michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef SANDBOX_SRC_CROSSCALL_CLIENT_H_
michael@0: #define SANDBOX_SRC_CROSSCALL_CLIENT_H_
michael@0: 
michael@0: #include "sandbox/win/src/crosscall_params.h"
michael@0: #include "sandbox/win/src/sandbox.h"
michael@0: 
michael@0: // This header defines the CrossCall(..) family of templated functions
michael@0: // Their purpose is to simulate the syntax of regular call but to generate
michael@0: // and IPC from the client-side.
michael@0: //
michael@0: // The basic pattern is to
michael@0: //   1) use template argument deduction to compute the size of each
michael@0: //      parameter and the appropriate copy method
michael@0: //   2) pack the parameters in the appropriate ActualCallParams< > object
michael@0: //   3) call the IPC interface IPCProvider::DoCall( )
michael@0: //
michael@0: // The general interface of CrossCall is:
michael@0: //  ResultCode CrossCall(IPCProvider& ipc_provider,
michael@0: //                       uint32 tag,
michael@0: //                       const Par1& p1, const Par2& p2,...pn
michael@0: //                       CrossCallReturn* answer)
michael@0: //
michael@0: //  where:
michael@0: //    ipc_provider: is a specific implementation of the ipc transport see
michael@0: //                  sharedmem_ipc_server.h for an example.
michael@0: //    tag : is the unique id for this IPC call. Is used to route the call to
michael@0: //          the appropriate service.
michael@0: //    p1, p2,.. pn : The input parameters of the IPC. Use only simple types
michael@0: //                   and wide strings (can add support for others).
michael@0: //    answer : If the IPC was successful. The server-side answer is here. The
michael@0: //             interpretation of the answer is private to client and server.
michael@0: //
michael@0: // The return value is ALL_OK if the IPC was delivered to the server, other
michael@0: // return codes indicate that the IPC transport failed to deliver it.
michael@0: namespace sandbox {
michael@0: 
michael@0: // this is the assumed channel size. This can be overridden in a given
michael@0: // IPC implementation.
michael@0: const uint32 kIPCChannelSize = 1024;
michael@0: 
michael@0: // The copy helper uses templates to deduce the appropriate copy function to
michael@0: // copy the input parameters in the buffer that is going to be send across the
michael@0: // IPC. These template facility can be made more sophisticated as need arises.
michael@0: 
michael@0: // The default copy helper. It catches the general case where no other
michael@0: // specialized template matches better. We set the type to ULONG_TYPE, so this
michael@0: // only works with objects whose size is 32 bits.
michael@0: template<typename T>
michael@0: class CopyHelper {
michael@0:  public:
michael@0:   CopyHelper(const T& t) : t_(t) {}
michael@0: 
michael@0:   // Returns the pointer to the start of the input.
michael@0:   const void* GetStart() const {
michael@0:     return &t_;
michael@0:   }
michael@0: 
michael@0:   // Update the stored value with the value in the buffer. This is not
michael@0:   // supported for this type.
michael@0:   bool Update(void* buffer) {
michael@0:     // Not supported;
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Returns the size of the input in bytes.
michael@0:   uint32 GetSize() const {
michael@0:     return sizeof(T);
michael@0:   }
michael@0: 
michael@0:   // Returns true if the current type is used as an In or InOut parameter.
michael@0:   bool IsInOut() {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   // Returns this object's type.
michael@0:   ArgType GetType() {
michael@0:     COMPILE_ASSERT(sizeof(T) == sizeof(uint32), need_specialization);
michael@0:     return ULONG_TYPE;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   const T& t_;
michael@0: };
michael@0: 
michael@0: // This copy helper template specialization if for the void pointer
michael@0: // case both 32 and 64 bit.
michael@0: template<>
michael@0: class CopyHelper<void*> {
michael@0:  public:
michael@0:   CopyHelper(void* t) : t_(t) {}
michael@0: 
michael@0:   // Returns the pointer to the start of the input.
michael@0:   const void* GetStart() const {
michael@0:     return &t_;
michael@0:   }
michael@0: 
michael@0:   // Update the stored value with the value in the buffer. This is not
michael@0:   // supported for this type.
michael@0:   bool Update(void* buffer) {
michael@0:     // Not supported;
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Returns the size of the input in bytes.
michael@0:   uint32 GetSize() const {
michael@0:     return sizeof(t_);
michael@0:   }
michael@0: 
michael@0:   // Returns true if the current type is used as an In or InOut parameter.
michael@0:   bool IsInOut() {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   // Returns this object's type.
michael@0:   ArgType GetType() {
michael@0:     return VOIDPTR_TYPE;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   const void* t_;
michael@0: };
michael@0: 
michael@0: // This copy helper template specialization catches the cases where the
michael@0: // parameter is a pointer to a string.
michael@0: template<>
michael@0: class CopyHelper<const wchar_t*> {
michael@0:  public:
michael@0:   CopyHelper(const wchar_t* t)
michael@0:       : t_(t) {
michael@0:   }
michael@0: 
michael@0:   // Returns the pointer to the start of the string.
