update vendor

cmd/gost/vendor/github.com/ginuerzh/gost/chain.go

 package gost
 
 import (
+	"crypto/rand"
 	"crypto/tls"
 	"encoding/base64"
 	"errors"
 	"github.com/golang/glog"
 	"golang.org/x/net/http2"
 	"io"
-	//"io/ioutil"
 	"net"
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"strconv"
 	"strings"
 	"sync"
+	"time"
 )
 
 // Proxy chain holds a list of proxy nodes
@@ -134,7 +136,15 @@ func (c *ProxyChain) initHttp2Client(config *tls.Config, nodes ...ProxyNode) {
 			if err != nil {
 				return conn, err
 			}
-			return tls.Client(conn, cfg), nil
+			conn = tls.Client(conn, cfg)
+
+			// enable HTTP2 ping-pong
+			pingIntvl, _ := strconv.Atoi(http2Node.Get("ping"))
+			if pingIntvl > 0 {
+				enablePing(conn, time.Duration(pingIntvl)*time.Second)
+			}
+
+			return conn, nil
 		},
 	}
 	c.http2Client = &http.Client{Transport: &tr}
@@ -142,6 +152,37 @@ func (c *ProxyChain) initHttp2Client(config *tls.Config, nodes ...ProxyNode) {
 
 }
 
+func enablePing(conn net.Conn, interval time.Duration) {
+	if conn == nil || interval == 0 {
+		return
+	}
+
+	glog.V(LINFO).Infoln("[http2] ping enabled, interval:", interval)
+	go func() {
+		t := time.NewTicker(interval)
+		var framer *http2.Framer
+		for {
+			select {
+			case <-t.C:
+				if framer == nil {
+					framer = http2.NewFramer(conn, conn)
+				}
+
+				var p [8]byte
+				rand.Read(p[:])
+				err := framer.WritePing(false, p)
+				if err != nil {
+					t.Stop()
+					framer = nil
+					glog.V(LWARNING).Infoln("[http2] ping:", err)
+					return
+				}
+				glog.V(LINFO).Infoln("[http2] ping OK")
+			}
+		}
+	}()
+}
+
 // Connect to addr through proxy chain
 func (c *ProxyChain) Dial(addr string) (net.Conn, error) {
 	if !strings.Contains(addr, ":") {

cmd/gost/vendor/github.com/ginuerzh/gost/gost.go

@@ -11,7 +11,7 @@ import (
 )
 
 const (
-	Version = "2.3-rc1"
+	Version = "2.3-rc2"
 )
 
 // Log level for glog

cmd/gost/vendor/golang.org/x/net/http2/frame.go

@@ -317,10 +317,12 @@ type Framer struct {
 	// non-Continuation or Continuation on a different stream is
 	// attempted to be written.
 
-	logReads bool
+	logReads, logWrites bool
 
-	debugFramer    *Framer // only use for logging written writes
-	debugFramerBuf *bytes.Buffer
+	debugFramer       *Framer // only use for logging written writes
+	debugFramerBuf    *bytes.Buffer
+	debugReadLoggerf  func(string, ...interface{})
+	debugWriteLoggerf func(string, ...interface{})
 }
 
 func (fr *Framer) maxHeaderListSize() uint32 {
@@ -355,7 +357,7 @@ func (f *Framer) endWrite() error {
 		byte(length>>16),
 		byte(length>>8),
 		byte(length))
-	if logFrameWrites {
+	if f.logWrites {
 		f.logWrite()
 	}
 
@@ -378,10 +380,10 @@ func (f *Framer) logWrite() {
 	f.debugFramerBuf.Write(f.wbuf)
 	fr, err := f.debugFramer.ReadFrame()
 	if err != nil {
-		log.Printf("http2: Framer %p: failed to decode just-written frame", f)
+		f.debugWriteLoggerf("http2: Framer %p: failed to decode just-written frame", f)
 		return
 	}
-	log.Printf("http2: Framer %p: wrote %v", f, summarizeFrame(fr))
+	f.debugWriteLoggerf("http2: Framer %p: wrote %v", f, summarizeFrame(fr))
 }
 
 func (f *Framer) writeByte(v byte)     { f.wbuf = append(f.wbuf, v) }
@@ -399,9 +401,12 @@ const (
 // NewFramer returns a Framer that writes frames to w and reads them from r.
 func NewFramer(w io.Writer, r io.Reader) *Framer {
 	fr := &Framer{
-		w:        w,
-		r:        r,
-		logReads: logFrameReads,
+		w:                 w,
+		r:                 r,
+		logReads:          logFrameReads,
+		logWrites:         logFrameWrites,
+		debugReadLoggerf:  log.Printf,
+		debugWriteLoggerf: log.Printf,
 	}
 	fr.getReadBuf = func(size uint32) []byte {
 		if cap(fr.readBuf) >= int(size) {
@@ -483,7 +488,7 @@ func (fr *Framer) ReadFrame() (Frame, error) {
 		return nil, err
 	}
 	if fr.logReads {
-		log.Printf("http2: Framer %p: read %v", fr, summarizeFrame(f))
+		fr.debugReadLoggerf("http2: Framer %p: read %v", fr, summarizeFrame(f))
 	}
 	if fh.Type == FrameHeaders && fr.ReadMetaHeaders != nil {
 		return fr.readMetaFrame(f.(*HeadersFrame))
@@ -1419,8 +1424,8 @@ func (fr *Framer) readMetaFrame(hf *HeadersFrame) (*MetaHeadersFrame, error) {
 	hdec.SetEmitEnabled(true)
 	hdec.SetMaxStringLength(fr.maxHeaderStringLen())
 	hdec.SetEmitFunc(func(hf hpack.HeaderField) {
-		if VerboseLogs && logFrameReads {
-			log.Printf("http2: decoded hpack field %+v", hf)
+		if VerboseLogs && fr.logReads {
+			fr.debugReadLoggerf("http2: decoded hpack field %+v", hf)
 		}
 		if !httplex.ValidHeaderFieldValue(hf.Value) {
 			invalid = headerFieldValueError(hf.Value)

cmd/gost/vendor/golang.org/x/net/http2/go18.go

@@ -6,6 +6,45 @@
 
 package http2
 
-import "crypto/tls"
+import (
+	"crypto/tls"
+	"io"
+	"net/http"
+)
 
 func cloneTLSConfig(c *tls.Config) *tls.Config { return c.Clone() }
+
+var _ http.Pusher = (*responseWriter)(nil)
+
+// Push implements http.Pusher.
+func (w *responseWriter) Push(target string, opts *http.PushOptions) error {
+	internalOpts := pushOptions{}
+	if opts != nil {
+		internalOpts.Method = opts.Method
+		internalOpts.Header = opts.Header
+	}
+	return w.push(target, internalOpts)
+}
+
+func configureServer18(h1 *http.Server, h2 *Server) error {
+	if h2.IdleTimeout == 0 {
+		if h1.IdleTimeout != 0 {
+			h2.IdleTimeout = h1.IdleTimeout
+		} else {
+			h2.IdleTimeout = h1.ReadTimeout
+		}
+	}
+	return nil
+}
+
+func shouldLogPanic(panicValue interface{}) bool {
+	return panicValue != nil && panicValue != http.ErrAbortHandler
+}
+
+func reqGetBody(req *http.Request) func() (io.ReadCloser, error) {
+	return req.GetBody
+}
+
+func reqBodyIsNoBody(body io.ReadCloser) bool {
+	return body == http.NoBody
+}

cmd/gost/vendor/golang.org/x/net/http2/http2.go

@@ -78,13 +78,23 @@ var (
 
 type streamState int
 
+// HTTP/2 stream states.
+//
+// See http://tools.ietf.org/html/rfc7540#section-5.1.
+//
+// For simplicity, the server code merges "reserved (local)" into
+// "half-closed (remote)". This is one less state transition to track.
+// The only downside is that we send PUSH_PROMISEs slightly less
+// liberally than allowable. More discussion here:
+// https://lists.w3.org/Archives/Public/ietf-http-wg/2016JulSep/0599.html
+//
+// "reserved (remote)" is omitted since the client code does not
+// support server push.
 const (
 	stateIdle streamState = iota
 	stateOpen
 	stateHalfClosedLocal
 	stateHalfClosedRemote
-	stateResvLocal
-	stateResvRemote
 	stateClosed
 )
 
@@ -93,8 +103,6 @@ var stateName = [...]string{
 	stateOpen:             "Open",
 	stateHalfClosedLocal:  "HalfClosedLocal",
 	stateHalfClosedRemote: "HalfClosedRemote",
-	stateResvLocal:        "ResvLocal",
-	stateResvRemote:       "ResvRemote",
 	stateClosed:           "Closed",
 }
 

cmd/gost/vendor/golang.org/x/net/http2/not_go18.go

+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.8
+
+package http2
+
+import (
+	"io"
+	"net/http"
+)
+
+func configureServer18(h1 *http.Server, h2 *Server) error {
+	// No IdleTimeout to sync prior to Go 1.8.
+	return nil
+}
+
+func shouldLogPanic(panicValue interface{}) bool {
+	return panicValue != nil
+}
+
+func reqGetBody(req *http.Request) func() (io.ReadCloser, error) {
+	return nil
+}
+
+func reqBodyIsNoBody(io.ReadCloser) bool { return false }

cmd/gost/vendor/golang.org/x/net/http2/server.go

@@ -33,6 +33,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"math"
 	"net"
 	"net/http"
 	"net/textproto"
@@ -134,9 +135,15 @@ func (s *Server) maxConcurrentStreams() uint32 {
 //
 // ConfigureServer must be called before s begins serving.
 func ConfigureServer(s *http.Server, conf *Server) error {
+	if s == nil {
+		panic("nil *http.Server")
+	}
 	if conf == nil {
 		conf = new(Server)
 	}
+	if err := configureServer18(s, conf); err != nil {
+		return err
+	}
 
 	if s.TLSConfig == nil {
 		s.TLSConfig = new(tls.Config)
@@ -181,9 +188,6 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 	if !haveNPN {
 		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, NextProtoTLS)
 	}
-	// h2-14 is temporary (as of 2015-03-05) while we wait for all browsers
-	// to switch to "h2".
-	s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "h2-14")
 
 	if s.TLSNextProto == nil {
 		s.TLSNextProto = map[string]func(*http.Server, *tls.Conn, http.Handler){}
@@ -198,7 +202,6 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 		})
 	}
 	s.TLSNextProto[NextProtoTLS] = protoHandler
-	s.TLSNextProto["h2-14"] = protoHandler // temporary; see above.
 	return nil
 }
 
