bgpd: Optimize the way parsing communities if no community alias exists

If at least one community alias is configured, then let's do the work,
otherwise we don't need to spend time on splitting stuff and creating
a new string.

This should improve the performance.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

bgpd/bgp_clist.c

@@ -534,20 +534,29 @@ static bool community_regexp_match(struct community *com, regex_t *reg)
 	const char *str;
 	char *regstr;
 	int rv;
+	bool translate_alias = !!bgp_ca_alias_hash->count;
 
 	/* When there is no communities attribute it is treated as empty
 	   string.  */
 	if (com == NULL || com->size == 0)
-		str = "";
-	else
-		str = community_str(com, false, true);
+		return false;
 
-	regstr = bgp_alias2community_str(str);
+	str = community_str(com, false, translate_alias);
+
+	/* If at least one community alias is configured, then let's
+	 * do the work, otherwise we don't need to spend time on splitting
+	 * stuff and creating a new string.
+	 */
+	regstr = translate_alias ? bgp_alias2community_str(str) : (char *)str;
 
 	/* Regular expression match.  */
 	rv = regexec(reg, regstr, 0, NULL, 0);
 
-	XFREE(MTYPE_TMP, regstr);
+	/* This is allocated by frrstr_join(), and needs to be freed
+	 * only if it was created.
+	 */
+	if (translate_alias)
+		XFREE(MTYPE_TMP, regstr);
 
 	return rv == 0;
 }
@@ -608,20 +617,29 @@ static bool lcommunity_regexp_match(struct lcommunity *com, regex_t *reg)
 	const char *str;
 	char *regstr;
 	int rv;
+	bool translate_alias = !!bgp_ca_alias_hash->count;
 
 	/* When there is no communities attribute it is treated as empty
 	   string.  */
 	if (com == NULL || com->size == 0)
-		str = "";
-	else
-		str = lcommunity_str(com, false, true);
+		return false;
 
-	regstr = bgp_alias2community_str(str);
+	str = lcommunity_str(com, false, translate_alias);
+
+	/* If at least one community alias is configured, then let's
+	 * do the work, otherwise we don't need to spend time on splitting
+	 * stuff and creating a new string.
+	 */
+	regstr = translate_alias ? bgp_alias2community_str(str) : (char *)str;
 
 	/* Regular expression match.  */
 	rv = regexec(reg, regstr, 0, NULL, 0);
 
-	XFREE(MTYPE_TMP, regstr);
+	/* This is allocated by frrstr_join(), and needs to be freed
+	 * only if it was created.
+	 */
+	if (translate_alias)
+		XFREE(MTYPE_TMP, regstr);
 
 	return rv == 0;
 }

bgpd/bgp_community_alias.c

@@ -13,7 +13,7 @@
 #include "bgpd/bgpd.h"
 #include "bgpd/bgp_community_alias.h"
 
-static struct hash *bgp_ca_alias_hash;
+struct hash *bgp_ca_alias_hash;
 static struct hash *bgp_ca_community_hash;
 
 static unsigned int bgp_ca_community_hash_key(const void *p)

bgpd/bgp_community_alias.h

@@ -17,6 +17,7 @@ struct community_alias {
 	char alias[BUFSIZ];
 };
 
+extern struct hash *bgp_ca_alias_hash;
 extern void bgp_community_alias_init(void);
 extern void bgp_community_alias_finish(void);
 extern struct community_alias *bgp_ca_alias_lookup(struct community_alias *ca);