Re: [PATCH 1/3] netlink: add netlink_dump_control structure for netlink_dump_start()

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Sat, Feb 25, 2012 at 02:12:22AM +0100, Jan Engelhardt wrote:
> On Saturday 2012-02-25 01:30, pablo@netfilter.org wrote:
> 
> >From: Pablo Neira Ayuso <pablo@netfilter.org>
> >
> >Davem considers that the argument list of this interface is getting
> >out of control. This patch tries to address this issue following
> >his proposal:
> >
> >struct netlink_dump_control c = { .dump = dump, .done = done, ... };
> >
> >netlink_dump_start(..., &c);
> 
> What about adding skb and nlh into c as well? After all, skb
> is not nearly as much {used directly} as it is in Xtables.

If you look at all netlink_dump_start invocations. Those are always
included. The idea was to add to the structure fields that may be
unset.

> >+		{
> >+			struct netlink_dump_control c = {
> >+				.dump = link->dump,
> >+				.done = link->done,
> >+			};
> >+			return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
> >+		}
> 
> You can also use
> 
> 		return netlink_dump_start(crypto_nlsk, skb,
> 		       &(const struct netlink_dump_control)
> 		       {.dump = link->dump, .done = link->done}));

Nice to know, thanks. Haven't see this in any other part of the kernel
code though and it looks a bit ugly IMO. I think I prefer the way it is
now.