| 1 | /* Copyright (C) 1993-2024 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 | <https://www.gnu.org/licenses/>. */ |
|---|
| 17 | |
|---|
| 18 | #include <errno.h> |
|---|
| 19 | #include <stddef.h> |
|---|
| 20 | #include <dirent.h> |
|---|
| 21 | #include <unistd.h> |
|---|
| 22 | #include <endian.h> |
|---|
| 23 | #include <assert.h> |
|---|
| 24 | #include <hurd.h> |
|---|
| 25 | |
|---|
| 26 | /* Read a directory entry from DIRP. */ |
|---|
| 27 | struct dirent * |
|---|
| 28 | __readdir (DIR *dirp) |
|---|
| 29 | { |
|---|
| 30 | struct dirent64 *entry64 = __readdir64 (dirp); |
|---|
| 31 | |
|---|
| 32 | if (sizeof (struct dirent64) == sizeof (struct dirent)) |
|---|
| 33 | /* We should in fact just be an alias to readdir64 on this machine. */ |
|---|
| 34 | return (struct dirent *) entry64; |
|---|
| 35 | |
|---|
| 36 | /* These are all compile-time constants. We know that d_ino is the first |
|---|
| 37 | member and that the layout of the following members matches exactly in |
|---|
| 38 | both structures. */ |
|---|
| 39 | assert (offsetof (struct dirent, d_ino) == 0); |
|---|
| 40 | assert (offsetof (struct dirent64, d_ino) == 0); |
|---|
| 41 | # define MATCH(memb) \ |
|---|
| 42 | assert (offsetof (struct dirent64, memb) - sizeof (entry64->d_ino) \ |
|---|
| 43 | == offsetof (struct dirent, memb) - sizeof (ino_t)) |
|---|
| 44 | MATCH (d_reclen); |
|---|
| 45 | MATCH (d_type); |
|---|
| 46 | MATCH (d_namlen); |
|---|
| 47 | # undef MATCH |
|---|
| 48 | |
|---|
| 49 | if (entry64 == NULL) |
|---|
| 50 | return NULL; |
|---|
| 51 | |
|---|
| 52 | struct dirent *const entry = ((void *) (&entry64->d_ino + 1) |
|---|
| 53 | - sizeof entry->d_ino); |
|---|
| 54 | const ino_t d_ino = entry64->d_ino; |
|---|
| 55 | if (d_ino != entry64->d_ino) |
|---|
| 56 | return __hurd_fail (EOVERFLOW), NULL; |
|---|
| 57 | # if BYTE_ORDER != BIG_ENDIAN /* We just skipped over the zero high word. */ |
|---|
| 58 | entry->d_ino = d_ino; /* ... or the nonzero low word, swap it. */ |
|---|
| 59 | # endif |
|---|
| 60 | entry->d_reclen -= sizeof entry64->d_ino - sizeof entry->d_ino; |
|---|
| 61 | return entry; |
|---|
| 62 | } |
|---|
| 63 | |
|---|
| 64 | weak_alias (__readdir, readdir) |
|---|
| 65 | |
|---|
