From: Igor Ryzhov <iryzhov@nfware.com>
Date: Wed, 24 Nov 2021 12:01:41 +0000 (+0300)
Subject: bfdd: fix detection timeout update
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=f2e3af6f97f7f5e451e6a3a0231c8ebd6190b01f;p=mirror%2Ffrr.git

bfdd: fix detection timeout update

Per RFC 5880 section 6.8.12, the use of a Poll Sequence is not necessary
when the Detect Multiplier is changed. Currently, we update the Detection
Timeout only when a Poll Sequence is terminated, therefore we ignore the
Detect Multiplier change if it's not accompanied with RX/TX timer change.
To fix the problem, we should update the Detection Timeout on every
received packet.

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>
(cherry picked from commit 074f76812bb1961a5d8a4e7b01d7f70f5da1978b)
---

diff --git a/bfdd/bfd.c b/bfdd/bfd.c
index c66fccb853..96a9b3672a 100644
--- a/bfdd/bfd.c
+++ b/bfdd/bfd.c
@@ -1256,27 +1256,6 @@ void bs_final_handler(struct bfd_session *bs)
 	/* Apply new transmission timer immediately. */
 	ptm_bfd_start_xmt_timer(bs, false);
 
-	/*
-	 * Detection timeout calculation:
-	 * The minimum detection timeout is the remote detection
-	 * multipler (number of packets to be missed) times the agreed
-	 * transmission interval.
-	 *
-	 * RFC 5880, Section 6.8.4.
-	 *
-	 * TODO: support sending/counting more packets inside detection
-	 * timeout.
-	 */
-	if (bs->timers.required_min_rx > bs->remote_timers.desired_min_tx)
-		bs->detect_TO = bs->remote_detect_mult
-				* bs->timers.required_min_rx;
-	else
-		bs->detect_TO = bs->remote_detect_mult
-				* bs->remote_timers.desired_min_tx;
-
-	/* Apply new receive timer immediately. */
-	bfd_recvtimer_update(bs);
-
 	/* Notify watchers about changed timers. */
 	control_notify_config(BCM_NOTIFY_CONFIG_UPDATE, bs);
 }
diff --git a/bfdd/bfd_packet.c b/bfdd/bfd_packet.c
index 3d6ca6ddd3..b9efea21d9 100644
--- a/bfdd/bfd_packet.c
+++ b/bfdd/bfd_packet.c
@@ -693,11 +693,26 @@ int bfd_recv_cb(struct thread *t)
 
 		/* Handle poll finalization. */
 		bs_final_handler(bfd);
-	} else {
-		/* Received a packet, lets update the receive timer. */
-		bfd_recvtimer_update(bfd);
 	}
 
+	/*
+	 * Detection timeout calculation:
+	 * The minimum detection timeout is the remote detection
+	 * multipler (number of packets to be missed) times the agreed
+	 * transmission interval.
+	 *
+	 * RFC 5880, Section 6.8.4.
+	 */
+	if (bfd->cur_timers.required_min_rx > bfd->remote_timers.desired_min_tx)
+		bfd->detect_TO = bfd->remote_detect_mult
+				 * bfd->cur_timers.required_min_rx;
+	else
+		bfd->detect_TO = bfd->remote_detect_mult
+				 * bfd->remote_timers.desired_min_tx;
+
+	/* Apply new receive timer immediately. */
+	bfd_recvtimer_update(bfd);
+
 	/* Handle echo timers changes. */
 	bs_echo_timer_handler(bfd);