use dep as denpendency managment tool

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

@@ -27,9 +27,9 @@ import (
 	"sync"
 	"time"
 
+	"golang.org/x/net/http/httpguts"
 	"golang.org/x/net/http2/hpack"
 	"golang.org/x/net/idna"
-	"golang.org/x/net/lex/httplex"
 )
 
 const (
@@ -87,7 +87,7 @@ type Transport struct {
 
 	// MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to
 	// send in the initial settings frame. It is how many bytes
-	// of response headers are allow. Unlike the http2 spec, zero here
+	// of response headers are allowed. Unlike the http2 spec, zero here
 	// means to use a default limit (currently 10MB). If you actually
 	// want to advertise an ulimited value to the peer, Transport
 	// interprets the highest possible value here (0xffffffff or 1<<32-1)
@@ -172,9 +172,10 @@ type ClientConn struct {
 	fr              *Framer
 	lastActive      time.Time
 	// Settings from peer: (also guarded by mu)
-	maxFrameSize         uint32
-	maxConcurrentStreams uint32
-	initialWindowSize    uint32
+	maxFrameSize          uint32
+	maxConcurrentStreams  uint32
+	peerMaxHeaderListSize uint64
+	initialWindowSize     uint32
 
 	hbuf    bytes.Buffer // HPACK encoder writes into this
 	henc    *hpack.Encoder
@@ -273,6 +274,13 @@ func (cs *clientStream) checkResetOrDone() error {
 	}
 }
 
+func (cs *clientStream) getStartedWrite() bool {
+	cc := cs.cc
+	cc.mu.Lock()
+	defer cc.mu.Unlock()
+	return cs.startedWrite
+}
+
 func (cs *clientStream) abortRequestBodyWrite(err error) {
 	if err == nil {
 		panic("nil error")
@@ -298,7 +306,26 @@ func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
 	return
 }
 
-var ErrNoCachedConn = errors.New("http2: no cached connection was available")
+// noCachedConnError is the concrete type of ErrNoCachedConn, which
+// needs to be detected by net/http regardless of whether it's its
+// bundled version (in h2_bundle.go with a rewritten type name) or
+// from a user's x/net/http2. As such, as it has a unique method name
+// (IsHTTP2NoCachedConnError) that net/http sniffs for via func
+// isNoCachedConnError.
+type noCachedConnError struct{}
+
+func (noCachedConnError) IsHTTP2NoCachedConnError() {}
+func (noCachedConnError) Error() string             { return "http2: no cached connection was available" }
+
+// isNoCachedConnError reports whether err is of type noCachedConnError
+// or its equivalent renamed type in net/http2's h2_bundle.go. Both types
+// may coexist in the same running program.
+func isNoCachedConnError(err error) bool {
+	_, ok := err.(interface{ IsHTTP2NoCachedConnError() })
+	return ok
+}
+
+var ErrNoCachedConn error = noCachedConnError{}
 
 // RoundTripOpt are options for the Transport.RoundTripOpt method.
 type RoundTripOpt struct {
@@ -348,14 +375,9 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res
 			return nil, err
 		}
 		traceGotConn(req, cc)
-		res, err := cc.RoundTrip(req)
+		res, gotErrAfterReqBodyWrite, err := cc.roundTrip(req)
 		if err != nil && retry <= 6 {
-			afterBodyWrite := false
-			if e, ok := err.(afterReqBodyWriteError); ok {
-				err = e
-				afterBodyWrite = true
-			}
-			if req, err = shouldRetryRequest(req, err, afterBodyWrite); err == nil {
+			if req, err = shouldRetryRequest(req, err, gotErrAfterReqBodyWrite); err == nil {
 				// After the first retry, do exponential backoff with 10% jitter.
 				if retry == 0 {
 					continue
@@ -393,16 +415,6 @@ var (
 	errClientConnGotGoAway = errors.New("http2: Transport received Server's graceful shutdown GOAWAY")
 )
 
