updated GHA

Update to v2 SDK
updated dependencies

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

@@ -20,13 +20,17 @@ package transport
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"runtime"
+	"strconv"
 	"sync"
 	"sync/atomic"
 
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/status"
 )
 
 var updateHeaderTblSize = func(e *hpack.Encoder, v uint32) {
@@ -128,6 +132,16 @@ type cleanupStream struct {
 
 func (c *cleanupStream) isTransportResponseFrame() bool { return c.rst } // Results in a RST_STREAM
 
+type earlyAbortStream struct {
+	httpStatus     uint32
+	streamID       uint32
+	contentSubtype string
+	status         *status.Status
+	rst            bool
+}
+
+func (*earlyAbortStream) isTransportResponseFrame() bool { return false }
+
 type dataFrame struct {
 	streamID  uint32
 	endStream bool
@@ -284,7 +298,7 @@ type controlBuffer struct {
 	// closed and nilled when transportResponseFrames drops below the
 	// threshold.  Both fields are protected by mu.
 	transportResponseFrames int
-	trfChan                 atomic.Value // *chan struct{}
+	trfChan                 atomic.Value // chan struct{}
 }
 
 func newControlBuffer(done <-chan struct{}) *controlBuffer {
@@ -298,10 +312,10 @@ func newControlBuffer(done <-chan struct{}) *controlBuffer {
 // throttle blocks if there are too many incomingSettings/cleanupStreams in the
 // controlbuf.
 func (c *controlBuffer) throttle() {
-	ch, _ := c.trfChan.Load().(*chan struct{})
+	ch, _ := c.trfChan.Load().(chan struct{})
 	if ch != nil {
 		select {
-		case <-*ch:
+		case <-ch:
 		case <-c.done:
 		}
 	}
@@ -335,8 +349,7 @@ func (c *controlBuffer) executeAndPut(f func(it interface{}) bool, it cbItem) (b
 		if c.transportResponseFrames == maxQueuedTransportResponseFrames {
 			// We are adding the frame that puts us over the threshold; create
 			// a throttling channel.
-			ch := make(chan struct{})
-			c.trfChan.Store(&ch)
+			c.trfChan.Store(make(chan struct{}))
 		}
 	}
 	c.mu.Unlock()
@@ -377,9 +390,9 @@ func (c *controlBuffer) get(block bool) (interface{}, error) {
 				if c.transportResponseFrames == maxQueuedTransportResponseFrames {
 					// We are removing the frame that put us over the
 					// threshold; close and clear the throttling channel.
-					ch := c.trfChan.Load().(*chan struct{})
-					close(*ch)
-					c.trfChan.Store((*chan struct{})(nil))
+					ch := c.trfChan.Load().(chan struct{})
+					close(ch)
+					c.trfChan.Store((chan struct{})(nil))
 				}
 				c.transportResponseFrames--
 			}
@@ -395,7 +408,6 @@ func (c *controlBuffer) get(block bool) (interface{}, error) {
 		select {
 		case <-c.ch:
 		case <-c.done:
-			c.finish()
 			return nil, ErrConnClosing
 		}
 	}
@@ -420,6 +432,14 @@ func (c *controlBuffer) finish() {
 			hdr.onOrphaned(ErrConnClosing)
 		}
 	}
+	// In case throttle() is currently in flight, it needs to be unblocked.
+	// Otherwise, the transport may not close, since the transport is closed by
+	// the reader encountering the connection error.
+	ch, _ := c.trfChan.Load().(chan struct{})
+	if ch != nil {
+		close(ch)
+	}
+	c.trfChan.Store((chan struct{})(nil))
 	c.mu.Unlock()
 }
 
@@ -505,7 +525,9 @@ func (l *loopyWriter) run() (err error) {
 			// 1. When the connection is closed by some other known issue.
 			// 2. User closed the connection.
 			// 3. A graceful close of connection.
-			infof("transport: loopyWriter.run returning. %v", err)
+			if logger.V(logLevel) {
+				logger.Infof("transport: loopyWriter.run returning. %v", err)
+			}
 			err = nil
 		}
 	}()
@@ -605,7 +627,9 @@ func (l *loopyWriter) headerHandler(h *headerFrame) error {
 	if l.side == serverSide {
 		str, ok := l.estdStreams[h.streamID]
 		if !ok {
-			warningf("transport: loopy doesn't recognize the stream: %d", h.streamID)
+			if logger.V(logLevel) {
+				logger.Warningf("transport: loopy doesn't recognize the stream: %d", h.streamID)
+			}
 			return nil
 		}
 		// Case 1.A: Server is responding back with headers.
@@ -658,7 +682,9 @@ func (l *loopyWriter) writeHeader(streamID uint32, endStream bool, hf []hpack.He
 	l.hBuf.Reset()
 	for _, f := range hf {
 		if err := l.hEnc.WriteField(f); err != nil {
-			warningf("transport: loopyWriter.writeHeader encountered error while encoding headers:", err)
+			if logger.V(logLevel) {
+				logger.Warningf("transport: loopyWriter.writeHeader encountered error while encoding headers: %v", err)
+			}
 		}
 	}
 	var (
@@ -743,6 +769,32 @@ func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
 	return nil
 }
 
+func (l *loopyWriter) earlyAbortStreamHandler(eas *earlyAbortStream) error {
+	if l.side == clientSide {
+		return errors.New("earlyAbortStream not handled on client")
+	}
+	// In case the caller forgets to set the http status, default to 200.
+	if eas.httpStatus == 0 {
+		eas.httpStatus = 200
+	}
+	headerFields := []hpack.HeaderField{
+		{Name: ":status", Value: strconv.Itoa(int(eas.httpStatus))},
+		{Name: "content-type", Value: grpcutil.ContentType(eas.contentSubtype)},
+		{Name: "grpc-status", Value: strconv.Itoa(int(eas.status.Code()))},
+		{Name: "grpc-message", Value: encodeGrpcMessage(eas.status.Message())},
+	}
+
+	if err := l.writeHeader(eas.streamID, true, headerFields, nil); err != nil {
+		return err
+	}
+	if eas.rst {
+		if err := l.framer.fr.WriteRSTStream(eas.streamID, http2.ErrCodeNo); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 func (l *loopyWriter) incomingGoAwayHandler(*incomingGoAway) error {
 	if l.side == clientSide {
 		l.draining = true
@@ -781,6 +833,8 @@ func (l *loopyWriter) handle(i interface{}) error {
 		return l.registerStreamHandler(i)
 	case *cleanupStream:
 		return l.cleanupStreamHandler(i)
+	case *earlyAbortStream:
+		return l.earlyAbortStreamHandler(i)
 	case *incomingGoAway:
 		return l.incomingGoAwayHandler(i)
 	case *dataFrame:
@@ -857,38 +911,45 @@ func (l *loopyWriter) processData() (bool, error) {
 		return false, nil
 	}
 	var (
-		idx int
 		buf []byte
 	)
-	if len(dataItem.h) != 0 { // data header has not been written out yet.
-		buf = dataItem.h
-	} else {
-		idx = 1
-		buf = dataItem.d
-	}
-	size := http2MaxFrameLen
-	if len(buf) < size {
-		size = len(buf)
-	}
+	// Figure out the maximum size we can send
+	maxSize := http2MaxFrameLen
 	if strQuota := int(l.oiws) - str.bytesOutStanding; strQuota <= 0 { // stream-level flow control.
 		str.state = waitingOnStreamQuota
 		return false, nil
-	} else if strQuota < size {
-		size = strQuota
+	} else if maxSize > strQuota {
+		maxSize = strQuota
+	}
+	if maxSize > int(l.sendQuota) { // connection-level flow control.
+		maxSize = int(l.sendQuota)
+	}
+	// Compute how much of the header and data we can send within quota and max frame length
+	hSize := min(maxSize, len(dataItem.h))
+	dSize := min(maxSize-hSize, len(dataItem.d))
+	if hSize != 0 {
+		if dSize == 0 {
+			buf = dataItem.h
+		} else {
+			// We can add some data to grpc message header to distribute bytes more equally across frames.
+			// Copy on the stack to avoid generating garbage
+			var localBuf [http2MaxFrameLen]byte
+			copy(localBuf[:hSize], dataItem.h)
+			copy(localBuf[hSize:], dataItem.d[:dSize])
+			buf = localBuf[:hSize+dSize]
+		}
+	} else {
+		buf = dataItem.d
 	}
 
-	if l.sendQuota < uint32(size) { // connection-level flow control.
-		size = int(l.sendQuota)
-	}
+	size := hSize + dSize
+
 	// Now that outgoing flow controls are checked we can replenish str's write quota
 	str.wq.replenish(size)
 	var endStream bool
 	// If this is the last data message on this stream and all of it can be written in this iteration.
-	if dataItem.endStream && size == len(buf) {
-		// buf contains either data or it contains header but data is empty.
-		if idx == 1 || len(dataItem.d) == 0 {
-			endStream = true
-		}
+	if dataItem.endStream && len(dataItem.h)+len(dataItem.d) <= size {
+		endStream = true
 	}
 	if dataItem.onEachWrite != nil {
 		dataItem.onEachWrite()
@@ -896,14 +957,10 @@ func (l *loopyWriter) processData() (bool, error) {
 	if err := l.framer.fr.WriteData(dataItem.streamID, endStream, buf[:size]); err != nil {
 		return false, err
 	}
-	buf = buf[size:]
 	str.bytesOutStanding += size
 	l.sendQuota -= uint32(size)
-	if idx == 0 {
-		dataItem.h = buf
-	} else {
-		dataItem.d = buf
-	}
+	dataItem.h = dataItem.h[hSize:]
+	dataItem.d = dataItem.d[dSize:]
 
 	if len(dataItem.h) == 0 && len(dataItem.d) == 0 { // All the data from that message was written out.
 		str.itl.dequeue()
@@ -924,3 +981,10 @@ func (l *loopyWriter) processData() (bool, error) {
 	}
 	return false, nil
 }
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

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

@@ -136,12 +136,10 @@ type inFlow struct {
 
 // newLimit updates the inflow window to a new value n.
 // It assumes that n is always greater than the old limit.
-func (f *inFlow) newLimit(n uint32) uint32 {
+func (f *inFlow) newLimit(n uint32) {
 	f.mu.Lock()
-	d := n - f.limit
 	f.limit = n
 	f.mu.Unlock()
-	return d
 }
 
 func (f *inFlow) maybeAdjust(n uint32) uint32 {

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

@@ -39,6 +39,7 @@ import (
 	"golang.org/x/net/http2"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
 	"google.golang.org/grpc/stats"
@@ -48,7 +49,7 @@ import (
 // NewServerHandlerTransport returns a ServerTransport handling gRPC
 // from inside an http.Handler. It requires that the http Server
 // supports HTTP/2.
-func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats stats.Handler) (ServerTransport, error) {
+func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats []stats.Handler) (ServerTransport, error) {
 	if r.ProtoMajor != 2 {
 		return nil, errors.New("gRPC requires HTTP/2")
 	}
@@ -57,7 +58,7 @@ func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats sta
 	}
 	contentType := r.Header.Get("Content-Type")
 	// TODO: do we assume contentType is lowercase? we did before
-	contentSubtype, validContentType := contentSubtype(contentType)
+	contentSubtype, validContentType := grpcutil.ContentSubtype(contentType)
 	if !validContentType {
 		return nil, errors.New("invalid gRPC request content-type")
 	}
@@ -112,11 +113,10 @@ func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request, stats sta
 // at this point to be speaking over HTTP/2, so it's able to speak valid
 // gRPC.
 type serverHandlerTransport struct {
-	rw               http.ResponseWriter
-	req              *http.Request
-	timeoutSet       bool
-	timeout          time.Duration
-	didCommonHeaders bool
+	rw         http.ResponseWriter
+	req        *http.Request
+	timeoutSet bool
+	timeout    time.Duration
 
 	headerMD metadata.MD
 
@@ -138,12 +138,11 @@ type serverHandlerTransport struct {
 	// TODO make sure this is consistent across handler_server and http2_server
 	contentSubtype string
 
-	stats stats.Handler
+	stats []stats.Handler
 }
 
-func (ht *serverHandlerTransport) Close() error {
+func (ht *serverHandlerTransport) Close() {
 	ht.closeOnce.Do(ht.closeCloseChanOnce)
-	return nil
 }
 
 func (ht *serverHandlerTransport) closeCloseChanOnce() { close(ht.closedCh) }
@@ -186,8 +185,11 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 	ht.writeStatusMu.Lock()
 	defer ht.writeStatusMu.Unlock()
 
+	headersWritten := s.updateHeaderSent()
 	err := ht.do(func() {
-		ht.writeCommonHeaders(s)
+		if !headersWritten {
+			ht.writePendingHeaders(s)
+		}
 
 		// And flush, in case no header or body has been sent yet.
 		// This forces a separation of headers and trailers if this is the
@@ -226,8 +228,10 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 	})
 
 	if err == nil { // transport has not been closed
-		if ht.stats != nil {
-			ht.stats.HandleRPC(s.Context(), &stats.OutTrailer{
+		// Note: The trailer fields are compressed with hpack after this call returns.
+		// No WireLength field is set here.
+		for _, sh := range ht.stats {
+			sh.HandleRPC(s.Context(), &stats.OutTrailer{
 				Trailer: s.trailer.Copy(),
 			})
 		}
@@ -236,14 +240,16 @@ func (ht *serverHandlerTransport) WriteStatus(s *Stream, st *status.Status) erro
 	return err
 }
 
+// writePendingHeaders sets common and custom headers on the first
+// write call (Write, WriteHeader, or WriteStatus)
+func (ht *serverHandlerTransport) writePendingHeaders(s *Stream) {
+	ht.writeCommonHeaders(s)
+	ht.writeCustomHeaders(s)
+}
+
 // writeCommonHeaders sets common headers on the first write
 // call (Write, WriteHeader, or WriteStatus).
 func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
-	if ht.didCommonHeaders {
-		return
-	}
-	ht.didCommonHeaders = true
-
 	h := ht.rw.Header()
 	h["Date"] = nil // suppress Date to make tests happy; TODO: restore
 	h.Set("Content-Type", ht.contentType)
@@ -262,9 +268,30 @@ func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) {
 	}
 }
 