@@ -262,9 +265,11 @@ func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
 		streams:           make(map[uint32]*stream),
 		readFrameCh:       make(chan readFrameResult),
 		wantWriteFrameCh:  make(chan FrameWriteRequest, 8),
+		wantStartPushCh:   make(chan startPushRequest, 8),
 		wroteFrameCh:      make(chan frameWriteResult, 1), // buffered; one send in writeFrameAsync
 		bodyReadCh:        make(chan bodyReadMsg),         // buffering doesn't matter either way
 		doneServing:       make(chan struct{}),
+		clientMaxStreams:  math.MaxUint32, // Section 6.5.2: "Initially, there is no limit to this value"
 		advMaxStreams:     s.maxConcurrentStreams(),
 		initialWindowSize: initialWindowSize,
 		maxFrameSize:      initialMaxFrameSize,
@@ -273,6 +278,16 @@ func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
 		pushEnabled:       true,
 	}
 
+	// The net/http package sets the write deadline from the
+	// http.Server.WriteTimeout during the TLS handshake, but then
+	// passes the connection off to us with the deadline already
+	// set. Disarm it here so that it is not applied to additional
+	// streams opened on this connection.
+	// TODO: implement WriteTimeout fully. See Issue 18437.
+	if sc.hs.WriteTimeout != 0 {
+		sc.conn.SetWriteDeadline(time.Time{})
+	}
+
 	if s.NewWriteScheduler != nil {
 		sc.writeSched = s.NewWriteScheduler()
 	} else {
@@ -361,6 +376,7 @@ type serverConn struct {
 	doneServing      chan struct{}          // closed when serverConn.serve ends
 	readFrameCh      chan readFrameResult   // written by serverConn.readFrames
 	wantWriteFrameCh chan FrameWriteRequest // from handlers -> serve
+	wantStartPushCh  chan startPushRequest  // from handlers -> serve
 	wroteFrameCh     chan frameWriteResult  // from writeFrameAsync -> serve, tickles more frame writes
 	bodyReadCh       chan bodyReadMsg       // from handlers -> serve
 	testHookCh       chan func(int)         // code to run on the serve loop
@@ -378,17 +394,21 @@ type serverConn struct {
 	unackedSettings       int    // how many SETTINGS have we sent without ACKs?
 	clientMaxStreams      uint32 // SETTINGS_MAX_CONCURRENT_STREAMS from client (our PUSH_PROMISE limit)
 	advMaxStreams         uint32 // our SETTINGS_MAX_CONCURRENT_STREAMS advertised the client
-	curOpenStreams        uint32 // client's number of open streams
-	maxStreamID           uint32 // max ever seen
+	curClientStreams      uint32 // number of open streams initiated by the client
+	curPushedStreams      uint32 // number of open streams initiated by server push
+	maxClientStreamID     uint32 // max ever seen from client (odd), or 0 if there have been no client requests
+	maxPushPromiseID      uint32 // ID of the last push promise (even), or 0 if there have been no pushes
 	streams               map[uint32]*stream
 	initialWindowSize     int32
 	maxFrameSize          int32
 	headerTableSize       uint32
 	peerMaxHeaderListSize uint32            // zero means unknown (default)
 	canonHeader           map[string]string // http2-lower-case -> Go-Canonical-Case
-	writingFrame          bool              // started write goroutine but haven't heard back on wroteFrameCh
+	writingFrame          bool              // started writing a frame (on serve goroutine or separate)
+	writingFrameAsync     bool              // started a frame on its own goroutine but haven't heard back on wroteFrameCh
 	needsFrameFlush       bool              // last frame write wasn't a flush
 	inGoAway              bool              // we've started to or sent GOAWAY
+	inFrameScheduleLoop   bool              // whether we're in the scheduleFrameWrite loop
 	needToSendGoAway      bool              // we need to schedule a GOAWAY frame write
 	goAwayCode            ErrCode
 	shutdownTimerCh       <-chan time.Time // nil until used
@@ -413,6 +433,11 @@ func (sc *serverConn) maxHeaderListSize() uint32 {
 	return uint32(n + typicalHeaders*perFieldOverhead)
 }
 
+func (sc *serverConn) curOpenStreams() uint32 {
+	sc.serveG.check()
+	return sc.curClientStreams + sc.curPushedStreams
+}
+
 // stream represents a stream. This is the minimal metadata needed by
 // the serve goroutine. Most of the actual stream state is owned by
 // the http.Handler's goroutine in the responseWriter. Because the
@@ -438,8 +463,7 @@ type stream struct {
 	numTrailerValues int64
 	weight           uint8
 	state            streamState
-	sentReset        bool   // only true once detached from streams map
-	gotReset         bool   // only true once detacted from streams map
+	resetQueued      bool   // RST_STREAM queued for write; set by sc.resetStream
 	gotTrailerHeader bool   // HEADER frame for trailers was seen
 	wroteHeaders     bool   // whether we wrote headers (not status 100)
 	reqBuf           []byte // if non-nil, body pipe buffer to return later at EOF
@@ -457,7 +481,7 @@ func (sc *serverConn) HeaderEncoder() (*hpack.Encoder, *bytes.Buffer) {
 
 func (sc *serverConn) state(streamID uint32) (streamState, *stream) {
 	sc.serveG.check()
-	// http://http2.github.io/http2-spec/#rfc.section.5.1
+	// http://tools.ietf.org/html/rfc7540#section-5.1
 	if st, ok := sc.streams[streamID]; ok {
 		return st.state, st
 	}
@@ -467,8 +491,14 @@ func (sc *serverConn) state(streamID uint32) (streamState, *stream) {
 	// a client sends a HEADERS frame on stream 7 without ever sending a
 	// frame on stream 5, then stream 5 transitions to the "closed"
 	// state when the first frame for stream 7 is sent or received."
-	if streamID <= sc.maxStreamID {
-		return stateClosed, nil
+	if streamID%2 == 1 {
+		if streamID <= sc.maxClientStreamID {
+			return stateClosed, nil
+		}
+	} else {
+		if streamID <= sc.maxPushPromiseID {
+			return stateClosed, nil
+		}
 	}
 	return stateIdle, nil
 }
@@ -692,6 +722,11 @@ func (sc *serverConn) serve() {
 		sc.idleTimerCh = sc.idleTimer.C
 	}
 
+	var gracefulShutdownCh <-chan struct{}
+	if sc.hs != nil {
+		gracefulShutdownCh = h1ServerShutdownChan(sc.hs)
+	}
+
 	go sc.readFrames() // closed by defer sc.conn.Close above
 
 	settingsTimer := time.NewTimer(firstSettingsTimeout)
@@ -701,6 +736,8 @@ func (sc *serverConn) serve() {
 		select {
 		case wr := <-sc.wantWriteFrameCh:
 			sc.writeFrame(wr)
+		case spr := <-sc.wantStartPushCh:
+			sc.startPush(spr)
 		case res := <-sc.wroteFrameCh:
 			sc.wroteFrame(res)
 		case res := <-sc.readFrameCh:
@@ -717,6 +754,9 @@ func (sc *serverConn) serve() {
 		case <-settingsTimer.C:
 			sc.logf("timeout waiting for SETTINGS frames from %v", sc.conn.RemoteAddr())
 			return
+		case <-gracefulShutdownCh:
+			gracefulShutdownCh = nil
+			sc.startGracefulShutdown()
 		case <-sc.shutdownTimerCh:
 			sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr())
 			return
@@ -726,6 +766,10 @@ func (sc *serverConn) serve() {
 		case fn := <-sc.testHookCh:
 			fn(loopNum)
 		}
+
+		if sc.inGoAway && sc.curOpenStreams() == 0 && !sc.needToSendGoAway && !sc.writingFrame {
+			return
+		}
 	}
 }
 
@@ -839,8 +883,34 @@ func (sc *serverConn) writeFrameFromHandler(wr FrameWriteRequest) error {
 func (sc *serverConn) writeFrame(wr FrameWriteRequest) {
 	sc.serveG.check()
 
+	// If true, wr will not be written and wr.done will not be signaled.
 	var ignoreWrite bool
 
