Move NEXT_HOP attribute so that we can exclude it.

[l2tpns.git] / bgp.c

diff --git a/bgp.c b/bgp.c
index 2309a9c..10f06a3 100644 (file)
--- a/bgp.c
+++ b/bgp.c
@@ -193,15 +193,6 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
 
     ADD_ATTRIBUTE();
 
-    /* NEXT_HOP */
-    a.flags = BGP_PATH_ATTR_FLAG_TRANS;
-    a.code = BGP_PATH_ATTR_CODE_NEXT_HOP;
-    ip = my_address; /* we're it */
-    a.data.s.len = sizeof(ip);
-    memcpy(a.data.s.value, &ip, sizeof(ip));
-
-    ADD_ATTRIBUTE();
-
     /* MULTI_EXIT_DISC */
     a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL;
     a.code = BGP_PATH_ATTR_CODE_MULTI_EXIT_DISC;
@@ -231,6 +222,18 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
 
     ADD_ATTRIBUTE();
 
+    /* remember the len before adding NEXT_HOP */
+    peer->path_attr_len_without_nexthop = peer->path_attr_len;
+
+    /* NEXT_HOP */
+    a.flags = BGP_PATH_ATTR_FLAG_TRANS;
+    a.code = BGP_PATH_ATTR_CODE_NEXT_HOP;
+    ip = my_address; /* we're it */
+    a.data.s.len = sizeof(ip);
+    memcpy(a.data.s.value, &ip, sizeof(ip));
+
+    ADD_ATTRIBUTE();
+
     if (!(peer->path_attrs = malloc(peer->path_attr_len)))
     {
        LOG(0, 0, 0, "Can't allocate path_attrs for %s (%s)\n",
@@ -996,7 +999,7 @@ static int bgp_handle_input(struct bgp_peer *peer)
                }
 
                /* we know only one parameter type */
-               if (param->type != BGP_CAPABILITY_PARAM_TYPE)
+               if (param->type != BGP_PARAM_TYPE_CAPABILITY)
                {
                    LOG(1, 0, 0, "Unsupported Optional Parameter type %d from BGP peer %s\n",
                        param->type, peer->name);
@@ -1044,7 +1047,7 @@ 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 (mp_cap->afi != AF_INET6 && mp_cap->safi != BGP_MP_SAFI_UNICAST)
+                   if (ntohs(mp_cap->afi) != AF_INET6 && 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);
@@ -1093,6 +1096,17 @@ static int bgp_handle_input(struct bgp_peer *peer)
                return 0;
            }
 
+           if (notification->error_code == BGP_ERR_OPEN
+                   && notification->error_subcode == BGP_ERR_OPN_UNSUP_CAP)
+           {
+               /* the only capability we advertise is this one, so upon receiving
+                  an "unsupported capability" message, we disable IPv6 routes for
+                  this peer */
+               LOG(4, 0, 0, "BGP peer %s doesn't support IPv6 routes advertisement\n", peer->name);
+               peer->handle_ipv6_routes = 0;
+               break;
+           }
+
            /* FIXME: should handle more notifications */
            LOG(4, 0, 0, "BGP peer %s sent unhandled NOTIFICATION %d\n",
                peer->name, (int) notification->error_code);
@@ -1123,6 +1137,9 @@ 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_capability cap_mp_ipv6;
+    struct bgp_opt_param param_cap_mp_ipv6;
     uint16_t len = sizeof(peer->outbuf->packet.header);
 
     memset(peer->outbuf->packet.header.marker, 0xff,
@@ -1134,7 +1151,18 @@ static int bgp_send_open(struct bgp_peer *peer)
     data.as = htons(our_as);
     data.hold_time = htons(peer->hold);
     data.identifier = my_address;
-    data.opt_len = 0;
+
+    /* construct the param and capability */
+    cap_mp_ipv6.code = BGP_CAP_CODE_MP;
+    cap_mp_ipv6.len = sizeof(mp_ipv6);
+    memcpy(&cap_mp_ipv6.value, &mp_ipv6, cap_mp_ipv6.len);
+
+    param_cap_mp_ipv6.type = BGP_PARAM_TYPE_CAPABILITY;
+    param_cap_mp_ipv6.len = 2 + sizeof(mp_ipv6);
+    memcpy(&param_cap_mp_ipv6.value, &cap_mp_ipv6, param_cap_mp_ipv6.len);
+
+    data.opt_len = 2 + param_cap_mp_ipv6.len;
+    memcpy(&data.opt_params, &param_cap_mp_ipv6, data.opt_len);
 
     memcpy(peer->outbuf->packet.data, &data, BGP_DATA_OPEN_SIZE);
     len += BGP_DATA_OPEN_SIZE;