Source code for aiohttp.connector

import asyncio
import dataclasses
import functools
import logging
import random
import sys
import traceback
import warnings
from collections import defaultdict, deque
from contextlib import suppress
from http.cookies import SimpleCookie
from itertools import cycle, islice
from time import monotonic
from types import TracebackType
from typing import (  # noqa
    TYPE_CHECKING,
    Any,
    Awaitable,
    Callable,
    DefaultDict,
    Dict,
    Iterator,
    List,
    Optional,
    Set,
    Tuple,
    Type,
    Union,
    cast,
)

from . import hdrs, helpers
from .abc import AbstractResolver
from .client_exceptions import (
    ClientConnectionError,
    ClientConnectorCertificateError,
    ClientConnectorError,
    ClientConnectorSSLError,
    ClientHttpProxyError,
    ClientProxyConnectionError,
    ServerFingerprintMismatch,
    UnixClientConnectorError,
    cert_errors,
    ssl_errors,
)
from .client_proto import ResponseHandler
from .client_reqrep import SSL_ALLOWED_TYPES, ClientRequest, Fingerprint
from .helpers import _SENTINEL, ceil_timeout, is_ip_address, sentinel
from .http import RESPONSES
from .locks import EventResultOrError
from .resolver import DefaultResolver

try:
    import ssl

    SSLContext = ssl.SSLContext
except ImportError:  # pragma: no cover
    ssl = None  # type: ignore[assignment]
    SSLContext = object  # type: ignore[misc,assignment]


__all__ = ("BaseConnector", "TCPConnector", "UnixConnector", "NamedPipeConnector")


if TYPE_CHECKING:  # pragma: no cover
    from .client import ClientTimeout
    from .client_reqrep import ConnectionKey
    from .tracing import Trace


class Connection:

    _source_traceback = None
    _transport = None

    def __init__(
        self,
        connector: "BaseConnector",
        key: "ConnectionKey",
        protocol: ResponseHandler,
        loop: asyncio.AbstractEventLoop,
    ) -> None:
        self._key = key
        self._connector = connector
        self._loop = loop
        self._protocol = protocol  # type: Optional[ResponseHandler]
        self._callbacks = []  # type: List[Callable[[], None]]

        if loop.get_debug():
            self._source_traceback = traceback.extract_stack(sys._getframe(1))

    def __repr__(self) -> str:
        return f"Connection<{self._key}>"

    def __del__(self, _warnings: Any = warnings) -> None:
        if self._protocol is not None:
            _warnings.warn(
                f"Unclosed connection {self!r}", ResourceWarning, source=self
            )
            if self._loop.is_closed():
                return

            self._connector._release(self._key, self._protocol, should_close=True)

            context = {"client_connection": self, "message": "Unclosed connection"}
            if self._source_traceback is not None:
                context["source_traceback"] = self._source_traceback
            self._loop.call_exception_handler(context)

    @property
    def transport(self) -> Optional[asyncio.Transport]:
        if self._protocol is None:
            return None
        return self._protocol.transport

    @property
    def protocol(self) -> Optional[ResponseHandler]:
        return self._protocol

    def add_callback(self, callback: Callable[[], None]) -> None:
        if callback is not None:
            self._callbacks.append(callback)

    def _notify_release(self) -> None:
        callbacks, self._callbacks = self._callbacks[:], []

        for cb in callbacks:
            with suppress(Exception):
                cb()

    def close(self) -> None:
        self._notify_release()

        if self._protocol is not None:
            self._connector._release(self._key, self._protocol, should_close=True)
            self._protocol = None

    def release(self) -> None:
        self._notify_release()

        if self._protocol is not None:
            self._connector._release(
                self._key, self._protocol, should_close=self._protocol.should_close
            )
            self._protocol = None