+	// We are not allowed to write frames on closed streams. RFC 7540 Section
+	// 5.1.1 says: "An endpoint MUST NOT send frames other than PRIORITY on
+	// a closed stream." Our server never sends PRIORITY, so that exception
+	// does not apply.
+	//
+	// The serverConn might close an open stream while the stream's handler
+	// is still running. For example, the server might close a stream when it
+	// receives bad data from the client. If this happens, the handler might
+	// attempt to write a frame after the stream has been closed (since the
+	// handler hasn't yet been notified of the close). In this case, we simply
+	// ignore the frame. The handler will notice that the stream is closed when
+	// it waits for the frame to be written.
+	//
+	// As an exception to this rule, we allow sending RST_STREAM after close.
+	// This allows us to immediately reject new streams without tracking any
+	// state for those streams (except for the queued RST_STREAM frame). This
+	// may result in duplicate RST_STREAMs in some cases, but the client should
+	// ignore those.
+	if wr.StreamID() != 0 {
+		_, isReset := wr.write.(StreamError)
+		if state, _ := sc.state(wr.StreamID()); state == stateClosed && !isReset {
+			ignoreWrite = true
+		}
+	}
+
 	// Don't send a 100-continue response if we've already sent headers.
 	// See golang.org/issue/14030.
 	switch wr.write.(type) {
@@ -848,6 +918,11 @@ func (sc *serverConn) writeFrame(wr FrameWriteRequest) {
 		wr.stream.wroteHeaders = true
 	case write100ContinueHeadersFrame:
 		if wr.stream.wroteHeaders {
+			// We do not need to notify wr.done because this frame is
+			// never written with wr.done != nil.
+			if wr.done != nil {
+				panic("wr.done != nil for write100ContinueHeadersFrame")
+			}
 			ignoreWrite = true
 		}
 	}
@@ -871,23 +946,35 @@ func (sc *serverConn) startFrameWrite(wr FrameWriteRequest) {
 	if st != nil {
 		switch st.state {
 		case stateHalfClosedLocal:
-			panic("internal error: attempt to send frame on half-closed-local stream")
-		case stateClosed:
-			if st.sentReset || st.gotReset {
-				// Skip this frame.
-				sc.scheduleFrameWrite()
-				return
+			switch wr.write.(type) {
+			case StreamError, handlerPanicRST, writeWindowUpdate:
+				// RFC 7540 Section 5.1 allows sending RST_STREAM, PRIORITY, and WINDOW_UPDATE
+				// in this state. (We never send PRIORITY from the server, so that is not checked.)
+			default:
+				panic(fmt.Sprintf("internal error: attempt to send frame on a half-closed-local stream: %v", wr))
 			}
-			panic(fmt.Sprintf("internal error: attempt to send a write %v on a closed stream", wr))
+		case stateClosed:
+			panic(fmt.Sprintf("internal error: attempt to send frame on a closed stream: %v", wr))
+		}
+	}
+	if wpp, ok := wr.write.(*writePushPromise); ok {
+		var err error
+		wpp.promisedID, err = wpp.allocatePromisedID()
+		if err != nil {
+			sc.writingFrameAsync = false
+			wr.replyToWriter(err)
+			return
 		}
 	}
 
 	sc.writingFrame = true
 	sc.needsFrameFlush = true
 	if wr.write.staysWithinBuffer(sc.bw.Available()) {
+		sc.writingFrameAsync = false
 		err := wr.write.writeFrame(sc)
 		sc.wroteFrame(frameWriteResult{wr, err})
 	} else {
+		sc.writingFrameAsync = true
 		go sc.writeFrameAsync(wr)
 	}
 }
@@ -905,27 +992,12 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 		panic("internal error: expected to be already writing a frame")
 	}
 	sc.writingFrame = false
+	sc.writingFrameAsync = false
 
 	wr := res.wr
-	st := wr.stream
-
-	closeStream := endsStream(wr.write)
-
-	if _, ok := wr.write.(handlerPanicRST); ok {
-		sc.closeStream(st, errHandlerPanicked)
-	}
 
-	// Reply (if requested) to the blocked ServeHTTP goroutine.
-	if ch := wr.done; ch != nil {
-		select {
-		case ch <- res.err:
-		default:
-			panic(fmt.Sprintf("unbuffered done channel passed in for type %T", wr.write))
-		}
-	}
-	wr.write = nil // prevent use (assume it's tainted after wr.done send)
-
-	if closeStream {
+	if writeEndsStream(wr.write) {
+		st := wr.stream
 		if st == nil {
 			panic("internal error: expecting non-nil stream")
 		}
@@ -938,15 +1010,29 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 			// reading data (see possible TODO at top of
 			// this file), we go into closed state here
 			// anyway, after telling the peer we're
-			// hanging up on them.
-			st.state = stateHalfClosedLocal // won't last long, but necessary for closeStream via resetStream
-			errCancel := streamError(st.id, ErrCodeCancel)
-			sc.resetStream(errCancel)
+			// hanging up on them. We'll transition to
+			// stateClosed after the RST_STREAM frame is
+			// written.
+			st.state = stateHalfClosedLocal
+			sc.resetStream(streamError(st.id, ErrCodeCancel))
 		case stateHalfClosedRemote:
 			sc.closeStream(st, errHandlerComplete)
 		}
+	} else {
+		switch v := wr.write.(type) {
+		case StreamError:
+			// st may be unknown if the RST_STREAM was generated to reject bad input.
+			if st, ok := sc.streams[v.StreamID]; ok {
+				sc.closeStream(st, v)
+			}
+		case handlerPanicRST:
+			sc.closeStream(wr.stream, errHandlerPanicked)
+		}
 	}
 
+	// Reply (if requested) to unblock the ServeHTTP goroutine.
+	wr.replyToWriter(res.err)
+
 	sc.scheduleFrameWrite()
 }
 
@@ -964,47 +1050,68 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 // flush the write buffer.
 func (sc *serverConn) scheduleFrameWrite() {
 	sc.serveG.check()
-	if sc.writingFrame {
-		return
-	}
-	if sc.needToSendGoAway {
-		sc.needToSendGoAway = false
-		sc.startFrameWrite(FrameWriteRequest{
-			write: &writeGoAway{
-				maxStreamID: sc.maxStreamID,
-				code:        sc.goAwayCode,
-			},
-		})
+	if sc.writingFrame || sc.inFrameScheduleLoop {
 		return
 	}
-	if sc.needToSendSettingsAck {
-		sc.needToSendSettingsAck = false
-		sc.startFrameWrite(FrameWriteRequest{write: writeSettingsAck{}})
-		return
-	}
-	if !sc.inGoAway {
-		if wr, ok := sc.writeSched.Pop(); ok {
-			sc.startFrameWrite(wr)
-			return
+	sc.inFrameScheduleLoop = true
+	for !sc.writingFrameAsync {
+		if sc.needToSendGoAway {
+			sc.needToSendGoAway = false
+			sc.startFrameWrite(FrameWriteRequest{
+				write: &writeGoAway{
+					maxStreamID: sc.maxClientStreamID,
+					code:        sc.goAwayCode,
+				},
+			})
+			continue
 		}
+		if sc.needToSendSettingsAck {
+			sc.needToSendSettingsAck = false
+			sc.startFrameWrite(FrameWriteRequest{write: writeSettingsAck{}})
+			continue
+		}
+		if !sc.inGoAway || sc.goAwayCode == ErrCodeNo {
+			if wr, ok := sc.writeSched.Pop(); ok {
+				sc.startFrameWrite(wr)
+				continue
+			}
+		}
+		if sc.needsFrameFlush {
+			sc.startFrameWrite(FrameWriteRequest{write: flushFrameWriter{}})
+			sc.needsFrameFlush = false // after startFrameWrite, since it sets this true
+			continue
+		}
+		break
 	}
-	if sc.needsFrameFlush {
-		sc.startFrameWrite(FrameWriteRequest{write: flushFrameWriter{}})
-		sc.needsFrameFlush = false // after startFrameWrite, since it sets this true
-		return
-	}
+	sc.inFrameScheduleLoop = false
+}
+
+// startGracefulShutdown sends a GOAWAY with ErrCodeNo to tell the
+// client we're gracefully shutting down. The connection isn't closed
+// until all current streams are done.
+func (sc *serverConn) startGracefulShutdown() {
+	sc.goAwayIn(ErrCodeNo, 0)
 }
 
 func (sc *serverConn) goAway(code ErrCode) {
 	sc.serveG.check()
-	if sc.inGoAway {
-		return
-	}
+	var forceCloseIn time.Duration
 	if code != ErrCodeNo {
-		sc.shutDownIn(250 * time.Millisecond)
+		forceCloseIn = 250 * time.Millisecond
 	} else {
 		// TODO: configurable
-		sc.shutDownIn(1 * time.Second)
+		forceCloseIn = 1 * time.Second
+	}
+	sc.goAwayIn(code, forceCloseIn)
+}
+
+func (sc *serverConn) goAwayIn(code ErrCode, forceCloseIn time.Duration) {
+	sc.serveG.check()
+	if sc.inGoAway {
+		return
+	}
+	if forceCloseIn != 0 {
+		sc.shutDownIn(forceCloseIn)
 	}
 	sc.inGoAway = true
 	sc.needToSendGoAway = true
@@ -1022,8 +1129,7 @@ func (sc *serverConn) resetStream(se StreamError) {
 	sc.serveG.check()
 	sc.writeFrame(FrameWriteRequest{write: se})
 	if st, ok := sc.streams[se.StreamID]; ok {
-		st.sentReset = true
-		sc.closeStream(st, se)
+		st.resetQueued = true
 	}
 }
 
