544 lines
12 KiB
C
544 lines
12 KiB
C
/* Copyright (C) 1991-2014 Free Software Foundation, Inc.
|
||
This file is part of the GNU C Library.
|
||
|
||
The GNU C Library is free software; you can redistribute it and/or
|
||
modify it under the terms of the GNU Lesser General Public
|
||
License as published by the Free Software Foundation; either
|
||
version 2.1 of the License, or (at your option) any later version.
|
||
|
||
The GNU C Library 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
|
||
Lesser General Public License for more details.
|
||
|
||
You should have received a copy of the GNU Lesser General Public
|
||
License along with the GNU C Library; if not, see
|
||
<http://www.gnu.org/licenses/>. */
|
||
|
||
/* Wants:
|
||
AC_STDC_HEADERS
|
||
AC_DIR_HEADER
|
||
AC_UNISTD_H
|
||
AC_MEMORY_H
|
||
AC_CONST
|
||
AC_ALLOCA
|
||
*/
|
||
|
||
/* AIX requires this to be the first thing in the file. */
|
||
#if defined _AIX && !defined __GNUC__
|
||
#pragma alloca
|
||
#endif
|
||
|
||
#ifdef HAVE_CONFIG_H
|
||
# include "config.h"
|
||
#endif
|
||
|
||
#include <errno.h>
|
||
#include <fcntl.h>
|
||
#include <sys/types.h>
|
||
#include <sys/stat.h>
|
||
|
||
#ifdef STDC_HEADERS
|
||
# include <stddef.h>
|
||
#endif
|
||
|
||
#if !defined __GNU_LIBRARY__ && !defined STDC_HEADERS
|
||
extern int errno;
|
||
#endif
|
||
#ifndef __set_errno
|
||
# define __set_errno(val) errno = (val)
|
||
#endif
|
||
|
||
#ifndef NULL
|
||
# define NULL 0
|
||
#endif
|
||
|
||
#if defined USGr3 && !defined DIRENT
|
||
# define DIRENT
|
||
#endif /* USGr3 */
|
||
#if defined Xenix && !defined SYSNDIR
|
||
# define SYSNDIR
|
||
#endif /* Xenix */
|
||
|
||
#if defined POSIX || defined DIRENT || defined __GNU_LIBRARY__
|
||
# include <dirent.h>
|
||
# ifndef __GNU_LIBRARY__
|
||
# define D_NAMLEN(d) strlen((d)->d_name)
|
||
# else
|
||
# define HAVE_D_NAMLEN
|
||
# define D_NAMLEN(d) ((d)->d_namlen)
|
||
# endif
|
||
#else /* not POSIX or DIRENT */
|
||
# define dirent direct
|
||
# define D_NAMLEN(d) ((d)->d_namlen)
|
||
# define HAVE_D_NAMLEN
|
||
# if defined USG && !defined sgi
|
||
# if defined SYSNDIR
|
||
# include <sys/ndir.h>
|
||
# else /* Not SYSNDIR */
|
||
# include "ndir.h"
|
||
# endif /* SYSNDIR */
|
||
# else /* not USG */
|
||
# include <sys/dir.h>
|
||
# endif /* USG */
|
||
#endif /* POSIX or DIRENT or __GNU_LIBRARY__ */
|
||
|
||
#if defined HAVE_UNISTD_H || defined __GNU_LIBRARY__
|
||
# include <unistd.h>
|
||
#endif
|
||
|
||
#if defined STDC_HEADERS || defined __GNU_LIBRARY__ || defined POSIX
|
||
# include <stdlib.h>
|
||
# include <string.h>
|
||
# define ANSI_STRING
|
||
#else /* No standard headers. */
|
||
|
||
# ifdef USG
|
||
|
||
# include <string.h>
|
||
# ifdef NEED_MEMORY_H
|
||
# include <memory.h>
|
||
# endif
|
||
# define ANSI_STRING
|
