1 files changed, 15 insertions, 11 deletions

diff --git a/lib/northbound.h b/lib/northbound.h
index ce79d907f9..fbd7771db7 100644
--- a/lib/northbound.h
+++ b/lib/northbound.h
@@ -72,6 +72,7 @@ enum nb_operation {
 	NB_OP_MODIFY,
 	NB_OP_DESTROY,
 	NB_OP_MOVE,
+	NB_OP_PRE_VALIDATE,
 	NB_OP_APPLY_FINISH,
 	NB_OP_GET_ELEM,
 	NB_OP_GET_NEXT,
@@ -199,6 +200,19 @@ struct nb_callbacks {
 	/*
 	 * Optional configuration callback.
 	 *
+	 * This callback can be used to validate subsections of the
+	 * configuration being committed before validating the configuration
+	 * changes themselves. It's useful to perform more complex validations
+	 * that depend on the relationship between multiple nodes.
+	 *
+	 * dnode
+	 *    libyang data node associated with the 'pre_validate' callback.
+	 */
+	int (*pre_validate)(const struct lyd_node *dnode);
+
+	/*
+	 * Optional configuration callback.
+	 *
 	 * The 'apply_finish' callbacks are called after all other callbacks
 	 * during the apply phase (NB_EV_APPLY). These callbacks are called only
 	 * under one of the following two cases:
@@ -435,25 +449,15 @@ enum nb_client {
 
 /* Northbound configuration. */
 struct nb_config {
-	/* Configuration data. */
 	struct lyd_node *dnode;
-
-	/* Configuration version. */
 	uint32_t version;
-
-	/*
-	 * Lock protecting this structure. The use of this lock is always
-	 * necessary when reading or modifying the global running configuration.
-	 * For candidate configurations, use of this lock is optional depending
-	 * on the threading scheme of the northbound plugin.
-	 */
-	pthread_rwlock_t lock;
 };
 
 /* Northbound configuration callback. */
 struct nb_config_cb {
 	RB_ENTRY(nb_config_cb) entry;
 	enum nb_operation operation;
+	uint32_t seq;
 	char xpath[XPATH_MAXLEN];
 	const struct nb_node *nb_node;
 	const struct lyd_node *dnode;