openwebrx-clone/owrx/kiss.py
2021-04-07 16:20:10 +02:00

192 lines
5.8 KiB
Python

import socket
import time
import logging
import random
from owrx.config import Config
from abc import ABC, abstractmethod
logger = logging.getLogger(__name__)
FEND = 0xC0
FESC = 0xDB
TFEND = 0xDC
TFESC = 0xDD
FEET_PER_METER = 3.28084
class DirewolfConfigSubscriber(ABC):
@abstractmethod
def onConfigChanged(self):
pass
class DirewolfConfig(object):
config_keys = [
"aprs_callsign",
"aprs_igate_enabled",
"aprs_igate_server",
"aprs_igate_password",
"receiver_gps",
"aprs_igate_symbol",
"aprs_igate_beacon",
"aprs_igate_gain",
"aprs_igate_dir",
"aprs_igate_comment",
"aprs_igate_height",
]
def __init__(self):
self.subscribers = []
self.configSub = None
self.port = None
def wire(self, subscriber: DirewolfConfigSubscriber):
self.subscribers.append(subscriber)
if self.configSub is None:
pm = Config.get()
self.configSub = pm.filter(*DirewolfConfig.config_keys).wire(self._fireChanged)
def unwire(self, subscriber: DirewolfConfigSubscriber):
self.subscribers.remove(subscriber)
if not self.subscribers and self.configSub is not None:
self.configSub.cancel()
def _fireChanged(self, changes):
for sub in self.subscribers:
try:
sub.onConfigChanged()
except Exception:
logger.exception("Error while notifying Direwolf subscribers")
def getPort(self):
# direwolf has some strange hardcoded port ranges
while self.port is None:
try:
port = random.randrange(1024, 49151)
# test if port is available for use
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(("localhost", port))
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.close()
self.port = port
except OSError:
pass
return self.port
def getConfig(self, is_service):
pm = Config.get()
config = """
ACHANNELS 1
ADEVICE stdin null
CHANNEL 0
MYCALL {callsign}
MODEM 1200
KISSPORT {port}
AGWPORT off
""".format(
port=self.getPort(), callsign=pm["aprs_callsign"]
)
if is_service and pm["aprs_igate_enabled"]:
pbeacon = ""
if pm["aprs_igate_beacon"]:
# Format beacon lat/lon
lat = pm["receiver_gps"]["lat"]
lon = pm["receiver_gps"]["lon"]
direction_ns = "N" if lat > 0 else "S"
direction_we = "E" if lon > 0 else "W"
lat = abs(lat)
lon = abs(lon)
lat = "{0:02d}^{1:05.2f}{2}".format(int(lat), (lat - int(lat)) * 60, direction_ns)
lon = "{0:03d}^{1:05.2f}{2}".format(int(lon), (lon - int(lon)) * 60, direction_we)
# Convert height from meters to feet if specified
height = ""
if "aprs_igate_height" in pm:
try:
height_m = float(pm["aprs_igate_height"])
height_ft = round(height_m * FEET_PER_METER)
height = "HEIGHT=" + str(height_ft)
except:
logger.error(
"Cannot parse 'aprs_igate_height', expected float: " + str(pm["aprs_igate_height"])
)
pbeacon = 'PBEACON sendto=IG delay=0:30 every=60:00 symbol={symbol} lat={lat} long={lon} {height} {gain} {adir} comment="{comment}"'.format(
symbol=pm["aprs_igate_symbol"],
lat=lat,
lon=lon,
height=height,
gain="GAIN=" + str(pm["aprs_igate_gain"]) if "aprs_igate_gain" in pm else "",
adir="DIR=" + str(pm["aprs_igate_dir"]) if "aprs_igate_dir" in pm else "",
comment=pm["aprs_igate_comment"],
)
logger.info("APRS PBEACON String: " + pbeacon)
config += """
IGSERVER {server}
IGLOGIN {callsign} {password}
{pbeacon}
""".format(
server=pm["aprs_igate_server"],
callsign=pm["aprs_callsign"],
password=pm["aprs_igate_password"],
pbeacon=pbeacon,
)
return config
class KissClient(object):
def __init__(self, port):
delay = 0.5
retries = 0
while True:
try:
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.socket.connect(("localhost", port))
break
except ConnectionError:
if retries > 20:
logger.error("maximum number of connection attempts reached. did direwolf start up correctly?")
raise
retries += 1
time.sleep(delay)
def read(self):
return self.socket.recv(1)
class KissDeframer(object):
def __init__(self):
self.escaped = False
self.buf = bytearray()
def parse(self, input):
frames = []
for b in input:
if b == FESC:
self.escaped = True
elif self.escaped:
if b == TFEND:
self.buf.append(FEND)
elif b == TFESC:
self.buf.append(FESC)
else:
logger.warning("invalid escape char: %s", str(input[0]))
self.escaped = False
elif input[0] == FEND:
# data frames start with 0x00
if len(self.buf) > 1 and self.buf[0] == 0x00:
frames += [self.buf[1:]]
self.buf = bytearray()
else:
self.buf.append(b)
return frames