 3, nil)
+			}
+			break
+		}
+	}
+
+	pkt := &raven.Packet{
+		Message:     string(subjectLine),
+		Platform:    "go",
+		Release:     version.tag,
+		Environment: version.environment(),
+		Tags: raven.Tags{
+			raven.Tag{Key: "version", Value: version.version},
+			raven.Tag{Key: "tag", Value: version.tag},
+			raven.Tag{Key: "codename", Value: version.codename},
+			raven.Tag{Key: "runtime", Value: version.runtime},
+			raven.Tag{Key: "goos", Value: version.goos},
+			raven.Tag{Key: "goarch", Value: version.goarch},
+			raven.Tag{Key: "builder", Value: version.builder},
+		},
+		Extra: raven.Extra{
+			"url": reportServer + path,
+		},
+		Interfaces: []raven.Interface{&trace},
+	}
+	if version.commit != "" {
+		pkt.Tags = append(pkt.Tags, raven.Tag{Key: "commit", Value: version.commit})
+	}
+	for _, tag := range version.extra {
+		pkt.Tags = append(pkt.Tags, raven.Tag{Key: tag, Value: "1"})
+	}
+
+	return pkt, nil
+}
+
+// syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC [foo, bar]
+var longVersionRE = regexp.MustCompile(`syncthing\s+(v[^\s]+)\s+"([^"]+)"\s\(([^\s]+)\s+([^-]+)-([^)]+)\)\s+([^\s]+)[^\[]*(?:\[(.+)\])?$`)
+
+type version struct {
+	version  string   // "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep"
+	tag      string   // "v1.1.4-rc.1"
+	commit   string   // "6aaae618", blank when absent
+	codename string   // "Erbium Earthworm"
+	runtime  string   // "go1.12.5"
+	goos     string   // "darwin"
+	goarch   string   // "amd64"
+	builder  string   // "jb@kvin.kastelo.net"
+	extra    []string // "foo", "bar"
+}
+
+func (v version) environment() string {
+	if v.commit != "" {
+		return "Development"
+	}
+	if strings.Contains(v.tag, "-rc.") {
+		return "Candidate"
+	}
+	if strings.Contains(v.tag, "-") {
+		return "Beta"
+	}
+	return "Stable"
+}
+
+func parseVersion(line string) (version, error) {
+	m := longVersionRE.FindStringSubmatch(line)
+	if len(m) == 0 {
+		return version{}, errors.New("unintelligeble version string")
+	}
+
+	v := version{
+		version:  m[1],
+		codename: m[2],
+		runtime:  m[3],
+		goos:     m[4],
+		goarch:   m[5],
+		builder:  m[6],
+	}
+
+	parts := strings.Split(v.version, "+")
+	v.tag = parts[0]
+	if len(parts) > 1 {
+		fields := strings.Split(parts[1], "-")
+		if len(fields) >= 2 && strings.HasPrefix(fields[1], "g") {
+			v.commit = fields[1][1:]
+		}
+	}
+
+	if len(m) >= 8 && m[7] != "" {
+		tags := strings.Split(m[7], ",")
+		for i := range tags {
+			tags[i] = strings.TrimSpace(tags[i])
+		}
+		v.extra = tags
+	}
+
+	return v, nil
+}
--- a/cmd/stcrashreceiver/sentry_test.go
+++ b/cmd/stcrashreceiver/sentry_test.go
@@ -0,0 +1,78 @@
+// Copyright (C) 2019 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"
+	"io/ioutil"
+	"testing"
+)
+
+func TestParseVersion(t *testing.T) {
+	cases := []struct {
+		longVersion string
+		parsed      version
+	}{
+		{
+			longVersion: `syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC`,
+			parsed: version{
+				version:  "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep",
+				tag:      "v1.1.4-rc.1",
+				commit:   "6aaae618",
+				codename: "Erbium Earthworm",
+				runtime:  "go1.12.5",
+				goos:     "darwin",
+				goarch:   "amd64",
+				builder:  "jb@kvin.kastelo.net",
+			},
+		},
+		{
+			longVersion: `syncthing v1.1.4-rc.1+30-g6aaae618-dirty-crashrep "Erbium Earthworm" (go1.12.5 darwin-amd64) jb@kvin.kastelo.net 2019-05-23 16:08:14 UTC [foo, bar]`,
+			parsed: version{
+				version:  "v1.1.4-rc.1+30-g6aaae618-dirty-crashrep",
+				tag:      "v1.1.4-rc.1",
+				commit:   "6aaae618",
+				codename: "Erbium Earthworm",
+				runtime:  "go1.12.5",
+				goos:     "darwin",
+				goarch:   "amd64",
+				builder:  "jb@kvin.kastelo.net",
+				extra:    []string{"foo", "bar"},
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		v, err := parseVersion(tc.longVersion)
+		if err != nil {
+			t.Errorf("%s\nerror: %v\n", tc.longVersion, err)
+			continue
+		}
+		if fmt.Sprint(v) != fmt.Sprint(tc.parsed) {
+			t.Errorf("%s\nA: %v\nE: %v\n", tc.longVersion, v, tc.parsed)
+		}
+	}
+}
+
+func TestParseReport(t *testing.T) {
+	bs, err := ioutil.ReadFile("_testdata/panic.log")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pkt, err := parseReport("1/2/345", bs)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	bs, err = pkt.JSON()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fmt.Printf("%s\n", bs)
+}
--- a/cmd/stcrashreceiver/sourcecodeloader.go
+++ b/cmd/stcrashreceiver/sourcecodeloader.go
@@ -0,0 +1,114 @@
+// Copyright (C) 2019 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"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	urlPrefix   = "https://raw.githubusercontent.com/syncthing/syncthing/"
+	httpTimeout = 10 * time.Second
+)
+
+type githubSourceCodeLoader struct {
+	mut     sync.Mutex
+	version string
+	cache   map[string]map[string][][]byte // version -> file -> lines
+	client  *http.Client
+}
+
+func newGithubSourceCodeLoader() *githubSourceCodeLoader {
+	return &githubSourceCodeLoader{
+		cache:  make(map[string]map[string][][]byte),
+		client: &http.Client{Timeout: httpTimeout},
+	}
+}
+
+func (l *githubSourceCodeLoader) LockWithVersion(version string) {
+	l.mut.Lock()
+	l.version = version
+	if _, ok := l.cache[version]; !ok {
+		l.cache[version] = make(map[string][][]byte)
+	}
+}
+
+func (l *githubSourceCodeLoader) Unlock() {
+	l.mut.Unlock()
+}
+
+func (l *githubSourceCodeLoader) Load(filename string, line, context int) ([][]byte, int) {
+	filename = filepath.ToSlash(filename)
+	lines, ok := l.cache[l.version][filename]
+	if !ok {
+		// Cache whatever we managed to find (or nil if nothing, so we don't try again)
+		defer func() {
+			l.cache[l.version][filename] = lines
+		}()
+
+		knownPrefixes := []string{"/lib/", "/cmd/"}
+		var idx int
+		for _, pref := range knownPrefixes {
+			idx = strings.Index(filename, pref)
+			if idx >= 0 {
+				break
+			}
+		}
+		if idx == -1 {
+			return nil, 0
+		}
+
+		url := urlPrefix + l.version + filename[idx:]
+		resp, err := l.client.Get(url)
+
+		if err != nil || resp.StatusCode != http.StatusOK {
+			fmt.Println("Loading source:", err.Error())
+			return nil, 0
+		}
+		data, err := ioutil.ReadAll(resp.Body)
+		_ = resp.Body.Close()
+		if err != nil {
+			fmt.Println("Loading source:", err.Error())
+			return nil, 0
+		}
+		lines = bytes.Split(data, []byte{'\n'})
+	}
+
+	return getLineFromLines(lines, line, context)
+}
+
+func getLineFromLines(lines [][]byte, line, context int) ([][]byte, int) {
+	if lines == nil {
+		// cached error from ReadFile: return no lines
+		return nil, 0
+	}
+
+	line-- // stack trace lines are 1-indexed
+	start := line - context
+	var idx int
+	if start < 0 {
+		start = 0
+		idx = line
+	} else {
+		idx = context
+	}
+	end := line + context + 1
+	if line >= len(lines) {
+		return nil, 0
+	}
+	if end > len(lines) {
+		end = len(lines)
+	}
+	return lines[start:end], idx
+}
--- a/cmd/stcrashreceiver/stcrashreceiver.go
+++ b/cmd/stcrashreceiver/stcrashreceiver.go
@@ -0,0 +1,185 @@
+// Copyright (C) 2019 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/.
+
+// Command stcrashreceiver is a trivial HTTP server that allows two things:
+//
+// - uploading files (crash reports) named like a SHA256 hash using a PUT request
+// - checking whether such file exists using a HEAD request
+//
+// Typically this should be deployed behind something that manages HTTPS.
+package main
+
+import (
+	"bytes"
+	"compress/gzip"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/syncthing/syncthing/lib/sha256"
+)
+
+const maxRequestSize = 1 << 20 // 1 MiB
+
+func main() {
+	dir := flag.String("dir", ".", "Directory to store reports in")
+	dsn := flag.String("dsn", "", "Sentry DSN")
+	listen := flag.String("listen", ":22039", "HTTP listen address")
+	flag.Parse()
+
+	cr := &crashReceiver{
+		dir: *dir,
+		dsn: *dsn,
+	}
+
+	log.SetOutput(os.Stdout)
+	if err := http.ListenAndServe(*listen, cr); err != nil {
+		log.Fatalln("HTTP serve:", err)
+	}
+}
+
+type crashReceiver struct {
+	dir string
+	dsn string
+}
+
+func (r *crashReceiver) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	// The final path component should be a SHA256 hash in hex, so 64 hex
+	// characters. We don't care about case on the request but use lower
+	// case internally.
+	reportID := strings.ToLower(path.Base(req.URL.Path))
+	if len(reportID) != 64 {
+		http.Error(w, "Bad request", http.StatusBadRequest)
+		return
+	}
+	for _, c := range reportID {
+		if c >= 'a' && c <= 'f' {
+			continue
+		}
+		if c >= '0' && c <= '9' {
+			continue
+		}
+		http.Error(w, "Bad request", http.StatusBadRequest)
