vendor: udpate golang.org/x/net

2026-05-01 21:49:11 +08:00 · 2018-05-04 18:37:43 +08:00
parent 30af32728a
commit cd37d22f3b
146 changed files with 23560 additions and 14829 deletions
--- a/vendor/golang.org/x/net/http2/ciphers.go
+++ b/vendor/golang.org/x/net/http2/ciphers.go
@@ -5,7 +5,7 @@
 package http2

 // A list of the possible cipher suite ids. Taken from
-// http://www.iana.org/assignments/tls-parameters/tls-parameters.txt
+// https://www.iana.org/assignments/tls-parameters/tls-parameters.txt

 const (
 	cipher_TLS_NULL_WITH_NULL_NULL               uint16 = 0x0000
--- a/vendor/golang.org/x/net/http2/ciphers_test.go
+++ b/vendor/golang.org/x/net/http2/ciphers_test.go
@@ -9,7 +9,7 @@ import "testing"
 func TestIsBadCipherBad(t *testing.T) {
 	for _, c := range badCiphers {
 		if !isBadCipher(c) {
-			t.Errorf("Wrong result for isBadCipher(%d), want true")
+			t.Errorf("Wrong result for isBadCipher(%d), want true", c)
 		}
 	}
 }
--- a/vendor/golang.org/x/net/http2/configure_transport.go
+++ b/vendor/golang.org/x/net/http2/configure_transport.go
@@ -73,7 +73,7 @@ type noDialH2RoundTripper struct{ t *Transport }

 func (rt noDialH2RoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
 	res, err := rt.t.RoundTrip(req)
-	if err == ErrNoCachedConn {
+	if isNoCachedConnError(err) {
 		return nil, http.ErrSkipAltProtocol
 	}
 	return res, err
--- a/vendor/golang.org/x/net/http2/errors.go
+++ b/vendor/golang.org/x/net/http2/errors.go
@@ -87,13 +87,16 @@ type goAwayFlowError struct{}

 func (goAwayFlowError) Error() string { return "connection exceeded flow control window size" }

-// connErrorReason wraps a ConnectionError with an informative error about why it occurs.
-
+// connError represents an HTTP/2 ConnectionError error code, along
+// with a string (for debugging) explaining why.
+//
 // Errors of this type are only returned by the frame parser functions
-// and converted into ConnectionError(ErrCodeProtocol).
+// and converted into ConnectionError(Code), after stashing away
+// the Reason into the Framer's errDetail field, accessible via
+// the (*Framer).ErrorDetail method.
 type connError struct {
-	Code   ErrCode
-	Reason string
+	Code   ErrCode // the ConnectionError error code
+	Reason string  // additional reason
 }

