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Streaming.cpp
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/*
* Copyright (c) 2013-2020, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/
#include "Crypto.h"
#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
{
void SendBufferQueue::Add (const uint8_t * buf, size_t len, SendHandler handler)
{
m_Buffers.push_back (std::make_shared<SendBuffer>(buf, len, handler));
m_Size += len;
}
size_t SendBufferQueue::Get (uint8_t * buf, size_t len)
{
size_t offset = 0;
while (!m_Buffers.empty () && offset < len)
{
auto nextBuffer = m_Buffers.front ();
auto rem = nextBuffer->GetRemainingSize ();
if (offset + rem <= len)
{
// whole buffer
memcpy (buf + offset, nextBuffer->GetRemaningBuffer (), rem);
offset += rem;
m_Buffers.pop_front (); // delete it
}
else
{
// partially
rem = len - offset;
memcpy (buf + offset, nextBuffer->GetRemaningBuffer (), len - offset);
nextBuffer->offset += (len - offset);
offset = len; // break
}
}
m_Size -= offset;
return offset;
}
void SendBufferQueue::CleanUp ()
{
if (!m_Buffers.empty ())
{
for (auto it: m_Buffers)
it->Cancel ();
m_Buffers.clear ();
m_Size = 0;
}
}
Stream::Stream (boost::asio::io_service& service, StreamingDestination& local,
std::shared_ptr<const i2p::data::LeaseSet> remote, int port): m_Service (service),
m_SendStreamID (0), m_SequenceNumber (0), m_LastReceivedSequenceNumber (-1),
m_Status (eStreamStatusNew), 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_WindowSize (MIN_WINDOW_SIZE), m_RTT (INITIAL_RTT), m_RTO (INITIAL_RTO),
m_AckDelay (local.GetOwner ()->GetStreamingAckDelay ()),
m_LastWindowSizeIncreaseTime (0), m_NumResendAttempts (0), m_MTU (STREAMING_MTU)
{
RAND_bytes ((uint8_t *)&m_RecvStreamID, 4);
m_RemoteIdentity = remote->GetIdentity ();
}
Stream::Stream (boost::asio::io_service& service, StreamingDestination& local):
m_Service (service), m_SendStreamID (0), m_SequenceNumber (0), m_LastReceivedSequenceNumber (-1),
m_Status (eStreamStatusNew), 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_WindowSize (MIN_WINDOW_SIZE),
m_RTT (INITIAL_RTT), m_RTO (INITIAL_RTO), m_AckDelay (local.GetOwner ()->GetStreamingAckDelay ()),
m_LastWindowSizeIncreaseTime (0), m_NumResendAttempts (0), m_MTU (STREAMING_MTU)
{
RAND_bytes ((uint8_t *)&m_RecvStreamID, 4);
}
Stream::~Stream ()
{
CleanUp ();
LogPrint (eLogDebug, "Streaming: Stream deleted");
}
void Stream::Terminate (bool deleteFromDestination) // shoudl be called from StreamingDestination::Stop only
{
m_AckSendTimer.cancel ();
m_ReceiveTimer.cancel ();
m_ResendTimer.cancel ();
//CleanUp (); /* Need to recheck - broke working on windows */
if (deleteFromDestination)
m_LocalDestination.DeleteStream (shared_from_this ());
}
void Stream::CleanUp ()
{
{
std::unique_lock<std::mutex> l(m_SendBufferMutex);
m_SendBuffer.CleanUp ();
}
while (!m_ReceiveQueue.empty ())
{
auto packet = m_ReceiveQueue.front ();
m_ReceiveQueue.pop ();
m_LocalDestination.DeletePacket (packet);
}
for (auto it: m_SentPackets)
m_LocalDestination.DeletePacket (it);
m_SentPackets.clear ();
for (auto it: m_SavedPackets)
m_LocalDestination.DeletePacket (it);
m_SavedPackets.clear ();
}
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, "Streaming: Plain ACK received");
m_LocalDestination.DeletePacket (packet);
return;
}
LogPrint (eLogDebug, "Streaming: Received seqn=", receivedSeqn, " on sSID=", m_SendStreamID);
