gui: Prioritize non-idle folder states (fixes #6169) (#6170)

We incorrectly gave a too small buffer to lz4.Compress, causing it to
allocate in some cases (when the data actually becomes larger when
compressed). This then panicked when passed to the buffer pool.

This ensures a buffer that is large enough, and adds tripwires closer to
the source in case this ever pops up again. There is a test that
exercises the issue.

.golangci.yml

@@ -12,9 +12,12 @@ linters:
     - gochecknoglobals
     - gofmt
     - scopelint
+    - gocyclo
+    - funlen
+    - wsl
 
 service:
-  golangci-lint-version: 1.17.x
+  golangci-lint-version: 1.21.x
   prepare:
     - rm -f go.sum # 1.12 -> 1.13 issues with QUIC-go
     - GO111MODULE=on go mod vendor

Dockerfile

@@ -19,10 +19,10 @@ RUN apk add --no-cache ca-certificates su-exec
 COPY --from=builder /src/syncthing /bin/syncthing
 COPY --from=builder /src/script/docker-entrypoint.sh /bin/entrypoint.sh
 
-ENV PUID=1000 PGID=1000
+ENV PUID=1000 PGID=1000 HOME=/var/syncthing
 
 HEALTHCHECK --interval=1m --timeout=10s \
   CMD nc -z localhost 8384 || exit 1
 
 ENV STGUIADDRESS=0.0.0.0:8384
-ENTRYPOINT ["/bin/entrypoint.sh", "-home", "/var/syncthing/config"]
+ENTRYPOINT ["/bin/entrypoint.sh", "/bin/syncthing", "-home", "/var/syncthing/config"]

Dockerfile.stdiscosrv

@@ -0,0 +1,28 @@
+FROM golang:1.13 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"]

Dockerfile.strelaysrv

@@ -0,0 +1,28 @@
+FROM golang:1.13 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"]

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 https://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 its resource usage in two
-// ways: human readable to stderr, and CSV to stdout.
-func report(p *rc.Process, wallTime time.Duration) {
-	sv, err := p.SystemVersion()
-	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)
-}

cmd/stcli/utils.go

@@ -12,7 +12,6 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
-	"text/tabwriter"
 
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/urfave/cli"
@@ -45,12 +44,6 @@ func dumpOutput(url string) cli.ActionFunc {
 	}
 }
 
-func newTableWriter() *tabwriter.Writer {
-	writer := new(tabwriter.Writer)
-	writer.Init(os.Stdout, 0, 8, 0, '\t', 0)
-	return writer
-}
-
 func getConfig(c *APIClient) (config.Configuration, error) {
 	cfg := config.Configuration{}
 	response, err := c.Get("system/config")

cmd/stdiscosrv/apisrv.go

@@ -18,6 +18,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
@@ -279,6 +280,10 @@ func (s *apiSrv) handleAnnounce(remote net.IP, deviceID protocol.DeviceID, addre
 		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)
@@ -295,28 +300,66 @@ func certificateBytes(req *http.Request) []byte {
 		return req.TLS.PeerCertificates[0].Raw
 	}
 
+	var bs []byte
+
 	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'
+		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'
+				}
 			}
 		}
-		block, _ := pem.Decode(bs)
-		if block == nil {
+	} 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
 		}
-		return block.Bytes
+
+		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)
 	}
 
-	return nil
+	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

cmd/stdiscosrv/database.go

@@ -10,6 +10,7 @@
 package main
 
 import (
+	"log"
 	"sort"
 	"time"
 
@@ -263,12 +264,15 @@ func (s *levelDBStore) Stop() {
 // chosen for any duplicates.
 func merge(a, b DatabaseRecord) DatabaseRecord {
 	// Both lists must be sorted for this to work.
-	sort.Slice(a.Addresses, func(i, j int) bool {
-		return a.Addresses[i].Address < a.Addresses[j].Address
-	})
-	sort.Slice(b.Addresses, func(i, j int) bool {
-		return b.Addresses[i].Address < b.Addresses[j].Address
-	})
+	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)),
@@ -352,3 +356,24 @@ func expire(addrs []DatabaseAddress, now int64) []DatabaseAddress {
 	}
 	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)
+}

cmd/stdiscosrv/database.pb.go

@@ -773,6 +773,7 @@ func (m *DatabaseAddress) Unmarshal(dAtA []byte) error {
 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 {
@@ -804,10 +805,8 @@ func skipDatabase(dAtA []byte) (n int, err error) {
 					break
 				}
 			}
-			return iNdEx, nil
 		case 1:
 			iNdEx += 8
-			return iNdEx, nil
 		case 2:
 			var length int
 			for shift := uint(0); ; shift += 7 {
@@ -828,55 +827,30 @@ func skipDatabase(dAtA []byte) (n int, err error) {
 				return 0, ErrInvalidLengthDatabase
 			}
 			iNdEx += length
-			if iNdEx < 0 {
-				return 0, ErrInvalidLengthDatabase
-			}
-			return iNdEx, nil
 		case 3:
-			for {
-				var innerWire uint64
-				var start int = iNdEx
-				for shift := uint(0); ; shift += 7 {
-					if shift >= 64 {
-						return 0, ErrIntOverflowDatabase
-					}
-					if iNdEx >= l {
-						return 0, io.ErrUnexpectedEOF
-					}
-					b := dAtA[iNdEx]
-					iNdEx++
-					innerWire |= (uint64(b) & 0x7F) << shift
-					if b < 0x80 {
-						break
-					}
-				}
-				innerWireType := int(innerWire & 0x7)
-				if innerWireType == 4 {
-					break
-				}
-				next, err := skipDatabase(dAtA[start:])
-				if err != nil {
-					return 0, err
-				}
-				iNdEx = start + next
-				if iNdEx < 0 {
-					return 0, ErrInvalidLengthDatabase
-				}
-			}
-			return iNdEx, nil
+			depth++
 		case 4:
-			return iNdEx, nil
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupDatabase
+			}
+			depth--
 		case 5:
 			iNdEx += 4
-			return iNdEx, nil
 		default:
 			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
 		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthDatabase
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
 	}
-	panic("unreachable")
+	return 0, io.ErrUnexpectedEOF
 }
 
 var (
-	ErrInvalidLengthDatabase = fmt.Errorf("proto: negative length found during unmarshaling")
-	ErrIntOverflowDatabase   = fmt.Errorf("proto: integer overflow")
+	ErrInvalidLengthDatabase        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowDatabase          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupDatabase = fmt.Errorf("proto: unexpected end of group")
 )

cmd/stdiscosrv/main.go

@@ -100,7 +100,7 @@ func main() {
 	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
 	if err != nil {
 		log.Println("Failed to load keypair. Generating one, this might take a while...")
-		cert, err = tlsutil.NewCertificate(certFile, keyFile, "stdiscosrv")
+		cert, err = tlsutil.NewCertificate(certFile, keyFile, "stdiscosrv", 20*365)
 		if err != nil {
 			log.Fatalln("Failed to generate X509 key pair:", err)
 		}

cmd/strelaypoolsrv/main.go

@@ -633,7 +633,7 @@ func createTestCertificate() tls.Certificate {
 	}
 
 	certFile, keyFile := filepath.Join(tmpDir, "cert.pem"), filepath.Join(tmpDir, "key.pem")
-	cert, err := tlsutil.NewCertificate(certFile, keyFile, "relaypoolsrv")
+	cert, err := tlsutil.NewCertificate(certFile, keyFile, "relaypoolsrv", 20*365)
 	if err != nil {
 		log.Fatalln("Failed to create test X509 key pair:", err)
 	}

cmd/strelaysrv/main.go

@@ -155,7 +155,7 @@ func main() {
 	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
 	if err != nil {
 		log.Println("Failed to load keypair. Generating one, this might take a while...")
-		cert, err = tlsutil.NewCertificate(certFile, keyFile, "strelaysrv")
+		cert, err = tlsutil.NewCertificate(certFile, keyFile, "strelaysrv", 20*365)
 		if err != nil {
 			log.Fatalln("Failed to generate X509 key pair:", err)
 		}

cmd/syncthing/main.go

@@ -45,19 +45,8 @@ import (
 )
 
 const (
-	exitSuccess            = 0
-	exitError              = 1
-	exitNoUpgradeAvailable = 2
-	exitRestarting         = 3
-	exitUpgrading          = 4
-)
-
-const (
-	bepProtocolName      = "bep/1.0"
-	tlsDefaultCommonName = "syncthing"
-	maxSystemErrors      = 5
-	initialSystemLog     = 10
-	maxSystemLog         = 250
+	tlsDefaultCommonName   = "syncthing"
+	deviceCertLifetimeDays = 20 * 365
 )
 
 const (
@@ -271,7 +260,7 @@ func main() {
 	// default location
 	if options.noRestart && (options.logFile != "" && options.logFile != "-") {
 		l.Warnln("-logfile may not be used with -no-restart or STNORESTART")
-		os.Exit(exitError)
+		os.Exit(syncthing.ExitError.AsInt())
 	}
 
 	if options.hideConsole {
@@ -285,12 +274,12 @@ func main() {
 			options.confDir, err = filepath.Abs(options.confDir)
 			if err != nil {
 				l.Warnln("Failed to make options path absolute:", err)
-				os.Exit(exitError)
+				os.Exit(syncthing.ExitError.AsInt())
 			}
 		}
 		if err := locations.SetBaseDir(locations.ConfigBaseDir, options.confDir); err != nil {
 			l.Warnln(err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 	}
 
@@ -328,7 +317,7 @@ func main() {
 		)
 		if err != nil {
 			l.Warnln("Error reading device ID:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 
 		fmt.Println(protocol.NewDeviceID(cert.Certificate[0]))
@@ -338,7 +327,7 @@ func main() {
 	if options.browserOnly {
 		if err := openGUI(protocol.EmptyDeviceID); err != nil {
 			l.Warnln("Failed to open web UI:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		return
 	}
@@ -346,7 +335,7 @@ func main() {
 	if options.generateDir != "" {
 		if err := generate(options.generateDir); err != nil {
 			l.Warnln("Failed to generate config and keys:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		return
 	}
@@ -354,14 +343,14 @@ func main() {
 	// Ensure that our home directory exists.
 	if err := ensureDir(locations.GetBaseDir(locations.ConfigBaseDir), 0700); err != nil {
 		l.Warnln("Failure on home directory:", err)
-		os.Exit(exitError)
+		os.Exit(syncthing.ExitError.AsInt())
 	}
 
 	if options.upgradeTo != "" {
 		err := upgrade.ToURL(options.upgradeTo)
 		if err != nil {
 			l.Warnln("Error while Upgrading:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		l.Infoln("Upgraded from", options.upgradeTo)
 		return
@@ -381,7 +370,7 @@ func main() {
 	if options.resetDatabase {
 		if err := resetDB(); err != nil {
 			l.Warnln("Resetting database:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		return
 	}
@@ -424,7 +413,7 @@ func generate(generateDir string) error {
 	if err == nil {
 		l.Warnln("Key exists; will not overwrite.")
 	} else {
-		cert, err = tlsutil.NewCertificate(certFile, keyFile, tlsDefaultCommonName)
+		cert, err = tlsutil.NewCertificate(certFile, keyFile, tlsDefaultCommonName, deviceCertLifetimeDays)
 		if err != nil {
 			return errors.Wrap(err, "create certificate")
 		}
@@ -476,13 +465,13 @@ func checkUpgrade() upgrade.Release {
 	release, err := upgrade.LatestRelease(opts.ReleasesURL, build.Version, opts.UpgradeToPreReleases)
 	if err != nil {
 		l.Warnln("Upgrade:", err)
-		os.Exit(exitError)
+		os.Exit(syncthing.ExitError.AsInt())
 	}
 
 	if upgrade.CompareVersions(release.Tag, build.Version) <= 0 {
 		noUpgradeMessage := "No upgrade available (current %q >= latest %q)."
 		l.Infof(noUpgradeMessage, build.Version, release.Tag)
-		os.Exit(exitNoUpgradeAvailable)
+		os.Exit(syncthing.ExitNoUpgradeAvailable.AsInt())
 	}
 
 	l.Infof("Upgrade available (current %q < latest %q)", build.Version, release.Tag)
@@ -496,7 +485,7 @@ func performUpgrade(release upgrade.Release) {
 		err = upgrade.To(release)
 		if err != nil {
 			l.Warnln("Upgrade:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		l.Infof("Upgraded to %q", release.Tag)
 	} else {
@@ -504,10 +493,10 @@ func performUpgrade(release upgrade.Release) {
 		err = upgradeViaRest()
 		if err != nil {
 			l.Warnln("Upgrade:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		l.Infoln("Syncthing upgrading")
-		os.Exit(exitUpgrading)
+		os.Exit(syncthing.ExitUpgrade.AsInt())
 	}
 }
 
@@ -573,7 +562,7 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 	cfg, err := syncthing.LoadConfigAtStartup(locations.Get(locations.ConfigFile), cert, evLogger, runtimeOptions.allowNewerConfig, noDefaultFolder)
 	if err != nil {
 		l.Warnln("Failed to initialize config:", err)
-		os.Exit(exitError)
+		os.Exit(syncthing.ExitError.AsInt())
 	}
 
 	if runtimeOptions.unpaused {
@@ -610,11 +599,11 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 		f, err := os.Create(fmt.Sprintf("cpu-%d.pprof", os.Getpid()))
 		if err != nil {
 			l.Warnln("Creating profile:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		if err := pprof.StartCPUProfile(f); err != nil {
 			l.Warnln("Starting profile:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 	}
 
@@ -647,7 +636,9 @@ func syncthingMain(runtimeOptions RuntimeOptions) {
 		}
 	}
 
-	app.Start()
+	if err := app.Start(); err != nil {
+		os.Exit(syncthing.ExitError.AsInt())
+	}
 
 	cleanConfigDirectory()
 
