*: revendor and regenerate protobuf files

vendor/google.golang.org/grpc/transport/control.go

@@ -35,7 +35,9 @@ package transport
 
 import (
 	"fmt"
+	"math"
 	"sync"
+	"time"
 
 	"golang.org/x/net/http2"
 )
@@ -44,8 +46,18 @@ const (
 	// The default value of flow control window size in HTTP2 spec.
 	defaultWindowSize = 65535
 	// The initial window size for flow control.
-	initialWindowSize     = defaultWindowSize      // for an RPC
-	initialConnWindowSize = defaultWindowSize * 16 // for a connection
+	initialWindowSize             = defaultWindowSize      // for an RPC
+	initialConnWindowSize         = defaultWindowSize * 16 // for a connection
+	infinity                      = time.Duration(math.MaxInt64)
+	defaultClientKeepaliveTime    = infinity
+	defaultClientKeepaliveTimeout = time.Duration(20 * time.Second)
+	defaultMaxStreamsClient       = 100
+	defaultMaxConnectionIdle      = infinity
+	defaultMaxConnectionAge       = infinity
+	defaultMaxConnectionAgeGrace  = infinity
+	defaultServerKeepaliveTime    = time.Duration(2 * time.Hour)
+	defaultServerKeepaliveTimeout = time.Duration(20 * time.Second)
+	defaultKeepalivePolicyMinTime = time.Duration(5 * time.Minute)
 )
 
 // The following defines various control items which could flow through
@@ -73,6 +85,8 @@ type resetStream struct {
 func (*resetStream) item() {}
 
 type goAway struct {
+	code      http2.ErrCode
+	debugData []byte
 }
 
 func (*goAway) item() {}
@@ -111,35 +125,9 @@ func newQuotaPool(q int) *quotaPool {
 	return qb
 }
 
-// add adds n to the available quota and tries to send it on acquire.
-func (qb *quotaPool) add(n int) {
-	qb.mu.Lock()
-	defer qb.mu.Unlock()
-	qb.quota += n
-	if qb.quota <= 0 {
-		return
-	}
-	select {
-	case qb.c <- qb.quota:
-		qb.quota = 0
-	default:
-	}
-}
-
-// cancel cancels the pending quota sent on acquire, if any.
-func (qb *quotaPool) cancel() {
-	qb.mu.Lock()
-	defer qb.mu.Unlock()
-	select {
-	case n := <-qb.c:
-		qb.quota += n
-	default:
-	}
-}
-
-// reset cancels the pending quota sent on acquired, incremented by v and sends
+// add cancels the pending quota sent on acquired, incremented by v and sends
 // it back on acquire.
-func (qb *quotaPool) reset(v int) {
+func (qb *quotaPool) add(v int) {
 	qb.mu.Lock()
 	defer qb.mu.Unlock()
 	select {
@@ -151,6 +139,10 @@ func (qb *quotaPool) reset(v int) {
 	if qb.quota <= 0 {
 		return
 	}
+	// After the pool has been created, this is the only place that sends on
+	// the channel. Since mu is held at this point and any quota that was sent
+	// on the channel has been retrieved, we know that this code will always
+	// place any positive quota value on the channel.
 	select {
 	case qb.c <- qb.quota:
 		qb.quota = 0

vendor/google.golang.org/grpc/transport/handler_server.go

@@ -53,6 +53,7 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/status"
 )
 
 // NewServerHandlerTransport returns a ServerTransport handling gRPC
@@ -182,7 +183,7 @@ func (ht *serverHandlerTransport) do(fn func()) error {
 	}
 }
 
-func (ht *serverHandlerTransport) WriteStatus(s *Stream, statusCode codes.Code, statusDesc string) error {
+func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) error {
 	err := ht.do(func() {
 		ht.writeCommonHeaders(s)
 
@@ -192,10 +193,13 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, statusCode codes.Code,
 		ht.rw.(http.Flusher).Flush()
 
 		h := ht.rw.Header()
-		h.Set("Grpc-Status", fmt.Sprintf("%d", statusCode))
-		if statusDesc != "" {
-			h.Set("Grpc-Message", encodeGrpcMessage(statusDesc))
+		h.Set("Grpc-Status", fmt.Sprintf("%d", st.Code()))
+		if m := st.Message(); m != "" {
+			h.Set("Grpc-Message", encodeGrpcMessage(m))
 		}
+
+		// TODO: Support Grpc-Status-Details-Bin
+
 		if md := s.Trailer(); len(md) > 0 {
 			for k, vv := range md {
 				// Clients don't tolerate reading restricted headers after some non restricted ones were sent.
@@ -234,6 +238,7 @@ func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
 	// and https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
 	h.Add("Trailer", "Grpc-Status")
 	h.Add("Trailer", "Grpc-Message")
+	// TODO: Support Grpc-Status-Details-Bin
 
 	if s.sendCompress != "" {
 		h.Set("Grpc-Encoding", s.sendCompress)
@@ -268,7 +273,7 @@ func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
 	})
 }
 
-func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream)) {
+func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream), traceCtx func(context.Context, string) context.Context) {
 	// With this transport type there will be exactly 1 stream: this HTTP request.
 
 	var ctx context.Context
@@ -314,7 +319,7 @@ func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream)) {
 	if req.TLS != nil {
 		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS}
 	}
-	ctx = metadata.NewContext(ctx, ht.headerMD)
+	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
 	ctx = peer.NewContext(ctx, pr)
 	s.ctx = newContextWithStream(ctx, s)
 	s.dec = &recvBufferReader{ctx: s.ctx, recv: s.buf}

vendor/google.golang.org/grpc/transport/http2_client.go

@@ -35,12 +35,12 @@ package transport
 
 import (
 	"bytes"
-	"fmt"
 	"io"
 	"math"
 	"net"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"golang.org/x/net/context"
@@ -49,17 +49,24 @@ import (
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
 )
 
 // http2Client implements the ClientTransport interface with HTTP2.
 type http2Client struct {
-	target    string // server name/addr
-	userAgent string
-	conn      net.Conn             // underlying communication channel
-	authInfo  credentials.AuthInfo // auth info about the connection
-	nextID    uint32               // the next stream ID to be used
+	ctx        context.Context
+	target     string // server name/addr
+	userAgent  string
+	md         interface{}
+	conn       net.Conn // underlying communication channel
+	remoteAddr net.Addr
+	localAddr  net.Addr
+	authInfo   credentials.AuthInfo // auth info about the connection
+	nextID     uint32               // the next stream ID to be used
 
 	// writableChan synchronizes write access to the transport.
 	// A writer acquires the write lock by sending a value on writableChan
@@ -75,6 +82,8 @@ type http2Client struct {
 	// goAway is closed to notify the upper layer (i.e., addrConn.transportMonitor)
 	// that the server sent GoAway on this transport.
 	goAway chan struct{}
+	// awakenKeepalive is used to wake up keepalive when after it has gone dormant.
+	awakenKeepalive chan struct{}
 
 	framer *framer
 	hBuf   *bytes.Buffer  // the buffer for HPACK encoding
@@ -94,6 +103,13 @@ type http2Client struct {
 
 	creds []credentials.PerRPCCredentials
 
+	// Boolean to keep track of reading activity on transport.
+	// 1 is true and 0 is false.
+	activity uint32 // Accessed atomically.
+	kp       keepalive.ClientParameters
+
+	statsHandler stats.Handler
+
 	mu            sync.Mutex     // guard the following variables
 	state         transportState // the state of underlying connection
 	activeStreams map[uint32]*Stream
@@ -105,9 +121,12 @@ type http2Client struct {
 	goAwayID uint32
 	// prevGoAway ID records the Last-Stream-ID in the previous GOAway frame.
 	prevGoAwayID uint32
+	// goAwayReason records the http2.ErrCode and debug data received with the
+	// GoAway frame.
+	goAwayReason GoAwayReason
 }
 
