from .Interface import Interface from time import sleep import sys import threading import time import RNS class KISS(): 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 class AX25(): PID_NOLAYER3 = 0xF0 CTRL_UI = 0x03 CRC_CORRECT = bytes([0xF0])+bytes([0xB8]) HEADER_SIZE = 16 class AX25KISSInterface(Interface): MAX_CHUNK = 32768 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() self.rxb = 0 self.txb = 0 self.pyserial = serial 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.packet_queue = [] self.flow_control = flow_control self.interface_ready = False self.flow_control_timeout = 5 self.flow_control_locked = time.time() 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() 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() 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.setDaemon(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") 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): self.rxb += len(data) self.owner.inbound(data[AX25.HEADER_SIZE:], self) def processOutgoing(self,data): datalen = len(data) if self.online: if self.interface_ready: if self.flow_control: self.interface_ready = False self.flow_control_locked = time.time() 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) self.txb += datalen 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) < RNS.Reticulum.MTU+AX25.HEADER_SIZE): 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): # TODO: add timeout and reset if ready # command never arrives 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() 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() 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 __str__(self): return "AX25KISSInterface["+self.name+"]"