summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/get_cgroup_id_user.c
blob: b8d6aef99db4e138d3c586fd0d8a37e1ab7dac35 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 Facebook

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <syscall.h>
#include <unistd.h>
#include <linux/perf_event.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <linux/bpf.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>

#include "cgroup_helpers.h"
#include "bpf_rlimit.h"

#define CHECK(condition, tag, format...) ({		\
	int __ret = !!(condition);			\
	if (__ret) {					\
		printf("%s:FAIL:%s ", __func__, tag);	\
		printf(format);				\
	} else {					\
		printf("%s:PASS:%s\n", __func__, tag);	\
	}						\
	__ret;						\
})

static int bpf_find_map(const char *test, struct bpf_object *obj,
			const char *name)
{
	struct bpf_map *map;

	map = bpf_object__find_map_by_name(obj, name);
	if (!map)
		return -1;
	return bpf_map__fd(map);
}

#define TEST_CGROUP "/test-bpf-get-cgroup-id/"

int main(int argc, char **argv)
{
	const char *probe_name = "syscalls/sys_enter_nanosleep";
	const char *file = "get_cgroup_id_kern.o";
	int err, bytes, efd, prog_fd, pmu_fd;
	int cgroup_fd, cgidmap_fd, pidmap_fd;
	struct perf_event_attr attr = {};
	struct bpf_object *obj;
	__u64 kcgid = 0, ucgid;
	__u32 key = 0, pid;
	int exit_code = 1;
	char buf[256];

	cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
	if (CHECK(cgroup_fd < 0, "cgroup_setup_and_join", "err %d errno %d\n", cgroup_fd, errno))
		return 1;

	err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
	if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno))
		goto cleanup_cgroup_env;

	cgidmap_fd = bpf_find_map(__func__, obj, "cg_ids");
	if (CHECK(cgidmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
		  cgidmap_fd, errno))
		goto close_prog;

	pidmap_fd = bpf_find_map(__func__, obj, "pidmap");
	if (CHECK(pidmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
		  pidmap_fd, errno))
		goto close_prog;

	pid = getpid();
	bpf_map_update_elem(pidmap_fd, &key, &pid, 0);

	snprintf(buf, sizeof(buf),
		 "/sys/kernel/debug/tracing/events/%s/id", probe_name);
	efd = open(buf, O_RDONLY, 0);
	if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
		goto close_prog;
	bytes = read(efd, buf, sizeof(buf));
	close(efd);
	if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read",
		  "bytes %d errno %d\n", bytes, errno))
		goto close_prog;

	attr.config = strtol(buf, NULL, 0);
	attr.type = PERF_TYPE_TRACEPOINT;
	attr.sample_type = PERF_SAMPLE_RAW;
	attr.sample_period = 1;
	attr.wakeup_events = 1;

	/* attach to this pid so the all bpf invocations will be in the
	 * cgroup associated with this pid.
	 */
	pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0);
	if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd,
		  errno))
		goto close_prog;

	err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
	if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err,
		  errno))
		goto close_pmu;

	err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
	if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err,
		  errno))
		goto close_pmu;

	/* trigger some syscalls */
	sleep(1);

	err = bpf_map_lookup_elem(cgidmap_fd, &key, &kcgid);
	if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno))
		goto close_pmu;

	ucgid = get_cgroup_id(TEST_CGROUP);
	if (CHECK(kcgid != ucgid, "compare_cgroup_id",
		  "kern cgid %llx user cgid %llx", kcgid, ucgid))
		goto close_pmu;

	exit_code = 0;
	printf("%s:PASS\n", argv[0]);

close_pmu:
	close(pmu_fd);
close_prog:
	bpf_object__close(obj);
cleanup_cgroup_env:
	cleanup_cgroup_environment();
	return exit_code;
}