From e10ca637da74b6d0db7470ec8c52c74fff604f2c Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Fri, 22 Apr 2022 15:03:49 -0400
Subject: [PATCH] handle RelayIntro
---
libi2pd/SSU2.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++----
libi2pd/SSU2.h | 4 +++-
2 files changed, 51 insertions(+), 5 deletions(-)
diff --git a/libi2pd/SSU2.cpp b/libi2pd/SSU2.cpp
index fbec0a5b..d33592c1 100644
--- a/libi2pd/SSU2.cpp
+++ b/libi2pd/SSU2.cpp
@@ -853,6 +853,8 @@ namespace transport
}
break;
case eSSU2BlkRelayTag:
+ LogPrint (eLogDebug, "SSU2: RelayTag");
+ m_RelayTag = bufbe32toh (buf + offset);
break;
case eSSU2BlkNewToken:
{
@@ -1026,8 +1028,8 @@ namespace transport
s.Insert (session->GetRemoteIdentity ()->GetIdentHash (), 32); // chash
s.Insert (buf + 1, 14); // nonce, relay tag, timestamp, ver, asz
uint8_t asz = buf[14];
- s.Insert (buf + 15, asz + 2); // Alice IP, Alice Port
- if (!s.Verify (GetRemoteIdentity (), buf + 17 + asz))
+ s.Insert (buf + 15, asz); // Alice Port, Alice IP
+ if (!s.Verify (GetRemoteIdentity (), buf + 15 + asz))
{
LogPrint (eLogWarning, "SSU2: RelayRequest signature verification failed");
return; // TODO: send relay response
@@ -1039,6 +1041,29 @@ namespace transport
payloadSize += CreatePaddingBlock (payload + payloadSize, SSU2_MTU - payloadSize);
session->SendData (payload, payloadSize);
}
+
+ void SSU2Session::HandleRelayIntro (const uint8_t * buf, size_t len)
+ {
+ // we are Charlie
+ SignedData s;
+ s.Insert ((const uint8_t *)"RelayRequestData", 16); // prologue
+ s.Insert (GetRemoteIdentity ()->GetIdentHash (), 32); // bhash
+ s.Insert (i2p::context.GetIdentHash (), 32); // chash
+ s.Insert (buf + 33, 14); // nonce, relay tag, timestamp, ver, asz
+ uint8_t asz = buf[46];
+ s.Insert (buf + 47, asz); // Alice Port, Alice IP
+ if (!s.Verify (GetRemoteIdentity (), buf + 47 + asz))
+ {
+ LogPrint (eLogWarning, "SSU2: RelayIntro signature verification failed");
+ return; // TODO: send relay response
+ }
+
+ // TODO: send RelayResponse to Bob
+
+ boost::asio::ip::udp::endpoint ep;
+ if (ExtractEndpoint (buf + 47, asz, ep))
+ m_Server.SendHolePunch (ep);
+ }
bool SSU2Session::ExtractEndpoint (const uint8_t * buf, size_t size, boost::asio::ip::udp::endpoint& ep)
{
@@ -1580,7 +1605,10 @@ namespace transport
m_SocketV6.send_to (bufs, to, 0, ec);
else
m_SocketV4.send_to (bufs, to, 0, ec);
- i2p::transport::transports.UpdateSentBytes (headerLen + payloadLen);
+ if (!ec)
+ i2p::transport::transports.UpdateSentBytes (headerLen + payloadLen);
+ else
+ LogPrint (eLogError, "SSU2: Send exception: ", ec.message (), " to ", to);
}
void SSU2Server::Send (const uint8_t * header, size_t headerLen, const uint8_t * headerX, size_t headerXLen,
@@ -1597,9 +1625,25 @@ namespace transport
m_SocketV6.send_to (bufs, to, 0, ec);
else
m_SocketV4.send_to (bufs, to, 0, ec);
- i2p::transport::transports.UpdateSentBytes (headerLen + headerXLen + payloadLen);
+
+ if (!ec)
+ i2p::transport::transports.UpdateSentBytes (headerLen + headerXLen + payloadLen);
+ else
+ LogPrint (eLogError, "SSU2: Send exception: ", ec.message (), " to ", to);
}
+ void SSU2Server::SendHolePunch (const boost::asio::ip::udp::endpoint& to)
+ {
+ boost::system::error_code ec;
+ if (to.address ().is_v6 ())
+ m_SocketV6.send_to (boost::asio::buffer ((uint8_t *)nullptr, 0), to, 0, ec);
+ else
+ m_SocketV4.send_to (boost::asio::buffer ((uint8_t *)nullptr, 0), to, 0, ec);
+
+ if (ec)
+ LogPrint (eLogError, "SSU2: Send exception: ", ec.message (), " to ", to);
+ }
+
bool SSU2Server::CreateSession (std::shared_ptr<const i2p::data::RouterInfo> router,
std::shared_ptr<const i2p::data::RouterInfo::Address> address)
{
diff --git a/libi2pd/SSU2.h b/libi2pd/SSU2.h
index b70b1ebe..1bd930f6 100644
--- a/libi2pd/SSU2.h
+++ b/libi2pd/SSU2.h
@@ -186,6 +186,7 @@ namespace transport
void HandleFollowOnFragment (const uint8_t * buf, size_t len);
bool ConcatOutOfSequenceFragments (std::shared_ptr<SSU2IncompleteMessage> m); // true if message complete
void HandleRelayRequest (const uint8_t * buf, size_t len);
+ void HandleRelayIntro (const uint8_t * buf, size_t len);
size_t CreateAddressBlock (const boost::asio::ip::udp::endpoint& ep, uint8_t * buf, size_t len);
size_t CreateAckBlock (uint8_t * buf, size_t len);
@@ -257,7 +258,8 @@ namespace transport
const boost::asio::ip::udp::endpoint& to);
void Send (const uint8_t * header, size_t headerLen, const uint8_t * headerX, size_t headerXLen,
const uint8_t * payload, size_t payloadLen, const boost::asio::ip::udp::endpoint& to);
-
+ void SendHolePunch (const boost::asio::ip::udp::endpoint& to);
+
bool CreateSession (std::shared_ptr<const i2p::data::RouterInfo> router,
std::shared_ptr<const i2p::data::RouterInfo::Address> address);