+		return
+	}
+
+	// The location of the report on disk, compressed
+	fullPath := filepath.Join(r.dir, r.dirFor(reportID), reportID) + ".gz"
+
+	switch req.Method {
+	case http.MethodGet:
+		r.serveGet(fullPath, w, req)
+	case http.MethodHead:
+		r.serveHead(fullPath, w, req)
+	case http.MethodPut:
+		r.servePut(reportID, fullPath, w, req)
+	default:
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+	}
+}
+
+// serveGet responds to GET requests by serving the uncompressed report.
+func (r *crashReceiver) serveGet(fullPath string, w http.ResponseWriter, _ *http.Request) {
+	fd, err := os.Open(fullPath)
+	if err != nil {
+		http.Error(w, "Not found", http.StatusNotFound)
+		return
+	}
+
+	defer fd.Close()
+	gr, err := gzip.NewReader(fd)
+	if err != nil {
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+	_, _ = io.Copy(w, gr) // best effort
+}
+
+// serveHead responds to HEAD requests by checking if the named report
+// already exists in the system.
+func (r *crashReceiver) serveHead(fullPath string, w http.ResponseWriter, _ *http.Request) {
+	if _, err := os.Lstat(fullPath); err != nil {
+		http.Error(w, "Not found", http.StatusNotFound)
+	}
+}
+
+// servePut accepts and stores the given report.
+func (r *crashReceiver) servePut(reportID, fullPath string, w http.ResponseWriter, req *http.Request) {
+	// Ensure the destination directory exists
+	if err := os.MkdirAll(filepath.Dir(fullPath), 0755); err != nil {
+		log.Println("Creating directory:", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	// Read at most maxRequestSize of report data.
+	log.Println("Receiving report", reportID)
+	lr := io.LimitReader(req.Body, maxRequestSize)
+	bs, err := ioutil.ReadAll(lr)
+	if err != nil {
+		log.Println("Reading report:", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	// Compress the report for storage
+	buf := new(bytes.Buffer)
+	gw := gzip.NewWriter(buf)
+	_, _ = gw.Write(bs) // can't fail
+	gw.Close()
+
+	// Create an output file with the compressed report
+	err = ioutil.WriteFile(fullPath, buf.Bytes(), 0644)
+	if err != nil {
+		log.Println("Saving report:", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	// Send the report to Sentry
+	if r.dsn != "" {
+		// Remote ID
+		user := userIDFor(req)
+
+		go func() {
+			// There's no need for the client to have to wait for this part.
+			if err := sendReport(r.dsn, reportID, bs, user); err != nil {
+				log.Println("Failed to send report:", err)
+			}
+		}()
+	}
+}
+
+// 01234567890abcdef... => 01/23
+func (r *crashReceiver) dirFor(base string) string {
+	return filepath.Join(base[0:2], base[2:4])
+}
+
+// userIDFor returns a string we can use as the user ID for the purpose of
+// counting affected users. It's the truncated hash of a salt, the user
+// remote IP, and the current month.
+func userIDFor(req *http.Request) string {
+	addr := req.RemoteAddr
+	if fwd := req.Header.Get("x-forwarded-for"); fwd != "" {
+		addr = fwd
+	}
+	if host, _, err := net.SplitHostPort(addr); err == nil {
+		addr = host
+	}
+	now := time.Now().Format("200601")
+	salt := "stcrashreporter"
+	hash := sha256.Sum256([]byte(salt + addr + now))
+	return fmt.Sprintf("%x", hash[:8])
+}
--- a/cmd/stdisco/main.go
+++ b/cmd/stdisco/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/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
@@ -1,44 +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.
-
-##### Third-party attribution
-
-[cznic/lldb](https://github.com/cznic/lldb), Copyright (C) 2014 The lldb Authors.
--- a/cmd/stdiscosrv/apisrv.go
+++ b/cmd/stdiscosrv/apisrv.go
@@ -0,0 +1,454 @@
+// 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"
+	"sort"
+	"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
+	}
+
+	// The address slice must always be sorted for database merges to work
+	// properly.
+	sort.Sort(databaseAddressOrder(dbAddrs))
+
+	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
+	}
+
+	var bs []byte
+
+	if hdr := req.Header.Get("X-SSL-Cert"); hdr != "" {
+		if strings.Contains(hdr, "%") {
+			// Nginx using $ssl_client_escaped_cert
+			// The certificate is in PEM format with url encoding.
+			// We need to decode for the PEM decoder
+			hdr, err := url.QueryUnescape(hdr)
+			if err != nil {
+				// Decoding failed
+				return nil
+			}
+
+			bs = []byte(hdr)
+		} else {
+			// Nginx using $ssl_client_cert
+			// 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.
+			bs = []byte(hdr)
+			firstSpace := bytes.Index(bs, []byte(" "))
+			lastSpace := bytes.LastIndex(bs, []byte(" "))
+			for i := firstSpace + 1; i < lastSpace; i++ {
+				if bs[i] == ' ' {
+					bs[i] = '\n'
+				}
+			}
+		}
+	} else if hdr := req.Header.Get("X-Forwarded-Tls-Client-Cert"); hdr != "" {
+		// Traefik 2 passtlsclientcert
+		// The certificate is in PEM format with url encoding but without newlines
+		// and start/end statements. We need to decode, reinstate the newlines every 64
+		// character and add statements for the PEM decoder
+		hdr, err := url.QueryUnescape(hdr)
+		if err != nil {
+			// Decoding failed
+			return nil
+		}
+
+		for i := 64; i < len(hdr); i += 65 {
+			hdr = hdr[:i] + "\n" + hdr[i:]
+		}
+
+		hdr = "-----BEGIN CERTIFICATE-----\n" + hdr
+		hdr = hdr + "\n-----END CERTIFICATE-----\n"
+		bs = []byte(hdr)
+	}
+
+	if bs == nil {
+		return nil
+	}
+
+	block, _ := pem.Decode(bs)
+	if block == nil {
+		// Decoding failed
+		return nil
+	}
+
+	return block.Bytes
+}
+
+// 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 +1,379 @@
+// 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 . --gogofast_out=. database.proto
+
+package main
+
+import (
+	"log"
+	"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.
+	if !sort.IsSorted(databaseAddressOrder(a.Addresses)) {
+		log.Println("Warning: bug: addresses not correctly sorted in merge")
+		a.Addresses = sortedAddressCopy(a.Addresses)
+	}
+	if !sort.IsSorted(databaseAddressOrder(b.Addresses)) {
+		// no warning because this is the side we read from disk and it may
+		// legitimately predate correct sorting.
+		b.Addresses = sortedAddressCopy(b.Addresses)
+	}
+
+	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
+}
+
+func sortedAddressCopy(addrs []DatabaseAddress) []DatabaseAddress {
+	sorted := make([]DatabaseAddress, len(addrs))
+	copy(sorted, addrs)
+	sort.Sort(databaseAddressOrder(sorted))
+	return sorted
+}
+
+type databaseAddressOrder []DatabaseAddress
+
+func (s databaseAddressOrder) Less(a, b int) bool {
+	return s[a].Address < s[b].Address
+}
+
+func (s databaseAddressOrder) Swap(a, b int) {
+	s[a], s[b] = s[b], s[a]
+}
+
+func (s databaseAddressOrder) Len() int {
+	return len(s)
+}
--- a/cmd/stdiscosrv/database.pb.go
+++ b/cmd/stdiscosrv/database.pb.go
@@ -0,0 +1,856 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: database.proto
+
+package main
+
+import (
+	fmt "fmt"
+	_ "github.com/gogo/protobuf/gogoproto"
+	proto "github.com/gogo/protobuf/proto"
+	io "io"
+	math "math"
+	math_bits "math/bits"
+)
+
+// 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.GoGoProtoPackageIsVersion3 // please upgrade the proto package
+
+type DatabaseRecord struct {
+	Addresses []DatabaseAddress `protobuf:"bytes,1,rep,name=addresses,proto3" 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 fileDescriptor_b90fe3356ea5df07, []int{0}
+}
+func (m *DatabaseRecord) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *DatabaseRecord) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_DatabaseRecord.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *DatabaseRecord) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_DatabaseRecord.Merge(m, src)
+}
+func (m *DatabaseRecord) XXX_Size() int {
+	return m.Size()
+}
+func (m *DatabaseRecord) XXX_DiscardUnknown() {
+	xxx_messageInfo_DatabaseRecord.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_DatabaseRecord proto.InternalMessageInfo
+
+type ReplicationRecord struct {
+	Key       string            `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+	Addresses []DatabaseAddress `protobuf:"bytes,2,rep,name=addresses,proto3" 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 fileDescriptor_b90fe3356ea5df07, []int{1}
+}
+func (m *ReplicationRecord) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *ReplicationRecord) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_ReplicationRecord.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *ReplicationRecord) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_ReplicationRecord.Merge(m, src)
+}
+func (m *ReplicationRecord) XXX_Size() int {
+	return m.Size()
+}
+func (m *ReplicationRecord) XXX_DiscardUnknown() {
