django1/django/http/request.py

662 lines
24 KiB
Python

import cgi
import codecs
import copy
from io import BytesIO
from itertools import chain
from urllib.parse import parse_qsl, quote, urlencode, urljoin, urlsplit
from django.conf import settings
from django.core import signing
from django.core.exceptions import (
DisallowedHost, ImproperlyConfigured, RequestDataTooBig, TooManyFieldsSent,
)
from django.core.files import uploadhandler
from django.http.multipartparser import MultiPartParser, MultiPartParserError
from django.utils.datastructures import (
CaseInsensitiveMapping, ImmutableList, MultiValueDict,
)
from django.utils.encoding import escape_uri_path, iri_to_uri
from django.utils.functional import cached_property
from django.utils.http import is_same_domain
from django.utils.regex_helper import _lazy_re_compile
from .multipartparser import parse_header
RAISE_ERROR = object()
host_validation_re = _lazy_re_compile(r"^([a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9\.:]+\])(:\d+)?$")
class UnreadablePostError(OSError):
pass
class RawPostDataException(Exception):
"""
You cannot access raw_post_data from a request that has
multipart/* POST data if it has been accessed via POST,
FILES, etc..
"""
pass
class HttpRequest:
"""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 = QueryDict(mutable=True)
self.POST = QueryDict(mutable=True)
self.COOKIES = {}
self.META = {}
self.FILES = MultiValueDict()
self.path = ''
self.path_info = ''
self.method = None
self.resolver_match = None
self.content_type = None
self.content_params = None
def __repr__(self):
if self.method is None or not self.get_full_path():
return '<%s>' % self.__class__.__name__
return '<%s: %s %r>' % (self.__class__.__name__, self.method, self.get_full_path())
@cached_property
def headers(self):
return HttpHeaders(self.META)
@cached_property
def accepted_types(self):
"""Return a list of MediaType instances."""
return parse_accept_header(self.headers.get('Accept', '*/*'))
def accepts(self, media_type):
return any(
accepted_type.match(media_type)
for accepted_type in self.accepted_types
)
def _set_content_type_params(self, meta):
"""Set content_type, content_params, and encoding."""
self.content_type, self.content_params = cgi.parse_header(meta.get('CONTENT_TYPE', ''))
if 'charset' in self.content_params:
try:
codecs.lookup(self.content_params['charset'])
except LookupError:
pass
else:
self.encoding = self.content_params['charset']
def _get_raw_host(self):
"""
Return the HTTP host using the environment or request headers. Skip
allowed hosts protection, so may return an insecure host.
"""
# 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 = self.get_port()
if server_port != ('443' if self.is_secure() else '80'):
host = '%s:%s' % (host, server_port)
return host
def get_host(self):
"""Return the HTTP host using the environment or request headers."""
host = self._get_raw_host()
# Allow variants of localhost if ALLOWED_HOSTS is empty and DEBUG=True.
allowed_hosts = settings.ALLOWED_HOSTS
if settings.DEBUG and not allowed_hosts:
allowed_hosts = ['.localhost', '127.0.0.1', '[::1]']
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
else:
msg += " The domain name provided is not valid according to RFC 1034/1035."
raise DisallowedHost(msg)
def get_port(self):
"""Return the port number for the request as a string."""
if settings.USE_X_FORWARDED_PORT and 'HTTP_X_FORWARDED_PORT' in self.META:
port = self.META['HTTP_X_FORWARDED_PORT']
else:
port = self.META['SERVER_PORT']
return str(port)
def get_full_path(self, force_append_slash=False):
return self._get_full_path(self.path, force_append_slash)
def get_full_path_info(self, force_append_slash=False):
return self._get_full_path(self.path_info, force_append_slash)
def _get_full_path(self, path, force_append_slash):
# 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%s' % (
escape_uri_path(path),
'/' if force_append_slash and not path.endswith('/') else '',
('?' + iri_to_uri(self.META.get('QUERY_STRING', ''))) if self.META.get('QUERY_STRING', '') else ''
)
def get_signed_cookie(self, key, default=RAISE_ERROR, salt='', max_age=None):
"""
Attempt to return a signed cookie. If the signature fails or the
cookie has expired, raise an exception, unless the `default` argument
is provided, in which case return that value.
"""
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
def build_absolute_uri(self, location=None):
"""
Build an absolute URI from the location and the variables available in
this request. If no ``location`` is specified, build the absolute URI
using request.get_full_path(). If the location is absolute, convert it
to an RFC 3987 compliant URI and return it. If location is relative or
is scheme-relative (i.e., ``//example.com/``), urljoin() it to a base
URL constructed from the request variables.
