Remove global cfg variable (fixes #2294)

Not necessarily the easiest way to fix just this bug, but the root cause
was using the (at that point uninitialized) cfg variable, so it seemed
sensible to just get rid of it to avoid that kind of crap.

cmd/syncthing/gui.go

@@ -55,7 +55,7 @@ var (
 
 type apiSvc struct {
 	id              protocol.DeviceID
-	cfg             config.GUIConfiguration
+	cfg             *config.Wrapper
 	assetDir        string
 	model           *model.Model
 	eventSub        *events.BufferedSubscription
@@ -67,7 +67,7 @@ type apiSvc struct {
 	systemConfigMut sync.Mutex
 }
 
-func newAPISvc(id protocol.DeviceID, cfg config.GUIConfiguration, assetDir string, m *model.Model, eventSub *events.BufferedSubscription, discoverer *discover.CachingMux, relaySvc *relay.Svc) (*apiSvc, error) {
+func newAPISvc(id protocol.DeviceID, cfg *config.Wrapper, assetDir string, m *model.Model, eventSub *events.BufferedSubscription, discoverer *discover.CachingMux, relaySvc *relay.Svc) (*apiSvc, error) {
 	svc := &apiSvc{
 		id:              id,
 		cfg:             cfg,
@@ -80,7 +80,7 @@ func newAPISvc(id protocol.DeviceID, cfg config.GUIConfiguration, assetDir strin
 	}
 
 	var err error
-	svc.listener, err = svc.getListener(cfg)
+	svc.listener, err = svc.getListener(cfg.GUI())
 	return svc, err
 }
 
@@ -195,20 +195,22 @@ func (s *apiSvc) Serve() {
 		assets:   auto.Assets(),
 	})
 
+	guiCfg := s.cfg.GUI()
+
 	// Wrap everything in CSRF protection. The /rest prefix should be
 	// protected, other requests will grant cookies.
-	handler := csrfMiddleware(s.id.String()[:5], "/rest", s.cfg.APIKey, mux)
+	handler := csrfMiddleware(s.id.String()[:5], "/rest", guiCfg.APIKey, mux)
 
 	// Add our version and ID as a header to responses
 	handler = withDetailsMiddleware(s.id, handler)
 
 	// Wrap everything in basic auth, if user/password is set.
-	if len(s.cfg.User) > 0 && len(s.cfg.Password) > 0 {
-		handler = basicAuthAndSessionMiddleware("sessionid-"+s.id.String()[:5], s.cfg, handler)
+	if len(guiCfg.User) > 0 && len(guiCfg.Password) > 0 {
+		handler = basicAuthAndSessionMiddleware("sessionid-"+s.id.String()[:5], guiCfg, handler)
 	}
 
 	// Redirect to HTTPS if we are supposed to
-	if s.cfg.UseTLS {
+	if guiCfg.UseTLS {
 		handler = redirectToHTTPSMiddleware(handler)
 	}
 
@@ -221,7 +223,7 @@ func (s *apiSvc) Serve() {
 		ReadTimeout: 10 * time.Second,
 	}
 
-	s.fss = newFolderSummarySvc(s.model)
+	s.fss = newFolderSummarySvc(s.cfg, s.model)
 	defer s.fss.Stop()
 	s.fss.ServeBackground()
 
@@ -273,7 +275,6 @@ func (s *apiSvc) CommitConfiguration(from, to config.Configuration) bool {
 		// method.
 		return false
 	}
-	s.cfg = to.GUI
 
 	close(s.stop)
 
@@ -409,12 +410,12 @@ func (s *apiSvc) getDBCompletion(w http.ResponseWriter, r *http.Request) {
 func (s *apiSvc) getDBStatus(w http.ResponseWriter, r *http.Request) {
 	qs := r.URL.Query()
 	folder := qs.Get("folder")
-	res := folderSummary(s.model, folder)
+	res := folderSummary(s.cfg, s.model, folder)
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	json.NewEncoder(w).Encode(res)
 }
 