    @property
    def closed(self) -> bool:
        return self._protocol is None or not self._protocol.is_connected()


class _TransportPlaceholder:
    """placeholder for BaseConnector.connect function"""

    def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
        fut = loop.create_future()
        fut.set_result(None)
        self.closed = fut  # type: asyncio.Future[Optional[Exception]]

    def close(self) -> None:
        pass


[docs]class BaseConnector: """Base connector class. keepalive_timeout - (optional) Keep-alive timeout. force_close - Set to True to force close and do reconnect after each request (and between redirects). limit - The total number of simultaneous connections. limit_per_host - Number of simultaneous connections to one host. enable_cleanup_closed - Enables clean-up closed ssl transports. Disabled by default. loop - Optional event loop. """ _closed = True # prevent AttributeError in __del__ if ctor was failed _source_traceback = None # abort transport after 2 seconds (cleanup broken connections) _cleanup_closed_period = 2.0 def __init__( self, *, keepalive_timeout: Union[_SENTINEL, None, float] = sentinel, force_close: bool = False, limit: int = 100, limit_per_host: int = 0, enable_cleanup_closed: bool = False, ) -> None: if force_close: if keepalive_timeout is not None and keepalive_timeout is not sentinel: raise ValueError( "keepalive_timeout cannot " "be set if force_close is True" ) else: if keepalive_timeout is sentinel: keepalive_timeout = 15.0 loop = asyncio.get_running_loop() self._closed = False if loop.get_debug(): self._source_traceback = traceback.extract_stack(sys._getframe(1)) self._conns = ( {} ) # type: Dict[ConnectionKey, List[Tuple[ResponseHandler, float]]] self._limit = limit self._limit_per_host = limit_per_host self._acquired = set() # type: Set[ResponseHandler] self._acquired_per_host = defaultdict( set ) # type: DefaultDict[ConnectionKey, Set[ResponseHandler]] self._keepalive_timeout = cast(float, keepalive_timeout) self._force_close = force_close # {host_key: FIFO list of waiters} self._waiters = defaultdict(deque) # type: ignore[var-annotated] self._loop = loop self._factory = functools.partial(ResponseHandler, loop=loop) self.cookies = SimpleCookie() # type: SimpleCookie[str] # start keep-alive connection cleanup task self._cleanup_handle: Optional[asyncio.TimerHandle] = None # start cleanup closed transports task self._cleanup_closed_handle: Optional[asyncio.TimerHandle] = None self._cleanup_closed_disabled = not enable_cleanup_closed self._cleanup_closed_transports = [] # type: List[Optional[asyncio.Transport]] self._cleanup_closed() def __del__(self, _warnings: Any = warnings) -> None: if self._closed: return if not self._conns: return conns = [repr(c) for c in self._conns.values()] self._close_immediately() _warnings.warn(f"Unclosed connector {self!r}", ResourceWarning, source=self) context = { "connector": self, "connections": conns, "message": "Unclosed connector", } if self._source_traceback is not None: context["source_traceback"] = self._source_traceback self._loop.call_exception_handler(context) async def __aenter__(self) -> "BaseConnector": return self async def __aexit__( self, exc_type: Optional[Type[BaseException]] = None, exc_value: Optional[BaseException] = None, exc_traceback: Optional[TracebackType] = None, ) -> None: await self.close() @property def force_close(self) -> bool: """Ultimately close connection on releasing if True.""" return self._force_close @property def limit(self) -> int: """The total number for simultaneous connections. If limit is 0 the connector has no limit. The default limit size is 100. """ return self._limit @property def limit_per_host(self) -> int: """The limit for simultaneous connections to the same endpoint. Endpoints are the same if they are have equal (host, port, is_ssl) triple. """ return self._limit_per_host def _cleanup(self) -> None: """Cleanup unused transports.""" if self._cleanup_handle: self._cleanup_handle.cancel() # _cleanup_handle should be unset, otherwise _release() will not # recreate it ever! self._cleanup_handle = None now = self._loop.time() timeout = self._keepalive_timeout if self._conns: connections = {} deadline = now - timeout for key, conns in self._conns.items(): alive = [] for proto, use_time in conns: if proto.is_connected(): if use_time - deadline < 0: transport = proto.transport proto.close() if key.is_ssl and not self._cleanup_closed_disabled: self._cleanup_closed_transports.append(transport) else: alive.append((proto, use_time)) else: transport = proto.transport proto.close() if key.is_ssl and not self._cleanup_closed_disabled: self._cleanup_closed_transports.append(transport) if alive: connections[key] = alive self._conns = connections if self._conns: self._cleanup_handle = helpers.weakref_handle( self, "_cleanup", timeout, self._loop ) def _drop_acquired_per_host( self, key: "ConnectionKey", val: ResponseHandler ) -> None: acquired_per_host = self._acquired_per_host if key not in acquired_per_host: return conns = acquired_per_host[key] conns.remove(val) if not conns: del self._acquired_per_host[key] def _cleanup_closed(self) -> None: """Double confirmation for transport close. Some broken ssl servers may leave socket open without proper close. """ if self._cleanup_closed_handle: self._cleanup_closed_handle.cancel() for transport in self._cleanup_closed_transports: if transport is not None: transport.abort() self._cleanup_closed_transports = [] if not self._cleanup_closed_disabled: self._cleanup_closed_handle = helpers.weakref_handle( self, "_cleanup_closed", self._cleanup_closed_period, self._loop )
[docs] async def close(self) -> None: """Close all opened transports.""" waiters = self._close_immediately() if waiters: results = await asyncio.gather(*waiters, return_exceptions=True) for res in results: if isinstance(res, Exception): err_msg = "Error while closing connector: " + repr(res) logging.error(err_msg)
def _close_immediately(self) -> List["asyncio.Future[None]"]: waiters = [] # type: List['asyncio.Future[None]'] if self._closed: return waiters self._closed = True try: if self._loop.is_closed(): return waiters # cancel cleanup task if self._cleanup_handle: self._cleanup_handle.cancel() # cancel cleanup close task if self._cleanup_closed_handle: self._cleanup_closed_handle.cancel() for data in self._conns.values(): for proto, t0 in data: proto.close() waiters.append(proto.closed) for proto in self._acquired: proto.close() waiters.append(proto.closed) # TODO (A.Yushovskiy, 24-May-2019) collect transp. closing futures for transport in self._cleanup_closed_transports: if transport is not None: transport.abort() return waiters finally: self._conns.clear() self._acquired.clear() self._waiters.clear() self._cleanup_handle = None self._cleanup_closed_transports.clear() self._cleanup_closed_handle = None @property def closed(self) -> bool: """Is connector closed. A readonly property. """ return self._closed def _available_connections(self, key: "ConnectionKey") -> int: """ Return number of available connections. The limit, limit_per_host and the connection key are taken into account. If it returns less than 1 means that there are no connections available. """ if self._limit: # total calc available connections available = self._limit - len(self._acquired) # check limit per host if ( self._limit_per_host and available > 0 and key in self._acquired_per_host ): acquired = self._acquired_per_host.get(key) assert acquired is not None available = self._limit_per_host - len(acquired) elif self._limit_per_host and key in self._acquired_per_host: # check limit per host acquired = self._acquired_per_host.get(key) assert acquired is not None available = self._limit_per_host - len(acquired) else: available = 1 return available
[docs] async def connect( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout" ) -> Connection: """Get from pool or create new connection.""" key = req.connection_key available = self._available_connections(key) # Wait if there are no available connections or if there are/were # waiters (i.e. don't steal connection from a waiter about to wake up) if available <= 0 or key in self._waiters: fut = self._loop.create_future() # This connection will now count towards the limit. self._waiters[key].append(fut) if traces: for trace in traces: await trace.send_connection_queued_start() try: await fut except BaseException as e: if key in self._waiters: # remove a waiter even if it was cancelled, normally it's # removed when it's notified try: self._waiters[key].remove(fut) except ValueError: # fut may no longer be in list pass raise e finally: if key in self._waiters and not self._waiters[key]: del self._waiters[key] if traces: for trace in traces: await trace.send_connection_queued_end() proto = self._get(key) if proto is None: placeholder = cast(ResponseHandler, _TransportPlaceholder(self._loop)) self._acquired.add(placeholder) self._acquired_per_host[key].add(placeholder) if traces: for trace in traces: await