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1 // Copyright (c) 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_SANDBOX_NT_UTIL_H_
6 #define SANDBOX_SRC_SANDBOX_NT_UTIL_H_
7 
8 #include <intrin.h>
9 
10 #include "base/basictypes.h"
11 #include "sandbox/win/src/nt_internals.h"
12 #include "sandbox/win/src/sandbox_nt_types.h"
13 
14 // Placement new and delete to be used from ntdll interception code.
15 void* __cdecl operator new(size_t size, sandbox::AllocationType type,
16                            void* near_to = NULL);
17 void __cdecl operator delete(void* memory, sandbox::AllocationType type);
18 // Add operator delete that matches the placement form of the operator new
19 // above. This is required by compiler to generate code to call operator delete
20 // in case the object's constructor throws an exception.
21 // See http://msdn.microsoft.com/en-us/library/cxdxz3x6.aspx
22 void __cdecl operator delete(void* memory, sandbox::AllocationType type,
23                              void* near_to);
24 
25 // Regular placement new and delete
26 void* __cdecl operator new(size_t size, void* buffer,
27                            sandbox::AllocationType type);
28 void __cdecl operator delete(void* memory, void* buffer,
29                              sandbox::AllocationType type);
30 
31 // DCHECK_NT is defined to be pretty much an assert at this time because we
32 // don't have logging from the ntdll layer on the child.
33 //
34 // VERIFY_NT and VERIFY_SUCCESS_NT are the standard asserts on debug, but
35 // execute the actual argument on release builds. VERIFY_NT expects an action
36 // returning a bool, while VERIFY_SUCCESS_NT expects an action returning
37 // NTSTATUS.
38 #ifndef NDEBUG
39 #define DCHECK_NT(condition) { (condition) ? (void)0 : __debugbreak(); }
40 #define VERIFY(action) DCHECK_NT(action)
41 #define VERIFY_SUCCESS(action) DCHECK_NT(NT_SUCCESS(action))
42 #else
43 #define DCHECK_NT(condition)
44 #define VERIFY(action) (action)
45 #define VERIFY_SUCCESS(action) (action)
46 #endif
47 
48 #define CHECK_NT(condition) { (condition) ? (void)0 : __debugbreak(); }
49 
50 #define NOTREACHED_NT() DCHECK_NT(false)
51 
52 namespace sandbox {
53 
54 #if defined(_M_X64)
55 #pragma intrinsic(_InterlockedCompareExchange)
56 #pragma intrinsic(_InterlockedCompareExchangePointer)
57 
58 #elif defined(_M_IX86)
59 extern "C" long _InterlockedCompareExchange(long volatile* destination,
60                                             long exchange, long comperand);
61 
62 #pragma intrinsic(_InterlockedCompareExchange)
63 
64 // We want to make sure that we use an intrinsic version of the function, not
65 // the one provided by kernel32.
66 __forceinline void* _InterlockedCompareExchangePointer(
67     void* volatile* destination, void* exchange, void* comperand) {
68   size_t ret = _InterlockedCompareExchange(
69       reinterpret_cast<long volatile*>(destination),
70       static_cast<long>(reinterpret_cast<size_t>(exchange)),
71       static_cast<long>(reinterpret_cast<size_t>(comperand)));
72 
73   return reinterpret_cast<void*>(static_cast<size_t>(ret));
74 }
75 
76 #else
77 #error Architecture not supported.
78 
79 #endif
80 
81 // Returns a pointer to the IPC shared memory.
82 void* GetGlobalIPCMemory();
83 
84 // Returns a pointer to the Policy shared memory.
85 void* GetGlobalPolicyMemory();
86 
87 enum RequiredAccess {
88   READ,
89   WRITE
90 };
91 
92 // Performs basic user mode buffer validation. In any case, buffers access must
93 // be protected by SEH. intent specifies if the buffer should be tested for read
94 // or write.
