bgpd: Adding BGP GR change mode config apply on notification sent & received.

* Changing GR mode on a router needs a session reset from the
SAME router to negotiate new GR capability.
* The present GR implementation needs a session reset after every
new BGP GR mode change.
* When BGP session reset happens due to sending or receiving BGP
notification after changing BGP GR mode, there is no need of
explicit session reset.

Signed-off-by: Biswajit Sadhu <sadhub@vmware.com>

bgpd/bgp_fsm.c

@@ -1308,7 +1308,6 @@ int bgp_stop(struct peer *peer)
 	} else {
 		bgp_peer_conf_if_to_su_update(peer);
 	}
-
 	return ret;
 }
 

bgpd/bgp_packet.c

@@ -759,6 +759,8 @@ void bgp_notify_send_with_data(struct peer *peer, uint8_t code,
 	/* Add packet to peer's output queue */
 	stream_fifo_push(peer->obuf, s);
 
+	bgp_peer_gr_flags_update(peer);
+
 	bgp_write_notify(peer);
 }
 
@@ -1796,6 +1798,8 @@ static int bgp_notify_receive(struct peer *peer, bgp_size_t size)
 	    && bgp_notify.subcode == BGP_NOTIFY_OPEN_UNSUP_PARAM)
 		UNSET_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN);
 
+	bgp_peer_gr_flags_update(peer);
+
 	return Receive_NOTIFICATION_message;
 }
 

bgpd/bgp_vty.c

@@ -843,6 +843,8 @@ static int bgp_clear(struct vty *vty, struct bgp *bgp, afi_t afi, safi_t safi,
 
 			if (ret < 0)
 				bgp_clear_vty_error(vty, peer, afi, safi, ret);
+
+			bgp_peer_gr_flags_update(peer);
 		}
 
 		/* This is to apply read-only mode on this clear. */
@@ -2145,6 +2147,9 @@ DEFUN (bgp_graceful_restart,
       )
 {
 	int ret = BGP_GR_FAILURE;
+	struct peer *peer;
+	struct listnode *node = {0};
+	struct listnode *nnode = {0};
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug("BGP_GR:: bgp_graceful_restart_cmd : START ");
@@ -2152,6 +2157,11 @@ DEFUN (bgp_graceful_restart,
 
 	ret = bgp_gr_update_all(bgp, GLOBAL_GR_CMD);
 
+	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
+		if (peer->bgp->t_startup)
+			bgp_peer_gr_flags_update(peer);
+	}
+
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug("BGP_GR:: bgp_graceful_restart_cmd : END ");
 	return bgp_vty_return(vty, ret);
@@ -2166,6 +2176,9 @@ DEFUN (no_bgp_graceful_restart,
       )
 {
 	VTY_DECLVAR_CONTEXT(bgp, bgp);
+	struct peer *peer;
+	struct listnode *node = {0};
+	struct listnode *nnode = {0};
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug("BGP_GR:: no_bgp_graceful_restart_cmd : START ");
@@ -2174,6 +2187,11 @@ DEFUN (no_bgp_graceful_restart,
 
 	ret = bgp_gr_update_all(bgp, NO_GLOBAL_GR_CMD);
 
+	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
+		if (peer->bgp->t_startup)
+			bgp_peer_gr_flags_update(peer);
+	}
+
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug("BGP_GR:: no_bgp_graceful_restart_cmd : END ");
 
@@ -2315,6 +2333,9 @@ DEFUN (bgp_graceful_restart_disable,
 		GR_DISABLE)
 {
 	int ret = BGP_GR_FAILURE;
+	struct peer *peer;
+	struct listnode *node = {0};
+	struct listnode *nnode = {0};
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
@@ -2323,6 +2344,11 @@ DEFUN (bgp_graceful_restart_disable,
 
 	ret = bgp_gr_update_all(bgp, GLOBAL_DISABLE_CMD);
 
+	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
+		if (peer->bgp->t_startup)
+			bgp_peer_gr_flags_update(peer);
+	}
+
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
 				"BGP_GR:: bgp_graceful_restart_disable_cmd : END ");
@@ -2338,6 +2364,9 @@ DEFUN (no_bgp_graceful_restart_disable,
       )
 {
 	VTY_DECLVAR_CONTEXT(bgp, bgp);
+	struct peer *peer;
+	struct listnode *node = {0};
+	struct listnode *nnode = {0};
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
@@ -2347,6 +2376,11 @@ DEFUN (no_bgp_graceful_restart_disable,
 
 	ret = bgp_gr_update_all(bgp, NO_GLOBAL_DISABLE_CMD);
 
+	for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
+		if (peer->bgp->t_startup)
+			bgp_peer_gr_flags_update(peer);
+	}
+
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
 				"BGP_GR:: no_bgp_graceful_restart_disable_cmd : END ");
@@ -2413,7 +2447,7 @@ DEFUN (no_bgp_neighbor_graceful_restart,
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
-				"BGP_GR:: no_bgp_neighbor_graceful_restart_set_cmd : END ");
+				"BGP_GR:: no_bgp_neighbor_graceful_restart_helper_set_cmd : END ");
 
 	return bgp_vty_return(vty, ret);
 }
@@ -2432,17 +2466,18 @@ DEFUN (bgp_neighbor_graceful_restart_helper_set,
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
-				"BGP_GR:: bgp_neighbor_graceful_restart_set_helper_cmd : START ");
+				"BGP_GR:: bgp_neighbor_graceful_restart_helper_set_cmd : START ");
 	peer = peer_and_group_lookup_vty(vty, argv[idx_peer]->arg);
 
-	if (peer->bgp->t_startup)
-		bgp_peer_gr_flags_update(peer);
-
 	if (!peer)
 		return CMD_WARNING_CONFIG_FAILED;
 
 
 	ret = bgp_neighbor_graceful_restart(peer, PEER_HELPER_CMD);
+
+	if (peer->bgp->t_startup)
+		bgp_peer_gr_flags_update(peer);
+
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
 				"BGP_GR:: bgp_neighbor_graceful_restart_helper_set_cmd : END ");
@@ -2479,7 +2514,7 @@ DEFUN (no_bgp_neighbor_graceful_restart_helper,
 
 	if (BGP_DEBUG(graceful_restart, GRACEFUL_RESTART))
 		zlog_debug(
-				"BGP_GR:: no_bgp_neighbor_graceful_restart_set_cmd : END ");
+				"BGP_GR:: no_bgp_neighbor_graceful_restart_disable_set_cmd : END ");
 
 	return bgp_vty_return(vty, ret);
 }
@@ -2506,7 +2541,7 @@ DEFUN (bgp_neighbor_graceful_restart_disable_set,
 
 
 	ret = bgp_neighbor_graceful_restart(peer,
-			PEER_DISABLE_cmd);
+				PEER_DISABLE_cmd);
 
 	if (peer->bgp->t_startup)
 		bgp_peer_gr_flags_update(peer);