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      1 // Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef SANDBOX_SRC_WIN_UTILS_H_
      6 #define SANDBOX_SRC_WIN_UTILS_H_
      7 
      8 #include <windows.h>
      9 #include <string>
     10 #include "base/basictypes.h"
     11 
     12 namespace sandbox {
     13 
     14 // Prefix for path used by NT calls.
     15 const wchar_t kNTPrefix[] = L"\\??\\";
     16 const size_t kNTPrefixLen = arraysize(kNTPrefix) - 1;
     17 
     18 const wchar_t kNTObjManPrefix[] = L"\\Device\\";
     19 const size_t kNTObjManPrefixLen = arraysize(kNTObjManPrefix) - 1;
     20 
     21 // Automatically acquires and releases a lock when the object is
     22 // is destroyed.
     23 class AutoLock {
     24  public:
     25   // Acquires the lock.
     26   explicit AutoLock(CRITICAL_SECTION *lock) : lock_(lock) {
     27     ::EnterCriticalSection(lock);
     28   };
     29 
     30   // Releases the lock;
     31   ~AutoLock() {
     32     ::LeaveCriticalSection(lock_);
     33   };
     34 
     35  private:
     36   CRITICAL_SECTION *lock_;
     37   DISALLOW_IMPLICIT_CONSTRUCTORS(AutoLock);
     38 };
     39 
     40 // Basic implementation of a singleton which calls the destructor
     41 // when the exe is shutting down or the DLL is being unloaded.
     42 template <typename Derived>
     43 class SingletonBase {
     44  public:
     45   static Derived* GetInstance() {
     46     static Derived* instance = NULL;
     47     if (NULL == instance) {
     48       instance = new Derived();
     49       // Microsoft CRT extension. In an exe this this called after
     50       // winmain returns, in a dll is called in DLL_PROCESS_DETACH
     51       _onexit(OnExit);
     52     }
     53     return instance;
     54   }
     55 
     56  private:
     57   // this is the function that gets called by the CRT when the
     58   // process is shutting down.
     59   static int __cdecl OnExit() {
     60     delete GetInstance();
     61     return 0;
     62   }
     63 };
     64 
     65 // Convert a short path (C:\path~1 or \\??\\c:\path~1) to the long version of
     66 // the path. If the path is not a valid filesystem path, the function returns
     67 // false and the output parameter is not modified.
     68 bool ConvertToLongPath(const std::wstring& short_path, std::wstring* long_path);
     69 
     70 // Sets result to true if the path contains a reparse point. The return value
     71 // is ERROR_SUCCESS when the function succeeds or the appropriate error code
     72 // when the function fails.
     73 // This function is not smart. It looks for each element in the path and
     74 // returns true if any of them is a reparse point.
     75 DWORD IsReparsePoint(const std::wstring& full_path, bool* result);
     76 
     77 // Returns true if the handle corresponds to the object pointed by this path.
     78 bool SameObject(HANDLE handle, const wchar_t* full_path);
     79 
     80 // Resolves a handle to an nt path. Returns true if the handle can be resolved.
     81 bool GetPathFromHandle(HANDLE handle, std::wstring* path);
     82 
     83 // Resolves a win32 path to an nt path using GetPathFromHandle. The path must
     84 // exist. Returs true if the translation was succesful.
     85 bool GetNtPathFromWin32Path(const std::wstring& path, std::wstring* nt_path);
     86 
     87 // Translates a reserved key name to its handle.
     88 // For example "HKEY_LOCAL_MACHINE" returns HKEY_LOCAL_MACHINE.
     89 // Returns NULL if the name does not represent any reserved key name.
     90 HKEY GetReservedKeyFromName(const std::wstring& name);
     91 
     92 // Resolves a user-readable registry path to a system-readable registry path.
     93 // For example, HKEY_LOCAL_MACHINE\\Software\\microsoft is translated to
     94 // \\registry\\machine\\software\\microsoft. Returns false if the path
     95 // cannot be resolved.
     96 bool ResolveRegistryName(std::wstring name, std::wstring* resolved_name);
     97 
     98 // Writes |length| bytes from the provided |buffer| into the address space of
     99 // |child_process|, at the specified |address|, preserving the original write
    100 // protection attributes. Returns true on success.
    101 bool WriteProtectedChildMemory(HANDLE child_process, void* address,
    102                                const void* buffer, size_t length);
    103 
    104 }  // namespace sandbox
    105 
    106 // Resolves a function name in NTDLL to a function pointer. The second parameter
    107 // is a pointer to the function pointer.
    108 void ResolveNTFunctionPtr(const char* name, void* ptr);
    109 
    110 #endif  // SANDBOX_SRC_WIN_UTILS_H_
    111