1 // Copyright (c) 2012 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.
5 #ifndef SANDBOX_SRC_CROSSCALL_CLIENT_H_
6 #define SANDBOX_SRC_CROSSCALL_CLIENT_H_
8 #include "sandbox/win/src/crosscall_params.h"
9 #include "sandbox/win/src/sandbox.h"
11 // This header defines the CrossCall(..) family of templated functions
12 // Their purpose is to simulate the syntax of regular call but to generate
13 // and IPC from the client-side.
15 // The basic pattern is to
16 // 1) use template argument deduction to compute the size of each
17 // parameter and the appropriate copy method
18 // 2) pack the parameters in the appropriate ActualCallParams< > object
19 // 3) call the IPC interface IPCProvider::DoCall( )
21 // The general interface of CrossCall is:
22 // ResultCode CrossCall(IPCProvider& ipc_provider,
24 // const Par1& p1, const Par2& p2,...pn
25 // CrossCallReturn* answer)
28 // ipc_provider: is a specific implementation of the ipc transport see
29 // sharedmem_ipc_server.h for an example.
30 // tag : is the unique id for this IPC call. Is used to route the call to
31 // the appropriate service.
32 // p1, p2,.. pn : The input parameters of the IPC. Use only simple types
33 // and wide strings (can add support for others).
34 // answer : If the IPC was successful. The server-side answer is here. The
35 // interpretation of the answer is private to client and server.
37 // The return value is ALL_OK if the IPC was delivered to the server, other
38 // return codes indicate that the IPC transport failed to deliver it.
41 // this is the assumed channel size. This can be overridden in a given
42 // IPC implementation.
43 const uint32 kIPCChannelSize
= 1024;
45 // The copy helper uses templates to deduce the appropriate copy function to
46 // copy the input parameters in the buffer that is going to be send across the
47 // IPC. These template facility can be made more sophisticated as need arises.
49 // The default copy helper. It catches the general case where no other
50 // specialized template matches better. We set the type to ULONG_TYPE, so this
51 // only works with objects whose size is 32 bits.
55 CopyHelper(const T
& t
) : t_(t
) {}
57 // Returns the pointer to the start of the input.
58 const void* GetStart() const {
62 // Update the stored value with the value in the buffer. This is not
63 // supported for this type.
64 bool Update(void* buffer
) {
69 // Returns the size of the input in bytes.
70 uint32
GetSize() const {
74 // Returns true if the current type is used as an In or InOut parameter.
79 // Returns this object's type.
81 COMPILE_ASSERT(sizeof(T
) == sizeof(uint32
), need_specialization
);
89 // This copy helper template specialization if for the void pointer
90 // case both 32 and 64 bit.
92 class CopyHelper
<void*> {
94 CopyHelper(void* t
) : t_(t
) {}
96 // Returns the pointer to the start of the input.
97 const void* GetStart() const {
101 // Update the stored value with the value in the buffer. This is not
102 // supported for this type.
103 bool Update(void* buffer
) {
108 // Returns the size of the input in bytes.
109 uint32
GetSize() const {
113 // Returns true if the current type is used as an In or InOut parameter.
118 // Returns this object's type.
127 // This copy helper template specialization catches the cases where the
128 // parameter is a pointer to a string.
130 class CopyHelper
<const wchar_t*> {
132 CopyHelper(const wchar_t* t
)
136 // Returns the pointer to the start of the string.
137 const void* GetStart() const {
141 // Update the stored value with the value in the buffer. This is not
142 // supported for this type.
143 bool Update(void* buffer
) {
148 // Returns the size of the string in bytes. We define a NULL string to
149 // be of zero length.
150 uint32
GetSize() const {
152 return (!t_
) ? 0 : static_cast<uint32
>(StringLength(t_
) * sizeof(t_
[0]));
154 __except(EXCEPTION_EXECUTE_HANDLER
) {
159 // Returns true if the current type is used as an In or InOut parameter.
