[apple/libc.git] / gen / opendir-fbsd.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 <pthread.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;

	/*
	 * Use O_DIRECTORY to only open directories (because opening of
	 * special files may be harmful).  errno is set to ENOTDIR if
	 * not a directory.
	 */
	if ((fd = _open(name, O_RDONLY | O_NONBLOCK | O_DIRECTORY)) == -1)
		return (NULL);
	dirp = NULL;
	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);
			}

#if __DARWIN_64_BIT_INO_T
			n = __getdirentries64(fd, ddptr, space, &dirp->dd_td->seekoff);
#else /* !__DARWIN_64_BIT_INO_T */
			n = _getdirentries(fd, ddptr, space, &dirp->dd_seek);
#endif /* __DARWIN_64_BIT_INO_T */
			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;
#if __DARWIN_64_BIT_INO_T
		dirp->dd_td->seekoff = 0;
#else /* !__DARWIN_64_BIT_INO_T */
		dirp->dd_seek = 0;
#endif /* __DARWIN_64_BIT_INO_T */
		flags &= ~DTF_REWIND;
	}

	dirp->dd_loc = 0;
	dirp->dd_fd = fd;
	dirp->dd_flags = flags;
	dirp->dd_lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;

	/*
	 * 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
224c7076 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
	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>
	38	__FBSDID("$FreeBSD: src/lib/libc/gen/opendir.c,v 1.22 2004/08/14 17:46:10 stefanf Exp $");
	39
	40	#include "namespace.h"
	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>
	49	#include <string.h>
	50	#include <unistd.h>
	51	#include <pthread.h>
	52	#include "un-namespace.h"
	53
	54	#include "telldir.h"
	55	/*
	56	* Open a directory.
	57	*/
	58	DIR *
	59	opendir(name)
	60	const char *name;
	61	{
	62
	63	return (__opendir2(name, DTF_HIDEW\|DTF_NODUP));
	64	}
65
66	DIR *
67	__opendir2(name, flags)
68	const char *name;
69	int flags;
70	{
71	DIR *dirp;
72	int fd;
73	int incr;
74	int saved_errno;
75	int unionstack;
76
77	/*
78	* Use O_DIRECTORY to only open directories (because opening of
79	* special files may be harmful). errno is set to ENOTDIR if
80	* not a directory.
81	*/
82	if ((fd = _open(name, O_RDONLY \| O_NONBLOCK \| O_DIRECTORY)) == -1)
83	return (NULL);
84	dirp = NULL;
85	if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 \|\|
86	(dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
87	goto fail;
88
89	dirp->dd_td = (struct _telldir )((char )dirp + sizeof(DIR));
90	LIST_INIT(&dirp->dd_td->td_locq);
91	dirp->dd_td->td_loccnt = 0;
92
93	/*
94	* Use the system page size if that is a multiple of DIRBLKSIZ.
95	* Hopefully this can be a big win someday by allowing page
96	* trades to user space to be done by _getdirentries().
97	*/
98	incr = getpagesize();
99	if ((incr % DIRBLKSIZ) != 0)
100	incr = DIRBLKSIZ;
101
102	/*
103	* Determine whether this directory is the top of a union stack.
104	*/
105	if (flags & DTF_NODUP) {
106	struct statfs sfb;
107
108	if (_fstatfs(fd, &sfb) < 0)
109	goto fail;
110	unionstack = !strcmp(sfb.f_fstypename, "unionfs")
111	\|\| (sfb.f_flags & MNT_UNION);
112	} else {
113	unionstack = 0;
114	}
115
116	if (unionstack) {
117	int len = 0;
118	int space = 0;
119	char *buf = 0;
120	char *ddptr = 0;
121	char *ddeptr;
122	int n;
123	struct dirent **dpv;
124
125	/*
126	* The strategy here is to read all the directory
127	* entries into a buffer, sort the buffer, and
128	* remove duplicate entries by setting the inode
