lib: move all userdata when changing node xpath

All userdata pointers need to be rekeyed to their new xpaths, not just
the one associated with the dnode being moved.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

lib/if.c

@@ -263,15 +263,21 @@ void if_update_to_new_vrf(struct interface *ifp, vrf_id_t vrf_id)
 	 */
 	if (yang_module_find("frr-interface")) {
 		struct lyd_node *if_dnode;
+		char oldpath[XPATH_MAXLEN];
+		char newpath[XPATH_MAXLEN];
 
 		if_dnode = yang_dnode_get(
 			running_config->dnode,
 			"/frr-interface:lib/interface[name='%s'][vrf='%s']/vrf",
 			ifp->name, old_vrf->name);
+
 		if (if_dnode) {
-			nb_running_unset_entry(if_dnode->parent);
+			yang_dnode_get_path(if_dnode->parent, oldpath,
+					    sizeof(oldpath));
 			yang_dnode_change_leaf(if_dnode, vrf->name);
-			nb_running_set_entry(if_dnode->parent, ifp);
+			yang_dnode_get_path(if_dnode->parent, newpath,
+					    sizeof(newpath));
+			nb_running_move_tree(oldpath, newpath);
 			running_config->version++;
 		}
 	}

lib/northbound.c

@@ -30,6 +30,7 @@
 #include "northbound.h"
 #include "northbound_cli.h"
 #include "northbound_db.h"
+#include "frrstr.h"
 
 DEFINE_MTYPE_STATIC(LIB, NB_NODE, "Northbound Node")
 DEFINE_MTYPE_STATIC(LIB, NB_CONFIG, "Northbound Configuration")
@@ -1789,6 +1790,29 @@ void nb_running_set_entry(const struct lyd_node *dnode, void *entry)
 	config->entry = entry;
 }
 
+void nb_running_move_tree(const char *xpath_from, const char *xpath_to)
+{
+	struct nb_config_entry *entry;
+	struct list *entries = hash_to_list(running_config_entries);
+	struct listnode *ln;
+
+	for (ALL_LIST_ELEMENTS_RO(entries, ln, entry)) {
+		if (!frrstr_startswith(entry->xpath, xpath_from))
+			continue;
+
+		hash_release(running_config_entries, entry);
+
+		char *newpath =
+			frrstr_replace(entry->xpath, xpath_from, xpath_to);
+		strlcpy(entry->xpath, newpath, sizeof(entry->xpath));
+		XFREE(MTYPE_TMP, newpath);
+
+		hash_get(running_config_entries, entry, hash_alloc_intern);
+	}
+
+	list_delete(&entries);
+}
+
 static void *nb_running_unset_entry_helper(const struct lyd_node *dnode)
 {
 	struct nb_config_entry *config, s;

lib/northbound.h

@@ -992,6 +992,23 @@ extern int nb_notification_send(const char *xpath, struct list *arguments);
  */
 extern void nb_running_set_entry(const struct lyd_node *dnode, void *entry);
 
+/*
+ * Move an entire tree of user pointer nodes.
+ *
+ * Suppose we have xpath A/B/C/D, with user pointers associated to C and D. We
+ * need to move B to be under Z, so the new xpath is Z/B/C/D. Because user
+ * pointers are indexed with their absolute path, We need to move all user
+ * pointers at and below B to their new absolute paths; this function does
+ * that.
+ *
+ * xpath_from
+ *    base xpath of tree to move (A/B)
+ *
+ * xpath_to
+ *    base xpath of new location of tree (Z/B)
+ */
+extern void nb_running_move_tree(const char *xpath_from, const char *xpath_to);
+
 /*
  * Unset the user pointer associated to a configuration node.
  *