michael@0:   const void* GetStart() const {
michael@0:     return t_;
michael@0:   }
michael@0: 
michael@0:   // Update the stored value with the value in the buffer. This is not
michael@0:   // supported for this type.
michael@0:   bool Update(void* buffer) {
michael@0:     // Not supported;
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Returns the size of the string in bytes. We define a NULL string to
michael@0:   // be of zero length.
michael@0:   uint32 GetSize() const {
michael@0:     __try {
michael@0:       return (!t_) ? 0 : static_cast<uint32>(StringLength(t_) * sizeof(t_[0]));
michael@0:     }
michael@0:     __except(EXCEPTION_EXECUTE_HANDLER) {
michael@0:       return kuint32max;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // Returns true if the current type is used as an In or InOut parameter.
michael@0:   bool IsInOut() {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   ArgType GetType() {
michael@0:     return WCHAR_TYPE;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   // We provide our not very optimized version of wcslen(), since we don't
michael@0:   // want to risk having the linker use the version in the CRT since the CRT
michael@0:   // might not be present when we do an early IPC call.
michael@0:   static size_t __cdecl StringLength(const wchar_t* wcs) {
michael@0:     const wchar_t *eos = wcs;
michael@0:     while (*eos++);
michael@0:     return static_cast<size_t>(eos - wcs - 1);
michael@0:   }
michael@0: 
michael@0:   const wchar_t* t_;
michael@0: };
michael@0: 
michael@0: // Specialization for non-const strings. We just reuse the implementation of the
michael@0: // const string specialization.
michael@0: template<>
michael@0: class CopyHelper<wchar_t*> : public CopyHelper<const wchar_t*> {
michael@0:  public:
michael@0:   typedef CopyHelper<const wchar_t*> Base;
michael@0:   CopyHelper(wchar_t* t) : Base(t) {}
michael@0: 
michael@0:   const void* GetStart() const {
michael@0:     return Base::GetStart();
michael@0:   }
michael@0: 
michael@0:   bool Update(void* buffer) {
michael@0:     return Base::Update(buffer);
michael@0:   }
michael@0: 
michael@0:   uint32 GetSize() const {
michael@0:     return Base::GetSize();
michael@0:   }
michael@0: 
michael@0:   bool IsInOut() {
michael@0:     return Base::IsInOut();
michael@0:   }
michael@0: 
michael@0:   ArgType GetType() {
michael@0:     return Base::GetType();
michael@0:   }
michael@0: };
michael@0: 
michael@0: // Specialization for wchar_t arrays strings. We just reuse the implementation
michael@0: // of the const string specialization.
michael@0: template<size_t n>
michael@0: class CopyHelper<const wchar_t[n]> : public CopyHelper<const wchar_t*> {
michael@0:  public:
michael@0:   typedef const wchar_t array[n];
michael@0:   typedef CopyHelper<const wchar_t*> Base;
michael@0:   CopyHelper(array t) : Base(t) {}
michael@0: 
michael@0:   const void* GetStart() const {
michael@0:     return Base::GetStart();
michael@0:   }
michael@0: 
michael@0:   bool Update(void* buffer) {
michael@0:     return Base::Update(buffer);
michael@0:   }
michael@0: 
michael@0:   uint32 GetSize() const {
michael@0:     return Base::GetSize();
michael@0:   }
michael@0: 
michael@0:   bool IsInOut() {
michael@0:     return Base::IsInOut();
michael@0:   }
michael@0: 
michael@0:   ArgType GetType() {
michael@0:     return Base::GetType();
michael@0:   }
michael@0: };
michael@0: 
michael@0: // Generic encapsulation class containing a pointer to a buffer and the
michael@0: // size of the buffer. It is used by the IPC to be able to pass in/out
michael@0: // parameters.
michael@0: class InOutCountedBuffer : public CountedBuffer {
michael@0:  public:
michael@0:   InOutCountedBuffer(void* buffer, uint32 size) : CountedBuffer(buffer, size) {}
michael@0: };
michael@0: 
michael@0: // This copy helper template specialization catches the cases where the
michael@0: // parameter is a an input/output buffer.
michael@0: template<>
michael@0: class CopyHelper<InOutCountedBuffer> {
michael@0:  public:
michael@0:   CopyHelper(const InOutCountedBuffer t) : t_(t) {}
michael@0: 
michael@0:   // Returns the pointer to the start of the string.
michael@0:   const void* GetStart() const {
michael@0:     return t_.Buffer();
michael@0:   }
michael@0: 
michael@0:   // Updates the buffer with the value from the new buffer in parameter.
michael@0:   bool Update(void* buffer) {
michael@0:     // We are touching user memory, this has to be done from inside a try
michael@0:     // except.
michael@0:     __try {
michael@0:       memcpy(t_.Buffer(), buffer, t_.Size());
michael@0:     }
michael@0:     __except(EXCEPTION_EXECUTE_HANDLER) {
michael@0:       return false;
michael@0:     }
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   // Returns the size of the string in bytes. We define a NULL string to
michael@0:   // be of zero length.