trace.send_connection_create_start() try: proto = await self._create_connection(req, traces, timeout) if self._closed: proto.close() raise ClientConnectionError("Connector is closed.") except BaseException: if not self._closed: self._acquired.remove(placeholder) self._drop_acquired_per_host(key, placeholder) self._release_waiter() raise else: if not self._closed: self._acquired.remove(placeholder) self._drop_acquired_per_host(key, placeholder) if traces: for trace in traces: await trace.send_connection_create_end() else: if traces: # Acquire the connection to prevent race conditions with limits placeholder = cast(ResponseHandler, _TransportPlaceholder(self._loop)) self._acquired.add(placeholder) self._acquired_per_host[key].add(placeholder) for trace in traces: await trace.send_connection_reuseconn() self._acquired.remove(placeholder) self._drop_acquired_per_host(key, placeholder) self._acquired.add(proto) self._acquired_per_host[key].add(proto) return Connection(self, key, proto, self._loop)
def _get(self, key: "ConnectionKey") -> Optional[ResponseHandler]: try: conns = self._conns[key] except KeyError: return None t1 = self._loop.time() while conns: proto, t0 = conns.pop() if proto.is_connected(): if t1 - t0 > self._keepalive_timeout: transport = proto.transport proto.close() # only for SSL transports if key.is_ssl and not self._cleanup_closed_disabled: self._cleanup_closed_transports.append(transport) else: if not conns: # The very last connection was reclaimed: drop the key del self._conns[key] return proto else: transport = proto.transport proto.close() if key.is_ssl and not self._cleanup_closed_disabled: self._cleanup_closed_transports.append(transport) # No more connections: drop the key del self._conns[key] return None def _release_waiter(self) -> None: """ Iterates over all waiters until one to be released is found. The one to be released is not finsihed and belongs to a host that has available connections. """ if not self._waiters: return # Having the dict keys ordered this avoids to iterate # at the same order at each call. queues = list(self._waiters.keys()) random.shuffle(queues) for key in queues: if self._available_connections(key) < 1: continue waiters = self._waiters[key] while waiters: waiter = waiters.popleft() if not waiter.done(): waiter.set_result(None) return def _release_acquired(self, key: "ConnectionKey", proto: ResponseHandler) -> None: if self._closed: # acquired connection is already released on connector closing return try: self._acquired.remove(proto) self._drop_acquired_per_host(key, proto) except KeyError: # pragma: no cover # this may be result of undetermenistic order of objects # finalization due garbage collection. pass else: self._release_waiter() def _release( self, key: "ConnectionKey", protocol: ResponseHandler, *, should_close: bool = False, ) -> None: if self._closed: # acquired connection is already released on connector closing return self._release_acquired(key, protocol) if self._force_close: should_close = True if should_close or protocol.should_close: transport = protocol.transport protocol.close() if key.is_ssl and not self._cleanup_closed_disabled: self._cleanup_closed_transports.append(transport) else: conns = self._conns.get(key) if conns is None: conns = self._conns[key] = [] conns.append((protocol, self._loop.time())) if self._cleanup_handle is None: self._cleanup_handle = helpers.weakref_handle( self, "_cleanup", self._keepalive_timeout, self._loop )
[docs] async def _create_connection( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout" ) -> ResponseHandler: raise NotImplementedError()
class _DNSCacheTable: def __init__(self, ttl: Optional[float] = None) -> None: self._addrs_rr = ( {} ) # type: Dict[Tuple[str, int], Tuple[Iterator[Dict[str, Any]], int]] self._timestamps = {} # type: Dict[Tuple[str, int], float] self._ttl = ttl def __contains__(self, host: object) -> bool: return host in self._addrs_rr def add(self, key: Tuple[str, int], addrs: List[Dict[str, Any]]) -> None: self._addrs_rr[key] = (cycle(addrs), len(addrs)) if self._ttl: self._timestamps[key] = monotonic() def remove(self, key: Tuple[str, int]) -> None: self._addrs_rr.pop(key, None) if self._ttl: self._timestamps.pop(key, None) def clear(self) -> None: self._addrs_rr.clear() self._timestamps.clear() def next_addrs(self, key: Tuple[str, int]) -> List[Dict[str, Any]]: loop, length = self._addrs_rr[key] addrs = list(islice(loop, length)) # Consume one more element to shift internal state of `cycle` next(loop) return addrs def expired(self, key: Tuple[str, int]) -> bool: if self._ttl is None: return False return self._timestamps[key] + self._ttl < monotonic()
