116 lines
2.4 KiB
C
116 lines
2.4 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#define _GNU_SOURCE
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <bpf/bpf.h>
|
||
|
|
#include <bpf/libbpf.h>
|
||
|
|
#include "cgroup_helpers.h"
|
||
|
|
|
||
|
|
#define CGROUP_PATH "/my-cgroup"
|
||
|
|
|
||
|
|
int main(int argc, char **argv)
|
||
|
|
{
|
||
|
|
pid_t remote_pid, local_pid = getpid();
|
||
|
|
int cg2 = -1, idx = 0, rc = 1;
|
||
|
|
struct bpf_link *link = NULL;
|
||
|
|
struct bpf_program *prog;
|
||
|
|
struct bpf_object *obj;
|
||
|
|
char filename[256];
|
||
|
|
int map_fd[2];
|
||
|
|
|
||
|
|
snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
|
||
|
|
obj = bpf_object__open_file(filename, NULL);
|
||
|
|
if (libbpf_get_error(obj)) {
|
||
|
|
fprintf(stderr, "ERROR: opening BPF object file failed\n");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
|
||
|
|
if (!prog) {
|
||
|
|
printf("finding a prog in obj file failed\n");
|
||
|
|
goto cleanup;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* load BPF program */
|
||
|
|
if (bpf_object__load(obj)) {
|
||
|
|
fprintf(stderr, "ERROR: loading BPF object file failed\n");
|
||
|
|
goto cleanup;
|
||
|
|
}
|
||
|
|
|
||
|
|
map_fd[0] = bpf_object__find_map_fd_by_name(obj, "cgroup_map");
|
||
|
|
map_fd[1] = bpf_object__find_map_fd_by_name(obj, "perf_map");
|
||
|
|
if (map_fd[0] < 0 || map_fd[1] < 0) {
|
||
|
|
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
|
||
|
|
goto cleanup;
|
||
|
|
}
|
||
|
|
|
||
|
|
link = bpf_program__attach(prog);
|
||
|
|
if (libbpf_get_error(link)) {
|
||
|
|
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
|
||
|
|
link = NULL;
|
||
|
|
goto cleanup;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (setup_cgroup_environment())
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
cg2 = create_and_get_cgroup(CGROUP_PATH);
|
||
|
|
|
||
|
|
if (cg2 < 0)
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
if (bpf_map_update_elem(map_fd[0], &idx, &cg2, BPF_ANY)) {
|
||
|
|
log_err("Adding target cgroup to map");
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (join_cgroup(CGROUP_PATH))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The installed helper program catched the sync call, and should
|
||
|
|
* write it to the map.
|
||
|
|
*/
|
||
|
|
|
||
|
|
sync();
|
||
|
|
bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
|
||
|
|
|
||
|
|
if (local_pid != remote_pid) {
|
||
|
|
fprintf(stderr,
|
||
|
|
"BPF Helper didn't write correct PID to map, but: %d\n",
|
||
|
|
remote_pid);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Verify the negative scenario; leave the cgroup */
|
||
|
|
if (join_cgroup("/"))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
remote_pid = 0;
|
||
|
|
bpf_map_update_elem(map_fd[1], &idx, &remote_pid, BPF_ANY);
|
||
|
|
|
||
|
|
sync();
|
||
|
|
bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
|
||
|
|
|
||
|
|
if (local_pid == remote_pid) {
|
||
|
|
fprintf(stderr, "BPF cgroup negative test did not work\n");
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
rc = 0;
|
||
|
|
|
||
|
|
err:
|
||
|
|
if (cg2 != -1)
|
||
|
|
close(cg2);
|
||
|
|
|
||
|
|
cleanup_cgroup_environment();
|
||
|
|
|
||
|
|
cleanup:
|
||
|
|
bpf_link__destroy(link);
|
||
|
|
bpf_object__close(obj);
|
||
|
|
return rc;
|
||
|
|
}
|