From: Claudio Jeker <cjeker@diehard.n-r-g.com>
Subject: bgpd: fix session_notification 
To: tech@openbsd.org
Date: Tue, 9 Apr 2024 17:41:12 +0200

The early exit in session_notification no longer works since I moved the
clearing of last_sent_errcode when the session goes into ESTABLISHED
state. So if there is an error in the early phase of session establishment
(e.g. capability negotiation) then this only works the first time.

Instead of checking the last_sent_errcode look at the session state to
know if it makes sense to issue a notification or not.

I added a log_notification() in the early exit case just to know it
happened. Maybe that should be removed (depending how often this early
exit path is taken).

-- 
:wq Claudio

Index: session.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/session.c,v
diff -u -p -r1.468 session.c
--- session.c	9 Apr 2024 09:03:18 -0000	1.468
+++ session.c	9 Apr 2024 15:32:45 -0000
@@ -1720,8 +1720,16 @@ session_notification(struct peer *p, uin
 	int			 errs = 0;
 	size_t			 datalen = 0;
 
-	if (p->stats.last_sent_errcode)	/* some notification already sent */
+	switch (p->state) {
+	case STATE_OPENSENT:
+	case STATE_OPENCONFIRM:
+	case STATE_ESTABLISHED:
+		break;
+	default:
+		/* session not open, no need to send notification */
+		log_notification(p, errcode, subcode, ibuf, "dropping");
 		return;
+	}
 
 	log_notification(p, errcode, subcode, ibuf, "sending");