Re: [PATCH] headers_check fix: linux/netfilter/xt_osf.h

[Evgeniy Polyakov <zbr@ioremap.net>]

On Sun, Jun 28, 2009 at 12:00:07AM +0200, Sam Ravnborg (sam@ravnborg.org) wrote:
> What about the other potential issues in the same file?
> struct xt_osf_opt {
>         __u16                   kind, length;
>         struct xt_osf_wc        wc;
> };
> 
> Do we know that struct xt_osf_wc is always aligned at a two byte
> address also on 64 bit?

Why 2 bytes? It is 4 bytes aligned everywhere everytime.

> Do we know that sizeof(struct xt_osf_opt) is the same
> on all platforms?

Yes.

> struct xt_osf_user_finger {
>         struct xt_osf_wc        wss;
> 
>         __u8                    ttl, df;
>         __u16                   ss, mss;
>         __u16                   opt_num;
> 
>         char                    genre[MAXGENRELEN];
>         char                    version[MAXGENRELEN];
>         char                    subtype[MAXGENRELEN];
> 
>         /* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */
>         struct xt_osf_opt       opt[MAX_IPOPTLEN];
> };
> 
> Do we know that opt[MAX_IPOPTLEN] always start at the same offset
> with different architectures?

Yes.

> struct xt_osf_nlmsg {
>         struct xt_osf_user_finger       f;
>         struct iphdr            ip;
>         struct tcphdr           tcp;
> };
> 
> We do not knwo struct iphdr/tcphdr - missing include.
> Do we know the alignment of the above structs?
> Are they always the same on all archs?

You won't believe...

-- 
	Evgeniy Polyakov