Files
ddns-service/src/ddns_service/server.py

643 lines
20 KiB
Python

"""HTTP(S) server for DDNS updates."""
from __future__ import annotations
import base64
import ipaddress
import json
import logging
import signal
import ssl
import threading
from . import (
now_utc,
datetime_str,
STATUS_GOOD,
STATUS_NOCHG,
STATUS_BADAUTH,
STATUS_NOHOST,
STATUS_DNSERR,
STATUS_ABUSE,
STATUS_BADIP,
)
from .cleanup import ExpiredRecordsCleanupThread, RateLimitCleanupThread
from .dns import detect_ip_type
from .logging import clear_txn_id, set_txn_id
from .models import (
DatabaseError,
DoesNotExist,
EncodingError,
get_hostname_for_user,
get_user
)
from argon2.exceptions import VerifyMismatchError
from concurrent.futures import ThreadPoolExecutor
from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
from urllib.parse import parse_qs, urlparse
def extract_param(params, aliases):
"""Extract first matching param from query params."""
for alias in aliases:
val = params.get(alias, [None])[0]
if val is not None:
return val
return None
class ProxyHeaderError(Exception):
"""Raised when expected proxy header is missing."""
pass
def _parse_trusted_proxies(proxies):
"""Parse list of IPs/networks into ip_network objects."""
networks = []
for proxy in proxies:
try:
if "/" not in proxy:
addr = ipaddress.ip_address(proxy)
if addr.version == 4:
proxy = proxy + "/32"
else:
proxy = proxy + "/128"
networks.append(ipaddress.ip_network(proxy, strict=False))
except ValueError:
logging.warning(f"Invalid trusted proxy: {proxy}")
return networks
def _is_trusted_proxy(client_ip, trusted_networks):
"""Check if client IP is in trusted proxy networks."""
try:
addr = ipaddress.ip_address(client_ip)
for network in trusted_networks:
if addr in network:
return True
except ValueError:
pass
return False
class DDNSServer(ThreadingHTTPServer):
"""HTTP server with Application instance and thread pool."""
def __init__(self, app, address):
"""
Initialize server with application.
Args:
app: Application instance.
address: (host, port) tuple.
"""
self.app = app
self.proxy_header = app.config["daemon"].get("proxy_header", "")
self.trusted_networks = _parse_trusted_proxies(
app.config["daemon"].get("trusted_proxies", [])
)
self.pool_size = app.config["daemon"]["thread_pool_size"]
self.request_timeout = app.config["daemon"]["request_timeout"]
self.executor = ThreadPoolExecutor(max_workers=self.pool_size)
self.active_requests = 0
self.requests_lock = threading.Lock()
self.requests_done = threading.Condition(self.requests_lock)
super().__init__(address, DDNSRequestHandler)
def process_request(self, request, client_address):
"""Submit request to thread pool."""
with self.requests_lock:
self.active_requests += 1
request.settimeout(self.request_timeout)
self.executor.submit(self._handle_request_wrapper, request, client_address)
def _handle_request_wrapper(self, request, client_address):
"""Wrap request handling to track active requests."""
try:
self.process_request_thread(request, client_address)
finally:
with self.requests_lock:
self.active_requests -= 1
if self.active_requests == 0:
self.requests_done.notify_all()
def wait_for_requests(self, timeout=5):
"""Wait for active requests to complete."""
with self.requests_lock:
if self.active_requests > 0:
logging.info(f"Waiting for {self.active_requests} active request(s)")
self.requests_done.wait(timeout=timeout)
if self.active_requests > 0:
logging.warning(
f"Shutdown timeout, {self.active_requests} request(s) still active"
)
def server_close(self):
"""Shutdown thread pool and close server."""
self.executor.shutdown(wait=True)
super().server_close()
class DDNSError(Exception):
def __init__(self, message, status, **kwargs):
super().__init__(self, message)
self.message = message
self.status = status
self.kwargs = kwargs
def __str__(self):
if not self.kwargs:
return self.message
string = f"{self.message}:"
for key, value in self.kwargs.items():
string += f" {key}={value}"
return string
class DDNSClientError(DDNSError):
def __init__(self, message, code, status, **kwargs):
super().__init__(message, status, **kwargs)
self.code = code
class DDNSRequestHandler(BaseHTTPRequestHandler):
"""HTTP request handler for DDNS updates."""
