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/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/async_tcp_socket.h"
#include <stdint.h>
#include <string.h>
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <memory>
#include "api/array_view.h"
#include "rtc_base/byte_order.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/network/sent_packet.h"
#include "rtc_base/time_utils.h" // for TimeMillis
#if defined(WEBRTC_POSIX)
#include <errno.h>
#endif // WEBRTC_POSIX
namespace rtc {
static const size_t kMaxPacketSize = 64 * 1024;
typedef uint16_t PacketLength;
static const size_t kPacketLenSize = sizeof(PacketLength);
static const size_t kBufSize = kMaxPacketSize + kPacketLenSize;
// The input buffer will be resized so that at least kMinimumRecvSize bytes can
// be received (but it will not grow above the maximum size passed to the
// constructor).
static const size_t kMinimumRecvSize = 128;
static const int kListenBacklog = 5;
// Binds and connects `socket`
Socket* AsyncTCPSocketBase::ConnectSocket(
rtc::Socket* socket,
const rtc::SocketAddress& bind_address,
const rtc::SocketAddress& remote_address) {
std::unique_ptr<rtc::Socket> owned_socket(socket);
if (socket->Bind(bind_address) < 0) {
RTC_LOG(LS_ERROR) << "Bind() failed with error " << socket->GetError();
return nullptr;
}
if (socket->Connect(remote_address) < 0) {
RTC_LOG(LS_ERROR) << "Connect() failed with error " << socket->GetError();
return nullptr;
}
return owned_socket.release();
}
AsyncTCPSocketBase::AsyncTCPSocketBase(Socket* socket, size_t max_packet_size)
: socket_(socket),
max_insize_(max_packet_size),
max_outsize_(max_packet_size) {
inbuf_.EnsureCapacity(kMinimumRecvSize);
socket_->SignalConnectEvent.connect(this,
&AsyncTCPSocketBase::OnConnectEvent);
socket_->SignalReadEvent.connect(this, &AsyncTCPSocketBase::OnReadEvent);
socket_->SignalWriteEvent.connect(this, &AsyncTCPSocketBase::OnWriteEvent);
socket_->SignalCloseEvent.connect(this, &AsyncTCPSocketBase::OnCloseEvent);
}
AsyncTCPSocketBase::~AsyncTCPSocketBase() {}
SocketAddress AsyncTCPSocketBase::GetLocalAddress() const {
return socket_->GetLocalAddress();
}
SocketAddress AsyncTCPSocketBase::GetRemoteAddress() const {
return socket_->GetRemoteAddress();
}
int AsyncTCPSocketBase::Close() {
return socket_->Close();
}
AsyncTCPSocket::State AsyncTCPSocketBase::GetState() const {
switch (socket_->GetState()) {
case Socket::CS_CLOSED:
return STATE_CLOSED;
case Socket::CS_CONNECTING:
return STATE_CONNECTING;
case Socket::CS_CONNECTED:
return STATE_CONNECTED;
default:
RTC_DCHECK_NOTREACHED();
return STATE_CLOSED;
}
}
int AsyncTCPSocketBase::GetOption(Socket::Option opt, int* value) {
return socket_->GetOption(opt, value);
}
int AsyncTCPSocketBase::SetOption(Socket::Option opt, int value) {
return socket_->SetOption(opt, value);
}
int AsyncTCPSocketBase::GetError() const {
return socket_->GetError();
}
void AsyncTCPSocketBase::SetError(int error) {
return socket_->SetError(error);
}
int AsyncTCPSocketBase::SendTo(const void* pv,
size_t cb,
const SocketAddress& addr,
const rtc::PacketOptions& options) {
const SocketAddress& remote_address = GetRemoteAddress();
if (addr == remote_address)
return Send(pv, cb, options);
// Remote address may be empty if there is a sudden network change.
RTC_DCHECK(remote_address.IsNil());
socket_->SetError(ENOTCONN);
return -1;
}
int AsyncTCPSocketBase::FlushOutBuffer() {
RTC_DCHECK_GT(outbuf_.size(), 0);
rtc::ArrayView<uint8_t> view = outbuf_;
int res;
while (view.size() > 0) {
res = socket_->Send(view.data(), view.size());
if (res <= 0) {
break;
}
if (static_cast<size_t>(res) > view.size()) {
RTC_DCHECK_NOTREACHED();
res = -1;
break;
}
view = view.subview(res);
}
if (res > 0) {
// The output buffer may have been written out over multiple partial Send(),
// so reconstruct the total written length.
RTC_DCHECK_EQ(view.size(), 0);
res = outbuf_.size();
outbuf_.Clear();
} else {
// There was an error when calling Send(), so there will still be data left
// to send at a later point.
RTC_DCHECK_GT(view.size(), 0);
// In the special case of EWOULDBLOCK, signal that we had a partial write.
if (socket_->GetError() == EWOULDBLOCK) {
res = outbuf_.size() - view.size();
}
if (view.size() < outbuf_.size()) {
memmove(outbuf_.data(), view.data(), view.size());
outbuf_.SetSize(view.size());
}
}
return res;
}
void AsyncTCPSocketBase::AppendToOutBuffer(const void* pv, size_t cb) {
RTC_DCHECK(outbuf_.size() + cb <= max_outsize_);
outbuf_.AppendData(static_cast<const uint8_t*>(pv), cb);
}
void AsyncTCPSocketBase::OnConnectEvent(Socket* socket) {
SignalConnect(this);
}
void AsyncTCPSocketBase::OnReadEvent(Socket* socket) {
RTC_DCHECK(socket_.get() == socket);
size_t total_recv = 0;
while (true) {
size_t free_size = inbuf_.capacity() - inbuf_.size();
if (free_size < kMinimumRecvSize && inbuf_.capacity() < max_insize_) {
inbuf_.EnsureCapacity(std::min(max_insize_, inbuf_.capacity() * 2));
free_size = inbuf_.capacity() - inbuf_.size();
}
int len = socket_->Recv(inbuf_.data() + inbuf_.size(), free_size, nullptr);
if (len < 0) {
// TODO(stefan): Do something better like forwarding the error to the
// user.
