Implements ADD-PATH extension for BGP.

Allows to send and receive multiple routes for one network by one BGP
session. Also contains necessary core changes to support this (routing
tables accepting several routes for one network from one protocol).
It needs some more cleanup before merging to the master branch.

1 files changed, 19 insertions, 12 deletions

diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index dbc59eea..f290f227 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -362,7 +362,9 @@ bgp_conn_enter_established_state(struct bgp_conn *conn)
   p->conn = conn;
   p->last_error_class = 0;
   p->last_error_code = 0;
-  bgp_attr_init(conn->bgp);
+  bgp_init_bucket_table(p);
+  bgp_init_prefix_table(p, 8);
+
   bgp_conn_set_state(conn, BS_ESTABLISHED);
   proto_notify_state(&p->p, PS_UP);
 }
@@ -410,8 +412,11 @@ static void
 bgp_send_open(struct bgp_conn *conn)
 {
   conn->start_state = conn->bgp->start_state;
-  conn->want_as4_support = conn->bgp->cf->enable_as4 && (conn->start_state != BSS_CONNECT_NOCAP);
-  conn->peer_as4_support = 0;	// Default value, possibly changed by receiving capability.
+
+  // Default values, possibly changed by receiving capabilities.
+  conn->peer_refresh_support = 0;
+  conn->peer_as4_support = 0;
+  conn->peer_add_path = 0;
   conn->advertised_as = 0;
 
   DBG("BGP: Sending open\n");
@@ -920,19 +925,17 @@ get_igp_table(struct bgp_config *cf)
 static struct proto *
 bgp_init(struct proto_config *C)
 {
-  struct bgp_config *c = (struct bgp_config *) C;
   struct proto *P = proto_new(C, sizeof(struct bgp_proto));
+  struct bgp_config *c = (struct bgp_config *) C;
   struct bgp_proto *p = (struct bgp_proto *) P;
 
   P->accept_ra_types = c->secondary ? RA_ACCEPTED : RA_OPTIMAL;
   P->rt_notify = bgp_rt_notify;
-  P->rte_better = bgp_rte_better;
   P->import_control = bgp_import_control;
   P->neigh_notify = bgp_neigh_notify;
   P->reload_routes = bgp_reload_routes;
-
-  if (c->deterministic_med)
-    P->rte_recalculate = bgp_rte_recalculate;
+  P->rte_better = bgp_rte_better;
+  P->rte_recalculate = c->deterministic_med ? bgp_rte_recalculate : NULL;
 
   p->cf = c;
   p->local_as = c->local_as;
@@ -1176,15 +1179,19 @@ bgp_show_proto_info(struct proto *P)
   else if (P->proto_state == PS_UP)
     {
       cli_msg(-1006, "    Neighbor ID:      %R", p->remote_id);
-      cli_msg(-1006, "    Neighbor caps:   %s%s",
+      cli_msg(-1006, "    Neighbor caps:   %s%s%s%s",
 	      c->peer_refresh_support ? " refresh" : "",
-	      c->peer_as4_support ? " AS4" : "");
-      cli_msg(-1006, "    Session:          %s%s%s%s%s",
+	      c->peer_as4_support ? " AS4" : "",
+	      (c->peer_add_path & ADD_PATH_RX) ? " add-path-rx" : "",
+	      (c->peer_add_path & ADD_PATH_TX) ? " add-path-tx" : "");
+      cli_msg(-1006, "    Session:          %s%s%s%s%s%s%s",
 	      p->is_internal ? "internal" : "external",
 	      p->cf->multihop ? " multihop" : "",
 	      p->rr_client ? " route-reflector" : "",
 	      p->rs_client ? " route-server" : "",
-	      p->as4_session ? " AS4" : "");
+	      p->as4_session ? " AS4" : "",
+	      p->add_path_rx ? " add-path-rx" : "",
+	      p->add_path_tx ? " add-path-tx" : "");
       cli_msg(-1006, "    Source address:   %I", p->source_addr);
       if (P->cf->in_limit)
 	cli_msg(-1006, "    Route limit:      %d/%d",