-func folderSummary(m *model.Model, folder string) map[string]interface{} {
+func folderSummary(cfg *config.Wrapper, m *model.Model, folder string) map[string]interface{} {
 	var res = make(map[string]interface{})
 
 	res["invalid"] = cfg.Folders()[folder].Invalid
@@ -524,7 +525,7 @@ func (s *apiSvc) getDBFile(w http.ResponseWriter, r *http.Request) {
 
 func (s *apiSvc) getSystemConfig(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	json.NewEncoder(w).Encode(cfg.Raw())
+	json.NewEncoder(w).Encode(s.cfg.Raw())
 }
 
 func (s *apiSvc) postSystemConfig(w http.ResponseWriter, r *http.Request) {
@@ -539,7 +540,7 @@ func (s *apiSvc) postSystemConfig(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if to.GUI.Password != cfg.GUI().Password {
+	if to.GUI.Password != s.cfg.GUI().Password {
 		if to.GUI.Password != "" {
 			hash, err := bcrypt.GenerateFromPassword([]byte(to.GUI.Password), 0)
 			if err != nil {
@@ -554,7 +555,7 @@ func (s *apiSvc) postSystemConfig(w http.ResponseWriter, r *http.Request) {
 
 	// Fixup usage reporting settings
 
-	if curAcc := cfg.Options().URAccepted; to.Options.URAccepted > curAcc {
+	if curAcc := s.cfg.Options().URAccepted; to.Options.URAccepted > curAcc {
 		// UR was enabled
 		to.Options.URAccepted = usageReportVersion
 		to.Options.URUniqueID = randomString(8)
@@ -566,9 +567,9 @@ func (s *apiSvc) postSystemConfig(w http.ResponseWriter, r *http.Request) {
 
 	// Activate and save
 
-	resp := cfg.Replace(to)
+	resp := s.cfg.Replace(to)
 	configInSync = !resp.RequiresRestart
-	cfg.Save()
+	s.cfg.Save()
 }
 
 func (s *apiSvc) getSystemConfigInsync(w http.ResponseWriter, r *http.Request) {
@@ -586,7 +587,7 @@ func (s *apiSvc) postSystemReset(w http.ResponseWriter, r *http.Request) {
 	folder := qs.Get("folder")
 
 	if len(folder) > 0 {
-		if _, ok := cfg.Folders()[folder]; !ok {
+		if _, ok := s.cfg.Folders()[folder]; !ok {
 			http.Error(w, "Invalid folder ID", 500)
 			return
 		}
@@ -594,7 +595,7 @@ func (s *apiSvc) postSystemReset(w http.ResponseWriter, r *http.Request) {
 
 	if len(folder) == 0 {
 		// Reset all folders.
-		for folder := range cfg.Folders() {
+		for folder := range s.cfg.Folders() {
 			s.model.ResetFolder(folder)
 		}
 		s.flushResponse(`{"ok": "resetting database"}`, w)
@@ -632,7 +633,7 @@ func (s *apiSvc) getSystemStatus(w http.ResponseWriter, r *http.Request) {
 	res["alloc"] = m.Alloc
 	res["sys"] = m.Sys - m.HeapReleased
 	res["tilde"] = tilde
-	if cfg.Options().LocalAnnEnabled || cfg.Options().GlobalAnnEnabled {
+	if s.cfg.Options().LocalAnnEnabled || s.cfg.Options().GlobalAnnEnabled {
 		res["discoveryEnabled"] = true
 		discoErrors := make(map[string]string)
 		discoMethods := 0
@@ -718,7 +719,7 @@ func (s *apiSvc) getSystemDiscovery(w http.ResponseWriter, r *http.Request) {
 
 func (s *apiSvc) getReport(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	json.NewEncoder(w).Encode(reportData(s.model))
+	json.NewEncoder(w).Encode(reportData(s.cfg, s.model))
 }
 
 func (s *apiSvc) getDBIgnores(w http.ResponseWriter, r *http.Request) {
@@ -787,7 +788,7 @@ func (s *apiSvc) getSystemUpgrade(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, upgrade.ErrUpgradeUnsupported.Error(), 500)
 		return
 	}
-	rel, err := upgrade.LatestRelease(cfg.Options().ReleasesURL, Version)
+	rel, err := upgrade.LatestRelease(s.cfg.Options().ReleasesURL, Version)
 	if err != nil {
 		http.Error(w, err.Error(), 500)
 		return
@@ -830,7 +831,7 @@ func (s *apiSvc) getLang(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *apiSvc) postSystemUpgrade(w http.ResponseWriter, r *http.Request) {
-	rel, err := upgrade.LatestRelease(cfg.Options().ReleasesURL, Version)
+	rel, err := upgrade.LatestRelease(s.cfg.Options().ReleasesURL, Version)
 	if err != nil {
 		l.Warnln("getting latest release:", err)
 		http.Error(w, err.Error(), 500)
@@ -928,7 +929,7 @@ func (s *apiSvc) getPeerCompletion(w http.ResponseWriter, r *http.Request) {
 	tot := map[string]float64{}
 	count := map[string]float64{}
 