if (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_Status == eStreamStatusOpen)
{
if (!m_IsAckSendScheduled)
{
m_IsAckSendScheduled = true;
auto ackTimeout = m_RTT/10;
if (ackTimeout > m_AckDelay) ackTimeout = m_AckDelay;
m_AckSendTimer.expires_from_now (boost::posix_time::milliseconds(ackTimeout));
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
SendBuffer (); // also sets m_IsOpen
}
else
{
if (receivedSeqn <= m_LastReceivedSequenceNumber)
{
// we have received duplicate
LogPrint (eLogWarning, "Streaming: Duplicate message ", receivedSeqn, " on sSID=", m_SendStreamID);
SendQuickAck (); // resend ack for previous message again
m_LocalDestination.DeletePacket (packet); // packet dropped
}
else
{
LogPrint (eLogWarning, "Streaming: Missing messages on sSID=", m_SendStreamID, ": from ", m_LastReceivedSequenceNumber + 1, " to ", receivedSeqn - 1);
// save message and wait for missing message again
SavePacket (packet);
if (m_LastReceivedSequenceNumber >= 0)
{
// send NACKs for missing messages ASAP
if (m_IsAckSendScheduled)
{
m_IsAckSendScheduled = false;
m_AckSendTimer.cancel ();
}
SendQuickAck ();
}
else
{
// wait for SYN
m_IsAckSendScheduled = true;
m_AckSendTimer.expires_from_now (boost::posix_time::milliseconds(SYN_TIMEOUT));
m_AckSendTimer.async_wait (std::bind (&Stream::HandleAckSendTimer,
shared_from_this (), std::placeholders::_1));
}
}
}
}
void Stream::SavePacket (Packet * packet)
{
if (!m_SavedPackets.insert (packet).second)
m_LocalDestination.DeletePacket (packet);
}
void Stream::ProcessPacket (Packet * packet)
{
uint32_t receivedSeqn = packet->GetSeqn ();
uint16_t flags = packet->GetFlags ();
LogPrint (eLogDebug, "Streaming: Process seqn=", receivedSeqn, ", flags=", flags);
if (!ProcessOptions (flags, packet))
{
m_LocalDestination.DeletePacket (packet);
Terminate ();
return;
}
packet->offset = packet->GetPayload () - packet->buf;
if (packet->GetLength () > 0)
{
m_ReceiveQueue.push (packet);
m_ReceiveTimer.cancel ();
}
else
m_LocalDestination.DeletePacket (packet);
m_LastReceivedSequenceNumber = receivedSeqn;
if (flags & PACKET_FLAG_RESET)
{
LogPrint (eLogDebug, "Streaming: closing stream sSID=", m_SendStreamID, ", rSID=", m_RecvStreamID, ": reset flag received in packet #", receivedSeqn);
m_Status = eStreamStatusReset;
Close ();
}
else if (flags & PACKET_FLAG_CLOSE)
{
if (m_Status != eStreamStatusClosed)
SendClose ();
m_Status = eStreamStatusClosed;
Terminate ();
}
}
bool Stream::ProcessOptions (uint16_t flags, Packet * packet)
{
const uint8_t * optionData = packet->GetOptionData ();
size_t optionSize = packet->GetOptionSize ();
if (flags & PACKET_FLAG_DELAY_REQUESTED)
optionData += 2;
if (flags & PACKET_FLAG_FROM_INCLUDED)
{
if (m_RemoteLeaseSet) m_RemoteIdentity = m_RemoteLeaseSet->GetIdentity ();
if (!m_RemoteIdentity)
m_RemoteIdentity = std::make_shared<i2p::data::IdentityEx>(optionData, optionSize);
if (m_RemoteIdentity->IsRSA ())
{
LogPrint (eLogInfo, "Streaming: Incoming stream from RSA destination ", m_RemoteIdentity->GetIdentHash ().ToBase64 (), " Discarded");
return false;
}
optionData += m_RemoteIdentity->GetFullLen ();
if (!m_RemoteLeaseSet)
LogPrint (eLogDebug, "Streaming: Incoming stream from ", m_RemoteIdentity->GetIdentHash ().ToBase64 (), ", sSID=", m_SendStreamID, ", rSID=", m_RecvStreamID);
}
if (flags & PACKET_FLAG_MAX_PACKET_SIZE_INCLUDED)
{
uint16_t maxPacketSize = bufbe16toh (optionData);
