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

From: Vijay Subramanian <redacted>
Date: Tue, 20 Dec 2011 12:02:52 -0800

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.

Within the kernel he means, please put a TCP_* prefix onto these
values.

quoted

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?

I think he's saying it could be done better.  Probably something
like:

	tcp_opt->sack_ok = (options & (1 << 4)) ? SACK_SEEN : 0;