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/*
* Copyright (c) 2004-2005 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 <config.h>
#include <sys/types.h>
#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#include <fcntl.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
#include "sudo.h"
#ifndef lint
__unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.6.2.3 2007/06/20 11:06:50 millert Exp $";
#endif /* lint */
#ifndef HAVE_FCNTL_CLOSEM
# ifndef HAVE_DIRFD
# define closefrom_fallback closefrom
# endif
#endif
/*
* Close all file descriptors greater than or equal to lowfd.
* This is the expensive (ballback) method.
*/
void
closefrom_fallback(lowfd)
int lowfd;
{
long fd, maxfd;
/*
* 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);
}
/*
* Close all file descriptors greater than or equal to lowfd.
* We try the fast way first, falling back on the slow method.
*/
#ifdef HAVE_FCNTL_CLOSEM
void
closefrom(lowfd)
int lowfd;
{
if (fcntl(lowfd, F_CLOSEM, 0) == -1)
closefrom_fallback(lowfd);
}
#else
# ifdef HAVE_DIRFD
void
closefrom(lowfd)
int lowfd;
{
struct dirent *dent;
DIR *dirp;
char *endp;
long fd;
/* Use /proc/self/fd directory if it exists. */
if ((dirp = opendir("/proc/self/fd")) != NULL) {
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
closefrom_fallback(lowfd);
}
#endif /* HAVE_DIRFD */
#endif /* HAVE_FCNTL_CLOSEM */
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