From: Frédéric Lécaille <flecaille@haproxy.com>
Date: Thu, 27 Jan 2022 11:19:28 +0000 (+0100)
Subject: MINOR: quic: Do not reset a full RX buffer
X-Git-Tag: v2.6-dev1~50
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=320744b53d6d422346348c800f7f624cce8df93e;p=thirdparty%2Fhaproxy.git

MINOR: quic: Do not reset a full RX buffer

As the RX buffer is not consumed by the sock i/o handler as soon as a datagram
is produced, when full an RX buffer must not be reset. The remaining room is
consumed without modifying it. The consumer has a represention of its contents:
a list of datagrams.
---

diff --git a/src/quic_sock.c b/src/quic_sock.c
index 468cf64db6..37e7f1b7c0 100644
--- a/src/quic_sock.c
+++ b/src/quic_sock.c
@@ -173,7 +173,7 @@ void quic_sock_fd_iocb(int fd)
 	struct quic_transport_params *params;
 	/* Source address */
 	struct sockaddr_storage saddr = {0};
-	size_t max_sz;
+	size_t max_sz, cspace;
 	socklen_t saddrlen;
 	struct quic_dgram *dgram, *dgramp, *new_dgram;
 
@@ -207,9 +207,10 @@ void quic_sock_fd_iocb(int fd)
 
 	params = &l->bind_conf->quic_params;
 	max_sz = params->max_udp_payload_size;
-	if (b_contig_space(buf) < max_sz) {
-		/* Note that when we enter this function, <buf> is always empty */
-		b_reset(buf);
+	cspace = b_contig_space(buf);
+	if (cspace < max_sz) {
+		/* Consume the remaining space */
+		b_add(buf, cspace);
 		if (b_contig_space(buf) < max_sz)
 			goto out;
 	}