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1021 lines
41 KiB
Python
1021 lines
41 KiB
Python
#!/usr/bin/env python
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#
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# Copyright 2009 Facebook
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""Utility classes to write to and read from non-blocking files and sockets.
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Contents:
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* `BaseIOStream`: Generic interface for reading and writing.
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* `IOStream`: Implementation of BaseIOStream using non-blocking sockets.
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* `SSLIOStream`: SSL-aware version of IOStream.
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* `PipeIOStream`: Pipe-based IOStream implementation.
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"""
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from __future__ import absolute_import, division, print_function, with_statement
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import collections
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import errno
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import numbers
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import os
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import socket
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import ssl
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import sys
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import re
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from tornado import ioloop
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from tornado.log import gen_log, app_log
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from tornado.netutil import ssl_wrap_socket, ssl_match_hostname, SSLCertificateError
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from tornado import stack_context
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from tornado.util import bytes_type
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try:
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from tornado.platform.posix import _set_nonblocking
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except ImportError:
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_set_nonblocking = None
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class StreamClosedError(IOError):
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"""Exception raised by `IOStream` methods when the stream is closed.
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Note that the close callback is scheduled to run *after* other
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callbacks on the stream (to allow for buffered data to be processed),
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so you may see this error before you see the close callback.
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"""
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pass
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class BaseIOStream(object):
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"""A utility class to write to and read from a non-blocking file or socket.
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We support a non-blocking ``write()`` and a family of ``read_*()`` methods.
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All of the methods take callbacks (since writing and reading are
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non-blocking and asynchronous).
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When a stream is closed due to an error, the IOStream's ``error``
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attribute contains the exception object.
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Subclasses must implement `fileno`, `close_fd`, `write_to_fd`,
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`read_from_fd`, and optionally `get_fd_error`.
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"""
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def __init__(self, io_loop=None, max_buffer_size=None,
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read_chunk_size=4096):
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self.io_loop = io_loop or ioloop.IOLoop.current()
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self.max_buffer_size = max_buffer_size or 104857600
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self.read_chunk_size = read_chunk_size
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self.error = None
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self._read_buffer = collections.deque()
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self._write_buffer = collections.deque()
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self._read_buffer_size = 0
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self._write_buffer_frozen = False
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self._read_delimiter = None
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self._read_regex = None
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self._read_bytes = None
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self._read_until_close = False
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self._read_callback = None
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self._streaming_callback = None
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self._write_callback = None
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self._close_callback = None
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self._connect_callback = None
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self._connecting = False
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self._state = None
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self._pending_callbacks = 0
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self._closed = False
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def fileno(self):
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"""Returns the file descriptor for this stream."""
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raise NotImplementedError()
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def close_fd(self):
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"""Closes the file underlying this stream.
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``close_fd`` is called by `BaseIOStream` and should not be called
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elsewhere; other users should call `close` instead.
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"""
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raise NotImplementedError()
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def write_to_fd(self, data):
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"""Attempts to write ``data`` to the underlying file.
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Returns the number of bytes written.
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"""
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raise NotImplementedError()
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def read_from_fd(self):
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"""Attempts to read from the underlying file.
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Returns ``None`` if there was nothing to read (the socket
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returned `~errno.EWOULDBLOCK` or equivalent), otherwise
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returns the data. When possible, should return no more than
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``self.read_chunk_size`` bytes at a time.
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"""
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raise NotImplementedError()
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def get_fd_error(self):
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"""Returns information about any error on the underlying file.
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This method is called after the `.IOLoop` has signaled an error on the
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file descriptor, and should return an Exception (such as `socket.error`
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with additional information, or None if no such information is
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available.
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"""
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return None
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def read_until_regex(self, regex, callback):
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"""Run ``callback`` when we read the given regex pattern.
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The callback will get the data read (including the data that
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matched the regex and anything that came before it) as an argument.
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"""
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self._set_read_callback(callback)
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self._read_regex = re.compile(regex)
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self._try_inline_read()
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def read_until(self, delimiter, callback):
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"""Run ``callback`` when we read the given delimiter.
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The callback will get the data read (including the delimiter)
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as an argument.
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"""
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self._set_read_callback(callback)
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self._read_delimiter = delimiter
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self._try_inline_read()
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def read_bytes(self, num_bytes, callback, streaming_callback=None):
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"""Run callback when we read the given number of bytes.
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If a ``streaming_callback`` is given, it will be called with chunks
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of data as they become available, and the argument to the final
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``callback`` will be empty. Otherwise, the ``callback`` gets
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the data as an argument.
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"""
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self._set_read_callback(callback)
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assert isinstance(num_bytes, numbers.Integral)
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self._read_bytes = num_bytes
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self._streaming_callback = stack_context.wrap(streaming_callback)
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self._try_inline_read()
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def read_until_close(self, callback, streaming_callback=None):
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"""Reads all data from the socket until it is closed.