-// afterReqBodyWriteError is a wrapper around errors returned by ClientConn.RoundTrip.
-// It is used to signal that err happened after part of Request.Body was sent to the server.
-type afterReqBodyWriteError struct {
-	err error
-}
-
-func (e afterReqBodyWriteError) Error() string {
-	return e.err.Error() + "; some request body already written"
-}
-
 // 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
@@ -519,17 +531,18 @@ func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
 
 func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, error) {
 	cc := &ClientConn{
-		t:                    t,
-		tconn:                c,
-		readerDone:           make(chan struct{}),
-		nextStreamID:         1,
-		maxFrameSize:         16 << 10, // spec default
-		initialWindowSize:    65535,    // spec default
-		maxConcurrentStreams: 1000,     // "infinite", per spec. 1000 seems good enough.
-		streams:              make(map[uint32]*clientStream),
-		singleUse:            singleUse,
-		wantSettingsAck:      true,
-		pings:                make(map[[8]byte]chan struct{}),
+		t:                     t,
+		tconn:                 c,
+		readerDone:            make(chan struct{}),
+		nextStreamID:          1,
+		maxFrameSize:          16 << 10,           // spec default
+		initialWindowSize:     65535,              // spec default
+		maxConcurrentStreams:  1000,               // "infinite", per spec. 1000 seems good enough.
+		peerMaxHeaderListSize: 0xffffffffffffffff, // "infinite", per spec. Use 2^64-1 instead.
+		streams:               make(map[uint32]*clientStream),
+		singleUse:             singleUse,
+		wantSettingsAck:       true,
+		pings:                 make(map[[8]byte]chan struct{}),
 	}
 	if d := t.idleConnTimeout(); d != 0 {
 		cc.idleTimeout = d
@@ -554,6 +567,10 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro
 	// henc in response to SETTINGS frames?
 	cc.henc = hpack.NewEncoder(&cc.hbuf)
 
+	if t.AllowHTTP {
+		cc.nextStreamID = 3
+	}
+
 	if cs, ok := c.(connectionStater); ok {
 		state := cs.ConnectionState()
 		cc.tlsState = &state
@@ -750,8 +767,13 @@ func actualContentLength(req *http.Request) int64 {
 }
 
 func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
+	resp, _, err := cc.roundTrip(req)
+	return resp, err
+}
+
+func (cc *ClientConn) roundTrip(req *http.Request) (res *http.Response, gotErrAfterReqBodyWrite bool, err error) {
 	if err := checkConnHeaders(req); err != nil {
-		return nil, err
+		return nil, false, err
 	}
 	if cc.idleTimer != nil {
 		cc.idleTimer.Stop()
@@ -759,14 +781,14 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 
 	trailers, err := commaSeparatedTrailers(req)
 	if err != nil {
-		return nil, err
+		return nil, false, err
 	}
 	hasTrailers := trailers != ""
 
 	cc.mu.Lock()
 	if err := cc.awaitOpenSlotForRequest(req); err != nil {
 		cc.mu.Unlock()
-		return nil, err
+		return nil, false, err
 	}
 
 	body := req.Body
@@ -800,7 +822,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 	hdrs, err := cc.encodeHeaders(req, requestedGzip, trailers, contentLen)
 	if err != nil {
 		cc.mu.Unlock()
-		return nil, err
+		return nil, false, err
 	}
 
 	cs := cc.newStream()
@@ -812,7 +834,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 
 	cc.wmu.Lock()
 	endStream := !hasBody && !hasTrailers
-	werr := cc.writeHeaders(cs.ID, endStream, hdrs)
+	werr := cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs)
 	cc.wmu.Unlock()
 	traceWroteHeaders(cs.trace)
 	cc.mu.Unlock()
@@ -826,7 +848,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 		// Don't bother sending a RST_STREAM (our write already failed;
 		// no need to keep writing)
 		traceWroteRequest(cs.trace, werr)
-		return nil, werr
+		return nil, false, werr
 	}
 
 	var respHeaderTimer <-chan time.Time
@@ -845,7 +867,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 	bodyWritten := false
 	ctx := reqContext(req)
 
