Teknium
314 lines
14 KiB
Python
314 lines
14 KiB
Python
"""Telegram network helpers: a hostname-preserving fallback transport (Host + SNI stay
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api.telegram.org while TCP retries known IPv4 literals) plus DoH-based IP discovery."""
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from __future__ import annotations
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import asyncio
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import ipaddress
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import logging
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import socket
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from typing import Iterable, Optional
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import httpx
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logger = logging.getLogger(__name__)
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_TELEGRAM_API_HOST = "api.telegram.org"
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# TCP keepalive so a half-open/CLOSE-WAIT long-poll errors out instead of blocking
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# getUpdates forever (Windows leaves SO_KEEPALIVE off by default). Idle/interval knobs
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# are best-effort — not every Python/OS combo exposes TCP_KEEPIDLE / TCP_KEEPALIVE.
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_TCP_KEEPALIVE_IDLE_S = 30
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_TCP_KEEPALIVE_INTERVAL_S = 10
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_TCP_KEEPALIVE_COUNT = 3
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def tcp_keepalive_socket_options() -> list[tuple[int, int, int]]:
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"""``setsockopt`` tuples for httpx ``socket_options``: always SO_KEEPALIVE, plus
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idle/interval/count when the interpreter exposes those option names."""
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options: list[tuple[int, int, int]] = [(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)]
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idle = getattr(socket, "TCP_KEEPIDLE", None) or getattr(socket, "TCP_KEEPALIVE", None)
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if idle is not None:
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options.append((socket.IPPROTO_TCP, idle, _TCP_KEEPALIVE_IDLE_S))
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interval = getattr(socket, "TCP_KEEPINTVL", None)
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if interval is not None:
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options.append((socket.IPPROTO_TCP, interval, _TCP_KEEPALIVE_INTERVAL_S))
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count = getattr(socket, "TCP_KEEPCNT", None)
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if count is not None:
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options.append((socket.IPPROTO_TCP, count, _TCP_KEEPALIVE_COUNT))
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return options
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# DNS-over-HTTPS providers: discover Telegram API IPs that may differ from the
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# (possibly unreachable) one the local resolver returns. Bounded so connect() isn't delayed.
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_DOH_TIMEOUT = 4.0
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_DOH_PROVIDERS: list[dict] = [
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{"url": "https://dns.google/resolve", "params": {"name": _TELEGRAM_API_HOST, "type": "A"}, "headers": {}},
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{
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"url": "https://cloudflare-dns.com/dns-query",
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"params": {"name": _TELEGRAM_API_HOST, "type": "A"},
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"headers": {"Accept": "application/dns-json"},
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},
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]
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# Last-resort IPv4 Bot API endpoints (149.154.160.0/20). Used when DoH is blocked AND as
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# first-try connect targets so a blackholed IPv6 AAAA for the hostname can't pin initialize().
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SEED_FALLBACK_IPS: list[str] = ["149.154.166.110", "149.154.167.220"]
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_UNSET = object()
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def _resolve_proxy_url(target_hosts=None) -> str | None:
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from gateway.platforms.base import resolve_proxy_url # env vars + macOS system proxy
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return resolve_proxy_url("TELEGRAM_PROXY", target_hosts=target_hosts)
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class TelegramFallbackTransport(httpx.AsyncBaseTransport):
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"""Reach the Bot API via known IPv4 literals first, dual-stack hostname last.
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Logically requests still target https://api.telegram.org (Host + SNI stay on the
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hostname) — like ``curl --resolve api.telegram.org:443:<ip>`` — so a blackholed
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IPv6 AAAA can't pin initialize(); the hostname remains for IPv6-only networks.
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"""
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# Bound every pool: httpx's 100-connection default × (wedged endpoint + seed IPs)
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# can outgrow the process fd limit on its own.
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_POOL_LIMITS = httpx.Limits(max_connections=8, max_keepalive_connections=4)
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def __init__(self, fallback_ips: Iterable[str], **transport_kwargs):
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self._fallback_ips = list(dict.fromkeys(_normalize_fallback_ips(fallback_ips)))
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proxy_url = _resolve_proxy_url(target_hosts=[_TELEGRAM_API_HOST, *self._fallback_ips])
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if proxy_url and "proxy" not in transport_kwargs:
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transport_kwargs["proxy"] = proxy_url
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transport_kwargs.setdefault("limits", self._POOL_LIMITS)
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transport_kwargs.setdefault("socket_options", tcp_keepalive_socket_options())
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self._transport_kwargs = transport_kwargs
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self._primary = httpx.AsyncHTTPTransport(**transport_kwargs)
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self._primary_lock = asyncio.Lock()
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self._primary_closed = False
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# Built on demand and discarded on failure — see _reset_fallback.
