1ca86bcf2SDag-Erling Smørgrav /* $OpenBSD: getcwd.c,v 1.14 2005/08/08 08:05:34 espie Exp */
283d2307dSDag-Erling Smørgrav /*
383d2307dSDag-Erling Smørgrav * Copyright (c) 1989, 1991, 1993
483d2307dSDag-Erling Smørgrav * The Regents of the University of California. All rights reserved.
583d2307dSDag-Erling Smørgrav *
683d2307dSDag-Erling Smørgrav * Redistribution and use in source and binary forms, with or without
783d2307dSDag-Erling Smørgrav * modification, are permitted provided that the following conditions
883d2307dSDag-Erling Smørgrav * are met:
983d2307dSDag-Erling Smørgrav * 1. Redistributions of source code must retain the above copyright
1083d2307dSDag-Erling Smørgrav * notice, this list of conditions and the following disclaimer.
1183d2307dSDag-Erling Smørgrav * 2. Redistributions in binary form must reproduce the above copyright
1283d2307dSDag-Erling Smørgrav * notice, this list of conditions and the following disclaimer in the
1383d2307dSDag-Erling Smørgrav * documentation and/or other materials provided with the distribution.
14d95e11bfSDag-Erling Smørgrav * 3. Neither the name of the University nor the names of its contributors
15d95e11bfSDag-Erling Smørgrav * may be used to endorse or promote products derived from this software
16d95e11bfSDag-Erling Smørgrav * without specific prior written permission.
1783d2307dSDag-Erling Smørgrav *
1883d2307dSDag-Erling Smørgrav * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
1983d2307dSDag-Erling Smørgrav * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2083d2307dSDag-Erling Smørgrav * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2183d2307dSDag-Erling Smørgrav * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2283d2307dSDag-Erling Smørgrav * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2383d2307dSDag-Erling Smørgrav * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2483d2307dSDag-Erling Smørgrav * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2583d2307dSDag-Erling Smørgrav * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2683d2307dSDag-Erling Smørgrav * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2783d2307dSDag-Erling Smørgrav * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2883d2307dSDag-Erling Smørgrav * SUCH DAMAGE.
2983d2307dSDag-Erling Smørgrav */
3083d2307dSDag-Erling Smørgrav
31021d409fSDag-Erling Smørgrav /* OPENBSD ORIGINAL: lib/libc/gen/getcwd.c */
32021d409fSDag-Erling Smørgrav
334b17dab0SDag-Erling Smørgrav #include "includes.h"
3483d2307dSDag-Erling Smørgrav
3583d2307dSDag-Erling Smørgrav #if !defined(HAVE_GETCWD)
3683d2307dSDag-Erling Smørgrav
3783d2307dSDag-Erling Smørgrav #include <sys/stat.h>
3883d2307dSDag-Erling Smørgrav #include <errno.h>
3983d2307dSDag-Erling Smørgrav #include <dirent.h>
4083d2307dSDag-Erling Smørgrav #include <sys/dir.h>
4183d2307dSDag-Erling Smørgrav #include <stdio.h>
4283d2307dSDag-Erling Smørgrav #include <stdlib.h>
4383d2307dSDag-Erling Smørgrav #include <string.h>
4483d2307dSDag-Erling Smørgrav #include "includes.h"
4583d2307dSDag-Erling Smørgrav
4683d2307dSDag-Erling Smørgrav #define ISDOT(dp) \
4783d2307dSDag-Erling Smørgrav (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
4883d2307dSDag-Erling Smørgrav (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
4983d2307dSDag-Erling Smørgrav
5083d2307dSDag-Erling Smørgrav char *
getcwd(char * pt,size_t size)5183d2307dSDag-Erling Smørgrav getcwd(char *pt, size_t size)
5283d2307dSDag-Erling Smørgrav {
53021d409fSDag-Erling Smørgrav struct dirent *dp;
54021d409fSDag-Erling Smørgrav DIR *dir = NULL;
55021d409fSDag-Erling Smørgrav dev_t dev;
56021d409fSDag-Erling Smørgrav ino_t ino;
57021d409fSDag-Erling Smørgrav int first;
58021d409fSDag-Erling Smørgrav char *bpt, *bup;
5983d2307dSDag-Erling Smørgrav struct stat s;
6083d2307dSDag-Erling Smørgrav dev_t root_dev;
6183d2307dSDag-Erling Smørgrav ino_t root_ino;
6283d2307dSDag-Erling Smørgrav size_t ptsize, upsize;
6383d2307dSDag-Erling Smørgrav int save_errno;
6483d2307dSDag-Erling Smørgrav char *ept, *eup, *up;
6583d2307dSDag-Erling Smørgrav
6683d2307dSDag-Erling Smørgrav /*
6783d2307dSDag-Erling Smørgrav * If no buffer specified by the user, allocate one as necessary.
