// Copyright 2020 Google LLC

//

// 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 <stddef.h>

#include <stdint.h>

#include <unistd.h>

#include <assert.h>

#include <sys/syscall.h>

#include <linux/memfd.h>

#include <fuzzer/FuzzedDataProvider.h>

#include "ext2fs/ext2fs.h"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

  enum FuzzerType {

    ext2fsImageBitmapRead,

    ext2fsImageInodeRead,

    ext2fsImageSuperRead,

    ext2fsImageBitmapWrite,

    ext2fsImageInodeWrite,

    ext2fsImageSuperWrite,

    kMaxValue = ext2fsImageSuperWrite

  };

  FuzzedDataProvider stream(data, size);

  const FuzzerType f = stream.ConsumeEnum<FuzzerType>();

  (void) stream.ConsumeIntegral<int>();

  // Keep this here to not spoil the corpus or reproducers

  static const char* fname = "ext2_test_file";

  // Write our data to a temp file.

  int fd = syscall(SYS_memfd_create, fname, 0);

  std::vector<char> buffer = stream.ConsumeRemainingBytes<char>();

  write(fd, buffer.data(), buffer.size());

  std::string fspath("/proc/self/fd/" + std::to_string(fd));

  ext2_filsys fs;

  errcode_t retval = ext2fs_open(

      fspath.c_str(),

      EXT2_FLAG_IGNORE_CSUM_ERRORS, 0, 0,

      unix_io_manager,

      &fs);

  if (!retval) {

    switch (f) {

      case ext2fsImageBitmapRead: {

        ext2fs_image_bitmap_read(fs, fd, 0);

        break;

      }

      case ext2fsImageInodeRead: {

        ext2fs_image_inode_read(fs, fd, 0);

        break;

      }

      case ext2fsImageSuperRead: {

        ext2fs_image_super_read(fs, fd, 0);

        break;

      }

      case ext2fsImageBitmapWrite: {

        ext2fs_image_bitmap_write(fs, fd, 0);

        break;

      }

      case ext2fsImageInodeWrite: {

        ext2fs_image_inode_write(fs, fd, 0);

        break;

      }

      case ext2fsImageSuperWrite: {

        ext2fs_image_super_write(fs, fd, 0);

        break;

      }

      default: {

        assert(false);

      }

    }

    ext2fs_close(fs);

  }

  close(fd);

  return 0;

}