-func dial(fn func(context.Context, string) (net.Conn, error), ctx context.Context, addr string) (net.Conn, error) {
+func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr string) (net.Conn, error) {
 	if fn != nil {
 		return fn(ctx, addr)
 	}
@@ -145,10 +164,13 @@ func isTemporary(err error) bool {
 // newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2
 // and starts to receive messages on it. Non-nil error returns if construction
 // fails.
-func newHTTP2Client(ctx context.Context, addr string, opts ConnectOptions) (_ ClientTransport, err error) {
+func newHTTP2Client(ctx context.Context, addr TargetInfo, opts ConnectOptions) (_ ClientTransport, err error) {
 	scheme := "http"
-	conn, err := dial(opts.Dialer, ctx, addr)
+	conn, err := dial(ctx, opts.Dialer, addr.Addr)
 	if err != nil {
+		if opts.FailOnNonTempDialError {
+			return nil, connectionErrorf(isTemporary(err), err, "transport: %v", err)
+		}
 		return nil, connectionErrorf(true, err, "transport: %v", err)
 	}
 	// Any further errors will close the underlying connection
@@ -160,7 +182,7 @@ func newHTTP2Client(ctx context.Context, addr string, opts ConnectOptions) (_ Cl
 	var authInfo credentials.AuthInfo
 	if creds := opts.TransportCredentials; creds != nil {
 		scheme = "https"
-		conn, authInfo, err = creds.ClientHandshake(ctx, addr, conn)
+		conn, authInfo, err = creds.ClientHandshake(ctx, addr.Addr, conn)
 		if err != nil {
 			// Credentials handshake errors are typically considered permanent
 			// to avoid retrying on e.g. bad certificates.
@@ -168,22 +190,31 @@ func newHTTP2Client(ctx context.Context, addr string, opts ConnectOptions) (_ Cl
 			return nil, connectionErrorf(temp, err, "transport: %v", err)
 		}
 	}
-	ua := primaryUA
-	if opts.UserAgent != "" {
-		ua = opts.UserAgent + " " + ua
+	kp := opts.KeepaliveParams
+	// Validate keepalive parameters.
+	if kp.Time == 0 {
+		kp.Time = defaultClientKeepaliveTime
+	}
+	if kp.Timeout == 0 {
+		kp.Timeout = defaultClientKeepaliveTimeout
 	}
 	var buf bytes.Buffer
 	t := &http2Client{
-		target:    addr,
-		userAgent: ua,
-		conn:      conn,
-		authInfo:  authInfo,
+		ctx:        ctx,
+		target:     addr.Addr,
+		userAgent:  opts.UserAgent,
+		md:         addr.Metadata,
+		conn:       conn,
+		remoteAddr: conn.RemoteAddr(),
+		localAddr:  conn.LocalAddr(),
+		authInfo:   authInfo,
 		// The client initiated stream id is odd starting from 1.
 		nextID:          1,
 		writableChan:    make(chan int, 1),
 		shutdownChan:    make(chan struct{}),
 		errorChan:       make(chan struct{}),
 		goAway:          make(chan struct{}),
+		awakenKeepalive: make(chan struct{}, 1),
 		framer:          newFramer(conn),
 		hBuf:            &buf,
 		hEnc:            hpack.NewEncoder(&buf),
@@ -194,8 +225,24 @@ func newHTTP2Client(ctx context.Context, addr string, opts ConnectOptions) (_ Cl
 		state:           reachable,
 		activeStreams:   make(map[uint32]*Stream),
 		creds:           opts.PerRPCCredentials,
-		maxStreams:      math.MaxInt32,
+		maxStreams:      defaultMaxStreamsClient,
+		streamsQuota:    newQuotaPool(defaultMaxStreamsClient),
 		streamSendQuota: defaultWindowSize,
+		kp:              kp,
+		statsHandler:    opts.StatsHandler,
+	}
+	// Make sure awakenKeepalive can't be written upon.
+	// keepalive routine will make it writable, if need be.
+	t.awakenKeepalive <- struct{}{}
+	if t.statsHandler != nil {
+		t.ctx = t.statsHandler.TagConn(t.ctx, &stats.ConnTagInfo{
+			RemoteAddr: t.remoteAddr,
+			LocalAddr:  t.localAddr,
+		})
+		connBegin := &stats.ConnBegin{
+			Client: true,
+		}
+		t.statsHandler.HandleConn(t.ctx, connBegin)
 	}
 	// Start the reader goroutine for incoming message. Each transport has
 	// a dedicated goroutine which reads HTTP2 frame from network. Then it
@@ -231,6 +278,9 @@ func newHTTP2Client(ctx context.Context, addr string, opts ConnectOptions) (_ Cl
 		}
 	}
 	go t.controller()
+	if t.kp.Time != infinity {
+		go t.keepalive()
+	}
 	t.writableChan <- 0
 	return t, nil
 }
@@ -264,16 +314,17 @@ func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
 	return s
 }
 
-// NewStream creates a stream and register it into the transport as "active"
+// NewStream creates a stream and registers it into the transport as "active"
 // streams.
 func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) {
 	pr := &peer.Peer{
-		Addr: t.conn.RemoteAddr(),
+		Addr: t.remoteAddr,
 	}
 	// Attach Auth info if there is any.
 	if t.authInfo != nil {
 		pr.AuthInfo = t.authInfo
 	}
+	userCtx := ctx
 	ctx = peer.NewContext(ctx, pr)
 	authData := make(map[string]string)
 	for _, c := range t.creds {
@@ -311,21 +362,18 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 		t.mu.Unlock()
 		return nil, ErrConnClosing
 	}
-	checkStreamsQuota := t.streamsQuota != nil
 	t.mu.Unlock()
-	if checkStreamsQuota {
-		sq, err := wait(ctx, nil, nil, t.shutdownChan, t.streamsQuota.acquire())
-		if err != nil {
-			return nil, err
-		}
-		// Returns the quota balance back.
-		if sq > 1 {
-			t.streamsQuota.add(sq - 1)
-		}
+	sq, err := wait(ctx, nil, nil, t.shutdownChan, t.streamsQuota.acquire())
+	if err != nil {
+		return nil, err
+	}
+	// Returns the quota balance back.
+	if sq > 1 {
+		t.streamsQuota.add(sq - 1)
 	}
 	if _, err := wait(ctx, nil, nil, t.shutdownChan, t.writableChan); err != nil {
 		// Return the quota back now because there is no stream returned to the caller.
-		if _, ok := err.(StreamError); ok && checkStreamsQuota {
+		if _, ok := err.(StreamError); ok {
 			t.streamsQuota.add(1)
 		}
 		return nil, err
@@ -333,9 +381,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 	t.mu.Lock()
 	if t.state == draining {
 		t.mu.Unlock()
-		if checkStreamsQuota {
-			t.streamsQuota.add(1)
-		}
+		t.streamsQuota.add(1)
 		// Need to make t writable again so that the rpc in flight can still proceed.
 		t.writableChan <- 0
 		return nil, ErrStreamDrain
@@ -345,18 +391,19 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 		return nil, ErrConnClosing
 	}
 	s := t.newStream(ctx, callHdr)
+	s.clientStatsCtx = userCtx
 	t.activeStreams[s.id] = s
+	// If the number of active streams change from 0 to 1, then check if keepalive
+	// has gone dormant. If so, wake it up.
+	if len(t.activeStreams) == 1 {
+		select {
+		case t.awakenKeepalive <- struct{}{}:
+			t.framer.writePing(false, false, [8]byte{})
+		default:
+		}
+	}
 
-	// This stream is not counted when applySetings(...) initialize t.streamsQuota.
-	// Reset t.streamsQuota to the right value.
-	var reset bool
-	if !checkStreamsQuota && t.streamsQuota != nil {
-		reset = true
-	}
 	t.mu.Unlock()
-	if reset {
-		t.streamsQuota.reset(-1)
-	}
 
 	// HPACK encodes various headers. Note that once WriteField(...) is
 	// called, the corresponding headers/continuation frame has to be sent
@@ -388,7 +435,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 		hasMD      bool
 		endHeaders bool
 	)
-	if md, ok := metadata.FromContext(ctx); ok {
+	if md, ok := metadata.FromOutgoingContext(ctx); ok {
 		hasMD = true
 		for k, v := range md {
 			// HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set.
@@ -400,7 +447,18 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 			}
 		}
 	}
+	if md, ok := t.md.(*metadata.MD); ok {
+		for k, v := range *md {
+			if isReservedHeader(k) {
+				continue
+			}
+			for _, entry := range v {
+				t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry})
+			}
+		}
+	}
 	first := true
+	bufLen := t.hBuf.Len()
 	// Sends the headers in a single batch even when they span multiple frames.
 	for !endHeaders {
 		size := t.hBuf.Len()
@@ -435,6 +493,17 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 			return nil, connectionErrorf(true, err, "transport: %v", err)
 		}
 	}
+	if t.statsHandler != nil {
+		outHeader := &stats.OutHeader{
+			Client:      true,
+			WireLength:  bufLen,
+			FullMethod:  callHdr.Method,
+			RemoteAddr:  t.remoteAddr,
+			LocalAddr:   t.localAddr,
+			Compression: callHdr.SendCompress,
+		}
+		t.statsHandler.HandleRPC(s.clientStatsCtx, outHeader)
+	}
 	t.writableChan <- 0
 	return s, nil
 }
@@ -442,15 +511,11 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 // CloseStream clears the footprint of a stream when the stream is not needed any more.
 // This must not be executed in reader's goroutine.
 func (t *http2Client) CloseStream(s *Stream, err error) {
-	var updateStreams bool
 	t.mu.Lock()
 	if t.activeStreams == nil {
 		t.mu.Unlock()
 		return
 	}
-	if t.streamsQuota != nil {
-		updateStreams = true
-	}
 	delete(t.activeStreams, s.id)
 	if t.state == draining && len(t.activeStreams) == 0 {
 		// The transport is draining and s is the last live stream on t.
@@ -459,10 +524,27 @@ func (t *http2Client) CloseStream(s *Stream, err error) {
 		return
 	}
 	t.mu.Unlock()
-	if updateStreams {
-		t.streamsQuota.add(1)
-	}
+	// rstStream is true in case the stream is being closed at the client-side
+	// and the server needs to be intimated about it by sending a RST_STREAM
+	// frame.
+	// To make sure this frame is written to the wire before the headers of the
+	// next stream waiting for streamsQuota, we add to streamsQuota pool only
+	// after having acquired the writableChan to send RST_STREAM out (look at
+	// the controller() routine).
+	var rstStream bool
+	var rstError http2.ErrCode
+	defer func() {
+		// In case, the client doesn't have to send RST_STREAM to server
+		// we can safely add back to streamsQuota pool now.
+		if !rstStream {
+			t.streamsQuota.add(1)
+			return
+		}
+		t.controlBuf.put(&resetStream{s.id, rstError})
+	}()
 	s.mu.Lock()
+	rstStream = s.rstStream
+	rstError = s.rstError
 	if q := s.fc.resetPendingData(); q > 0 {
 		if n := t.fc.onRead(q); n > 0 {
 			t.controlBuf.put(&windowUpdate{0, n})
@@ -478,8 +560,9 @@ func (t *http2Client) CloseStream(s *Stream, err error) {
 	}
 	s.state = streamDone
 	s.mu.Unlock()
-	if se, ok := err.(StreamError); ok && se.Code != codes.DeadlineExceeded {
-		t.controlBuf.put(&resetStream{s.id, http2.ErrCodeCancel})
+	if _, ok := err.(StreamError); ok {
+		rstStream = true
+		rstError = http2.ErrCodeCancel
 	}
 }
 
