/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*! \file */

#include <ctype.h>

#include <errno.h>

#include <netdb.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <unistd.h>

#include <isc/dir.h>

#include <isc/magic.h>

#include <isc/string.h>

#include <isc/util.h>

#include "errno2result.h"

#define ISC_DIR_MAGIC  ISC_MAGIC('D', 'I', 'R', '*')

#define VALID_DIR(dir) ISC_MAGIC_VALID(dir, ISC_DIR_MAGIC)

void

isc_dir_init(isc_dir_t *dir) {

  REQUIRE(dir != NULL);

  dir->entry.name[0] = '\0';

  dir->entry.length = 0;

  dir->handle = NULL;

  dir->magic = ISC_DIR_MAGIC;

}

/*!

 * \brief Allocate workspace and open directory stream. If either one fails,

 * NULL will be returned.

 */

isc_result_t

isc_dir_open(isc_dir_t *dir, const char *dirname) {

  char *p;

  isc_result_t result = ISC_R_SUCCESS;

  REQUIRE(VALID_DIR(dir));

  REQUIRE(dirname != NULL);

  /*

   * Copy directory name.  Need to have enough space for the name,

   * a possible path separator, the wildcard, and the final NUL.

   */

  if (strlen(dirname) + 3 > sizeof(dir->dirname)) {

    /* XXXDCL ? */

    return ISC_R_NOSPACE;

  }

  strlcpy(dir->dirname, dirname, sizeof(dir->dirname));

  /*

   * Append path separator, if needed, and "*".

   */

  p = dir->dirname + strlen(dir->dirname);

  if (dir->dirname < p && *(p - 1) != '/') {

    *p++ = '/';

  }

  *p++ = '*';

  *p = '\0';

  /*

   * Open stream.

   */

  dir->handle = opendir(dirname);

  if (dir->handle == NULL) {

    return isc__errno2result(errno);

  }

  return result;

}

/*!

 * \brief Return previously retrieved file or get next one.

 *

 * Unix's dirent has

 * separate open and read functions, but the Win32 and DOS interfaces open

 * the dir stream and reads the first file in one operation.

 */

isc_result_t

isc_dir_read(isc_dir_t *dir) {

  struct dirent *entry;

  REQUIRE(VALID_DIR(dir) && dir->handle != NULL);

  /*

   * Fetch next file in directory.

   */

  entry = readdir(dir->handle);

  if (entry == NULL) {

    return ISC_R_NOMORE;

  }

  /*

   * Make sure that the space for the name is long enough.

   */

  if (sizeof(dir->entry.name) <= strlen(entry->d_name)) {

    return ISC_R_UNEXPECTED;

  }

  strlcpy(dir->entry.name, entry->d_name, sizeof(dir->entry.name));

  /*

   * Some dirents have d_namlen, but it is not portable.

   */

  dir->entry.length = strlen(entry->d_name);

  return ISC_R_SUCCESS;

}

/*!

 * \brief Close directory stream.

 */

void

isc_dir_close(isc_dir_t *dir) {

  REQUIRE(VALID_DIR(dir) && dir->handle != NULL);

  (void)closedir(dir->handle);

  dir->handle = NULL;

}

/*!

 * \brief Reposition directory stream at start.

 */

isc_result_t

isc_dir_reset(isc_dir_t *dir) {

  REQUIRE(VALID_DIR(dir) && dir->handle != NULL);

  rewinddir(dir->handle);

  return ISC_R_SUCCESS;

}

isc_result_t

isc_dir_chdir(const char *dirname) {

  /*!

   * \brief Change the current directory to 'dirname'.

   */

  REQUIRE(dirname != NULL);

  if (chdir(dirname) < 0) {

    return isc__errno2result(errno);

  }

  return ISC_R_SUCCESS;

}

isc_result_t

isc_dir_chroot(const char *dirname) {

#ifdef HAVE_CHROOT

  void *tmp;

#endif /* ifdef HAVE_CHROOT */

  REQUIRE(dirname != NULL);

#ifdef HAVE_CHROOT

  /*

   * Try to use getservbyname and getprotobyname before chroot.

   * If WKS records are used in a zone under chroot, Name Service Switch

   * may fail to load library in chroot.

   * Do not report errors if it fails, we do not need any result now.

   */

  tmp = getprotobyname("udp");

  if (tmp != NULL) {

    (void)getservbyname("domain", "udp");

  }

  if (chroot(dirname) < 0 || chdir("/") < 0) {

    return isc__errno2result(errno);

  }

  return ISC_R_SUCCESS;

#else  /* ifdef HAVE_CHROOT */

  return ISC_R_NOTIMPLEMENTED;

#endif /* ifdef HAVE_CHROOT */

}