michael@0: // Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "sandbox/win/src/resolver.h"
michael@0: 
michael@0: #include "sandbox/win/src/sandbox_nt_util.h"
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: #pragma pack(push, 1)
michael@0: struct InternalThunk {
michael@0:   // This struct contains roughly the following code:
michael@0:   // sub esp, 8                             // Create working space
michael@0:   // push edx                               // Save register
michael@0:   // mov edx, [esp + 0xc]                   // Get return adddress
michael@0:   // mov [esp + 8], edx                     // Store return address
michael@0:   // mov dword ptr [esp + 0xc], 0x7c401200  // Store extra argument
michael@0:   // mov dword ptr [esp + 4], 0x40010203    // Store address to jump to
michael@0:   // pop edx                                // Restore register
michael@0:   // ret                                    // Jump to interceptor
michael@0:   //
michael@0:   // This code only modifies esp and eip so it must work with to normal calling
michael@0:   // convention. It is assembled as:
michael@0:   //
michael@0:   // 00 83ec08           sub     esp,8
michael@0:   // 03 52               push    edx
michael@0:   // 04 8b54240c         mov     edx,dword ptr [esp + 0Ch]
michael@0:   // 08 89542408         mov     dword ptr [esp + 8], edx
michael@0:   // 0c c744240c0012407c mov     dword ptr [esp + 0Ch], 7C401200h
michael@0:   // 14 c744240403020140 mov     dword ptr [esp + 4], 40010203h
michael@0:   // 1c 5a               pop     edx
michael@0:   // 1d c3               ret
michael@0:   InternalThunk() {
michael@0:     opcodes_1 = 0x5208ec83;
michael@0:     opcodes_2 = 0x0c24548b;
michael@0:     opcodes_3 = 0x08245489;
michael@0:     opcodes_4 = 0x0c2444c7;
michael@0:     opcodes_5 = 0x042444c7;
michael@0:     opcodes_6 = 0xc35a;
michael@0:     extra_argument = 0;
michael@0:     interceptor_function = 0;
michael@0:   };
michael@0:   ULONG opcodes_1;         // = 0x5208ec83
michael@0:   ULONG opcodes_2;         // = 0x0c24548b
michael@0:   ULONG opcodes_3;         // = 0x08245489
michael@0:   ULONG opcodes_4;         // = 0x0c2444c7
michael@0:   ULONG extra_argument;
michael@0:   ULONG opcodes_5;         // = 0x042444c7
michael@0:   ULONG interceptor_function;
michael@0:   USHORT opcodes_6;         // = 0xc35a
michael@0: };
michael@0: #pragma pack(pop)
michael@0: 
michael@0: };  // namespace
michael@0: 
michael@0: namespace sandbox {
michael@0: 
michael@0: bool ResolverThunk::SetInternalThunk(void* storage, size_t storage_bytes,
michael@0:                                      const void* original_function,
michael@0:                                      const void* interceptor) {
michael@0:   if (storage_bytes < sizeof(InternalThunk))
michael@0:     return false;
michael@0: 
michael@0:   InternalThunk* thunk = new(storage, NT_PLACE) InternalThunk;
michael@0: 
michael@0: #pragma warning(push)
michael@0: #pragma warning(disable: 4311)
michael@0:   // These casts generate warnings because they are 32 bit specific.
michael@0:   thunk->interceptor_function = reinterpret_cast<ULONG>(interceptor);
michael@0:   thunk->extra_argument = reinterpret_cast<ULONG>(original_function);
michael@0: #pragma warning(pop)
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: size_t ResolverThunk::GetInternalThunkSize() const {
michael@0:   return sizeof(InternalThunk);
michael@0: }
michael@0: 
michael@0: NTSTATUS ResolverThunk::ResolveTarget(const void* module,
michael@0:                                       const char* function_name,
michael@0:                                       void** address) {
michael@0:   const void** casted = const_cast<const void**>(address);
michael@0:   return ResolverThunk::ResolveInterceptor(module, function_name, casted);
michael@0: }
michael@0: 
michael@0: }  // namespace sandbox