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Diffstat (limited to 'cherrypy/lib/httputil.py')
| -rwxr-xr-x | cherrypy/lib/httputil.py | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/cherrypy/lib/httputil.py b/cherrypy/lib/httputil.py new file mode 100755 index 0000000..e005875 --- /dev/null +++ b/cherrypy/lib/httputil.py @@ -0,0 +1,469 @@ +"""HTTP library functions. + +This module contains functions for building an HTTP application +framework: any one, not just one whose name starts with "Ch". ;) If you +reference any modules from some popular framework inside *this* module, +FuManChu will personally hang you up by your thumbs and submit you +to a public caning. +""" + +from binascii import b2a_base64 +from cherrypy._cpcompat import BaseHTTPRequestHandler, HTTPDate, ntob, ntou, reversed, sorted +from cherrypy._cpcompat import basestring, iteritems, unicodestr, unquote_qs +response_codes = BaseHTTPRequestHandler.responses.copy() + +# From http://www.cherrypy.org/ticket/361 +response_codes[500] = ('Internal Server Error', + 'The server encountered an unexpected condition ' + 'which prevented it from fulfilling the request.') +response_codes[503] = ('Service Unavailable', + 'The server is currently unable to handle the ' + 'request due to a temporary overloading or ' + 'maintenance of the server.') + +import re +import urllib + + + +def urljoin(*atoms): + """Return the given path \*atoms, joined into a single URL. + + This will correctly join a SCRIPT_NAME and PATH_INFO into the + original URL, even if either atom is blank. + """ + url = "/".join([x for x in atoms if x]) + while "//" in url: + url = url.replace("//", "/") + # Special-case the final url of "", and return "/" instead. + return url or "/" + +def protocol_from_http(protocol_str): + """Return a protocol tuple from the given 'HTTP/x.y' string.""" + return int(protocol_str[5]), int(protocol_str[7]) + +def get_ranges(headervalue, content_length): + """Return a list of (start, stop) indices from a Range header, or None. + + Each (start, stop) tuple will be composed of two ints, which are suitable + for use in a slicing operation. That is, the header "Range: bytes=3-6", + if applied against a Python string, is requesting resource[3:7]. This + function will return the list [(3, 7)]. + + If this function returns an empty list, you should return HTTP 416. + """ + + if not headervalue: + return None + + result = [] + bytesunit, byteranges = headervalue.split("=", 1) + for brange in byteranges.split(","): + start, stop = [x.strip() for x in brange.split("-", 1)] + if start: + if not stop: + stop = content_length - 1 + start, stop = int(start), int(stop) + if start >= content_length: + # From rfc 2616 sec 14.16: + # "If the server receives a request (other than one + # including an If-Range request-header field) with an + # unsatisfiable Range request-header field (that is, + # all of whose byte-range-spec values have a first-byte-pos + # value greater than the current length of the selected + # resource), it SHOULD return a response code of 416 + # (Requested range not satisfiable)." + continue + if stop < start: + # From rfc 2616 sec 14.16: + # "If the server ignores a byte-range-spec because it + # is syntactically invalid, the server SHOULD treat + # the request as if the invalid Range header field + # did not exist. (Normally, this means return a 200 + # response containing the full entity)." + return None + result.append((start, stop + 1)) + else: + if not stop: + # See rfc quote above. + return None + # Negative subscript (last N bytes) + result.append((content_length - int(stop), content_length)) + + return result + + +class HeaderElement(object): + """An element (with parameters) from an HTTP header's element list.""" + + def __init__(self, value, params=None): + self.value = value + if params is None: + params = {} + self.params = params + + def __cmp__(self, other): + return cmp(self.value, other.value) + + def __str__(self): + p = [";%s=%s" % (k, v) for k, v in iteritems(self.params)] + return "%s%s" % (self.value, "".join(p)) + + def __unicode__(self): + return ntou(self.