@@ -1108,6 +1214,8 @@ func (sc *serverConn) processFrame(f Frame) error {
 		return sc.processResetStream(f)
 	case *PriorityFrame:
 		return sc.processPriority(f)
+	case *GoAwayFrame:
+		return sc.processGoAway(f)
 	case *PushPromiseFrame:
 		// A client cannot push. Thus, servers MUST treat the receipt of a PUSH_PROMISE
 		// frame as a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
@@ -1133,7 +1241,7 @@ func (sc *serverConn) processPing(f *PingFrame) error {
 		// PROTOCOL_ERROR."
 		return ConnectionError(ErrCodeProtocol)
 	}
-	if sc.inGoAway {
+	if sc.inGoAway && sc.goAwayCode != ErrCodeNo {
 		return nil
 	}
 	sc.writeFrame(FrameWriteRequest{write: writePingAck{f}})
@@ -1142,9 +1250,6 @@ func (sc *serverConn) processPing(f *PingFrame) error {
 
 func (sc *serverConn) processWindowUpdate(f *WindowUpdateFrame) error {
 	sc.serveG.check()
-	if sc.inGoAway {
-		return nil
-	}
 	switch {
 	case f.StreamID != 0: // stream-level flow control
 		state, st := sc.state(f.StreamID)
@@ -1177,9 +1282,6 @@ func (sc *serverConn) processWindowUpdate(f *WindowUpdateFrame) error {
 
 func (sc *serverConn) processResetStream(f *RSTStreamFrame) error {
 	sc.serveG.check()
-	if sc.inGoAway {
-		return nil
-	}
 
 	state, st := sc.state(f.StreamID)
 	if state == stateIdle {
@@ -1191,7 +1293,6 @@ func (sc *serverConn) processResetStream(f *RSTStreamFrame) error {
 		return ConnectionError(ErrCodeProtocol)
 	}
 	if st != nil {
-		st.gotReset = true
 		st.cancelCtx()
 		sc.closeStream(st, streamError(f.StreamID, f.ErrCode))
 	}
@@ -1204,13 +1305,20 @@ func (sc *serverConn) closeStream(st *stream, err error) {
 		panic(fmt.Sprintf("invariant; can't close stream in state %v", st.state))
 	}
 	st.state = stateClosed
-	sc.curOpenStreams--
-	if sc.curOpenStreams == 0 {
-		sc.setConnState(http.StateIdle)
+	if st.isPushed() {
+		sc.curPushedStreams--
+	} else {
+		sc.curClientStreams--
 	}
 	delete(sc.streams, st.id)
-	if len(sc.streams) == 0 && sc.srv.IdleTimeout != 0 {
-		sc.idleTimer.Reset(sc.srv.IdleTimeout)
+	if len(sc.streams) == 0 {
+		sc.setConnState(http.StateIdle)
+		if sc.srv.IdleTimeout != 0 {
+			sc.idleTimer.Reset(sc.srv.IdleTimeout)
+		}
+		if h1ServerKeepAlivesDisabled(sc.hs) {
+			sc.startGracefulShutdown()
+		}
 	}
 	if p := st.body; p != nil {
 		// Return any buffered unread bytes worth of conn-level flow control.
@@ -1235,9 +1343,6 @@ func (sc *serverConn) processSettings(f *SettingsFrame) error {
 		}
 		return nil
 	}
-	if sc.inGoAway {
-		return nil
-	}
 	if err := f.ForeachSetting(sc.processSetting); err != nil {
 		return err
 	}
@@ -1309,7 +1414,7 @@ func (sc *serverConn) processSettingInitialWindowSize(val uint32) error {
 
 func (sc *serverConn) processData(f *DataFrame) error {
 	sc.serveG.check()
-	if sc.inGoAway {
+	if sc.inGoAway && sc.goAwayCode != ErrCodeNo {
 		return nil
 	}
 	data := f.Data()
@@ -1326,7 +1431,7 @@ func (sc *serverConn) processData(f *DataFrame) error {
 		// type PROTOCOL_ERROR."
 		return ConnectionError(ErrCodeProtocol)
 	}
-	if st == nil || state != stateOpen || st.gotTrailerHeader {
+	if st == nil || state != stateOpen || st.gotTrailerHeader || st.resetQueued {
 		// This includes sending a RST_STREAM if the stream is
 		// in stateHalfClosedLocal (which currently means that
 		// the http.Handler returned, so it's done reading &
@@ -1346,6 +1451,10 @@ func (sc *serverConn) processData(f *DataFrame) error {
 		sc.inflow.take(int32(f.Length))
 		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
 
+		if st != nil && st.resetQueued {
+			// Already have a stream error in flight. Don't send another.
+			return nil
+		}
 		return streamError(id, ErrCodeStreamClosed)
 	}
 	if st.body == nil {
@@ -1388,6 +1497,25 @@ func (sc *serverConn) processData(f *DataFrame) error {
 	return nil
 }
 
+func (sc *serverConn) processGoAway(f *GoAwayFrame) error {
+	sc.serveG.check()
+	if f.ErrCode != ErrCodeNo {
+		sc.logf("http2: received GOAWAY %+v, starting graceful shutdown", f)
+	} else {
+		sc.vlogf("http2: received GOAWAY %+v, starting graceful shutdown", f)
+	}
+	sc.startGracefulShutdown()
+	// http://tools.ietf.org/html/rfc7540#section-6.8
+	// We should not create any new streams, which means we should disable push.
+	sc.pushEnabled = false
+	return nil
+}
+
+// isPushed reports whether the stream is server-initiated.
+func (st *stream) isPushed() bool {
+	return st.id%2 == 0
+}
+
 // endStream closes a Request.Body's pipe. It is called when a DATA
 // frame says a request body is over (or after trailers).
 func (st *stream) endStream() {
@@ -1417,12 +1545,12 @@ func (st *stream) copyTrailersToHandlerRequest() {
 
 func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	sc.serveG.check()
-	id := f.Header().StreamID
+	id := f.StreamID
 	if sc.inGoAway {
 		// Ignore.
 		return nil
 	}
-	// http://http2.github.io/http2-spec/#rfc.section.5.1.1
+	// http://tools.ietf.org/html/rfc7540#section-5.1.1
 	// Streams initiated by a client MUST use odd-numbered stream
 	// identifiers. [...] An endpoint that receives an unexpected
 	// stream identifier MUST respond with a connection error
@@ -1434,8 +1562,12 @@ func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	// send a trailer for an open one. If we already have a stream
 	// open, let it process its own HEADERS frame (trailers at this
 	// point, if it's valid).
-	st := sc.streams[f.Header().StreamID]
-	if st != nil {
+	if st := sc.streams[f.StreamID]; st != nil {
+		if st.resetQueued {
+			// We're sending RST_STREAM to close the stream, so don't bother
+			// processing this frame.
+			return nil
+		}
 		return st.processTrailerHeaders(f)
 	}
 
@@ -1444,57 +1576,40 @@ func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	// endpoint has opened or reserved. [...]  An endpoint that
 	// receives an unexpected stream identifier MUST respond with
 	// a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
-	if id <= sc.maxStreamID {
+	if id <= sc.maxClientStreamID {
 		return ConnectionError(ErrCodeProtocol)
 	}
-	sc.maxStreamID = id
+	sc.maxClientStreamID = id
 
 	if sc.idleTimer != nil {
 		sc.idleTimer.Stop()
 	}
 
-	ctx, cancelCtx := contextWithCancel(sc.baseCtx)
-	st = &stream{
-		sc:        sc,
-		id:        id,
-		state:     stateOpen,
-		ctx:       ctx,
-		cancelCtx: cancelCtx,
-	}
-	if f.StreamEnded() {
-		st.state = stateHalfClosedRemote
-	}
-	st.cw.Init()
-
-	st.flow.conn = &sc.flow // link to conn-level counter
-	st.flow.add(sc.initialWindowSize)
-	st.inflow.conn = &sc.inflow      // link to conn-level counter
-	st.inflow.add(initialWindowSize) // TODO: update this when we send a higher initial window size in the initial settings
-
-	sc.streams[id] = st
-	sc.writeSched.OpenStream(st.id, OpenStreamOptions{})
-	sc.curOpenStreams++
-	if sc.curOpenStreams == 1 {
-		sc.setConnState(http.StateActive)
-	}
-	if sc.curOpenStreams > sc.advMaxStreams {
-		// "Endpoints MUST NOT exceed the limit set by their
-		// peer. An endpoint that receives a HEADERS frame
-		// that causes their advertised concurrent stream
-		// limit to be exceeded MUST treat this as a stream
-		// error (Section 5.4.2) of type PROTOCOL_ERROR or
-		// REFUSED_STREAM."
+	// http://tools.ietf.org/html/rfc7540#section-5.1.2
+	// [...] Endpoints MUST NOT exceed the limit set by their peer. An
+	// endpoint that receives a HEADERS frame that causes their
+	// advertised concurrent stream limit to be exceeded MUST treat
+	// this as a stream error (Section 5.4.2) of type PROTOCOL_ERROR
+	// or REFUSED_STREAM.
+	if sc.curClientStreams+1 > sc.advMaxStreams {
 		if sc.unackedSettings == 0 {
 			// They should know better.
-			return streamError(st.id, ErrCodeProtocol)
+			return streamError(id, ErrCodeProtocol)
 		}
 		// Assume it's a network race, where they just haven't
 		// received our last SETTINGS update. But actually
 		// this can't happen yet, because we don't yet provide
 		// a way for users to adjust server parameters at
 		// runtime.
-		return streamError(st.id, ErrCodeRefusedStream)
+		return streamError(id, ErrCodeRefusedStream)
 	}
+
+	initialState := stateOpen
+	if f.StreamEnded() {
+		initialState = stateHalfClosedRemote
+	}
+	st := sc.newStream(id, 0, initialState)
+
 	if f.HasPriority() {
 		if err := checkPriority(f.StreamID, f.Priority); err != nil {
 			return err
@@ -1517,19 +1632,17 @@ func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	if f.Truncated {
 		// Their header list was too long. Send a 431 error.
 		handler = handleHeaderListTooLong
-	} else if err := checkValidHTTP2Request(req); err != nil {
+	} else if err := checkValidHTTP2RequestHeaders(req.Header); err != nil {
 		handler = new400Handler(err)
 	}
 