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If a ``streaming_callback`` is given, it will be called with chunks
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of data as they become available, and the argument to the final
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``callback`` will be empty. Otherwise, the ``callback`` gets the
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data as an argument.
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Subject to ``max_buffer_size`` limit from `IOStream` constructor if
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a ``streaming_callback`` is not used.
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"""
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self._set_read_callback(callback)
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self._streaming_callback = stack_context.wrap(streaming_callback)
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if self.closed():
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if self._streaming_callback is not None:
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self._run_callback(self._streaming_callback,
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self._consume(self._read_buffer_size))
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self._run_callback(self._read_callback,
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self._consume(self._read_buffer_size))
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self._streaming_callback = None
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self._read_callback = None
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return
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self._read_until_close = True
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self._streaming_callback = stack_context.wrap(streaming_callback)
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self._try_inline_read()
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def write(self, data, callback=None):
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"""Write the given data to this stream.
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If ``callback`` is given, we call it when all of the buffered write
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data has been successfully written to the stream. If there was
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previously buffered write data and an old write callback, that
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callback is simply overwritten with this new callback.
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"""
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assert isinstance(data, bytes_type)
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self._check_closed()
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# We use bool(_write_buffer) as a proxy for write_buffer_size>0,
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# so never put empty strings in the buffer.
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if data:
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# Break up large contiguous strings before inserting them in the
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# write buffer, so we don't have to recopy the entire thing
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# as we slice off pieces to send to the socket.
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WRITE_BUFFER_CHUNK_SIZE = 128 * 1024
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if len(data) > WRITE_BUFFER_CHUNK_SIZE:
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for i in range(0, len(data), WRITE_BUFFER_CHUNK_SIZE):
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self._write_buffer.append(data[i:i + WRITE_BUFFER_CHUNK_SIZE])
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else:
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self._write_buffer.append(data)
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self._write_callback = stack_context.wrap(callback)
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if not self._connecting:
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self._handle_write()
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if self._write_buffer:
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self._add_io_state(self.io_loop.WRITE)
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self._maybe_add_error_listener()
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def set_close_callback(self, callback):
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"""Call the given callback when the stream is closed."""
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self._close_callback = stack_context.wrap(callback)
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def close(self, exc_info=False):
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"""Close this stream.
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If ``exc_info`` is true, set the ``error`` attribute to the current
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exception from `sys.exc_info` (or if ``exc_info`` is a tuple,
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use that instead of `sys.exc_info`).
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"""
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if not self.closed():
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if exc_info:
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if not isinstance(exc_info, tuple):
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exc_info = sys.exc_info()
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if any(exc_info):
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self.error = exc_info[1]
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if self._read_until_close:
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if (self._streaming_callback is not None and
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self._read_buffer_size):
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self._run_callback(self._streaming_callback,
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self._consume(self._read_buffer_size))
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callback = self._read_callback
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self._read_callback = None
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self._read_until_close = False
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self._run_callback(callback,
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self._consume(self._read_buffer_size))
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if self._state is not None:
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self.io_loop.remove_handler(self.fileno())
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self._state = None
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self.close_fd()
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self._closed = True
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self._maybe_run_close_callback()
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def _maybe_run_close_callback(self):
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if (self.closed() and self._close_callback and
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self._pending_callbacks == 0):
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# if there are pending callbacks, don't run the close callback
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# until they're done (see _maybe_add_error_handler)
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cb = self._close_callback
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self._close_callback = None
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self._run_callback(cb)
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# Delete any unfinished callbacks to break up reference cycles.
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self._read_callback = self._write_callback = None
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def reading(self):
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"""Returns true if we are currently reading from the stream."""
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return self._read_callback is not None
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def writing(self):
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"""Returns true if we are currently writing to the stream."""
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return bool(self._write_buffer)
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def closed(self):
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"""Returns true if the stream has been closed."""
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return self._closed
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def set_nodelay(self, value):
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"""Sets the no-delay flag for this stream.
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By default, data written to TCP streams may be held for a time
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to make the most efficient use of bandwidth (according to
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Nagle's algorithm). The no-delay flag requests that data be
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written as soon as possible, even if doing so would consume
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additional bandwidth.
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This flag is currently defined only for TCP-based ``IOStreams``.
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.. versionadded:: 3.1
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"""
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pass
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def _handle_events(self, fd, events):
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if self.closed():
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gen_log.warning("Got events for closed stream %d", fd)
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return
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try:
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if events & self.io_loop.READ:
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self._handle_read()
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if self.closed():
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return
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if events & self.io_loop.WRITE:
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if self._connecting:
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self._handle_connect()
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self._handle_write()
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if self.closed():
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return
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if events & self.io_loop.ERROR:
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self.error = self.get_fd_error()
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# We may have queued up a user callback in _handle_read or
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# _handle_write, so don't close the IOStream until those
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# callbacks have had a chance to run.
