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| 1 | +/* |
| 2 | + * Copyright (c) 2004-2005 Todd C. Miller <[email protected]> |
| 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 | +#ifndef HAVE_CLOSEFROM |
| 18 | + |
| 19 | +#include <sys/types.h> |
| 20 | +#include <sys/param.h> |
| 21 | +#include <unistd.h> |
| 22 | +#include <stdio.h> |
| 23 | +#ifdef HAVE_FCNTL_H |
| 24 | +# include <fcntl.h> |
| 25 | +#endif |
| 26 | +#include <limits.h> |
| 27 | +#include <stdlib.h> |
| 28 | +#include <stddef.h> |
| 29 | +#include <string.h> |
| 30 | +#include <unistd.h> |
| 31 | +#ifdef HAVE_DIRENT_H |
| 32 | +# include <dirent.h> |
| 33 | +# define NAMLEN(dirent) strlen((dirent)->d_name) |
| 34 | +#else |
| 35 | +# define dirent direct |
| 36 | +# define NAMLEN(dirent) (dirent)->d_namlen |
| 37 | +# ifdef HAVE_SYS_NDIR_H |
| 38 | +# include <sys/ndir.h> |
| 39 | +# endif |
| 40 | +# ifdef HAVE_SYS_DIR_H |
| 41 | +# include <sys/dir.h> |
| 42 | +# endif |
| 43 | +# ifdef HAVE_NDIR_H |
| 44 | +# include <ndir.h> |
| 45 | +# endif |
| 46 | +#endif |
| 47 | +#if defined(HAVE_LIBPROC_H) |
| 48 | +# include <libproc.h> |
| 49 | +#endif |
| 50 | + |
| 51 | +#ifndef OPEN_MAX |
| 52 | +# define OPEN_MAX 256 |
| 53 | +#endif |
| 54 | + |
| 55 | +#if 0 |
| 56 | +__unused static const char rcsid[] = "$Sudo: closefrom.c,v 1.11 2006/08/17 15:26:54 millert Exp $"; |
| 57 | +#endif /* lint */ |
| 58 | + |
| 59 | +#ifndef HAVE_FCNTL_CLOSEM |
| 60 | +/* |
| 61 | + * Close all file descriptors greater than or equal to lowfd. |
| 62 | + */ |
| 63 | +static void |
| 64 | +closefrom_fallback(int lowfd) |
| 65 | +{ |
| 66 | + long fd, maxfd; |
| 67 | + |
| 68 | + /* |
| 69 | + * Fall back on sysconf() or getdtablesize(). We avoid checking |
| 70 | + * resource limits since it is possible to open a file descriptor |
| 71 | + * and then drop the rlimit such that it is below the open fd. |
| 72 | + */ |
| 73 | +#ifdef HAVE_SYSCONF |
| 74 | + maxfd = sysconf(_SC_OPEN_MAX); |
| 75 | +#else |
| 76 | + maxfd = getdtablesize(); |
| 77 | +#endif /* HAVE_SYSCONF */ |
| 78 | + if (maxfd < 0) |
| 79 | + maxfd = OPEN_MAX; |
| 80 | + |
| 81 | + for (fd = lowfd; fd < maxfd; fd++) |
| 82 | + (void) close((int) fd); |
| 83 | +} |
| 84 | +#endif /* HAVE_FCNTL_CLOSEM */ |
| 85 | + |
| 86 | +#ifdef HAVE_FCNTL_CLOSEM |
| 87 | +void |
| 88 | +closefrom(int lowfd) |
| 89 | +{ |
| 90 | + (void) fcntl(lowfd, F_CLOSEM, 0); |
| 91 | +} |
| 92 | +#elif defined(HAVE_LIBPROC_H) && defined(HAVE_PROC_PIDINFO) |
| 93 | +void |
| 94 | +closefrom(int lowfd) |
| 95 | +{ |
| 96 | + int i, r, sz; |
| 97 | + pid_t pid = getpid(); |
| 98 | + struct proc_fdinfo *fdinfo_buf = NULL; |
| 99 | + |
| 100 | + sz = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, NULL, 0); |
| 101 | + if (sz == 0) |
| 102 | + return; /* no fds, really? */ |
| 103 | + else if (sz == -1) |
| 104 | + goto fallback; |
| 105 | + if ((fdinfo_buf = malloc(sz)) == NULL) |
| 106 | + goto fallback; |
| 107 | + r = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, fdinfo_buf, sz); |
| 108 | + if (r < 0 || r > sz) |
| 109 | + goto fallback; |
| 110 | + for (i = 0; i < r / (int)PROC_PIDLISTFD_SIZE; i++) { |
| 111 | + if (fdinfo_buf[i].proc_fd >= lowfd) |
| 112 | + close(fdinfo_buf[i].proc_fd); |
| 113 | + } |
| 114 | + free(fdinfo_buf); |
| 115 | + return; |
| 116 | + fallback: |
| 117 | + free(fdinfo_buf); |
| 118 | + closefrom_fallback(lowfd); |
| 119 | + return; |
| 120 | +} |
| 121 | +#elif defined(HAVE_DIRFD) && defined(HAVE_PROC_PID) |
| 122 | +void |
| 123 | +closefrom(int lowfd) |
| 124 | +{ |
| 125 | + long fd; |
| 126 | + char fdpath[PATH_MAX], *endp; |
| 127 | + struct dirent *dent; |
| 128 | + DIR *dirp; |
| 129 | + int len; |
| 130 | + |
| 131 | + /* Check for a /proc/$$/fd directory. */ |
| 132 | + len = snprintf(fdpath, sizeof(fdpath), "/proc/%ld/fd", (long)getpid()); |
| 133 | + if (len > 0 && (size_t)len < sizeof(fdpath) && (dirp = opendir(fdpath))) { |
| 134 | + while ((dent = readdir(dirp)) != NULL) { |
| 135 | + fd = strtol(dent->d_name, &endp, 10); |
| 136 | + if (dent->d_name != endp && *endp == '\0' && |
| 137 | + fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp)) |
| 138 | + (void) close((int) fd); |
| 139 | + } |
| 140 | + (void) closedir(dirp); |
| 141 | + return; |
| 142 | + } |
| 143 | + /* /proc/$$/fd strategy failed, fall back to brute force closure */ |
| 144 | + closefrom_fallback(lowfd); |
| 145 | +} |
| 146 | +#else |
| 147 | +void |
| 148 | +closefrom(int lowfd) |
| 149 | +{ |
| 150 | + closefrom_fallback(lowfd); |
| 151 | +} |
| 152 | +#endif /* !HAVE_FCNTL_CLOSEM */ |
| 153 | +#endif /* HAVE_CLOSEFROM */ |
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