bgpd: Generate and advertise gateway IP overlay index with EVPN RT-5

Gateway IP overlay index is generated for EVPN RT-5 when following CLI is
configured.

router bgp 100 vrf vrf-blue
 address-family l2vpn evpn
  advertise ipv4 unicast gateway-ip
  advertise ipv6 unicast gateway-ip

BGP nexthop of the VRF IP/IPv6 route is set as the gateway IP of the
corresponding EVPN RT-5

Signed-off-by: Ameya Dharkar <adharkar@vmware.com>

6 files changed, 75 insertions, 30 deletions

diff --git a/bgpd/bgp_debug.c b/bgpd/bgp_debug.c
index 8f286e66df..856afb05f8 100644
--- a/bgpd/bgp_debug.c
+++ b/bgpd/bgp_debug.c
@@ -2680,10 +2680,14 @@ const char *bgp_debug_rdpfxpath2str(afi_t afi, safi_t safi,
 				    union prefixconstptr pu,
 				    mpls_label_t *label, uint32_t num_labels,
 				    int addpath_valid, uint32_t addpath_id,
+				    struct bgp_route_evpn *overlay_index,
 				    char *str, int size)
 {
 	char rd_buf[RD_ADDRSTRLEN];
 	char tag_buf[30];
+	char overlay_index_buf[INET6_ADDRSTRLEN + 14];
+	const struct prefix_evpn *evp;
+
 	/* ' with addpath ID '          17
 	 * max strlen of uint32       + 10
 	 * +/- (just in case)         +  1
@@ -2701,6 +2705,23 @@ const char *bgp_debug_rdpfxpath2str(afi_t afi, safi_t safi,
 		snprintf(pathid_buf, sizeof(pathid_buf), " with addpath ID %u",
 			 addpath_id);
 
+	overlay_index_buf[0] = '\0';
+	if (overlay_index && overlay_index->type == OVERLAY_INDEX_GATEWAY_IP) {
+		char obuf[INET6_ADDRSTRLEN];
+
+		obuf[0] = '\0';
+		evp = pu.evp;
+		if (is_evpn_prefix_ipaddr_v4(evp))
+			inet_ntop(AF_INET, &overlay_index->gw_ip, obuf,
+				  sizeof(obuf));
+		else if (is_evpn_prefix_ipaddr_v6(evp))
+			inet_ntop(AF_INET6, &overlay_index->gw_ip, obuf,
+				  sizeof(obuf));
+
+		snprintf(overlay_index_buf, sizeof(overlay_index_buf),
+			 " gateway IP %s", obuf);
+	}
+
 	tag_buf[0] = '\0';
 	if (bgp_labeled_safi(safi) && num_labels) {
 
@@ -2720,9 +2741,10 @@ const char *bgp_debug_rdpfxpath2str(afi_t afi, safi_t safi,
 	}
 
 	if (prd)
-		snprintfrr(str, size, "RD %s %pFX%s%s %s %s",
+		snprintfrr(str, size, "RD %s %pFX%s%s%s %s %s",
 			   prefix_rd2str(prd, rd_buf, sizeof(rd_buf)), pu.p,
-			   tag_buf, pathid_buf, afi2str(afi), safi2str(safi));
+			   overlay_index_buf, tag_buf, pathid_buf, afi2str(afi),
+			   safi2str(safi));
 	else if (safi == SAFI_FLOWSPEC) {
 		char return_string[BGP_FLOWSPEC_NLRI_STRING_MAX];
 		const struct prefix_fs *fs = pu.fs;
diff --git a/bgpd/bgp_debug.h b/bgpd/bgp_debug.h
index fa8da1c345..d847fb84e7 100644
--- a/bgpd/bgp_debug.h
+++ b/bgpd/bgp_debug.h
@@ -37,7 +37,8 @@
 #define DUMP_DETAIL   32
 
