zebra: Add link_nsid to zebra interface

Create VRF and interfaces:

    ip netns add vrf1
    ip link add veth1 index 100 type veth
    ip link add link veth1 veth1.200 type vlan id 200
    ip link set veth1.200 netns vrf1
    ip -n vrf1 link add veth2 index 100 type veth

After reloading zebra, "show interface veth1.200" shows wrong parent
interface:

    test# show interface veth1.200
    Interface veth1.200 is down
      ...
      Parent interface: veth2

This is because veth1.200 and veth1 are in different netns, and veth2
happens to have the same ifindex as veth1, in the same netns of
veth1.200.
When looking for parent, link-ifindex 100 should be looked up within
link-netns, rather than that of the child interface.

Add link_nsid to zebra interface, so that the <link_nsid, link_ifindex>
pair can uniquely identify the link interface.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/zebra/interface.h b/zebra/interface.h
index c8ae906c91..09df42bc53 100644
--- a/zebra/interface.h
+++ b/zebra/interface.h
@@ -195,6 +195,7 @@ struct zebra_if {
 	struct list *mac_list;
 
 	/* Link fields - for sub-interfaces. */
+	ns_id_t link_nsid;
 	ifindex_t link_ifindex;
 	struct interface *link;
 
@@ -259,6 +260,8 @@ extern struct interface *if_lookup_by_index_per_ns(struct zebra_ns *, uint32_t);
 extern struct interface *if_lookup_by_name_per_ns(struct zebra_ns *,
 						  const char *);
 extern struct interface *if_link_per_ns(struct zebra_ns *, struct interface *);
+extern struct interface *if_lookup_by_index_per_nsid(ns_id_t nsid,
+						     uint32_t ifindex);
 extern const char *ifindex2ifname_per_ns(struct zebra_ns *, unsigned int);
 
 extern void if_unlink_per_ns(struct interface *);