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"""
A high-speed, production ready, thread pooled, generic HTTP server.
For those of you wanting to understand internals of this module, here's the
basic call flow. The server's listening thread runs a very tight loop,
sticking incoming connections onto a Queue::
server = HTTPServer(...)
server.start()
-> serve()
while ready:
_connections.run()
while not stop_requested:
child = socket.accept() # blocks until a request comes in
conn = HTTPConnection(child, ...)
server.process_conn(conn) # adds conn to threadpool
Worker threads are kept in a pool and poll the Queue, popping off and then
handling each connection in turn. Each connection can consist of an arbitrary
number of requests and their responses, so we run a nested loop::
while True:
conn = server.requests.get()
conn.communicate()
-> while True:
req = HTTPRequest(...)
req.parse_request()
-> # Read the Request-Line, e.g. "GET /page HTTP/1.1"
req.rfile.readline()
read_headers(req.rfile, req.inheaders)
req.respond()
-> response = app(...)
try:
for chunk in response:
if chunk:
req.write(chunk)
finally:
if hasattr(response, "close"):
response.close()
if req.close_connection:
return
For running a server you can invoke :func:`start() <HTTPServer.start()>` (it
will run the server forever) or use invoking :func:`prepare()
<HTTPServer.prepare()>` and :func:`serve() <HTTPServer.serve()>` like this::
server = HTTPServer(...)
server.prepare()
try:
threading.Thread(target=server.serve).start()
# waiting/detecting some appropriate stop condition here
...
finally:
server.stop()
And now for a trivial doctest to exercise the test suite
.. testsetup::
from cheroot.server import HTTPServer
>>> 'HTTPServer' in globals()
True
"""
import os
import io
import re
import email.utils
import socket
import sys
import time
import traceback as traceback_
import logging
import platform
import queue
import contextlib
import threading
import urllib.parse
from functools import lru_cache
from . import connections, errors, __version__
from ._compat import bton
from ._compat import IS_PPC
from .workers import threadpool
from .makefile import MakeFile, StreamWriter
__all__ = (
'HTTPRequest', 'HTTPConnection', 'HTTPServer',
'HeaderReader', 'DropUnderscoreHeaderReader',
'SizeCheckWrapper', 'KnownLengthRFile', 'ChunkedRFile',
'Gateway', 'get_ssl_adapter_class',
)
IS_WINDOWS = platform.system() == 'Windows'
"""Flag indicating whether the app is running under Windows."""
IS_GAE = os.getenv('SERVER_SOFTWARE', '').startswith('Google App Engine/')
"""Flag indicating whether the app is running in GAE env.
Ref:
https://cloud.google.com/appengine/docs/standard/python/tools
/using-local-server#detecting_application_runtime_environment
"""
IS_UID_GID_RESOLVABLE = not IS_WINDOWS and not IS_GAE
"""Indicates whether UID/GID resolution's available under current platform."""
if IS_UID_GID_RESOLVABLE:
try:
import grp
import pwd
except ImportError:
"""Unavailable in the current env.
This shouldn't be happening normally.
All of the known cases are excluded via the if clause.
"""
IS_UID_GID_RESOLVABLE = False
grp, pwd = None, None
import struct
if IS_WINDOWS and hasattr(socket, 'AF_INET6'):
if not hasattr(socket, 'IPPROTO_IPV6'):
socket.IPPROTO_IPV6 = 41
if not hasattr(socket, 'IPV6_V6ONLY'):
socket.IPV6_V6ONLY = 27
if not hasattr(socket, 'SO_PEERCRED'):
"""
NOTE: the value for SO_PEERCRED can be architecture specific, in
which case the getsockopt() will hopefully fail. The arch
specific value could be derived from platform.processor()
"""
socket.SO_PEERCRED = 21 if IS_PPC else 17
LF = b'\n'
CRLF = b'\r\n'
TAB = b'\t'
SPACE = b' '
COLON = b':'
SEMICOLON = b';'
EMPTY = b''
ASTERISK = b'*'
FORWARD_SLASH = b'/'
QUOTED_SLASH = b'%2F'
QUOTED_SLASH_REGEX = re.compile(b''.join((b'(?i)', QUOTED_SLASH)))
_STOPPING_FOR_INTERRUPT = object() # sentinel used during shutdown
comma_separated_headers = [
b'Accept', b'Accept-Charset', b'Accept-Encoding',
b'Accept-Language', b'Accept-Ranges', b'Allow', b'Cache-Control',
b'Connection', b'Content-Encoding', b'Content-Language', b'Expect',
b'If-Match', b'If-None-Match', b'Pragma', b'Proxy-Authenticate', b'TE',
b'Trailer', b'Transfer-Encoding', b'Upgrade', b'Vary', b'Via', b'Warning',
b'WWW-Authenticate',
]
if not hasattr(logging, 'statistics'):
logging.statistics = {}
class HeaderReader:
"""Object for reading headers from an HTTP request.
Interface and default implementation.
"""
def __call__(self, rfile, hdict=None): # noqa: C901 # FIXME
"""
Read headers from the given stream into the given header dict.
If hdict is None, a new header dict is created. Returns the populated
header dict.
Headers which are repeated are folded together using a comma if their
specification so dictates.
This function raises ValueError when the read bytes violate the HTTP
spec.
You should probably return "400 Bad Request" if this happens.
"""
if hdict is None:
hdict = {}
while True:
line = rfile.readline()
if not line:
# No more data--illegal end of headers
raise ValueError('Illegal end of headers.')
if line == CRLF:
# Normal end of headers
break
if not line.endswith(CRLF):
raise ValueError('HTTP requires CRLF terminators')
if line[0] in (SPACE, TAB):
# It's a continuation line.
v = line.strip()
else:
try:
k, v = line.split(COLON, 1)
except ValueError:
raise ValueError('Illegal header line.')
v = v.strip()
k = self._transform_key(k)
hname = k
if not self._allow_header(k):
continue
if k in comma_separated_headers:
existing = hdict.get(hname)
if existing:
v = b', '.join((existing, v))
hdict[hname] = v
return hdict
def _allow_header(self, key_name):
return True
def _transform_key(self, key_name):
# TODO: what about TE and WWW-Authenticate?
return key_name.strip().title()
class DropUnderscoreHeaderReader(HeaderReader):
"""Custom HeaderReader to exclude any headers with underscores in them."""
def _allow_header(self, key_name):
orig = super(DropUnderscoreHeaderReader, self)._allow_header(key_name)
return orig and '_' not in key_name
class SizeCheckWrapper:
"""Wraps a file-like object, raising MaxSizeExceeded if too large.
:param rfile: ``file`` of a limited size
:param int maxlen: maximum length of the file being read
"""
def __init__(self, rfile, maxlen):
"""Initialize SizeCheckWrapper instance."""
self.rfile = rfile
self.maxlen = maxlen
self.bytes_read = 0
def _check_length(self):
if self.maxlen and self.bytes_read > self.maxlen:
raise errors.MaxSizeExceeded()
def read(self, size=None):
"""Read a chunk from ``rfile`` buffer and return it.
:param size: amount of data to read
:type size: int
:returns: chunk from ``rfile``, limited by size if specified
:rtype: bytes
"""
data = self.rfile.read(size)
self.bytes_read += len(data)
self._check_length()
return data
def readline(self, size=None):
"""Read a single line from ``rfile`` buffer and return it.
