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mirror of https://github.com/golang/go synced 2024-11-21 17:14:45 -07:00

net/http: add Protocols field to Server and Transport

Support configuring which HTTP version(s) a server or client use
via an explicit set of protocols. The Protocols field takes
precedence over TLSNextProto and ForceAttemptHTTP2.

Fixes #67814

Change-Id: I09ece88f78ad4d98ca1f213157b5f62ae11e063f
Reviewed-on: https://go-review.googlesource.com/c/go/+/607496
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit is contained in:
Damien Neil 2024-05-29 09:24:20 -07:00
parent 635c2dce04
commit bfc8f28068
8 changed files with 429 additions and 22 deletions

8
api/next/67814.txt Normal file
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@ -0,0 +1,8 @@
pkg net/http, method (*Protocols) SetHTTP1(bool) #67814
pkg net/http, method (*Protocols) SetHTTP2(bool) #67814
pkg net/http, method (Protocols) String() string #67814
pkg net/http, method (Protocols) HTTP1() bool #67814
pkg net/http, method (Protocols) HTTP2() bool #67814
pkg net/http, type Protocols struct #67814
pkg net/http, type Server struct, Protocols *Protocols #67814
pkg net/http, type Transport struct, Protocols *Protocols #67814

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@ -0,0 +1,2 @@
The new [Server.Protocols] and [Transport.Protocols] fields provide
a simple way to configure what HTTP protocols a server or client use.

View File

@ -193,3 +193,31 @@ func ExampleNotFoundHandler() {
log.Fatal(http.ListenAndServe(":8080", mux))
}
func ExampleProtocols_http1() {
srv := http.Server{
Addr: ":8443",
}
// Serve only HTTP/1.
srv.Protocols = new(http.Protocols)
srv.Protocols.SetHTTP1(true)
log.Fatal(srv.ListenAndServeTLS("cert.pem", "key.pem"))
}
func ExampleProtocols_http1or2() {
t := http.DefaultTransport.(*http.Transport).Clone()
// Use either HTTP/1 and HTTP/2.
t.Protocols = new(http.Protocols)
t.Protocols.SetHTTP1(true)
t.Protocols.SetHTTP2(true)
cli := &http.Client{Transport: t}
res, err := cli.Get("http://www.google.com/robots.txt")
if err != nil {
log.Fatal(err)
}
res.Body.Close()
}

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@ -16,6 +16,54 @@ import (
"golang.org/x/net/http/httpguts"
)
// Protocols is a set of HTTP protocols.
//
// The supported protocols are:
//
// - HTTP1 is the HTTP/1.0 and HTTP/1.1 protocols.
// HTTP1 is supported on both unsecured TCP and secured TLS connections.
//
// - HTTP2 is the HTTP/2 protcol over a TLS connection.
type Protocols struct {
bits uint8
}
const (
protoHTTP1 = 1 << iota
protoHTTP2
)
// HTTP1 reports whether p includes HTTP/1.
func (p Protocols) HTTP1() bool { return p.bits&protoHTTP1 != 0 }
// SetHTTP1 adds or removes HTTP/1 from p.
func (p *Protocols) SetHTTP1(ok bool) { p.setBit(protoHTTP1, ok) }
// HTTP2 reports whether p includes HTTP/2.
func (p Protocols) HTTP2() bool { return p.bits&protoHTTP2 != 0 }
// SetHTTP2 adds or removes HTTP/2 from p.
func (p *Protocols) SetHTTP2(ok bool) { p.setBit(protoHTTP2, ok) }
func (p *Protocols) setBit(bit uint8, ok bool) {
if ok {
p.bits |= bit
} else {
p.bits &^= bit
}
}
func (p Protocols) String() string {
var s []string
if p.HTTP1() {
s = append(s, "HTTP1")
}
if p.HTTP2() {
s = append(s, "HTTP2")
}
return "{" + strings.Join(s, ",") + "}"
}
// incomparable is a zero-width, non-comparable type. Adding it to a struct
// makes that struct also non-comparable, and generally doesn't add
// any size (as long as it's first).