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self.io_loop.add_callback(self.close)
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return
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state = self.io_loop.ERROR
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if self.reading():
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state |= self.io_loop.READ
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if self.writing():
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state |= self.io_loop.WRITE
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if state == self.io_loop.ERROR:
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state |= self.io_loop.READ
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if state != self._state:
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assert self._state is not None, \
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"shouldn't happen: _handle_events without self._state"
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self._state = state
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self.io_loop.update_handler(self.fileno(), self._state)
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except Exception:
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gen_log.error("Uncaught exception, closing connection.",
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exc_info=True)
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self.close(exc_info=True)
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raise
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def _run_callback(self, callback, *args):
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def wrapper():
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self._pending_callbacks -= 1
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try:
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callback(*args)
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except Exception:
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app_log.error("Uncaught exception, closing connection.",
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exc_info=True)
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# Close the socket on an uncaught exception from a user callback
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# (It would eventually get closed when the socket object is
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# gc'd, but we don't want to rely on gc happening before we
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# run out of file descriptors)
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self.close(exc_info=True)
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# Re-raise the exception so that IOLoop.handle_callback_exception
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# can see it and log the error
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raise
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self._maybe_add_error_listener()
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# We schedule callbacks to be run on the next IOLoop iteration
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# rather than running them directly for several reasons:
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# * Prevents unbounded stack growth when a callback calls an
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# IOLoop operation that immediately runs another callback
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# * Provides a predictable execution context for e.g.
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# non-reentrant mutexes
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# * Ensures that the try/except in wrapper() is run outside
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# of the application's StackContexts
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with stack_context.NullContext():
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# stack_context was already captured in callback, we don't need to
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# capture it again for IOStream's wrapper. This is especially
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# important if the callback was pre-wrapped before entry to
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# IOStream (as in HTTPConnection._header_callback), as we could
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# capture and leak the wrong context here.
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self._pending_callbacks += 1
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self.io_loop.add_callback(wrapper)
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def _handle_read(self):
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try:
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try:
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# Pretend to have a pending callback so that an EOF in
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# _read_to_buffer doesn't trigger an immediate close
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# callback. At the end of this method we'll either
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# estabilsh a real pending callback via
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# _read_from_buffer or run the close callback.
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#
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# We need two try statements here so that
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# pending_callbacks is decremented before the `except`
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# clause below (which calls `close` and does need to
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# trigger the callback)
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self._pending_callbacks += 1
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while not self.closed():
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# Read from the socket until we get EWOULDBLOCK or equivalent.
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# SSL sockets do some internal buffering, and if the data is
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# sitting in the SSL object's buffer select() and friends
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# can't see it; the only way to find out if it's there is to
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# try to read it.
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if self._read_to_buffer() == 0:
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break
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finally:
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self._pending_callbacks -= 1
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except Exception:
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gen_log.warning("error on read", exc_info=True)
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self.close(exc_info=True)
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return
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if self._read_from_buffer():
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return
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else:
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self._maybe_run_close_callback()
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def _set_read_callback(self, callback):
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assert not self._read_callback, "Already reading"
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self._read_callback = stack_context.wrap(callback)
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def _try_inline_read(self):
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"""Attempt to complete the current read operation from buffered data.
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If the read can be completed without blocking, schedules the
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read callback on the next IOLoop iteration; otherwise starts
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listening for reads on the socket.
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"""
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# See if we've already got the data from a previous read
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if self._read_from_buffer():
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return
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self._check_closed()
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try:
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try:
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# See comments in _handle_read about incrementing _pending_callbacks
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self._pending_callbacks += 1
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while not self.closed():
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if self._read_to_buffer() == 0:
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break
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finally:
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self._pending_callbacks -= 1
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except Exception:
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# If there was an in _read_to_buffer, we called close() already,
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# but couldn't run the close callback because of _pending_callbacks.
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# Before we escape from this function, run the close callback if
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# applicable.
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self._maybe_run_close_callback()
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raise
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if self._read_from_buffer():
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return
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self._maybe_add_error_listener()
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def _read_to_buffer(self):
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"""Reads from the socket and appends the result to the read buffer.
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Returns the number of bytes read. Returns 0 if there is nothing
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to read (i.e. the read returns EWOULDBLOCK or equivalent). On
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error closes the socket and raises an exception.
