[mirror_ubuntu-hirsute-kernel.git] / samples / bpf / xdp_adjust_tail_user.c

/* SPDX-License-Identifier: GPL-2.0
 * Copyright (c) 2018 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.
 */
#include <linux/bpf.h>
#include <linux/if_link.h>
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <arpa/inet.h>
#include <netinet/ether.h>
#include <unistd.h>
#include <time.h>
#include "bpf/bpf.h"
#include "bpf/libbpf.h"

#define STATS_INTERVAL_S 2U

static int ifindex = -1;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static __u32 prog_id;

static void int_exit(int sig)
{
	__u32 curr_prog_id = 0;

	if (ifindex > -1) {
		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
			printf("bpf_get_link_xdp_id failed\n");
			exit(1);
		}
		if (prog_id == curr_prog_id)
			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
		else if (!curr_prog_id)
			printf("couldn't find a prog id on a given iface\n");
		else
			printf("program on interface changed, not removing\n");
	}
	exit(0);
}

/* simple "icmp packet too big sent" counter
 */
static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)
{
	time_t started_at = time(NULL);
	__u64 value = 0;
	int key = 0;


	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
		sleep(STATS_INTERVAL_S);

		assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);

		printf("icmp \"packet too big\" sent: %10llu pkts\n", value);
	}
}

static void usage(const char *cmd)
{
	printf("Start a XDP prog which send ICMP \"packet too big\" \n"
		"messages if ingress packet is bigger then MAX_SIZE bytes\n");
	printf("Usage: %s [...]\n", cmd);
	printf("    -i <ifindex> Interface Index\n");
	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
	printf("    -S use skb-mode\n");
	printf("    -N enforce native mode\n");
	printf("    -F force loading prog\n");
	printf("    -h Display this help\n");
}

int main(int argc, char **argv)
{
	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
	struct bpf_prog_load_attr prog_load_attr = {
		.prog_type	= BPF_PROG_TYPE_XDP,
	};
	unsigned char opt_flags[256] = {};
	const char *optstr = "i:T:SNFh";
	struct bpf_prog_info info = {};
	__u32 info_len = sizeof(info);
	unsigned int kill_after_s = 0;
	int i, prog_fd, map_fd, opt;
	struct bpf_object *obj;
	struct bpf_map *map;
	char filename[256];
	int err;

	for (i = 0; i < strlen(optstr); i++)
		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
			opt_flags[(unsigned char)optstr[i]] = 1;

	while ((opt = getopt(argc, argv, optstr)) != -1) {

		switch (opt) {
		case 'i':
			ifindex = atoi(optarg);
			break;
		case 'T':
			kill_after_s = atoi(optarg);
			break;
		case 'S':
			xdp_flags |= XDP_FLAGS_SKB_MODE;
			break;
		case 'N':
			xdp_flags |= XDP_FLAGS_DRV_MODE;
			break;
		case 'F':
			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
			break;
		default:
			usage(argv[0]);
			return 1;
		}
		opt_flags[opt] = 0;
	}

	for (i = 0; i < strlen(optstr); i++) {
		if (opt_flags[(unsigned int)optstr[i]]) {
			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
			usage(argv[0]);
			return 1;
		}
	}

	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
		return 1;
	}

	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
	prog_load_attr.file = filename;

	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
		return 1;

	map = bpf_map__next(NULL, obj);
	if (!map) {
		printf("finding a map in obj file failed\n");
		return 1;
	}
	map_fd = bpf_map__fd(map);

	if (!prog_fd) {
		printf("load_bpf_file: %s\n", strerror(errno));
		return 1;
	}

	signal(SIGINT, int_exit);
	signal(SIGTERM, int_exit);

	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
		printf("link set xdp fd failed\n");
		return 1;
	}

	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
	if (err) {
		printf("can't get prog info - %s\n", strerror(errno));
		return 1;
	}
	prog_id = info.id;

	poll_stats(map_fd, kill_after_s);
	int_exit(0);