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@ -187,6 +187,28 @@ func TestNoUnicodeStrings(t *testing.T) {
}
}
func TestProtocols(t *testing.T) {
var p Protocols
if p.HTTP1() {
t.Errorf("zero-value protocols: p.HTTP1() = true, want false")
}
p.SetHTTP1(true)
p.SetHTTP2(true)
if !p.HTTP1() {
t.Errorf("initialized protocols: p.HTTP1() = false, want true")
}
if !p.HTTP2() {
t.Errorf("initialized protocols: p.HTTP2() = false, want true")
}
p.SetHTTP1(false)
if p.HTTP1() {
t.Errorf("after unsetting HTTP1: p.HTTP1() = true, want false")
}
if !p.HTTP2() {
t.Errorf("after unsetting HTTP1: p.HTTP2() = false, want true")
}
}
const redirectURL = "/thisaredirect细雪withasciilettersのけぶabcdefghijk.html"
func BenchmarkHexEscapeNonASCII(b *testing.B) {

View File

@ -2979,6 +2979,13 @@ type Server struct {
// See https://go.dev/issue/67813.
HTTP2 *HTTP2Config
// Protocols is the set of protocols accepted by the server.
//
// If Protocols is nil, the default is usually HTTP/1 and HTTP/2.
// If TLSNextProto is non-nil and does not contain an "h2" entry,
// the default is HTTP/1 only.
Protocols *Protocols
inShutdown atomic.Bool // true when server is in shutdown
disableKeepAlives atomic.Bool
@ -3389,9 +3396,7 @@ func (s *Server) ServeTLS(l net.Listener, certFile, keyFile string) error {
}
config := cloneTLSConfig(s.TLSConfig)
if !slices.Contains(config.NextProtos, "http/1.1") {
config.NextProtos = append(config.NextProtos, "http/1.1")
}
config.NextProtos = adjustNextProtos(config.NextProtos, s.protocols())
configHasCert := len(config.Certificates) > 0 || config.GetCertificate != nil || config.GetConfigForClient != nil
if !configHasCert || certFile != "" || keyFile != "" {
@ -3407,6 +3412,59 @@ func (s *Server) ServeTLS(l net.Listener, certFile, keyFile string) error {
return s.Serve(tlsListener)
}
func (s *Server) protocols() Protocols {
if s.Protocols != nil {
return *s.Protocols // user-configured set
}
// The historic way of disabling HTTP/2 is to set TLSNextProto to
// a non-nil map with no "h2" entry.
_, hasH2 := s.TLSNextProto["h2"]
http2Disabled := s.TLSNextProto != nil && !hasH2
// If GODEBUG=http2server=0, then HTTP/2 is disabled unless
// the user has manually added an "h2" entry to TLSNextProto
// (probably by using x/net/http2 directly).
if http2server.Value() == "0" && !hasH2 {
http2Disabled = true
}
var p Protocols
p.SetHTTP1(true) // default always includes HTTP/1
if !http2Disabled {
p.SetHTTP2(true)
}
return p
}
// adjustNextProtos adds or removes "http/1.1" and "h2" entries from
// a tls.Config.NextProtos list, according to the set of protocols in protos.
func adjustNextProtos(nextProtos []string, protos Protocols) []string {
var have Protocols
nextProtos = slices.DeleteFunc(nextProtos, func(s string) bool {
switch s {
case "http/1.1":
if !protos.HTTP1() {
return true
}
have.SetHTTP1(true)
case "h2":
if !protos.HTTP2() {
return true
}
have.SetHTTP2(true)
}
return false
})
if protos.HTTP2() && !have.HTTP2() {
nextProtos = append(nextProtos, "h2")
}
if protos.HTTP1() && !have.HTTP1() {
nextProtos = append(nextProtos, "http/1.1")
}
return nextProtos
}
// trackListener adds or removes a net.Listener to the set of tracked
// listeners.
//
@ -3600,16 +3658,21 @@ func (s *Server) onceSetNextProtoDefaults() {
if omitBundledHTTP2 {
return
}
if !s.protocols().HTTP2() {
return
}
if http2server.Value() == "0" {
http2server.IncNonDefault()
return
}
// Enable HTTP/2 by default if the user hasn't otherwise
// configured their TLSNextProto map.
if s.TLSNextProto == nil {
conf := &http2Server{}
s.nextProtoErr = http2ConfigureServer(s, conf)
if _, ok := s.TLSNextProto["h2"]; ok {
// TLSNextProto already contains an HTTP/2 implementation.
// The user probably called golang.org/x/net/http2.ConfigureServer
// to add it.
return
}
conf := &http2Server{}
s.nextProtoErr = http2ConfigureServer(s, conf)
}
// TimeoutHandler returns a [Handler] that runs h with the given time limit.

