sandbox/src/service_resolver_32.cc - chromium/src - Git at Google

 // Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "sandbox/src/service_resolver.h"

 #include "base/logging.h"
 #include "base/scoped_ptr.h"
 #include "sandbox/src/sandbox_utils.h"
 #include "sandbox/src/win_utils.h"

 namespace {
 #pragma pack(push, 1)

 const BYTE kMovEax = 0xB8;
 const BYTE kMovEdx = 0xBA;
 const USHORT kCallPtrEdx = 0x12FF;
 const USHORT kCallEdx = 0xD2FF;
 const BYTE kRet = 0xC2;
 const BYTE kNop = 0x90;
 const USHORT kJmpEdx = 0xE2FF;
 const USHORT kXorEcx = 0xC933;
 const ULONG kLeaEdx = 0x0424548D;
 const ULONG kCallFs1 = 0xC015FF64;
 const USHORT kCallFs2 = 0;
 const BYTE kCallFs3 = 0;
 const BYTE kAddEsp1 = 0x83;
 const USHORT kAddEsp2 = 0x4C4;
 const BYTE kJmp32 = 0xE9;

 const int kMaxService = 1000;

 // Service code for 32 bit systems.
 // NOTE: on win2003 "call dword ptr [edx]" is "call edx".
 struct ServiceEntry {
   // this struct contains roughly the following code:
   // 00 mov     eax,25h
   // 05 mov     edx,offset SharedUserData!SystemCallStub (7ffe0300)
   // 0a call    dword ptr [edx]
   // 0c ret     2Ch
   // 0f nop
   BYTE mov_eax;         // = B8
   ULONG service_id;
   BYTE mov_edx;         // = BA
   ULONG stub;
   USHORT call_ptr_edx;  // = FF 12
   BYTE ret;             // = C2
   USHORT num_params;
   BYTE nop;
   ULONG pad1;           // Extend the structure to be the same size as the
   ULONG pad2;           // 64 version (Wow64Entry)
 };

 // Service code for a 32 bit process running on a 64 bit os.
 struct Wow64Entry {
   // This struct may contain one of two versions of code:
   // 1. For XP, Vista and 2K3:
   // 00 b852000000      mov     eax, 25h
   // 05 33c9            xor     ecx, ecx
   // 07 8d542404        lea     edx, [esp + 4]
   // 0b 64ff15c0000000  call    dword ptr fs:[0C0h]
   // 12 c22c00          ret     2Ch
   //
   // 2. For Windows 7:
   // 00 b852000000      mov     eax, 25h
   // 05 33c9            xor     ecx, ecx
   // 07 8d542404        lea     edx, [esp + 4]
   // 0b 64ff15c0000000  call    dword ptr fs:[0C0h]
   // 12 83c404          add     esp, 4
   // 15 c22c00          ret     2Ch
   //
   // So we base the structure on the bigger one:
   BYTE mov_eax;         // = B8
   ULONG service_id;
   USHORT xor_ecx;       // = 33 C9
   ULONG lea_edx;        // = 8D 54 24 04
   ULONG call_fs1;       // = 64 FF 15 C0
   USHORT call_fs2;      // = 00 00
   BYTE call_fs3;        // = 00
   BYTE add_esp1;        // = 83             or ret
   USHORT add_esp2;      // = C4 04          or num_params
   BYTE ret;             // = C2
   USHORT num_params;
 };

 // Make sure that relaxed patching works as expected.
 COMPILE_ASSERT(sizeof(ServiceEntry) == sizeof(Wow64Entry), wrong_service_len);

 struct ServiceFullThunk {
   union {
     ServiceEntry original;
     Wow64Entry wow_64;
   };
   int internal_thunk;  // Dummy member to the beginning of the internal thunk.
 };

 #pragma pack(pop)

 };  // namespace

 namespace sandbox {

 NTSTATUS ServiceResolverThunk::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) {
   NTSTATUS ret = Init(target_module, interceptor_module, target_name,
                       interceptor_name, interceptor_entry_point,
                       thunk_storage, storage_bytes);
   if (!NT_SUCCESS(ret))
     return ret;

   size_t thunk_bytes = GetThunkSize();
   scoped_array<char> thunk_buffer(new char[thunk_bytes]);
   ServiceFullThunk* thunk = reinterpret_cast<ServiceFullThunk*>(
                                 thunk_buffer.get());

   if (!IsFunctionAService(&thunk->original) &&
       (!relaxed_ || !SaveOriginalFunction(&thunk->original, thunk_storage)))
     return STATUS_UNSUCCESSFUL;