@@ -513,6 +596,12 @@ func (t *http2Client) Close() (err error) {
 		s.mu.Unlock()
 		s.write(recvMsg{err: ErrConnClosing})
 	}
+	if t.statsHandler != nil {
+		connEnd := &stats.ConnEnd{
+			Client: true,
+		}
+		t.statsHandler.HandleConn(t.ctx, connEnd)
+	}
 	return
 }
 
@@ -570,19 +659,14 @@ func (t *http2Client) Write(s *Stream, data []byte, opts *Options) error {
 		var p []byte
 		if r.Len() > 0 {
 			size := http2MaxFrameLen
-			s.sendQuotaPool.add(0)
 			// Wait until the stream has some quota to send the data.
 			sq, err := wait(s.ctx, s.done, s.goAway, t.shutdownChan, s.sendQuotaPool.acquire())
 			if err != nil {
 				return err
 			}
-			t.sendQuotaPool.add(0)
 			// Wait until the transport has some quota to send the data.
 			tq, err := wait(s.ctx, s.done, s.goAway, t.shutdownChan, t.sendQuotaPool.acquire())
 			if err != nil {
-				if _, ok := err.(StreamError); ok || err == io.EOF {
-					t.sendQuotaPool.cancel()
-				}
 				return err
 			}
 			if sq < size {
@@ -692,7 +776,7 @@ func (t *http2Client) updateWindow(s *Stream, n uint32) {
 }
 
 func (t *http2Client) handleData(f *http2.DataFrame) {
-	size := len(f.Data())
+	size := f.Header().Length
 	if err := t.fc.onData(uint32(size)); err != nil {
 		t.notifyError(connectionErrorf(true, err, "%v", err))
 		return
@@ -706,6 +790,11 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 		return
 	}
 	if size > 0 {
+		if f.Header().Flags.Has(http2.FlagDataPadded) {
+			if w := t.fc.onRead(uint32(size) - uint32(len(f.Data()))); w > 0 {
+				t.controlBuf.put(&windowUpdate{0, w})
+			}
+		}
 		s.mu.Lock()
 		if s.state == streamDone {
 			s.mu.Unlock()
@@ -716,22 +805,27 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 			return
 		}
 		if err := s.fc.onData(uint32(size)); err != nil {
-			s.state = streamDone
-			s.statusCode = codes.Internal
-			s.statusDesc = err.Error()
-			close(s.done)
+			s.rstStream = true
+			s.rstError = http2.ErrCodeFlowControl
+			s.finish(status.New(codes.Internal, err.Error()))
 			s.mu.Unlock()
 			s.write(recvMsg{err: io.EOF})
-			t.controlBuf.put(&resetStream{s.id, http2.ErrCodeFlowControl})
 			return
 		}
+		if f.Header().Flags.Has(http2.FlagDataPadded) {
+			if w := s.fc.onRead(uint32(size) - uint32(len(f.Data()))); w > 0 {
+				t.controlBuf.put(&windowUpdate{s.id, w})
+			}
+		}
 		s.mu.Unlock()
 		// TODO(bradfitz, zhaoq): A copy is required here because there is no
 		// guarantee f.Data() is consumed before the arrival of next frame.
 		// Can this copy be eliminated?
-		data := make([]byte, size)
-		copy(data, f.Data())
-		s.write(recvMsg{data: data})
+		if len(f.Data()) > 0 {
+			data := make([]byte, len(f.Data()))
+			copy(data, f.Data())
+			s.write(recvMsg{data: data})
+		}
 	}
 	// The server has closed the stream without sending trailers.  Record that
 	// the read direction is closed, and set the status appropriately.
@@ -741,10 +835,7 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 			s.mu.Unlock()
 			return
 		}
-		s.state = streamDone
-		s.statusCode = codes.Internal
-		s.statusDesc = "server closed the stream without sending trailers"
-		close(s.done)
+		s.finish(status.New(codes.Internal, "server closed the stream without sending trailers"))
 		s.mu.Unlock()
 		s.write(recvMsg{err: io.EOF})
 	}
@@ -760,18 +851,16 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
 		s.mu.Unlock()
 		return
 	}
-	s.state = streamDone
 	if !s.headerDone {
 		close(s.headerChan)
 		s.headerDone = true
 	}
-	s.statusCode, ok = http2ErrConvTab[http2.ErrCode(f.ErrCode)]
+	statusCode, ok := http2ErrConvTab[http2.ErrCode(f.ErrCode)]
 	if !ok {
 		grpclog.Println("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error ", f.ErrCode)
-		s.statusCode = codes.Unknown
+		statusCode = codes.Unknown
 	}
-	s.statusDesc = fmt.Sprintf("stream terminated by RST_STREAM with error code: %d", f.ErrCode)
-	close(s.done)
+	s.finish(status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %d", f.ErrCode))
 	s.mu.Unlock()
 	s.write(recvMsg{err: io.EOF})
 }
@@ -790,12 +879,18 @@ func (t *http2Client) handleSettings(f *http2.SettingsFrame) {
 }
 
 func (t *http2Client) handlePing(f *http2.PingFrame) {
+	if f.IsAck() { // Do nothing.
+		return
+	}
 	pingAck := &ping{ack: true}
 	copy(pingAck.data[:], f.Data[:])
 	t.controlBuf.put(pingAck)
 }
 
 func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
+	if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
+		grpclog.Printf("Client received GoAway with http2.ErrCodeEnhanceYourCalm.")
+	}
 	t.mu.Lock()
 	if t.state == reachable || t.state == draining {
 		if f.LastStreamID > 0 && f.LastStreamID%2 != 1 {
@@ -817,6 +912,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 			t.mu.Unlock()
 			return
 		default:
+			t.setGoAwayReason(f)
 		}
 		t.goAwayID = f.LastStreamID
 		close(t.goAway)
@@ -824,6 +920,26 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 	t.mu.Unlock()
 }
 
+// setGoAwayReason sets the value of t.goAwayReason based
+// on the GoAway frame received.
+// It expects a lock on transport's mutext to be held by
+// the caller.
+func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
+	t.goAwayReason = NoReason
+	switch f.ErrCode {
+	case http2.ErrCodeEnhanceYourCalm:
+		if string(f.DebugData()) == "too_many_pings" {
+			t.goAwayReason = TooManyPings
+		}
+	}
+}
+
+func (t *http2Client) GetGoAwayReason() GoAwayReason {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.goAwayReason
+}
+
 func (t *http2Client) handleWindowUpdate(f *http2.WindowUpdateFrame) {
 	id := f.Header().StreamID
 	incr := f.Increment
@@ -844,21 +960,38 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 	}
 	var state decodeState
 	for _, hf := range frame.Fields {
-		state.processHeaderField(hf)
-	}
-	if state.err != nil {
-		s.mu.Lock()
-		if !s.headerDone {
-			close(s.headerChan)
-			s.headerDone = true
+		if err := state.processHeaderField(hf); err != nil {
+			s.mu.Lock()
+			if !s.headerDone {
+				close(s.headerChan)
+				s.headerDone = true
+			}
+			s.mu.Unlock()
+			s.write(recvMsg{err: err})
+			// Something wrong. Stops reading even when there is remaining.
+			return
 		}
-		s.mu.Unlock()
-		s.write(recvMsg{err: state.err})
-		// Something wrong. Stops reading even when there is remaining.
-		return
 	}
 
 	endStream := frame.StreamEnded()
+	var isHeader bool
+	defer func() {
+		if t.statsHandler != nil {
+			if isHeader {
+				inHeader := &stats.InHeader{
+					Client:     true,
+					WireLength: int(frame.Header().Length),
+				}
+				t.statsHandler.HandleRPC(s.clientStatsCtx, inHeader)
+			} else {
+				inTrailer := &stats.InTrailer{
+					Client:     true,
+					WireLength: int(frame.Header().Length),
+				}
+				t.statsHandler.HandleRPC(s.clientStatsCtx, inTrailer)
+			}
+		}
+	}()
 
