Re: [PATCH v2] net-netlink: Add a new attribute to expose TOS values via netlink

[Stephen Hemminger <shemminger@vyatta.com>]

On Mon, 10 Oct 2011 13:32:25 -0700
Muraliraja Muniraju <muralira@google.com> wrote:

> From: Murali Raja <muralira@google.com>
> 
> This patch exposes the tos value for the TCP sockets when the TOS flag
> is requested in the ext_flags for the inet_diag request. This would mainly be
> used to expose TOS values for both for TCP and UDP sockets. Currently it is
> supported for TCP. When netlink support for UDP would be added the support
> to expose the TOS values would alse be done.
> 
> Signed-off-by: Murali Raja <muralira@google.com>
> ---
> Changelog since v1:
> - Removing the reserved field.
> 
>  include/linux/inet_diag.h |    9 ++++++++-
>  net/ipv4/inet_diag.c      |    7 +++++++
>  2 files changed, 15 insertions(+), 1 deletions(-)
> 
> diff --git a/include/linux/inet_diag.h b/include/linux/inet_diag.h
> index bc8c490..e36093d 100644
> --- a/include/linux/inet_diag.h
> +++ b/include/linux/inet_diag.h
> @@ -97,9 +97,10 @@ enum {
>  	INET_DIAG_INFO,
>  	INET_DIAG_VEGASINFO,
>  	INET_DIAG_CONG,
> +	INET_DIAG_TOS,
>  };
>  
> -#define INET_DIAG_MAX INET_DIAG_CONG
> +#define INET_DIAG_MAX INET_DIAG_TOS
>  
>  
>  /* INET_DIAG_MEM */
> @@ -120,6 +121,12 @@ struct tcpvegas_info {
>  	__u32	tcpv_minrtt;
>  };
>  
> +/* INET_DIAG_TOS */
> +
> +struct inet_diag_tos {
> +	__u8	idiag_tos;
> +};

I think the idea is a good one, and useful, but want to make the
ABI right.
With only one entry, this doesn't need to be wrapped in a structure.

Also does this work for IPv6 (Transport class) as well?