http2: support CONNECT requests

Support CONNECT requests in both the server & transport.

See https://httpwg.github.io/specs/rfc7540.html#CONNECT

When I bundle this into the main Go repo I will also add h1-vs-h2
compatibility tests there, making sure they match behavior. (I now
expect that they do match)

Updates golang/go#13717

Change-Id: I0c65ad47b029419027efb616fed3d8e0e2a363f4
Reviewed-on: https://go-review.googlesource.com/18266Reviewed-by: Andrew Gerrand <adg@golang.org>

http2/server.go

@@ -1545,7 +1545,17 @@ func (sc *serverConn) resetPendingRequest() {
 func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, error) {
 	sc.serveG.check()
 	rp := &sc.req
-	if rp.invalidHeader || rp.method == "" || rp.path == "" ||
+
+	if rp.invalidHeader {
+		return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
+	}
+
+	isConnect := rp.method == "CONNECT"
+	if isConnect {
+		if rp.path != "" || rp.scheme != "" || rp.authority == "" {
+			return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
+		}
+	} else if rp.method == "" || rp.path == "" ||
 		(rp.scheme != "https" && rp.scheme != "http") {
 		// See 8.1.2.6 Malformed Requests and Responses:
 		//
@@ -1559,12 +1569,14 @@ func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, err
 		// pseudo-header fields"
 		return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
 	}
+
 	bodyOpen := rp.stream.state == stateOpen
 	if rp.method == "HEAD" && bodyOpen {
 		// HEAD requests can't have bodies
 		return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
 	}
 	var tlsState *tls.ConnectionState // nil if not scheme https
+
 	if rp.scheme == "https" {
 		tlsState = sc.tlsState
 	}
@@ -1605,18 +1617,26 @@ func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, err
 		stream:        rp.stream,
 		needsContinue: needsContinue,
 	}
-	// TODO: handle asterisk '*' requests + test
-	url, err := url.ParseRequestURI(rp.path)
-	if err != nil {
-		// TODO: find the right error code?
-		return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
+	var url_ *url.URL
+	var requestURI string
+	if isConnect {
+		url_ = &url.URL{Host: rp.authority}
+		requestURI = rp.authority // mimic HTTP/1 server behavior
+	} else {
+		var err error
+		// TODO: handle asterisk '*' requests + test
+		url_, err = url.ParseRequestURI(rp.path)
+		if err != nil {
+			return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
+		}
+		requestURI = rp.path
 	}
 	req := &http.Request{
 		Method:     rp.method,
-		URL:        url,
+		URL:        url_,
 		RemoteAddr: sc.remoteAddrStr,
 		Header:     rp.header,
-		RequestURI: rp.path,
+		RequestURI: requestURI,
 		Proto:      "HTTP/2.0",
 		ProtoMajor: 2,
 		ProtoMinor: 0,

http2/server_test.go

@@ -901,6 +901,60 @@ func testRejectRequest(t *testing.T, send func(*serverTester)) {
 	st.wantRSTStream(1, ErrCodeProtocol)
 }
 
+func TestServer_Request_Connect(t *testing.T) {
+	testServerRequest(t, func(st *serverTester) {
+		st.writeHeaders(HeadersFrameParam{
+			StreamID: 1,
+			BlockFragment: st.encodeHeaderRaw(
+				":method", "CONNECT",
+				":authority", "example.com:123",
+			),
+			EndStream:  true,
+			EndHeaders: true,
+		})
+	}, func(r *http.Request) {
+		if g, w := r.Method, "CONNECT"; g != w {
+			t.Errorf("Method = %q; want %q", g, w)
+		}
+		if g, w := r.RequestURI, "example.com:123"; g != w {
+			t.Errorf("RequestURI = %q; want %q", g, w)
+		}
+		if g, w := r.URL.Host, "example.com:123"; g != w {
+			t.Errorf("URL.Host = %q; want %q", g, w)
+		}
+	})
+}
+
+func TestServer_Request_Connect_InvalidPath(t *testing.T) {
+	testServerRejectsStream(t, ErrCodeProtocol, func(st *serverTester) {
+		st.writeHeaders(HeadersFrameParam{
+			StreamID: 1,
+			BlockFragment: st.encodeHeaderRaw(
+				":method", "CONNECT",
+				":authority", "example.com:123",
+				":path", "/bogus",
+			),
+			EndStream:  true,
+			EndHeaders: true,
+		})
+	})
+}
+
+func TestServer_Request_Connect_InvalidScheme(t *testing.T) {
+	testServerRejectsStream(t, ErrCodeProtocol, func(st *serverTester) {
+		st.writeHeaders(HeadersFrameParam{
+			StreamID: 1,
+			BlockFragment: st.encodeHeaderRaw(
+				":method", "CONNECT",
+				":authority", "example.com:123",
+				":scheme", "https",
+			),
+			EndStream:  true,
+			EndHeaders: true,
+		})
+	})
+}
+
 func TestServer_Ping(t *testing.T) {
 	st := newServerTester(t, nil)
 	defer st.Close()
@@ -1222,7 +1276,7 @@ func TestServer_StateTransitions(t *testing.T) {
 
 // test HEADERS w/o EndHeaders + another HEADERS (should get rejected)
 func TestServer_Rejects_HeadersNoEnd_Then_Headers(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		st.writeHeaders(HeadersFrameParam{
 			StreamID:      1,
 			BlockFragment: st.encodeHeader(),
@@ -1240,7 +1294,7 @@ func TestServer_Rejects_HeadersNoEnd_Then_Headers(t *testing.T) {
 
