Initial router DynDNS service

router_dyndns/ddns_dns.py

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+from __future__ import annotations
+
+import json
+import urllib.error
+import urllib.parse
+import urllib.request
+
+from .ddns_models import DdnsSettings, UpdateResult
+
+
+def publish_dns(result: UpdateResult, settings: DdnsSettings) -> None:
+    provider = settings.dns_provider.strip().lower()
+    if provider == "cloudflare":
+        publish_cloudflare(result, settings)
+        return
+    if settings.rfc2136_server or provider == "rfc2136":
+        publish_rfc2136(result, settings)
+        return
+    if settings.require_dns_provider:
+        raise RuntimeError("DNS provider is required but not configured")
+
+
+def delete_dns_records(hostname: str, settings: DdnsSettings) -> None:
+    provider = settings.dns_provider.strip().lower()
+    if provider == "cloudflare":
+        delete_cloudflare_records(hostname, settings)
+        return
+    if settings.rfc2136_server or provider == "rfc2136":
+        delete_rfc2136_records(hostname, settings)
+        return
+    if settings.require_dns_provider:
+        raise RuntimeError("DNS provider is required but not configured")
+
+
+def dns_backend_configured(settings: DdnsSettings) -> bool:
+    provider = settings.dns_provider.strip().lower()
+    return provider == "cloudflare" or provider == "rfc2136" or bool(settings.rfc2136_server)
+
+
+def publish_rfc2136(result: UpdateResult, settings: DdnsSettings) -> None:
+    if not settings.rfc2136_server:
+        return
+
+    import dns.query
+    import dns.tsigkeyring
+    import dns.update
+
+    keyring = None
+    if settings.rfc2136_key_name and settings.rfc2136_key_secret:
+        keyring = dns.tsigkeyring.from_text({settings.rfc2136_key_name: settings.rfc2136_key_secret})
+
+    zone = settings.rfc2136_zone or ".".join(result.hostname.split(".")[1:])
+    update = dns.update.Update(zone, keyring=keyring)
+    relative = result.hostname.removesuffix("." + zone).rstrip(".") or "@"
+    if result.update_ipv4 and result.ipv4:
+        update.replace(relative, settings.ttl, "A", result.ipv4)
+    elif result.update_ipv4:
+        update.delete(relative, "A")
+    if result.update_ipv6 and result.ipv6:
+        update.replace(relative, settings.ttl, "AAAA", result.ipv6)
+    elif result.update_ipv6:
+        update.delete(relative, "AAAA")
+    response = dns.query.tcp(update, settings.rfc2136_server, timeout=5)
+    rcode = response.rcode()
+    if rcode != 0:
+        import dns.rcode
+
+        raise RuntimeError(f"RFC2136 update failed: {dns.rcode.to_text(rcode)}")
+
+
+def delete_rfc2136_records(hostname: str, settings: DdnsSettings) -> None:
+    if not settings.rfc2136_server:
+        return
+
+    import dns.query
+    import dns.tsigkeyring
+    import dns.update
+
+    keyring = None
+    if settings.rfc2136_key_name and settings.rfc2136_key_secret:
+        keyring = dns.tsigkeyring.from_text({settings.rfc2136_key_name: settings.rfc2136_key_secret})
+
+    zone = settings.rfc2136_zone or ".".join(hostname.split(".")[1:])
+    update = dns.update.Update(zone, keyring=keyring)
+    relative = hostname.removesuffix("." + zone).rstrip(".") or "@"
+    update.delete(relative, "A")
+    update.delete(relative, "AAAA")
+    dns.query.tcp(update, settings.rfc2136_server, timeout=5)
+
+
+def publish_cloudflare(result: UpdateResult, settings: DdnsSettings) -> None:
+    if not settings.cloudflare_api_token or not settings.cloudflare_zone_id:
+        raise RuntimeError("DDNS_CLOUDFLARE_API_TOKEN and DDNS_CLOUDFLARE_ZONE_ID are required")
+    if result.update_ipv4:
+        _cloudflare_upsert_record(settings, result.hostname, "A", result.ipv4)
+    if result.update_ipv6:
+        _cloudflare_upsert_record(settings, result.hostname, "AAAA", result.ipv6)
+
+
+def delete_cloudflare_records(hostname: str, settings: DdnsSettings) -> None:
+    if not settings.cloudflare_api_token or not settings.cloudflare_zone_id:
+        raise RuntimeError("DDNS_CLOUDFLARE_API_TOKEN and DDNS_CLOUDFLARE_ZONE_ID are required")
+    for record_type in ("A", "AAAA"):
+        record = _cloudflare_find_record(settings, hostname, record_type)
+        if record:
+            _cloudflare_request(settings, f"/dns_records/{record['id']}", method="DELETE")
+
+
+def _cloudflare_upsert_record(settings: DdnsSettings, hostname: str, record_type: str, value: str | None) -> None:
+    record = _cloudflare_find_record(settings, hostname, record_type)
+    if value is None:
+        if record:
+            _cloudflare_request(settings, f"/dns_records/{record['id']}", method="DELETE")
+        return
+
+    payload = {
+        "type": record_type,
+        "name": hostname,
+        "content": value,
+        "ttl": settings.ttl,
+        "proxied": False,
+    }
+    if record:
+        _cloudflare_request(settings, f"/dns_records/{record['id']}", method="PATCH", payload=payload)
+    else:
+        _cloudflare_request(settings, "/dns_records", method="POST", payload=payload)
+
+
+def _cloudflare_find_record(settings: DdnsSettings, hostname: str, record_type: str) -> dict[str, str] | None:
+    query = urllib.parse.urlencode({"type": record_type, "name": hostname})
+    response = _cloudflare_request(settings, f"/dns_records?{query}")
+    records = response.get("result", [])
+    return records[0] if records else None
+
+
+def _cloudflare_request(
+    settings: DdnsSettings,
+    path: str,
+    method: str = "GET",
+    payload: dict[str, object] | None = None,
+) -> dict[str, object]:
+    url = f"https://api.cloudflare.com/client/v4/zones/{settings.cloudflare_zone_id}{path}"
+    body = json.dumps(payload).encode("utf-8") if payload is not None else None
+    request = urllib.request.Request(url, data=body, method=method)
+    request.add_header("Authorization", f"Bearer {settings.cloudflare_api_token}")
+    request.add_header("Content-Type", "application/json")
+    try:
+        with urllib.request.urlopen(request, timeout=10) as response:
+            parsed = json.loads(response.read().decode("utf-8"))
+    except urllib.error.HTTPError as exc:
+        detail = exc.read().decode("utf-8", errors="replace")
+        raise RuntimeError(f"Cloudflare API {exc.code}: {detail}") from exc
+    if not parsed.get("success", False):
+        raise RuntimeError(f"Cloudflare API error: {parsed}")
+    return parsed