 	// The net/http package sets the read deadline from the
 	// http.Server.ReadTimeout during the TLS handshake, but then
 	// passes the connection off to us with the deadline already
-	// set. Disarm it here after the request headers are read, similar
-	// to how the http1 server works.
-	// Unlike http1, though, we never re-arm it yet, though.
-	// TODO(bradfitz): figure out golang.org/issue/14204
-	// (IdleTimeout) and how this relates. Maybe the default
-	// IdleTimeout is ReadTimeout.
+	// set. Disarm it here after the request headers are read,
+	// similar to how the http1 server works. Here it's
+	// technically more like the http1 Server's ReadHeaderTimeout
+	// (in Go 1.8), though. That's a more sane option anyway.
 	if sc.hs.ReadTimeout != 0 {
 		sc.conn.SetReadDeadline(time.Time{})
 	}
@@ -1590,21 +1703,56 @@ func (sc *serverConn) processPriority(f *PriorityFrame) error {
 	return nil
 }
 
+func (sc *serverConn) newStream(id, pusherID uint32, state streamState) *stream {
+	sc.serveG.check()
+	if id == 0 {
+		panic("internal error: cannot create stream with id 0")
+	}
+
+	ctx, cancelCtx := contextWithCancel(sc.baseCtx)
+	st := &stream{
+		sc:        sc,
+		id:        id,
+		state:     state,
+		ctx:       ctx,
+		cancelCtx: cancelCtx,
+	}
+	st.cw.Init()
+	st.flow.conn = &sc.flow // link to conn-level counter
+	st.flow.add(sc.initialWindowSize)
+	st.inflow.conn = &sc.inflow      // link to conn-level counter
+	st.inflow.add(initialWindowSize) // TODO: update this when we send a higher initial window size in the initial settings
+
+	sc.streams[id] = st
+	sc.writeSched.OpenStream(st.id, OpenStreamOptions{PusherID: pusherID})
+	if st.isPushed() {
+		sc.curPushedStreams++
+	} else {
+		sc.curClientStreams++
+	}
+	if sc.curOpenStreams() == 1 {
+		sc.setConnState(http.StateActive)
+	}
+
+	return st
+}
+
 func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*responseWriter, *http.Request, error) {
 	sc.serveG.check()
 
-	method := f.PseudoValue("method")
-	path := f.PseudoValue("path")
-	scheme := f.PseudoValue("scheme")
-	authority := f.PseudoValue("authority")
+	rp := requestParam{
+		method:    f.PseudoValue("method"),
+		scheme:    f.PseudoValue("scheme"),
+		authority: f.PseudoValue("authority"),
+		path:      f.PseudoValue("path"),
+	}
 
-	isConnect := method == "CONNECT"
+	isConnect := rp.method == "CONNECT"
 	if isConnect {
-		if path != "" || scheme != "" || authority == "" {
+		if rp.path != "" || rp.scheme != "" || rp.authority == "" {
 			return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
 		}
-	} else if method == "" || path == "" ||
-		(scheme != "https" && scheme != "http") {
+	} else if rp.method == "" || rp.path == "" || (rp.scheme != "https" && rp.scheme != "http") {
 		// See 8.1.2.6 Malformed Requests and Responses:
 		//
 		// Malformed requests or responses that are detected
@@ -1619,36 +1767,64 @@ func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*res
 	}
 
 	bodyOpen := !f.StreamEnded()
-	if method == "HEAD" && bodyOpen {
+	if rp.method == "HEAD" && bodyOpen {
 		// HEAD requests can't have bodies
 		return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
 	}
-	var tlsState *tls.ConnectionState // nil if not scheme https
 
-	if scheme == "https" {
-		tlsState = sc.tlsState
+	rp.header = make(http.Header)
+	for _, hf := range f.RegularFields() {
+		rp.header.Add(sc.canonicalHeader(hf.Name), hf.Value)
+	}
+	if rp.authority == "" {
+		rp.authority = rp.header.Get("Host")
 	}
 
-	header := make(http.Header)
-	for _, hf := range f.RegularFields() {
-		header.Add(sc.canonicalHeader(hf.Name), hf.Value)
+	rw, req, err := sc.newWriterAndRequestNoBody(st, rp)
+	if err != nil {
+		return nil, nil, err
 	}
+	if bodyOpen {
+		st.reqBuf = getRequestBodyBuf()
+		req.Body.(*requestBody).pipe = &pipe{
+			b: &fixedBuffer{buf: st.reqBuf},
+		}
 
-	if authority == "" {
-		authority = header.Get("Host")
+		if vv, ok := rp.header["Content-Length"]; ok {
+			req.ContentLength, _ = strconv.ParseInt(vv[0], 10, 64)
+		} else {
+			req.ContentLength = -1
+		}
+	}
+	return rw, req, nil
+}
+
+type requestParam struct {
+	method                  string
+	scheme, authority, path string
+	header                  http.Header
+}
+
+func (sc *serverConn) newWriterAndRequestNoBody(st *stream, rp requestParam) (*responseWriter, *http.Request, error) {
+	sc.serveG.check()
+
+	var tlsState *tls.ConnectionState // nil if not scheme https
+	if rp.scheme == "https" {
+		tlsState = sc.tlsState
 	}
-	needsContinue := header.Get("Expect") == "100-continue"
+
+	needsContinue := rp.header.Get("Expect") == "100-continue"
 	if needsContinue {
-		header.Del("Expect")
+		rp.header.Del("Expect")
 	}
 	// Merge Cookie headers into one "; "-delimited value.
-	if cookies := header["Cookie"]; len(cookies) > 1 {
-		header.Set("Cookie", strings.Join(cookies, "; "))
+	if cookies := rp.header["Cookie"]; len(cookies) > 1 {
+		rp.header.Set("Cookie", strings.Join(cookies, "; "))
 	}
 
 	// Setup Trailers
 	var trailer http.Header
-	for _, v := range header["Trailer"] {
+	for _, v := range rp.header["Trailer"] {
 		for _, key := range strings.Split(v, ",") {
 			key = http.CanonicalHeaderKey(strings.TrimSpace(key))
 			switch key {
@@ -1663,53 +1839,42 @@ func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*res
 			}
 		}
 	}
-	delete(header, "Trailer")
+	delete(rp.header, "Trailer")
 
-	body := &requestBody{
-		conn:          sc,
-		stream:        st,
-		needsContinue: needsContinue,
-	}
 	var url_ *url.URL
 	var requestURI string
-	if isConnect {
-		url_ = &url.URL{Host: authority}
-		requestURI = authority // mimic HTTP/1 server behavior
+	if rp.method == "CONNECT" {
+		url_ = &url.URL{Host: rp.authority}
+		requestURI = rp.authority // mimic HTTP/1 server behavior
 	} else {
 		var err error
-		url_, err = url.ParseRequestURI(path)
+		url_, err = url.ParseRequestURI(rp.path)
 		if err != nil {
-			return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
+			return nil, nil, streamError(st.id, ErrCodeProtocol)
 		}
-		requestURI = path
+		requestURI = rp.path
+	}
+
+	body := &requestBody{
+		conn:          sc,
+		stream:        st,
+		needsContinue: needsContinue,
 	}
 	req := &http.Request{
-		Method:     method,
+		Method:     rp.method,
 		URL:        url_,
 		RemoteAddr: sc.remoteAddrStr,
-		Header:     header,
+		Header:     rp.header,
 		RequestURI: requestURI,
 		Proto:      "HTTP/2.0",
 		ProtoMajor: 2,
 		ProtoMinor: 0,
 		TLS:        tlsState,
-		Host:       authority,
+		Host:       rp.authority,
 		Body:       body,
 		Trailer:    trailer,
 	}
 	req = requestWithContext(req, st.ctx)
-	if bodyOpen {
-		st.reqBuf = getRequestBodyBuf()
-		body.pipe = &pipe{
-			b: &fixedBuffer{buf: st.reqBuf},
-		}
-
-		if vv, ok := header["Content-Length"]; ok {
-			req.ContentLength, _ = strconv.ParseInt(vv[0], 10, 64)
-		} else {
-			req.ContentLength = -1
-		}
-	}
 
 	rws := responseWriterStatePool.Get().(*responseWriterState)
 	bwSave := rws.bw
@@ -1750,15 +1915,17 @@ func (sc *serverConn) runHandler(rw *responseWriter, req *http.Request, handler
 		rw.rws.stream.cancelCtx()
 		if didPanic {
 			e := recover()
-			// Same as net/http:
-			const size = 64 << 10
-			buf := make([]byte, size)
-			buf = buf[:runtime.Stack(buf, false)]
 			sc.writeFrameFromHandler(FrameWriteRequest{
 				write:  handlerPanicRST{rw.rws.stream.id},
 				stream: rw.rws.stream,
 			})
-			sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf)
+			// Same as net/http:
+			if shouldLogPanic(e) {
+				const size = 64 << 10
+				buf := make([]byte, size)
+				buf = buf[:runtime.Stack(buf, false)]
+				sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf)
+			}
 			return
 		}
 		rw.handlerDone()
@@ -2170,8 +2337,9 @@ func (w *responseWriter) CloseNotify() <-chan bool {
 	if ch == nil {
 		ch = make(chan bool, 1)
 		rws.closeNotifierCh = ch
+		cw := rws.stream.cw
 		go func() {
-			rws.stream.cw.Wait() // wait for close
+			cw.Wait() // wait for close
 			ch <- true
 		}()
 	}
@@ -2267,6 +2435,200 @@ func (w *responseWriter) handlerDone() {
 	responseWriterStatePool.Put(rws)
 }
 
