| // Copyright 2013 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 "components/nacl/loader/nacl_ipc_adapter.h" |
| |
| #include <limits.h> |
| #include <string.h> |
| |
| #include "base/basictypes.h" |
| #include "base/bind.h" |
| #include "base/location.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "base/memory/shared_memory.h" |
| #include "build/build_config.h" |
| #include "ipc/ipc_channel.h" |
| #include "ipc/ipc_platform_file.h" |
| #include "native_client/src/trusted/desc/nacl_desc_base.h" |
| #include "native_client/src/trusted/desc/nacl_desc_custom.h" |
| #include "native_client/src/trusted/desc/nacl_desc_imc_shm.h" |
| #include "native_client/src/trusted/desc/nacl_desc_io.h" |
| #include "native_client/src/trusted/desc/nacl_desc_sync_socket.h" |
| #include "native_client/src/trusted/desc/nacl_desc_wrapper.h" |
| #include "native_client/src/trusted/service_runtime/include/sys/fcntl.h" |
| #include "ppapi/c/ppb_file_io.h" |
| #include "ppapi/proxy/ppapi_messages.h" |
| #include "ppapi/proxy/serialized_handle.h" |
| |
| namespace { |
| |
| enum BufferSizeStatus { |
| // The buffer contains a full message with no extra bytes. |
| MESSAGE_IS_COMPLETE, |
| |
| // The message doesn't fit and the buffer contains only some of it. |
| MESSAGE_IS_TRUNCATED, |
| |
| // The buffer contains a full message + extra data. |
| MESSAGE_HAS_EXTRA_DATA |
| }; |
| |
| BufferSizeStatus GetBufferStatus(const char* data, size_t len) { |
| if (len < sizeof(NaClIPCAdapter::NaClMessageHeader)) |
| return MESSAGE_IS_TRUNCATED; |
| |
| const NaClIPCAdapter::NaClMessageHeader* header = |
| reinterpret_cast<const NaClIPCAdapter::NaClMessageHeader*>(data); |
| uint32 message_size = |
| sizeof(NaClIPCAdapter::NaClMessageHeader) + header->payload_size; |
| |
| if (len == message_size) |
| return MESSAGE_IS_COMPLETE; |
| if (len > message_size) |
| return MESSAGE_HAS_EXTRA_DATA; |
| return MESSAGE_IS_TRUNCATED; |
| } |
| |
| // This object allows the NaClDesc to hold a reference to a NaClIPCAdapter and |
| // forward calls to it. |
| struct DescThunker { |
| explicit DescThunker(NaClIPCAdapter* adapter_param) |
| : adapter(adapter_param) { |
| } |
| scoped_refptr<NaClIPCAdapter> adapter; |
| }; |
| |
| NaClIPCAdapter* ToAdapter(void* handle) { |
| return static_cast<DescThunker*>(handle)->adapter.get(); |
| } |
| |
| // NaClDescCustom implementation. |
| void NaClDescCustomDestroy(void* handle) { |
| delete static_cast<DescThunker*>(handle); |
| } |
| |
| ssize_t NaClDescCustomSendMsg(void* handle, const NaClImcTypedMsgHdr* msg, |
| int /* flags */) { |
| return static_cast<ssize_t>(ToAdapter(handle)->Send(msg)); |
| } |
| |
| ssize_t NaClDescCustomRecvMsg(void* handle, NaClImcTypedMsgHdr* msg, |
| int /* flags */) { |
| return static_cast<ssize_t>(ToAdapter(handle)->BlockingReceive(msg)); |
| } |
| |
| NaClDesc* MakeNaClDescCustom(NaClIPCAdapter* adapter) { |
| NaClDescCustomFuncs funcs = NACL_DESC_CUSTOM_FUNCS_INITIALIZER; |
| funcs.Destroy = NaClDescCustomDestroy; |
| funcs.SendMsg = NaClDescCustomSendMsg; |
| funcs.RecvMsg = NaClDescCustomRecvMsg; |
| // NaClDescMakeCustomDesc gives us a reference on the returned NaClDesc. |
| return NaClDescMakeCustomDesc(new DescThunker(adapter), &funcs); |
| } |
| |
| void DeleteChannel(IPC::Channel* channel) { |
| delete channel; |
| } |
| |
| // Translates Pepper's read/write open flags into the NaCl equivalents. |
