zebra: Use the rule ifindex as a hash key, not ifp

Use the ifindex value as a primary hash key/identifier, not
the ifp pointer. It is possible for that data to be freed
and then we would not be able to hash and find the rule entry
anymore. Using the ifindex, we can still find the rule even
if the interface is removed.

Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>

3 files changed, 12 insertions, 19 deletions

diff --git a/zebra/rule_netlink.c b/zebra/rule_netlink.c
index 711c4e087..1b465b033 100644
--- a/zebra/rule_netlink.c
+++ b/zebra/rule_netlink.c
@@ -123,7 +123,7 @@ static int netlink_rule_update(int cmd, struct zebra_pbr_rule *rule)
 			"Tx %s family %s IF %s(%u) Pref %u Fwmark %u Src %s Dst %s Table %u",
 			nl_msg_type_to_str(cmd), nl_family_to_str(family),
 			rule->ifp ? rule->ifp->name : "Unknown",
-			rule->ifp ? rule->ifp->ifindex : 0, rule->rule.priority,
+			rule->rule.ifindex, rule->rule.priority,
 			rule->rule.filter.fwmark,
 			prefix2str(&rule->rule.filter.src_ip, buf1,
 				   sizeof(buf1)),
diff --git a/zebra/zapi_msg.c b/zebra/zapi_msg.c
index b0488b755..96faf6f1f 100644
--- a/zebra/zapi_msg.c
+++ b/zebra/zapi_msg.c
@@ -2294,7 +2294,6 @@ static inline void zread_rule(ZAPI_HANDLER_ARGS)
 	struct zebra_pbr_rule zpr;
 	struct stream *s;
 	uint32_t total, i;
-	ifindex_t ifindex;
 
 	s = msg;
 	STREAM_GETL(s, total);
@@ -2319,15 +2318,14 @@ static inline void zread_rule(ZAPI_HANDLER_ARGS)
 		STREAM_GETW(s, zpr.rule.filter.dst_port);
 		STREAM_GETL(s, zpr.rule.filter.fwmark);
 		STREAM_GETL(s, zpr.rule.action.table);
-		STREAM_GETL(s, ifindex);
+		STREAM_GETL(s, zpr.rule.ifindex);
 
-		if (ifindex) {
-			zpr.ifp = if_lookup_by_index_per_ns(
-						zvrf->zns,
-						ifindex);
+		if (zpr.rule.ifindex) {
+			zpr.ifp = if_lookup_by_index_per_ns(zvrf->zns,
+							    zpr.rule.ifindex);
 			if (!zpr.ifp) {
 				zlog_debug("Failed to lookup ifindex: %u",
-					   ifindex);
+					   zpr.rule.ifindex);
 				return;
 			}
 		}
diff --git a/zebra/zebra_pbr.c b/zebra/zebra_pbr.c
index 9a7d50673..e77e29f13 100644
--- a/zebra/zebra_pbr.c
+++ b/zebra/zebra_pbr.c
@@ -144,17 +144,12 @@ uint32_t zebra_pbr_rules_hash_key(const void *arg)
 	key = jhash_3words(rule->rule.seq, rule->rule.priority,
 			   rule->rule.action.table,
 			   prefix_hash_key(&rule->rule.filter.src_ip));
-	if (rule->ifp)
-		key = jhash_1word(rule->ifp->ifindex, key);
-	else
-		key = jhash_1word(0, key);
 
 	if (rule->rule.filter.fwmark)
-		key = jhash_1word(rule->rule.filter.fwmark, key);
+		key = jhash_3words(rule->rule.filter.fwmark, rule->vrf_id,
+				   rule->rule.ifindex, key);
 	else
-		key = jhash_1word(0, key);
-
-	key = jhash_1word(rule->vrf_id, key);
+		key = jhash_2words(rule->vrf_id, rule->rule.ifindex, key);
 
 	return jhash_3words(rule->rule.filter.src_port,
 			    rule->rule.filter.dst_port,
@@ -208,7 +203,7 @@ bool zebra_pbr_rules_hash_equal(const void *arg1, const void *arg2)
 struct pbr_rule_unique_lookup {
 	struct zebra_pbr_rule *rule;
 	uint32_t unique;
-	struct interface *ifp;
+	ifindex_t ifindex;
 	vrf_id_t vrf_id;
 };
 
@@ -218,7 +213,7 @@ static int pbr_rule_lookup_unique_walker(struct hash_bucket *b, void *data)
 	struct zebra_pbr_rule *rule = b->data;
 
 	if (pul->unique == rule->rule.unique
-	    && pul->ifp == rule->ifp
+	    && pul->ifindex == rule->rule.ifindex
 	    && pul->vrf_id == rule->vrf_id) {
 		pul->rule = rule;
 		return HASHWALK_ABORT;
@@ -233,7 +228,7 @@ pbr_rule_lookup_unique(struct zebra_pbr_rule *zrule)
 	struct pbr_rule_unique_lookup pul;
 
 	pul.unique = zrule->rule.unique;
-	pul.ifp = zrule->ifp;
+	pul.ifindex = zrule->rule.ifindex;
 	pul.rule = NULL;
 	pul.vrf_id = zrule->vrf_id;
 	hash_walk(zrouter.rules_hash, &pbr_rule_lookup_unique_walker, &pul);