from __future__ import print_function from Interface import Interface from time import sleep import sys import serial import threading import time import RNS class KISS(): FEND = chr(0xC0) FESC = chr(0xDB) TFEND = chr(0xDC) TFESC = chr(0xDD) CMD_UNKNOWN = chr(0xFE) CMD_DATA = chr(0x00) CMD_TXDELAY = chr(0x01) CMD_P = chr(0x02) CMD_SLOTTIME = chr(0x03) CMD_TXTAIL = chr(0x04) CMD_FULLDUPLEX = chr(0x05) CMD_SETHARDWARE = chr(0x06) CMD_READY = chr(0x0F) CMD_RETURN = chr(0xFF) class AX25(): PID_NOLAYER3 = chr(0xF0) CTRL_UI = chr(0x03) CRC_CORRECT = chr(0xF0)+chr(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): self.serial = None self.owner = owner self.name = name self.src_call = callsign.upper() self.src_ssid = ssid self.dst_call = "APZRNS" 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.txdelay = 0.25 self.packet_queue = [] self.flow_control = flow_control self.interface_ready = False 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: RNS.log("Opening serial port "+self.port+"...") self.serial = serial.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, ) 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: # 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") sleep(2) else: raise IOError("Could not open serial port") def setPreamble(self, preamble): preamble_ms = preamble preamble = int(preamble_ms / 10) if preamble < 0: preamble = 0 if preamble > 255: preamble = 255 kiss_command = KISS.FEND+KISS.CMD_TXDELAY+chr(preamble)+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 = KISS.FEND+KISS.CMD_TXTAIL+chr(txtail)+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 = KISS.FEND+KISS.CMD_P+chr(persistence)+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 = KISS.FEND+KISS.CMD_SLOTTIME+chr(slottime)+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 = KISS.FEND+KISS.CMD_READY+chr(0x01)+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.owner.inbound(data[AX25.HEADER_SIZE:], self) def processOutgoing(self,data): if self.online: if self.interface_ready: if self.flow_control: self.interface_ready = False encoded_dst_ssid = 0x60 | (self.dst_ssid << 1) encoded_src_ssid = 0x60 | (self.src_ssid << 1) | 0x01 addr = "" for i in range(0,6): if (i < len(self.dst_call)): addr += chr(ord(self.dst_call[i])<<1) else: addr += chr(0x20) addr += chr(encoded_dst_ssid) for i in range(0,6): if (i < len(self.src_call)): addr += chr(ord(self.src_call[i])<<1) else: addr += chr(0x20) addr += chr(encoded_src_ssid) data = addr+AX25.CTRL_UI+AX25.PID_NOLAYER3+data data = data.replace(chr(0xdb), chr(0xdb)+chr(0xdd)) data = data.replace(chr(0xc0), chr(0xdb)+chr(0xdc)) kiss_frame = chr(0xc0)+chr(0x00)+data+chr(0xc0) if (self.txdelay > 0): RNS.log(str(self.name)+" delaying TX for "+str(self.txdelay)+" seconds", RNS.LOG_EXTREME) sleep(self.txdelay) written = self.serial.write(kiss_frame) 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 = "" last_read_ms = int(time.time()*1000) while self.serial.is_open: if self.serial.in_waiting: byte = 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 = "" 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 = chr(ord(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+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 = "" in_frame = False command = KISS.CMD_UNKNOWN escape = False sleep(0.08) 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.name)+" is now offline. Restart Reticulum to attempt reconnection.", RNS.LOG_ERROR) def __str__(self): return "AX25KISSInterface["+self.name+"]"