http2: avoid Transport hang with Connection: close and AllowHTTP
CL 111835 changed Transport stream ID numbering to start at
stream 3 when AllowHTTP is set. This was based on a
misunderstanding:
When a connection upgrades an HTTP/1.1 request to HTTP/2,
the initial HTTP/1.1 request occupies stream 1.
However, Transport does not perform HTTP protocol upgrades.
When using a Transport to send unencrypted HTTP/2 requests,
the entire connection uses HTTP/2, the first request is
sent as HTTP/2, and there is no reason not to use stream 1
for this request.
Starting from stream 3 is mostly harmless,
but ClientConn.idleStateLocked assumes that client streams
start from 1. This causes it to misidentify new single-use
connections as having already sent a request (when AllowHTTP
is set), and therefore not suitable for use.
Revert to always starting stream IDs at 1.
Fixes golang/go#67671
Change-Id: I97c89de4ae49623d916f9dbd200f8252d2fd4247
Reviewed-on: https://go-review.googlesource.com/c/net/+/591275
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/http2/transport.go b/http2/transport.go
index 98a49c6..61f511f 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -827,10 +827,6 @@
cc.henc.SetMaxDynamicTableSizeLimit(t.maxEncoderHeaderTableSize())
cc.peerMaxHeaderTableSize = initialHeaderTableSize
- if t.AllowHTTP {
- cc.nextStreamID = 3
- }
-
if cs, ok := c.(connectionStater); ok {
state := cs.ConnectionState()
cc.tlsState = &state
diff --git a/http2/transport_test.go b/http2/transport_test.go
index ddeaf61..498e279 100644
--- a/http2/transport_test.go
+++ b/http2/transport_test.go
@@ -5401,3 +5401,23 @@
<-donec
}
+
+// Issue 67671: Sending a Connection: close request on a Transport with AllowHTTP
+// set caused a the transport to wedge.
+func TestIssue67671(t *testing.T) {
+ ts := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {})
+ tr := &Transport{
+ TLSClientConfig: tlsConfigInsecure,
+ AllowHTTP: true,
+ }
+ defer tr.CloseIdleConnections()
+ req, _ := http.NewRequest("GET", ts.URL, nil)
+ req.Close = true
+ for i := 0; i < 2; i++ {
+ res, err := tr.RoundTrip(req)
+ if err != nil {
+ t.Fatal(err)
+ }
+ res.Body.Close()
+ }
+}
