84 строки
2.2 KiB
C
84 строки
2.2 KiB
C
/* Copyright (c) 2017 Facebook
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*
|
|
* BPF program to set initial congestion window and initial receive
|
|
* window to 40 packets and send and receive buffers to 1.5MB. This
|
|
* would usually be done after doing appropriate checks that indicate
|
|
* the hosts are far enough away (i.e. large RTT).
|
|
*
|
|
* Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
|
|
*/
|
|
|
|
#include <uapi/linux/bpf.h>
|
|
#include <uapi/linux/if_ether.h>
|
|
#include <uapi/linux/if_packet.h>
|
|
#include <uapi/linux/ip.h>
|
|
#include <linux/socket.h>
|
|
#include "bpf_helpers.h"
|
|
#include "bpf_endian.h"
|
|
|
|
#define DEBUG 1
|
|
|
|
SEC("sockops")
|
|
int bpf_iw(struct bpf_sock_ops *skops)
|
|
{
|
|
int bufsize = 1500000;
|
|
int rwnd_init = 40;
|
|
int iw = 40;
|
|
int rv = 0;
|
|
int op;
|
|
|
|
/* For testing purposes, only execute rest of BPF program
|
|
* if neither port numberis 55601
|
|
*/
|
|
if (bpf_ntohl(skops->remote_port) != 55601 &&
|
|
skops->local_port != 55601) {
|
|
skops->reply = -1;
|
|
return 1;
|
|
}
|
|
|
|
op = (int) skops->op;
|
|
|
|
#ifdef DEBUG
|
|
bpf_printk("BPF command: %d\n", op);
|
|
#endif
|
|
|
|
/* Usually there would be a check to insure the hosts are far
|
|
* from each other so it makes sense to increase buffer sizes
|
|
*/
|
|
switch (op) {
|
|
case BPF_SOCK_OPS_RWND_INIT:
|
|
rv = rwnd_init;
|
|
break;
|
|
case BPF_SOCK_OPS_TCP_CONNECT_CB:
|
|
/* Set sndbuf and rcvbuf of active connections */
|
|
rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
|
|
sizeof(bufsize));
|
|
rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
|
|
&bufsize, sizeof(bufsize));
|
|
break;
|
|
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
|
|
rv = bpf_setsockopt(skops, SOL_TCP, TCP_BPF_IW, &iw,
|
|
sizeof(iw));
|
|
break;
|
|
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
|
|
/* Set sndbuf and rcvbuf of passive connections */
|
|
rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
|
|
sizeof(bufsize));
|
|
rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
|
|
&bufsize, sizeof(bufsize));
|
|
break;
|
|
default:
|
|
rv = -1;
|
|
}
|
|
#ifdef DEBUG
|
|
bpf_printk("Returning %d\n", rv);
|
|
#endif
|
|
skops->reply = rv;
|
|
return 1;
|
|
}
|
|
char _license[] SEC("license") = "GPL";
|