[14/53] ip6_tunnel: copy parms.name after register_netdevice

Greg KH
2011-11-23T00:52:49Z

From: Josh Boyer <jwboyer@redhat.com>

commit 731abb9cb27aef6013ce60808a04e04a545f3f4e upstream.

Commit 1c5cae815d removed an explicit call to dev_alloc_name in ip6_tnl_create
because register_netdevice will now create a valid name. This works for the
net_device itself.

However the tunnel keeps a copy of the name in the parms structure for the
ip6_tnl associated with the tunnel. parms.name is set by copying the net_device
name in ip6_tnl_dev_init_gen. That function is called from ip6_tnl_dev_init in
ip6_tnl_create, but it is done before register_netdevice is called so the name
is set to a bogus value in the parms.name structure.

This shows up if you do a simple tunnel add, followed by a tunnel show:

[root@localhost ~]# ip -6 tunnel add remote fec0::100 local fec0::200
[root@localhost ~]# ip -6 tunnel show
ip6tnl0: ipv6/ipv6 remote :: local :: encaplimit 0 hoplimit 0 tclass 0x00 flowlabel 0x00000 (flowinfo 0x00000000)
ip6tnl%d: ipv6/ipv6 remote fec0::100 local fec0::200 encaplimit 4 hoplimit 64 tclass 0x00 flowlabel 0x00000 (flowinfo 0x00000000)
[root@localhost ~]#

Fix this by moving the strcpy out of ip6_tnl_dev_init_gen, and calling it after
register_netdevice has successfully returned.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/ipv6/ip6_tunnel.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -289,6 +289,8 @@ static struct ip6_tnl *ip6_tnl_create(st
if ((err = register_netdevice(dev)) < 0)
goto failed_free;

+ strcpy(t->parms.name, dev->name);
+
dev_hold(dev);
ip6_tnl_link(ip6n, t);
return t;
@@ -1397,7 +1399,6 @@ ip6_tnl_dev_init_gen(struct net_device *
struct ip6_tnl *t = netdev_priv(dev);

t->dev = dev;
- strcpy(t->parms.name, dev->name);
dev->tstats = alloc_percpu(struct pcpu_tstats);
if (!dev->tstats)
return -ENOMEM;
@@ -1477,6 +1478,7 @@ static void __net_exit ip6_tnl_destroy_t
static int __net_init ip6_tnl_init_net(struct net *net)
{
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
+ struct ip6_tnl *t = NULL;
int err;

ip6n->tnls[0] = ip6n->tnls_wc;
@@ -1497,6 +1499,10 @@ static int __net_init ip6_tnl_init_net(s
err = register_netdev(ip6n->fb_tnl_dev);
if (err < 0)
goto err_register;
+
+ t = netdev_priv(ip6n->fb_tnl_dev);
+
+ strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
return 0;