bgpd: propagate flood mode to zebra based on the tunnel-type in the IMET route

IMET/type-3 routes are used by VTEPs to advertise the flood mode for BUM
traffic via the PMSI tunnel attribute. If a type-3 route is not rxed from
a remote-VTEP we default to "no-head-end-rep" for that remote-VTEP. In such
cases static-config such as PIM is likely used for BUM flooding.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

diff --git a/bgpd/bgp_evpn.c b/bgpd/bgp_evpn.c
index 977f0f2f34a7c16a6787f9c3fe108600a686dc92..5d191a787ccf1d6f353daff3518d0c290efa5ad1 100644 (file)
--- a/bgpd/bgp_evpn.c
+++ b/bgpd/bgp_evpn.c
@@ -609,7 +609,8 @@ static int bgp_zebra_send_remote_macip(struct bgp *bgp, struct bgpevpn *vpn,
  * Add (update) or delete remote VTEP from zebra.
  */
 static int bgp_zebra_send_remote_vtep(struct bgp *bgp, struct bgpevpn *vpn,
-                                     struct prefix_evpn *p, int add)
+                               struct prefix_evpn *p,
+                               int flood_control, int add)
 {
        struct stream *s;
 
@@ -641,6 +642,7 @@ static int bgp_zebra_send_remote_vtep(struct bgp *bgp, struct bgpevpn *vpn,
                        add ? "ADD" : "DEL", vpn->vni);
                return -1;
        }
+       stream_putl(s, flood_control);
 
        stream_putw_at(s, 0, stream_get_endp(s));
 
@@ -889,6 +891,7 @@ static int evpn_zebra_install(struct bgp *bgp, struct bgpevpn *vpn,
 {
        int ret;
        uint8_t flags;
+       int flood_control;
 
        if (p->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE) {
                flags = 0;
@@ -903,7 +906,20 @@ static int evpn_zebra_install(struct bgp *bgp, struct bgpevpn *vpn,
                        bgp, vpn, p, pi->attr->nexthop, 1, flags,
                        mac_mobility_seqnum(pi->attr));
        } else {
-               ret = bgp_zebra_send_remote_vtep(bgp, vpn, p, 1);
+               switch (pi->attr->pmsi_tnl_type) {
+               case PMSI_TNLTYPE_INGR_REPL:
+                       flood_control = VXLAN_FLOOD_HEAD_END_REPL;
+                       break;
+
+               case PMSI_TNLTYPE_PIM_SM:
+                       flood_control = VXLAN_FLOOD_PIM_SM;
+                       break;
+
+               default:
+                       flood_control = VXLAN_FLOOD_DISABLED;
+                       break;
+               }
+               ret = bgp_zebra_send_remote_vtep(bgp, vpn, p, flood_control, 1);
        }
 
        return ret;
@@ -920,7 +936,8 @@ static int evpn_zebra_uninstall(struct bgp *bgp, struct bgpevpn *vpn,
                ret = bgp_zebra_send_remote_macip(bgp, vpn, p, remote_vtep_ip,
                                                  0, 0, 0);
        else
-               ret = bgp_zebra_send_remote_vtep(bgp, vpn, p, 0);
+               ret = bgp_zebra_send_remote_vtep(bgp, vpn, p,
+                                       VXLAN_FLOOD_DISABLED, 0);
 
        return ret;
 }
@@ -3900,12 +3917,12 @@ static int process_type3_route(struct peer *peer, afi_t afi, safi_t safi,
         */
        if (attr &&
            (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PMSI_TUNNEL))) {
-               if (attr->pmsi_tnl_type != PMSI_TNLTYPE_INGR_REPL) {
-                       flog_warn(
-                               EC_BGP_EVPN_PMSI_PRESENT,
-                               "%u:%s - Rx EVPN Type-3 NLRI with unsupported PTA %d",
-                               peer->bgp->vrf_id, peer->host,
-                               attr->pmsi_tnl_type);
+               if (attr->pmsi_tnl_type != PMSI_TNLTYPE_INGR_REPL &&
+                       attr->pmsi_tnl_type != PMSI_TNLTYPE_PIM_SM) {
+                       flog_warn(EC_BGP_EVPN_PMSI_PRESENT,
+                                 "%u:%s - Rx EVPN Type-3 NLRI with unsupported PTA %d",
+                                 peer->bgp->vrf_id, peer->host,
+                                 attr->pmsi_tnl_type);
                }
        }