1 files changed, 21 insertions, 33 deletions

diff --git a/lib/if.c b/lib/if.c
index dabf66799d..cc964106d0 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -582,23 +582,39 @@ struct interface *if_get_by_ifindex(ifindex_t ifindex, vrf_id_t vrf_id)
 	return NULL;
 }
 
-void if_set_index(struct interface *ifp, ifindex_t ifindex)
+int if_set_index(struct interface *ifp, ifindex_t ifindex)
 {
 	struct vrf *vrf;
 
+	if (ifp->ifindex == ifindex)
+		return 0;
+
 	vrf = vrf_get(ifp->vrf_id, NULL);
 	assert(vrf);
 
-	if (ifp->ifindex == ifindex)
-		return;
+	/*
+	 * If there is already an interface with this ifindex, we will collide
+	 * on insertion, so don't even try.
+	 */
+	if (if_lookup_by_ifindex(ifindex, ifp->vrf_id))
+		return -1;
 
 	if (ifp->ifindex != IFINDEX_INTERNAL)
 		IFINDEX_RB_REMOVE(vrf, ifp);
 
 	ifp->ifindex = ifindex;
 
-	if (ifp->ifindex != IFINDEX_INTERNAL)
-		IFINDEX_RB_INSERT(vrf, ifp)
+	if (ifp->ifindex != IFINDEX_INTERNAL) {
+		/*
+		 * This should never happen, since we checked if there was
+		 * already an interface with the desired ifindex at the top of
+		 * the function. Nevertheless.
+		 */
+		if (IFINDEX_RB_INSERT(vrf, ifp))
+			return -1;
+	}
+
+	return 0;
 }
 
 void if_set_name(struct interface *ifp, const char *name)
@@ -1249,8 +1265,6 @@ struct if_link_params *if_link_params_get(struct interface *ifp)
 
 	struct if_link_params *iflp =
 		XCALLOC(MTYPE_IF_LINK_PARAMS, sizeof(struct if_link_params));
-	if (iflp == NULL)
-		return NULL;
 
 	/* Set TE metric equal to standard metric */
 	iflp->te_metric = ifp->metric;
@@ -1278,8 +1292,6 @@ struct if_link_params *if_link_params_get(struct interface *ifp)
 
 void if_link_params_free(struct interface *ifp)
 {
-	if (ifp->link_params == NULL)
-		return;
 	XFREE(MTYPE_IF_LINK_PARAMS, ifp->link_params);
 }
 
@@ -1657,31 +1669,7 @@ static int lib_interface_description_destroy(enum nb_event event,
 
 /* clang-format off */
 
-#if defined(__GNUC__) && ((__GNUC__ - 0) < 5) && !defined(__clang__)
-/* gcc versions before 5.x miscalculate the size for structs with variable
- * length arrays (they just count it as size 0)
- */
-struct frr_yang_module_info_size3 {
-	/* YANG module name. */
-	const char *name;
-
-	/* Northbound callbacks. */
-	const struct {
-		/* Data path of this YANG node. */
-		const char *xpath;
-
-		/* Callbacks implemented for this node. */
-		struct nb_callbacks cbs;
-
-		/* Priority - lower priorities are processed first. */
-		uint32_t priority;
-	} nodes[3];
-};
-
-const struct frr_yang_module_info_size3 frr_interface_info_size3 asm("frr_interface_info") = {
-#else
 const struct frr_yang_module_info frr_interface_info = {
-#endif
 	.name = "frr-interface",
 	.nodes = {
 		{