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
 16static 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
 25int 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
100out:
101	if (array_fd != -1)
102		close(array_fd);
103	if (cg2_fd != -1)
104		close(cg2_fd);
105	return ret;
106}