 	s.mu.Lock()
 	if !endStream {
@@ -870,6 +1003,7 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		}
 		close(s.headerChan)
 		s.headerDone = true
+		isHeader = true
 	}
 	if !endStream || s.state == streamDone {
 		s.mu.Unlock()
@@ -879,10 +1013,7 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 	if len(state.mdata) > 0 {
 		s.trailer = state.mdata
 	}
-	s.statusCode = state.statusCode
-	s.statusDesc = state.statusDesc
-	close(s.done)
-	s.state = streamDone
+	s.finish(state.status())
 	s.mu.Unlock()
 	s.write(recvMsg{err: io.EOF})
 }
@@ -910,6 +1041,7 @@ func (t *http2Client) reader() {
 		t.notifyError(err)
 		return
 	}
+	atomic.CompareAndSwapUint32(&t.activity, 0, 1)
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
 		t.notifyError(err)
@@ -920,6 +1052,7 @@ func (t *http2Client) reader() {
 	// loop to keep reading incoming messages on this transport.
 	for {
 		frame, err := t.framer.readFrame()
+		atomic.CompareAndSwapUint32(&t.activity, 0, 1)
 		if err != nil {
 			// Abort an active stream if the http2.Framer returns a
 			// http2.StreamError. This can happen only if the server's response
@@ -971,21 +1104,15 @@ func (t *http2Client) applySettings(ss []http2.Setting) {
 				s.Val = math.MaxInt32
 			}
 			t.mu.Lock()
-			reset := t.streamsQuota != nil
-			if !reset {
-				t.streamsQuota = newQuotaPool(int(s.Val) - len(t.activeStreams))
-			}
 			ms := t.maxStreams
 			t.maxStreams = int(s.Val)
 			t.mu.Unlock()
-			if reset {
-				t.streamsQuota.reset(int(s.Val) - ms)
-			}
+			t.streamsQuota.add(int(s.Val) - ms)
 		case http2.SettingInitialWindowSize:
 			t.mu.Lock()
 			for _, stream := range t.activeStreams {
 				// Adjust the sending quota for each stream.
-				stream.sendQuotaPool.reset(int(s.Val - t.streamSendQuota))
+				stream.sendQuotaPool.add(int(s.Val - t.streamSendQuota))
 			}
 			t.streamSendQuota = s.Val
 			t.mu.Unlock()
@@ -1013,6 +1140,12 @@ func (t *http2Client) controller() {
 						t.framer.writeSettings(true, i.ss...)
 					}
 				case *resetStream:
+					// If the server needs to be to intimated about stream closing,
+					// then we need to make sure the RST_STREAM frame is written to
+					// the wire before the headers of the next stream waiting on
+					// streamQuota. We ensure this by adding to the streamsQuota pool
+					// only after having acquired the writableChan to send RST_STREAM.
+					t.streamsQuota.add(1)
 					t.framer.writeRSTStream(true, i.streamID, i.code)
 				case *flushIO:
 					t.framer.flushWrite()
@@ -1032,6 +1165,61 @@ func (t *http2Client) controller() {
 	}
 }
 
+// keepalive running in a separate goroutune makes sure the connection is alive by sending pings.
+func (t *http2Client) keepalive() {
+	p := &ping{data: [8]byte{}}
+	timer := time.NewTimer(t.kp.Time)
+	for {
+		select {
+		case <-timer.C:
+			if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
+				timer.Reset(t.kp.Time)
+				continue
+			}
+			// Check if keepalive should go dormant.
+			t.mu.Lock()
+			if len(t.activeStreams) < 1 && !t.kp.PermitWithoutStream {
+				// Make awakenKeepalive writable.
+				<-t.awakenKeepalive
+				t.mu.Unlock()
+				select {
+				case <-t.awakenKeepalive:
+					// If the control gets here a ping has been sent
+					// need to reset the timer with keepalive.Timeout.
+				case <-t.shutdownChan:
+					return
+				}
+			} else {
+				t.mu.Unlock()
+				// Send ping.
+				t.controlBuf.put(p)
+			}
+
+			// By the time control gets here a ping has been sent one way or the other.
+			timer.Reset(t.kp.Timeout)
+			select {
+			case <-timer.C:
+				if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
+					timer.Reset(t.kp.Time)
+					continue
+				}
+				t.Close()
+				return
+			case <-t.shutdownChan:
+				if !timer.Stop() {
+					<-timer.C
+				}
+				return
+			}
+		case <-t.shutdownChan:
+			if !timer.Stop() {
+				<-timer.C
+			}
+			return
+		}
+	}
+}
+
 func (t *http2Client) Error() <-chan struct{} {
 	return t.errorChan
 }

vendor/google.golang.org/grpc/transport/http2_server.go

@@ -38,18 +38,26 @@ import (
 	"errors"
 	"io"
 	"math"
+	"math/rand"
 	"net"
 	"strconv"
 	"sync"
+	"sync/atomic"
+	"time"
 
+	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/context"
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+	"google.golang.org/grpc/tap"
 )
 
 // ErrIllegalHeaderWrite indicates that setting header is illegal because of
@@ -58,9 +66,13 @@ var ErrIllegalHeaderWrite = errors.New("transport: the stream is done or WriteHe
 
 // http2Server implements the ServerTransport interface with HTTP2.
 type http2Server struct {
+	ctx         context.Context
 	conn        net.Conn
+	remoteAddr  net.Addr
+	localAddr   net.Addr
 	maxStreamID uint32               // max stream ID ever seen
 	authInfo    credentials.AuthInfo // auth info about the connection
+	inTapHandle tap.ServerInHandle
 	// writableChan synchronizes write access to the transport.
 	// A writer acquires the write lock by receiving a value on writableChan
 	// and releases it by sending on writableChan.
@@ -82,21 +94,46 @@ type http2Server struct {
 	// sendQuotaPool provides flow control to outbound message.
 	sendQuotaPool *quotaPool
 
+	stats stats.Handler
+
+	// Flag to keep track of reading activity on transport.
+	// 1 is true and 0 is false.
+	activity uint32 // Accessed atomically.
+	// Keepalive and max-age parameters for the server.
+	kp keepalive.ServerParameters
+
+	// Keepalive enforcement policy.
+	kep keepalive.EnforcementPolicy
+	// The time instance last ping was received.
+	lastPingAt time.Time
+	// Number of times the client has violated keepalive ping policy so far.
+	pingStrikes uint8
+	// Flag to signify that number of ping strikes should be reset to 0.
+	// This is set whenever data or header frames are sent.
+	// 1 means yes.
+	resetPingStrikes uint32 // Accessed atomically.
+
 	mu            sync.Mutex // guard the following
 	state         transportState
 	activeStreams map[uint32]*Stream
 	// the per-stream outbound flow control window size set by the peer.
 	streamSendQuota uint32
+	// idle is the time instant when the connection went idle.
+	// This is either the begining of the connection or when the number of
+	// RPCs go down to 0.
+	// When the connection is busy, this value is set to 0.
+	idle time.Time
 }
 
 // newHTTP2Server constructs a ServerTransport based on HTTP2. ConnectionError is
 // returned if something goes wrong.
-func newHTTP2Server(conn net.Conn, maxStreams uint32, authInfo credentials.AuthInfo) (_ ServerTransport, err error) {
+func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err error) {
 	framer := newFramer(conn)
 	// Send initial settings as connection preface to client.
 	var settings []http2.Setting
 	// TODO(zhaoq): Have a better way to signal "no limit" because 0 is
 	// permitted in the HTTP2 spec.
+	maxStreams := config.MaxStreams
 	if maxStreams == 0 {
 		maxStreams = math.MaxUint32
 	} else {
@@ -119,14 +156,40 @@ func newHTTP2Server(conn net.Conn, maxStreams uint32, authInfo credentials.AuthI
 			return nil, connectionErrorf(true, err, "transport: %v", err)
 		}
 	}
+	kp := config.KeepaliveParams
+	if kp.MaxConnectionIdle == 0 {
+		kp.MaxConnectionIdle = defaultMaxConnectionIdle
+	}
+	if kp.MaxConnectionAge == 0 {
+		kp.MaxConnectionAge = defaultMaxConnectionAge
+	}
+	// Add a jitter to MaxConnectionAge.
+	kp.MaxConnectionAge += getJitter(kp.MaxConnectionAge)
+	if kp.MaxConnectionAgeGrace == 0 {
+		kp.MaxConnectionAgeGrace = defaultMaxConnectionAgeGrace
+	}
+	if kp.Time == 0 {
+		kp.Time = defaultServerKeepaliveTime
+	}
+	if kp.Timeout == 0 {
+		kp.Timeout = defaultServerKeepaliveTimeout
+	}
+	kep := config.KeepalivePolicy
+	if kep.MinTime == 0 {
+		kep.MinTime = defaultKeepalivePolicyMinTime
+	}
 	var buf bytes.Buffer
 	t := &http2Server{
+		ctx:             context.Background(),
 		conn:            conn,
-		authInfo:        authInfo,
+		remoteAddr:      conn.RemoteAddr(),
+		localAddr:       conn.LocalAddr(),
+		authInfo:        config.AuthInfo,
 		framer:          framer,
 		hBuf:            &buf,
 		hEnc:            hpack.NewEncoder(&buf),
 		maxStreams:      maxStreams,
+		inTapHandle:     config.InTapHandle,
 		controlBuf:      newRecvBuffer(),
 		fc:              &inFlow{limit: initialConnWindowSize},
 		sendQuotaPool:   newQuotaPool(defaultWindowSize),
@@ -135,14 +198,27 @@ func newHTTP2Server(conn net.Conn, maxStreams uint32, authInfo credentials.AuthI
 		shutdownChan:    make(chan struct{}),
 		activeStreams:   make(map[uint32]*Stream),
 		streamSendQuota: defaultWindowSize,
+		stats:           config.StatsHandler,
+		kp:              kp,
+		idle:            time.Now(),
+		kep:             kep,
+	}
+	if t.stats != nil {
+		t.ctx = t.stats.TagConn(t.ctx, &stats.ConnTagInfo{
+			RemoteAddr: t.remoteAddr,
+			LocalAddr:  t.localAddr,
+		})
+		connBegin := &stats.ConnBegin{}
+		t.stats.HandleConn(t.ctx, connBegin)
 	}
 	go t.controller()
+	go t.keepalive()
 	t.writableChan <- 0
 	return t, nil
 }
 