"""
if location is None:
# Make it an absolute url (but schemeless and domainless) for the
# edge case that the path starts with '//'.
location = '//%s' % self.get_full_path()
else:
# Coerce lazy locations.
location = str(location)
bits = urlsplit(location)
if not (bits.scheme and bits.netloc):
# Handle the simple, most common case. If the location is absolute
# and a scheme or host (netloc) isn't provided, skip an expensive
# urljoin() as long as no path segments are '.' or '..'.
if (bits.path.startswith('/') and not bits.scheme and not bits.netloc and
'/./' not in bits.path and '/../' not in bits.path):
# If location starts with '//' but has no netloc, reuse the
# schema and netloc from the current request. Strip the double
# slashes and continue as if it wasn't specified.
if location.startswith('//'):
location = location[2:]
location = self._current_scheme_host + location
else:
# Join the constructed URL with the provided location, which
# allows the provided location to apply query strings to the
# base path.
location = urljoin(self._current_scheme_host + self.path, location)
return iri_to_uri(location)
@cached_property
def _current_scheme_host(self):
return '{}://{}'.format(self.scheme, self.get_host())
def _get_scheme(self):
"""
Hook for subclasses like WSGIRequest to implement. Return 'http' by
default.
"""
return 'http'
@property
def scheme(self):
if settings.SECURE_PROXY_SSL_HEADER:
try:
header, secure_value = settings.SECURE_PROXY_SSL_HEADER
except ValueError:
raise ImproperlyConfigured(
'The SECURE_PROXY_SSL_HEADER setting must be a tuple containing two values.'
)
header_value = self.META.get(header)
if header_value is not None:
return 'https' if header_value == secure_value else 'http'
return self._get_scheme()
def is_secure(self):
return self.scheme == 'https'
@property
def encoding(self):
return self._encoding
@encoding.setter
def encoding(self, val):
"""
Set the encoding used for GET/POST accesses. If the GET or POST
dictionary has already been created, remove and recreate it 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):
"""Return 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 RawPostDataException("You cannot access body after reading from request's data stream")
# Limit the maximum request data size that will be handled in-memory.
if (settings.DATA_UPLOAD_MAX_MEMORY_SIZE is not None and
int(self.META.get('CONTENT_LENGTH') or 0) > settings.DATA_UPLOAD_MAX_MEMORY_SIZE):
raise RequestDataTooBig('Request body exceeded settings.DATA_UPLOAD_MAX_MEMORY_SIZE.')
try:
self._body = self.read()
except OSError as e:
raise UnreadablePostError(*e.args) from e
self._stream = BytesIO(self._body)
return self._body
def _mark_post_parse_error(self):
self._post = QueryDict()
self._files = MultiValueDict()
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.content_type == '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 MultiPartParserError:
# An error occurred 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.
self._mark_post_parse_error()
raise
elif self.content_type == '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()
def close(self):
if hasattr(self, '_files'):
for f in chain.from_iterable(list_[1] for list_ in self._files.lists()):
f.close()
# 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.
def read(self, *args, **kwargs):
self._read_started = True
try:
return self._stream.read(*args, **kwargs)
except OSError as e:
raise UnreadablePostError(*e.args) from e
def readline(self, *args, **kwargs):
self._read_started = True
try:
return self._stream.readline(*args, **kwargs)
except OSError as e:
raise UnreadablePostError(*e.args) from e
def __iter__(self):
return iter(self.readline, b'')
def readlines(self):
return list(self)
class HttpHeaders(CaseInsensitiveMapping):
HTTP_PREFIX = 'HTTP_'
# PEP 333 gives two headers which aren't prepended with HTTP_.
UNPREFIXED_HEADERS = {'CONTENT_TYPE', 'CONTENT_LENGTH'}
def __init__(self, environ):
headers = {}
for header, value in environ.items():
name = self.parse_header_name(header)
if name:
headers[name] = value
super().__init__(headers)
def __getitem__(self, key):
"""Allow header lookup using underscores in place of hyphens."""
return super().__getitem__(key.replace('_', '-'))
@classmethod
def parse_header_name(cls, header):
if header.startswith(cls.HTTP_PREFIX):
header = header[len(cls.HTTP_PREFIX):]
elif header not in cls.UNPREFIXED_HEADERS:
return None
return header.replace('_', '-').title()
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 str.