 func (e connError) Error() string {
--- a/vendor/golang.org/x/net/http2/go18.go
+++ b/vendor/golang.org/x/net/http2/go18.go
@@ -52,3 +52,5 @@ func reqGetBody(req *http.Request) func() (io.ReadCloser, error) {
 func reqBodyIsNoBody(body io.ReadCloser) bool {
 	return body == http.NoBody
 }
+
+func go18httpNoBody() io.ReadCloser { return http.NoBody } // for tests only
--- a/vendor/golang.org/x/net/http2/go19_test.go
+++ b/vendor/golang.org/x/net/http2/go19_test.go
@@ -46,7 +46,6 @@ func TestServerGracefulShutdown(t *testing.T) {
 	wanth := [][2]string{
 		{":status", "200"},
 		{"x-foo", "bar"},
-		{"content-type", "text/plain; charset=utf-8"},
 		{"content-length", "0"},
 	}
 	if !reflect.DeepEqual(goth, wanth) {
--- a/vendor/golang.org/x/net/http2/h2demo/.gitignore
+++ b/vendor/golang.org/x/net/http2/h2demo/.gitignore
@@ -3,3 +3,4 @@ h2demo.linux
 client-id.dat
 client-secret.dat
 token.dat
+ca-certificates.crt
--- a/vendor/golang.org/x/net/http2/h2demo/Dockerfile
+++ b/vendor/golang.org/x/net/http2/h2demo/Dockerfile
@@ -0,0 +1,11 @@
+# Copyright 2018 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.
+
+FROM scratch
+LABEL maintainer "golang-dev@googlegroups.com"
+
+COPY ca-certificates.crt /etc/ssl/certs/
+COPY h2demo /
+ENTRYPOINT ["/h2demo", "-prod"]
+
--- a/vendor/golang.org/x/net/http2/h2demo/Dockerfile.0
+++ b/vendor/golang.org/x/net/http2/h2demo/Dockerfile.0
@@ -0,0 +1,134 @@
+# Copyright 2018 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.
+
+FROM golang:1.9
+LABEL maintainer "golang-dev@googlegroups.com"
+
+ENV CGO_ENABLED=0
+
+# BEGIN deps (run `make update-deps` to update)
+
+# Repo cloud.google.com/go at 1d0c2da (2018-01-30)
+ENV REV=1d0c2da40456a9b47f5376165f275424acc15c09
+RUN go get -d cloud.google.com/go/compute/metadata `#and 6 other pkgs` &&\
+    (cd /go/src/cloud.google.com/go && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo github.com/golang/protobuf at 9255415 (2018-01-25)
+ENV REV=925541529c1fa6821df4e44ce2723319eb2be768
+RUN go get -d github.com/golang/protobuf/proto `#and 6 other pkgs` &&\
+    (cd /go/src/github.com/golang/protobuf && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo github.com/googleapis/gax-go at 317e000 (2017-09-15)
+ENV REV=317e0006254c44a0ac427cc52a0e083ff0b9622f
+RUN go get -d github.com/googleapis/gax-go &&\
+    (cd /go/src/github.com/googleapis/gax-go && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo go4.org at 034d17a (2017-05-25)
+ENV REV=034d17a462f7b2dcd1a4a73553ec5357ff6e6c6e
+RUN go get -d go4.org/syncutil/singleflight &&\
+    (cd /go/src/go4.org && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo golang.org/x/build at 8aa9ee0 (2018-02-01)
+ENV REV=8aa9ee0e557fd49c14113e5ba106e13a5b455460
+RUN go get -d golang.org/x/build/autocertcache &&\
+    (cd /go/src/golang.org/x/build && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo golang.org/x/crypto at 1875d0a (2018-01-27)
+ENV REV=1875d0a70c90e57f11972aefd42276df65e895b9
+RUN go get -d golang.org/x/crypto/acme `#and 2 other pkgs` &&\
+    (cd /go/src/golang.org/x/crypto && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo golang.org/x/oauth2 at 30785a2 (2018-01-04)
+ENV REV=30785a2c434e431ef7c507b54617d6a951d5f2b4
+RUN go get -d golang.org/x/oauth2 `#and 5 other pkgs` &&\
+    (cd /go/src/golang.org/x/oauth2 && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo golang.org/x/text at e19ae14 (2017-12-27)
+ENV REV=e19ae1496984b1c655b8044a65c0300a3c878dd3
+RUN go get -d golang.org/x/text/secure/bidirule `#and 4 other pkgs` &&\
+    (cd /go/src/golang.org/x/text && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo google.golang.org/api at 7d0e2d3 (2018-01-30)
+ENV REV=7d0e2d350555821bef5a5b8aecf0d12cc1def633
+RUN go get -d google.golang.org/api/gensupport `#and 9 other pkgs` &&\
+    (cd /go/src/google.golang.org/api && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo google.golang.org/genproto at 4eb30f4 (2018-01-25)
+ENV REV=4eb30f4778eed4c258ba66527a0d4f9ec8a36c45
+RUN go get -d google.golang.org/genproto/googleapis/api/annotations `#and 3 other pkgs` &&\
+    (cd /go/src/google.golang.org/genproto && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Repo google.golang.org/grpc at 0bd008f (2018-01-25)
+ENV REV=0bd008f5fadb62d228f12b18d016709e8139a7af
+RUN go get -d google.golang.org/grpc `#and 23 other pkgs` &&\
+    (cd /go/src/google.golang.org/grpc && (git cat-file -t $REV 2>/dev/null || git fetch -q origin $REV) && git reset --hard $REV)
+
+# Optimization to speed up iterative development, not necessary for correctness:
+RUN go install cloud.google.com/go/compute/metadata \
+	cloud.google.com/go/iam \
+	cloud.google.com/go/internal \
+	cloud.google.com/go/internal/optional \
+	cloud.google.com/go/internal/version \
+	cloud.google.com/go/storage \
+	github.com/golang/protobuf/proto \
+	github.com/golang/protobuf/protoc-gen-go/descriptor \
+	github.com/golang/protobuf/ptypes \
+	github.com/golang/protobuf/ptypes/any \
+	github.com/golang/protobuf/ptypes/duration \
+	github.com/golang/protobuf/ptypes/timestamp \
+	github.com/googleapis/gax-go \
+	go4.org/syncutil/singleflight \
+	golang.org/x/build/autocertcache \
+	golang.org/x/crypto/acme \
+	golang.org/x/crypto/acme/autocert \
+	golang.org/x/oauth2 \
+	golang.org/x/oauth2/google \
+	golang.org/x/oauth2/internal \
+	golang.org/x/oauth2/jws \
+	golang.org/x/oauth2/jwt \
+	golang.org/x/text/secure/bidirule \
+	golang.org/x/text/transform \
+	golang.org/x/text/unicode/bidi \
+	golang.org/x/text/unicode/norm \
+	google.golang.org/api/gensupport \
+	google.golang.org/api/googleapi \
+	google.golang.org/api/googleapi/internal/uritemplates \
+	google.golang.org/api/googleapi/transport \
+	google.golang.org/api/internal \
+	google.golang.org/api/iterator \
+	google.golang.org/api/option \
+	google.golang.org/api/storage/v1 \
+	google.golang.org/api/transport/http \
+	google.golang.org/genproto/googleapis/api/annotations \
+	google.golang.org/genproto/googleapis/iam/v1 \
+	google.golang.org/genproto/googleapis/rpc/status \
+	google.golang.org/grpc \
+	google.golang.org/grpc/balancer \
+	google.golang.org/grpc/balancer/base \
+	google.golang.org/grpc/balancer/roundrobin \
+	google.golang.org/grpc/codes \
+	google.golang.org/grpc/connectivity \
+	google.golang.org/grpc/credentials \
+	google.golang.org/grpc/encoding \
+	google.golang.org/grpc/encoding/proto \
+	google.golang.org/grpc/grpclb/grpc_lb_v1/messages \
+	google.golang.org/grpc/grpclog \
+	google.golang.org/grpc/internal \
+	google.golang.org/grpc/keepalive \
+	google.golang.org/grpc/metadata \
+	google.golang.org/grpc/naming \
+	google.golang.org/grpc/peer \
+	google.golang.org/grpc/resolver \
+	google.golang.org/grpc/resolver/dns \
+	google.golang.org/grpc/resolver/passthrough \
+	google.golang.org/grpc/stats \
+	google.golang.org/grpc/status \
+	google.golang.org/grpc/tap \
+	google.golang.org/grpc/transport
+# END deps
+
+COPY . /go/src/golang.org/x/net/
+
+RUN go install -tags "h2demo netgo" -ldflags "-linkmode=external -extldflags '-static -pthread'" golang.org/x/net/http2/h2demo
+
--- a/vendor/golang.org/x/net/http2/h2demo/Makefile
+++ b/vendor/golang.org/x/net/http2/h2demo/Makefile
@@ -1,8 +1,55 @@
-h2demo.linux: h2demo.go
-	GOOS=linux go build --tags=h2demo -o h2demo.linux .
+# Copyright 2018 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.
+
+MUTABLE_VERSION ?= latest
+VERSION ?= $(shell git rev-parse --short HEAD)
+
+IMAGE_STAGING := gcr.io/go-dashboard-dev/h2demo
+IMAGE_PROD := gcr.io/symbolic-datum-552/h2demo
+
+DOCKER_IMAGE_build0=build0/h2demo:latest
+DOCKER_CTR_build0=h2demo-build0
+
+build0: *.go Dockerfile.0
+	docker build --force-rm -f Dockerfile.0 --tag=$(DOCKER_IMAGE_build0) ../..
+
+h2demo: build0
+	docker create --name $(DOCKER_CTR_build0) $(DOCKER_IMAGE_build0)
+	docker cp $(DOCKER_CTR_build0):/go/bin/$@ $@
+	docker rm $(DOCKER_CTR_build0)
+
+ca-certificates.crt:
+	docker create --name $(DOCKER_CTR_build0) $(DOCKER_IMAGE_build0)
+	docker cp $(DOCKER_CTR_build0):/etc/ssl/certs/$@ $@
+	docker rm $(DOCKER_CTR_build0)
+
+update-deps:
+	go install golang.org/x/build/cmd/gitlock
+	gitlock --update=Dockerfile.0 --ignore=golang.org/x/net --tags=h2demo golang.org/x/net/http2/h2demo
+
+docker-prod: Dockerfile h2demo ca-certificates.crt
+	docker build --force-rm --tag=$(IMAGE_PROD):$(VERSION) .
+	docker tag $(IMAGE_PROD):$(VERSION) $(IMAGE_PROD):$(MUTABLE_VERSION)
+docker-staging: Dockerfile h2demo ca-certificates.crt
+	docker build --force-rm --tag=$(IMAGE_STAGING):$(VERSION) .
+	docker tag $(IMAGE_STAGING):$(VERSION) $(IMAGE_STAGING):$(MUTABLE_VERSION)
+
+push-prod: docker-prod
+	gcloud docker -- push $(IMAGE_PROD):$(MUTABLE_VERSION)
+	gcloud docker -- push $(IMAGE_PROD):$(VERSION)
+push-staging: docker-staging
+	gcloud docker -- push $(IMAGE_STAGING):$(MUTABLE_VERSION)
+	gcloud docker -- push $(IMAGE_STAGING):$(VERSION)
+
+deploy-prod: push-prod
+	kubectl set image deployment/h2demo-deployment h2demo=$(IMAGE_PROD):$(VERSION)
+deploy-staging: push-staging
+	kubectl set image deployment/h2demo-deployment h2demo=$(IMAGE_STAGING):$(VERSION)
+
+.PHONY: clean
+clean:
+	$(RM) h2demo
+	$(RM) ca-certificates.crt