 // operateHeader takes action on the decoded headers.
-func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream)) (close bool) {
+func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream), traceCtx func(context.Context, string) context.Context) (close bool) {
 	buf := newRecvBuffer()
 	s := &Stream{
 		id:  frame.Header().StreamID,
@@ -153,13 +229,12 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 
 	var state decodeState
 	for _, hf := range frame.Fields {
-		state.processHeaderField(hf)
-	}
-	if err := state.err; err != nil {
-		if se, ok := err.(StreamError); ok {
-			t.controlBuf.put(&resetStream{s.id, statusCodeConvTab[se.Code]})
+		if err := state.processHeaderField(hf); err != nil {
+			if se, ok := err.(StreamError); ok {
+				t.controlBuf.put(&resetStream{s.id, statusCodeConvTab[se.Code]})
+			}
+			return
 		}
-		return
 	}
 
 	if frame.StreamEnded() {
@@ -168,12 +243,12 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	}
 	s.recvCompress = state.encoding
 	if state.timeoutSet {
-		s.ctx, s.cancel = context.WithTimeout(context.TODO(), state.timeout)
+		s.ctx, s.cancel = context.WithTimeout(t.ctx, state.timeout)
 	} else {
-		s.ctx, s.cancel = context.WithCancel(context.TODO())
+		s.ctx, s.cancel = context.WithCancel(t.ctx)
 	}
 	pr := &peer.Peer{
-		Addr: t.conn.RemoteAddr(),
+		Addr: t.remoteAddr,
 	}
 	// Attach Auth info if there is any.
 	if t.authInfo != nil {
@@ -186,7 +261,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	s.ctx = newContextWithStream(s.ctx, s)
 	// Attach the received metadata to the context.
 	if len(state.mdata) > 0 {
-		s.ctx = metadata.NewContext(s.ctx, state.mdata)
+		s.ctx = metadata.NewIncomingContext(s.ctx, state.mdata)
 	}
 
 	s.dec = &recvBufferReader{
@@ -195,6 +270,18 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	}
 	s.recvCompress = state.encoding
 	s.method = state.method
+	if t.inTapHandle != nil {
+		var err error
+		info := &tap.Info{
+			FullMethodName: state.method,
+		}
+		s.ctx, err = t.inTapHandle(s.ctx, info)
+		if err != nil {
+			// TODO: Log the real error.
+			t.controlBuf.put(&resetStream{s.id, http2.ErrCodeRefusedStream})
+			return
+		}
+	}
 	t.mu.Lock()
 	if t.state != reachable {
 		t.mu.Unlock()
@@ -214,17 +301,33 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	t.maxStreamID = s.id
 	s.sendQuotaPool = newQuotaPool(int(t.streamSendQuota))
 	t.activeStreams[s.id] = s
+	if len(t.activeStreams) == 1 {
+		t.idle = time.Time{}
+	}
 	t.mu.Unlock()
 	s.windowHandler = func(n int) {
 		t.updateWindow(s, uint32(n))
 	}
+	s.ctx = traceCtx(s.ctx, s.method)
+	if t.stats != nil {
+		s.ctx = t.stats.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
+		inHeader := &stats.InHeader{
+			FullMethod:  s.method,
+			RemoteAddr:  t.remoteAddr,
+			LocalAddr:   t.localAddr,
+			Compression: s.recvCompress,
+			WireLength:  int(frame.Header().Length),
+		}
+		t.stats.HandleRPC(s.ctx, inHeader)
+	}
 	handle(s)
 	return
 }
 
 // HandleStreams receives incoming streams using the given handler. This is
 // typically run in a separate goroutine.
-func (t *http2Server) HandleStreams(handle func(*Stream)) {
+// traceCtx attaches trace to ctx and returns the new context.
+func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.Context, string) context.Context) {
 	// Check the validity of client preface.
 	preface := make([]byte, len(clientPreface))
 	if _, err := io.ReadFull(t.conn, preface); err != nil {
@@ -248,6 +351,7 @@ func (t *http2Server) HandleStreams(handle func(*Stream)) {
 		t.Close()
 		return
 	}
+	atomic.StoreUint32(&t.activity, 1)
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
 		grpclog.Printf("transport: http2Server.HandleStreams saw invalid preface type %T from client", frame)
@@ -258,6 +362,7 @@ func (t *http2Server) HandleStreams(handle func(*Stream)) {
 
 	for {
 		frame, err := t.framer.readFrame()
+		atomic.StoreUint32(&t.activity, 1)
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
 				t.mu.Lock()
@@ -279,7 +384,7 @@ func (t *http2Server) HandleStreams(handle func(*Stream)) {
 		}
 		switch frame := frame.(type) {
 		case *http2.MetaHeadersFrame:
-			if t.operateHeaders(frame, handle) {
+			if t.operateHeaders(frame, handle, traceCtx) {
 				t.Close()
 				break
 			}
@@ -334,7 +439,7 @@ func (t *http2Server) updateWindow(s *Stream, n uint32) {
 }
 
 func (t *http2Server) handleData(f *http2.DataFrame) {
-	size := len(f.Data())
+	size := f.Header().Length
 	if err := t.fc.onData(uint32(size)); err != nil {
 		grpclog.Printf("transport: http2Server %v", err)
 		t.Close()
@@ -349,6 +454,11 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 		return
 	}
 	if size > 0 {
+		if f.Header().Flags.Has(http2.FlagDataPadded) {
+			if w := t.fc.onRead(uint32(size) - uint32(len(f.Data()))); w > 0 {
+				t.controlBuf.put(&windowUpdate{0, w})
+			}
+		}
 		s.mu.Lock()
 		if s.state == streamDone {
 			s.mu.Unlock()
@@ -364,13 +474,20 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 			t.controlBuf.put(&resetStream{s.id, http2.ErrCodeFlowControl})
 			return
 		}
+		if f.Header().Flags.Has(http2.FlagDataPadded) {
+			if w := s.fc.onRead(uint32(size) - uint32(len(f.Data()))); w > 0 {
+				t.controlBuf.put(&windowUpdate{s.id, w})
+			}
+		}
 		s.mu.Unlock()
 		// TODO(bradfitz, zhaoq): A copy is required here because there is no
 		// guarantee f.Data() is consumed before the arrival of next frame.
 		// Can this copy be eliminated?
-		data := make([]byte, size)
-		copy(data, f.Data())
-		s.write(recvMsg{data: data})
+		if len(f.Data()) > 0 {
+			data := make([]byte, len(f.Data()))
+			copy(data, f.Data())
+			s.write(recvMsg{data: data})
+		}
 	}
 	if f.Header().Flags.Has(http2.FlagDataEndStream) {
 		// Received the end of stream from the client.
@@ -404,10 +521,50 @@ func (t *http2Server) handleSettings(f *http2.SettingsFrame) {
 	t.controlBuf.put(&settings{ack: true, ss: ss})
 }
 
+const (
+	maxPingStrikes     = 2
+	defaultPingTimeout = 2 * time.Hour
+)
+
 func (t *http2Server) handlePing(f *http2.PingFrame) {
+	if f.IsAck() { // Do nothing.
+		return
+	}
 	pingAck := &ping{ack: true}
 	copy(pingAck.data[:], f.Data[:])
 	t.controlBuf.put(pingAck)
+
+	now := time.Now()
+	defer func() {
+		t.lastPingAt = now
+	}()
+	// A reset ping strikes means that we don't need to check for policy
+	// violation for this ping and the pingStrikes counter should be set
+	// to 0.
+	if atomic.CompareAndSwapUint32(&t.resetPingStrikes, 1, 0) {
+		t.pingStrikes = 0
+		return
+	}
+	t.mu.Lock()
+	ns := len(t.activeStreams)
+	t.mu.Unlock()
+	if ns < 1 && !t.kep.PermitWithoutStream {
+		// Keepalive shouldn't be active thus, this new ping should
+		// have come after atleast defaultPingTimeout.
+		if t.lastPingAt.Add(defaultPingTimeout).After(now) {
+			t.pingStrikes++
+		}
+	} else {
+		// Check if keepalive policy is respected.
+		if t.lastPingAt.Add(t.kep.MinTime).After(now) {
+			t.pingStrikes++
+		}
+	}
+
+	if t.pingStrikes > maxPingStrikes {
+		// Send goaway and close the connection.
+		t.controlBuf.put(&goAway{code: http2.ErrCodeEnhanceYourCalm, debugData: []byte("too_many_pings")})
+	}
 }
 
