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

/*
 * Copyright (c) 1989, 1991, 1993, 1995
 *	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[] = "@(#)getcwd.c	8.5 (Berkeley) 2/7/95";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/gen/getcwd.c,v 1.25 2003/10/29 10:45:01 tjr Exp $");

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

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

#define	ISDOT(dp) \
	(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
	    (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))

extern int __getcwd(char *, size_t);

char *
getcwd(pt, size)
	char *pt;
	size_t size;
{
	struct dirent *dp;
	DIR *dir = NULL;
	dev_t dev;
	ino_t ino;
	int first;
	char *bpt, *bup;
	struct stat s;
	dev_t root_dev;
	ino_t root_ino;
	size_t ptsize, upsize;
	int save_errno;
	char *ept, *eup, *up, c;

	/*
	 * If no buffer specified by the user, allocate one as necessary.
	 * If a buffer is specified, the size has to be non-zero.  The path
	 * is built from the end of the buffer backwards.
	 */
	if (pt) {
		ptsize = 0;
		if (!size) {
			errno = EINVAL;
			return (NULL);
		}
		if (size == 1) {
			errno = ERANGE;
			return (NULL);
		}
		ept = pt + size;
	} else {
		if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
			return (NULL);
		ept = pt + ptsize;
	}
	if (__getcwd(pt, ept - pt) == 0) {
		if (*pt != '/') {
			bpt = pt;
			ept = pt + strlen(pt) - 1;
			while (bpt < ept) {
				c = *bpt;
				*bpt++ = *ept;
				*ept-- = c;
			}
		}
		return (pt);
	}
	bpt = ept - 1;
	*bpt = '\0';

	/*
	 * Allocate bytes (1024 - malloc space) for the string of "../"'s.
	 * Should always be enough (it's 340 levels).  If it's not, allocate
	 * as necessary.  Special case the first stat, it's ".", not "..".
	 */
	if ((up = malloc(upsize = 1024 - 4)) == NULL)
		goto err;
	eup = up + MAXPATHLEN;
	bup = up;
	up[0] = '.';
	up[1] = '\0';

	/* Save root values, so know when to stop. */
	if (stat("/", &s))
		goto err;
	root_dev = s.st_dev;
	root_ino = s.st_ino;

	errno = 0;			/* XXX readdir has no error return. */

	for (first = 1;; first = 0) {
		/* Stat the current level. */
		if (lstat(up, &s))
			goto err;

		/* Save current node values. */
		ino = s.st_ino;
		dev = s.st_dev;

		/* Check for reaching root. */
		if (root_dev == dev && root_ino == ino) {
			*--bpt = '/';
			/*
			 * It's unclear that it's a requirement to copy the
			 * path to the beginning of the buffer, but it's always
			 * been that way and stuff would probably break.
			 */
			bcopy(bpt, pt, ept - bpt);
			free(up);
			return (pt);
		}

		/*
		 * Build pointer to the parent directory, allocating memory
		 * as necessary.  Max length is 3 for "../", the largest
		 * possible component name, plus a trailing NUL.
		 */
		if (bup + 3  + MAXNAMLEN + 1 >= eup) {
			if ((up = reallocf(up, upsize *= 2)) == NULL)
				goto err;
			bup = up;
			eup = up + upsize;
		}
		*bup++ = '.';
		*bup++ = '.';
		*bup = '\0';

		/* Open and stat parent directory. */
		if (!(dir = opendir(up)) || _fstat(dirfd(dir), &s))
			goto err;

		/* Add trailing slash for next directory. */
		*bup++ = '/';
		*bup = '\0';

		/*
		 * If it's a mount point, have to stat each element because
		 * the inode number in the directory is for the entry in the
		 * parent directory, not the inode number of the mounted file.
		 */
		save_errno = 0;
		if (s.st_dev == dev) {
			for (;;) {
				if (!(dp = readdir(dir)))
					goto notfound;
				if (dp->d_fileno == ino)
					break;
			}
		} else
			for (;;) {
				if (!(dp = readdir(dir)))
					goto notfound;
				if (ISDOT(dp))
					continue;
				bcopy(dp->d_name, bup, dp->d_namlen + 1);

				/* Save the first error for later. */
				if (lstat(up, &s)) {
					if (!save_errno)
						save_errno = errno;
					errno = 0;
					continue;
				}
				if (s.st_dev == dev && s.st_ino == ino)
					break;
			}