@@ -721,7 +712,7 @@ func auditWriter(auditFile string) io.Writer {
 		fd, err = os.OpenFile(auditFile, auditFlags, 0600)
 		if err != nil {
 			l.Warnln("Audit:", err)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 		auditDest = auditFile
 	}
@@ -897,6 +888,6 @@ func setPauseState(cfg config.Wrapper, paused bool) {
 	}
 	if _, err := cfg.Replace(raw); err != nil {
 		l.Warnln("Cannot adjust paused state:", err)
-		os.Exit(exitError)
+		os.Exit(syncthing.ExitError.AsInt())
 	}
 }

cmd/syncthing/monitor.go

@@ -23,6 +23,7 @@ import (
 	"github.com/syncthing/syncthing/lib/osutil"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/sync"
+	"github.com/syncthing/syncthing/lib/syncthing"
 )
 
 var (
@@ -81,7 +82,7 @@ func monitorMain(runtimeOptions RuntimeOptions) {
 
 		if t := time.Since(restarts[0]); t < loopThreshold {
 			l.Warnf("%d restarts in %v; not retrying further", countRestarts, t)
-			os.Exit(exitError)
+			os.Exit(syncthing.ExitError.AsInt())
 		}
 
 		copy(restarts[0:], restarts[1:])
@@ -150,17 +151,14 @@ func monitorMain(runtimeOptions RuntimeOptions) {
 				// Successful exit indicates an intentional shutdown
 				return
 			} else if exiterr, ok := err.(*exec.ExitError); ok {
-				if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
-					switch status.ExitStatus() {
-					case exitUpgrading:
-						// Restart the monitor process to release the .old
-						// binary as part of the upgrade process.
-						l.Infoln("Restarting monitor...")
-						if err = restartMonitor(args); err != nil {
-							l.Warnln("Restart:", err)
-						}
-						return
+				if exiterr.ExitCode() == syncthing.ExitUpgrade.AsInt() {
+					// Restart the monitor process to release the .old
+					// binary as part of the upgrade process.
+					l.Infoln("Restarting monitor...")
+					if err = restartMonitor(args); err != nil {
+						l.Warnln("Restart:", err)
 					}
+					return
 				}
 			}
 		}

go.mod

@@ -15,16 +15,16 @@ require (
 	github.com/getsentry/raven-go v0.2.0
 	github.com/go-ole/go-ole v1.2.4 // indirect
 	github.com/gobwas/glob v0.2.3
-	github.com/gogo/protobuf v1.3.0
+	github.com/gogo/protobuf v1.3.1
 	github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6
 	github.com/golang/mock v1.3.1 // indirect
 	github.com/jackpal/gateway v1.0.5
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/lib/pq v1.2.0
-	github.com/lucas-clemente/quic-go v0.12.0
+	github.com/lucas-clemente/quic-go v0.12.1
 	github.com/maruel/panicparse v1.3.0
-	github.com/mattn/go-isatty v0.0.9
+	github.com/mattn/go-isatty v0.0.10
 	github.com/minio/sha256-simd v0.1.1
 	github.com/onsi/ginkgo v1.9.0 // indirect
 	github.com/onsi/gomega v1.6.0 // indirect
@@ -32,9 +32,7 @@ require (
 	github.com/oschwald/maxminddb-golang v1.4.0 // indirect
 	github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 // indirect
 	github.com/pkg/errors v0.8.1
-	github.com/prometheus/client_golang v1.1.0
-	github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4 // indirect
-	github.com/prometheus/procfs v0.0.4 // indirect
+	github.com/prometheus/client_golang v1.2.1
 	github.com/rcrowley/go-metrics v0.0.0-20190826022208-cac0b30c2563
 	github.com/sasha-s/go-deadlock v0.2.0
 	github.com/shirou/gopsutil v0.0.0-20190714054239-47ef3260b6bf
@@ -45,7 +43,6 @@ require (
 	github.com/vitrun/qart v0.0.0-20160531060029-bf64b92db6b0
 	golang.org/x/crypto v0.0.0-20190829043050-9756ffdc2472
 	golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297
-	golang.org/x/sys v0.0.0-20190904154756-749cb33beabd // indirect
 	golang.org/x/text v0.3.2
 	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
 	gopkg.in/asn1-ber.v1 v1.0.0-20181015200546-f715ec2f112d // indirect

go.sum

@@ -10,7 +10,9 @@ github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6/go.mod h1:3eOhrU
 github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d h1:G0m3OIz70MZUWq3EgK3CesDbo8upS2Vm9/P3FtgI+Jk=
 github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
+github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 h1:xJ4a3vCFaGF/jqvzLMYoU8P317H5OQ+Via4RmuPwCS0=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
@@ -25,6 +27,8 @@ github.com/ccding/go-stun v0.0.0-20180726100737-be486d185f3d h1:As4937T5NVbJ/DmZ
 github.com/ccding/go-stun v0.0.0-20180726100737-be486d185f3d/go.mod h1:3FK1bMar37f7jqVY7q/63k3OMX1c47pGCufzt3X0sYE=
 github.com/certifi/gocertifi v0.0.0-20190905060710-a5e0173ced67 h1:8k9FLYBLKT+9v2HQJ/a95ZemmTx+/ltJcAiRhVushG8=
 github.com/certifi/gocertifi v0.0.0-20190905060710-a5e0173ced67/go.mod h1:GJKEexRPVJrBSOjoqN5VNOIKJ5Q3RViH6eu3puDRwx4=
+github.com/cespare/xxhash/v2 v2.1.0 h1:yTUvW7Vhb89inJ+8irsUqiWjh8iT6sQPZiQzI6ReGkA=
+github.com/cespare/xxhash/v2 v2.1.0/go.mod h1:dgIUBU3pDso/gPgZ1osOZ0iQf77oPR28Tjxl5dIMyVM=
 github.com/cheekybits/genny v1.0.0 h1:uGGa4nei+j20rOSeDeP5Of12XVm7TGUd4dJA9RDitfE=
 github.com/cheekybits/genny v1.0.0/go.mod h1:+tQajlRqAUrPI7DOSpB0XAqZYtQakVtB7wXkRAgjxjQ=
 github.com/chmduquesne/rollinghash v0.0.0-20180912150627-a60f8e7142b5 h1:Wg96Dh0MLTanEaPO0OkGtUIaa2jOnShAIOVUIzRHUxo=
@@ -43,6 +47,7 @@ github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMo
 github.com/getsentry/raven-go v0.2.0 h1:no+xWJRb5ZI7eE8TWgIq1jLulQiIoLG0IfYxv5JYMGs=
 github.com/getsentry/raven-go v0.2.0/go.mod h1:KungGk8q33+aIAZUIVWZDr2OfAEBsO49PX4NzFV5kcQ=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
+github.com/go-kit/kit v0.9.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-ole/go-ole v1.2.1 h1:2lOsA72HgjxAuMlKpFiCbHTvu44PIVkZ5hqm3RSdI/E=
@@ -55,6 +60,8 @@ github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJA
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.3.0 h1:G8O7TerXerS4F6sx9OV7/nRfJdnXgHZu/S/7F2SN+UE=
 github.com/gogo/protobuf v1.3.0/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
+github.com/gogo/protobuf v1.3.1 h1:DqDEcV5aeaTmdFBePNpYsp3FlcVH/2ISVVM9Qf8PSls=
+github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
 github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6 h1:ZgQEtGgCBiWRM39fZuwSd1LwSqqSW0hOdXCYYDX0R3I=
 github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.2.0 h1:28o5sBqPkBsMGnC6b4MvE2TzSr5/AT4c/1fLqVGIwlk=
@@ -95,6 +102,8 @@ github.com/lib/pq v1.2.0 h1:LXpIM/LZ5xGFhOpXAQUIMM1HdyqzVYM13zNdjCEEcA0=
 github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lucas-clemente/quic-go v0.12.0 h1:TRbvZ6F++sofeGbh+Z2IIyIOhl8KyGnYuA06g2yrHdI=
 github.com/lucas-clemente/quic-go v0.12.0/go.mod h1:UXJJPE4RfFef/xPO5wQm0tITK8gNfqwTxjbE7s3Vb8s=
+github.com/lucas-clemente/quic-go v0.12.1 h1:BPITli+6KnKogtTxBk2aS4okr5dUHz2LtIDAP1b8UL4=
+github.com/lucas-clemente/quic-go v0.12.1/go.mod h1:UXJJPE4RfFef/xPO5wQm0tITK8gNfqwTxjbE7s3Vb8s=
 github.com/marten-seemann/qpack v0.1.0/go.mod h1:LFt1NU/Ptjip0C2CPkhimBz5CGE3WGDAUWqna+CNTrI=
 github.com/marten-seemann/qtls v0.3.2 h1:O7awy4bHEzSX/K3h+fZig3/Vo03s/RxlxgsAk9sYamI=
 github.com/marten-seemann/qtls v0.3.2/go.mod h1:xzjG7avBwGGbdZ8dTGxlBnLArsVKLvwmjgmPuiQEcYk=
@@ -107,6 +116,8 @@ github.com/mattn/go-isatty v0.0.7 h1:UvyT9uN+3r7yLEYSlJsbQGdsaB/a0DlgWP3pql6iwOc
 github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
 github.com/mattn/go-isatty v0.0.9 h1:d5US/mDsogSGW37IV293h//ZFaeajb69h+EHFsv2xGg=
 github.com/mattn/go-isatty v0.0.9/go.mod h1:YNRxwqDuOph6SZLI9vUUz6OYw3QyUt7WiY2yME+cCiQ=
+github.com/mattn/go-isatty v0.0.10 h1:qxFzApOv4WsAL965uUPIsXzAKCZxN2p9UqdhFS4ZW10=
+github.com/mattn/go-isatty v0.0.10/go.mod h1:qgIWMr58cqv1PHHyhnkY9lrL7etaEgOFcMEpPG5Rm84=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/mgutz/ansi v0.0.0-20170206155736-9520e82c474b h1:j7+1HpAFS1zy5+Q4qx1fWh90gTKwiN4QCGoY9TWyyO4=
@@ -142,6 +153,8 @@ github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXP
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_golang v1.1.0 h1:BQ53HtBmfOitExawJ6LokA4x8ov/z0SYYb0+HxJfRI8=
 github.com/prometheus/client_golang v1.1.0/go.mod h1:I1FGZT9+L76gKKOs5djB6ezCbFQP1xR9D75/vuwEF3g=
+github.com/prometheus/client_golang v1.2.1 h1:JnMpQc6ppsNgw9QPAGF6Dod479itz7lvlsMzzNayLOI=
+github.com/prometheus/client_golang v1.2.1/go.mod h1:XMU6Z2MjaRKVu/dC1qupJI9SiNkDYzz3xecMgSW/F+U=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910 h1:idejC8f05m9MGOsuEi1ATq9shN03HrxNkD/luQvxCv8=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
@@ -152,6 +165,8 @@ github.com/prometheus/common v0.4.1 h1:K0MGApIoQvMw27RTdJkPbr3JZ7DNbtxQNyi5STVM6
 github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.6.0 h1:kRhiuYSXR3+uv2IbVbZhUxK5zVD/2pp3Gd2PpvPkpEo=
 github.com/prometheus/common v0.6.0/go.mod h1:eBmuwkDJBwy6iBfxCBob6t6dR6ENT/y+J+Zk0j9GMYc=
+github.com/prometheus/common v0.7.0 h1:L+1lyG48J1zAQXA3RBX/nG/B3gjlHq0zTt2tlbJLyCY=
+github.com/prometheus/common v0.7.0/go.mod h1:DjGbpBbp5NYNiECxcL/VnbXCCaQpKd3tt26CguLLsqA=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.2 h1:6LJUbpNm42llc4HRCuvApCSWB/WfhuNo9K98Q9sNGfs=
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
@@ -159,6 +174,8 @@ github.com/prometheus/procfs v0.0.3 h1:CTwfnzjQ+8dS6MhHHu4YswVAD99sL2wjPqP+VkURm
 github.com/prometheus/procfs v0.0.3/go.mod h1:4A/X28fw3Fc593LaREMrKMqOKvUAntwMDaekg4FpcdQ=
 github.com/prometheus/procfs v0.0.4 h1:w8DjqFMJDjuVwdZBQoOozr4MVWOnwF7RcL/7uxBjY78=
 github.com/prometheus/procfs v0.0.4/go.mod h1:4A/X28fw3Fc593LaREMrKMqOKvUAntwMDaekg4FpcdQ=
+github.com/prometheus/procfs v0.0.5 h1:3+auTFlqw+ZaQYJARz6ArODtkaIwtvBTx3N2NehQlL8=
+github.com/prometheus/procfs v0.0.5/go.mod h1:4A/X28fw3Fc593LaREMrKMqOKvUAntwMDaekg4FpcdQ=
 github.com/rcrowley/go-metrics v0.0.0-20190826022208-cac0b30c2563 h1:dY6ETXrvDG7Sa4vE8ZQG4yqWg6UnOcbqTAahkV813vQ=
 github.com/rcrowley/go-metrics v0.0.0-20190826022208-cac0b30c2563/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
@@ -171,6 +188,7 @@ github.com/shirou/w32 v0.0.0-20160930032740-bb4de0191aa4/go.mod h1:qsXQc7+bwAM3Q
 github.com/shurcooL/sanitized_anchor_name v1.0.0 h1:PdmoCO6wvbs+7yrJyMORt4/BmY5IYyJwS/kOiWx8mHo=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
+github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
@@ -221,11 +239,16 @@ golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190228124157-a34e9553db1e h1:ZytStCyV048ZqDsWHiYDdoI2Vd4msMcrDECFxS+tL9c=
 golang.org/x/sys v0.0.0-20190228124157-a34e9553db1e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190801041406-cbf593c0f2f3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a h1:aYOabOQFp6Vj6W1F80affTUvO9UxmJRx8K0gsfABByQ=
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190904154756-749cb33beabd h1:DBH9mDw0zluJT/R+nGuV3jWFWLFaHyYZWD4tOT+cjn0=
 golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191008105621-543471e840be h1:QAcqgptGM8IQBC9K/RC4o+O9YmqEm0diQn9QmZw/0mU=
+golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191010194322-b09406accb47 h1:/XfQ9z7ib8eEJX2hdgFTZJ/ntt0swNk5oYBziWeTCvY=
+golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=

gui/default/assets/css/theme.css

@@ -7,29 +7,5 @@
 
 */
 
-.panel-progress {
-    background: #3498db;
-}
-
-.identicon rect {
-    fill: #333;
-}
-
-.panel-warning .identicon rect {
-    fill: #fff;
-}
-
-.li-column {
-    background-color: rgb(236, 240, 241);
-    border-radius: 3px;
-}
-
-.panel-heading:hover, .panel-heading:focus {
-    text-decoration: none;
-}
-
-.fancytree-ext-filter-hide tr.fancytree-submatch span.fancytree-title,
-.fancytree-ext-filter-hide span.fancytree-node.fancytree-submatch span.fancytree-title {
-    color: black !important;
-    font-weight: lighter !important;
-}
+@import "../../theme-assets/dark/assets/css/theme.css" screen and (prefers-color-scheme: dark);
+@import "../../theme-assets/light/assets/css/theme.css" (prefers-color-scheme: light), (prefers-color-scheme: no-preference);

gui/default/index.html

@@ -323,6 +323,11 @@
                     <span class="visible-xs" aria-label="{{'Scanning' | translate}}"><i class="fas fa-fw fa-search"></i></span>
                   </span>
                   <span ng-switch-when="idle"><span class="hidden-xs" translate>Up to Date</span><span class="visible-xs" aria-label="{{'Up to Date' | translate}}"><i class="fas fa-fw fa-check"></i></span></span>
+                  <span ng-switch-when="localadditions"><span class="hidden-xs" translate>Local Additions</span><span class="visible-xs" aria-label="{{'Local Additions' | translate}}"><i class="fas fa-fw fa-check"></i></span></span>
+                  <span ng-switch-when="sync-preparing">
+                    <span class="hidden-xs" translate>Preparing to Sync</span>
+                    <span class="visible-xs" aria-label="{{'Preparing to Sync' | translate}}"><i class="fas fa-fw fa-hourglass-half"></i></span>
+                  </span>
                   <span ng-switch-when="syncing">
                     <span class="hidden-xs" translate>Syncing</span>
                     <span>({{syncPercentage(folder.id) | percent}}, {{model[folder.id].needBytes | binary}}B)</span>

gui/default/syncthing/app.js

@@ -66,6 +66,14 @@ function folderCompare(a, b) {
     return labelA > labelB;
 }
 
+function deviceMap(l) {
+    var m = {};
+    l.forEach(function (r) {
+        m[r.deviceID] = r;
+    });
+    return m;
+}
+
 function folderMap(l) {
     var m = {};
     l.forEach(function (r) {

gui/default/syncthing/core/syncthingController.js

@@ -60,7 +60,9 @@ angular.module('syncthing.core')
         } catch (exception) { }
 
         $scope.folderDefaults = {
+            sharedDevices: {},
             selectedDevices: {},
+            unrelatedDevices: {},
             type: "sendreceive",
             rescanIntervalS: 3600,
             fsWatcherDelayS: 10,
@@ -387,6 +389,7 @@ angular.module('syncthing.core')
             });
 
             refreshNoAuthWarning();
+            setDefaultTheme();
 
             if (!hasConfig) {
                 $scope.$emit('ConfigLoaded');
@@ -649,6 +652,23 @@ angular.module('syncthing.core')
             $scope.remoteNeedDevice = undefined;
         }
 
+
+        function setDefaultTheme() {
+            if (!document.getElementById("fallback-theme-css")){
+
+                // check if no support for prefers-color-scheme
+                var colorSchemeNotSupported = typeof window.matchMedia === "undefined" || window.matchMedia('(prefers-color-scheme: dark)').media === 'not all';
+
+                if ($scope.config.gui.theme === "default" && colorSchemeNotSupported) {
+                    document.documentElement.style.display = 'none';
+                    document.head.insertAdjacentHTML(
+                      'beforeend',
+                      '<link id="fallback-theme-css" rel="stylesheet" href="theme-assets/light/assets/css/theme.css" onload="document.documentElement.style.display = \'\'">'
+                    );
+                }
+            }
+        }
+
         function saveIgnores(ignores, cb) {
             $http.post(urlbase + '/db/ignores?folder=' + encodeURIComponent($scope.currentFolder.id), {
                 ignore: ignores
@@ -768,25 +788,31 @@ angular.module('syncthing.core')
                 return 'paused';
             }
 
