InSim examples

Python

Example #1

How to connect, send a packet and receive the response.

# Dependencies.
import socket
import struct

# Some constants.
INSIM_VERSION = 4
BUFFER_SIZE = 2048

# Packet types.
ISP_ISI = 1
ISP_VER = 2
ISP_TINY = 3
TINY_NONE = 0

# Initailise the socket in TCP mode.
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

# Connect to LFS.
sock.connect(('localhost', 29999))

# Pack the ISI packet into a string.
isi = struct.pack('BBBBHHBBH16s16s', 
                  44,          # Size
                  ISP_ISI,     # Type
                  1,           # ReqI - causes LFS to send an IS_VER. 
                  0,           # Zero
                  0,           # UDPPort
                  0,           # Flags
                  0,           # Sp0
                  0,           # Prefix
                  0,           # Interval
                  'password',  # Admin 
                  '^3example') # IName
                 
# Send the ISI packet to InSim. 
sock.send(isi)

buffer = ''

while True:
    data = sock.recv(BUFFER_SIZE)
    if data:
        buffer += data
        
        # Loop through completed packets.
        while len(buffer) > 0 and len(buffer) >= ord(buffer[0]):
            
            # Copy the packet from the buffer.
            packet = buffer[:ord(buffer[0])]
            buffer = buffer[ord(buffer[0]):]
            
            # Check packet type.
            if ord(buffer[1]) == ISP_TINY:
                # Unpack the TINY packet and check it for keep-alive signal.
                size, type, reqi, subt = struct.unpack('BBBB', packet)
                if subt == TINY_NONE:
                    sock.send(packet) # Respond to keep-alive.
            elif ord(buffer[1]) == ISP_VER:
                # Unpack the VER packet and check the InSim version.
                size, type, reqi, _, version, product, insimver = struct.unpack('BBBB8s6sH')
                if insimver != INSIM_VERSION:
                    print 'Invalid InSim version'
                    break
    else: 
        # InSim connection has been lost.
        break
        
# Release the socket.
sock.close()