[mirror_ubuntu-bionic-kernel.git] / samples / bpf / tcp_iw_kern.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 load_sock_ops 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

#define bpf_printk(fmt, ...)					\
({								\
	       char ____fmt[] = fmt;				\
	       bpf_trace_printk(____fmt, sizeof(____fmt),	\
				##__VA_ARGS__);			\
})

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";
Commit	Line	Data
7bc62e28 LB	1	/* Copyright (c) 2017 Facebook
	2	*
	3	* This program is free software; you can redistribute it and/or
	4	* modify it under the terms of version 2 of the GNU General Public
	5	* License as published by the Free Software Foundation.
	6	*
	7	* BPF program to set initial congestion window and initial receive
	8	* window to 40 packets and send and receive buffers to 1.5MB. This
	9	* would usually be done after doing appropriate checks that indicate
	10	* the hosts are far enough away (i.e. large RTT).
	11	*
	12	* Use load_sock_ops to load this BPF program.
	13	*/
	14
	15	#include <uapi/linux/bpf.h>
	16	#include <uapi/linux/if_ether.h>
	17	#include <uapi/linux/if_packet.h>
	18	#include <uapi/linux/ip.h>
	19	#include <linux/socket.h>
	20	#include "bpf_helpers.h"
	21	#include "bpf_endian.h"
	22
	23	#define DEBUG 1
	24
	25	#define bpf_printk(fmt, ...) \
	26	({ \
	27	char ____fmt[] = fmt; \
	28	bpf_trace_printk(____fmt, sizeof(____fmt), \
	29	##__VA_ARGS__); \
	30	})
	31
	32	SEC("sockops")
	33	int bpf_iw(struct bpf_sock_ops *skops)
	34	{
	35	int bufsize = 1500000;
	36	int rwnd_init = 40;
	37	int iw = 40;
	38	int rv = 0;
	39	int op;
	40
	41	/* For testing purposes, only execute rest of BPF program
	42	* if neither port numberis 55601
	43	*/
	44	if (bpf_ntohl(skops->remote_port) != 55601 &&
e1853319 LB	45	skops->local_port != 55601) {
	46	skops->reply = -1;
	47	return 1;
	48	}
7bc62e28 LB	49
	50	op = (int) skops->op;
	51
	52	#ifdef DEBUG
	53	bpf_printk("BPF command: %d\n", op);
	54	#endif
	55
	56	/* Usually there would be a check to insure the hosts are far
	57	* from each other so it makes sense to increase buffer sizes
	58	*/
	59	switch (op) {
	60	case BPF_SOCK_OPS_RWND_INIT:
	61	rv = rwnd_init;
	62	break;
	63	case BPF_SOCK_OPS_TCP_CONNECT_CB:
	64	/* Set sndbuf and rcvbuf of active connections */
	65	rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
	66	sizeof(bufsize));
e1853319 LB	67	rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
e1853319 LB	68	&bufsize, sizeof(bufsize));
7bc62e28 LB	69	break;
	70	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
	71	rv = bpf_setsockopt(skops, SOL_TCP, TCP_BPF_IW, &iw,
	72	sizeof(iw));
	73	break;
	74	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
	75	/* Set sndbuf and rcvbuf of passive connections */
	76	rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
	77	sizeof(bufsize));
e1853319 LB	78	rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
e1853319 LB	79	&bufsize, sizeof(bufsize));
7bc62e28 LB	80	break;
	81	default:
	82	rv = -1;
	83	}
	84	#ifdef DEBUG
	85	bpf_printk("Returning %d\n", rv);
	86	#endif
	87	skops->reply = rv;
	88	return 1;
	89	}
	90	char _license[] SEC("license") = "GPL";