||
|
||
# else /* Not USG. */
|
||
|
||
# ifdef NeXT
|
||
|
||
# include <string.h>
|
||
|
||
# else /* Not NeXT. */
|
||
|
||
# include <strings.h>
|
||
|
||
# ifndef bcmp
|
||
extern int bcmp ();
|
||
# endif
|
||
# ifndef bzero
|
||
extern void bzero ();
|
||
# endif
|
||
# ifndef bcopy
|
||
extern void bcopy ();
|
||
# endif
|
||
|
||
# endif /* NeXT. */
|
||
|
||
# endif /* USG. */
|
||
|
||
extern char *malloc (), *realloc ();
|
||
extern void free ();
|
||
|
||
#endif /* Standard headers. */
|
||
|
||
#ifndef ANSI_STRING
|
||
# define memcpy(d, s, n) bcopy((s), (d), (n))
|
||
# define memmove memcpy
|
||
#endif /* Not ANSI_STRING. */
|
||
|
||
#ifndef MAX
|
||
# define MAX(a, b) ((a) < (b) ? (b) : (a))
|
||
#endif
|
||
|
||
#ifdef _LIBC
|
||
# ifndef mempcpy
|
||
# define mempcpy __mempcpy
|
||
# endif
|
||
# define HAVE_MEMPCPY 1
|
||
#endif
|
||
|
||
#if !defined __alloca && !defined __GNU_LIBRARY__
|
||
|
||
# ifdef __GNUC__
|
||
# undef alloca
|
||
# define alloca(n) __builtin_alloca (n)
|
||
# else /* Not GCC. */
|
||
# if defined sparc || defined HAVE_ALLOCA_H
|
||
# include <alloca.h>
|
||
# else /* Not sparc or HAVE_ALLOCA_H. */
|
||
# ifndef _AIX
|
||
extern char *alloca ();
|
||
# endif /* Not _AIX. */
|
||
# endif /* sparc or HAVE_ALLOCA_H. */
|
||
# endif /* GCC. */
|
||
|
||
# define __alloca alloca
|
||
|
||
#endif
|
||
|
||
#if defined HAVE_LIMITS_H || defined STDC_HEADERS || defined __GNU_LIBRARY__
|
||
# include <limits.h>
|
||
#else
|
||
# include <sys/param.h>
|
||
#endif
|
||
|
||
#if defined _LIBC
|
||
# include <not-cancel.h>
|
||
# include <kernel-features.h>
|
||
#else
|
||
# define openat64_not_cancel_3(dfd, name, mode) openat64 (dfd, name, mode)
|
||
# define close_not_cancel_no_status(fd) close (fd)
|
||
#endif
|
||
|
||
#ifndef PATH_MAX
|
||
# ifdef MAXPATHLEN
|
||
# define PATH_MAX MAXPATHLEN
|
||
# else
|
||
# define PATH_MAX 1024
|
||
# endif
|
||
#endif
|
||
|
||
#if !defined STDC_HEADERS && !defined __GNU_LIBRARY__
|
||
# undef size_t
|
||
# define size_t unsigned int
|
||
#endif
|
||
|
||
#ifndef __GNU_LIBRARY__
|
||
# define __lstat64 stat64
|
||
#endif
|
||
|
||
#ifndef _LIBC
|
||
# define __rewinddir rewinddir
|
||
#endif
|
||
|
||
#ifndef _LIBC
|
||
# define __getcwd getcwd
|
||
#endif
|
||
|
||
#ifndef GETCWD_RETURN_TYPE
|
||
# define GETCWD_RETURN_TYPE char *
|
||
#endif
|
||
|
||
#ifdef __ASSUME_ATFCTS
|
||
# define __have_atfcts 1
|
||
#elif IS_IN (rtld)
|
||
static int __rtld_have_atfcts;
|
||
# define __have_atfcts __rtld_have_atfcts
|
||
#endif
|
||
|
||
/* Get the pathname of the current working directory, and put it in SIZE
|
||
bytes of BUF. Returns NULL if the directory couldn't be determined or
|
||
SIZE was too small. If successful, returns BUF. In GNU, if BUF is
|
||
