[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.
 *
 * 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 "config.h"

#if !defined(HAVE_GETCWD)

#if defined(LIBC_SCCS) && !defined(lint)
static char rcsid[] = "$OpenBSD: getcwd.c,v 1.6 2000/07/19 15:25:13 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 NULL.
		 */
		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.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	15	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	16	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	17	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	18	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	19	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	20	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	21	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	22	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	23	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	24	* SUCH DAMAGE.
	25	*/
	26
	27	#include "config.h"
	28
	29	#if !defined(HAVE_GETCWD)
	30
	31	#if defined(LIBC_SCCS) && !defined(lint)
	32	static char rcsid[] = "$OpenBSD: getcwd.c,v 1.6 2000/07/19 15:25:13 deraadt Exp $";
	33	#endif /* LIBC_SCCS and not lint */
	34
	35	#include <sys/param.h>
	36	#include <sys/stat.h>
	37	#include <errno.h>
	38	#include <dirent.h>
	39	#include <sys/dir.h>
	40	#include <stdio.h>
	41	#include <stdlib.h>
	42	#include <string.h>
	43	#include "includes.h"
	44
	45	#define ISDOT(dp) \
	46	(dp->d_name[0] == '.' && (dp->d_name[1] == '\0' \|\| \
	47	(dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
	48
	49	char *
	50	getcwd(char *pt,size_t size)
	51	{
	52	register struct dirent *dp;
	53	register DIR *dir = NULL;
	54	register dev_t dev;
	55	register ino_t ino;
	56	register int first;
	57	register char bpt, bup;
	58	struct stat s;
	59	dev_t root_dev;
	60	ino_t root_ino;
	61	size_t ptsize, upsize;
	62	int save_errno;
	63	char ept, eup, *up;
	64
65	/*
66	* If no buffer specified by the user, allocate one as necessary.
67	* If a buffer is specified, the size has to be non-zero. The path
68	* is built from the end of the buffer backwards.
69	*/
70	if (pt) {
71	ptsize = 0;
72	if (!size) {
73	errno = EINVAL;
74	return (NULL);
75	}
76	ept = pt + size;
77	} else {
78	if ((pt = malloc(ptsize = 1024 - 4)) == NULL)
79	return (NULL);
80	ept = pt + ptsize;
81	}
82	bpt = ept - 1;
83	*bpt = '\0';
84
85	/*
86	* Allocate bytes (1024 - malloc space) for the string of "../"'s.
87	* Should always be enough (it's 340 levels). If it's not, allocate
88	* as necessary. Special * case the first stat, it's ".", not "..".
89	*/
90	if ((up = malloc(upsize = 1024 - 4)) == NULL)
91	goto err;
92	eup = up + MAXPATHLEN;
93	bup = up;
94	up[0] = '.';
95	up[1] = '\0';
96
97	/* Save root values, so know when to stop. */
98	if (stat("/", &s))
99	goto err;
100	root_dev = s.st_dev;
101	root_ino = s.st_ino;
102
103	errno = 0; /* XXX readdir has no error return. */
104
105	for (first = 1;; first = 0) {
106	/* Stat the current level. */
107	if (lstat(up, &s))
108	goto err;
109
110	/* Save current node values. */
111	ino = s.st_ino;
112	dev = s.st_dev;
113
114	/* Check for reaching root. */
115	if (root_dev == dev && root_ino == ino) {
116	*--bpt = '/';
117	/*
118	* It's unclear that it's a requirement to copy the
119	* path to the beginning of the buffer, but it's always
120	* been that way and stuff would probably break.
121	*/
122	memmove(pt, bpt, ept - bpt);
123	free(up);
124	return (pt);
125	}
126
127	/*
128	* Build pointer to the parent directory, allocating memory
129	* as necessary. Max length is 3 for "../", the largest
130	* possible component name, plus a trailing NULL.
131	*/
132	if (bup + 3 + MAXNAMLEN + 1 >= eup) {
133	char *nup;
134
135	if ((nup = realloc(up, upsize *= 2)) == NULL)
136	goto err;
137	up = nup;
138	bup = up;
139	eup = up + upsize;
140	}
141	*bup++ = '.';
142	*bup++ = '.';
143	*bup = '\0';
144
145	/* Open and stat parent directory.
146	* RACE?? - replaced fstat(dirfd(dir), &s) w/ lstat(up,&s)
147	*/
148	if (!(dir = opendir(up)) \|\| lstat(up,&s))
149	goto err;
150
151	/* Add trailing slash for next directory. */
152	*bup++ = '/';
153
154	/*
155	* If it's a mount point, have to stat each element because
156	* the inode number in the directory is for the entry in the
157	* parent directory, not the inode number of the mounted file.
158	*/
159	save_errno = 0;
160	if (s.st_dev == dev) {
161	for (;;) {
162	if (!(dp = readdir(dir)))
163	goto notfound;
164	if (dp->d_fileno == ino)
165	break;
166	}
167	} else
168	for (;;) {
169	if (!(dp = readdir(dir)))
170	goto notfound;
171	if (ISDOT(dp))
172	continue;
173	memmove(bup, dp->d_name, dp->d_namlen + 1);
174
175	/* Save the first error for later. */
176	if (lstat(up, &s)) {
177	if (!save_errno)
178	save_errno = errno;
179	errno = 0;
180	continue;
181	}
182	if (s.st_dev == dev && s.st_ino == ino)
183	break;
184	}
185
186	/*
187	* Check for length of the current name, preceding slash,
188	* leading slash.
189	*/
190	if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
191	size_t len, off;
192	char *npt;
193
194	if (!ptsize) {
195	errno = ERANGE;
196	goto err;
197	}
198	off = bpt - pt;
199	len = ept - bpt;
200	if ((npt = realloc(pt, ptsize *= 2)) == NULL)
201	goto err;
202	pt = npt;
203	bpt = pt + off;
204	ept = pt + ptsize;
205	memmove(ept - len, bpt, len);
206	bpt = ept - len;
207	}
208	if (!first)
209	*--bpt = '/';
210	bpt -= dp->d_namlen;
211	memmove(bpt, dp->d_name, dp->d_namlen);
212	(void)closedir(dir);
213
214	/* Truncate any file name. */
215	*bup = '\0';
216	}
217
218	notfound:
219	/*
220	* If readdir set errno, use it, not any saved error; otherwise,
221	* didn't find the current directory in its parent directory, set
222	* errno to ENOENT.
223	*/
224	if (!errno)
225	errno = save_errno ? save_errno : ENOENT;
226	/* FALLTHROUGH */
227	err:
228	if (ptsize)
229	free(pt);
230	if (up)
231	free(up);
232	if (dir)
233	(void)closedir(dir);
234	return (NULL);
235	}
236
237	#endif /* !defined(HAVE_GETCWD) */