lib: fix next vrf interface lookup avoid loopback interface

When the default vrf is submitted, the returned interface may be the loopback interface, which may not be valid. Actually, on vrfs, the vrf interface is bypassed. When being on default vrf, the 'lo' interface should be bypassed too. Fix this by avoiding returning the lo interface too. Fixes: 0760a74 ("lib: add utility to get the next index in a vrf") Signed-off-by: Philippe Guibert <[email protected]>
FRRouting · Nov 27, 2024 · 9467957 · 9467957
1 parent 970ec0f
commit 9467957
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/lib/if.c b/lib/if.c
@@ -325,17 +325,17 @@ struct interface *if_vrf_lookup_by_index_next(ifindex_t ifindex,
 
 	if (ifindex == 0) {
 		tmp_ifp = RB_MIN(if_index_head, &vrf->ifaces_by_index);
-		/* skip the vrf interface */
-		if (tmp_ifp && if_is_vrf(tmp_ifp))
+		/* skip the vrf interface or the lo interface */
+		if (tmp_ifp && if_is_loopback(tmp_ifp))
 			ifindex = tmp_ifp->ifindex;
 		else
 			return tmp_ifp;
 	}
 
 	RB_FOREACH (tmp_ifp, if_index_head, &vrf->ifaces_by_index) {
 		if (found) {
-			/* skip the vrf interface */
-			if (tmp_ifp && if_is_vrf(tmp_ifp))
+			/* skip the vrf interface or the lo interface */
+			if (tmp_ifp && if_is_loopback(tmp_ifp))
 				continue;
 			else
 				return tmp_ifp;

diff --git a/lib/vrf.h b/lib/vrf.h
@@ -149,6 +149,9 @@ static inline uint32_t vrf_interface_count(struct vrf *vrf)
 	struct interface *ifp;
 
 	RB_FOREACH (ifp, if_name_head, &vrf->ifaces_by_name) {
+		/* skip the lo interface */
+		if (if_is_loopback_exact(ifp))
+			continue;
 		/* skip the l3mdev */
 		if (strncmp(ifp->name, vrf->name, VRF_NAMSIZ) == 0)
 			continue;