NULL, an array is allocated with `malloc'; the array is SIZE bytes long,
|
||
unless SIZE == 0, in which case it is as big as necessary. */
|
||
|
||
GETCWD_RETURN_TYPE
|
||
__getcwd (buf, size)
|
||
char *buf;
|
||
size_t size;
|
||
{
|
||
#ifndef __ASSUME_ATFCTS
|
||
static const char dots[]
|
||
= "../../../../../../../../../../../../../../../../../../../../../../../\
|
||
../../../../../../../../../../../../../../../../../../../../../../../../../../\
|
||
../../../../../../../../../../../../../../../../../../../../../../../../../..";
|
||
const char *dotp = &dots[sizeof (dots)];
|
||
const char *dotlist = dots;
|
||
size_t dotsize = sizeof (dots) - 1;
|
||
#endif
|
||
int prev_errno = errno;
|
||
DIR *dirstream = NULL;
|
||
bool fd_needs_closing = false;
|
||
int fd = AT_FDCWD;
|
||
|
||
char *path;
|
||
#ifndef NO_ALLOCATION
|
||
size_t allocated = size;
|
||
if (size == 0)
|
||
{
|
||
if (buf != NULL)
|
||
{
|
||
__set_errno (EINVAL);
|
||
return NULL;
|
||
}
|
||
|
||
allocated = PATH_MAX + 1;
|
||
}
|
||
|
||
if (buf == NULL)
|
||
{
|
||
path = malloc (allocated);
|
||
if (path == NULL)
|
||
return NULL;
|
||
}
|
||
else
|
||
#else
|
||
# define allocated size
|
||
#endif
|
||
path = buf;
|
||
|
||
char *pathp = path + allocated;
|
||
*--pathp = '\0';
|
||
|
||
struct stat64 st;
|
||
if (__lstat64 (".", &st) < 0)
|
||
goto lose;
|
||
dev_t thisdev = st.st_dev;
|
||
ino_t thisino = st.st_ino;
|
||
|
||
if (__lstat64 ("/", &st) < 0)
|
||
goto lose;
|
||
dev_t rootdev = st.st_dev;
|
||
ino_t rootino = st.st_ino;
|
||
|
||
while (!(thisdev == rootdev && thisino == rootino))
|
||
{
|
||
if (__have_atfcts >= 0)
|
||
{
|
||
int mode = O_RDONLY;
|
||
#ifdef O_CLOEXEC
|
||
mode |= O_CLOEXEC;
|
||
#endif
|
||
fd = openat64_not_cancel_3 (fd, "..", mode);
|
||
}
|
||
else
|
||
fd = -1;
|
||
if (fd >= 0)
|
||
{
|
||
fd_needs_closing = true;
|
||
if (__fstat64 (fd, &st) < 0)
|
||
goto lose;
|
||
}
|
||
#ifndef __ASSUME_ATFCTS
|
||
else if (errno == ENOSYS)
|
||
{
|
||
__have_atfcts = -1;
|
||
|
||
/* Look at the parent directory. */
|
||
if (dotp == dotlist)
|
||
{
|
||
# ifdef NO_ALLOCATION
|
||
__set_errno (ENOMEM);
|
||
goto lose;
|
||
# else
|
||
/* My, what a deep directory tree you have, Grandma. */
|
||
char *new;
|
||
if (dotlist == dots)
|
||
{
|
||
new = malloc (dotsize * 2 + 1);
|
||
if (new == NULL)
|
||
goto lose;
|
||
# ifdef HAVE_MEMPCPY
|
||
dotp = mempcpy (new, dots, dotsize);
|
||
# else
|
||
memcpy (new, dots, dotsize);
|
||
dotp = &new[dotsize];
|
||
# endif
|
||
}
|
||
else
|
||
{
|
||
new = realloc ((__ptr_t) dotlist, dotsize * 2 + 1);
|
||
if (new == NULL)
|
||
goto lose;
|
||
dotp = &new[dotsize];
|
||
}
|
||
# ifdef HAVE_MEMPCPY
|
||
*((char *) mempcpy ((char *) dotp, new, dotsize)) = '\0';
|
||
dotsize *= 2;
|
||
# else
|
||
memcpy ((char *) dotp, new, dotsize);
|
||