 /* RD + Prefix + Path-Id */
-#define BGP_PRD_PATH_STRLEN (PREFIX_STRLEN + RD_ADDRSTRLEN + 20)
+#define BGP_PRD_PATH_STRLEN                                                    \
+	(PREFIX_STRLEN + RD_ADDRSTRLEN + INET6_ADDRSTRLEN + 34)
 
 extern int dump_open;
 extern int dump_update;
@@ -179,11 +180,11 @@ extern bool bgp_debug_update(struct peer *peer, const struct prefix *p,
 extern bool bgp_debug_bestpath(struct bgp_dest *dest);
 extern bool bgp_debug_zebra(const struct prefix *p);
 
-extern const char *
-bgp_debug_rdpfxpath2str(afi_t afi, safi_t safi, const struct prefix_rd *prd,
-			union prefixconstptr pu, mpls_label_t *label,
-			uint32_t num_labels, int addpath_valid,
-			uint32_t addpath_id, char *str, int size);
+extern const char *bgp_debug_rdpfxpath2str(
+	afi_t afi, safi_t safi, const struct prefix_rd *prd,
+	union prefixconstptr pu, mpls_label_t *label, uint32_t num_labels,
+	int addpath_valid, uint32_t addpath_id,
+	struct bgp_route_evpn *overlay_index, char *str, int size);
 const char *bgp_notify_admin_message(char *buf, size_t bufsz, uint8_t *data,
 				     size_t datalen);
 
diff --git a/bgpd/bgp_evpn.c b/bgpd/bgp_evpn.c
index d8e57419ee..b29825afc5 100644
--- a/bgpd/bgp_evpn.c
+++ b/bgpd/bgp_evpn.c
@@ -1261,7 +1261,8 @@ static int update_evpn_type5_route_entry(struct bgp *bgp_evpn,
 
 /* update evpn type-5 route entry */
 static int update_evpn_type5_route(struct bgp *bgp_vrf, struct prefix_evpn *evp,
-				   struct attr *src_attr)
+				   struct attr *src_attr, afi_t src_afi,
+				   safi_t src_safi)
 {
 	afi_t afi = AFI_L2VPN;
 	safi_t safi = SAFI_EVPN;
@@ -1315,6 +1316,26 @@ static int update_evpn_type5_route(struct bgp *bgp_vrf, struct prefix_evpn *evp,
 
 	attr.mp_nexthop_len = BGP_ATTR_NHLEN_IPV4;
 
+	if (src_afi == AFI_IP6 &&
+	    CHECK_FLAG(bgp_vrf->af_flags[AFI_L2VPN][SAFI_EVPN],
+		       BGP_L2VPN_EVPN_ADV_IPV6_UNICAST_GW_IP)) {
+		if (src_attr &&
+		    !IN6_IS_ADDR_UNSPECIFIED(&src_attr->mp_nexthop_global)) {
+			attr.evpn_overlay.type = OVERLAY_INDEX_GATEWAY_IP;
+			memcpy(&attr.evpn_overlay.gw_ip.ipv6,
+			       &src_attr->mp_nexthop_global,
+			       sizeof(struct in6_addr));
+		}
+	} else if (src_afi == AFI_IP &&
+		   CHECK_FLAG(bgp_vrf->af_flags[AFI_L2VPN][SAFI_EVPN],
+			      BGP_L2VPN_EVPN_ADV_IPV4_UNICAST_GW_IP)) {
+		if (src_attr && src_attr->nexthop.s_addr != 0) {
+			attr.evpn_overlay.type = OVERLAY_INDEX_GATEWAY_IP;
+			memcpy(&attr.evpn_overlay.gw_ip.ipv4,
+			       &src_attr->nexthop, sizeof(struct in_addr));
+		}
+	}
+
 	/* Setup RT and encap extended community */
 	build_evpn_type5_route_extcomm(bgp_vrf, &attr);
 
