openssh/openbsd-compat/bsd-closefrom.c
Damien Miller 36f4965020 - (djm) [acconfig.h configure.ac openbsd-compat/Makefile.in
openbsd-compat/bsd-closefrom.c openbsd-compat/bsd-misc.c
   openbsd-compat/bsd-misc.h openbsd-compat/openbsd-compat.h] Use smarter
   closefrom() replacement from sudo; ok dtucker@
2004-08-15 18:40:59 +10:00

101 lines
2.7 KiB
C

/*
* Copyright (c) 2004 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "includes.h"
#ifndef HAVE_CLOSEFROM
#include <sys/types.h>
#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
#include <limits.h>
#include <stdlib.h>
#include <stddef.h>
#ifdef HAVE_DIRENT_H
# include <dirent.h>
# define NAMLEN(dirent) strlen((dirent)->d_name)
#else
# define dirent direct
# define NAMLEN(dirent) (dirent)->d_namlen
# ifdef HAVE_SYS_NDIR_H
# include <sys/ndir.h>
# endif
# ifdef HAVE_SYS_DIR_H
# include <sys/dir.h>
# endif
# ifdef HAVE_NDIR_H
# include <ndir.h>
# endif
#endif
#ifndef OPEN_MAX
# define OPEN_MAX 256
#endif
RCSID("$Id: bsd-closefrom.c,v 1.1 2004/08/15 08:41:00 djm Exp $");
#ifndef lint
static const char sudorcsid[] = "$Sudo: closefrom.c,v 1.6 2004/06/01 20:51:56 millert Exp $";
#endif /* lint */
/*
* Close all file descriptors greater than or equal to lowfd.
*/
void
closefrom(int lowfd)
{
long fd, maxfd;
#if defined(HAVE_DIRFD) && defined(HAVE_PROC_PID)
char fdpath[PATH_MAX], *endp;
struct dirent *dent;
DIR *dirp;
int len;
/* Check for a /proc/$$/fd directory. */
len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd", (long)getpid());
if (len != -1 && len <= sizeof(fdpath) && (dirp = opendir(fdpath))) {
while ((dent = readdir(dirp)) != NULL) {
fd = strtol(dent->d_name, &endp, 10);
if (dent->d_name != endp && *endp == '\0' &&
fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp))
(void) close((int) fd);
}
(void) closedir(dirp);
} else
#endif
{
/*
* Fall back on sysconf() or getdtablesize(). We avoid checking
* resource limits since it is possible to open a file descriptor
* and then drop the rlimit such that it is below the open fd.
*/
#ifdef HAVE_SYSCONF
maxfd = sysconf(_SC_OPEN_MAX);
#else
maxfd = getdtablesize();
#endif /* HAVE_SYSCONF */
if (maxfd < 0)
maxfd = OPEN_MAX;
for (fd = lowfd; fd < maxfd; fd++)
(void) close((int) fd);
}
}
#endif /* HAVE_CLOSEFROM */