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// 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];
err = setup_cgroup_environment();
if (CHECK(err, "setup_cgroup_environment", "err %d errno %d\n", err,
errno))
return 1;
cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
if (CHECK(cgroup_fd < 0, "create_and_get_cgroup", "err %d errno %d\n",
cgroup_fd, errno))
goto cleanup_cgroup_env;
err = join_cgroup(TEST_CGROUP);
if (CHECK(err, "join_cgroup", "err %d errno %d\n", err, errno))
goto cleanup_cgroup_env;
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;
}
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