On Sun, Mar 19, 2023 at 08:20:27PM +0900, Michael Paquier wrote: > I am not sure, TBH. As presented, the two GetFileType() calls in > _pgftello64() and _pgfseeko64() ignore the case where it returns > FILE_TYPE_UNKNOWN and GetLastError() has something else than > NO_ERROR. The code would return EINVAL for all the errors happening. > Perhaps that's fine, though I am wondering if we should report > something more exact, based on _dosmaperr(GetLastError())?
In short, I was thinking among the lines of something like the attached, where I have invented a pgwin32_get_file_type() that acts as a wrapper of GetFileType() in a new file called win32common.c, with all the error handling we would use between fstat(), fseeko() and ftello() centralized in a single code path. The refactoring with win32common.c had better be separated into its own patch, at the end, if using an approach like that. -- Michael
From 3e778828a58751a0b562908176dcb76cabcc7945 Mon Sep 17 00:00:00 2001
From: Michael Paquier <mich...@paquier.xyz>
Date: Sun, 19 Mar 2023 20:40:22 +0900
Subject: [PATCH v3] fix fseek detection of unseekable files for WIN32
Calling fseek() on a handle to a non-seeking device such as a pipe or
a communications device is not supported, even though the fseek() may
not return an error, so harden that funcion with our version.
---
src/include/port/win32_port.h | 12 ++++--
src/port/meson.build | 2 +
src/port/win32common.c | 68 ++++++++++++++++++++++++++++++++
src/port/win32fseek.c | 74 +++++++++++++++++++++++++++++++++++
src/port/win32stat.c | 22 ++---------
configure | 6 +++
configure.ac | 1 +
src/tools/msvc/Mkvcbuild.pm | 2 +
8 files changed, 165 insertions(+), 22 deletions(-)
create mode 100644 src/port/win32common.c
create mode 100644 src/port/win32fseek.c
diff --git a/src/include/port/win32_port.h b/src/include/port/win32_port.h
index 5116c2fc06..19206ce922 100644
--- a/src/include/port/win32_port.h
+++ b/src/include/port/win32_port.h
@@ -204,15 +204,21 @@ struct itimerval
int setitimer(int which, const struct itimerval *value, struct itimerval *ovalue);
+/* Convenience wrapper for GetFileType() */
+extern DWORD pgwin32_get_file_type(HANDLE hFile);
+
/*
* WIN32 does not provide 64-bit off_t, but does provide the functions operating
- * with 64-bit offsets.
+ * with 64-bit offsets. Also, fseek() might not give an error for unseekable
+ * streams, so harden that function with our version.
*/
#define pgoff_t __int64
#ifdef _MSC_VER
-#define fseeko(stream, offset, origin) _fseeki64(stream, offset, origin)
-#define ftello(stream) _ftelli64(stream)
+extern int _pgfseeko64(FILE *stream, pgoff_t offset, int origin);
+extern pgoff_t _pgftello64(FILE *stream);
+#define fseeko(stream, offset, origin) _pgfseeko64(stream, offset, origin)
+#define ftello(stream) _pgftello64(stream)
#else
#ifndef fseeko
#define fseeko(stream, offset, origin) fseeko64(stream, offset, origin)
diff --git a/src/port/meson.build b/src/port/meson.build
index b174b25021..24416b9bfc 100644
--- a/src/port/meson.build
+++ b/src/port/meson.build
@@ -29,10 +29,12 @@ if host_system == 'windows'
'kill.c',
'open.c',
'system.c',
+ 'win32common.c',
'win32dlopen.c',
'win32env.c',
'win32error.c',
'win32fdatasync.c',
+ 'win32fseek.c',
'win32getrusage.c',
'win32link.c',
'win32ntdll.c',
diff --git a/src/port/win32common.c b/src/port/win32common.c
new file mode 100644
index 0000000000..2fd78f7f93
--- /dev/null
+++ b/src/port/win32common.c
@@ -0,0 +1,68 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32common.c
+ * Common routines shared among the win32*.c ports.
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/port/win32common.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifdef FRONTEND
+#include "postgres_fe.h"
+#else
+#include "postgres.h"
+#endif
+
+#ifdef WIN32
+
+/*
+ * pgwin32_get_file_type
+ *
+ * Convenience wrapper for GetFileType() with specific error handling for all the
+ * port implementations. Returns the file type associated with a HANDLE.
+ *
+ * On error, sets errno with FILE_TYPE_UNKNOWN as file type.
+ */
+DWORD
+pgwin32_get_file_type(HANDLE hFile)
+{
+ DWORD fileType = FILE_TYPE_UNKNOWN;
+ DWORD lastError;
+
+ errno = 0;
+
+ /*
+ * When stdin, stdout, and stderr aren't associated with a stream the
+ * special value -2 is returned:
+ * https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/get-osfhandle
+ */
+ if (hFile == INVALID_HANDLE_VALUE || hFile == (HANDLE) -2)
+ {
+ errno = EINVAL;
+ return FILE_TYPE_UNKNOWN;
+ }
+
+ fileType = GetFileType(hFile);
+ lastError = GetLastError();
+
+ /*
+ * Invoke GetLastError in order to distinguish between a "valid" return of
+ * FILE_TYPE_UNKNOWN and its return due to a calling error. In case of
+ * success, GetLastError() returns NO_ERROR.
