BUG/MINOR: quic: fix trace crash on datagram receive

Recently, datagram reception architecture has been completely reworked
to improve performance. A regression has been introduced when using
traces in qc_rcv_buf() : datagram argument is uninitialized after recv
syscall. This may cause a crash as CIDs buffer is dereferenced.

Fix this by removing dgram argument from the affected trace. A new trace
is added after quic_dgram_init() to keep the ability to display the
received content.

This issue has caused failure of all QUIC interop testing.

No need to backport.

diff --git a/src/quic_sock.c b/src/quic_sock.c
index 291a5215339d768e5aba4e34af852d9ff622a504..20f0981f1f06d444aa5dd7a2ec36d6585e2ce158 100644 (file)
--- a/src/quic_sock.c
+++ b/src/quic_sock.c
@@ -217,7 +217,7 @@ struct task *quic_lstnr_dghdlr(struct task *t, void *ctx, unsigned int state)
        return t;
 }
 
-/* Retrieve the DCID from a QUIC datagram or packet at <pos> position,
+/* Retrieve the DCID from a QUIC datagram or packet at <start> position,
  * <end> being at one byte past the end of this datagram.
  * Returns 1 if succeeded, 0 if not.
  */
@@ -855,7 +855,7 @@ int qc_rcv_buf(struct quic_conn *qc)
 
                b_add(&buf, ret);
 
-               TRACE_DEVEL("read datagram", QUIC_EV_CONN_RCV, qc, new_dgram);
+               TRACE_DEVEL("read datagram", QUIC_EV_CONN_RCV, qc);
 
                if (!quic_get_dgram_dcid(dgram_buf, dgram_buf + ret, &dcid_off, &dcid_len))
                        continue;
@@ -873,6 +873,7 @@ int qc_rcv_buf(struct quic_conn *qc)
                }
 
                quic_dgram_init(new_dgram, dgram_buf, ret, NULL, dcid_off, dcid_len, &saddr, &daddr);
+               TRACE_DEVEL("datagram ready for parsing", QUIC_EV_CONN_RCV, qc, new_dgram);
                quic_dgram_parse(new_dgram, qc, l ? &l->obj_type :
                                 (qc->conn ? &__objt_server(qc->conn->target)->obj_type : NULL));
        } while (ret > 0);