Source code for tornado.httpserver

#!/usr/bin/env python
# Copyright 2009 Facebook
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

"""A non-blocking, single-threaded HTTP server.

Typical applications have little direct interaction with the `HTTPServer`
class except to start a server at the beginning of the process
(and even that is often done indirectly via `tornado.web.Application.listen`).

.. versionchanged:: 4.0

   The ``HTTPRequest`` class that used to live in this module has been moved
   to `tornado.httputil.HTTPServerRequest`.  The old name remains as an alias.

from __future__ import absolute_import, division, print_function

import socket

from tornado.escape import native_str
from tornado.http1connection import HTTP1ServerConnection, HTTP1ConnectionParameters
from tornado import gen
from tornado import httputil
from tornado import iostream
from tornado import netutil
from tornado.tcpserver import TCPServer
from tornado.util import Configurable

[docs]class HTTPServer(TCPServer, Configurable, httputil.HTTPServerConnectionDelegate): r"""A non-blocking, single-threaded HTTP server. A server is defined by a subclass of `.HTTPServerConnectionDelegate`, or, for backwards compatibility, a callback that takes an `.HTTPServerRequest` as an argument. The delegate is usually a `tornado.web.Application`. `HTTPServer` supports keep-alive connections by default (automatically for HTTP/1.1, or for HTTP/1.0 when the client requests ``Connection: keep-alive``). If ``xheaders`` is ``True``, we support the ``X-Real-Ip``/``X-Forwarded-For`` and ``X-Scheme``/``X-Forwarded-Proto`` headers, which override the remote IP and URI scheme/protocol for all requests. These headers are useful when running Tornado behind a reverse proxy or load balancer. The ``protocol`` argument can also be set to ``https`` if Tornado is run behind an SSL-decoding proxy that does not set one of the supported ``xheaders``. By default, when parsing the ``X-Forwarded-For`` header, Tornado will select the last (i.e., the closest) address on the list of hosts as the remote host IP address. To select the next server in the chain, a list of trusted downstream hosts may be passed as the ``trusted_downstream`` argument. These hosts will be skipped when parsing the ``X-Forwarded-For`` header. To make this server serve SSL traffic, send the ``ssl_options`` keyword argument with an `ssl.SSLContext` object. For compatibility with older versions of Python ``ssl_options`` may also be a dictionary of keyword arguments for the `ssl.wrap_socket` method.:: ssl_ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH) ssl_ctx.load_cert_chain(os.path.join(data_dir, "mydomain.crt"), os.path.join(data_dir, "mydomain.key")) HTTPServer(applicaton, ssl_options=ssl_ctx) `HTTPServer` initialization follows one of three patterns (the initialization methods are defined on `tornado.tcpserver.TCPServer`): 1. `~tornado.tcpserver.TCPServer.listen`: simple single-process:: server = HTTPServer(app) server.listen(8888) IOLoop.current().start() In many cases, `tornado.web.Application.listen` can be used to avoid the need to explicitly create the `HTTPServer`. 2. `~tornado.tcpserver.TCPServer.bind`/`~tornado.tcpserver.TCPServer.start`: simple multi-process:: server = HTTPServer(app) server.bind(8888) server.start(0) # Forks multiple sub-processes IOLoop.current().start() When using this interface, an `.IOLoop` must *not* be passed to the `HTTPServer` constructor. `~.TCPServer.start` will always start the server on the default singleton `.IOLoop`. 3. `~tornado.tcpserver.TCPServer.add_sockets`: advanced multi-process:: sockets = tornado.netutil.bind_sockets(8888) tornado.process.fork_processes(0) server = HTTPServer(app) server.add_sockets(sockets) IOLoop.current().start() The `~.TCPServer.add_sockets` interface is more complicated, but it can be used with `tornado.process.fork_processes` to give you more flexibility in when the fork happens. `~.TCPServer.add_sockets` can also be used in single-process servers if you want to create your listening sockets in some way other than `tornado.netutil.bind_sockets`. .. versionchanged:: 4.0 Added ``decompress_request``, ``chunk_size``, ``max_header_size``, ``idle_connection_timeout``, ``body_timeout``, ``max_body_size`` arguments. Added support for `.HTTPServerConnectionDelegate` instances as ``request_callback``. .. versionchanged:: 4.1 `.HTTPServerConnectionDelegate.start_request` is now called with two arguments ``(server_conn, request_conn)`` (in accordance with the documentation) instead of one ``(request_conn)``. .. versionchanged:: 4.2 `HTTPServer` is now a subclass of `tornado.util.Configurable`. .. versionchanged:: 4.5 Added the ``trusted_downstream`` argument. """ def __init__(self, *args, **kwargs): # Ignore args to __init__; real initialization belongs in # initialize since we're Configurable. (there's something # weird in initialization order between this class, # Configurable, and TCPServer so we can't leave __init__ out # completely) pass def initialize(self, request_callback, no_keep_alive=False, io_loop=None, xheaders=False, ssl_options=None, protocol=None, decompress_request=False, chunk_size=None, max_header_size=None, idle_connection_timeout=None, body_timeout=None, max_body_size=None, max_buffer_size=None, trusted_downstream=None): self.request_callback = request_callback self.no_keep_alive = no_keep_alive self.xheaders = xheaders self.protocol = protocol self.conn_params = HTTP1ConnectionParameters( decompress=decompress_request, chunk_size=chunk_size, max_header_size=max_header_size, header_timeout=idle_connection_timeout or 3600, max_body_size=max_body_size, body_timeout=body_timeout, no_keep_alive=no_keep_alive) TCPServer.__init__(self, io_loop=io_loop, ssl_options=ssl_options, max_buffer_size=max_buffer_size, read_chunk_size=chunk_size) self._connections = set() self.trusted_downstream = trusted_downstream @classmethod def configurable_base(cls): return HTTPServer @classmethod def configurable_default(cls): return HTTPServer @gen.coroutine def close_all_connections(self): while self._connections: # Peek at an arbitrary element of the set conn = next(iter(self._connections)) yield conn.close() def handle_stream(self, stream, address): context = _HTTPRequestContext(stream, address, self.protocol, self.trusted_downstream) conn = HTTP1ServerConnection( stream, self.conn_params, context) self._connections.add(conn) conn.start_serving(self) def start_request(self, server_conn, request_conn): if isinstance(self.request_callback, httputil.HTTPServerConnectionDelegate): delegate = self.request_callback.start_request(server_conn, request_conn) else: delegate = _CallableAdapter(self.request_callback, request_conn) if self.xheaders: delegate = _ProxyAdapter(delegate, request_conn) return delegate def on_close(self, server_conn): self._connections.remove(server_conn)
class _CallableAdapter(httputil.HTTPMessageDelegate): def __init__(self, request_callback, request_conn): self.connection = request_conn self.request_callback = request_callback self.request = None self.delegate = None self._chunks = [] def headers_received(self, start_line, headers): self.request = httputil.HTTPServerRequest( connection=self.connection, start_line=start_line, headers=headers) def data_received(self, chunk): self._chunks.append(chunk) def finish(self): self.request.body = b''.join(self._chunks) self.request._parse_body() self.request_callback(self.request) def on_connection_close(self): self._chunks = None class _HTTPRequestContext(object): def __init__(self, stream, address, protocol, trusted_downstream=None): self.address = address # Save the socket's address family now so we know how to # interpret self.address even after the stream is closed # and its socket attribute replaced with None. if stream.socket is not None: self.address_family = else: self.address_family = None # In HTTPServerRequest we want an IP, not a full socket address. if (self.address_family in (socket.AF_INET, socket.AF_INET6) and address is not None): self.remote_ip = address[0] else: # Unix (or other) socket; fake the remote address. self.remote_ip = '' if protocol: self.protocol = protocol elif isinstance(stream, iostream.SSLIOStream): self.protocol = "https" else: self.protocol = "http" self._orig_remote_ip = self.remote_ip self._orig_protocol = self.protocol self.trusted_downstream = set(trusted_downstream or []) def __str__(self): if self.address_family in (socket.AF_INET, socket.AF_INET6): return self.remote_ip elif isinstance(self.address, bytes): # Python 3 with the -bb option warns about str(bytes), # so convert it explicitly. # Unix socket addresses are str on mac but bytes on linux. return native_str(self.address) else: return str(self.address) def _apply_xheaders(self, headers): """Rewrite the ``remote_ip`` and ``protocol`` fields.""" # Squid uses X-Forwarded-For, others use X-Real-Ip ip = headers.get("X-Forwarded-For", self.remote_ip) # Skip trusted downstream hosts in X-Forwarded-For list for ip in (cand.strip() for cand in reversed(ip.split(','))): if ip not in self.trusted_downstream: break ip = headers.get("X-Real-Ip", ip) if netutil.is_valid_ip(ip): self.remote_ip = ip # AWS uses X-Forwarded-Proto proto_header = headers.get( "X-Scheme", headers.get("X-Forwarded-Proto", self.protocol)) if proto_header in ("http", "https"): self.protocol = proto_header def _unapply_xheaders(self): """Undo changes from `_apply_xheaders`. Xheaders are per-request so they should not leak to the next request on the same connection. """ self.remote_ip = self._orig_remote_ip self.protocol = self._orig_protocol class _ProxyAdapter(httputil.HTTPMessageDelegate): def __init__(self, delegate, request_conn): self.connection = request_conn self.delegate = delegate def headers_received(self, start_line, headers): self.connection.context._apply_xheaders(headers) return self.delegate.headers_received(start_line, headers) def data_received(self, chunk): return self.delegate.data_received(chunk) def finish(self): self.delegate.finish() self._cleanup() def on_connection_close(self): self.delegate.on_connection_close() self._cleanup() def _cleanup(self): self.connection.context._unapply_xheaders() HTTPRequest = httputil.HTTPServerRequest