#include #include "Log.h" #include "RouterInfo.h" #include "RouterContext.h" #include "Tunnel.h" #include "Timestamp.h" #include "Destination.h" #include "Streaming.h" namespace i2p { namespace stream { Stream::Stream (boost::asio::io_service& service, StreamingDestination& local, std::shared_ptr remote, int port): m_Service (service), m_SendStreamID (0), m_SequenceNumber (0), m_LastReceivedSequenceNumber (-1), m_IsOpen (false), m_IsReset (false), m_IsAckSendScheduled (false), m_LocalDestination (local), m_RemoteLeaseSet (remote), m_ReceiveTimer (m_Service), m_ResendTimer (m_Service), m_AckSendTimer (m_Service), m_NumSentBytes (0), m_NumReceivedBytes (0), m_Port (port) { m_RecvStreamID = i2p::context.GetRandomNumberGenerator ().GenerateWord32 (); UpdateCurrentRemoteLease (); } Stream::Stream (boost::asio::io_service& service, StreamingDestination& local): m_Service (service), m_SendStreamID (0), m_SequenceNumber (0), m_LastReceivedSequenceNumber (-1), m_IsOpen (false), m_IsReset (false), m_IsAckSendScheduled (false), m_LocalDestination (local), m_ReceiveTimer (m_Service), m_ResendTimer (m_Service), m_AckSendTimer (m_Service), m_NumSentBytes (0), m_NumReceivedBytes (0), m_Port (0) { m_RecvStreamID = i2p::context.GetRandomNumberGenerator ().GenerateWord32 (); } Stream::~Stream () { m_AckSendTimer.cancel (); while (!m_ReceiveQueue.empty ()) { auto packet = m_ReceiveQueue.front (); m_ReceiveQueue.pop (); delete packet; } m_ReceiveTimer.cancel (); for (auto it: m_SentPackets) delete it; m_SentPackets.clear (); m_ResendTimer.cancel (); for (auto it: m_SavedPackets) delete it; m_SavedPackets.clear (); LogPrint (eLogDebug, "Stream deleted"); } void Stream::HandleNextPacket (Packet * packet) { m_NumReceivedBytes += packet->GetLength (); if (!m_SendStreamID) m_SendStreamID = packet->GetReceiveStreamID (); if (!packet->IsNoAck ()) // ack received ProcessAck (packet); int32_t receivedSeqn = packet->GetSeqn (); bool isSyn = packet->IsSYN (); if (!receivedSeqn && !isSyn) { // plain ack LogPrint (eLogDebug, "Plain ACK received"); delete packet; return; } LogPrint (eLogDebug, "Received seqn=", receivedSeqn); if (isSyn || receivedSeqn == m_LastReceivedSequenceNumber + 1) { // we have received next in sequence message ProcessPacket (packet); // we should also try stored messages if any for (auto it = m_SavedPackets.begin (); it != m_SavedPackets.end ();) { if ((*it)->GetSeqn () == (uint32_t)(m_LastReceivedSequenceNumber + 1)) { Packet * savedPacket = *it; m_SavedPackets.erase (it++); ProcessPacket (savedPacket); } else break; } // schedule ack for last message if (m_IsOpen) { if (!m_IsAckSendScheduled) { m_IsAckSendScheduled = true; m_AckSendTimer.expires_from_now (boost::posix_time::milliseconds(ACK_SEND_TIMEOUT)); m_AckSendTimer.async_wait (std::bind (&Stream::HandleAckSendTimer, shared_from_this (), std::placeholders::_1)); } } else if (isSyn) // we have to send SYN back to incoming connection Send (nullptr, 0); // also sets m_IsOpen } else { if (receivedSeqn <= m_LastReceivedSequenceNumber) { // we have received duplicate. Most likely our outbound tunnel is dead LogPrint (eLogWarning, "Duplicate message ", receivedSeqn, " received"); m_CurrentOutboundTunnel = nullptr; // pick another outbound tunnel UpdateCurrentRemoteLease (); // pick another lease SendQuickAck (); // resend ack for previous message again delete packet; // packet dropped } else { LogPrint (eLogWarning, "Missing messages from ", m_LastReceivedSequenceNumber + 1, " to ", receivedSeqn - 1); // save message and wait for missing message again SavePacket (packet); // send NACKs for missing messages ASAP if (m_IsAckSendScheduled) { m_IsAckSendScheduled = false; m_AckSendTimer.cancel (); } SendQuickAck (); } } } void Stream::SavePacket (Packet * packet) { m_SavedPackets.insert (packet); } void Stream::ProcessPacket (Packet * packet) { // process flags uint32_t receivedSeqn = packet->GetSeqn (); uint16_t flags = packet->GetFlags (); LogPrint (eLogDebug, "Process seqn=", receivedSeqn, ", flags=", flags); const uint8_t * optionData = packet->GetOptionData (); if (flags & PACKET_FLAG_SYNCHRONIZE) LogPrint (eLogDebug, "Synchronize"); if (flags & PACKET_FLAG_DELAY_REQUESTED) { optionData += 2; } if (flags & PACKET_FLAG_FROM_INCLUDED) { optionData += m_RemoteIdentity.FromBuffer (optionData, packet->GetOptionSize ()); LogPrint (eLogInfo, "From identity ", m_RemoteIdentity.GetIdentHash ().ToBase64 ()); if (!m_RemoteLeaseSet) LogPrint (eLogDebug, "Incoming stream from ", m_RemoteIdentity.GetIdentHash ().ToBase64 ()); } if (flags & PACKET_FLAG_MAX_PACKET_SIZE_INCLUDED) { uint16_t maxPacketSize = bufbe16toh (optionData); LogPrint (eLogDebug, "Max packet size ", maxPacketSize); optionData += 2; } if (flags & PACKET_FLAG_SIGNATURE_INCLUDED) { LogPrint (eLogDebug, "Signature"); uint8_t signature[256]; auto signatureLen = m_RemoteIdentity.GetSignatureLen (); memcpy (signature, optionData, signatureLen); memset (const_cast(optionData), 0, signatureLen); if (!m_RemoteIdentity.Verify (packet->GetBuffer (), packet->GetLength (), signature)) { LogPrint (eLogError, "Signature verification failed"); Close (); flags |= PACKET_FLAG_CLOSE; } memcpy (const_cast(optionData), signature, signatureLen); optionData += signatureLen; } packet->offset = packet->GetPayload () - packet->buf; if (packet->GetLength () > 0) { m_ReceiveQueue.push (packet); m_ReceiveTimer.cancel (); } else delete packet; m_LastReceivedSequenceNumber = receivedSeqn; if (flags & PACKET_FLAG_CLOSE) { LogPrint (eLogInfo, "Closed"); Close (); m_IsOpen = false; m_IsReset = true; } } void Stream::ProcessAck (Packet * packet) { bool acknowledged = false; uint32_t ackThrough = packet->GetAckThrough (); int nackCount = packet->GetNACKCount (); for (auto it = m_SentPackets.begin (); it != m_SentPackets.end ();) { auto seqn = (*it)->GetSeqn (); if (seqn <= ackThrough) { if (nackCount > 0) { bool nacked = false; for (int i = 0; i < nackCount; i++) if (seqn == packet->GetNACK (i)) { nacked = true; break; } if (nacked) { LogPrint (eLogDebug, "Packet ", seqn, " NACK"); it++; continue; } } auto sentPacket = *it; LogPrint (eLogDebug, "Packet ", seqn, " acknowledged"); m_SentPackets.erase (it++); delete sentPacket; acknowledged = true; } else break; } if (m_SentPackets.empty ()) m_ResendTimer.cancel (); if (acknowledged) SendBuffer (); } size_t Stream::Send (const uint8_t * buf, size_t len) { if (len > 0 && buf) { std::unique_lock l(m_SendBufferMutex); m_SendBuffer.clear (); m_SendBuffer.write ((const char *)buf, len); } m_Service.post (std::bind (&Stream::SendBuffer, shared_from_this ())); return len; } void Stream::SendBuffer () { int numMsgs = WINDOW_SIZE - m_SentPackets.size (); if (numMsgs <= 0) return; // window is full bool isNoAck = m_LastReceivedSequenceNumber < 0; // first packet std::vector packets; { std::unique_lock l(m_SendBufferMutex); while (!m_IsOpen || (IsEstablished () && !m_SendBuffer.eof () && numMsgs > 0)) { Packet * p = new Packet (); uint8_t * packet = p->GetBuffer (); // TODO: implement setters size_t size = 0; htobe32buf (packet + size, m_SendStreamID); size += 4; // sendStreamID htobe32buf (packet + size, m_RecvStreamID); size += 4; // receiveStreamID htobe32buf (packet + size, m_SequenceNumber++); size += 4; // sequenceNum if (isNoAck) htobe32buf (packet + size, m_LastReceivedSequenceNumber); else htobuf32 (packet + size, 0); size += 4; // ack Through packet[size] = 0; size++; // NACK count packet[size] = RESEND_TIMEOUT; size++; // resend delay if (!m_IsOpen) { // initial packet m_IsOpen = true; m_IsReset = false; uint16_t flags = PACKET_FLAG_SYNCHRONIZE | PACKET_FLAG_FROM_INCLUDED | PACKET_FLAG_SIGNATURE_INCLUDED | PACKET_FLAG_MAX_PACKET_SIZE_INCLUDED; if (isNoAck) flags |= PACKET_FLAG_NO_ACK; htobe16buf (packet + size, flags); size += 2; // flags size_t identityLen = m_LocalDestination.GetOwner ().GetIdentity ().GetFullLen (); size_t signatureLen = m_LocalDestination.GetOwner ().GetIdentity ().GetSignatureLen (); htobe16buf (packet + size, identityLen + signatureLen + 2); // identity + signature + packet size size += 2; // options size m_LocalDestination.GetOwner ().GetIdentity ().ToBuffer (packet + size, identityLen); size += identityLen; // from htobe16buf (packet + size, STREAMING_MTU); size += 2; // max packet size uint8_t * signature = packet + size; // set it later memset (signature, 0, signatureLen); // zeroes for now size += signatureLen; // signature m_SendBuffer.read ((char *)(packet + size), STREAMING_MTU - size); size += m_SendBuffer.gcount (); // payload m_LocalDestination.GetOwner ().Sign (packet, size, signature); } else { // follow on packet htobuf16 (packet + size, 0); size += 2; // flags htobuf16 (packet + size, 0); // no options size += 2; // options size m_SendBuffer.read((char *)(packet + size), STREAMING_MTU - size); size += m_SendBuffer.gcount (); // payload } p->len = size; packets.push_back (p); numMsgs--; } } if (packets.size () > 0) { m_IsAckSendScheduled = false; m_AckSendTimer.cancel (); bool isEmpty = m_SentPackets.empty (); for (auto it: packets) m_SentPackets.insert (it); SendPackets (packets); if (isEmpty) ScheduleResend (); } } void Stream::SendQuickAck () { int32_t lastReceivedSeqn = m_LastReceivedSequenceNumber; if (!m_SavedPackets.empty ()) { int32_t seqn = (*m_SavedPackets.rbegin ())->GetSeqn (); if (seqn > lastReceivedSeqn) lastReceivedSeqn = seqn; } if (lastReceivedSeqn < 0) { LogPrint (eLogError, "No packets have been received yet"); return; } Packet p; uint8_t * packet = p.GetBuffer (); size_t size = 0; htobe32buf (packet + size, m_SendStreamID); size += 4; // sendStreamID htobe32buf (packet + size, m_RecvStreamID); size += 4; // receiveStreamID htobuf32 (packet + size, 0); // this is plain Ack message size += 4; // sequenceNum htobe32buf (packet + size, lastReceivedSeqn); size += 4; // ack Through uint8_t numNacks = 0; if (lastReceivedSeqn > m_LastReceivedSequenceNumber) { // fill NACKs uint8_t * nacks = packet + size + 1; auto nextSeqn = m_LastReceivedSequenceNumber + 1; for (auto it: m_SavedPackets) { auto seqn = it->GetSeqn (); if (numNacks + (seqn - nextSeqn) >= 256) { LogPrint (eLogError, "Number of NACKs exceeds 256"); htobe32buf (packet + 12, nextSeqn); // change ack Through break; } for (uint32_t i = nextSeqn; i < seqn; i++) { htobe32buf (nacks, i); nacks += 4; numNacks++; } nextSeqn = seqn + 1; } packet[size] = numNacks; size++; // NACK count size += numNacks*4; // NACKs } else { // No NACKs packet[size] = 0; size++; // NACK count } size++; // resend delay htobuf16 (packet + size, 0); // nof flags set size += 2; // flags htobuf16 (packet + size, 0); // no options size += 2; // options size p.len = size; SendPackets (std::vector { &p }); LogPrint ("Quick Ack sent. ", (int)numNacks, " NACKs"); } void Stream::Close () { if (m_IsOpen) { m_IsOpen = false; Packet * p = new Packet (); uint8_t * packet = p->GetBuffer (); size_t size = 0; htobe32buf (packet + size, m_SendStreamID); size += 4; // sendStreamID htobe32buf (packet + size, m_RecvStreamID); size += 4; // receiveStreamID htobe32buf (packet + size, m_SequenceNumber++); size += 4; // sequenceNum htobe32buf (packet + size, m_LastReceivedSequenceNumber); size += 4; // ack Through packet[size] = 0; size++; // NACK count size++; // resend delay htobe16buf (packet + size, PACKET_FLAG_CLOSE | PACKET_FLAG_SIGNATURE_INCLUDED); size += 2; // flags size_t signatureLen = m_LocalDestination.GetOwner ().GetIdentity ().GetSignatureLen (); htobe16buf (packet + size, signatureLen); // signature only size += 2; // options size uint8_t * signature = packet + size; memset (packet + size, 0, signatureLen); size += signatureLen; // signature m_LocalDestination.GetOwner ().Sign (packet, size, signature); p->len = size; m_Service.post (std::bind (&Stream::SendPacket, shared_from_this (), p)); LogPrint ("FIN sent"); } m_ReceiveTimer.cancel (); m_LocalDestination.DeleteStream (shared_from_this ()); } size_t Stream::ConcatenatePackets (uint8_t * buf, size_t len) { size_t pos = 0; while (pos < len && !m_ReceiveQueue.empty ()) { Packet * packet = m_ReceiveQueue.front (); size_t l = std::min (packet->GetLength (), len - pos); memcpy (buf + pos, packet->GetBuffer (), l); pos += l; packet->offset += l; if (!packet->GetLength ()) { m_ReceiveQueue.pop (); delete packet; } } return pos; } bool Stream::SendPacket (Packet * packet) { if (packet) { if (m_IsAckSendScheduled) { m_IsAckSendScheduled = false; m_AckSendTimer.cancel (); } SendPackets (std::vector { packet }); if (m_IsOpen) { bool isEmpty = m_SentPackets.empty (); m_SentPackets.insert (packet); if (isEmpty) ScheduleResend (); } else delete packet; return true; } else return false; } void Stream::SendPackets (const std::vector& packets) { if (!m_RemoteLeaseSet) { UpdateCurrentRemoteLease (); if (!m_RemoteLeaseSet) { LogPrint ("Can't send packets. Missing remote LeaseSet"); return; } } if (!m_CurrentOutboundTunnel || !m_CurrentOutboundTunnel->IsEstablished ()) m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ().GetTunnelPool ()->GetNextOutboundTunnel (); if (!m_CurrentOutboundTunnel) { LogPrint ("No outbound tunnels in the pool"); return; } auto ts = i2p::util::GetMillisecondsSinceEpoch (); if (ts >= m_CurrentRemoteLease.endDate) UpdateCurrentRemoteLease (); if (ts < m_CurrentRemoteLease.endDate) { std::vector msgs; for (auto it: packets) { auto msg = m_RoutingSession->WrapSingleMessage (CreateDataMessage (it->GetBuffer (), it->GetLength ())); msgs.push_back (i2p::tunnel::TunnelMessageBlock { i2p::tunnel::eDeliveryTypeTunnel, m_CurrentRemoteLease.tunnelGateway, m_CurrentRemoteLease.tunnelID, msg }); m_NumSentBytes += it->GetLength (); } m_CurrentOutboundTunnel->SendTunnelDataMsg (msgs); } else LogPrint ("All leases are expired"); } void Stream::ScheduleResend () { m_ResendTimer.cancel (); m_ResendTimer.expires_from_now (boost::posix_time::seconds(RESEND_TIMEOUT)); m_ResendTimer.async_wait (std::bind (&Stream::HandleResendTimer, shared_from_this (), std::placeholders::_1)); } void Stream::HandleResendTimer (const boost::system::error_code& ecode) { if (ecode != boost::asio::error::operation_aborted) { std::vector packets; for (auto it : m_SentPackets) { it->numResendAttempts++; if (it->numResendAttempts <= MAX_NUM_RESEND_ATTEMPTS) packets.push_back (it); else { LogPrint (eLogWarning, "Packet ", it->GetSeqn (), " was not ACKed after ", MAX_NUM_RESEND_ATTEMPTS, " attempts. Terminate"); m_IsOpen = false; m_IsReset = true; m_ReceiveTimer.cancel (); return; } } if (packets.size () > 0) { m_CurrentOutboundTunnel = nullptr; // pick another outbound tunnel UpdateCurrentRemoteLease (); // pick another lease SendPackets (packets); } ScheduleResend (); } } void Stream::HandleAckSendTimer (const boost::system::error_code& ecode) { if (m_IsAckSendScheduled) { if (m_IsOpen) SendQuickAck (); m_IsAckSendScheduled = false; } } void Stream::UpdateCurrentRemoteLease () { if (!m_RemoteLeaseSet) { m_RemoteLeaseSet = m_LocalDestination.GetOwner ().FindLeaseSet (m_RemoteIdentity.GetIdentHash ()); if (!m_RemoteLeaseSet) LogPrint ("LeaseSet ", m_RemoteIdentity.GetIdentHash ().ToBase64 (), " not found"); } if (m_RemoteLeaseSet) { if (!m_RoutingSession) m_RoutingSession = m_LocalDestination.GetOwner ().GetRoutingSession (m_RemoteLeaseSet, 32); auto leases = m_RemoteLeaseSet->GetNonExpiredLeases (); if (!leases.empty ()) { uint32_t i = i2p::context.GetRandomNumberGenerator ().GenerateWord32 (0, leases.size () - 1); m_CurrentRemoteLease = leases[i]; } else { m_RemoteLeaseSet = m_LocalDestination.GetOwner ().FindLeaseSet (m_RemoteIdentity.GetIdentHash ()); // re-request expired m_CurrentRemoteLease.endDate = 0; } } else m_CurrentRemoteLease.endDate = 0; } I2NPMessage * Stream::CreateDataMessage (const uint8_t * payload, size_t len) { I2NPMessage * msg = NewI2NPShortMessage (); CryptoPP::Gzip compressor; if (len <= i2p::stream::COMPRESSION_THRESHOLD_SIZE) compressor.SetDeflateLevel (CryptoPP::Gzip::MIN_DEFLATE_LEVEL); else compressor.SetDeflateLevel (CryptoPP::Gzip::DEFAULT_DEFLATE_LEVEL); compressor.Put (payload, len); compressor.MessageEnd(); int size = compressor.MaxRetrievable (); uint8_t * buf = msg->GetPayload (); htobe32buf (buf, size); // length buf += 4; compressor.Get (buf, size); htobuf16(buf + 4, 0); // source port htobe16buf (buf + 6, m_Port); // destination port buf[9] = i2p::client::PROTOCOL_TYPE_STREAMING; // streaming protocol msg->len += size + 4; FillI2NPMessageHeader (msg, eI2NPData); return msg; } void StreamingDestination::Start () { } void StreamingDestination::Stop () { ResetAcceptor (); { std::unique_lock l(m_StreamsMutex); m_Streams.clear (); } } void StreamingDestination::HandleNextPacket (Packet * packet) { uint32_t sendStreamID = packet->GetSendStreamID (); if (sendStreamID) { auto it = m_Streams.find (sendStreamID); if (it != m_Streams.end ()) it->second->HandleNextPacket (packet); else { LogPrint ("Unknown stream sendStreamID=", sendStreamID); delete packet; } } else { if (packet->IsSYN () && !packet->GetSeqn ()) // new incoming stream { auto incomingStream = CreateNewIncomingStream (); incomingStream->HandleNextPacket (packet); if (m_Acceptor != nullptr) m_Acceptor (incomingStream); else { LogPrint ("Acceptor for incoming stream is not set"); DeleteStream (incomingStream); } } else // follow on packet without SYN { uint32_t receiveStreamID = packet->GetReceiveStreamID (); for (auto it: m_Streams) if (it.second->GetSendStreamID () == receiveStreamID) { // found it.second->HandleNextPacket (packet); return; } // TODO: should queue it up LogPrint ("Unknown stream receiveStreamID=", receiveStreamID); delete packet; } } } std::shared_ptr StreamingDestination::CreateNewOutgoingStream (std::shared_ptr remote, int port) { auto s = std::make_shared (m_Owner.GetService (), *this, remote, port); std::unique_lock l(m_StreamsMutex); m_Streams[s->GetRecvStreamID ()] = s; return s; } std::shared_ptr StreamingDestination::CreateNewIncomingStream () { auto s = std::make_shared (m_Owner.GetService (), *this); std::unique_lock l(m_StreamsMutex); m_Streams[s->GetRecvStreamID ()] = s; return s; } void StreamingDestination::DeleteStream (std::shared_ptr stream) { if (stream) { std::unique_lock l(m_StreamsMutex); auto it = m_Streams.find (stream->GetRecvStreamID ()); if (it != m_Streams.end ()) m_Streams.erase (it); } } void StreamingDestination::HandleDataMessagePayload (const uint8_t * buf, size_t len) { // unzip it CryptoPP::Gunzip decompressor; decompressor.Put (buf, len); decompressor.MessageEnd(); Packet * uncompressed = new Packet; uncompressed->offset = 0; uncompressed->len = decompressor.MaxRetrievable (); if (uncompressed->len <= MAX_PACKET_SIZE) { decompressor.Get (uncompressed->buf, uncompressed->len); HandleNextPacket (uncompressed); } else { LogPrint ("Received packet size ", uncompressed->len, " exceeds max packet size. Skipped"); delete uncompressed; } } } }