-	handleReadLoopResponse := func(re resAndError) (*http.Response, error) {
+	handleReadLoopResponse := func(re resAndError) (*http.Response, bool, error) {
 		res := re.res
 		if re.err != nil || res.StatusCode > 299 {
 			// On error or status code 3xx, 4xx, 5xx, etc abort any
@@ -861,18 +883,12 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 			cs.abortRequestBodyWrite(errStopReqBodyWrite)
 		}
 		if re.err != nil {
-			cc.mu.Lock()
-			afterBodyWrite := cs.startedWrite
-			cc.mu.Unlock()
 			cc.forgetStreamID(cs.ID)
-			if afterBodyWrite {
-				return nil, afterReqBodyWriteError{re.err}
-			}
-			return nil, re.err
+			return nil, cs.getStartedWrite(), re.err
 		}
 		res.Request = req
 		res.TLS = cc.tlsState
-		return res, nil
+		return res, false, nil
 	}
 
 	for {
@@ -887,7 +903,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
 			cc.forgetStreamID(cs.ID)
-			return nil, errTimeout
+			return nil, cs.getStartedWrite(), errTimeout
 		case <-ctx.Done():
 			if !hasBody || bodyWritten {
 				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
@@ -896,7 +912,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
 			cc.forgetStreamID(cs.ID)
-			return nil, ctx.Err()
+			return nil, cs.getStartedWrite(), ctx.Err()
 		case <-req.Cancel:
 			if !hasBody || bodyWritten {
 				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
@@ -905,12 +921,12 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
 			cc.forgetStreamID(cs.ID)
-			return nil, errRequestCanceled
+			return nil, cs.getStartedWrite(), errRequestCanceled
 		case <-cs.peerReset:
 			// processResetStream already removed the
 			// stream from the streams map; no need for
 			// forgetStreamID.
-			return nil, cs.resetErr
+			return nil, cs.getStartedWrite(), cs.resetErr
 		case err := <-bodyWriter.resc:
 			// Prefer the read loop's response, if available. Issue 16102.
 			select {
@@ -919,7 +935,7 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 			default:
 			}
 			if err != nil {
-				return nil, err
+				return nil, cs.getStartedWrite(), err
 			}
 			bodyWritten = true
 			if d := cc.responseHeaderTimeout(); d != 0 {
@@ -939,6 +955,9 @@ func (cc *ClientConn) awaitOpenSlotForRequest(req *http.Request) error {
 	for {
 		cc.lastActive = time.Now()
 		if cc.closed || !cc.canTakeNewRequestLocked() {
+			if waitingForConn != nil {
+				close(waitingForConn)
+			}
 			return errClientConnUnusable
 		}
 		if int64(len(cc.streams))+1 <= int64(cc.maxConcurrentStreams) {
@@ -971,13 +990,12 @@ func (cc *ClientConn) awaitOpenSlotForRequest(req *http.Request) error {
 }
 
 // requires cc.wmu be held
-func (cc *ClientConn) writeHeaders(streamID uint32, endStream bool, hdrs []byte) error {
+func (cc *ClientConn) writeHeaders(streamID uint32, endStream bool, maxFrameSize int, hdrs []byte) error {
 	first := true // first frame written (HEADERS is first, then CONTINUATION)
-	frameSize := int(cc.maxFrameSize)
 	for len(hdrs) > 0 && cc.werr == nil {
 		chunk := hdrs
-		if len(chunk) > frameSize {
-			chunk = chunk[:frameSize]
+		if len(chunk) > maxFrameSize {
+			chunk = chunk[:maxFrameSize]
 		}
 		hdrs = hdrs[len(chunk):]
 		endHeaders := len(hdrs) == 0
@@ -1085,17 +1103,26 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (
 	var trls []byte
 	if hasTrailers {
 		cc.mu.Lock()
-		defer cc.mu.Unlock()
-		trls = cc.encodeTrailers(req)
+		trls, err = cc.encodeTrailers(req)
+		cc.mu.Unlock()
+		if err != nil {
+			cc.writeStreamReset(cs.ID, ErrCodeInternal, err)
+			cc.forgetStreamID(cs.ID)
+			return err
+		}
 	}
 