+// writeCustomHeaders sets custom headers set on the stream via SetHeader
+// on the first write call (Write, WriteHeader, or WriteStatus).
+func (ht *serverHandlerTransport) writeCustomHeaders(s *Stream) {
+	h := ht.rw.Header()
+
+	s.hdrMu.Lock()
+	for k, vv := range s.header {
+		if isReservedHeader(k) {
+			continue
+		}
+		for _, v := range vv {
+			h.Add(k, encodeMetadataHeader(k, v))
+		}
+	}
+
+	s.hdrMu.Unlock()
+}
+
 func (ht *serverHandlerTransport) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
+	headersWritten := s.updateHeaderSent()
 	return ht.do(func() {
-		ht.writeCommonHeaders(s)
+		if !headersWritten {
+			ht.writePendingHeaders(s)
+		}
 		ht.rw.Write(hdr)
 		ht.rw.Write(data)
 		ht.rw.(http.Flusher).Flush()
@@ -272,27 +299,27 @@ func (ht *serverHandlerTransport) Write(s *Stream, hdr []byte, data []byte, opts
 }
 
 func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error {
+	if err := s.SetHeader(md); err != nil {
+		return err
+	}
+
+	headersWritten := s.updateHeaderSent()
 	err := ht.do(func() {
-		ht.writeCommonHeaders(s)
-		h := ht.rw.Header()
-		for k, vv := range md {
-			// Clients don't tolerate reading restricted headers after some non restricted ones were sent.
-			if isReservedHeader(k) {
-				continue
-			}
-			for _, v := range vv {
-				v = encodeMetadataHeader(k, v)
-				h.Add(k, v)
-			}
+		if !headersWritten {
+			ht.writePendingHeaders(s)
 		}
+
 		ht.rw.WriteHeader(200)
 		ht.rw.(http.Flusher).Flush()
 	})
 
 	if err == nil {
-		if ht.stats != nil {
-			ht.stats.HandleRPC(s.Context(), &stats.OutHeader{
-				Header: md.Copy(),
+		for _, sh := range ht.stats {
+			// Note: The header fields are compressed with hpack after this call returns.
+			// No WireLength field is set here.
+			sh.HandleRPC(s.Context(), &stats.OutHeader{
+				Header:      md.Copy(),
+				Compression: s.sendCompress,
 			})
 		}
 	}
@@ -338,18 +365,18 @@ func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream), trace
 		Addr: ht.RemoteAddr(),
 	}
 	if req.TLS != nil {
-		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS, CommonAuthInfo: credentials.CommonAuthInfo{credentials.PrivacyAndIntegrity}}
+		pr.AuthInfo = credentials.TLSInfo{State: *req.TLS, CommonAuthInfo: credentials.CommonAuthInfo{SecurityLevel: credentials.PrivacyAndIntegrity}}
 	}
 	ctx = metadata.NewIncomingContext(ctx, ht.headerMD)
 	s.ctx = peer.NewContext(ctx, pr)
-	if ht.stats != nil {
-		s.ctx = ht.stats.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
+	for _, sh := range ht.stats {
+		s.ctx = sh.TagRPC(s.ctx, &stats.RPCTagInfo{FullMethodName: s.method})
 		inHeader := &stats.InHeader{
 			FullMethod:  s.method,
 			RemoteAddr:  ht.RemoteAddr(),
 			Compression: s.recvCompress,
 		}
-		ht.stats.HandleRPC(s.ctx, inHeader)
+		sh.HandleRPC(s.ctx, inHeader)
 	}
 	s.trReader = &transportReader{
 		reader:        &recvBufferReader{ctx: s.ctx, ctxDone: s.ctx.Done(), recv: s.buf, freeBuffer: func(*bytes.Buffer) {}},

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

@@ -24,6 +24,8 @@ import (
 	"io"
 	"math"
 	"net"
+	"net/http"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
@@ -32,15 +34,18 @@ import (
 
 	"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/internal"
 	"google.golang.org/grpc/internal/channelz"
+	icredentials "google.golang.org/grpc/internal/credentials"
+	"google.golang.org/grpc/internal/grpcutil"
+	imetadata "google.golang.org/grpc/internal/metadata"
 	"google.golang.org/grpc/internal/syscall"
+	"google.golang.org/grpc/internal/transport/networktype"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
 	"google.golang.org/grpc/peer"
+	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
 )
@@ -57,7 +62,7 @@ type http2Client struct {
 	cancel     context.CancelFunc
 	ctxDone    <-chan struct{} // Cache the ctx.Done() chan.
 	userAgent  string
-	md         interface{}
+	md         metadata.MD
 	conn       net.Conn // underlying communication channel
 	loopy      *loopyWriter
 	remoteAddr net.Addr
@@ -85,7 +90,7 @@ type http2Client struct {
 	kp               keepalive.ClientParameters
 	keepaliveEnabled bool
 
-	statsHandler stats.Handler
+	statsHandlers []stats.Handler
 
 	initialWindowSize int32
 
@@ -112,6 +117,9 @@ type http2Client struct {
 	// goAwayReason records the http2.ErrCode and debug data received with the
 	// GoAway frame.
 	goAwayReason GoAwayReason
+	// goAwayDebugMessage contains a detailed human readable string about a
+	// GoAway frame, useful for error messages.
+	goAwayDebugMessage string
 	// A condition variable used to signal when the keepalive goroutine should
 	// go dormant. The condition for dormancy is based on the number of active
 	// streams and the `PermitWithoutStream` keepalive client parameter. And
@@ -124,7 +132,7 @@ type http2Client struct {
 	kpDormant bool
 
 	// Fields below are for channelz metric collection.
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 
 	onGoAway func(GoAwayReason)
@@ -135,11 +143,34 @@ type http2Client struct {
 	connectionID uint64
 }
 
-func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr string) (net.Conn, error) {
+func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error), addr resolver.Address, useProxy bool, grpcUA string) (net.Conn, error) {
+	address := addr.Addr
+	networkType, ok := networktype.Get(addr)
 	if fn != nil {
-		return fn(ctx, addr)
+		// Special handling for unix scheme with custom dialer. Back in the day,
+		// we did not have a unix resolver and therefore targets with a unix
+		// scheme would end up using the passthrough resolver. So, user's used a
+		// custom dialer in this case and expected the original dial target to
+		// be passed to the custom dialer. Now, we have a unix resolver. But if
+		// a custom dialer is specified, we want to retain the old behavior in
+		// terms of the address being passed to the custom dialer.
+		if networkType == "unix" && !strings.HasPrefix(address, "\x00") {
+			// Supported unix targets are either "unix://absolute-path" or
+			// "unix:relative-path".
+			if filepath.IsAbs(address) {
+				return fn(ctx, "unix://"+address)
+			}
+			return fn(ctx, "unix:"+address)
+		}
+		return fn(ctx, address)
 	}
-	return (&net.Dialer{}).DialContext(ctx, "tcp", addr)
+	if !ok {
+		networkType, address = parseDialTarget(address)
+	}
+	if networkType == "tcp" && useProxy {
+		return proxyDial(ctx, address, grpcUA)
+	}
+	return (&net.Dialer{}).DialContext(ctx, networkType, address)
 }
 
 func isTemporary(err error) bool {
@@ -161,7 +192,7 @@ 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(connectCtx, ctx context.Context, addr TargetInfo, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (_ *http2Client, err error) {
+func newHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (_ *http2Client, err error) {
 	scheme := "http"
 	ctx, cancel := context.WithCancel(ctx)
 	defer func() {
@@ -170,7 +201,13 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 		}
 	}()
 
-	conn, err := dial(connectCtx, opts.Dialer, addr.Addr)
+	// gRPC, resolver, balancer etc. can specify arbitrary data in the
+	// Attributes field of resolver.Address, which is shoved into connectCtx
+	// and passed to the dialer and credential handshaker. This makes it possible for
+	// address specific arbitrary data to reach custom dialers and credential handshakers.
+	connectCtx = icredentials.NewClientHandshakeInfoContext(connectCtx, credentials.ClientHandshakeInfo{Attributes: addr.Attributes})
+
+	conn, err := dial(connectCtx, opts.Dialer, addr, opts.UseProxy, opts.UserAgent)
 	if err != nil {
 		if opts.FailOnNonTempDialError {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: error while dialing: %v", err)
@@ -214,12 +251,34 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 		}
 	}
 	if transportCreds != nil {
-		scheme = "https"
-		conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.Authority, conn)
+		rawConn := conn
+		// Pull the deadline from the connectCtx, which will be used for
+		// timeouts in the authentication protocol handshake. Can ignore the
+		// boolean as the deadline will return the zero value, which will make
+		// the conn not timeout on I/O operations.
+		deadline, _ := connectCtx.Deadline()
+		rawConn.SetDeadline(deadline)
+		conn, authInfo, err = transportCreds.ClientHandshake(connectCtx, addr.ServerName, rawConn)
+		rawConn.SetDeadline(time.Time{})
 		if err != nil {
 			return nil, connectionErrorf(isTemporary(err), err, "transport: authentication handshake failed: %v", err)
 		}
+		for _, cd := range perRPCCreds {
+			if cd.RequireTransportSecurity() {
+				if ci, ok := authInfo.(interface {
+					GetCommonAuthInfo() credentials.CommonAuthInfo
+				}); ok {
+					secLevel := ci.GetCommonAuthInfo().SecurityLevel
+					if secLevel != credentials.InvalidSecurityLevel && secLevel < credentials.PrivacyAndIntegrity {
+						return nil, connectionErrorf(true, nil, "transport: cannot send secure credentials on an insecure connection")
+					}
+				}
+			}
+		}
 		isSecure = true
+		if transportCreds.Info().SecurityProtocol == "tls" {
+			scheme = "https"
+		}
 	}
 	dynamicWindow := true
 	icwz := int32(initialWindowSize)
@@ -238,7 +297,6 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 		ctxDone:               ctx.Done(), // Cache Done chan.
 		cancel:                cancel,
 		userAgent:             opts.UserAgent,
-		md:                    addr.Metadata,
 		conn:                  conn,
 		remoteAddr:            conn.RemoteAddr(),
 		localAddr:             conn.LocalAddr(),
@@ -253,7 +311,7 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 		isSecure:              isSecure,
 		perRPCCreds:           perRPCCreds,
 		kp:                    kp,
-		statsHandler:          opts.StatsHandler,
+		statsHandlers:         opts.StatsHandlers,
 		initialWindowSize:     initialWindowSize,
 		onPrefaceReceipt:      onPrefaceReceipt,
 		nextID:                1,
@@ -266,6 +324,12 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 		keepaliveEnabled:      keepaliveEnabled,
 		bufferPool:            newBufferPool(),
 	}
+
+	if md, ok := addr.Metadata.(*metadata.MD); ok {
+		t.md = *md
+	} else if md := imetadata.Get(addr); md != nil {
+		t.md = md
+	}
 	t.controlBuf = newControlBuffer(t.ctxDone)
 	if opts.InitialWindowSize >= defaultWindowSize {
 		t.initialWindowSize = opts.InitialWindowSize
@@ -277,18 +341,19 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 			updateFlowControl: t.updateFlowControl,
 		}
 	}
-	if t.statsHandler != nil {
-		t.ctx = t.statsHandler.TagConn(t.ctx, &stats.ConnTagInfo{
+	for _, sh := range t.statsHandlers {
+		t.ctx = sh.TagConn(t.ctx, &stats.ConnTagInfo{
 			RemoteAddr: t.remoteAddr,
 			LocalAddr:  t.localAddr,
 		})
 		connBegin := &stats.ConnBegin{
 			Client: true,
 		}
-		t.statsHandler.HandleConn(t.ctx, connBegin)
+		sh.HandleConn(t.ctx, connBegin)
 	}
-	if channelz.IsOn() {
-		t.channelzID = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, opts.ChannelzParentID, fmt.Sprintf("%s -> %s", t.localAddr, t.remoteAddr))
+	if err != nil {
+		return nil, err
 	}
 	if t.keepaliveEnabled {
 		t.kpDormancyCond = sync.NewCond(&t.mu)
@@ -302,12 +367,14 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 	// Send connection preface to server.
 	n, err := t.conn.Write(clientPreface)
 	if err != nil {
-		t.Close()
-		return nil, connectionErrorf(true, err, "transport: failed to write client preface: %v", err)
+		err = connectionErrorf(true, err, "transport: failed to write client preface: %v", err)
+		t.Close(err)
+		return nil, err
 	}
 	if n != len(clientPreface) {
-		t.Close()
-		return nil, connectionErrorf(true, err, "transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface))
+		err = connectionErrorf(true, nil, "transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface))
+		t.Close(err)
+		return nil, err
 	}
 	var ss []http2.Setting
 
@@ -325,14 +392,16 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 	}
 	err = t.framer.fr.WriteSettings(ss...)
 	if err != nil {
-		t.Close()
-		return nil, connectionErrorf(true, err, "transport: failed to write initial settings frame: %v", err)
+		err = connectionErrorf(true, err, "transport: failed to write initial settings frame: %v", err)
+		t.Close(err)
+		return nil, err
 	}
 	// Adjust the connection flow control window if needed.
 	if delta := uint32(icwz - defaultWindowSize); delta > 0 {
 		if err := t.framer.fr.WriteWindowUpdate(0, delta); err != nil {
-			t.Close()
-			return nil, connectionErrorf(true, err, "transport: failed to write window update: %v", err)
+			err = connectionErrorf(true, err, "transport: failed to write window update: %v", err)
+			t.Close(err)
+			return nil, err
 		}
 	}
 
