[gssapi-openssh.git] / openssh / openbsd-compat / getcwd.c

/* OPENBSD ORIGINAL: lib/libc/gen/getcwd.c */

/*
 * Copyright (c) 1989, 1991, 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 "includes.h"

#if !defined(HAVE_GETCWD)

#if defined(LIBC_SCCS) && !defined(lint)
static char rcsid[] = "$OpenBSD: getcwd.c,v 1.9 2003/06/11 21:03:10 deraadt Exp $";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/stat.h>
#include <errno.h>
#include <dirent.h>
#include <sys/dir.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "includes.h"

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

char *
getcwd(char *pt, size_t size)
{
	register struct dirent *dp;
	register DIR *dir = NULL;
	register dev_t dev;
	register ino_t ino;
	register int first;
	register 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;

	/*
	 * 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);
		}
		ept = pt + size;
	} else {
		if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
			return (NULL);
		ept = pt + ptsize;
	}
	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.
			 */
			memmove(pt, bpt, 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) {
			char *nup;

			if ((nup = realloc(up, upsize *= 2)) == NULL)
				goto err;
			up = nup;
			bup = up;
			eup = up + upsize;
		}
		*bup++ = '.';
		*bup++ = '.';
		*bup = '\0';

		/* Open and stat parent directory. 
		 * RACE?? - replaced fstat(dirfd(dir), &s) w/ lstat(up,&s) 
                 */
		if (!(dir = opendir(up)) || lstat(up,&s))
			goto err;

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

		/*
		 * 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;
				memmove(bup, dp->d_name, 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;
			char *npt;

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

		/* 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:
	if (ptsize)
		free(pt);
	if (up)
		free(up);
	if (dir)
		(void)closedir(dir);
	return (NULL);
}