+	xxx_messageInfo_ReplicationRecord.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_ReplicationRecord proto.InternalMessageInfo
+
+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 fileDescriptor_b90fe3356ea5df07, []int{2}
+}
+func (m *DatabaseAddress) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *DatabaseAddress) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_DatabaseAddress.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *DatabaseAddress) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_DatabaseAddress.Merge(m, src)
+}
+func (m *DatabaseAddress) XXX_Size() int {
+	return m.Size()
+}
+func (m *DatabaseAddress) XXX_DiscardUnknown() {
+	xxx_messageInfo_DatabaseAddress.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_DatabaseAddress proto.InternalMessageInfo
+
+func init() {
+	proto.RegisterType((*DatabaseRecord)(nil), "main.DatabaseRecord")
+	proto.RegisterType((*ReplicationRecord)(nil), "main.ReplicationRecord")
+	proto.RegisterType((*DatabaseAddress)(nil), "main.DatabaseAddress")
+}
+
+func init() { proto.RegisterFile("database.proto", fileDescriptor_b90fe3356ea5df07) }
+
+var fileDescriptor_b90fe3356ea5df07 = []byte{
+	// 270 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x94, 0x90, 0x41, 0x4a, 0xc4, 0x30,
+	0x18, 0x85, 0x9b, 0x49, 0x1d, 0x99, 0x08, 0xa3, 0x06, 0x94, 0x20, 0x12, 0x4b, 0xdd, 0x74, 0xd5,
+	0x01, 0x5d, 0xb9, 0x74, 0xd0, 0x0b, 0xe4, 0x06, 0xe9, 0xe4, 0x77, 0x08, 0x3a, 0x4d, 0x49, 0x2a,
+	0xe8, 0x29, 0xf4, 0x58, 0x5d, 0xce, 0xd2, 0x95, 0x68, 0x7b, 0x11, 0x69, 0x26, 0x55, 0x14, 0x37,
+	0xb3, 0x7b, 0xdf, 0xff, 0xbf, 0x97, 0xbc, 0x84, 0x4c, 0x95, 0xac, 0x65, 0x21, 0x1d, 0xe4, 0x95,
+	0x35, 0xb5, 0xa1, 0xf1, 0x4a, 0xea, 0xf2, 0xe4, 0xdc, 0x42, 0x65, 0xdc, 0xcc, 0x8f, 0x8a, 0xc7,
+	0xbb, 0xd9, 0xd2, 0x2c, 0x8d, 0x07, 0xaf, 0x36, 0xd6, 0xf4, 0x05, 0x91, 0xe9, 0x4d, 0x48, 0x0b,
+	0x58, 0x18, 0xab, 0xe8, 0x15, 0x99, 0x48, 0xa5, 0x2c, 0x38, 0x07, 0x8e, 0xa1, 0x04, 0x67, 0x7b,
+	0x17, 0x47, 0x79, 0x7f, 0x62, 0x3e, 0x18, 0xaf, 0x37, 0xeb, 0x79, 0xdc, 0xbc, 0x9f, 0x45, 0xe2,
+	0xc7, 0x4d, 0x8f, 0xc9, 0x78, 0xa5, 0x7d, 0x6e, 0x94, 0xa0, 0x6c, 0x47, 0x04, 0xa2, 0x94, 0xc4,
+	0x0e, 0xa0, 0x64, 0x38, 0x41, 0x19, 0x16, 0x5e, 0x7f, 0x7b, 0x15, 0x8b, 0xfd, 0x34, 0x50, 0x5a,
+	0x93, 0x43, 0x01, 0xd5, 0x83, 0x5e, 0xc8, 0x5a, 0x9b, 0x32, 0x74, 0x3a, 0x20, 0xf8, 0x1e, 0x9e,
+	0x19, 0x4a, 0x50, 0x36, 0x11, 0xbd, 0xfc, 0xdd, 0x72, 0xb4, 0x55, 0xcb, 0x7f, 0xda, 0xa4, 0xb7,
+	0x64, 0xff, 0x4f, 0x8e, 0x32, 0xb2, 0x1b, 0x32, 0xe1, 0xde, 0x01, 0xfb, 0x0d, 0x3c, 0x55, 0xda,
+	0x86, 0x77, 0x62, 0x31, 0xe0, 0xfc, 0xb4, 0xf9, 0xe4, 0x51, 0xd3, 0x72, 0xb4, 0x6e, 0x39, 0xfa,
+	0x68, 0x39, 0x7a, 0xed, 0x78, 0xb4, 0xee, 0x78, 0xf4, 0xd6, 0xf1, 0xa8, 0x18, 0xfb, 0x3f, 0xbf,
+	0xfc, 0x0a, 0x00, 0x00, 0xff, 0xff, 0x7a, 0xa2, 0xf6, 0x1e, 0xb0, 0x01, 0x00, 0x00,
+}
+
+func (m *DatabaseRecord) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *DatabaseRecord) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *DatabaseRecord) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.Missed != 0 {
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Missed))
+		i--
+		dAtA[i] = 0x20
+	}
+	if m.Seen != 0 {
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Seen))
+		i--
+		dAtA[i] = 0x18
+	}
+	if m.Misses != 0 {
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Misses))
+		i--
+		dAtA[i] = 0x10
+	}
+	if len(m.Addresses) > 0 {
+		for iNdEx := len(m.Addresses) - 1; iNdEx >= 0; iNdEx-- {
+			{
+				size, err := m.Addresses[iNdEx].MarshalToSizedBuffer(dAtA[:i])
+				if err != nil {
+					return 0, err
+				}
+				i -= size
+				i = encodeVarintDatabase(dAtA, i, uint64(size))
+			}
+			i--
+			dAtA[i] = 0xa
+		}
+	}
+	return len(dAtA) - i, nil
+}
+
+func (m *ReplicationRecord) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ReplicationRecord) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *ReplicationRecord) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.Seen != 0 {
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Seen))
+		i--
+		dAtA[i] = 0x18
+	}
+	if len(m.Addresses) > 0 {
+		for iNdEx := len(m.Addresses) - 1; iNdEx >= 0; iNdEx-- {
+			{
+				size, err := m.Addresses[iNdEx].MarshalToSizedBuffer(dAtA[:i])
+				if err != nil {
+					return 0, err
+				}
+				i -= size
+				i = encodeVarintDatabase(dAtA, i, uint64(size))
+			}
+			i--
+			dAtA[i] = 0x12
+		}
+	}
+	if len(m.Key) > 0 {
+		i -= len(m.Key)
+		copy(dAtA[i:], m.Key)
+		i = encodeVarintDatabase(dAtA, i, uint64(len(m.Key)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func (m *DatabaseAddress) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *DatabaseAddress) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *DatabaseAddress) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if m.Expires != 0 {
+		i = encodeVarintDatabase(dAtA, i, uint64(m.Expires))
+		i--
+		dAtA[i] = 0x10
+	}
+	if len(m.Address) > 0 {
+		i -= len(m.Address)
+		copy(dAtA[i:], m.Address)
+		i = encodeVarintDatabase(dAtA, i, uint64(len(m.Address)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintDatabase(dAtA []byte, offset int, v uint64) int {
+	offset -= sovDatabase(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+func (m *DatabaseRecord) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	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) {
+	if m == nil {
+		return 0
+	}
+	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) {
+	if m == nil {
+		return 0
+	}
+	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) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+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 < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			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) < 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 < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			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 < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			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) < 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 < 0 {
+				return ErrInvalidLengthDatabase
+			}
+			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) < 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
+	depth := 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
+				}
+			}
+		case 1:
+			iNdEx += 8
+		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
+				}
+			}
+			if length < 0 {
+				return 0, ErrInvalidLengthDatabase
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupDatabase
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthDatabase
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthDatabase        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowDatabase          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupDatabase = fmt.Errorf("proto: unexpected end of group")
+)
--- a/cmd/stdiscosrv/database.proto
+++ b/cmd/stdiscosrv/database.proto
@@ -0,0 +1,36 @@
+// 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 "repos/protobuf/gogoproto/gogo.proto";
+
+option (gogoproto.goproto_getters_all) = false;
+option (gogoproto.goproto_unkeyed_all) = false;
+option (gogoproto.goproto_unrecognized_all) = false;
+option (gogoproto.goproto_sizecache_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/etc/firewall-ufw/stdiscosrv
+++ b/cmd/stdiscosrv/etc/firewall-ufw/stdiscosrv
@@ -0,0 +1,4 @@
+[stdiscosrv]
+title=Syncthing discovery server
+description=Lets syncthing clients discover each other
+ports=8443/tcp
--- a/cmd/stdiscosrv/etc/linux-systemd/default
+++ b/cmd/stdiscosrv/etc/linux-systemd/default
@@ -0,0 +1,3 @@
+# Default settings for syncthing-discosrv (stdiscosrv).
+## Add Options here:
+DISCOSRV_OPTS=
--- a/cmd/stdiscosrv/etc/linux-systemd/stdiscosrv.service
+++ b/cmd/stdiscosrv/etc/linux-systemd/stdiscosrv.service
@@ -0,0 +1,25 @@
+[Unit]
+Description=Syncthing Discovery Server
+After=network.target
+Documentation=man:stdiscosrv(1)
+
+[Service]
+WorkingDirectory=/var/lib/syncthing-discosrv
+EnvironmentFile=/etc/default/syncthing-discosrv
+ExecStart=/usr/bin/stdiscosrv $DISCOSRV_OPTS
+
+# Hardening
+User=syncthing-discosrv
+Group=syncthing
+ProtectSystem=strict
+ReadWritePaths=/var/lib/syncthing-discosrv
+NoNewPrivileges=true
+PrivateTmp=true
+PrivateDevices=true
+ProtectHome=true
+SystemCallArchitectures=native
+MemoryDenyWriteExecute=true
+
+[Install]
+WantedBy=multi-user.target
+Alias=syncthing-discosrv.service
--- a/cmd/stdiscosrv/main.go
+++ b/cmd/stdiscosrv/main.go
@@ -1,146 +1,187 @@
-// 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/build"
 	"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
 )