+	cc.mu.Lock()
+	maxFrameSize := int(cc.maxFrameSize)
+	cc.mu.Unlock()
+
 	cc.wmu.Lock()
 	defer cc.wmu.Unlock()
 
 	// Two ways to send END_STREAM: either with trailers, or
 	// with an empty DATA frame.
 	if len(trls) > 0 {
-		err = cc.writeHeaders(cs.ID, true, trls)
+		err = cc.writeHeaders(cs.ID, true, maxFrameSize, trls)
 	} else {
 		err = cc.fr.WriteData(cs.ID, true, nil)
 	}
@@ -1154,7 +1181,7 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 	if host == "" {
 		host = req.URL.Host
 	}
-	host, err := httplex.PunycodeHostPort(host)
+	host, err := httpguts.PunycodeHostPort(host)
 	if err != nil {
 		return nil, err
 	}
@@ -1179,72 +1206,96 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 	// potentially pollute our hpack state. (We want to be able to
 	// continue to reuse the hpack encoder for future requests)
 	for k, vv := range req.Header {
-		if !httplex.ValidHeaderFieldName(k) {
+		if !httpguts.ValidHeaderFieldName(k) {
 			return nil, fmt.Errorf("invalid HTTP header name %q", k)
 		}
 		for _, v := range vv {
-			if !httplex.ValidHeaderFieldValue(v) {
+			if !httpguts.ValidHeaderFieldValue(v) {
 				return nil, fmt.Errorf("invalid HTTP header value %q for header %q", v, k)
 			}
 		}
 	}
 
-	// 8.1.2.3 Request Pseudo-Header Fields
-	// The :path pseudo-header field includes the path and query parts of the
-	// target URI (the path-absolute production and optionally a '?' character
-	// followed by the query production (see Sections 3.3 and 3.4 of
-	// [RFC3986]).
-	cc.writeHeader(":authority", host)
-	cc.writeHeader(":method", req.Method)
-	if req.Method != "CONNECT" {
-		cc.writeHeader(":path", path)
-		cc.writeHeader(":scheme", req.URL.Scheme)
-	}
-	if trailers != "" {
-		cc.writeHeader("trailer", trailers)
+	enumerateHeaders := func(f func(name, value string)) {
+		// 8.1.2.3 Request Pseudo-Header Fields
+		// The :path pseudo-header field includes the path and query parts of the
+		// target URI (the path-absolute production and optionally a '?' character
+		// followed by the query production (see Sections 3.3 and 3.4 of
+		// [RFC3986]).
+		f(":authority", host)
+		f(":method", req.Method)
+		if req.Method != "CONNECT" {
+			f(":path", path)
+			f(":scheme", req.URL.Scheme)
+		}
+		if trailers != "" {
+			f("trailer", trailers)
+		}
+
+		var didUA bool
+		for k, vv := range req.Header {
+			if strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
+				// Host is :authority, already sent.
+				// Content-Length is automatic, set below.
+				continue
+			} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
+				strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
+				strings.EqualFold(k, "keep-alive") {
+				// Per 8.1.2.2 Connection-Specific Header
+				// Fields, don't send connection-specific
+				// fields. We have already checked if any
+				// are error-worthy so just ignore the rest.
+				continue
+			} else if strings.EqualFold(k, "user-agent") {
+				// Match Go's http1 behavior: at most one
+				// User-Agent. If set to nil or empty string,
+				// then omit it. Otherwise if not mentioned,
+				// include the default (below).
+				didUA = true
+				if len(vv) < 1 {
+					continue
+				}
+				vv = vv[:1]
+				if vv[0] == "" {
+					continue
+				}
+
+			}
+
+			for _, v := range vv {
+				f(k, v)
+			}
+		}
+		if shouldSendReqContentLength(req.Method, contentLength) {
+			f("content-length", strconv.FormatInt(contentLength, 10))
+		}
+		if addGzipHeader {
+			f("accept-encoding", "gzip")
+		}
+		if !didUA {
+			f("user-agent", defaultUserAgent)
+		}
 	}
 
