// Copyright (C) 2014 The Syncthing Authors. // // This Source Code Form is subject to the terms of the Mozilla Public // License, v. 2.0. If a copy of the MPL was not distributed with this file, // You can obtain one at https://mozilla.org/MPL/2.0/. // Package config implements reading and writing of the syncthing configuration file. package config import ( "encoding/json" "encoding/xml" "fmt" "io" "io/ioutil" "net" "net/url" "os" "runtime" "sort" "strconv" "strings" "github.com/pkg/errors" "github.com/syncthing/syncthing/lib/fs" "github.com/syncthing/syncthing/lib/protocol" "github.com/syncthing/syncthing/lib/rand" "github.com/syncthing/syncthing/lib/util" ) const ( OldestHandledVersion = 10 CurrentVersion = 30 MaxRescanIntervalS = 365 * 24 * 60 * 60 ) var ( // DefaultTCPPort defines default TCP port used if the URI does not specify one, for example tcp://0.0.0.0 DefaultTCPPort = 22000 // DefaultQUICPort defines default QUIC port used if the URI does not specify one, for example quic://0.0.0.0 DefaultQUICPort = 22000 // DefaultListenAddresses should be substituted when the configuration // contains default. This is done by the // "consumer" of the configuration as we don't want these saved to the // config. DefaultListenAddresses = []string{ util.Address("tcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultTCPPort))), "dynamic+https://relays.syncthing.net/endpoint", util.Address("quic", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultQUICPort))), } DefaultGUIPort = 8384 // DefaultDiscoveryServersV4 should be substituted when the configuration // contains default-v4. DefaultDiscoveryServersV4 = []string{ "https://discovery.syncthing.net/v2/?noannounce&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW", "https://discovery-v4.syncthing.net/v2/?nolookup&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW", } // DefaultDiscoveryServersV6 should be substituted when the configuration // contains default-v6. DefaultDiscoveryServersV6 = []string{ "https://discovery.syncthing.net/v2/?noannounce&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW", "https://discovery-v6.syncthing.net/v2/?nolookup&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW", } // DefaultDiscoveryServers should be substituted when the configuration // contains default. DefaultDiscoveryServers = append(DefaultDiscoveryServersV4, DefaultDiscoveryServersV6...) // DefaultTheme is the default and fallback theme for the web UI. DefaultTheme = "default" // Default stun servers should be substituted when the configuration // contains default. // DefaultPrimaryStunServers are servers provided by us (to avoid causing the public servers burden) DefaultPrimaryStunServers = []string{ "stun.syncthing.net:3478", } DefaultSecondaryStunServers = []string{ "stun.callwithus.com:3478", "stun.counterpath.com:3478", "stun.counterpath.net:3478", "stun.ekiga.net:3478", "stun.ideasip.com:3478", "stun.internetcalls.com:3478", "stun.schlund.de:3478", "stun.sipgate.net:10000", "stun.sipgate.net:3478", "stun.voip.aebc.com:3478", "stun.voiparound.com:3478", "stun.voipbuster.com:3478", "stun.voipstunt.com:3478", "stun.xten.com:3478", } ) var ( errFolderIDEmpty = errors.New("folder has empty ID") errFolderIDDuplicate = errors.New("folder has duplicate ID") errFolderPathEmpty = errors.New("folder has empty path") ) func New(myID protocol.DeviceID) Configuration { var cfg Configuration cfg.Version = CurrentVersion cfg.OriginalVersion = CurrentVersion util.SetDefaults(&cfg) util.SetDefaults(&cfg.Options) util.SetDefaults(&cfg.GUI) // Can't happen. if err := cfg.prepare(myID); err != nil { l.Warnln("bug: error in preparing new folder:", err) panic("error in preparing new folder") } return cfg } func NewWithFreePorts(myID protocol.DeviceID) (Configuration, error) { cfg := New(myID) port, err := getFreePort("127.0.0.1", DefaultGUIPort) if err != nil { return Configuration{}, errors.Wrap(err, "get free port (GUI)") } cfg.GUI.RawAddress = fmt.Sprintf("127.0.0.1:%d", port) port, err = getFreePort("0.0.0.0", DefaultTCPPort) if err != nil { return Configuration{}, errors.Wrap(err, "get free port (BEP)") } if port == DefaultTCPPort { cfg.Options.RawListenAddresses = []string{"default"} } else { cfg.Options.RawListenAddresses = []string{ fmt.Sprintf("tcp://%s", net.JoinHostPort("0.0.0.0", strconv.Itoa(port))), "dynamic+https://relays.syncthing.net/endpoint", } } return cfg, nil } func ReadXML(r io.Reader, myID protocol.DeviceID) (Configuration, error) { var cfg Configuration util.SetDefaults(&cfg) util.SetDefaults(&cfg.Options) util.SetDefaults(&cfg.GUI) if err := xml.NewDecoder(r).Decode(&cfg); err != nil { return Configuration{}, err } cfg.OriginalVersion = cfg.Version if err := cfg.prepare(myID); err != nil { return Configuration{}, err } return cfg, nil } func ReadJSON(r io.Reader, myID protocol.DeviceID) (Configuration, error) { var cfg Configuration util.SetDefaults(&cfg) util.SetDefaults(&cfg.Options) util.SetDefaults(&cfg.GUI) bs, err := ioutil.ReadAll(r) if err != nil { return Configuration{}, err } if err := json.Unmarshal(bs, &cfg); err != nil { return Configuration{}, err } cfg.OriginalVersion = cfg.Version if err := cfg.prepare(myID); err != nil { return Configuration{}, err } return cfg, nil } type Configuration struct { Version int `xml:"version,attr" json:"version"` Folders []FolderConfiguration `xml:"folder" json:"folders"` Devices []DeviceConfiguration `xml:"device" json:"devices"` GUI GUIConfiguration `xml:"gui" json:"gui"` LDAP LDAPConfiguration `xml:"ldap" json:"ldap"` Options OptionsConfiguration `xml:"options" json:"options"` IgnoredDevices []ObservedDevice `xml:"remoteIgnoredDevice" json:"remoteIgnoredDevices"` PendingDevices []ObservedDevice `xml:"pendingDevice" json:"pendingDevices"` XMLName xml.Name `xml:"configuration" json:"-"` MyID protocol.DeviceID `xml:"-" json:"-"` // Provided by the instantiator. OriginalVersion int `xml:"-" json:"-"` // The version we read from disk, before any conversion } func (cfg Configuration) Copy() Configuration { newCfg := cfg // Deep copy FolderConfigurations newCfg.Folders = make([]FolderConfiguration, len(cfg.Folders)) for i := range newCfg.Folders { newCfg.Folders[i] = cfg.Folders[i].Copy() } // Deep copy DeviceConfigurations newCfg.Devices = make([]DeviceConfiguration, len(cfg.Devices)) for i := range newCfg.Devices { newCfg.Devices[i] = cfg.Devices[i].Copy() } newCfg.Options = cfg.Options.Copy() newCfg.GUI = cfg.GUI.Copy() // DeviceIDs are values newCfg.IgnoredDevices = make([]ObservedDevice, len(cfg.IgnoredDevices)) copy(newCfg.IgnoredDevices, cfg.IgnoredDevices) newCfg.PendingDevices = make([]ObservedDevice, len(cfg.PendingDevices)) copy(newCfg.PendingDevices, cfg.PendingDevices) return newCfg } func (cfg *Configuration) WriteXML(w io.Writer) error { e := xml.NewEncoder(w) e.Indent("", " ") err := e.Encode(cfg) if err != nil { return err } _, err = w.Write([]byte("\n")) return err } func (cfg *Configuration) prepare(myID protocol.DeviceID) error { var myName string cfg.MyID = myID // Ensure this device is present in the config for _, device := range cfg.Devices { if device.DeviceID == myID { goto found } } myName, _ = os.Hostname() cfg.Devices = append(cfg.Devices, DeviceConfiguration{ DeviceID: myID, Name: myName, }) found: if err := cfg.clean(); err != nil { return err } // Ensure that we are part of the devices for i := range cfg.Folders { cfg.Folders[i].Devices = ensureDevicePresent(cfg.Folders[i].Devices, myID) } return nil } func (cfg *Configuration) clean() error { util.FillNilSlices(&cfg.Options) // Ensure that the device list is // - free from duplicates // - no devices with empty ID // - sorted by ID // Happen before preparting folders as that needs a correct device list. cfg.Devices = ensureNoDuplicateOrEmptyIDDevices(cfg.Devices) sort.Slice(cfg.Devices, func(a, b int) bool { return cfg.Devices[a].DeviceID.Compare(cfg.Devices[b].DeviceID) == -1 }) // Prepare folders and check for duplicates. Duplicates are bad and // dangerous, can't currently be resolved in the GUI, and shouldn't // happen when configured by the GUI. We return with an error in that // situation. existingFolders := make(map[string]*FolderConfiguration) for i := range cfg.Folders { folder := &cfg.Folders[i] folder.prepare() if folder.ID == "" { return errFolderIDEmpty } if folder.Path == "" { return fmt.Errorf("folder %q: %w", folder.ID, errFolderPathEmpty) } if _, ok := existingFolders[folder.ID]; ok { return fmt.Errorf("folder %q: %w", folder.ID, errFolderIDDuplicate) } existingFolders[folder.ID] = folder } cfg.Options.RawListenAddresses = util.UniqueTrimmedStrings(cfg.Options.RawListenAddresses) cfg.Options.RawGlobalAnnServers = util.UniqueTrimmedStrings(cfg.Options.RawGlobalAnnServers) if cfg.Version > 0 && cfg.Version < OldestHandledVersion { l.Warnf("Configuration version %d is deprecated. Attempting best effort conversion, but please verify manually.", cfg.Version) } // Upgrade configuration versions as appropriate migrations.apply(cfg) // Build a list of available devices existingDevices := make(map[protocol.DeviceID]bool) for _, device := range cfg.Devices { existingDevices[device.DeviceID] = true } // Ensure that the folder list is sorted by ID sort.Slice(cfg.Folders, func(a, b int) bool { return cfg.Folders[a].ID < cfg.Folders[b].ID }) // Ensure that in all folder configs // - any loose devices are not present in the wrong places // - there are no duplicate devices // - the versioning configuration parameter map is not nil sharedFolders := make(map[protocol.DeviceID][]string, len(cfg.Devices)) for i := range cfg.Folders { cfg.Folders[i].Devices = ensureExistingDevices(cfg.Folders[i].Devices, existingDevices) cfg.Folders[i].Devices = ensureNoDuplicateFolderDevices(cfg.Folders[i].Devices) if cfg.Folders[i].Versioning.Params == nil { cfg.Folders[i].Versioning.Params = map[string]string{} } sort.Slice(cfg.Folders[i].Devices, func(a, b int) bool { return cfg.Folders[i].Devices[a].DeviceID.Compare(cfg.Folders[i].Devices[b].DeviceID) == -1 }) for _, dev := range cfg.Folders[i].Devices { sharedFolders[dev.DeviceID] = append(sharedFolders[dev.DeviceID], cfg.Folders[i].ID) } } for i := range cfg.Devices { cfg.Devices[i].prepare(sharedFolders[cfg.Devices[i].DeviceID]) } // Very short reconnection intervals are annoying if cfg.Options.ReconnectIntervalS < 5 { cfg.Options.ReconnectIntervalS = 5 } if cfg.GUI.APIKey == "" { cfg.GUI.APIKey = rand.String(32) } // The list of ignored devices should not contain any devices that have // been manually added to the config. var newIgnoredDevices []ObservedDevice ignoredDevices := make(map[protocol.DeviceID]bool) for _, dev := range cfg.IgnoredDevices { if !existingDevices[dev.ID] { ignoredDevices[dev.ID] = true newIgnoredDevices = append(newIgnoredDevices, dev) } } cfg.IgnoredDevices = newIgnoredDevices // The list of pending devices should not contain devices that were added manually, nor should it contain // ignored devices. // Sort by time, so that in case of duplicates latest "time" is used. sort.Slice(cfg.PendingDevices, func(i, j int) bool { return cfg.PendingDevices[i].Time.Before(cfg.PendingDevices[j].Time) }) var newPendingDevices []ObservedDevice nextPendingDevice: for _, pendingDevice := range cfg.PendingDevices { if !existingDevices[pendingDevice.ID] && !ignoredDevices[pendingDevice.ID] { // Deduplicate for _, existingPendingDevice := range newPendingDevices { if existingPendingDevice.ID == pendingDevice.ID { continue nextPendingDevice } } newPendingDevices = append(newPendingDevices, pendingDevice) } } cfg.PendingDevices = newPendingDevices // Deprecated protocols are removed from the list of listeners and // device addresses. So far just kcp*. for _, prefix := range []string{"kcp"} { cfg.Options.RawListenAddresses = filterURLSchemePrefix(cfg.Options.RawListenAddresses, prefix) for i := range cfg.Devices { dev := &cfg.Devices[i] dev.Addresses = filterURLSchemePrefix(dev.Addresses, prefix) } } // Initialize any empty slices if cfg.Folders == nil { cfg.Folders = []FolderConfiguration{} } if cfg.IgnoredDevices == nil { cfg.IgnoredDevices = []ObservedDevice{} } if cfg.PendingDevices == nil { cfg.PendingDevices = []ObservedDevice{} } if cfg.Options.AlwaysLocalNets == nil { cfg.Options.AlwaysLocalNets = []string{} } if cfg.Options.UnackedNotificationIDs == nil { cfg.Options.UnackedNotificationIDs = []string{} } return nil } // DeviceMap returns a map of device ID to device configuration for the given configuration. func (cfg *Configuration) DeviceMap() map[protocol.DeviceID]DeviceConfiguration { m := make(map[protocol.DeviceID]DeviceConfiguration, len(cfg.Devices)) for _, dev := range cfg.Devices { m[dev.DeviceID] = dev } return m } func ensureDevicePresent(devices []FolderDeviceConfiguration, myID protocol.DeviceID) []FolderDeviceConfiguration { for _, device := range devices { if device.DeviceID.Equals(myID) { return devices } } devices = append(devices, FolderDeviceConfiguration{ DeviceID: myID, }) return devices } func ensureExistingDevices(devices []FolderDeviceConfiguration, existingDevices map[protocol.DeviceID]bool) []FolderDeviceConfiguration { count := len(devices) i := 0 loop: for i < count { if _, ok := existingDevices[devices[i].DeviceID]; !ok { devices[i] = devices[count-1] count-- continue loop } i++ } return devices[0:count] } func ensureNoDuplicateFolderDevices(devices []FolderDeviceConfiguration) []FolderDeviceConfiguration { count := len(devices) i := 0 seenDevices := make(map[protocol.DeviceID]bool) loop: for i < count { id := devices[i].DeviceID if _, ok := seenDevices[id]; ok { devices[i] = devices[count-1] count-- continue loop } seenDevices[id] = true i++ } return devices[0:count] } func ensureNoDuplicateOrEmptyIDDevices(devices []DeviceConfiguration) []DeviceConfiguration { count := len(devices) i := 0 seenDevices := make(map[protocol.DeviceID]bool) loop: for i < count { id := devices[i].DeviceID if _, ok := seenDevices[id]; ok || id == protocol.EmptyDeviceID { devices[i] = devices[count-1] count-- continue loop } seenDevices[id] = true i++ } return devices[0:count] } func cleanSymlinks(filesystem fs.Filesystem, dir string) { if runtime.GOOS == "windows" { // We don't do symlinks on Windows. Additionally, there may // be things that look like symlinks that are not, which we // should leave alone. Deduplicated files, for example. return } filesystem.Walk(dir, func(path string, info fs.FileInfo, err error) error { if err != nil { return err } if info.IsSymlink() { l.Infoln("Removing incorrectly versioned symlink", path) filesystem.Remove(path) return fs.SkipDir } return nil }) } // filterURLSchemePrefix returns the list of addresses after removing all // entries whose URL scheme matches the given prefix. func filterURLSchemePrefix(addrs []string, prefix string) []string { for i := 0; i < len(addrs); i++ { uri, err := url.Parse(addrs[i]) if err != nil { continue } if strings.HasPrefix(uri.Scheme, prefix) { // Remove this entry copy(addrs[i:], addrs[i+1:]) addrs = addrs[:len(addrs)-1] i-- } } return addrs } // tried in succession and the first to succeed is returned. If none succeed, // a random high port is returned. func getFreePort(host string, ports ...int) (int, error) { for _, port := range ports { c, err := net.Listen("tcp", fmt.Sprintf("%s:%d", host, port)) if err == nil { c.Close() return port, nil } } c, err := net.Listen("tcp", host+":0") if err != nil { return 0, err } addr := c.Addr().(*net.TCPAddr) c.Close() return addr.Port, nil }