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: #include "base/callback.h"
michael@0: #include "base/logging.h"
michael@0: #include "base/memory/scoped_ptr.h"
michael@0: #include "sandbox/win/src/sharedmem_ipc_server.h"
michael@0: #include "sandbox/win/src/sharedmem_ipc_client.h"
michael@0: #include "sandbox/win/src/sandbox.h"
michael@0: #include "sandbox/win/src/sandbox_types.h"
michael@0: #include "sandbox/win/src/crosscall_params.h"
michael@0: #include "sandbox/win/src/crosscall_server.h"
michael@0: 
michael@0: namespace sandbox {
michael@0: 
michael@0: SharedMemIPCServer::SharedMemIPCServer(HANDLE target_process,
michael@0:                                        DWORD target_process_id,
michael@0:                                        HANDLE target_job,
michael@0:                                        ThreadProvider* thread_provider,
michael@0:                                        Dispatcher* dispatcher)
michael@0:     : client_control_(NULL),
michael@0:       thread_provider_(thread_provider),
michael@0:       target_process_(target_process),
michael@0:       target_process_id_(target_process_id),
michael@0:       target_job_object_(target_job),
michael@0:       call_dispatcher_(dispatcher) {
michael@0: }
michael@0: 
michael@0: SharedMemIPCServer::~SharedMemIPCServer() {
michael@0:   // Free the wait handles associated with the thread pool.
michael@0:   if (!thread_provider_->UnRegisterWaits(this)) {
michael@0:     // Better to leak than to crash.
michael@0:     return;
michael@0:   }
michael@0:   // Free the IPC signal events.
michael@0:   ServerContexts::iterator it;
michael@0:   for (it = server_contexts_.begin(); it != server_contexts_.end(); ++it) {
michael@0:     ServerControl* context = (*it);
michael@0:     ::CloseHandle(context->ping_event);
michael@0:     ::CloseHandle(context->pong_event);
michael@0:     delete context;
michael@0:   }
michael@0: }
michael@0: 
michael@0: bool SharedMemIPCServer::Init(void* shared_mem, uint32 shared_size,
michael@0:                               uint32 channel_size) {
michael@0:   // The shared memory needs to be at least as big as a channel.
michael@0:   if (shared_size < channel_size) {
michael@0:     return false;
michael@0:   }
michael@0:   // The channel size should be aligned.
michael@0:   if (0 != (channel_size % 32)) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   // Calculate how many channels we can fit in the shared memory.
michael@0:   shared_size -= offsetof(IPCControl, channels);
michael@0:   size_t channel_count = shared_size / (sizeof(ChannelControl) + channel_size);
michael@0: 
michael@0:   // If we cannot fit even one channel we bail out.
michael@0:   if (0 == channel_count) {
michael@0:     return false;
michael@0:   }
michael@0:   // Calculate the start of the first channel.
michael@0:   size_t base_start = (sizeof(ChannelControl)* channel_count) +
michael@0:                        offsetof(IPCControl, channels);
michael@0: 
michael@0:   client_control_ = reinterpret_cast<IPCControl*>(shared_mem);
michael@0:   client_control_->channels_count = 0;
michael@0: 
michael@0:   // This is the initialization that we do per-channel. Basically:
michael@0:   // 1) make two events (ping & pong)
michael@0:   // 2) create handles to the events for the client and the server.
michael@0:   // 3) initialize the channel (client_context) with the state.
michael@0:   // 4) initialize the server side of the channel (service_context).
michael@0:   // 5) call the thread provider RegisterWait to register the ping events.