+            var folderInfo = $scope.model[folderCfg.id];
+
             // after restart syncthing process state may be empty
-            if (!$scope.model[folderCfg.id].state) {
+            if (!folderInfo.state) {
                 return 'unknown';
             }
 
-            var state = '' + $scope.model[folderCfg.id].state;
+            var state = '' + folderInfo.state;
             if (state === 'error') {
                 return 'stopped'; // legacy, the state is called "stopped" in the GUI
             }
-            if (state === 'idle' && $scope.model[folderCfg.id].needTotalItems > 0) {
+
+            if (state !== 'idle') {
+                return state;
+            }
+
+            if (folderInfo.needTotalItems > 0) {
                 return 'outofsync';
             }
             if ($scope.hasFailedFiles(folderCfg.id)) {
                 return 'faileditems';
             }
-            if (state === 'scanning') {
-                return state;
+            if (folderInfo.receiveOnlyTotalItems) {
+                return 'localadditions';
             }
-
             if (folderCfg.devices.length <= 1) {
                 return 'unshared';
             }
@@ -797,13 +823,13 @@ angular.module('syncthing.core')
         $scope.folderClass = function (folderCfg) {
             var status = $scope.folderStatus(folderCfg);
 
-            if (status === 'idle') {
+            if (status === 'idle' || status === 'localadditions') {
                 return 'success';
             }
             if (status == 'paused') {
                 return 'default';
             }
-            if (status === 'syncing' || status === 'scanning') {
+            if (status === 'syncing' || status === 'sync-preparing' || status === 'scanning') {
                 return 'primary';
             }
             if (status === 'unknown') {
@@ -968,6 +994,7 @@ angular.module('syncthing.core')
             for (var i = 0; i < folderListCache.length; i++) {
                 var status = $scope.folderStatus(folderListCache[i]);
                 switch (status) {
+                    case 'sync-preparing':
                     case 'syncing':
                         syncCount++;
                         break;
@@ -1398,13 +1425,13 @@ angular.module('syncthing.core')
         };
 
         $scope.selectAllFolders = function () {
-            angular.forEach($scope.folders, function (id) {
+            angular.forEach($scope.folders, function (_, id) {
                 $scope.currentDevice.selectedFolders[id] = true;
             });
         };
 
         $scope.deSelectAllFolders = function () {
-            angular.forEach($scope.folders, function (id) {
+            angular.forEach($scope.folders, function (_, id) {
                 $scope.currentDevice.selectedFolders[id] = false;
             });
         };
@@ -1678,10 +1705,20 @@ angular.module('syncthing.core')
             if ($scope.currentFolder.path.length > 1 && $scope.currentFolder.path.slice(-1) === $scope.system.pathSeparator) {
                 $scope.currentFolder.path = $scope.currentFolder.path.slice(0, -1);
             }
+            // Cache complete device objects indexed by ID for lookups
+            var devMap = deviceMap($scope.devices)
+            $scope.currentFolder.sharedDevices = [];
             $scope.currentFolder.selectedDevices = {};
             $scope.currentFolder.devices.forEach(function (n) {
+                if (n.deviceID !== $scope.myID) {
+                    $scope.currentFolder.sharedDevices.push(devMap[n.deviceID]);
+                }
                 $scope.currentFolder.selectedDevices[n.deviceID] = true;
             });
+            $scope.currentFolder.unrelatedDevices = $scope.devices.filter(function (n) {
+                return n.deviceID !== $scope.myID
+                    && ! $scope.currentFolder.selectedDevices[n.deviceID]
+            });
             if ($scope.currentFolder.versioning && $scope.currentFolder.versioning.type === "trashcan") {
                 $scope.currentFolder.trashcanFileVersioning = true;
                 $scope.currentFolder.fileVersioningSelector = "trashcan";
@@ -1732,17 +1769,17 @@ angular.module('syncthing.core')
             $scope.editFolderModal();
         };
 
-        $scope.selectAllDevices = function () {
-            var devices = $scope.otherDevices();
+        $scope.selectAllSharedDevices = function (state) {
+            var devices = $scope.currentFolder.sharedDevices;
             for (var i = 0; i < devices.length; i++) {
-                $scope.currentFolder.selectedDevices[devices[i].deviceID] = true;
+                $scope.currentFolder.selectedDevices[devices[i].deviceID] = !!state;
             }
         };
 
-        $scope.deSelectAllDevices = function () {
-            var devices = $scope.otherDevices();
+        $scope.selectAllUnrelatedDevices = function (state) {
+            var devices = $scope.currentFolder.unrelatedDevices;
             for (var i = 0; i < devices.length; i++) {
-                $scope.currentFolder.selectedDevices[devices[i].deviceID] = false;
+                $scope.currentFolder.selectedDevices[devices[i].deviceID] = !!state;
             }
         };
 
@@ -1751,6 +1788,7 @@ angular.module('syncthing.core')
                 $scope.editingExisting = false;
                 $scope.currentFolder = angular.copy($scope.folderDefaults);
                 $scope.currentFolder.id = (data.random.substr(0, 5) + '-' + data.random.substr(5, 5)).toLowerCase();
+                $scope.currentFolder.unrelatedDevices = $scope.otherDevices();
                 $('#folder-ignores textarea').val("");
                 $('#folder-ignores textarea').removeAttr('disabled');
                 $scope.editFolderModal();
@@ -1766,6 +1804,7 @@ angular.module('syncthing.core')
                 importFromOtherDevice: true
             };
             $scope.currentFolder.selectedDevices[device] = true;
+            $scope.currentFolder.unrelatedDevices = $scope.otherDevices();
             $('#folder-ignores textarea').val("");
             $('#folder-ignores textarea').removeAttr('disabled');
             $scope.editFolderModal();
@@ -1791,7 +1830,9 @@ angular.module('syncthing.core')
                     });
                 }
             }
+            delete folderCfg.sharedDevices;
             delete folderCfg.selectedDevices;
+            delete folderCfg.unrelatedDevices;
 
             if (folderCfg.fileVersioningSelector === "trashcan") {
                 folderCfg.versioning = {

gui/default/syncthing/folder/editFolderModalView.html

@@ -44,15 +44,35 @@
           </div>
         </div>
         <div id="folder-sharing" class="tab-pane">
-          <div class="form-group">
-            <label translate for="devices">Share With Devices</label>
+          <div class="form-group" ng-if="currentFolder.sharedDevices.length">
+            <label translate>Currently Shared With Devices</label>
             <p class="help-block">
-              <span translate>Select the devices to share this folder with.</span>&emsp;
-              <small><a href="#" ng-click="selectAllDevices()" translate>Select All</a>&emsp;
-                <a href="#" ng-click="deSelectAllDevices()" translate>Deselect All</a></small>
+              <span translate>Deselect devices to stop sharing this folder with.</span>&emsp;
+              <small><a href="#" ng-click="selectAllSharedDevices(true)" translate>Select All</a>&emsp;
+                <a href="#" ng-click="selectAllSharedDevices(false)" translate>Deselect All</a></small>
             </p>
             <div class="row">
-              <div class="col-md-4" ng-repeat="device in otherDevices()">
+              <div class="col-md-4" ng-repeat="device in currentFolder.sharedDevices">
+                <div class="checkbox">
+                  <label>
+                    <input type="checkbox" ng-model="currentFolder.selectedDevices[device.deviceID]" /> {{deviceName(device)}}
+                  </label>
+                </div>
+              </div>
+            </div>
+          </div>
+          <div class="form-group" ng-if="currentFolder.unrelatedDevices.length || otherDevices().length <= 0">
+            <label translate>Unshared Devices</label>
+            <p class="help-block" ng-if="otherDevices().length > 0">
+              <span translate>Select additional devices to share this folder with.</span>&emsp;
+              <small><a href="#" ng-click="selectAllUnrelatedDevices(true)" translate>Select All</a>&emsp;
+                <a href="#" ng-click="selectAllUnrelatedDevices(false)" translate>Deselect All</a></small>
+            </p>
+            <p class="help-block" ng-if="otherDevices().length <= 0">
+              <span translate>There are no devices to share this folder with.</span>
+            </p>
+            <div class="row">
+              <div class="col-md-4" ng-repeat="device in currentFolder.unrelatedDevices">
                 <div class="checkbox">
                   <label>
                     <input type="checkbox" ng-model="currentFolder.selectedDevices[device.deviceID]" /> {{deviceName(device)}}

gui/light/assets/css/theme.css

@@ -0,0 +1,35 @@
+/*
+// 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 https://mozilla.org/MPL/2.0/.
+
+*/
+
+.panel-progress {
+    background: #3498db;
+}
+
+.identicon rect {
+    fill: #333;
+}
+
+.panel-warning .identicon rect {
+    fill: #fff;
+}
+
+.li-column {
+    background-color: rgb(236, 240, 241);
+    border-radius: 3px;
+}
+
+.panel-heading:hover, .panel-heading:focus {
+    text-decoration: none;
+}
+
+.fancytree-ext-filter-hide tr.fancytree-submatch span.fancytree-title,
+.fancytree-ext-filter-hide span.fancytree-node.fancytree-submatch span.fancytree-title {
+    color: black !important;
+    font-weight: lighter !important;
+}

lib/api/api.go

@@ -9,7 +9,9 @@ package api
 import (
 	"bytes"
 	"crypto/tls"
+	"crypto/x509"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -56,10 +58,11 @@ import (
 var bcryptExpr = regexp.MustCompile(`^\$2[aby]\$\d+\$.{50,}`)
 
 const (
-	DefaultEventMask    = events.AllEvents &^ events.LocalChangeDetected &^ events.RemoteChangeDetected
-	DiskEventMask       = events.LocalChangeDetected | events.RemoteChangeDetected
-	EventSubBufferSize  = 1000
-	defaultEventTimeout = time.Minute
+	DefaultEventMask      = events.AllEvents &^ events.LocalChangeDetected &^ events.RemoteChangeDetected
+	DiskEventMask         = events.LocalChangeDetected | events.RemoteChangeDetected
+	EventSubBufferSize    = 1000
+	defaultEventTimeout   = time.Minute
+	httpsCertLifetimeDays = 820
 )
 
 type service struct {
@@ -146,6 +149,12 @@ func (s *service) getListener(guiCfg config.GUIConfiguration) (net.Listener, err
 	httpsCertFile := locations.Get(locations.HTTPSCertFile)
 	httpsKeyFile := locations.Get(locations.HTTPSKeyFile)
 	cert, err := tls.LoadX509KeyPair(httpsCertFile, httpsKeyFile)
+
+	// If the certificate has expired or will expire in the next month, fail
+	// it and generate a new one.
+	if err == nil {
+		err = checkExpiry(cert)
+	}
 	if err != nil {
 		l.Infoln("Loading HTTPS certificate:", err)
 		l.Infoln("Creating new HTTPS certificate")
@@ -158,7 +167,7 @@ func (s *service) getListener(guiCfg config.GUIConfiguration) (net.Listener, err
 			name = s.tlsDefaultCommonName
 		}
 
-		cert, err = tlsutil.NewCertificate(httpsCertFile, httpsKeyFile, name)
+		cert, err = tlsutil.NewCertificate(httpsCertFile, httpsKeyFile, name, httpsCertLifetimeDays)
 	}
 	if err != nil {
 		return nil, err
@@ -1573,10 +1582,10 @@ func (s *service) getHeapProf(w http.ResponseWriter, r *http.Request) {
 	pprof.WriteHeapProfile(w)
 }
 
-func toJsonFileInfoSlice(fs []db.FileInfoTruncated) []jsonDBFileInfo {
-	res := make([]jsonDBFileInfo, len(fs))
+func toJsonFileInfoSlice(fs []db.FileInfoTruncated) []jsonFileInfoTrunc {
+	res := make([]jsonFileInfoTrunc, len(fs))
 	for i, f := range fs {
-		res[i] = jsonDBFileInfo(f)
+		res[i] = jsonFileInfoTrunc(f)
 	}
 	return res
 }
@@ -1586,45 +1595,39 @@ func toJsonFileInfoSlice(fs []db.FileInfoTruncated) []jsonDBFileInfo {
 type jsonFileInfo protocol.FileInfo
 
 func (f jsonFileInfo) MarshalJSON() ([]byte, error) {
-	return json.Marshal(map[string]interface{}{
-		"name":          f.Name,
-		"type":          f.Type,
-		"size":          f.Size,
-		"permissions":   fmt.Sprintf("%#o", f.Permissions),
-		"deleted":       f.Deleted,
-		"invalid":       protocol.FileInfo(f).IsInvalid(),
-		"ignored":       protocol.FileInfo(f).IsIgnored(),
-		"mustRescan":    protocol.FileInfo(f).MustRescan(),
-		"noPermissions": f.NoPermissions,
-		"modified":      protocol.FileInfo(f).ModTime(),
-		"modifiedBy":    f.ModifiedBy.String(),
-		"sequence":      f.Sequence,
-		"numBlocks":     len(f.Blocks),
-		"version":       jsonVersionVector(f.Version),
-		"localFlags":    f.LocalFlags,
-	})
+	m := fileIntfJSONMap(protocol.FileInfo(f))
+	m["numBlocks"] = len(f.Blocks)
+	return json.Marshal(m)
 }
 
-type jsonDBFileInfo db.FileInfoTruncated
+type jsonFileInfoTrunc db.FileInfoTruncated
 
-func (f jsonDBFileInfo) MarshalJSON() ([]byte, error) {
-	return json.Marshal(map[string]interface{}{
-		"name":          f.Name,
-		"type":          f.Type.String(),
-		"size":          f.Size,
-		"permissions":   fmt.Sprintf("%#o", f.Permissions),
-		"deleted":       f.Deleted,
-		"invalid":       db.FileInfoTruncated(f).IsInvalid(),
-		"ignored":       db.FileInfoTruncated(f).IsIgnored(),
-		"mustRescan":    db.FileInfoTruncated(f).MustRescan(),
-		"noPermissions": f.NoPermissions,
-		"modified":      db.FileInfoTruncated(f).ModTime(),
-		"modifiedBy":    f.ModifiedBy.String(),
-		"sequence":      f.Sequence,
-		"numBlocks":     nil, // explicitly unknown
-		"version":       jsonVersionVector(f.Version),
-		"localFlags":    f.LocalFlags,
-	})
+func (f jsonFileInfoTrunc) MarshalJSON() ([]byte, error) {
+	m := fileIntfJSONMap(db.FileInfoTruncated(f))
+	m["numBlocks"] = nil // explicitly unknown
+	return json.Marshal(m)
+}
+
+func fileIntfJSONMap(f db.FileIntf) map[string]interface{} {
+	out := map[string]interface{}{
+		"name":          f.FileName(),
+		"type":          f.FileType().String(),
+		"size":          f.FileSize(),
+		"deleted":       f.IsDeleted(),
+		"invalid":       f.IsInvalid(),
+		"ignored":       f.IsIgnored(),
+		"mustRescan":    f.MustRescan(),
+		"noPermissions": !f.HasPermissionBits(),
+		"modified":      f.ModTime(),
+		"modifiedBy":    f.FileModifiedBy().String(),
+		"sequence":      f.SequenceNo(),
+		"version":       jsonVersionVector(f.FileVersion()),
+		"localFlags":    f.FileLocalFlags(),
+	}
+	if f.HasPermissionBits() {
+		out["permissions"] = fmt.Sprintf("%#o", f.FilePermissions())
+	}
+	return out
 }
 
 type jsonVersionVector protocol.Vector
@@ -1678,3 +1681,45 @@ func addressIsLocalhost(addr string) bool {
 		return ip.IsLoopback()
 	}
 }
+
+func checkExpiry(cert tls.Certificate) error {
+	leaf := cert.Leaf
+	if leaf == nil {
+		// Leaf can be nil or not, depending on how parsed the certificate
+		// was when we got it.
+		if len(cert.Certificate) < 1 {
+			// can't happen
+			return errors.New("no certificate in certificate")
+		}
+		var err error
+		leaf, err = x509.ParseCertificate(cert.Certificate[0])
+		if err != nil {
+			return err
+		}
+	}
+
+	if leaf.Subject.String() != leaf.Issuer.String() ||
+		len(leaf.DNSNames) != 0 || len(leaf.IPAddresses) != 0 {
+		// The certificate is not self signed, or has DNS/IP attributes we don't
+		// add, so we leave it alone.
+		return nil
+	}
+
+	if leaf.NotAfter.Before(time.Now()) {
+		return errors.New("certificate has expired")
+	}
+	if leaf.NotAfter.Before(time.Now().Add(30 * 24 * time.Hour)) {
+		return errors.New("certificate will soon expire")
+	}
+
+	// On macOS, check for certificates issued on or after July 1st, 2019,
+	// with a longer validity time than 825 days.
+	cutoff := time.Date(2019, 7, 1, 0, 0, 0, 0, time.UTC)
+	if runtime.GOOS == "darwin" &&
+		leaf.NotBefore.After(cutoff) &&
+		leaf.NotAfter.Sub(leaf.NotBefore) > 825*24*time.Hour {
+		return errors.New("certificate incompatible with macOS 10.15 (Catalina)")
+	}
+
+	return nil
+}

lib/api/api_statics.go

@@ -23,21 +23,25 @@ import (
 	"github.com/syncthing/syncthing/lib/sync"
 )
 