	return 0;
}
Commit	Line	Data
c6ffd1ff NS	1	/* SPDX-License-Identifier: GPL-2.0
	2	* Copyright (c) 2018 Facebook
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of version 2 of the GNU General Public
	6	* License as published by the Free Software Foundation.
	7	*/
	8	#include <linux/bpf.h>
	9	#include <linux/if_link.h>
	10	#include <assert.h>
	11	#include <errno.h>
	12	#include <signal.h>
	13	#include <stdio.h>
	14	#include <stdlib.h>
	15	#include <string.h>
	16	#include <sys/resource.h>
	17	#include <arpa/inet.h>
	18	#include <netinet/ether.h>
	19	#include <unistd.h>
	20	#include <time.h>
be5bca44 JK	21	#include "bpf/bpf.h"
be5bca44 JK	22	#include "bpf/libbpf.h"
c6ffd1ff NS	23
	24	#define STATS_INTERVAL_S 2U
	25
	26	static int ifindex = -1;
743e568c	27	static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
3b7a8ec2	28	static __u32 prog_id;
c6ffd1ff NS	29
	30	static void int_exit(int sig)
	31	{
3b7a8ec2 MF	32	__u32 curr_prog_id = 0;
	33
	34	if (ifindex > -1) {
	35	if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
	36	printf("bpf_get_link_xdp_id failed\n");
	37	exit(1);
	38	}
	39	if (prog_id == curr_prog_id)
	40	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
	41	else if (!curr_prog_id)
	42	printf("couldn't find a prog id on a given iface\n");
	43	else
	44	printf("program on interface changed, not removing\n");
	45	}
c6ffd1ff NS	46	exit(0);
	47	}
	48
	49	/* simple "icmp packet too big sent" counter
	50	*/
be5bca44	51	static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)
c6ffd1ff NS	52	{
	53	time_t started_at = time(NULL);
	54	__u64 value = 0;
	55	int key = 0;
	56
	57
	58	while (!kill_after_s \|\| time(NULL) - started_at <= kill_after_s) {
	59	sleep(STATS_INTERVAL_S);
	60
be5bca44	61	assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
c6ffd1ff NS	62
	63	printf("icmp \"packet too big\" sent: %10llu pkts\n", value);
	64	}
	65	}
	66
	67	static void usage(const char *cmd)
	68	{
	69	printf("Start a XDP prog which send ICMP \"packet too big\" \n"
	70	"messages if ingress packet is bigger then MAX_SIZE bytes\n");
	71	printf("Usage: %s [...]\n", cmd);
	72	printf(" -i <ifindex> Interface Index\n");
	73	printf(" -T <stop-after-X-seconds> Default: 0 (forever)\n");
	74	printf(" -S use skb-mode\n");
	75	printf(" -N enforce native mode\n");
743e568c	76	printf(" -F force loading prog\n");
c6ffd1ff NS	77	printf(" -h Display this help\n");
	78	}
	79
	80	int main(int argc, char **argv)
	81	{
be5bca44 JK	82	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
	83	struct bpf_prog_load_attr prog_load_attr = {
	84	.prog_type = BPF_PROG_TYPE_XDP,
	85	};
c6ffd1ff	86	unsigned char opt_flags[256] = {};
743e568c	87	const char *optstr = "i:T:SNFh";
3b7a8ec2 MF	88	struct bpf_prog_info info = {};
3b7a8ec2 MF	89	__u32 info_len = sizeof(info);
c6ffd1ff	90	unsigned int kill_after_s = 0;
be5bca44 JK	91	int i, prog_fd, map_fd, opt;
	92	struct bpf_object *obj;
	93	struct bpf_map *map;
c6ffd1ff	94	char filename[256];
3b7a8ec2	95	int err;
c6ffd1ff NS	96
	97	for (i = 0; i < strlen(optstr); i++)
	98	if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
	99	opt_flags[(unsigned char)optstr[i]] = 1;
	100
	101	while ((opt = getopt(argc, argv, optstr)) != -1) {
	102
	103	switch (opt) {
	104	case 'i':
	105	ifindex = atoi(optarg);
	106	break;
	107	case 'T':
	108	kill_after_s = atoi(optarg);
	109	break;
	110	case 'S':
	111	xdp_flags \|= XDP_FLAGS_SKB_MODE;
	112	break;
	113	case 'N':
	114	xdp_flags \|= XDP_FLAGS_DRV_MODE;
	115	break;
743e568c MF	116	case 'F':
	117	xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
	118	break;
c6ffd1ff NS	119	default:
	120	usage(argv[0]);
	121	return 1;
	122	}
	123	opt_flags[opt] = 0;
	124	}
	125
	126	for (i = 0; i < strlen(optstr); i++) {
	127	if (opt_flags[(unsigned int)optstr[i]]) {
	128	fprintf(stderr, "Missing argument -%c\n", optstr[i]);
	129	usage(argv[0]);
	130	return 1;
	131	}
	132	}
	133
	134	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
	135	perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
	136	return 1;
	137	}
	138
	139	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
be5bca44 JK	140	prog_load_attr.file = filename;
	141
	142	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
	143	return 1;
c6ffd1ff	144
be5bca44 JK	145	map = bpf_map__next(NULL, obj);
	146	if (!map) {
	147	printf("finding a map in obj file failed\n");
c6ffd1ff NS	148	return 1;
c6ffd1ff NS	149	}
be5bca44	150	map_fd = bpf_map__fd(map);
c6ffd1ff	151
be5bca44	152	if (!prog_fd) {
c6ffd1ff NS	153	printf("load_bpf_file: %s\n", strerror(errno));
	154	return 1;
	155	}
	156
	157	signal(SIGINT, int_exit);
	158	signal(SIGTERM, int_exit);
	159
be5bca44	160	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
c6ffd1ff NS	161	printf("link set xdp fd failed\n");
	162	return 1;
	163	}
	164
3b7a8ec2 MF	165	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
	166	if (err) {
	167	printf("can't get prog info - %s\n", strerror(errno));
	168	return 1;
	169	}
	170	prog_id = info.id;
c6ffd1ff	171
3b7a8ec2 MF	172	poll_stats(map_fd, kill_after_s);
3b7a8ec2 MF	173	int_exit(0);
c6ffd1ff NS	174
	175	return 0;
	176	}