mkpath.c

/*
 * Copyright (c) 1983, 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include "config.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdint.h>
#include <string.h>

#include "extern.h"

/*
 * We're using AT_RESOLVE_BENEATH in a couple of places just for some
 * additional safety on platforms that support it, so it's not a hard
 * requirement.
 */
#ifndef AT_RESOLVE_BENEATH
# define AT_RESOLVE_BENEATH	0
#else /* AT_RESOLVE_BENEATH */
/*
 * We need to be able to pick out fstatat() errors due to 'sandbox'
 * restrictions on systems that support it, so we map the errno here.
 */
# ifdef ENOTCAPABLE
#  define AT_RESOLVE_BENEATH_ERRNO ENOTCAPABLE
# else
#  error This system supports AT_RESOLVE_BENEATH, but needs a mapping for ENOTCAPABLE
# endif
#endif /* !AT_RESOLVE_BENEATH */

/*
 * Code taken directly from mkdir(1).
 * Difference: added "mode".
 *
 * mkpath -- create directories.
 *	path     - path
 */
int
mkpath(char *path, mode_t mode)
{
	struct stat sb;
	char *slash;
	int done;

	slash = path;

	for (;;) {
		slash += strspn(slash, "/");
		slash += strcspn(slash, "/");

		done = (*slash == '\0');
		*slash = '\0';

		if (mkdir(path, mode) != 0) {
			int mkdir_errno = errno;

			if (stat(path, &sb) == -1) {
				/* Not there; use mkdir()s errno */
				errno = mkdir_errno;
				return (-1);
			}
			if (!S_ISDIR(sb.st_mode)) {
				/* Is there, but isn't a directory */
				errno = ENOTDIR;
				return (-1);
			}
		}

		if (done)
			break;

		*slash = '/';
	}

	return (0);
}

int
mkpathat(int fd, char *path, mode_t mode)
{
	struct stat	 sb;
	char		*slash;
	bool		 done;

	slash = path;

	for (;;) {
		slash += strspn(slash, "/");
		slash += strcspn(slash, "/");

		done = (*slash == '\0');
		*slash = '\0';

		if (mkdirat(fd, path, mode) != 0) {
			int mkdir_errno = errno;

			if (fstatat(fd, path, &sb, AT_RESOLVE_BENEATH) == -1) {
				/*
				 * fstatat() likely failed because the
				 * directory is not there, but there are
				 * other reasons.  We'll largely ignore
				 * those and just kick back the original
				 * mkdir() error, but if it's an
				 * AT_RESOLVE_BENEATH violation then we
				 * want to kick that back instead.
				 */
				*slash = '/';
#ifdef AT_RESOLVE_BENEATH_ERRNO
				if (errno == AT_RESOLVE_BENEATH_ERRNO)
					return -1;
#endif
				errno = mkdir_errno;
				return -1;
			}
			if (!S_ISDIR(sb.st_mode)) {
				/* Is there, but isn't a directory */
				errno = ENOTDIR;
				*slash = '/';
				return -1;
			}
		}

		if (done)
			break;

		*slash = '/';
	}

	return 0;
}