| // Since the host has already opened the file, flags such as O_CREAT, O_TRUNC, |
| // and O_EXCL don't make sense, so we filter those out. If no read or write |
| // flags are set, the function returns NACL_ABI_O_RDONLY as a safe fallback. |
| int TranslatePepperFileReadWriteOpenFlags(int32_t pp_open_flags) { |
| bool read = (pp_open_flags & PP_FILEOPENFLAG_READ) != 0; |
| bool write = (pp_open_flags & PP_FILEOPENFLAG_WRITE) != 0; |
| bool append = (pp_open_flags & PP_FILEOPENFLAG_APPEND) != 0; |
| |
| int nacl_open_flag = NACL_ABI_O_RDONLY; // NACL_ABI_O_RDONLY == 0. |
| if (read && (write || append)) { |
| nacl_open_flag = NACL_ABI_O_RDWR; |
| } else if (write || append) { |
| nacl_open_flag = NACL_ABI_O_WRONLY; |
| } else if (!read) { |
| DLOG(WARNING) << "One of PP_FILEOPENFLAG_READ, PP_FILEOPENFLAG_WRITE, " |
| << "or PP_FILEOPENFLAG_APPEND should be set."; |
| } |
| if (append) |
| nacl_open_flag |= NACL_ABI_O_APPEND; |
| |
| return nacl_open_flag; |
| } |
| |
| class NaClDescWrapper { |
| public: |
| explicit NaClDescWrapper(NaClDesc* desc): desc_(desc) {} |
| ~NaClDescWrapper() { |
| NaClDescUnref(desc_); |
| } |
| |
| NaClDesc* desc() { return desc_; } |
| |
| private: |
| NaClDesc* desc_; |
| DISALLOW_COPY_AND_ASSIGN(NaClDescWrapper); |
| }; |
| |
| } // namespace |
| |
| class NaClIPCAdapter::RewrittenMessage |
| : public base::RefCounted<RewrittenMessage> { |
| public: |
| RewrittenMessage(); |
| |
| bool is_consumed() const { return data_read_cursor_ == data_len_; } |
| |
| void SetData(const NaClIPCAdapter::NaClMessageHeader& header, |
| const void* payload, size_t payload_length); |
| |
| int Read(NaClImcTypedMsgHdr* msg); |
| |
| void AddDescriptor(NaClDescWrapper* desc) { descs_.push_back(desc); } |
| |
| size_t desc_count() const { return descs_.size(); } |
| |
| private: |
| friend class base::RefCounted<RewrittenMessage>; |
| ~RewrittenMessage() {} |
| |
| scoped_ptr<char[]> data_; |
| size_t data_len_; |
| |
| // Offset into data where the next read will happen. This will be equal to |
| // data_len_ when all data has been consumed. |
| size_t data_read_cursor_; |
| |
| // Wrapped descriptors for transfer to untrusted code. |
| ScopedVector<NaClDescWrapper> descs_; |
| }; |
| |
| NaClIPCAdapter::RewrittenMessage::RewrittenMessage() |
| : data_len_(0), |
| data_read_cursor_(0) { |
| } |
| |
| void NaClIPCAdapter::RewrittenMessage::SetData( |
| const NaClIPCAdapter::NaClMessageHeader& header, |
| const void* payload, |
| size_t payload_length) { |
| DCHECK(!data_.get() && data_len_ == 0); |
| size_t header_len = sizeof(NaClIPCAdapter::NaClMessageHeader); |
| data_len_ = header_len + payload_length; |
| data_.reset(new char[data_len_]); |
| |
| memcpy(data_.get(), &header, sizeof(NaClIPCAdapter::NaClMessageHeader)); |
| memcpy(&data_[header_len], payload, payload_length); |
| } |
| |
| int NaClIPCAdapter::RewrittenMessage::Read(NaClImcTypedMsgHdr* msg) { |
| CHECK(data_len_ >= data_read_cursor_); |
| char* dest_buffer = static_cast<char*>(msg->iov[0].base); |
| size_t dest_buffer_size = msg->iov[0].length; |
| size_t bytes_to_write = std::min(dest_buffer_size, |
| data_len_ - data_read_cursor_); |
| if (bytes_to_write == 0) |
| return 0; |
| |
| memcpy(dest_buffer, &data_[data_read_cursor_], bytes_to_write); |
| data_read_cursor_ += bytes_to_write; |
| |
| // Once all data has been consumed, transfer any file descriptors. |
| if (is_consumed()) { |