michael@0:   uint32 GetSize() const {
michael@0:     return t_.Size();
michael@0:   }
michael@0: 
michael@0:   // Returns true if the current type is used as an In or InOut parameter.
michael@0:   bool IsInOut() {
michael@0:     return true;
michael@0:   }
michael@0: 
michael@0:   ArgType GetType() {
michael@0:     return INOUTPTR_TYPE;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   const InOutCountedBuffer t_;
michael@0: };
michael@0: 
michael@0: // The following two macros make it less error prone the generation
michael@0: // of CrossCall functions with ever more input parameters.
michael@0: 
michael@0: #define XCALL_GEN_PARAMS_OBJ(num, params) \
michael@0:   typedef ActualCallParams<num, kIPCChannelSize> ActualParams; \
michael@0:   void* raw_mem = ipc_provider.GetBuffer(); \
michael@0:   if (NULL == raw_mem) \
michael@0:     return SBOX_ERROR_NO_SPACE; \
michael@0:   ActualParams* params = new(raw_mem) ActualParams(tag);
michael@0: 
michael@0: #define XCALL_GEN_COPY_PARAM(num, params) \
michael@0:   COMPILE_ASSERT(kMaxIpcParams >= num, too_many_parameters); \
michael@0:   CopyHelper<Par##num> ch##num(p##num); \
michael@0:   if (!params->CopyParamIn(num - 1, ch##num.GetStart(), ch##num.GetSize(), \
michael@0:                            ch##num.IsInOut(), ch##num.GetType())) \
michael@0:     return SBOX_ERROR_NO_SPACE;
michael@0: 
michael@0: #define XCALL_GEN_UPDATE_PARAM(num, params) \
michael@0:   if (!ch##num.Update(params->GetParamPtr(num-1))) {\
michael@0:     ipc_provider.FreeBuffer(raw_mem); \
michael@0:     return SBOX_ERROR_BAD_PARAMS; \
michael@0:   }
michael@0: 
michael@0: #define XCALL_GEN_FREE_CHANNEL() \
michael@0:   ipc_provider.FreeBuffer(raw_mem);
michael@0: 
michael@0: // CrossCall template with one input parameter
michael@0: template <typename IPCProvider, typename Par1>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0: 
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // CrossCall template with two input parameters.
michael@0: template <typename IPCProvider, typename Par1, typename Par2>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      const Par2& p2, CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(2, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(2, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(2, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // CrossCall template with three input parameters.
michael@0: template <typename IPCProvider, typename Par1, typename Par2, typename Par3>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      const Par2& p2, const Par3& p3, CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(3, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(2, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(3, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(2, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(3, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // CrossCall template with four input parameters.
michael@0: template <typename IPCProvider, typename Par1, typename Par2, typename Par3,
michael@0:           typename Par4>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      const Par2& p2, const Par3& p3, const Par4& p4,
michael@0:                      CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(4, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(2, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(3, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(4, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(2, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(3, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(4, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // CrossCall template with five input parameters.
michael@0: template <typename IPCProvider, typename Par1, typename Par2, typename Par3,
michael@0:           typename Par4, typename Par5>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      const Par2& p2, const Par3& p3, const Par4& p4,
michael@0:                      const Par5& p5, CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(5, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(2, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(3, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(4, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(5, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(2, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(3, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(4, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(5, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // CrossCall template with six input parameters.
michael@0: template <typename IPCProvider, typename Par1, typename Par2, typename Par3,
michael@0:           typename Par4, typename Par5, typename Par6>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      const Par2& p2, const Par3& p3, const Par4& p4,
michael@0:                      const Par5& p5, const Par6& p6, CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(6, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(2, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(3, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(4, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(5, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(6, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(2, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(3, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(4, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(5, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(6, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // CrossCall template with seven input parameters.
michael@0: template <typename IPCProvider, typename Par1, typename Par2, typename Par3,
michael@0:           typename Par4, typename Par5, typename Par6, typename Par7>
michael@0: ResultCode CrossCall(IPCProvider& ipc_provider, uint32 tag, const Par1& p1,
michael@0:                      const Par2& p2, const Par3& p3, const Par4& p4,
michael@0:                      const Par5& p5, const Par6& p6, const Par7& p7,
michael@0:                      CrossCallReturn* answer) {
michael@0:   XCALL_GEN_PARAMS_OBJ(7, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(1, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(2, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(3, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(4, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(5, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(6, call_params);
michael@0:   XCALL_GEN_COPY_PARAM(7, call_params);
michael@0: 
michael@0:   ResultCode result = ipc_provider.DoCall(call_params, answer);
michael@0: 
michael@0:   if (SBOX_ERROR_CHANNEL_ERROR != result) {
michael@0:     XCALL_GEN_UPDATE_PARAM(1, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(2, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(3, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(4, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(5, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(6, call_params);
michael@0:     XCALL_GEN_UPDATE_PARAM(7, call_params);
michael@0:     XCALL_GEN_FREE_CHANNEL();
michael@0:   }
michael@0:   return result;
michael@0: }
michael@0: }  // namespace sandbox
michael@0: 
michael@0: #endif  // SANDBOX_SRC_CROSSCALL_CLIENT_H__