lib: Allow interface lookup by VRF_UNKNOWN

Modify if_lookup_by_index to accept a VRF_UNKNOWN
as a vrf_id.  This will cause it to look in all
vrf's for the interface pointer.

Subsequently all if_XXXX functions that call this function
will also get this behavior.

VRF_UNKNOWN *should* not be used for interface creation
as that this will break some core assumptions.

This work is part of allowing vrf route leaking.  Currently
it is possible to create a route in the linux kernel that has
a nexthop across vrf boundaries.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/if.c b/lib/if.c
index 8e6a9a6968..fdcd563a5d 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -219,6 +219,18 @@ struct interface *if_lookup_by_index(ifindex_t ifindex, vrf_id_t vrf_id)
 	struct vrf *vrf;
 	struct interface if_tmp;
 
+	if (vrf_id == VRF_UNKNOWN) {
+		struct interface *ifp;
+
+		RB_FOREACH(vrf, vrf_id_head, &vrfs_by_id) {
+			ifp = if_lookup_by_index(ifindex, vrf->vrf_id);
+			if (ifp)
+				return ifp;
+		}
+
+		return NULL;
+	}
+
 	vrf = vrf_lookup_by_id(vrf_id);
 	if (!vrf)
 		return NULL;