:param size: minimum amount of data to read
:type size: int
:returns: one line from ``rfile``
:rtype: bytes
"""
if size is not None:
data = self.rfile.readline(size)
self.bytes_read += len(data)
self._check_length()
return data
# User didn't specify a size ...
# We read the line in chunks to make sure it's not a 100MB line !
res = []
while True:
data = self.rfile.readline(256)
self.bytes_read += len(data)
self._check_length()
res.append(data)
# See https://github.com/cherrypy/cherrypy/issues/421
if len(data) < 256 or data[-1:] == LF:
return EMPTY.join(res)
def readlines(self, sizehint=0):
"""Read all lines from ``rfile`` buffer and return them.
:param sizehint: hint of minimum amount of data to read
:type sizehint: int
:returns: lines of bytes read from ``rfile``
:rtype: list[bytes]
"""
# Shamelessly stolen from StringIO
total = 0
lines = []
line = self.readline(sizehint)
while line:
lines.append(line)
total += len(line)
if 0 < sizehint <= total:
break
line = self.readline(sizehint)
return lines
def close(self):
"""Release resources allocated for ``rfile``."""
self.rfile.close()
def __iter__(self):
"""Return file iterator."""
return self
def __next__(self):
"""Generate next file chunk."""
data = next(self.rfile)
self.bytes_read += len(data)
self._check_length()
return data
next = __next__
class KnownLengthRFile:
"""Wraps a file-like object, returning an empty string when exhausted.
:param rfile: ``file`` of a known size
:param int content_length: length of the file being read
"""
def __init__(self, rfile, content_length):
"""Initialize KnownLengthRFile instance."""
self.rfile = rfile
self.remaining = content_length
def read(self, size=None):
"""Read a chunk from ``rfile`` buffer and return it.
:param size: amount of data to read
:type size: int
:rtype: bytes
:returns: chunk from ``rfile``, limited by size if specified
"""
if self.remaining == 0:
return b''
if size is None:
size = self.remaining
else:
size = min(size, self.remaining)
data = self.rfile.read(size)
self.remaining -= len(data)
return data
def readline(self, size=None):
"""Read a single line from ``rfile`` buffer and return it.
:param size: minimum amount of data to read
:type size: int
:returns: one line from ``rfile``
:rtype: bytes
"""
if self.remaining == 0:
return b''
if size is None:
size = self.remaining
else:
size = min(size, self.remaining)
data = self.rfile.readline(size)
self.remaining -= len(data)
return data
def readlines(self, sizehint=0):
"""Read all lines from ``rfile`` buffer and return them.
:param sizehint: hint of minimum amount of data to read
:type sizehint: int
:returns: lines of bytes read from ``rfile``
:rtype: list[bytes]
"""
# Shamelessly stolen from StringIO
total = 0
lines = []
line = self.readline(sizehint)
while line:
lines.append(line)
total += len(line)
if 0 < sizehint <= total:
break
line = self.readline(sizehint)
return lines
def close(self):
"""Release resources allocated for ``rfile``."""
self.rfile.close()
def __iter__(self):
"""Return file iterator."""
return self
def __next__(self):
"""Generate next file chunk."""
data = next(self.rfile)
self.remaining -= len(data)
return data
next = __next__
class ChunkedRFile:
"""Wraps a file-like object, returning an empty string when exhausted.
This class is intended to provide a conforming wsgi.input value for
request entities that have been encoded with the 'chunked' transfer
encoding.
:param rfile: file encoded with the 'chunked' transfer encoding
:param int maxlen: maximum length of the file being read
:param int bufsize: size of the buffer used to read the file
"""
def __init__(self, rfile, maxlen, bufsize=8192):
"""Initialize ChunkedRFile instance."""
self.rfile = rfile
self.maxlen = maxlen
self.bytes_read = 0
self.buffer = EMPTY
self.bufsize = bufsize
self.closed = False
def _fetch(self):
if self.closed:
return
line = self.rfile.readline()
self.bytes_read += len(line)
if self.maxlen and self.bytes_read > self.maxlen:
raise errors.MaxSizeExceeded(
'Request Entity Too Large', self.maxlen,
)
line = line.strip().split(SEMICOLON, 1)
try:
chunk_size = line.pop(0)
chunk_size = int(chunk_size, 16)
except ValueError:
raise ValueError(
'Bad chunked transfer size: {chunk_size!r}'.
format(chunk_size=chunk_size),
)
if chunk_size <= 0:
self.closed = True
return
# if line: chunk_extension = line[0]
if self.maxlen and self.bytes_read + chunk_size > self.maxlen:
raise IOError('Request Entity Too Large')
chunk = self.rfile.read(chunk_size)
self.bytes_read += len(chunk)
self.buffer += chunk
crlf = self.rfile.read(2)
if crlf != CRLF:
raise ValueError(
"Bad chunked transfer coding (expected '\\r\\n', "
'got ' + repr(crlf) + ')',
)
def read(self, size=None):
"""Read a chunk from ``rfile`` buffer and return it.
:param size: amount of data to read
:type size: int
:returns: chunk from ``rfile``, limited by size if specified
:rtype: bytes
"""
data = EMPTY
if size == 0:
return data
while True:
if size and len(data) >= size:
return data
if not self.buffer:
self._fetch()
if not self.buffer:
# EOF
return data
if size:
remaining = size - len(data)
data += self.buffer[:remaining]
self.buffer = self.buffer[remaining:]
else:
data += self.buffer
self.buffer = EMPTY
def readline(self, size=None):
"""Read a single line from ``rfile`` buffer and return it.
:param size: minimum amount of data to read
:type size: int
:returns: one line from ``rfile``
:rtype: bytes
"""
data = EMPTY
if size == 0:
return data
while True:
if size and len(data) >= size:
return data
if not self.buffer:
self._fetch()
if not self.buffer:
# EOF
return data
newline_pos = self.buffer.find(LF)
if size:
if newline_pos == -1:
remaining = size - len(data)
data += self.buffer[:remaining]
self.buffer = self.buffer[remaining:]
else:
remaining = min(size - len(data), newline_pos)
data += self.buffer[:remaining]
self.buffer = self.buffer[remaining:]
else:
if newline_pos == -1:
data += self.buffer
self.buffer = EMPTY
else:
data += self.buffer[:newline_pos]
self.buffer = self.buffer[newline_pos:]
def readlines(self, sizehint=0):
"""Read all lines from ``rfile`` buffer and return them.
:param sizehint: hint of minimum amount of data to read
:type sizehint: int
:returns: lines of bytes read from ``rfile``
:rtype: list[bytes]
"""
# Shamelessly stolen from StringIO
total = 0
lines = []
line = self.readline(sizehint)
while line:
lines.append(line)
total += len(line)
if 0 < sizehint <= total:
break
line = self.readline(sizehint)
return lines
def read_trailer_lines(self):
"""Read HTTP headers and yield them.
:yields: CRLF separated lines
:ytype: bytes
"""
if not self.closed:
raise ValueError(
'Cannot read trailers until the request body has been read.',
)
while True:
line = self.rfile.readline()
if not line:
# No more data--illegal end of headers
raise ValueError('Illegal end of headers.')
self.bytes_read += len(line)
if self.maxlen and self.bytes_read > self.maxlen:
raise IOError('Request Entity Too Large')
if line == CRLF:
# Normal end of headers
break
if not line.endswith(CRLF):
raise ValueError('HTTP requires CRLF terminators')
yield line
def close(self):
"""Release resources allocated for ``rfile``."""
self.rfile.close()
class HTTPRequest:
"""An HTTP Request (and response).
A single HTTP connection may consist of multiple request/response pairs.
"""
server = None
"""The HTTPServer object which is receiving this request."""
conn = None
"""The HTTPConnection object on which this request connected."""
inheaders = {}
"""A dict of request headers."""
outheaders = []
"""A list of header tuples to write in the response."""
ready = False
"""When True, the request has been parsed and is ready to begin generating
the response. When False, signals the calling Connection that the response
should not be generated and the connection should close."""
close_connection = False
"""Signals the calling Connection that the request should close. This does
not imply an error! The client and/or server may each request that the
connection be closed."""
chunked_write = False
"""If True, output will be encoded with the "chunked" transfer-coding.