 func (t *http2Server) handleWindowUpdate(f *http2.WindowUpdateFrame) {
@@ -426,6 +583,13 @@ func (t *http2Server) writeHeaders(s *Stream, b *bytes.Buffer, endStream bool) e
 	first := true
 	endHeaders := false
 	var err error
+	defer func() {
+		if err == nil {
+			// Reset ping strikes when seding headers since that might cause the
+			// peer to send ping.
+			atomic.StoreUint32(&t.resetPingStrikes, 1)
+		}
+	}()
 	// Sends the headers in a single batch.
 	for !endHeaders {
 		size := t.hBuf.Len()
@@ -462,6 +626,14 @@ func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 		return ErrIllegalHeaderWrite
 	}
 	s.headerOk = true
+	if md.Len() > 0 {
+		if s.header.Len() > 0 {
+			s.header = metadata.Join(s.header, md)
+		} else {
+			s.header = md
+		}
+	}
+	md = s.header
 	s.mu.Unlock()
 	if _, err := wait(s.ctx, nil, nil, t.shutdownChan, t.writableChan); err != nil {
 		return err
@@ -481,9 +653,16 @@ func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 			t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry})
 		}
 	}
+	bufLen := t.hBuf.Len()
 	if err := t.writeHeaders(s, t.hBuf, false); err != nil {
 		return err
 	}
+	if t.stats != nil {
+		outHeader := &stats.OutHeader{
+			WireLength: bufLen,
+		}
+		t.stats.HandleRPC(s.Context(), outHeader)
+	}
 	t.writableChan <- 0
 	return nil
 }
@@ -492,8 +671,8 @@ func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 // There is no further I/O operations being able to perform on this stream.
 // TODO(zhaoq): Now it indicates the end of entire stream. Revisit if early
 // OK is adopted.
-func (t *http2Server) WriteStatus(s *Stream, statusCode codes.Code, statusDesc string) error {
-	var headersSent bool
+func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
+	var headersSent, hasHeader bool
 	s.mu.Lock()
 	if s.state == streamDone {
 		s.mu.Unlock()
@@ -502,7 +681,16 @@ func (t *http2Server) WriteStatus(s *Stream, statusCode codes.Code, statusDesc s
 	if s.headerOk {
 		headersSent = true
 	}
+	if s.header.Len() > 0 {
+		hasHeader = true
+	}
 	s.mu.Unlock()
+
+	if !headersSent && hasHeader {
+		t.WriteHeader(s, nil)
+		headersSent = true
+	}
+
 	if _, err := wait(s.ctx, nil, nil, t.shutdownChan, t.writableChan); err != nil {
 		return err
 	}
@@ -514,9 +702,24 @@ func (t *http2Server) WriteStatus(s *Stream, statusCode codes.Code, statusDesc s
 	t.hEnc.WriteField(
 		hpack.HeaderField{
 			Name:  "grpc-status",
-			Value: strconv.Itoa(int(statusCode)),
+			Value: strconv.Itoa(int(st.Code())),
 		})
-	t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(statusDesc)})
+	t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(st.Message())})
+
+	if p := st.Proto(); p != nil && len(p.Details) > 0 {
+		stBytes, err := proto.Marshal(p)
+		if err != nil {
+			// TODO: return error instead, when callers are able to handle it.
+			panic(err)
+		}
+
+		for k, v := range metadata.New(map[string]string{"grpc-status-details-bin": (string)(stBytes)}) {
+			for _, entry := range v {
+				t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry})
+			}
+		}
+	}
+
 	// Attach the trailer metadata.
 	for k, v := range s.trailer {
 		// Clients don't tolerate reading restricted headers after some non restricted ones were sent.
@@ -527,10 +730,17 @@ func (t *http2Server) WriteStatus(s *Stream, statusCode codes.Code, statusDesc s
 			t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry})
 		}
 	}
+	bufLen := t.hBuf.Len()
 	if err := t.writeHeaders(s, t.hBuf, true); err != nil {
 		t.Close()
 		return err
 	}
+	if t.stats != nil {
+		outTrailer := &stats.OutTrailer{
+			WireLength: bufLen,
+		}
+		t.stats.HandleRPC(s.Context(), outTrailer)
+	}
 	t.closeStream(s)
 	t.writableChan <- 0
 	return nil
@@ -538,7 +748,7 @@ func (t *http2Server) WriteStatus(s *Stream, statusCode codes.Code, statusDesc s
 
 // Write converts the data into HTTP2 data frame and sends it out. Non-nil error
 // is returns if it fails (e.g., framing error, transport error).
-func (t *http2Server) Write(s *Stream, data []byte, opts *Options) error {
+func (t *http2Server) Write(s *Stream, data []byte, opts *Options) (err error) {
 	// TODO(zhaoq): Support multi-writers for a single stream.
 	var writeHeaderFrame bool
 	s.mu.Lock()
@@ -548,49 +758,32 @@ func (t *http2Server) Write(s *Stream, data []byte, opts *Options) error {
 	}
 	if !s.headerOk {
 		writeHeaderFrame = true
-		s.headerOk = true
 	}
 	s.mu.Unlock()
 	if writeHeaderFrame {
-		if _, err := wait(s.ctx, nil, nil, t.shutdownChan, t.writableChan); err != nil {
-			return err
-		}
-		t.hBuf.Reset()
-		t.hEnc.WriteField(hpack.HeaderField{Name: ":status", Value: "200"})
-		t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"})
-		if s.sendCompress != "" {
-			t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-encoding", Value: s.sendCompress})
-		}
-		p := http2.HeadersFrameParam{
-			StreamID:      s.id,
-			BlockFragment: t.hBuf.Bytes(),
-			EndHeaders:    true,
-		}
-		if err := t.framer.writeHeaders(false, p); err != nil {
-			t.Close()
-			return connectionErrorf(true, err, "transport: %v", err)
-		}
-		t.writableChan <- 0
+		t.WriteHeader(s, nil)
 	}
+	defer func() {
+		if err == nil {
+			// Reset ping strikes when sending data since this might cause
+			// the peer to send ping.
+			atomic.StoreUint32(&t.resetPingStrikes, 1)
+		}
+	}()
 	r := bytes.NewBuffer(data)
 	for {
 		if r.Len() == 0 {
 			return nil
 		}
 		size := http2MaxFrameLen
-		s.sendQuotaPool.add(0)
 		// Wait until the stream has some quota to send the data.
 		sq, err := wait(s.ctx, nil, nil, t.shutdownChan, s.sendQuotaPool.acquire())
 		if err != nil {
 			return err
 		}
-		t.sendQuotaPool.add(0)
 		// Wait until the transport has some quota to send the data.
 		tq, err := wait(s.ctx, nil, nil, t.shutdownChan, t.sendQuotaPool.acquire())
 		if err != nil {
-			if _, ok := err.(StreamError); ok {
-				t.sendQuotaPool.cancel()
-			}
 			return err
 		}
 		if sq < size {
@@ -658,7 +851,7 @@ func (t *http2Server) applySettings(ss []http2.Setting) {
 			t.mu.Lock()
 			defer t.mu.Unlock()
 			for _, stream := range t.activeStreams {
-				stream.sendQuotaPool.reset(int(s.Val - t.streamSendQuota))
+				stream.sendQuotaPool.add(int(s.Val - t.streamSendQuota))
 			}
 			t.streamSendQuota = s.Val
 		}
@@ -666,6 +859,91 @@ func (t *http2Server) applySettings(ss []http2.Setting) {
 	}
 }
 
