Reticulum/RNS/Interfaces/AX25KISSInterface.py

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# MIT License
#
# Copyright (c) 2016-2022 Mark Qvist / unsigned.io
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
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from .Interface import Interface
from time import sleep
import sys
import threading
import time
import RNS
class KISS():
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FEND = 0xC0
FESC = 0xDB
TFEND = 0xDC
TFESC = 0xDD
CMD_UNKNOWN = 0xFE
CMD_DATA = 0x00
CMD_TXDELAY = 0x01
CMD_P = 0x02
CMD_SLOTTIME = 0x03
CMD_TXTAIL = 0x04
CMD_FULLDUPLEX = 0x05
CMD_SETHARDWARE = 0x06
CMD_READY = 0x0F
CMD_RETURN = 0xFF
@staticmethod
def escape(data):
data = data.replace(bytes([0xdb]), bytes([0xdb, 0xdd]))
data = data.replace(bytes([0xc0]), bytes([0xdb, 0xdc]))
return data
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class AX25():
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PID_NOLAYER3 = 0xF0
CTRL_UI = 0x03
CRC_CORRECT = bytes([0xF0])+bytes([0xB8])
HEADER_SIZE = 16
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class AX25KISSInterface(Interface):
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MAX_CHUNK = 32768
BITRATE_GUESS = 1200
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owner = None
port = None
speed = None
databits = None
parity = None
stopbits = None
serial = None
def __init__(self, owner, name, callsign, ssid, port, speed, databits, parity, stopbits, preamble, txtail, persistence, slottime, flow_control):
import importlib
if importlib.util.find_spec('serial') != None:
import serial
else:
RNS.log("Using the AX.25 KISS interface requires a serial communication module to be installed.", RNS.LOG_CRITICAL)
RNS.log("You can install one with the command: python3 -m pip install pyserial", RNS.LOG_CRITICAL)
RNS.panic()
super().__init__()
self.HW_MTU = 564
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self.pyserial = serial
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self.serial = None
self.owner = owner
self.name = name
self.src_call = callsign.upper().encode("ascii")
self.src_ssid = ssid
self.dst_call = "APZRNS".encode("ascii")
self.dst_ssid = 0
self.port = port
self.speed = speed
self.databits = databits
self.parity = serial.PARITY_NONE
self.stopbits = stopbits
self.timeout = 100
self.online = False
self.bitrate = KISSInterface.BITRATE_GUESS
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self.packet_queue = []
self.flow_control = flow_control
self.interface_ready = False
self.flow_control_timeout = 5
self.flow_control_locked = time.time()
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if (len(self.src_call) < 3 or len(self.src_call) > 6):
raise ValueError("Invalid callsign for "+str(self))
if (self.src_ssid < 0 or self.src_ssid > 15):
raise ValueError("Invalid SSID for "+str(self))
self.preamble = preamble if preamble != None else 350;
self.txtail = txtail if txtail != None else 20;
self.persistence = persistence if persistence != None else 64;
self.slottime = slottime if slottime != None else 20;
if parity.lower() == "e" or parity.lower() == "even":
self.parity = serial.PARITY_EVEN
if parity.lower() == "o" or parity.lower() == "odd":
self.parity = serial.PARITY_ODD
try:
self.open_port()
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except Exception as e:
RNS.log("Could not open serial port for interface "+str(self), RNS.LOG_ERROR)
raise e
if self.serial.is_open:
self.configure_device()
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else:
raise IOError("Could not open serial port")
def open_port(self):
RNS.log("Opening serial port "+self.port+"...", RNS.LOG_VERBOSE)
self.serial = self.pyserial.Serial(
port = self.port,
baudrate = self.speed,
bytesize = self.databits,
parity = self.parity,
stopbits = self.stopbits,
xonxoff = False,
rtscts = False,
timeout = 0,
inter_byte_timeout = None,
write_timeout = None,
dsrdtr = False,
)
def configure_device(self):
# Allow time for interface to initialise before config
sleep(2.0)
thread = threading.Thread(target=self.readLoop)
thread.daemon = True
thread.start()
self.online = True
RNS.log("Serial port "+self.port+" is now open")
RNS.log("Configuring AX.25 KISS interface parameters...")
