/*

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

 *

 * 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 http://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*! \file */

#include <config.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <ctype.h>

#include <errno.h>

#include <unistd.h>

#include <isc/dir.h>

#include <isc/magic.h>

#include <isc/netdb.h>

#include <isc/print.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

	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

	return (ISC_R_NOTIMPLEMENTED);

#endif

}

isc_result_t

isc_dir_createunique(char *templet) {

	isc_result_t result;

	char *x;

	char *p;

	int i;

	int pid;

	REQUIRE(templet != NULL);

	/*!

	 * \brief mkdtemp is not portable, so this emulates it.

	 */

	pid = getpid();

	/*

	 * Replace trailing Xs with the process-id, zero-filled.

	 */

	for (x = templet + strlen(templet) - 1; *x == 'X' && x >= templet;

	     x--, pid /= 10)

		*x = pid % 10 + '0';

	x++;			/* Set x to start of ex-Xs. */

	do {

		i = mkdir(templet, 0700);

		if (i == 0 || errno != EEXIST)

			break;

		/*

		 * The BSD algorithm.

		 */

		p = x;

		while (*p != '\0') {

			if (isdigit(*p & 0xff))

				*p = 'a';

			else if (*p != 'z')

				++*p;

			else {

				/*

				 * Reset character and move to next.

				 */

				*p++ = 'a';

				continue;

			}

			break;

		}

		if (*p == '\0') {

			/*

			 * Tried all combinations.  errno should already

			 * be EEXIST, but ensure it is anyway for

			 * isc__errno2result().

			 */

			errno = EEXIST;

			break;

		}

	} while (1);

	if (i == -1)

		result = isc__errno2result(errno);

	else

		result = ISC_R_SUCCESS;

	return (result);

}