django1/django/core/handlers/wsgi.py

207 lines
7.3 KiB
Python

import re
from io import BytesIO
from django.conf import settings
from django.core import signals
from django.core.handlers import base
from django.http import HttpRequest, QueryDict, parse_cookie
from django.urls import set_script_prefix
from django.utils.encoding import repercent_broken_unicode
from django.utils.functional import cached_property
_slashes_re = re.compile(br'/+')
class LimitedStream:
"""Wrap another stream to disallow reading it past a number of bytes."""
def __init__(self, stream, limit, buf_size=64 * 1024 * 1024):
self.stream = stream
self.remaining = limit
self.buffer = b''
self.buf_size = buf_size
def _read_limited(self, size=None):
if size is None or size > self.remaining:
size = self.remaining
if size == 0:
return b''
result = self.stream.read(size)
self.remaining -= len(result)
return result
def read(self, size=None):
if size is None:
result = self.buffer + self._read_limited()
self.buffer = b''
elif size < len(self.buffer):
result = self.buffer[:size]
self.buffer = self.buffer[size:]
else: # size >= len(self.buffer)
result = self.buffer + self._read_limited(size - len(self.buffer))
self.buffer = b''
return result
def readline(self, size=None):
while b'\n' not in self.buffer and \
(size is None or len(self.buffer) < size):
if size:
# since size is not None here, len(self.buffer) < size
chunk = self._read_limited(size - len(self.buffer))
else:
chunk = self._read_limited()
if not chunk:
break
self.buffer += chunk
sio = BytesIO(self.buffer)
if size:
line = sio.readline(size)
else:
line = sio.readline()
self.buffer = sio.read()
return line
class WSGIRequest(HttpRequest):
def __init__(self, environ):
script_name = get_script_name(environ)
# If PATH_INFO is empty (e.g. accessing the SCRIPT_NAME URL without a
# trailing slash), operate as if '/' was requested.
path_info = get_path_info(environ) or '/'
self.environ = environ
self.path_info = path_info
# be careful to only replace the first slash in the path because of
# http://test/something and http://test//something being different as
# stated in https://www.ietf.org/rfc/rfc2396.txt
self.path = '%s/%s' % (script_name.rstrip('/'),
path_info.replace('/', '', 1))
self.META = environ
self.META['PATH_INFO'] = path_info
self.META['SCRIPT_NAME'] = script_name
self.method = environ['REQUEST_METHOD'].upper()
# Set content_type, content_params, and encoding.
self._set_content_type_params(environ)
try:
content_length = int(environ.get('CONTENT_LENGTH'))
except (ValueError, TypeError):
content_length = 0
self._stream = LimitedStream(self.environ['wsgi.input'], content_length)
self._read_started = False
self.resolver_match = None
def _get_scheme(self):
return self.environ.get('wsgi.url_scheme')
@cached_property
def GET(self):
# The WSGI spec says 'QUERY_STRING' may be absent.
raw_query_string = get_bytes_from_wsgi(self.environ, 'QUERY_STRING', '')
return QueryDict(raw_query_string, encoding=self._encoding)
def _get_post(self):
if not hasattr(self, '_post'):
self._load_post_and_files()
return self._post
def _set_post(self, post):
self._post = post
@cached_property
def COOKIES(self):
raw_cookie = get_str_from_wsgi(self.environ, 'HTTP_COOKIE', '')
return parse_cookie(raw_cookie)
@property
def FILES(self):
if not hasattr(self, '_files'):
self._load_post_and_files()
return self._files
POST = property(_get_post, _set_post)
class WSGIHandler(base.BaseHandler):
request_class = WSGIRequest
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.load_middleware()
def __call__(self, environ, start_response):
set_script_prefix(get_script_name(environ))
signals.request_started.send(sender=self.__class__, environ=environ)
request = self.request_class(environ)
response = self.get_response(request)
response._handler_class = self.__class__
status = '%d %s' % (response.status_code, response.reason_phrase)
response_headers = [
*response.items(),
*(('Set-Cookie', c.output(header='')) for c in response.cookies.values()),
]
start_response(status, response_headers)
if getattr(response, 'file_to_stream', None) is not None and environ.get('wsgi.file_wrapper'):
response = environ['wsgi.file_wrapper'](response.file_to_stream, response.block_size)
return response
def get_path_info(environ):
"""Return the HTTP request's PATH_INFO as a string."""
path_info = get_bytes_from_wsgi(environ, 'PATH_INFO', '/')
return repercent_broken_unicode(path_info).decode()
def get_script_name(environ):
"""
Return the equivalent of the HTTP request's SCRIPT_NAME environment
variable. If Apache mod_rewrite is used, return what would have been
the script name prior to any rewriting (so it's the script name as seen
from the client's perspective), unless the FORCE_SCRIPT_NAME setting is
set (to anything).
"""
if settings.FORCE_SCRIPT_NAME is not None:
return settings.FORCE_SCRIPT_NAME
# If Apache's mod_rewrite had a whack at the URL, Apache set either
# SCRIPT_URL or REDIRECT_URL to the full resource URL before applying any
# rewrites. Unfortunately not every Web server (lighttpd!) passes this
# information through all the time, so FORCE_SCRIPT_NAME, above, is still
# needed.
script_url = get_bytes_from_wsgi(environ, 'SCRIPT_URL', '') or get_bytes_from_wsgi(environ, 'REDIRECT_URL', '')
if script_url:
if b'//' in script_url:
# mod_wsgi squashes multiple successive slashes in PATH_INFO,
# do the same with script_url before manipulating paths (#17133).
script_url = _slashes_re.sub(b'/', script_url)
path_info = get_bytes_from_wsgi(environ, 'PATH_INFO', '')
script_name = script_url[:-len(path_info)] if path_info else script_url
else:
script_name = get_bytes_from_wsgi(environ, 'SCRIPT_NAME', '')
return script_name.decode()
def get_bytes_from_wsgi(environ, key, default):
"""
Get a value from the WSGI environ dictionary as bytes.
key and default should be strings.
"""
value = environ.get(key, default)
# Non-ASCII values in the WSGI environ are arbitrarily decoded with
# ISO-8859-1. This is wrong for Django websites where UTF-8 is the default.
# Re-encode to recover the original bytestring.
return value.encode('iso-8859-1')
def get_str_from_wsgi(environ, key, default):
"""
Get a value from the WSGI environ dictionary as str.
key and default should be str objects.
"""
value = get_bytes_from_wsgi(environ, key, default)
return value.decode(errors='replace')