from __future__ import absolute_import, unicode_literals
import copy
import os
import re
import sys
from io import BytesIO
from pprint import pformat
from django.conf import settings
from django.core import signing
from django.core.exceptions import DisallowedHost, ImproperlyConfigured
from django.core.files import uploadhandler
from django.http.multipartparser import MultiPartParser
from django.utils import six
from django.utils.datastructures import MultiValueDict, ImmutableList
from django.utils.encoding import force_bytes, force_text, force_str, iri_to_uri
from django.utils.six.moves.urllib.parse import parse_qsl, urlencode, quote, urljoin
RAISE_ERROR = object()
absolute_http_url_re = re.compile(r"^https?://", re.I)
host_validation_re = re.compile(r"^([a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9:]+\])(:\d+)?$")
[docs]class HttpRequest(object):
"""A basic HTTP request."""
# The encoding used in GET/POST dicts. None means use default setting.
_encoding = None
_upload_handlers = []
def __init__(self):
# WARNING: The `WSGIRequest` subclass doesn't call `super`.
# Any variable assignment made here should also happen in
# `WSGIRequest.__init__()`.
self.GET, self.POST, self.COOKIES, self.META, self.FILES = {}, {}, {}, {}, {}
self.path = ''
self.path_info = ''
self.method = None
self.resolver_match = None
self._post_parse_error = False
def __repr__(self):
return build_request_repr(self)
[docs] def get_host(self):
"""Returns the HTTP host using the environment or request headers."""
# We try three options, in order of decreasing preference.
if settings.USE_X_FORWARDED_HOST and (
'HTTP_X_FORWARDED_HOST' in self.META):
host = self.META['HTTP_X_FORWARDED_HOST']
elif 'HTTP_HOST' in self.META:
host = self.META['HTTP_HOST']
else:
# Reconstruct the host using the algorithm from PEP 333.
host = self.META['SERVER_NAME']
server_port = str(self.META['SERVER_PORT'])
if server_port != ('443' if self.is_secure() else '80'):
host = '%s:%s' % (host, server_port)
allowed_hosts = ['*'] if settings.DEBUG else settings.ALLOWED_HOSTS
domain, port = split_domain_port(host)
if domain and validate_host(domain, allowed_hosts):
return host
else:
msg = "Invalid HTTP_HOST header: %r." % host
if domain:
msg += "You may need to add %r to ALLOWED_HOSTS." % domain
raise DisallowedHost(msg)
[docs] def get_full_path(self):
# RFC 3986 requires query string arguments to be in the ASCII range.
# Rather than crash if this doesn't happen, we encode defensively.
return '%s%s' % (self.path, ('?' + iri_to_uri(self.META.get('QUERY_STRING', ''))) if self.META.get('QUERY_STRING', '') else '')
[docs] def get_signed_cookie(self, key, default=RAISE_ERROR, salt='', max_age=None):
"""
Attempts to return a signed cookie. If the signature fails or the
cookie has expired, raises an exception... unless you provide the
default argument in which case that value will be returned instead.
"""
try:
cookie_value = self.COOKIES[key]
except KeyError:
if default is not RAISE_ERROR:
return default
else:
raise
try:
value = signing.get_cookie_signer(salt=key + salt).unsign(
cookie_value, max_age=max_age)
except signing.BadSignature:
if default is not RAISE_ERROR:
return default
else:
raise
return value
[docs] def build_absolute_uri(self, location=None):
"""
Builds an absolute URI from the location and the variables available in
this request. If no location is specified, the absolute URI is built on
``request.get_full_path()``.
"""
if not location:
location = self.get_full_path()
if not absolute_http_url_re.match(location):
current_uri = '%s://%s%s' % ('https' if self.is_secure() else 'http',
self.get_host(), self.path)
location = urljoin(current_uri, location)
return iri_to_uri(location)
def _is_secure(self):
return os.environ.get("HTTPS") == "on"
[docs] def is_secure(self):
# First, check the SECURE_PROXY_SSL_HEADER setting.
if settings.SECURE_PROXY_SSL_HEADER:
try:
header, value = settings.SECURE_PROXY_SSL_HEADER
except ValueError:
raise ImproperlyConfigured('The SECURE_PROXY_SSL_HEADER setting must be a tuple containing two values.')
if self.META.get(header, None) == value:
return True
# Failing that, fall back to _is_secure(), which is a hook for
# subclasses to implement.
return self._is_secure()
@property
def encoding(self):
return self._encoding
@encoding.setter
def encoding(self, val):
"""
Sets the encoding used for GET/POST accesses. If the GET or POST
dictionary has already been created, it is removed and recreated on the
next access (so that it is decoded correctly).