		/*
		 * Check for length of the current name, preceding slash,
		 * leading slash.
		 */
		if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
			size_t len, off;

			if (!ptsize) {
				errno = ERANGE;
				goto err;
			}
			off = bpt - pt;
			len = ept - bpt;
			if ((pt = reallocf(pt, ptsize *= 2)) == NULL)
				goto err;
			bpt = pt + off;
			ept = pt + ptsize;
			bcopy(bpt, ept - len, len);
			bpt = ept - len;
		}
		if (!first)
			*--bpt = '/';
		bpt -= dp->d_namlen;
		bcopy(dp->d_name, bpt, dp->d_namlen);
		(void) closedir(dir);
		dir = NULL;

		/* Truncate any file name. */
		*bup = '\0';
	}

notfound:
	/*
	 * If readdir set errno, use it, not any saved error; otherwise,
	 * didn't find the current directory in its parent directory, set
	 * errno to ENOENT.
	 */
	if (!errno)
		errno = save_errno ? save_errno : ENOENT;
	/* FALLTHROUGH */
err:
	save_errno = errno;

	if (ptsize)
		free(pt);
	if (dir)
		(void) closedir(dir);
	free(up);

	errno = save_errno;
	return (NULL);
}
Commit	Line	Data
e9ce8d39	1	/*
9385eb3d	2	* Copyright (c) 1989, 1991, 1993, 1995
e9ce8d39 A	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[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95";
	36	#endif /* LIBC_SCCS and not lint */
	37	#include <sys/cdefs.h>
3d9156a7	38	__FBSDID("$FreeBSD: src/lib/libc/gen/getcwd.c,v 1.25 2003/10/29 10:45:01 tjr Exp $");
e9ce8d39	39
9385eb3d	40	#include "namespace.h"
e9ce8d39 A	41	#include <sys/param.h>
	42	#include <sys/stat.h>
	43
	44	#include <dirent.h>
	45	#include <errno.h>
	46	#include <fcntl.h>
	47	#include <stdio.h>
	48	#include <stdlib.h>
	49	#include <string.h>
	50	#include <unistd.h>
9385eb3d	51	#include "un-namespace.h"
e9ce8d39 A	52
	53	#define ISDOT(dp) \
	54	(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' \|\| \
9385eb3d A	55	(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
	56
	57	extern int __getcwd(char *, size_t);
e9ce8d39 A	58
	59	char *
	60	getcwd(pt, size)
	61	char *pt;
	62	size_t size;
	63	{
9385eb3d A	64	struct dirent *dp;
9385eb3d A	65	DIR *dir = NULL;
e9ce8d39 A	66	dev_t dev;
e9ce8d39 A	67	ino_t ino;
9385eb3d A	68	int first;
9385eb3d A	69	char bpt, bup;
e9ce8d39 A	70	struct stat s;
	71	dev_t root_dev;
	72	ino_t root_ino;
	73	size_t ptsize, upsize;
	74	int save_errno;
9385eb3d	75	char ept, eup, *up, c;
e9ce8d39 A	76
	77	/*
	78	* If no buffer specified by the user, allocate one as necessary.
	79	* If a buffer is specified, the size has to be non-zero. The path
	80	* is built from the end of the buffer backwards.
	81	*/
	82	if (pt) {
	83	ptsize = 0;
	84	if (!size) {
	85	errno = EINVAL;
	86	return (NULL);
	87	}
9385eb3d A	88	if (size == 1) {
	89	errno = ERANGE;
	90	return (NULL);
	91	}
e9ce8d39 A	92	ept = pt + size;
	93	} else {
	94	if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
	95	return (NULL);
	96	ept = pt + ptsize;
	97	}
9385eb3d A	98	if (__getcwd(pt, ept - pt) == 0) {
	99	if (*pt != '/') {
	100	bpt = pt;
	101	ept = pt + strlen(pt) - 1;
	102	while (bpt < ept) {
	103	c = *bpt;
	104	bpt++ = ept;
	105	*ept-- = c;
	106	}
	107	}
	108	return (pt);
	109	}
e9ce8d39 A	110	bpt = ept - 1;
	111	*bpt = '\0';
	112
	113	/*
	114	* Allocate bytes (1024 - malloc space) for the string of "../"'s.
	115	* Should always be enough (it's 340 levels). If it's not, allocate
	116	* as necessary. Special case the first stat, it's ".", not "..".
	117	*/
	118	if ((up = malloc(upsize = 1024 - 4)) == NULL)
	119	goto err;
	120	eup = up + MAXPATHLEN;
	121	bup = up;
	122	up[0] = '.';
	123	up[1] = '\0';
	124
	125	/* Save root values, so know when to stop. */