169 // We provide our not very optimized version of wcslen(), since we don't
170 // want to risk having the linker use the version in the CRT since the CRT
171 // might not be present when we do an early IPC call.
172 static size_t __cdecl
StringLength(const wchar_t* wcs
) {
173 const wchar_t *eos
= wcs
;
175 return static_cast<size_t>(eos
- wcs
- 1);
181 // Specialization for non-const strings. We just reuse the implementation of the
182 // const string specialization.
184 class CopyHelper
<wchar_t*> : public CopyHelper
<const wchar_t*> {
186 typedef CopyHelper
<const wchar_t*> Base
;
187 CopyHelper(wchar_t* t
) : Base(t
) {}
189 const void* GetStart() const {
190 return Base::GetStart();
193 bool Update(void* buffer
) {
194 return Base::Update(buffer
);
197 uint32
GetSize() const {
198 return Base::GetSize();
202 return Base::IsInOut();
206 return Base::GetType();
210 // Specialization for wchar_t arrays strings. We just reuse the implementation
211 // of the const string specialization.
213 class CopyHelper
<const wchar_t[n
]> : public CopyHelper
<const wchar_t*> {
215 typedef const wchar_t array
[n
];
216 typedef CopyHelper
<const wchar_t*> Base
;
217 CopyHelper(array t
) : Base(t
) {}
219 const void* GetStart() const {
220 return Base::GetStart();
223 bool Update(void* buffer
) {
224 return Base::Update(buffer
);
227 uint32
GetSize() const {
228 return Base::GetSize();
232 return Base::IsInOut();
236 return Base::GetType();
240 // Generic encapsulation class containing a pointer to a buffer and the
241 // size of the buffer. It is used by the IPC to be able to pass in/out
243 class InOutCountedBuffer
: public CountedBuffer
{
245 InOutCountedBuffer(void* buffer
, uint32 size
) : CountedBuffer(buffer
, size
) {}
248 // This copy helper template specialization catches the cases where the
249 // parameter is a an input/output buffer.
251 class CopyHelper
<InOutCountedBuffer
> {
253 CopyHelper(const InOutCountedBuffer t
) : t_(t
) {}
255 // Returns the pointer to the start of the string.
256 const void* GetStart() const {
260 // Updates the buffer with the value from the new buffer in parameter.
261 bool Update(void* buffer
) {
262 // We are touching user memory, this has to be done from inside a try
265 memcpy(t_
.Buffer(), buffer
, t_
.Size());
267 __except(EXCEPTION_EXECUTE_HANDLER
) {
273 // Returns the size of the string in bytes. We define a NULL string to
274 // be of zero length.
275 uint32
GetSize() const {
279 // Returns true if the current type is used as an In or InOut parameter.
285 return INOUTPTR_TYPE
;
289 const InOutCountedBuffer t_
;
292 // The following two macros make it less error prone the generation
293 // of CrossCall functions with ever more input parameters.
295 #define XCALL_GEN_PARAMS_OBJ(num, params) \
296 typedef ActualCallParams<num, kIPCChannelSize> ActualParams; \
297 void* raw_mem = ipc_provider.GetBuffer(); \
298 if (NULL == raw_mem) \
299 return SBOX_ERROR_NO_SPACE; \
300 ActualParams* params = new(raw_mem) ActualParams(tag);
302 #define XCALL_GEN_COPY_PARAM(num, params) \
303 COMPILE_ASSERT(kMaxIpcParams >= num, too_many_parameters); \
304 CopyHelper<Par##num> ch##num(p##num); \
305 if (!params->CopyParamIn(num - 1, ch##num.GetStart(), ch##num.GetSize(), \
306 ch##num.IsInOut(), ch##num.GetType())) \
307 return SBOX_ERROR_NO_SPACE;
309 #define XCALL_GEN_UPDATE_PARAM(num, params) \
310 if (!ch##num.Update(params->GetParamPtr(num-1))) {\
311 ipc_provider.FreeBuffer(raw_mem); \
312 return SBOX_ERROR_BAD_PARAMS; \
315 #define XCALL_GEN_FREE_CHANNEL() \
316 ipc_provider.FreeBuffer(raw_mem);
318 // CrossCall template with one input parameter
319 template <typename IPCProvider
, typename Par1
>
320 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
321 CrossCallReturn
* answer
) {
322 XCALL_GEN_PARAMS_OBJ(1, call_params
);
323 XCALL_GEN_COPY_PARAM(1, call_params
);
325 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
327 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
328 XCALL_GEN_UPDATE_PARAM(1, call_params
);
329 XCALL_GEN_FREE_CHANNEL();
335 // CrossCall template with two input parameters.
