Method HandleRelayRequest

libi2pd/SSU2Session.cpp:2206–2253

	}

	void SSU2Session::HandleRelayRequest (const uint8_t * buf, size_t len)
	{
		// we are Bob
		if (len < 9) return;
		auto mts = i2p::util::GetMillisecondsSinceEpoch ();
		uint32_t nonce = bufbe32toh (buf + 1); // nonce
		uint32_t relayTag = bufbe32toh (buf + 5); // relay tag
		auto session = m_Server.FindRelaySession (relayTag);
		if (!session)
		{
			LogPrint (eLogWarning, "SSU2: RelayRequest session with relay tag ", relayTag, " not found");
			// send relay response back to Alice
			auto packet = m_Server.GetSentPacketsPool ().AcquireShared ();
			packet->payloadSize = CreateAckBlock (packet->payload, m_MaxPayloadSize);
			packet->payloadSize += CreateRelayResponseBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize,
				eSSU2RelayResponseCodeBobRelayTagNotFound, nonce, 0, false);
			packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize);
			uint32_t packetNum = SendData (packet->payload, packet->payloadSize);
			if (m_RemoteVersion >= SSU2_MIN_RELAY_RESPONSE_RESEND_VERSION)
			{
				// sometimes Alice doesn't ack this RelayResponse in older versions
				packet->sendTime = mts;
				m_SentPackets.emplace (packetNum, packet);
			}
			return;
		}
		if (session->m_RelaySessions.emplace (nonce, std::make_pair (shared_from_this (), mts/1000)).second)
		{
			// send relay intro to Charlie
			auto r = i2p::data::netdb.FindRouter (GetRemoteIdentity ()->GetIdentHash ()); // Alice's RI
			if (r && (r->IsUnreachable () || !i2p::data::netdb.PopulateRouterInfoBuffer (r))) r = nullptr;
			if (!r) LogPrint (eLogWarning, "SSU2: RelayRequest Alice's router info not found");

			auto packet = m_Server.GetSentPacketsPool ().AcquireShared ();
			packet->payloadSize = r ? CreateRouterInfoBlock (packet->payload, m_MaxPayloadSize - len - 32, r) : 0;
			if (!packet->payloadSize && r)
				session->SendFragmentedMessage (CreateDatabaseStoreMsg (r));
			packet->payloadSize += CreateRelayIntroBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize, buf + 1, len - 1);
			if (packet->payloadSize < m_MaxPayloadSize)
				packet->payloadSize += CreatePaddingBlock (packet->payload + packet->payloadSize, m_MaxPayloadSize - packet->payloadSize);
			uint32_t packetNum = session->SendData (packet->payload, packet->payloadSize);
			packet->sendTime = mts;
			// Charlie always responds with RelayResponse
			session->m_SentPackets.emplace (packetNum, packet);
		}
		else
			LogPrint (eLogInfo, "SSU2: Relay request nonce ", nonce, " already exists. Ignore");
	}

	void SSU2Session::HandleRelayIntro (const uint8_t * buf, size_t len, int attempts)
	{