513004a23d
While here also cleanup some surrounding code; particularly drop some malloc() casts. Found with devel/coccinelle. Reviewed by: bde (previous version - all new bugs are mine)
361 lines
8.4 KiB
C
361 lines
8.4 KiB
C
/*-
|
|
* Copyright (c) 1983, 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.
|
|
* 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 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.
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
static char sccsid[] = "@(#)opendir.c 8.8 (Berkeley) 5/1/95";
|
|
#endif /* LIBC_SCCS and not lint */
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "namespace.h"
|
|
#include <sys/param.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include <dirent.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include "un-namespace.h"
|
|
|
|
#include "gen-private.h"
|
|
#include "telldir.h"
|
|
|
|
static DIR * __opendir_common(int, int, bool);
|
|
|
|
/*
|
|
* Open a directory.
|
|
*/
|
|
DIR *
|
|
opendir(const char *name)
|
|
{
|
|
|
|
return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
|
|
}
|
|
|
|
/*
|
|
* Open a directory with existing file descriptor.
|
|
*/
|
|
DIR *
|
|
fdopendir(int fd)
|
|
{
|
|
|
|
if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
|
|
return (NULL);
|
|
return (__opendir_common(fd, DTF_HIDEW|DTF_NODUP, true));
|
|
}
|
|
|
|
DIR *
|
|
__opendir2(const char *name, int flags)
|
|
{
|
|
int fd;
|
|
DIR *dir;
|
|
int saved_errno;
|
|
|
|
if ((flags & (__DTF_READALL | __DTF_SKIPREAD)) != 0)
|
|
return (NULL);
|
|
if ((fd = _open(name,
|
|
O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_CLOEXEC)) == -1)
|
|
return (NULL);
|
|
|
|
dir = __opendir_common(fd, flags, false);
|
|
if (dir == NULL) {
|
|
saved_errno = errno;
|
|
_close(fd);
|
|
errno = saved_errno;
|
|
}
|
|
return (dir);
|
|
}
|
|
|
|
static int
|
|
opendir_compar(const void *p1, const void *p2)
|
|
{
|
|
|
|
return (strcmp((*(const struct dirent **)p1)->d_name,
|
|
(*(const struct dirent **)p2)->d_name));
|
|
}
|
|
|
|
/*
|
|
* For a directory at the top of a unionfs stack, the entire directory's
|
|
* contents are read and cached locally until the next call to rewinddir().
|
|
* For the fdopendir() case, the initial seek position must be preserved.
|
|
* For rewinddir(), the full directory should always be re-read from the
|
|
* beginning.
|
|
*
|
|
* If an error occurs, the existing buffer and state of 'dirp' is left
|
|
* unchanged.
|
|
*/
|
|
bool
|
|
_filldir(DIR *dirp, bool use_current_pos)
|
|
{
|
|
struct dirent **dpv;
|
|
char *buf, *ddptr, *ddeptr;
|
|
off_t pos;
|
|
int fd2, incr, len, n, saved_errno, space;
|
|
|
|
len = 0;
|
|
space = 0;
|
|
buf = NULL;
|
|
ddptr = NULL;
|
|
|
|
/*
|
|
* Use the system page size if that is a multiple of DIRBLKSIZ.
|
|
* Hopefully this can be a big win someday by allowing page
|
|
* trades to user space to be done by _getdirentries().
|
|
*/
|
|
incr = getpagesize();
|
|
if ((incr % DIRBLKSIZ) != 0)
|
|
incr = DIRBLKSIZ;
|
|
|
|
/*
|
|
* The strategy here is to read all the directory
|
|
* entries into a buffer, sort the buffer, and
|
|
* remove duplicate entries by setting the inode
|
|
* number to zero.
|
|
*
|
|
* We reopen the directory because _getdirentries()
|
|
* on a MNT_UNION mount modifies the open directory,
|
|
* making it refer to the lower directory after the
|
|
* upper directory's entries are exhausted.
|
|
* This would otherwise break software that uses
|
|
* the directory descriptor for fchdir or *at
|
|
* functions, such as fts.c.
|
|
*/
|
|
if ((fd2 = _openat(dirp->dd_fd, ".", O_RDONLY | O_CLOEXEC)) == -1)
|
|
return (false);
|
|
|
|
if (use_current_pos) {
|
|
pos = lseek(dirp->dd_fd, 0, SEEK_CUR);
|
|
if (pos == -1 || lseek(fd2, pos, SEEK_SET) == -1) {
|
|
saved_errno = errno;
|
|
_close(fd2);
|
|
errno = saved_errno;
|
|
return (false);
|
|
}
|
|
}
|
|
|
|
do {
|
|
/*
|
|
* Always make at least DIRBLKSIZ bytes
|
|
* available to _getdirentries
|
|
*/
|
|
if (space < DIRBLKSIZ) {
|
|
space += incr;
|
|
len += incr;
|
|
buf = reallocf(buf, len);
|
|
if (buf == NULL) {
|
|
saved_errno = errno;
|
|
_close(fd2);
|
|
errno = saved_errno;
|
|
return (false);
|
|
}
|
|
ddptr = buf + (len - space);
|
|
}
|
|
|
|
n = _getdirentries(fd2, ddptr, space, &dirp->dd_seek);
|
|
if (n > 0) {
|
|
ddptr += n;
|
|
space -= n;
|
|
}
|
|
if (n < 0) {
|
|
saved_errno = errno;
|
|
_close(fd2);
|
|
errno = saved_errno;
|
|
return (false);
|
|
}
|
|
} while (n > 0);
|
|
_close(fd2);
|
|
|
|
ddeptr = ddptr;
|
|
|
|
/*
|
|
* There is now a buffer full of (possibly) duplicate
|
|
* names.