LogPrint (eLogDebug, "Streaming: Max packet size ", maxPacketSize);
optionData += 2;
}
if (flags & PACKET_FLAG_OFFLINE_SIGNATURE)
{
if (!m_RemoteIdentity)
{
LogPrint (eLogInfo, "Streaming: offline signature without identity");
return false;
}
// if we have it in LeaseSet already we don't need to parse it again
if (m_RemoteLeaseSet) m_TransientVerifier = m_RemoteLeaseSet->GetTransientVerifier ();
if (m_TransientVerifier)
{
// skip option data
optionData += 6; // timestamp and key type
optionData += m_TransientVerifier->GetPublicKeyLen (); // public key
optionData += m_RemoteIdentity->GetSignatureLen (); // signature
}
else
{
// transient key
size_t offset = 0;
m_TransientVerifier = i2p::data::ProcessOfflineSignature (m_RemoteIdentity, optionData, optionSize - (optionData - packet->GetOptionData ()), offset);
optionData += offset;
if (!m_TransientVerifier)
{
LogPrint (eLogError, "Streaming: offline signature failed");
return false;
}
}
}
if (flags & PACKET_FLAG_SIGNATURE_INCLUDED)
{
uint8_t signature[256];
auto signatureLen = m_RemoteIdentity->GetSignatureLen ();
if(signatureLen <= sizeof(signature))
{
memcpy (signature, optionData, signatureLen);
memset (const_cast<uint8_t *>(optionData), 0, signatureLen);
bool verified = m_TransientVerifier ?
m_TransientVerifier->Verify (packet->GetBuffer (), packet->GetLength (), signature) :
m_RemoteIdentity->Verify (packet->GetBuffer (), packet->GetLength (), signature);
if (!verified)
{
LogPrint (eLogError, "Streaming: Signature verification failed, sSID=", m_SendStreamID, ", rSID=", m_RecvStreamID);
Close ();
flags |= PACKET_FLAG_CLOSE;
}
memcpy (const_cast<uint8_t *>(optionData), signature, signatureLen);
optionData += signatureLen;
}
else
{
LogPrint (eLogError, "Streaming: Signature too big, ", signatureLen, " bytes");
return false;
}
}
return true;
}
void Stream::ProcessAck (Packet * packet)
{
bool acknowledged = false;
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
uint32_t ackThrough = packet->GetAckThrough ();
if (ackThrough > m_SequenceNumber)
{
LogPrint (eLogError, "Streaming: Unexpected ackThrough=", ackThrough, " > seqn=", m_SequenceNumber);
return;
}
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, "Streaming: Packet ", seqn, " NACK");
++it;
continue;
}
}
auto sentPacket = *it;
uint64_t rtt = ts - sentPacket->sendTime;
if(ts < sentPacket->sendTime)
{
LogPrint(eLogError, "Streaming: Packet ", seqn, "sent from the future, sendTime=", sentPacket->sendTime);
rtt = 1;
}
m_RTT = (m_RTT*seqn + rtt)/(seqn + 1);
m_RTO = m_RTT*1.5; // TODO: implement it better
LogPrint (eLogDebug, "Streaming: Packet ", seqn, " acknowledged rtt=", rtt, " sentTime=", sentPacket->sendTime);
m_SentPackets.erase (it++);
m_LocalDestination.DeletePacket (sentPacket);
acknowledged = true;
if (m_WindowSize < WINDOW_SIZE)
m_WindowSize++; // slow start
else
{
// linear growth
if (ts > m_LastWindowSizeIncreaseTime + m_RTT)
{
m_WindowSize++;
if (m_WindowSize > MAX_WINDOW_SIZE) m_WindowSize = MAX_WINDOW_SIZE;
m_LastWindowSizeIncreaseTime = ts;
}
}
if (!seqn && m_RoutingSession) // first message confirmed
m_RoutingSession->SetSharedRoutingPath (
std::make_shared<i2p::garlic::GarlicRoutingPath> (
i2p::garlic::GarlicRoutingPath{m_CurrentOutboundTunnel, m_CurrentRemoteLease, m_RTT, 0, 0}));
}
else
break;
}
if (m_SentPackets.empty ())
m_ResendTimer.cancel ();
if (acknowledged)
{
m_NumResendAttempts = 0;
SendBuffer ();
