ubuntu-linux-kernel/samples/bpf/test_cgrp2_array_pin.c

110 lines
2.2 KiB
C

/* Copyright (c) 2016 Facebook
*
* 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.
*/
#include <linux/unistd.h>
#include <linux/bpf.h>
#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include "libbpf.h"
static void usage(void)
{
printf("Usage: test_cgrp2_array_pin [...]\n");
printf(" -F <file> File to pin an BPF cgroup array\n");
printf(" -U <file> Update an already pinned BPF cgroup array\n");
printf(" -v <value> Full path of the cgroup2\n");
printf(" -h Display this help\n");
}
int main(int argc, char **argv)
{
const char *pinned_file = NULL, *cg2 = NULL;
int create_array = 1;
int array_key = 0;
int array_fd = -1;
int cg2_fd = -1;
int ret = -1;
int opt;
while ((opt = getopt(argc, argv, "F:U:v:")) != -1) {
switch (opt) {
/* General args */
case 'F':
pinned_file = optarg;
break;
case 'U':
pinned_file = optarg;
create_array = 0;
break;
case 'v':
cg2 = optarg;
break;
default:
usage();
goto out;
}
}
if (!cg2 || !pinned_file) {
usage();
goto out;
}
cg2_fd = open(cg2, O_RDONLY);
if (cg2_fd < 0) {
fprintf(stderr, "open(%s,...): %s(%d)\n",
cg2, strerror(errno), errno);
goto out;
}
if (create_array) {
array_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,
sizeof(uint32_t), sizeof(uint32_t),
1, 0);
if (array_fd < 0) {
fprintf(stderr,
"bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,...): %s(%d)\n",
strerror(errno), errno);
goto out;
}
} else {
array_fd = bpf_obj_get(pinned_file);
if (array_fd < 0) {
fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
pinned_file, strerror(errno), errno);
goto out;
}
}
ret = bpf_map_update_elem(array_fd, &array_key, &cg2_fd, 0);
if (ret) {
perror("bpf_map_update_elem");
goto out;
}
if (create_array) {
ret = bpf_obj_pin(array_fd, pinned_file);
if (ret) {
fprintf(stderr, "bpf_obj_pin(..., %s): %s(%d)\n",
pinned_file, strerror(errno), errno);
goto out;
}
}
out:
if (array_fd != -1)
close(array_fd);
if (cg2_fd != -1)
close(cg2_fd);
return ret;
}