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"""
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try:
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chunk = self.read_from_fd()
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except (socket.error, IOError, OSError) as e:
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# ssl.SSLError is a subclass of socket.error
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if e.args[0] == errno.ECONNRESET:
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# Treat ECONNRESET as a connection close rather than
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# an error to minimize log spam (the exception will
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# be available on self.error for apps that care).
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self.close(exc_info=True)
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return
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self.close(exc_info=True)
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raise
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if chunk is None:
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return 0
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self._read_buffer.append(chunk)
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self._read_buffer_size += len(chunk)
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if self._read_buffer_size >= self.max_buffer_size:
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gen_log.error("Reached maximum read buffer size")
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self.close()
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raise IOError("Reached maximum read buffer size")
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return len(chunk)
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def _read_from_buffer(self):
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"""Attempts to complete the currently-pending read from the buffer.
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Returns True if the read was completed.
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"""
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if self._streaming_callback is not None and self._read_buffer_size:
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bytes_to_consume = self._read_buffer_size
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if self._read_bytes is not None:
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bytes_to_consume = min(self._read_bytes, bytes_to_consume)
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self._read_bytes -= bytes_to_consume
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self._run_callback(self._streaming_callback,
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self._consume(bytes_to_consume))
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if self._read_bytes is not None and self._read_buffer_size >= self._read_bytes:
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num_bytes = self._read_bytes
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callback = self._read_callback
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self._read_callback = None
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self._streaming_callback = None
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self._read_bytes = None
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self._run_callback(callback, self._consume(num_bytes))
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return True
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elif self._read_delimiter is not None:
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# Multi-byte delimiters (e.g. '\r\n') may straddle two
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# chunks in the read buffer, so we can't easily find them
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# without collapsing the buffer. However, since protocols
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# using delimited reads (as opposed to reads of a known
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# length) tend to be "line" oriented, the delimiter is likely
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# to be in the first few chunks. Merge the buffer gradually
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# since large merges are relatively expensive and get undone in
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# consume().
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if self._read_buffer:
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while True:
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loc = self._read_buffer[0].find(self._read_delimiter)
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|
if loc != -1:
|
|
callback = self._read_callback
|
|
delimiter_len = len(self._read_delimiter)
|
|
self._read_callback = None
|
|
self._streaming_callback = None
|
|
self._read_delimiter = None
|
|
self._run_callback(callback,
|
|
self._consume(loc + delimiter_len))
|
|
return True
|
|
if len(self._read_buffer) == 1:
|
|
break
|
|
_double_prefix(self._read_buffer)
|
|
elif self._read_regex is not None:
|
|
if self._read_buffer:
|
|
while True:
|
|
m = self._read_regex.search(self._read_buffer[0])
|
|
if m is not None:
|
|
callback = self._read_callback
|
|
self._read_callback = None
|
|
self._streaming_callback = None
|
|
self._read_regex = None
|
|
self._run_callback(callback, self._consume(m.end()))
|
|
return True
|
|
if len(self._read_buffer) == 1:
|
|
break
|
|
_double_prefix(self._read_buffer)
|
|
return False
|
|
|
|
def _handle_write(self):
|
|
while self._write_buffer:
|
|
try:
|
|
if not self._write_buffer_frozen:
|
|
# On windows, socket.send blows up if given a
|
|
# write buffer that's too large, instead of just
|
|
# returning the number of bytes it was able to
|
|
# process. Therefore we must not call socket.send
|
|
# with more than 128KB at a time.
|
|
_merge_prefix(self._write_buffer, 128 * 1024)
|
|
num_bytes = self.write_to_fd(self._write_buffer[0])
|
|
if num_bytes == 0:
|
|
# With OpenSSL, if we couldn't write the entire buffer,
|
|
# the very same string object must be used on the
|
|
# next call to send. Therefore we suppress
|
|
# merging the write buffer after an incomplete send.
|
|
# A cleaner solution would be to set
|
|
# SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, but this is
|
|
# not yet accessible from python
|
|
# (http://bugs.python.org/issue8240)
|
|
self._write_buffer_frozen = True
|
|
break
|
|
self._write_buffer_frozen = False
|
|
_merge_prefix(self._write_buffer, num_bytes)
|
|
self._write_buffer.popleft()
|
|
except socket.error as e:
|
|
if e.args[0] in (errno.EWOULDBLOCK, errno.EAGAIN):
|
|
self._write_buffer_frozen = True
|
|
break
|
|
else:
|
|
if e.args[0] not in (errno.EPIPE, errno.ECONNRESET):
|
|
# Broken pipe errors are usually caused by connection
|
|
# reset, and its better to not log EPIPE errors to
|
|
# minimize log spam
|
|
gen_log.warning("Write error on %d: %s",
|
|
self.fileno(), e)
|
|
self.close(exc_info=True)
|
|
return
|
|
if not self._write_buffer and self._write_callback:
|
|
callback = self._write_callback
|
|
self._write_callback = None
|
|
self._run_callback(callback)
|
|
|
|
def _consume(self, loc):
|
|
if loc == 0:
|
|
return b""
|
|
_merge_prefix(self._read_buffer, loc)
|
|
self._read_buffer_size -= loc
|
|
return self._read_buffer.popleft()
|
|
|
|
def _check_closed(self):
|
|
if self.closed():
|
|
raise StreamClosedError("Stream is closed")
|
|
|
|
def _maybe_add_error_listener(self):
|
|
if self._state is None and self._pending_callbacks == 0:
|
|
if self.closed():
|
|
self._maybe_run_close_callback()
|
|
else:
|
|
self._add_io_state(ioloop.IOLoop.READ)
|
|
|
|
def _add_io_state(self, state):
|
|
"""Adds `state` (IOLoop.{READ,WRITE} flags) to our event handler.
|
|
|
|
Implementation notes: Reads and writes have a fast path and a
|
|
slow path. The fast path reads synchronously from socket
|
|
buffers, while the slow path uses `_add_io_state` to schedule
|
|
an IOLoop callback. Note that in both cases, the callback is
|
|
run asynchronously with `_run_callback`.
|
|
|
|
To detect closed connections, we must have called
|
|
`_add_io_state` at some point, but we want to delay this as
|
|
much as possible so we don't have to set an `IOLoop.ERROR`
|
|
listener that will be overwritten by the next slow-path
|
|
operation. As long as there are callbacks scheduled for
|
|
fast-path ops, those callbacks may do more reads.
|
|
If a sequence of fast-path ops do not end in a slow-path op,
|
|
(e.g. for an @asynchronous long-poll request), we must add
|
|
the error handler. This is done in `_run_callback` and `write`
|
|
(since the write callback is optional so we can have a
|
|
fast-path write with no `_run_callback`)
|
|
"""
|
|
if self.closed():
|
|
# connection has been closed, so there can be no future events
|
|
return
|
|
if self._state is None:
|
|
self._state = ioloop.IOLoop.ERROR | state
|
|
with stack_context.NullContext():
|
|
self.io_loop.add_handler(
|
|
self.fileno(), self._handle_events, self._state)
|
|
elif not self._state & state:
|
|
self._state = self._state | state
|
|
self.io_loop.update_handler(self.fileno(), self._state)
|
|
|
|
|
|
class IOStream(BaseIOStream):
|
|
r"""Socket-based `IOStream` implementation.
|
|
|
|
This class supports the read and write methods from `BaseIOStream`
|
|
plus a `connect` method.
|
|
|
|
The ``socket`` parameter may either be connected or unconnected.
|
|
For server operations the socket is the result of calling
|
|
`socket.accept <socket.socket.accept>`. For client operations the
|
|
socket is created with `socket.socket`, and may either be
|
|
connected before passing it to the `IOStream` or connected with
|
|
`IOStream.connect`.
|
|
|
|
A very simple (and broken) HTTP client using this class::
|
|
|
|
import tornado.ioloop
|
|
import tornado.iostream
|
|
import socket
|
|
|
|
def send_request():
|
|
stream.write(b"GET / HTTP/1.0\r\nHost: friendfeed.com\r\n\r\n")
|
|
stream.read_until(b"\r\n\r\n", on_headers)
|
|
|
|
def on_headers(data):
|
|
headers = {}
|
|
for line in data.split(b"\r\n"):
|
|
parts = line.split(b":")
|
|
if len(parts) == 2:
|
|
headers[parts[0].strip()] = parts[1].strip()
|
|
stream.read_bytes(int(headers[b"Content-Length"]), on_body)
|
|
|
|
def on_body(data):
|
|
print data
|
|
stream.close()
|
|
tornado.ioloop.IOLoop.instance().stop()
|
|
|
|
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
|
|
stream = tornado.iostream.IOStream(s)
|
|
stream.connect(("friendfeed.com", 80), send_request)
|
|
tornado.ioloop.IOLoop.instance().start()
|
|
"""
|
|
def __init__(self, socket, *args, **kwargs):
|
|
self.socket = socket
|
|
self.socket.setblocking(False)
|
|
super(IOStream, self).__init__(*args, **kwargs)
|
|
|
|
def fileno(self):
|
|
return self.socket.fileno()
|
|
|
|
def close_fd(self):
|
|
self.socket.close()
|
|
self.socket = None
|
|
|
|
def get_fd_error(self):
|
|
errno = self.socket.getsockopt(socket.SOL_SOCKET,
|
|
socket.SO_ERROR)
|
|
return socket.error(errno, os.strerror(errno))
|
|
|
|
def read_from_fd(self):
|
|
try:
|
|
chunk = self.socket.recv(self.read_chunk_size)
|
|
except socket.error as e:
|
|
if e.args[0] in (errno.EWOULDBLOCK, errno.EAGAIN):
|
|
return None
|
|
else:
|
|
raise
|
|
if not chunk:
|
|
self.close()
|
|
return None
|
|
return chunk
|
|
|
|
def write_to_fd(self, data):
|
|
return self.socket.send(data)
|
|
|
|
def connect(self, address, callback=None, server_hostname=None):
|
|
"""Connects the socket to a remote address without blocking.
