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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2017 Daniel Estevez <daniel@destevez.net>
#
# This file is part of gr-satellites
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
import struct
class CSP(object):
def __init__(self, csp_packet):
if len(csp_packet) < 4:
raise ValueError('Malformed CSP packet (too short)')
csp = struct.unpack('!I', csp_packet[0:4])[0]
self.priority = (csp >> 30) & 0x3
self.source = (csp >> 25) & 0x1f
self.destination = (csp >> 20) & 0x1f
self.dest_port = (csp >> 14) & 0x3f
self.source_port = (csp >> 8) & 0x3f
self.reserved = (csp >> 4) & 0xf
self.hmac = (csp >> 3) & 1
self.xtea = (csp >> 2) & 1
self.rdp = (csp >> 1) & 1
self.crc = csp & 1
def __str__(self):
return ("""CSP header:
Priority:\t\t{}
Source:\t\t\t{}
Destination:\t\t{}
Destination port:\t{}
Source port:\t\t{}
Reserved field:\t\t{}
HMAC:\t\t\t{}
XTEA:\t\t\t{}
RDP:\t\t\t{}
CRC:\t\t\t{}""".format(
self.priority, self.source, self.destination, self.dest_port,
self.source_port, self.reserved, self.hmac, self.xtea, self.rdp,
self.crc))
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