/* Copyright 2021 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 <fcntl.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <unistd.h>

/*

 * Libdwarf library callers can only use these headers.

 */

#include "dwarf.h"

#include "libdwarf.h"

/*

 * Fuzzer function targeting dwarf_crc32

 */

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

  char filename[256];

  sprintf(filename, "/tmp/libfuzzer.%d", getpid());

  FILE *fp = fopen(filename, "wb");

  if (!fp) {

    return 0;

  }

  fwrite(data, size, 1, fp);

  fclose(fp);

  int fuzz_fd = 0;

  Dwarf_Ptr errarg = 0;

  Dwarf_Handler errhand = 0;

  Dwarf_Error error = 0;

  Dwarf_Debug dbg = 0;

  off_t size_left = 0;

  off_t fsize = 0;

  unsigned char *crcbuf = 0;

  int res = 0;

  fuzz_fd = open(filename, O_RDONLY);

  fsize = size_left = lseek(fuzz_fd, 0L, SEEK_END);

  if (fuzz_fd != -1) {

    dwarf_init_b(fuzz_fd, DW_GROUPNUMBER_ANY, errhand, errarg, &dbg, &error);

    /*  By not checking the return code, on a failed in we

        cannot dealloc the error field, so

        there is a leak from 

        _dwarf_special_no_dbg_error_malloc()  */

    res = dwarf_crc32(dbg, crcbuf, &error);

    dwarf_finish(dbg);

  }

  close(fuzz_fd);

  unlink(filename);

  return 0;

}