Re: eliminate struct protosw::pr_output

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

On 2016/01/17 8:57, Taylor R Campbell wrote:
> The ip_output function must be called as
> 
> 	ip_output(m, opt, ro, flags, mopt, so)
> 
> where the arguments have the types
> 
> 	struct mbuf *m;
> 	struct mbuf *opt;
> 	struct route *ro;
> 	int flags;
> 	struct ip_moptions *mopt;
> 	struct socket *so;
> 
> However, the prototype for ip_output is variadic:
> 
> 	int ip_output(struct mbuf *, ...);
> 
> This is silly.  The only reason it is like this is that it is put in
> the pr_output member of a struct protosw somewhere -- and then never
> used via that path.  There's no way you could use it if you didn't
> know the protocol you were using, so this pr_output member can't be
> used anyway unless you know a priori that you're in netinet.  The same
> is true of every other pr_output routine.
> 
> The only pr_output members that are ever actually used are (net/route)
> rtsock's and (netipsec) keysock's, via raw_send.
> 
> The attached patch eliminates the pr_output member of struct protosw
> (and struct ip6protosw), and adds an explicit (fully typed) callback
> to raw_send for use by rtsock and keysock.
> 
> A subsequent patch may give ip_output &c. fully typed prototypes and
> avoid varargs altogether, but I'll defer that for now.  I would like
> to apply similar treatment to pr_input, but again in another (somewhat
> more involved) patch.
> 
> Thoughts?  Objections?

I agree. The patch looks good to me.
I think you could commit it.


Thanks,

-- 
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Internet Initiative Japan Inc.

Device Engineering Section,
Core Product Development Department,
Product Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>