michael@0:   for (size_t ix = 0; ix != channel_count; ++ix) {
michael@0:     ChannelControl* client_context = &client_control_->channels[ix];
michael@0:     ServerControl* service_context = new ServerControl;
michael@0:     server_contexts_.push_back(service_context);
michael@0: 
michael@0:     if (!MakeEvents(&service_context->ping_event,
michael@0:                     &service_context->pong_event,
michael@0:                     &client_context->ping_event,
michael@0:                     &client_context->pong_event)) {
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     client_context->channel_base = base_start;
michael@0:     client_context->state = kFreeChannel;
michael@0: 
michael@0:     // Note that some of these values are available as members of this
michael@0:     // object but we put them again into the service_context because we
michael@0:     // will be called on a static method (ThreadPingEventReady)
michael@0:     service_context->shared_base = reinterpret_cast<char*>(shared_mem);
michael@0:     service_context->channel_size = channel_size;
michael@0:     service_context->channel = client_context;
michael@0:     service_context->channel_buffer = service_context->shared_base +
michael@0:                                       client_context->channel_base;
michael@0:     service_context->dispatcher = call_dispatcher_;
michael@0:     service_context->target_info.process = target_process_;
michael@0:     service_context->target_info.process_id = target_process_id_;
michael@0:     service_context->target_info.job_object = target_job_object_;
michael@0:     // Advance to the next channel.
michael@0:     base_start += channel_size;
michael@0:     // Register the ping event with the threadpool.
michael@0:     thread_provider_->RegisterWait(this, service_context->ping_event,
michael@0:                                    ThreadPingEventReady, service_context);
michael@0:   }
michael@0: 
michael@0:   // We create a mutex that the server locks. If the server dies unexpectedly,
michael@0:   // the thread that owns it will fail to release the lock and windows will
michael@0:   // report to the target (when it tries to acquire it) that the wait was
michael@0:   // abandoned. Note: We purposely leak the local handle because we want it to
michael@0:   // be closed by Windows itself so it is properly marked as abandoned if the
michael@0:   // server dies.
michael@0:   if (!::DuplicateHandle(::GetCurrentProcess(),
michael@0:                          ::CreateMutexW(NULL, TRUE, NULL),
michael@0:                          target_process_, &client_control_->server_alive,
michael@0:                          SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, 0)) {
michael@0:     return false;
michael@0:   }
michael@0:   // This last setting indicates to the client all is setup.
michael@0:   client_control_->channels_count = channel_count;
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: // Releases memory allocated for IPC arguments, if needed.
michael@0: void ReleaseArgs(const IPCParams* ipc_params, void* args[kMaxIpcParams]) {
michael@0:   for (size_t i = 0; i < kMaxIpcParams; i++) {
michael@0:     switch (ipc_params->args[i]) {
michael@0:       case WCHAR_TYPE: {
michael@0:         delete reinterpret_cast<std::wstring*>(args[i]);
michael@0:         args[i] = NULL;
michael@0:         break;
michael@0:       }
michael@0:       case INOUTPTR_TYPE: {
michael@0:         delete reinterpret_cast<CountedBuffer*>(args[i]);
michael@0:         args[i] = NULL;
michael@0:         break;
michael@0:       }
michael@0:       default: break;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: // Fills up the list of arguments (args and ipc_params) for an IPC call.
michael@0: bool GetArgs(CrossCallParamsEx* params, IPCParams* ipc_params,
michael@0:              void* args[kMaxIpcParams]) {
michael@0:   if (kMaxIpcParams < params->GetParamsCount())
michael@0:     return false;
michael@0: 
michael@0:   for (uint32 i = 0; i < params->GetParamsCount(); i++) {
michael@0:     uint32 size;
michael@0:     ArgType type;
michael@0:     args[i] = params->GetRawParameter(i, &size, &type);
michael@0:     if (args[i]) {
michael@0:       ipc_params->args[i] = type;
michael@0:       switch (type) {
michael@0:         case WCHAR_TYPE: {
michael@0:           scoped_ptr<std::wstring> data(new std::wstring);
michael@0:           if (!params->GetParameterStr(i, data.get())) {
michael@0:             args[i] = 0;
michael@0:             ReleaseArgs(ipc_params, args);
michael@0:             return false;
michael@0:           }
michael@0:           args[i] = data.release();
michael@0:           break;
michael@0:         }
michael@0:         case ULONG_TYPE: {
michael@0:           uint32 data;
michael@0:           if (!params->GetParameter32(i, &data)) {
michael@0:             ReleaseArgs(ipc_params, args);
michael@0:             return false;
michael@0:           }
michael@0:           IPCInt ipc_int(data);
michael@0:           args[i] = ipc_int.AsVoidPtr();
michael@0:           break;
michael@0:         }
michael@0:         case VOIDPTR_TYPE : {
michael@0:           void* data;
michael@0:           if (!params->GetParameterVoidPtr(i, &data)) {
michael@0:             ReleaseArgs(ipc_params, args);
michael@0:             return false;
michael@0:           }
michael@0:           args[i] = data;
michael@0:           break;
michael@0:         }