95 // Note that write intent implies destruction of the buffer content (we actually
96 // write)
97 bool ValidParameter(void* buffer, size_t size, RequiredAccess intent);
98 
99 // Copies data from a user buffer to our buffer. Returns the operation status.
100 NTSTATUS CopyData(void* destination, const void* source, size_t bytes);
101 
102 // Copies the name from an object attributes.
103 NTSTATUS AllocAndCopyName(const OBJECT_ATTRIBUTES* in_object,
104                           wchar_t** out_name, uint32* attributes, HANDLE* root);
105 
106 // Initializes our ntdll level heap
107 bool InitHeap();
108 
109 // Returns true if the provided handle refers to the current process.
110 bool IsSameProcess(HANDLE process);
111 
112 enum MappedModuleFlags {
113   MODULE_IS_PE_IMAGE     = 1,   // Module is an executable.
114   MODULE_HAS_ENTRY_POINT = 2,   // Execution entry point found.
115   MODULE_HAS_CODE =        4    // Non zero size of executable sections.
116 };
117 
118 // Returns the name and characteristics for a given PE module. The return
119 // value is the name as defined by the export table and the flags is any
120 // combination of the MappedModuleFlags enumeration.
121 //
122 // The returned buffer must be freed with a placement delete from the ntdll
123 // level allocator:
124 //
125 // UNICODE_STRING* name = GetPEImageInfoFromModule(HMODULE module, &flags);
126 // if (!name) {
127 //   // probably not a valid dll
128 //   return;
129 // }
130 // InsertYourLogicHere(name);
131 // operator delete(name, NT_ALLOC);
132 UNICODE_STRING* GetImageInfoFromModule(HMODULE module, uint32* flags);
133 
134 // Returns the full path and filename for a given dll.
135 // May return NULL if the provided address is not backed by a named section, or
136 // if the current OS version doesn't support the call. The returned buffer must
137 // be freed with a placement delete (see GetImageNameFromModule example).
138 UNICODE_STRING* GetBackingFilePath(PVOID address);
139 
140 // Returns the last component of a path that contains the module name.
141 // It will return NULL if the path ends with the path separator. The returned
142 // buffer must be freed with a placement delete (see GetImageNameFromModule
143 // example).
144 UNICODE_STRING* ExtractModuleName(const UNICODE_STRING* module_path);
145 
146 // Returns true if the parameters correspond to a dll mapped as code.
147 bool IsValidImageSection(HANDLE section, PVOID *base, PLARGE_INTEGER offset,
148                          PSIZE_T view_size);
149 
150 // Converts an ansi string to an UNICODE_STRING.
151 UNICODE_STRING* AnsiToUnicode(const char* string);
152 
153 // Provides a simple way to temporarily change the protection of a memory page.
154 class AutoProtectMemory {
155  public:
AutoProtectMemory()156   AutoProtectMemory()
157       : changed_(false), address_(NULL), bytes_(0), old_protect_(0) {}
158 
~AutoProtectMemory()159   ~AutoProtectMemory() {
160     RevertProtection();
161   }
162 
163   // Sets the desired protection of a given memory range.
164   NTSTATUS ChangeProtection(void* address, size_t bytes, ULONG protect);
165 
166   // Restores the original page protection.
167   NTSTATUS RevertProtection();
168 
169  private:
170   bool changed_;
171   void* address_;
172   size_t bytes_;
173   ULONG old_protect_;
174 
175   DISALLOW_COPY_AND_ASSIGN(AutoProtectMemory);
176 };
177 
178 // Returns true if the file_rename_information structure is supported by our
179 // rename handler.
180 bool IsSupportedRenameCall(FILE_RENAME_INFORMATION* file_info, DWORD length,
181                            uint32 file_info_class);
182 
183 }  // namespace sandbox
184 
185 
186 #endif  // SANDBOX_SRC_SANDBOX_NT_UTIL_H__
187