bgpd: Add route-map match alias command

Will be handy to filter BGP prefixes by using BGP community alias
instead of numerical community values.

Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>

bgpd/bgp_routemap.c

@@ -52,6 +52,7 @@
 #include "bgpd/bgp_zebra.h"
 #include "bgpd/bgp_regex.h"
 #include "bgpd/bgp_community.h"
+#include "bgpd/bgp_community_alias.h"
 #include "bgpd/bgp_clist.h"
 #include "bgpd/bgp_filter.h"
 #include "bgpd/bgp_mplsvpn.h"
@@ -1179,6 +1180,55 @@ static const struct route_map_rule_cmd route_match_vrl_source_vrf_cmd = {
 	route_match_vrl_source_vrf_free
 };
 
+/* `match alias` */
+static enum route_map_cmd_result_t
+route_match_alias(void *rule, const struct prefix *prefix, void *object)
+{
+	char *alias = rule;
+	struct bgp_path_info *path = object;
+	char **communities;
+	int num;
+
+	if (path->attr->community) {
+		frrstr_split(path->attr->community->str, " ", &communities,
+			     &num);
+		for (int i = 0; i < num; i++) {
+			const char *com2alias =
+				bgp_community2alias(communities[i]);
+			if (strncmp(alias, com2alias, strlen(com2alias)) == 0)
+				return RMAP_MATCH;
+		}
+	}
+
+	if (path->attr->lcommunity) {
+		frrstr_split(path->attr->lcommunity->str, " ", &communities,
+			     &num);
+		for (int i = 0; i < num; i++) {
+			const char *com2alias =
+				bgp_community2alias(communities[i]);
+			if (strncmp(alias, com2alias, strlen(com2alias)) == 0)
+				return RMAP_MATCH;
+		}
+	}
+
+	return RMAP_NOMATCH;
+}
+
+static void *route_match_alias_compile(const char *arg)
+{
+
+	return XSTRDUP(MTYPE_ROUTE_MAP_COMPILED, arg);
+}
+
+static void route_match_alias_free(void *rule)
+{
+	XFREE(MTYPE_ROUTE_MAP_COMPILED, rule);
+}
+
+static const struct route_map_rule_cmd route_match_alias_cmd = {
+	"alias", route_match_alias, route_match_alias_compile,
+	route_match_alias_free};
+
 /* `match local-preference LOCAL-PREF' */
 
 /* Match function return 1 if match is success else return zero. */
@@ -4597,6 +4647,58 @@ DEFUN_YANG (no_match_local_pref,
 	return nb_cli_apply_changes(vty, NULL);
 }
 
+DEFUN_YANG(match_alias, match_alias_cmd, "match alias ALIAS_NAME",
+	   MATCH_STR
+	   "Match BGP community alias name\n"
+	   "BGP community alias name\n")
+{
+	const char *alias = argv[2]->arg;
+	struct community_alias ca1;
+	struct community_alias *lookup_alias;
+
+	const char *xpath =
+		"./match-condition[condition='frr-bgp-route-map:match-alias']";
+	char xpath_value[XPATH_MAXLEN];
+
+	memset(&ca1, 0, sizeof(ca1));
+	strlcpy(ca1.alias, alias, sizeof(ca1.alias));
+	lookup_alias = bgp_ca_alias_lookup(&ca1);
+	if (!lookup_alias) {
+		vty_out(vty, "%% BGP alias name '%s' does not exist\n", alias);
+		return CMD_WARNING_CONFIG_FAILED;
+	}
+
+	nb_cli_enqueue_change(vty, xpath, NB_OP_CREATE, NULL);
+	snprintf(xpath_value, sizeof(xpath_value),
+		 "%s/rmap-match-condition/frr-bgp-route-map:alias", xpath);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_MODIFY, alias);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+
+DEFUN_YANG(no_match_alias, no_match_alias_cmd, "no match alias [ALIAS_NAME]",
+	   NO_STR MATCH_STR
+	   "Match BGP community alias name\n"
+	   "BGP community alias name\n")
+{
+	int idx_alias = 3;
+	const char *xpath =
+		"./match-condition[condition='frr-bgp-route-map:match-alias']";
+	char xpath_value[XPATH_MAXLEN];
+
+	nb_cli_enqueue_change(vty, xpath, NB_OP_DESTROY, NULL);
+
+	if (argc <= idx_alias)
+		return nb_cli_apply_changes(vty, NULL);
+
+	snprintf(xpath_value, sizeof(xpath_value),
+		 "%s/rmap-match-condition/frr-bgp-route-map:alias", xpath);
+	nb_cli_enqueue_change(vty, xpath_value, NB_OP_DESTROY,
+			      argv[idx_alias]->arg);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
 