This value is set automatically inside send_headers."""
header_reader = HeaderReader()
"""
A HeaderReader instance or compatible reader.
"""
def __init__(self, server, conn, proxy_mode=False, strict_mode=True):
"""Initialize HTTP request container instance.
Args:
server (HTTPServer): web server object receiving this request
conn (HTTPConnection): HTTP connection object for this request
proxy_mode (bool): whether this HTTPServer should behave as a PROXY
server for certain requests
strict_mode (bool): whether we should return a 400 Bad Request when
we encounter a request that a HTTP compliant client should not be
making
"""
self.server = server
self.conn = conn
self.ready = False
self.started_request = False
self.scheme = b'http'
if self.server.ssl_adapter is not None:
self.scheme = b'https'
# Use the lowest-common protocol in case read_request_line errors.
self.response_protocol = 'HTTP/1.0'
self.inheaders = {}
self.status = ''
self.outheaders = []
self.sent_headers = False
self.close_connection = self.__class__.close_connection
self.chunked_read = False
self.chunked_write = self.__class__.chunked_write
self.proxy_mode = proxy_mode
self.strict_mode = strict_mode
def parse_request(self):
"""Parse the next HTTP request start-line and message-headers."""
self.rfile = SizeCheckWrapper(
self.conn.rfile,
self.server.max_request_header_size,
)
try:
success = self.read_request_line()
except errors.MaxSizeExceeded:
self.simple_response(
'414 Request-URI Too Long',
'The Request-URI sent with the request exceeds the maximum '
'allowed bytes.',
)
return
else:
if not success:
return
try:
success = self.read_request_headers()
except errors.MaxSizeExceeded:
self.simple_response(
'413 Request Entity Too Large',
'The headers sent with the request exceed the maximum '
'allowed bytes.',
)
return
else:
if not success:
return
self.ready = True
def read_request_line(self): # noqa: C901 # FIXME
"""Read and parse first line of the HTTP request.
Returns:
bool: True if the request line is valid or False if it's malformed.
"""
# HTTP/1.1 connections are persistent by default. If a client
# requests a page, then idles (leaves the connection open),
# then rfile.readline() will raise socket.error("timed out").
# Note that it does this based on the value given to settimeout(),
# and doesn't need the client to request or acknowledge the close
# (although your TCP stack might suffer for it: cf Apache's history
# with FIN_WAIT_2).
request_line = self.rfile.readline()
# Set started_request to True so communicate() knows to send 408
# from here on out.
self.started_request = True
if not request_line:
return False
if request_line == CRLF:
# RFC 2616 sec 4.1: "...if the server is reading the protocol
# stream at the beginning of a message and receives a CRLF
# first, it should ignore the CRLF."
# But only ignore one leading line! else we enable a DoS.
request_line = self.rfile.readline()
if not request_line:
return False
if not request_line.endswith(CRLF):
self.simple_response(
'400 Bad Request', 'HTTP requires CRLF terminators',
)
return False
try:
method, uri, req_protocol = request_line.strip().split(SPACE, 2)
if not req_protocol.startswith(b'HTTP/'):
self.simple_response(
'400 Bad Request', 'Malformed Request-Line: bad protocol',
)
return False
rp = req_protocol[5:].split(b'.', 1)
if len(rp) != 2:
self.simple_response(
'400 Bad Request', 'Malformed Request-Line: bad version',
)
return False
rp = tuple(map(int, rp)) # Minor.Major must be threat as integers
if rp > (1, 1):
self.simple_response(
'505 HTTP Version Not Supported', 'Cannot fulfill request',
)
return False
except (ValueError, IndexError):
self.simple_response('400 Bad Request', 'Malformed Request-Line')
return False
self.uri = uri
self.method = method.upper()
if self.strict_mode and method != self.method:
resp = (
'Malformed method name: According to RFC 2616 '
'(section 5.1.1) and its successors '
'RFC 7230 (section 3.1.1) and RFC 7231 (section 4.1) '
'method names are case-sensitive and uppercase.'
)
self.simple_response('400 Bad Request', resp)
return False
try:
scheme, authority, path, qs, fragment = urllib.parse.urlsplit(uri)
except UnicodeError:
self.simple_response('400 Bad Request', 'Malformed Request-URI')
return False
uri_is_absolute_form = (scheme or authority)
if self.method == b'OPTIONS':
# TODO: cover this branch with tests
path = (
uri
# https://tools.ietf.org/html/rfc7230#section-5.3.4
if (self.proxy_mode and uri_is_absolute_form)
else path
)
elif self.method == b'CONNECT':
# TODO: cover this branch with tests
if not self.proxy_mode:
self.simple_response('405 Method Not Allowed')
return False
# `urlsplit()` above parses "example.com:3128" as path part of URI.
# this is a workaround, which makes it detect netloc correctly
uri_split = urllib.parse.urlsplit(b''.join((b'//', uri)))
_scheme, _authority, _path, _qs, _fragment = uri_split
_port = EMPTY
try:
_port = uri_split.port
except ValueError:
pass
# FIXME: use third-party validation to make checks against RFC
# the validation doesn't take into account, that urllib parses
# invalid URIs without raising errors
# https://tools.ietf.org/html/rfc7230#section-5.3.3
invalid_path = (
_authority != uri
or not _port
or any((_scheme, _path, _qs, _fragment))
)
if invalid_path:
self.simple_response(
'400 Bad Request',
'Invalid path in Request-URI: request-'
'target must match authority-form.',
)
return False
authority = path = _authority
scheme = qs = fragment = EMPTY
else:
disallowed_absolute = (
self.strict_mode
and not self.proxy_mode
and uri_is_absolute_form
)
if disallowed_absolute:
# https://tools.ietf.org/html/rfc7230#section-5.3.2
# (absolute form)
"""Absolute URI is only allowed within proxies."""
self.simple_response(
'400 Bad Request',
'Absolute URI not allowed if server is not a proxy.',
)
return False
invalid_path = (
self.strict_mode
and not uri.startswith(FORWARD_SLASH)
and not uri_is_absolute_form
)
if invalid_path:
# https://tools.ietf.org/html/rfc7230#section-5.3.1
# (origin_form) and
"""Path should start with a forward slash."""
resp = (
'Invalid path in Request-URI: request-target must contain '
'origin-form which starts with absolute-path (URI '
'starting with a slash "/").'
)
self.simple_response('400 Bad Request', resp)
return False
if fragment:
self.simple_response(
'400 Bad Request',
'Illegal #fragment in Request-URI.',
)
return False
if path is None:
# FIXME: It looks like this case cannot happen
self.simple_response(
'400 Bad Request',
'Invalid path in Request-URI.',
)
return False
# Unquote the path+params (e.g. "/this%20path" -> "/this path").
# https://www.w3.org/Protocols/rfc2616/rfc2616-sec5.html#sec5.1.2
#
# But note that "...a URI must be separated into its components
# before the escaped characters within those components can be
# safely decoded." https://www.ietf.org/rfc/rfc2396.txt, sec 2.4.2
# Therefore, "/this%2Fpath" becomes "/this%2Fpath", not
# "/this/path".
try:
