From: Donatas Abraitis <donatas.abraitis@gmail.com>
Date: Wed, 2 Oct 2019 15:06:37 +0000 (+0300)
Subject: bgpd: Keep the session down if maximum-prefix is reached
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=cb84b33e827eddc99f745ffbafc68ed488579c71;p=mirror%2Ffrr.git

bgpd: Keep the session down if maximum-prefix is reached

Under high load instances with hundreds of thousands of prefixes this
could result in very unstable systems.

When maximum-prefix is set, but restart timer is not set then the session
flaps between Idle(Pfx) -> Established -> Idle(Pfx) states.

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
---

diff --git a/bgpd/bgp_network.c b/bgpd/bgp_network.c
index 1bbcf8ca2b..0db2c3cce4 100644
--- a/bgpd/bgp_network.c
+++ b/bgpd/bgp_network.c
@@ -440,12 +440,15 @@ static int bgp_accept(struct thread *thread)
 		return -1;
 	}
 
-	/* Check whether max prefix restart timer is set for the peer */
-	if (peer1->t_pmax_restart) {
+	/* Do not try to reconnect if the peer reached maximum
+	 * prefixes, restart timer is still running or the peer
+	 * is shutdown.
+	 */
+	if (BGP_PEER_START_SUPPRESSED(peer1)) {
 		if (bgp_debug_neighbor_events(peer1))
 			zlog_debug(
-				"%s - incoming conn rejected - "
-				"peer max prefix timer is active",
+				"[Event] Incoming BGP connection rejected from %s "
+				"due to maximum-prefix or shutdown",
 				peer1->host);
 		close(bgp_sock);
 		return -1;