On Wed, 2006-01-11 at 00:00 -0800, David S. Miller wrote:
> From: Ulrich Drepper <[email protected]>
> Date: Tue, 10 Jan 2006 14:02:52 -0800
>
> > I just saw this in a patch:
> >
> > + if (ntohs(ih->frag_off) & IP_OFFSET)
> > + return EBT_NOMATCH;
> >
> > This isn't optimal, it requires a byte switch little endian machines.
> > The compiler isn't smart enough. It would be better to use
> >
> > if (ih->frag_off & ntohs(IP_OFFSET))
> >
> > where the byte-swap can be done at compile time. This is kind of ugly,
> > I guess, so maybe a dedicate macro
> >
> > net_host_bit_p(ih->frag_off, IP_OFFSET)
>
> The first suggestion isn't considered ugly, and the best form is:
>
> if (ih->frag_off & __constant_htons(IP_OFFSET))
why this __constant_htons and not just plain htons ??
htons() gets auto-remapped to that anyway via the builtin "is this a
constant" thing...... and to be honest htons() is more readable.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
