| 1 | /* Test duplicating non-inheritable file descriptors. | 
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| 2 | Copyright (C) 2009-2022 Free Software Foundation, Inc. | 
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| 3 |  | 
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| 4 | This program is free software: you can redistribute it and/or modify | 
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| 5 | it under the terms of the GNU General Public License as published by | 
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| 6 | the Free Software Foundation, either version 3 of the License, or | 
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| 7 | (at your option) any later version. | 
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| 8 |  | 
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| 9 | This program is distributed in the hope that it will be useful, | 
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
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| 12 | GNU General Public License for more details. | 
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| 13 |  | 
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| 14 | You should have received a copy of the GNU General Public License | 
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| 15 | along with this program.  If not, see <https://www.gnu.org/licenses/>.  */ | 
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| 16 |  | 
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| 17 | /* Written by Eric Blake <ebb9@byu.net>, 2009.  */ | 
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| 18 |  | 
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| 19 | #include <config.h> | 
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| 20 |  | 
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| 21 | #include "cloexec.h" | 
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| 22 |  | 
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| 23 | #include <errno.h> | 
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| 24 | #include <fcntl.h> | 
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| 25 | #include <unistd.h> | 
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| 26 |  | 
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| 27 | #if defined _WIN32 && ! defined __CYGWIN__ | 
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| 28 | /* Get declarations of the native Windows API functions.  */ | 
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| 29 | # define WIN32_LEAN_AND_MEAN | 
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| 30 | # include <windows.h> | 
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| 31 | /* Get _get_osfhandle.  */ | 
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| 32 | # if GNULIB_MSVC_NOTHROW | 
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| 33 | #  include "msvc-nothrow.h" | 
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| 34 | # else | 
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| 35 | #  include <io.h> | 
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| 36 | # endif | 
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| 37 | #endif | 
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| 38 |  | 
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| 39 | #include "binary-io.h" | 
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| 40 | #include "macros.h" | 
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| 41 |  | 
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| 42 | /* Return non-zero if FD is open and inheritable across exec/spawn.  */ | 
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| 43 | static int | 
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| 44 | is_inheritable (int fd) | 
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| 45 | { | 
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| 46 | #if defined _WIN32 && ! defined __CYGWIN__ | 
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| 47 | /* On native Windows, the initial state of unassigned standard file | 
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| 48 | descriptors is that they are open but point to an | 
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| 49 | INVALID_HANDLE_VALUE, and there is no fcntl.  */ | 
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| 50 | HANDLE h = (HANDLE) _get_osfhandle (fd); | 
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| 51 | DWORD flags; | 
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| 52 | if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0) | 
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| 53 | return 0; | 
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| 54 | return (flags & HANDLE_FLAG_INHERIT) != 0; | 
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| 55 | #else | 
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| 56 | # ifndef F_GETFD | 
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| 57 | #  error Please port fcntl to your platform | 
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| 58 | # endif | 
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| 59 | int i = fcntl (fd, F_GETFD); | 
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| 60 | return 0 <= i && (i & FD_CLOEXEC) == 0; | 
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| 61 | #endif | 
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| 62 | } | 
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| 63 |  | 
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| 64 | #if !O_BINARY | 
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| 65 | # define set_binary_mode(f,m) zero () | 
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| 66 | static int zero (void) { return 0; } | 
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| 67 | #endif | 
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| 68 |  | 
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| 69 | /* Return non-zero if FD is open in the given MODE, which is either | 
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| 70 | O_TEXT or O_BINARY.  */ | 
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| 71 | static int | 
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| 72 | is_mode (int fd, int mode) | 
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| 73 | { | 
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| 74 | int value = set_binary_mode (fd, O_BINARY); | 
