[SPOOLSS]

Implement the undocumented AlignRpcPtr and UndoAlignRpcPtr functions used by many Rpc* functions in spoolsv according to traced callchains.
I could reverse engineer them entirely using rohitab.com's API Monitor and black-box testing.
I also add documented tests covering all cases I found out. We now pass 17/17 tests on Windows Server 2003 and ReactOS.

Also const-ify a parameter in PackStrings.

svn path=/trunk/; revision=74297

reactos/win32ss/printing/base/spoolss/memory.c

@@ -2,12 +2,42 @@
  * PROJECT:     ReactOS Spooler Router
  * LICENSE:     GNU LGPL v2.1 or any later version as published by the Free Software Foundation
  * PURPOSE:     Functions for allocating and freeing memory
- * COPYRIGHT:   Copyright 2015 Colin Finck <[email protected]>
+ * COPYRIGHT:   Copyright 2015-2017 Colin Finck <[email protected]>
  */
 
 #include "precomp.h"
 
 
+/**
+ * @name AlignRpcPtr
+ *
+ * Checks if the input buffer and buffer size are 4-byte aligned.
+ * If the buffer size is not 4-byte aligned, it is aligned down.
+ * If the input buffer is not 4-byte aligned, a 4-byte aligned buffer of the aligned down buffer size is allocated and returned.
+ *
+ * @param pBuffer
+ * The buffer to check.
+ *
+ * @param pcbBuffer
+ * Pointer to the buffer size to check. Its value is aligned down if needed.
+ *
+ * @return
+ * pBuffer if pBuffer is already 4-byte aligned, or a newly allocated 4-byte aligned buffer of the aligned down buffer size otherwise.
+ * If a buffer was allocated, you have to free it using UndoAlignRpcPtr.
+ */
+PVOID WINAPI
+AlignRpcPtr(PVOID pBuffer, PDWORD pcbBuffer)
+{
+    // Align down the buffer size in pcbBuffer to a 4-byte boundary.
+    *pcbBuffer -= *pcbBuffer % sizeof(DWORD);
+
+    // Check if pBuffer is 4-byte aligned. If not, allocate a 4-byte aligned buffer.
+    if ((ULONG_PTR)pBuffer % sizeof(DWORD))
+        pBuffer = DllAllocSplMem(*pcbBuffer);
+
+    return pBuffer;
+}
+
 /**
  * @name AllocSplStr
  *
@@ -163,6 +193,59 @@ ReallocSplStr(PWSTR* ppwszString, PCWSTR pwszInput)
         DllFreeSplStr(*ppwszString);
 
     *ppwszString = AllocSplStr(pwszInput);
-    
+
     return TRUE;
 }
+
+/**
+ * @name UndoAlignRpcPtr
+ *
+ * Copies the data from the aligned buffer previously allocated by AlignRpcPtr back to the original unaligned buffer.
+ * The aligned buffer is freed.
+ *
+ * Also aligns up the returned required buffer size of a function to a 4-byte boundary.
+ *
+ * @param pDestinationBuffer
+ * The original unaligned buffer, which you input as pBuffer to AlignRpcPtr.
+ * The data from pSourceBuffer is copied into this buffer before pSourceBuffer is freed.
+ * If AlignRpcPtr did not allocate a buffer, pDestinationBuffer equals pSourceBuffer and no memory is copied or freed.
+ * This parameter may be NULL if pSourceBuffer is NULL.
+ *
+ * @param pSourceBuffer
+ * The aligned buffer, which is returned by AlignRpcPtr.
+ * Its data is copied into pDestinationBuffer and then pSourceBuffer is freed.
+ * If AlignRpcPtr did not allocate a buffer, pDestinationBuffer equals pSourceBuffer and no memory is copied or freed.
+ * This parameter may be NULL.
+ *
+ * @param cbBuffer
+ * Number of bytes to copy.
+ * Set this to the size returned by AlignRpcPtr's pcbBuffer or less.
+ *
+ * @param pcbNeeded
+ * Let this parameter point to your variable calculating the needed bytes for a buffer and returning this value to the user.
+ * It is then aligned up to a 4-byte boundary, so that the user supplies a large enough buffer in the next call.
+ * Otherwise, AlignRpcPtr would align down the buffer size in the next call and your buffer would be smaller than intended.
+ * This parameter may be NULL.
+ *
+ * @return
+ * pcbNeeded
+ */
+PDWORD WINAPI
+UndoAlignRpcPtr(PVOID pDestinationBuffer, PVOID pSourceBuffer, DWORD cbBuffer, PDWORD pcbNeeded)
+{
+    // If pSourceBuffer is given, and source and destination pointers don't match,
+    // we assume that pSourceBuffer is the buffer allocated by AlignRpcPtr.
+    if (pSourceBuffer && pSourceBuffer != pDestinationBuffer)
+    {
+        // Copy back the buffer data to the (usually unaligned) destination buffer
+        // and free the buffer allocated by AlignRpcPtr.
+        CopyMemory(pDestinationBuffer, pSourceBuffer, cbBuffer);
+        DllFreeSplMem(pSourceBuffer);
+    }
+
+    // If pcbNeeded is given, align it up to a 4-byte boundary.
+    if (pcbNeeded && *pcbNeeded % sizeof(DWORD))
+        *pcbNeeded += sizeof(DWORD) - *pcbNeeded % sizeof(DWORD);
+
+    return pcbNeeded;
+}

