summaryrefslogtreecommitdiffstats
path: root/samples/bpf/xdp_redirect_user.c
blob: 41d705c3a1f7f25c10953876934fda2416ffbdb0 (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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
 */
#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 <stdbool.h>
#include <string.h>
#include <net/if.h>
#include <unistd.h>
#include <libgen.h>
#include <sys/resource.h>

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

static int ifindex_in;
static int ifindex_out;
static bool ifindex_out_xdp_dummy_attached = true;
static __u32 prog_id;
static __u32 dummy_prog_id;

static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int rxcnt_map_fd;

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

	if (bpf_get_link_xdp_id(ifindex_in, &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_in, -1, xdp_flags);
	else if (!curr_prog_id)
		printf("couldn't find a prog id on iface IN\n");
	else
		printf("program on iface IN changed, not removing\n");

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

static void poll_stats(int interval, int ifindex)
{
	unsigned int nr_cpus = bpf_num_possible_cpus();
	__u64 values[nr_cpus], prev[nr_cpus];

	memset(prev, 0, sizeof(prev));

	while (1) {
		__u64 sum = 0;
		__u32 key = 0;
		int i;

		sleep(interval);
		assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
		for (i = 0; i < nr_cpus; i++)
			sum += (values[i] - prev[i]);
		if (sum)
			printf("ifindex %i: %10llu pkt/s\n",
			       ifindex, sum / interval);
		memcpy(prev, values, sizeof(values));
	}
}

static void usage(const char *prog)
{
	fprintf(stderr,
		"usage: %s [OPTS] <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n\n"
		"OPTS:\n"
		"    -S    use skb-mode\n"
		"    -N    enforce native mode\n"
		"    -F    force loading prog\n",
		prog);
}


int main(int argc, char **argv)
{
	struct bpf_prog_load_attr prog_load_attr = {
		.prog_type	= BPF_PROG_TYPE_XDP,
	};
	struct bpf_program *prog, *dummy_prog;
	int prog_fd, tx_port_map_fd, opt;
	struct bpf_prog_info info = {};
	__u32 info_len = sizeof(info);
	const char *optstr = "FSN";
	struct bpf_object *obj;
	char filename[256];
	int dummy_prog_fd;
	int ret, key = 0;

	while ((opt = getopt(argc, argv, optstr)) != -1) {
		switch (opt) {
		case 'S':
			xdp_flags |= XDP_FLAGS_SKB_MODE;
			break;
		case 'N':
			/* default, set below */
			break;
		case 'F':
			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
			break;
		default:
			usage(basename(argv[0]));
			return 1;
		}
	}

	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
		xdp_flags |= XDP_FLAGS_DRV_MODE;

	if (optind == argc) {
		printf("usage: %s <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n", argv[0]);
		return 1;
	}

	ifindex_in = if_nametoindex(argv[optind]);
	if (!ifindex_in)
		ifindex_in = strtoul(argv[optind], NULL, 0);

	ifindex_out = if_nametoindex(argv[optind + 1]);
	if (!ifindex_out)
		ifindex_out = strtoul(argv[optind + 1], NULL, 0);

	printf("input: %d output: %d\n", ifindex_in, ifindex_out);

	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;

	prog = bpf_program__next(NULL, obj);
	dummy_prog = bpf_program__next(prog, obj);
	if (!prog || !dummy_prog) {
		printf("finding a prog in obj file failed\n");
		return 1;
	}
	/* bpf_prog_load_xattr gives us the pointer to first prog's fd,
	 * so we're missing only the fd for dummy prog
	 */
	dummy_prog_fd = bpf_program__fd(dummy_prog);
	if (prog_fd < 0 || dummy_prog_fd < 0) {
		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
		return 1;
	}

	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
	if (tx_port_map_fd < 0 || rxcnt_map_fd < 0) {
		printf("bpf_object__find_map_fd_by_name failed\n");
		return 1;
	}

	if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
		printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
		return 1;
	}

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

	/* Loading dummy XDP prog on out-device */
	if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
			    (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
		printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
		ifindex_out_xdp_dummy_attached = false;
	}

	memset(&info, 0, sizeof(info));
	ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len);
	if (ret) {
		printf("can't get prog info - %s\n", strerror(errno));
		return ret;
	}
	dummy_prog_id = info.id;

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

	/* bpf redirect port */
	ret = bpf_map_update_elem(tx_port_map_fd, &key, &ifindex_out, 0);
	if (ret) {
		perror("bpf_update_elem");
		goto out;
	}

	poll_stats(2, ifindex_out);

out:
	return 0;
}