+// Push errors.
+var (
+	ErrRecursivePush    = errors.New("http2: recursive push not allowed")
+	ErrPushLimitReached = errors.New("http2: push would exceed peer's SETTINGS_MAX_CONCURRENT_STREAMS")
+)
+
+// pushOptions is the internal version of http.PushOptions, which we
+// cannot include here because it's only defined in Go 1.8 and later.
+type pushOptions struct {
+	Method string
+	Header http.Header
+}
+
+func (w *responseWriter) push(target string, opts pushOptions) error {
+	st := w.rws.stream
+	sc := st.sc
+	sc.serveG.checkNotOn()
+
+	// No recursive pushes: "PUSH_PROMISE frames MUST only be sent on a peer-initiated stream."
+	// http://tools.ietf.org/html/rfc7540#section-6.6
+	if st.isPushed() {
+		return ErrRecursivePush
+	}
+
+	// Default options.
+	if opts.Method == "" {
+		opts.Method = "GET"
+	}
+	if opts.Header == nil {
+		opts.Header = http.Header{}
+	}
+	wantScheme := "http"
+	if w.rws.req.TLS != nil {
+		wantScheme = "https"
+	}
+
+	// Validate the request.
+	u, err := url.Parse(target)
+	if err != nil {
+		return err
+	}
+	if u.Scheme == "" {
+		if !strings.HasPrefix(target, "/") {
+			return fmt.Errorf("target must be an absolute URL or an absolute path: %q", target)
+		}
+		u.Scheme = wantScheme
+		u.Host = w.rws.req.Host
+	} else {
+		if u.Scheme != wantScheme {
+			return fmt.Errorf("cannot push URL with scheme %q from request with scheme %q", u.Scheme, wantScheme)
+		}
+		if u.Host == "" {
+			return errors.New("URL must have a host")
+		}
+	}
+	for k := range opts.Header {
+		if strings.HasPrefix(k, ":") {
+			return fmt.Errorf("promised request headers cannot include pseudo header %q", k)
+		}
+		// These headers are meaningful only if the request has a body,
+		// but PUSH_PROMISE requests cannot have a body.
+		// http://tools.ietf.org/html/rfc7540#section-8.2
+		// Also disallow Host, since the promised URL must be absolute.
+		switch strings.ToLower(k) {
+		case "content-length", "content-encoding", "trailer", "te", "expect", "host":
+			return fmt.Errorf("promised request headers cannot include %q", k)
+		}
+	}
+	if err := checkValidHTTP2RequestHeaders(opts.Header); err != nil {
+		return err
+	}
+
+	// The RFC effectively limits promised requests to GET and HEAD:
+	// "Promised requests MUST be cacheable [GET, HEAD, or POST], and MUST be safe [GET or HEAD]"
+	// http://tools.ietf.org/html/rfc7540#section-8.2
+	if opts.Method != "GET" && opts.Method != "HEAD" {
+		return fmt.Errorf("method %q must be GET or HEAD", opts.Method)
+	}
+
+	msg := startPushRequest{
+		parent: st,
+		method: opts.Method,
+		url:    u,
+		header: cloneHeader(opts.Header),
+		done:   errChanPool.Get().(chan error),
+	}
+
+	select {
+	case <-sc.doneServing:
+		return errClientDisconnected
+	case <-st.cw:
+		return errStreamClosed
+	case sc.wantStartPushCh <- msg:
+	}
+
+	select {
+	case <-sc.doneServing:
+		return errClientDisconnected
+	case <-st.cw:
+		return errStreamClosed
+	case err := <-msg.done:
+		errChanPool.Put(msg.done)
+		return err
+	}
+}
+
+type startPushRequest struct {
+	parent *stream
+	method string
+	url    *url.URL
+	header http.Header
+	done   chan error
+}
+
+func (sc *serverConn) startPush(msg startPushRequest) {
+	sc.serveG.check()
+
+	// http://tools.ietf.org/html/rfc7540#section-6.6.
+	// PUSH_PROMISE frames MUST only be sent on a peer-initiated stream that
+	// is in either the "open" or "half-closed (remote)" state.
+	if msg.parent.state != stateOpen && msg.parent.state != stateHalfClosedRemote {
+		// responseWriter.Push checks that the stream is peer-initiaed.
+		msg.done <- errStreamClosed
+		return
+	}
+
+	// http://tools.ietf.org/html/rfc7540#section-6.6.
+	if !sc.pushEnabled {
+		msg.done <- http.ErrNotSupported
+		return
+	}
+
+	// PUSH_PROMISE frames must be sent in increasing order by stream ID, so
+	// we allocate an ID for the promised stream lazily, when the PUSH_PROMISE
+	// is written. Once the ID is allocated, we start the request handler.
+	allocatePromisedID := func() (uint32, error) {
+		sc.serveG.check()
+
+		// Check this again, just in case. Technically, we might have received
+		// an updated SETTINGS by the time we got around to writing this frame.
+		if !sc.pushEnabled {
+			return 0, http.ErrNotSupported
+		}
+		// http://tools.ietf.org/html/rfc7540#section-6.5.2.
+		if sc.curPushedStreams+1 > sc.clientMaxStreams {
+			return 0, ErrPushLimitReached
+		}
+
+		// http://tools.ietf.org/html/rfc7540#section-5.1.1.
+		// Streams initiated by the server MUST use even-numbered identifiers.
+		// A server that is unable to establish a new stream identifier can send a GOAWAY
+		// frame so that the client is forced to open a new connection for new streams.
+		if sc.maxPushPromiseID+2 >= 1<<31 {
+			sc.startGracefulShutdown()
+			return 0, ErrPushLimitReached
+		}
+		sc.maxPushPromiseID += 2
+		promisedID := sc.maxPushPromiseID
+
+		// http://tools.ietf.org/html/rfc7540#section-8.2.
+		// Strictly speaking, the new stream should start in "reserved (local)", then
+		// transition to "half closed (remote)" after sending the initial HEADERS, but
+		// we start in "half closed (remote)" for simplicity.
+		// See further comments at the definition of stateHalfClosedRemote.
+		promised := sc.newStream(promisedID, msg.parent.id, stateHalfClosedRemote)
+		rw, req, err := sc.newWriterAndRequestNoBody(promised, requestParam{
+			method:    msg.method,
+			scheme:    msg.url.Scheme,
+			authority: msg.url.Host,
+			path:      msg.url.RequestURI(),
+			header:    cloneHeader(msg.header), // clone since handler runs concurrently with writing the PUSH_PROMISE
+		})
+		if err != nil {
+			// Should not happen, since we've already validated msg.url.
+			panic(fmt.Sprintf("newWriterAndRequestNoBody(%+v): %v", msg.url, err))
+		}
+
+		go sc.runHandler(rw, req, sc.handler.ServeHTTP)
+		return promisedID, nil
+	}
+
+	sc.writeFrame(FrameWriteRequest{
+		write: &writePushPromise{
+			streamID:           msg.parent.id,
+			method:             msg.method,
+			url:                msg.url,
+			h:                  msg.header,
+			allocatePromisedID: allocatePromisedID,
+		},
+		stream: msg.parent,
+		done:   msg.done,
+	})
+}
+
 // foreachHeaderElement splits v according to the "#rule" construction
 // in RFC 2616 section 2.1 and calls fn for each non-empty element.
 func foreachHeaderElement(v string, fn func(string)) {
@@ -2294,16 +2656,16 @@ var connHeaders = []string{
 	"Upgrade",
 }
 
-// checkValidHTTP2Request checks whether req is a valid HTTP/2 request,
+// checkValidHTTP2RequestHeaders checks whether h is a valid HTTP/2 request,
 // per RFC 7540 Section 8.1.2.2.
 // The returned error is reported to users.
-func checkValidHTTP2Request(req *http.Request) error {
-	for _, h := range connHeaders {
-		if _, ok := req.Header[h]; ok {
-			return fmt.Errorf("request header %q is not valid in HTTP/2", h)
+func checkValidHTTP2RequestHeaders(h http.Header) error {
+	for _, k := range connHeaders {
+		if _, ok := h[k]; ok {
+			return fmt.Errorf("request header %q is not valid in HTTP/2", k)
 		}
 	}
-	te := req.Header["Te"]
+	te := h["Te"]
 	if len(te) > 0 && (len(te) > 1 || (te[0] != "trailers" && te[0] != "")) {
 		return errors.New(`request header "TE" may only be "trailers" in HTTP/2`)
 	}
@@ -2350,3 +2712,42 @@ var badTrailer = map[string]bool{
 	"Transfer-Encoding":   true,
 	"Www-Authenticate":    true,
 }
+
+// h1ServerShutdownChan returns a channel that will be closed when the
+// provided *http.Server wants to shut down.
+//
+// This is a somewhat hacky way to get at http1 innards. It works
+// when the http2 code is bundled into the net/http package in the
+// standard library. The alternatives ended up making the cmd/go tool
+// depend on http Servers. This is the lightest option for now.
+// This is tested via the TestServeShutdown* tests in net/http.
+func h1ServerShutdownChan(hs *http.Server) <-chan struct{} {
+	if fn := testh1ServerShutdownChan; fn != nil {
+		return fn(hs)
+	}
+	var x interface{} = hs
+	type I interface {
+		getDoneChan() <-chan struct{}
+	}
+	if hs, ok := x.(I); ok {
+		return hs.getDoneChan()
+	}
+	return nil
+}
+
+// optional test hook for h1ServerShutdownChan.
+var testh1ServerShutdownChan func(hs *http.Server) <-chan struct{}
+
+// h1ServerKeepAlivesDisabled reports whether hs has its keep-alives
+// disabled. See comments on h1ServerShutdownChan above for why
+// the code is written this way.
+func h1ServerKeepAlivesDisabled(hs *http.Server) bool {
+	var x interface{} = hs
+	type I interface {
+		doKeepAlives() bool
+	}
+	if hs, ok := x.(I); ok {
+		return !hs.doKeepAlives()
+	}
+	return false
+}

cmd/gost/vendor/golang.org/x/net/http2/transport.go

@@ -191,6 +191,7 @@ type clientStream struct {
 	ID            uint32
 	resc          chan resAndError
 	bufPipe       pipe // buffered pipe with the flow-controlled response payload
+	startedWrite  bool // started request body write; guarded by cc.mu
 	requestedGzip bool
 	on100         func() // optional code to run if get a 100 continue response
 