6883d2307dSDag-Erling Smørgrav * If a buffer is specified, the size has to be non-zero. The path
6983d2307dSDag-Erling Smørgrav * is built from the end of the buffer backwards.
7083d2307dSDag-Erling Smørgrav */
7183d2307dSDag-Erling Smørgrav if (pt) {
7283d2307dSDag-Erling Smørgrav ptsize = 0;
7338a52bd3SEd Maste if (size == 0) {
7483d2307dSDag-Erling Smørgrav errno = EINVAL;
7583d2307dSDag-Erling Smørgrav return (NULL);
7638a52bd3SEd Maste } else if (size == 1) {
7738a52bd3SEd Maste errno = ERANGE;
7838a52bd3SEd Maste return (NULL);
7983d2307dSDag-Erling Smørgrav }
8083d2307dSDag-Erling Smørgrav ept = pt + size;
8183d2307dSDag-Erling Smørgrav } else {
82021d409fSDag-Erling Smørgrav if ((pt = malloc(ptsize = MAXPATHLEN)) == NULL)
8383d2307dSDag-Erling Smørgrav return (NULL);
8483d2307dSDag-Erling Smørgrav ept = pt + ptsize;
8583d2307dSDag-Erling Smørgrav }
8683d2307dSDag-Erling Smørgrav bpt = ept - 1;
8783d2307dSDag-Erling Smørgrav *bpt = '\0';
8883d2307dSDag-Erling Smørgrav
8983d2307dSDag-Erling Smørgrav /*
90021d409fSDag-Erling Smørgrav * Allocate bytes for the string of "../"'s.
9183d2307dSDag-Erling Smørgrav * Should always be enough (it's 340 levels). If it's not, allocate
9283d2307dSDag-Erling Smørgrav * as necessary. Special * case the first stat, it's ".", not "..".
9383d2307dSDag-Erling Smørgrav */
94021d409fSDag-Erling Smørgrav if ((up = malloc(upsize = MAXPATHLEN)) == NULL)
9583d2307dSDag-Erling Smørgrav goto err;
96021d409fSDag-Erling Smørgrav eup = up + upsize;
9783d2307dSDag-Erling Smørgrav bup = up;
9883d2307dSDag-Erling Smørgrav up[0] = '.';
9983d2307dSDag-Erling Smørgrav up[1] = '\0';
10083d2307dSDag-Erling Smørgrav
10183d2307dSDag-Erling Smørgrav /* Save root values, so know when to stop. */
10283d2307dSDag-Erling Smørgrav if (stat("/", &s))
10383d2307dSDag-Erling Smørgrav goto err;
10483d2307dSDag-Erling Smørgrav root_dev = s.st_dev;
10583d2307dSDag-Erling Smørgrav root_ino = s.st_ino;
10683d2307dSDag-Erling Smørgrav
10783d2307dSDag-Erling Smørgrav errno = 0; /* XXX readdir has no error return. */
10883d2307dSDag-Erling Smørgrav
10983d2307dSDag-Erling Smørgrav for (first = 1;; first = 0) {
11083d2307dSDag-Erling Smørgrav /* Stat the current level. */
11183d2307dSDag-Erling Smørgrav if (lstat(up, &s))
11283d2307dSDag-Erling Smørgrav goto err;
11383d2307dSDag-Erling Smørgrav
11483d2307dSDag-Erling Smørgrav /* Save current node values. */
11583d2307dSDag-Erling Smørgrav ino = s.st_ino;
11683d2307dSDag-Erling Smørgrav dev = s.st_dev;
11783d2307dSDag-Erling Smørgrav
11883d2307dSDag-Erling Smørgrav /* Check for reaching root. */
11983d2307dSDag-Erling Smørgrav if (root_dev == dev && root_ino == ino) {
12083d2307dSDag-Erling Smørgrav *--bpt = '/';
12183d2307dSDag-Erling Smørgrav /*
12283d2307dSDag-Erling Smørgrav * It's unclear that it's a requirement to copy the
12383d2307dSDag-Erling Smørgrav * path to the beginning of the buffer, but it's always
12483d2307dSDag-Erling Smørgrav * been that way and stuff would probably break.
