summaryrefslogtreecommitdiffstats
path: root/samples/bpf/xdp_fwd_user.c
blob: f88e1d7093d62d0c52fffa1da0a1f972d02561a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 */

#include <linux/bpf.h>
#include <linux/if_link.h>
#include <linux/limits.h>
#include <net/if.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <libgen.h>

#include "bpf/libbpf.h"
#include <bpf/bpf.h>


static int do_attach(int idx, int fd, const char *name)
{
	int err;

	err = bpf_set_link_xdp_fd(idx, fd, 0);
	if (err < 0)
		printf("ERROR: failed to attach program to %s\n", name);

	return err;
}

static int do_detach(int idx, const char *name)
{
	int err;

	err = bpf_set_link_xdp_fd(idx, -1, 0);
	if (err < 0)
		printf("ERROR: failed to detach program from %s\n", name);

	return err;
}

static void usage(const char *prog)
{
	fprintf(stderr,
		"usage: %s [OPTS] interface-list\n"
		"\nOPTS:\n"
		"    -d    detach program\n"
		"    -D    direct table lookups (skip fib rules)\n",
		prog);
}

int main(int argc, char **argv)
{
	struct bpf_prog_load_attr prog_load_attr = {
		.prog_type	= BPF_PROG_TYPE_XDP,
	};
	const char *prog_name = "xdp_fwd";
	struct bpf_program *prog;
	char filename[PATH_MAX];
	struct bpf_object *obj;
	int opt, i, idx, err;
	int prog_fd, map_fd;
	int attach = 1;
	int ret = 0;

	while ((opt = getopt(argc, argv, ":dD")) != -1) {
		switch (opt) {
		case 'd':
			attach = 0;
			break;
		case 'D':
			prog_name = "xdp_fwd_direct";
			break;
		default:
			usage(basename(argv[0]));
			return 1;
		}
	}

	if (optind == argc) {
		usage(basename(argv[0]));
		return 1;
	}

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

		if (access(filename, O_RDONLY) < 0) {
			printf("error accessing file %s: %s\n",
				filename, strerror(errno));
			return 1;
		}

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

		prog = bpf_object__find_program_by_title(obj, prog_name);
		prog_fd = bpf_program__fd(prog);
		if (prog_fd < 0) {
			printf("program not found: %s\n", strerror(prog_fd));
			return 1;
		}
		map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj,
								  "tx_port"));
		if (map_fd < 0) {
			printf("map not found: %s\n", strerror(map_fd));
			return 1;
		}
	}
	if (attach) {
		for (i = 1; i < 64; ++i)
			bpf_map_update_elem(map_fd, &i, &i, 0);
	}

	for (i = optind; i < argc; ++i) {
		idx = if_nametoindex(argv[i]);
		if (!idx)
			idx = strtoul(argv[i], NULL, 0);

		if (!idx) {
			fprintf(stderr, "Invalid arg\n");
			return 1;
		}
		if (!attach) {
			err = do_detach(idx, argv[i]);
			if (err)
				ret = err;
		} else {
			err = do_attach(idx, prog_fd, argv[i]);
			if (err)
				ret = err;
		}
	}

	return ret;
}