[docs]class TCPConnector(BaseConnector): """TCP connector. verify_ssl - Set to True to check ssl certifications. fingerprint - Pass the binary sha256 digest of the expected certificate in DER format to verify that the certificate the server presents matches. See also https://en.wikipedia.org/wiki/Transport_Layer_Security#Certificate_pinning resolver - Enable DNS lookups and use this resolver use_dns_cache - Use memory cache for DNS lookups. ttl_dns_cache - Max seconds having cached a DNS entry, None forever. family - socket address family local_addr - local tuple of (host, port) to bind socket to keepalive_timeout - (optional) Keep-alive timeout. force_close - Set to True to force close and do reconnect after each request (and between redirects). limit - The total number of simultaneous connections. limit_per_host - Number of simultaneous connections to one host. enable_cleanup_closed - Enables clean-up closed ssl transports. Disabled by default. loop - Optional event loop. """ def __init__( self, *, use_dns_cache: bool = True, ttl_dns_cache: Optional[int] = 10, family: int = 0, ssl: Union[None, bool, Fingerprint, SSLContext] = None, local_addr: Optional[Tuple[str, int]] = None, resolver: Optional[AbstractResolver] = None, keepalive_timeout: Union[None, float, _SENTINEL] = sentinel, force_close: bool = False, limit: int = 100, limit_per_host: int = 0, enable_cleanup_closed: bool = False, ) -> None: super().__init__( keepalive_timeout=keepalive_timeout, force_close=force_close, limit=limit, limit_per_host=limit_per_host, enable_cleanup_closed=enable_cleanup_closed, ) if not isinstance(ssl, SSL_ALLOWED_TYPES): raise TypeError( "ssl should be SSLContext, bool, Fingerprint, " "or None, got {!r} instead.".format(ssl) ) self._ssl = ssl if resolver is None: resolver = DefaultResolver() self._resolver: AbstractResolver = resolver self._use_dns_cache = use_dns_cache self._cached_hosts = _DNSCacheTable(ttl=ttl_dns_cache) self._throttle_dns_events = ( {} ) # type: Dict[Tuple[str, int], EventResultOrError] self._family = family self._local_addr = local_addr def _close_immediately(self) -> List["asyncio.Future[None]"]: for ev in self._throttle_dns_events.values(): ev.cancel() return super()._close_immediately() @property def family(self) -> int: """Socket family like AF_INET.""" return self._family @property def use_dns_cache(self) -> bool: """True if local DNS caching is enabled.""" return self._use_dns_cache
[docs] def clear_dns_cache( self, host: Optional[str] = None, port: Optional[int] = None ) -> None: """Remove specified host/port or clear all dns local cache.""" if host is not None and port is not None: self._cached_hosts.remove((host, port)) elif host is not None or port is not None: raise ValueError("either both host and port " "or none of them are allowed") else: self._cached_hosts.clear()
async def _resolve_host( self, host: str, port: int, traces: Optional[List["Trace"]] = None ) -> List[Dict[str, Any]]: if is_ip_address(host): return [ { "hostname": host, "host": host, "port": port, "family": self._family, "proto": 0, "flags": 0, } ] if not self._use_dns_cache: if traces: for trace in traces: await trace.send_dns_resolvehost_start(host) res = await self._resolver.resolve(host, port, family=self._family) if traces: for trace in traces: await trace.send_dns_resolvehost_end(host) return res key = (host, port) if (key in self._cached_hosts) and (not self._cached_hosts.expired(key)): # get result early, before any await (#4014) result = self._cached_hosts.next_addrs(key) if traces: for trace in traces: await trace.send_dns_cache_hit(host) return result if key in self._throttle_dns_events: # get event early, before any await (#4014) event = self._throttle_dns_events[key] if traces: for trace in traces: await trace.send_dns_cache_hit(host) await event.wait() else: # update dict early, before any await (#4014) self._throttle_dns_events[key] = EventResultOrError(self._loop) if traces: for trace in traces: await trace.send_dns_cache_miss(host) try: if traces: for trace in traces: await trace.send_dns_resolvehost_start(host) addrs = await self._resolver.resolve(host, port, family=self._family) if traces: for trace in traces: await trace.send_dns_resolvehost_end(host) self._cached_hosts.add(key, addrs) self._throttle_dns_events[key].set() except BaseException as e: # any DNS exception, independently of the implementation # is set