336 template <typename IPCProvider
, typename Par1
, typename Par2
>
337 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
338 const Par2
& p2
, CrossCallReturn
* answer
) {
339 XCALL_GEN_PARAMS_OBJ(2, call_params
);
340 XCALL_GEN_COPY_PARAM(1, call_params
);
341 XCALL_GEN_COPY_PARAM(2, call_params
);
343 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
345 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
346 XCALL_GEN_UPDATE_PARAM(1, call_params
);
347 XCALL_GEN_UPDATE_PARAM(2, call_params
);
348 XCALL_GEN_FREE_CHANNEL();
353 // CrossCall template with three input parameters.
354 template <typename IPCProvider
, typename Par1
, typename Par2
, typename Par3
>
355 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
356 const Par2
& p2
, const Par3
& p3
, CrossCallReturn
* answer
) {
357 XCALL_GEN_PARAMS_OBJ(3, call_params
);
358 XCALL_GEN_COPY_PARAM(1, call_params
);
359 XCALL_GEN_COPY_PARAM(2, call_params
);
360 XCALL_GEN_COPY_PARAM(3, call_params
);
362 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
364 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
365 XCALL_GEN_UPDATE_PARAM(1, call_params
);
366 XCALL_GEN_UPDATE_PARAM(2, call_params
);
367 XCALL_GEN_UPDATE_PARAM(3, call_params
);
368 XCALL_GEN_FREE_CHANNEL();
373 // CrossCall template with four input parameters.
374 template <typename IPCProvider
, typename Par1
, typename Par2
, typename Par3
,
376 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
377 const Par2
& p2
, const Par3
& p3
, const Par4
& p4
,
378 CrossCallReturn
* answer
) {
379 XCALL_GEN_PARAMS_OBJ(4, call_params
);
380 XCALL_GEN_COPY_PARAM(1, call_params
);
381 XCALL_GEN_COPY_PARAM(2, call_params
);
382 XCALL_GEN_COPY_PARAM(3, call_params
);
383 XCALL_GEN_COPY_PARAM(4, call_params
);
385 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
387 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
388 XCALL_GEN_UPDATE_PARAM(1, call_params
);
389 XCALL_GEN_UPDATE_PARAM(2, call_params
);
390 XCALL_GEN_UPDATE_PARAM(3, call_params
);
391 XCALL_GEN_UPDATE_PARAM(4, call_params
);
392 XCALL_GEN_FREE_CHANNEL();
397 // CrossCall template with five input parameters.
398 template <typename IPCProvider
, typename Par1
, typename Par2
, typename Par3
,
399 typename Par4
, typename Par5
>
400 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
401 const Par2
& p2
, const Par3
& p3
, const Par4
& p4
,
402 const Par5
& p5
, CrossCallReturn
* answer
) {
403 XCALL_GEN_PARAMS_OBJ(5, call_params
);
404 XCALL_GEN_COPY_PARAM(1, call_params
);
405 XCALL_GEN_COPY_PARAM(2, call_params
);
406 XCALL_GEN_COPY_PARAM(3, call_params
);
407 XCALL_GEN_COPY_PARAM(4, call_params
);
408 XCALL_GEN_COPY_PARAM(5, call_params
);
410 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
412 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
413 XCALL_GEN_UPDATE_PARAM(1, call_params
);
414 XCALL_GEN_UPDATE_PARAM(2, call_params
);
415 XCALL_GEN_UPDATE_PARAM(3, call_params
);
416 XCALL_GEN_UPDATE_PARAM(4, call_params
);
417 XCALL_GEN_UPDATE_PARAM(5, call_params
);
418 XCALL_GEN_FREE_CHANNEL();
423 // CrossCall template with six input parameters.
