bgpd: update route leak when vrf state changes

Locally leaked routes remain active after the nexthop VRF interface goes down. Update route leaking when the loopback or a VRF interface state change is received from zebra. Signed-off-by: Louis Scalbert <[email protected]>
opensourcerouting · Feb 14, 2024 · b45c5cd · b45c5cd
1 parent c102add
commit b45c5cd
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Showing 5 changed files with 46 additions and 1 deletion.
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
@@ -2347,6 +2347,12 @@ int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 				return BGP_ATTR_PARSE_WITHDRAW;
 			}
 			attr->nh_ifindex = peer->nexthop.ifp->ifindex;
+			if (if_is_operative(peer->nexthop.ifp))
+				SET_FLAG(attr->nh_flags,
+					 BGP_ATTR_NH_IF_OPERSTATE);
+			else
+				UNSET_FLAG(attr->nh_flags,
+					   BGP_ATTR_NH_IF_OPERSTATE);
 		}
 		break;
 	case BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL:
@@ -2364,6 +2370,12 @@ int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
 				return BGP_ATTR_PARSE_WITHDRAW;
 			}
 			attr->nh_ifindex = peer->nexthop.ifp->ifindex;
+			if (if_is_operative(peer->nexthop.ifp))
+				SET_FLAG(attr->nh_flags,
+					 BGP_ATTR_NH_IF_OPERSTATE);
+			else
+				UNSET_FLAG(attr->nh_flags,
+					   BGP_ATTR_NH_IF_OPERSTATE);
 		}
 		if (attr->mp_nexthop_len
 		    == BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL) {

diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h
@@ -158,6 +158,7 @@ struct attr {
 	uint8_t nh_flags;
 
 #define BGP_ATTR_NH_VALID 0x01
+#define BGP_ATTR_NH_IF_OPERSTATE 0x02
 
 	/* Path origin attribute */
 	uint8_t origin;

diff --git a/bgpd/bgp_mplsvpn.c b/bgpd/bgp_mplsvpn.c
@@ -2093,8 +2093,9 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *to_bgp,   /* to */
 	struct bgp_path_info *bpi;
 	int origin_local = 0;
 	struct bgp *src_vrf;
-	struct interface *ifp;
+	struct interface *ifp = NULL;
 	char rd_buf[RD_ADDRSTRLEN];
+
 	int debug = BGP_DEBUG(vpn, VPN_LEAK_TO_VRF);
 
 	if (!vpn_leak_from_vpn_active(to_bgp, afi, &debugmsg)) {
@@ -2260,6 +2261,15 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *to_bgp,   /* to */
 		break;
 	}
 
+	if (!ifp && static_attr.nh_ifindex)
+		ifp = if_lookup_by_index(static_attr.nh_ifindex,
+					 src_vrf->vrf_id);
+
+	if (ifp && if_is_operative(ifp))
+		SET_FLAG(static_attr.nh_flags, BGP_ATTR_NH_IF_OPERSTATE);
+	else
+		UNSET_FLAG(static_attr.nh_flags, BGP_ATTR_NH_IF_OPERSTATE);
+
 	/*
 	 * route map handling
 	 */

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
@@ -8569,6 +8569,7 @@ void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
 	afi_t afi;
 	route_map_result_t ret;
 	struct bgp_redist *red;
+	struct interface *ifp;
 
 	if (CHECK_FLAG(bgp->flags, BGP_FLAG_DELETE_IN_PROGRESS) ||
 	    bgp->peer_self == NULL)
@@ -8628,6 +8629,11 @@ void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
 	}
 	attr.nh_type = nhtype;
 	attr.nh_ifindex = ifindex;
+	ifp = if_lookup_by_index(ifindex, bgp->vrf_id);
+	if (ifp && if_is_operative(ifp))
+		SET_FLAG(attr.nh_flags, BGP_ATTR_NH_IF_OPERSTATE);
+	else
+		UNSET_FLAG(attr.nh_flags, BGP_ATTR_NH_IF_OPERSTATE);
 
 	attr.med = metric;
 	attr.distance = distance;

diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
@@ -235,6 +235,14 @@ static int bgp_ifp_up(struct interface *ifp)
 	hook_call(bgp_vrf_status_changed, bgp, ifp);
 	bgp_nht_ifp_up(ifp);
 
+	if (bgp_get_default() && if_is_loopback(ifp)) {
+		vpn_leak_zebra_vrf_label_update(bgp, AFI_IP);
+		vpn_leak_zebra_vrf_label_update(bgp, AFI_IP6);
+		vpn_leak_zebra_vrf_sid_update(bgp, AFI_IP);
+		vpn_leak_zebra_vrf_sid_update(bgp, AFI_IP6);
+		vpn_leak_postchange_all();
+	}
+
 	return 0;
 }
 
@@ -282,6 +290,14 @@ static int bgp_ifp_down(struct interface *ifp)
 	hook_call(bgp_vrf_status_changed, bgp, ifp);
 	bgp_nht_ifp_down(ifp);
 
+	if (bgp_get_default() && if_is_loopback(ifp)) {
+		vpn_leak_zebra_vrf_label_withdraw(bgp, AFI_IP);
+		vpn_leak_zebra_vrf_label_withdraw(bgp, AFI_IP6);
+		vpn_leak_zebra_vrf_sid_withdraw(bgp, AFI_IP);
+		vpn_leak_zebra_vrf_sid_withdraw(bgp, AFI_IP6);
+		vpn_leak_postchange_all();
+	}
+
 	return 0;
 }