 FORCE:
-
-upload: FORCE
-	go install golang.org/x/build/cmd/upload
-	upload --verbose --osarch=linux-amd64 --tags=h2demo --file=go:golang.org/x/net/http2/h2demo --public http2-demo-server-tls/h2demo
--- a/vendor/golang.org/x/net/http2/h2demo/deployment-prod.yaml
+++ b/vendor/golang.org/x/net/http2/h2demo/deployment-prod.yaml
@@ -0,0 +1,28 @@
+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  name: h2demo-deployment
+spec:
+  replicas: 1
+  template:
+    metadata:
+      labels:
+        app: h2demo
+      annotations:
+        container.seccomp.security.alpha.kubernetes.io/h2demo: docker/default
+        container.apparmor.security.beta.kubernetes.io/h2demo: runtime/default
+    spec:
+      containers:
+      - name: h2demo
+        image: gcr.io/symbolic-datum-552/h2demo:latest
+        imagePullPolicy: Always
+        command: ["/h2demo", "-prod"]
+        ports:
+        - containerPort: 80
+        - containerPort: 443
+        resources:
+          requests:
+            cpu: "1"
+            memory: "1Gi"
+          limits:
+            memory: "2Gi"
--- a/vendor/golang.org/x/net/http2/h2demo/h2demo.go
+++ b/vendor/golang.org/x/net/http2/h2demo/h2demo.go
@@ -8,6 +8,7 @@ package main

 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"flag"
 	"fmt"
@@ -19,7 +20,6 @@ import (
 	"log"
 	"net"
 	"net/http"
-	"os"
 	"path"
 	"regexp"
 	"runtime"
@@ -28,7 +28,9 @@ import (
 	"sync"
 	"time"

+	"cloud.google.com/go/storage"
 	"go4.org/syncutil/singleflight"
+	"golang.org/x/build/autocertcache"
 	"golang.org/x/crypto/acme/autocert"
 	"golang.org/x/net/http2"
 )
@@ -426,19 +428,10 @@ func httpHost() string {
 	}
 }

-func serveProdTLS() error {
-	const cacheDir = "/var/cache/autocert"
-	if err := os.MkdirAll(cacheDir, 0700); err != nil {
-		return err
-	}
-	m := autocert.Manager{
-		Cache:      autocert.DirCache(cacheDir),
-		Prompt:     autocert.AcceptTOS,
-		HostPolicy: autocert.HostWhitelist("http2.golang.org"),
-	}
+func serveProdTLS(autocertManager *autocert.Manager) error {
 	srv := &http.Server{
 		TLSConfig: &tls.Config{
-			GetCertificate: m.GetCertificate,
+			GetCertificate: autocertManager.GetCertificate,
 		},
 	}
 	http2.ConfigureServer(srv, &http2.Server{
@@ -468,9 +461,21 @@ func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
 }

 func serveProd() error {
+	log.Printf("running in production mode")
+
+	storageClient, err := storage.NewClient(context.Background())
+	if err != nil {
+		log.Fatalf("storage.NewClient: %v", err)
+	}
+	autocertManager := &autocert.Manager{
+		Prompt:     autocert.AcceptTOS,
+		HostPolicy: autocert.HostWhitelist("http2.golang.org"),
+		Cache:      autocertcache.NewGoogleCloudStorageCache(storageClient, "golang-h2demo-autocert"),
+	}
+
 	errc := make(chan error, 2)
-	go func() { errc <- http.ListenAndServe(":80", nil) }()
-	go func() { errc <- serveProdTLS() }()
+	go func() { errc <- http.ListenAndServe(":80", autocertManager.HTTPHandler(http.DefaultServeMux)) }()
+	go func() { errc <- serveProdTLS(autocertManager) }()
 	return <-errc
 }

--- a/vendor/golang.org/x/net/http2/h2demo/service.yaml
+++ b/vendor/golang.org/x/net/http2/h2demo/service.yaml
@@ -0,0 +1,17 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: h2demo
+spec:
+  externalTrafficPolicy: Local
+  ports:
+    - port: 80
+      targetPort: 80
+      name: http
+    - port: 443
+      targetPort: 443
+      name: https
+  selector:
+    app: h2demo
+  type: LoadBalancer
+  loadBalancerIP: 130.211.116.44
--- a/vendor/golang.org/x/net/http2/h2i/h2i.go
+++ b/vendor/golang.org/x/net/http2/h2i/h2i.go
@@ -45,6 +45,7 @@ var (
 	flagNextProto = flag.String("nextproto", "h2,h2-14", "Comma-separated list of NPN/ALPN protocol names to negotiate.")
 	flagInsecure  = flag.Bool("insecure", false, "Whether to skip TLS cert validation")
 	flagSettings  = flag.String("settings", "empty", "comma-separated list of KEY=value settings for the initial SETTINGS frame. The magic value 'empty' sends an empty initial settings frame, and the magic value 'omit' causes no initial settings frame to be sent.")
+	flagDial      = flag.String("dial", "", "optional ip:port to dial, to connect to a host:port but use a different SNI name (including a SNI name without DNS)")
 )

 type command struct {
@@ -147,11 +148,14 @@ func (app *h2i) Main() error {
 		InsecureSkipVerify: *flagInsecure,
 	}

-	hostAndPort := withPort(app.host)
+	hostAndPort := *flagDial
+	if hostAndPort == "" {
+		hostAndPort = withPort(app.host)
+	}
 	log.Printf("Connecting to %s ...", hostAndPort)
 	tc, err := tls.Dial("tcp", hostAndPort, cfg)
 	if err != nil {
-		return fmt.Errorf("Error dialing %s: %v", withPort(app.host), err)
+		return fmt.Errorf("Error dialing %s: %v", hostAndPort, err)
 	}
 	log.Printf("Connected to %v", tc.RemoteAddr())
 	defer tc.Close()
@@ -460,6 +464,15 @@ func (app *h2i) readFrames() error {
 				app.hdec = hpack.NewDecoder(tableSize, app.onNewHeaderField)
 			}
 			app.hdec.Write(f.HeaderBlockFragment())
+		case *http2.PushPromiseFrame:
+			if app.hdec == nil {
+				// TODO: if the user uses h2i to send a SETTINGS frame advertising
+				// something larger, we'll need to respect SETTINGS_HEADER_TABLE_SIZE
+				// and stuff here instead of using the 4k default. But for now:
+				tableSize := uint32(4 << 10)
+				app.hdec = hpack.NewDecoder(tableSize, app.onNewHeaderField)
+			}
+			app.hdec.Write(f.HeaderBlockFragment())
 		}
 	}
 }
--- a/vendor/golang.org/x/net/http2/hpack/encode.go
+++ b/vendor/golang.org/x/net/http2/hpack/encode.go
@@ -206,7 +206,7 @@ func appendVarInt(dst []byte, n byte, i uint64) []byte {
 }

 // appendHpackString appends s, as encoded in "String Literal"
-// representation, to dst and returns the the extended buffer.
+// representation, to dst and returns the extended buffer.
 //
 // s will be encoded in Huffman codes only when it produces strictly
 // shorter byte string.
--- a/vendor/golang.org/x/net/http2/http2.go
+++ b/vendor/golang.org/x/net/http2/http2.go
@@ -312,7 +312,7 @@ func mustUint31(v int32) uint32 {
 }

