Verbose Reno Example

load_module.sh

sudo sysctl net.ipv4.tcp_congestion_control=reno_verbose 

Makefile

obj-m += tcp_reno_verbose.o

IDIR= /lib/modules/$(shell uname -r)/kernel/net/ipv4/
KDIR := /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)

all:
	make -C $(KDIR) M=$(PWD) modules

install:
	install -v -m 644 tcp_reno_verbose.ko $(IDIR)
	depmod
	modprobe tcp_reno_verbose
	sysctl -w net.ipv4.tcp_allowed_congestion_control="cubic reno reno_verbose"

clean:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
	rm -rf Module.markers modules.order Module.symvers tcp_reno_verbose.ko tcp_reno_verbose.mod.c tcp_reno_verbose.mod.o tcp_reno_verbose.o

tcp_reno_verbose.c

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



void tcp_vreno_in_ack_event(struct sock *sk, u32 flags){
	const struct tcp_sock *tp = tcp_sk(sk);
	const struct inet_sock *isock = inet_sk(sk);

	printk(KERN_INFO "ACK Received. sourcep: %u dstp: %u proto%u send window: %u recv window %u\n",
			ntohs(isock->inet_sport), ntohs(isock->inet_dport), sk->sk_protocol, tp->snd_cwnd, tp->rcv_wnd);

}


struct tcp_congestion_ops tcp_reno_verbose = {
	.flags		= TCP_CONG_NON_RESTRICTED,
	.name		= "reno_verbose",
	.owner		= THIS_MODULE,
	.ssthresh	= tcp_reno_ssthresh,
	.cong_avoid	= tcp_reno_cong_avoid,
	.undo_cwnd	= tcp_reno_undo_cwnd,
	.in_ack_event = tcp_vreno_in_ack_event,
};


static int __init tcp_reno_verbose_register(void)
{
    printk(KERN_INFO "Verbose Reno Going Up4");
	return tcp_register_congestion_control(&tcp_reno_verbose);
}


static void __exit tcp_reno_verbose_unregister(void)
{
    printk(KERN_INFO "Verbose Reno Shutting Down4");
    tcp_unregister_congestion_control(&tcp_reno_verbose);
}



module_init(tcp_reno_verbose_register);
module_exit(tcp_reno_verbose_unregister);

MODULE_AUTHOR("Yanev");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Verbose reno");

unload_module.sh

sudo sysctl net.ipv4.tcp_congestion_control=cubic
sudo rmmod tcp_reno_verbose