[NET]: Introduce inet_connection_sock

This creates struct inet_connection_sock, moving members out of struct
tcp_sock that are shareable with other INET connection oriented
protocols, such as DCCP, that in my private tree already uses most of
these members.

The functions that operate on these members were renamed, using a
inet_csk_ prefix while not being moved yet to a new file, so as to
ease the review of these changes.

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

1 files changed, 46 insertions, 40 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index a4d1eb9..6f0a7e3 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -105,8 +105,9 @@ static __u16 tcp_advertise_mss(struct sock *sk)
 
 /* RFC2861. Reset CWND after idle period longer RTO to "restart window".
  * This is the first part of cwnd validation mechanism. */
-static void tcp_cwnd_restart(struct tcp_sock *tp, struct dst_entry *dst)
+static void tcp_cwnd_restart(struct sock *sk, struct dst_entry *dst)
 {
+	struct tcp_sock *tp = tcp_sk(sk);
 	s32 delta = tcp_time_stamp - tp->lsndtime;
 	u32 restart_cwnd = tcp_init_cwnd(tp, dst);
 	u32 cwnd = tp->snd_cwnd;
@@ -116,7 +117,7 @@ static void tcp_cwnd_restart(struct tcp_sock *tp, struct dst_entry *dst)
 	tp->snd_ssthresh = tcp_current_ssthresh(tp);
 	restart_cwnd = min(restart_cwnd, cwnd);
 
-	while ((delta -= tp->rto) > 0 && cwnd > restart_cwnd)
+	while ((delta -= inet_csk(sk)->icsk_rto) > 0 && cwnd > restart_cwnd)
 		cwnd >>= 1;
 	tp->snd_cwnd = max(cwnd, restart_cwnd);
 	tp->snd_cwnd_stamp = tcp_time_stamp;
@@ -126,26 +127,25 @@ static void tcp_cwnd_restart(struct tcp_sock *tp, struct dst_entry *dst)
 static inline void tcp_event_data_sent(struct tcp_sock *tp,
 				       struct sk_buff *skb, struct sock *sk)
 {
-	u32 now = tcp_time_stamp;
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	const u32 now = tcp_time_stamp;
 
-	if (!tp->packets_out && (s32)(now - tp->lsndtime) > tp->rto)
-		tcp_cwnd_restart(tp, __sk_dst_get(sk));
+	if (!tp->packets_out && (s32)(now - tp->lsndtime) > icsk->icsk_rto)
+		tcp_cwnd_restart(sk, __sk_dst_get(sk));
 
 	tp->lsndtime = now;
 
 	/* If it is a reply for ato after last received
 	 * packet, enter pingpong mode.
 	 */
-	if ((u32)(now - tp->ack.lrcvtime) < tp->ack.ato)
-		tp->ack.pingpong = 1;
+	if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
+		icsk->icsk_ack.pingpong = 1;
 }
 
 static __inline__ void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
-
-	tcp_dec_quickack_mode(tp, pkts);
-	tcp_clear_xmit_timer(sk, TCP_TIME_DACK);
+	tcp_dec_quickack_mode(sk, pkts);
+	inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
 }
 
 /* Determine a window scaling and initial window to offer.
@@ -696,7 +696,7 @@ static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
 		if (tp->packets_out > tp->snd_cwnd_used)
 			tp->snd_cwnd_used = tp->packets_out;
 
-		if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= tp->rto)
+		if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
 			tcp_cwnd_application_limited(sk);
 	}
 }
@@ -1147,6 +1147,7 @@ void tcp_push_one(struct sock *sk, unsigned int mss_now)
  */
 u32 __tcp_select_window(struct sock *sk)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	/* MSS for the peer's data.  Previous verions used mss_clamp
 	 * here.  I don't know if the value based on our guesses
@@ -1154,7 +1155,7 @@ u32 __tcp_select_window(struct sock *sk)
 	 * but may be worse for the performance because of rcv_mss
 	 * fluctuations.  --SAW  1998/11/1
 	 */
-	int mss = tp->ack.rcv_mss;
+	int mss = icsk->icsk_ack.rcv_mss;
 	int free_space = tcp_space(sk);
 	int full_space = min_t(int, tp->window_clamp, tcp_full_space(sk));
 	int window;
@@ -1163,7 +1164,7 @@ u32 __tcp_select_window(struct sock *sk)
 		mss = full_space; 
 
 	if (free_space < full_space/2) {
-		tp->ack.quick = 0;
+		icsk->icsk_ack.quick = 0;
 
 		if (tcp_memory_pressure)
 			tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U*tp->advmss);
@@ -1491,7 +1492,8 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 
 					if (skb ==
 					    skb_peek(&sk->sk_write_queue))
-						tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+						inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+									  inet_csk(sk)->icsk_rto);
 				}
 
 				packet_cnt -= tcp_skb_pcount(skb);
@@ -1544,7 +1546,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 			break;
 
 		if (skb == skb_peek(&sk->sk_write_queue))
-			tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, inet_csk(sk)->icsk_rto);
 
 		NET_INC_STATS_BH(LINUX_MIB_TCPFORWARDRETRANS);
 	}
@@ -1780,8 +1782,8 @@ static inline void tcp_connect_init(struct sock *sk)
 	tp->rcv_wup = 0;
 	tp->copied_seq = 0;
 
-	tp->rto = TCP_TIMEOUT_INIT;
-	tp->retransmits = 0;
+	inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+	inet_csk(sk)->icsk_retransmits = 0;
 	tcp_clear_retrans(tp);
 }
 
@@ -1824,7 +1826,7 @@ int tcp_connect(struct sock *sk)
 	TCP_INC_STATS(TCP_MIB_ACTIVEOPENS);
 
 	/* Timer for repeating the SYN until an answer. */
-	tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, inet_csk(sk)->icsk_rto);
 	return 0;
 }
 
@@ -1834,20 +1836,21 @@ int tcp_connect(struct sock *sk)
  */
 void tcp_send_delayed_ack(struct sock *sk)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
-	int ato = tp->ack.ato;
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int ato = icsk->icsk_ack.ato;
 	unsigned long timeout;
 
 	if (ato > TCP_DELACK_MIN) {
+		const struct tcp_sock *tp = tcp_sk(sk);
 		int max_ato = HZ/2;
 
-		if (tp->ack.pingpong || (tp->ack.pending&TCP_ACK_PUSHED))
+		if (icsk->icsk_ack.pingpong || (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
 			max_ato = TCP_DELACK_MAX;
 
 		/* Slow path, intersegment interval is "high". */
 
 		/* If some rtt estimate is known, use it to bound delayed ack.
-		 * Do not use tp->rto here, use results of rtt measurements
+		 * Do not use inet_csk(sk)->icsk_rto here, use results of rtt measurements
 		 * directly.
 		 */
 		if (tp->srtt) {
@@ -1864,21 +1867,22 @@ void tcp_send_delayed_ack(struct sock *sk)
 	timeout = jiffies + ato;
 
 	/* Use new timeout only if there wasn't a older one earlier. */
-	if (tp->ack.pending&TCP_ACK_TIMER) {
+	if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
 		/* If delack timer was blocked or is about to expire,
 		 * send ACK now.
 		 */
-		if (tp->ack.blocked || time_before_eq(tp->ack.timeout, jiffies+(ato>>2))) {
+		if (icsk->icsk_ack.blocked ||
+		    time_before_eq(icsk->icsk_ack.timeout, jiffies + (ato >> 2))) {
 			tcp_send_ack(sk);
 			return;
 		}
 
-		if (!time_before(timeout, tp->ack.timeout))
-			timeout = tp->ack.timeout;
+		if (!time_before(timeout, icsk->icsk_ack.timeout))
+			timeout = icsk->icsk_ack.timeout;
 	}
-	tp->ack.pending |= TCP_ACK_SCHED|TCP_ACK_TIMER;
-	tp->ack.timeout = timeout;
-	sk_reset_timer(sk, &tp->delack_timer, timeout);
+	icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
+	icsk->icsk_ack.timeout = timeout;
+	sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
 }
 
 /* This routine sends an ack and also updates the window. */
@@ -1895,9 +1899,9 @@ void tcp_send_ack(struct sock *sk)
 		 */
 		buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
 		if (buff == NULL) {
-			tcp_schedule_ack(tp);
-			tp->ack.ato = TCP_ATO_MIN;
-			tcp_reset_xmit_timer(sk, TCP_TIME_DACK, TCP_DELACK_MAX);
+			inet_csk_schedule_ack(sk);
+			inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, TCP_DELACK_MAX);
 			return;
 		}
 
@@ -2011,6 +2015,7 @@ int tcp_write_wakeup(struct sock *sk)
  */
 void tcp_send_probe0(struct sock *sk)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	int err;
 
@@ -2019,16 +2024,16 @@ void tcp_send_probe0(struct sock *sk)
 	if (tp->packets_out || !sk->sk_send_head) {
 		/* Cancel probe timer, if it is not required. */
 		tp->probes_out = 0;
-		tp->backoff = 0;
+		icsk->icsk_backoff = 0;
 		return;
 	}
 
 	if (err <= 0) {
-		if (tp->backoff < sysctl_tcp_retries2)
-			tp->backoff++;
+		if (icsk->icsk_backoff < sysctl_tcp_retries2)
+			icsk->icsk_backoff++;
 		tp->probes_out++;
-		tcp_reset_xmit_timer (sk, TCP_TIME_PROBE0, 
-				      min(tp->rto << tp->backoff, TCP_RTO_MAX));
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, 
+					  min(icsk->icsk_rto << icsk->icsk_backoff, TCP_RTO_MAX));
 	} else {
 		/* If packet was not sent due to local congestion,
 		 * do not backoff and do not remember probes_out.
@@ -2038,8 +2043,9 @@ void tcp_send_probe0(struct sock *sk)
 		 */
 		if (!tp->probes_out)
 			tp->probes_out=1;
-		tcp_reset_xmit_timer (sk, TCP_TIME_PROBE0, 
-				      min(tp->rto << tp->backoff, TCP_RESOURCE_PROBE_INTERVAL));
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, 
+					  min(icsk->icsk_rto << icsk->icsk_backoff,
+					      TCP_RESOURCE_PROBE_INTERVAL));
 	}
 }