| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame^] | 1 | /* Copyright (C) 1991-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include <errno.h> |
| 19 | #include <limits.h> |
| 20 | #include <stddef.h> |
| 21 | #include <string.h> |
| 22 | #include <dirent.h> |
| 23 | #include <unistd.h> |
| 24 | #include <sys/types.h> |
| 25 | #include <assert.h> |
| 26 | |
| 27 | #include <dirstream.h> |
| 28 | |
| 29 | #ifndef __READDIR |
| 30 | # define __READDIR __readdir |
| 31 | # define __GETDENTS __getdents |
| 32 | # define DIRENT_TYPE struct dirent |
| 33 | # define __READDIR_ALIAS |
| 34 | #endif |
| 35 | |
| 36 | /* Read a directory entry from DIRP. */ |
| 37 | DIRENT_TYPE * |
| 38 | __READDIR (DIR *dirp) |
| 39 | { |
| 40 | DIRENT_TYPE *dp; |
| 41 | int saved_errno = errno; |
| 42 | |
| 43 | #if IS_IN (libc) |
| 44 | __libc_lock_lock (dirp->lock); |
| 45 | #endif |
| 46 | |
| 47 | do |
| 48 | { |
| 49 | size_t reclen; |
| 50 | |
| 51 | if (dirp->offset >= dirp->size) |
| 52 | { |
| 53 | /* We've emptied out our buffer. Refill it. */ |
| 54 | |
| 55 | size_t maxread; |
| 56 | ssize_t bytes; |
| 57 | |
| 58 | #ifndef _DIRENT_HAVE_D_RECLEN |
| 59 | /* Fixed-size struct; must read one at a time (see below). */ |
| 60 | maxread = sizeof *dp; |
| 61 | #else |
| 62 | maxread = dirp->allocation; |
| 63 | #endif |
| 64 | |
| 65 | bytes = __GETDENTS (dirp->fd, dirp->data, maxread); |
| 66 | if (bytes <= 0) |
| 67 | { |
| 68 | /* On some systems getdents fails with ENOENT when the |
| 69 | open directory has been rmdir'd already. POSIX.1 |
| 70 | requires that we treat this condition like normal EOF. */ |
| 71 | if (bytes < 0 && errno == ENOENT) |
| 72 | bytes = 0; |
| 73 | |
| 74 | /* Don't modifiy errno when reaching EOF. */ |
| 75 | if (bytes == 0) |
| 76 | __set_errno (saved_errno); |
| 77 | dp = NULL; |
| 78 | break; |
| 79 | } |
| 80 | dirp->size = (size_t) bytes; |
| 81 | |
| 82 | /* Reset the offset into the buffer. */ |
| 83 | dirp->offset = 0; |
| 84 | } |
| 85 | |
| 86 | dp = (DIRENT_TYPE *) &dirp->data[dirp->offset]; |
| 87 | |
| 88 | #ifdef _DIRENT_HAVE_D_RECLEN |
| 89 | reclen = dp->d_reclen; |
| 90 | #else |
| 91 | /* The only version of `struct dirent*' that lacks `d_reclen' |
| 92 | is fixed-size. */ |
| 93 | assert (sizeof dp->d_name > 1); |
| 94 | reclen = sizeof *dp; |
| 95 | /* The name is not terminated if it is the largest possible size. |
| 96 | Clobber the following byte to ensure proper null termination. We |
| 97 | read jst one entry at a time above so we know that byte will not |
| 98 | be used later. */ |
| 99 | dp->d_name[sizeof dp->d_name] = '\0'; |
| 100 | #endif |
| 101 | |
| 102 | dirp->offset += reclen; |
| 103 | |
| 104 | #ifdef _DIRENT_HAVE_D_OFF |
| 105 | dirp->filepos = dp->d_off; |
| 106 | #else |
| 107 | dirp->filepos += reclen; |
| 108 | #endif |
| 109 | |
| 110 | /* Skip deleted files. */ |
| 111 | } while (dp->d_ino == 0); |
| 112 | |
| 113 | #if IS_IN (libc) |
| 114 | __libc_lock_unlock (dirp->lock); |
| 115 | #endif |
| 116 | |
| 117 | return dp; |
| 118 | } |
| 119 | |
| 120 | #ifdef __READDIR_ALIAS |
| 121 | weak_alias (__readdir, readdir) |
| 122 | #endif |