Re: [PATCH v3 net 1/5] ipv6: Refactor common ip6gre_tunnel_init codes

Martin KaFai Lau
2015-09-11T23:20:38Z

On Fri, Sep 11, 2015 at 03:30:59PM -0700, David Miller wrote:
> From: Martin KaFai Lau <kafai@fb.com>
> Date: Fri, 11 Sep 2015 11:06:17 -0700
>
> > @@ -1460,19 +1474,16 @@ static void ip6gre_netlink_parms(struct nlattr *data[],
> > static int ip6gre_tap_init(struct net_device *dev)
> > {
> > struct ip6_tnl *tunnel;
> > + int ret;
> >
> > - tunnel = netdev_priv(dev);
> > + ret = ip6gre_tunnel_init_common(dev);
> > + if (ret)
> > + return ret;
> >
> > - tunnel->dev = dev;
> > - tunnel->net = dev_net(dev);
> > - strcpy(tunnel->parms.name, dev->name);
> > + tunnel = netdev_priv(dev);
> >
> > ip6gre_tnl_link_config(tunnel, 1);
> >
> > - dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
> > - if (!dev->tstats)
> > - return -ENOMEM;
> > -
> > return 0;
> > }
>
> Is this really equivalent?
>
> The existing code for GRE tap device initialization would use whatever
> ether_setup() left in the broadcast address, it would leave
> dev->dev_addr alone, and unconditionally use eth_header_ops.
The new ip6gre_tunnel_init_common() does not set the dev->dev_addr
or dev->header_ops. The change in ip6gre_tap_init() is to initialize
dev->tstats before ip6gre_tnl_link_config().

or I am missing something and have overlooked a bug?

Thanks,
Martin