-var (
-	Version    string
-	BuildStamp string
-	BuildUser  string
-	BuildHost  string
-
-	BuildDate   time.Time
-	LongVersion string
-)
-
-func init() {
-	stamp, _ := strconv.Atoi(BuildStamp)
-	BuildDate = time.Unix(int64(stamp), 0)
-
-	date := BuildDate.UTC().Format("2006-01-02 15:04:05 MST")
-	LongVersion = fmt.Sprintf(`stdiscosrv %s (%s %s-%s) %s@%s %s`, Version, runtime.Version(), runtime.GOOS, runtime.GOARCH, BuildUser, BuildHost, date)
+// 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 (
-	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() {
-	const (
-		cleanIntv = 1 * time.Hour
-		statsIntv = 5 * time.Minute
-	)
-
 	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")
+	showVersion := flag.Bool("version", false, "Show version")
 	flag.Parse()

-	log.Println(LongVersion)
+	log.Println(build.LongVersionFor("stdiscosrv"))
+	if *showVersion {
+		return
+	}

-	var cert tls.Certificate
-	var err error
-	if !useHTTP {
-		cert, err = tls.LoadX509KeyPair(certFile, keyFile)
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if os.IsNotExist(err) {
+		log.Println("Failed to load keypair. Generating one, this might take a while...")
+		cert, err = tlsutil.NewCertificate(certFile, keyFile, "stdiscosrv", 20*365)
 		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)
 		}
+	} else if err != nil {
+		log.Fatalln("Failed to load keypair:", err)
+	}
+	devID := protocol.NewDeviceID(cert.Certificate[0])
+	log.Println("Server device ID is", devID)

-		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)
+		}
 	}

-	db, err := sql.Open(backend, dsn)
+	// 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
@@ -1,492 +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/syncthing/syncthing/lib/protocol"
-	"golang.org/x/net/context"
-	"golang.org/x/time/rate"
-)
-
-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))
-}
-
-type contextKey int
-
-const idKey contextKey = iota
-
-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, idKey, 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(idKey).(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(idKey).(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(idKey).(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.(*rate.Limiter)
-		if !bkt.Allow() {
-			// Rate limit exceeded; ignore packet
-			return true
-		}
-	} else {
-		// limitAvg is in packets per ten seconds.
-		s.limiter.Add(key, rate.NewLimiter(rate.Limit(limitAvg)/10, limitBurst))
-	}
-
-	return false
-}
-
-func (s *querysrv) updateDevice(ctx context.Context, tx *sql.Tx, device protocol.DeviceID) error {
-	reqID := ctx.Value(idKey).(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/scripts/preinst
+++ b/cmd/stdiscosrv/scripts/preinst
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+addgroup --system syncthing
+adduser --system --home /var/lib/syncthing-discosrv --ingroup syncthing syncthing-discosrv
--- 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, true)
+		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
@@ -2,11 +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"
 	"crypto/tls"
 	"errors"
 	"flag"
@@ -17,6 +18,7 @@ import (

 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/discover"
+	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/protocol"
 )

