add files

Makefile

@@ -0,0 +1,5 @@
+obj-m += tcp_const.o
+
+all:
+	make -C /lib/modules/`uname -r`/build M=`pwd` modules
+

tcp_const.c

@@ -0,0 +1,62 @@
+#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");