From 487d04f6d7410059b44b69d56c53be7802963bab Mon Sep 17 00:00:00 2001
From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Tue, 11 Oct 2022 16:22:18 +0200
Subject: [PATCH] BUG/MINOR: quic: set IP_PKTINFO socket option for QUIC
 receivers only

Move code which activates IP_PKTINFO socket option (or affiliated
options) from sock_inet_bind_receiver() to quic_bind_listener()
function. This change is useful for two reasons :

* first, and the most important one : this activates IP_PKTINFO only for
  QUIC receivers. The previous version impacted all datagram receivers,
  used for example by log-forwarder. This should reduce memory usage for
  these datagram sockets which do not need this option.

* second, USE_QUIC preprocessor statements are removed from
  src/sock_inet.c which clean up the code.

IP_PKTINFO was introduced recently by the following patch :
  97ecc7a8ea5339a753507c3d4e4cd83028c6d038 (quic-dev/qns)
  MEDIUM: quic: retrieve frontend destination address

For the moment, this does not impact any stable release. However, as
previous patch is scheduled for 2.6 backporting, the current change must
also be backported to the same versions.
---
 src/proto_quic.c | 22 +++++++++++++++++++++-
 src/sock_inet.c  | 19 -------------------
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/src/proto_quic.c b/src/proto_quic.c
index 34e22b8dc..cf1e0ded1 100644
--- a/src/proto_quic.c
+++ b/src/proto_quic.c
@@ -592,7 +592,8 @@ static int quic_alloc_rxbufs_listener(struct listener *l)
  */
 static int quic_bind_listener(struct listener *listener, char *errmsg, int errlen)
 {
-	int err = ERR_NONE;
+	const struct sockaddr_storage addr = listener->rx.addr;
+	int fd, err = ERR_NONE;
 	char *msg = NULL;
 
 	/* ensure we never return garbage */
@@ -607,6 +608,25 @@ static int quic_bind_listener(struct listener *listener, char *errmsg, int errle
 		goto udp_return;
 	}
 
+	/* Set IP_PKTINFO to retrieve destination address on recv. */
+	fd = listener->rx.fd;
+	switch (addr.ss_family) {
+	case AF_INET:
+#if defined(IP_PKTINFO)
+		setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
+#elif defined(IP_RECVDSTADDR)
+		setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &one, sizeof(one));
+#endif /* IP_PKTINFO || IP_RECVDSTADDR */
+		break;
+	case AF_INET6:
+#ifdef IPV6_RECVPKTINFO
+		setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
+#endif
+		break;
+	default:
+		break;
+	}
+
 	if (!quic_alloc_rxbufs_listener(listener)) {
 		msg = "could not initialize tx/rx rings";
 		err |= ERR_WARN;
diff --git a/src/sock_inet.c b/src/sock_inet.c
index f8e872cbf..d517e4c42 100644
--- a/src/sock_inet.c
+++ b/src/sock_inet.c
@@ -381,25 +381,6 @@ int sock_inet_bind_receiver(struct receiver *rx, char **errmsg)
 	}
 #endif
 
-#ifdef USE_QUIC
-	if (rx->proto->proto_type == PROTO_TYPE_DGRAM) {
-		switch (addr_inet.ss_family) {
-		case AF_INET:
-#if defined(IP_PKTINFO)
-			setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
-#elif defined(IP_RECVDSTADDR)
-			setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &one, sizeof(one));
-#endif /* IP_PKTINFO || IP_RECVDSTADDR */
-			break;
-		case AF_INET6:
-#ifdef IPV6_RECVPKTINFO
-			setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
-#endif
-			break;
-		}
-	}
-#endif /* USE_QUIC */
-
 	if (!ext && bind(fd, (struct sockaddr *)&addr_inet, rx->proto->fam->sock_addrlen) == -1) {
 		err |= ERR_RETRYABLE | ERR_ALERT;
 		memprintf(errmsg, "cannot bind socket (%s)", strerror(errno));