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>

2 files changed, 4 insertions, 6 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 4f9f5eb478f1..ebc54fef85a5 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -500,8 +500,7 @@ static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
         return &rt->dst;
 }
 
-static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
-                                 struct request_values *rv_unused)
+static int dccp_v4_send_response(struct sock *sk, struct request_sock *req)
 {
         int err = -1;
         struct sk_buff *skb;
@@ -658,7 +657,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         dreq->dreq_gss     = dreq->dreq_iss;
         dreq->dreq_service = service;
 
-        if (dccp_v4_send_response(sk, req, NULL))
+        if (dccp_v4_send_response(sk, req))
                 goto drop_and_free;
 
         inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 6e05981f271e..9c61f9c02fdb 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -213,8 +213,7 @@ out:
 }
 
 
-static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
-                                 struct request_values *rv_unused)
+static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
 {
         struct inet6_request_sock *ireq6 = inet6_rsk(req);
         struct ipv6_pinfo *np = inet6_sk(sk);
@@ -428,7 +427,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
         dreq->dreq_gss     = dreq->dreq_iss;
         dreq->dreq_service = service;
 
-        if (dccp_v6_send_response(sk, req, NULL))
+        if (dccp_v6_send_response(sk, req))
                 goto drop_and_free;
 
         inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);