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// Copyright (c) 2012 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 "ipc/ipc_channel_reader.h"
#include <algorithm>
#include "ipc/ipc_listener.h"
#include "ipc/ipc_logging.h"
#include "ipc/ipc_message.h"
#include "ipc/ipc_message_attachment_set.h"
#include "ipc/ipc_message_macros.h"
namespace IPC {
namespace internal {
ChannelReader::ChannelReader(Listener* listener) : listener_(listener) {
memset(input_buf_, 0, sizeof(input_buf_));
}
ChannelReader::~ChannelReader() {
DCHECK(blocked_ids_.empty());
}
ChannelReader::DispatchState ChannelReader::ProcessIncomingMessages() {
while (true) {
int bytes_read = 0;
ReadState read_state = ReadData(input_buf_, Channel::kReadBufferSize,
&bytes_read);
if (read_state == READ_FAILED)
return DISPATCH_ERROR;
if (read_state == READ_PENDING)
return DISPATCH_FINISHED;
DCHECK(bytes_read > 0);
if (!TranslateInputData(input_buf_, bytes_read))
return DISPATCH_ERROR;
DispatchState state = DispatchMessages();
if (state != DISPATCH_FINISHED)
return state;
}
}
ChannelReader::DispatchState ChannelReader::AsyncReadComplete(int bytes_read) {
if (!TranslateInputData(input_buf_, bytes_read))
return DISPATCH_ERROR;
return DispatchMessages();
}
bool ChannelReader::IsInternalMessage(const Message& m) {
return m.routing_id() == MSG_ROUTING_NONE &&
m.type() >= Channel::CLOSE_FD_MESSAGE_TYPE &&
m.type() <= Channel::HELLO_MESSAGE_TYPE;
}
bool ChannelReader::IsHelloMessage(const Message& m) {
return m.routing_id() == MSG_ROUTING_NONE &&
m.type() == Channel::HELLO_MESSAGE_TYPE;
}
void ChannelReader::CleanUp() {
if (!blocked_ids_.empty()) {
StopObservingAttachmentBroker();
blocked_ids_.clear();
}
}
bool ChannelReader::TranslateInputData(const char* input_data,
int input_data_len) {
const char* p;
const char* end;
// Possibly combine with the overflow buffer to make a larger buffer.
if (input_overflow_buf_.empty()) {
p = input_data;
end = input_data + input_data_len;
} else {
if (input_overflow_buf_.size() + input_data_len >
Channel::kMaximumMessageSize) {
input_overflow_buf_.clear();
LOG(ERROR) << "IPC message is too big";
return false;
}
input_overflow_buf_.append(input_data, input_data_len);
p = input_overflow_buf_.data();
end = p + input_overflow_buf_.size();
}
// Dispatch all complete messages in the data buffer.
while (p < end) {
Message::NextMessageInfo info;
Message::FindNext(p, end, &info);
if (info.message_found) {
int pickle_len = static_cast<int>(info.pickle_end - p);
Message translated_message(p, pickle_len);
for (const auto& id : info.attachment_ids)
translated_message.AddPlaceholderBrokerableAttachmentWithId(id);
if (!GetNonBrokeredAttachments(&translated_message))
return false;
// If there are no queued messages, attempt to immediately dispatch the
// newly translated message.
if (queued_messages_.empty()) {
DCHECK(blocked_ids_.empty());
AttachmentIdSet blocked_ids =
GetBrokeredAttachments(&translated_message);
if (blocked_ids.empty()) {
// Dispatch the message and continue the loop.
DispatchMessage(&translated_message);
p = info.message_end;
continue;
}
blocked_ids_.swap(blocked_ids);
StartObservingAttachmentBroker();
}
// Make a deep copy of |translated_message| to add to the queue.
scoped_ptr<Message> m(new Message(translated_message));
queued_messages_.push_back(m.release());
p = info.message_end;
} else {
// Last message is partial.
break;
}
}
// Save any partial data in the overflow buffer.
input_overflow_buf_.assign(p, end - p);
if (input_overflow_buf_.empty() && !DidEmptyInputBuffers())
return false;
return true;
}
ChannelReader::DispatchState ChannelReader::DispatchMessages() {
while (!queued_messages_.empty()) {
if (!blocked_ids_.empty())
return DISPATCH_WAITING_ON_BROKER;
Message* m = queued_messages_.front();
AttachmentIdSet blocked_ids = GetBrokeredAttachments(m);
if (!blocked_ids.empty()) {
blocked_ids_.swap(blocked_ids);
StartObservingAttachmentBroker();
return DISPATCH_WAITING_ON_BROKER;
}
DispatchMessage(m);
queued_messages_.erase(queued_messages_.begin());
}
return DISPATCH_FINISHED;
}
void ChannelReader::DispatchMessage(Message* m) {
m->set_sender_pid(GetSenderPID());
#ifdef IPC_MESSAGE_LOG_ENABLED
std::string name;
Logging::GetInstance()->GetMessageText(m->type(), &name, m, NULL);
TRACE_EVENT_WITH_FLOW1("ipc,toplevel",
"ChannelReader::DispatchInputData",
m->flags(),
TRACE_EVENT_FLAG_FLOW_IN,
"name", name);
#else
TRACE_EVENT_WITH_FLOW2("ipc,toplevel",
"ChannelReader::DispatchInputData",
m->flags(),
TRACE_EVENT_FLAG_FLOW_IN,
"class", IPC_MESSAGE_ID_CLASS(m->type()),
"line", IPC_MESSAGE_ID_LINE(m->type()));
#endif
bool handled = false;
if (IsInternalMessage(*m)) {
HandleInternalMessage(*m);
handled = true;
}
#if USE_ATTACHMENT_BROKER
if (!handled && IsAttachmentBrokerEndpoint() && GetAttachmentBroker()) {
handled = GetAttachmentBroker()->OnMessageReceived(*m);
}
#endif // USE_ATTACHMENT_BROKER
if (!handled)
listener_->OnMessageReceived(*m);
if (m->dispatch_error())
listener_->OnBadMessageReceived(*m);
}
ChannelReader::AttachmentIdSet ChannelReader::GetBrokeredAttachments(
Message* msg) {
std::set<BrokerableAttachment::AttachmentId> blocked_ids;
#if USE_ATTACHMENT_BROKER
MessageAttachmentSet* set = msg->attachment_set();
std::vector<const BrokerableAttachment*> brokerable_attachments_copy =
set->PeekBrokerableAttachments();
for (const BrokerableAttachment* attachment : brokerable_attachments_copy) {
if (attachment->NeedsBrokering()) {
AttachmentBroker* broker = GetAttachmentBroker();
scoped_refptr<BrokerableAttachment> brokered_attachment;
bool result = broker->GetAttachmentWithId(attachment->GetIdentifier(),
&brokered_attachment);
if (!result) {
blocked_ids.insert(attachment->GetIdentifier());
continue;
}
set->ReplacePlaceholderWithAttachment(brokered_attachment);
}
}
#endif // USE_ATTACHMENT_BROKER
return blocked_ids;
}
void ChannelReader::ReceivedBrokerableAttachmentWithId(
const BrokerableAttachment::AttachmentId& id) {
if (blocked_ids_.empty())
return;
auto it = find(blocked_ids_.begin(), blocked_ids_.end(), id);
if (it != blocked_ids_.end())
blocked_ids_.erase(it);
if (blocked_ids_.empty()) {
StopObservingAttachmentBroker();
DispatchMessages();
}
}
void ChannelReader::StartObservingAttachmentBroker() {
#if USE_ATTACHMENT_BROKER
GetAttachmentBroker()->AddObserver(this);
#endif // USE_ATTACHMENT_BROKER
}
void ChannelReader::StopObservingAttachmentBroker() {
#if USE_ATTACHMENT_BROKER
GetAttachmentBroker()->RemoveObserver(this);
#endif // USE_ATTACHMENT_BROKER
}
} // namespace internal
} // namespace IPC
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