@@ -82,7 +84,7 @@ func checkServers(deviceID protocol.DeviceID, servers ...string) {
 }

 func checkServer(deviceID protocol.DeviceID, server string) checkResult {
-	disco, err := discover.NewGlobal(server, tls.Certificate{}, nil)
+	disco, err := discover.NewGlobal(server, tls.Certificate{}, nil, events.NoopLogger)
 	if err != nil {
 		return checkResult{error: err}
 	}
@@ -94,7 +96,7 @@ func checkServer(deviceID protocol.DeviceID, server string) checkResult {
 	})

 	go func() {
-		addresses, err := disco.Lookup(deviceID)
+		addresses, err := disco.Lookup(context.Background(), deviceID)
 		res <- checkResult{addresses: addresses, error: err}
 	}()

--- 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

@@ -82,7 +82,7 @@ func generateOneFile(fd io.ReadSeeker, p1 string, s int64) error {
 		return err
 	}

-	_ = os.Chmod(p1, os.FileMode(rand.Intn(0777)|0400))
+	os.Chmod(p1, os.FileMode(rand.Intn(0777)|0400))

 	t := time.Now().Add(-time.Duration(rand.Intn(30*86400)) * time.Second)
 	return os.Chtimes(p1, t, t)
--- a/cmd/stindex/accounting.go
+++ b/cmd/stindex/accounting.go
@@ -0,0 +1,58 @@
+// Copyright (C) 2020 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"
+	"log"
+	"os"
+	"text/tabwriter"
+
+	"github.com/syncthing/syncthing/lib/db/backend"
+)
+
+// account prints key and data size statistics per class
+func account(ldb backend.Backend) {
+	it, err := ldb.NewPrefixIterator(nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var ksizes [256]int
+	var dsizes [256]int
+	var counts [256]int
+	var max [256]int
+
+	for it.Next() {
+		key := it.Key()
+		t := key[0]
+		ds := len(it.Value())
+		ks := len(key)
+		s := ks + ds
+
+		counts[t]++
+		ksizes[t] += ks
+		dsizes[t] += ds
+		if s > max[t] {
+			max[t] = s
+		}
+	}
+
+	tw := tabwriter.NewWriter(os.Stdout, 1, 1, 1, ' ', tabwriter.AlignRight)
+	toti, totds, totks := 0, 0, 0
+	for t := range ksizes {
+		if ksizes[t] > 0 {
+			// yes metric kilobytes 🤘
+			fmt.Fprintf(tw, "0x%02x:\t%d items,\t%d KB keys +\t%d KB data,\t%d B +\t%d B avg,\t%d B max\t\n", t, counts[t], ksizes[t]/1000, dsizes[t]/1000, ksizes[t]/counts[t], dsizes[t]/counts[t], max[t])
+			toti += counts[t]
+			totds += dsizes[t]
+			totks += ksizes[t]
+		}
+	}
+	fmt.Fprintf(tw, "Total\t%d items,\t%d KB keys +\t%d KB data.\t\n", toti, totks/1000, totds/1000)
+	tw.Flush()
+}
--- 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

@@ -13,11 +13,15 @@ import (
 	"time"

 	"github.com/syncthing/syncthing/lib/db"
+	"github.com/syncthing/syncthing/lib/db/backend"
 	"github.com/syncthing/syncthing/lib/protocol"
 )

-func dump(ldb *db.Instance) {
-	it := ldb.NewIterator(nil, nil)
+func dump(ldb backend.Backend) {
+	it, err := ldb.NewPrefixIterator(nil)
+	if err != nil {
+		log.Fatal(err)
+	}
 	for it.Next() {
 		key := it.Key()
 		switch key[0] {
@@ -48,10 +52,10 @@ func dump(ldb *db.Instance) {
 			fmt.Printf("[block] F:%d H:%x N:%q I:%d\n", folder, hash, name, binary.BigEndian.Uint32(it.Value()))

 		case db.KeyTypeDeviceStatistic:
-			fmt.Printf("[dstat] K:%x V:%x\n", it.Key(), it.Value())
+			fmt.Printf("[dstat] K:%x V:%x\n", key, it.Value())

 		case db.KeyTypeFolderStatistic:
-			fmt.Printf("[fstat] K:%x V:%x\n", it.Key(), it.Value())
+			fmt.Printf("[fstat] K:%x V:%x\n", key, it.Value())

 		case db.KeyTypeVirtualMtime:
 			folder := binary.BigEndian.Uint32(key[1:])
@@ -63,21 +67,59 @@ func dump(ldb *db.Instance) {
 			fmt.Printf("[mtime] F:%d N:%q R:%v V:%v\n", folder, name, real, virt)

 		case db.KeyTypeFolderIdx:
-			key := binary.BigEndian.Uint32(it.Key()[1:])
+			key := binary.BigEndian.Uint32(key[1:])
 			fmt.Printf("[folderidx] K:%d V:%q\n", key, it.Value())

 		case db.KeyTypeDeviceIdx:
-			key := binary.BigEndian.Uint32(it.Key()[1:])
+			key := binary.BigEndian.Uint32(key[1:])
 			val := it.Value()
-			if len(val) == 0 {
-				fmt.Printf("[deviceidx] K:%d V:<nil>\n", key)
-			} else {
-				dev := protocol.DeviceIDFromBytes(val)
-				fmt.Printf("[deviceidx] K:%d V:%s\n", key, dev)
+			device := "<nil>"
+			if len(val) > 0 {
+				dev, err := protocol.DeviceIDFromBytes(val)
+				if err != nil {
+					device = fmt.Sprintf("<invalid %d bytes>", len(val))
+				} else {
+					device = dev.String()
+				}
 			}
+			fmt.Printf("[deviceidx] K:%d V:%s\n", key, device)
+
+		case db.KeyTypeIndexID:
+			device := binary.BigEndian.Uint32(key[1:])
+			folder := binary.BigEndian.Uint32(key[5:])
+			fmt.Printf("[indexid] D:%d F:%d I:%x\n", device, folder, it.Value())
+
+		case db.KeyTypeFolderMeta:
+			folder := binary.BigEndian.Uint32(key[1:])
+			fmt.Printf("[foldermeta] F:%d V:%x\n", folder, it.Value())
+
+		case db.KeyTypeMiscData:
+			fmt.Printf("[miscdata] K:%q V:%q\n", key[1:], it.Value())
+
+		case db.KeyTypeSequence:
+			folder := binary.BigEndian.Uint32(key[1:])
+			seq := binary.BigEndian.Uint64(key[5:])
+			fmt.Printf("[sequence] F:%d S:%d V:%q\n", folder, seq, it.Value())
+
+		case db.KeyTypeNeed:
+			folder := binary.BigEndian.Uint32(key[1:])
+			file := string(key[5:])
+			fmt.Printf("[need] F:%d V:%q\n", folder, file)
+
+		case db.KeyTypeBlockList:
+			fmt.Printf("[blocklist] H:%x\n", key[1:])
+
+		case db.KeyTypeBlockListMap:
+			folder := binary.BigEndian.Uint32(key[1:])
+			hash := key[5:37]
+			fileName := string(key[37:])
+			fmt.Printf("[blocklistmap] F:%d H:%x N:%s\n", folder, hash, fileName)
+
+		case db.KeyTypeVersion:
+			fmt.Printf("[version] H:%x\n", key[1:])

 		default:
-			fmt.Printf("[???]\n  %x\n  %x\n", it.Key(), it.Value())
+			fmt.Printf("[??? %d]\n  %x\n  %x\n", key[0], key, it.Value())
 		}
 	}
 }
--- 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

@@ -10,8 +10,10 @@ import (
 	"container/heap"
 	"encoding/binary"
 	"fmt"
+	"log"

 	"github.com/syncthing/syncthing/lib/db"
+	"github.com/syncthing/syncthing/lib/db/backend"
 )

 type SizedElement struct {
@@ -37,11 +39,14 @@ func (h *ElementHeap) Pop() interface{} {
 	return x
 }

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

-	it := ldb.NewIterator(nil, nil)
+	it, err := ldb.NewPrefixIterator(nil)
+	if err != nil {
+		log.Fatal(err)
+	}
 	var ele SizedElement
 	for it.Next() {
 		key := it.Key()
--- a/cmd/stindex/idxck.go
+++ b/cmd/stindex/idxck.go
@@ -0,0 +1,342 @@
+// 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"
+	"log"
+	"sort"
+
+	"github.com/syncthing/syncthing/lib/db"
+	"github.com/syncthing/syncthing/lib/db/backend"
+	"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 backend.Backend) (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{})
+	blocklists := make(map[string]struct{})
+	versions := make(map[string]protocol.Vector)
+	usedBlocklists := make(map[string]struct{})
+	usedVersions := make(map[string]struct{})
+	var localDeviceKey uint32
+	success = true
+
+	it, err := ldb.NewPrefixIterator(nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	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{}{}
+
+		case db.KeyTypeBlockList:
+			hash := string(key[1:])
+			blocklists[hash] = struct{}{}
+
+		case db.KeyTypeVersion:
+			hash := string(key[1:])
+			var v protocol.Vector
+			if err := v.Unmarshal(it.Value()); err != nil {
+				fmt.Println("Unable to unmarshal Vector:", err)
+				success = false
+				continue
+			}
+			versions[hash] = v
+		}
+	}
+
+	if localDeviceKey == 0 {
+		fmt.Println("Missing key for local device in device index (bailing out)")
+		success = false
+		return
+	}
+
+	var missingSeq []sequenceKey
+	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 {
+			sk := sequenceKey{fk.folder, uint64(fi.Sequence)}
+			name, ok := sequences[sk]
+			if !ok {
+				fmt.Printf("Sequence entry missing for FileInfo %q, folder %q, seq %d\n", fi.Name, folder, fi.Sequence)
+				missingSeq = append(missingSeq, sk)
+				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
+			}
+		}
+
+		if len(fi.Blocks) == 0 && len(fi.BlocksHash) != 0 {
+			key := string(fi.BlocksHash)
+			if _, ok := blocklists[key]; !ok {
+				fmt.Printf("Missing block list for file %q, block list hash %x\n", fi.Name, fi.BlocksHash)
+				success = false
+			} else {
+				usedBlocklists[key] = struct{}{}
+			}
+		}
+
+		if fi.VersionHash != nil {
+			key := string(fi.VersionHash)
+			if _, ok := versions[key]; !ok {
+				fmt.Printf("Missing version vector for file %q, version hash %x\n", fi.Name, fi.VersionHash)
+				success = false
+			} else {
+				usedVersions[key] = struct{}{}
+			}
+		}
+
+		_, ok := globals[globalKey{fk.folder, fk.name}]
+		if !ok {
+			fmt.Printf("Missing global for file %q\n", fi.Name)
+			success = false
+			continue
+		}
+	}
+
+	// Aggregate the ranges of missing sequence entries, print them
+
+	sort.Slice(missingSeq, func(a, b int) bool {
+		if missingSeq[a].folder != missingSeq[b].folder {
+			return missingSeq[a].folder < missingSeq[b].folder
+		}
+		return missingSeq[a].sequence < missingSeq[b].sequence
+	})
+
+	var folder uint32
+	var startSeq, prevSeq uint64
+	for _, sk := range missingSeq {
+		if folder != sk.folder || sk.sequence != prevSeq+1 {
+			if folder != 0 {
+				fmt.Printf("Folder %d missing %d sequence entries: #%d - #%d\n", folder, prevSeq-startSeq+1, startSeq, prevSeq)
+			}
+			startSeq = sk.sequence
+			folder = sk.folder
+		}
+		prevSeq = sk.sequence
+	}
+	if folder != 0 {
+		fmt.Printf("Folder %d missing %d sequence entries: #%d - #%d\n", folder, prevSeq-startSeq+1, startSeq, prevSeq)
+	}
+
+	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
+		}
+		checkGlobal := func(i int, device []byte, version protocol.Vector, invalid, deleted bool) {
+			dev, ok := deviceToIDs[string(device)]
+			if !ok {
+				fmt.Printf("VersionList %q, folder %q refers to unknown device %q\n", gk.name, folder, 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
+			}
+
+			fiv := fi.Version
+			if fi.VersionHash != nil {
+				fiv = versions[string(fi.VersionHash)]
+			}
+			if !fiv.Equal(version) {
+				fmt.Printf("VersionList %q, folder %q, entry %d, FileInfo version mismatch, %v (VersionList) != %v (FileInfo)\n", gk.name, folder, i, version, fi.Version)
+				success = false
+			}
+			if fi.IsInvalid() != invalid {
+				fmt.Printf("VersionList %q, folder %q, entry %d, FileInfo invalid mismatch, %v (VersionList) != %v (FileInfo)\n", gk.name, folder, i, invalid, fi.IsInvalid())
+				success = false
+			}
+			if fi.IsDeleted() != deleted {
+				fmt.Printf("VersionList %q, folder %q, entry %d, FileInfo deleted mismatch, %v (VersionList) != %v (FileInfo)\n", gk.name, folder, i, deleted, fi.IsDeleted())
+				success = false
+			}
+		}
+		for i, fv := range vl.RawVersions {
+			for _, device := range fv.Devices {
+				checkGlobal(i, device, fv.Version, false, fv.Deleted)
+			}
+			for _, device := range fv.InvalidDevices {
+				checkGlobal(i, device, fv.Version, true, fv.Deleted)
+			}
+		}
+
+		// 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 {
+				fv, _ := vl.GetGlobal()
+				devB, _ := fv.FirstDevice()
+				dev := deviceToIDs[string(devB)]
+				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
+		}
+	}
+
+	if d := len(blocklists) - len(usedBlocklists); d > 0 {
+		fmt.Printf("%d block list entries out of %d needs GC\n", d, len(blocklists))
+	}
+	if d := len(versions) - len(usedVersions); d > 0 {
+		fmt.Printf("%d version entries out of %d needs GC\n", d, len(versions))
+	}
+
+	return
+}
+
+func needsLocally(vl db.VersionList) bool {
+	fv, ok := vl.Get(protocol.LocalDeviceID[:])
+	if !ok {
+		return true // proviosinally, it looks like we need the file
+	}
+	gfv, _ := vl.GetGlobal() // Can't not have a global if we got something above
+	return !fv.Version.GreaterEqual(gfv.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

@@ -13,7 +13,7 @@ import (
 	"os"
 	"path/filepath"

-	"github.com/syncthing/syncthing/lib/db"
+	"github.com/syncthing/syncthing/lib/db/backend"
 )

 func 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()

@@ -30,18 +30,34 @@ func main() {
 		path = filepath.Join(defaultConfigDir(), "index-v0.14.0.db")
 	}

-	fmt.Println("Path:", path)
-
-	ldb, err := db.Open(path)
+	var ldb backend.Backend
+	var err error
+	if looksLikeBadger(path) {
+		ldb, err = backend.OpenBadger(path)
+	} else {
+		ldb, err = backend.OpenLevelDBRO(path)
+	}
 	if err != nil {
 		log.Fatal(err)
 	}

-	if mode == "dump" {
+	switch mode {
+	case "dump":
 		dump(ldb)
-	} else if mode == "dumpsize" {
+	case "dumpsize":
 		dumpsize(ldb)
-	} else {
+	case "idxck":
+		if !idxck(ldb) {
+			os.Exit(1)
+		}
+	case "account":
+		account(ldb)
+	default:
 		fmt.Println("Unknown mode")
 	}
 }
+
+func looksLikeBadger(path string) bool {
+	_, err := os.Stat(filepath.Join(path, "KEYREGISTRY"))
+	return err == nil
+}
--- 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
@@ -1,16 +1,19 @@
 # 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.