424 template <typename IPCProvider
, typename Par1
, typename Par2
, typename Par3
,
425 typename Par4
, typename Par5
, typename Par6
>
426 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
427 const Par2
& p2
, const Par3
& p3
, const Par4
& p4
,
428 const Par5
& p5
, const Par6
& p6
, CrossCallReturn
* answer
) {
429 XCALL_GEN_PARAMS_OBJ(6, call_params
);
430 XCALL_GEN_COPY_PARAM(1, call_params
);
431 XCALL_GEN_COPY_PARAM(2, call_params
);
432 XCALL_GEN_COPY_PARAM(3, call_params
);
433 XCALL_GEN_COPY_PARAM(4, call_params
);
434 XCALL_GEN_COPY_PARAM(5, call_params
);
435 XCALL_GEN_COPY_PARAM(6, call_params
);
437 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
439 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
440 XCALL_GEN_UPDATE_PARAM(1, call_params
);
441 XCALL_GEN_UPDATE_PARAM(2, call_params
);
442 XCALL_GEN_UPDATE_PARAM(3, call_params
);
443 XCALL_GEN_UPDATE_PARAM(4, call_params
);
444 XCALL_GEN_UPDATE_PARAM(5, call_params
);
445 XCALL_GEN_UPDATE_PARAM(6, call_params
);
446 XCALL_GEN_FREE_CHANNEL();
451 // CrossCall template with seven input parameters.
452 template <typename IPCProvider
, typename Par1
, typename Par2
, typename Par3
,
453 typename Par4
, typename Par5
, typename Par6
, typename Par7
>
454 ResultCode
CrossCall(IPCProvider
& ipc_provider
, uint32 tag
, const Par1
& p1
,
455 const Par2
& p2
, const Par3
& p3
, const Par4
& p4
,
456 const Par5
& p5
, const Par6
& p6
, const Par7
& p7
,
457 CrossCallReturn
* answer
) {
458 XCALL_GEN_PARAMS_OBJ(7, call_params
);
459 XCALL_GEN_COPY_PARAM(1, call_params
);
460 XCALL_GEN_COPY_PARAM(2, call_params
);
461 XCALL_GEN_COPY_PARAM(3, call_params
);
462 XCALL_GEN_COPY_PARAM(4, call_params
);
463 XCALL_GEN_COPY_PARAM(5, call_params
);
464 XCALL_GEN_COPY_PARAM(6, call_params
);
465 XCALL_GEN_COPY_PARAM(7, call_params
);
467 ResultCode result
= ipc_provider
.DoCall(call_params
, answer
);
469 if (SBOX_ERROR_CHANNEL_ERROR
!= result
) {
470 XCALL_GEN_UPDATE_PARAM(1, call_params
);
471 XCALL_GEN_UPDATE_PARAM(2, call_params
);
472 XCALL_GEN_UPDATE_PARAM(3, call_params
);
473 XCALL_GEN_UPDATE_PARAM(4, call_params
);
474 XCALL_GEN_UPDATE_PARAM(5, call_params
);
475 XCALL_GEN_UPDATE_PARAM(6, call_params
);
476 XCALL_GEN_UPDATE_PARAM(7, call_params
);
477 XCALL_GEN_FREE_CHANNEL();
481 } // namespace sandbox
483 #endif // SANDBOX_SRC_CROSSCALL_CLIENT_H__