 // test HEADERS w/o EndHeaders + PING (should get rejected)
 func TestServer_Rejects_HeadersNoEnd_Then_Ping(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		st.writeHeaders(HeadersFrameParam{
 			StreamID:      1,
 			BlockFragment: st.encodeHeader(),
@@ -1255,7 +1309,7 @@ func TestServer_Rejects_HeadersNoEnd_Then_Ping(t *testing.T) {
 
 // test HEADERS w/ EndHeaders + a continuation HEADERS (should get rejected)
 func TestServer_Rejects_HeadersEnd_Then_Continuation(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		st.writeHeaders(HeadersFrameParam{
 			StreamID:      1,
 			BlockFragment: st.encodeHeader(),
@@ -1271,7 +1325,7 @@ func TestServer_Rejects_HeadersEnd_Then_Continuation(t *testing.T) {
 
 // test HEADERS w/o EndHeaders + a continuation HEADERS on wrong stream ID
 func TestServer_Rejects_HeadersNoEnd_Then_ContinuationWrongStream(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		st.writeHeaders(HeadersFrameParam{
 			StreamID:      1,
 			BlockFragment: st.encodeHeader(),
@@ -1286,7 +1340,7 @@ func TestServer_Rejects_HeadersNoEnd_Then_ContinuationWrongStream(t *testing.T)
 
 // No HEADERS on stream 0.
 func TestServer_Rejects_Headers0(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		st.fr.AllowIllegalWrites = true
 		st.writeHeaders(HeadersFrameParam{
 			StreamID:      0,
@@ -1299,7 +1353,7 @@ func TestServer_Rejects_Headers0(t *testing.T) {
 
 // No CONTINUATION on stream 0.
 func TestServer_Rejects_Continuation0(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		st.fr.AllowIllegalWrites = true
 		if err := st.fr.WriteContinuation(0, true, st.encodeHeader()); err != nil {
 			t.Fatal(err)
@@ -1308,7 +1362,7 @@ func TestServer_Rejects_Continuation0(t *testing.T) {
 }
 
 func TestServer_Rejects_PushPromise(t *testing.T) {
-	testServerRejects(t, func(st *serverTester) {
+	testServerRejectsConn(t, func(st *serverTester) {
 		pp := PushPromiseParam{
 			StreamID:  1,
 			PromiseID: 3,
@@ -1319,10 +1373,10 @@ func TestServer_Rejects_PushPromise(t *testing.T) {
 	})
 }
 
-// testServerRejects tests that the server hangs up with a GOAWAY
+// testServerRejectsConn tests that the server hangs up with a GOAWAY
 // frame and a server close after the client does something
 // deserving a CONNECTION_ERROR.
-func testServerRejects(t *testing.T, writeReq func(*serverTester)) {
+func testServerRejectsConn(t *testing.T, writeReq func(*serverTester)) {
 	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {})
 	st.addLogFilter("connection error: PROTOCOL_ERROR")
 	defer st.Close()
@@ -1348,6 +1402,16 @@ func testServerRejects(t *testing.T, writeReq func(*serverTester)) {
 	}
 }
 
+// testServerRejectsStream tests that the server sends a RST_STREAM with the provided
+// error code after a client sends a bogus request.
+func testServerRejectsStream(t *testing.T, code ErrCode, writeReq func(*serverTester)) {
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {})
+	defer st.Close()
+	st.greet()
+	writeReq(st)
+	st.wantRSTStream(1, code)
+}
+
 // testServerRequest sets up an idle HTTP/2 connection and lets you
 // write a single request with writeReq, and then verify that the
 // *http.Request is built correctly in checkReq.

http2/transport.go

@@ -775,8 +775,10 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 	// [RFC3986]).
 	cc.writeHeader(":authority", host) // probably not right for all sites
 	cc.writeHeader(":method", req.Method)
-	cc.writeHeader(":path", req.URL.RequestURI())
-	cc.writeHeader(":scheme", "https")
+	if req.Method != "CONNECT" {
+		cc.writeHeader(":path", req.URL.RequestURI())
+		cc.writeHeader(":scheme", "https")
+	}
 	if trailers != "" {
 		cc.writeHeader("trailer", trailers)
 	}

http2/transport_test.go

@@ -760,3 +760,62 @@ func TestTransportFullDuplex(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestTransportConnectRequest(t *testing.T) {
+	gotc := make(chan *http.Request, 1)
+	st := newServerTester(t, func(w http.ResponseWriter, r *http.Request) {
+		gotc <- r
+	}, optOnlyServer)
+	defer st.Close()
+
+	u, err := url.Parse(st.ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tr := &Transport{TLSClientConfig: tlsConfigInsecure}
+	defer tr.CloseIdleConnections()
+	c := &http.Client{Transport: tr}
+
+	tests := []struct {
+		req  *http.Request
+		want string
+	}{
+		{
+			req: &http.Request{
+				Method: "CONNECT",
+				Header: http.Header{},
+				URL:    u,
+			},
+			want: u.Host,
+		},
+		{
+			req: &http.Request{
+				Method: "CONNECT",
+				Header: http.Header{},
+				URL:    u,
+				Host:   "example.com:123",
+			},
+			want: "example.com:123",
+		},
+	}
+
+	for i, tt := range tests {
+		res, err := c.Do(tt.req)
+		if err != nil {
+			t.Errorf("%d. RoundTrip = %v", i, err)
+			continue
+		}
+		res.Body.Close()
+		req := <-gotc
+		if req.Method != "CONNECT" {
+			t.Errorf("method = %q; want CONNECT", req.Method)
+		}
+		if req.Host != tt.want {
+			t.Errorf("Host = %q; want %q", req.Host, tt.want)
+		}
+		if req.URL.Host != tt.want {
+			t.Errorf("URL.Host = %q; want %q", req.URL.Host, tt.want)
+		}
+	}
+}