1 /* Work around an fstatat bug on Solaris 9. 2 3 Copyright (C) 2006, 2009-2022 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 */ 149