	126	if (stat("/", &s))
	127	goto err;
	128	root_dev = s.st_dev;
	129	root_ino = s.st_ino;
	130
	131	errno = 0; /* XXX readdir has no error return. */
	132
	133	for (first = 1;; first = 0) {
	134	/* Stat the current level. */
	135	if (lstat(up, &s))
	136	goto err;
	137
	138	/* Save current node values. */
	139	ino = s.st_ino;
	140	dev = s.st_dev;
	141
	142	/* Check for reaching root. */
	143	if (root_dev == dev && root_ino == ino) {
	144	*--bpt = '/';
	145	/*
	146	* It's unclear that it's a requirement to copy the
	147	* path to the beginning of the buffer, but it's always
	148	* been that way and stuff would probably break.
	149	*/
9385eb3d	150	bcopy(bpt, pt, ept - bpt);
e9ce8d39 A	151	free(up);
	152	return (pt);
	153	}
	154
	155	/*
	156	* Build pointer to the parent directory, allocating memory
	157	* as necessary. Max length is 3 for "../", the largest
9385eb3d	158	* possible component name, plus a trailing NUL.
e9ce8d39 A	159	*/
e9ce8d39 A	160	if (bup + 3 + MAXNAMLEN + 1 >= eup) {
9385eb3d	161	if ((up = reallocf(up, upsize *= 2)) == NULL)
e9ce8d39 A	162	goto err;
	163	bup = up;
	164	eup = up + upsize;
	165	}
	166	*bup++ = '.';
	167	*bup++ = '.';
	168	*bup = '\0';
	169
	170	/* Open and stat parent directory. */
9385eb3d	171	if (!(dir = opendir(up)) \|\| _fstat(dirfd(dir), &s))
e9ce8d39 A	172	goto err;
	173
	174	/* Add trailing slash for next directory. */
	175	*bup++ = '/';
9385eb3d	176	*bup = '\0';
e9ce8d39 A	177
	178	/*
	179	* If it's a mount point, have to stat each element because
	180	* the inode number in the directory is for the entry in the
	181	* parent directory, not the inode number of the mounted file.
	182	*/
	183	save_errno = 0;
	184	if (s.st_dev == dev) {
	185	for (;;) {
	186	if (!(dp = readdir(dir)))
	187	goto notfound;
	188	if (dp->d_fileno == ino)
	189	break;
	190	}
	191	} else
	192	for (;;) {
	193	if (!(dp = readdir(dir)))
	194	goto notfound;
	195	if (ISDOT(dp))
	196	continue;
	197	bcopy(dp->d_name, bup, dp->d_namlen + 1);
	198
	199	/* Save the first error for later. */
	200	if (lstat(up, &s)) {
	201	if (!save_errno)
	202	save_errno = errno;
	203	errno = 0;
	204	continue;
	205	}
	206	if (s.st_dev == dev && s.st_ino == ino)
	207	break;
	208	}
	209
	210	/*
	211	* Check for length of the current name, preceding slash,
	212	* leading slash.
	213	*/
9385eb3d	214	if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
e9ce8d39 A	215	size_t len, off;
	216
	217	if (!ptsize) {
	218	errno = ERANGE;
	219	goto err;
	220	}
	221	off = bpt - pt;
	222	len = ept - bpt;
9385eb3d	223	if ((pt = reallocf(pt, ptsize *= 2)) == NULL)
e9ce8d39 A	224	goto err;
	225	bpt = pt + off;
	226	ept = pt + ptsize;
9385eb3d	227	bcopy(bpt, ept - len, len);
e9ce8d39 A	228	bpt = ept - len;
	229	}
	230	if (!first)
	231	*--bpt = '/';
	232	bpt -= dp->d_namlen;
	233	bcopy(dp->d_name, bpt, dp->d_namlen);
9385eb3d A	234	(void) closedir(dir);
9385eb3d A	235	dir = NULL;
e9ce8d39 A	236
	237	/* Truncate any file name. */
	238	*bup = '\0';
	239	}
	240
	241	notfound:
	242	/*
	243	* If readdir set errno, use it, not any saved error; otherwise,
	244	* didn't find the current directory in its parent directory, set
	245	* errno to ENOENT.
	246	*/
	247	if (!errno)
	248	errno = save_errno ? save_errno : ENOENT;
	249	/* FALLTHROUGH */
	250	err:
9385eb3d A	251	save_errno = errno;
9385eb3d A	252
e9ce8d39 A	253	if (ptsize)
e9ce8d39 A	254	free(pt);
9385eb3d A	255	if (dir)
9385eb3d A	256	(void) closedir(dir);
e9ce8d39	257	free(up);
9385eb3d A	258
9385eb3d A	259	errno = save_errno;
e9ce8d39 A	260	return (NULL);
e9ce8d39 A	261	}