@@ -345,13 +414,14 @@ func newHTTP2Client(connectCtx, ctx context.Context, addr TargetInfo, opts Conne
 		t.loopy = newLoopyWriter(clientSide, t.framer, t.controlBuf, t.bdpEst)
 		err := t.loopy.run()
 		if err != nil {
-			errorf("transport: loopyWriter.run returning. Err: %v", err)
-		}
-		// If it's a connection error, let reader goroutine handle it
-		// since there might be data in the buffers.
-		if _, ok := err.(net.Error); !ok {
-			t.conn.Close()
+			if logger.V(logLevel) {
+				logger.Errorf("transport: loopyWriter.run returning. Err: %v", err)
+			}
 		}
+		// Do not close the transport.  Let reader goroutine handle it since
+		// there might be data in the buffers.
+		t.conn.Close()
+		t.controlBuf.finish()
 		close(t.writerDone)
 	}()
 	return t, nil
@@ -367,6 +437,7 @@ func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
 		buf:            newRecvBuffer(),
 		headerChan:     make(chan struct{}),
 		contentSubtype: callHdr.ContentSubtype,
+		doneFunc:       callHdr.DoneFunc,
 	}
 	s.wq = newWriteQuota(defaultWriteQuota, s.done)
 	s.requestRead = func(n int) {
@@ -406,7 +477,7 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 		Method:   callHdr.Method,
 		AuthInfo: t.authInfo,
 	}
-	ctxWithRequestInfo := internal.NewRequestInfoContext.(func(context.Context, credentials.RequestInfo) context.Context)(ctx, ri)
+	ctxWithRequestInfo := icredentials.NewRequestInfoContext(ctx, ri)
 	authData, err := t.getTrAuthData(ctxWithRequestInfo, aud)
 	if err != nil {
 		return nil, err
@@ -425,7 +496,7 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 	headerFields = append(headerFields, hpack.HeaderField{Name: ":scheme", Value: t.scheme})
 	headerFields = append(headerFields, hpack.HeaderField{Name: ":path", Value: callHdr.Method})
 	headerFields = append(headerFields, hpack.HeaderField{Name: ":authority", Value: callHdr.Host})
-	headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: contentType(callHdr.ContentSubtype)})
+	headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: grpcutil.ContentType(callHdr.ContentSubtype)})
 	headerFields = append(headerFields, hpack.HeaderField{Name: "user-agent", Value: t.userAgent})
 	headerFields = append(headerFields, hpack.HeaderField{Name: "te", Value: "trailers"})
 	if callHdr.PreviousAttempts > 0 {
@@ -440,7 +511,7 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 		// Send out timeout regardless its value. The server can detect timeout context by itself.
 		// TODO(mmukhi): Perhaps this field should be updated when actually writing out to the wire.
 		timeout := time.Until(dl)
-		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-timeout", Value: encodeTimeout(timeout)})
+		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-timeout", Value: grpcutil.EncodeDuration(timeout)})
 	}
 	for k, v := range authData {
 		headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
@@ -469,25 +540,23 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 		for _, vv := range added {
 			for i, v := range vv {
 				if i%2 == 0 {
-					k = v
+					k = strings.ToLower(v)
 					continue
 				}
 				// HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set.
 				if isReservedHeader(k) {
 					continue
 				}
-				headerFields = append(headerFields, hpack.HeaderField{Name: strings.ToLower(k), Value: encodeMetadataHeader(k, v)})
+				headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
 			}
 		}
 	}
-	if md, ok := t.md.(*metadata.MD); ok {
-		for k, vv := range *md {
-			if isReservedHeader(k) {
-				continue
-			}
-			for _, v := range vv {
-				headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
-			}
+	for k, vv := range t.md {
+		if isReservedHeader(k) {
+			continue
+		}
+		for _, v := range vv {
+			headerFields = append(headerFields, hpack.HeaderField{Name: k, Value: encodeMetadataHeader(k, v)})
 		}
 	}
 	return headerFields, nil
@@ -520,7 +589,7 @@ func (t *http2Client) getTrAuthData(ctx context.Context, audience string) (map[s
 				return nil, err
 			}
 
-			return nil, status.Errorf(codes.Unauthenticated, "transport: %v", err)
+			return nil, status.Errorf(codes.Unauthenticated, "transport: per-RPC creds failed due to error: %v", err)
 		}
 		for k, v := range data {
 			// Capital header names are illegal in HTTP/2.
@@ -537,8 +606,11 @@ func (t *http2Client) getCallAuthData(ctx context.Context, audience string, call
 	// Note: if these credentials are provided both via dial options and call
 	// options, then both sets of credentials will be applied.
 	if callCreds := callHdr.Creds; callCreds != nil {
-		if !t.isSecure && callCreds.RequireTransportSecurity() {
-			return nil, status.Error(codes.Unauthenticated, "transport: cannot send secure credentials on an insecure connection")
+		if callCreds.RequireTransportSecurity() {
+			ri, _ := credentials.RequestInfoFromContext(ctx)
+			if !t.isSecure || credentials.CheckSecurityLevel(ri.AuthInfo, credentials.PrivacyAndIntegrity) != nil {
+				return nil, status.Error(codes.Unauthenticated, "transport: cannot send secure credentials on an insecure connection")
+			}
 		}
 		data, err := callCreds.GetRequestMetadata(ctx, audience)
 		if err != nil {
@@ -554,13 +626,34 @@ func (t *http2Client) getCallAuthData(ctx context.Context, audience string, call
 	return callAuthData, nil
 }
 
+// NewStreamError wraps an error and reports additional information.  Typically
+// NewStream errors result in transparent retry, as they mean nothing went onto
+// the wire.  However, there are two notable exceptions:
+//
+// 1. If the stream headers violate the max header list size allowed by the
+//    server.  It's possible this could succeed on another transport, even if
+//    it's unlikely, but do not transparently retry.
+// 2. If the credentials errored when requesting their headers.  In this case,
+//    it's possible a retry can fix the problem, but indefinitely transparently
+//    retrying is not appropriate as it is likely the credentials, if they can
+//    eventually succeed, would need I/O to do so.
+type NewStreamError struct {
+	Err error
+
+	AllowTransparentRetry bool
+}
+
+func (e NewStreamError) Error() string {
+	return e.Err.Error()
+}
+
 // 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) {
+// streams.  All non-nil errors returned will be *NewStreamError.
+func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error) {
 	ctx = peer.NewContext(ctx, t.getPeer())
 	headerFields, err := t.createHeaderFields(ctx, callHdr)
 	if err != nil {
-		return nil, err
+		return nil, &NewStreamError{Err: err, AllowTransparentRetry: false}
 	}
 	s := t.newStream(ctx, callHdr)
 	cleanup := func(err error) {
@@ -660,36 +753,47 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 			return true
 		}, hdr)
 		if err != nil {
-			return nil, err
+			// Connection closed.
+			return nil, &NewStreamError{Err: err, AllowTransparentRetry: true}
 		}
 		if success {
 			break
 		}
 		if hdrListSizeErr != nil {
-			return nil, hdrListSizeErr
+			return nil, &NewStreamError{Err: hdrListSizeErr}
 		}
 		firstTry = false
 		select {
 		case <-ch:
-		case <-s.ctx.Done():
-			return nil, ContextErr(s.ctx.Err())
+		case <-ctx.Done():
+			return nil, &NewStreamError{Err: ContextErr(ctx.Err())}
 		case <-t.goAway:
-			return nil, errStreamDrain
+			return nil, &NewStreamError{Err: errStreamDrain, AllowTransparentRetry: true}
 		case <-t.ctx.Done():
-			return nil, ErrConnClosing
+			return nil, &NewStreamError{Err: ErrConnClosing, AllowTransparentRetry: true}
 		}
 	}
-	if t.statsHandler != nil {
-		header, _, _ := metadata.FromOutgoingContextRaw(ctx)
-		outHeader := &stats.OutHeader{
-			Client:      true,
-			FullMethod:  callHdr.Method,
-			RemoteAddr:  t.remoteAddr,
-			LocalAddr:   t.localAddr,
-			Compression: callHdr.SendCompress,
-			Header:      header.Copy(),
+	if len(t.statsHandlers) != 0 {
+		header, ok := metadata.FromOutgoingContext(ctx)
+		if ok {
+			header.Set("user-agent", t.userAgent)
+		} else {
+			header = metadata.Pairs("user-agent", t.userAgent)
+		}
+		for _, sh := range t.statsHandlers {
+			// Note: The header fields are compressed with hpack after this call returns.
+			// No WireLength field is set here.
+			// Note: Creating a new stats object to prevent pollution.
+			outHeader := &stats.OutHeader{
+				Client:      true,
+				FullMethod:  callHdr.Method,
+				RemoteAddr:  t.remoteAddr,
+				LocalAddr:   t.localAddr,
+				Compression: callHdr.SendCompress,
+				Header:      header,
+			}
+			sh.HandleRPC(s.ctx, outHeader)
 		}
-		t.statsHandler.HandleRPC(s.ctx, outHeader)
 	}
 	return s, nil
 }
@@ -764,6 +868,9 @@ func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.
 	t.controlBuf.executeAndPut(addBackStreamQuota, cleanup)
 	// This will unblock write.
 	close(s.done)
+	if s.doneFunc != nil {
+		s.doneFunc()
+	}
 }
 
 // Close kicks off the shutdown process of the transport. This should be called
@@ -773,12 +880,12 @@ func (t *http2Client) closeStream(s *Stream, err error, rst bool, rstCode http2.
 // This method blocks until the addrConn that initiated this transport is
 // re-connected. This happens because t.onClose() begins reconnect logic at the
 // addrConn level and blocks until the addrConn is successfully connected.
-func (t *http2Client) Close() error {
+func (t *http2Client) Close(err error) {
 	t.mu.Lock()
 	// Make sure we only Close once.
 	if t.state == closing {
 		t.mu.Unlock()
-		return nil
+		return
 	}
 	// Call t.onClose before setting the state to closing to prevent the client
 	// from attempting to create new streams ASAP.
@@ -794,21 +901,30 @@ func (t *http2Client) Close() error {
 	t.mu.Unlock()
 	t.controlBuf.finish()
 	t.cancel()
-	err := t.conn.Close()
-	if channelz.IsOn() {
-		channelz.RemoveEntry(t.channelzID)
+	t.conn.Close()
+	channelz.RemoveEntry(t.channelzID)
+	// Append info about previous goaways if there were any, since this may be important
+	// for understanding the root cause for this connection to be closed.
+	_, goAwayDebugMessage := t.GetGoAwayReason()
+
+	var st *status.Status
+	if len(goAwayDebugMessage) > 0 {
+		st = status.Newf(codes.Unavailable, "closing transport due to: %v, received prior goaway: %v", err, goAwayDebugMessage)
+		err = st.Err()
+	} else {
+		st = status.New(codes.Unavailable, err.Error())
 	}
+
 	// Notify all active streams.
 	for _, s := range streams {
-		t.closeStream(s, ErrConnClosing, false, http2.ErrCodeNo, status.New(codes.Unavailable, ErrConnClosing.Desc), nil, false)
+		t.closeStream(s, err, false, http2.ErrCodeNo, st, nil, false)
 	}
-	if t.statsHandler != nil {
+	for _, sh := range t.statsHandlers {
 		connEnd := &stats.ConnEnd{
 			Client: true,
 		}
-		t.statsHandler.HandleConn(t.ctx, connEnd)
+		sh.HandleConn(t.ctx, connEnd)
 	}
-	return err
 }
 
 // GracefulClose sets the state to draining, which prevents new streams from
@@ -827,7 +943,7 @@ func (t *http2Client) GracefulClose() {
 	active := len(t.activeStreams)
 	t.mu.Unlock()
 	if active == 0 {
-		t.Close()
+		t.Close(ErrConnClosing)
 		return
 	}
 	t.controlBuf.put(&incomingGoAway{})
@@ -847,18 +963,10 @@ func (t *http2Client) Write(s *Stream, hdr []byte, data []byte, opts *Options) e
 	df := &dataFrame{
 		streamID:  s.id,
 		endStream: opts.Last,
+		h:         hdr,
+		d:         data,
 	}
-	if hdr != nil || data != nil { // If it's not an empty data frame.
-		// Add some data to grpc message header so that we can equally
-		// distribute bytes across frames.
-		emptyLen := http2MaxFrameLen - len(hdr)
-		if emptyLen > len(data) {
-			emptyLen = len(data)
-		}
-		hdr = append(hdr, data[:emptyLen]...)
-		data = data[emptyLen:]
-		df.h, df.d = hdr, data
-		// TODO(mmukhi): The above logic in this if can be moved to loopyWriter's data handler.
+	if hdr != nil || data != nil { // If it's not an empty data frame, check quota.
 		if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
 			return err
 		}
@@ -976,7 +1084,7 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 	}
 	// The server has closed the stream without sending trailers.  Record that
 	// the read direction is closed, and set the status appropriately.
-	if f.FrameHeader.Flags.Has(http2.FlagDataEndStream) {
+	if f.StreamEnded() {
 		t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.New(codes.Internal, "server closed the stream without sending trailers"), nil, true)
 	}
 }
@@ -992,7 +1100,9 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
 	}
 	statusCode, ok := http2ErrConvTab[f.ErrCode]
 	if !ok {
-		warningf("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error %v", f.ErrCode)
+		if logger.V(logLevel) {
+			logger.Warningf("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error %v", f.ErrCode)
+		}
 		statusCode = codes.Unknown
 	}
 	if statusCode == codes.Canceled {
@@ -1074,12 +1184,14 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 		return
 	}
 	if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
-		infof("Client received GoAway with http2.ErrCodeEnhanceYourCalm.")
+		if logger.V(logLevel) {
+			logger.Infof("Client received GoAway with http2.ErrCodeEnhanceYourCalm.")
+		}
 	}
 	id := f.LastStreamID
-	if id > 0 && id%2 != 1 {
+	if id > 0 && id%2 == 0 {
 		t.mu.Unlock()
-		t.Close()
+		t.Close(connectionErrorf(true, nil, "received goaway with non-zero even-numbered numbered stream id: %v", id))
 		return
 	}
 	// A client can receive multiple GoAways from the server (see
@@ -1097,7 +1209,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 		// If there are multiple GoAways the first one should always have an ID greater than the following ones.
 		if id > t.prevGoAwayID {
 			t.mu.Unlock()
-			t.Close()
+			t.Close(connectionErrorf(true, nil, "received goaway with stream id: %v, which exceeds stream id of previous goaway: %v", id, t.prevGoAwayID))
 			return
 		}
 	default:
@@ -1127,7 +1239,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) {
 	active := len(t.activeStreams)
 	t.mu.Unlock()
 	if active == 0 {
-		t.Close()
+		t.Close(connectionErrorf(true, nil, "received goaway and there are no active streams"))
 	}
 }
 