# TODO: Figure out whether exception can really happen here.
# It looks like it's caught on urlsplit() call above.
atoms = [
urllib.parse.unquote_to_bytes(x)
for x in QUOTED_SLASH_REGEX.split(path)
]
except ValueError as ex:
self.simple_response('400 Bad Request', ex.args[0])
return False
path = QUOTED_SLASH.join(atoms)
if not path.startswith(FORWARD_SLASH):
path = FORWARD_SLASH + path
if scheme is not EMPTY:
self.scheme = scheme
self.authority = authority
self.path = path
# Note that, like wsgiref and most other HTTP servers,
# we "% HEX HEX"-unquote the path but not the query string.
self.qs = qs
# Compare request and server HTTP protocol versions, in case our
# server does not support the requested protocol. Limit our output
# to min(req, server). We want the following output:
# request server actual written supported response
# protocol protocol response protocol feature set
# a 1.0 1.0 1.0 1.0
# b 1.0 1.1 1.1 1.0
# c 1.1 1.0 1.0 1.0
# d 1.1 1.1 1.1 1.1
# Notice that, in (b), the response will be "HTTP/1.1" even though
# the client only understands 1.0. RFC 2616 10.5.6 says we should
# only return 505 if the _major_ version is different.
sp = int(self.server.protocol[5]), int(self.server.protocol[7])
if sp[0] != rp[0]:
self.simple_response('505 HTTP Version Not Supported')
return False
self.request_protocol = req_protocol
self.response_protocol = 'HTTP/%s.%s' % min(rp, sp)
return True
def read_request_headers(self): # noqa: C901 # FIXME
"""Read ``self.rfile`` into ``self.inheaders``.
Ref: :py:attr:`self.inheaders <HTTPRequest.outheaders>`.
:returns: success status
:rtype: bool
"""
# then all the http headers
try:
self.header_reader(self.rfile, self.inheaders)
except ValueError as ex:
self.simple_response('400 Bad Request', ex.args[0])
return False
mrbs = self.server.max_request_body_size
try:
cl = int(self.inheaders.get(b'Content-Length', 0))
except ValueError:
self.simple_response(
'400 Bad Request',
'Malformed Content-Length Header.',
)
return False
if mrbs and cl > mrbs:
self.simple_response(
'413 Request Entity Too Large',
'The entity sent with the request exceeds the maximum '
'allowed bytes.',
)
return False
# Persistent connection support
if self.response_protocol == 'HTTP/1.1':
# Both server and client are HTTP/1.1
if self.inheaders.get(b'Connection', b'') == b'close':
self.close_connection = True
else:
# Either the server or client (or both) are HTTP/1.0
if self.inheaders.get(b'Connection', b'') != b'Keep-Alive':
self.close_connection = True
# Transfer-Encoding support
te = None
if self.response_protocol == 'HTTP/1.1':
te = self.inheaders.get(b'Transfer-Encoding')
if te:
te = [x.strip().lower() for x in te.split(b',') if x.strip()]
self.chunked_read = False
if te:
for enc in te:
if enc == b'chunked':
self.chunked_read = True
else:
# Note that, even if we see "chunked", we must reject
# if there is an extension we don't recognize.
self.simple_response('501 Unimplemented')
self.close_connection = True
return False
# From PEP 333:
# "Servers and gateways that implement HTTP 1.1 must provide
# transparent support for HTTP 1.1's "expect/continue" mechanism.
# This may be done in any of several ways:
# 1. Respond to requests containing an Expect: 100-continue request
# with an immediate "100 Continue" response, and proceed normally.
# 2. Proceed with the request normally, but provide the application
# with a wsgi.input stream that will send the "100 Continue"
# response if/when the application first attempts to read from
# the input stream. The read request must then remain blocked
# until the client responds.
# 3. Wait until the client decides that the server does not support
# expect/continue, and sends the request body on its own.
# (This is suboptimal, and is not recommended.)
#
# We used to do 3, but are now doing 1. Maybe we'll do 2 someday,
# but it seems like it would be a big slowdown for such a rare case.
if self.inheaders.get(b'Expect', b'') == b'100-continue':
# Don't use simple_response here, because it emits headers
# we don't want. See
# https://github.com/cherrypy/cherrypy/issues/951
msg = b''.join((
self.server.protocol.encode('ascii'), SPACE, b'100 Continue',
CRLF, CRLF,
))
try:
self.conn.wfile.write(msg)
except socket.error as ex:
if ex.args[0] not in errors.socket_errors_to_ignore:
raise
return True
def respond(self):
"""Call the gateway and write its iterable output."""
mrbs = self.server.max_request_body_size
if self.chunked_read:
self.rfile = ChunkedRFile(self.conn.rfile, mrbs)
else:
cl = int(self.inheaders.get(b'Content-Length', 0))
if mrbs and mrbs < cl:
if not self.sent_headers:
self.simple_response(
'413 Request Entity Too Large',
'The entity sent with the request exceeds the '
'maximum allowed bytes.',
)
return
self.rfile = KnownLengthRFile(self.conn.rfile, cl)
self.server.gateway(self).respond()
self.ready and self.ensure_headers_sent()
if self.chunked_write:
self.conn.wfile.write(b'0\r\n\r\n')
def simple_response(self, status, msg=''):
"""Write a simple response back to the client."""
status = str(status)
proto_status = '%s %s\r\n' % (self.server.protocol, status)
content_length = 'Content-Length: %s\r\n' % len(msg)
content_type = 'Content-Type: text/plain\r\n'
buf = [
proto_status.encode('ISO-8859-1'),
content_length.encode('ISO-8859-1'),
content_type.encode('ISO-8859-1'),
]
if status[:3] in ('413', '414'):
# Request Entity Too Large / Request-URI Too Long
self.close_connection = True
if self.response_protocol == 'HTTP/1.1':
# This will not be true for 414, since read_request_line
# usually raises 414 before reading the whole line, and we
# therefore cannot know the proper response_protocol.
buf.append(b'Connection: close\r\n')
else:
# HTTP/1.0 had no 413/414 status nor Connection header.
# Emit 400 instead and trust the message body is enough.
status = '400 Bad Request'
buf.append(CRLF)
if msg:
if isinstance(msg, str):
msg = msg.encode('ISO-8859-1')
buf.append(msg)
try:
self.conn.wfile.write(EMPTY.join(buf))
except socket.error as ex:
if ex.args[0] not in errors.socket_errors_to_ignore:
raise
def ensure_headers_sent(self):
"""Ensure headers are sent to the client if not already sent."""
if not self.sent_headers:
self.sent_headers = True
self.send_headers()
def write(self, chunk):
"""Write unbuffered data to the client."""
if self.chunked_write and chunk:
chunk_size_hex = hex(len(chunk))[2:].encode('ascii')
buf = [chunk_size_hex, CRLF, chunk, CRLF]
self.conn.wfile.write(EMPTY.join(buf))
else:
self.conn.wfile.write(chunk)
def send_headers(self): # noqa: C901 # FIXME
"""Assert, process, and send the HTTP response message-headers.
You must set ``self.status``, and :py:attr:`self.outheaders
<HTTPRequest.outheaders>` before calling this.
