/*

 * libgit2 packfile fuzzer target.

 *

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include <stdio.h>

#include "git2.h"

#include "git2/sys/mempack.h"

#include "common.h"

#include "str.h"

#include "standalone_driver.h"

static git_odb *odb = NULL;

static git_odb_backend *mempack = NULL;

/* Arbitrary object to seed the ODB. */

static const unsigned char base_obj[] = { 07, 076 };

static const unsigned int base_obj_len = 2;

int LLVMFuzzerInitialize(int *argc, char ***argv)

{

  GIT_UNUSED(argc);

  GIT_UNUSED(argv);

  if (git_libgit2_init() < 0) {

    fprintf(stderr, "Failed to initialize libgit2\n");

    abort();

  }

  if (git_libgit2_opts(GIT_OPT_SET_PACK_MAX_OBJECTS, 10000000) < 0) {

    fprintf(stderr, "Failed to limit maximum pack object count\n");

    abort();

  }

  if (git_odb_new(&odb) < 0) {

    fprintf(stderr, "Failed to create the odb\n");

    abort();

  }

  if (git_mempack_new(&mempack) < 0) {

    fprintf(stderr, "Failed to create the mempack\n");

    abort();

  }

  if (git_odb_add_backend(odb, mempack, 999) < 0) {

    fprintf(stderr, "Failed to add the mempack\n");

    abort();

  }

  return 0;

}

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

  git_indexer_progress stats = {0, 0};

  git_indexer *indexer = NULL;

  git_str path = GIT_STR_INIT;

  git_oid oid;

  bool append_hash = false;

  int error;

  if (size == 0)

    return 0;

  if (!odb || !mempack) {

    fprintf(stderr, "Global state not initialized\n");

    abort();

  }

  git_mempack_reset(mempack);

  if (git_odb_write(&oid, odb, base_obj, base_obj_len, GIT_OBJECT_BLOB) < 0) {

    fprintf(stderr, "Failed to add an object to the odb\n");

    abort();

  }

#ifdef GIT_EXPERIMENTAL_SHA256

  error = git_indexer_new(&indexer, ".", NULL);

#else

  error = git_indexer_new(&indexer, ".", 0, odb, NULL);

#endif

  if (error < 0) {

    fprintf(stderr, "Failed to create the indexer: %s\n",

      git_error_last()->message);

    abort();

  }

  /*

   * If the first byte in the stream has the high bit set, append the

   * SHA1 hash so that the packfile is somewhat valid.

   */

  append_hash = *data & 0x80;

  ++data;

  --size;

  if (git_indexer_append(indexer, data, size, &stats) < 0)

    goto cleanup;

  if (append_hash) {

#ifdef GIT_EXPERIMENTAL_SHA256

    if (git_odb_hash(&oid, data, size, GIT_OBJECT_BLOB, GIT_OID_SHA1) < 0) {

      fprintf(stderr, "Failed to compute the SHA1 hash\n");

      abort();

    }

#else

    if (git_odb_hash(&oid, data, size, GIT_OBJECT_BLOB) < 0) {

      fprintf(stderr, "Failed to compute the SHA1 hash\n");

      abort();

    }

#endif

    if (git_indexer_append(indexer, &oid.id, GIT_OID_SHA1_SIZE, &stats) < 0) {

      goto cleanup;

    }

  }

  if (git_indexer_commit(indexer, &stats) < 0)

    goto cleanup;

  if (git_str_printf(&path, "pack-%s.idx", git_indexer_name(indexer)) < 0)

    goto cleanup;

  p_unlink(git_str_cstr(&path));

  git_str_clear(&path);

  if (git_str_printf(&path, "pack-%s.pack", git_indexer_name(indexer)) < 0)

    goto cleanup;

  p_unlink(git_str_cstr(&path));

cleanup:

  git_mempack_reset(mempack);

  git_indexer_free(indexer);

  git_str_dispose(&path);

  return 0;

}