@@ -4078,7 +4099,7 @@ static void evpn_mpattr_encode_type5(struct stream *s, const struct prefix *p,
 	/* Prefix contains RD, ESI, EthTag, IP length, IP, GWIP and VNI */
 	stream_putc(s, 8 + 10 + 4 + 1 + len + 3);
 	stream_put(s, prd->val, 8);
-	if (attr)
+	if (attr && attr->evpn_overlay.type == OVERLAY_INDEX_ESI)
 		stream_put(s, &attr->esi, sizeof(esi_t));
 	else
 		stream_put(s, 0, sizeof(esi_t));
@@ -4088,7 +4109,7 @@ static void evpn_mpattr_encode_type5(struct stream *s, const struct prefix *p,
 		stream_put_ipv4(s, p_evpn_p->prefix_addr.ip.ipaddr_v4.s_addr);
 	else
 		stream_put(s, &p_evpn_p->prefix_addr.ip.ipaddr_v6, 16);
-	if (attr) {
+	if (attr && attr->evpn_overlay.type == OVERLAY_INDEX_GATEWAY_IP) {
 		const struct bgp_route_evpn *evpn_overlay =
 			bgp_attr_get_evpn_overlay(attr);
 
@@ -4301,7 +4322,7 @@ void bgp_evpn_advertise_type5_route(struct bgp *bgp_vrf, const struct prefix *p,
 	struct prefix_evpn evp;
 
 	build_type5_prefix_from_ip_prefix(&evp, p);
-	ret = update_evpn_type5_route(bgp_vrf, &evp, src_attr);
+	ret = update_evpn_type5_route(bgp_vrf, &evp, src_attr, afi, safi);
 	if (ret)
 		flog_err(EC_BGP_EVPN_ROUTE_CREATE,
 			 "%u: Failed to create type-5 route for prefix %pFX",
diff --git a/bgpd/bgp_mac.c b/bgpd/bgp_mac.c
index 3d7bc08ac5..02b7e64869 100644
--- a/bgpd/bgp_mac.c
+++ b/bgpd/bgp_mac.c
@@ -200,8 +200,8 @@ static void bgp_process_mac_rescan_table(struct bgp *bgp, struct peer *peer,
 						AFI_L2VPN, SAFI_EVPN, &prd,
 						p, label_pnt, num_labels,
 						pi->addpath_rx_id ? 1 : 0,
-						pi->addpath_rx_id, pfx_buf,
-						sizeof(pfx_buf));
+						pi->addpath_rx_id, NULL,
+						pfx_buf, sizeof(pfx_buf));
 					zlog_debug(
 						   "%s skip update of %s marked as removed",
 						   peer->host, pfx_buf);
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 8438621f68..c539bccb62 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -3867,7 +3867,7 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 					bgp_debug_rdpfxpath2str(
 						afi, safi, prd, p, label,
 						num_labels, addpath_id ? 1 : 0,
-						addpath_id, pfx_buf,
+						addpath_id, NULL, pfx_buf,
 						sizeof(pfx_buf));
 					zlog_debug("%s rcvd %s", peer->host,
 						   pfx_buf);
@@ -3893,7 +3893,7 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 					bgp_debug_rdpfxpath2str(
 						afi, safi, prd, p, label,
 						num_labels, addpath_id ? 1 : 0,
-						addpath_id, pfx_buf,
+						addpath_id, NULL, pfx_buf,
 						sizeof(pfx_buf));
 					zlog_debug(
 						"%s rcvd %s...duplicate ignored",
@@ -3920,8 +3920,8 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 			if (bgp_debug_update(peer, p, NULL, 1)) {
 				bgp_debug_rdpfxpath2str(
 					afi, safi, prd, p, label, num_labels,
-					addpath_id ? 1 : 0, addpath_id, pfx_buf,
-					sizeof(pfx_buf));
+					addpath_id ? 1 : 0, addpath_id, NULL,
+					pfx_buf, sizeof(pfx_buf));
 				zlog_debug(
 					"%s rcvd %s, flapped quicker than processing",
 					peer->host, pfx_buf);
@@ -3934,7 +3934,7 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 		if (bgp_debug_update(peer, p, NULL, 1)) {
 			bgp_debug_rdpfxpath2str(afi, safi, prd, p, label,
 						num_labels, addpath_id ? 1 : 0,
-						addpath_id, pfx_buf,
+						addpath_id, NULL, pfx_buf,
 						sizeof(pfx_buf));
 			zlog_debug("%s rcvd %s", peer->host, pfx_buf);
 		}
@@ -4207,8 +4207,8 @@ int bgp_update(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 		}
 
 		bgp_debug_rdpfxpath2str(afi, safi, prd, p, label, num_labels,
-					addpath_id ? 1 : 0, addpath_id, pfx_buf,
-					sizeof(pfx_buf));
+					addpath_id ? 1 : 0, addpath_id, NULL,
+					pfx_buf, sizeof(pfx_buf));
 		zlog_debug("%s rcvd %s", peer->host, pfx_buf);
 	}
 
