Fix "list index out of range"

[Dmitriusan]

Sometimes the script fails with:

[badralgalal8-tech]

This module handles the low-level interaction with Mikrotik RouterOS API using socket.

It includes connection, authentication, and response parsing.

import socket

class Api:
def init(self, host, port=8728, use_ssl=False):
# Initialize basic connection parameters
self.host = host
self.port = port
self.use_ssl = use_ssl
self.sock = None

def connect(self):
    # Establishes a basic TCP socket connection (SSL not supported in RouterOS API on 8728)
    self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    self.sock.settimeout(5)
    self.sock.connect((self.host, self.port))

def disconnect(self):
    # Close socket connection if exists
    if self.sock:
        self.sock.close()
        self.sock = None

def send(self, words):
    # Send encoded data to Mikrotik API socket
    if not self.sock:
        self.connect()
    for word in words:
        self.sock.send(self.encode_length(len(word)))
        self.sock.send(word.encode())
    self.sock.send(b'\x00')  # End of sentence

def read_sentence(self):
    # Reads a complete API sentence (multiple words)
    words = []
    while True:
        length = self.read_length()
        if length == 0:
            break
        word = self.sock.recv(length).decode()
        words.append(word)
    return words

def read_length(self):
    # Decodes the length prefix used in RouterOS API protocol
    c = self.sock.recv(1)
    if not c:
        return 0
    b = c[0]
    if b < 0x80:
        return b
    elif b < 0xC0:
        c += self.sock.recv(1)
        return ((b & 0x3F) << 8) + c[1]
    elif b < 0xE0:
        c += self.sock.recv(2)
        return ((b & 0x1F) << 16) + (c[1] << 8) + c[2]
    elif b < 0xF0:
        c += self.sock.recv(3)
        return ((b & 0x0F) << 24) + (c[1] << 16) + (c[2] << 8) + c[3]
    else:
        c += self.sock.recv(4)
        return (c[1] << 24) + (c[2] << 16) + (c[3] << 8) + c[4]

def encode_length(self, length):
    # Encodes the length prefix to send to API
    if length < 0x80:
        return bytes([length])
    elif length < 0x4000:
        length |= 0x8000
        return bytes([(length >> 8) & 0xFF, length & 0xFF])
    elif length < 0x200000:
        length |= 0xC00000
        return bytes([(length >> 16) & 0xFF, (length >> 8) & 0xFF, length & 0xFF])
    elif length < 0x10000000:
        length |= 0xE0000000
        return bytes([(length >> 24) & 0xFF, (length >> 16) & 0xFF, (length >> 8) & 0xFF, length & 0xFF])
    else:
        return bytes([0xF0, (length >> 24) & 0xFF, (length >> 16) & 0xFF, (length >> 8) & 0xFF, length & 0xFF])

def login(self, username, password):
    # Perform login using Mikrotik API protocol
    try:
        self.connect()
        self.send(['/login', '=name=' + username, '=password=' + password])
        response = self.read_sentence()
        self.disconnect()
        return '!done' in response
    except:
        self.disconnect()

        return False