| 1 | /* Work around an fstatat bug on Solaris 9. |
| 2 | |
| 3 | Copyright (C) 2006, 2009-2019 Free Software Foundation, Inc. |
| 4 | |
| 5 | This program is free software: you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | /* Written by Paul Eggert and Jim Meyering. */ |
| 19 | |
| 20 | /* If the user's config.h happens to include <sys/stat.h>, let it include only |
| 21 | the system's <sys/stat.h> here, so that orig_fstatat doesn't recurse to |
| 22 | rpl_fstatat. */ |
| 23 | #define __need_system_sys_stat_h |
| 24 | #include <config.h> |
| 25 | |
| 26 | /* Get the original definition of fstatat. It might be defined as a macro. */ |
| 27 | #include <sys/types.h> |
| 28 | #include <sys/stat.h> |
| 29 | #undef __need_system_sys_stat_h |
| 30 | |
| 31 | #if HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG |
| 32 | static int |
| 33 | orig_fstatat (int fd, char const *filename, struct stat *buf, int flags) |
| 34 | { |
| 35 | return fstatat (fd, filename, buf, flags); |
| 36 | } |
| 37 | #endif |
| 38 | |
| 39 | #ifdef __osf__ |
| 40 | /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc |
| 41 | eliminates this include because of the preliminary #include <sys/stat.h> |
| 42 | above. */ |
| 43 | # include "sys/stat.h" |
| 44 | #else |
| 45 | # include <sys/stat.h> |
| 46 | #endif |
| 47 | |
| 48 | #include "stat-time.h" |
| 49 | |
| 50 | #include <errno.h> |
| 51 | #include <fcntl.h> |
| 52 | #include <stdlib.h> |
| 53 | #include <string.h> |
| 54 | |
| 55 | #if HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG |
| 56 | |
| 57 | # ifndef LSTAT_FOLLOWS_SLASHED_SYMLINK |
| 58 | # define LSTAT_FOLLOWS_SLASHED_SYMLINK 0 |
| 59 | # endif |
| 60 | |
| 61 | static int |
| 62 | normal_fstatat (int fd, char const *file, struct stat *st, int flag) |
| 63 | { |
| 64 | return stat_time_normalize (orig_fstatat (fd, file, st, flag), st); |
| 65 | } |
| 66 | |
| 67 | /* fstatat should always follow symbolic links that end in /, but on |
| 68 | Solaris 9 it doesn't if AT_SYMLINK_NOFOLLOW is specified. |
| 69 | Likewise, trailing slash on a non-directory should be an error. |
| 70 | These are the same problems that lstat.c and stat.c address, so |
| 71 | solve it in a similar way. |
| 72 | |
| 73 | AIX 7.1 fstatat (AT_FDCWD, ..., 0) always fails, which is a bug. |
| 74 | Work around this bug if FSTATAT_AT_FDCWD_0_BROKEN is nonzero. */ |
| 75 | |
| 76 | int |
| 77 | rpl_fstatat (int fd, char const *file, struct stat *st, int flag) |
| 78 | { |
| 79 | int result = normal_fstatat (fd, file, st, flag); |
| 80 | size_t len; |
| 81 | |
| 82 | if (LSTAT_FOLLOWS_SLASHED_SYMLINK || result != 0) |
| 83 | return result; |
| 84 | len = strlen (file); |
| 85 | if (flag & AT_SYMLINK_NOFOLLOW) |
| 86 | { |
| 87 | /* Fix lstat behavior. */ |
| 88 | if (file[len - 1] != '/' || S_ISDIR (st->st_mode)) |
| 89 | return 0; |
| 90 | if (!S_ISLNK (st->st_mode)) |
| 91 | { |
| 92 | errno = ENOTDIR; |
| 93 | return -1; |
| 94 | } |
| 95 | result = normal_fstatat (fd, file, st, flag & ~AT_SYMLINK_NOFOLLOW); |
| 96 | } |
| 97 | /* Fix stat behavior. */ |
| 98 | if (result == 0 && !S_ISDIR (st->st_mode) && file[len - 1] == '/') |
| 99 | { |
| 100 | errno = ENOTDIR; |
| 101 | return -1; |
| 102 | } |
| 103 | return result; |
| 104 | } |
| 105 | |
| 106 | #else /* ! (HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG) */ |
| 107 | |
| 108 | /* On mingw, the gnulib <sys/stat.h> defines 'stat' as a function-like |
| 109 | macro; but using it in AT_FUNC_F2 causes compilation failure |
| 110 | because the preprocessor sees a use of a macro that requires two |
| 111 | arguments but is only given one. Hence, we need an inline |
| 112 | forwarder to get past the preprocessor. */ |
| 113 | static int |
| 114 | stat_func (char const *name, struct stat *st) |
| 115 | { |
| 116 | return stat (name, st); |
| 117 | } |
| 118 | |
| 119 | /* Likewise, if there is no native 'lstat', then the gnulib |
| 120 | <sys/stat.h> defined it as stat, which also needs adjustment. */ |
| 121 | # if !HAVE_LSTAT |
| 122 | # undef lstat |
| 123 | # define lstat stat_func |
| 124 | # endif |
| 125 | |
| 126 | /* Replacement for Solaris' function by the same name. |
| 127 | <https://www.google.com/search?q=fstatat+site:docs.oracle.com> |
| 128 | First, try to simulate it via l?stat ("/proc/self/fd/FD/FILE"). |
| 129 | Failing that, simulate it via save_cwd/fchdir/(stat|lstat)/restore_cwd. |
| 130 | If either the save_cwd or the restore_cwd fails (relatively unlikely), |
| 131 | then give a diagnostic and exit nonzero. |
| 132 | Otherwise, this function works just like Solaris' fstatat. */ |
| 133 | |
| 134 | # define AT_FUNC_NAME fstatat |
| 135 | # define AT_FUNC_F1 lstat |
| 136 | # define AT_FUNC_F2 stat_func |
| 137 | # define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW |
| 138 | # define AT_FUNC_POST_FILE_PARAM_DECLS , struct stat *st, int flag |
| 139 | # define AT_FUNC_POST_FILE_ARGS , st |
| 140 | # include "at-func.c" |
| 141 | # undef AT_FUNC_NAME |
| 142 | # undef AT_FUNC_F1 |
| 143 | # undef AT_FUNC_F2 |
| 144 | # undef AT_FUNC_USE_F1_COND |
| 145 | # undef AT_FUNC_POST_FILE_PARAM_DECLS |
| 146 | # undef AT_FUNC_POST_FILE_ARGS |
| 147 | |
| 148 | #endif /* !HAVE_FSTATAT */ |