lib: nb: call child destroy CBs when YANG container is deleted

Previously the code was only calling the child destroy callbacks if the target
deleted node was a non-presence container. We now add a flag to the callback
structure to instruct northbound to perform the rescursive delete for code that
wishes for this to happen.

- Fix wrong relative path lookup in keychain destroy callback

Signed-off-by: Christian Hopps <chopps@labn.net>

lib/keychain_nb.c

@@ -587,9 +587,9 @@ static int key_chains_key_chain_key_crypto_algorithm_destroy(
 	if (args->event != NB_EV_APPLY)
 		return NB_OK;
 
-	name = yang_dnode_get_string(args->dnode, "../../../name");
+	name = yang_dnode_get_string(args->dnode, "../../name");
 	keychain = keychain_lookup(name);
-	index = (uint32_t)yang_dnode_get_uint64(args->dnode, "../../key-id");
+	index = (uint32_t)yang_dnode_get_uint64(args->dnode, "../key-id");
 	key = key_lookup(keychain, index);
 	key->hash_algo = KEYCHAIN_ALGO_NULL;
 	keychain_touch(keychain);

lib/northbound.c

@@ -516,20 +516,33 @@ void nb_config_diff_created(const struct lyd_node *dnode, uint32_t *seq,
 static void nb_config_diff_deleted(const struct lyd_node *dnode, uint32_t *seq,
 				   struct nb_config_cbs *changes)
 {
+	struct nb_node *nb_node = dnode->schema->priv;
+	struct lyd_node *child;
+	bool recursed = false;
+
 	/* Ignore unimplemented nodes. */
-	if (!dnode->schema->priv)
+	if (!nb_node)
 		return;
 
+	/*
+	 * If the CB structure indicates it (recurse flag set), call the destroy
+	 * callbacks for the children of a containment node.
+	 */
+	if (CHECK_FLAG(dnode->schema->nodetype, LYS_CONTAINER | LYS_LIST) &&
+	    CHECK_FLAG(nb_node->cbs.flags, F_NB_CB_DESTROY_RECURSE)) {
+		recursed = true;
+		LY_LIST_FOR (lyd_child(dnode), child) {
+			nb_config_diff_deleted(child, seq, changes);
+		}
+	}
+
 	if (nb_cb_operation_is_valid(NB_CB_DESTROY, dnode->schema))
 		nb_config_diff_add_change(changes, NB_CB_DESTROY, seq, dnode);
-	else if (CHECK_FLAG(dnode->schema->nodetype, LYS_CONTAINER)) {
+	else if (CHECK_FLAG(dnode->schema->nodetype, LYS_CONTAINER) && !recursed) {
-		struct lyd_node *child;
-
 		/*
-		 * Non-presence containers need special handling since they
+		 * If we didn't already above, call destroy on the children of
-		 * don't have "destroy" callbacks. In this case, what we need to
+		 * this container (it's an NP container) as NP containers have
-		 * do is to call the "destroy" callbacks of their child nodes
+		 * no destroy CB themselves.
-		 * when applicable (i.e. optional nodes).
 		 */
 		LY_LIST_FOR (lyd_child(dnode), child) {
 			nb_config_diff_deleted(child, seq, changes);

lib/northbound.h

@@ -385,6 +385,11 @@ struct nb_callbacks {
 	 */
 	int (*destroy)(struct nb_cb_destroy_args *args);
 
+	/*
+	 * Flags to control the how northbound callbacks are invoked.
+	 */
+	uint flags;
+
 	/*
 	 * Configuration callback.
 	 *
@@ -622,6 +627,12 @@ struct nb_callbacks {
 	void (*cli_show_end)(struct vty *vty, const struct lyd_node *dnode);
 };
 
+/*
+ * Flag indicating the northbound should recurse destroy the children of this
+ * node when it is destroyed.
+ */
+#define F_NB_CB_DESTROY_RECURSE 0x01
+
 struct nb_dependency_callbacks {
 	void (*get_dependant_xpath)(const struct lyd_node *dnode, char *xpath);
 	void (*get_dependency_xpath)(const struct lyd_node *dnode, char *xpath);