/*
- * CU sudo version 1.5.6
+ * Copyright (c) 1989, 1991, 1993
+ * The Regents of the University of California. All rights reserved.
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 1, or (at your option)
- * any later version.
+ * 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 program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * Please send bugs, changes, problems to sudo-bugs@courtesan.com
- *
- *******************************************************************
- *
- * This module contains getcwd(3) for those systems that lack it.
- * getcwd(3) returns a pointer to the current working dir. It uses
- * path as a copy-out parameter and malloc(3)s space if path is NULL.
- * This implementation of getcwd(3) restricts len(path) to be < MAXPATHLEN.
- *
- * Todd C. Miller (millert@colorado.edu) Fri Jun 3 18:32:19 MDT 1994
+ * 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.
*/
-#ifndef lint
-static char rcsid[] = "$Id$";
-#endif /* lint */
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$OpenBSD: getcwd.c,v 1.5 1998/08/14 21:39:26 deraadt Exp $";
+#endif /* LIBC_SCCS and not lint */
#include "config.h"
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
#include <stdio.h>
#ifdef STDC_HEADERS
#include <stdlib.h>
#endif /* STDC_HEADERS */
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif /* HAVE_UNISTD_H */
#ifdef HAVE_STRING_H
#include <string.h>
#endif /* HAVE_STRING_H */
#include <strings.h>
#endif /* HAVE_STRINGS_H */
#if defined(HAVE_MALLOC_H) && !defined(STDC_HEADERS)
-# include <malloc.h>
+#include <malloc.h>
#endif /* HAVE_MALLOC_H && !STDC_HEADERS */
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/param.h>
-#include <sys/in.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+#if HAVE_DIRENT_H
+# include <dirent.h>
+# define NAMLEN(dirent) strlen((dirent)->d_name)
+#else
+# define dirent direct
+# define NAMLEN(dirent) (dirent)->d_namlen
+# if HAVE_SYS_NDIR_H
+# include <sys/ndir.h>
+# endif
+# if HAVE_SYS_DIR_H
+# include <sys/dir.h>
+# endif
+# if HAVE_NDIR_H
+# include <ndir.h>
+# endif
+#endif
-#include <pathnames.h>
#include "compat.h"
-#ifndef STDC_HEADERS
-#ifndef __GNUC__ /* gcc has its own malloc */
-extern char *malloc __P((size_t));
-#endif /* __GNUC__ */
-extern char *strcpy __P((char *, const char *));
-extern int strlen __P((const char *));
-extern char *getwd __P((char *));
-extern char *fgets __P((char *, int, FILE *));
-#endif /* !STDC_HEADERS */
+#define ISDOT(dp) \
+ (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
+ (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
+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;
-/*
- * Since we can't count on this being defined...
- */
-extern int errno;
+ /*
+ * 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';
-/******************************************************************
- *
- * getcwd()
- *
- * getcwd() returns a pointer to the current working dir. It uses
- * path as a copy-out parameter and malloc(3)s space if path is NULL.
- */
+ /* Save root values, so know when to stop. */
+ if (stat("/", &s))
+ goto err;
+ root_dev = s.st_dev;
+ root_ino = s.st_ino;
-char * getcwd(path, psize)
- char * path; /* path to copy into */
- size_t psize; /* size of path */
-{
- char buf[MAXPATHLEN+1]; /* +1 for the newline */
- size_t blen; /* length of buf */
- FILE * pwd; /* stream for "pwd" process */
- int fd[2]; /* for pipe(2) */
- pid_t pid; /* pid of "pwd" process */
- int status; /* status from wait(2) */
-
- /* sanity check */
- if (path && psize == 0) {
- errno = EINVAL;
- return(NULL);
- }
-
- /*
- * open a pipe to pwd and read a line
- */
- if (pipe(fd) < 0)
- return(NULL);
- switch ((pid = fork())) {
- case -1:
- /* fork failed */
- (void) close(fd[0]);
- (void) close(fd[1]);
- return(NULL);
- case 0:
- /* in child */
- (void) dup2(fd[0], 0);
- (void) dup2(fd[1], 1);
- (void) close(fd[0]);
- (void) close(fd[1]);
- execl(_PATH_PWD, "pwd", NULL);
- _exit(-1); /* should not happen */
- }
-
- /* in parent */
- if ((pwd = fdopen(fd[0], "r")) == NULL) {
- (void) close(fd[0]);
- (void) close(fd[1]);
- return(NULL);
- }
-
- if (!fgets(buf, sizeof(buf), pwd)) {
- errno = EACCES; /* what an assumption... */
- pclose(pwd);
- return(NULL);
- }
-
- /* wait for the pipe to close */
- while (wait(&status) != pid)
- ;
-
- blen = strlen(buf);
- if (buf[blen - 1] == '\n')
- buf[--blen] = '\0'; /* remove newline */
- else if (blen >= MAXPATHLEN) {
- errno = ENAMETOOLONG; /* only possible w/o newline */
- return(NULL);
- }
-
- /* sanity check */
- if (path && psize < blen + 1) {
- errno = ERANGE;
- return(NULL);
- }
-
- if (path == NULL) {
- if (!(path = (char *) malloc(MAXPATHLEN))) {
- errno = ENOMEM;
- return(NULL);
+ 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 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. */
+ if (!(dir = opendir(up)) || fstat(dirfd(dir), &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;
+ bcopy(dp->d_name, bup, NAMLEN(dp) + 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 <= NAMLEN(dp) + (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;
+ bcopy(bpt, ept - len, len);
+ bpt = ept - len;
+ }
+ if (!first)
+ *--bpt = '/';
+ bpt -= NAMLEN(dp);
+ bcopy(dp->d_name, bpt, NAMLEN(dp));
+ (void)closedir(dir);
+
+ /* Truncate any file name. */
+ *bup = '\0';
}
- }
- (void) strcpy(path, buf);
- return(path);
+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);
}
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