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