tcp: Remove TCPCT

TCPCT uses option-number 253, reserved for experimental use and should
not be used in production environments.
Further, TCPCT does not fully implement RFC 6013.

As a nice side-effect, removing TCPCT increases TCP's performance for
very short flows:

Doing an apache-benchmark with -c 100 -n 100000, sending HTTP-requests
for files of 1KB size.

before this patch:
	average (among 7 runs) of 20845.5 Requests/Second
after:
	average (among 7 runs) of 21403.6 Requests/Second

Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 26 deletions

diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 6b1ead0b0c9d..8d776ebc4829 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -102,7 +102,6 @@ enum {
 #define TCP_QUICKACK            12      /* Block/reenable quick acks */
 #define TCP_CONGESTION          13      /* Congestion control algorithm */
 #define TCP_MD5SIG              14      /* TCP MD5 Signature (RFC2385) */
-#define TCP_COOKIE_TRANSACTIONS 15      /* TCP Cookie Transactions */
 #define TCP_THIN_LINEAR_TIMEOUTS 16      /* Use linear timeouts for thin streams*/
 #define TCP_THIN_DUPACK         17      /* Fast retrans. after 1 dupack */
 #define TCP_USER_TIMEOUT        18      /* How long for loss retry before timeout */
@@ -199,29 +198,4 @@ struct tcp_md5sig {
         __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
 };
 
-/* for TCP_COOKIE_TRANSACTIONS (TCPCT) socket option */
-#define TCP_COOKIE_MIN           8              /*  64-bits */
-#define TCP_COOKIE_MAX          16              /* 128-bits */
-#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,
-                                                 * supercedes everything. */
-
-/* Flags for getsockopt */
-#define TCP_S_DATA_IN           (1 << 2)        /* Was data received? */
-#define TCP_S_DATA_OUT          (1 << 3)        /* Was data sent? */
-
-/* TCP_COOKIE_TRANSACTIONS data */
-struct tcp_cookie_transactions {
-        __u16   tcpct_flags;                    /* see above */
-        __u8    __tcpct_pad1;                   /* zero */
-        __u8    tcpct_cookie_desired;           /* bytes */
-        __u16   tcpct_s_data_desired;           /* bytes of variable data */
-        __u16   tcpct_used;                     /* bytes in value */
-        __u8    tcpct_value[TCP_MSS_DEFAULT];
-};
-
-
 #endif /* _UAPI_LINUX_TCP_H */