 // bodyAllowedForStatus reports whether a given response status code
-// permits a body. See RFC 2616, section 4.4.
+// permits a body. See RFC 7230, section 3.3.
 func bodyAllowedForStatus(status int) bool {
 	switch {
 	case status >= 100 && status <= 199:
@@ -376,12 +376,16 @@ func (s *sorter) SortStrings(ss []string) {
 // validPseudoPath reports whether v is a valid :path pseudo-header
 // value. It must be either:
 //
-//     *) a non-empty string starting with '/', but not with with "//",
+//     *) a non-empty string starting with '/'
 //     *) the string '*', for OPTIONS requests.
 //
 // For now this is only used a quick check for deciding when to clean
 // up Opaque URLs before sending requests from the Transport.
 // See golang.org/issue/16847
+//
+// We used to enforce that the path also didn't start with "//", but
+// Google's GFE accepts such paths and Chrome sends them, so ignore
+// that part of the spec. See golang.org/issue/19103.
 func validPseudoPath(v string) bool {
-	return (len(v) > 0 && v[0] == '/' && (len(v) == 1 || v[1] != '/')) || v == "*"
+	return (len(v) > 0 && v[0] == '/') || v == "*"
 }
--- a/vendor/golang.org/x/net/http2/not_go18.go
+++ b/vendor/golang.org/x/net/http2/not_go18.go
@@ -25,3 +25,5 @@ func reqGetBody(req *http.Request) func() (io.ReadCloser, error) {
 }

 func reqBodyIsNoBody(io.ReadCloser) bool { return false }
+
+func go18httpNoBody() io.ReadCloser { return nil } // for tests only
--- a/vendor/golang.org/x/net/http2/server.go
+++ b/vendor/golang.org/x/net/http2/server.go
@@ -46,6 +46,7 @@ import (
 	"sync"
 	"time"

+	"golang.org/x/net/http/httpguts"
 	"golang.org/x/net/http2/hpack"
 )

@@ -220,12 +221,15 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 	} else if s.TLSConfig.CipherSuites != nil {
 		// If they already provided a CipherSuite list, return
 		// an error if it has a bad order or is missing
-		// ECDHE_RSA_WITH_AES_128_GCM_SHA256.
-		const requiredCipher = tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
+		// ECDHE_RSA_WITH_AES_128_GCM_SHA256 or ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
 		haveRequired := false
 		sawBad := false
 		for i, cs := range s.TLSConfig.CipherSuites {
-			if cs == requiredCipher {
+			switch cs {
+			case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+				// Alternative MTI cipher to not discourage ECDSA-only servers.
+				// See http://golang.org/cl/30721 for further information.
+				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
 				haveRequired = true
 			}
 			if isBadCipher(cs) {
@@ -235,7 +239,7 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 			}
 		}
 		if !haveRequired {
-			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing HTTP/2-required TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256")
+			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher.")
 		}
 	}

@@ -403,7 +407,7 @@ func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
 			// addresses during development.
 			//
 			// TODO: optionally enforce? Or enforce at the time we receive
-			// a new request, and verify the the ServerName matches the :authority?
+			// a new request, and verify the ServerName matches the :authority?
 			// But that precludes proxy situations, perhaps.
 			//
 			// So for now, do nothing here again.
@@ -649,7 +653,7 @@ func (sc *serverConn) condlogf(err error, format string, args ...interface{}) {
 	if err == nil {
 		return
 	}
-	if err == io.EOF || err == io.ErrUnexpectedEOF || isClosedConnError(err) {
+	if err == io.EOF || err == io.ErrUnexpectedEOF || isClosedConnError(err) || err == errPrefaceTimeout {
 		// Boring, expected errors.
 		sc.vlogf(format, args...)
 	} else {
@@ -853,8 +857,13 @@ func (sc *serverConn) serve() {
 			}
 		}

-		if sc.inGoAway && sc.curOpenStreams() == 0 && !sc.needToSendGoAway && !sc.writingFrame {
-			return
+		// Start the shutdown timer after sending a GOAWAY. When sending GOAWAY
+		// with no error code (graceful shutdown), don't start the timer until
+		// all open streams have been completed.
+		sentGoAway := sc.inGoAway && !sc.needToSendGoAway && !sc.writingFrame
+		gracefulShutdownComplete := sc.goAwayCode == ErrCodeNo && sc.curOpenStreams() == 0
+		if sentGoAway && sc.shutdownTimer == nil && (sc.goAwayCode != ErrCodeNo || gracefulShutdownComplete) {
+			sc.shutDownIn(goAwayTimeout)
 		}
 	}
 }
@@ -889,8 +898,11 @@ func (sc *serverConn) sendServeMsg(msg interface{}) {
 	}
 }

-// readPreface reads the ClientPreface greeting from the peer
-// or returns an error on timeout or an invalid greeting.
+var errPrefaceTimeout = errors.New("timeout waiting for client preface")
+
+// readPreface reads the ClientPreface greeting from the peer or
+// returns errPrefaceTimeout on timeout, or an error if the greeting
+// is invalid.
 func (sc *serverConn) readPreface() error {
 	errc := make(chan error, 1)
 	go func() {
@@ -908,7 +920,7 @@ func (sc *serverConn) readPreface() error {
 	defer timer.Stop()
 	select {
 	case <-timer.C:
-		return errors.New("timeout waiting for client preface")
+		return errPrefaceTimeout
 	case err := <-errc:
 		if err == nil {
 			if VerboseLogs {
@@ -1218,30 +1230,31 @@ func (sc *serverConn) startGracefulShutdown() {
 	sc.shutdownOnce.Do(func() { sc.sendServeMsg(gracefulShutdownMsg) })
 }

+// After sending GOAWAY, the connection will close after goAwayTimeout.
+// If we close the connection immediately after sending GOAWAY, there may
+// be unsent data in our kernel receive buffer, which will cause the kernel
+// to send a TCP RST on close() instead of a FIN. This RST will abort the
+// connection immediately, whether or not the client had received the GOAWAY.
+//
+// Ideally we should delay for at least 1 RTT + epsilon so the client has
+// a chance to read the GOAWAY and stop sending messages. Measuring RTT
+// is hard, so we approximate with 1 second. See golang.org/issue/18701.
+//
+// This is a var so it can be shorter in tests, where all requests uses the
+// loopback interface making the expected RTT very small.
+//
+// TODO: configurable?
+var goAwayTimeout = 1 * time.Second
+
 func (sc *serverConn) startGracefulShutdownInternal() {
-	sc.goAwayIn(ErrCodeNo, 0)
+	sc.goAway(ErrCodeNo)
 }

 func (sc *serverConn) goAway(code ErrCode) {
-	sc.serveG.check()
-	var forceCloseIn time.Duration
-	if code != ErrCodeNo {
-		forceCloseIn = 250 * time.Millisecond
-	} else {
-		// TODO: configurable
-		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
 	sc.goAwayCode = code
@@ -1805,7 +1818,7 @@ func (st *stream) processTrailerHeaders(f *MetaHeadersFrame) error {
 	if st.trailer != nil {
 		for _, hf := range f.RegularFields() {
 			key := sc.canonicalHeader(hf.Name)
-			if !ValidTrailerHeader(key) {
+			if !httpguts.ValidTrailerHeader(key) {
 				// TODO: send more details to the peer somehow. But http2 has
 				// no way to send debug data at a stream level. Discuss with
 				// HTTP folk.
@@ -2252,6 +2265,7 @@ type responseWriterState struct {
 	wroteHeader   bool        // WriteHeader called (explicitly or implicitly). Not necessarily sent to user yet.
 	sentHeader    bool        // have we sent the header frame?
 	handlerDone   bool        // handler has finished
+	dirty         bool        // a Write failed; don't reuse this responseWriterState

