+#---------- SLIP handling ----------
+
+slip_end = b'\300'
+slip_esc = b'\333'
+slip_esc_end = b'\334'
+slip_esc_esc = b'\335'
+slip_delimiter = slip_end
+
+def slip_encode(packet):
+ return (packet
+ .replace(slip_esc, slip_esc + slip_esc_esc)
+ .replace(slip_end, slip_esc + slip_esc_end))
+
+def slip_decode(data):
+ print('DECODE ', repr(data))
+ out = []
+ for packet in data.split(slip_end):
+ pdata = b''
+ while True:
+ eix = packet.find(slip_esc)
+ if eix == -1:
+ pdata += packet
+ break
+ #print('ESC ', repr((pdata, packet, eix)))
+ pdata += packet[0 : eix]
+ ck = packet[eix+1]
+ if ck == slip_esc_esc: pdata += slip_esc
+ elif ck == slip_esc_end: pdata += slip_end
+ else: raise ValueError('invalid SLIP escape')
+ packet = packet[eix+2 : ]
+ out.append(pdata)
+ print('DECODED ', repr(out))
+ return out
+
+#---------- packet parsing ----------
+
+def packet_addrs(packet):
+ pass
+