BGP: Dynamic BGP

Support for dynamically spawning BGP protocols for incoming connections.
Use 'neighbor range' to specify range of valid neighbor addresses, then
incoming connections from these addresses spawn new BGP instances.

sysdep/unix/io.c

@@ -1082,6 +1082,7 @@ sk_passive_connected(sock *s, int type)
   t->fd = fd;
   t->ttl = s->ttl;
   t->tos = s->tos;
+  t->vrf = s->vrf;
   t->rbsize = s->rbsize;
   t->tbsize = s->tbsize;