limit SSU message size to 32K

libi2pd/SSUData.cpp

@@ -320,7 +320,7 @@ namespace transport
 		uint8_t * msgBuf = msg->GetSSUHeader ();
 
 		uint32_t fragmentNum = 0;
-		while (len > 0)
+		while (len > 0 && fragmentNum <= 127)
 		{
 			Fragment * fragment = new Fragment;
 			fragment->fragmentNum = fragmentNum;
@@ -332,7 +332,7 @@ namespace transport
 			payload++;
 			htobe32buf (payload, msgID);
 			payload += 4;
-			bool isLast = (len <= payloadSize);
+			bool isLast = (len <= payloadSize) || fragmentNum == 127; // 127 fragments max
 			size_t size = isLast ? len : payloadSize;
 			uint32_t fragmentInfo = (fragmentNum << 17);
 			if (isLast)

libi2pd/SSUSession.cpp

@@ -929,7 +929,13 @@ namespace transport
 		if (m_State == eSessionStateEstablished)
 		{
 			for (const auto& it: msgs)
-				if (it) m_Data.Send (it);
+				if (it)
+				{
+					if (it->GetLength () <= SSU_MAX_I2NP_MESSAGE_SIZE) 
+						m_Data.Send (it);
+					else
+						LogPrint (eLogError, "SSU: I2NP message of size ", it->GetLength (), " can't be sent. Dropped");
+				}
 		}
 	}
 

libi2pd/SSUSession.h

@@ -28,6 +28,7 @@ namespace transport
 	const int SSU_CONNECT_TIMEOUT = 5; // 5 seconds
 	const int SSU_TERMINATION_TIMEOUT = 330; // 5.5 minutes
 	const int SSU_CLOCK_SKEW = 60; // in seconds
+	const size_t SSU_MAX_I2NP_MESSAGE_SIZE = 32768;	
 
 	// payload types (4 bits)
 	const uint8_t PAYLOAD_TYPE_SESSION_REQUEST = 0;