   ret = PerformPatch(thunk, thunk_storage);

   if (NULL != storage_used)
     *storage_used = thunk_bytes;

   return ret;
 }

 size_t ServiceResolverThunk::GetThunkSize() const {
   return offsetof(ServiceFullThunk, internal_thunk) + GetInternalThunkSize();
 }

 bool ServiceResolverThunk::IsFunctionAService(void* local_thunk) const {
   ServiceEntry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;

   if (sizeof(function_code) != read)
     return false;

   if (kMovEax != function_code.mov_eax ||
       kMovEdx != function_code.mov_edx ||
       (kCallPtrEdx != function_code.call_ptr_edx &&
        kCallEdx != function_code.call_ptr_edx) ||
       kRet != function_code.ret)
     return false;

   // Find the system call pointer if we don't already have it.
   if (kCallEdx != function_code.call_ptr_edx) {
     DWORD ki_system_call;
     if (!::ReadProcessMemory(process_,
                              bit_cast<const void*>(function_code.stub),
                              &ki_system_call, sizeof(ki_system_call), &read))
       return false;

     if (sizeof(ki_system_call) != read)
       return false;

     HMODULE module_1, module_2;
     // last check, call_stub should point to a KiXXSystemCall function on ntdll
     if (!GetModuleHandleHelper(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
                                   GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
                                bit_cast<const wchar_t*>(ki_system_call),
                                &module_1))
       return false;

     if (NULL != ntdll_base_) {
       // This path is only taken when running the unit tests. We want to be
       // able to patch a buffer in memory, so target_ is not inside ntdll.
       module_2 = ntdll_base_;
     } else {
       if (!GetModuleHandleHelper(
               GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS |
                   GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
               reinterpret_cast<const wchar_t*>(target_),
               &module_2)) {
         return false;
       }
     }

     if (module_1 != module_2)
       return false;
   }

   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));

   return true;
 }

 NTSTATUS ServiceResolverThunk::PerformPatch(void* local_thunk,
                                             void* remote_thunk) {
   ServiceEntry intercepted_code;
   size_t bytes_to_write = sizeof(intercepted_code);
   ServiceFullThunk *full_local_thunk = reinterpret_cast<ServiceFullThunk*>(
       local_thunk);
   ServiceFullThunk *full_remote_thunk = reinterpret_cast<ServiceFullThunk*>(
       remote_thunk);

   // patch the original code
   memcpy(&intercepted_code, &full_local_thunk->original,
          sizeof(intercepted_code));
   intercepted_code.mov_eax = kMovEax;
   intercepted_code.service_id = full_local_thunk->original.service_id;
   intercepted_code.mov_edx = kMovEdx;
   intercepted_code.stub = bit_cast<ULONG>(&full_remote_thunk->internal_thunk);
   intercepted_code.call_ptr_edx = kJmpEdx;
   if (!win2k_) {
     intercepted_code.ret = kRet;
     intercepted_code.num_params = full_local_thunk->original.num_params;
     intercepted_code.nop = kNop;
   } else {
     bytes_to_write = offsetof(ServiceEntry, ret);
   }

   if (relative_jump_) {
     intercepted_code.mov_eax = kJmp32;
     intercepted_code.service_id = relative_jump_;
     bytes_to_write = offsetof(ServiceEntry, mov_edx);
   }

   // setup the thunk
   SetInternalThunk(&full_local_thunk->internal_thunk, GetInternalThunkSize(),
                    remote_thunk, interceptor_);

   size_t thunk_size = GetThunkSize();

   // copy the local thunk buffer to the child
   SIZE_T written;
   if (!::WriteProcessMemory(process_, remote_thunk, local_thunk,
                             thunk_size, &written))
     return STATUS_UNSUCCESSFUL;

   if (thunk_size != written)
     return STATUS_UNSUCCESSFUL;

   // and now change the function to intercept, on the child
   if (NULL != ntdll_base_) {
     // running a unit test
     if (!::WriteProcessMemory(process_, target_, &intercepted_code,
                               bytes_to_write, &written))
       return STATUS_UNSUCCESSFUL;
   } else {
     if (!WriteProtectedChildMemory(process_, target_, &intercepted_code,
                                    bytes_to_write))
       return STATUS_UNSUCCESSFUL;
   }

   return STATUS_SUCCESS;
 }

 bool ServiceResolverThunk::SaveOriginalFunction(void* local_thunk,
                                                 void* remote_thunk) {
   ServiceEntry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;

   if (sizeof(function_code) != read)
     return false;

   if (kJmp32 == function_code.mov_eax) {
     // Plain old entry point patch. The relative jump address follows it.
     ULONG relative = function_code.service_id;