}
if (m_Status == eStreamStatusClosed)
Terminate ();
else if (m_Status == eStreamStatusClosing)
Close (); // check is all outgoing messages have been sent and we can send close
}
size_t Stream::Send (const uint8_t * buf, size_t len)
{
AsyncSend (buf, len, nullptr);
return len;
}
void Stream::AsyncSend (const uint8_t * buf, size_t len, SendHandler handler)
{
if (len > 0 && buf)
{
std::unique_lock<std::mutex> l(m_SendBufferMutex);
m_SendBuffer.Add (buf, len, handler);
}
else if (handler)
handler(boost::system::error_code ());
m_Service.post (std::bind (&Stream::SendBuffer, shared_from_this ()));
}
void Stream::SendBuffer ()
{
int numMsgs = m_WindowSize - m_SentPackets.size ();
if (numMsgs <= 0) return; // window is full
bool isNoAck = m_LastReceivedSequenceNumber < 0; // first packet
std::vector<Packet *> packets;
{
std::unique_lock<std::mutex> l(m_SendBufferMutex);
while ((m_Status == eStreamStatusNew) || (IsEstablished () && !m_SendBuffer.IsEmpty () && numMsgs > 0))
{
Packet * p = m_LocalDestination.NewPacket ();
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)
htobuf32 (packet + size, 0);
else
htobe32buf (packet + size, m_LastReceivedSequenceNumber);
size += 4; // ack Through
packet[size] = 0;
size++; // NACK count
packet[size] = m_RTO/1000;
size++; // resend delay
if (m_Status == eStreamStatusNew)
{
// initial packet
m_Status = eStreamStatusOpen;
if (!m_RemoteLeaseSet) m_RemoteLeaseSet = m_LocalDestination.GetOwner ()->FindLeaseSet (m_RemoteIdentity->GetIdentHash ());;
if (m_RemoteLeaseSet)
{
m_RoutingSession = m_LocalDestination.GetOwner ()->GetRoutingSession (m_RemoteLeaseSet, true);
m_MTU = m_RoutingSession->IsRatchets () ? STREAMING_MTU_RATCHETS : STREAMING_MTU;
}
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;
bool isOfflineSignature = m_LocalDestination.GetOwner ()->GetPrivateKeys ().IsOfflineSignature ();
if (isOfflineSignature) flags |= PACKET_FLAG_OFFLINE_SIGNATURE;
htobe16buf (packet + size, flags);
size += 2; // flags
size_t identityLen = m_LocalDestination.GetOwner ()->GetIdentity ()->GetFullLen ();
size_t signatureLen = m_LocalDestination.GetOwner ()->GetPrivateKeys ().GetSignatureLen ();
uint8_t * optionsSize = packet + size; // set options size later
size += 2; // options size
m_LocalDestination.GetOwner ()->GetIdentity ()->ToBuffer (packet + size, identityLen);
size += identityLen; // from
htobe16buf (packet + size, m_MTU);
size += 2; // max packet size
if (isOfflineSignature)
{
const auto& offlineSignature = m_LocalDestination.GetOwner ()->GetPrivateKeys ().GetOfflineSignature ();
memcpy (packet + size, offlineSignature.data (), offlineSignature.size ());
size += offlineSignature.size (); // offline signature
}
uint8_t * signature = packet + size; // set it later
memset (signature, 0, signatureLen); // zeroes for now
size += signatureLen; // signature
htobe16buf (optionsSize, packet + size - 2 - optionsSize); // actual options size
size += m_SendBuffer.Get (packet + size, m_MTU); // 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
size += m_SendBuffer.Get(packet + size, m_MTU); // payload
}
p->len = size;
packets.push_back (p);
numMsgs--;
}
}
if (packets.size () > 0)
{
if (m_SavedPackets.empty ()) // no NACKS
{
m_IsAckSendScheduled = false;
m_AckSendTimer.cancel ();
}
bool isEmpty = m_SentPackets.empty ();
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
for (auto& it: packets)
{
