[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, 14 insertions, 12 deletions

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 72cec6981830..415ee47ac1c5 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -233,11 +233,12 @@ out_unlock:
 
 static void tcp_probe_timer(struct sock *sk)
 {
+        struct inet_connection_sock *icsk = inet_csk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
         int max_probes;
 
         if (tp->packets_out || !sk->sk_send_head) {
-                tp->probes_out = 0;
+                icsk->icsk_probes_out = 0;
                 return;
         }
 
@@ -248,7 +249,7 @@ static void tcp_probe_timer(struct sock *sk)
          * FIXME: We ought not to do it, Solaris 2.5 actually has fixing
          * this behaviour in Solaris down as a bug fix. [AC]
          *
-         * Let me to explain. probes_out is zeroed by incoming ACKs
+         * Let me to explain. icsk_probes_out is zeroed by incoming ACKs
          * even if they advertise zero window. Hence, connection is killed only
          * if we received no ACKs for normal connection timeout. It is not killed
          * only because window stays zero for some time, window may be zero
@@ -259,16 +260,15 @@ static void tcp_probe_timer(struct sock *sk)
         max_probes = sysctl_tcp_retries2;
 
         if (sock_flag(sk, SOCK_DEAD)) {
-                const struct inet_connection_sock *icsk = inet_csk(sk);
                 const int alive = ((icsk->icsk_rto << icsk->icsk_backoff) < TCP_RTO_MAX);
  
                 max_probes = tcp_orphan_retries(sk, alive);
 
-                if (tcp_out_of_resources(sk, alive || tp->probes_out <= max_probes))
+                if (tcp_out_of_resources(sk, alive || icsk->icsk_probes_out <= max_probes))
                         return;
         }
 
-        if (tp->probes_out > max_probes) {
+        if (icsk->icsk_probes_out > max_probes) {
                 tcp_write_err(sk);
         } else {
                 /* Only send another probe if we didn't close things up. */
@@ -319,19 +319,20 @@ static void tcp_retransmit_timer(struct sock *sk)
                 goto out;
 
         if (icsk->icsk_retransmits == 0) {
-                if (tp->ca_state == TCP_CA_Disorder || tp->ca_state == TCP_CA_Recovery) {
+                if (icsk->icsk_ca_state == TCP_CA_Disorder ||
+                    icsk->icsk_ca_state == TCP_CA_Recovery) {
                         if (tp->rx_opt.sack_ok) {
-                                if (tp->ca_state == TCP_CA_Recovery)
+                                if (icsk->icsk_ca_state == TCP_CA_Recovery)
                                         NET_INC_STATS_BH(LINUX_MIB_TCPSACKRECOVERYFAIL);
                                 else
                                         NET_INC_STATS_BH(LINUX_MIB_TCPSACKFAILURES);
                         } else {
-                                if (tp->ca_state == TCP_CA_Recovery)
+                                if (icsk->icsk_ca_state == TCP_CA_Recovery)
                                         NET_INC_STATS_BH(LINUX_MIB_TCPRENORECOVERYFAIL);
                                 else
                                         NET_INC_STATS_BH(LINUX_MIB_TCPRENOFAILURES);
                         }
-                } else if (tp->ca_state == TCP_CA_Loss) {
+                } else if (icsk->icsk_ca_state == TCP_CA_Loss) {
                         NET_INC_STATS_BH(LINUX_MIB_TCPLOSSFAILURES);
                 } else {
                         NET_INC_STATS_BH(LINUX_MIB_TCPTIMEOUTS);
@@ -449,6 +450,7 @@ void tcp_set_keepalive(struct sock *sk, int val)
 static void tcp_keepalive_timer (unsigned long data)
 {
         struct sock *sk = (struct sock *) data;
+        struct inet_connection_sock *icsk = inet_csk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
         __u32 elapsed;
 
@@ -490,14 +492,14 @@ static void tcp_keepalive_timer (unsigned long data)
         elapsed = tcp_time_stamp - tp->rcv_tstamp;
 
         if (elapsed >= keepalive_time_when(tp)) {
-                if ((!tp->keepalive_probes && tp->probes_out >= sysctl_tcp_keepalive_probes) ||
-                     (tp->keepalive_probes && tp->probes_out >= tp->keepalive_probes)) {
+                if ((!tp->keepalive_probes && icsk->icsk_probes_out >= sysctl_tcp_keepalive_probes) ||
+                     (tp->keepalive_probes && icsk->icsk_probes_out >= tp->keepalive_probes)) {
                         tcp_send_active_reset(sk, GFP_ATOMIC);
                         tcp_write_err(sk);
                         goto out;
                 }
                 if (tcp_write_wakeup(sk) <= 0) {
-                        tp->probes_out++;
+                        icsk->icsk_probes_out++;
                         elapsed = keepalive_intvl_when(tp);
                 } else {
                         /* If keepalive was lost due to local congestion,