+const themePrefix = "theme-assets/"
+
 type staticsServer struct {
 	assetDir        string
 	assets          map[string][]byte
 	availableThemes []string
 
-	mut   sync.RWMutex
-	theme string
+	mut             sync.RWMutex
+	theme           string
+	lastThemeChange time.Time
 }
 
 func newStaticsServer(theme, assetDir string) *staticsServer {
 	s := &staticsServer{
-		assetDir: assetDir,
-		assets:   auto.Assets(),
-		mut:      sync.NewRWMutex(),
-		theme:    theme,
+		assetDir:        assetDir,
+		assets:          auto.Assets(),
+		mut:             sync.NewRWMutex(),
+		theme:           theme,
+		lastThemeChange: time.Now().UTC(),
 	}
 
 	seen := make(map[string]struct{})
@@ -86,8 +90,23 @@ func (s *staticsServer) serveAsset(w http.ResponseWriter, r *http.Request) {
 
 	s.mut.RLock()
 	theme := s.theme
+	modificationTime := s.lastThemeChange
 	s.mut.RUnlock()
 
+	// If path starts with special prefix, get theme and file from path
+	if strings.HasPrefix(file, themePrefix) {
+		path := file[len(themePrefix):]
+		i := strings.IndexRune(path, '/')
+
+		if i == -1 {
+			http.NotFound(w, r)
+			return
+		}
+
+		theme = path[:i]
+		file = path[i+1:]
+	}
+
 	// Check for an override for the current theme.
 	if s.assetDir != "" {
 		p := filepath.Join(s.assetDir, theme, filepath.FromSlash(file))
@@ -125,14 +144,12 @@ func (s *staticsServer) serveAsset(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	etag := fmt.Sprintf("%d", auto.Generated)
-	modified := time.Unix(auto.Generated, 0).UTC()
-
-	w.Header().Set("Last-Modified", modified.Format(http.TimeFormat))
+	etag := fmt.Sprintf("%d", modificationTime.Unix())
+	w.Header().Set("Last-Modified", modificationTime.Format(http.TimeFormat))
 	w.Header().Set("Etag", etag)
 
 	if t, err := time.Parse(http.TimeFormat, r.Header.Get("If-Modified-Since")); err == nil {
-		if modified.Equal(t) || modified.Before(t) {
+		if modificationTime.Equal(t) || modificationTime.Before(t) {
 			w.WriteHeader(http.StatusNotModified)
 			return
 		}
@@ -199,6 +216,7 @@ func (s *staticsServer) mimeTypeForFile(file string) string {
 func (s *staticsServer) setTheme(theme string) {
 	s.mut.Lock()
 	s.theme = theme
+	s.lastThemeChange = time.Now().UTC()
 	s.mut.Unlock()
 }
 

lib/api/api_test.go

@@ -32,6 +32,7 @@ import (
 	"github.com/syncthing/syncthing/lib/model"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/sync"
+	"github.com/syncthing/syncthing/lib/tlsutil"
 	"github.com/syncthing/syncthing/lib/ur"
 	"github.com/thejerf/suture"
 )
@@ -565,7 +566,7 @@ func TestCSRFRequired(t *testing.T) {
 	}
 
 	cli := &http.Client{
-		Timeout: time.Second,
+		Timeout: time.Minute,
 	}
 
 	// Getting the base URL (i.e. "/") should succeed.
@@ -1119,6 +1120,44 @@ func TestPrefixMatch(t *testing.T) {
 	}
 }
 
+func TestCheckExpiry(t *testing.T) {
+	dir, err := ioutil.TempDir("", "syncthing-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	// Self signed certificates expiring in less than a month are errored so we
+	// can regenerate in time.
+	crt, err := tlsutil.NewCertificate(filepath.Join(dir, "crt"), filepath.Join(dir, "key"), "foo.example.com", 29)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := checkExpiry(crt); err == nil {
+		t.Error("expected expiry error")
+	}
+
+	// Certificates with at least 31 days of life left are fine.
+	crt, err = tlsutil.NewCertificate(filepath.Join(dir, "crt"), filepath.Join(dir, "key"), "foo.example.com", 31)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := checkExpiry(crt); err != nil {
+		t.Error("expected no error:", err)
+	}
+
+	if runtime.GOOS == "darwin" {
+		// Certificates with too long an expiry time are not allowed on macOS
+		crt, err = tlsutil.NewCertificate(filepath.Join(dir, "crt"), filepath.Join(dir, "key"), "foo.example.com", 1000)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := checkExpiry(crt); err == nil {
+			t.Error("expected expiry error")
+		}
+	}
+}
+
 func equalStrings(a, b []string) bool {
 	if len(a) != len(b) {
 		return false

lib/api/mocked_model_test.go

@@ -10,7 +10,6 @@ import (
 	"net"
 	"time"
 
-	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/connections"
 	"github.com/syncthing/syncthing/lib/db"
 	"github.com/syncthing/syncthing/lib/model"
@@ -180,10 +179,4 @@ func (m *mockedModel) GetHello(protocol.DeviceID) protocol.HelloIntf {
 	return nil
 }
 
-func (m *mockedModel) AddFolder(cfg config.FolderConfiguration) {}
-
-func (m *mockedModel) RestartFolder(from, to config.FolderConfiguration) {}
-
-func (m *mockedModel) StartFolder(folder string) {}
-
 func (m *mockedModel) StartDeadlockDetector(timeout time.Duration) {}

lib/connections/quic_listen.go

@@ -16,6 +16,7 @@ import (
 	"strings"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"github.com/lucas-clemente/quic-go"
 
@@ -110,6 +111,9 @@ func (t *quicListener) serve(stop chan struct{}) error {
 	l.Infof("QUIC listener (%v) starting", packetConn.LocalAddr())
 	defer l.Infof("QUIC listener (%v) shutting down", packetConn.LocalAddr())
 
+	acceptFailures := 0
+	const maxAcceptFailures = 10
+
 	for {
 		select {
 		case <-ctx.Done():
@@ -121,9 +125,23 @@ func (t *quicListener) serve(stop chan struct{}) error {
 		if err == context.Canceled {
 			return nil
 		} else if err != nil {
-			l.Warnln("Listen (BEP/quic): Accepting connection:", err)
+			l.Infoln("Listen (BEP/quic): Accepting connection:", err)
+
+			acceptFailures++
+			if acceptFailures > maxAcceptFailures {
+				// Return to restart the listener, because something
+				// seems permanently damaged.
+				return err
+			}
+
+			// Slightly increased delay for each failure.
+			time.Sleep(time.Duration(acceptFailures) * time.Second)
+
 			continue
 		}
+
+		acceptFailures = 0
+
 		l.Debugln("connect from", session.RemoteAddr())
 
 		streamCtx, cancel := context.WithTimeout(ctx, quicOperationTimeout)

lib/connections/service.go

@@ -83,7 +83,7 @@ var tlsCipherSuiteNames = map[uint16]string{
 
 var tlsVersionNames = map[uint16]string{
 	tls.VersionTLS12: "TLS1.2",
-	772:              "TLS1.3", // tls.VersionTLS13 constant available in Go 1.12+
+	tls.VersionTLS13: "TLS1.3",
 }
 
 // Service listens and dials all configured unconnected devices, via supported

lib/db/set.go

@@ -51,6 +51,10 @@ type FileIntf interface {
 	SequenceNo() int64
 	BlockSize() int
 	FileVersion() protocol.Vector
+	FileType() protocol.FileInfoType
+	FilePermissions() uint32
+	FileModifiedBy() protocol.ShortID
+	ModTime() time.Time
 }
 
 // The Iterator is called with either a protocol.FileInfo or a

lib/db/structs.go

@@ -116,6 +116,17 @@ func (f FileInfoTruncated) FileVersion() protocol.Vector {
 	return f.Version
 }
 
+func (f FileInfoTruncated) FileType() protocol.FileInfoType {
+	return f.Type
+}
+
+func (f FileInfoTruncated) FilePermissions() uint32 {
+	return f.Permissions
+}
+
+func (f FileInfoTruncated) FileModifiedBy() protocol.ShortID {
+	return f.ModifiedBy
+}
 func (f FileInfoTruncated) ConvertToIgnoredFileInfo(by protocol.ShortID) protocol.FileInfo {
 	return protocol.FileInfo{
 		Name:         f.Name,

lib/db/structs.pb.go

@@ -1712,6 +1712,7 @@ func (m *CountsSet) Unmarshal(dAtA []byte) error {
 func skipStructs(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 {
@@ -1743,10 +1744,8 @@ func skipStructs(dAtA []byte) (n int, err error) {
 					break
 				}
 			}
-			return iNdEx, nil
 		case 1:
 			iNdEx += 8
-			return iNdEx, nil
 		case 2:
 			var length int
 			for shift := uint(0); ; shift += 7 {
@@ -1767,55 +1766,30 @@ func skipStructs(dAtA []byte) (n int, err error) {
 				return 0, ErrInvalidLengthStructs
 			}
 			iNdEx += length
-			if iNdEx < 0 {
-				return 0, ErrInvalidLengthStructs
-			}
-			return iNdEx, nil
 		case 3:
-			for {
-				var innerWire uint64
-				var start int = iNdEx
-				for shift := uint(0); ; shift += 7 {
-					if shift >= 64 {
-						return 0, ErrIntOverflowStructs
-					}
-					if iNdEx >= l {
-						return 0, io.ErrUnexpectedEOF
-					}
-					b := dAtA[iNdEx]
-					iNdEx++
-					innerWire |= (uint64(b) & 0x7F) << shift
-					if b < 0x80 {
-						break
-					}
-				}
-				innerWireType := int(innerWire & 0x7)
-				if innerWireType == 4 {
-					break
-				}
-				next, err := skipStructs(dAtA[start:])
-				if err != nil {
-					return 0, err
-				}
-				iNdEx = start + next
-				if iNdEx < 0 {
-					return 0, ErrInvalidLengthStructs
-				}
-			}
-			return iNdEx, nil
+			depth++
 		case 4:
-			return iNdEx, nil
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupStructs
+			}
+			depth--
 		case 5:
 			iNdEx += 4
-			return iNdEx, nil
 		default:
 			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
 		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthStructs
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
 	}
-	panic("unreachable")
+	return 0, io.ErrUnexpectedEOF
 }
 
 var (
-	ErrInvalidLengthStructs = fmt.Errorf("proto: negative length found during unmarshaling")
-	ErrIntOverflowStructs   = fmt.Errorf("proto: integer overflow")
+	ErrInvalidLengthStructs        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowStructs          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupStructs = fmt.Errorf("proto: unexpected end of group")
 )

lib/discover/global_test.go

@@ -112,7 +112,7 @@ func TestGlobalOverHTTPS(t *testing.T) {
 	}
 
 	// Generate a server certificate.
-	cert, err := tlsutil.NewCertificate(dir+"/cert.pem", dir+"/key.pem", "syncthing")
+	cert, err := tlsutil.NewCertificate(dir+"/cert.pem", dir+"/key.pem", "syncthing", 30)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -177,7 +177,7 @@ func TestGlobalAnnounce(t *testing.T) {
 	}
 
 	// Generate a server certificate.
-	cert, err := tlsutil.NewCertificate(dir+"/cert.pem", dir+"/key.pem", "syncthing")
+	cert, err := tlsutil.NewCertificate(dir+"/cert.pem", dir+"/key.pem", "syncthing", 30)
 	if err != nil {
 		t.Fatal(err)
 	}

lib/discover/local.pb.go

@@ -313,6 +313,7 @@ func (m *Announce) Unmarshal(dAtA []byte) error {
 func skipLocal(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 {
@@ -344,10 +345,8 @@ func skipLocal(dAtA []byte) (n int, err error) {
 					break
 				}
 			}
-			return iNdEx, nil
 		case 1:
 			iNdEx += 8
-			return iNdEx, nil
 		case 2:
 			var length int
 			for shift := uint(0); ; shift += 7 {
@@ -368,55 +367,30 @@ func skipLocal(dAtA []byte) (n int, err error) {
 				return 0, ErrInvalidLengthLocal
 			}
 			iNdEx += length
-			if iNdEx < 0 {
-				return 0, ErrInvalidLengthLocal
-			}
-			return iNdEx, nil
 		case 3:
-			for {
-				var innerWire uint64
-				var start int = iNdEx
-				for shift := uint(0); ; shift += 7 {
-					if shift >= 64 {
-						return 0, ErrIntOverflowLocal
-					}
-					if iNdEx >= l {
-						return 0, io.ErrUnexpectedEOF
-					}
-					b := dAtA[iNdEx]
-					iNdEx++
-					innerWire |= (uint64(b) & 0x7F) << shift
-					if b < 0x80 {
-						break
-					}
-				}
-				innerWireType := int(innerWire & 0x7)
-				if innerWireType == 4 {
-					break
-				}
-				next, err := skipLocal(dAtA[start:])
-				if err != nil {
-					return 0, err
-				}
-				iNdEx = start + next
-				if iNdEx < 0 {
-					return 0, ErrInvalidLengthLocal
-				}
-			}
-			return iNdEx, nil
+			depth++
 		case 4:
-			return iNdEx, nil
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupLocal
+			}
+			depth--
 		case 5:
 			iNdEx += 4
-			return iNdEx, nil
 		default:
 			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
 		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthLocal
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
 	}
-	panic("unreachable")
+	return 0, io.ErrUnexpectedEOF
 }
 
 var (
-	ErrInvalidLengthLocal = fmt.Errorf("proto: negative length found during unmarshaling")
-	ErrIntOverflowLocal   = fmt.Errorf("proto: integer overflow")
+	ErrInvalidLengthLocal        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowLocal          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupLocal = fmt.Errorf("proto: unexpected end of group")
 )

lib/fs/util.go

@@ -35,23 +35,16 @@ func ExpandTilde(path string) (string, error) {
 }
 
 func getHomeDir() (string, error) {
-	var home string
-
-	switch runtime.GOOS {
-	case "windows":
-		home = filepath.Join(os.Getenv("HomeDrive"), os.Getenv("HomePath"))
-		if home == "" {
-			home = os.Getenv("UserProfile")
+	if runtime.GOOS == "windows" {
+		// Legacy -- we prioritize this for historical reasons, whereas
+		// os.UserHomeDir uses %USERPROFILE% always.
+		home := filepath.Join(os.Getenv("HomeDrive"), os.Getenv("HomePath"))
+		if home != "" {
+			return home, nil
 		}
-	default:
-		home = os.Getenv("HOME")
 	}
 
-	if home == "" {
-		return "", errNoHome
-	}
-
-	return home, nil
+	return os.UserHomeDir()
 }
 
 var windowsDisallowedCharacters = string([]rune{

lib/model/folder_recvonly_test.go

@@ -54,7 +54,7 @@ func TestRecvOnlyRevertDeletes(t *testing.T) {
 
 	// Start the folder. This will cause a scan, should discover the other stuff in the folder
 
-	m.StartFolder("ro")
+	m.startFolder("ro")
 	m.ScanFolder("ro")
 
 	// We should now have two files and two directories.
@@ -125,7 +125,7 @@ func TestRecvOnlyRevertNeeds(t *testing.T) {
 
 	// Start the folder. This will cause a scan.
 