@@ -1143,12 +1255,17 @@ func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 			t.goAwayReason = GoAwayTooManyPings
 		}
 	}
+	if len(f.DebugData()) == 0 {
+		t.goAwayDebugMessage = fmt.Sprintf("code: %s", f.ErrCode)
+	} else {
+		t.goAwayDebugMessage = fmt.Sprintf("code: %s, debug data: %q", f.ErrCode, string(f.DebugData()))
+	}
 }
 
-func (t *http2Client) GetGoAwayReason() GoAwayReason {
+func (t *http2Client) GetGoAwayReason() (GoAwayReason, string) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	return t.goAwayReason
+	return t.goAwayReason, t.goAwayDebugMessage
 }
 
 func (t *http2Client) handleWindowUpdate(f *http2.WindowUpdateFrame) {
@@ -1175,34 +1292,128 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		return
 	}
 
-	state := &decodeState{}
-	// Initialize isGRPC value to be !initialHeader, since if a gRPC Response-Headers has already been received, then it means that the peer is speaking gRPC and we are in gRPC mode.
-	state.data.isGRPC = !initialHeader
-	if err := state.decodeHeader(frame); err != nil {
-		t.closeStream(s, err, true, http2.ErrCodeProtocol, status.Convert(err), nil, endStream)
+	// frame.Truncated is set to true when framer detects that the current header
+	// list size hits MaxHeaderListSize limit.
+	if frame.Truncated {
+		se := status.New(codes.Internal, "peer header list size exceeded limit")
+		t.closeStream(s, se.Err(), true, http2.ErrCodeFrameSize, se, nil, endStream)
+		return
+	}
+
+	var (
+		// If a gRPC Response-Headers has already been received, then it means
+		// that the peer is speaking gRPC and we are in gRPC mode.
+		isGRPC         = !initialHeader
+		mdata          = make(map[string][]string)
+		contentTypeErr = "malformed header: missing HTTP content-type"
+		grpcMessage    string
+		statusGen      *status.Status
+		recvCompress   string
+		httpStatusCode *int
+		httpStatusErr  string
+		rawStatusCode  = codes.Unknown
+		// headerError is set if an error is encountered while parsing the headers
+		headerError string
+	)
+
+	if initialHeader {
+		httpStatusErr = "malformed header: missing HTTP status"
+	}
+
+	for _, hf := range frame.Fields {
+		switch hf.Name {
+		case "content-type":
+			if _, validContentType := grpcutil.ContentSubtype(hf.Value); !validContentType {
+				contentTypeErr = fmt.Sprintf("transport: received unexpected content-type %q", hf.Value)
+				break
+			}
+			contentTypeErr = ""
+			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
+			isGRPC = true
+		case "grpc-encoding":
+			recvCompress = hf.Value
+		case "grpc-status":
+			code, err := strconv.ParseInt(hf.Value, 10, 32)
+			if err != nil {
+				se := status.New(codes.Internal, fmt.Sprintf("transport: malformed grpc-status: %v", err))
+				t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
+				return
+			}
+			rawStatusCode = codes.Code(uint32(code))
+		case "grpc-message":
+			grpcMessage = decodeGrpcMessage(hf.Value)
+		case "grpc-status-details-bin":
+			var err error
+			statusGen, err = decodeGRPCStatusDetails(hf.Value)
+			if err != nil {
+				headerError = fmt.Sprintf("transport: malformed grpc-status-details-bin: %v", err)
+			}
+		case ":status":
+			if hf.Value == "200" {
+				httpStatusErr = ""
+				statusCode := 200
+				httpStatusCode = &statusCode
+				break
+			}
+
+			c, err := strconv.ParseInt(hf.Value, 10, 32)
+			if err != nil {
+				se := status.New(codes.Internal, fmt.Sprintf("transport: malformed http-status: %v", err))
+				t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
+				return
+			}
+			statusCode := int(c)
+			httpStatusCode = &statusCode
+
+			httpStatusErr = fmt.Sprintf(
+				"unexpected HTTP status code received from server: %d (%s)",
+				statusCode,
+				http.StatusText(statusCode),
+			)
+		default:
+			if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
+				break
+			}
+			v, err := decodeMetadataHeader(hf.Name, hf.Value)
+			if err != nil {
+				headerError = fmt.Sprintf("transport: malformed %s: %v", hf.Name, err)
+				logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
+				break
+			}
+			mdata[hf.Name] = append(mdata[hf.Name], v)
+		}
+	}
+
+	if !isGRPC || httpStatusErr != "" {
+		var code = codes.Internal // when header does not include HTTP status, return INTERNAL
+
+		if httpStatusCode != nil {
+			var ok bool
+			code, ok = HTTPStatusConvTab[*httpStatusCode]
+			if !ok {
+				code = codes.Unknown
+			}
+		}
+		var errs []string
+		if httpStatusErr != "" {
+			errs = append(errs, httpStatusErr)
+		}
+		if contentTypeErr != "" {
+			errs = append(errs, contentTypeErr)
+		}
+		// Verify the HTTP response is a 200.
+		se := status.New(code, strings.Join(errs, "; "))
+		t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
+		return
+	}
+
+	if headerError != "" {
+		se := status.New(codes.Internal, headerError)
+		t.closeStream(s, se.Err(), true, http2.ErrCodeProtocol, se, nil, endStream)
 		return
 	}
 
 	isHeader := false
-	defer func() {
-		if t.statsHandler != nil {
-			if isHeader {
-				inHeader := &stats.InHeader{
-					Client:     true,
-					WireLength: int(frame.Header().Length),
-					Header:     s.header.Copy(),
-				}
-				t.statsHandler.HandleRPC(s.ctx, inHeader)
-			} else {
-				inTrailer := &stats.InTrailer{
-					Client:     true,
-					WireLength: int(frame.Header().Length),
-					Trailer:    s.trailer.Copy(),
-				}
-				t.statsHandler.HandleRPC(s.ctx, inTrailer)
-			}
-		}
-	}()
 
 	// If headerChan hasn't been closed yet
 	if atomic.CompareAndSwapUint32(&s.headerChanClosed, 0, 1) {
@@ -1213,9 +1424,9 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 			// These values can be set without any synchronization because
 			// stream goroutine will read it only after seeing a closed
 			// headerChan which we'll close after setting this.
-			s.recvCompress = state.data.encoding
-			if len(state.data.mdata) > 0 {
-				s.header = state.data.mdata
+			s.recvCompress = recvCompress
+			if len(mdata) > 0 {
+				s.header = mdata
 			}
 		} else {
 			// HEADERS frame block carries a Trailers-Only.
@@ -1224,13 +1435,36 @@ func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) {
 		close(s.headerChan)
 	}
 
+	for _, sh := range t.statsHandlers {
+		if isHeader {
+			inHeader := &stats.InHeader{
+				Client:      true,
+				WireLength:  int(frame.Header().Length),
+				Header:      metadata.MD(mdata).Copy(),
+				Compression: s.recvCompress,
+			}
+			sh.HandleRPC(s.ctx, inHeader)
+		} else {
+			inTrailer := &stats.InTrailer{
+				Client:     true,
+				WireLength: int(frame.Header().Length),
+				Trailer:    metadata.MD(mdata).Copy(),
+			}
+			sh.HandleRPC(s.ctx, inTrailer)
+		}
+	}
+
 	if !endStream {
 		return
 	}
 
+	if statusGen == nil {
+		statusGen = status.New(rawStatusCode, grpcMessage)
+	}
+
 	// if client received END_STREAM from server while stream was still active, send RST_STREAM
 	rst := s.getState() == streamActive
-	t.closeStream(s, io.EOF, rst, http2.ErrCodeNo, state.status(), state.data.mdata, true)
+	t.closeStream(s, io.EOF, rst, http2.ErrCodeNo, statusGen, mdata, true)
 }
 
 // reader runs as a separate goroutine in charge of reading data from network
@@ -1244,7 +1478,8 @@ func (t *http2Client) reader() {
 	// Check the validity of server preface.
 	frame, err := t.framer.fr.ReadFrame()
 	if err != nil {
-		t.Close() // this kicks off resetTransport, so must be last before return
+		err = connectionErrorf(true, err, "error reading server preface: %v", err)
+		t.Close(err) // this kicks off resetTransport, so must be last before return
 		return
 	}
 	t.conn.SetReadDeadline(time.Time{}) // reset deadline once we get the settings frame (we didn't time out, yay!)
@@ -1253,7 +1488,8 @@ func (t *http2Client) reader() {
 	}
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
-		t.Close() // this kicks off resetTransport, so must be last before return
+		// this kicks off resetTransport, so must be last before return
+		t.Close(connectionErrorf(true, nil, "initial http2 frame from server is not a settings frame: %T", frame))
 		return
 	}
 	t.onPrefaceReceipt()
@@ -1277,13 +1513,19 @@ func (t *http2Client) reader() {
 				if s != nil {
 					// use error detail to provide better err message
 					code := http2ErrConvTab[se.Code]
-					msg := t.framer.fr.ErrorDetail().Error()
+					errorDetail := t.framer.fr.ErrorDetail()
+					var msg string
+					if errorDetail != nil {
+						msg = errorDetail.Error()
+					} else {
+						msg = "received invalid frame"
+					}
 					t.closeStream(s, status.Error(code, msg), true, http2.ErrCodeProtocol, status.New(code, msg), nil, false)
 				}
 				continue
 			} else {
 				// Transport error.
-				t.Close()
+				t.Close(connectionErrorf(true, err, "error reading from server: %v", err))
 				return
 			}
 		}
@@ -1303,7 +1545,9 @@ func (t *http2Client) reader() {
 		case *http2.WindowUpdateFrame:
 			t.handleWindowUpdate(frame)
 		default:
-			errorf("transport: http2Client.reader got unhandled frame type %v.", frame)
+			if logger.V(logLevel) {
+				logger.Errorf("transport: http2Client.reader got unhandled frame type %v.", frame)
+			}
 		}
 	}
 }
@@ -1315,7 +1559,7 @@ func minTime(a, b time.Duration) time.Duration {
 	return b
 }
 
-// keepalive running in a separate goroutune makes sure the connection is alive by sending pings.
+// keepalive running in a separate goroutine makes sure the connection is alive by sending pings.
 func (t *http2Client) keepalive() {
 	p := &ping{data: [8]byte{}}
 	// True iff a ping has been sent, and no data has been received since then.
@@ -1340,7 +1584,7 @@ func (t *http2Client) keepalive() {
 				continue
 			}
 			if outstandingPing && timeoutLeft <= 0 {
-				t.Close()
+				t.Close(connectionErrorf(true, nil, "keepalive ping failed to receive ACK within timeout"))
 				return
 			}
 			t.mu.Lock()

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

@@ -21,11 +21,11 @@ package transport
 import (
 	"bytes"
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"math"
 	"net"
+	"net/http"
 	"strconv"
 	"sync"
 	"sync/atomic"
@@ -34,12 +34,11 @@ import (
 	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal/grpcutil"
+	"google.golang.org/grpc/internal/syscall"
 
-	spb "google.golang.org/genproto/googleapis/rpc/status"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
-	"google.golang.org/grpc/grpclog"
-	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/keepalive"
@@ -53,13 +52,10 @@ import (
 var (
 	// ErrIllegalHeaderWrite indicates that setting header is illegal because of
 	// the stream's state.
-	ErrIllegalHeaderWrite = errors.New("transport: the stream is done or WriteHeader was already called")
+	ErrIllegalHeaderWrite = status.Error(codes.Internal, "transport: SendHeader called multiple times")
 	// ErrHeaderListSizeLimitViolation indicates that the header list size is larger
 	// than the limit set by peer.
-	ErrHeaderListSizeLimitViolation = errors.New("transport: trying to send header list size larger than the limit set by peer")
-	// statusRawProto is a function to get to the raw status proto wrapped in a
-	// status.Status without a proto.Clone().
-	statusRawProto = internal.StatusRawProto.(func(*status.Status) *spb.Status)
+	ErrHeaderListSizeLimitViolation = status.Error(codes.Internal, "transport: trying to send header list size larger than the limit set by peer")
 )
 
 // serverConnectionCounter counts the number of connections a server has seen
@@ -77,7 +73,6 @@ type http2Server struct {
 	writerDone  chan struct{} // sync point to enable testing.
 	remoteAddr  net.Addr
 	localAddr   net.Addr
-	maxStreamID uint32               // max stream ID ever seen
 	authInfo    credentials.AuthInfo // auth info about the connection
 	inTapHandle tap.ServerInHandle
 	framer      *framer
@@ -87,7 +82,7 @@ type http2Server struct {
 	// updates, reset streams, and various settings) to the controller.
 	controlBuf *controlBuffer
 	fc         *trInFlow
-	stats      stats.Handler
+	stats      []stats.Handler
 	// Keepalive and max-age parameters for the server.
 	kp keepalive.ServerParameters
 	// Keepalive enforcement policy.
@@ -106,11 +101,11 @@ type http2Server struct {
 
 	mu sync.Mutex // guard the following
 
-	// drainChan is initialized when drain(...) is called the first time.
+	// drainChan is initialized when Drain() is called the first time.
 	// After which the server writes out the first GoAway(with ID 2^31-1) frame.
 	// Then an independent goroutine will be launched to later send the second GoAway.
 	// During this time we don't want to write another first GoAway(with ID 2^31 -1) frame.
-	// Thus call to drain(...) will be a no-op if drainChan is already initialized since draining is
+	// Thus call to Drain() will be a no-op if drainChan is already initialized since draining is
 	// already underway.
 	drainChan     chan struct{}
 	state         transportState
@@ -122,16 +117,42 @@ type http2Server struct {
 	idle time.Time
 