dotsize *= 2;
|
||
new[dotsize] = '\0';
|
||
# endif
|
||
dotlist = new;
|
||
# endif
|
||
}
|
||
|
||
dotp -= 3;
|
||
|
||
/* Figure out if this directory is a mount point. */
|
||
if (__lstat64 (dotp, &st) < 0)
|
||
goto lose;
|
||
}
|
||
#endif
|
||
else
|
||
goto lose;
|
||
|
||
if (dirstream && __closedir (dirstream) != 0)
|
||
{
|
||
dirstream = NULL;
|
||
goto lose;
|
||
}
|
||
|
||
dev_t dotdev = st.st_dev;
|
||
ino_t dotino = st.st_ino;
|
||
bool mount_point = dotdev != thisdev;
|
||
|
||
/* Search for the last directory. */
|
||
if (__have_atfcts >= 0)
|
||
dirstream = __fdopendir (fd);
|
||
#ifndef __ASSUME_ATFCTS
|
||
else
|
||
dirstream = __opendir (dotp);
|
||
#endif
|
||
if (dirstream == NULL)
|
||
goto lose;
|
||
fd_needs_closing = false;
|
||
|
||
struct dirent *d;
|
||
bool use_d_ino = true;
|
||
while (1)
|
||
{
|
||
/* Clear errno to distinguish EOF from error if readdir returns
|
||
NULL. */
|
||
__set_errno (0);
|
||
d = __readdir (dirstream);
|
||
if (d == NULL)
|
||
{
|
||
if (errno == 0)
|
||
{
|
||
/* When we've iterated through all directory entries
|
||
without finding one with a matching d_ino, rewind the
|
||
stream and consider each name again, but this time, using
|
||
lstat64. This is necessary in a chroot on at least one
|
||
system. */
|
||
if (use_d_ino)
|
||
{
|
||
use_d_ino = false;
|
||
__rewinddir (dirstream);
|
||
continue;
|
||
}
|
||
|
||
/* EOF on dirstream, which means that the current directory
|
||
has been removed. */
|
||
__set_errno (ENOENT);
|
||
}
|
||
goto lose;
|
||
}
|
||
|
||
#ifdef _DIRENT_HAVE_D_TYPE
|
||
if (d->d_type != DT_DIR && d->d_type != DT_UNKNOWN)
|
||
continue;
|
||
#endif
|
||
if (d->d_name[0] == '.'
|
||
&& (d->d_name[1] == '\0'
|
||
|| (d->d_name[1] == '.' && d->d_name[2] == '\0')))
|
||
continue;
|
||
if (use_d_ino && !mount_point && (ino_t) d->d_ino != thisino)
|
||
continue;
|
||
|
||
if (__have_atfcts >= 0)
|
||
{
|
||
/* We don't fail here if we cannot stat64() a directory entry.
|
||
This can happen when (network) filesystems fail. If this
|
||
entry is in fact the one we are looking for we will find
|
||
out soon as we reach the end of the directory without
|
||
having found anything. */
|
||
if (__fstatat64 (fd, d->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
|
||
continue;
|
||
}
|
||
#ifndef __ASSUME_ATFCTS
|
||
else
|
||
{
|
||
char name[dotlist + dotsize - dotp + 1 + _D_ALLOC_NAMLEN (d)];
|
||
# ifdef HAVE_MEMPCPY
|
||
char *tmp = mempcpy (name, dotp, dotlist + dotsize - dotp);
|
||
*tmp++ = '/';
|
||
strcpy (tmp, d->d_name);
|
||
# else
|
||
memcpy (name, dotp, dotlist + dotsize - dotp);
|
||
name[dotlist + dotsize - dotp] = '/';
|
||
strcpy (&name[dotlist + dotsize - dotp + 1], d->d_name);
|
||
# endif
|
||
/* We don't fail here if we cannot stat64() a directory entry.
