zebra: Allow rule replace semantics

When we get a rule that is supposed to replace
an existing rule, make it look like a rule replace
semantics.

Install new rule, then delete the old original rule.

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

1 files changed, 40 insertions, 0 deletions

diff --git a/zebra/zebra_pbr.c b/zebra/zebra_pbr.c
index 090ec2c50..a9bc8450e 100644
--- a/zebra/zebra_pbr.c
+++ b/zebra/zebra_pbr.c
@@ -99,6 +99,36 @@ int zebra_pbr_rules_hash_equal(const void *arg1, const void *arg2)
 	return 1;
 }
 
+struct pbr_unique_lookup {
+	struct zebra_pbr_rule *rule;
+	uint32_t unique;
+};
+
+static int pbr_rule_lookup_unique_walker(struct hash_backet *b, void *data)
+{
+	struct pbr_unique_lookup *pul = data;
+	struct zebra_pbr_rule *rule = b->data;
+
+	if (pul->unique == rule->unique) {
+		pul->rule = rule;
+		return HASHWALK_ABORT;
+	}
+
+	return HASHWALK_CONTINUE;
+}
+
+static struct zebra_pbr_rule *pbr_rule_lookup_unique(struct zebra_ns *zns,
+						     uint32_t unique)
+{
+	struct pbr_unique_lookup pul;
+
+	pul.unique = unique;
+	pul.rule = NULL;
+	hash_walk(zns->rules_hash, &pbr_rule_lookup_unique_walker, &pul);
+
+	return pul.rule;
+}
+
 static void *pbr_rule_alloc_intern(void *arg)
 {
 	struct zebra_pbr_rule *zpr;
@@ -115,8 +145,18 @@ static void *pbr_rule_alloc_intern(void *arg)
 
 void zebra_pbr_add_rule(struct zebra_ns *zns, struct zebra_pbr_rule *rule)
 {
+	struct zebra_pbr_rule *unique =
+		pbr_rule_lookup_unique(zns, rule->unique);
+
 	(void)hash_get(zns->rules_hash, rule, pbr_rule_alloc_intern);
 	kernel_add_pbr_rule(rule);
+
+	/*
+	 * Rule Replace semantics, if we have an old, install the
+	 * new rule, look above, and then delete the old
+	 */
+	if (unique)
+		zebra_pbr_del_rule(zns, unique);
 }
 
 void zebra_pbr_del_rule(struct zebra_ns *zns, struct zebra_pbr_rule *rule)