+// keepalive running in a separate goroutine does the following:
+// 1. Gracefully closes an idle connection after a duration of keepalive.MaxConnectionIdle.
+// 2. Gracefully closes any connection after a duration of keepalive.MaxConnectionAge.
+// 3. Forcibly closes a connection after an additive period of keepalive.MaxConnectionAgeGrace over keepalive.MaxConnectionAge.
+// 4. Makes sure a connection is alive by sending pings with a frequency of keepalive.Time and closes a non-resposive connection
+// after an additional duration of keepalive.Timeout.
+func (t *http2Server) keepalive() {
+	p := &ping{}
+	var pingSent bool
+	maxIdle := time.NewTimer(t.kp.MaxConnectionIdle)
+	maxAge := time.NewTimer(t.kp.MaxConnectionAge)
+	keepalive := time.NewTimer(t.kp.Time)
+	// NOTE: All exit paths of this function should reset their
+	// respecitve timers. A failure to do so will cause the
+	// following clean-up to deadlock and eventually leak.
+	defer func() {
+		if !maxIdle.Stop() {
+			<-maxIdle.C
+		}
+		if !maxAge.Stop() {
+			<-maxAge.C
+		}
+		if !keepalive.Stop() {
+			<-keepalive.C
+		}
+	}()
+	for {
+		select {
+		case <-maxIdle.C:
+			t.mu.Lock()
+			idle := t.idle
+			if idle.IsZero() { // The connection is non-idle.
+				t.mu.Unlock()
+				maxIdle.Reset(t.kp.MaxConnectionIdle)
+				continue
+			}
+			val := t.kp.MaxConnectionIdle - time.Since(idle)
+			if val <= 0 {
+				// The connection has been idle for a duration of keepalive.MaxConnectionIdle or more.
+				// Gracefully close the connection.
+				t.state = draining
+				t.mu.Unlock()
+				t.Drain()
+				// Reseting the timer so that the clean-up doesn't deadlock.
+				maxIdle.Reset(infinity)
+				return
+			}
+			t.mu.Unlock()
+			maxIdle.Reset(val)
+		case <-maxAge.C:
+			t.mu.Lock()
+			t.state = draining
+			t.mu.Unlock()
+			t.Drain()
+			maxAge.Reset(t.kp.MaxConnectionAgeGrace)
+			select {
+			case <-maxAge.C:
+				// Close the connection after grace period.
+				t.Close()
+				// Reseting the timer so that the clean-up doesn't deadlock.
+				maxAge.Reset(infinity)
+			case <-t.shutdownChan:
+			}
+			return
+		case <-keepalive.C:
+			if atomic.CompareAndSwapUint32(&t.activity, 1, 0) {
+				pingSent = false
+				keepalive.Reset(t.kp.Time)
+				continue
+			}
+			if pingSent {
+				t.Close()
+				// Reseting the timer so that the clean-up doesn't deadlock.
+				keepalive.Reset(infinity)
+				return
+			}
+			pingSent = true
+			t.controlBuf.put(p)
+			keepalive.Reset(t.kp.Timeout)
+		case <-t.shutdownChan:
+			return
+		}
+	}
+}
+
 // controller running in a separate goroutine takes charge of sending control
 // frames (e.g., window update, reset stream, setting, etc.) to the server.
 func (t *http2Server) controller() {
@@ -697,7 +975,10 @@ func (t *http2Server) controller() {
 					sid := t.maxStreamID
 					t.state = draining
 					t.mu.Unlock()
-					t.framer.writeGoAway(true, sid, http2.ErrCodeNo, nil)
+					t.framer.writeGoAway(true, sid, i.code, i.debugData)
+					if i.code == http2.ErrCodeEnhanceYourCalm {
+						t.Close()
+					}
 				case *flushIO:
 					t.framer.flushWrite()
 				case *ping:
@@ -735,6 +1016,10 @@ func (t *http2Server) Close() (err error) {
 	for _, s := range streams {
 		s.cancel()
 	}
+	if t.stats != nil {
+		connEnd := &stats.ConnEnd{}
+		t.stats.HandleConn(t.ctx, connEnd)
+	}
 	return
 }
 
@@ -743,6 +1028,9 @@ func (t *http2Server) Close() (err error) {
 func (t *http2Server) closeStream(s *Stream) {
 	t.mu.Lock()
 	delete(t.activeStreams, s.id)
+	if len(t.activeStreams) == 0 {
+		t.idle = time.Now()
+	}
 	if t.state == draining && len(t.activeStreams) == 0 {
 		defer t.Close()
 	}
@@ -766,9 +1054,21 @@ func (t *http2Server) closeStream(s *Stream) {
 }
 
 func (t *http2Server) RemoteAddr() net.Addr {
-	return t.conn.RemoteAddr()
+	return t.remoteAddr
 }
 
 func (t *http2Server) Drain() {
-	t.controlBuf.put(&goAway{})
+	t.controlBuf.put(&goAway{code: http2.ErrCodeNo})
+}
+
+var rgen = rand.New(rand.NewSource(time.Now().UnixNano()))
+
+func getJitter(v time.Duration) time.Duration {
+	if v == infinity {
+		return 0
+	}
+	// Generate a jitter between +/- 10% of the value.
+	r := int64(v / 10)
+	j := rgen.Int63n(2*r) - r
+	return time.Duration(j)
 }

vendor/google.golang.org/grpc/transport/http_util.go

@@ -44,16 +44,17 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/grpclog"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 const (
-	// The primary user agent
-	primaryUA = "grpc-go/1.0"
 	// http2MaxFrameLen specifies the max length of a HTTP2 frame.
 	http2MaxFrameLen = 16384 // 16KB frame
 	// http://http2.github.io/http2-spec/#SettingValues
@@ -92,13 +93,15 @@ var (
 // Records the states during HPACK decoding. Must be reset once the
 // decoding of the entire headers are finished.
 type decodeState struct {
-	err error // first error encountered decoding
-
 	encoding string
-	// statusCode caches the stream status received from the trailer
-	// the server sent. Client side only.
-	statusCode codes.Code
-	statusDesc string
+	// statusGen caches the stream status received from the trailer the server
+	// sent.  Client side only.  Do not access directly.  After all trailers are
+	// parsed, use the status method to retrieve the status.
+	statusGen *status.Status
+	// rawStatusCode and rawStatusMsg are set from the raw trailer fields and are not
+	// intended for direct access outside of parsing.
+	rawStatusCode int32
+	rawStatusMsg  string
 	// Server side only fields.
 	timeoutSet bool
 	timeout    time.Duration
@@ -121,6 +124,7 @@ func isReservedHeader(hdr string) bool {
 		"grpc-message",
 		"grpc-status",
 		"grpc-timeout",
+		"grpc-status-details-bin",
 		"te":
 		return true
 	default:
@@ -139,12 +143,6 @@ func isWhitelistedPseudoHeader(hdr string) bool {
 	}
 }
 
-func (d *decodeState) setErr(err error) {
-	if d.err == nil {
-		d.err = err
-	}
-}
-
 func validContentType(t string) bool {
 	e := "application/grpc"
 	if !strings.HasPrefix(t, e) {
@@ -158,56 +156,62 @@ func validContentType(t string) bool {
 	return true
 }
 
-func (d *decodeState) processHeaderField(f hpack.HeaderField) {
+func (d *decodeState) status() *status.Status {
+	if d.statusGen == nil {
+		// No status-details were provided; generate status using code/msg.
+		d.statusGen = status.New(codes.Code(d.rawStatusCode), d.rawStatusMsg)
+	}
+	return d.statusGen
+}
+
+func (d *decodeState) processHeaderField(f hpack.HeaderField) error {
 	switch f.Name {
 	case "content-type":
 		if !validContentType(f.Value) {
-			d.setErr(streamErrorf(codes.FailedPrecondition, "transport: received the unexpected content-type %q", f.Value))
-			return
+			return streamErrorf(codes.FailedPrecondition, "transport: received the unexpected content-type %q", f.Value)
 		}
 	case "grpc-encoding":
 		d.encoding = f.Value
 	case "grpc-status":
 		code, err := strconv.Atoi(f.Value)
 		if err != nil {
-			d.setErr(streamErrorf(codes.Internal, "transport: malformed grpc-status: %v", err))
-			return
+			return streamErrorf(codes.Internal, "transport: malformed grpc-status: %v", err)
 		}
-		d.statusCode = codes.Code(code)
+		d.rawStatusCode = int32(code)
 	case "grpc-message":
-		d.statusDesc = decodeGrpcMessage(f.Value)
+		d.rawStatusMsg = decodeGrpcMessage(f.Value)
+	case "grpc-status-details-bin":
+		_, v, err := metadata.DecodeKeyValue("grpc-status-details-bin", f.Value)
+		if err != nil {
+			return streamErrorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
+		}
+		s := &spb.Status{}
+		if err := proto.Unmarshal([]byte(v), s); err != nil {
+			return streamErrorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
+		}
+		d.statusGen = status.FromProto(s)
 	case "grpc-timeout":
 		d.timeoutSet = true
 		var err error
-		d.timeout, err = decodeTimeout(f.Value)
-		if err != nil {
-			d.setErr(streamErrorf(codes.Internal, "transport: malformed time-out: %v", err))
-			return
+		if d.timeout, err = decodeTimeout(f.Value); err != nil {
+			return streamErrorf(codes.Internal, "transport: malformed time-out: %v", err)
 		}
 	case ":path":
 		d.method = f.Value
 	default:
 		if !isReservedHeader(f.Name) || isWhitelistedPseudoHeader(f.Name) {
-			if f.Name == "user-agent" {
-				i := strings.LastIndex(f.Value, " ")
-				if i == -1 {
-					// There is no application user agent string being set.
-					return
-				}
-				// Extract the application user agent string.
-				f.Value = f.Value[:i]
-			}
 			if d.mdata == nil {
 				d.mdata = make(map[string][]string)
 			}
 			k, v, err := metadata.DecodeKeyValue(f.Name, f.Value)
 			if err != nil {
 				grpclog.Printf("Failed to decode (%q, %q): %v", f.Name, f.Value, err)
-				return
+				return nil
 			}
 			d.mdata[k] = append(d.mdata[k], v)
 		}
 	}
+	return nil
 }
 
 type timeoutUnit uint8
@@ -379,6 +383,9 @@ func newFramer(conn net.Conn) *framer {
 		writer: bufio.NewWriterSize(conn, http2IOBufSize),
 	}
 	f.fr = http2.NewFramer(f.writer, f.reader)
+	// Opt-in to Frame reuse API on framer to reduce garbage.
+	// Frames aren't safe to read from after a subsequent call to ReadFrame.
+	f.fr.SetReuseFrames()
 	f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
 	return f
 }

vendor/google.golang.org/grpc/transport/pre_go16.go

@@ -1,51 +0,0 @@
-// +build !go1.6
-
-/*
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-package transport
-
-import (
-	"net"
-	"time"
-
-	"golang.org/x/net/context"
-)
-
-// dialContext connects to the address on the named network.
-func dialContext(ctx context.Context, network, address string) (net.Conn, error) {
-	var dialer net.Dialer
-	if deadline, ok := ctx.Deadline(); ok {
-		dialer.Timeout = deadline.Sub(time.Now())
-	}
-	return dialer.Dial(network, address)
-}

vendor/google.golang.org/grpc/transport/transport.go

@@ -45,10 +45,14 @@ import (
 	"sync"
 
