From: Tobias Brunner <tobias@strongswan.org>
Date: Thu, 22 Sep 2022 15:33:52 +0000 (+0200)
Subject: socket-default: Use IPv6-only mode for IPv6 sockets
X-Git-Tag: 5.9.8rc1~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ebaaacc4596bfa581fead707aa107234c6bd064c;p=thirdparty%2Fstrongswan.git

socket-default: Use IPv6-only mode for IPv6 sockets

Otherwise, we can't open a dedicated IPv4 socket on the same port as the
IPv6 socket already is set up do receive IPv4 packets (unless we'd again
enable SO_REUSEADDR).

Fixes: 83da13371292 ("socket-default: Don't set SO_REUSEADDR on IKE sockets anymore")
---

diff --git a/src/libcharon/plugins/socket_default/socket_default_socket.c b/src/libcharon/plugins/socket_default/socket_default_socket.c
index f551710177..89d2ac15c8 100644
--- a/src/libcharon/plugins/socket_default/socket_default_socket.c
+++ b/src/libcharon/plugins/socket_default/socket_default_socket.c
@@ -699,6 +699,14 @@ static int open_socket(private_socket_default_socket_t *this,
 		return -1;
 	}
 
+	if (family == AF_INET6 &&
+		setsockopt(skt, SOL_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0)
+	{
+		DBG1(DBG_NET, "unable to set IPV6_V6ONLY on socket: %s", strerror(errno));
+		close(skt);
+		return -1;
+	}
+
 	/* bind the socket */
 	if (bind(skt, &addr.sockaddr, addrlen) < 0)
 	{