freebsd-skq/contrib/cpio/lib/savedir.c
Peter Wemm c6acfe86c7 Merge gnu cpio 2.6 -> 2.8 changes. Unfortunately, we have massive
conflicts due to radically different approaches to security and bug fixes.
In some cases I re-started from the vendor version and reimplemented our
patches.  Fortunately, this is not enabled by default in -current.
2008-07-10 02:08:00 +00:00

138 lines
3.6 KiB
C

/* savedir.c -- save the list of files in a directory in a string
Copyright (C) 1990, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005,
2006 Free Software Foundation, Inc.
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 2, or (at your option)
any later version.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
#include <config.h>
#include "savedir.h"
#include <sys/types.h>
#include <errno.h>
#include <dirent.h>
#ifndef _D_EXACT_NAMLEN
# define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
#endif
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "openat.h"
#include "xalloc.h"
#ifndef NAME_SIZE_DEFAULT
# define NAME_SIZE_DEFAULT 512
#endif
/* The results of opendir() in this file are not used with dirfd and fchdir,
therefore save some unnecessary work in fchdir.c. */
#undef opendir
#undef closedir
/* Return a freshly allocated string containing the file names
in directory DIRP, separated by '\0' characters;
the end is marked by two '\0' characters in a row.
Return NULL (setting errno) if DIRP cannot be read or closed.
If DIRP is NULL, return NULL without affecting errno. */
static char *
savedirstream (DIR *dirp)
{
char *name_space;
size_t allocated = NAME_SIZE_DEFAULT;
size_t used = 0;
int save_errno;
if (dirp == NULL)
return NULL;
name_space = xmalloc (allocated);
for (;;)
{
struct dirent const *dp;
char const *entry;
errno = 0;
dp = readdir (dirp);
if (! dp)
break;
/* Skip "", ".", and "..". "" is returned by at least one buggy
implementation: Solaris 2.4 readdir on NFS file systems. */
entry = dp->d_name;
if (entry[entry[0] != '.' ? 0 : entry[1] != '.' ? 1 : 2] != '\0')
{
size_t entry_size = _D_EXACT_NAMLEN (dp) + 1;
if (used + entry_size < used)
xalloc_die ();
if (allocated <= used + entry_size)
{
do
{
if (2 * allocated < allocated)
xalloc_die ();
allocated *= 2;
}
while (allocated <= used + entry_size);
name_space = xrealloc (name_space, allocated);
}
memcpy (name_space + used, entry, entry_size);
used += entry_size;
}
}
name_space[used] = '\0';
save_errno = errno;
if (closedir (dirp) != 0)
save_errno = errno;
if (save_errno != 0)
{
free (name_space);
errno = save_errno;
return NULL;
}
return name_space;
}
/* Return a freshly allocated string containing the file names
in directory DIR, separated by '\0' characters;
the end is marked by two '\0' characters in a row.
Return NULL (setting errno) if DIR cannot be opened, read, or closed. */
char *
savedir (char const *dir)
{
return savedirstream (opendir (dir));
}
/* Return a freshly allocated string containing the file names
in directory FD, separated by '\0' characters;
the end is marked by two '\0' characters in a row.
Return NULL (setting errno) if FD cannot be read or closed. */
char *
fdsavedir (int fd)
{
return savedirstream (fdopendir (fd));
}