@@ -199,6 +200,7 @@ type clientStream struct {
 	bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read
 	readErr     error // sticky read error; owned by transportResponseBody.Read
 	stopReqBody error // if non-nil, stop writing req body; guarded by cc.mu
+	didReset    bool  // whether we sent a RST_STREAM to the server; guarded by cc.mu
 
 	peerReset chan struct{} // closed on peer reset
 	resetErr  error         // populated before peerReset is closed
@@ -226,15 +228,26 @@ func (cs *clientStream) awaitRequestCancel(req *http.Request) {
 	}
 	select {
 	case <-req.Cancel:
+		cs.cancelStream()
 		cs.bufPipe.CloseWithError(errRequestCanceled)
-		cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
 	case <-ctx.Done():
+		cs.cancelStream()
 		cs.bufPipe.CloseWithError(ctx.Err())
-		cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
 	case <-cs.done:
 	}
 }
 
+func (cs *clientStream) cancelStream() {
+	cs.cc.mu.Lock()
+	didReset := cs.didReset
+	cs.didReset = true
+	cs.cc.mu.Unlock()
+
+	if !didReset {
+		cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+	}
+}
+
 // checkResetOrDone reports any error sent in a RST_STREAM frame by the
 // server, or errStreamClosed if the stream is complete.
 func (cs *clientStream) checkResetOrDone() error {
@@ -302,6 +315,10 @@ func authorityAddr(scheme string, authority string) (addr string) {
 	if a, err := idna.ToASCII(host); err == nil {
 		host = a
 	}
+	// IPv6 address literal, without a port:
+	if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") {
+		return host + ":" + port
+	}
 	return net.JoinHostPort(host, port)
 }
 
@@ -320,8 +337,10 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res
 		}
 		traceGotConn(req, cc)
 		res, err := cc.RoundTrip(req)
-		if shouldRetryRequest(req, err) {
-			continue
+		if err != nil {
+			if req, err = shouldRetryRequest(req, err); err == nil {
+				continue
+			}
 		}
 		if err != nil {
 			t.vlogf("RoundTrip failure: %v", err)
@@ -343,12 +362,41 @@ func (t *Transport) CloseIdleConnections() {
 var (
 	errClientConnClosed   = errors.New("http2: client conn is closed")
 	errClientConnUnusable = errors.New("http2: client conn not usable")
+
+	errClientConnGotGoAway                 = errors.New("http2: Transport received Server's graceful shutdown GOAWAY")
+	errClientConnGotGoAwayAfterSomeReqBody = errors.New("http2: Transport received Server's graceful shutdown GOAWAY; some request body already written")
 )
 
-func shouldRetryRequest(req *http.Request, err error) bool {
-	// TODO: retry GET requests (no bodies) more aggressively, if shutdown
-	// before response.
-	return err == errClientConnUnusable
+// shouldRetryRequest is called by RoundTrip when a request fails to get
+// response headers. It is always called with a non-nil error.
+// It returns either a request to retry (either the same request, or a
+// modified clone), or an error if the request can't be replayed.
+func shouldRetryRequest(req *http.Request, err error) (*http.Request, error) {
+	switch err {
+	default:
+		return nil, err
+	case errClientConnUnusable, errClientConnGotGoAway:
+		return req, nil
+	case errClientConnGotGoAwayAfterSomeReqBody:
+		// If the Body is nil (or http.NoBody), it's safe to reuse
+		// this request and its Body.
+		if req.Body == nil || reqBodyIsNoBody(req.Body) {
+			return req, nil
+		}
+		// Otherwise we depend on the Request having its GetBody
+		// func defined.
+		getBody := reqGetBody(req) // Go 1.8: getBody = req.GetBody
+		if getBody == nil {
+			return nil, errors.New("http2: Transport: peer server initiated graceful shutdown after some of Request.Body was written; define Request.GetBody to avoid this error")
+		}
+		body, err := getBody()
+		if err != nil {
+			return nil, err
+		}
+		newReq := *req
+		newReq.Body = body
+		return &newReq, nil
+	}
 }
 
 func (t *Transport) dialClientConn(addr string, singleUse bool) (*ClientConn, error) {
@@ -501,6 +549,15 @@ func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
 	if old != nil && old.ErrCode != ErrCodeNo {
 		cc.goAway.ErrCode = old.ErrCode
 	}
+	last := f.LastStreamID
+	for streamID, cs := range cc.streams {
+		if streamID > last {
+			select {
+			case cs.resc <- resAndError{err: errClientConnGotGoAway}:
+			default:
+			}
+		}
+	}
 }
 
 func (cc *ClientConn) CanTakeNewRequest() bool {
@@ -601,8 +658,6 @@ func commaSeparatedTrailers(req *http.Request) (string, error) {
 	}
 	if len(keys) > 0 {
 		sort.Strings(keys)
-		// TODO: could do better allocation-wise here, but trailers are rare,
-		// so being lazy for now.
 		return strings.Join(keys, ","), nil
 	}
 	return "", nil
@@ -761,6 +816,13 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 			cs.abortRequestBodyWrite(errStopReqBodyWrite)
 		}
 		if re.err != nil {
+			if re.err == errClientConnGotGoAway {
+				cc.mu.Lock()
+				if cs.startedWrite {
+					re.err = errClientConnGotGoAwayAfterSomeReqBody
+				}
+				cc.mu.Unlock()
+			}
 			cc.forgetStreamID(cs.ID)
 			return nil, re.err
 		}
@@ -1666,9 +1728,10 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error {
 			cc.bw.Flush()
 			cc.wmu.Unlock()
 		}
+		didReset := cs.didReset
 		cc.mu.Unlock()
 
-		if len(data) > 0 {
+		if len(data) > 0 && !didReset {
 			if _, err := cs.bufPipe.Write(data); err != nil {
 				rl.endStreamError(cs, err)
 				return err
@@ -2000,6 +2063,9 @@ func (t *Transport) getBodyWriterState(cs *clientStream, body io.Reader) (s body
 	resc := make(chan error, 1)
 	s.resc = resc
 	s.fn = func() {
+		cs.cc.mu.Lock()
+		cs.startedWrite = true
+		cs.cc.mu.Unlock()
 		resc <- cs.writeRequestBody(body, cs.req.Body)
 	}
 	s.delay = t.expectContinueTimeout()

cmd/gost/vendor/golang.org/x/net/http2/write.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"net/url"
 	"time"
 
 	"golang.org/x/net/http2/hpack"
@@ -44,9 +45,10 @@ type writeContext interface {
 	HeaderEncoder() (*hpack.Encoder, *bytes.Buffer)
 }
 
-// endsStream reports whether the given frame writer w will locally
-// close the stream.
-func endsStream(w writeFramer) bool {
+// writeEndsStream reports whether w writes a frame that will transition
+// the stream to a half-closed local state. This returns false for RST_STREAM,
+// which closes the entire stream (not just the local half).
+func writeEndsStream(w writeFramer) bool {
 	switch v := w.(type) {
 	case *writeData:
 		return v.endStream
@@ -56,7 +58,7 @@ func endsStream(w writeFramer) bool {
 		// This can only happen if the caller reuses w after it's
 		// been intentionally nil'ed out to prevent use. Keep this
 		// here to catch future refactoring breaking it.
-		panic("endsStream called on nil writeFramer")
+		panic("writeEndsStream called on nil writeFramer")
 	}
 	return false
 }
@@ -150,6 +152,33 @@ func (writeSettingsAck) writeFrame(ctx writeContext) error {
 
 func (writeSettingsAck) staysWithinBuffer(max int) bool { return frameHeaderLen <= max }
 
