1    :  // Copyright 2012 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  
  15    :  #ifndef SYZYGY_PE_PE_UTILS_H_
  16    :  #define SYZYGY_PE_PE_UTILS_H_
  17    :  
  18    :  #include <windows.h>
  19    :  #include <winnt.h>
  20    :  
  21    :  #include "syzygy/block_graph/block_graph.h"
  22    :  
  23  m :  namespace pe {
  24    :  
  25    :  // Typical section names.
  26  m :  extern const char kCodeSectionName[];
  27  m :  extern const char kReadOnlyDataSectionName[];
  28  m :  extern const char kReadWriteDataSectionName[];
  29  m :  extern const char kRelocSectionName[];
  30  m :  extern const char kResourceSectionName[];
  31  m :  extern const char kTlsSectionName[];
  32    :  
  33    :  // Typical section characteristics.
  34  m :  extern const DWORD kCodeCharacteristics;
  35  m :  extern const DWORD kReadOnlyDataCharacteristics;
  36  m :  extern const DWORD kReadWriteDataCharacteristics;
  37  m :  extern const DWORD kRelocCharacteristics;
  38    :  
  39    :  // Validates @p dos_header_block for the size, magic constants and other
  40    :  // properties of a valid DOS header.
  41    :  // @returns true iff @p dos_header_block has all the correct properties
  42    :  //     of a DOS header.
  43  m :  bool IsValidDosHeaderBlock(
  44  m :      const block_graph::BlockGraph::Block* dos_header_block);
  45    :  
  46    :  // Validates @p nt_headers_block for the the size, magic constants and
  47    :  // other properties of valid NT headers.
  48    :  // @returns true iff block has correct size and signature for a DOS
  49    :  //     header block.
  50  m :  bool IsValidNtHeadersBlock(
  51  m :      const block_graph::BlockGraph::Block* nt_headers_block);
  52    :  
  53    :  // Retrieves and validates the NT headers block from a valid DOS headers block.
  54    :  // @returns the NT headers block, iff it can be retrieved from the DOS headers
  55    :  //     block, and if the NT headers block has valid signatures.
  56  m :  const block_graph::BlockGraph::Block* GetNtHeadersBlockFromDosHeaderBlock(
  57  m :      const block_graph::BlockGraph::Block* dos_header_block);
  58  m :  block_graph::BlockGraph::Block* GetNtHeadersBlockFromDosHeaderBlock(
  59  m :      block_graph::BlockGraph::Block* dos_header_block);
  60    :  
  61    :  // Updates the provided DOS header block in preparation for writing a module
  62    :  // from a BlockGraph. Trims any superfluous data and inserts a new DOS stub.
  63    :  // After this has been applied IsValidDosHeaderBlock will succeed.
  64    :  // @param dos_header_block the DOS header block to update.
  65    :  // @returns true on success, false otherwise.
  66  m :  bool UpdateDosHeader(block_graph::BlockGraph::Block* dos_header_block);
  67    :  
  68  m :  typedef std::pair<block_graph::BlockGraph::Block*,
  69  m :                    block_graph::BlockGraph::Offset> EntryPoint;
  70  m :  typedef std::set<EntryPoint> EntryPointSet;
  71    :  
  72    :  // Retrieves the image entry point into @p entry_points IFF the image is an
  73    :  // EXE. If the image is not an EXE then this is a NOP.
  74    :  // @param dos_header_block the DOS header block of the image.
  75    :  // @param entry_points the entry-point will be inserted into this set if the
  76    :  //     image in question is an executable.
  77    :  // @returns true on success, false otherwise. It is not considered a failure
  78    :  //     if @p entry_points is left unchanged because @p dos_header_block
  79    :  //     indicates that the image is not an executable.
  80    :  // @note The returned @p entry_point will have a call-signature taking no
  81    :  //     arguments.
  82  m :  bool GetExeEntryPoint(block_graph::BlockGraph::Block* dos_header_block,
  83  m :                        EntryPoint* entry_point);
  84    :  
  85    :  // Retrieves the image entry point into @p entry_points IFF the image is a
  86    :  // DLL. If the image is not a DLL, or if the DLL has no entry point, then this
  87    :  // is a NOP.
  88    :  // @param dos_header_block the DOS header block of the image.
  89    :  // @param entry_points the entry-point will be inserted into this set if the
  90    :  //     image in question is a DLL. Note that the entry-point for a DLL is
  91    :  //     optional; if the DLL has no entry point, the Block* of the returned
  92    :  //     EntryPoint structure will be NULL.
  93    :  // @returns true on success, false otherwise. It is not considered a failure
  94    :  //     if @p entry_points is left unchanged because @p dos_header_block
  95    :  //     indicates that the image is not a DLL.
  96    :  // @note The returned @p entry_point, if any, will have a call-signature
  97    :  //     matching that of DllMain.
  98  m :  bool GetDllEntryPoint(block_graph::BlockGraph::Block* dos_header_block,
  99  m :                        EntryPoint* entry_point);
 100    :  
 101    :  // Retrieves the TLS initializer entry-points into @p entry_points.
 102    :  // @param dos_header_block the DOS header block of the image.
 103    :  // @param entry_points the entry-point will be inserted into this set if the
 104    :  //     image in question is a DLL. If the set already contains elements it will
 105    :  //     be added to.
 106    :  // @returns true on success, false otherwise.
 107    :  // @note The returned @p entry_points, if any, will have a call-signature
 108    :  //     matching that of DllMain.
 109    :  // TODO(rogerm): We may want to change this to output to an EntryPointVector
 110    :  //     instead of to a set. This would be more consistent with the actual
 111    :  //     representation of the TLS initializers. That said, our actual usage of
 112    :  //     the returned entry-points would require us to eliminate duplicates after
 113    :  //     the fact. Left as a set for now, under suspicion of YAGNI.
 114  m :  bool GetTlsInitializers(block_graph::BlockGraph::Block* dos_header_block,
 115  m :                          EntryPointSet* entry_points);
 116    :  
 117    :  // Check if an image contains an import entry.
 118    :  // @param The image's header-block.
 119    :  // @param dll_name The name of the DLL.
 120    :  // @param contains_dependence Boolean to indicate if the image contains the
 121    :  //     import entry.
 122    :  // @returns true in case of success, false otherwise.
 123  m :  bool HasImportEntry(block_graph::BlockGraph::Block* header_block,
 124  m :                      const base::StringPiece& dll_name,
 125  m :                      bool* has_import_entry);
 126  m :  }  // namespace pe
 127    :  
 128    :  #endif  // SYZYGY_PE_PE_UTILS_H_