 DEFPY_YANG (match_community,
        match_community_cmd,
@@ -6286,6 +6388,7 @@ void bgp_route_map_init(void)
 	route_map_no_set_tag_hook(generic_set_delete);
 
 	route_map_install_match(&route_match_peer_cmd);
+	route_map_install_match(&route_match_alias_cmd);
 	route_map_install_match(&route_match_local_pref_cmd);
 #ifdef HAVE_SCRIPTING
 	route_map_install_match(&route_match_script_cmd);
@@ -6370,6 +6473,8 @@ void bgp_route_map_init(void)
 	install_element(RMAP_NODE, &no_match_aspath_cmd);
 	install_element(RMAP_NODE, &match_local_pref_cmd);
 	install_element(RMAP_NODE, &no_match_local_pref_cmd);
+	install_element(RMAP_NODE, &match_alias_cmd);
+	install_element(RMAP_NODE, &no_match_alias_cmd);
 	install_element(RMAP_NODE, &match_community_cmd);
 	install_element(RMAP_NODE, &no_match_community_cmd);
 	install_element(RMAP_NODE, &match_lcommunity_cmd);

bgpd/bgp_routemap_nb.c

@@ -38,6 +38,13 @@ const struct frr_yang_module_info frr_bgp_route_map_info = {
 				.destroy = lib_route_map_entry_match_condition_rmap_match_condition_local_preference_destroy,
 			}
 		},
+		{
+			.xpath = "/frr-route-map:lib/route-map/entry/match-condition/rmap-match-condition/frr-bgp-route-map:alias",
+			.cbs = {
+				.modify = lib_route_map_entry_match_condition_rmap_match_condition_alias_modify,
+				.destroy = lib_route_map_entry_match_condition_rmap_match_condition_alias_destroy,
+			}
+		},
 		{
 			.xpath = "/frr-route-map:lib/route-map/entry/match-condition/rmap-match-condition/frr-bgp-route-map:script",
 			.cbs = {

bgpd/bgp_routemap_nb.h

@@ -29,6 +29,10 @@ extern const struct frr_yang_module_info frr_bgp_route_map_info;
 /* prototypes */
 int lib_route_map_entry_match_condition_rmap_match_condition_local_preference_modify(struct nb_cb_modify_args *args);
 int lib_route_map_entry_match_condition_rmap_match_condition_local_preference_destroy(struct nb_cb_destroy_args *args);
+int lib_route_map_entry_match_condition_rmap_match_condition_alias_modify(
+	struct nb_cb_modify_args *args);
+int lib_route_map_entry_match_condition_rmap_match_condition_alias_destroy(
+	struct nb_cb_destroy_args *args);
 int lib_route_map_entry_match_condition_rmap_match_condition_script_modify(struct nb_cb_modify_args *args);
 int lib_route_map_entry_match_condition_rmap_match_condition_script_destroy(struct nb_cb_destroy_args *args);
 int lib_route_map_entry_match_condition_rmap_match_condition_origin_modify(struct nb_cb_modify_args *args);

bgpd/bgp_routemap_nb_config.c

@@ -159,6 +159,62 @@ lib_route_map_entry_match_condition_rmap_match_condition_local_preference_destro
 	return NB_OK;
 }
 
