Eric Lee / smarc-ti-linux-kernel | Embedian Git Server

Commit e6f8f1a739b652c56e6f959d6714d92e05621e21

Authored by Pavel Emelyanov 2012-08-09 05:53:03 +0800

Committed by David S. Miller 2012-08-10 07:18:07 +0800

veth: Allow to create peer link with given ifindex

The ifinfomsg is in there (thanks kaber@ for foreseeing this long time ago),
so take the given ifidex and register netdev with it.

Ben noticed, that this code path previously ignored ifmp->ifi_index and
userland could be passing in garbage. Thus it may now fail occasionally
because the value clashes with an existing interface.

To address this it's assumed that if the caller specifies the ifindex for
the veth master device, then it's aware of this possibility and should
explicitly specify (or set to 0 for auto-assignment) the peer's ifindex as
well. With this the compatibility with old tools not setting ifindex is
preserved.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 1 changed file with 3 additions and 0 deletions Side-by-side Diff

drivers/net/veth.c

drivers/net/veth.c

Diff comments View file @ e6f8f1a

...	...	@@ -348,6 +348,9 @@
348	348	if (tbp[IFLA_ADDRESS] == NULL)
349	349	eth_hw_addr_random(peer);
350	350
	351	+ if (ifmp && (dev->ifindex != 0))
	352	+ peer->ifindex = ifmp->ifi_index;
	353	+
351	354	err = register_netdevice(peer);
352	355	put_net(net);
353	356	net = NULL;