bgpd: Add command to display EVPN type-5 per-prefix

Add support for command
show bgp l2vpn evpn route rd <rd> prefix <prefix> [json]

This is currently a Cumulus-specific change. Multiple of the EVPN operational
commands need to be unified with upstream changes which have now caught up
to display most of the needed information of the global EVPN table but differ
in some aspects from existing Cumulus commands. The unification also needs
to handle per-VNI (per-EVI) information and will be post CL 4.2.

Signed-off-by: Vivek Venkatraman <[email protected]>

Ticket: CM-26918
Reviewed By:  Output reviewed by Mahesh & Chirag
Testing Done:
1. Manual check
2. Precommit -
https://trdb.cumulusnetworks.com/trdb3/product/1/userjobs?user=vivek&job=32

bgpd/bgp_evpn_vty.c

@@ -2832,6 +2832,67 @@ static void evpn_show_route_rd_macip(struct vty *vty, struct bgp *bgp,
 	bgp_dest_unlock_node(dest);
 }
 
+/*
+ * Display BGP EVPN routing table -- for specific RD and prefix
+ * (vty handler). By definition, only matching type-5 route will be
+ * displayed.
+ */
+static void evpn_show_route_rd_prefix(struct vty *vty, struct bgp *bgp,
+				      struct prefix_rd *prd,
+				      struct prefix *ip_prefix,
+				      json_object *json)
+{
+	struct prefix_evpn p;
+	struct bgp_dest *dest;
+	struct bgp_path_info *pi;
+	afi_t afi;
+	safi_t safi;
+	uint32_t path_cnt = 0;
+	json_object *json_paths = NULL;
+	char prefix_str[BUFSIZ];
+
+	afi = AFI_L2VPN;
+	safi = SAFI_EVPN;
+
+	/* Build type-5 prefix. */
+	build_type5_prefix_from_ip_prefix(&p, ip_prefix);
+
+	/* See if route exists. */
+	dest = bgp_safi_node_lookup(bgp->rib[afi][safi], safi,
+				 (struct prefix *)&p, prd);
+	if (!dest || !bgp_dest_has_bgp_path_info_data(dest)) {
+		if (!json)
+			vty_out(vty, "%% Network not in table\n");
+		return;
+	}
+
+	prefix2str((struct prefix_evpn *)&p, prefix_str,
+			   sizeof(prefix_str));
+
+	/* Prefix and num paths displayed once per prefix. */
+	route_vty_out_detail_header(vty, bgp, dest, bgp_dest_get_prefix(dest), prd,
+				    afi, safi, json, false, false);
+
+	if (json)
+		json_paths = json_object_new_array();
+
+	/* Display each path for this prefix. */
+	for (pi = bgp_dest_get_bgp_path_info(dest); pi; pi = pi->next) {
+		route_vty_out_detail(vty, bgp, dest, bgp_dest_get_prefix(dest), pi,
+				     afi, safi, RPKI_NOT_BEING_USED, json_paths);
+		path_cnt++;
+	}
+
+	if (json && path_cnt) {
+		if (path_cnt)
+			json_object_object_add(json, "paths", json_paths);
+		json_object_int_add(json, "numPaths", path_cnt);
+	} else {
+		vty_out(vty, "\nDisplayed %u paths for requested prefix\n",
+			path_cnt);
+	}
+}
+
 /*
  * Display BGP EVPN routing table -- for specific RD (vty handler)
  * If 'type' is non-zero, only routes matching that type are shown.
@@ -5118,6 +5179,71 @@ DEFUN(show_bgp_l2vpn_evpn_route_rd_macip,
 	return CMD_SUCCESS;
 }
 