-	for _, folder := range cfg.Folders() {
+	for _, folder := range s.cfg.Folders() {
 		for _, device := range folder.DeviceIDs() {
 			deviceStr := device.String()
 			if s.model.ConnectedTo(device) {

cmd/syncthing/main.go

@@ -26,7 +26,6 @@ import (
 	"time"
 
 	"github.com/calmh/logger"
-	"github.com/juju/ratelimit"
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/connections"
 	"github.com/syncthing/syncthing/lib/db"
@@ -108,15 +107,12 @@ func init() {
 }
 
 var (
-	cfg            *config.Wrapper
-	myID           protocol.DeviceID
-	confDir        string
-	logFlags       = log.Ltime
-	writeRateLimit *ratelimit.Bucket
-	readRateLimit  *ratelimit.Bucket
-	stop           = make(chan int)
-	cert           tls.Certificate
-	lans           []*net.IPNet
+	myID     protocol.DeviceID
+	confDir  string
+	logFlags = log.Ltime
+	stop     = make(chan int)
+	cert     tls.Certificate
+	lans     []*net.IPNet
 )
 
 const (
@@ -346,7 +342,11 @@ func main() {
 	}
 
 	if doUpgrade || doUpgradeCheck {
-		rel, err := upgrade.LatestRelease(cfg.Options().ReleasesURL, Version)
+		releasesURL := "https://api.github.com/repos/syncthing/syncthing/releases?per_page=30"
+		if cfg, _, err := loadConfig(locations[locConfigFile]); err == nil {
+			releasesURL = cfg.Options().ReleasesURL
+		}
+		rel, err := upgrade.LatestRelease(releasesURL, Version)
 		if err != nil {
 			l.Fatalln("Upgrade:", err) // exits 1
 		}
@@ -497,33 +497,21 @@ func syncthingMain() {
 
 	cfgFile := locations[locConfigFile]
 
-	var myName string
-
 	// Load the configuration file, if it exists.
 	// If it does not, create a template.
 
-	if info, err := os.Stat(cfgFile); err == nil {
-		if !info.Mode().IsRegular() {
-			l.Fatalln("Config file is not a file?")
-		}
-		cfg, err = config.Load(cfgFile, myID)
-		if err == nil {
-			myCfg := cfg.Devices()[myID]
-			if myCfg.Name == "" {
-				myName, _ = os.Hostname()
-			} else {
-				myName = myCfg.Name
-			}
+	cfg, myName, err := loadConfig(cfgFile)
+	if err != nil {
+		if os.IsNotExist(err) {
+			l.Infoln("No config file; starting with empty defaults")
+			myName, _ = os.Hostname()
+			newCfg := defaultConfig(myName)
+			cfg = config.Wrap(cfgFile, newCfg)
+			cfg.Save()
+			l.Infof("Edit %s to taste or use the GUI\n", cfgFile)
 		} else {
-			l.Fatalln("Configuration:", err)
+			l.Fatalln("Loading config:", err)
 		}
-	} else {
-		l.Infoln("No config file; starting with empty defaults")
-		myName, _ = os.Hostname()
-		newCfg := defaultConfig(myName)
-		cfg = config.Wrap(cfgFile, newCfg)
-		cfg.Save()
-		l.Infof("Edit %s to taste or use the GUI\n", cfgFile)
 	}
 
 	if cfg.Raw().OriginalVersion != config.CurrentVersion {
@@ -596,9 +584,10 @@ func syncthingMain() {
 	}
 
