mirror of git://anongit.mindrot.org/openssh.git
161 lines
3.9 KiB
C
161 lines
3.9 KiB
C
/*
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* Copyright (c) 2004-2005 Todd C. Miller <Todd.Miller@courtesan.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "includes.h"
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#if !defined(HAVE_CLOSEFROM) || defined(BROKEN_CLOSEFROM)
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#include <sys/types.h>
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#include <sys/param.h>
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#include <unistd.h>
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#include <stdio.h>
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#ifdef HAVE_FCNTL_H
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# include <fcntl.h>
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#endif
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#include <limits.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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#include <unistd.h>
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#ifdef HAVE_DIRENT_H
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# include <dirent.h>
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# define NAMLEN(dirent) strlen((dirent)->d_name)
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#else
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# define dirent direct
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# define NAMLEN(dirent) (dirent)->d_namlen
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# ifdef HAVE_SYS_NDIR_H
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# include <sys/ndir.h>
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# endif
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# ifdef HAVE_SYS_DIR_H
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# include <sys/dir.h>
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# endif
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# ifdef HAVE_NDIR_H
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# include <ndir.h>
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# endif
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#endif
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#if defined(HAVE_LIBPROC_H)
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# include <libproc.h>
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#endif
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#ifndef OPEN_MAX
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# define OPEN_MAX 256
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#endif
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#if 0
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__unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.11 2006/08/17 15:26:54 millert Exp $";
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#endif /* lint */
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#ifndef HAVE_FCNTL_CLOSEM
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/*
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* Close all file descriptors greater than or equal to lowfd.
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*/
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static void
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closefrom_fallback(int lowfd)
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{
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long fd, maxfd;
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/*
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* Fall back on sysconf() or getdtablesize(). We avoid checking
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* resource limits since it is possible to open a file descriptor
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* and then drop the rlimit such that it is below the open fd.
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*/
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#ifdef HAVE_SYSCONF
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maxfd = sysconf(_SC_OPEN_MAX);
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#else
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maxfd = getdtablesize();
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#endif /* HAVE_SYSCONF */
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if (maxfd < 0)
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maxfd = OPEN_MAX;
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for (fd = lowfd; fd < maxfd; fd++)
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(void) close((int) fd);
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}
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#endif /* HAVE_FCNTL_CLOSEM */
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#ifdef HAVE_FCNTL_CLOSEM
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void
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closefrom(int lowfd)
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{
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(void) fcntl(lowfd, F_CLOSEM, 0);
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}
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#elif defined(HAVE_LIBPROC_H) && defined(HAVE_PROC_PIDINFO)
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void
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closefrom(int lowfd)
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{
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int i, r, sz;
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pid_t pid = getpid();
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struct proc_fdinfo *fdinfo_buf = NULL;
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sz = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, NULL, 0);
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if (sz == 0)
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return; /* no fds, really? */
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else if (sz == -1)
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goto fallback;
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if ((fdinfo_buf = malloc(sz)) == NULL)
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goto fallback;
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r = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, fdinfo_buf, sz);
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if (r < 0 || r > sz)
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goto fallback;
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for (i = 0; i < r / (int)PROC_PIDLISTFD_SIZE; i++) {
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if (fdinfo_buf[i].proc_fd >= lowfd)
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close(fdinfo_buf[i].proc_fd);
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}
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free(fdinfo_buf);
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return;
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fallback:
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free(fdinfo_buf);
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closefrom_fallback(lowfd);
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return;
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}
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#elif defined(HAVE_DIRFD) && defined(HAVE_PROC_PID)
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void
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closefrom(int lowfd)
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{
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long fd;
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char fdpath[PATH_MAX], *endp;
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struct dirent *dent;
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DIR *dirp;
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int len;
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#ifdef HAVE_CLOSE_RANGE
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if (close_range(lowfd, INT_MAX, 0) == 0)
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return;
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#endif
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/* Check for a /proc/$$/fd directory. */
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len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd", (long)getpid());
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if (len > 0 && (size_t)len < sizeof(fdpath) && (dirp = opendir(fdpath))) {
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while ((dent = readdir(dirp)) != NULL) {
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fd = strtol(dent->d_name, &endp, 10);
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if (dent->d_name != endp && *endp == '\0' &&
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fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp))
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(void) close((int) fd);
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}
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(void) closedir(dirp);
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return;
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}
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/* /proc/$$/fd strategy failed, fall back to brute force closure */
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closefrom_fallback(lowfd);
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}
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#else
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void
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closefrom(int lowfd)
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{
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closefrom_fallback(lowfd);
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}
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#endif /* !HAVE_FCNTL_CLOSEM */
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#endif /* HAVE_CLOSEFROM */
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