-	m.StartFolder("ro")
+	m.startFolder("ro")
 	m.ScanFolder("ro")
 
 	// Everything should be in sync.
@@ -221,7 +221,7 @@ func TestRecvOnlyUndoChanges(t *testing.T) {
 
 	// Start the folder. This will cause a scan.
 
-	m.StartFolder("ro")
+	m.startFolder("ro")
 	m.ScanFolder("ro")
 
 	// Everything should be in sync.
@@ -317,7 +317,7 @@ func setupROFolder() (*model, *sendOnlyFolder) {
 	w.SetFolder(fcfg)
 
 	m := newModel(w, myID, "syncthing", "dev", db.OpenMemory(), nil)
-	m.AddFolder(fcfg)
+	m.addFolder(fcfg)
 
 	f := &sendOnlyFolder{
 		folder: folder{

lib/model/folder_sendrecv.go

@@ -176,7 +176,6 @@ func (f *sendReceiveFolder) pull() bool {
 
 	l.Debugf("%v pulling", f)
 
-	f.setState(FolderSyncing)
 	f.clearPullErrors()
 
 	scanChan := make(chan string)
@@ -194,6 +193,10 @@ func (f *sendReceiveFolder) pull() bool {
 		default:
 		}
 
+		// Needs to be set on every loop, as the puller might have set
+		// it to FolderSyncing during the last iteration.
+		f.setState(FolderSyncPreparing)
+
 		changed := f.pullerIteration(scanChan)
 
 		l.Debugln(f, "changed", changed, "on try", tries+1)
@@ -844,10 +847,17 @@ func (f *sendReceiveFolder) deleteFileWithCurrent(file, cur protocol.FileInfo, h
 
 	if !hasCur {
 		// We should never try to pull a deletion for a file we don't have in the DB.
-		l.Debugln(f, "not deleting file we don't have", file.Name)
+		l.Debugln(f, "not deleting file we don't have, but update db", file.Name)
 		dbUpdateChan <- dbUpdateJob{file, dbUpdateDeleteFile}
 		return
 	}
+
+	if err = osutil.TraversesSymlink(f.fs, filepath.Dir(file.Name)); err != nil {
+		l.Debugln(f, "not deleting file behind symlink on disk, but update db", file.Name)
+		dbUpdateChan <- dbUpdateJob{file, dbUpdateDeleteFile}
+		return
+	}
+
 	if err = f.checkToBeDeleted(cur, scanChan); err != nil {
 		return
 	}
@@ -1396,6 +1406,8 @@ func (f *sendReceiveFolder) pullerRoutine(in <-chan pullBlockState, out chan<- *
 			continue
 		}
 
+		f.setState(FolderSyncing) // Does nothing if already FolderSyncing
+
 		// The requestLimiter limits how many pending block requests we have
 		// ongoing at any given time, based on the size of the blocks
 		// themselves.
@@ -1834,6 +1846,10 @@ func (f *sendReceiveFolder) deleteItemOnDisk(item protocol.FileInfo, scanChan ch
 // deleteDirOnDisk attempts to delete a directory. It checks for files/dirs inside
 // the directory and removes them if possible or returns an error if it fails
 func (f *sendReceiveFolder) deleteDirOnDisk(dir string, scanChan chan<- string) error {
+	if err := osutil.TraversesSymlink(f.fs, filepath.Dir(dir)); err != nil {
+		return err
+	}
+
 	files, _ := f.fs.DirNames(dir)
 
 	toBeDeleted := make([]string, 0, len(files))

lib/model/folder_sendrecv_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/fs"
 	"github.com/syncthing/syncthing/lib/ignore"
+	"github.com/syncthing/syncthing/lib/osutil"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/scanner"
 	"github.com/syncthing/syncthing/lib/sync"
@@ -92,7 +93,7 @@ func setupSendReceiveFolder(files ...protocol.FileInfo) (*model, *sendReceiveFol
 	w := createTmpWrapper(defaultCfg)
 	model := newModel(w, myID, "syncthing", "dev", db.OpenMemory(), nil)
 	fcfg := testFolderConfigTmp()
-	model.AddFolder(fcfg)
+	model.addFolder(fcfg)
 
 	f := &sendReceiveFolder{
 		folder: folder{
@@ -124,7 +125,7 @@ func setupSendReceiveFolder(files ...protocol.FileInfo) (*model, *sendReceiveFol
 func cleanupSRFolder(f *sendReceiveFolder, m *model) {
 	m.evLogger.Stop()
 	os.Remove(m.cfg.ConfigPath())
-	os.Remove(f.Filesystem().URI())
+	os.RemoveAll(f.Filesystem().URI())
 }
 
 // Layout of the files: (indexes from the above array)
@@ -252,8 +253,22 @@ func TestCopierFinder(t *testing.T) {
 
 	f.handleFile(requiredFile, copyChan, dbUpdateChan)
 
-	pulls := []pullBlockState{<-pullChan, <-pullChan, <-pullChan, <-pullChan}
-	finish := <-finisherChan
+	timeout := time.After(10 * time.Second)
+	pulls := make([]pullBlockState, 4)
+	for i := 0; i < 4; i++ {
+		select {
+		case pulls[i] = <-pullChan:
+		case <-timeout:
+			t.Fatalf("Timed out before receiving all 4 states on pullChan (already got %v)", i)
+		}
+	}
+	var finish *sharedPullerState
+	select {
+	case finish = <-finisherChan:
+	case <-timeout:
+		t.Fatal("Timed out before receiving 4 states on pullChan")
+	}
+
 	defer cleanupSharedPullerState(finish)
 
 	select {
@@ -907,6 +922,58 @@ func TestSRConflictReplaceFileByLink(t *testing.T) {
 	}
 }
 
+// TestDeleteBehindSymlink checks that we don't delete or schedule a scan
+// when trying to delete a file behind a symlink.
+func TestDeleteBehindSymlink(t *testing.T) {
+	m, f := setupSendReceiveFolder()
+	defer cleanupSRFolder(f, m)
+	ffs := f.Filesystem()
+
+	destDir := createTmpDir()
+	defer os.RemoveAll(destDir)
+	destFs := fs.NewFilesystem(fs.FilesystemTypeBasic, destDir)
+
+	link := "link"
+	file := filepath.Join(link, "file")
+
+	must(t, ffs.MkdirAll(link, 0755))
+	fi := createFile(t, file, ffs)
+	f.updateLocalsFromScanning([]protocol.FileInfo{fi})
+	must(t, osutil.RenameOrCopy(ffs, destFs, file, "file"))
+	must(t, ffs.RemoveAll(link))
+
+	if err := osutil.DebugSymlinkForTestsOnly(destFs.URI(), filepath.Join(ffs.URI(), link)); err != nil {
+		if runtime.GOOS == "windows" {
+			// Probably we require permissions we don't have.
+			t.Skip("Need admin permissions or developer mode to run symlink test on Windows: " + err.Error())
+		} else {
+			t.Fatal(err)
+		}
+	}
+
+	fi.Deleted = true
+	fi.Version = fi.Version.Update(device1.Short())
+	scanChan := make(chan string, 1)
+	dbUpdateChan := make(chan dbUpdateJob, 1)
+	f.deleteFile(fi, dbUpdateChan, scanChan)
+	select {
+	case f := <-scanChan:
+		t.Fatalf("Received %v on scanChan", f)
+	case u := <-dbUpdateChan:
+		if u.jobType != dbUpdateDeleteFile {
+			t.Errorf("Expected jobType %v, got %v", dbUpdateDeleteFile, u.jobType)
+		}
+		if u.file.Name != fi.Name {
+			t.Errorf("Expected update for %v, got %v", fi.Name, u.file.Name)
+		}
+	default:
+		t.Fatalf("No db update received")
+	}
+	if _, err := destFs.Stat("file"); err != nil {
+		t.Errorf("Expected no error when stating file behind symlink, got %v", err)
+	}
+}
+
 func cleanupSharedPullerState(s *sharedPullerState) {
 	s.mut.Lock()
 	defer s.mut.Unlock()

lib/model/folderstate.go

@@ -19,6 +19,7 @@ const (
 	FolderIdle folderState = iota
 	FolderScanning
 	FolderScanWaiting
+	FolderSyncPreparing
 	FolderSyncing
 	FolderError
 )
@@ -31,6 +32,8 @@ func (s folderState) String() string {
 		return "scanning"
 	case FolderScanWaiting:
 		return "scan-waiting"
+	case FolderSyncPreparing:
+		return "sync-preparing"
 	case FolderSyncing:
 		return "syncing"
 	case FolderError:
@@ -65,29 +68,32 @@ func (s *stateTracker) setState(newState folderState) {
 	}
 
 	s.mut.Lock()
-	if newState != s.current {
-		/* This should hold later...
-		if s.current != FolderIdle && (newState == FolderScanning || newState == FolderSyncing) {
-			panic("illegal state transition " + s.current.String() + " -> " + newState.String())
-		}
-		*/
+	defer s.mut.Unlock()
 
-		eventData := map[string]interface{}{
-			"folder": s.folderID,
-			"to":     newState.String(),
-			"from":   s.current.String(),
-		}
-
-		if !s.changed.IsZero() {
-			eventData["duration"] = time.Since(s.changed).Seconds()
-		}
-
-		s.current = newState
-		s.changed = time.Now()
-
-		s.evLogger.Log(events.StateChanged, eventData)
+	if newState == s.current {
+		return
 	}
-	s.mut.Unlock()
+
+	/* This should hold later...
+	if s.current != FolderIdle && (newState == FolderScanning || newState == FolderSyncing) {
+		panic("illegal state transition " + s.current.String() + " -> " + newState.String())
+	}
+	*/
+
+	eventData := map[string]interface{}{
+		"folder": s.folderID,
+		"to":     newState.String(),
+		"from":   s.current.String(),
+	}
+
+	if !s.changed.IsZero() {
+		eventData["duration"] = time.Since(s.changed).Seconds()
+	}
+
+	s.current = newState
+	s.changed = time.Now()
+
+	s.evLogger.Log(events.StateChanged, eventData)
 }
 
 // getState returns the current state, the time when it last changed, and the

lib/model/model.go

@@ -72,9 +72,6 @@ type Model interface {
 
 	connections.Model
 
-	AddFolder(cfg config.FolderConfiguration)
-	RestartFolder(from, to config.FolderConfiguration)
-	StartFolder(folder string)
 	ResetFolder(folder string)
 	DelayScan(folder string, next time.Duration)
 	ScanFolder(folder string) error
@@ -210,6 +207,9 @@ func NewModel(cfg config.Wrapper, id protocol.DeviceID, clientName, clientVersio
 		fmut:                sync.NewRWMutex(),
 		pmut:                sync.NewRWMutex(),
 	}
+	for devID := range cfg.Devices() {
+		m.deviceStatRefs[devID] = stats.NewDeviceStatisticsReference(m.db, devID.String())
+	}
 	m.Add(m.progressEmitter)
 	scanLimiter.setCapacity(cfg.Options().MaxConcurrentScans)
 	cfg.Subscribe(m)
@@ -217,6 +217,19 @@ func NewModel(cfg config.Wrapper, id protocol.DeviceID, clientName, clientVersio
 	return m
 }
 
+func (m *model) Serve() {
+	// Add and start folders
+	for _, folderCfg := range m.cfg.Folders() {
+		if folderCfg.Paused {
+			folderCfg.CreateRoot()
+			continue
+		}
+		m.addFolder(folderCfg)
+		m.startFolder(folderCfg.ID)
+	}
+	m.Supervisor.Serve()
+}
+
 func (m *model) Stop() {
 	m.Supervisor.Stop()
 	devs := m.cfg.Devices()
@@ -238,8 +251,8 @@ func (m *model) StartDeadlockDetector(timeout time.Duration) {
 	detector.Watch("pmut", m.pmut)
 }
 
-// StartFolder constructs the folder service and starts it.
-func (m *model) StartFolder(folder string) {
+// startFolder constructs the folder service and starts it.
+func (m *model) startFolder(folder string) {
 	m.fmut.Lock()
 	defer m.fmut.Unlock()
 	folderCfg := m.folderCfgs[folder]
@@ -356,7 +369,7 @@ func (m *model) warnAboutOverwritingProtectedFiles(folder string) {
 	}
 }
 
-func (m *model) AddFolder(cfg config.FolderConfiguration) {
+func (m *model) addFolder(cfg config.FolderConfiguration) {
 	if len(cfg.ID) == 0 {
 		panic("cannot add empty folder id")
 	}
@@ -385,12 +398,21 @@ func (m *model) addFolderLocked(cfg config.FolderConfiguration, fset *db.FileSet
 	m.folderIgnores[cfg.ID] = ignores
 }
 
-func (m *model) RemoveFolder(cfg config.FolderConfiguration) {
+func (m *model) removeFolder(cfg config.FolderConfiguration) {
 	m.fmut.Lock()
 	defer m.fmut.Unlock()
 
-	// Delete syncthing specific files
-	cfg.Filesystem().RemoveAll(config.DefaultMarkerName)
+	isPathUnique := true
+	for folderID, folderCfg := range m.folderCfgs {
+		if folderID != cfg.ID && folderCfg.Path == cfg.Path {
+			isPathUnique = false
+			break
+		}
+	}
+	if isPathUnique {
+		// Delete syncthing specific files
+		cfg.Filesystem().RemoveAll(config.DefaultMarkerName)
+	}
 
 	m.tearDownFolderLocked(cfg, fmt.Errorf("removing folder %v", cfg.Description()))
 	// Remove it from the database
@@ -428,7 +450,7 @@ func (m *model) tearDownFolderLocked(cfg config.FolderConfiguration, err error)
 	delete(m.folderRunnerTokens, cfg.ID)
 }
 
-func (m *model) RestartFolder(from, to config.FolderConfiguration) {
+func (m *model) restartFolder(from, to config.FolderConfiguration) {
 	if len(to.ID) == 0 {
 		panic("bug: cannot restart empty folder ID")
 	}
@@ -2501,8 +2523,8 @@ func (m *model) CommitConfiguration(from, to config.Configuration) bool {
 				l.Infoln("Paused folder", cfg.Description())
 			} else {
 				l.Infoln("Adding folder", cfg.Description())
-				m.AddFolder(cfg)
-				m.StartFolder(folderID)
+				m.addFolder(cfg)
+				m.startFolder(folderID)
 			}
 		}
 	}
@@ -2511,7 +2533,7 @@ func (m *model) CommitConfiguration(from, to config.Configuration) bool {
 		toCfg, ok := toFolders[folderID]
 		if !ok {
 			// The folder was removed.
-			m.RemoveFolder(fromCfg)
+			m.removeFolder(fromCfg)
 			continue
 		}
 
@@ -2522,7 +2544,7 @@ func (m *model) CommitConfiguration(from, to config.Configuration) bool {
 		// This folder exists on both sides. Settings might have changed.
 		// Check if anything differs that requires a restart.
 		if !reflect.DeepEqual(fromCfg.RequiresRestartOnly(), toCfg.RequiresRestartOnly()) {
-			m.RestartFolder(fromCfg, toCfg)
+			m.restartFolder(fromCfg, toCfg)
 		}
 
 		// Emit the folder pause/resume event

lib/model/model_test.go

@@ -405,8 +405,8 @@ func TestClusterConfig(t *testing.T) {
 
 	wrapper := createTmpWrapper(cfg)
 	m := newModel(wrapper, myID, "syncthing", "dev", db, nil)
-	m.AddFolder(cfg.Folders[0])
-	m.AddFolder(cfg.Folders[1])
+	m.addFolder(cfg.Folders[0])
+	m.addFolder(cfg.Folders[1])
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -1454,8 +1454,8 @@ func TestIgnores(t *testing.T) {
 	m := setupModel(defaultCfgWrapper)
 	defer cleanupModel(m)
 
-	m.RemoveFolder(defaultFolderConfig)
-	m.AddFolder(defaultFolderConfig)
+	m.removeFolder(defaultFolderConfig)
+	m.addFolder(defaultFolderConfig)
 	// Reach in and update the ignore matcher to one that always does
 	// reloads when asked to, instead of checking file mtimes. This is
 	// because we will be changing the files on disk often enough that the
@@ -1463,7 +1463,7 @@ func TestIgnores(t *testing.T) {
 	m.fmut.Lock()
 	m.folderIgnores["default"] = ignore.New(defaultFs, ignore.WithCache(true), ignore.WithChangeDetector(newAlwaysChanged()))
 	m.fmut.Unlock()
-	m.StartFolder("default")
+	m.startFolder("default")
 
 	// Make sure the initial scan has finished (ScanFolders is blocking)
 	m.ScanFolders()
@@ -1486,7 +1486,7 @@ func TestIgnores(t *testing.T) {
 	}
 
 	// Invalid path, marker should be missing, hence returns an error.
-	m.AddFolder(config.FolderConfiguration{ID: "fresh", Path: "XXX"})
+	m.addFolder(config.FolderConfiguration{ID: "fresh", Path: "XXX"})
 	_, _, err = m.GetIgnores("fresh")
 	if err == nil {
 		t.Error("No error")
@@ -1496,7 +1496,7 @@ func TestIgnores(t *testing.T) {
 	pausedDefaultFolderConfig := defaultFolderConfig
 	pausedDefaultFolderConfig.Paused = true
 
-	m.RestartFolder(defaultFolderConfig, pausedDefaultFolderConfig)
+	m.restartFolder(defaultFolderConfig, pausedDefaultFolderConfig)
 	// Here folder initialization is not an issue as a paused folder isn't
 	// added to the model and thus there is no initial scan happening.
 