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@ -76,8 +76,7 @@ const DefaultMaxIdleConnsPerHost = 2
// Transport uses HTTP/1.1 for HTTP URLs and either HTTP/1.1 or HTTP/2
// for HTTPS URLs, depending on whether the server supports HTTP/2,
// and how the Transport is configured. The [DefaultTransport] supports HTTP/2.
// To explicitly enable HTTP/2 on a transport, use golang.org/x/net/http2
// and call ConfigureTransport. See the package docs for more about HTTP/2.
// To explicitly enable HTTP/2 on a transport, set [Transport.Protocols].
//
// Responses with status codes in the 1xx range are either handled
// automatically (100 expect-continue) or ignored. The one
@ -300,6 +299,13 @@ type Transport struct {
// This field does not yet have any effect.
// See https://go.dev/issue/67813.
HTTP2 *HTTP2Config
// Protocols is the set of protocols supported by the transport.
//
// If Protocols is nil, the default is usually HTTP/1 only.
// If ForceAttemptHTTP2 is true, or if TLSNextProto contains an "h2" entry,
// the default is HTTP/1 and HTTP/2.
Protocols *Protocols
}
func (t *Transport) writeBufferSize() int {
@ -349,6 +355,10 @@ func (t *Transport) Clone() *Transport {
t2.HTTP2 = &HTTP2Config{}
*t2.HTTP2 = *t.HTTP2
}
if t.Protocols != nil {
t2.Protocols = &Protocols{}
*t2.Protocols = *t.Protocols
}
if !t.tlsNextProtoWasNil {
npm := maps.Clone(t.TLSNextProto)
if npm == nil {
@ -399,18 +409,8 @@ func (t *Transport) onceSetNextProtoDefaults() {
}
}
if t.TLSNextProto != nil {
// This is the documented way to disable http2 on a
// Transport.
return
}
if !t.ForceAttemptHTTP2 && (t.TLSClientConfig != nil || t.Dial != nil || t.DialContext != nil || t.hasCustomTLSDialer()) {
// Be conservative and don't automatically enable
// http2 if they've specified a custom TLS config or
// custom dialers. Let them opt-in themselves via
// http2.ConfigureTransport so we don't surprise them
// by modifying their tls.Config. Issue 14275.
// However, if ForceAttemptHTTP2 is true, it overrides the above checks.
protocols := t.protocols()
if !protocols.HTTP2() {
return
}
if omitBundledHTTP2 {
@ -437,6 +437,40 @@ func (t *Transport) onceSetNextProtoDefaults() {
t2.MaxHeaderListSize = uint32(limit1)
}
}
// Server.ServeTLS clones the tls.Config before modifying it.
// Transport doesn't. We may want to make the two consistent some day.
//
// http2configureTransport will have already set NextProtos, but adjust it again
// here to remove HTTP/1.1 if the user has disabled it.
t.TLSClientConfig.NextProtos = adjustNextProtos(t.TLSClientConfig.NextProtos, protocols)
}
func (t *Transport) protocols() Protocols {
if t.Protocols != nil {
return *t.Protocols // user-configured set
}
var p Protocols
p.SetHTTP1(true) // default always includes HTTP/1
switch {
case t.TLSNextProto != nil:
// Setting TLSNextProto to an empty map is is a documented way
// to disable HTTP/2 on a Transport.
if t.TLSNextProto["h2"] != nil {
p.SetHTTP2(true)
}
case !t.ForceAttemptHTTP2 && (t.TLSClientConfig != nil || t.Dial != nil || t.DialContext != nil || t.hasCustomTLSDialer()):
// Be conservative and don't automatically enable
// http2 if they've specified a custom TLS config or
// custom dialers. Let them opt-in themselves via
// Transport.Protocols.SetHTTP2(true) so we don't surprise them
// by modifying their tls.Config. Issue 14275.
// However, if ForceAttemptHTTP2 is true, it overrides the above checks.
case http2client.Value() == "0":
default:
p.SetHTTP2(true)
}
return p
}
// ProxyFromEnvironment returns the URL of the proxy to use for a

