Add Options message to protocol

main.go

@@ -295,6 +295,11 @@ func listen(myID string, addr string, m *model.Model, cfg *tls.Config) {
 	l, err := tls.Listen("tcp", addr, cfg)
 	fatalErr(err)
 
+	connOpts := map[string]string{
+		"clientId":      "syncthing",
+		"clientVersion": Version,
+	}
+
 listen:
 	for {
 		conn, err := l.Accept()
@@ -329,7 +334,7 @@ listen:
 
 		for nodeID := range nodeAddrs {
 			if nodeID == remoteID {
-				protoConn := protocol.NewConnection(remoteID, conn, conn, m)
+				protoConn := protocol.NewConnection(remoteID, conn, conn, m, connOpts)
 				m.AddConnection(conn, protoConn)
 				continue listen
 			}
@@ -361,6 +366,11 @@ func connect(myID string, addr string, nodeAddrs map[string][]string, m *model.M
 		warnf("No discovery possible (%v)", err)
 	}
 
+	connOpts := map[string]string{
+		"clientId":      "syncthing",
+		"clientVersion": Version,
+	}
+
 	for {
 	nextNode:
 		for nodeID, addrs := range nodeAddrs {
@@ -399,7 +409,7 @@ func connect(myID string, addr string, nodeAddrs map[string][]string, m *model.M
 					continue
 				}
 
-				protoConn := protocol.NewConnection(remoteID, conn, conn, m)
+				protoConn := protocol.NewConnection(remoteID, conn, conn, m, connOpts)
 				m.AddConnection(conn, protoConn)
 				continue nextNode
 			}

model/model.go

@@ -59,6 +59,7 @@ type Connection interface {
 	Index([]protocol.FileInfo)
 	Request(name string, offset int64, size uint32, hash []byte) ([]byte, error)
 	Statistics() protocol.Statistics
+	Option(key string) string
 }
 
 const (
@@ -155,7 +156,9 @@ func (m *Model) LocalAge() float64 {
 
 type ConnectionInfo struct {
 	protocol.Statistics
-	Address string
+	Address       string
+	ClientID      string
+	ClientVersion string
 }
 
 // ConnectionStats returns a map with connection statistics for each connected node.
@@ -169,7 +172,9 @@ func (m *Model) ConnectionStats() map[string]ConnectionInfo {
 	var res = make(map[string]ConnectionInfo)
 	for node, conn := range m.protoConn {
 		ci := ConnectionInfo{
-			Statistics: conn.Statistics(),
+			Statistics:    conn.Statistics(),
+			ClientID:      conn.Option("clientId"),
+			ClientVersion: conn.Option("clientVersion"),
 		}
 		if nc, ok := m.rawConn[node].(remoteAddrer); ok {
 			ci.Address = nc.RemoteAddr().String()

model/model_test.go

@@ -12,7 +12,7 @@ import (
 )
 
 func TestNewModel(t *testing.T) {
-	m := NewModel("foo")
+	m := NewModel("foo", 1e6)
 
 	if m == nil {
 		t.Fatalf("NewModel returned nil")
@@ -53,7 +53,7 @@ func init() {
 }
 
 func TestUpdateLocal(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -95,7 +95,7 @@ func TestUpdateLocal(t *testing.T) {
 }
 
 func TestRemoteUpdateExisting(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -112,7 +112,7 @@ func TestRemoteUpdateExisting(t *testing.T) {
 }
 
 func TestRemoteAddNew(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -129,7 +129,7 @@ func TestRemoteAddNew(t *testing.T) {
 }
 
 func TestRemoteUpdateOld(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -147,7 +147,7 @@ func TestRemoteUpdateOld(t *testing.T) {
 }
 
 func TestRemoteIndexUpdate(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -180,7 +180,7 @@ func TestRemoteIndexUpdate(t *testing.T) {
 }
 
 func TestDelete(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -282,7 +282,7 @@ func TestDelete(t *testing.T) {
 }
 
 func TestForgetNode(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -335,7 +335,7 @@ func TestForgetNode(t *testing.T) {
 }
 
 func TestRequest(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -357,7 +357,7 @@ func TestRequest(t *testing.T) {
 }
 
 func TestIgnoreWithUnknownFlags(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 
@@ -404,7 +404,7 @@ func prepareModel(n int, m *Model) []protocol.FileInfo {
 }
 
 func BenchmarkRecomputeGlobal10k(b *testing.B) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	prepareModel(10000, m)
 
 	b.ResetTimer()
@@ -414,7 +414,7 @@ func BenchmarkRecomputeGlobal10k(b *testing.B) {
 }
 
 func BenchmarkRecomputeNeed10K(b *testing.B) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	prepareModel(10000, m)
 
 	b.ResetTimer()
@@ -424,7 +424,7 @@ func BenchmarkRecomputeNeed10K(b *testing.B) {
 }
 
 func BenchmarkIndexUpdate10000(b *testing.B) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	files := prepareModel(10000, m)
 
 	b.ResetTimer()
@@ -446,6 +446,10 @@ func (f FakeConnection) ID() string {
 	return string(f.id)
 }
 
