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import asyncio
import functools
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 (
TYPE_CHECKING,
Any,
Awaitable,
Callable,
DefaultDict,
Dict,
Iterator,
List,
Optional,
Set,
Tuple,
Type,
Union,
cast,
)
import attr
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 ClientRequest, Fingerprint, _merge_ssl_params
from .helpers import (
PY_36,
ceil_timeout,
get_running_loop,
is_ip_address,
noop,
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 _DeprecationWaiter:
__slots__ = ("_awaitable", "_awaited")
def __init__(self, awaitable: Awaitable[Any]) -> None:
self._awaitable = awaitable
self._awaited = False
def __await__(self) -> Any:
self._awaited = True
return self._awaitable.__await__()
def __del__(self) -> None:
if not self._awaited:
warnings.warn(
"Connector.close() is a coroutine, "
"please use await connector.close()",
DeprecationWarning,
)
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: Optional[ResponseHandler] = protocol
self._callbacks: 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:
if PY_36:
kwargs = {"source": self}
else:
kwargs = {}
_warnings.warn(f"Unclosed connection {self!r}", ResourceWarning, **kwargs)
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 loop(self) -> asyncio.AbstractEventLoop:
warnings.warn(
"connector.loop property is deprecated", DeprecationWarning, stacklevel=2
)
return self._loop
@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 close(self) -> None:
pass
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[object, None, float] = sentinel,
force_close: bool = False,
limit: int = 100,
limit_per_host: int = 0,
enable_cleanup_closed: bool = False,
loop: Optional[asyncio.AbstractEventLoop] = None,
) -> 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 = get_running_loop(loop)
self._closed = False
if loop.get_debug():
self._source_traceback = traceback.extract_stack(sys._getframe(1))
self._conns: Dict[ConnectionKey, List[Tuple[ResponseHandler, float]]] = {}
self._limit = limit
self._limit_per_host = limit_per_host
self._acquired: Set[ResponseHandler] = set()
self._acquired_per_host: DefaultDict[
ConnectionKey, Set[ResponseHandler]
] = defaultdict(set)
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[str] = SimpleCookie()
# 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: 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()
if PY_36:
kwargs = {"source": self}
else:
kwargs = {}
_warnings.warn(f"Unclosed connector {self!r}", ResourceWarning, **kwargs)
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)
def __enter__(self) -> "BaseConnector":
warnings.warn(
'"with Connector():" is deprecated, '
'use "async with Connector():" instead',
DeprecationWarning,
)
return self
def __exit__(self, *exc: Any) -> None:
self._close()
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
)
def close(self) -> Awaitable[None]:
"""Close all opened transports."""
self._close()
return _DeprecationWaiter(noop())
def _close(self) -> None:
if self._closed:
return
self._closed = True
try:
if self._loop.is_closed():
return
# 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()
for proto in self._acquired:
proto.close()
for transport in self._cleanup_closed_transports:
if transport is not None:
transport.abort()
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
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._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._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
)
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: Dict[Tuple[str, int], Tuple[Iterator[Dict[str, Any]], int]] = {}
self._timestamps: 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()
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
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,
*,
verify_ssl: bool = True,
fingerprint: Optional[bytes] = None,
use_dns_cache: bool = True,
ttl_dns_cache: Optional[int] = 10,
family: int = 0,
ssl_context: Optional[SSLContext] = None,
ssl: Union[None, bool, Fingerprint, SSLContext] = None,
local_addr: Optional[Tuple[str, int]] = None,
resolver: Optional[AbstractResolver] = None,
keepalive_timeout: Union[None, float, object] = sentinel,
force_close: bool = False,
limit: int = 100,
limit_per_host: int = 0,
enable_cleanup_closed: bool = False,
loop: Optional[asyncio.AbstractEventLoop] = 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,
loop=loop,
)
self._ssl = _merge_ssl_params(ssl, verify_ssl, ssl_context, fingerprint)
if resolver is None:
resolver = DefaultResolver(loop=self._loop)
self._resolver = resolver
self._use_dns_cache = use_dns_cache
self._cached_hosts = _DNSCacheTable(ttl=ttl_dns_cache)
self._throttle_dns_events: Dict[Tuple[str, int], EventResultOrError] = {}
self._family = family
self._local_addr = local_addr
def close(self) -> Awaitable[None]:
"""Close all ongoing DNS calls."""