self.setPreamble(self.preamble)
self.setTxTail(self.txtail)
self.setPersistence(self.persistence)
self.setSlotTime(self.slottime)
self.setFlowControl(self.flow_control)
self.interface_ready = True
RNS.log("AX.25 KISS interface configured")
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def setPreamble(self, preamble):
preamble_ms = preamble
preamble = int(preamble_ms / 10)
if preamble < 0:
preamble = 0
if preamble > 255:
preamble = 255
kiss_command = bytes([KISS.FEND])+bytes([KISS.CMD_TXDELAY])+bytes([preamble])+bytes([KISS.FEND])
written = self.serial.write(kiss_command)
if written != len(kiss_command):
raise IOError("Could not configure AX.25 KISS interface preamble to "+str(preamble_ms)+" (command value "+str(preamble)+")")
def setTxTail(self, txtail):
txtail_ms = txtail
txtail = int(txtail_ms / 10)
if txtail < 0:
txtail = 0
if txtail > 255:
txtail = 255
kiss_command = bytes([KISS.FEND])+bytes([KISS.CMD_TXTAIL])+bytes([txtail])+bytes([KISS.FEND])
written = self.serial.write(kiss_command)
if written != len(kiss_command):
raise IOError("Could not configure AX.25 KISS interface TX tail to "+str(txtail_ms)+" (command value "+str(txtail)+")")
def setPersistence(self, persistence):
if persistence < 0:
persistence = 0
if persistence > 255:
persistence = 255
kiss_command = bytes([KISS.FEND])+bytes([KISS.CMD_P])+bytes([persistence])+bytes([KISS.FEND])
written = self.serial.write(kiss_command)
if written != len(kiss_command):
raise IOError("Could not configure AX.25 KISS interface persistence to "+str(persistence))
def setSlotTime(self, slottime):
slottime_ms = slottime
slottime = int(slottime_ms / 10)
if slottime < 0:
slottime = 0
if slottime > 255:
slottime = 255
kiss_command = bytes([KISS.FEND])+bytes([KISS.CMD_SLOTTIME])+bytes([slottime])+bytes([KISS.FEND])
written = self.serial.write(kiss_command)
if written != len(kiss_command):
raise IOError("Could not configure AX.25 KISS interface slot time to "+str(slottime_ms)+" (command value "+str(slottime)+")")
def setFlowControl(self, flow_control):
kiss_command = bytes([KISS.FEND])+bytes([KISS.CMD_READY])+bytes([0x01])+bytes([KISS.FEND])
written = self.serial.write(kiss_command)
if written != len(kiss_command):
if (flow_control):
raise IOError("Could not enable AX.25 KISS interface flow control")
else:
raise IOError("Could not enable AX.25 KISS interface flow control")
def processIncoming(self, data):
if (len(data) > AX25.HEADER_SIZE):
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self.rxb += len(data)
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self.owner.inbound(data[AX25.HEADER_SIZE:], self)
def processOutgoing(self,data):
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datalen = len(data)
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if self.online:
if self.interface_ready:
if self.flow_control:
self.interface_ready = False
self.flow_control_locked = time.time()
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encoded_dst_ssid = bytes([0x60 | (self.dst_ssid << 1)])
encoded_src_ssid = bytes([0x60 | (self.src_ssid << 1) | 0x01])
addr = b""
for i in range(0,6):
if (i < len(self.dst_call)):
addr += bytes([self.dst_call[i]<<1])
else:
addr += bytes([0x20])
addr += encoded_dst_ssid
for i in range(0,6):
if (i < len(self.src_call)):
addr += bytes([self.src_call[i]<<1])
else:
addr += bytes([0x20])
addr += encoded_src_ssid
data = addr+bytes([AX25.CTRL_UI])+bytes([AX25.PID_NOLAYER3])+data
data = data.replace(bytes([0xdb]), bytes([0xdb])+bytes([0xdd]))