| nacl_abi_size_t desc_count = static_cast<nacl_abi_size_t>(descs_.size()); |
| CHECK(desc_count <= msg->ndesc_length); |
| msg->ndesc_length = desc_count; |
| for (nacl_abi_size_t i = 0; i < desc_count; i++) { |
| // Copy the NaClDesc to the buffer and add a ref so it won't be freed |
| // when we clear our ScopedVector. |
| msg->ndescv[i] = descs_[i]->desc(); |
| NaClDescRef(descs_[i]->desc()); |
| } |
| descs_.clear(); |
| } else { |
| msg->ndesc_length = 0; |
| } |
| return static_cast<int>(bytes_to_write); |
| } |
| |
| NaClIPCAdapter::LockedData::LockedData() |
| : channel_closed_(false) { |
| } |
| |
| NaClIPCAdapter::LockedData::~LockedData() { |
| } |
| |
| NaClIPCAdapter::IOThreadData::IOThreadData() { |
| } |
| |
| NaClIPCAdapter::IOThreadData::~IOThreadData() { |
| } |
| |
| NaClIPCAdapter::NaClIPCAdapter(const IPC::ChannelHandle& handle, |
| base::TaskRunner* runner) |
| : lock_(), |
| cond_var_(&lock_), |
| task_runner_(runner), |
| locked_data_() { |
| io_thread_data_.channel_.reset( |
| new IPC::Channel(handle, IPC::Channel::MODE_SERVER, this)); |
| // Note, we can not PostTask for ConnectChannelOnIOThread here. If we did, |
| // and that task ran before this constructor completes, the reference count |
| // would go to 1 and then to 0 because of the Task, before we've been returned |
| // to the owning scoped_refptr, which is supposed to give us our first |
| // ref-count. |
| } |
| |
| NaClIPCAdapter::NaClIPCAdapter(scoped_ptr<IPC::Channel> channel, |
| base::TaskRunner* runner) |
| : lock_(), |
| cond_var_(&lock_), |
| task_runner_(runner), |
| locked_data_() { |
| io_thread_data_.channel_ = channel.Pass(); |
| } |
| |
| void NaClIPCAdapter::ConnectChannel() { |
| task_runner_->PostTask(FROM_HERE, |
| base::Bind(&NaClIPCAdapter::ConnectChannelOnIOThread, this)); |
| } |
| |
| // Note that this message is controlled by the untrusted code. So we should be |
| // skeptical of anything it contains and quick to give up if anything is fishy. |
| int NaClIPCAdapter::Send(const NaClImcTypedMsgHdr* msg) { |
| if (msg->iov_length != 1) |
| return -1; |
| |
| base::AutoLock lock(lock_); |
| |
| const char* input_data = static_cast<char*>(msg->iov[0].base); |
| size_t input_data_len = msg->iov[0].length; |
| if (input_data_len > IPC::Channel::kMaximumMessageSize) { |
| ClearToBeSent(); |
| return -1; |
| } |
| |
| // current_message[_len] refers to the total input data received so far. |
| const char* current_message; |
| size_t current_message_len; |
| bool did_append_input_data; |
| if (locked_data_.to_be_sent_.empty()) { |
| // No accumulated data, we can avoid a copy by referring to the input |
| // buffer (the entire message fitting in one call is the common case). |
| current_message = input_data; |
| current_message_len = input_data_len; |
| did_append_input_data = false; |
| } else { |
| // We've already accumulated some data, accumulate this new data and |
| // point to the beginning of the buffer. |
| |
| // Make sure our accumulated message size doesn't overflow our max. Since |
| // we know that data_len < max size (checked above) and our current |
| // accumulated value is also < max size, we just need to make sure that |
| // 2x max size can never overflow. |
| COMPILE_ASSERT(IPC::Channel::kMaximumMessageSize < (UINT_MAX / 2), |
| MaximumMessageSizeWillOverflow); |
| size_t new_size = locked_data_.to_be_sent_.size() + input_data_len; |
| if (new_size > IPC::Channel::kMaximumMessageSize) { |
