freebsd-skq/lib/libc/gen/scandir.c
das 6f407f2920 scandir(3) previously used st_size to obtain an initial estimate
of the array length needed to store all the directory entries.
Although BSD has historically guaranteed that st_size is the size
of the directory file, POSIX does not, and more to the point, some
recent filesystems such as ZFS use st_size to mean something else.

The fix is to not stat the directory at all, set the initial
array size to 32 entries, and realloc it in powers of 2 if that
proves insufficient.

PR:	113668
2008-03-16 19:08:53 +00:00

137 lines
4.2 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[] = "@(#)scandir.c 8.3 (Berkeley) 1/2/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Scan the directory dirname calling select to make a list of selected
* directory entries then sort using qsort and compare routine dcomp.
* Returns the number of entries and a pointer to a list of pointers to
* struct dirent (through namelist). Returns -1 if there were any errors.
*/
#include "namespace.h"
#include <dirent.h>
#include <stdlib.h>
#include <string.h>
#include "un-namespace.h"
/*
* The DIRSIZ macro is the minimum record length which will hold the directory
* entry. This requires the amount of space in struct dirent without the
* d_name field, plus enough space for the name and a terminating nul byte
* (dp->d_namlen + 1), rounded up to a 4 byte boundary.
*/
#undef DIRSIZ
#define DIRSIZ(dp) \
((sizeof(struct dirent) - sizeof(dp)->d_name) + \
(((dp)->d_namlen + 1 + 3) &~ 3))
int
scandir(dirname, namelist, select, dcomp)
const char *dirname;
struct dirent ***namelist;
int (*select)(struct dirent *);
int (*dcomp)(const void *, const void *);
{
struct dirent *d, *p, **names = NULL;
size_t nitems = 0;
long arraysz;
DIR *dirp;
if ((dirp = opendir(dirname)) == NULL)
return(-1);
arraysz = 32; /* initial estimate of the array size */
names = (struct dirent **)malloc(arraysz * sizeof(struct dirent *));
if (names == NULL)
goto fail;
while ((d = readdir(dirp)) != NULL) {
if (select != NULL && !(*select)(d))
continue; /* just selected names */
/*
* Make a minimum size copy of the data
*/
p = (struct dirent *)malloc(DIRSIZ(d));
if (p == NULL)
goto fail;
p->d_fileno = d->d_fileno;
p->d_type = d->d_type;
p->d_reclen = d->d_reclen;
p->d_namlen = d->d_namlen;
bcopy(d->d_name, p->d_name, p->d_namlen + 1);
/*
* Check to make sure the array has space left and
* realloc the maximum size.
*/
if (nitems >= arraysz) {
struct dirent **names2;
names2 = (struct dirent **)realloc((char *)names,
(arraysz * 2) * sizeof(struct dirent *));
if (names2 == NULL) {
free(p);
goto fail;
}
names = names2;
arraysz *= 2;
}
names[nitems++] = p;
}
closedir(dirp);
if (nitems && dcomp != NULL)
qsort(names, nitems, sizeof(struct dirent *), dcomp);
*namelist = names;
return(nitems);
fail:
while (nitems > 0)
free(names[--nitems]);
free(names);
closedir(dirp);
return -1;
}
/*
* Alphabetic order comparison routine for those who want it.
*/
int
alphasort(d1, d2)
const void *d1;
const void *d2;
{
return(strcmp((*(struct dirent **)d1)->d_name,
(*(struct dirent **)d2)->d_name));
}