 	sentContentLen int64 // non-zero if handler set a Content-Length header
 	wroteBytes     int64
@@ -2271,8 +2285,8 @@ func (rws *responseWriterState) hasTrailers() bool { return len(rws.trailers) !=
 // written in the trailers at the end of the response.
 func (rws *responseWriterState) declareTrailer(k string) {
 	k = http.CanonicalHeaderKey(k)
-	if !ValidTrailerHeader(k) {
-		// Forbidden by RFC 2616 14.40.
+	if !httpguts.ValidTrailerHeader(k) {
+		// Forbidden by RFC 7230, section 4.1.2.
 		rws.conn.logf("ignoring invalid trailer %q", k)
 		return
 	}
@@ -2309,8 +2323,16 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 			clen = strconv.Itoa(len(p))
 		}
 		_, hasContentType := rws.snapHeader["Content-Type"]
-		if !hasContentType && bodyAllowedForStatus(rws.status) {
-			ctype = http.DetectContentType(p)
+		if !hasContentType && bodyAllowedForStatus(rws.status) && len(p) > 0 {
+			if cto := rws.snapHeader.Get("X-Content-Type-Options"); strings.EqualFold("nosniff", cto) {
+				// nosniff is an explicit directive not to guess a content-type.
+				// Content-sniffing is no less susceptible to polyglot attacks via
+				// hosted content when done on the server.
+				ctype = "application/octet-stream"
+				rws.conn.logf("http2: WriteHeader called with X-Content-Type-Options:nosniff but no Content-Type")
+			} else {
+				ctype = http.DetectContentType(p)
+			}
 		}
 		var date string
 		if _, ok := rws.snapHeader["Date"]; !ok {
@@ -2333,6 +2355,7 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 			date:          date,
 		})
 		if err != nil {
+			rws.dirty = true
 			return 0, err
 		}
 		if endStream {
@@ -2354,6 +2377,7 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 	if len(p) > 0 || endStream {
 		// only send a 0 byte DATA frame if we're ending the stream.
 		if err := rws.conn.writeDataFromHandler(rws.stream, p, endStream); err != nil {
+			rws.dirty = true
 			return 0, err
 		}
 	}
@@ -2365,6 +2389,9 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 			trailers:  rws.trailers,
 			endStream: true,
 		})
+		if err != nil {
+			rws.dirty = true
+		}
 		return len(p), err
 	}
 	return len(p), nil
@@ -2388,7 +2415,7 @@ const TrailerPrefix = "Trailer:"
 // after the header has already been flushed. Because the Go
 // ResponseWriter interface has no way to set Trailers (only the
 // Header), and because we didn't want to expand the ResponseWriter
-// interface, and because nobody used trailers, and because RFC 2616
+// interface, and because nobody used trailers, and because RFC 7230
 // says you SHOULD (but not must) predeclare any trailers in the
 // header, the official ResponseWriter rules said trailers in Go must
 // be predeclared, and then we reuse the same ResponseWriter.Header()
@@ -2472,6 +2499,24 @@ func (w *responseWriter) Header() http.Header {
 	return rws.handlerHeader
 }

+// checkWriteHeaderCode is a copy of net/http's checkWriteHeaderCode.
+func checkWriteHeaderCode(code int) {
+	// Issue 22880: require valid WriteHeader status codes.
+	// For now we only enforce that it's three digits.
+	// In the future we might block things over 599 (600 and above aren't defined
+	// at http://httpwg.org/specs/rfc7231.html#status.codes)
+	// and we might block under 200 (once we have more mature 1xx support).
+	// But for now any three digits.
+	//
+	// We used to send "HTTP/1.1 000 0" on the wire in responses but there's
+	// no equivalent bogus thing we can realistically send in HTTP/2,
+	// so we'll consistently panic instead and help people find their bugs
+	// early. (We can't return an error from WriteHeader even if we wanted to.)
+	if code < 100 || code > 999 {
+		panic(fmt.Sprintf("invalid WriteHeader code %v", code))
+	}
+}
+
 func (w *responseWriter) WriteHeader(code int) {
 	rws := w.rws
 	if rws == nil {
@@ -2482,6 +2527,7 @@ func (w *responseWriter) WriteHeader(code int) {

 func (rws *responseWriterState) writeHeader(code int) {
 	if !rws.wroteHeader {
+		checkWriteHeaderCode(code)
 		rws.wroteHeader = true
 		rws.status = code
 		if len(rws.handlerHeader) > 0 {
@@ -2504,7 +2550,7 @@ func cloneHeader(h http.Header) http.Header {
 //
 // * Handler calls w.Write or w.WriteString ->
 // * -> rws.bw (*bufio.Writer) ->
-// * (Handler migth call Flush)
+// * (Handler might call Flush)
 // * -> chunkWriter{rws}
 // * -> responseWriterState.writeChunk(p []byte)
 // * -> responseWriterState.writeChunk (most of the magic; see comment there)
@@ -2543,10 +2589,19 @@ func (w *responseWriter) write(lenData int, dataB []byte, dataS string) (n int,

 func (w *responseWriter) handlerDone() {
 	rws := w.rws
+	dirty := rws.dirty
 	rws.handlerDone = true
 	w.Flush()
 	w.rws = nil
-	responseWriterStatePool.Put(rws)
+	if !dirty {
+		// Only recycle the pool if all prior Write calls to
+		// the serverConn goroutine completed successfully. If
+		// they returned earlier due to resets from the peer
+		// there might still be write goroutines outstanding
+		// from the serverConn referencing the rws memory. See
+		// issue 20704.
+		responseWriterStatePool.Put(rws)
+	}
 }

 // Push errors.
@@ -2744,7 +2799,7 @@ func (sc *serverConn) startPush(msg *startPushRequest) {
 }

 // foreachHeaderElement splits v according to the "#rule" construction
-// in RFC 2616 section 2.1 and calls fn for each non-empty element.
+// in RFC 7230 section 7 and calls fn for each non-empty element.
 func foreachHeaderElement(v string, fn func(string)) {
 	v = textproto.TrimString(v)
 	if v == "" {
@@ -2792,41 +2847,6 @@ func new400Handler(err error) http.HandlerFunc {
 	}
 }

-// ValidTrailerHeader reports whether name is a valid header field name to appear
-// in trailers.
-// See: http://tools.ietf.org/html/rfc7230#section-4.1.2
-func ValidTrailerHeader(name string) bool {
-	name = http.CanonicalHeaderKey(name)
-	if strings.HasPrefix(name, "If-") || badTrailer[name] {
-		return false
-	}
-	return true
-}
-
-var badTrailer = map[string]bool{
-	"Authorization":       true,
-	"Cache-Control":       true,
-	"Connection":          true,
-	"Content-Encoding":    true,
-	"Content-Length":      true,
-	"Content-Range":       true,
-	"Content-Type":        true,
-	"Expect":              true,
-	"Host":                true,
-	"Keep-Alive":          true,
-	"Max-Forwards":        true,
-	"Pragma":              true,
-	"Proxy-Authenticate":  true,
-	"Proxy-Authorization": true,
-	"Proxy-Connection":    true,
-	"Range":               true,
-	"Realm":               true,
-	"Te":                  true,
-	"Trailer":             true,
-	"Transfer-Encoding":   true,
-	"Www-Authenticate":    true,
-}
-
 // h1ServerKeepAlivesDisabled reports whether hs has its keep-alives
 // disabled. See comments on h1ServerShutdownChan above for why
 // the code is written this way.
--- a/vendor/golang.org/x/net/http2/server_test.go
+++ b/vendor/golang.org/x/net/http2/server_test.go
@@ -68,6 +68,7 @@ type serverTester struct {