+// splitHeaderBlock splits headerBlock into fragments so that each fragment fits
+// in a single frame, then calls fn for each fragment. firstFrag/lastFrag are true
+// for the first/last fragment, respectively.
+func splitHeaderBlock(ctx writeContext, headerBlock []byte, fn func(ctx writeContext, frag []byte, firstFrag, lastFrag bool) error) error {
+	// For now we're lazy and just pick the minimum MAX_FRAME_SIZE
+	// that all peers must support (16KB). Later we could care
+	// more and send larger frames if the peer advertised it, but
+	// there's little point. Most headers are small anyway (so we
+	// generally won't have CONTINUATION frames), and extra frames
+	// only waste 9 bytes anyway.
+	const maxFrameSize = 16384
+
+	first := true
+	for len(headerBlock) > 0 {
+		frag := headerBlock
+		if len(frag) > maxFrameSize {
+			frag = frag[:maxFrameSize]
+		}
+		headerBlock = headerBlock[len(frag):]
+		if err := fn(ctx, frag, first, len(headerBlock) == 0); err != nil {
+			return err
+		}
+		first = false
+	}
+	return nil
+}
+
 // writeResHeaders is a request to write a HEADERS and 0+ CONTINUATION frames
 // for HTTP response headers or trailers from a server handler.
 type writeResHeaders struct {
@@ -207,39 +236,69 @@ func (w *writeResHeaders) writeFrame(ctx writeContext) error {
 		panic("unexpected empty hpack")
 	}
 
-	// For now we're lazy and just pick the minimum MAX_FRAME_SIZE
-	// that all peers must support (16KB). Later we could care
-	// more and send larger frames if the peer advertised it, but
-	// there's little point. Most headers are small anyway (so we
-	// generally won't have CONTINUATION frames), and extra frames
-	// only waste 9 bytes anyway.
-	const maxFrameSize = 16384
+	return splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock)
+}
 
-	first := true
-	for len(headerBlock) > 0 {
-		frag := headerBlock
-		if len(frag) > maxFrameSize {
-			frag = frag[:maxFrameSize]
-		}
-		headerBlock = headerBlock[len(frag):]
-		endHeaders := len(headerBlock) == 0
-		var err error
-		if first {
-			first = false
-			err = ctx.Framer().WriteHeaders(HeadersFrameParam{
-				StreamID:      w.streamID,
-				BlockFragment: frag,
-				EndStream:     w.endStream,
-				EndHeaders:    endHeaders,
-			})
-		} else {
-			err = ctx.Framer().WriteContinuation(w.streamID, endHeaders, frag)
-		}
-		if err != nil {
-			return err
-		}
+func (w *writeResHeaders) writeHeaderBlock(ctx writeContext, frag []byte, firstFrag, lastFrag bool) error {
+	if firstFrag {
+		return ctx.Framer().WriteHeaders(HeadersFrameParam{
+			StreamID:      w.streamID,
+			BlockFragment: frag,
+			EndStream:     w.endStream,
+			EndHeaders:    lastFrag,
+		})
+	} else {
+		return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag)
+	}
+}
+
+// writePushPromise is a request to write a PUSH_PROMISE and 0+ CONTINUATION frames.
+type writePushPromise struct {
+	streamID uint32   // pusher stream
+	method   string   // for :method
+	url      *url.URL // for :scheme, :authority, :path
+	h        http.Header
+
+	// Creates an ID for a pushed stream. This runs on serveG just before
+	// the frame is written. The returned ID is copied to promisedID.
+	allocatePromisedID func() (uint32, error)
+	promisedID         uint32
+}
+
+func (w *writePushPromise) staysWithinBuffer(max int) bool {
+	// TODO: see writeResHeaders.staysWithinBuffer
+	return false
+}
+
+func (w *writePushPromise) writeFrame(ctx writeContext) error {
+	enc, buf := ctx.HeaderEncoder()
+	buf.Reset()
+
+	encKV(enc, ":method", w.method)
+	encKV(enc, ":scheme", w.url.Scheme)
+	encKV(enc, ":authority", w.url.Host)
+	encKV(enc, ":path", w.url.RequestURI())
+	encodeHeaders(enc, w.h, nil)
+
+	headerBlock := buf.Bytes()
+	if len(headerBlock) == 0 {
+		panic("unexpected empty hpack")
+	}
+
+	return splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock)
+}
+
+func (w *writePushPromise) writeHeaderBlock(ctx writeContext, frag []byte, firstFrag, lastFrag bool) error {
+	if firstFrag {
+		return ctx.Framer().WritePushPromise(PushPromiseParam{
+			StreamID:      w.streamID,
+			PromiseID:     w.promisedID,
+			BlockFragment: frag,
+			EndHeaders:    lastFrag,
+		})
+	} else {
+		return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag)
 	}
-	return nil
 }
 
 type write100ContinueHeadersFrame struct {
@@ -274,6 +333,8 @@ func (wu writeWindowUpdate) writeFrame(ctx writeContext) error {
 	return ctx.Framer().WriteWindowUpdate(wu.streamID, wu.n)
 }
 
+// encodeHeaders encodes an http.Header. If keys is not nil, then (k, h[k])
+// is encoded only only if k is in keys.
 func encodeHeaders(enc *hpack.Encoder, h http.Header, keys []string) {
 	if keys == nil {
 		sorter := sorterPool.Get().(*sorter)

cmd/gost/vendor/golang.org/x/net/http2/writesched.go

@@ -25,7 +25,9 @@ type WriteScheduler interface {
 	// https://tools.ietf.org/html/rfc7540#section-5.1
 	AdjustStream(streamID uint32, priority PriorityParam)
 
-	// Push queues a frame in the scheduler.
+	// Push queues a frame in the scheduler. In most cases, this will not be
+	// called with wr.StreamID()!=0 unless that stream is currently open. The one
+	// exception is RST_STREAM frames, which may be sent on idle or closed streams.
 	Push(wr FrameWriteRequest)
 
 	// Pop dequeues the next frame to write. Returns false if no frames can
@@ -62,6 +64,13 @@ type FrameWriteRequest struct {
 // 0 is used for non-stream frames such as PING and SETTINGS.
 func (wr FrameWriteRequest) StreamID() uint32 {
 	if wr.stream == nil {
+		if se, ok := wr.write.(StreamError); ok {
+			// (*serverConn).resetStream doesn't set
+			// stream because it doesn't necessarily have
+			// one. So special case this type of write
+			// message.
+			return se.StreamID
+		}
 		return 0
 	}
 	return wr.stream.id
@@ -142,17 +151,27 @@ func (wr FrameWriteRequest) Consume(n int32) (FrameWriteRequest, FrameWriteReque
 
 // String is for debugging only.
 func (wr FrameWriteRequest) String() string {
-	var streamID uint32
-	if wr.stream != nil {
-		streamID = wr.stream.id
-	}
 	var des string
 	if s, ok := wr.write.(fmt.Stringer); ok {
 		des = s.String()
 	} else {
 		des = fmt.Sprintf("%T", wr.write)
 	}
-	return fmt.Sprintf("[FrameWriteRequest stream=%d, ch=%v, writer=%v]", streamID, wr.done != nil, des)
+	return fmt.Sprintf("[FrameWriteRequest stream=%d, ch=%v, writer=%v]", wr.StreamID(), wr.done != nil, des)
+}
+
+// replyToWriter sends err to wr.done and panics if the send must block
+// This does nothing if wr.done is nil.
+func (wr *FrameWriteRequest) replyToWriter(err error) {
+	if wr.done == nil {
+		return
+	}
+	select {
+	case wr.done <- err:
+	default:
+		panic(fmt.Sprintf("unbuffered done channel passed in for type %T", wr.write))
+	}
+	wr.write = nil // prevent use (assume it's tainted after wr.done send)
 }
 
 // writeQueue is used by implementations of WriteScheduler.

cmd/gost/vendor/golang.org/x/net/http2/writesched_priority.go

@@ -388,7 +388,15 @@ func (ws *priorityWriteScheduler) Push(wr FrameWriteRequest) {
 	} else {
 		n = ws.nodes[id]
 		if n == nil {
-			panic("add on non-open stream")
+			// id is an idle or closed stream. wr should not be a HEADERS or
+			// DATA frame. However, wr can be a RST_STREAM. In this case, we
+			// push wr onto the root, rather than creating a new priorityNode,
+			// since RST_STREAM is tiny and the stream's priority is unknown
+			// anyway. See issue #17919.
+			if wr.DataSize() > 0 {
+				panic("add DATA on non-open stream")
+			}
+			n = &ws.root
 		}
 	}
 	n.q.push(wr)

cmd/gost/vendor/vendor.json

@@ -15,10 +15,10 @@
 			"revisionTime": "2016-09-03T01:06:34Z"
 		},
 		{
-			"checksumSHA1": "QooLgOqsl0ivXxYygSepzSRAtjQ=",
+			"checksumSHA1": "omTjLIMmJwoaAJ99BOLRn7yWgtc=",
 			"path": "github.com/ginuerzh/gost",
-			"revision": "15a5d74b563e644a471fa42aab0a2876da6b1bb0",
-			"revisionTime": "2017-01-09T03:39:18Z"
+			"revision": "b244ce00c9cb4fa0051b5827b85e45241ab75935",
+			"revisionTime": "2017-01-13T07:27:51Z"
 		},
 		{
 			"checksumSHA1": "URsJa4y/sUUw/STmbeYx9EKqaYE=",
@@ -225,10 +225,10 @@
 			"revisionTime": "2016-10-24T22:38:16Z"
 		},
 		{
-			"checksumSHA1": "UovsbmfW33+DGfUh1geZpGzIoVo=",
+			"checksumSHA1": "N1akwAdrHVfPPrsFOhG2ouP21VA=",
 			"path": "golang.org/x/net/http2",
-			"revision": "65dfc08770ce66f74becfdff5f8ab01caef4e946",
-			"revisionTime": "2016-10-24T22:38:16Z"
+			"revision": "60c41d1de8da134c05b7b40154a9a82bf5b7edb9",
+			"revisionTime": "2017-01-10T03:16:11Z"
 		},
 		{
 			"checksumSHA1": "HzuGD7AwgC0p1az1WAQnEFnEk98=",