Re: [PATCH 1/1] tcp: Replace constants with #define macros

Thanks a lot for reviewing the patch. Please see responses below.

On 20 December 2011 02:27, David Laight [off-list ref] wrote:

quoted

+/*These are used to set the sack_ok field in struct
tcp_options_received */
+#define SACK_SEEN     (1 << 0)   /*1 = peer is SACK capable, */
+#define FACK_ENABLED  (1 << 1)   /*1 = FACK is enabled locally*/
+#define DSACK_SEEN    (1 << 2)   /*1 = DSACK was received from peer*/
+

Since that is a fairly public header, some namespace protection
might be sensible.

I assume you are talking about collision with userspace.  These
definitions are already protected by #ifdef  __KERNEL__.
That should be enough to protect against collisions with userspace I think.

quoted

-     tcp_opt->sack_ok = (options >> 4) & 0x1;
+     tcp_opt->sack_ok = (options >> 4) & SACK_SEEN;

Looks to me like that 0x1 isn't SAC_SEEK! So this is now misleading.

Can you please elaborate? Are you saying this is wrong or that it
could be done better?

Thanks for your time!
Vijay