[apple/libc.git] / gen / FreeBSD / opendir.c

/*
 * Copyright (c) 1983, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)opendir.c	8.8 (Berkeley) 5/1/95";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/gen/opendir.c,v 1.22 2004/08/14 17:46:10 stefanf Exp $");

#include "namespace.h"
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "un-namespace.h"

#include "telldir.h"
/*
 * Open a directory.
 */
DIR *
opendir(name)
	const char *name;
{

	return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
}

DIR *
__opendir2(name, flags)
	const char *name;
	int flags;
{
	DIR *dirp;
	int fd;
	int incr;
	int saved_errno;
	int unionstack;
	struct stat statb;

	/*
	 * stat() before _open() because opening of special files may be
	 * harmful.  _fstat() after open because the file may have changed.
	 */
	if (stat(name, &statb) != 0)
		return (NULL);
	if (!S_ISDIR(statb.st_mode)) {
		errno = ENOTDIR;
		return (NULL);
	}
	if ((fd = _open(name, O_RDONLY | O_NONBLOCK)) == -1)
		return (NULL);
	dirp = NULL;
	if (_fstat(fd, &statb) != 0)
		goto fail;
	if (!S_ISDIR(statb.st_mode)) {
		errno = ENOTDIR;
		goto fail;
	}
	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
	    (dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
		goto fail;

	dirp->dd_td = (struct _telldir *)((char *)dirp + sizeof(DIR));
	LIST_INIT(&dirp->dd_td->td_locq);
	dirp->dd_td->td_loccnt = 0;

	/*
	 * Use the system page size if that is a multiple of DIRBLKSIZ.
	 * Hopefully this can be a big win someday by allowing page
	 * trades to user space to be done by _getdirentries().
	 */
	incr = getpagesize();
	if ((incr % DIRBLKSIZ) != 0) 
		incr = DIRBLKSIZ;

	/*
	 * Determine whether this directory is the top of a union stack.
	 */
	if (flags & DTF_NODUP) {
		struct statfs sfb;

		if (_fstatfs(fd, &sfb) < 0)
			goto fail;
		unionstack = !strcmp(sfb.f_fstypename, "unionfs")
		    || (sfb.f_flags & MNT_UNION);
	} else {
		unionstack = 0;
	}

	if (unionstack) {
		int len = 0;
		int space = 0;
		char *buf = 0;
		char *ddptr = 0;
		char *ddeptr;
		int n;
		struct dirent **dpv;

		/*
		 * The strategy here is to read all the directory
		 * entries into a buffer, sort the buffer, and
		 * remove duplicate entries by setting the inode
		 * number to zero.
		 */

		do {
			/*
			 * Always make at least DIRBLKSIZ bytes
			 * available to _getdirentries
			 */
			if (space < DIRBLKSIZ) {
				space += incr;
				len += incr;
				buf = reallocf(buf, len);
				if (buf == NULL)
					goto fail;
				ddptr = buf + (len - space);
			}

			n = _getdirentries(fd, ddptr, space, &dirp->dd_seek);
			if (n > 0) {
				ddptr += n;
				space -= n;
			}
		} while (n > 0);

		ddeptr = ddptr;
		flags |= __DTF_READALL;

		/*
		 * Re-open the directory.
		 * This has the effect of rewinding back to the
		 * top of the union stack and is needed by
		 * programs which plan to fchdir to a descriptor
		 * which has also been read -- see fts.c.
		 */
		if (flags & DTF_REWIND) {
			(void)_close(fd);
			if ((fd = _open(name, O_RDONLY)) == -1) {
				saved_errno = errno;
				free(buf);
				free(dirp);
				errno = saved_errno;
				return (NULL);
			}
		}

		/*
		 * There is now a buffer full of (possibly) duplicate
		 * names.
		 */
		dirp->dd_buf = buf;

