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
InternalThunk__anon5780145e0111::InternalThunk38 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
SetInternalThunk(void * storage,size_t storage_bytes,const void * original_function,const void * interceptor)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
GetInternalThunkSize() const81 size_t ResolverThunk::GetInternalThunkSize() const {
82 return sizeof(InternalThunk);
83 }
84
ResolveTarget(const void * module,const char * function_name,void ** address)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
93