-	var didUA bool
-	for k, vv := range req.Header {
-		lowKey := strings.ToLower(k)
-		switch lowKey {
-		case "host", "content-length":
-			// Host is :authority, already sent.
-			// Content-Length is automatic, set below.
-			continue
-		case "connection", "proxy-connection", "transfer-encoding", "upgrade", "keep-alive":
-			// Per 8.1.2.2 Connection-Specific Header
-			// Fields, don't send connection-specific
-			// fields. We have already checked if any
-			// are error-worthy so just ignore the rest.
-			continue
-		case "user-agent":
-			// Match Go's http1 behavior: at most one
-			// User-Agent. If set to nil or empty string,
-			// then omit it. Otherwise if not mentioned,
-			// include the default (below).
-			didUA = true
-			if len(vv) < 1 {
-				continue
-			}
-			vv = vv[:1]
-			if vv[0] == "" {
-				continue
-			}
-		}
-		for _, v := range vv {
-			cc.writeHeader(lowKey, v)
-		}
-	}
-	if shouldSendReqContentLength(req.Method, contentLength) {
-		cc.writeHeader("content-length", strconv.FormatInt(contentLength, 10))
-	}
-	if addGzipHeader {
-		cc.writeHeader("accept-encoding", "gzip")
-	}
-	if !didUA {
-		cc.writeHeader("user-agent", defaultUserAgent)
+	// Do a first pass over the headers counting bytes to ensure
+	// we don't exceed cc.peerMaxHeaderListSize. This is done as a
+	// separate pass before encoding the headers to prevent
+	// modifying the hpack state.
+	hlSize := uint64(0)
+	enumerateHeaders(func(name, value string) {
+		hf := hpack.HeaderField{Name: name, Value: value}
+		hlSize += uint64(hf.Size())
+	})
+
+	if hlSize > cc.peerMaxHeaderListSize {
+		return nil, errRequestHeaderListSize
 	}
+
+	// Header list size is ok. Write the headers.
+	enumerateHeaders(func(name, value string) {
+		cc.writeHeader(strings.ToLower(name), value)
+	})
+
 	return cc.hbuf.Bytes(), nil
 }
 
@@ -1271,17 +1322,29 @@ func shouldSendReqContentLength(method string, contentLength int64) bool {
 }
 
 // requires cc.mu be held.
-func (cc *ClientConn) encodeTrailers(req *http.Request) []byte {
+func (cc *ClientConn) encodeTrailers(req *http.Request) ([]byte, error) {
 	cc.hbuf.Reset()
+
+	hlSize := uint64(0)
 	for k, vv := range req.Trailer {
-		// Transfer-Encoding, etc.. have already been filter at the
+		for _, v := range vv {
+			hf := hpack.HeaderField{Name: k, Value: v}
+			hlSize += uint64(hf.Size())
+		}
+	}
+	if hlSize > cc.peerMaxHeaderListSize {
+		return nil, errRequestHeaderListSize
+	}
+
+	for k, vv := range req.Trailer {
+		// Transfer-Encoding, etc.. have already been filtered at the
 		// start of RoundTrip
 		lowKey := strings.ToLower(k)
 		for _, v := range vv {
 			cc.writeHeader(lowKey, v)
 		}
 	}
-	return cc.hbuf.Bytes()
+	return cc.hbuf.Bytes(), nil
 }
 
 func (cc *ClientConn) writeHeader(name, value string) {
@@ -1339,17 +1402,12 @@ func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream {
 // clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop.
 type clientConnReadLoop struct {
 	cc            *ClientConn
-	activeRes     map[uint32]*clientStream // keyed by streamID
 	closeWhenIdle bool
 }
 