if (!socket_->IsBlocking()) {
RTC_LOG(LS_ERROR) << "Recv() returned error: " << socket_->GetError();
}
break;
}
total_recv += len;
inbuf_.SetSize(inbuf_.size() + len);
if (!len || static_cast<size_t>(len) < free_size) {
break;
}
}
if (!total_recv) {
return;
}
size_t processed = ProcessInput(inbuf_);
size_t bytes_remaining = inbuf_.size() - processed;
if (processed > inbuf_.size()) {
RTC_LOG(LS_ERROR) << "input buffer overflow";
RTC_DCHECK_NOTREACHED();
inbuf_.Clear();
} else {
if (bytes_remaining > 0) {
memmove(inbuf_.data(), inbuf_.data() + processed, bytes_remaining);
}
inbuf_.SetSize(bytes_remaining);
}
}
void AsyncTCPSocketBase::OnWriteEvent(Socket* socket) {
RTC_DCHECK(socket_.get() == socket);
if (outbuf_.size() > 0) {
FlushOutBuffer();
}
if (outbuf_.size() == 0) {
SignalReadyToSend(this);
}
}
void AsyncTCPSocketBase::OnCloseEvent(Socket* socket, int error) {
NotifyClosed(error);
}
// AsyncTCPSocket
// Binds and connects `socket` and creates AsyncTCPSocket for
// it. Takes ownership of `socket`. Returns null if bind() or
// connect() fail (`socket` is destroyed in that case).
AsyncTCPSocket* AsyncTCPSocket::Create(Socket* socket,
const SocketAddress& bind_address,
const SocketAddress& remote_address) {
return new AsyncTCPSocket(
AsyncTCPSocketBase::ConnectSocket(socket, bind_address, remote_address));
}
AsyncTCPSocket::AsyncTCPSocket(Socket* socket)
: AsyncTCPSocketBase(socket, kBufSize) {}
int AsyncTCPSocket::Send(const void* pv,
size_t cb,
const rtc::PacketOptions& options) {
if (cb > kBufSize) {
SetError(EMSGSIZE);
return -1;
}
// If we are blocking on send, then silently drop this packet
if (!IsOutBufferEmpty())
return static_cast<int>(cb);
PacketLength pkt_len = HostToNetwork16(static_cast<PacketLength>(cb));
AppendToOutBuffer(&pkt_len, kPacketLenSize);
AppendToOutBuffer(pv, cb);
int res = FlushOutBuffer();
if (res <= 0) {
// drop packet if we made no progress
ClearOutBuffer();
return res;
}
rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis(),
options.info_signaled_after_sent);
CopySocketInformationToPacketInfo(cb, *this, &sent_packet.info);
SignalSentPacket(this, sent_packet);
// We claim to have sent the whole thing, even if we only sent partial
return static_cast<int>(cb);
}
size_t AsyncTCPSocket::ProcessInput(rtc::ArrayView<const uint8_t> data) {
SocketAddress remote_addr(GetRemoteAddress());
size_t processed_bytes = 0;
while (true) {
size_t bytes_left = data.size() - processed_bytes;
if (bytes_left < kPacketLenSize)
return processed_bytes;
PacketLength pkt_len = rtc::GetBE16(data.data() + processed_bytes);
if (bytes_left < kPacketLenSize + pkt_len)
return processed_bytes;
rtc::ReceivedPacket received_packet(
data.subview(processed_bytes + kPacketLenSize, pkt_len), remote_addr,
webrtc::Timestamp::Micros(rtc::TimeMicros()));
NotifyPacketReceived(received_packet);
processed_bytes += kPacketLenSize + pkt_len;
}
}
AsyncTcpListenSocket::AsyncTcpListenSocket(std::unique_ptr<Socket> socket)
: socket_(std::move(socket)) {
RTC_DCHECK(socket_.get() != nullptr);
socket_->SignalReadEvent.connect(this, &AsyncTcpListenSocket::OnReadEvent);
if (socket_->Listen(kListenBacklog) < 0) {
RTC_LOG(LS_ERROR) << "Listen() failed with error " << socket_->GetError();
}
}
AsyncTcpListenSocket::State AsyncTcpListenSocket::GetState() const {
switch (socket_->GetState()) {
case Socket::CS_CLOSED:
return State::kClosed;
case Socket::CS_CONNECTING:
return State::kBound;
default:
RTC_DCHECK_NOTREACHED();
return State::kClosed;
}
}
SocketAddress AsyncTcpListenSocket::GetLocalAddress() const {
return socket_->GetLocalAddress();
}
void AsyncTcpListenSocket::OnReadEvent(Socket* socket) {
RTC_DCHECK(socket_.get() == socket);
rtc::SocketAddress address;
rtc::Socket* new_socket = socket->Accept(&address);
if (!new_socket) {
// TODO(stefan): Do something better like forwarding the error
// to the user.
RTC_LOG(LS_ERROR) << "TCP accept failed with error " << socket_->GetError();
return;
}
HandleIncomingConnection(new_socket);
// Prime a read event in case data is waiting.
new_socket->SignalReadEvent(new_socket);
}
void AsyncTcpListenSocket::HandleIncomingConnection(Socket* socket) {
SignalNewConnection(this, new AsyncTCPSocket(socket));
}
} // namespace rtc