|
|
|
|
May only be called if the socket passed to the constructor was
|
|
not previously connected. The address parameter is in the
|
|
same format as for `socket.connect <socket.socket.connect>`,
|
|
i.e. a ``(host, port)`` tuple. If ``callback`` is specified,
|
|
it will be called when the connection is completed.
|
|
|
|
If specified, the ``server_hostname`` parameter will be used
|
|
in SSL connections for certificate validation (if requested in
|
|
the ``ssl_options``) and SNI (if supported; requires
|
|
Python 3.2+).
|
|
|
|
Note that it is safe to call `IOStream.write
|
|
<BaseIOStream.write>` while the connection is pending, in
|
|
which case the data will be written as soon as the connection
|
|
is ready. Calling `IOStream` read methods before the socket is
|
|
connected works on some platforms but is non-portable.
|
|
"""
|
|
self._connecting = True
|
|
try:
|
|
self.socket.connect(address)
|
|
except socket.error as e:
|
|
# In non-blocking mode we expect connect() to raise an
|
|
# exception with EINPROGRESS or EWOULDBLOCK.
|
|
#
|
|
# On freebsd, other errors such as ECONNREFUSED may be
|
|
# returned immediately when attempting to connect to
|
|
# localhost, so handle them the same way as an error
|
|
# reported later in _handle_connect.
|
|
if e.args[0] not in (errno.EINPROGRESS, errno.EWOULDBLOCK):
|
|
gen_log.warning("Connect error on fd %d: %s",
|
|
self.socket.fileno(), e)
|
|
self.close(exc_info=True)
|
|
return
|
|
self._connect_callback = stack_context.wrap(callback)
|
|
self._add_io_state(self.io_loop.WRITE)
|
|
|
|
def _handle_connect(self):
|
|
err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
|
|
if err != 0:
|
|
self.error = socket.error(err, os.strerror(err))
|
|
# IOLoop implementations may vary: some of them return
|
|
# an error state before the socket becomes writable, so
|
|
# in that case a connection failure would be handled by the
|
|
# error path in _handle_events instead of here.
|
|
gen_log.warning("Connect error on fd %d: %s",
|
|
self.socket.fileno(), errno.errorcode[err])
|
|
self.close()
|
|
return
|
|
if self._connect_callback is not None:
|
|
callback = self._connect_callback
|
|
self._connect_callback = None
|
|
self._run_callback(callback)
|
|
self._connecting = False
|
|
|
|
def set_nodelay(self, value):
|
|
if (self.socket is not None and
|
|
self.socket.family in (socket.AF_INET, socket.AF_INET6)):
|
|
try:
|
|
self.socket.setsockopt(socket.IPPROTO_TCP,
|
|
socket.TCP_NODELAY, 1 if value else 0)
|
|
except socket.error as e:
|
|
# Sometimes setsockopt will fail if the socket is closed
|
|
# at the wrong time. This can happen with HTTPServer
|
|
# resetting the value to false between requests.
|
|
if e.errno != errno.EINVAL:
|
|
raise
|
|
|
|
|
|
class SSLIOStream(IOStream):
|
|
"""A utility class to write to and read from a non-blocking SSL socket.
|
|
|
|
If the socket passed to the constructor is already connected,
|
|
it should be wrapped with::
|
|
|
|
ssl.wrap_socket(sock, do_handshake_on_connect=False, **kwargs)
|
|
|
|
before constructing the `SSLIOStream`. Unconnected sockets will be
|
|
wrapped when `IOStream.connect` is finished.
|
|
"""
|
|
def __init__(self, *args, **kwargs):
|
|
"""The ``ssl_options`` keyword argument may either be a dictionary
|
|
of keywords arguments for `ssl.wrap_socket`, or an `ssl.SSLContext`
|
|
object.