data = data.replace(bytes([0xc0]), bytes([0xdb])+bytes([0xdc]))
kiss_frame = bytes([KISS.FEND])+bytes([0x00])+data+bytes([KISS.FEND])
written = self.serial.write(kiss_frame)
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self.txb += datalen
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if written != len(kiss_frame):
if self.flow_control:
self.interface_ready = True
raise IOError("AX.25 interface only wrote "+str(written)+" bytes of "+str(len(kiss_frame)))
else:
self.queue(data)
def queue(self, data):
self.packet_queue.append(data)
def process_queue(self):
if len(self.packet_queue) > 0:
data = self.packet_queue.pop(0)
self.interface_ready = True
self.processOutgoing(data)
elif len(self.packet_queue) == 0:
self.interface_ready = True
def readLoop(self):
try:
in_frame = False
escape = False
command = KISS.CMD_UNKNOWN
data_buffer = b""
last_read_ms = int(time.time()*1000)
while self.serial.is_open:
if self.serial.in_waiting:
byte = ord(self.serial.read(1))
last_read_ms = int(time.time()*1000)
if (in_frame and byte == KISS.FEND and command == KISS.CMD_DATA):
in_frame = False
self.processIncoming(data_buffer)
elif (byte == KISS.FEND):
in_frame = True
command = KISS.CMD_UNKNOWN
data_buffer = b""
elif (in_frame and len(data_buffer) < self.HW_MTU+AX25.HEADER_SIZE):
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if (len(data_buffer) == 0 and command == KISS.CMD_UNKNOWN):
# We only support one HDLC port for now, so
# strip off the port nibble
byte = byte & 0x0F
command = byte
elif (command == KISS.CMD_DATA):
if (byte == KISS.FESC):
escape = True
else:
if (escape):
if (byte == KISS.TFEND):
byte = KISS.FEND
if (byte == KISS.TFESC):
byte = KISS.FESC
escape = False
data_buffer = data_buffer+bytes([byte])
elif (command == KISS.CMD_READY):
self.process_queue()
else:
time_since_last = int(time.time()*1000) - last_read_ms
if len(data_buffer) > 0 and time_since_last > self.timeout:
data_buffer = b""
in_frame = False
command = KISS.CMD_UNKNOWN
escape = False
sleep(0.05)
if self.flow_control:
if not self.interface_ready:
if time.time() > self.flow_control_locked + self.flow_control_timeout:
RNS.log("Interface "+str(self)+" is unlocking flow control due to time-out. This should not happen. Your hardware might have missed a flow-control READY command, or maybe it does not support flow-control.", RNS.LOG_WARNING)
self.process_queue()
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except Exception as e:
self.online = False
RNS.log("A serial port error occurred, the contained exception was: "+str(e), RNS.LOG_ERROR)
RNS.log("The interface "+str(self)+" experienced an unrecoverable error and is now offline.", RNS.LOG_ERROR)
if RNS.Reticulum.panic_on_interface_error:
RNS.panic()
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RNS.log("Reticulum will attempt to reconnect the interface periodically.", RNS.LOG_ERROR)
self.online = False
self.serial.close()
self.reconnect_port()
def reconnect_port(self):
while not self.online:
try:
time.sleep(5)
RNS.log("Attempting to reconnect serial port "+str(self.port)+" for "+str(self)+"...", RNS.LOG_VERBOSE)
self.open_port()
if self.serial.is_open:
self.configure_device()
except Exception as e:
RNS.log("Error while reconnecting port, the contained exception was: "+str(e), RNS.LOG_ERROR)
RNS.log("Reconnected serial port for "+str(self))
def should_ingress_limit(self):
return False
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def __str__(self):
return "AX25KISSInterface["+self.name+"]"