#endif /* !defined(HAVE_GETCWD) */
Commit	Line	Data
cdd66111	1	/* OPENBSD ORIGINAL: lib/libc/gen/getcwd.c */
cdd66111	2
3c0ef626	3	/*
	4	* Copyright (c) 1989, 1991, 1993
	5	* The Regents of the University of California. All rights reserved.
	6	*
	7	* Redistribution and use in source and binary forms, with or without
	8	* modification, are permitted provided that the following conditions
	9	* are met:
	10	* 1. Redistributions of source code must retain the above copyright
	11	* notice, this list of conditions and the following disclaimer.
	12	* 2. Redistributions in binary form must reproduce the above copyright
	13	* notice, this list of conditions and the following disclaimer in the
	14	* documentation and/or other materials provided with the distribution.
0fff78ff	15	* 3. Neither the name of the University nor the names of its contributors
	16	* may be used to endorse or promote products derived from this software
	17	* without specific prior written permission.
3c0ef626	18	*
	19	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	20	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	21	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	22	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	23	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	24	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	25	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	26	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	27	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	28	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	29	* SUCH DAMAGE.
	30	*/
	31
41b2f314	32	#include "includes.h"
3c0ef626	33
	34	#if !defined(HAVE_GETCWD)
	35
	36	#if defined(LIBC_SCCS) && !defined(lint)
0fff78ff	37	static char rcsid[] = "$OpenBSD: getcwd.c,v 1.9 2003/06/11 21:03:10 deraadt Exp $";
3c0ef626	38	#endif /* LIBC_SCCS and not lint */
	39
	40	#include <sys/param.h>
	41	#include <sys/stat.h>
	42	#include <errno.h>
	43	#include <dirent.h>
	44	#include <sys/dir.h>
	45	#include <stdio.h>
	46	#include <stdlib.h>
	47	#include <string.h>
	48	#include "includes.h"
	49
	50	#define ISDOT(dp) \
	51	(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' \|\| \
	52	(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
	53
	54	char *
0fff78ff	55	getcwd(char *pt, size_t size)
3c0ef626	56	{
	57	register struct dirent *dp;
	58	register DIR *dir = NULL;
	59	register dev_t dev;
	60	register ino_t ino;
	61	register int first;
	62	register char bpt, bup;
	63	struct stat s;
	64	dev_t root_dev;
	65	ino_t root_ino;
	66	size_t ptsize, upsize;
	67	int save_errno;
	68	char ept, eup, *up;
	69
	70	/*
	71	* If no buffer specified by the user, allocate one as necessary.
	72	* If a buffer is specified, the size has to be non-zero. The path
	73	* is built from the end of the buffer backwards.
	74	*/
	75	if (pt) {
	76	ptsize = 0;
	77	if (!size) {
	78	errno = EINVAL;
	79	return (NULL);
	80	}
	81	ept = pt + size;
	82	} else {
	83	if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
	84	return (NULL);
	85	ept = pt + ptsize;
	86	}
	87	bpt = ept - 1;
	88	*bpt = '\0';
	89
	90	/*
	91	* Allocate bytes (1024 - malloc space) for the string of "../"'s.
	92	* Should always be enough (it's 340 levels). If it's not, allocate
	93	* as necessary. Special * case the first stat, it's ".", not "..".
	94	*/
	95	if ((up = malloc(upsize = 1024 - 4)) == NULL)
	96	goto err;
	97	eup = up + MAXPATHLEN;
	98	bup = up;
	99	up[0] = '.';
	100	up[1] = '\0';
	101
	102	/* Save root values, so know when to stop. */
	103	if (stat("/", &s))
	104	goto err;
	105	root_dev = s.st_dev;
	106	root_ino = s.st_ino;
	107
	108	errno = 0; /* XXX readdir has no error return. */
	109
	110	for (first = 1;; first = 0) {
	111	/* Stat the current level. */
	112	if (lstat(up, &s))
	113	goto err;
	114
	115	/* Save current node values. */
	116	ino = s.st_ino;
	117	dev = s.st_dev;
	118
	119	/* Check for reaching root. */
120	if (root_dev == dev && root_ino == ino) {
121	*--bpt = '/';
122	/*
123	* It's unclear that it's a requirement to copy the
124	* path to the beginning of the buffer, but it's always
125	* been that way and stuff would probably break.
126	*/
127	memmove(pt, bpt, ept - bpt);
128	free(up);
129	return (pt);
130	}
131
132	/*
133	* Build pointer to the parent directory, allocating memory
134	* as necessary. Max length is 3 for "../", the largest
6a9b3198	135	* possible component name, plus a trailing NUL.
3c0ef626	136	*/
	137	if (bup + 3 + MAXNAMLEN + 1 >= eup) {
	138	char *nup;
	139
	140	if ((nup = realloc(up, upsize *= 2)) == NULL)
	141	goto err;
	142	up = nup;
	143	bup = up;
	144	eup = up + upsize;
	145	}
	146	*bup++ = '.';
	147	*bup++ = '.';
	148	*bup = '\0';
	149
	150	/* Open and stat parent directory.
	151	* RACE?? - replaced fstat(dirfd(dir), &s) w/ lstat(up,&s)
	152	*/
	153	if (!(dir = opendir(up)) \|\| lstat(up,&s))
	154	goto err;
	155
	156	/* Add trailing slash for next directory. */
	157	*bup++ = '/';
	158
	159	/*
	160	* If it's a mount point, have to stat each element because
	161	* the inode number in the directory is for the entry in the
	162	* parent directory, not the inode number of the mounted file.
	163	*/
	164	save_errno = 0;
	165	if (s.st_dev == dev) {
	166	for (;;) {
	167	if (!(dp = readdir(dir)))
	168	goto notfound;
	169	if (dp->d_fileno == ino)
	170	break;
	171	}
	172	} else
	173	for (;;) {
	174	if (!(dp = readdir(dir)))
	175	goto notfound;
	176	if (ISDOT(dp))
	177	continue;
	178	memmove(bup, dp->d_name, dp->d_namlen + 1);
	179
	180	/* Save the first error for later. */
	181	if (lstat(up, &s)) {
	182	if (!save_errno)
	183	save_errno = errno;
	184	errno = 0;
	185	continue;
	186	}
	187	if (s.st_dev == dev && s.st_ino == ino)
	188	break;
	189	}
	190
	191	/*
	192	* Check for length of the current name, preceding slash,
	193	* leading slash.
	194	*/
	195	if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
	196	size_t len, off;
	197	char *npt;
	198
	199	if (!ptsize) {
200	errno = ERANGE;
201	goto err;
202	}
203	off = bpt - pt;
204	len = ept - bpt;
205	if ((npt = realloc(pt, ptsize *= 2)) == NULL)
206	goto err;
207	pt = npt;
208	bpt = pt + off;
209	ept = pt + ptsize;
210	memmove(ept - len, bpt, len);
211	bpt = ept - len;
212	}
213	if (!first)
214	*--bpt = '/';
215	bpt -= dp->d_namlen;
216	memmove(bpt, dp->d_name, dp->d_namlen);
217	(void)closedir(dir);
218
219	/* Truncate any file name. */
220	*bup = '\0';
221	}
222
223	notfound:
224	/*
225	* If readdir set errno, use it, not any saved error; otherwise,
226	* didn't find the current directory in its parent directory, set
227	* errno to ENOENT.
228	*/
229	if (!errno)
230	errno = save_errno ? save_errno : ENOENT;
231	/* FALLTHROUGH */
232	err:
233	if (ptsize)
234	free(pt);
235	if (up)
236	free(up);
237	if (dir)
238	(void)closedir(dir);
239	return (NULL);
240	}
241
242	#endif /* !defined(HAVE_GETCWD) */