Re: CTA_PROTO_NUM u_int8_t or u_int16_t

[Patrick McHardy <kaber@trash.net>]

Pablo Neira wrote:
> Krzysztof Oledzki wrote:
> 
>>AFAIK ip proto is u8 but I found that it is represented as u16 and used
>>both as u_int16_t and u_int8_t:
>>
>>include/linux/netfilter_ipv4/ipt_conntrack.h:           u16 protonum;
>>
>>net/ipv4/netfilter/ip_conntrack_netlink.c:      NFA_PUT(skb,
>>CTA_PROTO_NUM, sizeof(u_int8_t), &tuple->dst.protonum);
>>net/ipv4/netfilter/ip_conntrack_netlink.c:      [CTA_PROTO_NUM-1]      
>>= sizeof(u_int16_t),
>>net/ipv4/netfilter/ip_conntrack_netlink.c:      tuple->dst.protonum =
>>*(u_int16_t *)NFA_DATA(tb[CTA_PROTO_NUM-1]);
>>
>>Was this intentionally?
> 
> No :(, it has slipped through at some stage. I was aware of that, I
> found it some days ago. The problem is that if we fix that we could
> break backward compatibility for 2.6.14, so I'm still thinking about how
> to fix it.

If you have to break compatibility, please do it before 2.6.15 is
released. But the easiest solution looks like keeping it a u_int16_t
and adjusting the NFA_PUT.