[SSU] handle ICMP responses

Windows network stack can forward ICMP to socket and simple deleting of
packet can cause socket death. Same thing can happen on other systems
but without socket death.

Signed-off-by: R4SAS <r4sas@i2pmail.org>

libi2pd/SSU.cpp

@@ -242,10 +242,16 @@ namespace transport
 
 	void SSUServer::Send (const uint8_t * buf, size_t len, const boost::asio::ip::udp::endpoint& to)
 	{
+		boost::system::error_code ec;
 		if (to.protocol () == boost::asio::ip::udp::v4())
-			m_Socket.send_to (boost::asio::buffer (buf, len), to);
+			m_Socket.send_to (boost::asio::buffer (buf, len), to, 0, ec);
 		else
-			m_SocketV6.send_to (boost::asio::buffer (buf, len), to);
+			m_SocketV6.send_to (boost::asio::buffer (buf, len), to, 0, ec);
+
+		if (ec)
+		{
+			LogPrint (eLogError, "SSU: send exception: ", ec.message (), " while trying to send data to ", to.address (), ":", to.port (), " (length: ", len, ")");
+		}
 	}
 
 	void SSUServer::Receive ()
@@ -264,7 +270,13 @@ namespace transport
 
 	void SSUServer::HandleReceivedFrom (const boost::system::error_code& ecode, std::size_t bytes_transferred, SSUPacket * packet)
 	{
-		if (!ecode)
+		if (!ecode ||
+		    ecode == boost::asio::error::connection_refused ||
+		    ecode == boost::asio::error::connection_reset ||
+		    ecode == boost::asio::error::network_unreachable ||
+		    ecode == boost::asio::error::host_unreachable)
+		// just try continue reading when received ICMP response otherwise socket can crash,
+		// but better to find out which host were sent it and mark that router as unreachable
 		{
 			packet->len = bytes_transferred;
 			std::vector<SSUPacket *> packets;
@@ -286,7 +298,7 @@ namespace transport
 					}
 					else
 					{
-						LogPrint (eLogError, "SSU: receive_from error: ", ec.message ());
+						LogPrint (eLogError, "SSU: receive_from error: code ", ec.value(), ": ", ec.message ());
 						delete packet;
 						break;
 					}
@@ -301,7 +313,7 @@ namespace transport
 			delete packet;
 			if (ecode != boost::asio::error::operation_aborted)
 			{
-				LogPrint (eLogError, "SSU: receive error: ", ecode.message ());
+				LogPrint (eLogError, "SSU: receive error: code ", ecode.value(), ": ", ecode.message ());
 				m_Socket.close ();
 				OpenSocket ();
 				Receive ();
@@ -311,7 +323,13 @@ namespace transport
 
 	void SSUServer::HandleReceivedFromV6 (const boost::system::error_code& ecode, std::size_t bytes_transferred, SSUPacket * packet)
 	{
-		if (!ecode)
+		if (!ecode ||
+		    ecode == boost::asio::error::connection_refused ||
+		    ecode == boost::asio::error::connection_reset ||
+		    ecode == boost::asio::error::network_unreachable ||
+		    ecode == boost::asio::error::host_unreachable)
+		// just try continue reading when received ICMP response otherwise socket can crash,
+		// but better to find out which host were sent it and mark that router as unreachable
 		{
 			packet->len = bytes_transferred;
 			std::vector<SSUPacket *> packets;
@@ -333,7 +351,7 @@ namespace transport
 					}
 					else
 					{
-						LogPrint (eLogError, "SSU: v6 receive_from error: ", ec.message ());
+						LogPrint (eLogError, "SSU: v6 receive_from error: code ", ec.value(), ": ", ec.message ());
 						delete packet;
 						break;
 					}
@@ -348,7 +366,7 @@ namespace transport
 			delete packet;
 			if (ecode != boost::asio::error::operation_aborted)
 			{
-				LogPrint (eLogError, "SSU: v6 receive error: ", ecode.message ());
+				LogPrint (eLogError, "SSU: v6 receive error: code ", ecode.value(), ": ", ecode.message ());
 				m_SocketV6.close ();
 				OpenSocketV6 ();
 				ReceiveV6 ();