// Copyright 2021 The gVisor Authors.
//
// 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 <dirent.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/syscall.h>

#include <string>
#include <vector>

#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "test/util/capability_util.h"
#include "test/util/fs_util.h"
#include "test/util/temp_path.h"
#include "test/util/test_util.h"
#include "test/util/verity_util.h"

namespace gvisor {
namespace testing {

namespace {

class GetDentsTest : public ::testing::Test {
 protected:
  void SetUp() override {
    // Verity is implemented in VFS2.
    SKIP_IF(IsRunningWithVFS1());

    SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
    // Mount a tmpfs file system, to be wrapped by a verity fs.
    tmpfs_dir_ = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir());
    ASSERT_THAT(mount("", tmpfs_dir_.path().c_str(), "tmpfs", 0, ""),
                SyscallSucceeds());

    // Create a new file in the tmpfs mount.
    file_ = ASSERT_NO_ERRNO_AND_VALUE(
        TempPath::CreateFileWith(tmpfs_dir_.path(), kContents, 0777));
    filename_ = Basename(file_.path());
  }

  TempPath tmpfs_dir_;
  TempPath file_;
  std::string filename_;
};

TEST_F(GetDentsTest, GetDents) {
  std::string verity_dir = ASSERT_NO_ERRNO_AND_VALUE(
      MountVerity(tmpfs_dir_.path(), {EnableTarget(filename_, O_RDONLY)}));

  std::vector<std::string> expect = {".", "..", filename_};
  EXPECT_NO_ERRNO(DirContains(verity_dir, expect, /*exclude=*/{}));
}

TEST_F(GetDentsTest, Deleted) {
  std::string verity_dir = ASSERT_NO_ERRNO_AND_VALUE(
      MountVerity(tmpfs_dir_.path(), {EnableTarget(filename_, O_RDONLY)}));

  EXPECT_THAT(unlink(JoinPath(tmpfs_dir_.path(), filename_).c_str()),
              SyscallSucceeds());

  EXPECT_THAT(DirContains(verity_dir, /*expect=*/{}, /*exclude=*/{}),
              PosixErrorIs(EIO, ::testing::_));
}

TEST_F(GetDentsTest, Renamed) {
  std::string verity_dir = ASSERT_NO_ERRNO_AND_VALUE(
      MountVerity(tmpfs_dir_.path(), {EnableTarget(filename_, O_RDONLY)}));

  std::string new_file_name = "renamed-" + filename_;
  EXPECT_THAT(rename(JoinPath(tmpfs_dir_.path(), filename_).c_str(),
                     JoinPath(tmpfs_dir_.path(), new_file_name).c_str()),
              SyscallSucceeds());

  EXPECT_THAT(DirContains(verity_dir, /*expect=*/{}, /*exclude=*/{}),
              PosixErrorIs(EIO, ::testing::_));
}

}  // namespace

}  // namespace testing
}  // namespace gvisor