Adding upstream version 15.5.upstream/15.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 355 insertions, 0 deletions

diff --git a/src/port/dirmod.c b/src/port/dirmod.c
new file mode 100644
index 0000000..7ce042e
--- /dev/null
+++ b/src/port/dirmod.c
@@ -0,0 +1,355 @@
+/*-------------------------------------------------------------------------
+ *
+ * dirmod.c
+ *	  directory handling functions
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *	This includes replacement versions of functions that work on
+ *	Win32 (NT4 and newer).
+ *
+ * IDENTIFICATION
+ *	  src/port/dirmod.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+/* Don't modify declarations in system headers */
+#if defined(WIN32) || defined(__CYGWIN__)
+#undef rename
+#undef unlink
+#endif
+
+#include <unistd.h>
+#include <sys/stat.h>
+
+#if defined(WIN32) || defined(__CYGWIN__)
+#ifndef __CYGWIN__
+#include <winioctl.h>
+#else
+#include <windows.h>
+#include <w32api/winioctl.h>
+#endif
+#endif
+
+#if defined(WIN32) || defined(__CYGWIN__)
+
+/*
+ *	pgrename
+ */
+int
+pgrename(const char *from, const char *to)
+{
+	int			loops = 0;
+
+	/*
+	 * We need to loop because even though PostgreSQL uses flags that allow
+	 * rename while the file is open, other applications might have the file
+	 * open without those flags.  However, we won't wait indefinitely for
+	 * someone else to close the file, as the caller might be holding locks
+	 * and blocking other backends.
+	 */
+#if defined(WIN32) && !defined(__CYGWIN__)
+	while (!MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING))
+#else
+	while (rename(from, to) < 0)
+#endif
+	{
+#if defined(WIN32) && !defined(__CYGWIN__)
+		DWORD		err = GetLastError();
+
+		_dosmaperr(err);
+
+		/*
+		 * Modern NT-based Windows versions return ERROR_SHARING_VIOLATION if
+		 * another process has the file open without FILE_SHARE_DELETE.
+		 * ERROR_LOCK_VIOLATION has also been seen with some anti-virus
+		 * software. This used to check for just ERROR_ACCESS_DENIED, so
+		 * presumably you can get that too with some OS versions. We don't
+		 * expect real permission errors where we currently use rename().
+		 */
+		if (err != ERROR_ACCESS_DENIED &&
+			err != ERROR_SHARING_VIOLATION &&
+			err != ERROR_LOCK_VIOLATION)
+			return -1;
+#else
+		if (errno != EACCES)
+			return -1;
+#endif
+
+		if (++loops > 100)		/* time out after 10 sec */
+			return -1;
+		pg_usleep(100000);		/* us */
+	}
+	return 0;
+}
+
+
+/*
+ *	pgunlink
+ */
+int
+pgunlink(const char *path)
+{
+	int			loops = 0;
+
+	/*
+	 * We need to loop because even though PostgreSQL uses flags that allow
+	 * unlink while the file is open, other applications might have the file
+	 * open without those flags.  However, we won't wait indefinitely for
+	 * someone else to close the file, as the caller might be holding locks
+	 * and blocking other backends.
+	 */
+	while (unlink(path))
+	{
+		if (errno != EACCES)
+			return -1;
+		if (++loops > 100)		/* time out after 10 sec */
+			return -1;
+		pg_usleep(100000);		/* us */
+	}
+	return 0;
+}
+
+/* We undefined these above; now redefine for possible use below */
+#define rename(from, to)		pgrename(from, to)
+#define unlink(path)			pgunlink(path)
+#endif							/* defined(WIN32) || defined(__CYGWIN__) */
+
+
+#if defined(WIN32) && !defined(__CYGWIN__)	/* Cygwin has its own symlinks */
+
+/*
+ *	pgsymlink support:
+ *
+ *	This struct is a replacement for REPARSE_DATA_BUFFER which is defined in VC6 winnt.h
+ *	but omitted in later SDK functions.
