Implements TTL security for OSPF and RIP.

Interfaces for OSPF and RIP could be configured to use (and request)
TTL 255 for traffic to direct neighbors.

Thanks to Simon Dickhoven for the original patch for RIPng.

1 files changed, 3 insertions, 2 deletions

diff --git a/proto/ospf/iface.c b/proto/ospf/iface.c
index bc3b1ef6..698ef620 100644
--- a/proto/ospf/iface.c
+++ b/proto/ospf/iface.c
@@ -86,7 +86,7 @@ ospf_sk_open(struct ospf_iface *ifa)
   sk->rbsize = rxbufsize(ifa);
   sk->tbsize = rxbufsize(ifa);
   sk->data = (void *) ifa;
-  sk->flags = SKF_LADDR_RX;
+  sk->flags = SKF_LADDR_RX | (ifa->check_ttl ? SKF_TTL_RX : 0);
 
   if (sk_open(sk) != 0)
     goto err;
@@ -131,7 +131,7 @@ ospf_sk_open(struct ospf_iface *ifa)
     else
     {
       ifa->all_routers = AllSPFRouters;
-      sk->ttl = 1;	/* Hack, this will affect just multicast packets */
+      sk->ttl = ifa->cf->ttl_security ? 255 : 1;
 
       if (sk_setup_multicast(sk) < 0)
         goto err;
@@ -534,6 +534,7 @@ ospf_iface_new(struct ospf_area *oa, struct ifa *addr, struct ospf_iface_patt *i
   ifa->rxbuf = ip->rxbuf;
   ifa->check_link = ip->check_link;
   ifa->ecmp_weight = ip->ecmp_weight;
+  ifa->check_ttl = (ip->ttl_security == 1);
 
 #ifdef OSPFv2
   ifa->autype = ip->autype;