1 /*
2 * Copyright (c) 2004-2005 Todd C. Miller <Todd.Miller@courtesan.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 #include "includes.h"
18
19 #ifndef HAVE_CLOSEFROM
20
21 #include <sys/types.h>
22 #include <sys/param.h>
23 #include <unistd.h>
24 #include <stdio.h>
25 #ifdef HAVE_FCNTL_H
26 # include <fcntl.h>
27 #endif
28 #include <limits.h>
29 #include <stdlib.h>
30 #include <stddef.h>
31 #include <string.h>
32 #include <unistd.h>
33 #ifdef HAVE_DIRENT_H
34 # include <dirent.h>
35 # define NAMLEN(dirent) strlen((dirent)->d_name)
36 #else
37 # define dirent direct
38 # define NAMLEN(dirent) (dirent)->d_namlen
39 # ifdef HAVE_SYS_NDIR_H
40 # include <sys/ndir.h>
41 # endif
42 # ifdef HAVE_SYS_DIR_H
43 # include <sys/dir.h>
44 # endif
45 # ifdef HAVE_NDIR_H
46 # include <ndir.h>
47 # endif
48 #endif
49
50 #ifndef OPEN_MAX
51 # define OPEN_MAX 256
52 #endif
53
54 #if 0
55 __unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.11 2006/08/17 15:26:54 millert Exp $";
56 #endif /* lint */
57
58 /*
59 * Close all file descriptors greater than or equal to lowfd.
60 */
61 #ifdef HAVE_FCNTL_CLOSEM
62 void
closefrom(int lowfd)63 closefrom(int lowfd)
64 {
65 (void) fcntl(lowfd, F_CLOSEM, 0);
66 }
67 #else
68 void
closefrom(int lowfd)69 closefrom(int lowfd)
70 {
71 long fd, maxfd;
72 #if defined(HAVE_DIRFD) && defined(HAVE_PROC_PID)
73 char fdpath[PATH_MAX], *endp;
74 struct dirent *dent;
75 DIR *dirp;
76 int len;
77
78 /* Check for a /proc/$$/fd directory. */
79 len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd", (long)getpid());
80 if (len > 0 && (size_t)len <= sizeof(fdpath) && (dirp = opendir(fdpath))) {
81 while ((dent = readdir(dirp)) != NULL) {
82 fd = strtol(dent->d_name, &endp, 10);
83 if (dent->d_name != endp && *endp == '\0' &&
84 fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp))
85 (void) close((int) fd);
86 }
87 (void) closedir(dirp);
88 } else
89 #endif
90 {
91 /*
92 * Fall back on sysconf() or getdtablesize(). We avoid checking
93 * resource limits since it is possible to open a file descriptor
94 * and then drop the rlimit such that it is below the open fd.
95 */
96 #ifdef HAVE_SYSCONF
97 maxfd = sysconf(_SC_OPEN_MAX);
98 #else
99 maxfd = getdtablesize();
100 #endif /* HAVE_SYSCONF */
101 if (maxfd < 0)
102 maxfd = OPEN_MAX;
103
104 for (fd = lowfd; fd < maxfd; fd++)
105 (void) close((int) fd);
106 }
107 }
108 #endif /* !HAVE_FCNTL_CLOSEM */
109 #endif /* HAVE_CLOSEFROM */
110