ipv6: add flowlabel_consistency sysctl
With the introduction of IPV6_FL_F_REFLECT, there is no guarantee of
flow label unicity. This patch introduces a new sysctl to protect the old
behaviour, enable by default.
Changelog of V3:
* rename ip6_flowlabel_consistency to flowlabel_consistency
* use net_info_ratelimited()
* checkpatch cleanups
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 01bf252..dfa41bb 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -588,8 +588,15 @@
case IPV6_FL_A_GET:
if (freq.flr_flags & IPV6_FL_F_REFLECT) {
+ struct net *net = sock_net(sk);
+ if (net->ipv6.sysctl.flowlabel_consistency) {
+ net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
+ return -EPERM;
+ }
+
if (sk->sk_protocol != IPPROTO_TCP)
return -ENOPROTOOPT;
+
np->repflow = 1;
return 0;
}