[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, 20 deletions

diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index ec38d45d6649..b940346de4e7 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -86,11 +86,11 @@ static inline void bictcp_reset(struct bictcp *ca)
         ca->delayed_ack = 2 << ACK_RATIO_SHIFT;
 }
 
-static void bictcp_init(struct tcp_sock *tp)
+static void bictcp_init(struct sock *sk)
 {
-        bictcp_reset(tcp_ca(tp));
+        bictcp_reset(inet_csk_ca(sk));
         if (initial_ssthresh)
-                tp->snd_ssthresh = initial_ssthresh;
+                tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
 }
 
 /*
@@ -156,9 +156,10 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
 
 
 /* Detect low utilization in congestion avoidance */
-static inline void bictcp_low_utilization(struct tcp_sock *tp, int flag)
+static inline void bictcp_low_utilization(struct sock *sk, int flag)
 {
-        struct bictcp *ca = tcp_ca(tp);
+        const struct tcp_sock *tp = tcp_sk(sk);
+        struct bictcp *ca = inet_csk_ca(sk);
         u32 dist, delay;
 
         /* No time stamp */
@@ -208,12 +209,13 @@ static inline void bictcp_low_utilization(struct tcp_sock *tp, int flag)
 
 }
 
-static void bictcp_cong_avoid(struct tcp_sock *tp, u32 ack,
+static void bictcp_cong_avoid(struct sock *sk, u32 ack,
                               u32 seq_rtt, u32 in_flight, int data_acked)
 {
-        struct bictcp *ca = tcp_ca(tp);
+        struct tcp_sock *tp = tcp_sk(sk);
+        struct bictcp *ca = inet_csk_ca(sk);
 
-        bictcp_low_utilization(tp, data_acked);
+        bictcp_low_utilization(sk, data_acked);
 
         if (in_flight < tp->snd_cwnd)
                 return;
@@ -242,9 +244,10 @@ static void bictcp_cong_avoid(struct tcp_sock *tp, u32 ack,
  *      behave like Reno until low_window is reached,
  *      then increase congestion window slowly
  */
-static u32 bictcp_recalc_ssthresh(struct tcp_sock *tp)
+static u32 bictcp_recalc_ssthresh(struct sock *sk)
 {
-        struct bictcp *ca = tcp_ca(tp);
+        const struct tcp_sock *tp = tcp_sk(sk);
+        struct bictcp *ca = inet_csk_ca(sk);
 
         ca->epoch_start = 0;    /* end of epoch */
 
@@ -269,31 +272,34 @@ static u32 bictcp_recalc_ssthresh(struct tcp_sock *tp)
                 return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U);
 }
 
-static u32 bictcp_undo_cwnd(struct tcp_sock *tp)
+static u32 bictcp_undo_cwnd(struct sock *sk)
 {
-        struct bictcp *ca = tcp_ca(tp);
-
+        const struct tcp_sock *tp = tcp_sk(sk);
+        const struct bictcp *ca = inet_csk_ca(sk);
         return max(tp->snd_cwnd, ca->last_max_cwnd);
 }
 
-static u32 bictcp_min_cwnd(struct tcp_sock *tp)
+static u32 bictcp_min_cwnd(struct sock *sk)
 {
+        const struct tcp_sock *tp = tcp_sk(sk);
         return tp->snd_ssthresh;
 }
 
-static void bictcp_state(struct tcp_sock *tp, u8 new_state)
+static void bictcp_state(struct sock *sk, u8 new_state)
 {
         if (new_state == TCP_CA_Loss)
-                bictcp_reset(tcp_ca(tp));
+                bictcp_reset(inet_csk_ca(sk));
 }
 
 /* Track delayed acknowledgement ratio using sliding window
  * ratio = (15*ratio + sample) / 16
  */
-static void bictcp_acked(struct tcp_sock *tp, u32 cnt)
+static void bictcp_acked(struct sock *sk, u32 cnt)
 {
-        if (cnt > 0 &&  tp->ca_state == TCP_CA_Open) {
-                struct bictcp *ca = tcp_ca(tp);
+        const struct inet_connection_sock *icsk = inet_csk(sk);
+
+        if (cnt > 0 &&  icsk->icsk_ca_state == TCP_CA_Open) {
+                struct bictcp *ca = inet_csk_ca(sk);
                 cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
                 ca->delayed_ack += cnt;
         }
@@ -314,7 +320,7 @@ static struct tcp_congestion_ops bictcp = {
 
 static int __init bictcp_register(void)
 {
-        BUG_ON(sizeof(struct bictcp) > TCP_CA_PRIV_SIZE);
+        BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE);
         return tcp_register_congestion_control(&bictcp);
 }