		/*
		 * Go round this loop twice...
		 *
		 * Scan through the buffer, counting entries.
		 * On the second pass, save pointers to each one.
		 * Then sort the pointers and remove duplicate names.
		 */
		for (dpv = 0;;) {
			n = 0;
			ddptr = buf;
			while (ddptr < ddeptr) {
				struct dirent *dp;

				dp = (struct dirent *) ddptr;
				if ((long)dp & 03L)
					break;
				if ((dp->d_reclen <= 0) ||
				    (dp->d_reclen > (ddeptr + 1 - ddptr)))
					break;
				ddptr += dp->d_reclen;
				if (dp->d_fileno) {
					if (dpv)
						dpv[n] = dp;
					n++;
				}
			}

			if (dpv) {
				struct dirent *xp;

				/*
				 * This sort must be stable.
				 */
				mergesort(dpv, n, sizeof(*dpv), alphasort);

				dpv[n] = NULL;
				xp = NULL;

				/*
				 * Scan through the buffer in sort order,
				 * zapping the inode number of any
				 * duplicate names.
				 */
				for (n = 0; dpv[n]; n++) {
					struct dirent *dp = dpv[n];

					if ((xp == NULL) ||
					    strcmp(dp->d_name, xp->d_name)) {
						xp = dp;
					} else {
						dp->d_fileno = 0;
					}
					if (dp->d_type == DT_WHT &&
					    (flags & DTF_HIDEW))
						dp->d_fileno = 0;
				}

				free(dpv);
				break;
			} else {
				dpv = malloc((n+1) * sizeof(struct dirent *));
				if (dpv == NULL)
					break;
			}
		}

		dirp->dd_len = len;
		dirp->dd_size = ddptr - dirp->dd_buf;
	} else {
		dirp->dd_len = incr;
		dirp->dd_size = 0;
		dirp->dd_buf = malloc(dirp->dd_len);
		if (dirp->dd_buf == NULL)
			goto fail;
		dirp->dd_seek = 0;
		flags &= ~DTF_REWIND;
	}

	dirp->dd_loc = 0;
	dirp->dd_fd = fd;
	dirp->dd_flags = flags;
	dirp->dd_lock = NULL;

	/*
	 * Set up seek point for rewinddir.
	 */
	dirp->dd_rewind = telldir(dirp);

	return (dirp);

