Added support for sending and handling the multicast capability

4 files changed, 54 insertions, 13 deletions

diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index ba5d755..cbffc65 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -408,6 +408,8 @@ 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.
+  conn->want_multicast_support = conn->bgp->cf->c.global->enable_multicast && conn->bgp->cf->enable_multicast && (conn->start_state != BSS_CONNECT_NOCAP);
+  conn->peer_multicast_support = 0;	// Default value, possibly changed by receiving capability.
   conn->advertised_as = 0;
 
   DBG("BGP: Sending open\n");
@@ -1067,9 +1069,10 @@ bgp_show_proto_info(struct proto *P)
       cli_msg(-1006, "    Neighbor ID:      %R", p->remote_id);
       cli_msg(-1006, "    Neighbor address: %I", p->cf->remote_ip);
       cli_msg(-1006, "    Source address:   %I", p->source_addr);
-      cli_msg(-1006, "    Neighbor caps:   %s%s",
+      cli_msg(-1006, "    Neighbor caps:   %s%s%s",
 	      c->peer_refresh_support ? " refresh" : "",
-	      c->peer_as4_support ? " AS4" : "");
+        c->peer_as4_support ? " AS4" : "",
+        c->peer_multicast_support ? " multicast" : "");
       if (p->cf->route_limit)
 	cli_msg(-1006, "    Route limit:      %d/%d",
 		p->p.stats.imp_routes, p->cf->route_limit);
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index b06f20a..359bd9c 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -32,6 +32,7 @@ struct bgp_config {
   int capabilities;			/* Enable capability handshake [RFC3392] */
   int enable_refresh;			/* Enable local support for route refresh [RFC2918] */
   int enable_as4;			/* Enable local support for 4B AS numbers [RFC4893] */
+  int enable_multicast;			/* Enable local support for multicast routes [RFC4760] */
   u32 rr_cluster_id;			/* Route reflector cluster ID, if different from local ID */
   int rr_client;			/* Whether neighbor is RR client of me */
   int rs_client;			/* Whether neighbor is RS client of me */
@@ -73,6 +74,8 @@ struct bgp_conn {
   int start_state;			/* protocol start_state snapshot when connection established */
   int want_as4_support;			/* Connection tries to establish AS4 session */
   int peer_as4_support;			/* Peer supports 4B AS numbers [RFC4893] */
+  int want_multicast_support;			/* We want to exchange multicast routes */
+  int peer_multicast_support;			/* Peer supports multicast routes [RFC4760] */
   int peer_refresh_support;		/* Peer supports route refresh [RFC2918] */
   unsigned hold_time, keepalive_time;	/* Times calculated from my and neighbor's requirements */
 };
@@ -108,11 +111,9 @@ struct bgp_proto {
   u8 last_error_class; 			/* Error class of last error */
   u32 last_error_code;			/* Error code of last error. BGP protocol errors
 					   are encoded as (bgp_err_code << 16 | bgp_err_subcode) */
-#ifdef IPV6
   byte *mp_reach_start, *mp_unreach_start; /* Multiprotocol BGP attribute notes */
   unsigned mp_reach_len, mp_unreach_len;
   ip_addr local_link;			/* Link-level version of source_addr */
-#endif
 };
 
 struct bgp_prefix {
@@ -297,6 +298,12 @@ void bgp_log_error(struct bgp_proto *p, u8 class, char *msg, unsigned code, unsi
 #define ORIGIN_EGP		1
 #define ORIGIN_INCOMPLETE	2
 
+/* Capabilities */
+
+#define BGP_CAP_MP	1
+#define BGP_CAP_REFRESH	2
+#define BGP_CAP_AS4	65
+
 /* Address families */
 
 #define BGP_AF_IPV4		1
@@ -308,4 +315,7 @@ void bgp_log_error(struct bgp_proto *p, u8 class, char *msg, unsigned code, unsi
 #define BGP_AF BGP_AF_IPV4
 #endif
 
+#define BGP_SAF_UNICAST 1
+#define BGP_SAF_MULTICAST 2
+
 #endif
diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y
index e932a7f..2e76159 100644
--- a/proto/bgp/config.Y
+++ b/proto/bgp/config.Y
@@ -25,7 +25,7 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY,
 	ADVERTISE, IPV4, CAPABILITIES, LIMIT, PASSIVE, PREFER, OLDER,
 	MISSING, LLADDR, DROP, IGNORE, ROUTE, REFRESH, INTERPRET,
 	COMMUNITIES, BGP_ORIGINATOR_ID, BGP_CLUSTER_LIST, IGP, TABLE,
-	GATEWAY, DIRECT, RECURSIVE)
+	GATEWAY, DIRECT, RECURSIVE, MULTICAST)
 