 // readLoop runs in its own goroutine and reads and dispatches frames.
 func (cc *ClientConn) readLoop() {
-	rl := &clientConnReadLoop{
-		cc:        cc,
-		activeRes: make(map[uint32]*clientStream),
-	}
-
+	rl := &clientConnReadLoop{cc: cc}
 	defer rl.cleanup()
 	cc.readerErr = rl.run()
 	if ce, ok := cc.readerErr.(ConnectionError); ok {
@@ -1404,10 +1462,8 @@ func (rl *clientConnReadLoop) cleanup() {
 	} else if err == io.EOF {
 		err = io.ErrUnexpectedEOF
 	}
-	for _, cs := range rl.activeRes {
-		cs.bufPipe.CloseWithError(err)
-	}
 	for _, cs := range cc.streams {
+		cs.bufPipe.CloseWithError(err) // no-op if already closed
 		select {
 		case cs.resc <- resAndError{err: err}:
 		default:
@@ -1485,7 +1541,7 @@ func (rl *clientConnReadLoop) run() error {
 			}
 			return err
 		}
-		if rl.closeWhenIdle && gotReply && maybeIdle && len(rl.activeRes) == 0 {
+		if rl.closeWhenIdle && gotReply && maybeIdle {
 			cc.closeIfIdle()
 		}
 	}
@@ -1493,13 +1549,31 @@ func (rl *clientConnReadLoop) run() error {
 
 func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error {
 	cc := rl.cc
-	cs := cc.streamByID(f.StreamID, f.StreamEnded())
+	cs := cc.streamByID(f.StreamID, false)
 	if cs == nil {
 		// We'd get here if we canceled a request while the
 		// server had its response still in flight. So if this
 		// was just something we canceled, ignore it.
 		return nil
 	}
+	if f.StreamEnded() {
+		// Issue 20521: If the stream has ended, streamByID() causes
+		// clientStream.done to be closed, which causes the request's bodyWriter
+		// to be closed with an errStreamClosed, which may be received by
+		// clientConn.RoundTrip before the result of processing these headers.
+		// Deferring stream closure allows the header processing to occur first.
+		// clientConn.RoundTrip may still receive the bodyWriter error first, but
+		// the fix for issue 16102 prioritises any response.
+		//
+		// Issue 22413: If there is no request body, we should close the
+		// stream before writing to cs.resc so that the stream is closed
+		// immediately once RoundTrip returns.
+		if cs.req.Body != nil {
+			defer cc.forgetStreamID(f.StreamID)
+		} else {
+			cc.forgetStreamID(f.StreamID)
+		}
+	}
 	if !cs.firstByte {
 		if cs.trace != nil {
 			// TODO(bradfitz): move first response byte earlier,
@@ -1523,6 +1597,7 @@ func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error {
 		}
 		// Any other error type is a stream error.
 		cs.cc.writeStreamReset(f.StreamID, ErrCodeProtocol, err)
+		cc.forgetStreamID(cs.ID)
 		cs.resc <- resAndError{err: err}
 		return nil // return nil from process* funcs to keep conn alive
 	}
@@ -1530,9 +1605,6 @@ func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error {
 		// (nil, nil) special case. See handleResponse docs.
 		return nil
 	}
-	if res.Body != noBody {
-		rl.activeRes[cs.ID] = cs
-	}
 	cs.resTrailer = &res.Trailer
 	cs.resc <- resAndError{res: res}
 	return nil
@@ -1552,11 +1624,11 @@ func (rl *clientConnReadLoop) handleResponse(cs *clientStream, f *MetaHeadersFra
 