"""
hkeys = [key.lower() for key, value in self.outheaders]
status = int(self.status[:3])
if status == 413:
# Request Entity Too Large. Close conn to avoid garbage.
self.close_connection = True
elif b'content-length' not in hkeys:
# "All 1xx (informational), 204 (no content),
# and 304 (not modified) responses MUST NOT
# include a message-body." So no point chunking.
if status < 200 or status in (204, 205, 304):
pass
else:
needs_chunked = (
self.response_protocol == 'HTTP/1.1'
and self.method != b'HEAD'
)
if needs_chunked:
# Use the chunked transfer-coding
self.chunked_write = True
self.outheaders.append((b'Transfer-Encoding', b'chunked'))
else:
# Closing the conn is the only way to determine len.
self.close_connection = True
# Override the decision to not close the connection if the connection
# manager doesn't have space for it.
if not self.close_connection:
can_keep = self.server.can_add_keepalive_connection
self.close_connection = not can_keep
if b'connection' not in hkeys:
if self.response_protocol == 'HTTP/1.1':
# Both server and client are HTTP/1.1 or better
if self.close_connection:
self.outheaders.append((b'Connection', b'close'))
else:
# Server and/or client are HTTP/1.0
if not self.close_connection:
self.outheaders.append((b'Connection', b'Keep-Alive'))
if (b'Connection', b'Keep-Alive') in self.outheaders:
self.outheaders.append((
b'Keep-Alive',
u'timeout={connection_timeout}'.
format(connection_timeout=self.server.timeout).
encode('ISO-8859-1'),
))
if (not self.close_connection) and (not self.chunked_read):
# Read any remaining request body data on the socket.
# "If an origin server receives a request that does not include an
# Expect request-header field with the "100-continue" expectation,
# the request includes a request body, and the server responds
# with a final status code before reading the entire request body
# from the transport connection, then the server SHOULD NOT close
# the transport connection until it has read the entire request,
# or until the client closes the connection. Otherwise, the client
# might not reliably receive the response message. However, this
# requirement is not be construed as preventing a server from
# defending itself against denial-of-service attacks, or from
# badly broken client implementations."
remaining = getattr(self.rfile, 'remaining', 0)
if remaining > 0:
self.rfile.read(remaining)
if b'date' not in hkeys:
self.outheaders.append((
b'Date',
email.utils.formatdate(usegmt=True).encode('ISO-8859-1'),
))
if b'server' not in hkeys:
self.outheaders.append((
b'Server',
self.server.server_name.encode('ISO-8859-1'),
))
proto = self.server.protocol.encode('ascii')
buf = [proto + SPACE + self.status + CRLF]
for k, v in self.outheaders:
buf.append(k + COLON + SPACE + v + CRLF)
buf.append(CRLF)
self.conn.wfile.write(EMPTY.join(buf))
class HTTPConnection:
"""An HTTP connection (active socket)."""
remote_addr = None
remote_port = None
ssl_env = None
rbufsize = io.DEFAULT_BUFFER_SIZE
wbufsize = io.DEFAULT_BUFFER_SIZE
RequestHandlerClass = HTTPRequest
peercreds_enabled = False
peercreds_resolve_enabled = False
# Fields set by ConnectionManager.
last_used = None
def __init__(self, server, sock, makefile=MakeFile):
"""Initialize HTTPConnection instance.
Args:
server (HTTPServer): web server object receiving this request
sock (socket._socketobject): the raw socket object (usually
TCP) for this connection
makefile (file): a fileobject class for reading from the socket
"""
self.server = server
self.socket = sock
self.rfile = makefile(sock, 'rb', self.rbufsize)
self.wfile = makefile(sock, 'wb', self.wbufsize)
self.requests_seen = 0
self.peercreds_enabled = self.server.peercreds_enabled
self.peercreds_resolve_enabled = self.server.peercreds_resolve_enabled
# LRU cached methods:
# Ref: https://stackoverflow.com/a/14946506/595220
self.resolve_peer_creds = (
lru_cache(maxsize=1)(self.resolve_peer_creds)
)
self.get_peer_creds = (
lru_cache(maxsize=1)(self.get_peer_creds)
)
def communicate(self): # noqa: C901 # FIXME
"""Read each request and respond appropriately.
Returns true if the connection should be kept open.
"""
request_seen = False
try:
req = self.RequestHandlerClass(self.server, self)
req.parse_request()
if self.server.stats['Enabled']:
self.requests_seen += 1
if not req.ready:
# Something went wrong in the parsing (and the server has
# probably already made a simple_response). Return and
# let the conn close.
return False
request_seen = True
req.respond()
if not req.close_connection:
return True
except socket.error as ex:
errnum = ex.args[0]
# sadly SSL sockets return a different (longer) time out string
timeout_errs = 'timed out', 'The read operation timed out'
if errnum in timeout_errs:
# Don't error if we're between requests; only error
# if 1) no request has been started at all, or 2) we're
# in the middle of a request.
# See https://github.com/cherrypy/cherrypy/issues/853
if (not request_seen) or (req and req.started_request):
self._conditional_error(req, '408 Request Timeout')
elif errnum not in errors.socket_errors_to_ignore:
self.server.error_log(
'socket.error %s' % repr(errnum),
level=logging.WARNING, traceback=True,
)
self._conditional_error(req, '500 Internal Server Error')
except (KeyboardInterrupt, SystemExit):
raise
except errors.FatalSSLAlert:
pass
except errors.NoSSLError:
self._handle_no_ssl(req)
except Exception as ex:
self.server.error_log(
repr(ex), level=logging.ERROR, traceback=True,
)
self._conditional_error(req, '500 Internal Server Error')
return False
linger = False
def _handle_no_ssl(self, req):
if not req or req.sent_headers:
return
# Unwrap wfile
try:
resp_sock = self.socket._sock
except AttributeError:
# self.socket is of OpenSSL.SSL.Connection type
resp_sock = self.socket._socket
self.wfile = StreamWriter(resp_sock, 'wb', self.wbufsize)
msg = (
'The client sent a plain HTTP request, but '
'this server only speaks HTTPS on this port.'
)
req.simple_response('400 Bad Request', msg)
self.linger = True
def _conditional_error(self, req, response):
"""Respond with an error.
Don't bother writing if a response
has already started being written.
"""
if not req or req.sent_headers:
return
try:
req.simple_response(response)
except errors.FatalSSLAlert:
pass
except errors.NoSSLError:
self._handle_no_ssl(req)
def close(self):
"""Close the socket underlying this connection."""
self.rfile.close()
if not self.linger:
self._close_kernel_socket()
# close the socket file descriptor
# (will be closed in the OS if there is no
# other reference to the underlying socket)
self.socket.close()
else:
# On the other hand, sometimes we want to hang around for a bit
# to make sure the client has a chance to read our entire
# response. Skipping the close() calls here delays the FIN
# packet until the socket object is garbage-collected later.
# Someday, perhaps, we'll do the full lingering_close that
# Apache does, but not today.
pass
def get_peer_creds(self): # LRU cached on per-instance basis, see __init__
"""Return the PID/UID/GID tuple of the peer socket for UNIX sockets.
This function uses SO_PEERCRED to query the UNIX PID, UID, GID
of the peer, which is only available if the bind address is
a UNIX domain socket.
Raises:
NotImplementedError: in case of unsupported socket type
RuntimeError: in case of SO_PEERCRED lookup unsupported or disabled
"""
PEERCRED_STRUCT_DEF = '3i'
if IS_WINDOWS or self.socket.family != socket.AF_UNIX:
raise NotImplementedError(
'SO_PEERCRED is only supported in Linux kernel and WSL',
)
elif not self.peercreds_enabled:
raise RuntimeError(
'Peer creds lookup is disabled within this server',
)
try:
peer_creds = self.socket.getsockopt(
# FIXME: Use LOCAL_CREDS for BSD-like OSs
# Ref: https://gist.github.com/LucaFilipozzi/e4f1e118202aff27af6aadebda1b5d91 # noqa
socket.SOL_SOCKET, socket.SO_PEERCRED,
struct.calcsize(PEERCRED_STRUCT_DEF),
)
except socket.error as socket_err:
"""Non-Linux kernels don't support SO_PEERCRED.
Refs:
http://welz.org.za/notes/on-peer-cred.html
https://github.com/daveti/tcpSockHack
msdn.microsoft.com/en-us/commandline/wsl/release_notes#build-15025
"""
raise RuntimeError from socket_err
else:
pid, uid, gid = struct.unpack(PEERCRED_STRUCT_DEF, peer_creds)
return pid, uid, gid
@property
def peer_pid(self):
"""Return the id of the connected peer process."""
pid, _, _ = self.get_peer_creds()
return pid
@property
def peer_uid(self):
"""Return the user id of the connected peer process."""
