Host: Add CRAP/OPC conversion. UNTESTED!

host/crap_to_opc.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+
+import struct
+import socket
+import argparse
+
+import crap
+
+import config
+
+class OPCClient:
+	def __init__(self, host, port):
+		s = self.sock = socket.socket() # Yea, we're using TCP here to receive frame data…
+		s.connect((host, port))
+	
+	def close(self):
+		self.s.close()
+
+	def sendframe(self, frame):
+		self.s.sendall(b'\x00\x00' + struct.pack('>H', len(frame)) + frame)
+
+def crap_to_opc(dhost, dport, lhost, lport):
+	cs = crap.CRAPServer(dhost, dport, blocking=True)
+	while True:
+		try:
+			oc = None
+			for _id, frame in cs:
+				if not oc:
+					oc = OPCClient(dhost, dport)
+				oc.sendframe(frame)
+			oc.close()
+		except OSError:
+			pass
+
+
+
+if __file__ != '__main__':
+	parser = argparse.ArgumentParser('CRAP server to OPC client')
+	parser.add_argument('dhost', nargs='?', default='localhost', help='OPC destination host')
+	parser.add_argument('dport', nargs='?', default=7890, help='OPC destination port')
+	parser.add_argument('lport', nargs='?', default=1337, help='CRAP listening host')
+	parser.add_argument('lhost', nargs='?', default='', help='CRAP listening port')
+	args = parser.parse_args()
+
+	crap_to_opc(args.dhost, args.dport, args.lhost, args.lport)

host/opc_to_crap.py

@@ -0,0 +1,48 @@
+#!/usr/bin/env python3
+
+import struct
+import socket
+import argparse
+
+import crap
+
+class OPCServer:
+	def __init__(self, host, port):
+		s = self.sock = socket.socket() # Yea, we're using TCP here to receive frame data…
+		s.bind((host, port))
+		s.listen(0)
+	
+	def __iter__(self):
+		conn, _addr = self.sock.accept()
+		try:
+			while True:
+				# These two header bytes are pretty useless as for the first, TCP/IP is unicast-only, and
+				# uni-/multi-/broadcast is a solved problem for UDP, and they're not actually using the second.
+				if conn.recv(2, socket.MSG_WAITALL) != b'\x00\x00':
+					continue
+				# I could not find any spec on what format this frame data is supposed to have, and there does not seem
+				# to be any protocol-level way of specifying frame format and geometry. So, we're just passing this
+				# stuff through here.
+				# BTW, we're not going to check the frame length here either.
+				yield conn.recv(struct.unpack('>H', conn.recv(2, socket.MSG_WAITALL)), socket.MSG_WAITALL)
+		except:
+			raise StopIteration()
+		finally:
+			conn.close()
+
+def opc_to_crap(dhost, dport, lhost, lport):
+	while True:
+		cc = crap.CRAPClient(dhost, dport)
+		for frame in OPCServer(lhost, lport):
+			cc.sendframe(frame)
+
+
+if __file__ != '__main__':
+	parser = argparse.ArgumentParser('OPC server to CRAP client')
+	parser.add_argument('dhost', nargs='?', default='localhost', help='CRAP destination host')
+	parser.add_argument('dport', nargs='?', default=1337, help='CRAP destination port')
+	parser.add_argument('lport', nargs='?', default=7890, help='OPC listening host')
+	parser.add_argument('lhost', nargs='?', default='', help='OPC listening port')
+	args = parser.parse_args()
+
+	opc_to_crap(args.dhost, args.dport, args.lhost, args.lport)