From 3caff6ca60390aa5962b4aa3b66c50fc8b8006b9 Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@cumulusnetworks.com>
Date: Tue, 19 May 2015 18:29:15 -0700
Subject: [PATCH] Include loopback IP addresses in martian NEXTHOP check

---
 bgpd/bgp_nexthop.c | 54 ----------------------------------------------
 bgpd/bgp_nexthop.h |  1 -
 bgpd/bgp_route.c   | 14 ++++++++----
 3 files changed, 10 insertions(+), 59 deletions(-)

diff --git a/bgpd/bgp_nexthop.c b/bgpd/bgp_nexthop.c
index 7f516379bf..40b719fe31 100644
--- a/bgpd/bgp_nexthop.c
+++ b/bgpd/bgp_nexthop.c
@@ -92,45 +92,6 @@ bnc_free (struct bgp_nexthop_cache *bnc)
   XFREE (MTYPE_BGP_NEXTHOP_CACHE, bnc);
 }
 
-/* If nexthop exists on connected network return 1. */
-int
-bgp_nexthop_onlink (afi_t afi, struct attr *attr)
-{
-  struct bgp_node *rn;
-  
-  /* Lookup the address is onlink or not. */
-  if (afi == AFI_IP)
-    {
-      rn = bgp_node_match_ipv4 (bgp_connected_table[AFI_IP], &attr->nexthop);
-      if (rn)
-	{
-	  bgp_unlock_node (rn);
-	  return 1;
-	}
-    }
-#ifdef HAVE_IPV6
-  else if (afi == AFI_IP6)
-    {
-      if (attr->extra->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL)
-	return 1;
-      else if (attr->extra->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL)
-	{
-	  if (IN6_IS_ADDR_LINKLOCAL (&attr->extra->mp_nexthop_global))
-	    return 1;
-
-	  rn = bgp_node_match_ipv6 (bgp_connected_table[AFI_IP6],
-				      &attr->extra->mp_nexthop_global);
-	  if (rn)
-	    {
-	      bgp_unlock_node (rn);
-	      return 1;
-	    }
-	}
-    }
-#endif /* HAVE_IPV6 */
-  return 0;
-}
-
 /* Reset and free all BGP nexthop cache. */
 static void
 bgp_nexthop_cache_reset (struct bgp_table *table)
@@ -241,18 +202,9 @@ bgp_connected_add (struct connected *ifc)
 {
   struct prefix p;
   struct prefix *addr;
-  struct interface *ifp;
   struct bgp_node *rn;
   struct bgp_connected_ref *bc;
 
-  ifp = ifc->ifp;
-
-  if (! ifp)
-    return;
-
-  if (if_is_loopback (ifp))
-    return;
-
   addr = ifc->address;
 
   if (addr->family == AF_INET)
@@ -311,15 +263,9 @@ bgp_connected_delete (struct connected *ifc)
 {
   struct prefix p;
   struct prefix *addr;
-  struct interface *ifp;
   struct bgp_node *rn;
   struct bgp_connected_ref *bc;
 
-  ifp = ifc->ifp;
-
-  if (if_is_loopback (ifp))
-    return;
-
   addr = ifc->address;
 
   if (addr->family == AF_INET)
diff --git a/bgpd/bgp_nexthop.h b/bgpd/bgp_nexthop.h
index ffa726dad4..5485bb2c13 100644
--- a/bgpd/bgp_nexthop.h
+++ b/bgpd/bgp_nexthop.h
@@ -63,7 +63,6 @@ extern void bgp_connected_add (struct connected *c);
 extern void bgp_connected_delete (struct connected *c);
 extern int bgp_multiaccess_check_v4 (struct in_addr, struct peer *);
 extern int bgp_config_write_scan_time (struct vty *);
-extern int bgp_nexthop_onlink (afi_t, struct attr *);
 extern int bgp_nexthop_self (struct attr *);
 extern void bgp_address_init (void);
 extern struct bgp_nexthop_cache *bnc_new(void);
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 1a8fb3562b..530009d62d 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -2711,16 +2711,22 @@ bgp_update_main (struct peer *peer, struct prefix *p, u_int32_t addpath_id,
   /* IPv4 unicast next hop check.  */
   if (afi == AFI_IP && safi == SAFI_UNICAST)
     {
-      /* Next hop must not be 0.0.0.0 nor Class D/E address. Next hop
-	 must not be my own address.  */
+      /* Next hop must not be 0.0.0.0 nor Class D/E address. */
       if (new_attr.nexthop.s_addr == 0
-	  || IPV4_CLASS_DE (ntohl (new_attr.nexthop.s_addr))
-	  || bgp_nexthop_self (&new_attr))
+	  || IPV4_CLASS_DE (ntohl (new_attr.nexthop.s_addr)))
 	{
 	  reason = "martian next-hop;";
 	  bgp_attr_flush (&new_attr);
 	  goto filtered;
 	}
+
+      /* Next hop must not be my own address.  */
+      if (bgp_nexthop_self (&new_attr))
+	{
+	  reason = "local IP next-hop;";
+	  bgp_attr_flush (&new_attr);
+	  goto filtered;
+	}
     }
 
   attr_new = bgp_attr_intern (&new_attr);
-- 
2.39.5