+func (f FakeConnection) Option(string) string {
+	return ""
+}
+
 func (FakeConnection) Index([]protocol.FileInfo) {}
 
 func (f FakeConnection) Request(name string, offset int64, size uint32, hash []byte) ([]byte, error) {
@@ -461,7 +465,7 @@ func (FakeConnection) Statistics() protocol.Statistics {
 }
 
 func BenchmarkRequest(b *testing.B) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	fs, _ := m.Walk(false)
 	m.ReplaceLocal(fs)
 

model/walk_test.go

@@ -21,7 +21,7 @@ var correctIgnores = map[string][]string{
 }
 
 func TestWalk(t *testing.T) {
-	m := NewModel("testdata")
+	m := NewModel("testdata", 1e6)
 	files, ignores := m.Walk(false)
 
 	if l1, l2 := len(files), len(testdata); l1 != l2 {

protocol/PROTOCOL.md

@@ -193,6 +193,33 @@ model, the Index Update merely amends it with new or updated file
 information. Any files not mentioned in an Index Update are left
 unchanged.
 
+### Options (Type = 7)
+
+This informational message provides information about the client
+configuration, version, etc. It is sent at connection initiation and,
+optionally, when any of the sent parameters have changed. The message is
+in the form of a list of (key, value) pairs, both of string type.
+
+    struct OptionsMessage {
+        KeyValue Options<>;
+    }
+
+    struct KeyValue {
+        string Key;
+        string Value;
+    }
+
+Key ID:s apart from the well known ones are implementation
+specific. An implementation is expected to ignore unknown keys. An
+implementation may impose limits on key and value size.
+
+Well known keys:
+
+  - "clientId" -- The name of the implementation. Example: "syncthing".
+  - "clientVersion" -- The version of the client. Example: "v1.0.33-47". The
+    Following the SemVer 2.0 specification for version strings is
+    encouraged but not enforced.
+
 Example Exchange
 ----------------
 

protocol/messages.go

@@ -65,6 +65,14 @@ func (w *marshalWriter) writeResponse(data []byte) {
 	w.writeBytes(data)
 }
 
+func (w *marshalWriter) writeOptions(opts map[string]string) {
+	w.writeUint32(uint32(len(opts)))
+	for k, v := range opts {
+		w.writeString(k)
+		w.writeString(v)
+	}
+}
+
 func (r *marshalReader) readHeader() header {
 	return decodeHeader(r.readUint32())
 }
@@ -109,3 +117,14 @@ func (r *marshalReader) readRequest() request {
 func (r *marshalReader) readResponse() []byte {
 	return r.readBytes()
 }
+
+func (r *marshalReader) readOptions() map[string]string {
+	n := r.readUint32()
+	opts := make(map[string]string, n)
+	for i := 0; i < int(n); i++ {
+		k := r.readString()
+		v := r.readString()
+		opts[k] = v
+	}
+	return opts
+}

protocol/messages_test.go

@@ -117,3 +117,23 @@ func BenchmarkWriteRequest(b *testing.B) {
 		wr.writeRequest(req)
 	}
 }
+
+func TestOptions(t *testing.T) {
+	opts := map[string]string{
+		"foo":     "bar",
+		"someKey": "otherValue",
+		"hello":   "",
+		"":        "42",
+	}
+
+	var buf = new(bytes.Buffer)
+	var wr = marshalWriter{w: buf}
+	wr.writeOptions(opts)
+
+	var rd = marshalReader{r: buf}
+	var ropts = rd.readOptions()
+
+	if !reflect.DeepEqual(opts, ropts) {
+		t.Error("Incorrect options marshal/demarshal")
+	}
+}

protocol/protocol.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"sync"
 	"time"
 
@@ -18,6 +19,7 @@ const (
 	messageTypePing        = 4
 	messageTypePong        = 5
 	messageTypeIndexUpdate = 6
+	messageTypeOptions     = 7
 )
 
 const (
@@ -52,16 +54,18 @@ type Model interface {
 type Connection struct {
 	sync.RWMutex
 
-	id        string
-	receiver  Model
-	reader    io.Reader
-	mreader   *marshalReader
-	writer    io.Writer
-	mwriter   *marshalWriter
-	closed    bool
-	awaiting  map[int]chan asyncResult
-	nextId    int
-	indexSent map[string][2]int64
+	id          string
+	receiver    Model
+	reader      io.Reader
+	mreader     *marshalReader
+	writer      io.Writer
+	mwriter     *marshalWriter
+	closed      bool
+	awaiting    map[int]chan asyncResult
+	nextId      int
+	indexSent   map[string][2]int64
+	options     map[string]string
+	optionsLock sync.Mutex
 
 	hasSentIndex  bool
 	hasRecvdIndex bool
@@ -81,7 +85,7 @@ const (
 	pingIdleTime = 5 * time.Minute
 )
 
