cgroup_xattr.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */
 3
 4#include <errno.h>
 5#include <fcntl.h>
 6#include <sys/stat.h>
 7#include <string.h>
 8#include <unistd.h>
 9#include <sys/socket.h>
10#include <test_progs.h>
11#include "cgroup_helpers.h"
12
13#include "read_cgroupfs_xattr.skel.h"
14#include "cgroup_read_xattr.skel.h"
15
16#define CGROUP_FS_PARENT "foo/"
17#define CGROUP_FS_CHILD CGROUP_FS_PARENT "bar/"
18#define TMP_FILE "/tmp/selftests_cgroup_xattr"
19
20static const char xattr_value_a[] = "bpf_selftest_value_a";
21static const char xattr_value_b[] = "bpf_selftest_value_b";
22static const char xattr_name[] = "user.bpf_test";
23
24static void test_read_cgroup_xattr(void)
25{
26	int tmp_fd, parent_cgroup_fd = -1, child_cgroup_fd = -1;
27	struct read_cgroupfs_xattr *skel = NULL;
28
29	parent_cgroup_fd = test__join_cgroup(CGROUP_FS_PARENT);
30	if (!ASSERT_OK_FD(parent_cgroup_fd, "create parent cgroup"))
31		return;
32	if (!ASSERT_OK(set_cgroup_xattr(CGROUP_FS_PARENT, xattr_name, xattr_value_a),
33		       "set parent xattr"))
34		goto out;
35
36	child_cgroup_fd = test__join_cgroup(CGROUP_FS_CHILD);
37	if (!ASSERT_OK_FD(child_cgroup_fd, "create child cgroup"))
38		goto out;
39	if (!ASSERT_OK(set_cgroup_xattr(CGROUP_FS_CHILD, xattr_name, xattr_value_b),
40		       "set child xattr"))
41		goto out;
42
43	skel = read_cgroupfs_xattr__open_and_load();
44	if (!ASSERT_OK_PTR(skel, "read_cgroupfs_xattr__open_and_load"))
45		goto out;
46
47	skel->bss->target_pid = sys_gettid();
48
49	if (!ASSERT_OK(read_cgroupfs_xattr__attach(skel), "read_cgroupfs_xattr__attach"))
50		goto out;
51
52	tmp_fd = open(TMP_FILE, O_RDONLY | O_CREAT);
53	ASSERT_OK_FD(tmp_fd, "open tmp file");
54	close(tmp_fd);
55
56	ASSERT_TRUE(skel->bss->found_value_a, "found_value_a");
57	ASSERT_TRUE(skel->bss->found_value_b, "found_value_b");
58
59out:
60	close(child_cgroup_fd);
61	close(parent_cgroup_fd);
62	read_cgroupfs_xattr__destroy(skel);
63	unlink(TMP_FILE);
64}
65
66void test_cgroup_xattr(void)
67{
68	RUN_TESTS(cgroup_read_xattr);
69
70	if (test__start_subtest("read_cgroupfs_xattr"))
71		test_read_cgroup_xattr();
72}