sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND

[ Upstream commit b71d21c ] Commit 9b97420 ("sctp: support ipv6 nonlocal bind") introduced support for the above options as v4 sctp did, so patched sctp_v6_available(). In the v4 implementation it's enough, because sctp_inet_bind_verify() just returns with sctp_v4_available(). However sctp_inet6_bind_verify() has an extra check before that for link-local scope_id, which won't respect the above options. Added the checks before calling ipv6_chk_addr(), but not before the validation of scope_id. before (w/ both options): ./v6test fe80::10 sctp bind failed, errno: 99 (Cannot assign requested address) ./v6test fe80::10 tcp bind success, errno: 0 (Success) after (w/ both options): ./v6test fe80::10 sctp bind success, errno: 0 (Success) Signed-off-by: Laszlo Toth <[email protected]> Reviewed-by: Xin Long <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
TechNexion · Nov 18, 2017 · ec5caf5 · ec5caf5
1 parent 28fa583
commit ec5caf5
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
@@ -881,8 +881,10 @@ static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 			net = sock_net(&opt->inet.sk);
 			rcu_read_lock();
 			dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
-			if (!dev ||
-			    !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) {
+			if (!dev || !(opt->inet.freebind ||
+				      net->ipv6.sysctl.ip_nonlocal_bind ||
+				      ipv6_chk_addr(net, &addr->v6.sin6_addr,
+						    dev, 0))) {
 				rcu_read_unlock();
 				return 0;
 			}