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
InternalThunk__anon8c3d12cb0111::InternalThunk34 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
SetInternalThunk(void * storage,size_t storage_bytes,const void * original_function,const void * interceptor)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
GetInternalThunkSize() const77 size_t ResolverThunk::GetInternalThunkSize() const {
78 return sizeof(InternalThunk);
79 }
80
ResolveTarget(const void * module,const char * function_name,void ** address)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