Revert IPv4 mapped IPv6 stuff

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)
@@ -351,9 +356,7 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 			}
 			return 0;
 		}
-		if (afi == AFI_IP6 && p.family == AF_INET)
-			/* IPv4 mapped IPv6 nexthop address */
-			afi = AFI_IP;
+
 		srte_color = bgp_attr_get_color(pi->attr);
 
 	} else if (peer) {
@@ -1037,11 +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:
@@ -1057,7 +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 &&
@@ -1072,33 +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;
-						p->family = AF_INET;
-					} else
-						p->u.prefix6 =
-							pi->attr->mp_nexthop_global;
-				} else
-					p->u.prefix6 =
-						pi->attr->mp_nexthop_local;
-			} else {
-				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;
-					p->family = AF_INET;
-				} 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:

bgpd/bgp_route.c

@@ -9671,7 +9671,10 @@ void route_vty_out(struct vty *vty, const struct prefix *p,
 				json_object_string_add(json_nexthop_ll, "scope",
 						       "link-local");
 
-				if (!CHECK_FLAG(attr->nh_flags,
+				if ((IPV6_ADDR_CMP(&attr->mp_nexthop_global,
+						   &attr->mp_nexthop_local) !=
+				     0) &&
+				    !CHECK_FLAG(attr->nh_flags,
 						BGP_ATTR_NH_MP_PREFER_GLOBAL))
 					json_object_boolean_true_add(
 						json_nexthop_ll, "used");

bgpd/bgp_updgrp_packet.c

@@ -508,9 +508,6 @@ struct stream *bpacket_reformat_for_peer(struct bpacket *pkt,
 				gnh_modified = 1;
 			}
 		} else if (IN6_IS_ADDR_UNSPECIFIED(&v6nhglobal)) {
-			/* the UPDATE is originating from the local router.
-			 * Build the global nexthop.
-			 */
 			mod_v6nhg = &peer->nexthop.v6_global;
 			gnh_modified = 1;
 		} else if ((peer->sort == BGP_PEER_EBGP)
@@ -524,32 +521,16 @@ struct stream *bpacket_reformat_for_peer(struct bpacket *pkt,
 			 */
 			mod_v6nhg = &peer->nexthop.v6_global;
 			gnh_modified = 1;
-		} else if (IS_MAPPED_IPV6(&v6nhglobal) &&
-			   !IN6_IS_ADDR_LINKLOCAL(&peer->nexthop.v6_global)) {
-			/* prefer a IPv6 native global address over
-			 * an IPv4-mapped IPv6 address as nexthop when
-			 * forwarding UPDATEs.
-			 */
-			mod_v6nhg = &peer->nexthop.v6_global;
-			gnh_modified = 1;
 		}
 
-		if (peer->nexthop.v4.s_addr != INADDR_ANY &&
-		    (IN6_IS_ADDR_UNSPECIFIED(mod_v6nhg) ||
-		     (IN6_IS_ADDR_LINKLOCAL(mod_v6nhg) &&
-		      ((peer->connection->su.sa.sa_family == AF_INET6 &&
-			paf->afi == AFI_IP) ||
-		       (peer->connection->su.sa.sa_family == AF_INET &&
-			paf->afi == AFI_IP6))))) {
-			ipv4_to_ipv4_mapped_ipv6(mod_v6nhg, peer->nexthop.v4);
-			gnh_modified = 1;
+		if (IN6_IS_ADDR_UNSPECIFIED(mod_v6nhg)) {
+			if (peer->nexthop.v4.s_addr != INADDR_ANY) {
+				ipv4_to_ipv4_mapped_ipv6(mod_v6nhg,
+							 peer->nexthop.v4);
+			}
 		}
 
 		if (IS_MAPPED_IPV6(&peer->nexthop.v6_global)) {
-			/* If the interface to the peer has no global IPv6
-			 * address, replace the nexthop in UPDATE with
-			 * the IPv4-mapped IPv6 address if any.
-			 */
 			mod_v6nhg = &peer->nexthop.v6_global;
 			gnh_modified = 1;
 		}

bgpd/bgp_zebra.c

@@ -302,12 +302,11 @@ static int bgp_ifp_down(struct interface *ifp)
 
 static int bgp_interface_address_add(ZAPI_CALLBACK_ARGS)
 {
-	struct connected *ifc, *connected;
+	struct connected *ifc;
 	struct bgp *bgp;
 	struct peer *peer;
 	struct prefix *addr;
 	struct listnode *node, *nnode;
-	bool v6_ll_in_nh_global;
 	afi_t afi;
 	safi_t safi;
 