     // First, fix our copy of their patch.
     relative += bit_cast<ULONG>(target_) - bit_cast<ULONG>(remote_thunk);

     function_code.service_id = relative;

     // And now, remember how to re-patch it.
     ServiceFullThunk *full_thunk =
         reinterpret_cast<ServiceFullThunk*>(remote_thunk);

     const ULONG kJmp32Size = 5;

     relative_jump_ = bit_cast<ULONG>(&full_thunk->internal_thunk) -
                      bit_cast<ULONG>(target_) - kJmp32Size;
   }

   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));

   return true;
 }

 bool Wow64ResolverThunk::IsFunctionAService(void* local_thunk) const {
   Wow64Entry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;

   if (sizeof(function_code) != read)
     return false;

   if (kMovEax != function_code.mov_eax || kXorEcx != function_code.xor_ecx ||
       kLeaEdx != function_code.lea_edx || kCallFs1 != function_code.call_fs1 ||
       kCallFs2 != function_code.call_fs2 || kCallFs3 != function_code.call_fs3)
     return false;

   if ((kAddEsp1 == function_code.add_esp1 &&
        kAddEsp2 == function_code.add_esp2 &&
        kRet == function_code.ret) || kRet == function_code.add_esp1) {
     // Save the verified code
     memcpy(local_thunk, &function_code, sizeof(function_code));
     return true;
   }

   return false;
 }

 bool Win2kResolverThunk::IsFunctionAService(void* local_thunk) const {
   ServiceEntry function_code;
   SIZE_T read;
   if (!::ReadProcessMemory(process_, target_, &function_code,
                            sizeof(function_code), &read))
     return false;

   if (sizeof(function_code) != read)
     return false;

   if (kMovEax != function_code.mov_eax ||
       function_code.service_id > kMaxService)
     return false;

   // Save the verified code
   memcpy(local_thunk, &function_code, sizeof(function_code));

   return true;
 }

 }  // namespace sandbox
	// Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "sandbox/src/service_resolver.h"

	#include "base/logging.h"
	#include "base/scoped_ptr.h"
	#include "sandbox/src/sandbox_utils.h"
	#include "sandbox/src/win_utils.h"

	namespace {
	#pragma pack(push, 1)

	const BYTE kMovEax = 0xB8;
	const BYTE kMovEdx = 0xBA;
	const USHORT kCallPtrEdx = 0x12FF;
	const USHORT kCallEdx = 0xD2FF;
	const BYTE kRet = 0xC2;
	const BYTE kNop = 0x90;
	const USHORT kJmpEdx = 0xE2FF;
	const USHORT kXorEcx = 0xC933;
	const ULONG kLeaEdx = 0x0424548D;
	const ULONG kCallFs1 = 0xC015FF64;
	const USHORT kCallFs2 = 0;
	const BYTE kCallFs3 = 0;
	const BYTE kAddEsp1 = 0x83;
	const USHORT kAddEsp2 = 0x4C4;
	const BYTE kJmp32 = 0xE9;

	const int kMaxService = 1000;

	// Service code for 32 bit systems.
	// NOTE: on win2003 "call dword ptr [edx]" is "call edx".
	struct ServiceEntry {
	// this struct contains roughly the following code:
	// 00 mov eax,25h
	// 05 mov edx,offset SharedUserData!SystemCallStub (7ffe0300)
	// 0a call dword ptr [edx]
	// 0c ret 2Ch
	// 0f nop
	BYTE mov_eax; // = B8
	ULONG service_id;
	BYTE mov_edx; // = BA
	ULONG stub;
	USHORT call_ptr_edx; // = FF 12
	BYTE ret; // = C2
	USHORT num_params;
	BYTE nop;
	ULONG pad1; // Extend the structure to be the same size as the
	ULONG pad2; // 64 version (Wow64Entry)
	};

