1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2018 Facebook
3
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <syscall.h>
10 #include <unistd.h>
11 #include <linux/perf_event.h>
12 #include <sys/ioctl.h>
13 #include <sys/time.h>
14 #include <sys/types.h>
15 #include <sys/stat.h>
16
17 #include <linux/bpf.h>
18 #include <bpf/bpf.h>
19 #include <bpf/libbpf.h>
20
21 #include "cgroup_helpers.h"
22 #include "testing_helpers.h"
23
24 #define CHECK(condition, tag, format...) ({ \
25 int __ret = !!(condition); \
26 if (__ret) { \
27 printf("%s:FAIL:%s ", __func__, tag); \
28 printf(format); \
29 } else { \
30 printf("%s:PASS:%s\n", __func__, tag); \
31 } \
32 __ret; \
33 })
34
35 static int bpf_find_map(const char *test, struct bpf_object *obj,
36 const char *name)
37 {
38 struct bpf_map *map;
39
40 map = bpf_object__find_map_by_name(obj, name);
41 if (!map)
42 return -1;
43 return bpf_map__fd(map);
44 }
45
46 #define TEST_CGROUP "/test-bpf-get-cgroup-id/"
47
48 int main(int argc, char **argv)
49 {
50 const char *probe_name = "syscalls/sys_enter_nanosleep";
51 const char *file = "get_cgroup_id_kern.bpf.o";
52 int err, bytes, efd, prog_fd, pmu_fd;
53 int cgroup_fd, cgidmap_fd, pidmap_fd;
54 struct perf_event_attr attr = {};
55 struct bpf_object *obj;
56 __u64 kcgid = 0, ucgid;
57 __u32 key = 0, pid;
58 int exit_code = 1;
59 char buf[256];
60 const struct timespec req = {
61 .tv_sec = 1,
62 .tv_nsec = 0,
63 };
64
65 cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
66 if (CHECK(cgroup_fd < 0, "cgroup_setup_and_join", "err %d errno %d\n", cgroup_fd, errno))
67 return 1;
68
69 /* Use libbpf 1.0 API mode */
70 libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
71
72 err = bpf_prog_test_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
73 if (CHECK(err, "bpf_prog_test_load", "err %d errno %d\n", err, errno))
74 goto cleanup_cgroup_env;
75
76 cgidmap_fd = bpf_find_map(__func__, obj, "cg_ids");
77 if (CHECK(cgidmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
78 cgidmap_fd, errno))
79 goto close_prog;
80
81 pidmap_fd = bpf_find_map(__func__, obj, "pidmap");
82 if (CHECK(pidmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
83 pidmap_fd, errno))
84 goto close_prog;
85
86 pid = getpid();
87 bpf_map_update_elem(pidmap_fd, &key, &pid, 0);
88
89 if (access("/sys/kernel/tracing/trace", F_OK) == 0) {
90 snprintf(buf, sizeof(buf),
91 "/sys/kernel/tracing/events/%s/id", probe_name);
92 } else {
93 snprintf(buf, sizeof(buf),
94 "/sys/kernel/debug/tracing/events/%s/id", probe_name);
95 }
96 efd = open(buf, O_RDONLY, 0);
97 if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
98 goto close_prog;
99 bytes = read(efd, buf, sizeof(buf));
100 close(efd);
101 if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read",
102 "bytes %d errno %d\n", bytes, errno))
103 goto close_prog;
104
105 attr.config = strtol(buf, NULL, 0);
106 attr.type = PERF_TYPE_TRACEPOINT;
107 attr.sample_type = PERF_SAMPLE_RAW;
108 attr.sample_period = 1;
109 attr.wakeup_events = 1;
110
111 /* attach to this pid so the all bpf invocations will be in the
112 * cgroup associated with this pid.
113 */
114 pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0);
115 if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd,
116 errno))
117 goto close_prog;
118
119 err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
120 if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err,
121 errno))
122 goto close_pmu;
123
124 err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
125 if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err,
126 errno))
127 goto close_pmu;
128
129 /* trigger some syscalls */
130 syscall(__NR_nanosleep, &req, NULL);
131
132 err = bpf_map_lookup_elem(cgidmap_fd, &key, &kcgid);
133 if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno))
134 goto close_pmu;
135
136 ucgid = get_cgroup_id(TEST_CGROUP);
137 if (CHECK(kcgid != ucgid, "compare_cgroup_id",
138 "kern cgid %llx user cgid %llx", kcgid, ucgid))
139 goto close_pmu;
140
141 exit_code = 0;
142 printf("%s:PASS\n", argv[0]);
143
144 close_pmu:
145 close(pmu_fd);
146 close_prog:
147 bpf_object__close(obj);
148 cleanup_cgroup_env:
149 cleanup_cgroup_environment();
150 return exit_code;
151 }
152
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