 func init() {
 	testHookOnPanicMu = new(sync.Mutex)
+	goAwayTimeout = 25 * time.Millisecond
 }

 func resetHooks() {
@@ -286,7 +287,7 @@ func (st *serverTester) greetAndCheckSettings(checkSetting func(s Setting) error

 		case *WindowUpdateFrame:
 			if f.FrameHeader.StreamID != 0 {
-				st.t.Fatalf("WindowUpdate StreamID = %d; want 0", f.FrameHeader.StreamID, 0)
+				st.t.Fatalf("WindowUpdate StreamID = %d; want 0", f.FrameHeader.StreamID)
 			}
 			incr := uint32((&Server{}).initialConnRecvWindowSize() - initialWindowSize)
 			if f.Increment != incr {
@@ -1717,7 +1718,6 @@ func TestServer_Response_NoData_Header_FooBar(t *testing.T) {
 		wanth := [][2]string{
 			{":status", "200"},
 			{"foo-bar", "some-value"},
-			{"content-type", "text/plain; charset=utf-8"},
 			{"content-length", "0"},
 		}
 		if !reflect.DeepEqual(goth, wanth) {
@@ -1760,6 +1760,42 @@ func TestServer_Response_Data_Sniff_DoesntOverride(t *testing.T) {
 	})
 }

+func TestServer_Response_Nosniff_WithoutContentType(t *testing.T) {
+	const msg = "<html>this is HTML."
+	testServerResponse(t, func(w http.ResponseWriter, r *http.Request) error {
+		w.Header().Set("X-Content-Type-Options", "nosniff")
+		w.WriteHeader(200)
+		io.WriteString(w, msg)
+		return nil
+	}, func(st *serverTester) {
+		getSlash(st)
+		hf := st.wantHeaders()
+		if hf.StreamEnded() {
+			t.Fatal("don't want END_STREAM, expecting data")
+		}
+		if !hf.HeadersEnded() {
+			t.Fatal("want END_HEADERS flag")
+		}
+		goth := st.decodeHeader(hf.HeaderBlockFragment())
+		wanth := [][2]string{
+			{":status", "200"},
+			{"x-content-type-options", "nosniff"},
+			{"content-type", "application/octet-stream"},
+			{"content-length", strconv.Itoa(len(msg))},
+		}
+		if !reflect.DeepEqual(goth, wanth) {
+			t.Errorf("Got headers %v; want %v", goth, wanth)
+		}
+		df := st.wantData()
+		if !df.StreamEnded() {
+			t.Error("expected DATA to have END_STREAM flag")
+		}
+		if got := string(df.Data()); got != msg {
+			t.Errorf("got DATA %q; want %q", got, msg)
+		}
+	})
+}
+
 func TestServer_Response_TransferEncoding_chunked(t *testing.T) {
 	const msg = "hi"
 	testServerResponse(t, func(w http.ResponseWriter, r *http.Request) error {
@@ -2877,9 +2913,9 @@ func testServerWritesTrailers(t *testing.T, withFlush bool) {
 		w.Header().Set("Trailer:post-header-trailer2", "hi2")
 		w.Header().Set("Trailer:Range", "invalid")
 		w.Header().Set("Trailer:Foo\x01Bogus", "invalid")
-		w.Header().Set("Transfer-Encoding", "should not be included; Forbidden by RFC 2616 14.40")
-		w.Header().Set("Content-Length", "should not be included; Forbidden by RFC 2616 14.40")
-		w.Header().Set("Trailer", "should not be included; Forbidden by RFC 2616 14.40")
+		w.Header().Set("Transfer-Encoding", "should not be included; Forbidden by RFC 7230 4.1.2")
+		w.Header().Set("Content-Length", "should not be included; Forbidden by RFC 7230 4.1.2")
+		w.Header().Set("Trailer", "should not be included; Forbidden by RFC 7230 4.1.2")
 		return nil
 	}, func(st *serverTester) {
 		getSlash(st)
@@ -2952,7 +2988,6 @@ func TestServerDoesntWriteInvalidHeaders(t *testing.T) {
 		wanth := [][2]string{
 			{":status", "200"},
 			{"ok1", "x"},
-			{"content-type", "text/plain; charset=utf-8"},
 			{"content-length", "0"},
 		}
 		if !reflect.DeepEqual(goth, wanth) {
@@ -2972,7 +3007,7 @@ func BenchmarkServerGets(b *testing.B) {
 	defer st.Close()
 	st.greet()

-	// Give the server quota to reply. (plus it has the the 64KB)
+	// Give the server quota to reply. (plus it has the 64KB)
 	if err := st.fr.WriteWindowUpdate(0, uint32(b.N*len(msg))); err != nil {
 		b.Fatal(err)
 	}
@@ -3010,7 +3045,7 @@ func BenchmarkServerPosts(b *testing.B) {
 	defer st.Close()
 	st.greet()

-	// Give the server quota to reply. (plus it has the the 64KB)
+	// Give the server quota to reply. (plus it has the 64KB)
 	if err := st.fr.WriteWindowUpdate(0, uint32(b.N*len(msg))); err != nil {
 		b.Fatal(err)
 	}
@@ -3188,12 +3223,18 @@ func TestConfigureServer(t *testing.T) {
 				CipherSuites: []uint16{tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256},
 			},
 		},
+		{
+			name: "just the alternative required cipher suite",
+			tlsConfig: &tls.Config{
+				CipherSuites: []uint16{tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256},
+			},
+		},
 		{
 			name: "missing required cipher suite",
 			tlsConfig: &tls.Config{
 				CipherSuites: []uint16{tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384},
 			},
-			wantErr: "is missing HTTP/2-required TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+			wantErr: "is missing an HTTP/2-required AES_128_GCM_SHA256 cipher.",
 		},
 		{
 			name: "required after bad",
@@ -3259,7 +3300,6 @@ func TestServerNoAutoContentLengthOnHead(t *testing.T) {
 	headers := st.decodeHeader(h.HeaderBlockFragment())
 	want := [][2]string{
 		{":status", "200"},
-		{"content-type", "text/plain; charset=utf-8"},
 	}
 	if !reflect.DeepEqual(headers, want) {
 		t.Errorf("Headers mismatch.\n got: %q\nwant: %q\n", headers, want)
@@ -3312,7 +3352,7 @@ func BenchmarkServer_GetRequest(b *testing.B) {
 	defer st.Close()

 	st.greet()
-	// Give the server quota to reply. (plus it has the the 64KB)
+	// Give the server quota to reply. (plus it has the 64KB)
 	if err := st.fr.WriteWindowUpdate(0, uint32(b.N*len(msg))); err != nil {
 		b.Fatal(err)
 	}
@@ -3343,7 +3383,7 @@ func BenchmarkServer_PostRequest(b *testing.B) {
 	})
 	defer st.Close()
 	st.greet()
-	// Give the server quota to reply. (plus it has the the 64KB)
+	// Give the server quota to reply. (plus it has the 64KB)
 	if err := st.fr.WriteWindowUpdate(0, uint32(b.N*len(msg))); err != nil {
 		b.Fatal(err)
 	}
@@ -3685,3 +3725,37 @@ func TestRequestBodyReadCloseRace(t *testing.T) {
 		<-done
 	}
 }
+
+func TestIssue20704Race(t *testing.T) {
+	if testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
+		t.Skip("skipping in short mode")
+	}
+	const (
+		itemSize  = 1 << 10
+		itemCount = 100
+	)
+
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+		for i := 0; i < itemCount; i++ {
+			_, err := w.Write(make([]byte, itemSize))
+			if err != nil {
+				return
+			}
+		}
+	}, optOnlyServer)
+	defer st.Close()
+
+	tr := &Transport{TLSClientConfig: tlsConfigInsecure}
+	defer tr.CloseIdleConnections()
+	cl := &http.Client{Transport: tr}
+
+	for i := 0; i < 1000; i++ {
+		resp, err := cl.Get(st.ts.URL)
+		if err != nil {
+			t.Fatal(err)
+		}
+		// Force a RST stream to the server by closing without
+		// reading the body:
+		resp.Body.Close()
+	}
+}
--- a/vendor/golang.org/x/net/http2/transport.go
+++ b/vendor/golang.org/x/net/http2/transport.go
@@ -18,6 +18,7 @@ import (
 	"io/ioutil"
 	"log"
 	"math"
+	mathrand "math/rand"
 	"net"
 	"net/http"
 	"sort"
@@ -86,7 +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)
@@ -164,15 +165,17 @@ type ClientConn struct {
 	goAwayDebug     string                   // goAway frame's debug data, retained as a string
 	streams         map[uint32]*clientStream // client-initiated
 	nextStreamID    uint32
+	pendingRequests int                       // requests blocked and waiting to be sent because len(streams) == maxConcurrentStreams
 	pings           map[[8]byte]chan struct{} // in flight ping data to notification channel
 	bw              *bufio.Writer
 	br              *bufio.Reader
 	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
@@ -216,35 +219,45 @@ type clientStream struct {
 	resTrailer *http.Header // client's Response.Trailer
 }

-// awaitRequestCancel runs in its own goroutine and waits for the user
-// to cancel a RoundTrip request, its context to expire, or for the
-// request to be done (any way it might be removed from the cc.streams
-// map: peer reset, successful completion, TCP connection breakage,
-// etc)
-func (cs *clientStream) awaitRequestCancel(req *http.Request) {
+// awaitRequestCancel waits for the user to cancel a request or for the done
+// channel to be signaled. A non-nil error is returned only if the request was
+// canceled.
+func awaitRequestCancel(req *http.Request, done <-chan struct{}) error {
 	ctx := reqContext(req)
 	if req.Cancel == nil && ctx.Done() == nil {
-		return
+		return nil
 	}
 	select {
 	case <-req.Cancel:
-		cs.cancelStream()
-		cs.bufPipe.CloseWithError(errRequestCanceled)
+		return errRequestCanceled
 	case <-ctx.Done():
+		return ctx.Err()
+	case <-done:
+		return nil
+	}
+}
+
+// awaitRequestCancel waits for the user to cancel a request, its context to
+// expire, or for the request to be done (any way it might be removed from the
+// cc.streams map: peer reset, successful completion, TCP connection breakage,
+// etc). If the request is canceled, then cs will be canceled and closed.
+func (cs *clientStream) awaitRequestCancel(req *http.Request) {
+	if err := awaitRequestCancel(req, cs.done); err != nil {
 		cs.cancelStream()
-		cs.bufPipe.CloseWithError(ctx.Err())
-	case <-cs.done:
+		cs.bufPipe.CloseWithError(err)
 	}
 }

 func (cs *clientStream) cancelStream() {
-	cs.cc.mu.Lock()
+	cc := cs.cc
+	cc.mu.Lock()
 	didReset := cs.didReset
 	cs.didReset = true
-	cs.cc.mu.Unlock()
+	cc.mu.Unlock()

 	if !didReset {
-		cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+		cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+		cc.forgetStreamID(cs.ID)
 	}
 }

@@ -261,6 +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")
@@ -286,7 +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 {
@@ -329,17 +368,28 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res
 	}

 	addr := authorityAddr(req.URL.Scheme, req.URL.Host)
-	for {
+	for retry := 0; ; retry++ {
 		cc, err := t.connPool().GetClientConn(req, addr)
 		if err != nil {
 			t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err)
 			return nil, err
 		}
 		traceGotConn(req, cc)
-		res, err := cc.RoundTrip(req)
-		if err != nil {
-			if req, err = shouldRetryRequest(req, err); err == nil {
-				continue
+		res, gotErrAfterReqBodyWrite, err := cc.roundTrip(req)
+		if err != nil && retry <= 6 {
+			if req, err = shouldRetryRequest(req, err, gotErrAfterReqBodyWrite); err == nil {
+				// After the first retry, do exponential backoff with 10% jitter.
+				if retry == 0 {
+					continue
+				}
+				backoff := float64(uint(1) << (uint(retry) - 1))
+				backoff += backoff * (0.1 * mathrand.Float64())
+				select {
+				case <-time.After(time.Second * time.Duration(backoff)):
+					continue
+				case <-reqContext(req).Done():
+					return nil, reqContext(req).Err()
+				}
 			}
 		}
 		if err != nil {
@@ -360,43 +410,50 @@ 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")
+	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")
 )

 // 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:
+func shouldRetryRequest(req *http.Request, err error, afterBodyWrite bool) (*http.Request, error) {
+	if !canRetryError(err) {
 		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
 	}
+	if !afterBodyWrite {
+		return req, nil
+	}
+	// 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, fmt.Errorf("http2: Transport: cannot retry err [%v] after Request.Body was written; define Request.GetBody to avoid this error", err)
+	}
+	body, err := getBody()
+	if err != nil {
+		return nil, err
+	}
+	newReq := *req
+	newReq.Body = body
+	return &newReq, nil
+}
+
+func canRetryError(err error) bool {
+	if err == errClientConnUnusable || err == errClientConnGotGoAway {
+		return true
+	}
+	if se, ok := err.(StreamError); ok {
+		return se.Code == ErrCodeRefusedStream
+	}
+	return false
 }

 func (t *Transport) dialClientConn(addr string, singleUse bool) (*ClientConn, error) {
@@ -474,17 +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
@@ -560,6 +618,8 @@ func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
 	}
 }

+// CanTakeNewRequest reports whether the connection can take a new request,
+// meaning it has not been closed or received or sent a GOAWAY.
 func (cc *ClientConn) CanTakeNewRequest() bool {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
@@ -571,8 +631,7 @@ func (cc *ClientConn) canTakeNewRequestLocked() bool {
 		return false
 	}
 	return cc.goAway == nil && !cc.closed &&
-		int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams) &&
-		cc.nextStreamID < math.MaxInt32
+		int64(cc.nextStreamID)+int64(cc.pendingRequests) < math.MaxInt32
 }

 // onIdleTimeout is called from a time.AfterFunc goroutine. It will
@@ -694,7 +753,7 @@ func checkConnHeaders(req *http.Request) error {
 // req.ContentLength, where 0 actually means zero (not unknown) and -1
 // means unknown.
 func actualContentLength(req *http.Request) int64 {
-	if req.Body == nil {
+	if req.Body == nil || reqBodyIsNoBody(req.Body) {
 		return 0
 	}
 	if req.ContentLength != 0 {
@@ -704,8 +763,13 @@ 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()
@@ -713,20 +777,19 @@ 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()
-	cc.lastActive = time.Now()
-	if cc.closed || !cc.canTakeNewRequestLocked() {
+	if err := cc.awaitOpenSlotForRequest(req); err != nil {
 		cc.mu.Unlock()
-		return nil, errClientConnUnusable
+		return nil, false, err
 	}

 	body := req.Body
-	hasBody := body != nil
 	contentLen := actualContentLength(req)
+	hasBody := contentLen != 0

