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# -*- test-case-name: twisted.words.test.test_jabbererror -*-
#
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
XMPP Error support.
"""
import copy
from typing import Optional
from twisted.words.xish import domish
NS_XML = "http://www.w3.org/XML/1998/namespace"
NS_XMPP_STREAMS = "urn:ietf:params:xml:ns:xmpp-streams"
NS_XMPP_STANZAS = "urn:ietf:params:xml:ns:xmpp-stanzas"
STANZA_CONDITIONS = {
"bad-request": {"code": "400", "type": "modify"},
"conflict": {"code": "409", "type": "cancel"},
"feature-not-implemented": {"code": "501", "type": "cancel"},
"forbidden": {"code": "403", "type": "auth"},
"gone": {"code": "302", "type": "modify"},
"internal-server-error": {"code": "500", "type": "wait"},
"item-not-found": {"code": "404", "type": "cancel"},
"jid-malformed": {"code": "400", "type": "modify"},
"not-acceptable": {"code": "406", "type": "modify"},
"not-allowed": {"code": "405", "type": "cancel"},
"not-authorized": {"code": "401", "type": "auth"},
"payment-required": {"code": "402", "type": "auth"},
"recipient-unavailable": {"code": "404", "type": "wait"},
"redirect": {"code": "302", "type": "modify"},
"registration-required": {"code": "407", "type": "auth"},
"remote-server-not-found": {"code": "404", "type": "cancel"},
"remote-server-timeout": {"code": "504", "type": "wait"},
"resource-constraint": {"code": "500", "type": "wait"},
"service-unavailable": {"code": "503", "type": "cancel"},
"subscription-required": {"code": "407", "type": "auth"},
"undefined-condition": {"code": "500", "type": None},
"unexpected-request": {"code": "400", "type": "wait"},
}
CODES_TO_CONDITIONS = {
"302": ("gone", "modify"),
"400": ("bad-request", "modify"),
"401": ("not-authorized", "auth"),
"402": ("payment-required", "auth"),
"403": ("forbidden", "auth"),
"404": ("item-not-found", "cancel"),
"405": ("not-allowed", "cancel"),
"406": ("not-acceptable", "modify"),
"407": ("registration-required", "auth"),
"408": ("remote-server-timeout", "wait"),
"409": ("conflict", "cancel"),
"500": ("internal-server-error", "wait"),
"501": ("feature-not-implemented", "cancel"),
"502": ("service-unavailable", "wait"),
"503": ("service-unavailable", "cancel"),
"504": ("remote-server-timeout", "wait"),
"510": ("service-unavailable", "cancel"),
}
class BaseError(Exception):
"""
Base class for XMPP error exceptions.
@cvar namespace: The namespace of the C{error} element generated by
C{getElement}.
@type namespace: C{str}
@ivar condition: The error condition. The valid values are defined by
subclasses of L{BaseError}.
@type contition: C{str}
@ivar text: Optional text message to supplement the condition or application
specific condition.
@type text: C{unicode}
@ivar textLang: Identifier of the language used for the message in C{text}.
Values are as described in RFC 3066.
@type textLang: C{str}
@ivar appCondition: Application specific condition element, supplementing
the error condition in C{condition}.
@type appCondition: object providing L{domish.IElement}.
"""
namespace: Optional[str] = None
def __init__(self, condition, text=None, textLang=None, appCondition=None):
Exception.__init__(self)
self.condition = condition
self.text = text
self.textLang = textLang
self.appCondition = appCondition
def __str__(self) -> str:
message = "{} with condition {!r}".format(
self.__class__.__name__, self.condition
)
if self.text:
message += ": " + self.text
return message
def getElement(self):
"""
Get XML representation from self.
The method creates an L{domish} representation of the
error data contained in this exception.
@rtype: L{domish.Element}
"""
error = domish.Element((None, "error"))
error.addElement((self.namespace, self.condition))
if self.text:
text = error.addElement((self.namespace, "text"), content=self.text)
if self.textLang:
text[(NS_XML, "lang")] = self.textLang
if self.appCondition:
error.addChild(self.appCondition)
return error
class StreamError(BaseError):
"""
Stream Error exception.
Refer to RFC 3920, section 4.7.3, for the allowed values for C{condition}.
"""
namespace = NS_XMPP_STREAMS
def getElement(self):
"""
Get XML representation from self.
