from .Interface import Interface from time import sleep import sys import serial import threading import time import RNS class HDLC(): # The Serial Interface packetizes data using # simplified HDLC framing, similar to PPP FLAG = 0x7E ESC = 0x7D ESC_MASK = 0x20 @staticmethod def escape(data): data = data.replace(bytes([HDLC.ESC]), bytes([HDLC.ESC, HDLC.ESC^HDLC.ESC_MASK])) data = data.replace(bytes([HDLC.FLAG]), bytes([HDLC.ESC, HDLC.FLAG^HDLC.ESC_MASK])) return data class SerialInterface(Interface): MAX_CHUNK = 32768 owner = None port = None speed = None databits = None parity = None stopbits = None serial = None def __init__(self, owner, name, port, speed, databits, parity, stopbits): self.serial = None self.owner = owner self.name = name self.port = port self.speed = speed self.databits = databits self.parity = serial.PARITY_NONE self.stopbits = stopbits self.timeout = 100 self.online = False 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: sleep(0.5) thread = threading.Thread(target=self.readLoop) thread.setDaemon(True) thread.start() self.online = True RNS.log("Serial port "+self.port+" is now open") else: raise IOError("Could not open serial port") def processIncoming(self, data): self.owner.inbound(data, self) def processOutgoing(self,data): if self.online: data = bytes([HDLC.FLAG])+HDLC.escape(data)+bytes([HDLC.FLAG]) written = self.serial.write(data) if written != len(data): raise IOError("Serial interface only wrote "+str(written)+" bytes of "+str(len(data))) def readLoop(self): try: in_frame = False escape = False 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 == HDLC.FLAG): in_frame = False self.processIncoming(data_buffer) elif (byte == HDLC.FLAG): in_frame = True data_buffer = b"" elif (in_frame and len(data_buffer) < RNS.Reticulum.MTU): if (byte == HDLC.ESC): escape = True else: if (escape): if (byte == HDLC.FLAG ^ HDLC.ESC_MASK): byte = HDLC.FLAG if (byte == HDLC.ESC ^ HDLC.ESC_MASK): byte = HDLC.ESC escape = False data_buffer = data_buffer+bytes([byte]) 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 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 "SerialInterface["+self.name+"]"