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

From: Evgeniy Polyakov
Date: Sun Jun 28 2009 - 05:57:06 EST


On Sun, Jun 28, 2009 at 12:00:07AM +0200, Sam Ravnborg (sam@xxxxxxxxxxxx) 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
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