bgpd: fix "bgp as-pah access-list" with "set aspath exclude" set/unset issues

whith the following config

router bgp 65001
 no bgp ebgp-requires-policy
 neighbor 192.168.1.2 remote-as external
 neighbor 192.168.1.2 timers 3 10
 !
 address-family ipv4 unicast
  neighbor 192.168.1.2 route-map r2 in
 exit-address-family
exit
!
bgp as-path access-list FIRST seq 5 permit ^65
bgp as-path access-list SECOND seq 5 permit 2$
!
route-map r2 permit 6
 match ip address prefix-list p2
 set as-path exclude as-path-access-list SECOND
exit
!
route-map r2 permit 10
 match ip address prefix-list p1
 set as-path exclude 65003
exit
!
route-map r2 permit 20
 match ip address prefix-list p3
 set as-path exclude all
exit

making some
no bgp as-path access-list SECOND permit 2$
bgp as-path access-list SECOND permit 3$

clear bgp *

no bgp as-path access-list SECOND permit 3$
bgp as-path access-list SECOND permit 2$

clear bgp *

will induce some crashes

thus  we rework the links between aslists and aspath_exclude

Signed-off-by: Francois Dumontet <francois.dumontet@6wind.com>
(cherry picked from commit 094dcc3cdac19d3da65b38effc45aa88d960909f)

1 files changed, 23 insertions, 36 deletions

diff --git a/bgpd/bgp_routemap.c b/bgpd/bgp_routemap.c
index dbc3d6445d..e059357f09 100644
--- a/bgpd/bgp_routemap.c
+++ b/bgpd/bgp_routemap.c
@@ -2326,7 +2326,7 @@ static const struct route_map_rule_cmd route_set_aspath_prepend_cmd = {
 static void *route_aspath_exclude_compile(const char *arg)
 {
 	struct aspath_exclude *ase;
-	struct aspath_exclude_list *ael;
+	struct as_list *aux_aslist;
 	const char *str = arg;
 	static const char asp_acl[] = "as-path-access-list";
 
@@ -2338,44 +2338,37 @@ static void *route_aspath_exclude_compile(const char *arg)
 		while (*str == ' ')
 			str++;
 		ase->exclude_aspath_acl_name = XSTRDUP(MTYPE_TMP, str);
-		ase->exclude_aspath_acl = as_list_lookup(str);
+		aux_aslist = as_list_lookup(str);
+		if (!aux_aslist)
+			/* new orphan filter */
+			as_exclude_set_orphan(ase);
+		else
+			as_list_list_add_head(&aux_aslist->exclude_rule, ase);
+
+		ase->exclude_aspath_acl = aux_aslist;
 	} else
 		ase->aspath = aspath_str2aspath(str, bgp_get_asnotation(NULL));
 
-	if (ase->exclude_aspath_acl) {
-		ael = XCALLOC(MTYPE_ROUTE_MAP_COMPILED,
-				sizeof(struct aspath_exclude_list));
-		ael->bp_as_excl = ase;
-		ael->next = ase->exclude_aspath_acl->exclude_list;
-		ase->exclude_aspath_acl->exclude_list = ael;
-	}
-
 	return ase;
 }
 
 static void route_aspath_exclude_free(void *rule)
 {
 	struct aspath_exclude *ase = rule;
-	struct aspath_exclude_list *cur_ael = NULL;
-	struct aspath_exclude_list *prev_ael = NULL;
+	struct as_list *acl;
+
+	/* manage references to that rule*/
+	if (ase->exclude_aspath_acl) {
+		acl = ase->exclude_aspath_acl;
+		as_list_list_del(&acl->exclude_rule, ase);
+	} else {
+		/* no ref to acl, this aspath exclude is orphan */
+		as_exclude_remove_orphan(ase);
+	}
 
 	aspath_free(ase->aspath);
 	if (ase->exclude_aspath_acl_name)
 		XFREE(MTYPE_TMP, ase->exclude_aspath_acl_name);
-	if (ase->exclude_aspath_acl)
-		cur_ael = ase->exclude_aspath_acl->exclude_list;
-	while (cur_ael) {
-		if (cur_ael->bp_as_excl == ase) {
-			if (prev_ael)
-				prev_ael->next = cur_ael->next;
-			else
-				ase->exclude_aspath_acl->exclude_list = NULL;
-			XFREE(MTYPE_ROUTE_MAP_COMPILED, cur_ael);
-			break;
-		}
-		prev_ael = cur_ael;
-		cur_ael = cur_ael->next;
-	}
 	XFREE(MTYPE_ROUTE_MAP_COMPILED, ase);
 }
 
@@ -2410,16 +2403,10 @@ route_set_aspath_exclude(void *rule, const struct prefix *dummy, void *object)
 	else if (ase->exclude_all)
 		path->attr->aspath = aspath_filter_exclude_all(new_path);
 
-	else if (ase->exclude_aspath_acl_name) {
-		if (!ase->exclude_aspath_acl)
-			ase->exclude_aspath_acl =
-				as_list_lookup(ase->exclude_aspath_acl_name);
-		if (ase->exclude_aspath_acl)
-			path->attr->aspath =
-				aspath_filter_exclude_acl(new_path,
-							  ase->exclude_aspath_acl);
-	}
-
+	else if (ase->exclude_aspath_acl)
+		path->attr->aspath =
+			aspath_filter_exclude_acl(new_path,
+						  ase->exclude_aspath_acl);
 	return RMAP_OKAY;
 }