bgpd, zebra: rfc-5549-generic.patch

This adds support for BGP RFC 5549 (Extended Next Hop Encoding capability)

     * send and receive of the capability
     * processing of IPv4->IPv6 next-hops
     * for resolving these IPv6 next-hops, itsworks with the current
       next-hop-tracking support
     * added a new message type between BGP and Zebra for such route
       install/uninstall
     * zserv side of changes to process IPv4 prefix ->IPv6 next-hops
     * required show command changes for IPv4 prefix having IPv6 next-hops

Few points to note about the implementation:

     * It does an implicit next-hop-self when a [IPv4 prefix -> IPv6 LL next-hop]
       is to be considered for advertisement to IPv4 peering (or IPv6 peering
       without Extended next-hop capability negotiated)

     * Currently feature is off by default, enable it by configuring
       'neighbor <> capability extended-nexthop'

     * Current support is for IPv4 Unicast prefixes only.

IMPORTANT NOTE:

     This patch alone isn't enough to have IPv4->IPv6 routes installed into
     the kernel. A separate patch is needed for that to work for the netlink
     interface.

Signed-off-by: Vipin Kumar <vipin@cumulusnetworks.com>
Reviewed-by: Daniel Walton <dwalton@cumulusnetworks.com>
             Vivek Venkatraman <vivek@cumulusnetworks.com>
             Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 30 insertions, 15 deletions

diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index db679e8575..7adbcbe534 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -3221,7 +3221,7 @@ rib_add_ipv6 (int type, u_short instance, int flags, struct prefix_ipv6 *p,
 }
 
 int
-rib_add_ipv6_multipath (struct prefix_ipv6 *p, struct rib *rib, safi_t safi,
+rib_add_ipv6_multipath (struct prefix *p, struct rib *rib, safi_t safi,
 	                unsigned long ifindex)
 {
   struct route_table *table;
@@ -3231,26 +3231,41 @@ rib_add_ipv6_multipath (struct prefix_ipv6 *p, struct rib *rib, safi_t safi,
   int ret = 0;
   unsigned int table_id = 0;
 
-  if (rib)
-    table_id = rib->table;
-  else
-    return 0;			/* why are we getting called with NULL rib */
-
-  /* Lookup table.  */
-  if ((table_id == RT_TABLE_MAIN) || (table_id == zebrad.rtm_table_default))
+  if (p->family == AF_INET)
     {
-      table = vrf_table (AFI_IP6, safi, 0);
+      if (!rib)
+        return 0;
+
+      table = vrf_table (AFI_IP, safi, 0);
+      if (!table)
+        return 0;
+      /* Make it sure prefixlen is applied to the prefix. */
+      apply_mask_ipv4 (p);
     }
   else
     {
-      table = vrf_other_route_table(AFI_IP6, table_id, 0);
-    }
+      if (rib)
+        table_id = rib->table;
+      else
+        return 0;			/* why are we getting called with NULL rib */
 
-  if (! table)
-    return 0;
+      /* Lookup table.  */
+      if ((table_id == RT_TABLE_MAIN) || (table_id == zebrad.rtm_table_default))
+        {
+          table = vrf_table (AFI_IP6, safi, 0);
+        }
+      else
+        {
+          table = vrf_other_route_table(AFI_IP6, table_id, 0);
+        }
 
-  /* Make sure mask is applied. */
-  apply_mask_ipv6 (p);
+      if (! table)
+        return 0;
+
+      /* Make sure mask is applied. */
+      apply_mask_ipv6 (p);
+
+    }
 
   /* Set default distance by route type. */
   if (rib->distance == 0)