"""
# 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
def __init__(self, query_string=None, mutable=False, encoding=None):
super().__init__()
self.encoding = encoding or settings.DEFAULT_CHARSET
query_string = query_string or ''
parse_qsl_kwargs = {
'keep_blank_values': True,
'encoding': self.encoding,
'max_num_fields': settings.DATA_UPLOAD_MAX_NUMBER_FIELDS,
}
if isinstance(query_string, bytes):
# query_string normally contains URL-encoded data, a subset of ASCII.
try:
query_string = query_string.decode(self.encoding)
except UnicodeDecodeError:
# ... but some user agents are misbehaving :-(
query_string = query_string.decode('iso-8859-1')
try:
for key, value in parse_qsl(query_string, **parse_qsl_kwargs):
self.appendlist(key, value)
except ValueError as e:
# ValueError can also be raised if the strict_parsing argument to
# parse_qsl() is True. As that is not used by Django, assume that
# the exception was raised by exceeding the value of max_num_fields
# instead of fragile checks of exception message strings.
raise TooManyFieldsSent(
'The number of GET/POST parameters exceeded '
'settings.DATA_UPLOAD_MAX_NUMBER_FIELDS.'
) from e
self._mutable = mutable
@classmethod
def fromkeys(cls, iterable, value='', mutable=False, encoding=None):
"""
Return a new QueryDict with keys (may be repeated) from an iterable and
values from value.
"""
q = cls('', mutable=True, encoding=encoding)
for key in iterable:
q.appendlist(key, value)
if not mutable:
q._mutable = False
return q
@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")
def __setitem__(self, key, value):
self._assert_mutable()
key = bytes_to_text(key, self.encoding)
value = bytes_to_text(value, self.encoding)
super().__setitem__(key, value)
def __delitem__(self, key):
self._assert_mutable()
super().__delitem__(key)
def __copy__(self):
result = self.__class__('', mutable=True, encoding=self.encoding)
for key, value in self.lists():
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 self.lists():
result.setlist(copy.deepcopy(key, memo), copy.deepcopy(value, memo))
return result
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().setlist(key, list_)
def setlistdefault(self, key, default_list=None):
self._assert_mutable()
return super().setlistdefault(key, default_list)
def appendlist(self, key, value):
self._assert_mutable()
key = bytes_to_text(key, self.encoding)
value = bytes_to_text(value, self.encoding)
super().appendlist(key, value)
def pop(self, key, *args):
self._assert_mutable()
return super().pop(key, *args)
def popitem(self):
self._assert_mutable()
return super().popitem()
def clear(self):
self._assert_mutable()
super().clear()
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().setdefault(key, default)
def copy(self):
"""Return a mutable copy of this object."""
return self.__deepcopy__({})
def urlencode(self, safe=None):
"""
Return an encoded string of all query string arguments.
`safe` specifies characters which don't 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 = safe.encode(self.encoding)
def encode(k, v):
return '%s=%s' % ((quote(k, safe), quote(v, safe)))
else:
def encode(k, v):
return urlencode({k: v})
for k, list_ in self.lists():
output.extend(
encode(k.encode(self.encoding), str(v).encode(self.encoding))
for v in list_
)
return '&'.join(output)
class MediaType:
def __init__(self, media_type_raw_line):
full_type, self.params = parse_header(
media_type_raw_line.encode('ascii') if media_type_raw_line else b''
)
self.main_type, _, self.sub_type = full_type.partition('/')
def __str__(self):
params_str = ''.join(
'; %s=%s' % (k, v.decode('ascii'))
for k, v in self.params.items()
)
return '%s%s%s' % (
self.main_type,
('/%s' % self.sub_type) if self.sub_type else '',
params_str,
)
def __repr__(self):
return '<%s: %s>' % (self.__class__.__qualname__, self)
@property
def is_all_types(self):
return self.main_type == '*' and self.sub_type == '*'
def match(self, other):
if self.is_all_types:
return True
other = MediaType(other)
if self.main_type == other.main_type and self.sub_type in {'*', other.sub_type}:
return True
return False
# It's neither necessary nor appropriate to use
# django.utils.encoding.force_str() for parsing URLs and form inputs. Thus,
# this slightly more restricted function, used by QueryDict.
def bytes_to_text(s, encoding):
"""
Convert bytes objects to strings, using the given encoding. Illegally
encoded input characters are replaced with Unicode "unknown" codepoint
(\ufffd).
Return any non-bytes objects without change.
"""
if isinstance(s, bytes):
return str(s, encoding, 'replace')
else:
return s
def split_domain_port(host):
"""
Return a (domain, port) tuple from a given host.
Returned domain is lowercased. 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)
domain, port = bits if len(bits) == 2 else (bits[0], '')
# Remove a trailing dot (if present) from the domain.
domain = domain[:-1] if domain.endswith('.') else domain
return domain, port
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 lowercased and has
already had the port, if any, stripped off.
Return ``True`` for a valid host, ``False`` otherwise.
"""
return any(pattern == '*' or is_same_domain(host, pattern) for pattern in allowed_hosts)
def parse_accept_header(header):
return [MediaType(token) for token in header.split(',') if token.strip()]