Do minimal processing of gnubby data. Add request timeouts and send error

remoting/host/gnubby_socket.cc

Index: remoting/host/gnubby_socket.cc
diff --git a/remoting/host/gnubby_socket.cc b/remoting/host/gnubby_socket.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0337b61de01f156c2e73a2cfabf724ce3bdf5266
--- /dev/null
+++ b/remoting/host/gnubby_socket.cc
@@ -0,0 +1,111 @@
+// Copyright 2014 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 "remoting/host/gnubby_socket.h"
+
+#include "base/macros.h"
+
+namespace remoting {
+
+namespace {
+
+const size_t kRequestSizeBytes = 4;
+const size_t kMaxRequestLength = 16384;
+const unsigned int kRequestTimeoutSeconds = 60;
+
+// Length-prefixed SSH Failure Code
+const char kSshError[] = {0x00, 0x00, 0x00, 0x01, 0x05};
+
+}  // namespace
+
+GnubbySocket::GnubbySocket(scoped_ptr<net::StreamListenSocket> socket,
+                           const base::Closure& timeout_callback)
+    : socket_(socket.Pass()) {
+  timer_.reset(new base::Timer(false, false));
+  timer_->Start(FROM_HERE,
+                base::TimeDelta::FromSeconds(kRequestTimeoutSeconds),
+                timeout_callback);
+}
+
+void GnubbySocket::AddRequestData(const char* data, int data_len) {
+  DCHECK(CalledOnValidThread());
+
+  request_data_.insert(request_data_.end(), data, data + data_len);
+  ResetTimer();
+}
+
+void GnubbySocket::GetAndClearRequestData(std::string* data_out) {
+  DCHECK(CalledOnValidThread());
+  DCHECK(IsRequestComplete() && !IsRequestTooLarge());
+
+  // The request size is not part of the data; don't send it.
+  data_out->assign(request_data_.begin() + kRequestSizeBytes,
+                   request_data_.end());
+  request_data_.clear();
+}
+
+bool GnubbySocket::IsRequestComplete() const {
+  DCHECK(CalledOnValidThread());
+
+  if (request_data_.size() < kRequestSizeBytes)
+    return false;
+  return GetRequestLength() <= request_data_.size();
+}
+
+bool GnubbySocket::IsRequestTooLarge() const {
+  DCHECK(CalledOnValidThread());
+
+  if (request_data_.size() < kRequestSizeBytes)
+    return false;
+  return GetRequestLength() > kMaxRequestLength;
+}
+
+void GnubbySocket::SendResponse(const std::string& response_data) {
+  DCHECK(CalledOnValidThread());
+
+  socket_->Send(GetResponseLengthAsBytes(response_data));
+  socket_->Send(response_data);
+  ResetTimer();
+}
+
+void GnubbySocket::SendSshError() {
+  DCHECK(CalledOnValidThread());
+
+  socket_->Send(kSshError, arraysize(kSshError));

[Sergey Ulanov, 2014/03/21 22:53:16]

Can this invoke SendResponse?

[psj, 2014/03/21 23:24:17]

Done.

+}
+
+bool GnubbySocket::IsSocket(net::StreamListenSocket* socket) const {
+  return socket == socket_.get();
+}
+
+void GnubbySocket::SetTimerForTesting(scoped_ptr<base::Timer> timer) {
+  timer->Start(FROM_HERE, timer_->GetCurrentDelay(), timer_->user_task());
+  timer_ = timer.Pass();
+}
+
+size_t GnubbySocket::GetRequestLength() const {
+  DCHECK(request_data_.size() >= kRequestSizeBytes);
+
+  return ((request_data_[0] & 255) << 24) + ((request_data_[1] & 255) << 16) +
+         ((request_data_[2] & 255) << 8) + (request_data_[3] & 255) + 4;

[Sergey Ulanov, 2014/03/21 22:53:16]

+kRequestSizeBytes at the end

[psj, 2014/03/21 23:24:17]

Arggggg, I was sure I had gotten all of the 4's...

+}
+
+std::string GnubbySocket::GetResponseLengthAsBytes(
+    const std::string& response) const {
+  std::string response_len;
+  int len = response.size();
+
+  response_len.push_back((len >> 24) & 255);
+  response_len.push_back((len >> 16) & 255);
+  response_len.push_back((len >> 8) & 255);
+  response_len.push_back(len & 255);
+
+  return response_len;
+}
+
+void GnubbySocket::ResetTimer() {
+  timer_->Reset();
+}
+
+}  // namespace remoting