Subject: Re: [PATCH v1 2/2] TCPCT API sockopt update to draft -03

From: Stephen Hemminger <[email-masked]>
Date: Wed, 12 Jan 2011 10:56:08 -0800

On Wed, 12 Jan 2011 12:59:38 -0500
William Allen Simpson <[email-masked]> wrote:

> diff --git a/include/linux/tcp.h b/include/linux/tcp.h
> index e64f4c6..c8f4017 100644
> --- a/include/linux/tcp.h
> +++ b/include/linux/tcp.h
> @@ -185,22 +185,37 @@ struct tcp_md5sig {
>  #define TCP_COOKIE_PAIR_SIZE	(2*TCP_COOKIE_MAX)
>  
>  /* Flags for both getsockopt and setsockopt */
> -#define TCP_COOKIE_IN_ALWAYS	(1 << 0)	/* Discard SYN without cookie */
> -#define TCP_COOKIE_OUT_NEVER	(1 << 1)	/* Prohibit outgoing cookies,
> +#define TCPCT_IN_ALWAYS		(1 << 0)	/* Discard SYN without cookie */
> +#define TCPCT_OUT_NEVER		(1 << 1)	/* Prohibit outgoing cookies,

You end up changing values in kernel userspace API in a way
that is incompatible with older applications. This is not acceptable.