Revert "MPLS allocation mode per next hop"

Broken tests, let's revert now.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

1 files changed, 10 insertions, 293 deletions

diff --git a/bgpd/bgp_mplsvpn.c b/bgpd/bgp_mplsvpn.c
index ecc84533b0..63168f1e7a 100644
--- a/bgpd/bgp_mplsvpn.c
+++ b/bgpd/bgp_mplsvpn.c
@@ -1116,14 +1116,12 @@ leak_update(struct bgp *to_bgp, struct bgp_dest *bn,
 
 	/*
 	 * Routes that are redistributed into BGP from zebra do not get
-	 * nexthop tracking, unless MPLS allocation per nexthop is
-	 * performed. In the default case nexthop tracking does not apply,
-	 * if those routes are subsequently imported to other RIBs within
-	 * BGP, the leaked routes do not carry the original
-	 * BGP_ROUTE_REDISTRIBUTE sub_type. Therefore, in order to determine
-	 * if the route we are currently leaking should have nexthop
-	 * tracking, we must find the ultimate parent so we can check its
-	 * sub_type.
+	 * nexthop tracking. However, if those routes are subsequently
+	 * imported to other RIBs within BGP, the leaked routes do not
+	 * carry the original BGP_ROUTE_REDISTRIBUTE sub_type. Therefore,
+	 * in order to determine if the route we are currently leaking
+	 * should have nexthop tracking, we must find the ultimate
+	 * parent so we can check its sub_type.
 	 *
 	 * As of now, source_bpi may at most be a second-generation route
 	 * (only one hop back to ultimate parent for vrf-vpn-vrf scheme).
@@ -1338,265 +1336,6 @@ leak_update(struct bgp *to_bgp, struct bgp_dest *bn,
 	return new;
 }
 