| ClearToBeSent(); |
| return -1; |
| } |
| |
| locked_data_.to_be_sent_.append(input_data, input_data_len); |
| current_message = &locked_data_.to_be_sent_[0]; |
| current_message_len = locked_data_.to_be_sent_.size(); |
| did_append_input_data = true; |
| } |
| |
| // Check the total data we've accumulated so far to see if it contains a full |
| // message. |
| switch (GetBufferStatus(current_message, current_message_len)) { |
| case MESSAGE_IS_COMPLETE: { |
| // Got a complete message, can send it out. This will be the common case. |
| bool success = SendCompleteMessage(current_message, current_message_len); |
| ClearToBeSent(); |
| return success ? static_cast<int>(input_data_len) : -1; |
| } |
| case MESSAGE_IS_TRUNCATED: |
| // For truncated messages, just accumulate the new data (if we didn't |
| // already do so above) and go back to waiting for more. |
| if (!did_append_input_data) |
| locked_data_.to_be_sent_.append(input_data, input_data_len); |
| return static_cast<int>(input_data_len); |
| case MESSAGE_HAS_EXTRA_DATA: |
| default: |
| // When the plugin gives us too much data, it's an error. |
| ClearToBeSent(); |
| return -1; |
| } |
| } |
| |
| int NaClIPCAdapter::BlockingReceive(NaClImcTypedMsgHdr* msg) { |
| if (msg->iov_length != 1) |
| return -1; |
| |
| int retval = 0; |
| { |
| base::AutoLock lock(lock_); |
| while (locked_data_.to_be_received_.empty() && |
| !locked_data_.channel_closed_) |
| cond_var_.Wait(); |
| if (locked_data_.channel_closed_) { |
| retval = -1; |
| } else { |
| retval = LockedReceive(msg); |
| DCHECK(retval > 0); |
| } |
| } |
| cond_var_.Signal(); |
| return retval; |
| } |
| |
| void NaClIPCAdapter::CloseChannel() { |
| { |
| base::AutoLock lock(lock_); |
| locked_data_.channel_closed_ = true; |
| } |
| cond_var_.Signal(); |
| |
| task_runner_->PostTask(FROM_HERE, |
| base::Bind(&NaClIPCAdapter::CloseChannelOnIOThread, this)); |
| } |
| |
| NaClDesc* NaClIPCAdapter::MakeNaClDesc() { |
| return MakeNaClDescCustom(this); |
| } |
| |
| #if defined(OS_POSIX) |
| int NaClIPCAdapter::TakeClientFileDescriptor() { |
| return io_thread_data_.channel_->TakeClientFileDescriptor(); |
| } |
| #endif |
| |
| bool NaClIPCAdapter::OnMessageReceived(const IPC::Message& msg) { |
| { |
| base::AutoLock lock(lock_); |
| |
| scoped_refptr<RewrittenMessage> rewritten_msg(new RewrittenMessage); |
| |
| typedef std::vector<ppapi::proxy::SerializedHandle> Handles; |
| Handles handles; |
| scoped_ptr<IPC::Message> new_msg_ptr; |
| bool success = locked_data_.handle_converter_.ConvertNativeHandlesToPosix( |
| msg, &handles, &new_msg_ptr); |
| if (!success) |
| return false; |
| |
| // Now add any descriptors we found to rewritten_msg. |handles| is usually |
| // empty, unless we read a message containing a FD or handle. |
| for (Handles::const_iterator iter = handles.begin(); |
| iter != handles.end(); |
| ++iter) { |
| scoped_ptr<NaClDescWrapper> nacl_desc; |
| switch (iter->type()) { |
| case ppapi::proxy::SerializedHandle::SHARED_MEMORY: { |
| const base::SharedMemoryHandle& shm_handle = iter->shmem(); |
| uint32_t size = iter->size(); |
| nacl_desc.reset(new NaClDescWrapper(NaClDescImcShmMake( |
| #if defined(OS_WIN) |
| shm_handle, |
| #else |
| shm_handle.fd, |
| #endif |
| static_cast<size_t>(size)))); |
| break; |
| } |
| case ppapi::proxy::SerializedHandle::SOCKET: { |
| nacl_desc.reset(new NaClDescWrapper(NaClDescSyncSocketMake( |
