/*

 *   This program is free software; you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation; either version 2 of the License, or

 *   (at your option) any later version.

 *

 *   This program is distributed in the hope that it will be useful,

 *   but WITHOUT ANY WARRANTY; without even the implied warranty of

 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *   GNU General Public License for more details.

 *

 *   You should have received a copy of the GNU General Public License

 *   along with this program; if not, write to the Free Software

 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA

 */

/**

 * $Id: 4ebec1b64138d9666671808c30937bcb5ab1f6ad $

 *

 * @file src/fuzzer/common.c

 * @brief Common initialization for fuzzers

 *

 * @copyright 2026 Network RADIUS SAS (legal@networkradius.com)

 */

RCSID("$Id: 4ebec1b64138d9666671808c30937bcb5ab1f6ad $")

#include <freeradius-devel/fuzzer/common.h>

TALLOC_CTX    *autofree = NULL;

fr_dict_t   *dict = NULL;

fr_dict_attr_t const  *root_da = NULL;

fr_dict_protocol_t  *dl_proto = NULL;

static void exitHandler(void)

{

  if (dl_proto && dl_proto->free) dl_proto->free();

  fr_dict_free(&dict, __FILE__);

  talloc_free(autofree);

  /*

   *  Ensure our atexit handlers run before any other

   *  atexit handlers registered by third party libraries.

   */

  fr_atexit_global_trigger_all();

}

/**  Perform all bootstrapping for the fuzzer.

 *

 */

int fuzzer_common_init(int *argc, char ***argv, bool load_proto)

{

  char const    *lib_dir    = getenv("FR_LIBRARY_PATH");

  char const    *dict_dir = getenv("FR_DICTIONARY_DIR");

  char const    *debug_lvl_str  = getenv("FR_DEBUG_LVL");

  char const    *panic_action = getenv("PANIC_ACTION");

  char const    *proto      = getenv("FR_LIBRARY_FUZZ_PROTOCOL");

  char const    *root_attr  = getenv("FR_FUZZER_ROOT_ATTR");

  char      *p, buffer[256];

  if (!argc || !argv || !*argv) return -1; /* shut up clang scan */

  fr_time_start();

  if (debug_lvl_str) {

    fr_debug_lvl = atoi(debug_lvl_str);

  }

  autofree = talloc_autofree_context();

  if (fr_fault_setup(autofree, panic_action, (*argv)[0]) < 0) {

    fr_perror("fuzzer: Failed to register fault handler: %s", fr_syserror(errno));

    return -1;

  }

  /*

   *  Setup atexit handlers to free any thread local

   *  memory on exit

   */

  fr_atexit_global_setup();

  /*

   *  Initialise the talloc fault handlers.

   */

  fr_talloc_fault_setup();

  /*

   *  Initialise the error stack _before_ we run any

   *  tests so there's no chance of the memory

   *  appearing as a leak the first time an error

   *  is generated.

   */

  fr_strerror_const("fuzz"); /* allocate the pools */

  fr_strerror_clear(); /* clears the message, leaves the pools */

  /*

   *  Setup our own internal atexit handler

   */

  if (atexit(exitHandler)) {

    fr_perror("fuzzer: Failed to register exit handler: %s", fr_syserror(errno));

    return -1;

  }

  /*

   *  Disable hostname lookups, so we don't produce spurious DNS

   *  queries, and there's no chance of spurious failures if

   *  it takes a long time to get a response.

   */

  fr_hostname_lookups = fr_reverse_lookups = false;

  /*

   *  Look for -D dir

   *

   *  If found, nuke it from the argument list.

   */

  if (!dict_dir) {

    int i, j;

    for (i = 0; i < *argc - 1; i++) {

      p = (*argv)[i];

      if ((p[0] == '-') && (p[1] == 'D')) {

        dict_dir = (*argv)[i + 1];

        for (j = i + 2; j < *argc; i++, j++) {

          (*argv)[i] = (*argv)[j];

        }

        *argc -= 2;

        break;

      }

    }

  }

#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION

  /*

   *  oss-fuzz puts the dictionaries, etc. into subdirectories named after the location of the

   *  binary.  So we find the directory of the binary, and append "/dict" or "/lib" to find

   *  dictionaries and libraries.

   */

  p = strrchr((*argv)[0], '/');

  if (p) {

    if (!dict_dir) {

      dict_dir = talloc_asprintf(autofree, "%.*s/dict", (int) (p - (*argv)[0]), (*argv)[0]);

      if (!dict_dir) return -1;

    }

    if (!lib_dir) {

      lib_dir = talloc_asprintf(autofree, "%.*s/lib", (int) (p - (*argv)[0]), (*argv)[0]);

      if (!lib_dir) return -1;

    }

  }

#endif

  if (!dict_dir) dict_dir = DICTDIR;

  if (!lib_dir) lib_dir = LIBDIR;

  /*

   *  Set the global search path for all dynamic libraries we load.

   */

  if (dl_search_global_path_set(lib_dir) < 0) {

    fr_perror("fuzzer: Failed setting library path");

    return -1;

  }

  /*

   *  When jobs=N is specified the fuzzer spawns worker processes via

   *  a shell. We have removed any -D dictdir argument that were

   *  supplied, so we pass it to our children via the environment.

   */

  if (setenv("FR_DICTIONARY_DIR", dict_dir, 1)) {

    fprintf(stderr, "Failed to set FR_DICTIONARY_DIR env variable\n");

    return -1;

  }

  if (!fr_dict_global_ctx_init(NULL, true, dict_dir)) {

    fr_perror("fuzzer: Failed initializing global dictionary context");

    return -1;

  }

  if (fr_dict_internal_afrom_file(&dict, FR_DICTIONARY_INTERNAL_DIR, __FILE__) < 0) {

    fr_perror("fuzzer: Failed initializing internal dictionary");

    return -1;

  }

  if (!load_proto) return 0;

  /*

   *  Get the name from the binary name of fuzzer_foo

   */

  if (!proto) {

    proto = strrchr((*argv)[0], '_');

    if (proto) proto++;

  }

  if (!proto) {

    fr_perror("Failed to find protocol for fuzzer");

    return -1;

  }

  if (root_attr) {

    root_da = fr_dict_attr_by_name(NULL, fr_dict_root(dict), root_attr);

    if (!root_da) {

      fr_perror("Failed to find root attribute '%s'", root_attr);

      return -1;

    }

  }

  /*

   *  Search in our symbol space first.  We may have been dynamically

   *  or statically linked to the library we're fuzzing...

   */

  snprintf(buffer, sizeof(buffer), "libfreeradius_%s_dict_protocol", proto);

  dl_proto = dlsym(RTLD_DEFAULT, buffer);

  if (!dl_proto) return 0;

  if (dl_proto->init && (dl_proto->init() < 0)) {

    fr_perror("fuzzer: Failed initializing library %s", buffer);

    return -1;

  }

  return 0;

}