bgpd, zebra: Add ability for bgp to send AS-Path information to zebra

Add a bit of code to allow bgp to send the AS-Path associated with
the route being installed to zebra so it can be displayed and
used as part of the `show ip route A` command in zebra.

eva# show ip route 20.0.0.0/11
Routing entry for 20.0.0.0/11
  Known via "bgp", distance 20, metric 0, best
  Last update 00:00:00 ago
  * 192.168.161.1, via enp39s0, weight 1
    AS-Path: 60000 64539 15096 6939 8075

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

bgpd/bgp_vty.c

@@ -1596,6 +1596,19 @@ DEFPY (no_bgp_norib,
 	return CMD_SUCCESS;
 }
 
+DEFPY (no_bgp_send_extra_data,
+       no_bgp_send_extra_data_cmd,
+       "[no] bgp send-extra-data zebra",
+       NO_STR
+       BGP_STR
+       "Extra data to Zebra for display/use\n"
+       "To zebra\n")
+{
+	bgp_option_send_extra_data(!!no);
+
+	return CMD_SUCCESS;
+}
+
 DEFUN_YANG(bgp_confederation_identifier,
 	   bgp_confederation_identifier_cmd,
 	   "bgp confederation identifier (1-4294967295)",
@@ -16930,6 +16943,9 @@ int bgp_config_write(struct vty *vty)
 	if (bgp_option_check(BGP_OPT_NO_FIB))
 		vty_out(vty, "bgp no-rib\n");
 
+	if (bm->send_extra_data_to_zebra)
+		vty_out(vty, "no bgp send-extra-data zebra\n");
+
 	/* BGP configuration. */
 	for (ALL_LIST_ELEMENTS(bm->bgp, mnode, mnnode, bgp)) {
 
@@ -17485,6 +17501,8 @@ void bgp_vty_init(void)
 	install_element(CONFIG_NODE, &bgp_norib_cmd);
 	install_element(CONFIG_NODE, &no_bgp_norib_cmd);
 
+	install_element(CONFIG_NODE, &no_bgp_send_extra_data_cmd);
+
 	/* "bgp confederation" commands. */
 	install_element(BGP_NODE, &bgp_confederation_identifier_cmd);
 	install_element(BGP_NODE, &no_bgp_confederation_identifier_cmd);

bgpd/bgp_zebra.c

@@ -41,6 +41,7 @@
 #include "bgpd/bgpd.h"
 #include "bgpd/bgp_route.h"
 #include "bgpd/bgp_attr.h"
+#include "bgpd/bgp_aspath.h"
 #include "bgpd/bgp_nexthop.h"
 #include "bgpd/bgp_zebra.h"
 #include "bgpd/bgp_fsm.h"
@@ -1409,6 +1410,14 @@ void bgp_zebra_announce(struct bgp_dest *dest, const struct prefix *p,
 
 	is_add = (valid_nh_count || nhg_id) ? true : false;
 
+	if (is_add && bm->send_extra_data_to_zebra) {
+		struct aspath *aspath = info->attr->aspath;
+
+		SET_FLAG(api.message, ZAPI_MESSAGE_OPAQUE);
+		api.opaque.length = strlen(aspath->str) + 1;
+		memcpy(api.opaque.data, aspath->str, api.opaque.length);
+	}
+
 	/*
 	 * When we create an aggregate route we must also
 	 * install a Null0 route in the RIB, so overwrite

bgpd/bgpd.c

@@ -7395,6 +7395,11 @@ char *peer_uptime(time_t uptime2, char *buf, size_t len, bool use_json,
 	return buf;
 }
 
+void bgp_option_send_extra_data(bool send)
+{
+	bm->send_extra_data_to_zebra = send;
+}
+
 void bgp_master_init(struct thread_master *master, const int buffer_size)
 {
 	qobj_init();
@@ -7413,6 +7418,7 @@ void bgp_master_init(struct thread_master *master, const int buffer_size)
 	bm->v_establish_wait = BGP_UPDATE_DELAY_DEF;
 	bm->terminating = false;
 	bm->socket_buffer = buffer_size;
+	bm->send_extra_data_to_zebra = true;
 
 	bgp_mac_init();
 	/* init the rd id space.

bgpd/bgpd.h

@@ -169,6 +169,9 @@ struct bgp_master {
 	uint32_t flags;
 #define BM_FLAG_GRACEFUL_SHUTDOWN        (1 << 0)
 
+	/* Send extra data to zebra like aspath */
+	bool send_extra_data_to_zebra;
+
 	bool terminating;	/* global flag that sigint terminate seen */
 	QOBJ_FIELDS
 };
@@ -2246,6 +2249,8 @@ static inline bool bgp_in_graceful_shutdown(struct bgp *bgp)
 
 extern void bgp_unset_redist_vrf_bitmaps(struct bgp *, vrf_id_t);
 
+extern void bgp_option_send_extra_data(bool send);
+
 /* For benefit of rfapi */
 extern struct peer *peer_new(struct bgp *bgp);
 

zebra/zebra_vty.c

@@ -434,6 +434,13 @@ static void zebra_show_ip_route_opaque(struct vty *vty, struct route_entry *re,
 			vty_out(vty, "    Opaque Data: %s",
 				(char *)re->opaque->data);
 		break;
+	case ZEBRA_ROUTE_BGP:
+		if (json)
+			json_object_string_add(json, "asPath",
+					       (char *)re->opaque->data);
+		else
+			vty_out(vty, "    AS-Path: %s",
+				(char *)re->opaque->data);
 	default:
 		break;
 	}