From: Donatas Abraitis <donatas@opensourcerouting.org>
Date: Wed, 14 Aug 2024 17:14:59 +0000 (+0300)
Subject: Revert "bgpd: prefer link-local to a ipv4-mapped ipv6 global"
X-Git-Tag: docker/10.1.1~11^2~7
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=863da18d1e15b1538438f1e15b59419094ecd797;p=matthieu%2Ffrr.git

Revert "bgpd: prefer link-local to a ipv4-mapped ipv6 global"

This reverts commit 5dd731af8421e8b3070eec0b3af4ad234c95c6bb.
---

diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index 8ce45558e9..dc6dc54a3b 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -320,6 +320,11 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 			afi = BGP_ATTR_MP_NEXTHOP_LEN_IP6(pi->attr) ? AFI_IP6
 								    : AFI_IP;
 
+		/* Validation for the ipv4 mapped ipv6 nexthop. */
+		if (IS_MAPPED_IPV6(&pi->attr->mp_nexthop_global)) {
+			afi = AFI_IP;
+		}
+
 		/* This will return true if the global IPv6 NH is a link local
 		 * addr */
 		if (make_prefix(afi, pi, &p) < 0)
@@ -1035,11 +1040,19 @@ static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p)
 			p->u.prefix4 = p_orig->u.prefix4;
 			p->prefixlen = p_orig->prefixlen;
 		} else {
-			if (p_orig->family == AF_EVPN)
-				p->u.prefix4 = pi->attr->mp_nexthop_global_in;
-			else
-				p->u.prefix4 = pi->attr->nexthop;
-			p->prefixlen = IPV4_MAX_BITLEN;
+			if (IS_MAPPED_IPV6(&pi->attr->mp_nexthop_global)) {
+				ipv4_mapped_ipv6_to_ipv4(
+					&pi->attr->mp_nexthop_global, &ipv4);
+				p->u.prefix4 = ipv4;
+				p->prefixlen = IPV4_MAX_BITLEN;
+			} else {
+				if (p_orig->family == AF_EVPN)
+					p->u.prefix4 =
+						pi->attr->mp_nexthop_global_in;
+				else
+					p->u.prefix4 = pi->attr->nexthop;
+				p->prefixlen = IPV4_MAX_BITLEN;
+			}
 		}
 		break;
 	case AFI_IP6:
@@ -1055,7 +1068,6 @@ static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p)
 			/* If we receive MP_REACH nexthop with ::(LL)
 			 * or LL(LL), use LL address as nexthop cache.
 			 */
-			p->prefixlen = IPV6_MAX_BITLEN;
 			if (pi->attr &&
 			    pi->attr->mp_nexthop_len ==
 				    BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL &&
@@ -1070,22 +1082,15 @@ static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p)
 				 pi->attr->mp_nexthop_len ==
 					 BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL) {
 				if (CHECK_FLAG(pi->attr->nh_flags,
-					       BGP_ATTR_NH_MP_PREFER_GLOBAL)) {
-					if (IS_MAPPED_IPV6(
-						    &pi->attr->mp_nexthop_global)) {
-						ipv4_mapped_ipv6_to_ipv4(
-							&pi->attr->mp_nexthop_global,
-							&ipv4);
-						p->u.prefix4 = ipv4;
-						p->prefixlen = IPV4_MAX_BITLEN;
-					} else
-						p->u.prefix6 =
-							pi->attr->mp_nexthop_global;
-				} else
+					       BGP_ATTR_NH_MP_PREFER_GLOBAL))
+					p->u.prefix6 =
+						pi->attr->mp_nexthop_global;
+				else
 					p->u.prefix6 =
 						pi->attr->mp_nexthop_local;
 			} else
 				p->u.prefix6 = pi->attr->mp_nexthop_global;
+			p->prefixlen = IPV6_MAX_BITLEN;
 		}
 		break;
 	default: