GNU Linux-libre 6.6.15-gnu
[releases.git] / samples / bpf / test_cgrp2_array_pin.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2016 Facebook
3  */
4 #include <linux/unistd.h>
5 #include <linux/bpf.h>
6
7 #include <stdio.h>
8 #include <stdint.h>
9 #include <unistd.h>
10 #include <string.h>
11 #include <errno.h>
12 #include <fcntl.h>
13
14 #include <bpf/bpf.h>
15
16 static void usage(void)
17 {
18         printf("Usage: test_cgrp2_array_pin [...]\n");
19         printf("       -F <file>   File to pin an BPF cgroup array\n");
20         printf("       -U <file>   Update an already pinned BPF cgroup array\n");
21         printf("       -v <value>  Full path of the cgroup2\n");
22         printf("       -h          Display this help\n");
23 }
24
25 int main(int argc, char **argv)
26 {
27         const char *pinned_file = NULL, *cg2 = NULL;
28         int create_array = 1;
29         int array_key = 0;
30         int array_fd = -1;
31         int cg2_fd = -1;
32         int ret = -1;
33         int opt;
34
35         while ((opt = getopt(argc, argv, "F:U:v:")) != -1) {
36                 switch (opt) {
37                 /* General args */
38                 case 'F':
39                         pinned_file = optarg;
40                         break;
41                 case 'U':
42                         pinned_file = optarg;
43                         create_array = 0;
44                         break;
45                 case 'v':
46                         cg2 = optarg;
47                         break;
48                 default:
49                         usage();
50                         goto out;
51                 }
52         }
53
54         if (!cg2 || !pinned_file) {
55                 usage();
56                 goto out;
57         }
58
59         cg2_fd = open(cg2, O_RDONLY);
60         if (cg2_fd < 0) {
61                 fprintf(stderr, "open(%s,...): %s(%d)\n",
62                         cg2, strerror(errno), errno);
63                 goto out;
64         }
65
66         if (create_array) {
67                 array_fd = bpf_map_create(BPF_MAP_TYPE_CGROUP_ARRAY, NULL,
68                                           sizeof(uint32_t), sizeof(uint32_t),
69                                           1, NULL);
70                 if (array_fd < 0) {
71                         fprintf(stderr,
72                                 "bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,...): %s(%d)\n",
73                                 strerror(errno), errno);
74                         goto out;
75                 }
76         } else {
77                 array_fd = bpf_obj_get(pinned_file);
78                 if (array_fd < 0) {
79                         fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
80                                 pinned_file, strerror(errno), errno);
81                         goto out;
82                 }
83         }
84
85         ret = bpf_map_update_elem(array_fd, &array_key, &cg2_fd, 0);
86         if (ret) {
87                 perror("bpf_map_update_elem");
88                 goto out;
89         }
90
91         if (create_array) {
92                 ret = bpf_obj_pin(array_fd, pinned_file);
93                 if (ret) {
94                         fprintf(stderr, "bpf_obj_pin(..., %s): %s(%d)\n",
95                                 pinned_file, strerror(errno), errno);
96                         goto out;
97                 }
98         }
99
100 out:
101         if (array_fd != -1)
102                 close(array_fd);
103         if (cg2_fd != -1)
104                 close(cg2_fd);
105         return ret;
106 }