+/*
+ * Display global EVPN routing table for specific RD and prefix (type-5).
+ */
+DEFUN(show_bgp_l2vpn_evpn_route_rd_prefix,
+      show_bgp_l2vpn_evpn_route_rd_prefix_cmd,
+      "show bgp l2vpn evpn route rd ASN:NN_OR_IP-ADDRESS:NN prefix <A.B.C.D/M|X:X::X:X/M> [json]",
+      SHOW_STR
+      BGP_STR
+      L2VPN_HELP_STR
+      EVPN_HELP_STR
+      "EVPN route information\n"
+      "Route Distinguisher\n"
+      "ASN:XX or A.B.C.D:XX\n"
+      "prefix\n"
+      "IP prefix\n"
+      "IPv6 prefix\n"
+      JSON_STR)
+{
+	struct bgp *bgp;
+	int ret;
+	int idx = 0;
+	struct prefix_rd prd;
+	struct prefix ip_prefix;
+	bool uj = false;
+	json_object *json = NULL;
+
+	bgp = bgp_get_evpn();
+	if (!bgp)
+		return CMD_WARNING;
+
+	/* check if we need json output */
+	uj = use_json(argc, argv);
+	if (uj)
+		json = json_object_new_object();
+
+	/* get the prd */
+	if (argv_find(argv, argc, "rd", &idx)) {
+		ret = str2prefix_rd(argv[idx + 1]->arg, &prd);
+		if (!ret) {
+			vty_out(vty, "%% Malformed Route Distinguisher\n");
+			return CMD_WARNING;
+		}
+	}
+
+	/* get the prefix */
+	if (argv_find(argv, argc, "prefix", &idx)) {
+		ret = str2prefix(argv[idx + 1]->arg, &ip_prefix);
+		if (!ret) {
+			vty_out(vty, "prefix is malformed\n");
+			return CMD_WARNING;
+		}
+	} else
+		return CMD_WARNING;
+
+	evpn_show_route_rd_prefix(vty, bgp, &prd, &ip_prefix, json);
+
+	if (uj) {
+		vty_out(vty, "%s\n", json_object_to_json_string_ext(
+					     json, JSON_C_TO_STRING_PRETTY));
+		json_object_free(json);
+	}
+
+	return CMD_SUCCESS;
+}
+
 /* Display per ESI routing table */
 DEFUN(show_bgp_l2vpn_evpn_route_esi,
       show_bgp_l2vpn_evpn_route_esi_cmd,
@@ -6135,6 +6261,20 @@ ALIAS_HIDDEN(
 	"IP\n"
 	"IP address (IPv4 or IPv6)\n")
 
+ALIAS_HIDDEN(
+	show_bgp_l2vpn_evpn_route_rd_prefix, show_bgp_evpn_route_rd_prefix_cmd,
+	"show bgp evpn route rd ASN:NN_OR_IP-ADDRESS:NN prefix <A.B.C.D/M|X:X::X:X/M> [json]",
+	SHOW_STR
+	BGP_STR
+	EVPN_HELP_STR
+	"EVPN route information\n"
+	"Route Distinguisher\n"
+	"ASN:XX or A.B.C.D:XX\n"
+	"prefix\n"
+	"IP prefix\n"
+	"IPv6 prefix\n"
+	JSON_STR)
+
 ALIAS_HIDDEN(
 	show_bgp_l2vpn_evpn_route_vni, show_bgp_evpn_route_vni_cmd,
 	"show bgp evpn route vni " CMD_VNI_RANGE " [<type <macip|2|multicast|3> | vtep A.B.C.D>]",
@@ -7566,6 +7706,7 @@ void bgp_ethernetvpn_init(void)
 	install_element(VIEW_NODE, &show_bgp_l2vpn_evpn_route_cmd);
 	install_element(VIEW_NODE, &show_bgp_l2vpn_evpn_route_rd_cmd);
 	install_element(VIEW_NODE, &show_bgp_l2vpn_evpn_route_rd_macip_cmd);
+	install_element(VIEW_NODE, &show_bgp_l2vpn_evpn_route_rd_prefix_cmd);
 	install_element(VIEW_NODE, &show_bgp_l2vpn_evpn_route_esi_cmd);
 	install_element(VIEW_NODE, &show_bgp_l2vpn_evpn_route_vni_cmd);
 	install_element(VIEW_NODE,
@@ -7599,6 +7740,7 @@ void bgp_ethernetvpn_init(void)
 	install_element(VIEW_NODE, &show_bgp_evpn_route_cmd);
 	install_element(VIEW_NODE, &show_bgp_evpn_route_rd_cmd);
 	install_element(VIEW_NODE, &show_bgp_evpn_route_rd_macip_cmd);
+	install_element(VIEW_NODE, &show_bgp_evpn_route_rd_prefix_cmd);
 	install_element(VIEW_NODE, &show_bgp_evpn_route_vni_cmd);
 	install_element(VIEW_NODE, &show_bgp_evpn_route_vni_multicast_cmd);
 	install_element(VIEW_NODE, &show_bgp_evpn_route_vni_macip_cmd);