 	// Fields below are for channelz metric collection.
-	channelzID int64 // channelz unique identification number
+	channelzID *channelz.Identifier
 	czData     *channelzData
 	bufferPool *bufferPool
 
 	connectionID uint64
+
+	// maxStreamMu guards the maximum stream ID
+	// This lock may not be taken if mu is already held.
+	maxStreamMu sync.Mutex
+	maxStreamID uint32 // max stream ID ever seen
 }
 
-// newHTTP2Server constructs a ServerTransport based on HTTP2. ConnectionError is
-// returned if something goes wrong.
-func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err error) {
+// NewServerTransport creates a http2 transport with conn and configuration
+// options from config.
+//
+// It returns a non-nil transport and a nil error on success. On failure, it
+// returns a nil transport and a non-nil error. For a special case where the
+// underlying conn gets closed before the client preface could be read, it
+// returns a nil transport and a nil error.
+func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport, err error) {
+	var authInfo credentials.AuthInfo
+	rawConn := conn
+	if config.Credentials != nil {
+		var err error
+		conn, authInfo, err = config.Credentials.ServerHandshake(rawConn)
+		if err != nil {
+			// ErrConnDispatched means that the connection was dispatched away
+			// from gRPC; those connections should be left open. io.EOF means
+			// the connection was closed before handshaking completed, which can
+			// happen naturally from probers. Return these errors directly.
+			if err == credentials.ErrConnDispatched || err == io.EOF {
+				return nil, err
+			}
+			return nil, connectionErrorf(false, err, "ServerHandshake(%q) failed: %v", rawConn.RemoteAddr(), err)
+		}
+	}
 	writeBufSize := config.WriteBufferSize
 	readBufSize := config.ReadBufferSize
 	maxHeaderListSize := defaultServerMaxHeaderListSize
@@ -210,18 +231,24 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
 	if kp.Timeout == 0 {
 		kp.Timeout = defaultServerKeepaliveTimeout
 	}
+	if kp.Time != infinity {
+		if err = syscall.SetTCPUserTimeout(conn, kp.Timeout); err != nil {
+			return nil, connectionErrorf(false, err, "transport: failed to set TCP_USER_TIMEOUT: %v", err)
+		}
+	}
 	kep := config.KeepalivePolicy
 	if kep.MinTime == 0 {
 		kep.MinTime = defaultKeepalivePolicyMinTime
 	}
+
 	done := make(chan struct{})
 	t := &http2Server{
-		ctx:               context.Background(),
+		ctx:               setConnection(context.Background(), rawConn),
 		done:              done,
 		conn:              conn,
 		remoteAddr:        conn.RemoteAddr(),
 		localAddr:         conn.LocalAddr(),
-		authInfo:          config.AuthInfo,
+		authInfo:          authInfo,
 		framer:            framer,
 		readerDone:        make(chan struct{}),
 		writerDone:        make(chan struct{}),
@@ -230,7 +257,7 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
 		fc:                &trInFlow{limit: uint32(icwz)},
 		state:             reachable,
 		activeStreams:     make(map[uint32]*Stream),
-		stats:             config.StatsHandler,
+		stats:             config.StatsHandlers,
 		kp:                kp,
 		idle:              time.Now(),
 		kep:               kep,
@@ -245,20 +272,20 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
 			updateFlowControl: t.updateFlowControl,
 		}
 	}
-	if t.stats != nil {
-		t.ctx = t.stats.TagConn(t.ctx, &stats.ConnTagInfo{
+	for _, sh := range t.stats {
+		t.ctx = sh.TagConn(t.ctx, &stats.ConnTagInfo{
 			RemoteAddr: t.remoteAddr,
 			LocalAddr:  t.localAddr,
 		})
 		connBegin := &stats.ConnBegin{}
-		t.stats.HandleConn(t.ctx, connBegin)
+		sh.HandleConn(t.ctx, connBegin)
 	}
-	if channelz.IsOn() {
-		t.channelzID = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	t.channelzID, err = channelz.RegisterNormalSocket(t, config.ChannelzParentID, fmt.Sprintf("%s -> %s", t.remoteAddr, t.localAddr))
+	if err != nil {
+		return nil, err
 	}
 
 	t.connectionID = atomic.AddUint64(&serverConnectionCounter, 1)
-
 	t.framer.writer.Flush()
 
 	defer func() {
@@ -270,6 +297,14 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
 	// Check the validity of client preface.
 	preface := make([]byte, len(clientPreface))
 	if _, err := io.ReadFull(t.conn, preface); err != nil {
+		// In deployments where a gRPC server runs behind a cloud load balancer
+		// which performs regular TCP level health checks, the connection is
+		// closed immediately by the latter.  Returning io.EOF here allows the
+		// grpc server implementation to recognize this scenario and suppress
+		// logging to reduce spam.
+		if err == io.EOF {
+			return nil, io.EOF
+		}
 		return nil, connectionErrorf(false, err, "transport: http2Server.HandleStreams failed to receive the preface from client: %v", err)
 	}
 	if !bytes.Equal(preface, clientPreface) {
@@ -294,9 +329,12 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
 		t.loopy = newLoopyWriter(serverSide, t.framer, t.controlBuf, t.bdpEst)
 		t.loopy.ssGoAwayHandler = t.outgoingGoAwayHandler
 		if err := t.loopy.run(); err != nil {
-			errorf("transport: loopyWriter.run returning. Err: %v", err)
+			if logger.V(logLevel) {
+				logger.Errorf("transport: loopyWriter.run returning. Err: %v", err)
+			}
 		}
 		t.conn.Close()
+		t.controlBuf.finish()
 		close(t.writerDone)
 	}()
 	go t.keepalive()
@@ -305,38 +343,145 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
 
 // operateHeader takes action on the decoded headers.
 func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream), traceCtx func(context.Context, string) context.Context) (fatal bool) {
+	// Acquire max stream ID lock for entire duration
+	t.maxStreamMu.Lock()
+	defer t.maxStreamMu.Unlock()
+
 	streamID := frame.Header().StreamID
-	state := &decodeState{
-		serverSide: true,
-	}
-	if err := state.decodeHeader(frame); err != nil {
-		if se, ok := status.FromError(err); ok {
-			t.controlBuf.put(&cleanupStream{
-				streamID: streamID,
-				rst:      true,
-				rstCode:  statusCodeConvTab[se.Code()],
-				onWrite:  func() {},
-			})
-		}
+
+	// frame.Truncated is set to true when framer detects that the current header
+	// list size hits MaxHeaderListSize limit.
+	if frame.Truncated {
+		t.controlBuf.put(&cleanupStream{
+			streamID: streamID,
+			rst:      true,
+			rstCode:  http2.ErrCodeFrameSize,
+			onWrite:  func() {},
+		})
 		return false
 	}
 
+	if streamID%2 != 1 || streamID <= t.maxStreamID {
+		// illegal gRPC stream id.
+		if logger.V(logLevel) {
+			logger.Errorf("transport: http2Server.HandleStreams received an illegal stream id: %v", streamID)
+		}
+		return true
+	}
+	t.maxStreamID = streamID
+
 	buf := newRecvBuffer()
 	s := &Stream{
-		id:             streamID,
-		st:             t,
-		buf:            buf,
-		fc:             &inFlow{limit: uint32(t.initialWindowSize)},
-		recvCompress:   state.data.encoding,
-		method:         state.data.method,
-		contentSubtype: state.data.contentSubtype,
+		id:  streamID,
+		st:  t,
+		buf: buf,
+		fc:  &inFlow{limit: uint32(t.initialWindowSize)},
 	}
+	var (
+		// If a gRPC Response-Headers has already been received, then it means
+		// that the peer is speaking gRPC and we are in gRPC mode.
+		isGRPC     = false
+		mdata      = make(map[string][]string)
+		httpMethod string
+		// headerError is set if an error is encountered while parsing the headers
+		headerError bool
+
+		timeoutSet bool
+		timeout    time.Duration
+	)
+
+	for _, hf := range frame.Fields {
+		switch hf.Name {
+		case "content-type":
+			contentSubtype, validContentType := grpcutil.ContentSubtype(hf.Value)
+			if !validContentType {
+				break
+			}
+			mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
+			s.contentSubtype = contentSubtype
+			isGRPC = true
+		case "grpc-encoding":
+			s.recvCompress = hf.Value
+		case ":method":
+			httpMethod = hf.Value
+		case ":path":
+			s.method = hf.Value
+		case "grpc-timeout":
+			timeoutSet = true
+			var err error
+			if timeout, err = decodeTimeout(hf.Value); err != nil {
+				headerError = true
+			}
+		// "Transports must consider requests containing the Connection header
+		// as malformed." - A41
+		case "connection":
+			if logger.V(logLevel) {
+				logger.Errorf("transport: http2Server.operateHeaders parsed a :connection header which makes a request malformed as per the HTTP/2 spec")
+			}
+			headerError = true
+		default:
+			if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
+				break
+			}
+			v, err := decodeMetadataHeader(hf.Name, hf.Value)
+			if err != nil {
+				headerError = true
+				logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
+				break
+			}
+			mdata[hf.Name] = append(mdata[hf.Name], v)
+		}
+	}
+
+	// "If multiple Host headers or multiple :authority headers are present, the
+	// request must be rejected with an HTTP status code 400 as required by Host
+	// validation in RFC 7230 §5.4, gRPC status code INTERNAL, or RST_STREAM
+	// with HTTP/2 error code PROTOCOL_ERROR." - A41. Since this is a HTTP/2
+	// error, this takes precedence over a client not speaking gRPC.
+	if len(mdata[":authority"]) > 1 || len(mdata["host"]) > 1 {
+		errMsg := fmt.Sprintf("num values of :authority: %v, num values of host: %v, both must only have 1 value as per HTTP/2 spec", len(mdata[":authority"]), len(mdata["host"]))
+		if logger.V(logLevel) {
+			logger.Errorf("transport: %v", errMsg)
+		}
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     400,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         status.New(codes.Internal, errMsg),
+			rst:            !frame.StreamEnded(),
+		})
+		return false
+	}
+
+	if !isGRPC || headerError {
+		t.controlBuf.put(&cleanupStream{
+			streamID: streamID,
+			rst:      true,
+			rstCode:  http2.ErrCodeProtocol,
+			onWrite:  func() {},
+		})
+		return false
+	}
+
+	// "If :authority is missing, Host must be renamed to :authority." - A41
+	if len(mdata[":authority"]) == 0 {
+		// No-op if host isn't present, no eventual :authority header is a valid
+		// RPC.
+		if host, ok := mdata["host"]; ok {
+			mdata[":authority"] = host
+			delete(mdata, "host")
+		}
+	} else {
+		// "If :authority is present, Host must be discarded" - A41
+		delete(mdata, "host")
+	}
+
 	if frame.StreamEnded() {
 		// s is just created by the caller. No lock needed.
 		s.state = streamReadDone
 	}
-	if state.data.timeoutSet {
-		s.ctx, s.cancel = context.WithTimeout(t.ctx, state.data.timeout)
+	if timeoutSet {
+		s.ctx, s.cancel = context.WithTimeout(t.ctx, timeout)
 	} else {
 		s.ctx, s.cancel = context.WithCancel(t.ctx)
 	}
@@ -349,31 +494,13 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 	}
 	s.ctx = peer.NewContext(s.ctx, pr)
 	// Attach the received metadata to the context.
-	if len(state.data.mdata) > 0 {
-		s.ctx = metadata.NewIncomingContext(s.ctx, state.data.mdata)
-	}
-	if state.data.statsTags != nil {
-		s.ctx = stats.SetIncomingTags(s.ctx, state.data.statsTags)
-	}
-	if state.data.statsTrace != nil {
-		s.ctx = stats.SetIncomingTrace(s.ctx, state.data.statsTrace)
-	}
-	if t.inTapHandle != nil {
-		var err error
-		info := &tap.Info{
-			FullMethodName: state.data.method,
+	if len(mdata) > 0 {
+		s.ctx = metadata.NewIncomingContext(s.ctx, mdata)
+		if statsTags := mdata["grpc-tags-bin"]; len(statsTags) > 0 {
+			s.ctx = stats.SetIncomingTags(s.ctx, []byte(statsTags[len(statsTags)-1]))
 		}
-		s.ctx, err = t.inTapHandle(s.ctx, info)
-		if err != nil {
-			warningf("transport: http2Server.operateHeaders got an error from InTapHandle: %v", err)
-			t.controlBuf.put(&cleanupStream{
-				streamID: s.id,
-				rst:      true,
-				rstCode:  http2.ErrCodeRefusedStream,
-				onWrite:  func() {},
-			})
-			s.cancel()
-			return false
+		if statsTrace := mdata["grpc-trace-bin"]; len(statsTrace) > 0 {
+			s.ctx = stats.SetIncomingTrace(s.ctx, []byte(statsTrace[len(statsTrace)-1]))
 		}
 	}
 	t.mu.Lock()
@@ -393,14 +520,43 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 		s.cancel()
 		return false
 	}
-	if streamID%2 != 1 || streamID <= t.maxStreamID {
+	if httpMethod != http.MethodPost {
 		t.mu.Unlock()
-		// illegal gRPC stream id.
-		errorf("transport: http2Server.HandleStreams received an illegal stream id: %v", streamID)
+		errMsg := fmt.Sprintf("http2Server.operateHeaders parsed a :method field: %v which should be POST", httpMethod)
+		if logger.V(logLevel) {
+			logger.Infof("transport: %v", errMsg)
+		}
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     405,
+			streamID:       streamID,
+			contentSubtype: s.contentSubtype,
+			status:         status.New(codes.Internal, errMsg),
+			rst:            !frame.StreamEnded(),
+		})
 		s.cancel()
-		return true
+		return false
+	}
+	if t.inTapHandle != nil {
+		var err error
+		if s.ctx, err = t.inTapHandle(s.ctx, &tap.Info{FullMethodName: s.method}); err != nil {
+			t.mu.Unlock()
+			if logger.V(logLevel) {
+				logger.Infof("transport: http2Server.operateHeaders got an error from InTapHandle: %v", err)
+			}
+			stat, ok := status.FromError(err)
+			if !ok {
+				stat = status.New(codes.PermissionDenied, err.Error())
+			}
+			t.controlBuf.put(&earlyAbortStream{
+				httpStatus:     200,
+				streamID:       s.id,
+				contentSubtype: s.contentSubtype,
+				status:         stat,
+				rst:            !frame.StreamEnded(),
+			})
+			return false
+		}
 	}
-	t.maxStreamID = streamID
 	t.activeStreams[streamID] = s
 	if len(t.activeStreams) == 1 {
 		t.idle = time.Time{}
@@ -414,17 +570,17 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
 		t.adjustWindow(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})
+	for _, sh := range t.stats {
+		s.ctx = sh.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),
-			Header:      metadata.MD(state.data.mdata).Copy(),
+			Header:      metadata.MD(mdata).Copy(),
 		}
-		t.stats.HandleRPC(s.ctx, inHeader)
+		sh.HandleRPC(s.ctx, inHeader)
 	}
 	s.ctxDone = s.ctx.Done()
 	s.wq = newWriteQuota(defaultWriteQuota, s.ctxDone)
@@ -459,7 +615,9 @@ func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.
 		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
-				warningf("transport: http2Server.HandleStreams encountered http2.StreamError: %v", se)
+				if logger.V(logLevel) {
+					logger.Warningf("transport: http2Server.HandleStreams encountered http2.StreamError: %v", se)
+				}
 				t.mu.Lock()
 				s := t.activeStreams[se.StreamID]
 				t.mu.Unlock()
@@ -479,7 +637,9 @@ func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.
 				t.Close()
 				return
 			}
-			warningf("transport: http2Server.HandleStreams failed to read frame: %v", err)
+			if logger.V(logLevel) {
+				logger.Warningf("transport: http2Server.HandleStreams failed to read frame: %v", err)
+			}
 			t.Close()
 			return
 		}
@@ -502,7 +662,9 @@ func (t *http2Server) HandleStreams(handle func(*Stream), traceCtx func(context.
 		case *http2.GoAwayFrame:
 			// TODO: Handle GoAway from the client appropriately.
 		default:
-			errorf("transport: http2Server.HandleStreams found unhandled frame type %v.", frame)
+			if logger.V(logLevel) {
+				logger.Errorf("transport: http2Server.HandleStreams found unhandled frame type %v.", frame)
+			}
 		}
 	}
 }
@@ -604,6 +766,10 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 	if !ok {
 		return
 	}
+	if s.getState() == streamReadDone {
+		t.closeStream(s, true, http2.ErrCodeStreamClosed, false)
+		return
+	}
 	if size > 0 {
 		if err := s.fc.onData(size); err != nil {
 			t.closeStream(s, true, http2.ErrCodeFlowControl, false)
@@ -624,7 +790,7 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 			s.write(recvMsg{buffer: buffer})
 		}
 	}
-	if f.Header().Flags.Has(http2.FlagDataEndStream) {
+	if f.StreamEnded() {
 		// Received the end of stream from the client.
 		s.compareAndSwapState(streamActive, streamReadDone)
 		s.write(recvMsg{err: io.EOF})
@@ -724,7 +890,9 @@ func (t *http2Server) handlePing(f *http2.PingFrame) {
 