michael@0:         case INOUTPTR_TYPE: {
michael@0:           if (!args[i]) {
michael@0:             ReleaseArgs(ipc_params, args);
michael@0:             return false;
michael@0:           }
michael@0:           CountedBuffer* buffer = new CountedBuffer(args[i] , size);
michael@0:           args[i] = buffer;
michael@0:           break;
michael@0:         }
michael@0:         default: break;
michael@0:       }
michael@0:     }
michael@0:   }
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: bool SharedMemIPCServer::InvokeCallback(const ServerControl* service_context,
michael@0:                                         void* ipc_buffer,
michael@0:                                         CrossCallReturn* call_result) {
michael@0:   // Set the default error code;
michael@0:   SetCallError(SBOX_ERROR_INVALID_IPC, call_result);
michael@0:   uint32 output_size = 0;
michael@0:   // Parse, verify and copy the message. The handler operates on a copy
michael@0:   // of the message so the client cannot play dirty tricks by changing the
michael@0:   // data in the channel while the IPC is being processed.
michael@0:   scoped_ptr<CrossCallParamsEx> params(
michael@0:       CrossCallParamsEx::CreateFromBuffer(ipc_buffer,
michael@0:                                           service_context->channel_size,
michael@0:                                           &output_size));
michael@0:   if (!params.get())
michael@0:     return false;
michael@0: 
michael@0:   uint32 tag = params->GetTag();
michael@0:   COMPILE_ASSERT(0 == INVALID_TYPE, Incorrect_type_enum);
michael@0:   IPCParams ipc_params = {0};
michael@0:   ipc_params.ipc_tag = tag;
michael@0: 
michael@0:   void* args[kMaxIpcParams];
michael@0:   if (!GetArgs(params.get(), &ipc_params, args))
michael@0:     return false;
michael@0: 
michael@0:   IPCInfo ipc_info = {0};
michael@0:   ipc_info.ipc_tag = tag;
michael@0:   ipc_info.client_info = &service_context->target_info;
michael@0:   Dispatcher* dispatcher = service_context->dispatcher;
michael@0:   DCHECK(dispatcher);
michael@0:   bool error = true;
michael@0:   Dispatcher* handler = NULL;
michael@0: 
michael@0:   Dispatcher::CallbackGeneric callback_generic;
michael@0:   handler = dispatcher->OnMessageReady(&ipc_params, &callback_generic);
michael@0:   if (handler) {
michael@0:     switch (params->GetParamsCount()) {
michael@0:       case 0: {
michael@0:         // Ask the IPC dispatcher if she can service this IPC.
michael@0:         Dispatcher::Callback0 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback0>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 1: {
michael@0:         Dispatcher::Callback1 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback1>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 2: {
michael@0:         Dispatcher::Callback2 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback2>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 3: {
michael@0:         Dispatcher::Callback3 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback3>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 4: {
michael@0:         Dispatcher::Callback4 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback4>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2],
michael@0:                                   args[3]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 5: {
michael@0:         Dispatcher::Callback5 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback5>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3],
michael@0:                                   args[4]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 6: {
michael@0:         Dispatcher::Callback6 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback6>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3],
michael@0:                                   args[4], args[5]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 7: {
michael@0:         Dispatcher::Callback7 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback7>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3],
michael@0:                                   args[4], args[5], args[6]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 8: {
michael@0:         Dispatcher::Callback8 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback8>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3],
michael@0:                                   args[4], args[5], args[6], args[7]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       case 9: {
michael@0:         Dispatcher::Callback9 callback =
michael@0:             reinterpret_cast<Dispatcher::Callback9>(callback_generic);
michael@0:         if (!(handler->*callback)(&ipc_info, args[0], args[1], args[2], args[3],
michael@0:                                   args[4], args[5], args[6], args[7], args[8]))
michael@0:           break;
michael@0:         error = false;
michael@0:         break;
michael@0:       }
michael@0:       default:  {
michael@0:         NOTREACHED();
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (error) {
michael@0:     if (handler)
michael@0:       SetCallError(SBOX_ERROR_FAILED_IPC, call_result);
michael@0:   } else {
michael@0:     memcpy(call_result, &ipc_info.return_info, sizeof(*call_result));
michael@0:     SetCallSuccess(call_result);
michael@0:     if (params->IsInOut()) {
michael@0:       // Maybe the params got changed by the broker. We need to upadte the
michael@0:       // memory section.
michael@0:       memcpy(ipc_buffer, params.get(), output_size);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   ReleaseArgs(&ipc_params, args);
michael@0: 
michael@0:   return !error;
michael@0: }
michael@0: 
michael@0: // This function gets called by a thread from the thread pool when a
michael@0: // ping event fires. The context is the same as passed in the RegisterWait()
michael@0: // call above.
michael@0: void __stdcall SharedMemIPCServer::ThreadPingEventReady(void* context,
michael@0:                                                         unsigned char) {
michael@0:   if (NULL == context) {
michael@0:     DCHECK(false);
michael@0:     return;
michael@0:   }
michael@0:   ServerControl* service_context = reinterpret_cast<ServerControl*>(context);
michael@0:   // Since the event fired, the channel *must* be busy. Change to kAckChannel
michael@0:   // while we service it.
michael@0:   LONG last_state =
michael@0:     ::InterlockedCompareExchange(&service_context->channel->state,
michael@0:                                  kAckChannel, kBusyChannel);
michael@0:   if (kBusyChannel != last_state) {
michael@0:     DCHECK(false);
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   // Prepare the result structure. At this point we will return some result
michael@0:   // even if the IPC is invalid, malformed or has no handler.
michael@0:   CrossCallReturn call_result = {0};
michael@0:   void* buffer = service_context->channel_buffer;
michael@0: 
michael@0:   InvokeCallback(service_context, buffer, &call_result);
michael@0: 
michael@0:   // Copy the answer back into the channel and signal the pong event. This
michael@0:   // should wake up the client so he can finish the the ipc cycle.
michael@0:   CrossCallParams* call_params = reinterpret_cast<CrossCallParams*>(buffer);
michael@0:   memcpy(call_params->GetCallReturn(), &call_result, sizeof(call_result));
michael@0:   ::InterlockedExchange(&service_context->channel->state, kAckChannel);
michael@0:   ::SetEvent(service_context->pong_event);
michael@0: }
michael@0: 
michael@0: bool SharedMemIPCServer::MakeEvents(HANDLE* server_ping, HANDLE* server_pong,
michael@0:                                     HANDLE* client_ping, HANDLE* client_pong) {
michael@0:   // Note that the IPC client has no right to delete the events. That would
michael@0:   // cause problems. The server *owns* the events.
michael@0:   const DWORD kDesiredAccess = SYNCHRONIZE | EVENT_MODIFY_STATE;
michael@0: 
michael@0:   // The events are auto reset, and start not signaled.
michael@0:   *server_ping = ::CreateEventW(NULL, FALSE, FALSE, NULL);
michael@0:   if (!::DuplicateHandle(::GetCurrentProcess(), *server_ping, target_process_,
michael@0:                          client_ping, kDesiredAccess, FALSE, 0)) {
michael@0:     return false;
michael@0:   }
michael@0:   *server_pong = ::CreateEventW(NULL, FALSE, FALSE, NULL);
michael@0:   if (!::DuplicateHandle(::GetCurrentProcess(), *server_pong, target_process_,
michael@0:                          client_pong, kDesiredAccess, FALSE, 0)) {
michael@0:     return false;
michael@0:   }
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: }  // namespace sandbox