sandbox/win/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/win/src/resolver.h"
   6
   7 // For placement new. This file must not depend on the CRT at runtime, but
   8 // placement operator new is inline.
   9 #include <new>
  10
  11 #include "sandbox/win/src/sandbox_nt_util.h"
  12
  13 namespace {
  14
  15 #pragma pack(push, 1)
  16 struct InternalThunk {
  17   // This struct contains roughly the following code:
  18   // sub esp, 8                             // Create working space
  19   // push edx                               // Save register
  20   // mov edx, [esp + 0xc]                   // Get return adddress
  21   // mov [esp + 8], edx                     // Store return address
  22   // mov dword ptr [esp + 0xc], 0x7c401200  // Store extra argument
  23   // mov dword ptr [esp + 4], 0x40010203    // Store address to jump to
  24   // pop edx                                // Restore register
  25   // ret                                    // Jump to interceptor
  26   //
  27   // This code only modifies esp and eip so it must work with to normal calling
  28   // convention. It is assembled as:
  29   //
  30   // 00 83ec08           sub     esp,8
  31   // 03 52               push    edx
  32   // 04 8b54240c         mov     edx,dword ptr [esp + 0Ch]
  33   // 08 89542408         mov     dword ptr [esp + 8], edx
  34   // 0c c744240c0012407c mov     dword ptr [esp + 0Ch], 7C401200h
  35   // 14 c744240403020140 mov     dword ptr [esp + 4], 40010203h
  36   // 1c 5a               pop     edx
  37   // 1d c3               ret
  38   InternalThunk() {
  39     opcodes_1 = 0x5208ec83;
  40     opcodes_2 = 0x0c24548b;
  41     opcodes_3 = 0x08245489;
  42     opcodes_4 = 0x0c2444c7;
  43     opcodes_5 = 0x042444c7;
  44     opcodes_6 = 0xc35a;
  45     extra_argument = 0;
  46     interceptor_function = 0;
  47   };
  48   ULONG opcodes_1;         // = 0x5208ec83
  49   ULONG opcodes_2;         // = 0x0c24548b
  50   ULONG opcodes_3;         // = 0x08245489
  51   ULONG opcodes_4;         // = 0x0c2444c7
  52   ULONG extra_argument;
  53   ULONG opcodes_5;         // = 0x042444c7
  54   ULONG interceptor_function;
  55   USHORT opcodes_6;         // = 0xc35a
  56 };
  57 #pragma pack(pop)
  58
  59 };  // namespace
  60
  61 namespace sandbox {
  62
  63 bool ResolverThunk::SetInternalThunk(void* storage, size_t storage_bytes,
  64                                      const void* original_function,
  65                                      const void* interceptor) {
  66   if (storage_bytes < sizeof(InternalThunk))
  67     return false;
  68
  69   InternalThunk* thunk = new(storage) InternalThunk;
  70
  71 #pragma warning(push)
  72 #pragma warning(disable: 4311)
  73   // These casts generate warnings because they are 32 bit specific.
  74   thunk->interceptor_function = reinterpret_cast<ULONG>(interceptor);
  75   thunk->extra_argument = reinterpret_cast<ULONG>(original_function);
  76 #pragma warning(pop)
  77
  78   return true;
  79 }
  80
  81 size_t ResolverThunk::GetInternalThunkSize() const {
  82   return sizeof(InternalThunk);
  83 }
  84
  85 NTSTATUS ResolverThunk::ResolveTarget(const void* module,
  86                                       const char* function_name,
  87                                       void** address) {
  88   const void** casted = const_cast<const void**>(address);
  89   return ResolverThunk::ResolveInterceptor(module, function_name, casted);
  90 }
  91
  92 }  // namespace sandbox