[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, 26 insertions, 18 deletions

diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 4970d10..bbf2d66 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -73,33 +73,36 @@ void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
 EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
 
 /* Assign choice of congestion control. */
-void tcp_init_congestion_control(struct tcp_sock *tp)
+void tcp_init_congestion_control(struct sock *sk)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_congestion_ops *ca;
 
-	if (tp->ca_ops != &tcp_init_congestion_ops)
+	if (icsk->icsk_ca_ops != &tcp_init_congestion_ops)
 		return;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
 		if (try_module_get(ca->owner)) {
-			tp->ca_ops = ca;
+			icsk->icsk_ca_ops = ca;
 			break;
 		}
 
 	}
 	rcu_read_unlock();
 
-	if (tp->ca_ops->init)
-		tp->ca_ops->init(tp);
+	if (icsk->icsk_ca_ops->init)
+		icsk->icsk_ca_ops->init(sk);
 }
 
 /* Manage refcounts on socket close. */
-void tcp_cleanup_congestion_control(struct tcp_sock *tp)
+void tcp_cleanup_congestion_control(struct sock *sk)
 {
-	if (tp->ca_ops->release)
-		tp->ca_ops->release(tp);
-	module_put(tp->ca_ops->owner);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (icsk->icsk_ca_ops->release)
+		icsk->icsk_ca_ops->release(sk);
+	module_put(icsk->icsk_ca_ops->owner);
 }
 
 /* Used by sysctl to change default congestion control */
@@ -143,14 +146,15 @@ void tcp_get_default_congestion_control(char *name)
 }
 
 /* Change congestion control for socket */
-int tcp_set_congestion_control(struct tcp_sock *tp, const char *name)
+int tcp_set_congestion_control(struct sock *sk, const char *name)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_congestion_ops *ca;
 	int err = 0;
 
 	rcu_read_lock();
 	ca = tcp_ca_find(name);
-	if (ca == tp->ca_ops)
+	if (ca == icsk->icsk_ca_ops)
 		goto out;
 
 	if (!ca)
@@ -160,10 +164,10 @@ int tcp_set_congestion_control(struct tcp_sock *tp, const char *name)
 		err = -EBUSY;
 
 	else {
-		tcp_cleanup_congestion_control(tp);
-		tp->ca_ops = ca;
-		if (tp->ca_ops->init)
-			tp->ca_ops->init(tp);
+		tcp_cleanup_congestion_control(sk);
+		icsk->icsk_ca_ops = ca;
+		if (icsk->icsk_ca_ops->init)
+			icsk->icsk_ca_ops->init(sk);
 	}
  out:
 	rcu_read_unlock();
@@ -177,9 +181,11 @@ int tcp_set_congestion_control(struct tcp_sock *tp, const char *name)
 /* This is Jacobson's slow start and congestion avoidance.
  * SIGCOMM '88, p. 328.
  */
-void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt, u32 in_flight,
+void tcp_reno_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;
 
@@ -202,15 +208,17 @@ void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt, u32 in_flight,
 EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
 
 /* Slow start threshold is half the congestion window (min 2) */
-u32 tcp_reno_ssthresh(struct tcp_sock *tp)
+u32 tcp_reno_ssthresh(struct sock *sk)
 {
+	const struct tcp_sock *tp = tcp_sk(sk);
 	return max(tp->snd_cwnd >> 1U, 2U);
 }
 EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
 
 /* Lower bound on congestion window. */
-u32 tcp_reno_min_cwnd(struct tcp_sock *tp)
+u32 tcp_reno_min_cwnd(struct sock *sk)
 {
+	const struct tcp_sock *tp = tcp_sk(sk);
 	return tp->snd_ssthresh/2;
 }
 EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd);