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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>
#include "alloc-util.h"
#include "bpf-devices.h"
#include "bpf-program.h"
#include "cgroup-setup.h"
#include "errno-list.h"
#include "fd-util.h"
#include "fs-util.h"
#include "path-util.h"
#include "tests.h"
static void test_policy_closed(const char *cgroup_path, BPFProgram **installed_prog) {
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
unsigned wrong = 0;
int r;
log_info("/* %s */", __func__);
r = bpf_devices_cgroup_init(&prog, CGROUP_DEVICE_POLICY_CLOSED, true);
assert_se(r >= 0);
r = bpf_devices_allow_list_static(prog, cgroup_path);
assert_se(r >= 0);
r = bpf_devices_apply_policy(prog, CGROUP_DEVICE_POLICY_CLOSED, true, cgroup_path, installed_prog);
assert_se(r >= 0);
const char *s;
FOREACH_STRING(s, "/dev/null",
"/dev/zero",
"/dev/full",
"/dev/random",
"/dev/urandom",
"/dev/tty",
"/dev/ptmx") {
_cleanup_close_ int fd, fd2;
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd < 0 && errno == EPERM;
/* We ignore errors other than EPERM, e.g. ENOENT or ENXIO */
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 < 0 && errno == EPERM;
}
assert_se(wrong == 0);
}
static void test_policy_strict(const char *cgroup_path, BPFProgram **installed_prog) {
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
unsigned wrong = 0;
int r;
log_info("/* %s */", __func__);
r = bpf_devices_cgroup_init(&prog, CGROUP_DEVICE_POLICY_STRICT, true);
assert_se(r >= 0);
r = bpf_devices_allow_list_device(prog, cgroup_path, "/dev/null", "rw");
assert_se(r >= 0);
r = bpf_devices_allow_list_device(prog, cgroup_path, "/dev/random", "r");
assert_se(r >= 0);
r = bpf_devices_allow_list_device(prog, cgroup_path, "/dev/zero", "w");
assert_se(r >= 0);
r = bpf_devices_apply_policy(prog, CGROUP_DEVICE_POLICY_STRICT, true, cgroup_path, installed_prog);
assert_se(r >= 0);
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/null";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd < 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 < 0;
}
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/random";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd < 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 >= 0;
}
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/zero";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd >= 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 < 0;
}
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/full";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd >= 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 >= 0;
}
assert_se(wrong == 0);
}
static void test_policy_allow_list_major(const char *pattern, const char *cgroup_path, BPFProgram **installed_prog) {
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
unsigned wrong = 0;
int r;
log_info("/* %s(%s) */", __func__, pattern);
r = bpf_devices_cgroup_init(&prog, CGROUP_DEVICE_POLICY_STRICT, true);
assert_se(r >= 0);
r = bpf_devices_allow_list_major(prog, cgroup_path, pattern, 'c', "rw");
assert_se(r >= 0);
r = bpf_devices_apply_policy(prog, CGROUP_DEVICE_POLICY_STRICT, true, cgroup_path, installed_prog);
assert_se(r >= 0);
/* /dev/null, /dev/full have major==1, /dev/tty has major==5 */
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/null";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd < 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 < 0;
}
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/full";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd < 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 < 0;
}
{
_cleanup_close_ int fd, fd2;
const char *s = "/dev/tty";
fd = open(s, O_CLOEXEC|O_RDONLY|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd >= 0;
fd2 = open(s, O_CLOEXEC|O_WRONLY|O_NOCTTY);
log_debug("open(%s, \"w\") = %d/%s", s, fd2, fd2 < 0 ? errno_to_name(errno) : "-");
wrong += fd2 >= 0;
}
assert_se(wrong == 0);
}
static void test_policy_allow_list_major_star(char type, const char *cgroup_path, BPFProgram **installed_prog) {
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
unsigned wrong = 0;
int r;
log_info("/* %s(type=%c) */", __func__, type);
r = bpf_devices_cgroup_init(&prog, CGROUP_DEVICE_POLICY_STRICT, true);
assert_se(r >= 0);
r = bpf_devices_allow_list_major(prog, cgroup_path, "*", type, "rw");
assert_se(r >= 0);
r = bpf_devices_apply_policy(prog, CGROUP_DEVICE_POLICY_STRICT, true, cgroup_path, installed_prog);
assert_se(r >= 0);
{
_cleanup_close_ int fd;
const char *s = "/dev/null";
fd = open(s, O_CLOEXEC|O_RDWR|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
if (type == 'c')
wrong += fd < 0;
else
wrong += fd >= 0;
}
assert_se(wrong == 0);
}
static void test_policy_empty(bool add_mismatched, const char *cgroup_path, BPFProgram **installed_prog) {
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
unsigned wrong = 0;
int r;
log_info("/* %s(add_mismatched=%s) */", __func__, yes_no(add_mismatched));
r = bpf_devices_cgroup_init(&prog, CGROUP_DEVICE_POLICY_STRICT, add_mismatched);
assert_se(r >= 0);
if (add_mismatched) {
r = bpf_devices_allow_list_major(prog, cgroup_path, "foobarxxx", 'c', "rw");
assert_se(r < 0);
}
r = bpf_devices_apply_policy(prog, CGROUP_DEVICE_POLICY_STRICT, false, cgroup_path, installed_prog);
assert_se(r >= 0);
{
_cleanup_close_ int fd;
const char *s = "/dev/null";
fd = open(s, O_CLOEXEC|O_RDWR|O_NOCTTY);
log_debug("open(%s, \"r\") = %d/%s", s, fd, fd < 0 ? errno_to_name(errno) : "-");
wrong += fd >= 0;
}
assert_se(wrong == 0);
}
int main(int argc, char *argv[]) {
_cleanup_free_ char *cgroup = NULL, *parent = NULL;
_cleanup_(rmdir_and_freep) char *controller_path = NULL;
CGroupMask supported;
struct rlimit rl;
int r;
test_setup_logging(LOG_DEBUG);
assert_se(getrlimit(RLIMIT_MEMLOCK, &rl) >= 0);
rl.rlim_cur = rl.rlim_max = MAX(rl.rlim_max, CAN_MEMLOCK_SIZE);
(void) setrlimit(RLIMIT_MEMLOCK, &rl);
r = cg_all_unified();
if (r <= 0)
return log_tests_skipped("We don't seem to be running with unified cgroup hierarchy");
if (!can_memlock())
return log_tests_skipped("Can't use mlock()");
r = enter_cgroup_subroot(&cgroup);
if (r == -ENOMEDIUM)
return log_tests_skipped("cgroupfs not available");
r = bpf_devices_supported();
if (!r)
return log_tests_skipped("BPF device filter not supported");
assert_se(r == 1);
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, cgroup, NULL, &controller_path);
assert_se(r >= 0);
_cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL;
test_policy_closed(cgroup, &prog);
test_policy_strict(cgroup, &prog);
test_policy_allow_list_major("mem", cgroup, &prog);
test_policy_allow_list_major("1", cgroup, &prog);
test_policy_allow_list_major_star('c', cgroup, &prog);
test_policy_allow_list_major_star('b', cgroup, &prog);
test_policy_empty(false, cgroup, &prog);
test_policy_empty(true, cgroup, &prog);
assert_se(parent = dirname_malloc(cgroup));
assert_se(cg_mask_supported(&supported) >= 0);
r = cg_attach_everywhere(supported, parent, 0, NULL, NULL);
assert_se(r >= 0);
return 0;
}
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