 	dbFile := locations[locDatabase]
-	ldb, err := leveldb.OpenFile(dbFile, dbOpts())
+	dbOpts := dbOpts(cfg)
+	ldb, err := leveldb.OpenFile(dbFile, dbOpts)
 	if leveldbIsCorrupted(err) {
-		ldb, err = leveldb.RecoverFile(dbFile, dbOpts())
+		ldb, err = leveldb.RecoverFile(dbFile, dbOpts)
 	}
 	if leveldbIsCorrupted(err) {
 		// The database is corrupted, and we've tried to recover it but it
@@ -608,7 +597,7 @@ func syncthingMain() {
 		if err := resetDB(); err != nil {
 			l.Fatalln("Remove database:", err)
 		}
-		ldb, err = leveldb.OpenFile(dbFile, dbOpts())
+		ldb, err = leveldb.OpenFile(dbFile, dbOpts)
 	}
 	if err != nil {
 		l.Fatalln("Cannot open database:", err, "- Is another copy of Syncthing already running?")
@@ -780,7 +769,7 @@ func syncthingMain() {
 	// The usageReportingManager registers itself to listen to configuration
 	// changes, and there's nothing more we need to tell it from the outside.
 	// Hence we don't keep the returned pointer.
-	newUsageReportingManager(m, cfg)
+	newUsageReportingManager(cfg, m)
 
 	if opts.RestartOnWakeup {
 		go standbyMonitor()
@@ -790,7 +779,7 @@ func syncthingMain() {
 		if noUpgrade {
 			l.Infof("No automatic upgrades; STNOUPGRADE environment variable defined.")
 		} else if IsRelease {
-			go autoUpgrade()
+			go autoUpgrade(cfg)
 		} else {
 			l.Infof("No automatic upgrades; %s is not a release version.", Version)
 		}
@@ -816,7 +805,30 @@ func syncthingMain() {
 	os.Exit(code)
 }
 
-func dbOpts() *opt.Options {
+func loadConfig(cfgFile string) (*config.Wrapper, string, error) {
+	info, err := os.Stat(cfgFile)
+	if err != nil {
+		return nil, "", err
+	}
+	if !info.Mode().IsRegular() {
+		return nil, "", errors.New("configuration is not a file")
+	}
+
+	cfg, err := config.Load(cfgFile, myID)
+	if err != nil {
+		return nil, "", err
+	}
+
+	myCfg := cfg.Devices()[myID]
+	myName := myCfg.Name
+	if myName == "" {
+		myName, _ = os.Hostname()
+	}
+
+	return cfg, myName, nil
+}
+
+func dbOpts(cfg *config.Wrapper) *opt.Options {
 	// Calculate a suitable database block cache capacity.
 
 	// Default is 8 MiB.
@@ -896,7 +908,7 @@ func setupGUI(mainSvc *suture.Supervisor, cfg *config.Wrapper, m *model.Model, a
 
 			urlShow := fmt.Sprintf("%s://%s/", proto, net.JoinHostPort(hostShow, strconv.Itoa(addr.Port)))
 			l.Infoln("Starting web GUI on", urlShow)
-			api, err := newAPISvc(myID, guiCfg, guiAssets, m, apiSub, discoverer, relaySvc)
+			api, err := newAPISvc(myID, cfg, guiAssets, m, apiSub, discoverer, relaySvc)
 			if err != nil {
 				l.Fatalln("Cannot start GUI:", err)
 			}
@@ -1066,7 +1078,7 @@ func standbyMonitor() {
 	}
 }
 
-func autoUpgrade() {
+func autoUpgrade(cfg *config.Wrapper) {
 	timer := time.NewTimer(0)
 	sub := events.Default.Subscribe(events.DeviceConnected)
 	for {

cmd/syncthing/summarysvc.go

@@ -9,6 +9,7 @@ package main
 import (
 	"time"
 
+	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/model"
 	"github.com/syncthing/syncthing/lib/sync"
@@ -20,6 +21,7 @@ import (
 type folderSummarySvc struct {
 	*suture.Supervisor
 
+	cfg       *config.Wrapper
 	model     *model.Model
 	stop      chan struct{}
 	immediate chan string
@@ -33,9 +35,10 @@ type folderSummarySvc struct {
 	lastEventReqMut sync.Mutex
 }
 