fail:
	saved_errno = errno;
	free(dirp);
	(void)_close(fd);
	errno = saved_errno;
	return (NULL);
}
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1983, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
9385eb3d A	34	#if defined(LIBC_SCCS) && !defined(lint)
	35	static char sccsid[] = "@(#)opendir.c 8.8 (Berkeley) 5/1/95";
	36	#endif /* LIBC_SCCS and not lint */
	37	#include <sys/cdefs.h>
3d9156a7	38	__FBSDID("$FreeBSD: src/lib/libc/gen/opendir.c,v 1.22 2004/08/14 17:46:10 stefanf Exp $");
e9ce8d39	39
9385eb3d	40	#include "namespace.h"
e9ce8d39 A	41	#include <sys/param.h>
	42	#include <sys/mount.h>
	43	#include <sys/stat.h>
	44
	45	#include <dirent.h>
	46	#include <errno.h>
	47	#include <fcntl.h>
	48	#include <stdlib.h>
e9ce8d39	49	#include <string.h>
9385eb3d A	50	#include <unistd.h>
	51	#include "un-namespace.h"
	52
	53	#include "telldir.h"
	54	/*
	55	* Open a directory.
	56	*/
	57	DIR *
	58	opendir(name)
	59	const char *name;
	60	{
	61
	62	return (__opendir2(name, DTF_HIDEW\|DTF_NODUP));
	63	}
e9ce8d39	64
9385eb3d A	65	DIR *
	66	__opendir2(name, flags)
	67	const char *name;
	68	int flags;
e9ce8d39 A	69	{
	70	DIR *dirp;
	71	int fd;
	72	int incr;
9385eb3d	73	int saved_errno;
e9ce8d39 A	74	int unionstack;
	75	struct stat statb;
	76
9385eb3d A	77	/*
	78	* stat() before _open() because opening of special files may be
	79	* harmful. _fstat() after open because the file may have changed.
	80	*/
	81	if (stat(name, &statb) != 0)
e9ce8d39	82	return (NULL);
9385eb3d	83	if (!S_ISDIR(statb.st_mode)) {
e9ce8d39	84	errno = ENOTDIR;
e9ce8d39 A	85	return (NULL);
e9ce8d39 A	86	}
9385eb3d	87	if ((fd = _open(name, O_RDONLY \| O_NONBLOCK)) == -1)
e9ce8d39	88	return (NULL);
9385eb3d A	89	dirp = NULL;
	90	if (_fstat(fd, &statb) != 0)
	91	goto fail;
	92	if (!S_ISDIR(statb.st_mode)) {
	93	errno = ENOTDIR;
	94	goto fail;
e9ce8d39	95	}
9385eb3d A	96	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 \|\|
	97	(dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
	98	goto fail;
	99
3d9156a7	100	dirp->dd_td = (struct _telldir )((char )dirp + sizeof(DIR));
9385eb3d A	101	LIST_INIT(&dirp->dd_td->td_locq);
9385eb3d A	102	dirp->dd_td->td_loccnt = 0;
e9ce8d39 A	103
e9ce8d39 A	104	/*
9385eb3d	105	* Use the system page size if that is a multiple of DIRBLKSIZ.
e9ce8d39	106	* Hopefully this can be a big win someday by allowing page
9385eb3d	107	* trades to user space to be done by _getdirentries().
e9ce8d39	108	*/
9385eb3d A	109	incr = getpagesize();
9385eb3d A	110	if ((incr % DIRBLKSIZ) != 0)
e9ce8d39 A	111	incr = DIRBLKSIZ;
	112
	113	/*
	114	* Determine whether this directory is the top of a union stack.
	115	*/
	116	if (flags & DTF_NODUP) {
	117	struct statfs sfb;
	118
9385eb3d A	119	if (_fstatfs(fd, &sfb) < 0)
9385eb3d A	120	goto fail;
3d9156a7	121	unionstack = !strcmp(sfb.f_fstypename, "unionfs")
9385eb3d	122	\|\| (sfb.f_flags & MNT_UNION);
e9ce8d39 A	123	} else {
	124	unionstack = 0;
	125	}
	126
	127	if (unionstack) {
	128	int len = 0;
	129	int space = 0;
	130	char *buf = 0;
	131	char *ddptr = 0;
	132	char *ddeptr;
	133	int n;
	134	struct dirent **dpv;
	135
	136	/*
	137	* The strategy here is to read all the directory
	138	* entries into a buffer, sort the buffer, and
	139	* remove duplicate entries by setting the inode
	140	* number to zero.
	141	*/
	142
	143	do {
	144	/*
	145	* Always make at least DIRBLKSIZ bytes
9385eb3d	146	* available to _getdirentries
e9ce8d39 A	147	*/
	148	if (space < DIRBLKSIZ) {
	149	space += incr;
	150	len += incr;
9385eb3d A	151	buf = reallocf(buf, len);
	152	if (buf == NULL)
	153	goto fail;
e9ce8d39 A	154	ddptr = buf + (len - space);
	155	}
	156
9385eb3d	157	n = _getdirentries(fd, ddptr, space, &dirp->dd_seek);
e9ce8d39 A	158	if (n > 0) {
	159	ddptr += n;
	160	space -= n;
	161	}
	162	} while (n > 0);
	163
	164	ddeptr = ddptr;
	165	flags \|= __DTF_READALL;
	166
	167	/*
	168	* Re-open the directory.
	169	* This has the effect of rewinding back to the
	170	* top of the union stack and is needed by
	171	* programs which plan to fchdir to a descriptor
	172	* which has also been read -- see fts.c.
	173	*/
	174	if (flags & DTF_REWIND) {
9385eb3d A	175	(void)_close(fd);
	176	if ((fd = _open(name, O_RDONLY)) == -1) {
	177	saved_errno = errno;
e9ce8d39 A	178	free(buf);
e9ce8d39 A	179	free(dirp);
9385eb3d	180	errno = saved_errno;
e9ce8d39 A	181	return (NULL);
	182	}
	183	}
	184
	185	/*
	186	* There is now a buffer full of (possibly) duplicate
	187	* names.
	188	*/
	189	dirp->dd_buf = buf;
	190
	191	/*
	192	* Go round this loop twice...
	193	*
	194	* Scan through the buffer, counting entries.
	195	* On the second pass, save pointers to each one.
	196	* Then sort the pointers and remove duplicate names.
	197	*/
	198	for (dpv = 0;;) {
	199	n = 0;
	200	ddptr = buf;
	201	while (ddptr < ddeptr) {
	202	struct dirent *dp;
	203
	204	dp = (struct dirent *) ddptr;
9385eb3d	205	if ((long)dp & 03L)
e9ce8d39 A	206	break;
	207	if ((dp->d_reclen <= 0) \|\|
	208	(dp->d_reclen > (ddeptr + 1 - ddptr)))
	209	break;
	210	ddptr += dp->d_reclen;
	211	if (dp->d_fileno) {
	212	if (dpv)
	213	dpv[n] = dp;
	214	n++;
	215	}
	216	}
	217
	218	if (dpv) {
	219	struct dirent *xp;
	220
	221	/*
	222	* This sort must be stable.
	223	*/
	224	mergesort(dpv, n, sizeof(*dpv), alphasort);
	225
	226	dpv[n] = NULL;
	227	xp = NULL;
	228
	229	/*
	230	* Scan through the buffer in sort order,
	231	* zapping the inode number of any
	232	* duplicate names.
	233	*/
	234	for (n = 0; dpv[n]; n++) {
	235	struct dirent *dp = dpv[n];
	236
	237	if ((xp == NULL) \|\|
	238	strcmp(dp->d_name, xp->d_name)) {
	239	xp = dp;
	240	} else {
	241	dp->d_fileno = 0;
	242	}
	243	if (dp->d_type == DT_WHT &&
	244	(flags & DTF_HIDEW))
	245	dp->d_fileno = 0;
	246	}
	247
	248	free(dpv);
	249	break;
	250	} else {
	251	dpv = malloc((n+1) * sizeof(struct dirent *));
	252	if (dpv == NULL)
	253	break;
	254	}
	255	}
	256
	257	dirp->dd_len = len;
	258	dirp->dd_size = ddptr - dirp->dd_buf;
	259	} else {
	260	dirp->dd_len = incr;
3d9156a7	261	dirp->dd_size = 0;
e9ce8d39	262	dirp->dd_buf = malloc(dirp->dd_len);
9385eb3d A	263	if (dirp->dd_buf == NULL)
9385eb3d A	264	goto fail;
e9ce8d39 A	265	dirp->dd_seek = 0;
	266	flags &= ~DTF_REWIND;
	267	}
	268
	269	dirp->dd_loc = 0;
	270	dirp->dd_fd = fd;
	271	dirp->dd_flags = flags;
9385eb3d	272	dirp->dd_lock = NULL;
e9ce8d39 A	273
	274	/*
	275	* Set up seek point for rewinddir.
	276	*/
	277	dirp->dd_rewind = telldir(dirp);
	278
	279	return (dirp);
e9ce8d39	280
9385eb3d A	281	fail:
	282	saved_errno = errno;
	283	free(dirp);
	284	(void)_close(fd);
	285	errno = saved_errno;
	286	return (NULL);
e9ce8d39	287	}