package core import ( "crypto" "errors" "github.com/special/notricochet/core/utils" "github.com/special/notricochet/rpc" "github.com/yawning/bulb" bulbutils "github.com/yawning/bulb/utils" "golang.org/x/net/context" "golang.org/x/net/proxy" "log" "net" "strings" "sync" "time" ) // XXX Network disconnect should kill open connections ... somehow type Network struct { // Connection settings; can only change while stopped controlAddress string controlPassword string // Events events *utils.Publisher // nil when stopped, otherwise used to signal stop to active network stopSignal chan struct{} stoppedSignal chan struct{} // Mutex required to access below controlMutex sync.Mutex // Do not use while holding controlMutex; instead, copy ptr and unlock // mutex before use. conn *bulb.Conn // Modifications must be done while holding controlMutex and signalled // to events. Do not directly modify the child elements, as they are // pointers and may be shared. Instead, construct a new TorControlStatus // et al for each change. status ricochet.NetworkStatus socksAddress socksAddress onions []*OnionService } type OnionService struct { OnionID string Ports []bulb.OnionPortSpec PrivateKey crypto.PrivateKey } func CreateNetwork() *Network { return &Network{ events: utils.CreatePublisher(), } } // Start connection to the tor control port at 'address', with the optional // control password 'password'. This function blocks until the first connection // attempt is finished. The first return value says whether the connection has // been started; if true, the connection is up even if the first attempt failed. // The second return value is the connection attempt error, or nil on success. func (n *Network) Start(address, password string) (bool, error) { n.controlMutex.Lock() if n.stoppedSignal != nil { // This is an error, because address/password might not be the same n.controlMutex.Unlock() return false, errors.New("Network is already started") } n.stopSignal = make(chan struct{}) n.stoppedSignal = make(chan struct{}) n.controlAddress = address n.controlPassword = password n.controlMutex.Unlock() connectChannel := make(chan error) go n.run(connectChannel) err := <-connectChannel return true, err } // Stop the network connection. The externally-controlled tor instance // is not affected, but the control port connection will be closed and // the client will be offline until Start is called again. This call will // block until the connection is stopped. func (n *Network) Stop() { // Take mutex, copy channels, nil stopSignal to avoid race if Stop() // is called again. Other calls will still use stoppedSignal. n.controlMutex.Lock() stop := n.stopSignal stopped := n.stoppedSignal n.stopSignal = nil n.controlMutex.Unlock() if stop != nil { // Signal to stop stop <- struct{}{} } else if stopped == nil { // Already stopped return } // Wait until stopped; safe for multiple receivers, because the channel // is closed on stop. Sender is responsible for all other cleanup and state. <-stopped } func (n *Network) EventMonitor() utils.Subscribable { return n.events } func (n *Network) GetStatus() ricochet.NetworkStatus { n.controlMutex.Lock() status := n.status n.controlMutex.Unlock() return status } type socksAddress struct { Network string Address string IP net.IP } func (sa socksAddress) IsValid() bool { return sa.Network != "" && sa.Address != "" } func (sa socksAddress) PreferredTo(other socksAddress, preferredIP net.IP) bool { // Prefer, in order: // - any over null // - unix sockets over others // - same ip as control address // - loopback over other ips // - first seen if sa.Network == "" || other.Network == "" { return other.Network == "" } if sa.Network == "unix" || other.Network == "unix" { return other.Network != "unix" } if !preferredIP.IsUnspecified() && (net.IP.Equal(sa.IP, preferredIP) || net.IP.Equal(other.IP, preferredIP)) { return !net.IP.Equal(other.IP, preferredIP) } if sa.IP.IsLoopback() || other.IP.IsLoopback() { return !other.IP.IsLoopback() } return false } // Choose the best SOCKS address out of the list in 'addresses' // If controlAddress is non-empty, prefer a SOCKS port on the same host func chooseSocksAddress(addresses []string, controlAddress string) (socksAddress, error) { var selected socksAddress var preferredIP net.IP torOnLocalhost := true if len(addresses) == 0 { return selected, errors.New("No SOCKS port configured") } // controlAddress is in the form of tcp:// or unix:// if strings.HasPrefix(controlAddress, "tcp:") { _, addrport, _ := bulbutils.ParseControlPortString(controlAddress) addr, _, _ := net.SplitHostPort(addrport) preferredIP = net.ParseIP(addr) torOnLocalhost = preferredIP.IsLoopback() } // List of SOCKS ports, relative to the tor daemon // Can be in the form "127.0.0.1:9050", "unix:...", or "[::1]:9050" for _, addr := range addresses { var socks socksAddress // Parse into 'socks' and filter out localhost if necessary if strings.HasPrefix(addr, "unix:") { // Ignore unix ports for remote tor if !torOnLocalhost { log.Printf("Ignoring loopback SOCKS port %s", addr) continue } socks = socksAddress{ Network: "unix", Address: addr[5:], } } else { ipStr, _, err := net.SplitHostPort(addr) if err != nil { log.Printf("Ignoring malformed SOCKS address '%s': %s", addr, err) continue } socks = socksAddress{ Network: "tcp", Address: addr, IP: net.ParseIP(ipStr), } if !torOnLocalhost && socks.IP.IsLoopback() { log.Printf("Ignoring loopback SOCKS port %s", addr) continue } } // Compare to current selection if socks.PreferredTo(selected, preferredIP) { selected = socks } } if !selected.IsValid() { return selected, errors.New("No valid SOCKS configuration") } return selected, nil } func (n *Network) GetProxyDialer(forward proxy.Dialer) (proxy.Dialer, error) { n.controlMutex.Lock() socks := n.socksAddress n.controlMutex.Unlock() if !socks.IsValid() { return nil, errors.New("No valid SOCKS configuration") } return proxy.SOCKS5(socks.Network, socks.Address, nil, forward) } func (n *Network) WaitForProxyDialer(forward proxy.Dialer, c context.Context) (proxy.Dialer, error) { var monitor <-chan interface{} for { // Check if there's a proxy address available n.controlMutex.Lock() socks := n.socksAddress n.controlMutex.Unlock() if socks.IsValid() { return proxy.SOCKS5(socks.Network, socks.Address, nil, forward) } if monitor == nil { // Subscribe to connectivity change events; this is done after the first // check to avoid overhead for the common case monitor = n.EventMonitor().Subscribe(20) defer n.EventMonitor().Unsubscribe(monitor) // Check again before blocking on the monitor now that we're subscribed, // in case the state changed since unlocking the mutex. continue } select { case _, ok := <-monitor: if !ok { return nil, errors.New("Event monitor closed") } case <-c.Done(): return nil, c.Err() } } return nil, errors.New("No valid SOCKS configuration") } // Return the control connection, blocking until connected if necessary // May return nil on failure, and the returned connection can be closed // or otherwise fail at any time. func (n *Network) getConnection() *bulb.Conn { // Optimistically try to get a connection before subscribing to events n.controlMutex.Lock() conn := n.conn n.controlMutex.Unlock() if conn != nil { return conn } // Subscribe to connectivity change events monitor := n.EventMonitor().Subscribe(20) defer n.EventMonitor().Unsubscribe(monitor) for { // Check for connectivity; do this before blocking to avoid a // race with the subscription. n.controlMutex.Lock() conn := n.conn n.controlMutex.Unlock() if conn != nil { return conn } _, ok := <-monitor if !ok { return nil } } } // Add an onion service with the provided port mappings and private key. // If key is nil, a new RSA key is generated and returned in OnionService. // This function will block until a control connection is available and // the service is added or the command has failed. If the control connection // is lost and reconnected, the service will be re-added automatically. // BUG(special): Errors that occur after reconnecting cannot be detected. func (n *Network) AddOnionPorts(ports []bulb.OnionPortSpec, key crypto.PrivateKey) (*OnionService, error) { if key == nil { // Ask for a new key, force RSA1024 key = &bulb.OnionPrivateKey{ KeyType: "NEW", Key: "RSA1024", } } conn := n.getConnection() info, err := conn.AddOnion(ports, key, false) if err != nil { return nil, err } service := &OnionService{ OnionID: info.OnionID, Ports: ports, PrivateKey: info.PrivateKey, } if