it->sendTime = ts;
m_SentPackets.insert (it);
}
SendPackets (packets);
if (m_Status == eStreamStatusClosing && m_SendBuffer.IsEmpty ())
SendClose ();
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, "Streaming: 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, "Streaming: Number of NACKs exceeds 256. seqn=", seqn, " nextSeqn=", nextSeqn);
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); // no flags set
size += 2; // flags
htobuf16 (packet + size, 0); // no options
size += 2; // options size
p.len = size;
SendPackets (std::vector<Packet *> { &p });
LogPrint (eLogDebug, "Streaming: Quick Ack sent. ", (int)numNacks, " NACKs");
}
void Stream::Close ()
{
LogPrint(eLogDebug, "Streaming: closing stream with sSID=", m_SendStreamID, ", rSID=", m_RecvStreamID, ", status=", m_Status);
switch (m_Status)
{
case eStreamStatusOpen:
m_Status = eStreamStatusClosing;
Close (); // recursion
if (m_Status == eStreamStatusClosing) //still closing
LogPrint (eLogDebug, "Streaming: Trying to send stream data before closing, sSID=", m_SendStreamID);
break;
case eStreamStatusReset:
// TODO: send reset
Terminate ();
break;
case eStreamStatusClosing:
if (m_SentPackets.empty () && m_SendBuffer.IsEmpty ()) // nothing to send
{
m_Status = eStreamStatusClosed;
SendClose();
}
break;
case eStreamStatusClosed:
// already closed
Terminate ();
break;
default:
LogPrint (eLogWarning, "Streaming: Unexpected stream status ", (int)m_Status, "sSID=", m_SendStreamID);
};
}
void Stream::SendClose ()
{
Packet * p = m_LocalDestination.NewPacket ();
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 >= 0 ? m_LastReceivedSequenceNumber : 0);
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 (eLogDebug, "Streaming: FIN sent, sSID=", m_SendStreamID);
}
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 ();
m_LocalDestination.DeletePacket (packet);
}
}
return pos;
}
bool Stream::SendPacket (Packet * packet)
{
if (packet)
{
if (m_IsAckSendScheduled)
{
m_IsAckSendScheduled = false;
m_AckSendTimer.cancel ();
}
SendPackets (std::vector<Packet *> { packet });
bool isEmpty = m_SentPackets.empty ();
m_SentPackets.insert (packet);
if (isEmpty)
ScheduleResend ();
return true;
}
else
return false;
}
void Stream::SendPackets (const std::vector<Packet *>& packets)
{
if (!m_RemoteLeaseSet)
{
UpdateCurrentRemoteLease ();
if (!m_RemoteLeaseSet)
{
LogPrint (eLogError, "Streaming: Can't send packets, missing remote LeaseSet, sSID=", m_SendStreamID);
return;
}
}
if (!m_RoutingSession || !m_RoutingSession->GetOwner ()) // expired and detached
m_RoutingSession = m_LocalDestination.GetOwner ()->GetRoutingSession (m_RemoteLeaseSet, true);
if (!m_CurrentOutboundTunnel && m_RoutingSession) // first message to send
{
// try to get shared path first
auto routingPath = m_RoutingSession->GetSharedRoutingPath ();
if (routingPath)
{
m_CurrentOutboundTunnel = routingPath->outboundTunnel;
m_CurrentRemoteLease = routingPath->remoteLease;
m_RTT = routingPath->rtt;
m_RTO = m_RTT*1.5; // TODO: implement it better
}
}
if (!m_CurrentOutboundTunnel || !m_CurrentOutboundTunnel->IsEstablished ())
m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ()->GetTunnelPool ()->GetNewOutboundTunnel (m_CurrentOutboundTunnel);
if (!m_CurrentOutboundTunnel)
{
LogPrint (eLogError, "Streaming: No outbound tunnels in the pool, sSID=", m_SendStreamID);
return;
}
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
