sandbox/win/src/win_utils.h

   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
  11 #include "base/basictypes.h"
  12 #include "base/strings/string16.h"
  13
  14 namespace sandbox {
  15
  16 // Prefix for path used by NT calls.
  17 const wchar_t kNTPrefix[] = L"\\??\\";
  18 const size_t kNTPrefixLen = arraysize(kNTPrefix) - 1;
  19
  20 const wchar_t kNTDevicePrefix[] = L"\\Device\\";
  21 const size_t kNTDevicePrefixLen = arraysize(kNTDevicePrefix) - 1;
  22
  23 // Automatically acquires and releases a lock when the object is
  24 // is destroyed.
  25 class AutoLock {
  26  public:
  27   // Acquires the lock.
  28   explicit AutoLock(CRITICAL_SECTION *lock) : lock_(lock) {
  29     ::EnterCriticalSection(lock);
  30   };
  31
  32   // Releases the lock;
  33   ~AutoLock() {
  34     ::LeaveCriticalSection(lock_);
  35   };
  36
  37  private:
  38   CRITICAL_SECTION *lock_;
  39   DISALLOW_IMPLICIT_CONSTRUCTORS(AutoLock);
  40 };
  41
  42 // Basic implementation of a singleton which calls the destructor
  43 // when the exe is shutting down or the DLL is being unloaded.
  44 template <typename Derived>
  45 class SingletonBase {
  46  public:
  47   static Derived* GetInstance() {
  48     static Derived* instance = NULL;
  49     if (NULL == instance) {
  50       instance = new Derived();
  51       // Microsoft CRT extension. In an exe this this called after
  52       // winmain returns, in a dll is called in DLL_PROCESS_DETACH
  53       _onexit(OnExit);
  54     }
  55     return instance;
  56   }
  57
  58  private:
  59   // this is the function that gets called by the CRT when the
  60   // process is shutting down.
  61   static int __cdecl OnExit() {
  62     delete GetInstance();
  63     return 0;
  64   }
  65 };
  66
  67 // Convert a short path (C:\path~1 or \\??\\c:\path~1) to the long version of
  68 // the path. If the path is not a valid filesystem path, the function returns
  69 // false and the output parameter is not modified.
  70 bool ConvertToLongPath(const base::string16& short_path,
  71                        base::string16* long_path);
  72
  73 // Sets result to true if the path contains a reparse point. The return value
  74 // is ERROR_SUCCESS when the function succeeds or the appropriate error code
  75 // when the function fails.
  76 // This function is not smart. It looks for each element in the path and
  77 // returns true if any of them is a reparse point.
  78 DWORD IsReparsePoint(const base::string16& full_path, bool* result);
  79
  80 // Returns true if the handle corresponds to the object pointed by this path.
  81 bool SameObject(HANDLE handle, const wchar_t* full_path);
  82
  83 // Resolves a handle to an nt path. Returns true if the handle can be resolved.
  84 bool GetPathFromHandle(HANDLE handle, base::string16* path);
  85
  86 // Resolves a win32 path to an nt path using GetPathFromHandle. The path must
  87 // exist. Returs true if the translation was succesful.
  88 bool GetNtPathFromWin32Path(const base::string16& path,
  89                             base::string16* nt_path);
  90
  91 // Translates a reserved key name to its handle.
  92 // For example "HKEY_LOCAL_MACHINE" returns HKEY_LOCAL_MACHINE.
  93 // Returns NULL if the name does not represent any reserved key name.
  94 HKEY GetReservedKeyFromName(const base::string16& name);
  95
  96 // Resolves a user-readable registry path to a system-readable registry path.
  97 // For example, HKEY_LOCAL_MACHINE\\Software\\microsoft is translated to
  98 // \\registry\\machine\\software\\microsoft. Returns false if the path
  99 // cannot be resolved.
 100 bool ResolveRegistryName(base::string16 name, base::string16* resolved_name);
 101
 102 // Writes |length| bytes from the provided |buffer| into the address space of
 103 // |child_process|, at the specified |address|, preserving the original write
 104 // protection attributes. Returns true on success.
 105 bool WriteProtectedChildMemory(HANDLE child_process, void* address,
 106                                const void* buffer, size_t length);
 107
 108 // Returns true if the provided path points to a pipe.
 109 bool IsPipe(const base::string16& path);
 110
 111 }  // namespace sandbox
 112
 113 // Resolves a function name in NTDLL to a function pointer. The second parameter
 114 // is a pointer to the function pointer.
 115 void ResolveNTFunctionPtr(const char* name, void* ptr);
 116
 117 #endif  // SANDBOX_SRC_WIN_UTILS_H_