BUG/MINOR: h3: reject server push stream

Push streams are not supported by haproxy as a client. Thus, it never
emits any MAX_PUSH_ID frame. In this case, the server is not allowed to
initiate any push stream.

This patch ensures that such stream is closed with error H3_ID_ERROR, as
specified by HTTP/3 RFC.

This must be backported up to 3.3.

diff --git a/src/h3.c b/src/h3.c
index 6210f2c16ccfc2daa00d4167e3fd68d4a6b4b2fa..c412eb8ee030965ff8ea5ef254ce27e5c2384c9a 100644 (file)
--- a/src/h3.c
+++ b/src/h3.c
@@ -225,8 +225,20 @@ static ssize_t h3_init_uni_stream(struct h3c *h3c, struct qcs *qcs,
                        qcc_report_glitch(qcs->qcc, 1);
                        goto err;
                }
-               /* TODO not supported for the moment */
-               h3s->type = H3S_T_PUSH;
+               else {
+                       /* RFC 9114 4.6. Server Push
+                        *
+                        * A client MUST treat receipt of a push stream as a connection
+                        * error of type H3_ID_ERROR when no MAX_PUSH_ID frame has been sent or
+                        * when the stream references a push ID that is greater than the maximum
+                        * push ID.
+                        */
+                       TRACE_ERROR("reject push from server outside of MAX_PUSH_ID", H3_EV_H3S_NEW, qcs->qcc->conn, qcs);
+                       qcc_set_error(qcs->qcc, H3_ERR_ID_ERROR, 1,
+                                     muxc_tevt_type_proto_err);
+                       qcc_report_glitch(qcs->qcc, 1);
+                       goto err;
+               }
                break;
 
        case H3_UNI_S_T_QPACK_DEC: