MINOR: quic: Ignore out of packet padding.
We do not want to count the out of packet padding as being belonging
to an invalid packet, the firt byte of a QUIC packet being never null.
Some browsers like firefox proceeds this way to add PADDING frames
after an Initial packet and increase the size of their Initial packets.
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 41d7ef6..60051d8 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -5152,6 +5152,20 @@
return 1;
}
+/* Check that all the bytes between <buf> included and <end> address
+ * excluded are null. This is the responsability of the caller to
+ * check that there is at least one byte between <buf> end <end>.
+ * Return 1 if this all the bytes are null, 0 if not.
+ */
+static inline int quic_padding_check(const unsigned char *buf,
+ const unsigned char *end)
+{
+ while (buf < end && !*buf)
+ buf++;
+
+ return buf == end;
+}
+
/* Parse a QUIC packet from UDP datagram found in <buf> buffer with <end> the
* end of this buffer past one byte and populate <pkt> RX packet structure
* with the information collected from the packet.
@@ -5195,7 +5209,16 @@
/* Fixed bit */
if (!(*buf & QUIC_PACKET_FIXED_BIT)) {
- /* XXX TO BE DISCARDED */
+ if (!first_pkt && quic_padding_check(buf, end)) {
+ /* Some browsers may pad the remaining datagram space with null bytes.
+ * That is what we called add padding out of QUIC packets. Such
+ * datagrams must be considered as valid. But we can only consume
+ * the remaining space.
+ */
+ pkt->len = end - buf;
+ goto drop_no_conn;
+ }
+
TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
goto drop;
}