Subject: Re: [Patch net-next v2] gre: fix a regression in ioctl

From: Sergei Shtylyov <[email-masked]>
Date: Sat, 29 Jun 2013 19:52:44 +0400

Hello.

On 29-06-2013 6:24, Cong Wang wrote:

> From: Cong Wang <[email-masked]>

> When testing GRE tunnel, I got:

>   # ip tunnel show
>   get tunnel gre0 failed: Invalid argument
>   get tunnel gre1 failed: Invalid argument

> This is a regression introduced by commit c54419321455631079c7d
> ("GRE: Refactor GRE tunneling code.") because previously we
> only check the parameters for SIOCADDTUNNEL and SIOCCHGTUNNEL,
> after that commit, the check is moved for all commands.

> So, just move it back inside SIOCADDTUNNEL and SIOCCHGTUNNEL.

> After this patch I got:

>   # ip tunnel show
>   gre0: gre/ip  remote any  local any  ttl inherit  nopmtudisc
>   gre1: gre/ip  remote 192.168.122.101  local 192.168.122.45  ttl inherit

> Cc: Pravin B Shelar <[email-masked]>
> Cc: "David S. Miller" <[email-masked]>
> Signed-off-by: Cong Wang <[email-masked]>
> ---
> v2: check TUNNEL_* flags

[...]
> diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
> index 394cebc..dc7d7ac 100644
> --- a/net/ipv4/ip_tunnel.c
> +++ b/net/ipv4/ip_tunnel.c
> @@ -712,6 +712,11 @@ int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
>
>   	case SIOCADDTUNNEL:
>   	case SIOCCHGTUNNEL:
> +		if (p->iph.version != 4 || p->iph.protocol != IPPROTO_GRE ||
> +		    p->iph.ihl != 5 || (p->iph.frag_off&htons(~IP_DF)) ||
> +		    ((p->i_flags|p->o_flags)&(TUNNEL_VERSION|TUNNEL_ROUTING)))

    Maybe it's time to insert spaces around & to make the code formatted 
consistently?

WBR, Sergei