From ea0ec27eb4ab45f394d374f89684cafca3765a8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20L=C3=A9caille?= <flecaille@haproxy.com>
Date: Wed, 8 Jun 2022 13:22:17 +0200
Subject: [PATCH] MINOR: quic: Parse long packet version from
 qc_parse_hd_form()

This is to prepare the support for QUIC v2 version. The packet type
depends on the version. So, we must parse early enough the version
before defining the type of each packet.
---
 src/xprt_quic.c | 47 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 145cf00a86..a899ec796c 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -4537,8 +4537,7 @@ static inline int quic_packet_read_long_header(unsigned char **buf, const unsign
 {
 	unsigned char dcid_len, scid_len;
 
-	/* Version */
-	if (!quic_read_uint32(&pkt->version, (const unsigned char **)buf, end))
+	if (end == *buf)
 		return 0;
 
 	/* Destination Connection ID Length */
@@ -4662,21 +4661,51 @@ static inline int qc_try_rm_hp(struct quic_conn *qc,
 	return 0;
 }
 
-/* Parse the header form from <byte0> first byte of <pkt> pacekt to set type.
+/* Parse the header form from <byte0> first byte of <pkt> packet to set its type.
  * Also set <*long_header> to 1 if this form is long, 0 if not.
  */
-static inline void qc_parse_hd_form(struct quic_rx_packet *pkt,
-                                    unsigned char byte0, int *long_header)
+static inline int qc_parse_hd_form(struct quic_rx_packet *pkt,
+                                   unsigned char **buf, const unsigned char *end,
+                                   int *long_header)
 {
+	const unsigned char byte0 = **buf;
+
+	(*buf)++;
 	if (byte0 & QUIC_PACKET_LONG_HEADER_BIT) {
-		pkt->type =
+		unsigned char type =
 			(byte0 >> QUIC_PACKET_TYPE_SHIFT) & QUIC_PACKET_TYPE_BITMASK;
+
 		*long_header = 1;
+		/* Version */
+		if (!quic_read_uint32(&pkt->version, (const unsigned char **)buf, end))
+			return 0;
+
+		if (pkt->version != QUIC_PROTOCOL_VERSION_2_DRAFT) {
+			pkt->type = type;
+		}
+		else {
+			switch (type) {
+			case 0:
+				pkt->type = QUIC_PACKET_TYPE_RETRY;
+				break;
+			case 1:
+				pkt->type = QUIC_PACKET_TYPE_INITIAL;
+				break;
+			case 2:
+				pkt->type = QUIC_PACKET_TYPE_0RTT;
+				break;
+			case 3:
+				pkt->type = QUIC_PACKET_TYPE_HANDSHAKE;
+				break;
+			}
+		}
 	}
 	else {
 		pkt->type = QUIC_PACKET_TYPE_SHORT;
 		*long_header = 0;
 	}
+
+	return 1;
 }
 
 /*
@@ -5242,7 +5271,11 @@ static void qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
 	}
 
 	/* Header form */
-	qc_parse_hd_form(pkt, *buf++, &long_header);
+	if (!qc_parse_hd_form(pkt, &buf, end, &long_header)) {
+		TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
+		goto drop;
+	}
+
 	if (long_header) {
 		uint64_t len;
 		struct quic_cid odcid;