if (!m_CurrentRemoteLease || !m_CurrentRemoteLease->endDate || // excluded from LeaseSet
ts >= m_CurrentRemoteLease->endDate - i2p::data::LEASE_ENDDATE_THRESHOLD)
UpdateCurrentRemoteLease (true);
if (m_CurrentRemoteLease && ts < m_CurrentRemoteLease->endDate + i2p::data::LEASE_ENDDATE_THRESHOLD)
{
std::vector<i2p::tunnel::TunnelMessageBlock> msgs;
for (auto it: packets)
{
auto msg = m_RoutingSession->WrapSingleMessage (m_LocalDestination.CreateDataMessage (
it->GetBuffer (), it->GetLength (), m_Port, !m_RoutingSession->IsRatchets ()));
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 (eLogWarning, "Streaming: Remote lease is not available, sSID=", m_SendStreamID);
if (m_RoutingSession)
m_RoutingSession->SetSharedRoutingPath (nullptr); // invalidate routing path
}
}
void Stream::SendUpdatedLeaseSet ()
{
if (m_RoutingSession)
{
if (m_RoutingSession->IsLeaseSetNonConfirmed ())
{
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
if (ts > m_RoutingSession->GetLeaseSetSubmissionTime () + i2p::garlic::LEASET_CONFIRMATION_TIMEOUT)
{
// LeaseSet was not confirmed, should try other tunnels
LogPrint (eLogWarning, "Streaming: LeaseSet was not confirmed in ", i2p::garlic::LEASET_CONFIRMATION_TIMEOUT, " milliseconds. Trying to resubmit");
m_RoutingSession->SetSharedRoutingPath (nullptr);
m_CurrentOutboundTunnel = nullptr;
m_CurrentRemoteLease = nullptr;
SendQuickAck ();
}
}
else if (m_RoutingSession->IsLeaseSetUpdated ())
{
LogPrint (eLogDebug, "Streaming: sending updated LeaseSet");
SendQuickAck ();
}
}
}
void Stream::ScheduleResend ()
{
m_ResendTimer.cancel ();
// check for invalid value
if (m_RTO <= 0) m_RTO = INITIAL_RTO;
m_ResendTimer.expires_from_now (boost::posix_time::milliseconds(m_RTO));
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)
{
// check for resend attempts
if (m_NumResendAttempts >= MAX_NUM_RESEND_ATTEMPTS)
{
LogPrint (eLogWarning, "Streaming: packet was not ACKed after ", MAX_NUM_RESEND_ATTEMPTS, " attempts, terminate, rSID=", m_RecvStreamID, ", sSID=", m_SendStreamID);
m_Status = eStreamStatusReset;
Close ();
return;
}
// collect packets to resend
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
std::vector<Packet *> packets;
for (auto it : m_SentPackets)
{
if (ts >= it->sendTime + m_RTO)
{
it->sendTime = ts;
packets.push_back (it);
}
}
// select tunnels if necessary and send
if (packets.size () > 0)
{
m_NumResendAttempts++;
m_RTO *= 2;
switch (m_NumResendAttempts)
{
case 1: // congesion avoidance
m_WindowSize >>= 1; // /2
if (m_WindowSize < MIN_WINDOW_SIZE) m_WindowSize = MIN_WINDOW_SIZE;
break;
case 2:
m_RTO = INITIAL_RTO; // drop RTO to initial upon tunnels pair change first time
#if (__cplusplus >= 201703L) // C++ 17 or higher
[[fallthrough]];
#endif
// no break here
case 4:
if (m_RoutingSession) m_RoutingSession->SetSharedRoutingPath (nullptr);
UpdateCurrentRemoteLease (); // pick another lease
LogPrint (eLogWarning, "Streaming: Another remote lease has been selected for stream with rSID=", m_RecvStreamID, ", sSID=", m_SendStreamID);
break;
case 3:
// pick another outbound tunnel
if (m_RoutingSession) m_RoutingSession->SetSharedRoutingPath (nullptr);
m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ()->GetTunnelPool ()->GetNextOutboundTunnel (m_CurrentOutboundTunnel);
LogPrint (eLogWarning, "Streaming: Another outbound tunnel has been selected for stream with sSID=", m_SendStreamID);
break;
default: ;
