BUG/MINOR: quic: Do not drop too small datagrams with Initial packets
When receiving an Initial packet a peer must drop it if the datagram is smaller
than 1200. Before this patch, this is the entire datagram which was dropped.
In such a case, drop the packet after having parsed its length.
Must be backported to 2.6 and 2.7
diff --git a/src/quic_conn.c b/src/quic_conn.c
index ebbf003..83188c4 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -6287,13 +6287,6 @@
goto drop;
}
- if (pkt->type == QUIC_PACKET_TYPE_INITIAL &&
- dgram->len < QUIC_INITIAL_PACKET_MINLEN) {
- TRACE_PROTO("Too short datagram with an Initial packet", QUIC_EV_CONN_LPKT);
- HA_ATOMIC_INC(&prx_counters->too_short_initial_dgram);
- goto drop;
- }
-
/* When multiple QUIC packets are coalesced on the same UDP datagram,
* they must have the same DCID.
*/
@@ -6388,6 +6381,19 @@
pkt->pn_offset = buf - beg;
pkt->len = pkt->pn_offset + len;
+ /* RFC 9000. Initial Datagram Size
+ *
+ * A server MUST discard an Initial packet that is carried in a UDP datagram
+ * with a payload that is smaller than the smallest allowed maximum datagram
+ * size of 1200 bytes.
+ */
+ if (pkt->type == QUIC_PACKET_TYPE_INITIAL &&
+ dgram->len < QUIC_INITIAL_PACKET_MINLEN) {
+ TRACE_PROTO("Too short datagram with an Initial packet", QUIC_EV_CONN_LPKT);
+ HA_ATOMIC_INC(&prx_counters->too_short_initial_dgram);
+ goto drop;
+ }
+
/* Interrupt parsing after packet length retrieval : this
* ensures that only the packet is dropped but not the whole
* datagram.