![Arnaldo Carvalho de Melo](/assets/img/avatar_default.png)
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>
185 lines
4.8 KiB
C
185 lines
4.8 KiB
C
/*
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* Sally Floyd's High Speed TCP (RFC 3649) congestion control
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*
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* See http://www.icir.org/floyd/hstcp.html
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*
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* John Heffner <jheffner@psc.edu>
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <net/tcp.h>
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/* From AIMD tables from RFC 3649 appendix B,
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* with fixed-point MD scaled <<8.
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*/
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static const struct hstcp_aimd_val {
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unsigned int cwnd;
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unsigned int md;
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} hstcp_aimd_vals[] = {
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{ 38, 128, /* 0.50 */ },
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{ 118, 112, /* 0.44 */ },
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{ 221, 104, /* 0.41 */ },
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{ 347, 98, /* 0.38 */ },
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{ 495, 93, /* 0.37 */ },
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{ 663, 89, /* 0.35 */ },
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{ 851, 86, /* 0.34 */ },
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{ 1058, 83, /* 0.33 */ },
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{ 1284, 81, /* 0.32 */ },
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{ 1529, 78, /* 0.31 */ },
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{ 1793, 76, /* 0.30 */ },
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{ 2076, 74, /* 0.29 */ },
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{ 2378, 72, /* 0.28 */ },
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{ 2699, 71, /* 0.28 */ },
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{ 3039, 69, /* 0.27 */ },
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{ 3399, 68, /* 0.27 */ },
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{ 3778, 66, /* 0.26 */ },
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{ 4177, 65, /* 0.26 */ },
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{ 4596, 64, /* 0.25 */ },
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{ 5036, 62, /* 0.25 */ },
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{ 5497, 61, /* 0.24 */ },
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{ 5979, 60, /* 0.24 */ },
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{ 6483, 59, /* 0.23 */ },
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{ 7009, 58, /* 0.23 */ },
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{ 7558, 57, /* 0.22 */ },
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{ 8130, 56, /* 0.22 */ },
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{ 8726, 55, /* 0.22 */ },
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{ 9346, 54, /* 0.21 */ },
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{ 9991, 53, /* 0.21 */ },
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{ 10661, 52, /* 0.21 */ },
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{ 11358, 52, /* 0.20 */ },
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{ 12082, 51, /* 0.20 */ },
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{ 12834, 50, /* 0.20 */ },
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{ 13614, 49, /* 0.19 */ },
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{ 14424, 48, /* 0.19 */ },
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{ 15265, 48, /* 0.19 */ },
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{ 16137, 47, /* 0.19 */ },
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{ 17042, 46, /* 0.18 */ },
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{ 17981, 45, /* 0.18 */ },
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{ 18955, 45, /* 0.18 */ },
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{ 19965, 44, /* 0.17 */ },
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{ 21013, 43, /* 0.17 */ },
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{ 22101, 43, /* 0.17 */ },
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{ 23230, 42, /* 0.17 */ },
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{ 24402, 41, /* 0.16 */ },
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{ 25618, 41, /* 0.16 */ },
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{ 26881, 40, /* 0.16 */ },
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{ 28193, 39, /* 0.16 */ },
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{ 29557, 39, /* 0.15 */ },
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{ 30975, 38, /* 0.15 */ },
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{ 32450, 38, /* 0.15 */ },
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{ 33986, 37, /* 0.15 */ },
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{ 35586, 36, /* 0.14 */ },
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{ 37253, 36, /* 0.14 */ },
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{ 38992, 35, /* 0.14 */ },
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{ 40808, 35, /* 0.14 */ },
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{ 42707, 34, /* 0.13 */ },
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{ 44694, 33, /* 0.13 */ },
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{ 46776, 33, /* 0.13 */ },
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{ 48961, 32, /* 0.13 */ },
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{ 51258, 32, /* 0.13 */ },
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{ 53677, 31, /* 0.12 */ },
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{ 56230, 30, /* 0.12 */ },
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{ 58932, 30, /* 0.12 */ },
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{ 61799, 29, /* 0.12 */ },
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{ 64851, 28, /* 0.11 */ },
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{ 68113, 28, /* 0.11 */ },
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{ 71617, 27, /* 0.11 */ },
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{ 75401, 26, /* 0.10 */ },
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{ 79517, 26, /* 0.10 */ },
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{ 84035, 25, /* 0.10 */ },
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{ 89053, 24, /* 0.10 */ },
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};
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#define HSTCP_AIMD_MAX ARRAY_SIZE(hstcp_aimd_vals)
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struct hstcp {
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u32 ai;
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};
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static void hstcp_init(struct sock *sk)
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{
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struct tcp_sock *tp = tcp_sk(sk);
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struct hstcp *ca = inet_csk_ca(sk);
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ca->ai = 0;
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/* Ensure the MD arithmetic works. This is somewhat pedantic,
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* since I don't think we will see a cwnd this large. :) */
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tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
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}
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static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
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u32 in_flight, int good)
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{
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struct tcp_sock *tp = tcp_sk(sk);
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struct hstcp *ca = inet_csk_ca(sk);
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if (in_flight < tp->snd_cwnd)
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return;
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if (tp->snd_cwnd <= tp->snd_ssthresh) {
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if (tp->snd_cwnd < tp->snd_cwnd_clamp)
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tp->snd_cwnd++;
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} else {
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/* Update AIMD parameters */
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if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
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while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
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ca->ai < HSTCP_AIMD_MAX)
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ca->ai++;
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} else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
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while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
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ca->ai > 0)
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ca->ai--;
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}
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/* Do additive increase */
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if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
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tp->snd_cwnd_cnt += ca->ai;
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if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
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tp->snd_cwnd++;
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tp->snd_cwnd_cnt -= tp->snd_cwnd;
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}
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}
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}
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}
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static u32 hstcp_ssthresh(struct sock *sk)
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{
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const struct tcp_sock *tp = tcp_sk(sk);
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const struct hstcp *ca = inet_csk_ca(sk);
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/* Do multiplicative decrease */
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return max(tp->snd_cwnd - ((tp->snd_cwnd * hstcp_aimd_vals[ca->ai].md) >> 8), 2U);
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}
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static struct tcp_congestion_ops tcp_highspeed = {
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.init = hstcp_init,
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.ssthresh = hstcp_ssthresh,
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.cong_avoid = hstcp_cong_avoid,
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.min_cwnd = tcp_reno_min_cwnd,
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.owner = THIS_MODULE,
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.name = "highspeed"
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};
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static int __init hstcp_register(void)
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{
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BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
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return tcp_register_congestion_control(&tcp_highspeed);
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}
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static void __exit hstcp_unregister(void)
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{
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tcp_unregister_congestion_control(&tcp_highspeed);
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}
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module_init(hstcp_register);
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module_exit(hstcp_unregister);
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MODULE_AUTHOR("John Heffner");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("High Speed TCP");
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