-void bgp_mplsvpn_path_nh_label_unlink(struct bgp_path_info *pi)
-{
-	struct bgp_label_per_nexthop_cache *blnc;
-
-	if (!pi)
-		return;
-
-	blnc = pi->label_nexthop_cache;
-
-	if (!blnc)
-		return;
-
-	LIST_REMOVE(pi, label_nh_thread);
-	pi->label_nexthop_cache->path_count--;
-	pi->label_nexthop_cache = NULL;
-
-	if (LIST_EMPTY(&(blnc->paths)))
-		bgp_label_per_nexthop_free(blnc);
-}
-
-/* Called upon reception of a ZAPI Message from zebra, about
- * a new available label.
- */
-static int bgp_mplsvpn_get_label_per_nexthop_cb(mpls_label_t label,
-						void *context, bool allocated)
-{
-	struct bgp_label_per_nexthop_cache *blnc = context;
-	mpls_label_t old_label;
-	int debug = BGP_DEBUG(vpn, VPN_LEAK_LABEL);
-	struct bgp_path_info *pi;
-	struct bgp_table *table;
-
-	old_label = blnc->label;
-
-	if (debug)
-		zlog_debug("%s: label=%u, allocated=%d, nexthop=%pFX", __func__,
-			   label, allocated, &blnc->nexthop);
-	if (allocated)
-		/* update the entry with the new label */
-		blnc->label = label;
-	else
-		/*
-		 * previously-allocated label is now invalid
-		 * eg: zebra deallocated the labels and notifies it
-		 */
-		blnc->label = MPLS_INVALID_LABEL;
-
-	if (old_label == blnc->label)
-		return 0; /* no change */
-
-	/* update paths */
-	if (blnc->label != MPLS_INVALID_LABEL)
-		bgp_zebra_send_nexthop_label(
-			ZEBRA_MPLS_LABELS_ADD, blnc->label, blnc->nh->ifindex,
-			blnc->nh->vrf_id, ZEBRA_LSP_BGP, &blnc->nexthop);
-
-	LIST_FOREACH (pi, &(blnc->paths), label_nh_thread) {
-		if (!pi->net)
-			continue;
-		table = bgp_dest_table(pi->net);
-		if (!table)
-			continue;
-		vpn_leak_from_vrf_update(blnc->to_bgp, table->bgp, pi);
-	}
-
-	return 0;
-}
-
-/* Get a per label nexthop value:
- *  - Find and return a per label nexthop from the cache
- *  - else allocate a new per label nexthop cache entry and request a
- *    label to zebra. Return MPLS_INVALID_LABEL
- */
-static mpls_label_t _vpn_leak_from_vrf_get_per_nexthop_label(
-	struct bgp_path_info *pi, struct bgp *to_bgp, struct bgp *from_bgp,
-	afi_t afi, safi_t safi)
-{
-	struct bgp_nexthop_cache *bnc = pi->nexthop;
-	struct bgp_label_per_nexthop_cache *blnc;
-	struct bgp_label_per_nexthop_cache_head *tree;
-	struct prefix *nh_pfx = NULL;
-	struct prefix nh_gate = {0};
-
-	/* extract the nexthop from the BNC nexthop cache */
-	switch (bnc->nexthop->type) {
-	case NEXTHOP_TYPE_IPV4:
-	case NEXTHOP_TYPE_IPV4_IFINDEX:
-		/* the nexthop is recursive */
-		nh_gate.family = AF_INET;
-		nh_gate.prefixlen = IPV4_MAX_BITLEN;
-		IPV4_ADDR_COPY(&nh_gate.u.prefix4, &bnc->nexthop->gate.ipv4);
-		nh_pfx = &nh_gate;
-		break;
-	case NEXTHOP_TYPE_IPV6:
-	case NEXTHOP_TYPE_IPV6_IFINDEX:
-		/* the nexthop is recursive */
-		nh_gate.family = AF_INET6;
-		nh_gate.prefixlen = IPV6_MAX_BITLEN;
-		IPV6_ADDR_COPY(&nh_gate.u.prefix6, &bnc->nexthop->gate.ipv6);
-		nh_pfx = &nh_gate;
-		break;
-	case NEXTHOP_TYPE_IFINDEX:
-		/* the nexthop is direcly connected */
-		nh_pfx = &bnc->prefix;
-		break;
-	case NEXTHOP_TYPE_BLACKHOLE:
-		assert(!"Blackhole nexthop. Already checked by the caller.");
-	}
-
-	/* find or allocate a nexthop label cache entry */
-	tree = &from_bgp->mpls_labels_per_nexthop[family2afi(nh_pfx->family)];
-	blnc = bgp_label_per_nexthop_find(tree, nh_pfx);
-	if (!blnc) {
-		blnc = bgp_label_per_nexthop_new(tree, nh_pfx);
-		blnc->to_bgp = to_bgp;
-		/* request a label to zebra for this nexthop
-		 * the response from zebra will trigger the callback
-		 */
-		bgp_lp_get(LP_TYPE_NEXTHOP, blnc,
-			   bgp_mplsvpn_get_label_per_nexthop_cb);
-	}
-
-	if (pi->label_nexthop_cache == blnc)
-		/* no change */
-		return blnc->label;
-
-	/* Unlink from any existing nexthop cache. Free the entry if unused.
-	 */
-	bgp_mplsvpn_path_nh_label_unlink(pi);
-	if (blnc) {
-		/* updates NHT pi list reference */
-		LIST_INSERT_HEAD(&(blnc->paths), pi, label_nh_thread);
-		pi->label_nexthop_cache = blnc;
-		pi->label_nexthop_cache->path_count++;
-		blnc->last_update = monotime(NULL);
-	}
-
-	/* then add or update the selected nexthop */
-	if (!blnc->nh)
-		blnc->nh = nexthop_dup(bnc->nexthop, NULL);
-	else if (!nexthop_same(bnc->nexthop, blnc->nh)) {
-		nexthop_free(blnc->nh);
-		blnc->nh = nexthop_dup(bnc->nexthop, NULL);
-		if (blnc->label != MPLS_INVALID_LABEL) {
-			bgp_zebra_send_nexthop_label(
-				ZEBRA_MPLS_LABELS_REPLACE, blnc->label,