@@ -4353,8 +4353,8 @@ filtered:
 		}
 
 		bgp_debug_rdpfxpath2str(afi, safi, prd, p, label, num_labels,
-					addpath_id ? 1 : 0, addpath_id, pfx_buf,
-					sizeof(pfx_buf));
+					addpath_id ? 1 : 0, addpath_id, NULL,
+					pfx_buf, sizeof(pfx_buf));
 		zlog_debug("%s rcvd UPDATE about %s -- DENIED due to: %s",
 			   peer->host, pfx_buf, reason);
 	}
@@ -4438,8 +4438,8 @@ int bgp_withdraw(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 			if (bgp_debug_update(peer, p, NULL, 1)) {
 				bgp_debug_rdpfxpath2str(
 					afi, safi, prd, p, label, num_labels,
-					addpath_id ? 1 : 0, addpath_id, pfx_buf,
-					sizeof(pfx_buf));
+					addpath_id ? 1 : 0, addpath_id, NULL,
+					pfx_buf, sizeof(pfx_buf));
 				zlog_debug(
 					"%s withdrawing route %s not in adj-in",
 					peer->host, pfx_buf);
@@ -4458,8 +4458,8 @@ int bgp_withdraw(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 	/* Logging. */
 	if (bgp_debug_update(peer, p, NULL, 1)) {
 		bgp_debug_rdpfxpath2str(afi, safi, prd, p, label, num_labels,
-					addpath_id ? 1 : 0, addpath_id, pfx_buf,
-					sizeof(pfx_buf));
+					addpath_id ? 1 : 0, addpath_id, NULL,
+					pfx_buf, sizeof(pfx_buf));
 		zlog_debug("%s rcvd UPDATE about %s -- withdrawn", peer->host,
 			   pfx_buf);
 	}
@@ -4479,8 +4479,8 @@ int bgp_withdraw(struct peer *peer, const struct prefix *p, uint32_t addpath_id,
 		}
 	} else if (bgp_debug_update(peer, p, NULL, 1)) {
 		bgp_debug_rdpfxpath2str(afi, safi, prd, p, label, num_labels,
-					addpath_id ? 1 : 0, addpath_id, pfx_buf,
-					sizeof(pfx_buf));
+					addpath_id ? 1 : 0, addpath_id, NULL,
+					pfx_buf, sizeof(pfx_buf));
 		zlog_debug("%s Can't find the route %s", peer->host, pfx_buf);
 	}
 
diff --git a/bgpd/bgp_updgrp_packet.c b/bgpd/bgp_updgrp_packet.c
index 6418decd16..038ef4f798 100644
--- a/bgpd/bgp_updgrp_packet.c
+++ b/bgpd/bgp_updgrp_packet.c
@@ -862,6 +862,7 @@ struct bpacket *subgroup_update_packet(struct update_subgroup *subgrp)
 			bgp_debug_rdpfxpath2str(afi, safi, prd, dest_p,
 						label_pnt, num_labels,
 						addpath_encode, addpath_tx_id,
+						&adv->baa->attr->evpn_overlay,
 						pfx_buf, sizeof(pfx_buf));
 			zlog_debug("u%" PRIu64 ":s%" PRIu64 " send UPDATE %s",
 				   subgrp->update_group->id, subgrp->id,
@@ -1031,7 +1032,7 @@ struct bpacket *subgroup_withdraw_packet(struct update_subgroup *subgrp)
 
 			bgp_debug_rdpfxpath2str(afi, safi, prd, dest_p, NULL, 0,
 						addpath_encode, addpath_tx_id,
-						pfx_buf, sizeof(pfx_buf));
+						NULL, pfx_buf, sizeof(pfx_buf));
 			zlog_debug("u%" PRIu64 ":s%" PRIu64" send UPDATE %s -- unreachable",
 				   subgrp->update_group->id, subgrp->id,
 				   pfx_buf);