@@ -1555,8 +1555,8 @@ func TestROScanRecovery(t *testing.T) {
 	testOs.RemoveAll(fcfg.Path)
 
 	m := newModel(cfg, myID, "syncthing", "dev", ldb, nil)
-	m.AddFolder(fcfg)
-	m.StartFolder("default")
+	m.addFolder(fcfg)
+	m.startFolder("default")
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -1608,8 +1608,8 @@ func TestRWScanRecovery(t *testing.T) {
 	testOs.RemoveAll(fcfg.Path)
 
 	m := newModel(cfg, myID, "syncthing", "dev", ldb, nil)
-	m.AddFolder(fcfg)
-	m.StartFolder("default")
+	m.addFolder(fcfg)
+	m.startFolder("default")
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -1636,7 +1636,7 @@ func TestRWScanRecovery(t *testing.T) {
 func TestGlobalDirectoryTree(t *testing.T) {
 	db := db.OpenMemory()
 	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", db, nil)
-	m.AddFolder(defaultFolderConfig)
+	m.addFolder(defaultFolderConfig)
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -1888,7 +1888,7 @@ func TestGlobalDirectoryTree(t *testing.T) {
 func TestGlobalDirectorySelfFixing(t *testing.T) {
 	db := db.OpenMemory()
 	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", db, nil)
-	m.AddFolder(defaultFolderConfig)
+	m.addFolder(defaultFolderConfig)
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -2064,7 +2064,7 @@ func BenchmarkTree_100_10(b *testing.B) {
 func benchmarkTree(b *testing.B, n1, n2 int) {
 	db := db.OpenMemory()
 	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", db, nil)
-	m.AddFolder(defaultFolderConfig)
+	m.addFolder(defaultFolderConfig)
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -2262,8 +2262,8 @@ func TestIndexesForUnknownDevicesDropped(t *testing.T) {
 	}
 
 	m := newModel(defaultCfgWrapper, myID, "syncthing", "dev", dbi, nil)
-	m.AddFolder(defaultFolderConfig)
-	m.StartFolder("default")
+	m.addFolder(defaultFolderConfig)
+	m.startFolder("default")
 	defer cleanupModel(m)
 
 	// Remote sequence is cached, hence need to recreated.
@@ -2701,8 +2701,8 @@ func TestCustomMarkerName(t *testing.T) {
 	defer testOs.RemoveAll(fcfg.Path)
 
 	m := newModel(cfg, myID, "syncthing", "dev", ldb, nil)
-	m.AddFolder(fcfg)
-	m.StartFolder("default")
+	m.addFolder(fcfg)
+	m.startFolder("default")
 	m.ServeBackground()
 	defer cleanupModel(m)
 
@@ -3224,7 +3224,7 @@ func TestRequestLimit(t *testing.T) {
 	go func() {
 		second, err := m.Request(device1, "default", file, 2000, 0, nil, 0, false)
 		if err != nil {
-			t.Fatalf("Second request failed: %v", err)
+			t.Errorf("Second request failed: %v", err)
 		}
 		close(returned)
 		second.Close()
@@ -3290,7 +3290,7 @@ func TestConnCloseOnRestart(t *testing.T) {
 	newFcfg.Paused = true
 	done := make(chan struct{})
 	go func() {
-		m.RestartFolder(fcfg, newFcfg)
+		m.restartFolder(fcfg, newFcfg)
 		close(done)
 	}()
 	select {
@@ -3384,3 +3384,16 @@ func TestDevicePause(t *testing.T) {
 		t.Fatal("Timed out before device was paused")
 	}
 }
+
+func TestDeviceWasSeen(t *testing.T) {
+	m, _, fcfg := setupModelWithConnection()
+	defer cleanupModelAndRemoveDir(m, fcfg.Filesystem().URI())
+
+	m.deviceWasSeen(device1)
+
+	stats := m.DeviceStatistics()
+	entry := stats[device1.String()]
+	if time.Since(entry.LastSeen) > time.Second {
+		t.Error("device should have been seen now")
+	}
+}

lib/model/requests_test.go

@@ -244,31 +244,37 @@ func TestRequestVersioningSymlinkAttack(t *testing.T) {
 	}
 	fc.mut.Unlock()
 
+	waitForIdx := func() {
+		select {
+		case c := <-idx:
+			if c == 0 {
+				t.Fatal("Got empty index update")
+			}
+		case <-time.After(5 * time.Second):
+			t.Fatal("timed out before receiving index update")
+		}
+	}
+
 	// Send an update for the test file, wait for it to sync and be reported back.
 	fc.addFile("foo", 0644, protocol.FileInfoTypeSymlink, []byte(tmpdir))
 	fc.sendIndexUpdate()
-
-	for updates := 0; updates < 1; updates += <-idx {
-	}
+	waitForIdx()
 
 	// Delete the symlink, hoping for it to get versioned
 	fc.deleteFile("foo")
 	fc.sendIndexUpdate()
-	for updates := 0; updates < 1; updates += <-idx {
-	}
+	waitForIdx()
 
 	// Recreate foo and a file in it with some data
 	fc.updateFile("foo", 0755, protocol.FileInfoTypeDirectory, nil)
 	fc.addFile("foo/test", 0644, protocol.FileInfoTypeFile, []byte("testtesttest"))
 	fc.sendIndexUpdate()
-	for updates := 0; updates < 1; updates += <-idx {
-	}
+	waitForIdx()
 
 	// Remove the test file and see if it escaped
 	fc.deleteFile("foo/test")
 	fc.sendIndexUpdate()
-	for updates := 0; updates < 1; updates += <-idx {
-	}
+	waitForIdx()
 
 	path := filepath.Join(tmpdir, "test")
 	if _, err := os.Lstat(path); !os.IsNotExist(err) {
@@ -295,8 +301,8 @@ func pullInvalidIgnored(t *testing.T, ft config.FolderType) {
 	m := setupModel(w)
 	defer cleanupModelAndRemoveDir(m, fss.URI())
 
-	m.RemoveFolder(fcfg)
-	m.AddFolder(fcfg)
+	m.removeFolder(fcfg)
+	m.addFolder(fcfg)
 	// Reach in and update the ignore matcher to one that always does
 	// reloads when asked to, instead of checking file mtimes. This is
 	// because we might be changing the files on disk often enough that the
@@ -304,7 +310,7 @@ func pullInvalidIgnored(t *testing.T, ft config.FolderType) {
 	m.fmut.Lock()
 	m.folderIgnores["default"] = ignore.New(fss, ignore.WithChangeDetector(newAlwaysChanged()))
 	m.fmut.Unlock()
-	m.StartFolder(fcfg.ID)
+	m.startFolder(fcfg.ID)
 
 	fc := addFakeConn(m, device1)
 	fc.folder = "default"
@@ -1032,8 +1038,8 @@ func TestIgnoreDeleteUnignore(t *testing.T) {
 	tmpDir := fss.URI()
 	defer cleanupModelAndRemoveDir(m, tmpDir)
 
-	m.RemoveFolder(fcfg)
-	m.AddFolder(fcfg)
+	m.removeFolder(fcfg)
+	m.addFolder(fcfg)
 	// Reach in and update the ignore matcher to one that always does
 	// reloads when asked to, instead of checking file mtimes. This is
 	// because we might be changing the files on disk often enough that the
@@ -1041,7 +1047,7 @@ func TestIgnoreDeleteUnignore(t *testing.T) {
 	m.fmut.Lock()
 	m.folderIgnores["default"] = ignore.New(fss, ignore.WithChangeDetector(newAlwaysChanged()))
 	m.fmut.Unlock()
-	m.StartFolder(fcfg.ID)
+	m.startFolder(fcfg.ID)
 
 	fc := addFakeConn(m, device1)
 	fc.folder = "default"

lib/model/testutils_test.go

@@ -107,8 +107,8 @@ func setupModel(w config.Wrapper) *model {
 	m.ServeBackground()
 	for id, cfg := range w.Folders() {
 		if !cfg.Paused {
-			m.AddFolder(cfg)
-			m.StartFolder(id)
+			m.addFolder(cfg)
+			m.startFolder(id)
 		}
 	}
 

lib/osutil/net.go

@@ -7,37 +7,9 @@
 package osutil
 
 import (
-	"bytes"
 	"net"
 )
 
-// ResolveInterfaceAddresses returns available addresses of the given network
-// type for a given interface.
-func ResolveInterfaceAddresses(network, nameOrMac string) []string {
-	intf, err := net.InterfaceByName(nameOrMac)
-	if err == nil {
-		return interfaceAddresses(network, intf)
-	}
-
-	mac, err := net.ParseMAC(nameOrMac)
-	if err != nil {
-		return []string{nameOrMac}
-	}
-
-	intfs, err := net.Interfaces()
-	if err != nil {
-		return []string{nameOrMac}
-	}
-
-	for _, intf := range intfs {
-		if bytes.Equal(intf.HardwareAddr, mac) {
-			return interfaceAddresses(network, &intf)
-		}
-	}
-
-	return []string{nameOrMac}
-}
-
 func interfaceAddresses(network string, intf *net.Interface) []string {
 	var out []string
 	addrs, err := intf.Addrs()

lib/protocol/bep.pb.go

@@ -5045,6 +5045,7 @@ func (m *Close) Unmarshal(dAtA []byte) error {
 func skipBep(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 {
@@ -5076,10 +5077,8 @@ func skipBep(dAtA []byte) (n int, err error) {
 					break
 				}
 			}
-			return iNdEx, nil
 		case 1:
 			iNdEx += 8
-			return iNdEx, nil
 		case 2:
 			var length int
 			for shift := uint(0); ; shift += 7 {
@@ -5100,55 +5099,30 @@ func skipBep(dAtA []byte) (n int, err error) {
 				return 0, ErrInvalidLengthBep
 			}
 			iNdEx += length
-			if iNdEx < 0 {
-				return 0, ErrInvalidLengthBep
-			}
-			return iNdEx, nil
 		case 3:
-			for {
-				var innerWire uint64
-				var start int = iNdEx
-				for shift := uint(0); ; shift += 7 {
-					if shift >= 64 {
-						return 0, ErrIntOverflowBep
-					}
-					if iNdEx >= l {
-						return 0, io.ErrUnexpectedEOF
-					}
-					b := dAtA[iNdEx]
-					iNdEx++
-					innerWire |= (uint64(b) & 0x7F) << shift
-					if b < 0x80 {
-						break
-					}
-				}
-				innerWireType := int(innerWire & 0x7)
-				if innerWireType == 4 {
-					break
-				}
-				next, err := skipBep(dAtA[start:])
-				if err != nil {
-					return 0, err
-				}
-				iNdEx = start + next
-				if iNdEx < 0 {
-					return 0, ErrInvalidLengthBep
-				}
-			}
-			return iNdEx, nil
+			depth++
 		case 4:
-			return iNdEx, nil
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupBep
+			}
+			depth--
 		case 5:
 			iNdEx += 4
-			return iNdEx, nil
 		default:
 			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
 		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthBep
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
 	}
-	panic("unreachable")
+	return 0, io.ErrUnexpectedEOF
 }
 
 var (
-	ErrInvalidLengthBep = fmt.Errorf("proto: negative length found during unmarshaling")
-	ErrIntOverflowBep   = fmt.Errorf("proto: integer overflow")
+	ErrInvalidLengthBep        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowBep          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupBep = fmt.Errorf("proto: unexpected end of group")
 )

lib/protocol/bep_extensions.go

@@ -124,6 +124,18 @@ func (f FileInfo) FileVersion() Vector {
 	return f.Version
 }
 
+func (f FileInfo) FileType() FileInfoType {
+	return f.Type
+}
+
+func (f FileInfo) FilePermissions() uint32 {
+	return f.Permissions
+}
+
+func (f FileInfo) FileModifiedBy() ShortID {
+	return f.ModifiedBy
+}
+
 // WinsConflict returns true if "f" is the one to choose when it is in
 // conflict with "other".
 func (f FileInfo) WinsConflict(other FileInfo) bool {

lib/protocol/bufferpool.go

@@ -2,56 +2,71 @@
 
 package protocol
 
-import "sync"
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+)
 
 // Global pool to get buffers from. Requires Blocksizes to be initialised,
 // therefore it is initialized in the same init() as BlockSizes
 var BufferPool bufferPool
 
 type bufferPool struct {
-	pools []sync.Pool
+	puts   int64
+	skips  int64
+	misses int64
+	pools  []sync.Pool
+	hits   []int64 // start of slice allocation is always aligned
 }
 
 func newBufferPool() bufferPool {
-	return bufferPool{make([]sync.Pool, len(BlockSizes))}
+	return bufferPool{
+		pools: make([]sync.Pool, len(BlockSizes)),
+		hits:  make([]int64, len(BlockSizes)),
+	}
 }
 
 func (p *bufferPool) Get(size int) []byte {
 	// Too big, isn't pooled
 	if size > MaxBlockSize {
+		atomic.AddInt64(&p.skips, 1)
 		return make([]byte, size)
 	}
-	var i int
-	for i = range BlockSizes {
-		if size <= BlockSizes[i] {
-			break
-		}
-	}
-	var bs []byte
+
 	// Try the fitting and all bigger pools
-	for j := i; j < len(BlockSizes); j++ {
+	bkt := getBucketForLen(size)
+	for j := bkt; j < len(BlockSizes); j++ {
 		if intf := p.pools[j].Get(); intf != nil {
-			bs = *intf.(*[]byte)
+			atomic.AddInt64(&p.hits[j], 1)
+			bs := *intf.(*[]byte)
 			return bs[:size]
 		}
 	}
-	// All pools are empty, must allocate.
-	return make([]byte, BlockSizes[i])[:size]
+
+	atomic.AddInt64(&p.misses, 1)
+
+	// All pools are empty, must allocate. For very small slices where we
+	// didn't have a block to reuse, just allocate a small slice instead of
+	// a large one. We won't be able to reuse it, but avoid some overhead.
+	if size < MinBlockSize/64 {
+		return make([]byte, size)
+	}
+	return make([]byte, BlockSizes[bkt])[:size]
 }
 
