Re: [PATCH 1/1] netfilter: gre: Use the consitent GRE and PPTP struct instead of the structures defined in netfilter

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Fri, Aug 19, 2016 at 11:01:34PM +0800, fgao@ikuai8.com wrote:
> From: Gao Feng <fgao@ikuai8.com>
> 
> There are two structures which define the GRE header and PPTP
> header. So it is unneccessary to define duplicated structures in
> netfilter again.

Please, split this change in smaller patches, I'd suggest one to
replace GRE_* definitions and another to use generic GRE struct
definitions, so this makes it is easier to review.

> @@ -212,8 +212,8 @@ static bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
>  	if (!pgrehdr)
>  		return true;
>  
> -	if (ntohs(grehdr->protocol) != GRE_PROTOCOL_PPTP) {
> -		pr_debug("GRE_VERSION_PPTP but unknown proto\n");
> +	if (grehdr->protocol != GRE_PROTO_PPP) {
> +		pr_debug("Unknown GRE proto(0x%x)\n", ntohs(grehdr->protocol));

Something is fishy here, grehdr->protocol used to have ntohs(), the
pr_debug() still has it while the branch check does not.