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self._fallbacks: dict[str, httpx.AsyncHTTPTransport] = {}
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self._fallback_lock = asyncio.Lock()
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# ``_UNSET`` / ``None`` / ``str`` = no sticky yet / sticky hostname / sticky IPv4.
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self._sticky_ip: object = _UNSET
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self._sticky_lock = asyncio.Lock()
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async def _get_fallback(self, ip: str) -> httpx.AsyncHTTPTransport:
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async with self._fallback_lock:
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transport = self._fallbacks.get(ip)
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if transport is None:
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transport = httpx.AsyncHTTPTransport(**self._transport_kwargs)
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self._fallbacks[ip] = transport
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return transport
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async def _reset_primary(self, transport: httpx.AsyncHTTPTransport) -> None:
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# Retryable primary failures leave half-closed sockets in the pool; replace the
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# generation and close the old one before trying fallback.
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async with self._primary_lock:
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if self._primary_closed or transport is not self._primary:
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return
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self._primary = httpx.AsyncHTTPTransport(**self._transport_kwargs)
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try:
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await transport.aclose()
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except Exception as exc:
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logger.debug("[Telegram] Error closing primary transport: %s", exc)
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async def _reset_fallback(self, ip: str) -> None:
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"""Discard a failed fallback pool: a peer-closed connect leaves a CLOSE_WAIT socket
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in it, and keeping the poisoned pool leaks one fd per retry until the process limit."""
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async with self._fallback_lock:
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transport = self._fallbacks.pop(ip, None)
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if transport is None:
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return
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try:
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await transport.aclose()
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except Exception as exc: # closing a broken pool must never mask the real error
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logger.debug("[Telegram] Error closing fallback transport %s: %s", ip, exc)
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def _attempt_order(self) -> list[Optional[str]]:
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"""Sticky path first, then IPv4 literals, dual-stack hostname last.
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A blackholed IPv6 path never errors — Happy Eyeballs waits on AAAA until the OS
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TCP timeout and can pin the loop so the thread deadline never fires.
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"""
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order: list[Optional[str]] = []
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if self._sticky_ip is not _UNSET:
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sticky = self._sticky_ip
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order.append(sticky if sticky is None else str(sticky))
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for ip in self._fallback_ips:
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if ip not in order:
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order.append(ip)
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if None not in order:
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order.append(None)
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return order
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async def handle_async_request(self, request: httpx.Request) -> httpx.Response:
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if request.url.host != _TELEGRAM_API_HOST or not self._fallback_ips:
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return await self._primary.handle_async_request(request)
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attempt_order = self._attempt_order()
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last_error: Exception | None = None
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for ip in attempt_order:
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candidate = request if ip is None else _rewrite_request_for_ip(request, ip)
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transport = self._primary if ip is None else await self._get_fallback(ip)
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try:
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response = await transport.handle_async_request(candidate)
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if self._sticky_ip is _UNSET or self._sticky_ip != ip:
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async with self._sticky_lock:
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if self._sticky_ip is _UNSET or self._sticky_ip != ip:
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self._sticky_ip = ip
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if ip is not None:
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log = logger.warning if last_error is not None else logger.info
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log(
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"[Telegram] Using sticky IPv4 Telegram API path %s "
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"(dual-stack hostname tried last — #87015)", ip,
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)
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return response
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except Exception as exc:
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last_error = exc
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if not _is_retryable_connect_error(exc):
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raise
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if self._sticky_ip is not _UNSET and ip == self._sticky_ip:
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async with self._sticky_lock:
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if self._sticky_ip is not _UNSET and self._sticky_ip == ip:
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self._sticky_ip = _UNSET
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logger.warning(
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"[Telegram] Sticky Telegram path %s failed; "
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"re-walking IPv4 literals before the hostname",
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ip if ip is not None else "api.telegram.org",
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)
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if ip is None:
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await self._reset_primary(transport)
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logger.warning("[Telegram] Dual-stack api.telegram.org path failed (%s)", exc)
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continue
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logger.warning("[Telegram] IPv4 Telegram API IP %s failed: %s", ip, exc)
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await self._reset_fallback(ip)
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continue
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if last_error is None:
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raise RuntimeError("All Telegram fallback IPs exhausted but no error was recorded")
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raise last_error
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async def aclose(self) -> None:
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async with self._primary_lock:
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self._primary_closed = True
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primary = self._primary
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await primary.aclose()
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async with self._fallback_lock:
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transports = list(self._fallbacks.values())
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self._fallbacks.clear()
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for transport in transports:
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await transport.aclose()
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def _normalize_fallback_ips(values: Iterable[str]) -> list[str]:
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normalized: list[str] = []
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for value in values:
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raw = str(value).strip()
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if not raw:
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continue
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try:
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addr = ipaddress.ip_address(raw)
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except ValueError:
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logger.warning("Ignoring invalid Telegram fallback IP: %r", raw)
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continue
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if addr.version != 4:
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logger.warning("Ignoring non-IPv4 Telegram fallback IP: %s", raw)
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continue
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if addr.is_private or addr.is_loopback or addr.is_link_local or addr.is_unspecified:
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logger.warning("Ignoring private/internal Telegram fallback IP: %s", raw)
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continue
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normalized.append(str(addr))
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return normalized
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def parse_fallback_ip_env(value: str | None) -> list[str]:
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if not value:
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return []
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parts = [part.strip() for part in value.split(",")]
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return _normalize_fallback_ips(parts)
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def _resolve_system_dns() -> set[str]:
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"""Return the IPv4 addresses that the OS resolver gives for api.telegram.org."""