"""
self._encoding = val
if hasattr(self, '_get'):
del self._get
if hasattr(self, '_post'):
del self._post
def _initialize_handlers(self):
self._upload_handlers = [uploadhandler.load_handler(handler, self)
for handler in settings.FILE_UPLOAD_HANDLERS]
@property
def upload_handlers(self):
if not self._upload_handlers:
# If there are no upload handlers defined, initialize them from settings.
self._initialize_handlers()
return self._upload_handlers
@upload_handlers.setter
def upload_handlers(self, upload_handlers):
if hasattr(self, '_files'):
raise AttributeError("You cannot set the upload handlers after the upload has been processed.")
self._upload_handlers = upload_handlers
def parse_file_upload(self, META, post_data):
"""Returns a tuple of (POST QueryDict, FILES MultiValueDict)."""
self.upload_handlers = ImmutableList(
self.upload_handlers,
warning="You cannot alter upload handlers after the upload has been processed."
)
parser = MultiPartParser(META, post_data, self.upload_handlers, self.encoding)
return parser.parse()
@property
def body(self):
if not hasattr(self, '_body'):
if self._read_started:
raise Exception("You cannot access body after reading from request's data stream")
try:
self._body = self.read()
except IOError as e:
six.reraise(UnreadablePostError, UnreadablePostError(*e.args), sys.exc_info()[2])
self._stream = BytesIO(self._body)
return self._body
def _mark_post_parse_error(self):
self._post = QueryDict('')
self._files = MultiValueDict()
self._post_parse_error = True
def _load_post_and_files(self):
"""Populate self._post and self._files if the content-type is a form type"""
if self.method != 'POST':
self._post, self._files = QueryDict('', encoding=self._encoding), MultiValueDict()
return
if self._read_started and not hasattr(self, '_body'):
self._mark_post_parse_error()
return
if self.META.get('CONTENT_TYPE', '').startswith('multipart/form-data'):
if hasattr(self, '_body'):
# Use already read data
data = BytesIO(self._body)
else:
data = self
try:
self._post, self._files = self.parse_file_upload(self.META, data)
except:
# An error occured while parsing POST data. Since when
# formatting the error the request handler might access
# self.POST, set self._post and self._file to prevent
# attempts to parse POST data again.
# Mark that an error occured. This allows self.__repr__ to
# be explicit about it instead of simply representing an
# empty POST
self._mark_post_parse_error()
raise
elif self.META.get('CONTENT_TYPE', '').startswith('application/x-www-form-urlencoded'):
self._post, self._files = QueryDict(self.body, encoding=self._encoding), MultiValueDict()
else:
self._post, self._files = QueryDict('', encoding=self._encoding), MultiValueDict()
## File-like and iterator interface.
##
## Expects self._stream to be set to an appropriate source of bytes by
## a corresponding request subclass (e.g. WSGIRequest).
## Also when request data has already been read by request.POST or
## request.body, self._stream points to a BytesIO instance
## containing that data.
[docs] def read(self, *args, **kwargs):
self._read_started = True
try:
return self._stream.read(*args, **kwargs)
except IOError as e:
six.reraise(UnreadablePostError, UnreadablePostError(*e.args), sys.exc_info()[2])
[docs] def readline(self, *args, **kwargs):
self._read_started = True
try:
return self._stream.readline(*args, **kwargs)
except IOError as e:
six.reraise(UnreadablePostError, UnreadablePostError(*e.args), sys.exc_info()[2])
__iter__ = xreadlines
[docs]class QueryDict(MultiValueDict):
"""
A specialized MultiValueDict which represents a query string.
A QueryDict can be used to represent GET or POST data. It subclasses
MultiValueDict since keys in such data can be repeated, for instance
in the data from a form with a <select multiple> field.
By default QueryDicts are immutable, though the copy() method
will always return a mutable copy.
Both keys and values set on this class are converted from the given encoding
(DEFAULT_CHARSET by default) to unicode.
"""
# These are both reset in __init__, but is specified here at the class
# level so that unpickling will have valid values
_mutable = True
_encoding = None
[docs] def __init__(self, query_string, mutable=False, encoding=None):
super(QueryDict, self).__init__()
if not encoding:
encoding = settings.DEFAULT_CHARSET
self.encoding = encoding
if six.PY3:
if isinstance(query_string, bytes):