	// Service code for a 32 bit process running on a 64 bit os.
	struct Wow64Entry {
	// This struct may contain one of two versions of code:
	// 1. For XP, Vista and 2K3:
	// 00 b852000000 mov eax, 25h
	// 05 33c9 xor ecx, ecx
	// 07 8d542404 lea edx, [esp + 4]
	// 0b 64ff15c0000000 call dword ptr fs:[0C0h]
	// 12 c22c00 ret 2Ch
	//
	// 2. For Windows 7:
	// 00 b852000000 mov eax, 25h
	// 05 33c9 xor ecx, ecx
	// 07 8d542404 lea edx, [esp + 4]
	// 0b 64ff15c0000000 call dword ptr fs:[0C0h]
	// 12 83c404 add esp, 4
	// 15 c22c00 ret 2Ch
	//
	// So we base the structure on the bigger one:
	BYTE mov_eax; // = B8
	ULONG service_id;
	USHORT xor_ecx; // = 33 C9
	ULONG lea_edx; // = 8D 54 24 04
	ULONG call_fs1; // = 64 FF 15 C0
	USHORT call_fs2; // = 00 00
	BYTE call_fs3; // = 00
	BYTE add_esp1; // = 83 or ret
	USHORT add_esp2; // = C4 04 or num_params
	BYTE ret; // = C2
	USHORT num_params;
	};

	// Make sure that relaxed patching works as expected.
	COMPILE_ASSERT(sizeof(ServiceEntry) == sizeof(Wow64Entry), wrong_service_len);

	struct ServiceFullThunk {
	union {
	ServiceEntry original;
	Wow64Entry wow_64;
	};
	int internal_thunk; // Dummy member to the beginning of the internal thunk.
	};

	#pragma pack(pop)

	}; // namespace

	namespace sandbox {

	NTSTATUS ServiceResolverThunk::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) {
	NTSTATUS ret = Init(target_module, interceptor_module, target_name,
	interceptor_name, interceptor_entry_point,
	thunk_storage, storage_bytes);
	if (!NT_SUCCESS(ret))
	return ret;

	size_t thunk_bytes = GetThunkSize();
	scoped_array<char> thunk_buffer(new char[thunk_bytes]);
	ServiceFullThunk* thunk = reinterpret_cast<ServiceFullThunk*>(
	thunk_buffer.get());

	if (!IsFunctionAService(&thunk->original) &&
	(!relaxed_ \|\| !SaveOriginalFunction(&thunk->original, thunk_storage)))
	return STATUS_UNSUCCESSFUL;

	ret = PerformPatch(thunk, thunk_storage);

	if (NULL != storage_used)
	*storage_used = thunk_bytes;

	return ret;
	}

	size_t ServiceResolverThunk::GetThunkSize() const {
	return offsetof(ServiceFullThunk, internal_thunk) + GetInternalThunkSize();
	}

	bool ServiceResolverThunk::IsFunctionAService(void* local_thunk) const {
	ServiceEntry function_code;
	SIZE_T read;
	if (!::ReadProcessMemory(process_, target_, &function_code,
	sizeof(function_code), &read))
	return false;

	if (sizeof(function_code) != read)
	return false;

	if (kMovEax != function_code.mov_eax \|\|
	kMovEdx != function_code.mov_edx \|\|
	(kCallPtrEdx != function_code.call_ptr_edx &&
	kCallEdx != function_code.call_ptr_edx) \|\|
	kRet != function_code.ret)
	return false;

	// Find the system call pointer if we don't already have it.
	if (kCallEdx != function_code.call_ptr_edx) {
	DWORD ki_system_call;
	if (!::ReadProcessMemory(process_,
	bit_cast<const void*>(function_code.stub),
	&ki_system_call, sizeof(ki_system_call), &read))
	return false;

	if (sizeof(ki_system_call) != read)
	return false;

	HMODULE module_1, module_2;
	// last check, call_stub should point to a KiXXSystemCall function on ntdll
	if (!GetModuleHandleHelper(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS \|
	GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
	bit_cast<const wchar_t*>(ki_system_call),
	&module_1))
	return false;

	if (NULL != ntdll_base_) {
	// This path is only taken when running the unit tests. We want to be
	// able to patch a buffer in memory, so target_ is not inside ntdll.
	module_2 = ntdll_base_;
	} else {
	if (!GetModuleHandleHelper(
	GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS \|
	GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
	reinterpret_cast<const wchar_t*>(target_),
	&module_2)) {
	return false;
	}
	}

	if (module_1 != module_2)
	return false;
	}

	// Save the verified code
	memcpy(local_thunk, &function_code, sizeof(function_code));

	return true;
	}

	NTSTATUS ServiceResolverThunk::PerformPatch(void* local_thunk,
	void* remote_thunk) {
	ServiceEntry intercepted_code;
	size_t bytes_to_write = sizeof(intercepted_code);
	ServiceFullThunk full_local_thunk = reinterpret_cast<ServiceFullThunk>(
	local_thunk);
	ServiceFullThunk full_remote_thunk = reinterpret_cast<ServiceFullThunk>(
	remote_thunk);