+ *	We only need the SymbolicLinkReparseBuffer part of the original struct's union.
+ */
+typedef struct
+{
+	DWORD		ReparseTag;
+	WORD		ReparseDataLength;
+	WORD		Reserved;
+	/* SymbolicLinkReparseBuffer */
+	WORD		SubstituteNameOffset;
+	WORD		SubstituteNameLength;
+	WORD		PrintNameOffset;
+	WORD		PrintNameLength;
+	WCHAR		PathBuffer[FLEXIBLE_ARRAY_MEMBER];
+} REPARSE_JUNCTION_DATA_BUFFER;
+
+#define REPARSE_JUNCTION_DATA_BUFFER_HEADER_SIZE   \
+		FIELD_OFFSET(REPARSE_JUNCTION_DATA_BUFFER, SubstituteNameOffset)
+
+
+/*
+ *	pgsymlink - uses Win32 junction points
+ *
+ *	For reference:	http://www.codeproject.com/KB/winsdk/junctionpoints.aspx
+ */
+int
+pgsymlink(const char *oldpath, const char *newpath)
+{
+	HANDLE		dirhandle;
+	DWORD		len;
+	char		buffer[MAX_PATH * sizeof(WCHAR) + offsetof(REPARSE_JUNCTION_DATA_BUFFER, PathBuffer)];
+	char		nativeTarget[MAX_PATH];
+	char	   *p = nativeTarget;
+	REPARSE_JUNCTION_DATA_BUFFER *reparseBuf = (REPARSE_JUNCTION_DATA_BUFFER *) buffer;
+
+	CreateDirectory(newpath, 0);
+	dirhandle = CreateFile(newpath, GENERIC_READ | GENERIC_WRITE,
+						   0, 0, OPEN_EXISTING,
+						   FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, 0);
+
+	if (dirhandle == INVALID_HANDLE_VALUE)
+		return -1;
+
+	/* make sure we have an unparsed native win32 path */
+	if (memcmp("\\??\\", oldpath, 4) != 0)
+		snprintf(nativeTarget, sizeof(nativeTarget), "\\??\\%s", oldpath);
+	else
+		strlcpy(nativeTarget, oldpath, sizeof(nativeTarget));
+
+	while ((p = strchr(p, '/')) != NULL)
+		*p++ = '\\';
+
+	len = strlen(nativeTarget) * sizeof(WCHAR);
+	reparseBuf->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
+	reparseBuf->ReparseDataLength = len + 12;
+	reparseBuf->Reserved = 0;
+	reparseBuf->SubstituteNameOffset = 0;
+	reparseBuf->SubstituteNameLength = len;
+	reparseBuf->PrintNameOffset = len + sizeof(WCHAR);
+	reparseBuf->PrintNameLength = 0;
+	MultiByteToWideChar(CP_ACP, 0, nativeTarget, -1,
+						reparseBuf->PathBuffer, MAX_PATH);
+
+	/*
+	 * FSCTL_SET_REPARSE_POINT is coded differently depending on SDK version;
+	 * we use our own definition
+	 */
+	if (!DeviceIoControl(dirhandle,
+						 CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 41, METHOD_BUFFERED, FILE_ANY_ACCESS),
+						 reparseBuf,
+						 reparseBuf->ReparseDataLength + REPARSE_JUNCTION_DATA_BUFFER_HEADER_SIZE,
+						 0, 0, &len, 0))
+	{
+		LPSTR		msg;
+
+		errno = 0;
+		FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+					  FORMAT_MESSAGE_IGNORE_INSERTS |
+					  FORMAT_MESSAGE_FROM_SYSTEM,
+					  NULL, GetLastError(),
+					  MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
+					  (LPSTR) &msg, 0, NULL);
+#ifndef FRONTEND
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not set junction for \"%s\": %s",
+						nativeTarget, msg)));
+#else
+		fprintf(stderr, _("could not set junction for \"%s\": %s\n"),
