From: vivek <vivek@cumulusnetworks.com>
Date: Sun, 21 Mar 2021 20:39:51 +0000 (-0700)
Subject: bgpd: Reset LLA NHT's interface if there is a change
X-Git-Tag: base_8.0~241^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=4115b2966b8aa6dfc29756035d694a785c88855f;p=mirror%2Ffrr.git

bgpd: Reset LLA NHT's interface if there is a change

For link-local IPv6 next hops, the next hop tracking is implemented based
on interface status changes. For this purpose, the ifindex is stored in
the NHT. Reset this value if a change in ifindex is noticed, such as for
example after a restart of the networking service.

Also add some additional debug logs.

Signed-off-by: Vivek Venkatraman <vivek@nvidia.com>
Updates: "bgpd: Switch LL nexthop tracking to be interface based"

Ticket: RM 2575386
Testing Done:
1. Manual verification
2. Precommit (#156), evpn-smoke (#155), bgp-smoke (#157), vrl (#158)
-- Precommit is clean, reported failures in evpn-smoke & vrl are resolved
-- some other tests fail in evpn-smoke, bgp-smoke & vrl, appear to be existing
-- or unrelated failures
---

diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index 0fea198cd2..9c8d7878c5 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -194,6 +194,16 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 				   bnc->srte_color, bnc->bgp->name_pretty,
 				   peer);
 		}
+	} else {
+		if (BGP_DEBUG(nht, NHT)) {
+			char buf[PREFIX2STR_BUFFER];
+
+			zlog_debug(
+				"Found existing bnc %s(%s) flags 0x%x ifindex %d #paths %d peer %p",
+				bnc_str(bnc, buf, PREFIX2STR_BUFFER),
+				bnc->bgp->name_pretty, bnc->flags, bnc->ifindex,
+				bnc->path_count, bnc->nht_info);
+		}
 	}
 
 	if (is_bgp_static_route) {
@@ -237,6 +247,11 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
 		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
 	}
+	if (peer && (bnc->ifindex != ifindex)) {
+		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
+		UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
+		bnc->ifindex = ifindex;
+	}
 	if (bgp_route->inst_type == BGP_INSTANCE_TYPE_VIEW) {
 		SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
 		SET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
@@ -506,6 +521,11 @@ static int bgp_nht_ifp_initial(struct thread *thread)
 	if (!ifp)
 		return 0;
 
+	if (BGP_DEBUG(nht, NHT))
+		zlog_debug(
+			"Handle NHT initial update for Intf %s(%d) status %s",
+			ifp->name, ifp->ifindex, if_is_up(ifp) ? "up" : "down");
+
 	if (if_is_up(ifp))
 		bgp_nht_ifp_up(ifp);
 	else