	// patch the original code
	memcpy(&intercepted_code, &full_local_thunk->original,
	sizeof(intercepted_code));
	intercepted_code.mov_eax = kMovEax;
	intercepted_code.service_id = full_local_thunk->original.service_id;
	intercepted_code.mov_edx = kMovEdx;
	intercepted_code.stub = bit_cast<ULONG>(&full_remote_thunk->internal_thunk);
	intercepted_code.call_ptr_edx = kJmpEdx;
	if (!win2k_) {
	intercepted_code.ret = kRet;
	intercepted_code.num_params = full_local_thunk->original.num_params;
	intercepted_code.nop = kNop;
	} else {
	bytes_to_write = offsetof(ServiceEntry, ret);
	}

	if (relative_jump_) {
	intercepted_code.mov_eax = kJmp32;
	intercepted_code.service_id = relative_jump_;
	bytes_to_write = offsetof(ServiceEntry, mov_edx);
	}

	// setup the thunk
	SetInternalThunk(&full_local_thunk->internal_thunk, GetInternalThunkSize(),
	remote_thunk, interceptor_);

	size_t thunk_size = GetThunkSize();

	// copy the local thunk buffer to the child
	SIZE_T written;
	if (!::WriteProcessMemory(process_, remote_thunk, local_thunk,
	thunk_size, &written))
	return STATUS_UNSUCCESSFUL;

	if (thunk_size != written)
	return STATUS_UNSUCCESSFUL;

	// and now change the function to intercept, on the child
	if (NULL != ntdll_base_) {
	// running a unit test
	if (!::WriteProcessMemory(process_, target_, &intercepted_code,
	bytes_to_write, &written))
	return STATUS_UNSUCCESSFUL;
	} else {
	if (!WriteProtectedChildMemory(process_, target_, &intercepted_code,
	bytes_to_write))
	return STATUS_UNSUCCESSFUL;
	}

	return STATUS_SUCCESS;
	}

	bool ServiceResolverThunk::SaveOriginalFunction(void* local_thunk,
	void* remote_thunk) {
	ServiceEntry function_code;
	SIZE_T read;
	if (!::ReadProcessMemory(process_, target_, &function_code,
	sizeof(function_code), &read))
	return false;

	if (sizeof(function_code) != read)
	return false;

	if (kJmp32 == function_code.mov_eax) {
	// Plain old entry point patch. The relative jump address follows it.
	ULONG relative = function_code.service_id;

	// First, fix our copy of their patch.
	relative += bit_cast<ULONG>(target_) - bit_cast<ULONG>(remote_thunk);

	function_code.service_id = relative;

	// And now, remember how to re-patch it.
	ServiceFullThunk *full_thunk =
	reinterpret_cast<ServiceFullThunk*>(remote_thunk);

	const ULONG kJmp32Size = 5;

	relative_jump_ = bit_cast<ULONG>(&full_thunk->internal_thunk) -
	bit_cast<ULONG>(target_) - kJmp32Size;
	}

	// Save the verified code
	memcpy(local_thunk, &function_code, sizeof(function_code));

	return true;
	}

	bool Wow64ResolverThunk::IsFunctionAService(void* local_thunk) const {
	Wow64Entry function_code;
	SIZE_T read;
	if (!::ReadProcessMemory(process_, target_, &function_code,
	sizeof(function_code), &read))
	return false;

	if (sizeof(function_code) != read)
	return false;

	if (kMovEax != function_code.mov_eax \|\| kXorEcx != function_code.xor_ecx \|\|
	kLeaEdx != function_code.lea_edx \|\| kCallFs1 != function_code.call_fs1 \|\|
	kCallFs2 != function_code.call_fs2 \|\| kCallFs3 != function_code.call_fs3)
	return false;

	if ((kAddEsp1 == function_code.add_esp1 &&
	kAddEsp2 == function_code.add_esp2 &&
	kRet == function_code.ret) \|\| kRet == function_code.add_esp1) {
	// Save the verified code
	memcpy(local_thunk, &function_code, sizeof(function_code));
	return true;
	}

	return false;
	}

	bool Win2kResolverThunk::IsFunctionAService(void* local_thunk) const {
	ServiceEntry function_code;
	SIZE_T read;
	if (!::ReadProcessMemory(process_, target_, &function_code,
	sizeof(function_code), &read))
	return false;

	if (sizeof(function_code) != read)
	return false;

	if (kMovEax != function_code.mov_eax \|\|
	function_code.service_id > kMaxService)
	return false;

	// Save the verified code
	memcpy(local_thunk, &function_code, sizeof(function_code));

	return true;
	}

	} // namespace sandbox