|
|
*/
|
|
dirp->dd_buf = buf;
|
|
|
|
/*
|
|
* Go round this loop twice...
|
|
*
|
|
* Scan through the buffer, counting entries.
|
|
* On the second pass, save pointers to each one.
|
|
* Then sort the pointers and remove duplicate names.
|
|
*/
|
|
for (dpv = NULL;;) {
|
|
n = 0;
|
|
ddptr = buf;
|
|
while (ddptr < ddeptr) {
|
|
struct dirent *dp;
|
|
|
|
dp = (struct dirent *) ddptr;
|
|
if ((long)dp & 03L)
|
|
break;
|
|
if ((dp->d_reclen <= 0) ||
|
|
(dp->d_reclen > (ddeptr + 1 - ddptr)))
|
|
break;
|
|
ddptr += dp->d_reclen;
|
|
if (dp->d_fileno) {
|
|
if (dpv)
|
|
dpv[n] = dp;
|
|
n++;
|
|
}
|
|
}
|
|
|
|
if (dpv) {
|
|
struct dirent *xp;
|
|
|
|
/*
|
|
* This sort must be stable.
|
|
*/
|
|
mergesort(dpv, n, sizeof(*dpv), opendir_compar);
|
|
|
|
dpv[n] = NULL;
|
|
xp = NULL;
|
|
|
|
/*
|
|
* Scan through the buffer in sort order,
|
|
* zapping the inode number of any
|
|
* duplicate names.
|
|
*/
|
|
for (n = 0; dpv[n]; n++) {
|
|
struct dirent *dp = dpv[n];
|
|
|
|
if ((xp == NULL) ||
|
|
strcmp(dp->d_name, xp->d_name)) {
|
|
xp = dp;
|
|
} else {
|
|
dp->d_fileno = 0;
|
|
}
|
|
if (dp->d_type == DT_WHT &&
|
|
(dirp->dd_flags & DTF_HIDEW))
|
|
dp->d_fileno = 0;
|
|
}
|
|
|
|
free(dpv);
|
|
break;
|
|
} else {
|
|
dpv = malloc((n+1) * sizeof(struct dirent *));
|
|
if (dpv == NULL)
|
|
break;
|
|
}
|
|
}
|
|
|
|
dirp->dd_len = len;
|
|
dirp->dd_size = ddptr - dirp->dd_buf;
|
|
return (true);
|
|
}
|
|
|
|
|
|
/*
|
|
* Common routine for opendir(3), __opendir2(3) and fdopendir(3).
|
|
*/
|
|
static DIR *
|
|
__opendir_common(int fd, int flags, bool use_current_pos)
|
|
{
|
|
DIR *dirp;
|
|
int incr;
|
|
int saved_errno;
|
|
int unionstack;
|
|
|
|
if ((dirp = malloc(sizeof(DIR) + sizeof(struct _telldir))) == NULL)
|
|
return (NULL);
|
|
|
|
dirp->dd_buf = NULL;
|
|
dirp->dd_fd = fd;
|
|
dirp->dd_flags = flags;
|
|
dirp->dd_loc = 0;
|
|
dirp->dd_lock = NULL;
|
|
dirp->dd_td = (struct _telldir *)((char *)dirp + sizeof(DIR));
|
|
LIST_INIT(&dirp->dd_td->td_locq);
|
|
dirp->dd_td->td_loccnt = 0;
|
|
|
|
/*
|
|
* Use the system page size if that is a multiple of DIRBLKSIZ.
|
|
* Hopefully this can be a big win someday by allowing page
|
|
* trades to user space to be done by _getdirentries().
|
|
*/
|
|
incr = getpagesize();
|
|
if ((incr % DIRBLKSIZ) != 0)
|
|
incr = DIRBLKSIZ;
|
|
|
|
/*
|
|
* Determine whether this directory is the top of a union stack.
|
|
*/
|
|
if (flags & DTF_NODUP) {
|
|
struct statfs sfb;
|
|
|
|
if (_fstatfs(fd, &sfb) < 0)
|
|
goto fail;
|
|
unionstack = !strcmp(sfb.f_fstypename, "unionfs")
|
|
|| (sfb.f_flags & MNT_UNION);
|
|
} else {
|
|
unionstack = 0;
|
|
}
|
|
|
|
if (unionstack) {
|
|
if (!_filldir(dirp, use_current_pos))
|
|
goto fail;
|
|
dirp->dd_flags |= __DTF_READALL;
|
|
} else {
|
|
dirp->dd_len = incr;
|
|
dirp->dd_buf = malloc(dirp->dd_len);
|
|
if (dirp->dd_buf == NULL)
|
|
goto fail;
|
|
if (use_current_pos) {
|
|
/*
|
|
* Read the first batch of directory entries
|
|
* to prime dd_seek. This also checks if the
|
|
* fd passed to fdopendir() is a directory.
|
|
*/
|
|
dirp->dd_size = _getdirentries(dirp->dd_fd,
|
|
dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
|
|
if (dirp->dd_size < 0) {
|
|
if (errno == EINVAL)
|
|
errno = ENOTDIR;
|
|
goto fail;
|
|
}
|
|
dirp->dd_flags |= __DTF_SKIPREAD;
|
|
} else {
|
|
dirp->dd_size = 0;
|
|
dirp->dd_seek = 0;
|
|
}
|
|
}
|
|
|
|
return (dirp);
|
|
|
|
fail:
|
|
saved_errno = errno;
|
|
free(dirp->dd_buf);
|
|
free(dirp);
|
|
errno = saved_errno;
|
|
return (NULL);
|
|
}
|