 	status := f.PseudoValue("status")
 	if status == "" {
-		return nil, errors.New("missing status pseudo header")
+		return nil, errors.New("malformed response from server: missing status pseudo header")
 	}
 	statusCode, err := strconv.Atoi(status)
 	if err != nil {
-		return nil, errors.New("malformed non-numeric status pseudo header")
+		return nil, errors.New("malformed response from server: malformed non-numeric status pseudo header")
 	}
 
 	if statusCode == 100 {
@@ -1789,7 +1861,23 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error {
 		}
 		return nil
 	}
+	if !cs.firstByte {
+		cc.logf("protocol error: received DATA before a HEADERS frame")
+		rl.endStreamError(cs, StreamError{
+			StreamID: f.StreamID,
+			Code:     ErrCodeProtocol,
+		})
+		return nil
+	}
 	if f.Length > 0 {
+		if cs.req.Method == "HEAD" && len(data) > 0 {
+			cc.logf("protocol error: received DATA on a HEAD request")
+			rl.endStreamError(cs, StreamError{
+				StreamID: f.StreamID,
+				Code:     ErrCodeProtocol,
+			})
+			return nil
+		}
 		// Check connection-level flow control.
 		cc.mu.Lock()
 		if cs.inflow.available() >= int32(f.Length) {
@@ -1851,11 +1939,10 @@ func (rl *clientConnReadLoop) endStreamError(cs *clientStream, err error) {
 		err = io.EOF
 		code = cs.copyTrailers
 	}
-	cs.bufPipe.closeWithErrorAndCode(err, code)
-	delete(rl.activeRes, cs.ID)
 	if isConnectionCloseRequest(cs.req) {
 		rl.closeWhenIdle = true
 	}
+	cs.bufPipe.closeWithErrorAndCode(err, code)
 
 	select {
 	case cs.resc <- resAndError{err: err}:
@@ -1903,6 +1990,8 @@ func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error {
 			cc.maxFrameSize = s.Val
 		case SettingMaxConcurrentStreams:
 			cc.maxConcurrentStreams = s.Val
+		case SettingMaxHeaderListSize:
+			cc.peerMaxHeaderListSize = uint64(s.Val)
 		case SettingInitialWindowSize:
 			// Values above the maximum flow-control
 			// window size of 2^31-1 MUST be treated as a
@@ -1980,7 +2069,6 @@ func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error {
 		cs.bufPipe.CloseWithError(err)
 		cs.cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl
 	}
-	delete(rl.activeRes, cs.ID)
 	return nil
 }
 
@@ -2069,6 +2157,7 @@ func (cc *ClientConn) writeStreamReset(streamID uint32, code ErrCode, err error)
 
 var (
 	errResponseHeaderListSize = errors.New("http2: response header list larger than advertised limit")
+	errRequestHeaderListSize  = errors.New("http2: request header list larger than peer's advertised limit")
 	errPseudoTrailers         = errors.New("http2: invalid pseudo header in trailers")
 )
 
@@ -2162,7 +2251,7 @@ func (t *Transport) getBodyWriterState(cs *clientStream, body io.Reader) (s body
 	}
 	s.delay = t.expectContinueTimeout()
 	if s.delay == 0 ||
-		!httplex.HeaderValuesContainsToken(
+		!httpguts.HeaderValuesContainsToken(
 			cs.req.Header["Expect"],
 			"100-continue") {
 		return
@@ -2217,5 +2306,5 @@ func (s bodyWriterState) scheduleBodyWrite() {
 // isConnectionCloseRequest reports whether req should use its own
 // connection for a single request and then close the connection.
 func isConnectionCloseRequest(req *http.Request) bool {
-	return req.Close || httplex.HeaderValuesContainsToken(req.Header["Connection"], "close")
+	return req.Close || httpguts.HeaderValuesContainsToken(req.Header["Connection"], "close")
 }