sandbox/src/resolver_32.cc

   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/src/resolver.h"
   6
   7 #include "sandbox/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