service.PrivateKey == nil { service.PrivateKey = key } n.controlMutex.Lock() n.onions = append(n.onions, service) n.controlMutex.Unlock() return service, nil } // Add an onion service listening on the virtual onion port onionPort, // with the provided private key, and return a net.Listener for it. This // function behaves identically to AddOnionPorts, other than creating a // listener automatically. func (n *Network) NewOnionListener(onionPort uint16, key crypto.PrivateKey) (*OnionService, net.Listener, error) { listener, err := net.Listen("tcp", "127.0.0.1:0") if err != nil { return nil, nil, err } onionPorts := []bulb.OnionPortSpec{ bulb.OnionPortSpec{ VirtPort: onionPort, Target: listener.Addr().String(), }, } service, err := n.AddOnionPorts(onionPorts, key) if err != nil { listener.Close() return nil, nil, err } return service, listener, nil } func (n *Network) run(connectChannel chan<- error) { n.controlMutex.Lock() stopSignal := n.stopSignal stoppedSignal := n.stoppedSignal n.controlMutex.Unlock() for { // Status to CONNECTING n.controlMutex.Lock() n.status.Control = &ricochet.TorControlStatus{ Status: ricochet.TorControlStatus_CONNECTING, } n.status.Connection = &ricochet.TorConnectionStatus{} status := n.status n.controlMutex.Unlock() n.events.Publish(status) // Attempt connection errorChannel := make(chan error, 1) err := n.connectControl() if err != nil { errorChannel <- err } else { // The goroutine polls for control events, and signals // errorChannel on connection failure. go n.handleControlEvents(n.conn, errorChannel) } // Report result of the first connection attempt if connectChannel != nil { connectChannel <- err close(connectChannel) connectChannel = nil } // Wait for network stop or connection errors select { case <-stopSignal: // Close connection, clean up struct, signal status change n.controlMutex.Lock() if n.conn != nil { n.conn.Close() n.conn = nil } n.controlAddress = "" n.controlPassword = "" n.stoppedSignal = nil n.status = ricochet.NetworkStatus{} n.controlMutex.Unlock() n.events.Publish(ricochet.NetworkStatus{}) // Signal stopped and exit close(stoppedSignal) return case err := <-errorChannel: if err == nil { err = errors.New("Unknown error") } // Change status to ERROR n.controlMutex.Lock() if n.conn != nil { n.conn.Close() n.conn = nil } n.status.Control = &ricochet.TorControlStatus{ Status: ricochet.TorControlStatus_ERROR, ErrorMessage: err.Error(), } n.status.Connection = &ricochet.TorConnectionStatus{} status := n.status n.controlMutex.Unlock() n.events.Publish(status) // Loop to retry connection // BUG(x): This timeout is static and uninterruptable time.Sleep(5 * time.Second) } } } func (n *Network) connectControl() error { // Attempt connection conn, err := createConnection(n.controlAddress, n.controlPassword) if err != nil { return err } // Query ProtocolInfo for tor version pinfo, err := conn.ProtocolInfo() if err != nil { conn.Close() return err } // Subscribe to events _, err = conn.Request("SETEVENTS STATUS_CLIENT") if err != nil { conn.Close() return err } // Query initial tor state connStatus, err := queryTorState(conn) if err != nil { conn.Close() return err } // Choose default SOCKS port socks, err := chooseSocksAddress(connStatus.SocksAddress, n.controlAddress) if socks.IsValid() { log.Printf("Discovered SOCKS port %s %s", socks.Network, socks.Address) } else { log.Printf("No SOCKS port: %v", err) } n.controlMutex.Lock() // Copy list of onions to republish. This is done before the status // change to avoid racing with blocked calls to AddOnionPorts, which // will add to this list once the connection is available, but the // publication is done afterwards. onions := make([]*OnionService, len(n.onions)) copy(onions, n.onions) // Update network status and set connection n.conn = conn n.status.Control = &ricochet.TorControlStatus{ Status: ricochet.TorControlStatus_CONNECTED, TorVersion: pinfo.TorVersion, } n.status.Connection = &connStatus n.socksAddress = socks status := n.status n.controlMutex.Unlock() n.events.Publish(status) // Re-publish onion services. Errors are not fatal to conn. publishOnions(conn, onions) return nil } func createConnection(address, password string) (*bulb.Conn, error) { net, addr, err := bulbutils.ParseControlPortString(address) if err != nil { log.Printf("Parsing control network address '%s' failed: %v", address, err) return nil, err } conn, err := bulb.Dial(net, addr) if err != nil { log.Printf("Control connection failed: %v", err) return nil, err } err = conn.Authenticate(password) if err != nil { log.Printf("Control authentication failed: %v", err) conn.Close() return nil, err } conn.StartAsyncReader() log.Print("Control connected!") return conn, nil } /* XXX The CIRCUIT_ESTABLISHED based connectivity logic is buggy and not * reliable. We may not see CIRCUIT_ESTABLISHED if tor goes dormant due to * no activity, and CIRCUIT_NOT_ESTABLISHED is _only_ sent for clock jumps, * not any other case. For now, this is still worth using, because it at * least gives a decent idea of when startup has finished and detects * suspends from the clock jump. * * Tor also has a NETWORK_LIVENESS, but this is even less useful. In testing, * it's entirely unable to determine when tor loses connectivity. * * The most reliable indicator of connectivity is probably to track active * circs or orconns and assume connectivity if there is at least one built or * connected. This is a little more complex, but would give us better behavior * for figuring out when reconnection is necessary and whether we're connectable. * If we start tracking circuits, we could also use those to gain more insight * into the connectivity state of our services, the number of rendezvous, and * reasons for failed outbound connections. */ func queryTorState(conn *bulb.Conn) (ricochet.TorConnectionStatus, error) { status := ricochet.TorConnectionStatus{} response, err := conn.Request("GETINFO status/circuit-established status/bootstrap-phase net/listeners/socks") if err != nil { return status, err } results := make(map[string]string) for _, rawLine := range response.Data { line := strings.SplitN(rawLine, "=", 2) if len(line) != 2 { return status, errors.New("Invalid GETINFO response format") } results[line[0]] = strings.TrimSpace(line[1]) } if results["status/circuit-established"] == "0" { if strings.Contains(results["status/bootstrap-phase"], "TAG=done") { status.Status = ricochet.TorConnectionStatus_OFFLINE } else { status.Status = ricochet.TorConnectionStatus_BOOTSTRAPPING } } else if results["status/circuit-established"] == "1" { status.Status = ricochet.TorConnectionStatus_READY } else { return status, errors.New("Invalid GETINFO response format") } status.BootstrapProgress = results["status/bootstrap-phase"] status.SocksAddress = utils.UnquoteStringSplit(results["net/listeners/socks"], ' ') return status, nil } func (n *Network) handleControlEvents(conn *bulb.Conn, errorChannel chan<- error) { for { event, err := conn.NextEvent() if err != nil { log.Printf("Control connection failed: %v", err) errorChannel <- err return } if strings.HasPrefix(event.Reply, "STATUS_CLIENT ") || strings.HasPrefix(event.Reply, "STATUS_GENERAL ") { // StatusType StatusSeverity StatusAction StatusArguments eventInfo := strings.SplitN(event.Reply, " ", 4) if len(eventInfo) < 3 { log.Printf("Ignoring malformed control status event") continue } n.controlMutex.Lock() changed := true // Cannot directly modify n.status.Connection, because it may be shared; take a copy connStatus := *n.status.Connection if eventInfo[2] == "CIRCUIT_ESTABLISHED" { connStatus.Status = ricochet.TorConnectionStatus_READY } else if eventInfo[2] == "CIRCUIT_NOT_ESTABLISHED" { if strings.Contains(connStatus.BootstrapProgress, "TAG=done") { connStatus.Status = ricochet.TorConnectionStatus_OFFLINE } else { connStatus.Status = ricochet.TorConnectionStatus_BOOTSTRAPPING } } else if eventInfo[2] == "BOOTSTRAP" { connStatus.BootstrapProgress = strings.Join(eventInfo[1:], " ") } else { changed = false } if changed { n.status.Connection = &connStatus status := n.status n.controlMutex.Unlock() n.events.Publish(status) } else { n.controlMutex.Unlock() } } } } func publishOnions(conn *bulb.Conn, onions []*OnionService) { for _, service := range onions { _, err := conn.AddOnion(service.Ports, service.PrivateKey, false) if err != nil { log.Printf("Control error for onion republication: %v", err) } log.Printf("Re-published onion service %s", service.OnionID) } }