BUG/MINOR: mux-quic: do not decode if conn in error

Add an early return to qcc_decode_qcs() if QCC instance is flagged on
error and connection is scheduled for immediate closure.

The main objective is to ensure to not trigger BUG_ON() from
qcc_set_error() : if a stream decoding has set the connection error, do
not try to process decoding on other streams as they may also encounter
an error. Thus, the connection is closed asap with the first encountered
error case.

This should be backported up to 2.6, after a period of observation.

(cherry picked from commit 6c5030f703e29bfd8deeace111bcedc6835c7065)
[ad: context adjustement, due to multiple Rx bufs not available in 3.1]
Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
(cherry picked from commit 52235aed6248ff32832a24530ca8593610c76903)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/mux_quic.c b/src/mux_quic.c
index 8fe2fbc..cc9f304 100644 (file)
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -958,6 +958,10 @@ static void qcs_consume(struct qcs *qcs, uint64_t bytes)
 /* Decode the content of STREAM frames already received on the stream instance
  * <qcs>.
  *
+ * It is safe to remove <qcs> from <qcc> recv_list after decoding is done. Even
+ * if an error is returned, caller should consider that no further Rx
+ * processing can be performed for the stream, until new bytes are available.
+ *
  * Returns 0 on success else non-zero.
  */
 static int qcc_decode_qcs(struct qcc *qcc, struct qcs *qcs)
@@ -969,6 +973,12 @@ static int qcc_decode_qcs(struct qcc *qcc, struct qcs *qcs)
 
        TRACE_ENTER(QMUX_EV_QCS_RECV, qcc->conn, qcs);
 
+       if (qcc->flags & QC_CF_ERRL) {
+               TRACE_DATA("connection on error", QMUX_EV_QCC_RECV, qcc->conn);
+               ret = -1;
+               goto err;
+       }
+
        b = qcs_b_dup(&qcs->rx.ncbuf);
 
        /* Signal FIN to application if STREAM FIN received with all data. */