Better check for IPv6 compatibility with the BGP peer.

[l2tpns.git] / bgp.c

diff --git a/bgp.c b/bgp.c
index 7de3d3f..795ffc5 100644 (file)
--- a/bgp.c
+++ b/bgp.c
@@ -260,7 +260,7 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
        a.code = BGP_PATH_ATTR_CODE_MP_REACH_NLRI;
        a.data.s.len = 0; /* will be set on UPDATE */
 
-       mp_reach_nlri_partial.afi = htons(AF_INET6);
+       mp_reach_nlri_partial.afi = htons(BGP_MP_AFI_IPv6);
        mp_reach_nlri_partial.safi = BGP_MP_SAFI_UNICAST;
        mp_reach_nlri_partial.reserved = 0;
        mp_reach_nlri_partial.next_hop_len = 16;
@@ -286,7 +286,7 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
        a.code = BGP_PATH_ATTR_CODE_MP_UNREACH_NLRI;
        a.data.e.len = 0; /* will be set on UPDATE */
 
-       mp_unreach_nlri_partial.afi = htons(AF_INET6);
+       mp_unreach_nlri_partial.afi = htons(BGP_MP_AFI_IPv6);
        mp_unreach_nlri_partial.safi = BGP_MP_SAFI_UNICAST;
 
        memcpy(&a.data.e.value, &mp_unreach_nlri_partial,
@@ -556,7 +556,8 @@ int bgp_add_route6(struct in6_addr ip, int prefixlen)
 
     /* flag established peers for update */
     for (i = 0; i < BGP_NUM_PEERS; i++)
-       if (bgp_peers[i].state == Established)
+       if (bgp_peers[i].state == Established
+               && bgp_peers[i].mp_handling == HandleIPv6Routes)
            bgp_peers[i].update_routes6 = 1;
 
     LOG(4, 0, 0, "Registered BGP route %s/%d\n",
@@ -656,7 +657,8 @@ int bgp_del_route6(struct in6_addr ip, int prefixlen)
 
     /* flag established peers for update */
     for (i = 0; i < BGP_NUM_PEERS; i++)
-       if (bgp_peers[i].state == Established)
+       if (bgp_peers[i].state == Established
+               && bgp_peers[i].mp_handling == HandleIPv6Routes)
            bgp_peers[i].update_routes6 = 1;
 
     LOG(4, 0, 0, "Removed BGP route %s/%d\n",
@@ -1185,7 +1187,7 @@ static int bgp_handle_input(struct bgp_peer *peer)
                    param_offset < data.opt_len;
                    param_offset += 2 + param->len)
            {
-               param = (struct bgp_opt_param *)(&data.opt_params + param_offset);
+               param = (struct bgp_opt_param *)((char *)&data.opt_params + param_offset);
 
                /* sensible check */
                if (data.opt_len - param_offset < 2
@@ -1210,11 +1212,8 @@ static int bgp_handle_input(struct bgp_peer *peer)
 
                capabilities_len = param->len;
                capabilities = (char *)&param->value;
-           }
 
-           /* look for BGP multiprotocol capability */
-           if (capabilities)
-           {
+               /* look for BGP multiprotocol capability */
                for (capability_offset = 0;
                        capability_offset < capabilities_len;
                        capability_offset += 2 + capability->len)
@@ -1247,7 +1246,7 @@ static int bgp_handle_input(struct bgp_peer *peer)
 
                    mp_cap = (struct bgp_mp_cap_param *)&capability->value;
                    /* the only <AFI, SAFI> tuple we support */
-                   if (ntohs(mp_cap->afi) != AF_INET6 && mp_cap->safi != BGP_MP_SAFI_UNICAST)
+                   if (ntohs(mp_cap->afi) != BGP_MP_AFI_IPv6 && mp_cap->safi != BGP_MP_SAFI_UNICAST)
                    {
                        LOG(4, 0, 0, "Unsupported multiprotocol AFI %d and SAFI %d from BGP peer %s\n",
                            mp_cap->afi, mp_cap->safi, peer->name);
@@ -1258,10 +1257,19 @@ static int bgp_handle_input(struct bgp_peer *peer)
                        continue;
                    }
 
+                   /* yes it can! */
                    peer->mp_handling = HandleIPv6Routes;
                }
            }
 
+           if (peer->mp_handling != HandleIPv6Routes)
+           {
+               peer->mp_handling = DoesntHandleIPv6Routes;
+               if (config->ipv6_prefix.s6_addr[0])
+                   LOG(1, 0, 0, "Warning: BGP peer %s doesn't handle IPv6 prefixes updates\n",
+                           peer->name);
+           }
+
            /* next transition requires an exchange of keepalives */
            bgp_send_keepalive(peer);
        }
@@ -1346,7 +1354,7 @@ static int bgp_handle_input(struct bgp_peer *peer)
 static int bgp_send_open(struct bgp_peer *peer)
 {
     struct bgp_data_open data;
-    struct bgp_mp_cap_param mp_ipv6 = { htons(AF_INET6), 0, BGP_MP_SAFI_UNICAST };
+    struct bgp_mp_cap_param mp_ipv6 = { htons(BGP_MP_AFI_IPv6), 0, BGP_MP_SAFI_UNICAST };
     struct bgp_capability cap_mp_ipv6;
     struct bgp_opt_param param_cap_mp_ipv6;
     uint16_t len = sizeof(peer->outbuf->packet.header);
@@ -1363,8 +1371,9 @@ static int bgp_send_open(struct bgp_peer *peer)
 
     /* if we know peer doesn't support MP (mp_handling == DoesntHandleIPv6Routes)
        then don't add this parameter */
-    if (peer->mp_handling == HandlingUnknown
-           || peer->mp_handling == HandleIPv6Routes)
+    if (config->ipv6_prefix.s6_addr[0]
+           && (peer->mp_handling == HandlingUnknown
+               || peer->mp_handling == HandleIPv6Routes))
     {
        /* construct the param and capability */
        cap_mp_ipv6.code = BGP_CAP_CODE_MP;