Method SendDatagram

libi2pd/Datagram.cpp:59–117

	}

	void DatagramDestination::SendDatagram (std::shared_ptr<DatagramSession> session, const uint8_t * payload, size_t len,
		uint16_t fromPort, uint16_t toPort, const i2p::util::Mapping * options)
	{
		if (session)
		{
			std::shared_ptr<I2NPMessage>  msg;
			switch (session->GetVersion ())
			{
				case eDatagramV3:
				{
					uint8_t flags[] = { 0x00, 0x03 }; // datagram3, no options
					if (options)
					{
						uint8_t optionsBuf[256]; // TODO: evaluate actual size
						size_t optionsLen = options->ToBuffer (optionsBuf, 256);
						if (optionsLen) flags[1] |= DATAGRAM3_FLAG_OPTIONS;
						msg = CreateDataMessage ({{m_Owner->GetIdentity ()->GetIdentHash (), 32}, {flags, 2},
							{optionsBuf, optionsLen}, {payload, len}}, fromPort, toPort, i2p::client::PROTOCOL_TYPE_DATAGRAM3, false); // datagram3
					}
					else
						msg = CreateDataMessage ({{m_Owner->GetIdentity ()->GetIdentHash (), 32},
							{flags, 2}, {payload, len}}, fromPort, toPort, i2p::client::PROTOCOL_TYPE_DATAGRAM3, false); // datagram3
					break;
				}
				case eDatagramV1:
				{
					if (m_Owner->GetIdentity ()->GetSigningKeyType () == i2p::data::SIGNING_KEY_TYPE_DSA_SHA1)
					{
						uint8_t hash[32];
						SHA256(payload, len, hash);
						m_Owner->Sign (hash, 32, m_Signature.data ());
					}
					else
						m_Owner->Sign (payload, len, m_Signature.data ());
					msg = CreateDataMessage ({{m_From.data (), m_From.size ()}, {m_Signature.data (), m_Signature.size ()}, {payload, len}},
						fromPort, toPort, i2p::client::PROTOCOL_TYPE_DATAGRAM, !session->IsRatchets ()); // datagram1
					break;
				}
				case eDatagramV2:
				{
					constexpr uint8_t flags[] = { 0x00, 0x02 }; // datagram2, no options
					// signature
					std::vector<uint8_t> signedData (len + 32 + 2);
					memcpy (signedData.data (), m_Owner->GetIdentity ()->GetIdentHash (), 32);
					memcpy (signedData.data () + 32, flags, 2);
					memcpy (signedData.data () + 34, payload, len);
					m_Owner->Sign (signedData.data (), signedData.size (), m_Signature.data ());
					// TODO: offline signatures and options
					msg = CreateDataMessage ({{m_From.data (), m_From.size ()}, {flags, 2}, {payload, len},
						{m_Signature.data (), m_Signature.size ()}}, fromPort, toPort, i2p::client::PROTOCOL_TYPE_DATAGRAM2, false); // datagram2

					break;
				}
				default:
					LogPrint (eLogError, "Datagram: datagram type ", (int)session->GetVersion (), " is not supported");
			}
			if (msg) session->SendMsg(msg);
		}