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authorPavel Emelyanov <xemul@parallels.com>2012-08-08 21:52:46 +0000
committerDavid S. Miller <davem@davemloft.net>2012-08-09 16:18:06 -0700
commit9c7dafbfab1554705f85523fead578aa1a3d338c (patch)
tree462dc2a2b854b3c7ad80a351a0ef780b790bc109
parentb14f243a42c7aa43de71f878641acd003f223022 (diff)
net: Allow to create links with given ifindex
Currently the RTM_NEWLINK results in -EOPNOTSUPP if the ifinfomsg->ifi_index is not zero. I propose to allow requesting ifindices on link creation. This is required by the checkpoint-restore to correctly restore a net namespace (i.e. -- a container). Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/dev.c7
-rw-r--r--net/core/rtnetlink.c12
2 files changed, 13 insertions, 6 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index f91abf800161..3ca300d85271 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5579,7 +5579,12 @@ int register_netdevice(struct net_device *dev)
}
}
- dev->ifindex = dev_new_index(net);
+ ret = -EBUSY;
+ if (!dev->ifindex)
+ dev->ifindex = dev_new_index(net);
+ else if (__dev_get_by_index(net, dev->ifindex))
+ goto err_uninit;
+
if (dev->iflink == -1)
dev->iflink = dev->ifindex;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index db037c9a4c48..34d975b0f277 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1812,8 +1812,6 @@ replay:
return -ENODEV;
}
- if (ifm->ifi_index)
- return -EOPNOTSUPP;
if (tb[IFLA_MAP] || tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
return -EOPNOTSUPP;
@@ -1839,10 +1837,14 @@ replay:
return PTR_ERR(dest_net);
dev = rtnl_create_link(net, dest_net, ifname, ops, tb);
-
- if (IS_ERR(dev))
+ if (IS_ERR(dev)) {
err = PTR_ERR(dev);
- else if (ops->newlink)
+ goto out;
+ }
+
+ dev->ifindex = ifm->ifi_index;
+
+ if (ops->newlink)
err = ops->newlink(net, dev, tb, data);
else
err = register_netdevice(dev);