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| 75 | set_binary_mode (fd, value); | 
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| 76 | return mode == value; | 
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| 77 | } | 
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| 78 |  | 
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| 79 | int | 
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| 80 | main (void) | 
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| 81 | { | 
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| 82 | const char *file = "test-cloexec.tmp"; | 
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| 83 | int fd = creat (file, 0600); | 
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| 84 | int fd2; | 
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| 85 | int bad_fd = getdtablesize (); | 
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| 86 |  | 
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| 87 | /* Assume std descriptors were provided by invoker.  */ | 
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| 88 | ASSERT (STDERR_FILENO < fd); | 
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| 89 | ASSERT (is_inheritable (fd)); | 
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| 90 |  | 
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| 91 | /* Normal use of set_cloexec_flag.  */ | 
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| 92 | ASSERT (set_cloexec_flag (fd, true) == 0); | 
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| 93 | #if !(defined _WIN32 && ! defined __CYGWIN__) | 
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| 94 | ASSERT (!is_inheritable (fd)); | 
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| 95 | #endif | 
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| 96 | ASSERT (set_cloexec_flag (fd, false) == 0); | 
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| 97 | ASSERT (is_inheritable (fd)); | 
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| 98 |  | 
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| 99 | /* Normal use of dup_cloexec.  */ | 
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| 100 | fd2 = dup_cloexec (fd); | 
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| 101 | ASSERT (fd < fd2); | 
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| 102 | ASSERT (!is_inheritable (fd2)); | 
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| 103 | ASSERT (close (fd) == 0); | 
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| 104 | ASSERT (dup_cloexec (fd2) == fd); | 
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| 105 | ASSERT (!is_inheritable (fd)); | 
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| 106 | ASSERT (close (fd2) == 0); | 
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| 107 |  | 
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| 108 | /* On systems that distinguish between text and binary mode, | 
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| 109 | dup_cloexec reuses the mode of the source.  */ | 
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| 110 | set_binary_mode (fd, O_BINARY); | 
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| 111 | ASSERT (is_mode (fd, O_BINARY)); | 
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| 112 | fd2 = dup_cloexec (fd); | 
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| 113 | ASSERT (fd < fd2); | 
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| 114 | ASSERT (is_mode (fd2, O_BINARY)); | 
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| 115 | ASSERT (close (fd2) == 0); | 
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| 116 | set_binary_mode (fd, O_TEXT); | 
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| 117 | ASSERT (is_mode (fd, O_TEXT)); | 
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| 118 | fd2 = dup_cloexec (fd); | 
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| 119 | ASSERT (fd < fd2); | 
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| 120 | ASSERT (is_mode (fd2, O_TEXT)); | 
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| 121 | ASSERT (close (fd2) == 0); | 
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| 122 |  | 
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| 123 | /* Test error handling.  */ | 
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| 124 | errno = 0; | 
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| 125 | ASSERT (set_cloexec_flag (-1, false) == -1); | 
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| 126 | ASSERT (errno == EBADF); | 
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| 127 | errno = 0; | 
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| 128 | ASSERT (set_cloexec_flag (bad_fd, false) == -1); | 
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| 129 | ASSERT (errno == EBADF); | 
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| 130 | errno = 0; | 
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| 131 | ASSERT (set_cloexec_flag (fd2, false) == -1); | 
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| 132 | ASSERT (errno == EBADF); | 
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| 133 | errno = 0; | 
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| 134 | ASSERT (dup_cloexec (-1) == -1); | 
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| 135 | ASSERT (errno == EBADF); | 
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| 136 | errno = 0; | 
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| 137 | ASSERT (dup_cloexec (bad_fd) == -1); | 
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| 138 | ASSERT (errno == EBADF); | 
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| 139 | errno = 0; | 
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| 140 | ASSERT (dup_cloexec (fd2) == -1); | 
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| 141 | ASSERT (errno == EBADF); | 
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| 142 |  | 
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| 143 | /* Clean up.  */ | 
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| 144 | ASSERT (close (fd) == 0); | 
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| 145 | ASSERT (unlink (file) == 0); | 
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| 146 |  | 
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| 147 | return 0; | 
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| 148 | } | 
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