|
| 1 | +import asyncio |
| 2 | +import socket |
| 3 | +import ssl |
| 4 | +from typing import Any, Dict, Iterable, Optional, Type |
| 5 | + |
| 6 | +from .._exceptions import ( |
| 7 | + BrokenSocketError, |
| 8 | + ConnectError, |
| 9 | + ConnectTimeout, |
| 10 | + ReadError, |
| 11 | + ReadTimeout, |
| 12 | + WriteError, |
| 13 | + WriteTimeout, |
| 14 | + map_exceptions, |
| 15 | +) |
| 16 | +from .._utils import is_socket_readable |
| 17 | +from .base import SOCKET_OPTION, AsyncNetworkBackend, AsyncNetworkStream |
| 18 | + |
| 19 | + |
| 20 | +class AsyncIOStream(AsyncNetworkStream): |
| 21 | + def __init__( |
| 22 | + self, stream_reader: asyncio.StreamReader, stream_writer: asyncio.StreamWriter |
| 23 | + ): |
| 24 | + self._stream_reader = stream_reader |
| 25 | + self._stream_writer = stream_writer |
| 26 | + self._read_lock = asyncio.Lock() |
| 27 | + self._write_lock = asyncio.Lock() |
| 28 | + self._inner: Optional[AsyncIOStream] = None |
| 29 | + |
| 30 | + async def start_tls( |
| 31 | + self, |
| 32 | + ssl_context: ssl.SSLContext, |
| 33 | + server_hostname: Optional[str] = None, |
| 34 | + timeout: Optional[float] = None, |
| 35 | + ) -> AsyncNetworkStream: |
| 36 | + loop = asyncio.get_event_loop() |
| 37 | + |
| 38 | + stream_reader = asyncio.StreamReader() |
| 39 | + protocol = asyncio.StreamReaderProtocol(stream_reader) |
| 40 | + |
| 41 | + exc_map: Dict[Type[Exception], Type[Exception]] = { |
| 42 | + asyncio.TimeoutError: ConnectTimeout, |
| 43 | + OSError: ConnectError, |
| 44 | + } |
| 45 | + with map_exceptions(exc_map): |
| 46 | + transport_ssl = await asyncio.wait_for( |
| 47 | + loop.start_tls( |
| 48 | + self._stream_writer.transport, |
| 49 | + protocol, |
| 50 | + ssl_context, |
| 51 | + server_hostname=server_hostname, |
| 52 | + ), |
| 53 | + timeout, |
| 54 | + ) |
| 55 | + if transport_ssl is None: |
| 56 | + # https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.start_tls |
| 57 | + raise ConnectError("Transport closed while starting TLS") # pragma: nocover |
| 58 | + |
| 59 | + # Initialize the protocol, so it is made aware of being tied to |
| 60 | + # a TLS connection. |
| 61 | + # See: https://github.com/encode/httpx/issues/859 |
| 62 | + protocol.connection_made(transport_ssl) |
| 63 | + |
| 64 | + stream_writer = asyncio.StreamWriter( |
| 65 | + transport=transport_ssl, protocol=protocol, reader=stream_reader, loop=loop |
| 66 | + ) |
| 67 | + |
| 68 | + ssl_stream = AsyncIOStream(stream_reader, stream_writer) |
| 69 | + # When we return a new SocketStream with new StreamReader/StreamWriter instances |
| 70 | + # we need to keep references to the old StreamReader/StreamWriter so that they |
| 71 | + # are not garbage collected and closed while we're still using them. |
| 72 | + ssl_stream._inner = self |
| 73 | + return ssl_stream |
| 74 | + |
| 75 | + async def read(self, max_bytes: int, timeout: Optional[float] = None) -> bytes: |
| 76 | + exc_map: Dict[Type[Exception], Type[Exception]] = { |
| 77 | + asyncio.TimeoutError: ReadTimeout, |
| 78 | + OSError: ReadError, |
| 79 | + } |
| 80 | + async with self._read_lock: |
| 81 | + with map_exceptions(exc_map): |
| 82 | + try: |
| 83 | + return await asyncio.wait_for( |
| 84 | + self._stream_reader.read(max_bytes), timeout |
| 85 | + ) |
| 86 | + except AttributeError as exc: # pragma: nocover |
| 87 | + if "resume_reading" in str(exc): |
| 88 | + # Python's asyncio has a bug that can occur when a |
| 89 | + # connection has been closed, while it is paused. |
| 90 | + # See: https://github.com/encode/httpx/issues/1213 |
| 91 | + # |
| 92 | + # Returning an empty byte-string to indicate connection |
| 93 | + # close will eventually raise an httpcore.RemoteProtocolError |
| 94 | + # to the user when this goes through our HTTP parsing layer. |
| 95 | + return b"" |
| 96 | + raise |
| 97 | + |
| 98 | + async def write(self, data: bytes, timeout: Optional[float] = None) -> None: |
| 99 | + if not data: |
| 100 | + return |
| 101 | + |
| 102 | + exc_map: Dict[Type[Exception], Type[Exception]] = { |
| 103 | + asyncio.TimeoutError: WriteTimeout, |
| 104 | + OSError: WriteError, |
| 105 | + } |
| 106 | + async with self._write_lock: |
| 107 | + with map_exceptions(exc_map): |
| 108 | + self._stream_writer.write(data) |
| 109 | + return await asyncio.wait_for(self._stream_writer.drain(), timeout) |
| 110 | + |
| 111 | + async def aclose(self) -> None: |
| 112 | + # SSL connections should issue the close and then abort, rather than |
| 113 | + # waiting for the remote end of the connection to signal the EOF. |
| 114 | + # |
