[IPV6]: ROUTE: Add accept_ra_defrtr sysctl.

This controls whether we accept default router information
in RAs.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index cb8856b1d951..e17116796059 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1019,7 +1019,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
         struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
         struct neighbour *neigh = NULL;
         struct inet6_dev *in6_dev;
-        struct rt6_info *rt;
+        struct rt6_info *rt = NULL;
         int lifetime;
         struct ndisc_options ndopts;
         int optlen;
@@ -1081,6 +1081,9 @@ static void ndisc_router_discovery(struct sk_buff *skb)
                                 (ra_msg->icmph.icmp6_addrconf_other ?
                                         IF_RA_OTHERCONF : 0);
 
+        if (!in6_dev->cnf.accept_ra_defrtr)
+                goto skip_defrtr;
+
         lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
 
         rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);
@@ -1128,6 +1131,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
                         rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit;
         }
 
+skip_defrtr:
+
         /*
          *      Update Reachable Time and Retrans Timer
          */