From: Donald Sharp <sharpd@nvidia.com>
Date: Thu, 29 Aug 2024 19:06:31 +0000 (-0400)
Subject: zebra: Allow blackhole singleton nexthops to be v6
X-Git-Tag: base_10.2~140^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=f90989d52a7152cbd63f73c4761689aaf4c20f15;p=mirror%2Ffrr.git

zebra: Allow blackhole singleton nexthops to be v6

A blackhole nexthop, according to the linux kernel,
can be v4 or v6.  A v4 blackhole nexthop cannot be
used on a v6 route, but a v6 blackhole nexthop can
be used with a v4 route.  Convert all blackhole
singleton nexthops to v6 and just use that.
Possibly reducing the number of active nexthops by 1.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
---

diff --git a/zebra/zebra_nhg.c b/zebra/zebra_nhg.c
index 27b7f6340b..ffcdcdd6ff 100644
--- a/zebra/zebra_nhg.c
+++ b/zebra/zebra_nhg.c
@@ -356,18 +356,23 @@ void zebra_nhe_init(struct nhg_hash_entry *nhe, afi_t afi,
 	 */
 	if (nh && (nh->next == NULL)) {
 		switch (nh->type) {
-		case NEXTHOP_TYPE_IFINDEX:
-		case NEXTHOP_TYPE_BLACKHOLE:
 			/*
 			 * This switch case handles setting the afi different
-			 * for ipv4/v6 routes. Ifindex/blackhole nexthop
+			 * for ipv4/v6 routes. Ifindex nexthop
 			 * objects cannot be ambiguous, they must be Address
-			 * Family specific. If we get here, we will either use
-			 * the AF of the route, or the one we got passed from
-			 * here from the kernel.
+			 * Family specific as that the kernel relies on these
+			 * for some reason.  blackholes can be v6 because the
+			 * v4 kernel infrastructure allows the usage of v6
+			 * blackholes in this case.   if we get here, we will
+			 * either use the AF of the route, or the one we got
+			 * passed from here from the kernel.
 			 */
+		case NEXTHOP_TYPE_IFINDEX:
 			nhe->afi = afi;
 			break;
+		case NEXTHOP_TYPE_BLACKHOLE:
+			nhe->afi = AFI_IP6;
+			break;
 		case NEXTHOP_TYPE_IPV4_IFINDEX:
 		case NEXTHOP_TYPE_IPV4:
 			nhe->afi = AFI_IP;