@@ -325,70 +324,56 @@ static int bgp_interface_address_add(ZAPI_CALLBACK_ARGS)
 	if (!bgp)
 		return 0;
 
-	if (!if_is_operative(ifc->ifp))
-		return 0;
-
-	bgp_connected_add(bgp, ifc);
+	if (if_is_operative(ifc->ifp)) {
+		bgp_connected_add(bgp, ifc);
 
-	/* If we have learnt of any neighbors on this interface,
-	 * check to kick off any BGP interface-based neighbors,
-	 * but only if this is a link-local address.
-	 */
-	if (IN6_IS_ADDR_LINKLOCAL(&ifc->address->u.prefix6) &&
-	    !list_isempty(ifc->ifp->nbr_connected))
-		bgp_start_interface_nbrs(bgp, ifc->ifp);
-	else if (ifc->address->family == AF_INET6 &&
-		 !IN6_IS_ADDR_LINKLOCAL(&ifc->address->u.prefix6)) {
-		addr = ifc->address;
+		/* If we have learnt of any neighbors on this interface,
+		 * check to kick off any BGP interface-based neighbors,
+		 * but only if this is a link-local address.
+		 */
+		if (IN6_IS_ADDR_LINKLOCAL(&ifc->address->u.prefix6)
+		    && !list_isempty(ifc->ifp->nbr_connected))
+			bgp_start_interface_nbrs(bgp, ifc->ifp);
+		else {
+			addr = ifc->address;
 
-		for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
-			v6_ll_in_nh_global = false;
-
-			if (IN6_IS_ADDR_LINKLOCAL(&peer->nexthop.v6_global)) {
-				frr_each (if_connected, ifc->ifp->connected,
-					  connected) {
-					if (connected->address->family !=
-					    AF_INET6)
-						continue;
-					if (!IPV6_ADDR_SAME(&connected->address
-								     ->u.prefix6,
-							    &peer->nexthop
-								     .v6_global))
-						continue;
-					/* peer->nexthop.v6_global contains a link-local address
-					 * that needs to be replaced by the global address.
-					 */
-					v6_ll_in_nh_global = true;
-					break;
-				}
-			}
+			for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
+				if (addr->family == AF_INET)
+					continue;
 