 	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
 	var requestedGzip bool
@@ -755,7 +818,7 @@ 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()
@@ -767,7 +830,7 @@ 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()
@@ -781,7 +844,7 @@ 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
@@ -800,7 +863,7 @@ 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
@@ -816,19 +879,12 @@ 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
+			return nil, cs.getStartedWrite(), re.err
 		}
 		res.Request = req
 		res.TLS = cc.tlsState
-		return res, nil
+		return res, false, nil
 	}

 	for {
@@ -836,37 +892,37 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 		case re := <-readLoopResCh:
 			return handleReadLoopResponse(re)
 		case <-respHeaderTimer:
-			cc.forgetStreamID(cs.ID)
 			if !hasBody || bodyWritten {
 				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
 			} else {
 				bodyWriter.cancel()
 				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
-			return nil, errTimeout
+			cc.forgetStreamID(cs.ID)
+			return nil, cs.getStartedWrite(), errTimeout
 		case <-ctx.Done():
-			cc.forgetStreamID(cs.ID)
 			if !hasBody || bodyWritten {
 				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
 			} else {
 				bodyWriter.cancel()
 				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
-			return nil, ctx.Err()
+			cc.forgetStreamID(cs.ID)
+			return nil, cs.getStartedWrite(), ctx.Err()
 		case <-req.Cancel:
-			cc.forgetStreamID(cs.ID)
 			if !hasBody || bodyWritten {
 				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
 			} else {
 				bodyWriter.cancel()
 				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
-			return nil, errRequestCanceled
+			cc.forgetStreamID(cs.ID)
+			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 {
@@ -875,7 +931,7 @@ 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 {
@@ -887,14 +943,55 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 	}
 }

+// awaitOpenSlotForRequest waits until len(streams) < maxConcurrentStreams.
+// Must hold cc.mu.
+func (cc *ClientConn) awaitOpenSlotForRequest(req *http.Request) error {
+	var waitingForConn chan struct{}
+	var waitingForConnErr error // guarded by cc.mu
+	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) {
+			if waitingForConn != nil {
+				close(waitingForConn)
+			}
+			return nil
+		}
+		// Unfortunately, we cannot wait on a condition variable and channel at
+		// the same time, so instead, we spin up a goroutine to check if the
+		// request is canceled while we wait for a slot to open in the connection.
+		if waitingForConn == nil {
+			waitingForConn = make(chan struct{})
+			go func() {
+				if err := awaitRequestCancel(req, waitingForConn); err != nil {
+					cc.mu.Lock()
+					waitingForConnErr = err
+					cc.cond.Broadcast()
+					cc.mu.Unlock()
+				}
+			}()
+		}
+		cc.pendingRequests++
+		cc.cond.Wait()
+		cc.pendingRequests--
+		if waitingForConnErr != nil {
+			return waitingForConnErr
+		}
+	}
+}
+
 // 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
@@ -1002,17 +1099,26 @@ 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)
 	}
@@ -1106,62 +1212,86 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 		}
 	}

-	// 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
 }

@@ -1188,17 +1318,29 @@ 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) {
@@ -1246,7 +1388,9 @@ func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream {
 			cc.idleTimer.Reset(cc.idleTimeout)
 		}
 		close(cs.done)
-		cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl
+		// Wake up checkResetOrDone via clientStream.awaitFlowControl and
+		// wake up RoundTrip if there is a pending request.
+		cc.cond.Broadcast()
 	}
 	return cs
 }
@@ -1254,17 +1398,12 @@ 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 {
@@ -1319,10 +1458,8 @@ 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:
@@ -1345,8 +1482,9 @@ func (rl *clientConnReadLoop) run() error {
 			cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err)
 		}
 		if se, ok := err.(StreamError); ok {
-			if cs := cc.streamByID(se.StreamID, true /*ended; remove it*/); cs != nil {
+			if cs := cc.streamByID(se.StreamID, false); cs != nil {
 				cs.cc.writeStreamReset(cs.ID, se.Code, err)
+				cs.cc.forgetStreamID(cs.ID)
 				if se.Cause == nil {
 					se.Cause = cc.fr.errDetail
 				}
@@ -1399,7 +1537,7 @@ func (rl *clientConnReadLoop) run() error {
 			}
 			return err
 		}
-		if rl.closeWhenIdle && gotReply && maybeIdle && len(rl.activeRes) == 0 {
+		if rl.closeWhenIdle && gotReply && maybeIdle {
 			cc.closeIfIdle()
 		}
 	}
@@ -1407,13 +1545,31 @@ 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,
@@ -1437,6 +1593,7 @@ 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
 	}
@@ -1444,9 +1601,6 @@ 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
@@ -1466,11 +1620,11 @@ 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 {
@@ -1668,6 +1822,7 @@ func (b transportResponseBody) Close() error {
 	}

 	cs.bufPipe.BreakWithError(errClosedResponseBody)
+	cc.forgetStreamID(cs.ID)
 	return nil
 }

@@ -1702,7 +1857,23 @@ 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) {
@@ -1713,16 +1884,27 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error {
 		}
 		// Return any padded flow control now, since we won't
 		// refund it later on body reads.
-		if pad := int32(f.Length) - int32(len(data)); pad > 0 {
-			cs.inflow.add(pad)
-			cc.inflow.add(pad)
+		var refund int
+		if pad := int(f.Length) - len(data); pad > 0 {
+			refund += pad
+		}
+		// Return len(data) now if the stream is already closed,
+		// since data will never be read.
+		didReset := cs.didReset
+		if didReset {
+			refund += len(data)
+		}
+		if refund > 0 {
+			cc.inflow.add(int32(refund))
 			cc.wmu.Lock()
-			cc.fr.WriteWindowUpdate(0, uint32(pad))
-			cc.fr.WriteWindowUpdate(cs.ID, uint32(pad))
+			cc.fr.WriteWindowUpdate(0, uint32(refund))
+			if !didReset {
+				cs.inflow.add(int32(refund))
+				cc.fr.WriteWindowUpdate(cs.ID, uint32(refund))
+			}
 			cc.bw.Flush()
 			cc.wmu.Unlock()
 		}
-		didReset := cs.didReset
 		cc.mu.Unlock()

 		if len(data) > 0 && !didReset {
@@ -1753,11 +1935,10 @@ 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}:
@@ -1805,6 +1986,8 @@ 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
@@ -1882,7 +2065,6 @@ 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
 }

@@ -1971,6 +2153,7 @@ 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")
 )

--- a/vendor/golang.org/x/net/http2/transport_test.go
+++ b/vendor/golang.org/x/net/http2/transport_test.go
--- a/vendor/golang.org/x/net/http2/write.go
+++ b/vendor/golang.org/x/net/http2/write.go
@@ -10,7 +10,6 @@ import (
 	"log"
 	"net/http"
 	"net/url"
-	"time"

 	"golang.org/x/net/http2/hpack"
 	"golang.org/x/net/lex/httplex"
@@ -90,11 +89,7 @@ type writeGoAway struct {

 func (p *writeGoAway) writeFrame(ctx writeContext) error {
 	err := ctx.Framer().WriteGoAway(p.maxStreamID, p.code, nil)
-	if p.code != 0 {
-		ctx.Flush() // ignore error: we're hanging up on them anyway
-		time.Sleep(50 * time.Millisecond)
-		ctx.CloseConn()
-	}
+	ctx.Flush() // ignore error: we're hanging up on them anyway
 	return err
 }