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..4c5f8bb1a7691c834979b0f24bfe45b81bcd967f
--- /dev/null
+++ b/remoting/host/gnubby_socket.cc
@@ -0,0 +1,102 @@
+// 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"
+
+namespace remoting {
+
+namespace {
+
+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());
+

[Sergey Ulanov, 2014/03/21 02:09:37]

Add DCHECK(IsRequestComplete() && !IsRequestTooLarge())?

[psj, 2014/03/21 21:30:45]

Done.

+  // The first four bytes are not part of the request and need to be stripped.
+  data_out->assign(request_data_.data() + 4, request_data_.size() - 4);

[Sergey Ulanov, 2014/03/21 02:09:37]

define a const for 4, e.g. kRequestSizeBytes

[Sergey Ulanov, 2014/03/21 02:09:37]

You can replace the last parameter with request_data_.end(), then you wouldn't
need '-4'.

[psj, 2014/03/21 21:30:45]

Done.

[psj, 2014/03/21 21:30:45]

Done.

+  request_data_.clear();
+}
+
+bool GnubbySocket::IsRequestComplete() const {
+  DCHECK(CalledOnValidThread());
+
+  if (request_data_.size() < 4)

[Sergey Ulanov, 2014/03/21 02:09:37]

define a const for 4, e.g. kRequestSizeBytes

[psj, 2014/03/21 21:30:45]

Done.

+    return false;
+  return GetRequestLength() <= request_data_.size();
+}
+
+bool GnubbySocket::IsRequestTooLarge() const {
+  DCHECK(CalledOnValidThread());
+
+  if (request_data_.size() < 4)
+    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, sizeof(kSshError) / sizeof(*kSshError));

[Sergey Ulanov, 2014/03/21 02:09:37]

Use arraysize() from base/macros.h

[psj, 2014/03/21 21:30:45]

Done.

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

[Sergey Ulanov, 2014/03/21 02:09:37]

DCHECK that there are at least 4 bytes in |request_data_|

[psj, 2014/03/21 21:30:45]

Done.

+         ((request_data_[2] & 255) << 8) + (request_data_[3] & 255) + 4;
+}
+
+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(); }

[Sergey Ulanov, 2014/03/21 02:09:37]

move the body to a separate line

[psj, 2014/03/21 21:30:45]

Done. clang_format put it on one line...

+
+}  // namespace remoting