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@ -6361,12 +6361,15 @@ func TestTransportClone(t *testing.T) {
MaxResponseHeaderBytes: 1,
ForceAttemptHTTP2: true,
HTTP2: &HTTP2Config{MaxConcurrentStreams: 1},
Protocols: &Protocols{},
TLSNextProto: map[string]func(authority string, c *tls.Conn) RoundTripper{
"foo": func(authority string, c *tls.Conn) RoundTripper { panic("") },
},
ReadBufferSize: 1,
WriteBufferSize: 1,
}
tr.Protocols.SetHTTP1(true)
tr.Protocols.SetHTTP2(true)
tr2 := tr.Clone()
rv := reflect.ValueOf(tr2).Elem()
rt := rv.Type()
@ -7167,3 +7170,202 @@ func testValidateClientRequestTrailers(t *testing.T, mode testMode) {
})
}
}
func TestTransportServerProtocols(t *testing.T) {
CondSkipHTTP2(t)
DefaultTransport.(*Transport).CloseIdleConnections()
cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
if err != nil {
t.Fatal(err)
}
leafCert, err := x509.ParseCertificate(cert.Certificate[0])
if err != nil {
t.Fatal(err)
}
certpool := x509.NewCertPool()
certpool.AddCert(leafCert)
for _, test := range []struct {
name string
scheme string
setup func(t *testing.T)
transport func(*Transport)
server func(*Server)
want string
}{{
name: "http default",
scheme: "http",
want: "HTTP/1.1",
}, {
name: "https default",
scheme: "https",
transport: func(tr *Transport) {
// Transport default is HTTP/1.
},
want: "HTTP/1.1",
}, {
name: "https transport protocols include HTTP2",
scheme: "https",
transport: func(tr *Transport) {
// Server default is to support HTTP/2, so if the Transport enables
// HTTP/2 we get it.
tr.Protocols = &Protocols{}
tr.Protocols.SetHTTP1(true)
tr.Protocols.SetHTTP2(true)
},
want: "HTTP/2.0",
}, {
name: "https transport protocols only include HTTP1",
scheme: "https",
transport: func(tr *Transport) {
// Explicitly enable only HTTP/1.
tr.Protocols = &Protocols{}
tr.Protocols.SetHTTP1(true)
},
want: "HTTP/1.1",
}, {
name: "https transport ForceAttemptHTTP2",
scheme: "https",
transport: func(tr *Transport) {
// Pre-Protocols-field way of enabling HTTP/2.
tr.ForceAttemptHTTP2 = true
},
want: "HTTP/2.0",
}, {
name: "https transport protocols override TLSNextProto",
scheme: "https",
transport: func(tr *Transport) {
// Setting TLSNextProto to an empty map is the historical way
// of disabling HTTP/2. Explicitly enabling HTTP2 in the Protocols
// field takes precedence.
tr.Protocols = &Protocols{}
tr.Protocols.SetHTTP1(true)
tr.Protocols.SetHTTP2(true)
tr.TLSNextProto = map[string]func(string, *tls.Conn) RoundTripper{}
},
want: "HTTP/2.0",
}, {
name: "https server disables HTTP2 with TLSNextProto",
scheme: "https",
server: func(srv *Server) {
// Disable HTTP/2 on the server with TLSNextProto,
// use default Protocols value.
srv.TLSNextProto = map[string]func(*Server, *tls.Conn, Handler){}
},
want: "HTTP/1.1",
}, {
name: "https server Protocols overrides empty TLSNextProto",
scheme: "https",
server: func(srv *Server) {
// Explicitly enabling HTTP2 in the Protocols field takes precedence
// over setting an empty TLSNextProto.
srv.Protocols = &Protocols{}
srv.Protocols.SetHTTP1(true)
srv.Protocols.SetHTTP2(true)
srv.TLSNextProto = map[string]func(*Server, *tls.Conn, Handler){}
},
want: "HTTP/2.0",
}, {
name: "https server protocols only include HTTP1",
scheme: "https",
server: func(srv *Server) {
srv.Protocols = &Protocols{}
srv.Protocols.SetHTTP1(true)
},
want: "HTTP/1.1",
}, {
name: "https server protocols include HTTP2",
scheme: "https",
server: func(srv *Server) {
srv.Protocols = &Protocols{}
srv.Protocols.SetHTTP1(true)
srv.Protocols.SetHTTP2(true)
},
want: "HTTP/2.0",
}, {
name: "GODEBUG disables HTTP2 client",
scheme: "https",
setup: func(t *testing.T) {
t.Setenv("GODEBUG", "http2client=0")
},
transport: func(tr *Transport) {
// Server default is to support HTTP/2, so if the Transport enables
// HTTP/2 we get it.
tr.Protocols = &Protocols{}
tr.Protocols.SetHTTP1(true)
tr.Protocols.SetHTTP2(true)
},
want: "HTTP/1.1",
}, {
name: "GODEBUG disables HTTP2 server",
scheme: "https",
setup: func(t *testing.T) {
t.Setenv("GODEBUG", "http2server=0")
},
transport: func(tr *Transport) {
// Server default is to support HTTP/2, so if the Transport enables
// HTTP/2 we get it.
tr.Protocols = &Protocols{}
tr.Protocols.SetHTTP1(true)
tr.Protocols.SetHTTP2(true)
},
want: "HTTP/1.1",
}} {
t.Run(test.name, func(t *testing.T) {
// We don't use httptest here because it makes its own decisions
// about how to enable/disable HTTP/2.
srv := &Server{
TLSConfig: &tls.Config{
Certificates: []tls.Certificate{cert},
},
Handler: HandlerFunc(func(w ResponseWriter, req *Request) {
w.Header().Set("X-Proto", req.Proto)
}),
}
tr := &Transport{
TLSClientConfig: &tls.Config{
RootCAs: certpool,
},
}
if test.setup != nil {
test.setup(t)
}
if test.server != nil {
test.server(srv)
}
if test.transport != nil {
test.transport(tr)
} else {
tr.Protocols = &Protocols{}
tr.Protocols.SetHTTP1(true)
tr.Protocols.SetHTTP2(true)
}
listener := newLocalListener(t)
srvc := make(chan error, 1)
go func() {
switch test.scheme {
case "http":
srvc <- srv.Serve(listener)
case "https":
srvc <- srv.ServeTLS(listener, "", "")
}
}()
t.Cleanup(func() {
srv.Close()
<-srvc
})
client := &Client{Transport: tr}
resp, err := client.Get(test.scheme + "://" + listener.Addr().String())
if err != nil {
t.Fatal(err)
}
if got := resp.Header.Get("X-Proto"); got != test.want {
t.Fatalf("request proto %q, want %q", got, test.want)
}
})
}
}