SAMP 0.3 query info faker

# responds to SAMP server query info
# https://wiki.sa-mp.com/wiki/Query_Mechanism
# yanir3

import socket
import struct
import random

# SAMP-0.3 related consts:
OPCODE_INFO = "i"
OPCODE_PING = "p"
OPCODE_CLIENT_LIST = "c"
HEADER_SIZE = 11

# Server bindings:
BIND_ADDRESS = "0.0.0.0" # all interfaces
PORT = 7777 # samp default port
RECV_BUFFER = 1024


# Config:
SERVER_NAME = "2016"
GAMEMODE_NAME = "?"
LANGUAGE = "=]"
PLAYERS = 50
MAX_PLAYERS = 500
HAS_PASS = 0 # 1 = yes
FAKE_PLAYER_NAMES = ["0x01", "0x02", "0x03", "0x04"]

def make_client_list_response(players_amount):
    RESPONSE_TO_C = struct.pack("<H", players_amount)
    for i in range(players_amount + 1):
        name = random.choice(FAKE_PLAYER_NAMES)
        RESPONSE_TO_C += struct.pack(P_FORMAT % (len(name)), len(name), name, random.randint(1, 98999))
    return RESPONSE_TO_C

I_FORMAT = "<BHHI%dsI%dsI%ds" # has_pass, players, maxplayers, strlen_hostname, hostname, strlen_gamemode, gamemode, strlen_lang, lang
P_FORMAT = "<B%dsI" # len_of_name, name, score

RESPONSE_TO_I = struct.pack(I_FORMAT % (len(SERVER_NAME), len(GAMEMODE_NAME), len(LANGUAGE)), HAS_PASS, PLAYERS, MAX_PLAYERS, len(SERVER_NAME), SERVER_NAME, len(GAMEMODE_NAME), GAMEMODE_NAME, len(LANGUAGE), LANGUAGE)
DEFAULT_RESPONSE = struct.pack("H", 0)

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind((BIND_ADDRESS, PORT))

while True:
    data, addr = s.recvfrom(RECV_BUFFER)
    if len(data) < HEADER_SIZE:
        continue
    if data[10] == OPCODE_INFO: # INFO
        s.sendto(data + RESPONSE_TO_I, addr)
    elif data[10] == OPCODE_PING:
        s.sendto(data, addr)
    elif data[10] == OPCODE_CLIENT_LIST:
        s.sendto(data + make_client_list_response(PLAYERS), addr)
    else:
        s.sendto(data + DEFAULT_RESPONSE, addr)