#!/usr/bin/env python3 myip_url = "https://YOUR_IP_FETCH_URL" dyndns_url = "https://YOUR_DYNDNS_UPDATE_URL" dyndns_domain = "EXAMPLE.COM" dyndns_user = "USER" dyndns_pw = "PASSWORD" v6netlen = 64 import subprocess import ipaddress def wget(url, v4=None): args = ["wget", ] if v4 is not None: args.append("-4" if v4 else "-6") args.extend(["--quiet", "-O", "-", url]) print(" ".join(args)) p = subprocess.Popen(args, stdout=subprocess.PIPE) out, err = p.communicate() if p.returncode != 0 or not out: raise Exception("wget failed.") return out.decode("UTF-8") def getfield(raw, name): for line in raw.splitlines(): if line.startswith(name + "="): return line[len(name) + 1 : ] return "" raw_v4 = wget(myip_url, v4=True) raw_v6 = wget(myip_url, v4=False) ipv4 = getfield(raw_v4, "REMOTE_ADDR") ipv6 = getfield(raw_v6, "REMOTE_ADDR") if not ipv4 and not ipv6: raise Exception("Got neither v4 nor v6 address.") dualstack = "1" if ipv4 and ipv6 else "0" if ipv6: adr = int(ipaddress.ip_address(ipv6)) msk = ((1 << v6netlen) - 1) << (128 - v6netlen) ipv6pfx = f"{ipaddress.ip_address(adr & msk)}/{v6netlen}" else: ipv6pfx = "" r = wget(f"{dyndns_url}?" f"domain={dyndns_domain}&" f"user={dyndns_user}&" f"pw={dyndns_pw}&" f"ip4={ipv4}&" f"ip6={ipv6}&" f"ip6pfx={ipv6pfx}&" f"dualstack={dualstack}") print(f"result: {r.strip()}")