| #if defined(OS_WIN) |
| iter->descriptor() |
| #else |
| iter->descriptor().fd |
| #endif |
| ))); |
| break; |
| } |
| case ppapi::proxy::SerializedHandle::CHANNEL_HANDLE: { |
| // Check that this came from a PpapiMsg_CreateNaClChannel message. |
| // This code here is only appropriate for that message. |
| DCHECK(msg.type() == PpapiMsg_CreateNaClChannel::ID); |
| IPC::ChannelHandle channel_handle = |
| IPC::Channel::GenerateVerifiedChannelID("nacl"); |
| scoped_refptr<NaClIPCAdapter> ipc_adapter( |
| new NaClIPCAdapter(channel_handle, task_runner_.get())); |
| ipc_adapter->ConnectChannel(); |
| #if defined(OS_POSIX) |
| channel_handle.socket = base::FileDescriptor( |
| ipc_adapter->TakeClientFileDescriptor(), true); |
| #endif |
| nacl_desc.reset(new NaClDescWrapper(ipc_adapter->MakeNaClDesc())); |
| // Send back a message that the channel was created. |
| scoped_ptr<IPC::Message> response( |
| new PpapiHostMsg_ChannelCreated(channel_handle)); |
| task_runner_->PostTask(FROM_HERE, |
| base::Bind(&NaClIPCAdapter::SendMessageOnIOThread, this, |
| base::Passed(&response))); |
| break; |
| } |
| case ppapi::proxy::SerializedHandle::FILE: |
| // IMPORTANT: The NaClDescIoDescFromHandleAllocCtor function creates |
| // a NaClDesc that checks file flags before reading and writing. This |
| // is essential since PPB_FileIO now sends a file descriptor to the |
| // plugin which may have write capabilities. We can't allow the plugin |
| // to write with it since it could bypass quota checks, which still |
| // happen in the host. |
| nacl_desc.reset(new NaClDescWrapper(NaClDescIoDescFromHandleAllocCtor( |
| #if defined(OS_WIN) |
| iter->descriptor(), |
| #else |
| iter->descriptor().fd, |
| #endif |
| TranslatePepperFileReadWriteOpenFlags(iter->open_flag())))); |
| break; |
| case ppapi::proxy::SerializedHandle::INVALID: { |
| // Nothing to do. TODO(dmichael): Should we log this? Or is it |
| // sometimes okay to pass an INVALID handle? |
| break; |
| } |
| // No default, so the compiler will warn us if new types get added. |
| } |
| if (nacl_desc.get()) |
| rewritten_msg->AddDescriptor(nacl_desc.release()); |
| } |
| if (new_msg_ptr && !handles.empty()) |
| SaveMessage(*new_msg_ptr, rewritten_msg.get()); |
| else |
| SaveMessage(msg, rewritten_msg.get()); |
| } |
| cond_var_.Signal(); |
| return true; |
| } |
| |
| void NaClIPCAdapter::OnChannelConnected(int32 peer_pid) { |
| } |
| |
| void NaClIPCAdapter::OnChannelError() { |
| CloseChannel(); |
| } |
| |
| NaClIPCAdapter::~NaClIPCAdapter() { |
| // Make sure the channel is deleted on the IO thread. |
| task_runner_->PostTask(FROM_HERE, |
| base::Bind(&DeleteChannel, io_thread_data_.channel_.release())); |
| } |
| |
| int NaClIPCAdapter::LockedReceive(NaClImcTypedMsgHdr* msg) { |
| lock_.AssertAcquired(); |
| |
| if (locked_data_.to_be_received_.empty()) |
| return 0; |
| scoped_refptr<RewrittenMessage> current = |
| locked_data_.to_be_received_.front(); |
| |
| int retval = current->Read(msg); |
| |
| // When a message is entirely consumed, remove if from the waiting queue. |
| if (current->is_consumed()) |
| locked_data_.to_be_received_.pop(); |
| |
| return retval; |
| } |
| |
| bool NaClIPCAdapter::SendCompleteMessage(const char* buffer, |
| size_t buffer_len) { |
| lock_.AssertAcquired(); |
| // The message will have already been validated, so we know it's large enough |
| // for our header. |
| const NaClMessageHeader* header = |
| reinterpret_cast<const NaClMessageHeader*>(buffer); |
| |
| // Length of the message not including the body. The data passed to us by the |
| // plugin should match that in the message header. This should have already |
| // been validated by GetBufferStatus. |
| int body_len = static_cast<int>(buffer_len - sizeof(NaClMessageHeader)); |
| DCHECK(body_len == static_cast<int>(header->payload_size)); |
| |
| // We actually discard the flags and only copy the ones we care about. This |
| // is just because message doesn't have a constructor that takes raw flags. |
| scoped_ptr<IPC::Message> msg( |
| new IPC::Message(header->routing, header->type, |
| IPC::Message::PRIORITY_NORMAL)); |
| if (header->flags & IPC::Message::SYNC_BIT) |
| msg->set_sync(); |
| if (header->flags & IPC::Message::REPLY_BIT) |
| msg->set_reply(); |
| if (header->flags & IPC::Message::REPLY_ERROR_BIT) |
| msg->set_reply_error(); |
| if (header->flags & IPC::Message::UNBLOCK_BIT) |
| msg->set_unblock(true); |
| |
| msg->WriteBytes(&buffer[sizeof(NaClMessageHeader)], body_len); |
| |
| // Technically we didn't have to do any of the previous work in the lock. But |
| // sometimes our buffer will point to the to_be_sent_ string which is |
| // protected by the lock, and it's messier to factor Send() such that it can |
| // unlock for us. Holding the lock for the message construction, which is |
| // just some memcpys, shouldn't be a big deal. |
| lock_.AssertAcquired(); |
| if (locked_data_.channel_closed_) |
| return false; // TODO(brettw) clean up handles here when we add support! |
| |
| if (msg->is_sync()) { |
| locked_data_.handle_converter_.RegisterSyncMessageForReply(*msg); |
| } |
| // Actual send must be done on the I/O thread. |
| task_runner_->PostTask(FROM_HERE, |
| base::Bind(&NaClIPCAdapter::SendMessageOnIOThread, this, |
| base::Passed(&msg))); |
| return true; |
| } |
| |
| void NaClIPCAdapter::ClearToBeSent() { |
| lock_.AssertAcquired(); |
| |
| // Don't let the string keep its buffer behind our back. |
| std::string empty; |
| locked_data_.to_be_sent_.swap(empty); |
| } |
| |
| void NaClIPCAdapter::ConnectChannelOnIOThread() { |
| if (!io_thread_data_.channel_->Connect()) |
| NOTREACHED(); |
| } |
| |
| void NaClIPCAdapter::CloseChannelOnIOThread() { |
| io_thread_data_.channel_->Close(); |
| } |
| |
| void NaClIPCAdapter::SendMessageOnIOThread(scoped_ptr<IPC::Message> message) { |
| io_thread_data_.channel_->Send(message.release()); |
| } |
| |
| void NaClIPCAdapter::SaveMessage(const IPC::Message& msg, |
| RewrittenMessage* rewritten_msg) { |
| lock_.AssertAcquired(); |
| // There is some padding in this structure (the "padding" member is 16 |
| // bits but this then gets padded to 32 bits). We want to be sure not to |
| // leak data to the untrusted plugin, so zero everything out first. |
| NaClMessageHeader header; |
| memset(&header, 0, sizeof(NaClMessageHeader)); |
| |
| header.payload_size = static_cast<uint32>(msg.payload_size()); |
| header.routing = msg.routing_id(); |
| header.type = msg.type(); |
| header.flags = msg.flags(); |
| header.num_fds = static_cast<int>(rewritten_msg->desc_count()); |
| |
| rewritten_msg->SetData(header, msg.payload(), msg.payload_size()); |
| locked_data_.to_be_received_.push(rewritten_msg); |
| } |
| |
| int TranslatePepperFileReadWriteOpenFlagsForTesting(int32_t pp_open_flags) { |
| return TranslatePepperFileReadWriteOpenFlags(pp_open_flags); |
| } |