__str__()) + + def parse(elementstr): + """Transform 'token;key=val' to ('token', {'key': 'val'}).""" + # Split the element into a value and parameters. The 'value' may + # be of the form, "token=token", but we don't split that here. + atoms = [x.strip() for x in elementstr.split(";") if x.strip()] + if not atoms: + initial_value = '' + else: + initial_value = atoms.pop(0).strip() + params = {} + for atom in atoms: + atom = [x.strip() for x in atom.split("=", 1) if x.strip()] + key = atom.pop(0) + if atom: + val = atom[0] + else: + val = "" + params[key] = val + return initial_value, params + parse = staticmethod(parse) + + def from_str(cls, elementstr): + """Construct an instance from a string of the form 'token;key=val'.""" + ival, params = cls.parse(elementstr) + return cls(ival, params) + from_str = classmethod(from_str) + + +q_separator = re.compile(r'; *q *=') + +class AcceptElement(HeaderElement): + """An element (with parameters) from an Accept* header's element list. + + AcceptElement objects are comparable; the more-preferred object will be + "less than" the less-preferred object. They are also therefore sortable; + if you sort a list of AcceptElement objects, they will be listed in + priority order; the most preferred value will be first. Yes, it should + have been the other way around, but it's too late to fix now. + """ + + def from_str(cls, elementstr): + qvalue = None + # The first "q" parameter (if any) separates the initial + # media-range parameter(s) (if any) from the accept-params. + atoms = q_separator.split(elementstr, 1) + media_range = atoms.pop(0).strip() + if atoms: + # The qvalue for an Accept header can have extensions. The other + # headers cannot, but it's easier to parse them as if they did. + qvalue = HeaderElement.from_str(atoms[0].strip()) + + media_type, params = cls.parse(media_range) + if qvalue is not None: + params["q"] = qvalue + return cls(media_type, params) + from_str = classmethod(from_str) + + def qvalue(self): + val = self.params.get("q", "1") + if isinstance(val, HeaderElement): + val = val.value + return float(val) + qvalue = property(qvalue, doc="The qvalue, or priority, of this value.") + + def __cmp__(self, other): + diff = cmp(self.qvalue, other.qvalue) + if diff == 0: + diff = cmp(str(self), str(other)) + return diff + + +def header_elements(fieldname, fieldvalue): + """Return a sorted HeaderElement list from a comma-separated header string.""" + if not fieldvalue: + return [] + + result = [] + for element in fieldvalue.split(","): + if fieldname.startswith("Accept") or fieldname == 'TE': + hv = AcceptElement.from_str(element) + else: + hv = HeaderElement.from_str(element) + result.append(hv) + + return list(reversed(sorted(result))) + +def decode_TEXT(value): + r"""Decode :rfc:`2047` TEXT (e.g. "=?utf-8?q?f=C3=BCr?=" -> u"f\xfcr").""" + from email.Header import decode_header + atoms = decode_header(value) + decodedvalue = "" + for atom, charset in atoms: + if charset is not None: + atom = atom.decode(charset) + decodedvalue += atom + return decodedvalue + +def valid_status(status): + """Return legal HTTP status Code, Reason-phrase and Message. + + The status arg must be an int, or a str that begins with an int. + + If status is an int, or a str and no reason-phrase is supplied, + a default reason-phrase will be provided. + """ + + if not status: + status = 200 + + status = str(status) + parts = status.split(" ", 1) + if len(parts) == 1: + # No reason supplied. + code, = parts + reason = None + else: + code, reason = parts + reason = reason.strip() + + try: + code = int(code) + except ValueError: + raise ValueError("Illegal response status from server " + "(%s is non-numeric)." % repr(code)) + + if code < 100 or code > 599: + raise ValueError("Illegal response status from server " + "(%s is out of range)." % repr(code)) + + if code not in response_codes: + # code is unknown but not illegal + default_reason, message = "", "" + else: + default_reason, message = response_codes[code] + + if reason is None: + reason = default_reason + + return code, reason, message + + +def _parse_qs(qs, keep_blank_values=0, strict_parsing=0, encoding='utf-8'): + """Parse a query given as a string argument. + + Arguments: + + qs: URL-encoded query string to be parsed + + keep_blank_values: flag indicating whether blank values in + URL encoded queries should be treated as blank strings. A + true value indicates that blanks should be retained as blank + strings. The default false value indicates that blank values + are to be ignored and treated as if they were not included. + + strict_parsing: flag indicating what to do with parsing errors. If + false (the default), errors are silently ignored. If true, + errors raise a ValueError exception. + + Returns a dict, as G-d intended. + """ + pairs = [s2 for s1 in qs.split('&') for s2 in s1.split(';')] + d = {} + for name_value in pairs: + if not name_value and not strict_parsing: + continue + nv = name_value.split('=', 1) + if len(nv) != 2: + if strict_parsing: + raise ValueError("bad query field: %r" % (name_value,)) + # Handle case of a control-name with no equal sign + if keep_blank_values: + nv.append('') + else: + continue + if len(nv[1]) or keep_blank_values: + name = unquote_qs(nv[0], encoding) + value = unquote_qs(nv[1], encoding) + if name in d: + if not isinstance(d[name], list): + d[name] = [d[name]] + d[name].append(value) + else: + d[name] = value + return d + + +image_map_pattern = re.compile(r"[0-9]+,[0-9]+") + +def parse_query_string(query_string, keep_blank_values=True, encoding='utf-8'): + """Build a params dictionary from a query_string. + + Duplicate key/value pairs in the provided query_string will be + returned as {'key': [val1, val2, ...]