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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <linux/futex.h>
#include <pthread.h>
#include <sys/stat.h>
#include <unistd.h>
#include <atomic>
#include <chrono>
#include <string>
#include <thread>
#include <vector>
#include <android-base/file.h>
#include <android-base/scopeguard.h>
#include <gtest/gtest.h>
#include <selinux/android.h>
#include <selinux/label.h>
#include <selinux/selinux.h>
using namespace std::chrono_literals;
using namespace std::string_literals;
template <typename T, typename F>
void WriteFromMultipleThreads(std::vector<std::pair<std::string, T>>& files_and_parameters,
F function) {
auto num_threads = files_and_parameters.size();
pthread_barrier_t barrier;
pthread_barrier_init(&barrier, nullptr, num_threads);
auto barrier_destroy =
android::base::make_scope_guard([&barrier]() { pthread_barrier_destroy(&barrier); });
auto make_thread_function = [&function, &barrier](const auto& file, const auto& parameter) {
return [&]() {
function(parameter);
pthread_barrier_wait(&barrier);
android::base::WriteStringToFile("<empty>", file);
};
};
std::vector<std::thread> threads;
for (const auto& [file, parameter] : files_and_parameters) {
threads.emplace_back(std::thread(make_thread_function(file, parameter)));
}
for (auto& thread : threads) {
thread.join();
}
}
TEST(ueventd, setegid_IsPerThread) {
if (getuid() != 0) {
GTEST_SKIP() << "Skipping test, must be run as root.";
return;
}
TemporaryDir dir;
gid_t gid = 0;
std::vector<std::pair<std::string, gid_t>> files_and_gids;
std::generate_n(std::back_inserter(files_and_gids), 100, [&gid, &dir]() {
gid++;
return std::pair(dir.path + "/gid_"s + std::to_string(gid), gid);
});
WriteFromMultipleThreads(files_and_gids, [](gid_t gid) { EXPECT_EQ(0, setegid(gid)); });
for (const auto& [file, expected_gid] : files_and_gids) {
struct stat info;
ASSERT_EQ(0, stat(file.c_str(), &info));
EXPECT_EQ(expected_gid, info.st_gid);
}
}
TEST(ueventd, setfscreatecon_IsPerThread) {
if (getuid() != 0) {
GTEST_SKIP() << "Skipping test, must be run as root.";
return;
}
if (!is_selinux_enabled() || security_getenforce() == 1) {
GTEST_SKIP() << "Skipping test, SELinux must be enabled and in permissive mode.";
return;
}
const char* const contexts[] = {
"u:object_r:audio_device:s0",
"u:object_r:sensors_device:s0",
"u:object_r:video_device:s0",
"u:object_r:zero_device:s0",
};
TemporaryDir dir;
std::vector<std::pair<std::string, std::string>> files_and_contexts;
for (const char* context : contexts) {
files_and_contexts.emplace_back(dir.path + "/context_"s + context, context);
}
WriteFromMultipleThreads(files_and_contexts, [](const std::string& context) {
EXPECT_EQ(0, setfscreatecon(context.c_str()));
});
for (const auto& [file, expected_context] : files_and_contexts) {
char* file_context;
ASSERT_GT(getfilecon(file.c_str(), &file_context), 0);
EXPECT_EQ(expected_context, file_context);
freecon(file_context);
}
}
TEST(ueventd, selabel_lookup_MultiThreaded) {
if (getuid() != 0) {
GTEST_SKIP() << "Skipping test, must be run as root.";
return;
}
// Test parameters
constexpr auto num_threads = 10;
constexpr auto run_time = 200ms;
std::unique_ptr<selabel_handle, decltype(&selabel_close)> sehandle(
selinux_android_file_context_handle(), &selabel_close);
ASSERT_TRUE(sehandle);
struct {
const char* file;
int mode;
std::string expected_context;
} files_and_modes[] = {
{"/dev/zero", 020666, ""},
{"/dev/null", 020666, ""},
{"/dev/random", 020666, ""},
{"/dev/urandom", 020666, ""},
};
// Precondition, ensure that we can lookup all of these from a single thread, and store the
// expected context for each.
for (size_t i = 0; i < arraysize(files_and_modes); ++i) {
char* secontext;
ASSERT_EQ(0, selabel_lookup(sehandle.get(), &secontext, files_and_modes[i].file,
files_and_modes[i].mode));
files_and_modes[i].expected_context = secontext;
freecon(secontext);
}
// Now that we know we can access them, and what their context should be, run in parallel.
std::atomic_bool stopped = false;
std::atomic_uint num_api_failures = 0;
std::atomic_uint num_context_check_failures = 0;
std::atomic_uint num_successes = 0;
auto thread_function = [&]() {
while (!stopped) {
for (size_t i = 0; i < arraysize(files_and_modes); ++i) {
char* secontext;
int result = selabel_lookup(sehandle.get(), &secontext, files_and_modes[i].file,
files_and_modes[i].mode);
if (result != 0) {
num_api_failures++;
} else {
if (files_and_modes[i].expected_context != secontext) {
num_context_check_failures++;
} else {
num_successes++;
}
freecon(secontext);
}
}
}
};
std::vector<std::thread> threads;
std::generate_n(back_inserter(threads), num_threads,
[&]() { return std::thread(thread_function); });
std::this_thread::sleep_for(run_time);
stopped = true;
for (auto& thread : threads) {
thread.join();
}
EXPECT_EQ(0U, num_api_failures);
EXPECT_EQ(0U, num_context_check_failures);
EXPECT_GT(num_successes, 0U);
}
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