--- 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 +2,22 @@

 <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 rel="stylesheet" href="https://use.fontawesome.com/releases/v5.0.13/css/all.css"/>
+    <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet"/>
+    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.0.13/css/all.css"/>
+    <link rel="stylesheet" href="https://unpkg.com/leaflet@1.6.0/dist/leaflet.css"
+  integrity="sha512-xwE/Az9zrjBIphAcBb3F6JVqxf46+CDLwfLMHloNu6KEQCAWi6HcDUbeOfBIptF7tcCzusKFjFw2yuvEpDL9wQ=="
+  crossorigin=""/>
+  <script src="https://unpkg.com/leaflet@1.6.0/dist/leaflet.js"
+  integrity="sha512-gZwIG9x3wUXg2hdXF6+rVkLF/0Vi9U8D2Ntg4Ga5I5BZpVkVxlJWbSQtXPSiUTtC0TjtGOmxa1AJPuV0CPthew=="
+  crossorigin=""></script>

    <style>
      #map {
@@ -36,19 +43,21 @@

  <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="https://cdnjs.cloudflare.com/ajax/libs/galleriffic/2.0.1/css/loader.gif" alt=""/>
        <p>Please wait while we gather data</p>
      </div>
      <div>
        <div ng-show="relays !== undefined" class="ng-hide">
          <p>
-            Currently {{ relays.length }} relays online ({{ totals.goMaxProcs }} cores in total).
+            The relays listed on this page are not managed or vetted by the Syncthing project.
+            Each relay is the responsibility of the relay operator.
+            Currently {{ relays.length }} relays online.
          </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 +65,105 @@
            <tr>
              <th rowspan="2">Address</td>
              <th rowspan="2">
-                <a ng-click="sortType = 'status.numActiveSessions'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.numActiveSessions'; sortReverse = !sortReverse">
                  Sessions
-                  <span ng-show="sortType == 'status.numActiveSessions' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.numActiveSessions' && 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'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.numConnections'; sortReverse = !sortReverse">
                  Connections
-                  <span ng-show="sortType == 'status.numConnections' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.numConnections' && 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'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.bytesProxied'; sortReverse = !sortReverse">
                  Data relayed
-                  <span ng-show="sortType == 'status.bytesProxied' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.bytesProxied' && 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'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.uptimeSeconds'; sortReverse = !sortReverse">
                  Uptime hours
-                  <span ng-show="sortType == 'status.uptimeSeconds' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.uptimeSeconds' && 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]'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[0]'; sortReverse = !sortReverse">
                  10s
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[0]' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[0]' && 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]'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[1]'; sortReverse = !sortReverse">
                  1m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[1]' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[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]'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[2]'; sortReverse = !sortReverse">
                  5m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[2]' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[2]' && 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]'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[3]'; sortReverse = !sortReverse">
                  15m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[3]' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[3]' && 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]'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[4]'; sortReverse = !sortReverse">
                  30m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[4]' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[4]' && 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]'; sortReverse = !sortReverse">
+                <a ng-click="sortType = 'stats.kbps10s1m5m15m30m60m[5]'; sortReverse = !sortReverse">
                  60m
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[5]' && !sortReverse" class="fa fa-caret-down"></span>
-                  <span ng-show="sortType == 'status.kbps10s1m5m15m30m60m[5]' && 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:sortCompare">
+            <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>
@@ -184,18 +193,17 @@
    </div>


-    <script src="//code.jquery.com/jquery-2.1.4.min.js"></script>
-    <script src="//cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/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="https://code.jquery.com/jquery-2.1.4.min.js"></script>
+    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.8/angular.min.js"></script>
+    <script type="text/javascript" src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
  </body>

  <script>
  angular.module('syncthing', [
  ])
-  .config(function($httpProvider) {
+  .config(['$httpProvider', function($httpProvider) {
    $httpProvider.defaults.timeout = 5000;
-  })
+  }])
  .filter('bytes', function() {
    return function(bytes, precision) {
      if (isNaN(parseFloat(bytes)) || !isFinite(bytes)) return '-';
@@ -228,23 +236,24 @@
      numProxies: 0,
      uptimeSeconds: 0,
    };
-    $scope.map = new google.maps.Map(document.getElementById('map'), {
-      zoom: 1,
-      mapTypeId: google.maps.MapTypeId.ROADMAP
-    });
-    $scope.mapBounds = new google.maps.LatLngBounds();
+    $scope.map = L.map('map').setView([40.90296, 1.90925], 2);
+    L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
+    {
+      attribution: 'Leaflet',
+      maxZoom: 17
+    }).addTo($scope.map);
    $scope.tooltipTemplate = $('#infoTemplate').html();
    $scope.usedLocations = {};
-    $scope.sortType = 'status.numActiveSessions';
+    $scope.sortType = 'stats.numActiveSessions';
    $scope.sortReverse = true;
    $scope.sortCompare = function(a, b) {
      if (a.value == b.value) {
        return 0;
      }
-      if (a.type == "undefined") {
+      if (a.type == "undefined" || a.type == "null") {
        return -1;
      }
-      if (b.type == "undefined") {
+      if (b.type == "undefined" || b.type == "null") {
        return 1;
      }
      return a.value > b.value ? 1 : -1;
@@ -252,29 +261,36 @@

    $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);
      if ($scope.relays.length == 1) {
+        //Center to only relay with zoom
+        $scope.map.panTo(new L.LatLng(relays[0].location.latitude, relays[0].location.longitude));
        $scope.map.setZoom(13);
      }
    });
@@ -294,72 +310,50 @@

        var locParts = loc.split(',');

-        relay.marker = new google.maps.Marker({
-          map: $scope.map,
-          position: new google.maps.LatLng(locParts[0], locParts[1]),
+        relay.marker = new L.Marker([relay.location.latitude, relay.location.longitude],{
          title: relay.url,
        });

        var scope = $rootScope.$new(true);
        scope.relay = relay;

-        relay.marker.info = new google.maps.InfoWindow({
-          content: $compile($scope.tooltipTemplate)(scope)[0],
+        var icon = new L.Icon({
+          iconSize:     [18, 28], // size of the icon
+          iconAnchor:   [9, 28], // point of the icon which will correspond to marker's location
+          shadowAnchor: [0, 0],  // the same for the shadow
+          popupAnchor:  [0, -27], // popup anchor
+          shadowSize:   [0,0],
+          iconUrl: 'https://cdn.rawgit.com/pointhi/leaflet-color-markers/master/img/marker-icon-red.png',
+          shadowUrl: 'https://cdnjs.cloudflare.com/ajax/libs/leaflet/0.7.7/images/marker-shadow.png',
        });

-        relay.marker.addListener('mouseover', function() {
-          relay.marker.info.open($scope.map, relay.marker);
-        });
+        relay.marker = new L.marker(new L.latLng(locParts[0], locParts[1]),{icon})
+                            .bindPopup($compile($scope.tooltipTemplate)(scope)[0],{})
+                            .on('mouseover', function (e) {
+                                this.openPopup();
+                            }).on('mouseout', function (e) {
+                                this.closePopup();
+                            }).addTo($scope.map);

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

-        $scope.mapBounds.extend(relay.marker.position);
-    }

    function addCircleToMap(relay) {
-      relay.marker.circle = new google.maps.Circle({
-        strokeColor: '#FF0000',
-        strokeOpacity: 0.8,
-        strokeWeight: 2,
-        fillColor: '#FF0000',
-        fillOpacity: 0.35,
-        map: $scope.map,
-        center: relay.marker.position,
-        radius: ((relay.status.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();
-
-
-      $http.get("http://" + relay.uri.hostname + ':' + ((relay.uri.args.statusAddr && relay.uri.args.statusAddr.split(':')[1]) || "22070") + "/status", { timeout: timeoutRequest.promise }).then(function (response) {
-        relay.status = response.data;
-        resolveStatus.resolve();
-        angular.forEach($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;
+      console.log(relay.location.latitude)
+      L.circle([relay.location.latitude, relay.location.longitude], 
+        {
+          radius: ((relay.stats.bytesProxied * 100) / $scope.totals.bytesProxied) * 10000,
+          color: "FF0000",
+          fillColor: "#FF0000",
+          fillOpacity: 0.35,
+        }).addTo($scope.map);
    }

    function constructURI(url) {
@@ -382,25 +376,25 @@

  <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
@@ -1,30 +1,33 @@
 // Copyright (C) 2015 Audrius Butkevicius and Contributors (see the CONTRIBUTORS file).