_, uid, _ = self.get_peer_creds()
return uid
@property
def peer_gid(self):
"""Return the group id of the connected peer process."""
_, _, gid = self.get_peer_creds()
return gid
def resolve_peer_creds(self): # LRU cached on per-instance basis
"""Look up the username and group tuple of the ``PEERCREDS``.
:returns: the username and group tuple of the ``PEERCREDS``
:raises NotImplementedError: if the OS is unsupported
:raises RuntimeError: if UID/GID lookup is unsupported or disabled
"""
if not IS_UID_GID_RESOLVABLE:
raise NotImplementedError(
'UID/GID lookup is unavailable under current platform. '
'It can only be done under UNIX-like OS '
'but not under the Google App Engine',
)
elif not self.peercreds_resolve_enabled:
raise RuntimeError(
'UID/GID lookup is disabled within this server',
)
user = pwd.getpwuid(self.peer_uid).pw_name # [0]
group = grp.getgrgid(self.peer_gid).gr_name # [0]
return user, group
@property
def peer_user(self):
"""Return the username of the connected peer process."""
user, _ = self.resolve_peer_creds()
return user
@property
def peer_group(self):
"""Return the group of the connected peer process."""
_, group = self.resolve_peer_creds()
return group
def _close_kernel_socket(self):
"""Terminate the connection at the transport level."""
# Honor ``sock_shutdown`` for PyOpenSSL connections.
shutdown = getattr(
self.socket, 'sock_shutdown',
self.socket.shutdown,
)
try:
shutdown(socket.SHUT_RDWR) # actually send a TCP FIN
except errors.acceptable_sock_shutdown_exceptions:
pass
except socket.error as e:
if e.errno not in errors.acceptable_sock_shutdown_error_codes:
raise
class HTTPServer:
"""An HTTP server."""
_bind_addr = '127.0.0.1'
_interrupt = None
gateway = None
"""A Gateway instance."""
minthreads = None
"""The minimum number of worker threads to create (default 10)."""
maxthreads = None
"""The maximum number of worker threads to create.
(default -1 = no limit)"""
server_name = None
"""The name of the server; defaults to ``self.version``."""
protocol = 'HTTP/1.1'
"""The version string to write in the Status-Line of all HTTP responses.
For example, "HTTP/1.1" is the default. This also limits the supported
features used in the response."""
request_queue_size = 5
"""The 'backlog' arg to socket.listen(); max queued connections.
(default 5)."""
shutdown_timeout = 5
"""The total time to wait for worker threads to cleanly exit.
Specified in seconds."""
timeout = 10
"""The timeout in seconds for accepted connections (default 10)."""
expiration_interval = 0.5
"""The interval, in seconds, at which the server checks for
expired connections (default 0.5).
"""
version = 'Cheroot/{version!s}'.format(version=__version__)
"""A version string for the HTTPServer."""
software = None
"""The value to set for the SERVER_SOFTWARE entry in the WSGI environ.
If None, this defaults to ``'%s Server' % self.version``.
"""
ready = False
"""Internal flag which indicating the socket is accepting connections."""
max_request_header_size = 0
"""The maximum size, in bytes, for request headers, or 0 for no limit."""
max_request_body_size = 0
"""The maximum size, in bytes, for request bodies, or 0 for no limit."""
nodelay = True
"""If True (the default since 3.1), sets the TCP_NODELAY socket option."""
ConnectionClass = HTTPConnection
"""The class to use for handling HTTP connections."""
ssl_adapter = None
"""An instance of ``ssl.Adapter`` (or a subclass).
Ref: :py:class:`ssl.Adapter <cheroot.ssl.Adapter>`.
You must have the corresponding TLS driver library installed.
"""
peercreds_enabled = False
"""
If :py:data:`True`, peer creds will be looked up via UNIX domain socket.
"""
peercreds_resolve_enabled = False
"""
If :py:data:`True`, username/group will be looked up in the OS from
``PEERCREDS``-provided IDs.
"""
reuse_port = False
"""If True, set SO_REUSEPORT on the socket."""
keep_alive_conn_limit = 10
"""Maximum number of waiting keep-alive connections that will be kept open.
Default is 10. Set to None to have unlimited connections."""
def __init__(
self, bind_addr, gateway,
minthreads=10, maxthreads=-1, server_name=None,
peercreds_enabled=False, peercreds_resolve_enabled=False,
reuse_port=False,
):
"""Initialize HTTPServer instance.
Args:
bind_addr (tuple): network interface to listen to
gateway (Gateway): gateway for processing HTTP requests
minthreads (int): minimum number of threads for HTTP thread pool
maxthreads (int): maximum number of threads for HTTP thread pool
server_name (str): web server name to be advertised via Server
HTTP header
reuse_port (bool): if True SO_REUSEPORT option would be set to
socket
"""
self.bind_addr = bind_addr
self.gateway = gateway
self.requests = threadpool.ThreadPool(
self, min=minthreads or 1, max=maxthreads,
)
if not server_name:
server_name = self.version
self.server_name = server_name
self.peercreds_enabled = peercreds_enabled
self.peercreds_resolve_enabled = (
peercreds_resolve_enabled and peercreds_enabled
)
self.reuse_port = reuse_port
self.clear_stats()
def clear_stats(self):
"""Reset server stat counters.."""
self._start_time = None
self._run_time = 0
self.stats = {
'Enabled': False,
'Bind Address': lambda s: repr(self.bind_addr),
'Run time': lambda s: (not s['Enabled']) and -1 or self.runtime(),
'Accepts': 0,
'Accepts/sec': lambda s: s['Accepts'] / self.runtime(),
'Queue': lambda s: getattr(self.requests, 'qsize', None),
'Threads': lambda s: len(getattr(self.requests, '_threads', [])),
'Threads Idle': lambda s: getattr(self.requests, 'idle', None),
'Socket Errors': 0,
'Requests': lambda s: (not s['Enabled']) and -1 or sum(
(w['Requests'](w) for w in s['Worker Threads'].values()), 0,
),
'Bytes Read': lambda s: (not s['Enabled']) and -1 or sum(
(w['Bytes Read'](w) for w in s['Worker Threads'].values()), 0,
),
'Bytes Written': lambda s: (not s['Enabled']) and -1 or sum(
(w['Bytes Written'](w) for w in s['Worker Threads'].values()),
0,
),
'Work Time': lambda s: (not s['Enabled']) and -1 or sum(
(w['Work Time'](w) for w in s['Worker Threads'].values()), 0,
),
'Read Throughput': lambda s: (not s['Enabled']) and -1 or sum(
(
w['Bytes Read'](w) / (w['Work Time'](w) or 1e-6)
for w in s['Worker Threads'].values()
), 0,
),
'Write Throughput': lambda s: (not s['Enabled']) and -1 or sum(
(
w['Bytes Written'](w) / (w['Work Time'](w) or 1e-6)
for w in s['Worker Threads'].values()
), 0,
),
'Worker Threads': {},
}
logging.statistics['Cheroot HTTPServer %d' % id(self)] = self.stats
def runtime(self):
"""Return server uptime."""
if self._start_time is None:
return self._run_time
else:
return self._run_time + (time.time() - self._start_time)
def __str__(self):
"""Render Server instance representing bind address."""
return '%s.%s(%r)' % (
self.__module__, self.__class__.__name__,
self.bind_addr,
)
@property
def bind_addr(self):
"""Return the interface on which to listen for connections.
For TCP sockets, a (host, port) tuple. Host values may be any
:term:`IPv4` or :term:`IPv6` address, or any valid hostname.