 	if t.pingStrikes > maxPingStrikes {
 		// Send goaway and close the connection.
-		errorf("transport: Got too many pings from the client, closing the connection.")
+		if logger.V(logLevel) {
+			logger.Errorf("transport: Got too many pings from the client, closing the connection.")
+		}
 		t.controlBuf.put(&goAway{code: http2.ErrCodeEnhanceYourCalm, debugData: []byte("too_many_pings"), closeConn: true})
 	}
 }
@@ -757,18 +925,34 @@ func (t *http2Server) checkForHeaderListSize(it interface{}) bool {
 	var sz int64
 	for _, f := range hdrFrame.hf {
 		if sz += int64(f.Size()); sz > int64(*t.maxSendHeaderListSize) {
-			errorf("header list size to send violates the maximum size (%d bytes) set by client", *t.maxSendHeaderListSize)
+			if logger.V(logLevel) {
+				logger.Errorf("header list size to send violates the maximum size (%d bytes) set by client", *t.maxSendHeaderListSize)
+			}
 			return false
 		}
 	}
 	return true
 }
 
+func (t *http2Server) streamContextErr(s *Stream) error {
+	select {
+	case <-t.done:
+		return ErrConnClosing
+	default:
+	}
+	return ContextErr(s.ctx.Err())
+}
+
 // WriteHeader sends the header metadata md back to the client.
 func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
-	if s.updateHeaderSent() || s.getState() == streamDone {
+	if s.updateHeaderSent() {
 		return ErrIllegalHeaderWrite
 	}
+
+	if s.getState() == streamDone {
+		return t.streamContextErr(s)
+	}
+
 	s.hdrMu.Lock()
 	if md.Len() > 0 {
 		if s.header.Len() > 0 {
@@ -779,7 +963,7 @@ func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error {
 	}
 	if err := t.writeHeaderLocked(s); err != nil {
 		s.hdrMu.Unlock()
-		return err
+		return status.Convert(err).Err()
 	}
 	s.hdrMu.Unlock()
 	return nil
@@ -794,7 +978,7 @@ func (t *http2Server) writeHeaderLocked(s *Stream) error {
 	// first and create a slice of that exact size.
 	headerFields := make([]hpack.HeaderField, 0, 2) // at least :status, content-type will be there if none else.
 	headerFields = append(headerFields, hpack.HeaderField{Name: ":status", Value: "200"})
-	headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: contentType(s.contentSubtype)})
+	headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: grpcutil.ContentType(s.contentSubtype)})
 	if s.sendCompress != "" {
 		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-encoding", Value: s.sendCompress})
 	}
@@ -812,13 +996,14 @@ func (t *http2Server) writeHeaderLocked(s *Stream) error {
 		t.closeStream(s, true, http2.ErrCodeInternal, false)
 		return ErrHeaderListSizeLimitViolation
 	}
-	if t.stats != nil {
-		// Note: WireLength is not set in outHeader.
-		// TODO(mmukhi): Revisit this later, if needed.
+	for _, sh := range t.stats {
+		// Note: Headers are compressed with hpack after this call returns.
+		// No WireLength field is set here.
 		outHeader := &stats.OutHeader{
-			Header: s.header.Copy(),
+			Header:      s.header.Copy(),
+			Compression: s.sendCompress,
 		}
-		t.stats.HandleRPC(s.Context(), outHeader)
+		sh.HandleRPC(s.Context(), outHeader)
 	}
 	return nil
 }
@@ -843,17 +1028,17 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 			}
 		} else { // Send a trailer only response.
 			headerFields = append(headerFields, hpack.HeaderField{Name: ":status", Value: "200"})
-			headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: contentType(s.contentSubtype)})
+			headerFields = append(headerFields, hpack.HeaderField{Name: "content-type", Value: grpcutil.ContentType(s.contentSubtype)})
 		}
 	}
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status", Value: strconv.Itoa(int(st.Code()))})
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(st.Message())})
 
-	if p := statusRawProto(st); p != nil && len(p.Details) > 0 {
+	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.
-			grpclog.Errorf("transport: failed to marshal rpc status: %v, error: %v", p, err)
+			logger.Errorf("transport: failed to marshal rpc status: %v, error: %v", p, err)
 		} else {
 			headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status-details-bin", Value: encodeBinHeader(stBytes)})
 		}
@@ -879,8 +1064,10 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 	// Send a RST_STREAM after the trailers if the client has not already half-closed.
 	rst := s.getState() == streamActive
 	t.finishStream(s, rst, http2.ErrCodeNo, trailingHeader, true)
-	if t.stats != nil {
-		t.stats.HandleRPC(s.Context(), &stats.OutTrailer{
+	for _, sh := range t.stats {
+		// Note: The trailer fields are compressed with hpack after this call returns.
+		// No WireLength field is set here.
+		sh.HandleRPC(s.Context(), &stats.OutTrailer{
 			Trailer: s.trailer.Copy(),
 		})
 	}
@@ -892,32 +1079,14 @@ func (t *http2Server) WriteStatus(s *Stream, st *status.Status) error {
 func (t *http2Server) Write(s *Stream, hdr []byte, data []byte, opts *Options) error {
 	if !s.isHeaderSent() { // Headers haven't been written yet.
 		if err := t.WriteHeader(s, nil); err != nil {
-			if _, ok := err.(ConnectionError); ok {
-				return err
-			}
-			// TODO(mmukhi, dfawley): Make sure this is the right code to return.
-			return status.Errorf(codes.Internal, "transport: %v", err)
+			return err
 		}
 	} else {
 		// Writing headers checks for this condition.
 		if s.getState() == streamDone {
-			// TODO(mmukhi, dfawley): Should the server write also return io.EOF?
-			s.cancel()
-			select {
-			case <-t.done:
-				return ErrConnClosing
-			default:
-			}
-			return ContextErr(s.ctx.Err())
+			return t.streamContextErr(s)
 		}
 	}
-	// Add some data to header frame so that we can equally distribute bytes across frames.
-	emptyLen := http2MaxFrameLen - len(hdr)
-	if emptyLen > len(data) {
-		emptyLen = len(data)
-	}
-	hdr = append(hdr, data[:emptyLen]...)
-	data = data[emptyLen:]
 	df := &dataFrame{
 		streamID:    s.id,
 		h:           hdr,
@@ -925,12 +1094,7 @@ func (t *http2Server) Write(s *Stream, hdr []byte, data []byte, opts *Options) e
 		onEachWrite: t.setResetPingStrikes,
 	}
 	if err := s.wq.get(int32(len(hdr) + len(data))); err != nil {
-		select {
-		case <-t.done:
-			return ErrConnClosing
-		default:
-		}
-		return ContextErr(s.ctx.Err())
+		return t.streamContextErr(s)
 	}
 	return t.controlBuf.put(df)
 }
@@ -979,17 +1143,19 @@ func (t *http2Server) keepalive() {
 			if val <= 0 {
 				// The connection has been idle for a duration of keepalive.MaxConnectionIdle or more.
 				// Gracefully close the connection.
-				t.drain(http2.ErrCodeNo, []byte{})
+				t.Drain()
 				return
 			}
 			idleTimer.Reset(val)
 		case <-ageTimer.C:
-			t.drain(http2.ErrCodeNo, []byte{})
+			t.Drain()
 			ageTimer.Reset(t.kp.MaxConnectionAgeGrace)
 			select {
 			case <-ageTimer.C:
 				// Close the connection after grace period.
-				infof("transport: closing server transport due to maximum connection age.")
+				if logger.V(logLevel) {
+					logger.Infof("transport: closing server transport due to maximum connection age.")
+				}
 				t.Close()
 			case <-t.done:
 			}
@@ -1006,7 +1172,9 @@ func (t *http2Server) keepalive() {
 				continue
 			}
 			if outstandingPing && kpTimeoutLeft <= 0 {
-				infof("transport: closing server transport due to idleness.")
+				if logger.V(logLevel) {
+					logger.Infof("transport: closing server transport due to idleness.")
+				}
 				t.Close()
 				return
 			}
@@ -1034,11 +1202,11 @@ func (t *http2Server) keepalive() {
 // Close starts shutting down the http2Server transport.
 // TODO(zhaoq): Now the destruction is not blocked on any pending streams. This
 // could cause some resource issue. Revisit this later.
-func (t *http2Server) Close() error {
+func (t *http2Server) Close() {
 	t.mu.Lock()
 	if t.state == closing {
 		t.mu.Unlock()
-		return errors.New("transport: Close() was already called")
+		return
 	}
 	t.state = closing
 	streams := t.activeStreams
@@ -1046,27 +1214,22 @@ func (t *http2Server) Close() error {
 	t.mu.Unlock()
 	t.controlBuf.finish()
 	close(t.done)
-	err := t.conn.Close()
-	if channelz.IsOn() {
-		channelz.RemoveEntry(t.channelzID)
+	if err := t.conn.Close(); err != nil && logger.V(logLevel) {
+		logger.Infof("transport: error closing conn during Close: %v", err)
 	}
+	channelz.RemoveEntry(t.channelzID)
 	// Cancel all active streams.
 	for _, s := range streams {
 		s.cancel()
 	}
-	if t.stats != nil {
+	for _, sh := range t.stats {
 		connEnd := &stats.ConnEnd{}
-		t.stats.HandleConn(t.ctx, connEnd)
+		sh.HandleConn(t.ctx, connEnd)
 	}
-	return err
 }
 
 // deleteStream deletes the stream s from transport's active streams.
 func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
-	// In case stream sending and receiving are invoked in separate
-	// goroutines (e.g., bi-directional streaming), cancel needs to be
-	// called to interrupt the potential blocking on other goroutines.
-	s.cancel()
 
 	t.mu.Lock()
 	if _, ok := t.activeStreams[s.id]; ok {
@@ -1088,6 +1251,11 @@ func (t *http2Server) deleteStream(s *Stream, eosReceived bool) {
 
 // finishStream closes the stream and puts the trailing headerFrame into controlbuf.
 func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, hdr *headerFrame, eosReceived bool) {
+	// In case stream sending and receiving are invoked in separate
+	// goroutines (e.g., bi-directional streaming), cancel needs to be
+	// called to interrupt the potential blocking on other goroutines.
+	s.cancel()
+
 	oldState := s.swapState(streamDone)
 	if oldState == streamDone {
 		// If the stream was already done, return.
@@ -1107,6 +1275,11 @@ func (t *http2Server) finishStream(s *Stream, rst bool, rstCode http2.ErrCode, h
 