|
|
"""
|
|
self._ssl_options = kwargs.pop('ssl_options', {})
|
|
super(SSLIOStream, self).__init__(*args, **kwargs)
|
|
self._ssl_accepting = True
|
|
self._handshake_reading = False
|
|
self._handshake_writing = False
|
|
self._ssl_connect_callback = None
|
|
self._server_hostname = None
|
|
|
|
def reading(self):
|
|
return self._handshake_reading or super(SSLIOStream, self).reading()
|
|
|
|
def writing(self):
|
|
return self._handshake_writing or super(SSLIOStream, self).writing()
|
|
|
|
def _do_ssl_handshake(self):
|
|
# Based on code from test_ssl.py in the python stdlib
|
|
try:
|
|
self._handshake_reading = False
|
|
self._handshake_writing = False
|
|
self.socket.do_handshake()
|
|
except ssl.SSLError as err:
|
|
if err.args[0] == ssl.SSL_ERROR_WANT_READ:
|
|
self._handshake_reading = True
|
|
return
|
|
elif err.args[0] == ssl.SSL_ERROR_WANT_WRITE:
|
|
self._handshake_writing = True
|
|
return
|
|
elif err.args[0] in (ssl.SSL_ERROR_EOF,
|
|
ssl.SSL_ERROR_ZERO_RETURN):
|
|
return self.close(exc_info=True)
|
|
elif err.args[0] == ssl.SSL_ERROR_SSL:
|
|
try:
|
|
peer = self.socket.getpeername()
|
|
except Exception:
|
|
peer = '(not connected)'
|
|
gen_log.warning("SSL Error on %d %s: %s",
|
|
self.socket.fileno(), peer, err)
|
|
return self.close(exc_info=True)
|
|
raise
|
|
except socket.error as err:
|
|
if err.args[0] in (errno.ECONNABORTED, errno.ECONNRESET):
|
|
return self.close(exc_info=True)
|
|
except AttributeError:
|
|
# On Linux, if the connection was reset before the call to
|
|
# wrap_socket, do_handshake will fail with an
|
|
# AttributeError.
|
|
return self.close(exc_info=True)
|
|
else:
|
|
self._ssl_accepting = False
|
|
if not self._verify_cert(self.socket.getpeercert()):
|
|
self.close()
|
|
return
|
|
if self._ssl_connect_callback is not None:
|
|
callback = self._ssl_connect_callback
|
|
self._ssl_connect_callback = None
|
|
self._run_callback(callback)
|
|
|
|
def _verify_cert(self, peercert):
|
|
"""Returns True if peercert is valid according to the configured
|
|
validation mode and hostname.
|
|
|
|
The ssl handshake already tested the certificate for a valid
|
|
CA signature; the only thing that remains is to check
|
|
the hostname.
|
|
"""
|
|
if isinstance(self._ssl_options, dict):
|
|
verify_mode = self._ssl_options.get('cert_reqs', ssl.CERT_NONE)
|
|
elif isinstance(self._ssl_options, ssl.SSLContext):
|
|
verify_mode = self._ssl_options.verify_mode
|
|
assert verify_mode in (ssl.CERT_NONE, ssl.CERT_REQUIRED, ssl.CERT_OPTIONAL)
|
|
if verify_mode == ssl.CERT_NONE or self._server_hostname is None:
|
|
return True
|
|
cert = self.socket.getpeercert()
|
|
if cert is None and verify_mode == ssl.CERT_REQUIRED:
|
|
gen_log.warning("No SSL certificate given")
|
|
return False
|
|
try:
|
|
ssl_match_hostname(peercert, self._server_hostname)
|
|
except SSLCertificateError:
|
|
gen_log.warning("Invalid SSL certificate", exc_info=True)
|
|
return False
|
|
else:
|
|
return True
|
|
|
|
def _handle_read(self):
|
|
if self._ssl_accepting:
|
|
self._do_ssl_handshake()
|
|
return
|
|
super(SSLIOStream, self)._handle_read()
|
|
|
|
def _handle_write(self):
|
|
if self._ssl_accepting:
|
|
self._do_ssl_handshake()
|
|
return
|
|
super(SSLIOStream, self)._handle_write()
|
|
|
|
def connect(self, address, callback=None, server_hostname=None):
|
|
# Save the user's callback and run it after the ssl handshake
|
|
# has completed.
|
|
self._ssl_connect_callback = stack_context.wrap(callback)
|
|
self._server_hostname = server_hostname
|
|
super(SSLIOStream, self).connect(address, callback=None)
|
|
|
|
def _handle_connect(self):