# query_string normally contains URL-encoded data, a subset of ASCII.
try:
query_string = query_string.decode(encoding)
except UnicodeDecodeError:
# ... but some user agents are misbehaving :-(
query_string = query_string.decode('iso-8859-1')
for key, value in parse_qsl(query_string or '',
keep_blank_values=True,
encoding=encoding):
self.appendlist(key, value)
else:
for key, value in parse_qsl(query_string or '',
keep_blank_values=True):
self.appendlist(force_text(key, encoding, errors='replace'),
force_text(value, encoding, errors='replace'))
self._mutable = mutable
@property
def encoding(self):
if self._encoding is None:
self._encoding = settings.DEFAULT_CHARSET
return self._encoding
@encoding.setter
def encoding(self, value):
self._encoding = value
def _assert_mutable(self):
if not self._mutable:
raise AttributeError("This QueryDict instance is immutable")
[docs] def __setitem__(self, key, value):
self._assert_mutable()
key = bytes_to_text(key, self.encoding)
value = bytes_to_text(value, self.encoding)
super(QueryDict, self).__setitem__(key, value)
def __delitem__(self, key):
self._assert_mutable()
super(QueryDict, self).__delitem__(key)
def __copy__(self):
result = self.__class__('', mutable=True, encoding=self.encoding)
for key, value in six.iterlists(self):
result.setlist(key, value)
return result
def __deepcopy__(self, memo):
result = self.__class__('', mutable=True, encoding=self.encoding)
memo[id(self)] = result
for key, value in six.iterlists(self):
result.setlist(copy.deepcopy(key, memo), copy.deepcopy(value, memo))
return result
[docs] def setlist(self, key, list_):
self._assert_mutable()
key = bytes_to_text(key, self.encoding)
list_ = [bytes_to_text(elt, self.encoding) for elt in list_]
super(QueryDict, self).setlist(key, list_)
[docs] def setlistdefault(self, key, default_list=None):
self._assert_mutable()
return super(QueryDict, self).setlistdefault(key, default_list)
[docs] def appendlist(self, key, value):
self._assert_mutable()
key = bytes_to_text(key, self.encoding)
value = bytes_to_text(value, self.encoding)
super(QueryDict, self).appendlist(key, value)
[docs] def pop(self, key, *args):
self._assert_mutable()
return super(QueryDict, self).pop(key, *args)
def clear(self):
self._assert_mutable()
super(QueryDict, self).clear()
[docs] def setdefault(self, key, default=None):
self._assert_mutable()
key = bytes_to_text(key, self.encoding)
default = bytes_to_text(default, self.encoding)
return super(QueryDict, self).setdefault(key, default)
[docs] def urlencode(self, safe=None):
"""
Returns an encoded string of all query string arguments.
:arg safe: Used to specify characters which do not require quoting, for
example::
>>> q = QueryDict('', mutable=True)
>>> q['next'] = '/a&b/'
>>> q.urlencode()
'next=%2Fa%26b%2F'
>>> q.urlencode(safe='/')
'next=/a%26b/'
"""
output = []
if safe:
safe = force_bytes(safe, self.encoding)
encode = lambda k, v: '%s=%s' % ((quote(k, safe), quote(v, safe)))
else:
encode = lambda k, v: urlencode({k: v})
for k, list_ in self.lists():
k = force_bytes(k, self.encoding)
output.extend([encode(k, force_bytes(v, self.encoding))
for v in list_])
return '&'.join(output)
def build_request_repr(request, path_override=None, GET_override=None,
POST_override=None, COOKIES_override=None,
META_override=None):
"""
Builds and returns the request's representation string. The request's
attributes may be overridden by pre-processed values.
"""
# Since this is called as part of error handling, we need to be very
# robust against potentially malformed input.
try:
get = (pformat(GET_override)
if GET_override is not None
else pformat(request.GET))
except Exception:
get = '<could not parse>'
if request._post_parse_error:
post = '<could not parse>'
else:
try:
post = (pformat(POST_override)
if POST_override is not None
else pformat(request.POST))
except Exception:
post = '<could not parse>'
try:
cookies = (pformat(COOKIES_override)
if COOKIES_override is not None
else pformat(request.COOKIES))
except Exception:
cookies = '<could not parse>'
try:
meta = (pformat(META_override)
if META_override is not None
else pformat(request.META))
except Exception:
meta = '<could not parse>'
path = path_override if path_override is not None else request.path
return force_str('<%s\npath:%s,\nGET:%s,\nPOST:%s,\nCOOKIES:%s,\nMETA:%s>' %
(request.__class__.__name__,
path,
six.text_type(get),
six.text_type(post),
six.text_type(cookies),
six.text_type(meta)))
# It's neither necessary nor appropriate to use
# django.utils.encoding.smart_text for parsing URLs and form inputs. Thus,
# this slightly more restricted function, used by QueryDict.
def bytes_to_text(s, encoding):
"""
Converts basestring objects to unicode, using the given encoding. Illegally
encoded input characters are replaced with Unicode "unknown" codepoint
(\ufffd).
Returns any non-basestring objects without change.
"""
if isinstance(s, bytes):
return six.text_type(s, encoding, 'replace')
else:
return s
def split_domain_port(host):
"""
Return a (domain, port) tuple from a given host.
Returned domain is lower-cased. If the host is invalid, the domain will be
empty.
"""
host = host.lower()
if not host_validation_re.match(host):
return '', ''
if host[-1] == ']':
# It's an IPv6 address without a port.
return host, ''
bits = host.rsplit(':', 1)
if len(bits) == 2:
return tuple(bits)
return bits[0], ''
def validate_host(host, allowed_hosts):
"""
Validate the given host for this site.
Check that the host looks valid and matches a host or host pattern in the
given list of ``allowed_hosts``. Any pattern beginning with a period
matches a domain and all its subdomains (e.g. ``.example.com`` matches
``example.com`` and any subdomain), ``*`` matches anything, and anything
else must match exactly.
Note: This function assumes that the given host is lower-cased and has
already had the port, if any, stripped off.
Return ``True`` for a valid host, ``False`` otherwise.
"""
for pattern in allowed_hosts:
pattern = pattern.lower()
match = (
pattern == '*' or
pattern.startswith('.') and (
host.endswith(pattern) or host == pattern[1:]
) or
pattern == host
)
if match:
return True
return False
Oct 03, 2017