Overrides the base L{BaseError.getElement} to make sure the returned
element is in the XML Stream namespace.
@rtype: L{domish.Element}
"""
from twisted.words.protocols.jabber.xmlstream import NS_STREAMS
error = BaseError.getElement(self)
error.uri = NS_STREAMS
return error
class StanzaError(BaseError):
"""
Stanza Error exception.
Refer to RFC 3920, section 9.3, for the allowed values for C{condition} and
C{type}.
@ivar type: The stanza error type. Gives a suggestion to the recipient
of the error on how to proceed.
@type type: C{str}
@ivar code: A numeric identifier for the error condition for backwards
compatibility with pre-XMPP Jabber implementations.
"""
namespace = NS_XMPP_STANZAS
def __init__(
self, condition, type=None, text=None, textLang=None, appCondition=None
):
BaseError.__init__(self, condition, text, textLang, appCondition)
if type is None:
try:
type = STANZA_CONDITIONS[condition]["type"]
except KeyError:
pass
self.type = type
try:
self.code = STANZA_CONDITIONS[condition]["code"]
except KeyError:
self.code = None
self.children = []
self.iq = None
def getElement(self):
"""
Get XML representation from self.
Overrides the base L{BaseError.getElement} to make sure the returned
element has a C{type} attribute and optionally a legacy C{code}
attribute.
@rtype: L{domish.Element}
"""
error = BaseError.getElement(self)
error["type"] = self.type
if self.code:
error["code"] = self.code
return error
def toResponse(self, stanza):
"""
Construct error response stanza.
The C{stanza} is transformed into an error response stanza by
swapping the C{to} and C{from} addresses and inserting an error
element.
@note: This creates a shallow copy of the list of child elements of the
stanza. The child elements themselves are not copied themselves,
and references to their parent element will still point to the
original stanza element.
The serialization of an element does not use the reference to
its parent, so the typical use case of immediately sending out
the constructed error response is not affected.
@param stanza: the stanza to respond to
@type stanza: L{domish.Element}
"""
from twisted.words.protocols.jabber.xmlstream import toResponse
response = toResponse(stanza, stanzaType="error")
response.children = copy.copy(stanza.children)
response.addChild(self.getElement())
return response
def _parseError(error, errorNamespace):
"""
Parses an error element.
@param error: The error element to be parsed
@type error: L{domish.Element}
@param errorNamespace: The namespace of the elements that hold the error
condition and text.
@type errorNamespace: C{str}
@return: Dictionary with extracted error information. If present, keys
C{condition}, C{text}, C{textLang} have a string value,
and C{appCondition} has an L{domish.Element} value.
@rtype: C{dict}
"""
condition = None
text = None
textLang = None
appCondition = None
for element in error.elements():
if element.uri == errorNamespace:
if element.name == "text":
text = str(element)
textLang = element.getAttribute((NS_XML, "lang"))
else:
condition = element.name
else:
appCondition = element
return {
"condition": condition,
"text": text,
"textLang": textLang,
"appCondition": appCondition,
}
def exceptionFromStreamError(element):
"""
Build an exception object from a stream error.
@param element: the stream error
@type element: L{domish.Element}
@return: the generated exception object
@rtype: L{StreamError}
"""
error = _parseError(element, NS_XMPP_STREAMS)
exception = StreamError(
error["condition"], error["text"], error["textLang"], error["appCondition"]
)
return exception
def exceptionFromStanza(stanza):
"""
Build an exception object from an error stanza.
@param stanza: the error stanza
@type stanza: L{domish.Element}
@return: the generated exception object
@rtype: L{StanzaError}
"""
children = []
condition = text = textLang = appCondition = type = code = None
for element in stanza.elements():
if element.name == "error" and element.uri == stanza.uri:
code = element.getAttribute("code")
type = element.getAttribute("type")
error = _parseError(element, NS_XMPP_STANZAS)
condition = error["condition"]
text = error["text"]
textLang = error["textLang"]
appCondition = error["appCondition"]
if not condition and code:
condition, type = CODES_TO_CONDITIONS[code]
text = str(stanza.error)
else:
children.append(element)
if condition is None:
# TODO: raise exception instead?
return StanzaError(None)
exception = StanzaError(condition, type, text, textLang, appCondition)
exception.children = children
exception.stanza = stanza
return exception
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