| 115 | + # See: |
| 116 | + # |
| 117 | + # * https://bugs.python.org/issue39758 |
| 118 | + # * https://github.com/python-trio/trio/blob/ |
| 119 | + # 31e2ae866ad549f1927d45ce073d4f0ea9f12419/trio/_ssl.py#L779-L829 |
| 120 | + # |
| 121 | + # And related issues caused if we simply omit the 'wait_closed' call, |
| 122 | + # without first using `.abort()` |
| 123 | + # |
| 124 | + # * https://github.com/encode/httpx/issues/825 |
| 125 | + # * https://github.com/encode/httpx/issues/914 |
| 126 | + is_ssl = self._sslobj is not None |
| 127 | + |
| 128 | + async with self._write_lock: |
| 129 | + try: |
| 130 | + self._stream_writer.close() |
| 131 | + if is_ssl: |
| 132 | + # Give the connection a chance to write any data in the buffer, |
| 133 | + # and then forcibly tear down the SSL connection. |
| 134 | + await asyncio.sleep(0) |
| 135 | + self._stream_writer.transport.abort() |
| 136 | + await self._stream_writer.wait_closed() |
| 137 | + except OSError: # pragma: nocover |
| 138 | + pass |
| 139 | + |
| 140 | + def get_extra_info(self, info: str) -> Any: |
| 141 | + if info == "is_readable": |
| 142 | + return is_socket_readable(self._raw_socket) |
| 143 | + if info == "ssl_object": |
| 144 | + return self._sslobj |
| 145 | + if info in ("client_addr", "server_addr"): |
| 146 | + sock = self._raw_socket |
| 147 | + if sock is None: |
| 148 | + raise BrokenSocketError() # pragma: nocover |
| 149 | + return sock.getsockname() if info == "client_addr" else sock.getpeername() |
| 150 | + if info == "socket": |
| 151 | + return self._raw_socket |
| 152 | + return None |
| 153 | + |
| 154 | + @property |
| 155 | + def _raw_socket(self) -> Optional[socket.socket]: |
| 156 | + transport = self._stream_writer.transport |
| 157 | + sock: Optional[socket.socket] = transport.get_extra_info("socket") |
| 158 | + return sock |
| 159 | + |
| 160 | + @property |
| 161 | + def _sslobj(self) -> Optional[ssl.SSLObject]: |
| 162 | + transport = self._stream_writer.transport |
| 163 | + sslobj: Optional[ssl.SSLObject] = transport.get_extra_info("ssl_object") |
| 164 | + return sslobj |
| 165 | + |
| 166 | + |
| 167 | +class AsyncioBackend(AsyncNetworkBackend): |
| 168 | + async def connect_tcp( |
| 169 | + self, |
| 170 | + host: str, |
| 171 | + port: int, |
| 172 | + timeout: Optional[float] = None, |
| 173 | + local_address: Optional[str] = None, |
| 174 | + socket_options: Optional[Iterable[SOCKET_OPTION]] = None, |
| 175 | + ) -> AsyncNetworkStream: |
| 176 | + local_addr = None if local_address is None else (local_address, 0) |
| 177 | + |
| 178 | + exc_map: Dict[Type[Exception], Type[Exception]] = { |
| 179 | + asyncio.TimeoutError: ConnectTimeout, |
| 180 | + OSError: ConnectError, |
| 181 | + } |
| 182 | + with map_exceptions(exc_map): |
| 183 | + stream_reader, stream_writer = await asyncio.wait_for( |
| 184 | + asyncio.open_connection(host, port, local_addr=local_addr), |
| 185 | + timeout, |
| 186 | + ) |
| 187 | + self._set_socket_options(stream_writer, socket_options) |
| 188 | + return AsyncIOStream( |
| 189 | + stream_reader=stream_reader, stream_writer=stream_writer |
| 190 | + ) |
| 191 | + |
| 192 | + async def connect_unix_socket( |
| 193 | + self, |
| 194 | + path: str, |
| 195 | + timeout: Optional[float] = None, |
| 196 | + socket_options: Optional[Iterable[SOCKET_OPTION]] = None, |
| 197 | + ) -> AsyncNetworkStream: |
| 198 | + exc_map: Dict[Type[Exception], Type[Exception]] = { |
| 199 | + asyncio.TimeoutError: ConnectTimeout, |
| 200 | + OSError: ConnectError, |
| 201 | + } |
| 202 | + with map_exceptions(exc_map): |
| 203 | + stream_reader, stream_writer = await asyncio.wait_for( |
| 204 | + asyncio.open_unix_connection(path), timeout |
| 205 | + ) |
| 206 | + self._set_socket_options(stream_writer, socket_options) |
| 207 | + return AsyncIOStream( |
| 208 | + stream_reader=stream_reader, stream_writer=stream_writer |
| 209 | + ) |
| 210 | + |
| 211 | + async def sleep(self, seconds: float) -> None: |
| 212 | + await asyncio.sleep(seconds) # pragma: nocover |
| 213 | + |
| 214 | + def _set_socket_options( |
| 215 | + self, |
| 216 | + stream: asyncio.StreamWriter, |
| 217 | + socket_options: Optional[Iterable[SOCKET_OPTION]] = None, |
| 218 | + ) -> None: |
| 219 | + if not socket_options: |
| 220 | + return |
| 221 | + |
| 222 | + sock = stream.get_extra_info("socket") |
| 223 | + if sock is None: |
| 224 | + raise BrokenSocketError() # pragma: nocover |
| 225 | + |
| 226 | + for option in socket_options: |
| 227 | + sock.setsockopt(*option) |
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