From: William Dauchy <w.dauchy@criteo.com>
Date: Wed, 12 Feb 2020 14:53:04 +0000 (+0100)
Subject: BUG/MINOR: tcp: don't try to set defaultmss when value is negative
X-Git-Tag: v2.2-dev3~80
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=97a7bdac3e9e64e9f128943ee3d7b48de88a7daf;p=thirdparty%2Fhaproxy.git

BUG/MINOR: tcp: don't try to set defaultmss when value is negative

when `getsockopt` previously failed, we were trying to set defaultmss
with -2 value.

this is a followup of github issue #499

this should be backported to all versions >= v1.8

Fixes: 153659f1ae69a1 ("MINOR: tcp: When binding socket, attempt to
reuse one from the old proc.")
Signed-off-by: William Dauchy <w.dauchy@criteo.com>
---

diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 45d6a7c199..7668ec29c3 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -906,9 +906,9 @@ int tcp_bind_listener(struct listener *listener, char *errmsg, int errlen)
 			defaultmss = default_tcp6_maxseg;
 
 		getsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &tmpmaxseg, &len);
-		if (tmpmaxseg != defaultmss && setsockopt(fd, IPPROTO_TCP,
-						TCP_MAXSEG, &defaultmss,
-						sizeof(defaultmss)) == -1) {
+		if (defaultmss > 0 &&
+		    tmpmaxseg != defaultmss &&
+		    setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &defaultmss, sizeof(defaultmss)) == -1) {
 			msg = "cannot set MSS";
 			err |= ERR_WARN;
 		}