@property
def app(self):
"""Get application instance from server."""
return self.server.app
def log_message(self, format_str, *args):
"""Override to use our logger."""
msg = f"{self.address_string()} - {format_str % args}"
if self.app.config["daemon"]["log_requests"]:
logging.info(msg)
else:
logging.debug(msg)
def send_response_body(self, code, body, content_type="text/plain"):
"""Send response with body."""
self.send_response(code)
self.send_header("Content-Type", content_type)
self.send_header("Content-Length", str(len(body)))
self.end_headers()
self.wfile.write(body.encode())
def wants_json(self):
"""Check if client wants JSON response."""
accept = self.headers.get("Accept", "")
return "application/json" in accept
def respond(self, code, status, **kwargs):
"""Send response in appropriate format."""
if self.wants_json():
data = {"status": status, **kwargs}
self.send_response_body(code, json.dumps(data), "application/json")
else:
# DynDNS-compatible plain text
parts = [status]
if "ipv4" in kwargs and kwargs["ipv4"]:
parts.append(kwargs["ipv4"])
if "ipv6" in kwargs and kwargs["ipv6"]:
parts.append(kwargs["ipv6"])
self.send_response_body(code, " ".join(parts))
def get_client_ip(self):
"""Get client IP, considering configured proxy header if trusted."""
direct_ip = self.client_address[0]
proxy_header = self.server.proxy_header
if not proxy_header:
return direct_ip
if not _is_trusted_proxy(direct_ip, self.server.trusted_networks):
return direct_ip
forwarded = self.headers.get(proxy_header)
if not forwarded:
raise ProxyHeaderError(
f"Missing {proxy_header} header from trusted proxy"
)
return forwarded.split(",")[0].strip()
def parse_basic_auth(self):
"""Parse Basic Auth header."""
auth = self.headers.get("Authorization", "")
if not auth.startswith("Basic "):
return None, None
try:
decoded = base64.b64decode(auth[6:]).decode("utf-8")
if ":" in decoded:
username, password = decoded.split(":", 1)
return username, password
except Exception:
pass
return None, None
def do_GET(self):
"""Handle GET requests."""
set_txn_id()
try:
client_ip = self.get_client_ip()
except ProxyHeaderError as e:
logging.error(f"Proxy header error: {e}")
self.respond(400, "Bad Request")
return
try:
self._handle_get_request(client_ip)
except DDNSClientError as e:
if self.app.bad_limiter:
self.app.bad_limiter.record(client_ip)
logging.warning(e)
self.respond(e.code, e.status)
except DDNSError as e:
logging.error(e)
self.respond(500, e.status)
except DatabaseError as e:
logging.error(f"Database error: {e}")
self.respond(500, "Internal Server Error")
except Exception as e:
logging.exception(f"Uncaught exception: {e}")
self.respond(500, "Internal Server Error")
finally:
clear_txn_id()
def _handle_get_request(self, client_ip):
"""Handle GET request logic."""
# Parse URL
parsed = urlparse(self.path)
# Find matching endpoint
endpoint = self.app.config["_endpoint_map"].get(parsed.path)
if endpoint is None:
self.respond(404, "Not Found")
return
# Bad rate limit check
if self.app.bad_limiter:
blocked, retry_at = self.app.bad_limiter.is_blocked(client_ip)
if blocked:
raise DDNSClientError(
"Rate limited (bad requests)",
429,
STATUS_ABUSE,
client=client_ip,
retry_at=datetime_str(retry_at)
)
# Parse query parameters
params = parse_qs(parsed.query)
# Get credentials
username, password = self.parse_basic_auth()
if username is None:
username = extract_param(params, endpoint["params"]["username"])
password = extract_param(params, endpoint["params"]["password"])
if not username or not password:
raise DDNSClientError(
"Auth failed",
401,
STATUS_BADAUTH,
client_ip
)
# Get hostname parameter
hostname_param = extract_param(params, endpoint["params"]["hostname"])
if not hostname_param:
raise DDNSClientError(
"Missing hostname",
400,
STATUS_NOHOST,
client=client_ip,
username=username
)
# Validate credentials
user = self._authenticate(client_ip, username, password)
# Check hostname ownership
hostname = self._check_permissions(client_ip, user, hostname_param)
# Process myip parameter
ipv4 = None
myip = extract_param(params, endpoint["params"]["ipv4"])
if myip:
try:
rtype, myip = detect_ip_type(myip)
if rtype == "A":
ipv4 = myip
else:
ipv6 = myip
except ValueError:
raise DDNSClientError(
"Bad IP address",
400,
STATUS_BADIP,
client=client_ip,
username=username,
hostname=hostname.hostname,
zone=hostname.zone,
ip=myip
)
# Process myip6 parameter
ipv6 = None
myip6 = extract_param(params, endpoint["params"]["ipv6"])
if myip6:
try:
rtype, myip6 = detect_ip_type(myip6)
if rtype == "AAAA":
ipv6 = myip6
else:
raise ValueError
except ValueError:
raise DDNSClientError(
"Bad IP address",
400,
STATUS_BADIP,
client=client_ip,
username=username,
hostname=hostname.hostname,
zone=hostname.zone,
ipv6=myip6
)
# Auto-detect from client IP if no params
if ipv4 is None and ipv6 is None:
rtype, ip = detect_ip_type(client_ip)
if rtype == "A":
ipv4 = ip
else:
ipv6 = ip
# Process notify_change parameter
notify_change = extract_param(params, endpoint["params"]["notify_change"])
notify_change = notify_change.lower() in ["1", "y", "yes", "on", "true"] \
if notify_change else False
# Good rate limit check
if self.app.good_limiter:
blocked, retry_at = self.app.good_limiter.is_blocked(client_ip)
if blocked:
raise DDNSClientError(
"Rate limited (good requests)",
429,
STATUS_ABUSE,
client=client_ip,
username=username,
retry_at=datetime_str(retry_at)
)
# Record good request
if self.app.good_limiter:
self.app.good_limiter.record(client_ip)
# Process update request
self._process_ip_update(
client_ip,
user,
hostname,
ipv4,
ipv6,
notify_change
)
def _authenticate(self, client_ip, username, password):
try:
try:
user = get_user(username)
except DoesNotExist:
# User does not exist, Hash fake password to prevent time-based attacks
self.app.password_hasher.hash("FAKE-PASSWORD")
raise DoesNotExist
self.app.password_hasher.verify(user.password_hash, password)
except (DoesNotExist, VerifyMismatchError):
raise DDNSClientError(
"Auth failed",
401,
STATUS_BADAUTH,
client=client_ip,
username=username
)
return user
def _check_permissions(self, client_ip, user, hostname_param):
# Check hostname ownership
code = None
try:
hostname = get_hostname_for_user(hostname_param, user)
except DoesNotExist:
code = 403
except EncodingError:
code = 400
if code:
raise DDNSClientError(
"Access denied",
code,
STATUS_NOHOST,
client=client_ip,
username=user.username,
hostname=hostname_param
)
return hostname
def _process_ip_update(self, client_ip, user, hostname, ipv4, ipv6, notify_change):
"""Process IP update for hostname."""
