Subject: Re: [PATCH 12/14] netlink: add documentation for memory mapped I/O

From: Daniel Borkmann <[email-masked]>
Date: Wed, 17 Apr 2013 19:51:09 +0200

On 04/17/2013 06:47 PM, Patrick McHardy wrote:
> Signed-off-by: Patrick McHardy <[email-masked]>
> ---
[...]
> +Ring frames
> +------------
> +
> +Each frames contain a frame header, consisting of a synchronization word and some
> +meta-data, and the message itself.
> +
> +Frame:	[ header message ]
> +
> +The frame header is defined as follows:
> +
> +struct nl_mmap_hdr {
> +	unsigned int	nm_status;
> +	unsigned int	nm_len;
> +	__u32		nm_group;
> +	/* credentials */
> +	__u32		nm_pid;
> +	__u32		nm_uid;
> +	__u32		nm_gid;
> +};

Hm, just wondering, maybe it could be a safer path to make 'nm_status'
and 'nm_len' also of fixed width as the rest of nl_mmap_hdr, and as in
PF_PACKET's tpacket2_hdr and tpacket3_hdr ?