1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /* eBPF example program:
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * - Loads eBPF program
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * The eBPF program loads a filter from file and attaches the
7*4882a593Smuzhiyun * program to a cgroup using BPF_PROG_ATTACH
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #define _GNU_SOURCE
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <stdio.h>
13*4882a593Smuzhiyun #include <stdlib.h>
14*4882a593Smuzhiyun #include <stddef.h>
15*4882a593Smuzhiyun #include <string.h>
16*4882a593Smuzhiyun #include <unistd.h>
17*4882a593Smuzhiyun #include <assert.h>
18*4882a593Smuzhiyun #include <errno.h>
19*4882a593Smuzhiyun #include <fcntl.h>
20*4882a593Smuzhiyun #include <net/if.h>
21*4882a593Smuzhiyun #include <linux/bpf.h>
22*4882a593Smuzhiyun #include <bpf/bpf.h>
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun #include "bpf_insn.h"
25*4882a593Smuzhiyun #include "bpf_load.h"
26*4882a593Smuzhiyun
usage(const char * argv0)27*4882a593Smuzhiyun static int usage(const char *argv0)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun printf("Usage: %s cg-path filter-path [filter-id]\n", argv0);
30*4882a593Smuzhiyun return EXIT_FAILURE;
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun
main(int argc,char ** argv)33*4882a593Smuzhiyun int main(int argc, char **argv)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun int cg_fd, ret, filter_id = 0;
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun if (argc < 3)
38*4882a593Smuzhiyun return usage(argv[0]);
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY);
41*4882a593Smuzhiyun if (cg_fd < 0) {
42*4882a593Smuzhiyun printf("Failed to open cgroup path: '%s'\n", strerror(errno));
43*4882a593Smuzhiyun return EXIT_FAILURE;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun if (load_bpf_file(argv[2]))
47*4882a593Smuzhiyun return EXIT_FAILURE;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf);
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun if (argc > 3)
52*4882a593Smuzhiyun filter_id = atoi(argv[3]);
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun if (filter_id >= prog_cnt) {
55*4882a593Smuzhiyun printf("Invalid program id; program not found in file\n");
56*4882a593Smuzhiyun return EXIT_FAILURE;
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun ret = bpf_prog_attach(prog_fd[filter_id], cg_fd,
60*4882a593Smuzhiyun BPF_CGROUP_INET_SOCK_CREATE, 0);
61*4882a593Smuzhiyun if (ret < 0) {
62*4882a593Smuzhiyun printf("Failed to attach prog to cgroup: '%s'\n",
63*4882a593Smuzhiyun strerror(errno));
64*4882a593Smuzhiyun return EXIT_FAILURE;
65*4882a593Smuzhiyun }
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun return EXIT_SUCCESS;
68*4882a593Smuzhiyun }
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