netdev - Re: [iproute PATCH RFC] libnetlink: introduce DECLARE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20151126140001.GA14223@orbit.nwl.cc>
Date:	Thu, 26 Nov 2015 15:00:01 +0100
From:	Phil Sutter <phil@....cc>
To:	Hannes Frederic Sowa <hannes@...essinduktion.org>
Cc:	Stephen Hemminger <shemming@...cade.com>, netdev@...r.kernel.org
Subject: Re: [iproute PATCH RFC] libnetlink: introduce DECLARE_NLREQ

On Thu, Nov 26, 2015 at 02:56:30PM +0100, Hannes Frederic Sowa wrote:
> > +#define DECLARE_NLREQ(name, hdrname, payload, tailroom)                       \
> > +	struct {                                                              \
> > +		struct nlmsghdr hdrname;                                      \
> > +		payload;                                                      \
> > +		char __b[tailroom] __attribute__((aligned(NLMSG_ALIGNTO)));   \
> > +	} name = { .hdrname = {                                               \
> > +		.nlmsg_len = (unsigned long)&name.__b - (unsigned long)&name, \
> 
> offsetof(typeof(name), __b) ?

Ah, thanks! I already considered offsetof(), but the fact it needs a
type name and the declared struct is anonymous appeared unsolvable to
me. Good to know typeof() can be used this way!

Thanks, Phil
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html