-				bnc->nexthop->ifindex, bnc->nexthop->vrf_id,
-				ZEBRA_LSP_BGP, &blnc->nexthop);
-		}
-	}
-
-	return blnc->label;
-}
-
-/* Filter out all the cases where a per nexthop label is not possible:
- * - return an invalid label when the nexthop is invalid
- * - return the per VRF label when the per nexthop label is not supported
- * Otherwise, find or request a per label nexthop.
- */
-static mpls_label_t vpn_leak_from_vrf_get_per_nexthop_label(
-	afi_t afi, safi_t safi, struct bgp_path_info *pi, struct bgp *from_bgp,
-	struct bgp *to_bgp)
-{
-	struct bgp_path_info *bpi_ultimate = bgp_get_imported_bpi_ultimate(pi);
-	struct bgp *bgp_nexthop = NULL;
-	bool nh_valid;
-	afi_t nh_afi;
-	bool is_bgp_static_route;
-
-	is_bgp_static_route = bpi_ultimate->sub_type == BGP_ROUTE_STATIC &&
-			      bpi_ultimate->type == ZEBRA_ROUTE_BGP;
-
-	if (is_bgp_static_route == false && afi == AFI_IP &&
-	    CHECK_FLAG(pi->attr->flag, ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP)) &&
-	    (pi->attr->nexthop.s_addr == INADDR_ANY ||
-	     !ipv4_unicast_valid(&pi->attr->nexthop))) {
-		/* IPv4 nexthop in standard BGP encoding format.
-		 * Format of address is not valid (not any, not unicast).
-		 * Fallback to the per VRF label.
-		 */
-		bgp_mplsvpn_path_nh_label_unlink(pi);
-		return from_bgp->vpn_policy[afi].tovpn_label;
-	}
-
-	if (is_bgp_static_route == false && afi == AFI_IP &&
-	    pi->attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV4 &&
-	    (pi->attr->mp_nexthop_global_in.s_addr == INADDR_ANY ||
-	     !ipv4_unicast_valid(&pi->attr->mp_nexthop_global_in))) {
-		/* IPv4 nexthop is in MP-BGP encoding format.
-		 * Format of address is not valid (not any, not unicast).
-		 * Fallback to the per VRF label.
-		 */
-		bgp_mplsvpn_path_nh_label_unlink(pi);
-		return from_bgp->vpn_policy[afi].tovpn_label;
-	}
-
-	if (is_bgp_static_route == false && afi == AFI_IP6 &&
-	    (pi->attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL ||
-	     pi->attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL) &&
-	    (IN6_IS_ADDR_UNSPECIFIED(&pi->attr->mp_nexthop_global) ||
-	     IN6_IS_ADDR_LOOPBACK(&pi->attr->mp_nexthop_global) ||
-	     IN6_IS_ADDR_MULTICAST(&pi->attr->mp_nexthop_global))) {
-		/* IPv6 nexthop is in MP-BGP encoding format.
-		 * Format of address is not valid
-		 * Fallback to the per VRF label.
-		 */
-		bgp_mplsvpn_path_nh_label_unlink(pi);
-		return from_bgp->vpn_policy[afi].tovpn_label;
-	}
-
-	/* Check the next-hop reachability.
-	 * Get the bgp instance where the bgp_path_info originates.
-	 */
-	if (pi->extra && pi->extra->bgp_orig)
-		bgp_nexthop = pi->extra->bgp_orig;
-	else
-		bgp_nexthop = from_bgp;
-
-	nh_afi = BGP_ATTR_NH_AFI(afi, pi->attr);
-	nh_valid = bgp_find_or_add_nexthop(from_bgp, bgp_nexthop, nh_afi, safi,
-					   pi, NULL, 0, NULL);
-
-	if (!nh_valid && is_bgp_static_route &&
-	    !CHECK_FLAG(from_bgp->flags, BGP_FLAG_IMPORT_CHECK)) {
-		/* "network" prefixes not routable, but since 'no bgp network
-		 * import-check' is configured, they are always valid in the BGP
-		 * table. Fallback to the per-vrf label
-		 */
-		bgp_mplsvpn_path_nh_label_unlink(pi);
-		return from_bgp->vpn_policy[afi].tovpn_label;
-	}
-
-	if (!nh_valid || !pi->nexthop || pi->nexthop->nexthop_num == 0 ||
-	    !pi->nexthop->nexthop) {
-		/* invalid next-hop:
-		 * do not send the per-vrf label
-		 * otherwise, when the next-hop becomes valid,
-		 * we will have 2 BGP updates:
-		 * - one with the per-vrf label
-		 * - the second with the per-nexthop label
-		 */
-		bgp_mplsvpn_path_nh_label_unlink(pi);
-		return MPLS_INVALID_LABEL;
-	}
-
-	if (pi->nexthop->nexthop_num > 1 ||
-	    pi->nexthop->nexthop->type == NEXTHOP_TYPE_BLACKHOLE) {
-		/* Blackhole or ECMP routes
-		 * is not compatible with per-nexthop label.
-		 * Fallback to per-vrf label.
-		 */
-		bgp_mplsvpn_path_nh_label_unlink(pi);
-		return from_bgp->vpn_policy[afi].tovpn_label;
-	}
-
-	return _vpn_leak_from_vrf_get_per_nexthop_label(pi, to_bgp, from_bgp,
-							afi, safi);
-}
-
 /* cf vnc_import_bgp_add_route_mode_nvegroup() and add_vnc_route() */
 void vpn_leak_from_vrf_update(struct bgp *to_bgp,	     /* to */
 			      struct bgp *from_bgp,	   /* from */
@@ -1789,32 +1528,12 @@ void vpn_leak_from_vrf_update(struct bgp *to_bgp,	     /* to */
 		nexthop_self_flag = 1;
 	}
 
-	if (CHECK_FLAG(from_bgp->vpn_policy[afi].flags,
-		       BGP_VPN_POLICY_TOVPN_LABEL_PER_NEXTHOP))
-		/* per nexthop label mode */
-		label_val = vpn_leak_from_vrf_get_per_nexthop_label(
-			afi, safi, path_vrf, from_bgp, to_bgp);
-	else
-		/* per VRF label mode */
-		label_val = from_bgp->vpn_policy[afi].tovpn_label;
-
-	if (label_val == MPLS_INVALID_LABEL &&
-	    CHECK_FLAG(from_bgp->vpn_policy[afi].flags,
-		       BGP_VPN_POLICY_TOVPN_LABEL_PER_NEXTHOP)) {
-		/* no valid label for the moment
-		 * when the 'bgp_mplsvpn_get_label_per_nexthop_cb' callback gets
-		 * a valid label value, it will call the current function again.
-		 */
-		if (debug)
-			zlog_debug(
-				"%s: %s skipping: waiting for a valid per-label nexthop.",
-				__func__, from_bgp->name_pretty);
-		return;
-	}
-	if (label_val == MPLS_LABEL_NONE)
+	label_val = from_bgp->vpn_policy[afi].tovpn_label;
+	if (label_val == MPLS_LABEL_NONE) {
 		encode_label(MPLS_LABEL_IMPLICIT_NULL, &label);
-	else
+	} else {
 		encode_label(label_val, &label);
+	}
 
 	/* Set originator ID to "me" */
 	SET_FLAG(static_attr.flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID));
@@ -2051,8 +1770,6 @@ void vpn_leak_from_vrf_withdraw_all(struct bgp *to_bgp, struct bgp *from_bgp,
 						bpi, afi, safi);
 					bgp_path_info_delete(bn, bpi);
 					bgp_process(to_bgp, bn, afi, safi);
-					bgp_mplsvpn_path_nh_label_unlink(
-						bpi->extra->parent);
 				}
 			}
 		}