reactos/win32ss/printing/base/spoolss/spoolss.spec

@@ -16,7 +16,7 @@
 @ stub AdjustPointers
 @ stub AdjustPointersInStructuresArray
 @ stub AlignKMPtr
-@ stub AlignRpcPtr
+@ stdcall AlignRpcPtr(ptr ptr)
 @ stdcall AllocSplStr(ptr)
 @ stub AllowRemoteCalls
 @ stub AppendPrinterNotifyInfoData
@@ -165,7 +165,7 @@
 @ stdcall StartDocPrinterW(long long ptr)
 @ stdcall StartPagePrinter(long)
 @ stub UndoAlignKMPtr
-@ stub UndoAlignRpcPtr
+@ stdcall UndoAlignRpcPtr(ptr ptr long ptr)
 @ stub UnloadDriver
 @ stub UnloadDriverFile
 @ stub UpdateBufferSize

reactos/win32ss/printing/base/spoolss/tools.c

@@ -86,7 +86,7 @@ MarshallDownStructure(PVOID pStructure, PMARSHALL_DOWN_INFO pParameters, DWORD c
  * The strings are copied in reverse order, so this pointer will point to the last copied string of pSource.
  */
 PBYTE WINAPI
-PackStrings(PCWSTR* pSource, PBYTE pDest, PDWORD DestOffsets, PBYTE pEnd)
+PackStrings(PCWSTR* pSource, PBYTE pDest, const DWORD* DestOffsets, PBYTE pEnd)
 {
     DWORD cbString;
     ULONG_PTR StringAddress;

reactos/win32ss/printing/include/spoolss.h

@@ -2,7 +2,7 @@
  * PROJECT:     ReactOS Printing Include files
  * LICENSE:     GNU LGPLv2 or any later version as published by the Free Software Foundation
  * PURPOSE:     Undocumented APIs of the Spooler Router "spoolss.dll"
- * COPYRIGHT:   Copyright 2015 Colin Finck <[email protected]>
+ * COPYRIGHT:   Copyright 2015-2017 Colin Finck <[email protected]>
  */
 
 #ifndef _REACTOS_SPOOLSS_H
@@ -19,14 +19,16 @@ typedef struct _MARSHALL_DOWN_INFO
 }
 MARSHALL_DOWN_INFO, *PMARSHALL_DOWN_INFO;
 
+PVOID WINAPI AlignRpcPtr(PVOID pBuffer, PDWORD pcbBuffer);
 PWSTR WINAPI AllocSplStr(PCWSTR pwszInput);
 PVOID WINAPI DllAllocSplMem(DWORD dwBytes);
 BOOL WINAPI DllFreeSplMem(PVOID pMem);
 BOOL WINAPI DllFreeSplStr(PWSTR pwszString);
 BOOL WINAPI MarshallDownStructure(PVOID pStructure, PMARSHALL_DOWN_INFO pParameters, DWORD cbStructureSize, BOOL bSomeBoolean);
-PBYTE WINAPI PackStrings(PCWSTR* pSource, PBYTE pDest, PDWORD DestOffsets, PBYTE pEnd);
+PBYTE WINAPI PackStrings(PCWSTR* pSource, PBYTE pDest, const DWORD* DestOffsets, PBYTE pEnd);
 PVOID WINAPI ReallocSplMem(PVOID pOldMem, DWORD cbOld, DWORD cbNew);
 BOOL WINAPI ReallocSplStr(PWSTR* ppwszString, PCWSTR pwszInput);
 BOOL WINAPI SplInitializeWinSpoolDrv(PVOID* pTable);
+PDWORD WINAPI UndoAlignRpcPtr(PVOID pDestinationBuffer, PVOID pSourceBuffer, DWORD cbBuffer, PDWORD pcbNeeded);
 
 #endif