6b13f685e
김민수
BSP 최초 추가
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#include <linux/mm.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/inet_diag.h>
#include <net/tcp.h>
#include "tcp_vegas.h"
static int alpha = 2;
static int beta = 4;
static int gamma = 1;
module_param(alpha, int, 0644);
MODULE_PARM_DESC(alpha, "lower bound of packets in network");
module_param(beta, int, 0644);
MODULE_PARM_DESC(beta, "upper bound of packets in network");
module_param(gamma, int, 0644);
MODULE_PARM_DESC(gamma, "limit on increase (scale by 2)");
static void vegas_enable(struct sock *sk)
{
const struct tcp_sock *tp = tcp_sk(sk);
struct vegas *vegas = inet_csk_ca(sk);
vegas->doing_vegas_now = 1;
vegas->beg_snd_nxt = tp->snd_nxt;
vegas->cntRTT = 0;
vegas->minRTT = 0x7fffffff;
}
static inline void vegas_disable(struct sock *sk)
{
struct vegas *vegas = inet_csk_ca(sk);
vegas->doing_vegas_now = 0;
}
void tcp_vegas_init(struct sock *sk)
{
struct vegas *vegas = inet_csk_ca(sk);
vegas->baseRTT = 0x7fffffff;
vegas_enable(sk);
}
EXPORT_SYMBOL_GPL(tcp_vegas_init);
void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us)
{
struct vegas *vegas = inet_csk_ca(sk);
u32 vrtt;
if (rtt_us < 0)
return;
vrtt = rtt_us + 1;
if (vrtt < vegas->baseRTT)
vegas->baseRTT = vrtt;
vegas->minRTT = min(vegas->minRTT, vrtt);
vegas->cntRTT++;
}
EXPORT_SYMBOL_GPL(tcp_vegas_pkts_acked);
void tcp_vegas_state(struct sock *sk, u8 ca_state)
{
if (ca_state == TCP_CA_Open)
vegas_enable(sk);
else
vegas_disable(sk);
}
EXPORT_SYMBOL_GPL(tcp_vegas_state);
void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event)
{
if (event == CA_EVENT_CWND_RESTART ||
event == CA_EVENT_TX_START)
tcp_vegas_init(sk);
}
EXPORT_SYMBOL_GPL(tcp_vegas_cwnd_event);
static inline u32 tcp_vegas_ssthresh(struct tcp_sock *tp)
{
return min(tp->snd_ssthresh, tp->snd_cwnd-1);
}
static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 acked,
u32 in_flight)
{
struct tcp_sock *tp = tcp_sk(sk);
struct vegas *vegas = inet_csk_ca(sk);
if (!vegas->doing_vegas_now) {
tcp_reno_cong_avoid(sk, ack, acked, in_flight);
return;
}
if (after(ack, vegas->beg_snd_nxt)) {
vegas->beg_snd_nxt = tp->snd_nxt;
if (vegas->cntRTT <= 2) {
tcp_reno_cong_avoid(sk, ack, acked, in_flight);
} else {
u32 rtt, diff;
u64 target_cwnd;
rtt = vegas->minRTT;
target_cwnd = (u64)tp->snd_cwnd * vegas->baseRTT;
do_div(target_cwnd, rtt);
diff = tp->snd_cwnd * (rtt-vegas->baseRTT) / vegas->baseRTT;
if (diff > gamma && tp->snd_cwnd <= tp->snd_ssthresh) {
tp->snd_cwnd = min(tp->snd_cwnd, (u32)target_cwnd+1);
tp->snd_ssthresh = tcp_vegas_ssthresh(tp);
} else if (tp->snd_cwnd <= tp->snd_ssthresh) {
tcp_slow_start(tp, acked);
} else {
if (diff > beta) {
tp->snd_cwnd--;
tp->snd_ssthresh
= tcp_vegas_ssthresh(tp);
} else if (diff < alpha) {
tp->snd_cwnd++;
} else {
}
}
if (tp->snd_cwnd < 2)
tp->snd_cwnd = 2;
else if (tp->snd_cwnd > tp->snd_cwnd_clamp)
tp->snd_cwnd = tp->snd_cwnd_clamp;
tp->snd_ssthresh = tcp_current_ssthresh(sk);
}
vegas->cntRTT = 0;
vegas->minRTT = 0x7fffffff;
}
else if (tp->snd_cwnd <= tp->snd_ssthresh)
tcp_slow_start(tp, acked);
}
void tcp_vegas_get_info(struct sock *sk, u32 ext, struct sk_buff *skb)
{
const struct vegas *ca = inet_csk_ca(sk);
if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
struct tcpvegas_info info = {
.tcpv_enabled = ca->doing_vegas_now,
.tcpv_rttcnt = ca->cntRTT,
.tcpv_rtt = ca->baseRTT,
.tcpv_minrtt = ca->minRTT,
};
nla_put(skb, INET_DIAG_VEGASINFO, sizeof(info), &info);
}
}
EXPORT_SYMBOL_GPL(tcp_vegas_get_info);
static struct tcp_congestion_ops tcp_vegas __read_mostly = {
.flags = TCP_CONG_RTT_STAMP,
.init = tcp_vegas_init,
.ssthresh = tcp_reno_ssthresh,
.cong_avoid = tcp_vegas_cong_avoid,
.min_cwnd = tcp_reno_min_cwnd,
.pkts_acked = tcp_vegas_pkts_acked,
.set_state = tcp_vegas_state,
.cwnd_event = tcp_vegas_cwnd_event,
.get_info = tcp_vegas_get_info,
.owner = THIS_MODULE,
.name = "vegas",
};
static int __init tcp_vegas_register(void)
{
BUILD_BUG_ON(sizeof(struct vegas) > ICSK_CA_PRIV_SIZE);
tcp_register_congestion_control(&tcp_vegas);
return 0;
}
static void __exit tcp_vegas_unregister(void)
{
tcp_unregister_congestion_control(&tcp_vegas);
}
module_init(tcp_vegas_register);
module_exit(tcp_vegas_unregister);
MODULE_AUTHOR("Stephen Hemminger");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TCP Vegas");
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