129	* number to zero.
130	*/
131
132	do {
133	/*
134	* Always make at least DIRBLKSIZ bytes
135	* available to _getdirentries
136	*/
137	if (space < DIRBLKSIZ) {
138	space += incr;
139	len += incr;
140	buf = reallocf(buf, len);
141	if (buf == NULL)
142	goto fail;
143	ddptr = buf + (len - space);
144	}
145
146	#if __DARWIN_64_BIT_INO_T
147	n = __getdirentries64(fd, ddptr, space, &dirp->dd_td->seekoff);
148	#else /* !__DARWIN_64_BIT_INO_T */
149	n = _getdirentries(fd, ddptr, space, &dirp->dd_seek);
150	#endif /* __DARWIN_64_BIT_INO_T */
151	if (n > 0) {
152	ddptr += n;
153	space -= n;
154	}
155	} while (n > 0);
156
157	ddeptr = ddptr;
158	flags \|= __DTF_READALL;
159
160	/*
161	* Re-open the directory.
162	* This has the effect of rewinding back to the
163	* top of the union stack and is needed by
164	* programs which plan to fchdir to a descriptor
165	* which has also been read -- see fts.c.
166	*/
167	if (flags & DTF_REWIND) {
168	(void)_close(fd);
169	if ((fd = _open(name, O_RDONLY)) == -1) {
170	saved_errno = errno;
171	free(buf);
172	free(dirp);
173	errno = saved_errno;
174	return (NULL);
175	}
176	}
177
178	/*
179	* There is now a buffer full of (possibly) duplicate
180	* names.
181	*/
182	dirp->dd_buf = buf;
183
184	/*
185	* Go round this loop twice...
186	*
187	* Scan through the buffer, counting entries.
188	* On the second pass, save pointers to each one.
189	* Then sort the pointers and remove duplicate names.
190	*/
191	for (dpv = 0;;) {
192	n = 0;
193	ddptr = buf;
194	while (ddptr < ddeptr) {
195	struct dirent *dp;
196
197	dp = (struct dirent *) ddptr;
198	if ((long)dp & 03L)
199	break;
200	if ((dp->d_reclen <= 0) \|\|
201	(dp->d_reclen > (ddeptr + 1 - ddptr)))
202	break;
203	ddptr += dp->d_reclen;
204	if (dp->d_fileno) {
205	if (dpv)
206	dpv[n] = dp;
207	n++;
208	}
209	}
210
211	if (dpv) {
212	struct dirent *xp;
213
214	/*
215	* This sort must be stable.
216	*/
217	mergesort(dpv, n, sizeof(*dpv), alphasort);
218
219	dpv[n] = NULL;
220	xp = NULL;
221
222	/*
223	* Scan through the buffer in sort order,
224	* zapping the inode number of any
225	* duplicate names.
226	*/
227	for (n = 0; dpv[n]; n++) {
228	struct dirent *dp = dpv[n];
229
230	if ((xp == NULL) \|\|
231	strcmp(dp->d_name, xp->d_name)) {
232	xp = dp;
233	} else {
234	dp->d_fileno = 0;
235	}
236	if (dp->d_type == DT_WHT &&
237	(flags & DTF_HIDEW))
238	dp->d_fileno = 0;
239	}
240
241	free(dpv);
242	break;
243	} else {
244	dpv = malloc((n+1) * sizeof(struct dirent *));
245	if (dpv == NULL)
246	break;
247	}
248	}
249
250	dirp->dd_len = len;
251	dirp->dd_size = ddptr - dirp->dd_buf;
252	} else {
253	dirp->dd_len = incr;
254	dirp->dd_size = 0;
255	dirp->dd_buf = malloc(dirp->dd_len);
256	if (dirp->dd_buf == NULL)
257	goto fail;
258	#if __DARWIN_64_BIT_INO_T
259	dirp->dd_td->seekoff = 0;
260	#else /* !__DARWIN_64_BIT_INO_T */
261	dirp->dd_seek = 0;
262	#endif /* __DARWIN_64_BIT_INO_T */
263	flags &= ~DTF_REWIND;
264	}
265
266	dirp->dd_loc = 0;
267	dirp->dd_fd = fd;
268	dirp->dd_flags = flags;
269	dirp->dd_lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
270
271	/*
272	* Set up seek point for rewinddir.
273	*/
274	dirp->dd_rewind = telldir(dirp);
275
276	return (dirp);
277
278	fail:
279	saved_errno = errno;
280	free(dirp);
281	(void)_close(fd);
282	errno = saved_errno;
283	return (NULL);
284	}