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/eat_resolver.h"
6
7 #include "base/win/pe_image.h"
8 #include "sandbox/win/src/sandbox_nt_util.h"
9
10 namespace sandbox {
11
Setup(const void * target_module,const void * interceptor_module,const char * target_name,const char * interceptor_name,const void * interceptor_entry_point,void * thunk_storage,size_t storage_bytes,size_t * storage_used)12 NTSTATUS EatResolverThunk::Setup(const void* target_module,
13 const void* interceptor_module,
14 const char* target_name,
15 const char* interceptor_name,
16 const void* interceptor_entry_point,
17 void* thunk_storage,
18 size_t storage_bytes,
19 size_t* storage_used) {
20 NTSTATUS ret = Init(target_module, interceptor_module, target_name,
21 interceptor_name, interceptor_entry_point,
22 thunk_storage, storage_bytes);
23 if (!NT_SUCCESS(ret))
24 return ret;
25
26 if (!eat_entry_)
27 return STATUS_INVALID_PARAMETER;
28
29 size_t thunk_bytes = GetInternalThunkSize();
30
31 #if defined(_WIN64)
32 // We have two thunks, in order: the return path and the forward path.
33 if (!SetInternalThunk(thunk_storage, storage_bytes, NULL, target_))
34 return STATUS_BUFFER_TOO_SMALL;
35
36 storage_bytes -= thunk_bytes;
37 thunk_storage = reinterpret_cast<char*>(thunk_storage) + thunk_bytes;
38 #endif
39
40 if (!SetInternalThunk(thunk_storage, storage_bytes, target_, interceptor_))
41 return STATUS_BUFFER_TOO_SMALL;
42
43 AutoProtectMemory memory;
44 ret = memory.ChangeProtection(eat_entry_, sizeof(DWORD), PAGE_READWRITE);
45 if (!NT_SUCCESS(ret))
46 return ret;
47
48 // Perform the patch.
49 #pragma warning(push)
50 #pragma warning(disable: 4311)
51 // These casts generate warnings because they are 32 bit specific.
52 *eat_entry_ = reinterpret_cast<DWORD>(thunk_storage) -
53 reinterpret_cast<DWORD>(target_module);
54 #pragma warning(pop)
55
56 if (NULL != storage_used)
57 *storage_used = GetThunkSize();
58
59 return ret;
60 }
61
ResolveTarget(const void * module,const char * function_name,void ** address)62 NTSTATUS EatResolverThunk::ResolveTarget(const void* module,
63 const char* function_name,
64 void** address) {
65 DCHECK_NT(address);
66 if (!module)
67 return STATUS_INVALID_PARAMETER;
68
69 base::win::PEImage pe(module);
70 if (!pe.VerifyMagic())
71 return STATUS_INVALID_IMAGE_FORMAT;
72
73 eat_entry_ = pe.GetExportEntry(function_name);
74
75 if (!eat_entry_)
76 return STATUS_PROCEDURE_NOT_FOUND;
77
78 *address = pe.RVAToAddr(*eat_entry_);
79
80 return STATUS_SUCCESS;
81 }
82
GetThunkSize() const83 size_t EatResolverThunk::GetThunkSize() const {
84 #if defined(_WIN64)
85 return GetInternalThunkSize() * 2;
86 #else
87 return GetInternalThunkSize();
88 #endif
89 }
90
91 } // namespace sandbox
92