12583d2307dSDag-Erling Smørgrav */
12683d2307dSDag-Erling Smørgrav memmove(pt, bpt, ept - bpt);
12783d2307dSDag-Erling Smørgrav free(up);
12883d2307dSDag-Erling Smørgrav return (pt);
12983d2307dSDag-Erling Smørgrav }
13083d2307dSDag-Erling Smørgrav
13183d2307dSDag-Erling Smørgrav /*
13283d2307dSDag-Erling Smørgrav * Build pointer to the parent directory, allocating memory
13383d2307dSDag-Erling Smørgrav * as necessary. Max length is 3 for "../", the largest
134d0c8c0bcSDag-Erling Smørgrav * possible component name, plus a trailing NUL.
13583d2307dSDag-Erling Smørgrav */
13683d2307dSDag-Erling Smørgrav if (bup + 3 + MAXNAMLEN + 1 >= eup) {
13783d2307dSDag-Erling Smørgrav char *nup;
13883d2307dSDag-Erling Smørgrav
13983d2307dSDag-Erling Smørgrav if ((nup = realloc(up, upsize *= 2)) == NULL)
14083d2307dSDag-Erling Smørgrav goto err;
141021d409fSDag-Erling Smørgrav bup = nup + (bup - up);
14283d2307dSDag-Erling Smørgrav up = nup;
14383d2307dSDag-Erling Smørgrav eup = up + upsize;
14483d2307dSDag-Erling Smørgrav }
14583d2307dSDag-Erling Smørgrav *bup++ = '.';
14683d2307dSDag-Erling Smørgrav *bup++ = '.';
14783d2307dSDag-Erling Smørgrav *bup = '\0';
14883d2307dSDag-Erling Smørgrav
149021d409fSDag-Erling Smørgrav /* Open and stat parent directory. */
150021d409fSDag-Erling Smørgrav if (!(dir = opendir(up)) || fstat(dirfd(dir), &s))
15183d2307dSDag-Erling Smørgrav goto err;
15283d2307dSDag-Erling Smørgrav
15383d2307dSDag-Erling Smørgrav /* Add trailing slash for next directory. */
15483d2307dSDag-Erling Smørgrav *bup++ = '/';
15583d2307dSDag-Erling Smørgrav
15683d2307dSDag-Erling Smørgrav /*
15783d2307dSDag-Erling Smørgrav * If it's a mount point, have to stat each element because
15883d2307dSDag-Erling Smørgrav * the inode number in the directory is for the entry in the
15983d2307dSDag-Erling Smørgrav * parent directory, not the inode number of the mounted file.
16083d2307dSDag-Erling Smørgrav */
16183d2307dSDag-Erling Smørgrav save_errno = 0;
16283d2307dSDag-Erling Smørgrav if (s.st_dev == dev) {
16383d2307dSDag-Erling Smørgrav for (;;) {
16483d2307dSDag-Erling Smørgrav if (!(dp = readdir(dir)))
16583d2307dSDag-Erling Smørgrav goto notfound;
16683d2307dSDag-Erling Smørgrav if (dp->d_fileno == ino)
16783d2307dSDag-Erling Smørgrav break;
16883d2307dSDag-Erling Smørgrav }
16983d2307dSDag-Erling Smørgrav } else
17083d2307dSDag-Erling Smørgrav for (;;) {
17183d2307dSDag-Erling Smørgrav if (!(dp = readdir(dir)))
17283d2307dSDag-Erling Smørgrav goto notfound;
17383d2307dSDag-Erling Smørgrav if (ISDOT(dp))
17483d2307dSDag-Erling Smørgrav continue;
175021d409fSDag-Erling Smørgrav memcpy(bup, dp->d_name, dp->d_namlen + 1);
17683d2307dSDag-Erling Smørgrav
17783d2307dSDag-Erling Smørgrav /* Save the first error for later. */
17883d2307dSDag-Erling Smørgrav if (lstat(up, &s)) {
17983d2307dSDag-Erling Smørgrav if (!save_errno)
18083d2307dSDag-Erling Smørgrav save_errno = errno;
18183d2307dSDag-Erling Smørgrav errno = 0;
18283d2307dSDag-Erling Smørgrav continue;
18383d2307dSDag-Erling Smørgrav }
18483d2307dSDag-Erling Smørgrav if (s.st_dev == dev && s.st_ino == ino)
18583d2307dSDag-Erling Smørgrav break;
18683d2307dSDag-Erling Smørgrav }
18783d2307dSDag-Erling Smørgrav
18883d2307dSDag-Erling Smørgrav /*
18983d2307dSDag-Erling Smørgrav * Check for length of the current name, preceding slash,
19083d2307dSDag-Erling Smørgrav * leading slash.
