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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 "includes.h"
#ifndef HAVE_CLOSEFROM
#include <sys/types.h>
#include <sys/param.h>
#include <unistd.h>
#include <stdio.h>
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
#include <limits.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.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
#if defined(HAVE_LIBPROC_H)
# include <libproc.h>
#endif
#ifndef OPEN_MAX
# define OPEN_MAX 256
#endif
#if 0
__unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.11 2006/08/17 15:26:54 millert Exp $";
#endif /* lint */
#ifndef HAVE_FCNTL_CLOSEM
/*
* Close all file descriptors greater than or equal to lowfd.
*/
static void
closefrom_fallback(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);
}
#endif /* HAVE_FCNTL_CLOSEM */
#ifdef HAVE_FCNTL_CLOSEM
void
closefrom(int lowfd)
{
(void) fcntl(lowfd, F_CLOSEM, 0);
}
#elif defined(HAVE_LIBPROC_H) && defined(HAVE_PROC_PIDINFO)
void
closefrom(int lowfd)
{
int i, r, sz;
pid_t pid = getpid();
struct proc_fdinfo *fdinfo_buf = NULL;
sz = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, NULL, 0);
if (sz == 0)
return; /* no fds, really? */
else if (sz == -1)
goto fallback;
if ((fdinfo_buf = malloc(sz)) == NULL)
goto fallback;
r = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, fdinfo_buf, sz);
if (r < 0 || r > sz)
goto fallback;
for (i = 0; i < r / (int)PROC_PIDLISTFD_SIZE; i++) {
if (fdinfo_buf[i].proc_fd >= lowfd)
close(fdinfo_buf[i].proc_fd);
}
free(fdinfo_buf);
return;
fallback:
free(fdinfo_buf);
closefrom_fallback(lowfd);
return;
}
#elif defined(HAVE_DIRFD) && defined(HAVE_PROC_PID)
void
closefrom(int lowfd)
{
long fd;
char fdpath[PATH_MAX], *endp;
struct dirent *dent;
DIR *dirp;
int len;
/* Check for a /proc/$$/fd directory. */
len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd", (long)getpid());
if (len > 0 && (size_t)len < sizeof(fdpath) && (dirp = opendir(fdpath))) {
while ((dent = readdir(dirp)) != NULL) {
fd = strtol(dent->d_name, &endp, 10);
if (dent->d_name != endp && *endp == '\0' &&
fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp))
(void) close((int) fd);
}
(void) closedir(dirp);
return;
}
/* /proc/$$/fd strategy failed, fall back to brute force closure */
closefrom_fallback(lowfd);
}
#else
void
closefrom(int lowfd)
{
closefrom_fallback(lowfd);
}
#endif /* !HAVE_FCNTL_CLOSEM */
#endif /* HAVE_CLOSEFROM */
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