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

 import (
-	"bytes"
 	"compress/gzip"
+	"context"
 	"crypto/tls"
 	"encoding/json"
 	"flag"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
-	"math/rand"
-	"mime"
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"time"

 	"github.com/golang/groupcache/lru"
 	"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/assets"
+	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/relay/client"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/tlsutil"
@@ -34,12 +37,42 @@ import (
 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 {
@@ -47,9 +80,9 @@ 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 {
@@ -58,56 +91,72 @@ type result struct {
 }

 var (
-	testCert       tls.Certificate
-	listen         = ":80"
-	dir            string
-	evictionTime   = time.Hour
-	debug          bool
-	getLRUSize     = 10 << 10
-	getLimitBurst  = 10
-	getLimitAvg    = 1
-	postLRUSize    = 1 << 10
-	postLimitBurst = 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
+	requestQueueLen   = 10
+	requestProcessors = 1

-	getMut      = sync.NewRWMutex()
+	getMut      = sync.NewMutex()
 	getLRUCache *lru.Cache

-	postMut      = sync.NewRWMutex()
+	postMut      = sync.NewMutex()
 	postLRUCache *lru.Cache

-	requests = make(chan request, 10)
+	requests chan request

 	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() {
+	log.SetOutput(os.Stdout)
+	log.SetFlags(log.Lshortfile)
+
 	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.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.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.IntVar(&requestQueueLen, "request-queue", requestQueueLen, "Queue length for incoming test requests")
+	flag.IntVar(&requestProcessors, "request-processors", requestProcessors, "Number of request processor routines")

 	flag.Parse()

+	requests = make(chan request, requestQueueLen)
+
 	getLimit = 10 * time.Second / time.Duration(getLimitAvg)
 	postLimit = time.Minute / time.Duration(postLimitAvg)

@@ -118,12 +167,32 @@ func main() {
 	var err error

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

 	testCert = createTestCertificate()

-	go requestProcessor()
+	for i := 0; i < requestProcessors; i++ {
+		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 {
@@ -169,6 +238,7 @@ func main() {
 	handler := http.NewServeMux()
 	handler.HandleFunc("/", handleAssets)
 	handler.HandleFunc("/endpoint", handleRequest)
+	handler.HandleFunc("/metrics", handleMetrics)

 	srv := http.Server{
 		Handler:     handler,
@@ -181,66 +251,42 @@ 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) {
-	assets := auto.Assets()
+	w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+
 	path := r.URL.Path[1:]
 	if path == "" {
 		path = "index.html"
 	}

-	bs, ok := assets[path]
+	as, ok := auto.Assets()[path]
 	if !ok {
 		w.WriteHeader(http.StatusNotFound)
 		return
 	}

-	mtype := mimeTypeForFile(path)
-	if len(mtype) != 0 {
-		w.Header().Set("Content-Type", mtype)
-	}
-
-	if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
-		w.Header().Set("Content-Encoding", "gzip")
-	} else {
-		// ungzip if browser not send gzip accepted header
-		var gr *gzip.Reader
-		gr, _ = gzip.NewReader(bytes.NewReader(bs))
-		bs, _ = ioutil.ReadAll(gr)
-		gr.Close()
-	}
-	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(bs)))
-
-	w.Write(bs)
-}
-
-func 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.
-	ext := filepath.Ext(file)
-	switch ext {
-	case ".htm", ".html":
-		return "text/html"
-	case ".css":
-		return "text/css"
-	case ".js":
-		return "application/javascript"
-	case ".json":
-		return "application/json"
-	case ".png":
-		return "image/png"
-	case ".ttf":
-		return "application/x-font-ttf"
-	case ".woff":
-		return "application/x-font-woff"
-	case ".svg":
-		return "image/svg+xml"
-	default:
-		return mime.TypeByExtension(ext)
-	}
+	assets.Serve(w, r, as)
 }

 func handleRequest(w http.ResponseWriter, r *http.Request) {
+	timer := prometheus.NewTimer(apiRequestsSeconds.WithLabelValues(r.Method))
+
+	w = NewLoggingResponseWriter(w)
+	defer func() {
+		timer.ObserveDuration()
+		lw := w.(*loggingResponseWriter)
+		apiRequestsTotal.WithLabelValues(r.Method, strconv.Itoa(lw.statusCode)).Inc()
+	}()
+
 	if ipHeader != "" {
 		r.RemoteAddr = r.Header.Get(ipHeader)
 	}
@@ -248,13 +294,13 @@ func handleRequest(w http.ResponseWriter, r *http.Request) {
 	switch r.Method {
 	case "GET":
 		if limit(r.RemoteAddr, getLRUCache, getMut, getLimit, getLimitBurst) {
-			w.WriteHeader(429)
+			w.WriteHeader(httpStatusEnhanceYourCalm)
 			return
 		}
 		handleGetRequest(w, r)
 	case "POST":
 		if limit(r.RemoteAddr, postLRUCache, postMut, postLimit, postLimitBurst) {
-			w.WriteHeader(429)
+			w.WriteHeader(httpStatusEnhanceYourCalm)
 			return
 		}
 		handlePostRequest(w, r)
@@ -266,19 +312,24 @@ func handleRequest(w http.ResponseWriter, r *http.Request) {
 	}
 }

-func handleGetRequest(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+func handleGetRequest(rw http.ResponseWriter, r *http.Request) {
+	rw.Header().Set("Content-Type", "application/json; charset=utf-8")
 	mut.RLock()
 	relays := append(permanentRelays, knownRelays...)
 	mut.RUnlock()

 	// Shuffle
-	for i := range relays {
-		j := rand.Intn(i + 1)
-		relays[i], relays[j] = relays[j], relays[i]
+	rand.Shuffle(relays)
+
+	w := io.Writer(rw)
+	if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
+		rw.Header().Set("Content-Encoding", "gzip")
+		gw := gzip.NewWriter(rw)
+		defer gw.Close()
+		w = gw
 	}

-	json.NewEncoder(w).Encode(map[string][]relay{
+	_ = json.NewEncoder(w).Encode(map[string][]*relay{
 		"relays": relays,
 	})
 }
@@ -292,7 +343,7 @@ func handlePostRequest(w http.ResponseWriter, r *http.Request) {
 		if debug {
 			log.Println("Failed to parse payload")
 		}
-		http.Error(w, err.Error(), 500)
+		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}

@@ -301,7 +352,7 @@ func handlePostRequest(w http.ResponseWriter, r *http.Request) {
 		if debug {
 			log.Println("Failed to parse URI", newRelay.URL)
 		}
-		http.Error(w, err.Error(), 500)
+		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}

@@ -310,18 +361,14 @@ func handlePostRequest(w http.ResponseWriter, r *http.Request) {
 		if debug {
 			log.Println("Failed to split URI", newRelay.URL)
 		}
-		http.Error(w, err.Error(), 500)
+		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}

 	// 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)
@@ -333,18 +380,18 @@ func handlePostRequest(w http.ResponseWriter, r *http.Request) {
 		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
 		}
 	}
@@ -352,78 +399,105 @@ 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 err := client.TestRelay(context.TODO(), request.relay.uri, []tls.Certificate{testCert}, time.Second, 2*time.Second, 3); err != nil {
+		if debug {
+			log.Println("Test for relay", request.relay, "failed:", err)
+		}
+		request.result <- result{err, 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()
@@ -438,41 +512,38 @@ 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, intv time.Duration, burst int) bool {
-	host, _, err := net.SplitHostPort(addr)
-	if err != nil {
-		return false
+func limit(addr string, cache *lru.Cache, lock sync.Mutex, intv time.Duration, burst int) bool {
+	if host, _, err := net.SplitHostPort(addr); err == nil {
+		addr = host
 	}

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

-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
@@ -481,21 +552,30 @@ 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 {
@@ -505,7 +585,7 @@ 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", 20*365)
 	if err != nil {
 		log.Fatalln("Failed to create test X509 key pair:", err)
 	}
@@ -514,6 +594,8 @@ 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{}
@@ -531,7 +613,24 @@ 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.Since(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
@@ -1,18 +1,12 @@
 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 to 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 the `-pools=""` argument.

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