-			/*
-			 * If the Peer's interface name matches the
-			 * interface name for which BGP received the
-			 * update and if the received interface address
-			 * is a globalV6 and if the peer is currently
-			 * using a v4-mapped-v6 addr or a link local
-			 * address, then copy the Rxed global v6 addr
-			 * into peer's v6_global and send updates out
-			 * with new nexthop addr.
-			 */
-			if (v6_ll_in_nh_global ||
-			    (peer->conf_if &&
-			     strcmp(peer->conf_if, ifc->ifp->name) == 0 &&
-			     (IS_MAPPED_IPV6(&peer->nexthop.v6_global) ||
-			      IN6_IS_ADDR_LINKLOCAL(&peer->nexthop.v6_global)))) {
-				if (bgp_debug_zebra(ifc->address)) {
-					zlog_debug("Update peer %pBP's current intf global addr from %pI6 to %pI6 and send updates",
-						   peer,
-						   &peer->nexthop.v6_global,
-						   &addr->u.prefix6);
+				/*
+				 * If the Peer's interface name matches the
+				 * interface name for which BGP received the
+				 * update and if the received interface address
+				 * is a globalV6 and if the peer is currently
+				 * using a v4-mapped-v6 addr or a link local
+				 * address, then copy the Rxed global v6 addr
+				 * into peer's v6_global and send updates out
+				 * with new nexthop addr.
+				 */
+				if ((peer->conf_if &&
+				     (strcmp(peer->conf_if, ifc->ifp->name) ==
+				      0)) &&
+				    !IN6_IS_ADDR_LINKLOCAL(&addr->u.prefix6) &&
+				    ((IS_MAPPED_IPV6(
+					     &peer->nexthop.v6_global)) ||
+				     IN6_IS_ADDR_LINKLOCAL(
+					     &peer->nexthop.v6_global))) {
+
+					if (bgp_debug_zebra(ifc->address)) {
+						zlog_debug(
+							"Update peer %pBP's current intf addr %pI6 and send updates",
+							peer,
+							&peer->nexthop
+								 .v6_global);
+					}
+					memcpy(&peer->nexthop.v6_global,
+					       &addr->u.prefix6,
+					       IPV6_MAX_BYTELEN);
+					FOREACH_AFI_SAFI (afi, safi)
+						bgp_announce_route(peer, afi,
+								   safi, true);
 				}
-				memcpy(&peer->nexthop.v6_global,
-				       &addr->u.prefix6, IPV6_MAX_BYTELEN);
-				FOREACH_AFI_SAFI (afi, safi)
-					bgp_announce_route(peer, afi, safi,
-							   true);
 			}
 		}
 	}
@@ -399,14 +384,10 @@ static int bgp_interface_address_add(ZAPI_CALLBACK_ARGS)
 static int bgp_interface_address_delete(ZAPI_CALLBACK_ARGS)
 {
 	struct listnode *node, *nnode;
-	struct connected *ifc, *connected;
+	struct connected *ifc;
 	struct peer *peer;
 	struct bgp *bgp;
 	struct prefix *addr;
-	struct in6_addr *v6_global = NULL;
-	struct in6_addr *v6_local = NULL;
-	afi_t afi;
-	safi_t safi;
 
 	bgp = bgp_lookup_by_vrf_id(vrf_id);
 
@@ -425,18 +406,7 @@ static int bgp_interface_address_delete(ZAPI_CALLBACK_ARGS)
 
 	addr = ifc->address;
 
-	if (bgp && addr->family == AF_INET6 &&
-	    !IN6_IS_ADDR_LINKLOCAL(&addr->u.prefix6)) {
-		/* find another IPv6 global if possible and find the IPv6 link-local */
-		frr_each (if_connected, ifc->ifp->connected, connected) {
-			if (connected->address->family != AF_INET6)
-				continue;
-			if (IN6_IS_ADDR_LINKLOCAL(&connected->address->u.prefix6))
-				v6_local = &connected->address->u.prefix6;
-			else
-				v6_global = &connected->address->u.prefix6;
-		}
-
+	if (bgp) {
 		/*
 		 * When we are using the v6 global as part of the peering
 		 * nexthops and we are removing it, then we need to
@@ -445,17 +415,17 @@ static int bgp_interface_address_delete(ZAPI_CALLBACK_ARGS)
 		 * we do not want the peering to bounce.
 		 */
 		for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
-			if (IPV6_ADDR_SAME(&peer->nexthop.v6_global,
-					   &addr->u.prefix6)) {
-				if (v6_global)
-					IPV6_ADDR_COPY(&peer->nexthop.v6_global,
-						       v6_global);
-				else if (v6_local)
-					IPV6_ADDR_COPY(&peer->nexthop.v6_global,
-						       v6_local);
-				else
-					memset(&peer->nexthop.v6_global, 0,
-					       IPV6_MAX_BYTELEN);
+			afi_t afi;
+			safi_t safi;
+
+			if (addr->family == AF_INET)
+				continue;
+
+			if (!IN6_IS_ADDR_LINKLOCAL(&addr->u.prefix6)
+			    && memcmp(&peer->nexthop.v6_global,
+				      &addr->u.prefix6, 16)
+				       == 0) {
+				memset(&peer->nexthop.v6_global, 0, 16);
 				FOREACH_AFI_SAFI (afi, safi)
 					bgp_announce_route(peer, afi, safi,
 							   true);