src/target/trx_toolkit/data_if.py

   1 # -*- coding: utf-8 -*-
   2
   3 # TRX Toolkit
   4 # DATA interface implementation
   5 #
   6 # (C) 2017-2019 by Vadim Yanitskiy <axilirator@gmail.com>
   7 #
   8 # All Rights Reserved
   9 #
  10 # This program is free software; you can redistribute it and/or modify
  11 # it under the terms of the GNU General Public License as published by
  12 # the Free Software Foundation; either version 2 of the License, or
  13 # (at your option) any later version.
  14 #
  15 # This program is distributed in the hope that it will be useful,
  16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 # GNU General Public License for more details.
  19
  20 import logging as log
  21
  22 from udp_link import UDPLink
  23 from data_msg import *
  24
  25 class DATAInterface(UDPLink):
  26         def __init__(self, *udp_link_args):
  27                 # Default header version (legacy)
  28                 self._hdr_ver = 0x00
  29
  30                 UDPLink.__init__(self, *udp_link_args)
  31                 log.debug("Init TRXD interface (%s)" % self.desc_link())
  32
  33         def set_hdr_ver(self, ver):
  34                 if not ver in Msg.KNOWN_VERSIONS:
  35                         return False
  36
  37                 self._hdr_ver = ver
  38                 return True
  39
  40         def pick_hdr_ver(self, ver_req):
  41                 # Pick a version that is lower or equal to ver_req
  42                 for ver in Msg.KNOWN_VERSIONS[::-1]:
  43                         if ver <= ver_req:
  44                                 return ver
  45
  46                 # No suitable version found
  47                 return -1
  48
  49         def match_hdr_ver(self, msg):
  50                 if msg.ver == self._hdr_ver:
  51                         return True
  52
  53                 log.error("(%s) Rx DATA message (%s) with unexpected header "
  54                           "version %u (!= expected %u), ignoring..."
  55                         % (self.desc_link(), msg.desc_hdr(),
  56                            msg.ver, self._hdr_ver))
  57                 return False
  58
  59         def recv_raw_data(self):
  60                 data, _ = self.sock.recvfrom(512)
  61                 return data
  62
  63         def recv_tx_msg(self):
  64                 # Read raw data from socket
  65                 data = self.recv_raw_data()
  66
  67                 # Attempt to parse a TRXD Tx message
  68                 try:
  69                         msg = TxMsg()
  70                         msg.parse_msg(bytearray(data))
  71                 except:
  72                         log.error("Failed to parse a TRXD Tx message "
  73                                 "from R:%s:%u" % (self.remote_addr, self.remote_port))
  74                         return None
  75
  76                 # Make sure the header version matches
  77                 # the configured one (self._hdr_ver)
  78                 if not self.match_hdr_ver(msg):
  79                         return None
  80
  81                 return msg
  82
  83         def recv_rx_msg(self):
  84                 # Read raw data from socket
  85                 data = self.recv_raw_data()
  86
  87                 # Attempt to parse a TRXD Rx message
  88                 try:
  89                         msg = RxMsg()
  90                         msg.parse_msg(bytearray(data))
  91                 except:
  92                         log.error("Failed to parse a TRXD Rx message "
  93                                 "from R:%s:%u" % (self.remote_addr, self.remote_port))
  94                         return None
  95
  96                 # Make sure the header version matches
  97                 # the configured one (self._hdr_ver)
  98                 if not self.match_hdr_ver(msg):
  99                         return None
 100
 101                 return msg
 102
 103         def send_msg(self, msg, legacy = False):
 104                 try:
 105                         # Validate and encode a TRXD message
 106                         payload = msg.gen_msg(legacy)
 107                 except ValueError as e:
 108                         log.error("Failed to encode a TRXD message ('%s') "
 109                                 "due to error: %s" % (msg.desc_hdr(), e))
 110                         # TODO: we may want to send a NOPE.ind here
 111                         return
 112
 113                 # Send message
 114                 self.send(payload)