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// Copyright 2016 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/security_key/gnubby_socket.h"
#include <utility>
#include "base/callback_helpers.h"
#include "base/macros.h"
#include "base/timer/timer.h"
#include "net/base/io_buffer.h"
#include "net/base/net_errors.h"
#include "net/socket/stream_socket.h"
namespace remoting {
namespace {
const size_t kRequestSizeBytes = 4;
const size_t kMaxRequestLength = 16384;
const size_t kRequestReadBufferLength = kRequestSizeBytes + kMaxRequestLength;
// SSH Failure Code
const char kSshError[] = {0x05};
} // namespace
GnubbySocket::GnubbySocket(scoped_ptr<net::StreamSocket> socket,
base::TimeDelta timeout,
const base::Closure& timeout_callback)
: socket_(std::move(socket)),
read_completed_(false),
read_buffer_(new net::IOBufferWithSize(kRequestReadBufferLength)) {
timer_.reset(new base::Timer(false, false));
timer_->Start(FROM_HERE, timeout, timeout_callback);
}
GnubbySocket::~GnubbySocket() {}
bool GnubbySocket::GetAndClearRequestData(std::string* data_out) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(read_completed_);
if (!read_completed_)
return false;
if (!IsRequestComplete() || IsRequestTooLarge())
return false;
// 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();
return true;
}
void GnubbySocket::SendResponse(const std::string& response_data) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(!write_buffer_);
std::string response_length_string = GetResponseLengthAsBytes(response_data);
int response_len = response_length_string.size() + response_data.size();
scoped_ptr<std::string> response(
new std::string(response_length_string + response_data));
write_buffer_ = new net::DrainableIOBuffer(
new net::StringIOBuffer(std::move(response)), response_len);
DoWrite();
}
void GnubbySocket::SendSshError() {
DCHECK(thread_checker_.CalledOnValidThread());
SendResponse(std::string(kSshError, arraysize(kSshError)));
}
void GnubbySocket::StartReadingRequest(
const base::Closure& request_received_callback) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(request_received_callback_.is_null());
request_received_callback_ = request_received_callback;
DoRead();
}
void GnubbySocket::OnDataWritten(int result) {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(write_buffer_);
if (result < 0) {
LOG(ERROR) << "Error sending response: " << result;
return;
}
ResetTimer();
write_buffer_->DidConsume(result);
DoWrite();
}
void GnubbySocket::DoWrite() {
DCHECK(thread_checker_.CalledOnValidThread());
DCHECK(write_buffer_);
if (!write_buffer_->BytesRemaining()) {
write_buffer_ = nullptr;
return;
}
int result = socket_->Write(
write_buffer_.get(), write_buffer_->BytesRemaining(),
base::Bind(&GnubbySocket::OnDataWritten, base::Unretained(this)));
if (result != net::ERR_IO_PENDING)
OnDataWritten(result);
}
void GnubbySocket::OnDataRead(int result) {
DCHECK(thread_checker_.CalledOnValidThread());
if (result <= 0) {
if (result < 0)
LOG(ERROR) << "Error reading request: " << result;
read_completed_ = true;
base::ResetAndReturn(&request_received_callback_).Run();
return;
}
ResetTimer();
request_data_.insert(request_data_.end(), read_buffer_->data(),
read_buffer_->data() + result);
if (IsRequestComplete()) {
read_completed_ = true;
base::ResetAndReturn(&request_received_callback_).Run();
return;
}
DoRead();
}
void GnubbySocket::DoRead() {
DCHECK(thread_checker_.CalledOnValidThread());
int result = socket_->Read(
read_buffer_.get(), kRequestReadBufferLength,
base::Bind(&GnubbySocket::OnDataRead, base::Unretained(this)));
if (result != net::ERR_IO_PENDING)
OnDataRead(result);
}
bool GnubbySocket::IsRequestComplete() const {
DCHECK(thread_checker_.CalledOnValidThread());
if (request_data_.size() < kRequestSizeBytes)
return false;
return GetRequestLength() <= request_data_.size();
}
bool GnubbySocket::IsRequestTooLarge() const {
DCHECK(thread_checker_.CalledOnValidThread());
if (request_data_.size() < kRequestSizeBytes)
return false;
return GetRequestLength() > kMaxRequestLength;
}
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) +
kRequestSizeBytes;
}
std::string GnubbySocket::GetResponseLengthAsBytes(
const std::string& response) const {
std::string response_len;
response_len.reserve(kRequestSizeBytes);
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() {
if (timer_->IsRunning())
timer_->Reset();
}
} // namespace remoting
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