The string 'localhost' is a synonym for '127.0.0.1' (or '::1',
if your hosts file prefers :term:`IPv6`).
The string '0.0.0.0' is a special :term:`IPv4` entry meaning
"any active interface" (INADDR_ANY), and '::' is the similar
IN6ADDR_ANY for :term:`IPv6`.
The empty string or :py:data:`None` are not allowed.
For UNIX sockets, supply the file name as a string.
Systemd socket activation is automatic and doesn't require tempering
with this variable.
.. glossary::
:abbr:`IPv4 (Internet Protocol version 4)`
Internet Protocol version 4
:abbr:`IPv6 (Internet Protocol version 6)`
Internet Protocol version 6
"""
return self._bind_addr
@bind_addr.setter
def bind_addr(self, value):
"""Set the interface on which to listen for connections."""
if isinstance(value, tuple) and value[0] in ('', None):
# Despite the socket module docs, using '' does not
# allow AI_PASSIVE to work. Passing None instead
# returns '0.0.0.0' like we want. In other words:
# host AI_PASSIVE result
# '' Y 192.168.x.y
# '' N 192.168.x.y
# None Y 0.0.0.0
# None N 127.0.0.1
# But since you can get the same effect with an explicit
# '0.0.0.0', we deny both the empty string and None as values.
raise ValueError(
"Host values of '' or None are not allowed. "
"Use '0.0.0.0' (IPv4) or '::' (IPv6) instead "
'to listen on all active interfaces.',
)
self._bind_addr = value
def safe_start(self):
"""Run the server forever, and stop it cleanly on exit."""
try:
self.start()
except (KeyboardInterrupt, IOError):
# The time.sleep call might raise
# "IOError: [Errno 4] Interrupted function call" on KBInt.
self.error_log('Keyboard Interrupt: shutting down')
self.stop()
raise
except SystemExit:
self.error_log('SystemExit raised: shutting down')
self.stop()
raise
def prepare(self): # noqa: C901 # FIXME
"""Prepare server to serving requests.
It binds a socket's port, setups the socket to ``listen()`` and does
other preparing things.
"""
self._interrupt = None
if self.software is None:
self.software = '%s Server' % self.version
# Select the appropriate socket
self.socket = None
msg = 'No socket could be created'
if os.getenv('LISTEN_PID', None):
# systemd socket activation
self.socket = socket.fromfd(3, socket.AF_INET, socket.SOCK_STREAM)
elif isinstance(self.bind_addr, (str, bytes)):
# AF_UNIX socket
try:
self.bind_unix_socket(self.bind_addr)
except socket.error as serr:
msg = '%s -- (%s: %s)' % (msg, self.bind_addr, serr)
raise socket.error(msg) from serr
else:
# AF_INET or AF_INET6 socket
# Get the correct address family for our host (allows IPv6
# addresses)
host, port = self.bind_addr
try:
info = socket.getaddrinfo(
host, port, socket.AF_UNSPEC,
socket.SOCK_STREAM, 0, socket.AI_PASSIVE,
)
except socket.gaierror:
sock_type = socket.AF_INET
bind_addr = self.bind_addr
if ':' in host:
sock_type = socket.AF_INET6
bind_addr = bind_addr + (0, 0)
info = [(sock_type, socket.SOCK_STREAM, 0, '', bind_addr)]
for res in info:
af, socktype, proto, _canonname, sa = res
try:
self.bind(af, socktype, proto)
break
except socket.error as serr:
msg = '%s -- (%s: %s)' % (msg, sa, serr)
if self.socket:
self.socket.close()
self.socket = None
if not self.socket:
raise socket.error(msg)
# Timeout so KeyboardInterrupt can be caught on Win32
self.socket.settimeout(1)
self.socket.listen(self.request_queue_size)
# must not be accessed once stop() has been called
self._connections = connections.ConnectionManager(self)
# Create worker threads
self.requests.start()
self.ready = True
self._start_time = time.time()
def serve(self):
"""Serve requests, after invoking :func:`prepare()`."""
while self.ready and not self.interrupt:
try:
self._connections.run(self.expiration_interval)
except (KeyboardInterrupt, SystemExit):
raise
except Exception:
self.error_log(
'Error in HTTPServer.serve', level=logging.ERROR,
traceback=True,
)
# raise exceptions reported by any worker threads,
# such that the exception is raised from the serve() thread.
if self.interrupt:
while self._stopping_for_interrupt:
time.sleep(0.1)
if self.interrupt:
raise self.interrupt
def start(self):
"""Run the server forever.
It is shortcut for invoking :func:`prepare()` then :func:`serve()`.
"""
# We don't have to trap KeyboardInterrupt or SystemExit here,
# because cherrypy.server already does so, calling self.stop() for us.
# If you're using this server with another framework, you should
# trap those exceptions in whatever code block calls start().
self.prepare()
self.serve()
@contextlib.contextmanager
def _run_in_thread(self):
"""Context manager for running this server in a thread."""
self.prepare()
thread = threading.Thread(target=self.serve)
thread.daemon = True
thread.start()
try:
yield thread
finally:
self.stop()
@property
def can_add_keepalive_connection(self):
"""Flag whether it is allowed to add a new keep-alive connection."""
return self.ready and self._connections.can_add_keepalive_connection
def put_conn(self, conn):
"""Put an idle connection back into the ConnectionManager."""
if self.ready:
self._connections.put(conn)
else:
# server is shutting down, just close it
conn.close()
def error_log(self, msg='', level=20, traceback=False):
"""Write error message to log.
Args:
msg (str): error message
level (int): logging level
traceback (bool): add traceback to output or not
"""
# Override this in subclasses as desired
sys.stderr.write('{msg!s}\n'.format(msg=msg))
sys.stderr.flush()
if traceback:
tblines = traceback_.format_exc()
sys.stderr.write(tblines)
sys.stderr.flush()
def bind(self, family, type, proto=0):
"""Create (or recreate) the actual socket object."""
sock = self.prepare_socket(
self.bind_addr,
family, type, proto,
self.nodelay, self.ssl_adapter,
self.reuse_port,
)
sock = self.socket = self.bind_socket(sock, self.bind_addr)
self.bind_addr = self.resolve_real_bind_addr(sock)
return sock
def bind_unix_socket(self, bind_addr): # noqa: C901 # FIXME
"""Create (or recreate) a UNIX socket object."""
if IS_WINDOWS:
"""
Trying to access socket.AF_UNIX under Windows
causes an AttributeError.
"""
raise ValueError( # or RuntimeError?
'AF_UNIX sockets are not supported under Windows.',
)
fs_permissions = 0o777 # TODO: allow changing mode
try:
# Make possible reusing the socket...
os.unlink(self.bind_addr)
except OSError:
"""
File does not exist, which is the primary goal anyway.
"""
except TypeError as typ_err:
err_msg = str(typ_err)
if (
'remove() argument 1 must be encoded '
'string without null bytes, not unicode'
not in err_msg
):
raise
except ValueError as val_err:
err_msg = str(val_err)
if (
'unlink: embedded null '
'character in path' not in err_msg
and 'embedded null byte' not in err_msg
and 'argument must be a '
'string without NUL characters' not in err_msg # pypy3
):
raise
sock = self.prepare_socket(
bind_addr=bind_addr,
family=socket.AF_UNIX, type=socket.SOCK_STREAM, proto=0,
nodelay=self.nodelay, ssl_adapter=self.ssl_adapter,
reuse_port=self.reuse_port,
)
try:
"""Linux way of pre-populating fs mode permissions."""