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try:
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results = socket.getaddrinfo(_TELEGRAM_API_HOST, 443, socket.AF_INET)
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return {addr[4][0] for addr in results}
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except Exception:
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return set()
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async def _query_doh_provider(client: httpx.AsyncClient, provider: dict) -> list[str]:
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"""Query one DoH provider and return A-record IPs."""
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try:
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resp = await client.get(provider["url"], params=provider["params"], headers=provider["headers"])
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resp.raise_for_status()
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data = resp.json()
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ips: list[str] = []
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for answer in data.get("Answer", []):
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if answer.get("type") != 1: # A record
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continue
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raw = answer.get("data", "").strip()
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try:
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ipaddress.ip_address(raw)
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ips.append(raw)
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except ValueError:
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continue
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return ips
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except Exception as exc:
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logger.debug("DoH query to %s failed: %s", provider["url"], exc)
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return []
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async def discover_fallback_ips() -> list[str]:
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"""Resolve api.telegram.org via Google + Cloudflare DoH; unique A records, in order.
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IPs matching the system resolver are deliberately KEPT (often the most reliable
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path; a transient primary failure should retry it via IP-rewrite before the seed
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list). Falls back to ``SEED_FALLBACK_IPS`` only when DoH yields nothing usable.
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"""
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async with httpx.AsyncClient(timeout=httpx.Timeout(_DOH_TIMEOUT)) as client:
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doh_tasks = [_query_doh_provider(client, p) for p in _DOH_PROVIDERS]
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system_dns_task = asyncio.ensure_future(asyncio.to_thread(_resolve_system_dns))
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results = await asyncio.gather(*doh_tasks, return_exceptions=True)
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# The getaddrinfo leg has no timeout of its own (a wedged resolver can sit for
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# minutes) and only feeds the log line below — bound it, never gate discovery on it.
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system_ips: set[str] = set()
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try:
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system_result = await asyncio.wait_for(system_dns_task, timeout=_DOH_TIMEOUT)
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if isinstance(system_result, set):
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system_ips = system_result
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except Exception:
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logger.debug("System-DNS resolution for %s did not complete in time", _TELEGRAM_API_HOST)
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doh_ips: list[str] = []
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for r in results:
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if isinstance(r, list):
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doh_ips.extend(r)
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validated = _normalize_fallback_ips(list(dict.fromkeys(doh_ips))) # dedupe, keep order
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if validated:
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logger.debug("Discovered Telegram fallback IPs via DoH: %s", ", ".join(validated))
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return validated
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logger.info(
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"DoH discovery yielded no usable IPs (system DNS: %s); using seed fallback IPs %s",
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", ".join(system_ips) or "unknown",
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", ".join(SEED_FALLBACK_IPS),
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)
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return list(SEED_FALLBACK_IPS)
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def _rewrite_request_for_ip(request: httpx.Request, ip: str) -> httpx.Request:
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original_host = request.url.host or _TELEGRAM_API_HOST
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url = request.url.copy_with(host=ip)
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headers = request.headers.copy()
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headers["host"] = original_host
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extensions = dict(request.extensions)
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extensions["sni_hostname"] = original_host
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return httpx.Request(
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method=request.method, url=url, headers=headers, stream=request.stream, extensions=extensions,
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)
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def _is_retryable_connect_error(exc: Exception) -> bool:
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return isinstance(exc, (httpx.ConnectTimeout, httpx.ConnectError))
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