-func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver Model) *Connection {
+func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver Model, options map[string]string) *Connection {
 	flrd := flate.NewReader(reader)
 	flwr, err := flate.NewWriter(writer, flate.BestSpeed)
 	if err != nil {
@@ -101,6 +105,20 @@ func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver M
 	go c.readerLoop()
 	go c.pingerLoop()
 
+	if options != nil {
+		go func() {
+			c.Lock()
+			c.mwriter.writeHeader(header{0, c.nextId, messageTypeOptions})
+			c.mwriter.writeOptions(options)
+			err := c.flush()
+			if err != nil {
+				log.Printf("Warning:", err)
+			}
+			c.nextId++
+			c.Unlock()
+		}()
+	}
+
 	return &c
 }
 
@@ -328,6 +346,11 @@ loop:
 				c.Unlock()
 			}
 
+		case messageTypeOptions:
+			c.optionsLock.Lock()
+			c.options = c.mreader.readOptions()
+			c.optionsLock.Unlock()
+
 		default:
 			c.close(fmt.Errorf("Protocol error: %s: unknown message type %#x", c.ID, hdr.msgType))
 			break loop
@@ -396,3 +419,9 @@ func (c *Connection) Statistics() Statistics {
 
 	return stats
 }
+
+func (c *Connection) Option(key string) string {
+	c.optionsLock.Lock()
+	defer c.optionsLock.Unlock()
+	return c.options[key]
+}

protocol/protocol_test.go

@@ -43,8 +43,8 @@ func TestPing(t *testing.T) {
 	ar, aw := io.Pipe()
 	br, bw := io.Pipe()
 
-	c0 := NewConnection("c0", ar, bw, nil)
-	c1 := NewConnection("c1", br, aw, nil)
+	c0 := NewConnection("c0", ar, bw, nil, nil)
+	c1 := NewConnection("c1", br, aw, nil, nil)
 
 	if ok := c0.ping(); !ok {
 		t.Error("c0 ping failed")
@@ -67,8 +67,8 @@ func TestPingErr(t *testing.T) {
 			eaw := &ErrPipe{PipeWriter: *aw, max: i, err: e}
 			ebw := &ErrPipe{PipeWriter: *bw, max: j, err: e}
 
-			c0 := NewConnection("c0", ar, ebw, m0)
-			NewConnection("c1", br, eaw, m1)
+			c0 := NewConnection("c0", ar, ebw, m0, nil)
+			NewConnection("c1", br, eaw, m1, nil)
 
 			res := c0.ping()
 			if (i < 4 || j < 4) && res {
@@ -94,8 +94,8 @@ func TestRequestResponseErr(t *testing.T) {
 			eaw := &ErrPipe{PipeWriter: *aw, max: i, err: e}
 			ebw := &ErrPipe{PipeWriter: *bw, max: j, err: e}
 
-			NewConnection("c0", ar, ebw, m0)
-			c1 := NewConnection("c1", br, eaw, m1)
+			NewConnection("c0", ar, ebw, m0, nil)
+			c1 := NewConnection("c1", br, eaw, m1, nil)
 
 			d, err := c1.Request("tn", 1234, 3456, []byte("hashbytes"))
 			if err == e || err == ErrClosed {
@@ -143,8 +143,8 @@ func TestVersionErr(t *testing.T) {
 	ar, aw := io.Pipe()
 	br, bw := io.Pipe()
 
-	c0 := NewConnection("c0", ar, bw, m0)
-	NewConnection("c1", br, aw, m1)
+	c0 := NewConnection("c0", ar, bw, m0, nil)
+	NewConnection("c1", br, aw, m1, nil)
 
 	c0.mwriter.writeHeader(header{
 		version: 2,
@@ -165,8 +165,8 @@ func TestTypeErr(t *testing.T) {
 	ar, aw := io.Pipe()
 	br, bw := io.Pipe()
 
-	c0 := NewConnection("c0", ar, bw, m0)
-	NewConnection("c1", br, aw, m1)
+	c0 := NewConnection("c0", ar, bw, m0, nil)
+	NewConnection("c1", br, aw, m1, nil)
 
 	c0.mwriter.writeHeader(header{
 		version: 0,
@@ -187,8 +187,8 @@ func TestClose(t *testing.T) {
 	ar, aw := io.Pipe()
 	br, bw := io.Pipe()
 
-	c0 := NewConnection("c0", ar, bw, m0)
-	NewConnection("c1", br, aw, m1)
+	c0 := NewConnection("c0", ar, bw, m0, nil)
+	NewConnection("c1", br, aw, m1, nil)
 
 	c0.close(nil)