[202012][LLDPD] fix to port remove and immediately create problem (#12467)

Why I did it
Cherry pick #9519.

when we remove a port and add it back immediately - lldp is keep failing
warning message keeps appearing:
[WARN/lldp] unable to send packet on real device for Ethernet4: No such device or address

How I did it
on delete link events it will immediately execute delete without using aggregate events mechanism.

How to verify it
Run autorestart/test_container_autorestart.py in sonic-mgmt repo
Or manual test steps:
sudo config feature autorestart swss disabled
docker exec swss supervisorctl status
docker exec swss kill -SIGKILL 111(orchagent)
docker inspect -f {{.State.Running}} swss => make sure swss is running
docker exec swss supervisorctl start orchagent

Signed-off-by: Zhaohui Sun <[email protected]>

Author: ZhaohuiS

src/lldpd/patch/0012-fix-recreate-socket-on-ifindex-change.patch

@@ -0,0 +1,82 @@
+diff --git a/src/daemon/interfaces-linux.c b/src/daemon/interfaces-linux.c
+index a8280c8..a51440a 100644
+--- a/src/daemon/interfaces-linux.c
++++ b/src/daemon/interfaces-linux.c
+@@ -775,7 +775,7 @@ iflinux_handle_bond(struct lldpd *cfg, struct interfaces_device_list *interfaces
+ 			created = 1;
+ 		}
+ 		if (hardware->h_flags) continue;
+-		if (hardware->h_ops != &bond_ops) {
++		if (hardware->h_ops != &bond_ops || hardware->h_ifindex_changed) {
+ 			if (!created) {
+ 				log_debug("interfaces",
+ 				    "bond %s is converted from another type of interface",
+@@ -794,7 +794,7 @@ iflinux_handle_bond(struct lldpd *cfg, struct interfaces_device_list *interfaces
+ 		} else bmaster = hardware->h_data;
+ 		bmaster->index = master->index;
+ 		strlcpy(bmaster->name, master->name, IFNAMSIZ);
+-		if (hardware->h_ops != &bond_ops) {
++		if (hardware->h_ops != &bond_ops || hardware->h_ifindex_changed) {
+ 			if (iface_bond_init(cfg, hardware) != 0) {
+ 				log_warn("interfaces", "unable to initialize %s",
+ 				    hardware->h_ifname);
+diff --git a/src/daemon/interfaces.c b/src/daemon/interfaces.c
+index 3c6c255..58db018 100644
+--- a/src/daemon/interfaces.c
++++ b/src/daemon/interfaces.c
+@@ -623,7 +623,7 @@ interfaces_helper_physical(struct lldpd *cfg,
+ 		}
+ 		if (hardware->h_flags)
+ 			continue;
+-		if (hardware->h_ops != ops) {
++		if (hardware->h_ops != ops || hardware->h_ifindex_changed) {
+ 			if (!created) {
+ 				log_debug("interfaces",
+ 				    "interface %s is converted from another type of interface",
+diff --git a/src/daemon/lldpd.c b/src/daemon/lldpd.c
+index 1d92dd3..f3e82e5 100644
+--- a/src/daemon/lldpd.c
++++ b/src/daemon/lldpd.c
+@@ -147,6 +147,12 @@ lldpd_get_hardware(struct lldpd *cfg, char *name, int index)
+ 	TAILQ_FOREACH(hardware, &cfg->g_hardware, h_entries) {
+ 		if (strcmp(hardware->h_ifname, name) == 0) {
+ 			if (hardware->h_flags == 0) {
++				if (hardware->h_ifindex != 0 &&
++				    hardware->h_ifindex != index) {
++					log_debug("interfaces", "%s changed index: from %d to %d",
++					    hardware->h_ifname, hardware->h_ifindex, index);
++					hardware->h_ifindex_changed = 1;
++				}
+ 				hardware->h_ifindex = index;
+ 				break;
+ 			}
+@@ -392,7 +398,8 @@ lldpd_reset_timer(struct lldpd *cfg)
+ 		}
+ 
+ 		/* Compare with the previous value */
+-		if (hardware->h_lport_previous &&
++		if (!hardware->h_ifindex_changed &&
++		    hardware->h_lport_previous &&
+ 		    output_len == hardware->h_lport_previous_len &&
+ 		    !memcmp(output, hardware->h_lport_previous, output_len)) {
+ 			log_debug("localchassis",
+@@ -402,6 +409,7 @@ lldpd_reset_timer(struct lldpd *cfg)
+ 			log_debug("localchassis",
+ 			    "change detected for port %s, resetting its timer",
+ 			    hardware->h_ifname);
++			hardware->h_ifindex_changed = 0;
+ 			levent_schedule_pdu(hardware);
+ 		}
+ 
+diff --git a/src/lldpd-structs.h b/src/lldpd-structs.h
+index f6b03d7..213f306 100644
+--- a/src/lldpd-structs.h
++++ b/src/lldpd-structs.h
+@@ -454,6 +454,7 @@ struct lldpd_hardware {
+ 					     removed if this is left
+ 					     to 0. */
+ 	int			 h_ifindex; /* Interface index, used by SNMP */
++	int			 h_ifindex_changed;  /* Interface index has changed */
+ 	char			 h_ifname[IFNAMSIZ]; /* Should be unique */
+ 	u_int8_t		 h_lladdr[ETHER_ADDR_LEN];
+ 

src/lldpd/patch/series

@@ -5,3 +5,4 @@
 0007-lib-fix-memory-leak-when-handling-I-O.patch
 0010-Ported-fix-for-length-exceeded-from-lldp-community.patch
 0011-fix-med-location-len.patch
+0012-fix-recreate-socket-on-ifindex-change.patch