-// Put makes the given byte slice availabe again in the global pool
+// Put makes the given byte slice available again in the global pool.
+// You must only Put() slices that were returned by Get() or Upgrade().
 func (p *bufferPool) Put(bs []byte) {
-	c := cap(bs)
-	// Don't buffer huge byte slices
-	if c > 2*MaxBlockSize {
+	// Don't buffer slices outside of our pool range
+	if cap(bs) > MaxBlockSize || cap(bs) < MinBlockSize {
+		atomic.AddInt64(&p.skips, 1)
 		return
 	}
-	for i := range BlockSizes {
-		if c >= BlockSizes[i] {
-			p.pools[i].Put(&bs)
-			return
-		}
-	}
+
+	atomic.AddInt64(&p.puts, 1)
+	bkt := putBucketForCap(cap(bs))
+	p.pools[bkt].Put(&bs)
 }
 
 // Upgrade grows the buffer to the requested size, while attempting to reuse
@@ -67,3 +82,31 @@ func (p *bufferPool) Upgrade(bs []byte, size int) []byte {
 	p.Put(bs)
 	return p.Get(size)
 }
+
+// getBucketForLen returns the bucket where we should get a slice of a
+// certain length. Each bucket is guaranteed to hold slices that are
+// precisely the block size for that bucket, so if the block size is larger
+// than our size we are good.
+func getBucketForLen(len int) int {
+	for i, blockSize := range BlockSizes {
+		if len <= blockSize {
+			return i
+		}
+	}
+
+	panic(fmt.Sprintf("bug: tried to get impossible block len %d", len))
+}
+
+// putBucketForCap returns the bucket where we should put a slice of a
+// certain capacity. Each bucket is guaranteed to hold slices that are
+// precisely the block size for that bucket, so we just find the matching
+// one.
+func putBucketForCap(cap int) int {
+	for i, blockSize := range BlockSizes {
+		if cap == blockSize {
+			return i
+		}
+	}
+
+	panic(fmt.Sprintf("bug: tried to put impossible block cap %d", cap))
+}

lib/protocol/bufferpool_test.go

@@ -0,0 +1,132 @@
+// Copyright (C) 2019 The Protocol Authors.
+
+package protocol
+
+import (
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/syncthing/syncthing/lib/rand"
+)
+
+func TestGetBucketNumbers(t *testing.T) {
+	cases := []struct {
+		size   int
+		bkt    int
+		panics bool
+	}{
+		{size: 1024, bkt: 0},
+		{size: MinBlockSize, bkt: 0},
+		{size: MinBlockSize + 1, bkt: 1},
+		{size: 2*MinBlockSize - 1, bkt: 1},
+		{size: 2 * MinBlockSize, bkt: 1},
+		{size: 2*MinBlockSize + 1, bkt: 2},
+		{size: MaxBlockSize, bkt: len(BlockSizes) - 1},
+		{size: MaxBlockSize + 1, panics: true},
+	}
+
+	for _, tc := range cases {
+		if tc.panics {
+			shouldPanic(t, func() { getBucketForLen(tc.size) })
+		} else {
+			res := getBucketForLen(tc.size)
+			if res != tc.bkt {
+				t.Errorf("block of size %d should get from bucket %d, not %d", tc.size, tc.bkt, res)
+			}
+		}
+	}
+}
+
+func TestPutBucketNumbers(t *testing.T) {
+	cases := []struct {
+		size   int
+		bkt    int
+		panics bool
+	}{
+		{size: 1024, panics: true},
+		{size: MinBlockSize, bkt: 0},
+		{size: MinBlockSize + 1, panics: true},
+		{size: 2 * MinBlockSize, bkt: 1},
+		{size: MaxBlockSize, bkt: len(BlockSizes) - 1},
+		{size: MaxBlockSize + 1, panics: true},
+	}
+
+	for _, tc := range cases {
+		if tc.panics {
+			shouldPanic(t, func() { putBucketForCap(tc.size) })
+		} else {
+			res := putBucketForCap(tc.size)
+			if res != tc.bkt {
+				t.Errorf("block of size %d should put into bucket %d, not %d", tc.size, tc.bkt, res)
+			}
+		}
+	}
+}
+
+func TestStressBufferPool(t *testing.T) {
+	if testing.Short() {
+		t.Skip()
+	}
+
+	const routines = 10
+	const runtime = 2 * time.Second
+
+	bp := newBufferPool()
+	t0 := time.Now()
+
+	var wg sync.WaitGroup
+	fail := make(chan struct{}, routines)
+	for i := 0; i < routines; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for time.Since(t0) < runtime {
+				blocks := make([][]byte, 10)
+				for i := range blocks {
+					// Request a block of random size with the range
+					// covering smaller-than-min to larger-than-max and
+					// everything in between.
+					want := rand.Intn(1.5 * MaxBlockSize)
+					blocks[i] = bp.Get(want)
+					if len(blocks[i]) != want {
+						fail <- struct{}{}
+						return
+					}
+				}
+				for i := range blocks {
+					bp.Put(blocks[i])
+				}
+			}
+		}()
+	}
+
+	wg.Wait()
+	select {
+	case <-fail:
+		t.Fatal("a block was bad size")
+	default:
+	}
+
+	t.Log(bp.puts, bp.skips, bp.misses, bp.hits)
+	if bp.puts == 0 || bp.skips == 0 || bp.misses == 0 {
+		t.Error("didn't exercise some paths")
+	}
+	var hits int64
+	for _, h := range bp.hits {
+		hits += h
+	}
+	if hits == 0 {
+		t.Error("didn't exercise some paths")
+	}
+}
+
+func shouldPanic(t *testing.T, fn func()) {
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("did not panic")
+		}
+	}()
+
+	fn()
+}

lib/protocol/deviceid_test.pb.go

@@ -400,6 +400,7 @@ func (m *TestNewDeviceID) Unmarshal(dAtA []byte) error {
 func skipDeviceidTest(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 {
@@ -431,10 +432,8 @@ func skipDeviceidTest(dAtA []byte) (n int, err error) {
 					break
 				}
 			}
-			return iNdEx, nil
 		case 1:
 			iNdEx += 8
-			return iNdEx, nil
 		case 2:
 			var length int
 			for shift := uint(0); ; shift += 7 {
@@ -455,55 +454,30 @@ func skipDeviceidTest(dAtA []byte) (n int, err error) {
 				return 0, ErrInvalidLengthDeviceidTest
 			}
 			iNdEx += length
-			if iNdEx < 0 {
-				return 0, ErrInvalidLengthDeviceidTest
-			}
-			return iNdEx, nil
 		case 3:
-			for {
-				var innerWire uint64
-				var start int = iNdEx
-				for shift := uint(0); ; shift += 7 {
-					if shift >= 64 {
-						return 0, ErrIntOverflowDeviceidTest
-					}
-					if iNdEx >= l {
-						return 0, io.ErrUnexpectedEOF
-					}
-					b := dAtA[iNdEx]
-					iNdEx++
-					innerWire |= (uint64(b) & 0x7F) << shift
-					if b < 0x80 {
-						break
-					}
-				}
-				innerWireType := int(innerWire & 0x7)
-				if innerWireType == 4 {
-					break
-				}
-				next, err := skipDeviceidTest(dAtA[start:])
-				if err != nil {
-					return 0, err
-				}
-				iNdEx = start + next
-				if iNdEx < 0 {
-					return 0, ErrInvalidLengthDeviceidTest
-				}
-			}
-			return iNdEx, nil
+			depth++
 		case 4:
-			return iNdEx, nil
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupDeviceidTest
+			}
+			depth--
 		case 5:
 			iNdEx += 4
-			return iNdEx, nil
 		default:
 			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
 		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthDeviceidTest
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
 	}
-	panic("unreachable")
+	return 0, io.ErrUnexpectedEOF
 }
 
 var (
-	ErrInvalidLengthDeviceidTest = fmt.Errorf("proto: negative length found during unmarshaling")
-	ErrIntOverflowDeviceidTest   = fmt.Errorf("proto: integer overflow")
+	ErrInvalidLengthDeviceidTest        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowDeviceidTest          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupDeviceidTest = fmt.Errorf("proto: unexpected end of group")
 )

lib/protocol/protocol.go

@@ -79,28 +79,6 @@ const (
 	stateReady
 )
 
-// Request message flags
-const (
-	FlagFromTemporary uint32 = 1 << iota
-)
-
-// ClusterConfigMessage.Folders flags
-const (
-	FlagFolderReadOnly            uint32 = 1 << 0
-	FlagFolderIgnorePerms                = 1 << 1
-	FlagFolderIgnoreDelete               = 1 << 2
-	FlagFolderDisabledTempIndexes        = 1 << 3
-	FlagFolderAll                        = 1<<4 - 1
-)
-
-// ClusterConfigMessage.Folders.Devices flags
-const (
-	FlagShareTrusted  uint32 = 1 << 0
-	FlagShareReadOnly        = 1 << 1
-	FlagIntroducer           = 1 << 2
-	FlagShareBits            = 0x000000ff
-)
-
 // FileInfo.LocalFlags flags
 const (
 	FlagLocalUnsupported = 1 << 0 // The kind is unsupported, e.g. symlinks on Windows
@@ -120,15 +98,14 @@ const (
 )
 
 var (
-	ErrClosed               = errors.New("connection closed")
-	ErrTimeout              = errors.New("read timeout")
-	ErrSwitchingConnections = errors.New("switching connections")
-	errUnknownMessage       = errors.New("unknown message")
-	errInvalidFilename      = errors.New("filename is invalid")
-	errUncleanFilename      = errors.New("filename not in canonical format")
-	errDeletedHasBlocks     = errors.New("deleted file with non-empty block list")
-	errDirectoryHasBlocks   = errors.New("directory with non-empty block list")
-	errFileHasNoBlocks      = errors.New("file with empty block list")
+	ErrClosed             = errors.New("connection closed")
+	ErrTimeout            = errors.New("read timeout")
+	errUnknownMessage     = errors.New("unknown message")
+	errInvalidFilename    = errors.New("filename is invalid")
+	errUncleanFilename    = errors.New("filename not in canonical format")
+	errDeletedHasBlocks   = errors.New("deleted file with non-empty block list")
+	errDirectoryHasBlocks = errors.New("directory with non-empty block list")
+	errFileHasNoBlocks    = errors.New("file with empty block list")
 )
 
 type Model interface {
@@ -491,6 +468,8 @@ func (c *rawConnection) readMessageAfterHeader(hdr Header, fourByteBuf []byte) (
 	msgLen := int32(binary.BigEndian.Uint32(fourByteBuf))
 	if msgLen < 0 {
 		return nil, fmt.Errorf("negative message length %d", msgLen)
+	} else if msgLen > MaxMessageLen {
+		return nil, fmt.Errorf("message length %d exceeds maximum %d", msgLen, MaxMessageLen)
 	}
 
 	// Then comes the message
@@ -980,14 +959,17 @@ func (c *rawConnection) Statistics() Statistics {
 
 func (c *rawConnection) lz4Compress(src []byte) ([]byte, error) {
 	var err error
-	buf := BufferPool.Get(len(src))
-	buf, err = lz4.Encode(buf, src)
+	buf := BufferPool.Get(lz4.CompressBound(len(src)))
+	compressed, err := lz4.Encode(buf, src)
 	if err != nil {
 		return nil, err
 	}
+	if &compressed[0] != &buf[0] {
+		panic("bug: lz4.Compress allocated, which it must not (should use buffer pool)")
+	}
 
-	binary.BigEndian.PutUint32(buf, binary.LittleEndian.Uint32(buf))
-	return buf, nil
+	binary.BigEndian.PutUint32(compressed, binary.LittleEndian.Uint32(compressed))
+	return compressed, nil
 }
 
 func (c *rawConnection) lz4Decompress(src []byte) ([]byte, error) {
@@ -995,9 +977,12 @@ func (c *rawConnection) lz4Decompress(src []byte) ([]byte, error) {
 	binary.LittleEndian.PutUint32(src, size)
 	var err error
 	buf := BufferPool.Get(int(size))
-	buf, err = lz4.Decode(buf, src)
+	decoded, err := lz4.Decode(buf, src)
 	if err != nil {
 		return nil, err
 	}
-	return buf, nil
+	if &decoded[0] != &buf[0] {
+		panic("bug: lz4.Decode allocated, which it must not (should use buffer pool)")
+	}
+	return decoded, nil
 }

lib/protocol/protocol_test.go

@@ -434,6 +434,38 @@ func TestLZ4Compression(t *testing.T) {
 	}
 }
 
+func TestStressLZ4CompressGrows(t *testing.T) {
+	c := new(rawConnection)
+	success := 0
+	for i := 0; i < 100; i++ {
+		// Create a slize that is precisely one min block size, fill it with
+		// random data. This shouldn't compress at all, so will in fact
+		// become larger when LZ4 does its thing.
+		data := make([]byte, MinBlockSize)
+		if _, err := rand.Reader.Read(data); err != nil {
+			t.Fatal("randomness failure")
+		}
+
+		comp, err := c.lz4Compress(data)
+		if err != nil {
+			t.Fatal("unexpected compression error: ", err)
+		}
+		if len(comp) < len(data) {
+			// data size should grow. We must have been really unlucky in
+			// the random generation, try again.
+			continue
+		}
+
+		// Putting it into the buffer pool shouldn't panic because the block
+		// should come from there to begin with.
+		BufferPool.Put(comp)
+		success++
+	}
+	if success == 0 {
+		t.Fatal("unable to find data that grows when compressed")
+	}
+}
+
 func TestCheckFilename(t *testing.T) {
 	cases := []struct {
 		name string

lib/relay/protocol/protocol.go

@@ -16,7 +16,6 @@ var (
 	ResponseSuccess           = Response{0, "success"}
 	ResponseNotFound          = Response{1, "not found"}
 	ResponseAlreadyConnected  = Response{2, "already connected"}
-	ResponseInternalError     = Response{99, "internal error"}
 	ResponseUnexpectedMessage = Response{100, "unexpected message"}
 )
 

lib/scanner/walk.go

@@ -21,6 +21,7 @@ import (
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/fs"
 	"github.com/syncthing/syncthing/lib/ignore"
+	"github.com/syncthing/syncthing/lib/osutil"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"golang.org/x/text/unicode/norm"
 )
@@ -113,6 +114,10 @@ func (w *walker) walk(ctx context.Context) chan ScanResult {
 			w.Filesystem.Walk(".", hashFiles)
 		} else {
 			for _, sub := range w.Subs {
+				if err := osutil.TraversesSymlink(w.Filesystem, filepath.Dir(sub)); err != nil {
+					l.Debugf("Skip walking %v as it is below a symlink", sub)
+					continue
+				}
 				w.Filesystem.Walk(sub, hashFiles)
 			}
 		}

lib/scanner/walk_test.go

@@ -322,7 +322,7 @@ func TestWalkRootSymlink(t *testing.T) {
 	}
 	defer os.RemoveAll(tmp)
 
-	link := tmp + "/link"
+	link := filepath.Join(tmp, "link")
 	dest, _ := filepath.Abs("testdata/dir1")
 	if err := osutil.DebugSymlinkForTestsOnly(dest, link); err != nil {
 		if runtime.GOOS == "windows" {
@@ -333,13 +333,33 @@ func TestWalkRootSymlink(t *testing.T) {
 		}
 	}
 
-	// Scan it
+	// Scan root with symlink at FS root
 	files := walkDir(fs.NewFilesystem(fs.FilesystemTypeBasic, link), ".", nil, nil, 0)
 
 	// Verify that we got two files
 	if len(files) != 2 {
 		t.Errorf("expected two files, not %d", len(files))
 	}
+
+	// Scan symlink below FS root
+	files = walkDir(fs.NewFilesystem(fs.FilesystemTypeBasic, tmp), "link", nil, nil, 0)
+
+	// Verify that we got the one symlink, except on windows
+	if runtime.GOOS == "windows" {
+		if len(files) != 0 {
+			t.Errorf("expected no files, not %d", len(files))
+		}
+	} else if len(files) != 1 {
+		t.Errorf("expected one file, not %d", len(files))
+	}
+
+	// Scan path below symlink
+	files = walkDir(fs.NewFilesystem(fs.FilesystemTypeBasic, tmp), filepath.Join("link", "cfile"), nil, nil, 0)
+
+	// Verify that we get nothing
+	if len(files) != 0 {
+		t.Errorf("expected no files, not %d", len(files))
+	}
 }
 
 func TestBlocksizeHysteresis(t *testing.T) {

lib/sha256/sha256.go

@@ -28,11 +28,6 @@ const (
 	minioImpl              = "minio/sha256-simd"
 )
 