+				nativeTarget, msg);
+#endif
+		LocalFree(msg);
+
+		CloseHandle(dirhandle);
+		RemoveDirectory(newpath);
+		return -1;
+	}
+
+	CloseHandle(dirhandle);
+
+	return 0;
+}
+
+/*
+ *	pgreadlink - uses Win32 junction points
+ */
+int
+pgreadlink(const char *path, char *buf, size_t size)
+{
+	DWORD		attr;
+	HANDLE		h;
+	char		buffer[MAX_PATH * sizeof(WCHAR) + offsetof(REPARSE_JUNCTION_DATA_BUFFER, PathBuffer)];
+	REPARSE_JUNCTION_DATA_BUFFER *reparseBuf = (REPARSE_JUNCTION_DATA_BUFFER *) buffer;
+	DWORD		len;
+	int			r;
+
+	attr = GetFileAttributes(path);
+	if (attr == INVALID_FILE_ATTRIBUTES)
+	{
+		_dosmaperr(GetLastError());
+		return -1;
+	}
+	if ((attr & FILE_ATTRIBUTE_REPARSE_POINT) == 0)
+	{
+		errno = EINVAL;
+		return -1;
+	}
+
+	h = CreateFile(path,
+				   GENERIC_READ,
+				   FILE_SHARE_READ | FILE_SHARE_WRITE,
+				   NULL,
+				   OPEN_EXISTING,
+				   FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS,
+				   0);
+	if (h == INVALID_HANDLE_VALUE)
+	{
+		_dosmaperr(GetLastError());
+		return -1;
+	}
+
+	if (!DeviceIoControl(h,
+						 FSCTL_GET_REPARSE_POINT,
+						 NULL,
+						 0,
+						 (LPVOID) reparseBuf,
+						 sizeof(buffer),
+						 &len,
+						 NULL))
+	{
+		LPSTR		msg;
+
+		errno = 0;
+		FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+					  FORMAT_MESSAGE_IGNORE_INSERTS |
+					  FORMAT_MESSAGE_FROM_SYSTEM,
+					  NULL, GetLastError(),
+					  MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
+					  (LPSTR) &msg, 0, NULL);
+#ifndef FRONTEND
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not get junction for \"%s\": %s",
+						path, msg)));
+#else
+		fprintf(stderr, _("could not get junction for \"%s\": %s\n"),
+				path, msg);
+#endif
+		LocalFree(msg);
+		CloseHandle(h);
+		errno = EINVAL;
+		return -1;
+	}
+	CloseHandle(h);
+
+	/* Got it, let's get some results from this */
+	if (reparseBuf->ReparseTag != IO_REPARSE_TAG_MOUNT_POINT)
+	{
+		errno = EINVAL;
+		return -1;
+	}
+
+	r = WideCharToMultiByte(CP_ACP, 0,
+							reparseBuf->PathBuffer, -1,
+							buf,
+							size,
+							NULL, NULL);
+
+	if (r <= 0)
+	{
+		errno = EINVAL;
+		return -1;
+	}
+
+	/*
+	 * If the path starts with "\??\", which it will do in most (all?) cases,
+	 * strip those out.
+	 */
+	if (r > 4 && strncmp(buf, "\\??\\", 4) == 0)
+	{
+		memmove(buf, buf + 4, strlen(buf + 4) + 1);
+		r -= 4;
+	}
+	return r;
+}
+
+/*
+ * Assumes the file exists, so will return false if it doesn't
+ * (since a nonexistent file is not a junction)
+ */
+bool
+pgwin32_is_junction(const char *path)
+{
+	DWORD		attr = GetFileAttributes(path);
+
+	if (attr == INVALID_FILE_ATTRIBUTES)
+	{
+		_dosmaperr(GetLastError());
+		return false;
+	}
+	return ((attr & FILE_ATTRIBUTE_REPARSE_POINT) == FILE_ATTRIBUTE_REPARSE_POINT);
+}
+#endif							/* defined(WIN32) && !defined(__CYGWIN__) */