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 #include "sandbox/win/src/resolver.h" 6 7 #include "sandbox/win/src/sandbox_nt_util.h" 8 9 namespace { 10 11 #pragma pack(push, 1) 12 struct InternalThunk { 13 // This struct contains roughly the following code: 14 // sub esp, 8 // Create working space 15 // push edx // Save register 16 // mov edx, [esp + 0xc] // Get return adddress 17 // mov [esp + 8], edx // Store return address 18 // mov dword ptr [esp + 0xc], 0x7c401200 // Store extra argument 19 // mov dword ptr [esp + 4], 0x40010203 // Store address to jump to 20 // pop edx // Restore register 21 // ret // Jump to interceptor 22 // 23 // This code only modifies esp and eip so it must work with to normal calling 24 // convention. It is assembled as: 25 // 26 // 00 83ec08 sub esp,8 27 // 03 52 push edx 28 // 04 8b54240c mov edx,dword ptr [esp + 0Ch] 29 // 08 89542408 mov dword ptr [esp + 8], edx 30 // 0c c744240c0012407c mov dword ptr [esp + 0Ch], 7C401200h 31 // 14 c744240403020140 mov dword ptr [esp + 4], 40010203h 32 // 1c 5a pop edx 33 // 1d c3 ret 34 InternalThunk() { 35 opcodes_1 = 0x5208ec83; 36 opcodes_2 = 0x0c24548b; 37 opcodes_3 = 0x08245489; 38 opcodes_4 = 0x0c2444c7; 39 opcodes_5 = 0x042444c7; 40 opcodes_6 = 0xc35a; 41 extra_argument = 0; 42 interceptor_function = 0; 43 }; 44 ULONG opcodes_1; // = 0x5208ec83 45 ULONG opcodes_2; // = 0x0c24548b 46 ULONG opcodes_3; // = 0x08245489 47 ULONG opcodes_4; // = 0x0c2444c7 48 ULONG extra_argument; 49 ULONG opcodes_5; // = 0x042444c7 50 ULONG interceptor_function; 51 USHORT opcodes_6; // = 0xc35a 52 }; 53 #pragma pack(pop) 54 55 }; // namespace 56 57 namespace sandbox { 58 59 bool ResolverThunk::SetInternalThunk(void* storage, size_t storage_bytes, 60 const void* original_function, 61 const void* interceptor) { 62 if (storage_bytes < sizeof(InternalThunk)) 63 return false; 64 65 InternalThunk* thunk = new(storage, NT_PLACE) InternalThunk; 66 67 #pragma warning(push) 68 #pragma warning(disable: 4311) 69 // These casts generate warnings because they are 32 bit specific. 70 thunk->interceptor_function = reinterpret_cast<ULONG>(interceptor); 71 thunk->extra_argument = reinterpret_cast<ULONG>(original_function); 72 #pragma warning(pop) 73 74 return true; 75 } 76 77 size_t ResolverThunk::GetInternalThunkSize() const { 78 return sizeof(InternalThunk); 79 } 80 81 NTSTATUS ResolverThunk::ResolveTarget(const void* module, 82 const char* function_name, 83 void** address) { 84 const void** casted = const_cast<const void**>(address); 85 return ResolverThunk::ResolveInterceptor(module, function_name, casted); 86 } 87 88 } // namespace sandbox 89