}. Single key/values will + be returned as strings: {'key': 'value'}. + """ + if image_map_pattern.match(query_string): + # Server-side image map. Map the coords to 'x' and 'y' + # (like CGI::Request does). + pm = query_string.split(",") + pm = {'x': int(pm[0]), 'y': int(pm[1])} + else: + pm = _parse_qs(query_string, keep_blank_values, encoding=encoding) + return pm + + +class CaseInsensitiveDict(dict): + """A case-insensitive dict subclass. + + Each key is changed on entry to str(key).title(). + """ + + def __getitem__(self, key): + return dict.__getitem__(self, str(key).title()) + + def __setitem__(self, key, value): + dict.__setitem__(self, str(key).title(), value) + + def __delitem__(self, key): + dict.__delitem__(self, str(key).title()) + + def __contains__(self, key): + return dict.__contains__(self, str(key).title()) + + def get(self, key, default=None): + return dict.get(self, str(key).title(), default) + + def has_key(self, key): + return dict.has_key(self, str(key).title()) + + def update(self, E): + for k in E.keys(): + self[str(k).title()] = E[k] + + def fromkeys(cls, seq, value=None): + newdict = cls() + for k in seq: + newdict[str(k).title()] = value + return newdict + fromkeys = classmethod(fromkeys) + + def setdefault(self, key, x=None): + key = str(key).title() + try: + return self[key] + except KeyError: + self[key] = x + return x + + def pop(self, key, default): + return dict.pop(self, str(key).title(), default) + + +# TEXT = <any OCTET except CTLs, but including LWS> +# +# A CRLF is allowed in the definition of TEXT only as part of a header +# field continuation. It is expected that the folding LWS will be +# replaced with a single SP before interpretation of the TEXT value." +header_translate_table = ''.join([chr(i) for i in xrange(256)]) +header_translate_deletechars = ''.join([chr(i) for i in xrange(32)]) + chr(127) + + +class HeaderMap(CaseInsensitiveDict): + """A dict subclass for HTTP request and response headers. + + Each key is changed on entry to str(key).title(). This allows headers + to be case-insensitive and avoid duplicates. + + Values are header values (decoded according to :rfc:`2047` if necessary). + """ + + protocol=(1, 1) + encodings = ["ISO-8859-1"] + + # Someday, when http-bis is done, this will probably get dropped + # since few servers, clients, or intermediaries do it. But until then, + # we're going to obey the spec as is. + # "Words of *TEXT MAY contain characters from character sets other than + # ISO-8859-1 only when encoded according to the rules of RFC 2047." + use_rfc_2047 = True + + def elements(self, key): + """Return a sorted list of HeaderElements for the given header.""" + key = str(key).title() + value = self.get(key) + return header_elements(key, value) + + def values(self, key): + """Return a sorted list of HeaderElement.value for the given header.""" + return [e.value for e in self.elements(key)] + + def output(self): + """Transform self into a list of (name, value) tuples.""" + header_list = [] + for k, v in self.items(): + if isinstance(k, unicodestr): + k = self.encode(k) + + if not isinstance(v, basestring): + v = str(v) + + if isinstance(v, unicodestr): + v = self.encode(v) + + # See header_translate_* constants above. + # Replace only if you really know what you're doing. + k = k.translate(header_translate_table, header_translate_deletechars) + v = v.translate(header_translate_table, header_translate_deletechars) + + header_list.append((k, v)) + return header_list + + def encode(self, v): + """Return the given header name or value, encoded for HTTP output.""" + for enc in self.encodings: + try: + return v.encode(enc) + except UnicodeEncodeError: + continue + + if self.protocol == (1, 1) and self.use_rfc_2047: + # Encode RFC-2047 TEXT + # (e.g. u"\u8200" -> "=?utf-8?b?6IiA?="). + # We do our own here instead of using the email module + # because we never want to fold lines--folding has + # been deprecated by the HTTP working group. + v = b2a_base64(v.encode('utf-8')) + return (ntob('=?utf-8?b?') + v.strip(ntob('\n')) + ntob('?=')) + + raise ValueError("Could not encode header part %r using " + "any of the encodings %r." % + (v, self.encodings)) + + +class Host(object): + """An internet address. + + name + Should be the client's host name. If not available (because no DNS + lookup is performed), the IP address should be used instead. + + """ + + ip = "0.0.0.0" + port = 80 + name = "unknown.tld" + + def __init__(self, ip, port, name=None): + self.ip = ip + self.port = port + if name is None: + name = ip + self.name = name + + def __repr__(self): + return "httputil.Host(%r, %r, %r)" % (self.ip, self.port, self.name) |