# Allow everyone access the socket...
os.fchmod(sock.fileno(), fs_permissions)
FS_PERMS_SET = True
except OSError:
FS_PERMS_SET = False
try:
sock = self.bind_socket(sock, bind_addr)
except socket.error:
sock.close()
raise
bind_addr = self.resolve_real_bind_addr(sock)
try:
"""FreeBSD/macOS pre-populating fs mode permissions."""
if not FS_PERMS_SET:
try:
os.lchmod(bind_addr, fs_permissions)
except AttributeError:
os.chmod(bind_addr, fs_permissions, follow_symlinks=False)
FS_PERMS_SET = True
except OSError:
pass
if not FS_PERMS_SET:
self.error_log(
'Failed to set socket fs mode permissions',
level=logging.WARNING,
)
self.bind_addr = bind_addr
self.socket = sock
return sock
@staticmethod
def _make_socket_reusable(socket_, bind_addr):
host, port = bind_addr[:2]
IS_EPHEMERAL_PORT = port == 0
if socket_.family not in (socket.AF_INET, socket.AF_INET6):
raise ValueError('Cannot reuse a non-IP socket')
if IS_EPHEMERAL_PORT:
raise ValueError('Cannot reuse an ephemeral port (0)')
# Most BSD kernels implement SO_REUSEPORT the way that only the
# latest listener can read from socket. Some of BSD kernels also
# have SO_REUSEPORT_LB that works similarly to SO_REUSEPORT
# in Linux.
if hasattr(socket, 'SO_REUSEPORT_LB'):
socket_.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT_LB, 1)
elif hasattr(socket, 'SO_REUSEPORT'):
socket_.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
elif IS_WINDOWS:
socket_.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
else:
raise NotImplementedError(
'Current platform does not support port reuse',
)
@classmethod
def prepare_socket(
cls, bind_addr, family, type, proto, nodelay, ssl_adapter,
reuse_port=False,
):
"""Create and prepare the socket object."""
sock = socket.socket(family, type, proto)
connections.prevent_socket_inheritance(sock)
host, port = bind_addr[:2]
IS_EPHEMERAL_PORT = port == 0
if reuse_port:
cls._make_socket_reusable(socket_=sock, bind_addr=bind_addr)
if not (IS_WINDOWS or IS_EPHEMERAL_PORT):
"""Enable SO_REUSEADDR for the current socket.
Skip for Windows (has different semantics)
or ephemeral ports (can steal ports from others).
Refs:
* https://msdn.microsoft.com/en-us/library/ms740621(v=vs.85).aspx
* https://github.com/cherrypy/cheroot/issues/114
* https://gavv.github.io/blog/ephemeral-port-reuse/
"""
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
if nodelay and not isinstance(bind_addr, (str, bytes)):
sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
if ssl_adapter is not None:
sock = ssl_adapter.bind(sock)
# If listening on the IPV6 any address ('::' = IN6ADDR_ANY),
# activate dual-stack. See
# https://github.com/cherrypy/cherrypy/issues/871.
listening_ipv6 = (
hasattr(socket, 'AF_INET6')
and family == socket.AF_INET6
and host in ('::', '::0', '::0.0.0.0')
)
if listening_ipv6:
try:
sock.setsockopt(
socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, 0,
)
except (AttributeError, socket.error):
# Apparently, the socket option is not available in
# this machine's TCP stack
pass
return sock
@staticmethod
def bind_socket(socket_, bind_addr):
"""Bind the socket to given interface."""
socket_.bind(bind_addr)
return socket_
@staticmethod
def resolve_real_bind_addr(socket_):
"""Retrieve actual bind address from bound socket."""
# FIXME: keep requested bind_addr separate real bound_addr (port
# is different in case of ephemeral port 0)
bind_addr = socket_.getsockname()
if socket_.family in (
# Windows doesn't have socket.AF_UNIX, so not using it in check
socket.AF_INET,
socket.AF_INET6,
):
"""UNIX domain sockets are strings or bytes.
In case of bytes with a leading null-byte it's an abstract socket.
"""
return bind_addr[:2]
if isinstance(bind_addr, bytes):
bind_addr = bton(bind_addr)
return bind_addr
def process_conn(self, conn):
"""Process an incoming HTTPConnection."""
try:
self.requests.put(conn)
except queue.Full:
# Just drop the conn. TODO: write 503 back?
conn.close()
@property
def interrupt(self):
"""Flag interrupt of the server."""
return self._interrupt
@property
def _stopping_for_interrupt(self):
"""Return whether the server is responding to an interrupt."""
return self._interrupt is _STOPPING_FOR_INTERRUPT
@interrupt.setter
def interrupt(self, interrupt):
"""Perform the shutdown of this server and save the exception.
Typically invoked by a worker thread in
:py:mod:`~cheroot.workers.threadpool`, the exception is raised
from the thread running :py:meth:`serve` once :py:meth:`stop`
has completed.
"""
self._interrupt = _STOPPING_FOR_INTERRUPT
self.stop()
self._interrupt = interrupt
def stop(self): # noqa: C901 # FIXME
"""Gracefully shutdown a server that is serving forever."""
if not self.ready:
return # already stopped
self.ready = False
if self._start_time is not None:
self._run_time += (time.time() - self._start_time)
self._start_time = None
self._connections.stop()
sock = getattr(self, 'socket', None)
if sock:
if not isinstance(self.bind_addr, (str, bytes)):
# Touch our own socket to make accept() return immediately.
try:
host, port = sock.getsockname()[:2]
except socket.error as ex:
if ex.args[0] not in errors.socket_errors_to_ignore:
# Changed to use error code and not message
# See
# https://github.com/cherrypy/cherrypy/issues/860.
raise
else:
# Note that we're explicitly NOT using AI_PASSIVE,
# here, because we want an actual IP to touch.
# localhost won't work if we've bound to a public IP,
# but it will if we bound to '0.0.0.0' (INADDR_ANY).
for res in socket.getaddrinfo(
host, port, socket.AF_UNSPEC,
socket.SOCK_STREAM,
):
af, socktype, proto, _canonname, _sa = res
s = None
try:
s = socket.socket(af, socktype, proto)
# See
# https://groups.google.com/group/cherrypy-users/
# browse_frm/thread/bbfe5eb39c904fe0
s.settimeout(1.0)
s.connect((host, port))
s.close()
except socket.error:
if s:
s.close()
if hasattr(sock, 'close'):
sock.close()
self.socket = None
self._connections.close()
self.requests.stop(self.shutdown_timeout)
class Gateway:
"""Base class to interface HTTPServer with other systems, such as WSGI."""
def __init__(self, req):
"""Initialize Gateway instance with request.
Args:
req (HTTPRequest): current HTTP request
"""
self.req = req
def respond(self):
"""Process the current request. Must be overridden in a subclass."""
raise NotImplementedError # pragma: no cover
# These may either be ssl.Adapter subclasses or the string names
# of such classes (in which case they will be lazily loaded).
ssl_adapters = {
'builtin': 'cheroot.ssl.builtin.BuiltinSSLAdapter',
'pyopenssl': 'cheroot.ssl.pyopenssl.pyOpenSSLAdapter',
}
def get_ssl_adapter_class(name='builtin'):
"""Return an SSL adapter class for the given name."""
adapter = ssl_adapters[name.lower()]
if isinstance(adapter, str):
last_dot = adapter.rfind('.')
attr_name = adapter[last_dot + 1:]
mod_path = adapter[:last_dot]
try:
mod = sys.modules[mod_path]
if mod is None:
raise KeyError()
except KeyError:
# The last [''] is important.
mod = __import__(mod_path, globals(), locals(), [''])
# Let an AttributeError propagate outward.
try:
adapter = getattr(mod, attr_name)
except AttributeError:
raise AttributeError(
"'%s' object has no attribute '%s'"
% (mod_path, attr_name),
)
return adapter