[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, 22 deletions

diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
index 40168275acf9..e47b37984e95 100644
--- a/net/ipv4/tcp_htcp.c
+++ b/net/ipv4/tcp_htcp.c
@@ -55,18 +55,21 @@ static inline void htcp_reset(struct htcp *ca)
 	ca->snd_cwnd_cnt2 = 0;
 }
 
-static u32 htcp_cwnd_undo(struct tcp_sock *tp)
+static u32 htcp_cwnd_undo(struct sock *sk)
 {
-	struct htcp *ca = tcp_ca(tp);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
 	ca->ccount = ca->undo_ccount;
 	ca->maxRTT = ca->undo_maxRTT;
 	ca->old_maxB = ca->undo_old_maxB;
 	return max(tp->snd_cwnd, (tp->snd_ssthresh<<7)/ca->beta);
 }
 
-static inline void measure_rtt(struct tcp_sock *tp)
+static inline void measure_rtt(struct sock *sk)
 {
-	struct htcp *ca = tcp_ca(tp);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
 	u32 srtt = tp->srtt>>3;
 
 	/* keep track of minimum RTT seen so far, minRTT is zero at first */
@@ -74,7 +77,7 @@ static inline void measure_rtt(struct tcp_sock *tp)
 		ca->minRTT = srtt;
 
 	/* max RTT */
-	if (tp->ca_state == TCP_CA_Open && tp->snd_ssthresh < 0xFFFF && ca->ccount > 3) {
+	if (icsk->icsk_ca_state == TCP_CA_Open && tp->snd_ssthresh < 0xFFFF && ca->ccount > 3) {
 		if (ca->maxRTT < ca->minRTT)
 			ca->maxRTT = ca->minRTT;
 		if (ca->maxRTT < srtt && srtt <= ca->maxRTT+HZ/50)
@@ -82,13 +85,16 @@ static inline void measure_rtt(struct tcp_sock *tp)
 	}
 }
 
-static void measure_achieved_throughput(struct tcp_sock *tp, u32 pkts_acked)
+static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked)
 {
-	struct htcp *ca = tcp_ca(tp);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
 	u32 now = tcp_time_stamp;
 
 	/* achieved throughput calculations */
-	if (tp->ca_state != TCP_CA_Open && tp->ca_state != TCP_CA_Disorder) {
+	if (icsk->icsk_ca_state != TCP_CA_Open &&
+	    icsk->icsk_ca_state != TCP_CA_Disorder) {
 		ca->packetcount = 0;
 		ca->lasttime = now;
 		return;
@@ -173,9 +179,9 @@ static inline void htcp_alpha_update(struct htcp *ca)
  * that point do we really have a real sense of maxRTT (the queues en route
  * were getting just too full now).
  */
-static void htcp_param_update(struct tcp_sock *tp)
+static void htcp_param_update(struct sock *sk)
 {
-	struct htcp *ca = tcp_ca(tp);
+	struct htcp *ca = inet_csk_ca(sk);
 	u32 minRTT = ca->minRTT;
 	u32 maxRTT = ca->maxRTT;
 
@@ -187,17 +193,19 @@ static void htcp_param_update(struct tcp_sock *tp)
 		ca->maxRTT = minRTT + ((maxRTT-minRTT)*95)/100;
 }
 
-static u32 htcp_recalc_ssthresh(struct tcp_sock *tp)
+static u32 htcp_recalc_ssthresh(struct sock *sk)
 {
-	struct htcp *ca = tcp_ca(tp);
-	htcp_param_update(tp);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct htcp *ca = inet_csk_ca(sk);
+	htcp_param_update(sk);
 	return max((tp->snd_cwnd * ca->beta) >> 7, 2U);
 }
 
-static void htcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
+static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 rtt,
 			    u32 in_flight, int data_acked)
 {
-	struct htcp *ca = tcp_ca(tp);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
 
 	if (in_flight < tp->snd_cwnd)
 		return;
@@ -207,7 +215,7 @@ static void htcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
 		if (tp->snd_cwnd < tp->snd_cwnd_clamp)
 			tp->snd_cwnd++;
 	} else {
-		measure_rtt(tp);
+		measure_rtt(sk);
 
 		/* keep track of number of round-trip times since last backoff event */
 		if (ca->snd_cwnd_cnt2++ > tp->snd_cwnd) {
@@ -229,28 +237,29 @@ static void htcp_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
 }
 
 /* Lower bound on congestion window. */
-static u32 htcp_min_cwnd(struct tcp_sock *tp)
+static u32 htcp_min_cwnd(struct sock *sk)
 {
+	const struct tcp_sock *tp = tcp_sk(sk);
 	return tp->snd_ssthresh;
 }
 
 
-static void htcp_init(struct tcp_sock *tp)
+static void htcp_init(struct sock *sk)
 {
-	struct htcp *ca = tcp_ca(tp);
+	struct htcp *ca = inet_csk_ca(sk);
 
 	memset(ca, 0, sizeof(struct htcp));
 	ca->alpha = ALPHA_BASE;
 	ca->beta = BETA_MIN;
 }
 
-static void htcp_state(struct tcp_sock *tp, u8 new_state)
+static void htcp_state(struct sock *sk, u8 new_state)
 {
 	switch (new_state) {
 	case TCP_CA_CWR:
 	case TCP_CA_Recovery:
 	case TCP_CA_Loss:
-		htcp_reset(tcp_ca(tp));
+		htcp_reset(inet_csk_ca(sk));
 		break;
 	}
 }
@@ -269,7 +278,7 @@ static struct tcp_congestion_ops htcp = {
 
 static int __init htcp_register(void)
 {
-	BUG_ON(sizeof(struct htcp) > TCP_CA_PRIV_SIZE);
+	BUG_ON(sizeof(struct htcp) > ICSK_CA_PRIV_SIZE);
 	BUILD_BUG_ON(BETA_MIN >= BETA_MAX);
 	if (!use_bandwidth_switch)
 		htcp.pkts_acked = NULL;