for the waiters to raise the same exception. self._throttle_dns_events[key].set(exc=e) raise finally: self._throttle_dns_events.pop(key) return self._cached_hosts.next_addrs(key) async def _create_connection( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout" ) -> ResponseHandler: """Create connection. Has same keyword arguments as BaseEventLoop.create_connection. """ if req.proxy: _, proto = await self._create_proxy_connection(req, traces, timeout) else: _, proto = await self._create_direct_connection(req, traces, timeout) return proto @staticmethod @functools.lru_cache(None) def _make_ssl_context(verified: bool) -> SSLContext: if verified: return ssl.create_default_context() else: sslcontext = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT) sslcontext.options |= ssl.OP_NO_SSLv2 sslcontext.options |= ssl.OP_NO_SSLv3 sslcontext.check_hostname = False sslcontext.verify_mode = ssl.CERT_NONE try: sslcontext.options |= ssl.OP_NO_COMPRESSION except AttributeError as attr_err: warnings.warn( "{!s}: The Python interpreter is compiled " "against OpenSSL < 1.0.0. Ref: " "https://docs.python.org/3/library/ssl.html" "#ssl.OP_NO_COMPRESSION".format(attr_err), ) sslcontext.set_default_verify_paths() return sslcontext def _get_ssl_context(self, req: "ClientRequest") -> Optional[SSLContext]: """Logic to get the correct SSL context 0. if req.ssl is false, return None 1. if ssl_context is specified in req, use it 2. if _ssl_context is specified in self, use it 3. otherwise: 1. if verify_ssl is not specified in req, use self.ssl_context (will generate a default context according to self.verify_ssl) 2. if verify_ssl is True in req, generate a default SSL context 3. if verify_ssl is False in req, generate a SSL context that won't verify """ if req.is_ssl(): if ssl is None: # pragma: no cover raise RuntimeError("SSL is not supported.") sslcontext = req.ssl if isinstance(sslcontext, ssl.SSLContext): return sslcontext if sslcontext is not None: # not verified or fingerprinted return self._make_ssl_context(False) sslcontext = self._ssl if isinstance(sslcontext, ssl.SSLContext): return sslcontext if sslcontext is not None: # not verified or fingerprinted return self._make_ssl_context(False) return self._make_ssl_context(True) else: return None def _get_fingerprint(self, req: "ClientRequest") -> Optional["Fingerprint"]: ret = req.ssl if isinstance(ret, Fingerprint): return ret ret = self._ssl if isinstance(ret, Fingerprint): return ret return None async def _wrap_create_connection( self, *args: Any, req: "ClientRequest", timeout: "ClientTimeout", client_error: Type[Exception] = ClientConnectorError, **kwargs: Any, ) -> Tuple[asyncio.Transport, ResponseHandler]: try: async with ceil_timeout(timeout.sock_connect): return await self._loop.create_connection(*args, **kwargs) # type: ignore[return-value] # noqa except cert_errors as exc: raise ClientConnectorCertificateError(req.connection_key, exc) from exc except ssl_errors as exc: raise ClientConnectorSSLError(req.connection_key, exc) from exc except OSError as exc: raise client_error(req.connection_key, exc) from exc def _warn_about_tls_in_tls( self, underlying_transport: asyncio.Transport, req: "ClientRequest", ) -> None: """Issue a warning if the requested URL has HTTPS scheme.""" if req.request_info.url.scheme != "https": return asyncio_supports_tls_in_tls = getattr( underlying_transport, "_start_tls_compatible", False, ) if asyncio_supports_tls_in_tls: return warnings.warn( "An HTTPS request is being sent through an HTTPS proxy. " "This support for TLS in TLS is known to be disabled " "in the stdlib asyncio. This is why you'll probably see " "an error in the log below.\n\n" "It is possible to enable it via monkeypatching under " "Python 3.7 or higher. For more details, see:\n" "* https://bugs.python.org/issue37179\n" "* https://github.com/python/cpython/pull/28073\n\n" "You can temporarily patch this as follows:\n" "* https://docs.aiohttp.org/en/stable/client_advanced.html#proxy-support\n" "* https://github.com/aio-libs/aiohttp/discussions/6044\n", RuntimeWarning, source=self, # Why `4`? At least 3 of the calls in the stack originate # from the methods in this class. stacklevel=3, ) async def _start_tls_connection( self, underlying_transport: asyncio.Transport, req: "ClientRequest", timeout: "ClientTimeout", client_error: Type[Exception] = ClientConnectorError, ) -> Tuple[asyncio.BaseTransport, ResponseHandler]: """Wrap the raw TCP transport with TLS.""" tls_proto = self._factory() # Create a brand