-const (
-	BlockSize = cryptoSha256.BlockSize
-	Size      = cryptoSha256.Size
-)
-
 // May be switched out for another implementation
 var (
 	New    = cryptoSha256.New

lib/sync/sync_test.go

@@ -152,8 +152,7 @@ func TestRWMutex(t *testing.T) {
 
 	if len(messages) != 2 {
 		t.Errorf("Unexpected message count")
-	}
-	if !strings.Contains(messages[1], "RUnlockers while locking:\nat sync") || !strings.Contains(messages[1], "sync_test.go:") {
+	} else if !strings.Contains(messages[1], "RUnlockers while locking:\nat sync") || !strings.Contains(messages[1], "sync_test.go:") {
 		t.Error("Unexpected message")
 	}
 

lib/syncthing/syncthing.go

@@ -37,20 +37,26 @@ import (
 )
 
 const (
-	bepProtocolName      = "bep/1.0"
-	tlsDefaultCommonName = "syncthing"
-	maxSystemErrors      = 5
-	initialSystemLog     = 10
-	maxSystemLog         = 250
+	bepProtocolName        = "bep/1.0"
+	tlsDefaultCommonName   = "syncthing"
+	maxSystemErrors        = 5
+	initialSystemLog       = 10
+	maxSystemLog           = 250
+	deviceCertLifetimeDays = 20 * 365
 )
 
 type ExitStatus int
 
+func (s ExitStatus) AsInt() int {
+	return int(s)
+}
+
 const (
-	ExitSuccess ExitStatus = 0
-	ExitError   ExitStatus = 1
-	ExitRestart ExitStatus = 3
-	ExitUpgrade ExitStatus = 4
+	ExitSuccess            ExitStatus = 0
+	ExitError              ExitStatus = 1
+	ExitNoUpgradeAvailable ExitStatus = 2
+	ExitRestart            ExitStatus = 3
+	ExitUpgrade            ExitStatus = 4
 )
 
 type Options struct {
@@ -73,14 +79,13 @@ type App struct {
 	opts        Options
 	exitStatus  ExitStatus
 	err         error
-	startOnce   sync.Once
 	stopOnce    sync.Once
 	stop        chan struct{}
 	stopped     chan struct{}
 }
 
 func New(cfg config.Wrapper, ll *db.Lowlevel, evLogger events.Logger, cert tls.Certificate, opts Options) *App {
-	return &App{
+	a := &App{
 		cfg:      cfg,
 		ll:       ll,
 		evLogger: evLogger,
@@ -89,25 +94,21 @@ func New(cfg config.Wrapper, ll *db.Lowlevel, evLogger events.Logger, cert tls.C
 		stop:     make(chan struct{}),
 		stopped:  make(chan struct{}),
 	}
-}
-
-// Run does the same as start, but then does not return until the app stops. It
-// is equivalent to calling Start and then Wait.
-func (a *App) Run() ExitStatus {
-	a.Start()
-	return a.Wait()
+	close(a.stopped) // Hasn't been started, so shouldn't block on Wait.
+	return a
 }
 
 // Start executes the app and returns once all the startup operations are done,
 // e.g. the API is ready for use.
-func (a *App) Start() {
-	a.startOnce.Do(func() {
-		if err := a.startup(); err != nil {
-			a.stopWithErr(ExitError, err)
-			return
-		}
-		go a.run()
-	})
+// Must be called once only.
+func (a *App) Start() error {
+	if err := a.startup(); err != nil {
+		a.stopWithErr(ExitError, err)
+		return err
+	}
+	a.stopped = make(chan struct{})
+	go a.run()
+	return nil
 }
 
 func (a *App) startup() error {
@@ -238,16 +239,6 @@ func (a *App) startup() error {
 		m.StartDeadlockDetector(20 * time.Minute)
 	}
 
-	// Add and start folders
-	for _, folderCfg := range a.cfg.Folders() {
-		if folderCfg.Paused {
-			folderCfg.CreateRoot()
-			continue
-		}
-		m.AddFolder(folderCfg)
-		m.StartFolder(folderCfg.ID)
-	}
-
 	a.mainService.Add(m)
 
 	// Start discovery
@@ -378,7 +369,8 @@ func (a *App) run() {
 	close(a.stopped)
 }
 
-// Wait blocks until the app stops running.
+// Wait blocks until the app stops running. Also returns if the app hasn't been
+// started yet.
 func (a *App) Wait() ExitStatus {
 	<-a.stopped
 	return a.exitStatus
@@ -388,11 +380,11 @@ func (a *App) Wait() ExitStatus {
 // for the app to stop before returning.
 func (a *App) Error() error {
 	select {
-	case <-a.stopped:
-		return nil
+	case <-a.stop:
+		return a.err
 	default:
 	}
-	return a.err
+	return nil
 }
 
 // Stop stops the app and sets its exit status to given reason, unless the app
@@ -403,12 +395,8 @@ func (a *App) Stop(stopReason ExitStatus) ExitStatus {
 
 func (a *App) stopWithErr(stopReason ExitStatus, err error) ExitStatus {
 	a.stopOnce.Do(func() {
-		// ExitSuccess is the default value for a.exitStatus. If another status
-		// was already set, ignore the stop reason given as argument to Stop.
-		if a.exitStatus == ExitSuccess {
-			a.exitStatus = stopReason
-			a.err = err
-		}
+		a.exitStatus = stopReason
+		a.err = err
 		close(a.stop)
 	})
 	return a.exitStatus

lib/syncthing/syncthing_test.go

@@ -7,20 +7,36 @@
 package syncthing
 
 import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/lib/tlsutil"
 )
 
+func tempCfgFilename(t *testing.T) string {
+	t.Helper()
+	f, err := ioutil.TempFile("", "syncthing-testConfig-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	return f.Name()
+}
+
 func TestShortIDCheck(t *testing.T) {
-	cfg := config.Wrap("/tmp/test", config.Configuration{
+	cfg := config.Wrap(tempCfgFilename(t), config.Configuration{
 		Devices: []config.DeviceConfiguration{
 			{DeviceID: protocol.DeviceID{8, 16, 24, 32, 40, 48, 56, 0, 0}},
 			{DeviceID: protocol.DeviceID{8, 16, 24, 32, 40, 48, 56, 1, 1}}, // first 56 bits same, differ in the first 64 bits
 		},
 	}, events.NoopLogger)
+	defer os.Remove(cfg.ConfigPath())
 
 	if err := checkShortIDs(cfg); err != nil {
 		t.Error("Unexpected error:", err)
@@ -37,3 +53,54 @@ func TestShortIDCheck(t *testing.T) {
 		t.Error("Should have gotten an error")
 	}
 }
+
+func TestStartupFail(t *testing.T) {
+	tmpDir, err := ioutil.TempDir("", "syncthing-TestStartupFail-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	cert, err := tlsutil.NewCertificate(filepath.Join(tmpDir, "cert"), filepath.Join(tmpDir, "key"), "syncthing", 365)
+	if err != nil {
+		t.Fatal(err)
+	}
+	id := protocol.NewDeviceID(cert.Certificate[0])
+	conflID := protocol.DeviceID{}
+	copy(conflID[:8], id[:8])
+
+	cfg := config.Wrap(tempCfgFilename(t), config.Configuration{
+		Devices: []config.DeviceConfiguration{
+			{DeviceID: id},
+			{DeviceID: conflID},
+		},
+	}, events.NoopLogger)
+	defer os.Remove(cfg.ConfigPath())
+
+	app := New(cfg, nil, events.NoopLogger, cert, Options{})
+	startErr := app.Start()
+	if startErr == nil {
+		t.Fatal("Expected an error from Start, got nil")
+	}
+
+	done := make(chan struct{})
+	var waitE ExitStatus
+	go func() {
+		waitE = app.Wait()
+		close(done)
+	}()
+
+	select {
+	case <-time.After(time.Second):
+		t.Fatal("Wait did not return within 1s")
+	case <-done:
+	}
+
+	if waitE != ExitError {
+		t.Errorf("Got exit status %v, expected %v", waitE, ExitError)
+	}
+
+	if err = app.Error(); err != startErr {
+		t.Errorf(`Got different errors "%v" from Start and "%v" from Error`, startErr, err)
+	}
+}

lib/syncthing/utils.go

@@ -35,6 +35,7 @@ func LoadOrGenerateCertificate(certFile, keyFile string) (tls.Certificate, error
 			locations.Get(locations.CertFile),
 			locations.Get(locations.KeyFile),
 			tlsDefaultCommonName,
+			deviceCertLifetimeDays,
 		)
 	}
 	return cert, nil

lib/tlsutil/tlsutil.go

@@ -20,7 +20,6 @@ import (
 	"os"
 	"time"
 
-	"github.com/syncthing/syncthing/lib/build"
 	"github.com/syncthing/syncthing/lib/rand"
 )
 
@@ -70,11 +69,6 @@ var (
 func init() {
 	// Creates the list of ciper suites that SecureDefault uses.
 	cipherSuites = buildCipherSuites()
-	if build.IsBeta {
-		// Append "tls13=1" to GODEBUG before starting TLS, to enable TLS
-		// 1.3 in Go 1.12.
-		os.Setenv("GODEBUG", os.Getenv("GODEBUG")+",tls13=1")
-	}
 }
 
 // SecureDefault returns a tls.Config with reasonable, secure defaults set.
@@ -95,15 +89,17 @@ func SecureDefault() *tls.Config {
 }
 
 // NewCertificate generates and returns a new TLS certificate.
-func NewCertificate(certFile, keyFile, commonName string) (tls.Certificate, error) {
+func NewCertificate(certFile, keyFile, commonName string, lifetimeDays int) (tls.Certificate, error) {
 	priv, err := ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
 	if err != nil {
 		return tls.Certificate{}, fmt.Errorf("generate key: %s", err)
 	}
 
-	notBefore := time.Now()
-	notAfter := time.Date(2049, 12, 31, 23, 59, 59, 0, time.UTC)
+	notBefore := time.Now().Truncate(24 * time.Hour)
+	notAfter := notBefore.Add(time.Duration(lifetimeDays*24) * time.Hour)
 
+	// NOTE: update checkExpiry() appropriately if you add or change attributes
+	// in here, especially DNSNames or IPAddresses.
 	template := x509.Certificate{
 		SerialNumber: new(big.Int).SetInt64(rand.Int63()),
 		Subject: pkix.Name{

lib/upgrade/upgrade_common.go

@@ -21,6 +21,10 @@ type Release struct {
 	Tag        string  `json:"tag_name"`
 	Prerelease bool    `json:"prerelease"`
 	Assets     []Asset `json:"assets"`
+
+	// The HTML URL is needed for human readable links in the output created
+	// by cmd/stupgrades.
+	HTMLURL string `json:"html_url"`
 }
 
 type Asset struct {
@@ -33,7 +37,6 @@ type Asset struct {
 }
 
 var (
-	ErrVersionUpToDate    = errors.New("current version is up to date")
 	ErrNoReleaseDownload  = errors.New("couldn't find a release to download")
 	ErrNoVersionToSelect  = errors.New("no version to select")
 	ErrUpgradeUnsupported = errors.New("upgrade unsupported")

lib/upnp/upnp.go

@@ -133,7 +133,7 @@ nextResult:
 	return results
 }
 
-// Search for UPnP InternetGatewayDevices for <timeout> seconds, ignoring responses from any devices listed in knownDevices.
+// Search for UPnP InternetGatewayDevices for <timeout> seconds.
 // The order in which the devices appear in the result list is not deterministic
 func discover(intf *net.Interface, deviceType string, timeout time.Duration, results chan<- nat.Device) {
 	ssdp := &net.UDPAddr{IP: []byte{239, 255, 255, 250}, Port: 1900}

lib/util/utils.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"net/url"
 	"reflect"
+	"runtime"
 	"strconv"
 	"strings"
 
@@ -178,7 +179,7 @@ func Address(network, host string) string {
 // AsService wraps the given function to implement suture.Service by calling
 // that function on serve and closing the passed channel when Stop is called.
 func AsService(fn func(stop chan struct{})) suture.Service {
-	return AsServiceWithError(func(stop chan struct{}) error {
+	return asServiceWithError(func(stop chan struct{}) error {
 		fn(stop)
 		return nil
 	})
@@ -186,6 +187,7 @@ func AsService(fn func(stop chan struct{})) suture.Service {
 
 type ServiceWithError interface {
 	suture.Service
+	fmt.Stringer
 	Error() error
 	SetError(error)
 }
@@ -193,7 +195,21 @@ type ServiceWithError interface {
 // AsServiceWithError does the same as AsService, except that it keeps track
 // of an error returned by the given function.
 func AsServiceWithError(fn func(stop chan struct{}) error) ServiceWithError {
+	return asServiceWithError(fn)
+}
+
+// caller retrieves information about the creator of the service, i.e. the stack
+// two levels up from itself.
+func caller() string {
+	pc := make([]uintptr, 1)
+	_ = runtime.Callers(4, pc)
+	f, _ := runtime.CallersFrames(pc).Next()
+	return f.Function
+}
+
+func asServiceWithError(fn func(stop chan struct{}) error) ServiceWithError {
 	s := &service{
+		caller:  caller(),
 		serve:   fn,
 		stop:    make(chan struct{}),
 		stopped: make(chan struct{}),
@@ -204,6 +220,7 @@ func AsServiceWithError(fn func(stop chan struct{}) error) ServiceWithError {
 }
 
 type service struct {
+	caller  string
 	serve   func(stop chan struct{}) error
 	stop    chan struct{}
 	stopped chan struct{}
@@ -235,7 +252,12 @@ func (s *service) Serve() {
 
 func (s *service) Stop() {
 	s.mut.Lock()
-	close(s.stop)
+	select {
+	case <-s.stop:
+		panic(fmt.Sprintf("Stop called more than once on %v", s))
+	default:
+		close(s.stop)
+	}
 	s.mut.Unlock()
 	<-s.stopped
 }
@@ -251,3 +273,7 @@ func (s *service) SetError(err error) {
 	s.err = err
 	s.mut.Unlock()
 }
+
+func (s *service) String() string {
+	return fmt.Sprintf("Service@%p created by %v", s, s.caller)
+}

lib/util/utils_test.go

@@ -6,7 +6,10 @@
 
 package util
 
-import "testing"
+import (
+	"strings"
+	"testing"
+)
 
 type Defaulter struct {
 	Value string
@@ -222,3 +225,20 @@ func TestCopyMatching(t *testing.T) {
 		t.Error("NoCopy")
 	}
 }
+
+func TestUtilStopTwicePanic(t *testing.T) {
+	s := AsService(func(stop chan struct{}) {
+		<-stop
+	})
+
+	go s.Serve()
+	s.Stop()
+
+	defer func() {
+		expected := "lib/util.TestUtilStopTwicePanic"
+		if r := recover(); r == nil || !strings.Contains(r.(string), expected) {
+			t.Fatalf(`expected panic containing "%v", got "%v"`, expected, r)
+		}
+	}()
+	s.Stop()
+}

script/docker-entrypoint.sh

@@ -2,7 +2,6 @@
 
 set -eu
 
-chown "${PUID}:${PGID}" /var/syncthing \
+chown "${PUID}:${PGID}" "${HOME}" \
   && exec su-exec "${PUID}:${PGID}" \
-     env HOME=/var/syncthing \
-     /bin/syncthing "$@"
+     "$@"

snapcraft.yaml.template

@@ -20,6 +20,7 @@ apps:
       HOME: ${SNAP_USER_COMMON}
       XDG_CONFIG_HOME: ${SNAP_USER_COMMON}
     plugs:
+    - desktop
     - home
     - network
     - network-bind