|
|
# When the connection is complete, wrap the socket for SSL
|
|
# traffic. Note that we do this by overriding _handle_connect
|
|
# instead of by passing a callback to super().connect because
|
|
# user callbacks are enqueued asynchronously on the IOLoop,
|
|
# but since _handle_events calls _handle_connect immediately
|
|
# followed by _handle_write we need this to be synchronous.
|
|
self.socket = ssl_wrap_socket(self.socket, self._ssl_options,
|
|
server_hostname=self._server_hostname,
|
|
do_handshake_on_connect=False)
|
|
super(SSLIOStream, self)._handle_connect()
|
|
|
|
def read_from_fd(self):
|
|
if self._ssl_accepting:
|
|
# If the handshake hasn't finished yet, there can't be anything
|
|
# to read (attempting to read may or may not raise an exception
|
|
# depending on the SSL version)
|
|
return None
|
|
try:
|
|
# SSLSocket objects have both a read() and recv() method,
|
|
# while regular sockets only have recv().
|
|
# The recv() method blocks (at least in python 2.6) if it is
|
|
# called when there is nothing to read, so we have to use
|
|
# read() instead.
|
|
chunk = self.socket.read(self.read_chunk_size)
|
|
except ssl.SSLError as e:
|
|
# SSLError is a subclass of socket.error, so this except
|
|
# block must come first.
|
|
if e.args[0] == ssl.SSL_ERROR_WANT_READ:
|
|
return None
|
|
else:
|
|
raise
|
|
except socket.error as e:
|
|
if e.args[0] in (errno.EWOULDBLOCK, errno.EAGAIN):
|
|
return None
|
|
else:
|
|
raise
|
|
if not chunk:
|
|
self.close()
|
|
return None
|
|
return chunk
|
|
|
|
|
|
class PipeIOStream(BaseIOStream):
|
|
"""Pipe-based `IOStream` implementation.
|
|
|
|
The constructor takes an integer file descriptor (such as one returned
|
|
by `os.pipe`) rather than an open file object. Pipes are generally
|
|
one-way, so a `PipeIOStream` can be used for reading or writing but not
|
|
both.
|
|
"""
|
|
def __init__(self, fd, *args, **kwargs):
|
|
self.fd = fd
|
|
_set_nonblocking(fd)
|
|
super(PipeIOStream, self).__init__(*args, **kwargs)
|
|
|
|
def fileno(self):
|
|
return self.fd
|
|
|
|
def close_fd(self):
|
|
os.close(self.fd)
|
|
|
|
def write_to_fd(self, data):
|
|
return os.write(self.fd, data)
|
|
|
|
def read_from_fd(self):
|
|
try:
|
|
chunk = os.read(self.fd, self.read_chunk_size)
|
|
except (IOError, OSError) as e:
|
|
if e.args[0] in (errno.EWOULDBLOCK, errno.EAGAIN):
|
|
return None
|
|
elif e.args[0] == errno.EBADF:
|
|
# If the writing half of a pipe is closed, select will
|
|
# report it as readable but reads will fail with EBADF.
|
|
self.close(exc_info=True)
|
|
return None
|
|
else:
|
|
raise
|
|
if not chunk:
|
|
self.close()
|
|
return None
|
|
return chunk
|
|
|
|
|
|
def _double_prefix(deque):
|
|
"""Grow by doubling, but don't split the second chunk just because the
|
|
first one is small.
|
|
"""
|
|
new_len = max(len(deque[0]) * 2,
|
|
(len(deque[0]) + len(deque[1])))
|
|
_merge_prefix(deque, new_len)
|
|
|
|
|
|
def _merge_prefix(deque, size):
|
|
"""Replace the first entries in a deque of strings with a single
|
|
string of up to size bytes.
|
|
|
|
>>> d = collections.deque(['abc', 'de', 'fghi', 'j'])
|
|
>>> _merge_prefix(d, 5); print(d)
|
|
deque(['abcde', 'fghi', 'j'])
|
|
|
|
Strings will be split as necessary to reach the desired size.
|
|
>>> _merge_prefix(d, 7); print(d)
|
|
deque(['abcdefg', 'hi', 'j'])
|
|
|
|
>>> _merge_prefix(d, 3); print(d)
|
|
deque(['abc', 'defg', 'hi', 'j'])
|
|
|
|
>>> _merge_prefix(d, 100); print(d)
|
|
deque(['abcdefghij'])
|
|
"""
|
|
if len(deque) == 1 and len(deque[0]) <= size:
|
|
return
|
|
prefix = []
|
|
remaining = size
|
|
while deque and remaining > 0:
|
|
chunk = deque.popleft()
|
|
if len(chunk) > remaining:
|
|
deque.appendleft(chunk[remaining:])
|
|
chunk = chunk[:remaining]
|
|
prefix.append(chunk)
|
|
remaining -= len(chunk)
|
|
# This data structure normally just contains byte strings, but
|
|
# the unittest gets messy if it doesn't use the default str() type,
|
|
# so do the merge based on the type of data that's actually present.
|
|
if prefix:
|
|
deque.appendleft(type(prefix[0])().join(prefix))
|
|
if not deque:
|
|
deque.appendleft(b"")
|
|
|
|
|
|
def doctests():
|
|
import doctest
|
|
return doctest.DocTestSuite()
|