[ICSK]: Move TCP congestion avoidance members to icsk

This changeset basically moves tcp_sk()->{ca_ops,ca_state,etc} to inet_csk(),
minimal renaming/moving done in this changeset to ease review.

Most of it is just changes of struct tcp_sock * to struct sock * parameters.

With this we move to a state closer to two interesting goals:

1. Generalisation of net/ipv4/tcp_diag.c, becoming inet_diag.c, being used
   for any INET transport protocol that has struct inet_hashinfo and are
   derived from struct inet_connection_sock. Keeps the userspace API, that will
   just not display DCCP sockets, while newer versions of tools can support
   DCCP.

2. INET generic transport pluggable Congestion Avoidance infrastructure, using
   the current TCP CA infrastructure with DCCP.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index 70e108e15c71..327770bf5522 100644
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -16,9 +16,10 @@
 #define TCP_SCALABLE_AI_CNT     50U
 #define TCP_SCALABLE_MD_SCALE   3
 
-static void tcp_scalable_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
+static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
                                     u32 in_flight, int flag)
 {
+        struct tcp_sock *tp = tcp_sk(sk);
         if (in_flight < tp->snd_cwnd)
                 return;
 
@@ -35,8 +36,9 @@ static void tcp_scalable_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
         tp->snd_cwnd_stamp = tcp_time_stamp;
 }
 
-static u32 tcp_scalable_ssthresh(struct tcp_sock *tp)
+static u32 tcp_scalable_ssthresh(struct sock *sk)
 {
+        const struct tcp_sock *tp = tcp_sk(sk);
         return max(tp->snd_cwnd - (tp->snd_cwnd>>TCP_SCALABLE_MD_SCALE), 2U);
 }