| /* Test that dup_safer leaves standard fds alone. |
| Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| /* Written by Eric Blake <ebb9@byu.net>, 2009. */ |
| |
| #include <config.h> |
| |
| #include "unistd--.h" |
| |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include "binary-io.h" |
| #include "cloexec.h" |
| |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| /* Get declarations of the native Windows API functions. */ |
| # define WIN32_LEAN_AND_MEAN |
| # include <windows.h> |
| /* Get _get_osfhandle. */ |
| # if GNULIB_MSVC_NOTHROW |
| # include "msvc-nothrow.h" |
| # else |
| # include <io.h> |
| # endif |
| #endif |
| |
| #if !O_BINARY |
| # define setmode(f,m) zero () |
| static int zero (void) { return 0; } |
| #endif |
| |
| /* This test intentionally closes stderr. So, we arrange to have fd 10 |
| (outside the range of interesting fd's during the test) set up to |
| duplicate the original stderr. */ |
| |
| #define BACKUP_STDERR_FILENO 10 |
| #define ASSERT_STREAM myerr |
| #include "macros.h" |
| |
| static FILE *myerr; |
| |
| /* Return true if FD is open. */ |
| static bool |
| is_open (int fd) |
| { |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| /* On native Windows, the initial state of unassigned standard file |
| descriptors is that they are open but point to an |
| INVALID_HANDLE_VALUE, and there is no fcntl. */ |
| return (HANDLE) _get_osfhandle (fd) != INVALID_HANDLE_VALUE; |
| #else |
| # ifndef F_GETFL |
| # error Please port fcntl to your platform |
| # endif |
| return 0 <= fcntl (fd, F_GETFL); |
| #endif |
| } |
| |
| /* Return true if FD is open and inheritable across exec/spawn. */ |
| static bool |
| is_inheritable (int fd) |
| { |
| #if defined _WIN32 && ! defined __CYGWIN__ |
| /* On native Windows, the initial state of unassigned standard file |
| descriptors is that they are open but point to an |
| INVALID_HANDLE_VALUE, and there is no fcntl. */ |
| HANDLE h = (HANDLE) _get_osfhandle (fd); |
| DWORD flags; |
| if (h == INVALID_HANDLE_VALUE || GetHandleInformation (h, &flags) == 0) |
| return 0; |
| return (flags & HANDLE_FLAG_INHERIT) != 0; |
| #else |
| # ifndef F_GETFD |
| # error Please port fcntl to your platform |
| # endif |
| int i = fcntl (fd, F_GETFD); |
| return 0 <= i && (i & FD_CLOEXEC) == 0; |
| #endif |
| } |
| |
| /* Return true if FD is open in the given MODE, which is either |
| O_TEXT or O_BINARY. */ |
| static bool |
| is_mode (int fd, int mode) |
| { |
| int value = setmode (fd, O_BINARY); |
| setmode (fd, value); |
| return mode == value; |
| } |
| |
| #define witness "test-dup-safer.txt" |
| |
| int |
| main (void) |
| { |
| int i; |
| int fd; |
| int bad_fd = getdtablesize (); |
| |
| /* We close fd 2 later, so save it in fd 10. */ |
| if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO |
| || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL) |
| return 2; |
| |
| /* Create file for later checks. */ |
| fd = creat (witness, 0600); |
| ASSERT (STDERR_FILENO < fd); |
| |
| /* Four iterations, with progressively more standard descriptors |
| closed. */ |
| for (i = -1; i <= STDERR_FILENO; i++) |
| { |
| if (0 <= i) |
| ASSERT (close (i) == 0); |
| |
| /* Detect errors. */ |
| errno = 0; |
| ASSERT (dup (-1) == -1); |
| ASSERT (errno == EBADF); |
| errno = 0; |
| ASSERT (dup (bad_fd) == -1); |
| ASSERT (errno == EBADF); |
| close (fd + 1); |
| errno = 0; |
| ASSERT (dup (fd + 1) == -1); |
| ASSERT (errno == EBADF); |
| |
| /* Preserve text vs. binary. */ |
| setmode (fd, O_BINARY); |
| ASSERT (dup (fd) == fd + 1); |
| ASSERT (is_open (fd + 1)); |
| ASSERT (is_inheritable (fd + 1)); |
| ASSERT (is_mode (fd + 1, O_BINARY)); |
| |
| ASSERT (close (fd + 1) == 0); |
| setmode (fd, O_TEXT); |
| ASSERT (dup (fd) == fd + 1); |
| ASSERT (is_open (fd + 1)); |
| ASSERT (is_inheritable (fd + 1)); |
| ASSERT (is_mode (fd + 1, O_TEXT)); |
| |
| /* Create cloexec copy. */ |
| ASSERT (close (fd + 1) == 0); |
| ASSERT (fd_safer_flag (dup_cloexec (fd), O_CLOEXEC) == fd + 1); |
| ASSERT (set_cloexec_flag (fd + 1, true) == 0); |
| ASSERT (is_open (fd + 1)); |
| ASSERT (!is_inheritable (fd + 1)); |
| ASSERT (close (fd) == 0); |
| |
| /* dup always creates inheritable copies. Also, check that |
| earliest slot past std fds is used. */ |
| ASSERT (dup (fd + 1) == fd); |
| ASSERT (is_open (fd)); |
| ASSERT (is_inheritable (fd)); |
| ASSERT (close (fd + 1) == 0); |
| } |
| |
| /* Cleanup. */ |
| ASSERT (close (fd) == 0); |
| ASSERT (unlink (witness) == 0); |
| |
| return 0; |
| } |