+/*
+ * XPath:
+ * /frr-route-map:lib/route-map/entry/match-condition/rmap-match-condition/frr-bgp-route-map:alias
+ */
+int lib_route_map_entry_match_condition_rmap_match_condition_alias_modify(
+	struct nb_cb_modify_args *args)
+{
+	struct routemap_hook_context *rhc;
+	const char *alias;
+	enum rmap_compile_rets ret;
+
+	switch (args->event) {
+	case NB_EV_VALIDATE:
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		/* Add configuration. */
+		rhc = nb_running_get_entry(args->dnode, NULL, true);
+		alias = yang_dnode_get_string(args->dnode, NULL);
+
+		/* Set destroy information. */
+		rhc->rhc_mhook = bgp_route_match_delete;
+		rhc->rhc_rule = "alias";
+		rhc->rhc_event = RMAP_EVENT_MATCH_DELETED;
+
+		ret = bgp_route_match_add(rhc->rhc_rmi, "alias", alias,
+					  RMAP_EVENT_MATCH_ADDED, args->errmsg,
+					  args->errmsg_len);
+
+		if (ret != RMAP_COMPILE_SUCCESS) {
+			rhc->rhc_mhook = NULL;
+			return NB_ERR_VALIDATION;
+		}
+
+		break;
+	}
+
+	return NB_OK;
+}
+
+int lib_route_map_entry_match_condition_rmap_match_condition_alias_destroy(
+	struct nb_cb_destroy_args *args)
+{
+	switch (args->event) {
+	case NB_EV_VALIDATE:
+	case NB_EV_PREPARE:
+	case NB_EV_ABORT:
+		break;
+	case NB_EV_APPLY:
+		return lib_route_map_entry_match_destroy(args);
+	}
+
+	return NB_OK;
+}
+
 /*
  * XPath: /frr-route-map:lib/route-map/entry/match-condition/rmap-match-condition/frr-bgp-route-map:script
  */

lib/routemap.h

@@ -270,6 +270,7 @@ DECLARE_QOBJ_TYPE(route_map);
 /* BGP route-map match conditions */
 #define IS_MATCH_LOCAL_PREF(C)                                                 \
 	(strmatch(C, "frr-bgp-route-map:match-local-preference"))
+#define IS_MATCH_ALIAS(C) (strmatch(C, "frr-bgp-route-map:match-alias"))
 #define IS_MATCH_ORIGIN(C)                                                     \
 	(strmatch(C, "frr-bgp-route-map:match-origin"))
 #define IS_MATCH_RPKI(C) (strmatch(C, "frr-bgp-route-map:rpki"))

lib/routemap_cli.c

@@ -634,6 +634,11 @@ void route_map_condition_show(struct vty *vty, struct lyd_node *dnode,
 			yang_dnode_get_string(
 				dnode,
 				"./rmap-match-condition/frr-bgp-route-map:local-preference"));
+	} else if (IS_MATCH_ALIAS(condition)) {
+		vty_out(vty, " match alias %s\n",
+			yang_dnode_get_string(
+				dnode,
+				"./rmap-match-condition/frr-bgp-route-map:alias"));
 	} else if (IS_MATCH_ORIGIN(condition)) {
 		vty_out(vty, " match origin %s\n",
 			yang_dnode_get_string(

yang/frr-bgp-route-map.yang

@@ -36,6 +36,12 @@ module frr-bgp-route-map {
       "Initial revision";
   }
 
+  identity match-alias {
+    base frr-route-map:rmap-match-type;
+    description
+      "Match BGP community alias name";
+  }
+
   identity match-local-preference {
     base frr-route-map:rmap-match-type;
     description
@@ -352,7 +358,14 @@ module frr-bgp-route-map {
       }
     }
 
-    case script { 
+    case alias {
+      when "derived-from-or-self(/frr-route-map:lib/frr-route-map:route-map/frr-route-map:entry/frr-route-map:match-condition/frr-route-map:condition, 'frr-bgp-route-map:match-alias')";
+      leaf alias {
+        type string;
+      }
+    }
+
+    case script {
       when "derived-from-or-self(/frr-route-map:lib/frr-route-map:route-map/frr-route-map:entry/frr-route-map:match-condition/frr-route-map:condition, 'frr-bgp-route-map:match-script')";
       leaf script {
         type string;