 // closeStream clears the footprint of a stream when the stream is not needed any more.
 func (t *http2Server) closeStream(s *Stream, rst bool, rstCode http2.ErrCode, eosReceived bool) {
+	// In case stream sending and receiving are invoked in separate
+	// goroutines (e.g., bi-directional streaming), cancel needs to be
+	// called to interrupt the potential blocking on other goroutines.
+	s.cancel()
+
 	s.swapState(streamDone)
 	t.deleteStream(s, eosReceived)
 
@@ -1123,17 +1296,13 @@ func (t *http2Server) RemoteAddr() net.Addr {
 }
 
 func (t *http2Server) Drain() {
-	t.drain(http2.ErrCodeNo, []byte{})
-}
-
-func (t *http2Server) drain(code http2.ErrCode, debugData []byte) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 	if t.drainChan != nil {
 		return
 	}
 	t.drainChan = make(chan struct{})
-	t.controlBuf.put(&goAway{code: code, debugData: debugData, headsUp: true})
+	t.controlBuf.put(&goAway{code: http2.ErrCodeNo, debugData: []byte{}, headsUp: true})
 }
 
 var goAwayPing = &ping{data: [8]byte{1, 6, 1, 8, 0, 3, 3, 9}}
@@ -1141,20 +1310,23 @@ var goAwayPing = &ping{data: [8]byte{1, 6, 1, 8, 0, 3, 3, 9}}
 // Handles outgoing GoAway and returns true if loopy needs to put itself
 // in draining mode.
 func (t *http2Server) outgoingGoAwayHandler(g *goAway) (bool, error) {
+	t.maxStreamMu.Lock()
 	t.mu.Lock()
 	if t.state == closing { // TODO(mmukhi): This seems unnecessary.
 		t.mu.Unlock()
+		t.maxStreamMu.Unlock()
 		// The transport is closing.
 		return false, ErrConnClosing
 	}
-	sid := t.maxStreamID
 	if !g.headsUp {
 		// Stop accepting more streams now.
 		t.state = draining
+		sid := t.maxStreamID
 		if len(t.activeStreams) == 0 {
 			g.closeConn = true
 		}
 		t.mu.Unlock()
+		t.maxStreamMu.Unlock()
 		if err := t.framer.fr.WriteGoAway(sid, g.code, g.debugData); err != nil {
 			return false, err
 		}
@@ -1167,6 +1339,7 @@ func (t *http2Server) outgoingGoAwayHandler(g *goAway) (bool, error) {
 		return true, nil
 	}
 	t.mu.Unlock()
+	t.maxStreamMu.Unlock()
 	// For a graceful close, send out a GoAway with stream ID of MaxUInt32,
 	// Follow that with a ping and wait for the ack to come back or a timer
 	// to expire. During this time accept new streams since they might have
@@ -1251,3 +1424,18 @@ func getJitter(v time.Duration) time.Duration {
 	j := grpcrand.Int63n(2*r) - r
 	return time.Duration(j)
 }
+
+type connectionKey struct{}
+
+// GetConnection gets the connection from the context.
+func GetConnection(ctx context.Context) net.Conn {
+	conn, _ := ctx.Value(connectionKey{}).(net.Conn)
+	return conn
+}
+
+// SetConnection adds the connection to the context to be able to get
+// information about the destination ip and port for an incoming RPC. This also
+// allows any unary or streaming interceptors to see the connection.
+func setConnection(ctx context.Context, conn net.Conn) context.Context {
+	return context.WithValue(ctx, connectionKey{}, conn)
+}

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

@@ -27,6 +27,7 @@ import (
 	"math"
 	"net"
 	"net/http"
+	"net/url"
 	"strconv"
 	"strings"
 	"time"
@@ -37,6 +38,7 @@ import (
 	"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/status"
 )
 
@@ -50,7 +52,7 @@ const (
 	// "proto" as a suffix after "+" or ";".  See
 	// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
 	// for more details.
-	baseContentType = "application/grpc"
+
 )
 
 var (
@@ -71,13 +73,6 @@ var (
 		http2.ErrCodeInadequateSecurity: codes.PermissionDenied,
 		http2.ErrCodeHTTP11Required:     codes.Internal,
 	}
-	statusCodeConvTab = map[codes.Code]http2.ErrCode{
-		codes.Internal:          http2.ErrCodeInternal,
-		codes.Canceled:          http2.ErrCodeCancel,
-		codes.Unavailable:       http2.ErrCodeRefusedStream,
-		codes.ResourceExhausted: http2.ErrCodeEnhanceYourCalm,
-		codes.PermissionDenied:  http2.ErrCodeInadequateSecurity,
-	}
 	// HTTPStatusConvTab is the HTTP status code to gRPC error code conversion table.
 	HTTPStatusConvTab = map[int]codes.Code{
 		// 400 Bad Request - INTERNAL.
@@ -97,54 +92,9 @@ var (
 		// 504 Gateway timeout - UNAVAILABLE.
 		http.StatusGatewayTimeout: codes.Unavailable,
 	}
+	logger = grpclog.Component("transport")
 )
 
-type parsedHeaderData struct {
-	encoding 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 *int
-	rawStatusMsg  string
-	httpStatus    *int
-	// Server side only fields.
-	timeoutSet bool
-	timeout    time.Duration
-	method     string
-	// key-value metadata map from the peer.
-	mdata          map[string][]string
-	statsTags      []byte
-	statsTrace     []byte
-	contentSubtype string
-
-	// isGRPC field indicates whether the peer is speaking gRPC (otherwise HTTP).
-	//
-	// We are in gRPC mode (peer speaking gRPC) if:
-	// 	* We are client side and have already received a HEADER frame that indicates gRPC peer.
-	//  * The header contains valid  a content-type, i.e. a string starts with "application/grpc"
-	// And we should handle error specific to gRPC.
-	//
-	// Otherwise (i.e. a content-type string starts without "application/grpc", or does not exist), we
-	// are in HTTP fallback mode, and should handle error specific to HTTP.
-	isGRPC         bool
-	grpcErr        error
-	httpErr        error
-	contentTypeErr string
-}
-
-// decodeState configures decoding criteria and records the decoded data.
-type decodeState struct {
-	// whether decoding on server side or not
-	serverSide bool
-
-	// Records the states during HPACK decoding. It will be filled with info parsed from HTTP HEADERS
-	// frame once decodeHeader function has been invoked and returned.
-	data parsedHeaderData
-}
-
 // isReservedHeader checks whether hdr belongs to HTTP2 headers
 // reserved by gRPC protocol. Any other headers are classified as the
 // user-specified metadata.
@@ -182,54 +132,6 @@ func isWhitelistedHeader(hdr string) bool {
 	}
 }
 
-// contentSubtype returns the content-subtype for the given content-type.  The
-// given content-type must be a valid content-type that starts with
-// "application/grpc". A content-subtype will follow "application/grpc" after a
-// "+" or ";". See
-// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
-// more details.
-//
-// If contentType is not a valid content-type for gRPC, the boolean
-// will be false, otherwise true. If content-type == "application/grpc",
-// "application/grpc+", or "application/grpc;", the boolean will be true,
-// but no content-subtype will be returned.
-//
-// contentType is assumed to be lowercase already.
-func contentSubtype(contentType string) (string, bool) {
-	if contentType == baseContentType {
-		return "", true
-	}
-	if !strings.HasPrefix(contentType, baseContentType) {
-		return "", false
-	}
-	// guaranteed since != baseContentType and has baseContentType prefix
-	switch contentType[len(baseContentType)] {
-	case '+', ';':
-		// this will return true for "application/grpc+" or "application/grpc;"
-		// which the previous validContentType function tested to be valid, so we
-		// just say that no content-subtype is specified in this case
-		return contentType[len(baseContentType)+1:], true
-	default:
-		return "", false
-	}
-}
-
-// contentSubtype is assumed to be lowercase
-func contentType(contentSubtype string) string {
-	if contentSubtype == "" {
-		return baseContentType
-	}
-	return baseContentType + "+" + contentSubtype
-}
-
-func (d *decodeState) status() *status.Status {
-	if d.data.statusGen == nil {
-		// No status-details were provided; generate status using code/msg.
-		d.data.statusGen = status.New(codes.Code(int32(*(d.data.rawStatusCode))), d.data.rawStatusMsg)
-	}
-	return d.data.statusGen
-}
-
 const binHdrSuffix = "-bin"
 
 func encodeBinHeader(v []byte) string {
@@ -259,164 +161,16 @@ func decodeMetadataHeader(k, v string) (string, error) {
 	return v, nil
 }
 
-func (d *decodeState) decodeHeader(frame *http2.MetaHeadersFrame) error {
-	// frame.Truncated is set to true when framer detects that the current header
-	// list size hits MaxHeaderListSize limit.
-	if frame.Truncated {
-		return status.Error(codes.Internal, "peer header list size exceeded limit")
+func decodeGRPCStatusDetails(rawDetails string) (*status.Status, error) {
+	v, err := decodeBinHeader(rawDetails)
+	if err != nil {
+		return nil, err
 	}
-
-	for _, hf := range frame.Fields {
-		d.processHeaderField(hf)
-	}
-
-	if d.data.isGRPC {
-		if d.data.grpcErr != nil {
-			return d.data.grpcErr
-		}
-		if d.serverSide {
-			return nil
-		}
-		if d.data.rawStatusCode == nil && d.data.statusGen == nil {
-			// gRPC status doesn't exist.
-			// Set rawStatusCode to be unknown and return nil error.
-			// So that, if the stream has ended this Unknown status
-			// will be propagated to the user.
-			// Otherwise, it will be ignored. In which case, status from
-			// a later trailer, that has StreamEnded flag set, is propagated.
-			code := int(codes.Unknown)
-			d.data.rawStatusCode = &code
-		}
-		return nil
-	}
-
-	// HTTP fallback mode
-	if d.data.httpErr != nil {
-		return d.data.httpErr
-	}
-
-	var (
-		code = codes.Internal // when header does not include HTTP status, return INTERNAL
-		ok   bool
-	)
-
-	if d.data.httpStatus != nil {
-		code, ok = HTTPStatusConvTab[*(d.data.httpStatus)]
-		if !ok {
-			code = codes.Unknown
-		}
-	}
-
-	return status.Error(code, d.constructHTTPErrMsg())
-}
-
-// constructErrMsg constructs error message to be returned in HTTP fallback mode.
-// Format: HTTP status code and its corresponding message + content-type error message.
-func (d *decodeState) constructHTTPErrMsg() string {
-	var errMsgs []string
-
-	if d.data.httpStatus == nil {
-		errMsgs = append(errMsgs, "malformed header: missing HTTP status")
-	} else {
-		errMsgs = append(errMsgs, fmt.Sprintf("%s: HTTP status code %d", http.StatusText(*(d.data.httpStatus)), *d.data.httpStatus))
-	}
-
-	if d.data.contentTypeErr == "" {
-		errMsgs = append(errMsgs, "transport: missing content-type field")
-	} else {
-		errMsgs = append(errMsgs, d.data.contentTypeErr)
-	}
-
-	return strings.Join(errMsgs, "; ")
-}
-
-func (d *decodeState) addMetadata(k, v string) {
-	if d.data.mdata == nil {
-		d.data.mdata = make(map[string][]string)
-	}
-	d.data.mdata[k] = append(d.data.mdata[k], v)
-}
-
-func (d *decodeState) processHeaderField(f hpack.HeaderField) {
-	switch f.Name {
-	case "content-type":
-		contentSubtype, validContentType := contentSubtype(f.Value)
-		if !validContentType {
-			d.data.contentTypeErr = fmt.Sprintf("transport: received the unexpected content-type %q", f.Value)
-			return
-		}
-		d.data.contentSubtype = contentSubtype
-		// TODO: do we want to propagate the whole content-type in the metadata,
-		// or come up with a way to just propagate the content-subtype if it was set?
-		// ie {"content-type": "application/grpc+proto"} or {"content-subtype": "proto"}
-		// in the metadata?
-		d.addMetadata(f.Name, f.Value)
-		d.data.isGRPC = true
-	case "grpc-encoding":
-		d.data.encoding = f.Value
-	case "grpc-status":
-		code, err := strconv.Atoi(f.Value)
-		if err != nil {
-			d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status: %v", err)
-			return
-		}
-		d.data.rawStatusCode = &code
-	case "grpc-message":
-		d.data.rawStatusMsg = decodeGrpcMessage(f.Value)
-	case "grpc-status-details-bin":
-		v, err := decodeBinHeader(f.Value)
-		if err != nil {
-			d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
-			return
-		}
-		s := &spb.Status{}
-		if err := proto.Unmarshal(v, s); err != nil {
-			d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
-			return
-		}
-		d.data.statusGen = status.FromProto(s)
-	case "grpc-timeout":
-		d.data.timeoutSet = true
-		var err error
-		if d.data.timeout, err = decodeTimeout(f.Value); err != nil {
-			d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed time-out: %v", err)
-		}
-	case ":path":
-		d.data.method = f.Value
-	case ":status":
-		code, err := strconv.Atoi(f.Value)
-		if err != nil {
-			d.data.httpErr = status.Errorf(codes.Internal, "transport: malformed http-status: %v", err)
-			return
-		}
-		d.data.httpStatus = &code
-	case "grpc-tags-bin":
-		v, err := decodeBinHeader(f.Value)
-		if err != nil {
-			d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-tags-bin: %v", err)
-			return
-		}
-		d.data.statsTags = v
-		d.addMetadata(f.Name, string(v))
-	case "grpc-trace-bin":
-		v, err := decodeBinHeader(f.Value)
-		if err != nil {
-			d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-trace-bin: %v", err)
-			return
-		}
-		d.data.statsTrace = v
-		d.addMetadata(f.Name, string(v))
-	default:
-		if isReservedHeader(f.Name) && !isWhitelistedHeader(f.Name) {
-			break
-		}
-		v, err := decodeMetadataHeader(f.Name, f.Value)
-		if err != nil {
-			errorf("Failed to decode metadata header (%q, %q): %v", f.Name, f.Value, err)
-			return
-		}
-		d.addMetadata(f.Name, v)
+	st := &spb.Status{}
+	if err = proto.Unmarshal(v, st); err != nil {
+		return nil, err
 	}
+	return status.FromProto(st), nil
 }
 
 type timeoutUnit uint8
@@ -449,41 +203,6 @@ func timeoutUnitToDuration(u timeoutUnit) (d time.Duration, ok bool) {
 	return
 }
 
