[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, 31 insertions, 27 deletions

diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
index ef82724..d8a5a2b 100644
--- a/net/ipv4/tcp_westwood.c
+++ b/net/ipv4/tcp_westwood.c
@@ -40,9 +40,9 @@ struct westwood {
  * way as soon as possible. It will reasonably happen within the first
  * RTT period of the connection lifetime.
  */
-static void tcp_westwood_init(struct tcp_sock *tp)
+static void tcp_westwood_init(struct sock *sk)
 {
-	struct westwood *w = tcp_ca(tp);
+	struct westwood *w = inet_csk_ca(sk);
 
 	w->bk = 0;
         w->bw_ns_est = 0;
@@ -51,7 +51,7 @@ static void tcp_westwood_init(struct tcp_sock *tp)
         w->cumul_ack = 0;
 	w->rtt_min = w->rtt = TCP_WESTWOOD_INIT_RTT;
 	w->rtt_win_sx = tcp_time_stamp;
-	w->snd_una = tp->snd_una;
+	w->snd_una = tcp_sk(sk)->snd_una;
 }
 
 /*
@@ -74,11 +74,11 @@ static inline void westwood_filter(struct westwood *w, u32 delta)
  * Called after processing group of packets.
  * but all westwood needs is the last sample of srtt.
  */
-static void tcp_westwood_pkts_acked(struct tcp_sock *tp, u32 cnt)
+static void tcp_westwood_pkts_acked(struct sock *sk, u32 cnt)
 {
-	struct westwood *w = tcp_ca(tp);
+	struct westwood *w = inet_csk_ca(sk);
 	if (cnt > 0)
-		w->rtt = tp->srtt >> 3;
+		w->rtt = tcp_sk(sk)->srtt >> 3;
 }
 
 /*
@@ -86,9 +86,9 @@ static void tcp_westwood_pkts_acked(struct tcp_sock *tp, u32 cnt)
  * It updates RTT evaluation window if it is the right moment to do
  * it. If so it calls filter for evaluating bandwidth.
  */
-static void westwood_update_window(struct tcp_sock *tp)
+static void westwood_update_window(struct sock *sk)
 {
-	struct westwood *w = tcp_ca(tp);
+	struct westwood *w = inet_csk_ca(sk);
 	s32 delta = tcp_time_stamp - w->rtt_win_sx;
 
 	/*
@@ -114,11 +114,12 @@ static void westwood_update_window(struct tcp_sock *tp)
  * header prediction is successful. In such case in fact update is
  * straight forward and doesn't need any particular care.
  */
-static inline void westwood_fast_bw(struct tcp_sock *tp)
+static inline void westwood_fast_bw(struct sock *sk)
 {
-	struct westwood *w = tcp_ca(tp);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct westwood *w = inet_csk_ca(sk);
 
-	westwood_update_window(tp);
+	westwood_update_window(sk);
 
 	w->bk += tp->snd_una - w->snd_una;
 	w->snd_una = tp->snd_una;
@@ -130,9 +131,10 @@ static inline void westwood_fast_bw(struct tcp_sock *tp)
  * This function evaluates cumul_ack for evaluating bk in case of
  * delayed or partial acks.
  */
-static inline u32 westwood_acked_count(struct tcp_sock *tp)
+static inline u32 westwood_acked_count(struct sock *sk)
 {
-	struct westwood *w = tcp_ca(tp);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct westwood *w = inet_csk_ca(sk);
 
 	w->cumul_ack = tp->snd_una - w->snd_una;
 
@@ -160,9 +162,10 @@ static inline u32 westwood_acked_count(struct tcp_sock *tp)
 	return w->cumul_ack;
 }
 
-static inline u32 westwood_bw_rttmin(const struct tcp_sock *tp)
+static inline u32 westwood_bw_rttmin(const struct sock *sk)
 {
-	struct westwood *w = tcp_ca(tp);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct westwood *w = inet_csk_ca(sk);
 	return max_t(u32, (w->bw_est * w->rtt_min) / tp->mss_cache, 2);
 }
 
@@ -172,31 +175,32 @@ static inline u32 westwood_bw_rttmin(const struct tcp_sock *tp)
  * in packets we use mss_cache). Rttmin is guaranteed to be >= 2
  * so avoids ever returning 0.
  */
-static u32 tcp_westwood_cwnd_min(struct tcp_sock *tp)
+static u32 tcp_westwood_cwnd_min(struct sock *sk)
 {
-	return westwood_bw_rttmin(tp);
+	return westwood_bw_rttmin(sk);
 }
 
-static void tcp_westwood_event(struct tcp_sock *tp, enum tcp_ca_event event)
+static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event)
 {
-	struct westwood *w = tcp_ca(tp);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct westwood *w = inet_csk_ca(sk);
 
 	switch(event) {
 	case CA_EVENT_FAST_ACK:
-		westwood_fast_bw(tp);
+		westwood_fast_bw(sk);
 		break;
 
 	case CA_EVENT_COMPLETE_CWR:
-		tp->snd_cwnd = tp->snd_ssthresh = westwood_bw_rttmin(tp);
+		tp->snd_cwnd = tp->snd_ssthresh = westwood_bw_rttmin(sk);
 		break;
 
 	case CA_EVENT_FRTO:
-		tp->snd_ssthresh = westwood_bw_rttmin(tp);
+		tp->snd_ssthresh = westwood_bw_rttmin(sk);
 		break;
 
 	case CA_EVENT_SLOW_ACK:
-		westwood_update_window(tp);
-		w->bk += westwood_acked_count(tp);
+		westwood_update_window(sk);
+		w->bk += westwood_acked_count(sk);
 		w->rtt_min = min(w->rtt, w->rtt_min);
 		break;
 
@@ -208,10 +212,10 @@ static void tcp_westwood_event(struct tcp_sock *tp, enum tcp_ca_event event)
 
 
 /* Extract info for Tcp socket info provided via netlink. */
-static void tcp_westwood_info(struct tcp_sock *tp, u32 ext,
+static void tcp_westwood_info(struct sock *sk, u32 ext,
 			      struct sk_buff *skb)
 {
-	const struct westwood *ca = tcp_ca(tp);
+	const struct westwood *ca = inet_csk_ca(sk);
 	if (ext & (1<<(TCPDIAG_VEGASINFO-1))) {
 		struct rtattr *rta;
 		struct tcpvegas_info *info;
@@ -242,7 +246,7 @@ static struct tcp_congestion_ops tcp_westwood = {
 
 static int __init tcp_westwood_register(void)
 {
-	BUG_ON(sizeof(struct westwood) > TCP_CA_PRIV_SIZE);
+	BUG_ON(sizeof(struct westwood) > ICSK_CA_PRIV_SIZE);
 	return tcp_register_congestion_control(&tcp_westwood);
 }