TCPCT part 1e: implement socket option TCP_COOKIE_TRANSACTIONS

[safe/jmp/linux-2.6] / net / ipv4 / tcp_highspeed.c

diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
index 1120245..8b6caaf 100644 (file)
--- a/net/ipv4/tcp_highspeed.c
+++ b/net/ipv4/tcp_highspeed.c
@@ -6,7 +6,6 @@
  * John Heffner <jheffner@psc.edu>
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <net/tcp.h>
 
@@ -15,8 +14,8 @@
  * with fixed-point MD scaled <<8.
  */
 static const struct hstcp_aimd_val {
-        unsigned int cwnd;
-        unsigned int md;
+       unsigned int cwnd;
+       unsigned int md;
 } hstcp_aimd_vals[] = {
  {     38,  128, /*  0.50 */ },
  {    118,  112, /*  0.44 */ },
@@ -98,10 +97,6 @@ struct hstcp {
        u32     ai;
 };
 
-static int max_ssthresh = 100;
-module_param(max_ssthresh, int, 0644);
-MODULE_PARM_DESC(max_ssthresh, "limited slow start threshold (RFC3742)");
-
 static void hstcp_init(struct sock *sk)
 {
        struct tcp_sock *tp = tcp_sk(sk);
@@ -114,8 +109,7 @@ static void hstcp_init(struct sock *sk)
        tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
 }
 
-static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
-                            u32 in_flight, int data_acked)
+static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 in_flight)
 {
        struct tcp_sock *tp = tcp_sk(sk);
        struct hstcp *ca = inet_csk_ca(sk);
@@ -123,31 +117,22 @@ static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
        if (!tcp_is_cwnd_limited(sk, in_flight))
                return;
 
-       if (tp->snd_cwnd <= tp->snd_ssthresh) {
-               /* RFC3742: limited slow start
-                * the window is increased by 1/K MSS for each arriving ACK,
-                * for K = int(cwnd/(0.5 max_ssthresh))
+       if (tp->snd_cwnd <= tp->snd_ssthresh)
+               tcp_slow_start(tp);
+       else {
+               /* Update AIMD parameters.
+                *
+                * We want to guarantee that:
+                *     hstcp_aimd_vals[ca->ai-1].cwnd <
+                *     snd_cwnd <=
+                *     hstcp_aimd_vals[ca->ai].cwnd
                 */
-               if (max_ssthresh > 0 && tp->snd_cwnd > max_ssthresh) {
-                       u32 k = max(tp->snd_cwnd / (max_ssthresh >> 1), 1U);
-                       if (++tp->snd_cwnd_cnt >= k) {
-                               if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                                       tp->snd_cwnd++;
-                               tp->snd_cwnd_cnt = 0;
-                       }
-               } else {
-                       if (tp->snd_cwnd < tp->snd_cwnd_clamp)
-                               tp->snd_cwnd++;
-               }
-       } else {
-               /* Update AIMD parameters */
                if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
                        while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
                               ca->ai < HSTCP_AIMD_MAX - 1)
                                ca->ai++;
-               } else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
-                       while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
-                              ca->ai > 0)
+               } else if (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd) {
+                       while (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd)
                                ca->ai--;
                }
 
@@ -185,7 +170,7 @@ static struct tcp_congestion_ops tcp_highspeed = {
 
 static int __init hstcp_register(void)
 {
-       BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
+       BUILD_BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
        return tcp_register_congestion_control(&tcp_highspeed);
 }