}
SendPackets (packets);
}
ScheduleResend ();
}
}
void Stream::HandleAckSendTimer (const boost::system::error_code& ecode)
{
if (m_IsAckSendScheduled)
{
if (m_LastReceivedSequenceNumber < 0)
{
LogPrint (eLogWarning, "Streaming: SYN has not been received after ", SYN_TIMEOUT, " milliseconds after follow on, terminate rSID=", m_RecvStreamID, ", sSID=", m_SendStreamID);
m_Status = eStreamStatusReset;
Close ();
return;
}
if (m_Status == eStreamStatusOpen)
{
if (m_RoutingSession && m_RoutingSession->IsLeaseSetNonConfirmed ())
{
// seems something went wrong and we should re-select tunnels
m_CurrentOutboundTunnel = nullptr;
m_CurrentRemoteLease = nullptr;
}
SendQuickAck ();
}
m_IsAckSendScheduled = false;
}
}
void Stream::UpdateCurrentRemoteLease (bool expired)
{
if (!m_RemoteLeaseSet || m_RemoteLeaseSet->IsExpired ())
{
m_RemoteLeaseSet = m_LocalDestination.GetOwner ()->FindLeaseSet (m_RemoteIdentity->GetIdentHash ());
if (!m_RemoteLeaseSet)
{
LogPrint (eLogWarning, "Streaming: LeaseSet ", m_RemoteIdentity->GetIdentHash ().ToBase64 (), " not found");
m_LocalDestination.GetOwner ()->RequestDestination (m_RemoteIdentity->GetIdentHash ()); // try to request for a next attempt
}
else
{
// LeaseSet updated
m_RemoteIdentity = m_RemoteLeaseSet->GetIdentity ();
m_TransientVerifier = m_RemoteLeaseSet->GetTransientVerifier ();
}
}
if (m_RemoteLeaseSet)
{
if (!m_RoutingSession)
m_RoutingSession = m_LocalDestination.GetOwner ()->GetRoutingSession (m_RemoteLeaseSet, true);
auto leases = m_RemoteLeaseSet->GetNonExpiredLeases (false); // try without threshold first
if (leases.empty ())
{
expired = false;
// time to request
if (m_RemoteLeaseSet->IsPublishedEncrypted ())
m_LocalDestination.GetOwner ()->RequestDestinationWithEncryptedLeaseSet (
std::make_shared<i2p::data::BlindedPublicKey>(m_RemoteIdentity));
else
m_LocalDestination.GetOwner ()->RequestDestination (m_RemoteIdentity->GetIdentHash ());
leases = m_RemoteLeaseSet->GetNonExpiredLeases (true); // then with threshold
}
if (!leases.empty ())
{
bool updated = false;
if (expired && m_CurrentRemoteLease)
{
for (const auto& it: leases)
if ((it->tunnelGateway == m_CurrentRemoteLease->tunnelGateway) && (it->tunnelID != m_CurrentRemoteLease->tunnelID))
{
m_CurrentRemoteLease = it;
updated = true;
break;
}
}
if (!updated)
{
uint32_t i = rand () % leases.size ();
if (m_CurrentRemoteLease && leases[i]->tunnelID == m_CurrentRemoteLease->tunnelID)
// make sure we don't select previous
i = (i + 1) % leases.size (); // if so, pick next
m_CurrentRemoteLease = leases[i];
}
}
else
{
LogPrint (eLogWarning, "Streaming: All remote leases are expired");
m_RemoteLeaseSet = nullptr;
m_CurrentRemoteLease = nullptr;
// we have requested expired before, no need to do it twice
}
}
else
{
LogPrint (eLogWarning, "Streaming: Remote LeaseSet not found");
m_CurrentRemoteLease = nullptr;
}
}
StreamingDestination::StreamingDestination (std::shared_ptr<i2p::client::ClientDestination> owner, uint16_t localPort, bool gzip):
m_Owner (owner), m_LocalPort (localPort), m_Gzip (gzip),
m_PendingIncomingTimer (m_Owner->GetService ())
{
}
StreamingDestination::~StreamingDestination ()
{
for (auto& it: m_SavedPackets)
{
for (auto it1: it.second) DeletePacket (it1);
it.second.clear ();
}
m_SavedPackets.clear ();
}
void StreamingDestination::Start ()
{
}
void StreamingDestination::Stop ()
{
ResetAcceptor ();
m_PendingIncomingTimer.cancel ();