-const maxTimeoutValue int64 = 100000000 - 1
-
-// div does integer division and round-up the result. Note that this is
-// equivalent to (d+r-1)/r but has less chance to overflow.
-func div(d, r time.Duration) int64 {
-	if m := d % r; m > 0 {
-		return int64(d/r + 1)
-	}
-	return int64(d / r)
-}
-
-// TODO(zhaoq): It is the simplistic and not bandwidth efficient. Improve it.
-func encodeTimeout(t time.Duration) string {
-	if t <= 0 {
-		return "0n"
-	}
-	if d := div(t, time.Nanosecond); d <= maxTimeoutValue {
-		return strconv.FormatInt(d, 10) + "n"
-	}
-	if d := div(t, time.Microsecond); d <= maxTimeoutValue {
-		return strconv.FormatInt(d, 10) + "u"
-	}
-	if d := div(t, time.Millisecond); d <= maxTimeoutValue {
-		return strconv.FormatInt(d, 10) + "m"
-	}
-	if d := div(t, time.Second); d <= maxTimeoutValue {
-		return strconv.FormatInt(d, 10) + "S"
-	}
-	if d := div(t, time.Minute); d <= maxTimeoutValue {
-		return strconv.FormatInt(d, 10) + "M"
-	}
-	// Note that maxTimeoutValue * time.Hour > MaxInt64.
-	return strconv.FormatInt(div(t, time.Hour), 10) + "H"
-}
-
 func decodeTimeout(s string) (time.Duration, error) {
 	size := len(s)
 	if size < 2 {
@@ -603,8 +322,6 @@ type bufWriter struct {
 	batchSize int
 	conn      net.Conn
 	err       error
-
-	onFlush func()
 }
 
 func newBufWriter(conn net.Conn, batchSize int) *bufWriter {
@@ -641,9 +358,6 @@ func (w *bufWriter) Flush() error {
 	if w.offset == 0 {
 		return nil
 	}
-	if w.onFlush != nil {
-		w.onFlush()
-	}
 	_, w.err = w.conn.Write(w.buf[:w.offset])
 	w.offset = 0
 	return w.err
@@ -675,3 +389,31 @@ func newFramer(conn net.Conn, writeBufferSize, readBufferSize int, maxHeaderList
 	f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
 	return f
 }
+
+// parseDialTarget returns the network and address to pass to dialer.
+func parseDialTarget(target string) (string, string) {
+	net := "tcp"
+	m1 := strings.Index(target, ":")
+	m2 := strings.Index(target, ":/")
+	// handle unix:addr which will fail with url.Parse
+	if m1 >= 0 && m2 < 0 {
+		if n := target[0:m1]; n == "unix" {
+			return n, target[m1+1:]
+		}
+	}
+	if m2 >= 0 {
+		t, err := url.Parse(target)
+		if err != nil {
+			return net, target
+		}
+		scheme := t.Scheme
+		addr := t.Path
+		if scheme == "unix" {
+			if addr == "" {
+				addr = t.Host
+			}
+			return scheme, addr
+		}
+	}
+	return net, target
+}

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

@@ -1,44 +0,0 @@
-/*
- *
- * Copyright 2017 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-// This file contains wrappers for grpclog functions.
-// The transport package only logs to verbose level 2 by default.
-
-package transport
-
-import "google.golang.org/grpc/grpclog"
-
-const logLevel = 2
-
-func infof(format string, args ...interface{}) {
-	if grpclog.V(logLevel) {
-		grpclog.Infof(format, args...)
-	}
-}
-
-func warningf(format string, args ...interface{}) {
-	if grpclog.V(logLevel) {
-		grpclog.Warningf(format, args...)
-	}
-}
-
-func errorf(format string, args ...interface{}) {
-	if grpclog.V(logLevel) {
-		grpclog.Errorf(format, args...)
-	}
-}

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

@@ -0,0 +1,46 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package networktype declares the network type to be used in the default
+// dialer. Attribute of a resolver.Address.
+package networktype
+
+import (
+	"google.golang.org/grpc/resolver"
+)
+
+// keyType is the key to use for storing State in Attributes.
+type keyType string
+
+const key = keyType("grpc.internal.transport.networktype")
+
+// Set returns a copy of the provided address with attributes containing networkType.
+func Set(address resolver.Address, networkType string) resolver.Address {
+	address.Attributes = address.Attributes.WithValue(key, networkType)
+	return address
+}
+
+// Get returns the network type in the resolver.Address and true, or "", false
+// if not present.
+func Get(address resolver.Address) (string, bool) {
+	v := address.Attributes.Value(key)
+	if v == nil {
+		return "", false
+	}
+	return v.(string), true
+}

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

@@ -0,0 +1,142 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"bufio"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+)
+
+const proxyAuthHeaderKey = "Proxy-Authorization"
+
+var (
+	// The following variable will be overwritten in the tests.
+	httpProxyFromEnvironment = http.ProxyFromEnvironment
+)
+
+func mapAddress(address string) (*url.URL, error) {
+	req := &http.Request{
+		URL: &url.URL{
+			Scheme: "https",
+			Host:   address,
+		},
+	}
+	url, err := httpProxyFromEnvironment(req)
+	if err != nil {
+		return nil, err
+	}
+	return url, nil
+}
+
+// To read a response from a net.Conn, http.ReadResponse() takes a bufio.Reader.
+// It's possible that this reader reads more than what's need for the response and stores
+// those bytes in the buffer.
+// bufConn wraps the original net.Conn and the bufio.Reader to make sure we don't lose the
+// bytes in the buffer.
+type bufConn struct {
+	net.Conn
+	r io.Reader
+}
+
+func (c *bufConn) Read(b []byte) (int, error) {
+	return c.r.Read(b)
+}
+
+func basicAuth(username, password string) string {
+	auth := username + ":" + password
+	return base64.StdEncoding.EncodeToString([]byte(auth))
+}
+
+func doHTTPConnectHandshake(ctx context.Context, conn net.Conn, backendAddr string, proxyURL *url.URL, grpcUA string) (_ net.Conn, err error) {
+	defer func() {
+		if err != nil {
+			conn.Close()
+		}
+	}()
+
+	req := &http.Request{
+		Method: http.MethodConnect,
+		URL:    &url.URL{Host: backendAddr},
+		Header: map[string][]string{"User-Agent": {grpcUA}},
+	}
+	if t := proxyURL.User; t != nil {
+		u := t.Username()
+		p, _ := t.Password()
+		req.Header.Add(proxyAuthHeaderKey, "Basic "+basicAuth(u, p))
+	}
+
+	if err := sendHTTPRequest(ctx, req, conn); err != nil {
+		return nil, fmt.Errorf("failed to write the HTTP request: %v", err)
+	}
+
+	r := bufio.NewReader(conn)
+	resp, err := http.ReadResponse(r, req)
+	if err != nil {
+		return nil, fmt.Errorf("reading server HTTP response: %v", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		dump, err := httputil.DumpResponse(resp, true)
+		if err != nil {
+			return nil, fmt.Errorf("failed to do connect handshake, status code: %s", resp.Status)
+		}
+		return nil, fmt.Errorf("failed to do connect handshake, response: %q", dump)
+	}
+
+	return &bufConn{Conn: conn, r: r}, nil
+}
+
+// proxyDial dials, connecting to a proxy first if necessary. Checks if a proxy
+// is necessary, dials, does the HTTP CONNECT handshake, and returns the
+// connection.
+func proxyDial(ctx context.Context, addr string, grpcUA string) (conn net.Conn, err error) {
+	newAddr := addr
+	proxyURL, err := mapAddress(addr)
+	if err != nil {
+		return nil, err
+	}
+	if proxyURL != nil {
+		newAddr = proxyURL.Host
+	}
+
+	conn, err = (&net.Dialer{}).DialContext(ctx, "tcp", newAddr)
+	if err != nil {
+		return
+	}
+	if proxyURL != nil {
+		// proxy is disabled if proxyURL is nil.
+		conn, err = doHTTPConnectHandshake(ctx, conn, addr, proxyURL, grpcUA)
+	}
+	return
+}
+
+func sendHTTPRequest(ctx context.Context, req *http.Request, conn net.Conn) error {
+	req = req.WithContext(ctx)
+	if err := req.Write(conn); err != nil {
+		return fmt.Errorf("failed to write the HTTP request: %v", err)
+	}
+	return nil
+}

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

@@ -30,16 +30,21 @@ import (
 	"net"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/internal/channelz"
 	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/resolver"
 	"google.golang.org/grpc/stats"
 	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/tap"
 )
 
+const logLevel = 2
+
 type bufferPool struct {
 	pool sync.Pool
 }
@@ -238,6 +243,7 @@ type Stream struct {
 	ctx          context.Context    // the associated context of the stream
 	cancel       context.CancelFunc // always nil for client side Stream
 	done         chan struct{}      // closed at the end of stream to unblock writers. On the client side.
+	doneFunc     func()             // invoked at the end of stream on client side.
 	ctxDone      <-chan struct{}    // same as done chan but for server side. Cache of ctx.Done() (for performance)
 	method       string             // the associated RPC method of the stream
 	recvCompress string
@@ -514,26 +520,21 @@ const (
 // ServerConfig consists of all the configurations to establish a server transport.
 type ServerConfig struct {
 	MaxStreams            uint32
-	AuthInfo              credentials.AuthInfo
+	ConnectionTimeout     time.Duration
+	Credentials           credentials.TransportCredentials
 	InTapHandle           tap.ServerInHandle
-	StatsHandler          stats.Handler
+	StatsHandlers         []stats.Handler
 	KeepaliveParams       keepalive.ServerParameters
 	KeepalivePolicy       keepalive.EnforcementPolicy
 	InitialWindowSize     int32
 	InitialConnWindowSize int32
 	WriteBufferSize       int
 	ReadBufferSize        int
-	ChannelzParentID      int64
+	ChannelzParentID      *channelz.Identifier
 	MaxHeaderListSize     *uint32
 	HeaderTableSize       *uint32
 }
 
-// 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.
@@ -552,8 +553,8 @@ type ConnectOptions struct {
 	CredsBundle credentials.Bundle
 	// KeepaliveParams stores the keepalive parameters.
 	KeepaliveParams keepalive.ClientParameters
-	// StatsHandler stores the handler for stats.
-	StatsHandler stats.Handler
+	// StatsHandlers stores the handler for stats.
+	StatsHandlers []stats.Handler
 	// InitialWindowSize sets the initial window size for a stream.
 	InitialWindowSize int32
 	// InitialConnWindowSize sets the initial window size for a connection.
@@ -563,22 +564,17 @@ type ConnectOptions struct {
 	// ReadBufferSize sets the size of read buffer, which in turn determines how much data can be read at most for one read syscall.
 	ReadBufferSize int
 	// ChannelzParentID sets the addrConn id which initiate the creation of this client transport.
-	ChannelzParentID int64
+	ChannelzParentID *channelz.Identifier
 	// MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
 	MaxHeaderListSize *uint32
-}
-
-// TargetInfo contains the information of the target such as network address and metadata.
-type TargetInfo struct {
-	Addr      string
-	Metadata  interface{}
-	Authority string
+	// UseProxy specifies if a proxy should be used.
+	UseProxy bool
 }
 
 // NewClientTransport establishes the transport with the required ConnectOptions
 // and returns it to the caller.
-func NewClientTransport(connectCtx, ctx context.Context, target TargetInfo, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
-	return newHTTP2Client(connectCtx, ctx, target, opts, onPrefaceReceipt, onGoAway, onClose)
+func NewClientTransport(connectCtx, ctx context.Context, addr resolver.Address, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
+	return newHTTP2Client(connectCtx, ctx, addr, opts, onPrefaceReceipt, onGoAway, onClose)
 }
 
 // Options provides additional hints and information for message
@@ -613,6 +609,8 @@ type CallHdr struct {
 	ContentSubtype string
 
 	PreviousAttempts int // value of grpc-previous-rpc-attempts header to set
+
+	DoneFunc func() // called when the stream is finished
 }
 
 // ClientTransport is the common interface for all gRPC client-side transport
@@ -621,7 +619,7 @@ type ClientTransport interface {
 	// Close tears down this transport. Once it returns, the transport
 	// should not be accessed any more. The caller must make sure this
 	// is called only once.
-	Close() error
+	Close(err error)
 
 	// GracefulClose starts to tear down the transport: the transport will stop
 	// accepting new RPCs and NewStream will return error. Once all streams are
@@ -655,8 +653,9 @@ type ClientTransport interface {
 	// HTTP/2).
 	GoAway() <-chan struct{}
 
-	// GetGoAwayReason returns the reason why GoAway frame was received.
-	GetGoAwayReason() GoAwayReason
+	// GetGoAwayReason returns the reason why GoAway frame was received, along
+	// with a human readable string with debug info.
+	GetGoAwayReason() (GoAwayReason, string)
 
 	// RemoteAddr returns the remote network address.
 	RemoteAddr() net.Addr
@@ -692,7 +691,7 @@ type ServerTransport interface {
 	// Close tears down the transport. Once it is called, the transport
 	// should not be accessed any more. All the pending streams and their
 	// handlers will be terminated asynchronously.
-	Close() error
+	Close()
 
 	// RemoteAddr returns the remote network address.
 	RemoteAddr() net.Addr
@@ -743,6 +742,12 @@ func (e ConnectionError) Origin() error {
 	return e.err
 }
 
+// Unwrap returns the original error of this connection error or nil when the
+// origin is nil.
+func (e ConnectionError) Unwrap() error {
+	return e.err
+}
+
 var (
 	// ErrConnClosing indicates that the transport is closing.
 	ErrConnClosing = connectionErrorf(true, nil, "transport is closing")