|
||
This can happen when (network) filesystems fail. If this
|
||
entry is in fact the one we are looking for we will find
|
||
out soon as we reach the end of the directory without
|
||
having found anything. */
|
||
if (__lstat64 (name, &st) < 0)
|
||
continue;
|
||
}
|
||
#endif
|
||
if (S_ISDIR (st.st_mode)
|
||
&& st.st_dev == thisdev && st.st_ino == thisino)
|
||
break;
|
||
}
|
||
|
||
size_t namlen = _D_EXACT_NAMLEN (d);
|
||
|
||
if ((size_t) (pathp - path) <= namlen)
|
||
{
|
||
#ifndef NO_ALLOCATION
|
||
if (size == 0)
|
||
{
|
||
size_t oldsize = allocated;
|
||
|
||
allocated = 2 * MAX (allocated, namlen);
|
||
char *tmp = realloc (path, allocated);
|
||
if (tmp == NULL)
|
||
goto lose;
|
||
|
||
/* Move current contents up to the end of the buffer.
|
||
This is guaranteed to be non-overlapping. */
|
||
pathp = memcpy (tmp + allocated - (path + oldsize - pathp),
|
||
tmp + (pathp - path),
|
||
path + oldsize - pathp);
|
||
path = tmp;
|
||
}
|
||
else
|
||
#endif
|
||
{
|
||
__set_errno (ERANGE);
|
||
goto lose;
|
||
}
|
||
}
|
||
pathp -= namlen;
|
||
(void) memcpy (pathp, d->d_name, namlen);
|
||
*--pathp = '/';
|
||
|
||
thisdev = dotdev;
|
||
thisino = dotino;
|
||
}
|
||
|
||
if (dirstream != NULL && __closedir (dirstream) != 0)
|
||
{
|
||
dirstream = NULL;
|
||
goto lose;
|
||
}
|
||
|
||
if (pathp == &path[allocated - 1])
|
||
*--pathp = '/';
|
||
|
||
#ifndef __ASSUME_ATFCTS
|
||
if (dotlist != dots)
|
||
free ((__ptr_t) dotlist);
|
||
#endif
|
||
|
||
size_t used = path + allocated - pathp;
|
||
memmove (path, pathp, used);
|
||
|
||
if (size == 0)
|
||
/* Ensure that the buffer is only as large as necessary. */
|
||
buf = realloc (path, used);
|
||
|
||
if (buf == NULL)
|
||
/* Either buf was NULL all along, or `realloc' failed but
|
||
we still have the original string. */
|
||
buf = path;
|
||
|
||
/* Restore errno on successful return. */
|
||
__set_errno (prev_errno);
|
||
|
||
return buf;
|
||
|
||
lose:;
|
||
int save_errno = errno;
|
||
#ifndef __ASSUME_ATFCTS
|
||
if (dotlist != dots)
|
||
free ((__ptr_t) dotlist);
|
||
#endif
|
||
if (dirstream != NULL)
|
||
__closedir (dirstream);
|
||
if (fd_needs_closing)
|
||
close_not_cancel_no_status (fd);
|
||
#ifndef NO_ALLOCATION
|
||
if (buf == NULL)
|
||
free (path);
|
||
#endif
|
||
__set_errno (save_errno);
|
||
return NULL;
|
||
}
|
||
|
||
#if defined _LIBC && !defined __getcwd
|
||
weak_alias (__getcwd, getcwd)
|
||
#endif
|