+ */
+ if (fileType == FILE_TYPE_UNKNOWN && lastError != NO_ERROR)
+ {
+ _dosmaperr(lastError);
+ return FILE_TYPE_UNKNOWN;
+ }
+
+ return fileType;
+}
+
+#endif /* WIN32 */
diff --git a/src/port/win32fseek.c b/src/port/win32fseek.c
new file mode 100644
index 0000000000..85545c1f09
--- /dev/null
+++ b/src/port/win32fseek.c
@@ -0,0 +1,74 @@
+/*-------------------------------------------------------------------------
+ *
+ * win32fseek.c
+ * Replacements for fseeko() and ftello().
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/port/win32fseek.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifdef FRONTEND
+#include "postgres_fe.h"
+#else
+#include "postgres.h"
+#endif
+
+#if defined(WIN32) && defined(_MSC_VER)
+
+/*
+ * _pgfseeko64
+ *
+ * Calling fseek() on a handle to a non-seeking device such as a pipe or
+ * a communications device is not supported, even though the fseek() may
+ * not return an error.
+ */
+int
+_pgfseeko64(FILE *stream, pgoff_t offset, int origin)
+{
+ DWORD fileType;
+ HANDLE hFile = (HANDLE) _get_osfhandle(_fileno(stream));
+
+ fileType = pgwin32_get_file_type(hFile);
+ if (errno != 0)
+ return -1;
+
+ if (fileType == FILE_TYPE_DISK)
+ return _fseeki64(stream, offset, origin);
+ else if (fileType == FILE_TYPE_CHAR || fileType == FILE_TYPE_PIPE)
+ errno = ESPIPE;
+ else
+ errno = EINVAL;
+
+ return -1;
+}
+
+/*
+ * _pgftello64
+ *
+ * Same as _pgfseeko64().
+ */
+pgoff_t
+_pgftello64(FILE *stream)
+{
+ DWORD fileType;
+ HANDLE hFile = (HANDLE) _get_osfhandle(_fileno(stream));
+
+ fileType = pgwin32_get_file_type(hFile);
+ if (errno != 0)
+ return -1;
+
+ if (fileType == FILE_TYPE_DISK)
+ return _ftelli64(stream);
+ else if (fileType == FILE_TYPE_CHAR || fileType == FILE_TYPE_PIPE)
+ errno = ESPIPE;
+ else
+ errno = EINVAL;
+
+ return -1;
+}
+
+#endif /* defined(WIN32) && defined(_MSC_VER) */
diff --git a/src/port/win32stat.c b/src/port/win32stat.c
index b79da738b2..aa3a0c174e 100644
--- a/src/port/win32stat.c
+++ b/src/port/win32stat.c
@@ -258,33 +258,17 @@ _pgfstat64(int fileno, struct stat *buf)
{
HANDLE hFile = (HANDLE) _get_osfhandle(fileno);
DWORD fileType = FILE_TYPE_UNKNOWN;
- DWORD lastError;
unsigned short st_mode;
- /*
- * When stdin, stdout, and stderr aren't associated with a stream the
- * special value -2 is returned:
- * https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/get-osfhandle
- */
- if (hFile == INVALID_HANDLE_VALUE || hFile == (HANDLE) -2 || buf == NULL)
+ if (buf == NULL)
{
errno = EINVAL;
return -1;
}
- fileType = GetFileType(hFile);
- lastError = GetLastError();
-
- /*
- * Invoke GetLastError in order to distinguish between a "valid" return of
- * FILE_TYPE_UNKNOWN and its return due to a calling error. In case of
- * success, GetLastError returns NO_ERROR.
- */
- if (fileType == FILE_TYPE_UNKNOWN && lastError != NO_ERROR)
- {
- _dosmaperr(lastError);
+ fileType = pgwin32_get_file_type(hFile);
+ if (errno != 0)
return -1;
- }
switch (fileType)
{
diff --git a/configure b/configure
index e221dd5b0f..ded18a0ead 100755
--- a/configure
+++ b/configure
@@ -16490,6 +16490,12 @@ esac
;;
esac
+ case " $LIBOBJS " in
+ *" win32common.$ac_objext "* ) ;;
+ *) LIBOBJS="$LIBOBJS win32common.$ac_objext"
+ ;;
+esac
+
case " $LIBOBJS " in
*" win32dlopen.$ac_objext "* ) ;;
*) LIBOBJS="$LIBOBJS win32dlopen.$ac_objext"
diff --git a/configure.ac b/configure.ac
index 3aa6c15c13..7f6620a364 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1893,6 +1893,7 @@ if test "$PORTNAME" = "win32"; then
AC_LIBOBJ(kill)
AC_LIBOBJ(open)
AC_LIBOBJ(system)
+ AC_LIBOBJ(win32common)
AC_LIBOBJ(win32dlopen)
AC_LIBOBJ(win32env)
AC_LIBOBJ(win32error)
diff --git a/src/tools/msvc/Mkvcbuild.pm b/src/tools/msvc/Mkvcbuild.pm
index e3ffc653e5..24599feb33 100644
--- a/src/tools/msvc/Mkvcbuild.pm
+++ b/src/tools/msvc/Mkvcbuild.pm
@@ -108,9 +108,11 @@ sub mkvcbuild
pg_strong_random.c pgcheckdir.c pgmkdirp.c pgsleep.c pgstrcasecmp.c
pqsignal.c mkdtemp.c qsort.c qsort_arg.c bsearch_arg.c quotes.c system.c
strerror.c tar.c
+ win32common.c
win32dlopen.c
win32env.c win32error.c
win32fdatasync.c
+ win32fseek.c
win32getrusage.c
win32gettimeofday.c
win32link.c
--
2.39.2
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