for ev in self._throttle_dns_events.values():
ev.cancel()
return super().close()
@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
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: "
"#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:
if exc.errno is None and isinstance(exc, asyncio.TimeoutError):
raise
raise client_error(req.connection_key, exc) from exc
def _fail_on_no_start_tls(self, req: "ClientRequest") -> None:
"""Raise a :py:exc:`RuntimeError` on missing ``start_tls()``.
One case is that :py:meth:`asyncio.loop.start_tls` is not yet
implemented under Python 3.6. It is necessary for TLS-in-TLS so
that it is possible to send HTTPS queries through HTTPS proxies.
This doesn't affect regular HTTP requests, though.
"""
if not req.is_ssl():
return
proxy_url = req.proxy
assert proxy_url is not None
if proxy_url.scheme != "https":
return
self._check_loop_for_start_tls()
def _check_loop_for_start_tls(self) -> None:
try:
self._loop.start_tls
except AttributeError as attr_exc:
raise RuntimeError(
"An HTTPS request is being sent through an HTTPS proxy. "
"This needs support for TLS in TLS but it is not implemented "
"in your runtime for the stdlib asyncio.\n\n"
"Please upgrade to Python 3.7 or higher. For more details, "
"please see:\n"
"client_advanced.html#proxy-support\n"
) from attr_exc
def _loop_supports_start_tls(self) -> bool:
try:
self._check_loop_for_start_tls()
except RuntimeError:
return False
else:
return True
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"
"You can temporarily patch this as follows:\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:
if exc.errno is None and isinstance(exc, asyncio.TimeoutError):
raise
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:
if tls_transport is None:
msg = "Failed to start TLS (possibly caused by closing transport)"
raise client_error(req.connection_key, OSError(msg))
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:
if exc.errno is None and isinstance(exc, asyncio.TimeoutError):
raise
# 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: Optional[Exception] = None
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
else:
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]:
self._fail_on_no_start_tls(req)
runtime_has_start_tls = self._loop_supports_start_tls()
headers: 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():
if runtime_has_start_tls:
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 = attr.evolve(
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=runtime_has_start_tls)
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,
)
if not runtime_has_start_tls:
rawsock = transport.get_extra_info("socket", default=None)
if rawsock is None:
raise RuntimeError(
"Transport does not expose socket instance"
)
# Duplicate the socket, so now we can close proxy transport
rawsock = rawsock.dup()
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
finally:
if not runtime_has_start_tls:
transport.close()
if not runtime_has_start_tls:
# HTTP proxy with support for upgrade to HTTPS
sslcontext = self._get_ssl_context(req)
return await self._wrap_create_connection(
self._factory,
timeout=timeout,
ssl=sslcontext,
sock=rawsock,
server_hostname=req.host,
req=req,
)
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
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[object, float, None] = sentinel,
limit: int = 100,
limit_per_host: int = 0,
loop: Optional[asyncio.AbstractEventLoop] = None,
) -> None:
super().__init__(
force_close=force_close,
keepalive_timeout=keepalive_timeout,
limit=limit,
limit_per_host=limit_per_host,
loop=loop,
)
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:
if exc.errno is None and isinstance(exc, asyncio.TimeoutError):
raise
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.
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[object, float, None] = sentinel,
limit: int = 100,
limit_per_host: int = 0,
loop: Optional[asyncio.AbstractEventLoop] = None,
) -> None:
super().__init__(
force_close=force_close,
keepalive_timeout=keepalive_timeout,
limit=limit,
limit_per_host=limit_per_host,
loop=loop,
)
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:
if exc.errno is None and isinstance(exc, asyncio.TimeoutError):
raise
raise ClientConnectorError(req.connection_key, exc) from exc
return cast(ResponseHandler, proto)