From 5a215d4b32cd9ae1ed57a0f1b7737954de004c7b Mon Sep 17 00:00:00 2001
From: Vincent Bernat <vincent@bernat.im>
Date: Sat, 10 May 2014 17:57:08 +0200
Subject: [PATCH] lldp: support for shutdown LLDPU

We just accept 0 as a valid TTL and let the expiration mechanism do its
work. We ensure that we can handle those 0 TTL and avoid underflow.

Closes #5.
---
 NEWS                | 2 ++
 src/daemon/event.c  | 6 +++++-
 src/daemon/lldp.c   | 5 +++--
 src/lldpd-structs.c | 2 +-
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/NEWS b/NEWS
index bfe394fc..1199f5a0 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,8 @@ lldpd (0.7.9)
   * Fixes:
     + Fix `configure system bond-slave-src-mac-type local`. Also use
       it as default.
+  * Features:
+    + Add support for shutdown LLDPU
 
 lldpd (0.7.8)
   * Fixes:
diff --git a/src/daemon/event.c b/src/daemon/event.c
index 8c5c3b4a..45919371 100644
--- a/src/daemon/event.c
+++ b/src/daemon/event.c
@@ -692,8 +692,12 @@ levent_schedule_cleanup(struct lldpd *cfg)
 	struct lldpd_port *port;
 	TAILQ_FOREACH(hardware, &cfg->g_hardware, h_entries) {
 		TAILQ_FOREACH(port, &hardware->h_rports, p_entries) {
+			if (now + port->p_chassis->c_ttl >= port->p_lastupdate) {
+				tv.tv_sec = 0;
+				break;
+			}
 			next = port->p_chassis->c_ttl - (now - port->p_lastupdate);
-			if (next >= 0 && next < tv.tv_sec)
+			if (next < tv.tv_sec)
 				tv.tv_sec = next;
 		}
 	}
diff --git a/src/daemon/lldp.c b/src/daemon/lldp.c
index 5727bd73..d564c57f 100644
--- a/src/daemon/lldp.c
+++ b/src/daemon/lldp.c
@@ -483,7 +483,7 @@ lldp_decode(struct lldpd *cfg, char *frame, int s,
 	const char dot3[] = LLDP_TLV_ORG_DOT3;
 	const char med[] = LLDP_TLV_ORG_MED;
 	char orgid[3];
-	int length, gotend = 0;
+	int length, gotend = 0, ttl_received = 0;
 	int tlv_size, tlv_type, tlv_subtype;
 	u_int8_t *pos, *tlv;
 	char *b;
@@ -593,6 +593,7 @@ lldp_decode(struct lldpd *cfg, char *frame, int s,
 		case LLDP_TLV_TTL:
 			CHECK_TLV_SIZE(2, "TTL");
 			chassis->c_ttl = PEEK_UINT16;
+			ttl_received = 1;
 			break;
 		case LLDP_TLV_PORT_DESCR:
 		case LLDP_TLV_SYSTEM_NAME:
@@ -1008,7 +1009,7 @@ lldp_decode(struct lldpd *cfg, char *frame, int s,
 	/* Some random check */
 	if ((chassis->c_id == NULL) ||
 	    (port->p_id == NULL) ||
-	    (chassis->c_ttl == 0) ||
+	    (!ttl_received) ||
 	    (gotend == 0)) {
 		log_warnx("lldp", "some mandatory tlv are missing for frame received on %s",
 		    hardware->h_ifname);
diff --git a/src/lldpd-structs.c b/src/lldpd-structs.c
index 71d28087..63a824bf 100644
--- a/src/lldpd-structs.c
+++ b/src/lldpd-structs.c
@@ -124,7 +124,7 @@ lldpd_remote_cleanup(struct lldpd_hardware *hardware,
 		port_next = TAILQ_NEXT(port, p_entries);
 		del = all;
 		if (!all && expire &&
-		    (now - port->p_lastupdate >= port->p_chassis->c_ttl)) {
+		    (now >= port->p_lastupdate + port->p_chassis->c_ttl)) {
 			hardware->h_ageout_cnt++;
 			hardware->h_delete_cnt++;
 			del = 1;
-- 
2.39.5