 	"golang.org/x/net/context"
-	"golang.org/x/net/trace"
+	"golang.org/x/net/http2"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/stats"
+	"google.golang.org/grpc/status"
+	"google.golang.org/grpc/tap"
 )
 
 // recvMsg represents the received msg from the transport. All transport
@@ -167,6 +171,11 @@ type Stream struct {
 	id uint32
 	// nil for client side Stream.
 	st ServerTransport
+	// clientStatsCtx keeps the user context for stats handling.
+	// It's only valid on client side. Server side stats context is same as s.ctx.
+	// All client side stats collection should use the clientStatsCtx (instead of the stream context)
+	// so that all the generated stats for a particular RPC can be associated in the processing phase.
+	clientStatsCtx context.Context
 	// ctx is the associated context of the stream.
 	ctx context.Context
 	// cancel is always nil for client side Stream.
@@ -204,9 +213,13 @@ type Stream struct {
 	// true iff headerChan is closed. Used to avoid closing headerChan
 	// multiple times.
 	headerDone bool
-	// the status received from the server.
-	statusCode codes.Code
-	statusDesc string
+	// the status error received from the server.
+	status *status.Status
+	// rstStream indicates whether a RST_STREAM frame needs to be sent
+	// to the server to signify that this stream is closing.
+	rstStream bool
+	// rstError is the error that needs to be sent along with the RST_STREAM frame.
+	rstError http2.ErrCode
 }
 
 // RecvCompress returns the compression algorithm applied to the inbound
@@ -266,29 +279,37 @@ func (s *Stream) Context() context.Context {
 	return s.ctx
 }
 
-// TraceContext recreates the context of s with a trace.Trace.
-func (s *Stream) TraceContext(tr trace.Trace) {
-	s.ctx = trace.NewContext(s.ctx, tr)
-}
-
 // Method returns the method for the stream.
 func (s *Stream) Method() string {
 	return s.method
 }
 
-// StatusCode returns statusCode received from the server.
-func (s *Stream) StatusCode() codes.Code {
-	return s.statusCode
+// Status returns the status received from the server.
+func (s *Stream) Status() *status.Status {
+	return s.status
 }
 
-// StatusDesc returns statusDesc received from the server.
-func (s *Stream) StatusDesc() string {
-	return s.statusDesc
+// SetHeader sets the header metadata. This can be called multiple times.
+// Server side only.
+func (s *Stream) SetHeader(md metadata.MD) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.headerOk || s.state == streamDone {
+		return ErrIllegalHeaderWrite
+	}
+	if md.Len() == 0 {
+		return nil
+	}
+	s.header = metadata.Join(s.header, md)
+	return nil
 }
 
 // SetTrailer sets the trailer metadata which will be sent with the RPC status
 // by the server. This can be called multiple times. Server side only.
 func (s *Stream) SetTrailer(md metadata.MD) error {
+	if md.Len() == 0 {
+		return nil
+	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.trailer = metadata.Join(s.trailer, md)
@@ -312,6 +333,20 @@ func (s *Stream) Read(p []byte) (n int, err error) {
 	return
 }
 
+// finish sets the stream's state and status, and closes the done channel.
+// s.mu must be held by the caller.  st must always be non-nil.
+func (s *Stream) finish(st *status.Status) {
+	s.status = st
+	s.state = streamDone
+	close(s.done)
+}
+
+// GoString is implemented by Stream so context.String() won't
+// race when printing %#v.
+func (s *Stream) GoString() string {
+	return fmt.Sprintf("<stream: %p, %v>", s, s.method)
+}
+
 // The key to save transport.Stream in the context.
 type streamKey struct{}
 
@@ -337,27 +372,52 @@ const (
 	draining
 )
 
-// NewServerTransport creates a ServerTransport with conn or non-nil error
-// if it fails.
-func NewServerTransport(protocol string, conn net.Conn, maxStreams uint32, authInfo credentials.AuthInfo) (ServerTransport, error) {
-	return newHTTP2Server(conn, maxStreams, authInfo)
+// ServerConfig consists of all the configurations to establish a server transport.
+type ServerConfig struct {
+	MaxStreams      uint32
+	AuthInfo        credentials.AuthInfo
+	InTapHandle     tap.ServerInHandle
+	StatsHandler    stats.Handler
+	KeepaliveParams keepalive.ServerParameters
+	KeepalivePolicy keepalive.EnforcementPolicy
 }
 
-// ConnectOptions covers all relevant options for dialing a server.
+// NewServerTransport creates a ServerTransport with conn or non-nil error
+// if it fails.
+func NewServerTransport(protocol string, conn net.Conn, config *ServerConfig) (ServerTransport, error) {
+	return newHTTP2Server(conn, config)
+}
+
+// ConnectOptions covers all relevant options for communicating with the server.
 type ConnectOptions struct {
 	// UserAgent is the application user agent.
 	UserAgent string
+	// Authority is the :authority pseudo-header to use. This field has no effect if
+	// TransportCredentials is set.
+	Authority string
 	// Dialer specifies how to dial a network address.
 	Dialer func(context.Context, string) (net.Conn, error)
+	// FailOnNonTempDialError specifies if gRPC fails on non-temporary dial errors.
+	FailOnNonTempDialError bool
 	// PerRPCCredentials stores the PerRPCCredentials required to issue RPCs.
 	PerRPCCredentials []credentials.PerRPCCredentials
 	// TransportCredentials stores the Authenticator required to setup a client connection.
 	TransportCredentials credentials.TransportCredentials
+	// KeepaliveParams stores the keepalive parameters.
+	KeepaliveParams keepalive.ClientParameters
+	// StatsHandler stores the handler for stats.
+	StatsHandler stats.Handler
+}
+
+// TargetInfo contains the information of the target such as network address and metadata.
+type TargetInfo struct {
+	Addr     string
+	Metadata interface{}
 }
 
 // NewClientTransport establishes the transport with the required ConnectOptions
 // and returns it to the caller.
-func NewClientTransport(ctx context.Context, target string, opts ConnectOptions) (ClientTransport, error) {
+func NewClientTransport(ctx context.Context, target TargetInfo, opts ConnectOptions) (ClientTransport, error) {
 	return newHTTP2Client(ctx, target, opts)
 }
 
@@ -433,6 +493,9 @@ type ClientTransport interface {
 	// receives the draining signal from the server (e.g., GOAWAY frame in
 	// HTTP/2).
 	GoAway() <-chan struct{}
+
+	// GetGoAwayReason returns the reason why GoAway frame was received.
+	GetGoAwayReason() GoAwayReason
 }
 
 // ServerTransport is the common interface for all gRPC server-side transport
@@ -442,7 +505,7 @@ type ClientTransport interface {
 // Write methods for a given Stream will be called serially.
 type ServerTransport interface {
 	// HandleStreams receives incoming streams using the given handler.
-	HandleStreams(func(*Stream))
+	HandleStreams(func(*Stream), func(context.Context, string) context.Context)
 
 	// WriteHeader sends the header metadata for the given stream.
 	// WriteHeader may not be called on all streams.
@@ -452,10 +515,9 @@ type ServerTransport interface {
 	// Write may not be called on all streams.
 	Write(s *Stream, data []byte, opts *Options) error
 
-	// WriteStatus sends the status of a stream to the client.
-	// WriteStatus is the final call made on a stream and always
-	// occurs.
-	WriteStatus(s *Stream, statusCode codes.Code, statusDesc string) error
+	// WriteStatus sends the status of a stream to the client.  WriteStatus is
+	// the final call made on a stream and always occurs.
+	WriteStatus(s *Stream, st *status.Status) error
 
 	// Close tears down the transport. Once it is called, the transport
 	// should not be accessed any more. All the pending streams and their
@@ -521,6 +583,8 @@ var (
 	ErrStreamDrain = streamErrorf(codes.Unavailable, "the server stops accepting new RPCs")
 )
 
+// TODO: See if we can replace StreamError with status package errors.
+
 // StreamError is an error that only affects one stream within a connection.
 type StreamError struct {
 	Code codes.Code
@@ -528,7 +592,7 @@ type StreamError struct {
 }
 
 func (e StreamError) Error() string {
-	return fmt.Sprintf("stream error: code = %d desc = %q", e.Code, e.Desc)
+	return fmt.Sprintf("stream error: code = %s desc = %q", e.Code, e.Desc)
 }
 
 // ContextErr converts the error from context package into a StreamError.
@@ -569,3 +633,16 @@ func wait(ctx context.Context, done, goAway, closing <-chan struct{}, proceed <-
 		return i, nil
 	}
 }
+
+// GoAwayReason contains the reason for the GoAway frame received.
+type GoAwayReason uint8
+
+const (
+	// Invalid indicates that no GoAway frame is received.
+	Invalid GoAwayReason = 0
+	// NoReason is the default value when GoAway frame is received.
+	NoReason GoAwayReason = 1
+	// TooManyPings indicates that a GoAway frame with ErrCodeEnhanceYourCalm
+	// was recieved and that the debug data said "too_many_pings".
+	TooManyPings GoAwayReason = 2
+)