new proto for TLS # Safety of the `cast()` call here is based on the fact that # internally `_get_ssl_context()` only returns `None` when # `req.is_ssl()` evaluates to `False` which is never gonna happen # in this code path. Of course, it's rather fragile # maintainability-wise but this is to be solved separately. sslcontext = cast(ssl.SSLContext, self._get_ssl_context(req)) try: async with ceil_timeout(timeout.sock_connect): try: tls_transport = await self._loop.start_tls( underlying_transport, tls_proto, sslcontext, server_hostname=req.host, ssl_handshake_timeout=timeout.total, ) except BaseException: # We need to close the underlying transport since # `start_tls()` probably failed before it had a # chance to do this: underlying_transport.close() raise except cert_errors as exc: raise ClientConnectorCertificateError(req.connection_key, exc) from exc except ssl_errors as exc: raise ClientConnectorSSLError(req.connection_key, exc) from exc except OSError as exc: raise client_error(req.connection_key, exc) from exc except TypeError as type_err: # Example cause looks like this: # TypeError: transport <asyncio.sslproto._SSLProtocolTransport # object at 0x7f760615e460> is not supported by start_tls() raise ClientConnectionError( "Cannot initialize a TLS-in-TLS connection to host " f"{req.host!s}:{req.port:d} through an underlying connection " f"to an HTTPS proxy {req.proxy!s} ssl:{req.ssl or 'default'} " f"[{type_err!s}]" ) from type_err else: tls_proto.connection_made( tls_transport ) # Kick the state machine of the new TLS protocol return tls_transport, tls_proto async def _create_direct_connection( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout", *, client_error: Type[Exception] = ClientConnectorError, ) -> Tuple[asyncio.Transport, ResponseHandler]: sslcontext = self._get_ssl_context(req) fingerprint = self._get_fingerprint(req) host = req.url.raw_host assert host is not None port = req.port assert port is not None host_resolved = asyncio.ensure_future( self._resolve_host(host, port, traces=traces), loop=self._loop ) try: # Cancelling this lookup should not cancel the underlying lookup # or else the cancel event will get broadcast to all the waiters # across all connections. hosts = await asyncio.shield(host_resolved) except asyncio.CancelledError: def drop_exception(fut: "asyncio.Future[List[Dict[str, Any]]]") -> None: with suppress(Exception, asyncio.CancelledError): fut.result() host_resolved.add_done_callback(drop_exception) raise except OSError as exc: # in case of proxy it is not ClientProxyConnectionError # it is problem of resolving proxy ip itself raise ClientConnectorError(req.connection_key, exc) from exc last_exc = None # type: Optional[Exception] for hinfo in hosts: host = hinfo["host"] port = hinfo["port"] try: transp, proto = await self._wrap_create_connection( self._factory, host, port, timeout=timeout, ssl=sslcontext, family=hinfo["family"], proto=hinfo["proto"], flags=hinfo["flags"], server_hostname=hinfo["hostname"] if sslcontext else None, local_addr=self._local_addr, req=req, client_error=client_error, ) except ClientConnectorError as exc: last_exc = exc continue if req.is_ssl() and fingerprint: try: fingerprint.check(transp) except ServerFingerprintMismatch as exc: transp.close() if not self._cleanup_closed_disabled: self._cleanup_closed_transports.append(transp) last_exc = exc continue return transp, proto assert last_exc is not None raise last_exc async def _create_proxy_connection( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout" ) -> Tuple[asyncio.BaseTransport, ResponseHandler]: headers = {} # type: Dict[str, str] if req.proxy_headers is not None: headers = req.proxy_headers # type: ignore[assignment] headers[hdrs.HOST] = req.headers[hdrs.HOST] url = req.proxy assert url is not None proxy_req = ClientRequest( hdrs.METH_GET, url, headers=headers, auth=req.proxy_auth, loop=self._loop, ssl=req.ssl, ) # create connection to proxy server transport, proto = await self._create_direct_connection( proxy_req, [], timeout, client_error=ClientProxyConnectionError ) # Many HTTP proxies has buggy keepalive support. Let's not # reuse connection but close it after processing every # response. proto.force_close() auth = proxy_req.headers.pop(hdrs.AUTHORIZATION, None) if auth is not None: if not req.is_ssl(): req.headers[hdrs.PROXY_AUTHORIZATION] = auth else: proxy_req.headers[hdrs.PROXY_AUTHORIZATION] = auth if req.is_ssl(): self._warn_about_tls_in_tls(transport, req) # For HTTPS requests over HTTP proxy # we must