-func newFolderSummarySvc(m *model.Model) *folderSummarySvc {
+func newFolderSummarySvc(cfg *config.Wrapper, m *model.Model) *folderSummarySvc {
 	svc := &folderSummarySvc{
 		Supervisor:      suture.NewSimple("folderSummarySvc"),
+		cfg:             cfg,
 		model:           m,
 		stop:            make(chan struct{}),
 		immediate:       make(chan string),
@@ -162,13 +165,13 @@ func (c *folderSummarySvc) foldersToHandle() []string {
 func (c *folderSummarySvc) sendSummary(folder string) {
 	// The folder summary contains how many bytes, files etc
 	// are in the folder and how in sync we are.
-	data := folderSummary(c.model, folder)
+	data := folderSummary(c.cfg, c.model, folder)
 	events.Default.Log(events.FolderSummary, map[string]interface{}{
 		"folder":  folder,
 		"summary": data,
 	})
 
-	for _, devCfg := range cfg.Folders()[folder].Devices {
+	for _, devCfg := range c.cfg.Folders()[folder].Devices {
 		if devCfg.DeviceID.Equals(myID) {
 			// We already know about ourselves.
 			continue

cmd/syncthing/usage_report.go

@@ -32,12 +32,14 @@ import (
 const usageReportVersion = 2
 
 type usageReportingManager struct {
+	cfg   *config.Wrapper
 	model *model.Model
 	sup   *suture.Supervisor
 }
 
-func newUsageReportingManager(m *model.Model, cfg *config.Wrapper) *usageReportingManager {
+func newUsageReportingManager(cfg *config.Wrapper, m *model.Model) *usageReportingManager {
 	mgr := &usageReportingManager{
+		cfg:   cfg,
 		model: m,
 	}
 
@@ -58,9 +60,7 @@ func (m *usageReportingManager) VerifyConfiguration(from, to config.Configuratio
 func (m *usageReportingManager) CommitConfiguration(from, to config.Configuration) bool {
 	if to.Options.URAccepted >= usageReportVersion && m.sup == nil {
 		// Usage reporting was turned on; lets start it.
-		svc := &usageReportingService{
-			model: m.model,
-		}
+		svc := newUsageReportingService(m.cfg, m.model)
 		m.sup = suture.NewSimple("usageReporting")
 		m.sup.Add(svc)
 		m.sup.ServeBackground()
@@ -79,7 +79,7 @@ func (m *usageReportingManager) String() string {
 
 // reportData returns the data to be sent in a usage report. It's used in
 // various places, so not part of the usageReportingSvc object.
-func reportData(m *model.Model) map[string]interface{} {
+func reportData(cfg *config.Wrapper, m *model.Model) map[string]interface{} {
 	res := make(map[string]interface{})
 	res["urVersion"] = usageReportVersion
 	res["uniqueID"] = cfg.Options().URUniqueID
@@ -238,12 +238,21 @@ func stringIn(needle string, haystack []string) bool {
 }
 
 type usageReportingService struct {
+	cfg   *config.Wrapper
 	model *model.Model
 	stop  chan struct{}
 }
 
+func newUsageReportingService(cfg *config.Wrapper, model *model.Model) *usageReportingService {
+	return &usageReportingService{
+		cfg:   cfg,
+		model: model,
+		stop:  make(chan struct{}),
+	}
+}
+
 func (s *usageReportingService) sendUsageReport() error {
-	d := reportData(s.model)
+	d := reportData(s.cfg, s.model)
 	var b bytes.Buffer
 	json.NewEncoder(&b).Encode(d)
 
@@ -256,12 +265,12 @@ func (s *usageReportingService) sendUsageReport() error {
 		}
 	}
 
-	if cfg.Options().URPostInsecurely {
+	if s.cfg.Options().URPostInsecurely {
 		transp.TLSClientConfig = &tls.Config{
 			InsecureSkipVerify: true,
 		}
 	}
-	_, err := client.Post(cfg.Options().URURL, "application/json", &b)
+	_, err := client.Post(s.cfg.Options().URURL, "application/json", &b)
 	return err
 }
 
@@ -271,7 +280,7 @@ func (s *usageReportingService) Serve() {
 	l.Infoln("Starting usage reporting")
 	defer l.Infoln("Stopping usage reporting")
 
-	t := time.NewTimer(time.Duration(cfg.Options().URInitialDelayS) * time.Second) // time to initial report at start
+	t := time.NewTimer(time.Duration(s.cfg.Options().URInitialDelayS) * time.Second) // time to initial report at start
 	for {
 		select {
 		case <-s.stop: