root/jingle/glue/chrome_async_socket.cc

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DEFINITIONS

This source file includes following definitions.
  1. weak_ptr_factory_
  2. state
  3. error
  4. GetError
  5. IsOpen
  6. DoNonNetError
  7. DoNetError
  8. DoNetErrorFromStatus
  9. Connect
  10. ProcessConnectDone
  11. PostDoRead
  12. DoRead
  13. ProcessReadDone
  14. Read
  15. Write
  16. PostDoWrite
  17. DoWrite
  18. ProcessWriteDone
  19. Close
  20. DoClose
  21. StartTls
  22. ProcessSSLConnectDone

// 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 "jingle/glue/chrome_async_socket.h"

#include <algorithm>
#include <cstdlib>
#include <cstring>

#include "base/basictypes.h"
#include "base/bind.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "jingle/glue/resolving_client_socket_factory.h"
#include "net/base/address_list.h"
#include "net/base/host_port_pair.h"
#include "net/base/io_buffer.h"
#include "net/base/net_util.h"
#include "net/socket/client_socket_handle.h"
#include "net/socket/ssl_client_socket.h"
#include "net/socket/tcp_client_socket.h"
#include "net/ssl/ssl_config_service.h"
#include "third_party/libjingle/source/talk/base/socketaddress.h"

namespace jingle_glue {

ChromeAsyncSocket::ChromeAsyncSocket(
    ResolvingClientSocketFactory* resolving_client_socket_factory,
    size_t read_buf_size,
    size_t write_buf_size)
    : resolving_client_socket_factory_(resolving_client_socket_factory),
      state_(STATE_CLOSED),
      error_(ERROR_NONE),
      net_error_(net::OK),
      read_state_(IDLE),
      read_buf_(new net::IOBufferWithSize(read_buf_size)),
      read_start_(0U),
      read_end_(0U),
      write_state_(IDLE),
      write_buf_(new net::IOBufferWithSize(write_buf_size)),
      write_end_(0U),
      weak_ptr_factory_(this) {
  DCHECK(resolving_client_socket_factory_.get());
  DCHECK_GT(read_buf_size, 0U);
  DCHECK_GT(write_buf_size, 0U);
}

ChromeAsyncSocket::~ChromeAsyncSocket() {}

ChromeAsyncSocket::State ChromeAsyncSocket::state() {
  return state_;
}

ChromeAsyncSocket::Error ChromeAsyncSocket::error() {
  return error_;
}

int ChromeAsyncSocket::GetError() {
  return net_error_;
}

bool ChromeAsyncSocket::IsOpen() const {
  return (state_ == STATE_OPEN) || (state_ == STATE_TLS_OPEN);
}

void ChromeAsyncSocket::DoNonNetError(Error error) {
  DCHECK_NE(error, ERROR_NONE);
  DCHECK_NE(error, ERROR_WINSOCK);
  error_ = error;
  net_error_ = net::OK;
}

void ChromeAsyncSocket::DoNetError(net::Error net_error) {
  error_ = ERROR_WINSOCK;
  net_error_ = net_error;
}

void ChromeAsyncSocket::DoNetErrorFromStatus(int status) {
  DCHECK_LT(status, net::OK);
  DoNetError(static_cast<net::Error>(status));
}

// STATE_CLOSED -> STATE_CONNECTING

bool ChromeAsyncSocket::Connect(const talk_base::SocketAddress& address) {
  if (state_ != STATE_CLOSED) {
    LOG(DFATAL) << "Connect() called on non-closed socket";
    DoNonNetError(ERROR_WRONGSTATE);
    return false;
  }
  if (address.hostname().empty() || address.port() == 0) {
    DoNonNetError(ERROR_DNS);
    return false;
  }

  DCHECK_EQ(state_, buzz::AsyncSocket::STATE_CLOSED);
  DCHECK_EQ(read_state_, IDLE);
  DCHECK_EQ(write_state_, IDLE);

  state_ = STATE_CONNECTING;

  DCHECK(!weak_ptr_factory_.HasWeakPtrs());
  weak_ptr_factory_.InvalidateWeakPtrs();

  net::HostPortPair dest_host_port_pair(address.hostname(), address.port());

  transport_socket_ =
      resolving_client_socket_factory_->CreateTransportClientSocket(
          dest_host_port_pair);
  int status = transport_socket_->Connect(
      base::Bind(&ChromeAsyncSocket::ProcessConnectDone,
                 weak_ptr_factory_.GetWeakPtr()));
  if (status != net::ERR_IO_PENDING) {
    // We defer execution of ProcessConnectDone instead of calling it
    // directly here as the caller may not expect an error/close to
    // happen here.  This is okay, as from the caller's point of view,
    // the connect always happens asynchronously.
    base::MessageLoop* message_loop = base::MessageLoop::current();
    CHECK(message_loop);
    message_loop->PostTask(
        FROM_HERE,
        base::Bind(&ChromeAsyncSocket::ProcessConnectDone,
                   weak_ptr_factory_.GetWeakPtr(), status));
  }
  return true;
}

// STATE_CONNECTING -> STATE_OPEN
// read_state_ == IDLE -> read_state_ == POSTED (via PostDoRead())

void ChromeAsyncSocket::ProcessConnectDone(int status) {
  DCHECK_NE(status, net::ERR_IO_PENDING);
  DCHECK_EQ(read_state_, IDLE);
  DCHECK_EQ(write_state_, IDLE);
  DCHECK_EQ(state_, STATE_CONNECTING);
  if (status != net::OK) {
    DoNetErrorFromStatus(status);
    DoClose();
    return;
  }
  state_ = STATE_OPEN;
  PostDoRead();
  // Write buffer should be empty.
  DCHECK_EQ(write_end_, 0U);
  SignalConnected();
}

// read_state_ == IDLE -> read_state_ == POSTED

void ChromeAsyncSocket::PostDoRead() {
  DCHECK(IsOpen());
  DCHECK_EQ(read_state_, IDLE);
  DCHECK_EQ(read_start_, 0U);
  DCHECK_EQ(read_end_, 0U);
  base::MessageLoop* message_loop = base::MessageLoop::current();
  CHECK(message_loop);
  message_loop->PostTask(
      FROM_HERE,
      base::Bind(&ChromeAsyncSocket::DoRead,
                 weak_ptr_factory_.GetWeakPtr()));
  read_state_ = POSTED;
}

// read_state_ == POSTED -> read_state_ == PENDING

void ChromeAsyncSocket::DoRead() {
  DCHECK(IsOpen());
  DCHECK_EQ(read_state_, POSTED);
  DCHECK_EQ(read_start_, 0U);
  DCHECK_EQ(read_end_, 0U);
  // Once we call Read(), we cannot call StartTls() until the read
  // finishes.  This is okay, as StartTls() is called only from a read
  // handler (i.e., after a read finishes and before another read is
  // done).
  int status =
      transport_socket_->Read(
          read_buf_.get(), read_buf_->size(),
          base::Bind(&ChromeAsyncSocket::ProcessReadDone,
                     weak_ptr_factory_.GetWeakPtr()));
  read_state_ = PENDING;
  if (status != net::ERR_IO_PENDING) {
    ProcessReadDone(status);
  }
}

// read_state_ == PENDING -> read_state_ == IDLE

void ChromeAsyncSocket::ProcessReadDone(int status) {
  DCHECK_NE(status, net::ERR_IO_PENDING);
  DCHECK(IsOpen());
  DCHECK_EQ(read_state_, PENDING);
  DCHECK_EQ(read_start_, 0U);
  DCHECK_EQ(read_end_, 0U);
  read_state_ = IDLE;
  if (status > 0) {
    read_end_ = static_cast<size_t>(status);
    SignalRead();
  } else if (status == 0) {
    // Other side closed the connection.
    error_ = ERROR_NONE;
    net_error_ = net::OK;
    DoClose();
  } else {  // status < 0
    DoNetErrorFromStatus(status);
    DoClose();
  }
}

// (maybe) read_state_ == IDLE -> read_state_ == POSTED (via
// PostDoRead())

bool ChromeAsyncSocket::Read(char* data, size_t len, size_t* len_read) {
  if (!IsOpen() && (state_ != STATE_TLS_CONNECTING)) {
    // Read() may be called on a closed socket if a previous read
    // causes a socket close (e.g., client sends wrong password and
    // server terminates connection).
    //
    // TODO(akalin): Fix handling of this on the libjingle side.
    if (state_ != STATE_CLOSED) {
      LOG(DFATAL) << "Read() called on non-open non-tls-connecting socket";
    }
    DoNonNetError(ERROR_WRONGSTATE);
    return false;
  }
  DCHECK_LE(read_start_, read_end_);
  if ((state_ == STATE_TLS_CONNECTING) || read_end_ == 0U) {
    if (state_ == STATE_TLS_CONNECTING) {
      DCHECK_EQ(read_state_, IDLE);
      DCHECK_EQ(read_end_, 0U);
    } else {
      DCHECK_NE(read_state_, IDLE);
    }
    *len_read = 0;
    return true;
  }
  DCHECK_EQ(read_state_, IDLE);
  *len_read = std::min(len, read_end_ - read_start_);
  DCHECK_GT(*len_read, 0U);
  std::memcpy(data, read_buf_->data() + read_start_, *len_read);
  read_start_ += *len_read;
  if (read_start_ == read_end_) {
    read_start_ = 0U;
    read_end_ = 0U;
    // We defer execution of DoRead() here for similar reasons as
    // ProcessConnectDone().
    PostDoRead();
  }
  return true;
}

// (maybe) write_state_ == IDLE -> write_state_ == POSTED (via
// PostDoWrite())

bool ChromeAsyncSocket::Write(const char* data, size_t len) {
  if (!IsOpen() && (state_ != STATE_TLS_CONNECTING)) {
    LOG(DFATAL) << "Write() called on non-open non-tls-connecting socket";
    DoNonNetError(ERROR_WRONGSTATE);
    return false;
  }
  // TODO(akalin): Avoid this check by modifying the interface to have
  // a "ready for writing" signal.
  if ((static_cast<size_t>(write_buf_->size()) - write_end_) < len) {
    LOG(DFATAL) << "queueing " << len << " bytes would exceed the "
                << "max write buffer size = " << write_buf_->size()
                << " by " << (len - write_buf_->size()) << " bytes";
    DoNetError(net::ERR_INSUFFICIENT_RESOURCES);
    return false;
  }
  std::memcpy(write_buf_->data() + write_end_, data, len);
  write_end_ += len;
  // If we're TLS-connecting, the write buffer will get flushed once
  // the TLS-connect finishes.  Otherwise, start writing if we're not
  // already writing and we have something to write.
  if ((state_ != STATE_TLS_CONNECTING) &&
      (write_state_ == IDLE) && (write_end_ > 0U)) {
    // We defer execution of DoWrite() here for similar reasons as
    // ProcessConnectDone().
    PostDoWrite();
  }
  return true;
}

// write_state_ == IDLE -> write_state_ == POSTED

void ChromeAsyncSocket::PostDoWrite() {
  DCHECK(IsOpen());
  DCHECK_EQ(write_state_, IDLE);
  DCHECK_GT(write_end_, 0U);
  base::MessageLoop* message_loop = base::MessageLoop::current();
  CHECK(message_loop);
  message_loop->PostTask(
      FROM_HERE,
      base::Bind(&ChromeAsyncSocket::DoWrite,
                 weak_ptr_factory_.GetWeakPtr()));
  write_state_ = POSTED;
}

// write_state_ == POSTED -> write_state_ == PENDING

void ChromeAsyncSocket::DoWrite() {
  DCHECK(IsOpen());
  DCHECK_EQ(write_state_, POSTED);
  DCHECK_GT(write_end_, 0U);
  // Once we call Write(), we cannot call StartTls() until the write
  // finishes.  This is okay, as StartTls() is called only after we
  // have received a reply to a message we sent to the server and
  // before we send the next message.
  int status =
      transport_socket_->Write(
          write_buf_.get(), write_end_,
          base::Bind(&ChromeAsyncSocket::ProcessWriteDone,
                     weak_ptr_factory_.GetWeakPtr()));
  write_state_ = PENDING;
  if (status != net::ERR_IO_PENDING) {
    ProcessWriteDone(status);
  }
}

// write_state_ == PENDING -> write_state_ == IDLE or POSTED (the
// latter via PostDoWrite())

void ChromeAsyncSocket::ProcessWriteDone(int status) {
  DCHECK_NE(status, net::ERR_IO_PENDING);
  DCHECK(IsOpen());
  DCHECK_EQ(write_state_, PENDING);
  DCHECK_GT(write_end_, 0U);
  write_state_ = IDLE;
  if (status < net::OK) {
    DoNetErrorFromStatus(status);
    DoClose();
    return;
  }
  size_t written = static_cast<size_t>(status);
  if (written > write_end_) {
    LOG(DFATAL) << "bytes written = " << written
                << " exceeds bytes requested = " << write_end_;
    DoNetError(net::ERR_UNEXPECTED);
    DoClose();
    return;
  }
  // TODO(akalin): Figure out a better way to do this; perhaps a queue
  // of DrainableIOBuffers.  This'll also allow us to not have an
  // artificial buffer size limit.
  std::memmove(write_buf_->data(),
               write_buf_->data() + written,
               write_end_ - written);
  write_end_ -= written;
  if (write_end_ > 0U) {
    PostDoWrite();
  }
}

// * -> STATE_CLOSED

bool ChromeAsyncSocket::Close() {
  DoClose();
  return true;
}

// (not STATE_CLOSED) -> STATE_CLOSED

void ChromeAsyncSocket::DoClose() {
  weak_ptr_factory_.InvalidateWeakPtrs();
  if (transport_socket_.get()) {
    transport_socket_->Disconnect();
  }
  transport_socket_.reset();
  read_state_ = IDLE;
  read_start_ = 0U;
  read_end_ = 0U;
  write_state_ = IDLE;
  write_end_ = 0U;
  if (state_ != STATE_CLOSED) {
    state_ = STATE_CLOSED;
    SignalClosed();
  }
  // Reset error variables after SignalClosed() so slots connected
  // to it can read it.
  error_ = ERROR_NONE;
  net_error_ = net::OK;
}

// STATE_OPEN -> STATE_TLS_CONNECTING

bool ChromeAsyncSocket::StartTls(const std::string& domain_name) {
  if ((state_ != STATE_OPEN) || (read_state_ == PENDING) ||
      (write_state_ != IDLE)) {
    LOG(DFATAL) << "StartTls() called in wrong state";
    DoNonNetError(ERROR_WRONGSTATE);
    return false;
  }

  state_ = STATE_TLS_CONNECTING;
  read_state_ = IDLE;
  read_start_ = 0U;
  read_end_ = 0U;
  DCHECK_EQ(write_end_, 0U);

  // Clear out any posted DoRead() tasks.
  weak_ptr_factory_.InvalidateWeakPtrs();

  DCHECK(transport_socket_.get());
  scoped_ptr<net::ClientSocketHandle> socket_handle(
      new net::ClientSocketHandle());
  socket_handle->SetSocket(transport_socket_.Pass());
  transport_socket_ =
      resolving_client_socket_factory_->CreateSSLClientSocket(
          socket_handle.Pass(), net::HostPortPair(domain_name, 443));
  int status = transport_socket_->Connect(
      base::Bind(&ChromeAsyncSocket::ProcessSSLConnectDone,
                 weak_ptr_factory_.GetWeakPtr()));
  if (status != net::ERR_IO_PENDING) {
    base::MessageLoop* message_loop = base::MessageLoop::current();
    CHECK(message_loop);
    message_loop->PostTask(
        FROM_HERE,
        base::Bind(&ChromeAsyncSocket::ProcessSSLConnectDone,
                   weak_ptr_factory_.GetWeakPtr(), status));
  }
  return true;
}

// STATE_TLS_CONNECTING -> STATE_TLS_OPEN
// read_state_ == IDLE -> read_state_ == POSTED (via PostDoRead())
// (maybe) write_state_ == IDLE -> write_state_ == POSTED (via
// PostDoWrite())

void ChromeAsyncSocket::ProcessSSLConnectDone(int status) {
  DCHECK_NE(status, net::ERR_IO_PENDING);
  DCHECK_EQ(state_, STATE_TLS_CONNECTING);
  DCHECK_EQ(read_state_, IDLE);
  DCHECK_EQ(read_start_, 0U);
  DCHECK_EQ(read_end_, 0U);
  DCHECK_EQ(write_state_, IDLE);
  if (status != net::OK) {
    DoNetErrorFromStatus(status);
    DoClose();
    return;
  }
  state_ = STATE_TLS_OPEN;
  PostDoRead();
  if (write_end_ > 0U) {
    PostDoWrite();
  }
  SignalSSLConnected();
}

}  // namespace jingle_glue

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