now = now_utc()
ipv4_changed = False
ipv6_changed = False
if ipv4:
hostname.last_ipv4_update = now
if ipv4 != hostname.last_ipv4:
# Update DNS IPv4 record
try:
self.app.dns_service.update_record(
hostname.hostname,
hostname.zone,
ipv4,
hostname.dns_ttl
)
hostname.last_ipv4 = ipv4
ipv4_changed = True
except Exception as e:
hostname.save()
logging.error(f"DNS error: {e}")
raise DDNSError(
"Update failed",
STATUS_DNSERR,
client=client_ip,
hostname=hostname.hostname,
zone=hostname.zone,
ipv4=ipv4
)
if ipv6:
hostname.last_ipv6_update = now
if ipv6 != hostname.last_ipv6:
# Update DNS IPv6 record
try:
self.app.dns_service.update_record(
hostname.hostname,
hostname.zone,
ipv6,
hostname.dns_ttl
)
hostname.last_ipv6 = ipv6
ipv6_changed = True
except Exception as e:
hostname.save()
logging.error(f"DNS error: {e}")
raise DDNSError(
"Update failed",
STATUS_DNSERR,
client=client_ip,
hostname=hostname.hostname,
zone=hostname.zone,
ipv6=ipv6
)
# Update database
hostname.save()
changed_addrs = ""
if ipv4_changed:
changed_addrs += f" ipv4={ipv4}"
if ipv6_changed:
changed_addrs += f" ipv6={ipv6}"
if not ipv4_changed and not ipv6_changed:
logging.info(
f"No change: client={client_ip} hostname={hostname.hostname} "
f"zone={hostname.zone}{changed_addrs} notify_change={str(notify_change).lower()}"
)
self.respond(
200,
STATUS_NOCHG,
ipv4=hostname.last_ipv4,
ipv6=hostname.last_ipv6
)
return
logging.info(
f"Updated: client={client_ip} hostname={hostname.hostname} "
f"zone={hostname.zone}{changed_addrs} notify_change={str(notify_change).lower()}"
)
if notify_change:
try:
self.app.email_service.send_change_notification(
hostname.user.email,
hostname,
ipv4_changed,
ipv6_changed
)
except Exception as e:
logging.error(f"Sending change notification error: {e}")
self.respond(
200,
STATUS_GOOD,
ipv4=hostname.last_ipv4,
ipv6=hostname.last_ipv6
)
def run_daemon(app):
"""
Run the DDNS daemon.
Args:
app: Application instance with initialized services.
"""
config = app.config
# Setup server
host = config["daemon"]["host"]
port = config["daemon"]["port"]
server = DDNSServer(app, (host, port))
# Setup TLS if enabled
if config["daemon"]["ssl"]:
context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
context.load_cert_chain(
config["daemon"]["ssl_cert_file"],
config["daemon"]["ssl_key_file"]
)
server.socket = context.wrap_socket(server.socket, server_side=True)
proto = "https"
else:
proto = "http"
# Start cleanup threads
ratelimit_cleanup_thread = RateLimitCleanupThread(app)
ratelimit_cleanup_thread.start()
expired_cleanup_thread = ExpiredRecordsCleanupThread(app)
expired_cleanup_thread.start()
# Setup signal handlers
def signal_handler(signum, frame):
logging.info(f"Signal received: {signum}, shutting down")
app.signal_shutdown()
def sighup_handler(signum, frame):
logging.info("SIGHUP received, reloading configuration")
try:
app.reload_config()
# Update server attributes
server.proxy_header = app.config["daemon"].get("proxy_header", "")
server.trusted_networks = _parse_trusted_proxies(
app.config["daemon"].get("trusted_proxies", [])
)
# Reload SSL if enabled
if app.config["daemon"]["ssl"]:
new_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
new_context.load_cert_chain(
app.config["daemon"]["ssl_cert_file"],
app.config["daemon"]["ssl_key_file"]
)
# Note: existing connections use old cert, new connections use new
server.socket = new_context.wrap_socket(
server.socket.detach(), server_side=True
)
except Exception as e:
logging.error(f"Config reload failed: {e}")
signal.signal(signal.SIGTERM, signal_handler)
signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGHUP, sighup_handler)
paths = ", ".join(ep["path"] for ep in config["endpoints"])
logging.info(f"Daemon started: {proto}://{host}:{port} endpoints=[{paths}]")
# Run server
server.timeout = 1.0
while not app.is_shutting_down():
server.handle_request()
# Graceful shutdown - wait for active requests
server.wait_for_requests(5)
# Cleanup
expired_cleanup_thread.stop()
ratelimit_cleanup_thread.stop()
expired_cleanup_thread.join(timeout=5)
ratelimit_cleanup_thread.join(timeout=5)
server.server_close()
logging.info("Daemon stopped")