notify proxy to tunnel connection # so we send CONNECT command: # CONNECT www.python.org:443 HTTP/1.1 # Host: www.python.org # # next we must do TLS handshake and so on # to do this we must wrap raw socket into secure one # asyncio handles this perfectly proxy_req.method = hdrs.METH_CONNECT proxy_req.url = req.url key = dataclasses.replace( req.connection_key, proxy=None, proxy_auth=None, proxy_headers_hash=None ) conn = Connection(self, key, proto, self._loop) proxy_resp = await proxy_req.send(conn) try: protocol = conn._protocol assert protocol is not None # read_until_eof=True will ensure the connection isn't closed # once the response is received and processed allowing # START_TLS to work on the connection below. protocol.set_response_params(read_until_eof=True) resp = await proxy_resp.start(conn) except BaseException: proxy_resp.close() conn.close() raise else: conn._protocol = None conn._transport = None try: if resp.status != 200: message = resp.reason if message is None: message = RESPONSES[resp.status][0] raise ClientHttpProxyError( proxy_resp.request_info, resp.history, status=resp.status, message=message, headers=resp.headers, ) except BaseException: # It shouldn't be closed in `finally` because it's fed to # `loop.start_tls()` and the docs say not to touch it after # passing there. transport.close() raise return await self._start_tls_connection( # Access the old transport for the last time before it's # closed and forgotten forever: transport, req=req, timeout=timeout, ) finally: proxy_resp.close() return transport, proto
[docs]class UnixConnector(BaseConnector): """Unix socket connector. path - Unix socket path. keepalive_timeout - (optional) Keep-alive timeout. force_close - Set to True to force close and do reconnect after each request (and between redirects). limit - The total number of simultaneous connections. limit_per_host - Number of simultaneous connections to one host. loop - Optional event loop. """ def __init__( self, path: str, force_close: bool = False, keepalive_timeout: Union[_SENTINEL, float, None] = sentinel, limit: int = 100, limit_per_host: int = 0, ) -> None: super().__init__( force_close=force_close, keepalive_timeout=keepalive_timeout, limit=limit, limit_per_host=limit_per_host, ) self._path = path @property def path(self) -> str: """Path to unix socket.""" return self._path async def _create_connection( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout" ) -> ResponseHandler: try: async with ceil_timeout(timeout.sock_connect): _, proto = await self._loop.create_unix_connection( self._factory, self._path ) except OSError as exc: raise UnixClientConnectorError(self.path, req.connection_key, exc) from exc return cast(ResponseHandler, proto)
class NamedPipeConnector(BaseConnector): """Named pipe connector. Only supported by the proactor event loop. See also: https://docs.python.org/3.7/library/asyncio-eventloop.html path - Windows named pipe path. keepalive_timeout - (optional) Keep-alive timeout. force_close - Set to True to force close and do reconnect after each request (and between redirects). limit - The total number of simultaneous connections. limit_per_host - Number of simultaneous connections to one host. loop - Optional event loop. """ def __init__( self, path: str, force_close: bool = False, keepalive_timeout: Union[_SENTINEL, float, None] = sentinel, limit: int = 100, limit_per_host: int = 0, ) -> None: super().__init__( force_close=force_close, keepalive_timeout=keepalive_timeout, limit=limit, limit_per_host=limit_per_host, ) if not isinstance( self._loop, asyncio.ProactorEventLoop # type: ignore[attr-defined] ): raise RuntimeError( "Named Pipes only available in proactor " "loop under windows" ) self._path = path @property def path(self) -> str: """Path to the named pipe.""" return self._path async def _create_connection( self, req: "ClientRequest", traces: List["Trace"], timeout: "ClientTimeout" ) -> ResponseHandler: try: async with ceil_timeout(timeout.sock_connect): _, proto = await self._loop.create_pipe_connection( # type: ignore[attr-defined] # noqa: E501 self._factory, self._path ) # the drain is required so that the connection_made is called # and transport is set otherwise it is not set before the # `assert conn.transport is not None` # in client.py's _request method await asyncio.sleep(0) # other option is to manually set transport like # `proto.transport = trans` except OSError as exc: raise ClientConnectorError(req.connection_key, exc) from exc return cast(ResponseHandler, proto)