1 /* 2 * Copyright (c) 2004-2005 Todd C. Miller <Todd.Miller (at) 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 63 closefrom(int lowfd) 64 { 65 (void) fcntl(lowfd, F_CLOSEM, 0); 66 } 67 #else 68 void 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
