#include <linux/module.h>
#include <net/tcp.h>

static u32 const_cwnd = 1000;
module_param(const_cwnd, uint, 0664);

static void const_main(struct sock *sk, u32,int,const struct rate_sample *rs)
{
        tcp_sk(sk)->snd_cwnd = const_cwnd;
}

static void const_cong_avoid(struct sock *sk, u32 ack, u32 acked)
{
        tcp_sk(sk)->snd_cwnd = const_cwnd;
}

static void const_init(struct sock *sk)
{
        tcp_sk(sk)->snd_cwnd = const_cwnd;
}

static u32 const_ssthresh(struct sock *sk)
{
        return const_cwnd;
}

static void const_set_state(struct sock *sk, u8 new_state)
{
        if (new_state == TCP_CA_Loss) {
                tcp_sk(sk)->snd_cwnd = const_cwnd;
        }
}

static u32 const_undo(struct sock *sk)
{
        return tcp_sk(sk)->snd_cwnd;
}

static struct tcp_congestion_ops tcp_const_cong_ops __read_mostly = {
        .name                = "const",
        .undo_cwnd        = const_undo,
        .init                = const_init,
        .cong_control        = const_main,
        /*.cong_avoid        = const_cong_avoid,*/
        .ssthresh        = const_ssthresh,
        .set_state        = const_set_state,
};

static int __init const_register(void)
{
        return tcp_register_congestion_control(&tcp_const_cong_ops);
}

static void __exit const_unregister(void)
{
        tcp_unregister_congestion_control(&tcp_const_cong_ops);
}

module_init(const_register);
module_exit(const_unregister);

MODULE_LICENSE("GPL");