19183d2307dSDag-Erling Smørgrav */
19283d2307dSDag-Erling Smørgrav if (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
193021d409fSDag-Erling Smørgrav size_t len;
19483d2307dSDag-Erling Smørgrav char *npt;
19583d2307dSDag-Erling Smørgrav
19683d2307dSDag-Erling Smørgrav if (!ptsize) {
19783d2307dSDag-Erling Smørgrav errno = ERANGE;
19883d2307dSDag-Erling Smørgrav goto err;
19983d2307dSDag-Erling Smørgrav }
20083d2307dSDag-Erling Smørgrav len = ept - bpt;
20183d2307dSDag-Erling Smørgrav if ((npt = realloc(pt, ptsize *= 2)) == NULL)
20283d2307dSDag-Erling Smørgrav goto err;
203021d409fSDag-Erling Smørgrav bpt = npt + (bpt - pt);
20483d2307dSDag-Erling Smørgrav pt = npt;
20583d2307dSDag-Erling Smørgrav ept = pt + ptsize;
20683d2307dSDag-Erling Smørgrav memmove(ept - len, bpt, len);
20783d2307dSDag-Erling Smørgrav bpt = ept - len;
20883d2307dSDag-Erling Smørgrav }
20983d2307dSDag-Erling Smørgrav if (!first)
21083d2307dSDag-Erling Smørgrav *--bpt = '/';
21183d2307dSDag-Erling Smørgrav bpt -= dp->d_namlen;
212021d409fSDag-Erling Smørgrav memcpy(bpt, dp->d_name, dp->d_namlen);
21383d2307dSDag-Erling Smørgrav (void)closedir(dir);
21483d2307dSDag-Erling Smørgrav
21583d2307dSDag-Erling Smørgrav /* Truncate any file name. */
21683d2307dSDag-Erling Smørgrav *bup = '\0';
21783d2307dSDag-Erling Smørgrav }
21883d2307dSDag-Erling Smørgrav
21983d2307dSDag-Erling Smørgrav notfound:
22083d2307dSDag-Erling Smørgrav /*
22183d2307dSDag-Erling Smørgrav * If readdir set errno, use it, not any saved error; otherwise,
22283d2307dSDag-Erling Smørgrav * didn't find the current directory in its parent directory, set
22383d2307dSDag-Erling Smørgrav * errno to ENOENT.
22483d2307dSDag-Erling Smørgrav */
22583d2307dSDag-Erling Smørgrav if (!errno)
22683d2307dSDag-Erling Smørgrav errno = save_errno ? save_errno : ENOENT;
22783d2307dSDag-Erling Smørgrav /* FALLTHROUGH */
22883d2307dSDag-Erling Smørgrav err:
229021d409fSDag-Erling Smørgrav save_errno = errno;
230021d409fSDag-Erling Smørgrav
23183d2307dSDag-Erling Smørgrav if (ptsize)
23283d2307dSDag-Erling Smørgrav free(pt);
23383d2307dSDag-Erling Smørgrav free(up);
23483d2307dSDag-Erling Smørgrav if (dir)
23583d2307dSDag-Erling Smørgrav (void)closedir(dir);
236021d409fSDag-Erling Smørgrav
237021d409fSDag-Erling Smørgrav errno = save_errno;
238021d409fSDag-Erling Smørgrav
23983d2307dSDag-Erling Smørgrav return (NULL);
24083d2307dSDag-Erling Smørgrav }
24183d2307dSDag-Erling Smørgrav
24283d2307dSDag-Erling Smørgrav #endif /* !defined(HAVE_GETCWD) */
243