 CF_GRAMMAR
 
@@ -45,6 +45,7 @@ bgp_proto_start: proto_start BGP {
      BGP_CFG->error_delay_time_max = 300;
      BGP_CFG->enable_refresh = 1;
      BGP_CFG->enable_as4 = 1;
+     BGP_CFG->enable_multicast = 1;
      BGP_CFG->capabilities = 2;
      BGP_CFG->advertise_ipv4 = 1;
      BGP_CFG->interpret_communities = 1;
@@ -90,6 +91,7 @@ bgp_proto:
  | bgp_proto DISABLE AFTER ERROR bool ';' { BGP_CFG->disable_after_error = $5; }
  | bgp_proto ENABLE ROUTE REFRESH bool ';' { BGP_CFG->enable_refresh = $5; }
  | bgp_proto ENABLE AS4 bool ';' { BGP_CFG->enable_as4 = $4; }
+ | bgp_proto ENABLE MULTICAST bool ';' { BGP_CFG->enable_multicast = $4; }
  | bgp_proto CAPABILITIES bool ';' { BGP_CFG->capabilities = $3; }
  | bgp_proto ADVERTISE IPV4 bool ';' { BGP_CFG->advertise_ipv4 = $4; }
  | bgp_proto PASSWORD TEXT ';' { BGP_CFG->password = $3; }
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index bf98640..1a1e7b7 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -117,12 +117,12 @@ bgp_create_notification(struct bgp_conn *conn, byte *buf)
 static byte *
 bgp_put_cap_ipv6(struct bgp_conn *conn UNUSED, byte *buf)
 {
-  *buf++ = 1;		/* Capability 1: Multiprotocol extensions */
+  *buf++ = BGP_CAP_MP;		/* Capability 1: Multiprotocol extensions */
   *buf++ = 4;		/* Capability data length */
   *buf++ = 0;		/* We support AF IPv6 */
   *buf++ = BGP_AF_IPV6;
   *buf++ = 0;		/* RFU */
-  *buf++ = 1;		/* and SAFI 1 */
+  *buf++ = BGP_SAF_UNICAST;		/* and SAFI 1 */
   return buf;
 }
 
@@ -131,20 +131,32 @@ bgp_put_cap_ipv6(struct bgp_conn *conn UNUSED, byte *buf)
 static byte *
 bgp_put_cap_ipv4(struct bgp_conn *conn UNUSED, byte *buf)
 {
-  *buf++ = 1;		/* Capability 1: Multiprotocol extensions */
+  *buf++ = BGP_CAP_MP;		/* Capability 1: Multiprotocol extensions */
   *buf++ = 4;		/* Capability data length */
   *buf++ = 0;		/* We support AF IPv4 */
   *buf++ = BGP_AF_IPV4;
   *buf++ = 0;		/* RFU */
-  *buf++ = 1;		/* and SAFI 1 */
+  *buf++ = BGP_SAF_UNICAST;		/* and SAFI 1 */
   return buf;
 }
 #endif
 
 static byte *
+bgp_put_cap_multicast(struct bgp_conn *conn UNUSED, byte *buf)
+{
+  *buf++ = BGP_CAP_MP;		/* Capability 1: Multiprotocol extensions */
+  *buf++ = 4;		/* Capability data length */
+  *buf++ = 0;
+  *buf++ = BGP_AF;
+  *buf++ = 0;		/* RFU */
+  *buf++ = BGP_SAF_MULTICAST;		/* and SAFI 2 */
+  return buf;
+}
+
+static byte *
 bgp_put_cap_rr(struct bgp_conn *conn UNUSED, byte *buf)
 {
-  *buf++ = 2;		/* Capability 2: Support for route refresh */
+  *buf++ = BGP_CAP_REFRESH;		/* Capability 2: Support for route refresh */
   *buf++ = 0;		/* Capability data length */
   return buf;
 }
@@ -152,7 +164,7 @@ bgp_put_cap_rr(struct bgp_conn *conn UNUSED, byte *buf)
 static byte *
 bgp_put_cap_as4(struct bgp_conn *conn, byte *buf)
 {
-  *buf++ = 65;		/* Capability 65: Support for 4-octet AS number */
+  *buf++ = BGP_CAP_AS4;		/* Capability 65: Support for 4-octet AS number */
   *buf++ = 4;		/* Capability data length */
   put_u32(buf, conn->bgp->local_as);
   return buf + 4;
@@ -197,6 +209,9 @@ bgp_create_open(struct bgp_conn *conn, byte *buf)
   if (conn->want_as4_support)
     cap = bgp_put_cap_as4(conn, cap);
 
+  if (conn->want_multicast_support)
+    cap = bgp_put_cap_multicast(conn, cap);
+
   cap_len = cap - buf - 12;
   if (cap_len > 0)
     {
@@ -625,13 +640,24 @@ bgp_parse_capabilities(struct bgp_conn *conn, byte *opt, int len)
 
       switch (opt[0])
 	{
-	case 2:	/* Route refresh capability, RFC 2918 */
+	case BGP_CAP_MP:	/* Multiprotocol capability, RFC 4760 */
+	  if (cl != 4)
+	    goto err;
+	  
+	  if (get_u16(opt + 2) != BGP_AF)
+	    break;
+
+	  if (opt[5] == BGP_SAF_MULTICAST)
+	    conn->peer_multicast_support = 1;
+	  break;
+
+	case BGP_CAP_REFRESH:	/* Route refresh capability, RFC 2918 */
 	  if (cl != 0)
 	    goto err;
 	  conn->peer_refresh_support = 1;
 	  break;
 
-	case 65: /* AS4 capability, RFC 4893 */ 
+	case BGP_CAP_AS4: /* AS4 capability, RFC 4893 */ 
 	  if (cl != 4)
 	    goto err;
 	  conn->peer_as4_support = 1;