From 218b26ebd91fbc2cc440782a7a5142ee679126d1 Mon Sep 17 00:00:00 2001
From: PobreGato <315121269+pobregat0@users.noreply.github.com>
Date: Fri, 14 Aug 2026 04:14:16 +0300
Subject: [PATCH] datagram and raw subsessions for SAM 3.3

---
 libi2pd_client/SAM.cpp | 63 +++++++++++++++++++++++++++++++++++++++++-
 libi2pd_client/SAM.h   |  1 +
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/libi2pd_client/SAM.cpp b/libi2pd_client/SAM.cpp
index 1282c26a..b5240307 100644
--- a/libi2pd_client/SAM.cpp
+++ b/libi2pd_client/SAM.cpp
@@ -886,20 +886,81 @@ namespace client
 			}
 			std::string_view style = params[SAM_PARAM_STYLE];
 			SAMSessionType type = SAMSessionType::eSAMSessionTypeUnknown;
+			i2p::datagram::DatagramVersion datagramVersion = i2p::datagram::eDatagramV1;
 			if (style == SAM_VALUE_STREAM) type = SAMSessionType::eSAMSessionTypeStream;
-			// TODO: implement other styles
+#if __cplusplus >= 202002L // C++20
+			else if (style.starts_with (SAM_VALUE_DATAGRAM))
+#else
+			else if (style.substr (0, SAM_VALUE_DATAGRAM.size ()) == SAM_VALUE_DATAGRAM)
+#endif
+			{
+				// DATAGRAM, DATAGRAM1, DATAGRAM2, DATAGRAM3
+				type = SAMSessionType::eSAMSessionTypeDatagram;
+				if (style.size () > SAM_VALUE_DATAGRAM.size ())
+				{
+					switch (style[SAM_VALUE_DATAGRAM.size ()])
+					{
+						case '1': datagramVersion = i2p::datagram::eDatagramV1; break;
+						case '2': datagramVersion = i2p::datagram::eDatagramV2; break;
+						case '3': datagramVersion = i2p::datagram::eDatagramV3; break;
+						default: type = SAMSessionType::eSAMSessionTypeUnknown;
+					}
+				}
+			}
+			else if (style == SAM_VALUE_RAW) type = SAMSessionType::eSAMSessionTypeRaw;
 			if (type == SAMSessionType::eSAMSessionTypeUnknown)
 			{
 				// unknown style
 				SendSessionI2PError("Unsupported STYLE");
 				return;
 			}
+
+			std::shared_ptr<boost::asio::ip::udp::endpoint> forward = nullptr;
+			if ((type == SAMSessionType::eSAMSessionTypeDatagram || type == SAMSessionType::eSAMSessionTypeRaw) &&
+				params.Contains (SAM_PARAM_HOST) && params.Contains (SAM_PARAM_PORT))
+			{
+				// udp forward selected
+				boost::system::error_code e;
+				auto addr = boost::asio::ip::make_address (params[SAM_PARAM_HOST], e);
+				if (e)
+				{
+					SendSessionI2PError("Invalid IP Address in HOST");
+					return;
+				}
+				uint16_t port = 0;
+				if (!params.Get (SAM_PARAM_PORT, port))
+				{
+					SendSessionI2PError("Invalid port");
+					return;
+				}
+				forward = std::make_shared<boost::asio::ip::udp::endpoint>(addr, port);
+			}
+
 			uint16_t fromPort = 0;
 			params.Get (SAM_PARAM_FROM_PORT, fromPort);
+			// traffic from I2P is routed by port, LISTEN_PORT defaults to FROM_PORT
+			uint16_t listenPort = fromPort;
+			params.Get (SAM_PARAM_LISTEN_PORT, listenPort);
 
 			auto subsession = std::make_shared<SAMSubSession>(masterSession, id, type, fromPort);
 			if (m_Owner.AddSession (subsession))
 			{
+				if (type == SAMSessionType::eSAMSessionTypeDatagram || type == SAMSessionType::eSAMSessionTypeRaw)
+				{
+					subsession->DatagramVersion = datagramVersion;
+					subsession->UDPEndpoint = forward;
+					auto dest = masterSession->GetLocalDestination ()->CreateDatagramDestination (true, datagramVersion);
+					if (type == SAMSessionType::eSAMSessionTypeDatagram)
+						dest->SetReceiver (std::bind (&SAMSocket::HandleI2PDatagramReceive, shared_from_this (),
+							std::placeholders::_1, std::placeholders::_2, std::placeholders::_3,
+							std::placeholders::_4, std::placeholders::_5, std::placeholders::_6),
+							listenPort);
+					else
+						dest->SetRawReceiver (std::bind (&SAMSocket::HandleI2PRawDatagramReceive, shared_from_this (),
+							std::placeholders::_1, std::placeholders::_2, std::placeholders::_3,
+							std::placeholders::_4),
+							listenPort);
+				}
 				masterSession->subsessions.insert (std::string (id));
 				SendSessionCreateReplyOk ();
 			}
diff --git a/libi2pd_client/SAM.h b/libi2pd_client/SAM.h
index c65c1870..0f2e63a6 100644
--- a/libi2pd_client/SAM.h
+++ b/libi2pd_client/SAM.h
@@ -81,6 +81,7 @@ namespace client
 	const char SAM_PARAM_CRYPTO_TYPE[] = "CRYPTO_TYPE";
 	const char SAM_PARAM_SIZE[] = "SIZE";
 	const char SAM_PARAM_HOST[] = "HOST";
+	const char SAM_PARAM_LISTEN_PORT[] = "LISTEN_PORT";
 	const char SAM_PARAM_PORT[] = "PORT";
 	const char SAM_PARAM_FROM_PORT[] = "FROM_PORT";
 	const char SAM_PARAM_TO_PORT[] = "TO_PORT";