slixmpp/sleekxmpp/plugins/xep_0050/adhoc.py
2012-03-12 19:32:19 -07:00

611 lines
22 KiB
Python

"""
SleekXMPP: The Sleek XMPP Library
Copyright (C) 2011 Nathanael C. Fritz, Lance J.T. Stout
This file is part of SleekXMPP.
See the file LICENSE for copying permission.
"""
import logging
import time
from sleekxmpp import Iq
from sleekxmpp.exceptions import IqError
from sleekxmpp.xmlstream.handler import Callback
from sleekxmpp.xmlstream.matcher import StanzaPath
from sleekxmpp.xmlstream import register_stanza_plugin, JID
from sleekxmpp.plugins import BasePlugin
from sleekxmpp.plugins.xep_0050 import stanza
from sleekxmpp.plugins.xep_0050 import Command
from sleekxmpp.plugins.xep_0004 import Form
log = logging.getLogger(__name__)
class XEP_0050(BasePlugin):
"""
XEP-0050: Ad-Hoc Commands
XMPP's Adhoc Commands provides a generic workflow mechanism for
interacting with applications. The result is similar to menu selections
and multi-step dialogs in normal desktop applications. Clients do not
need to know in advance what commands are provided by any particular
application or agent. While adhoc commands provide similar functionality
to Jabber-RPC, adhoc commands are used primarily for human interaction.
Also see <http://xmpp.org/extensions/xep-0050.html>
Configuration Values:
threaded -- Indicates if command events should be threaded.
Defaults to True.
Events:
command_execute -- Received a command with action="execute"
command_next -- Received a command with action="next"
command_complete -- Received a command with action="complete"
command_cancel -- Received a command with action="cancel"
Attributes:
threaded -- Indicates if command events should be threaded.
Defaults to True.
commands -- A dictionary mapping JID/node pairs to command
names and handlers.
sessions -- A dictionary or equivalent backend mapping
session IDs to dictionaries containing data
relevant to a command's session.
Methods:
plugin_init -- Overrides base_plugin.plugin_init
post_init -- Overrides base_plugin.post_init
new_session -- Return a new session ID.
prep_handlers -- Placeholder. May call with a list of handlers
to prepare them for use with the session storage
backend, if needed.
set_backend -- Replace the default session storage with some
external storage mechanism, such as a database.
The provided backend wrapper must be able to
act using the same syntax as a dictionary.
add_command -- Add a command for use by external entitites.
get_commands -- Retrieve a list of commands provided by a
remote agent.
send_command -- Send a command request to a remote agent.
start_command -- Command user API: initiate a command session
continue_command -- Command user API: proceed to the next step
cancel_command -- Command user API: cancel a command
complete_command -- Command user API: finish a command
terminate_command -- Command user API: delete a command's session
"""
name = 'xep_0050'
description = 'XEP-0050: Ad-Hoc Commands'
dependencies = set(['xep_0030', 'xep_0004'])
stanza = stanza
def plugin_init(self):
"""Start the XEP-0050 plugin."""
self.threaded = self.config.get('threaded', True)
self.commands = {}
self.sessions = self.config.get('session_db', {})
self.xmpp.register_handler(
Callback("Ad-Hoc Execute",
StanzaPath('iq@type=set/command'),
self._handle_command))
register_stanza_plugin(Iq, Command)
register_stanza_plugin(Command, Form)
self.xmpp.add_event_handler('command_execute',
self._handle_command_start,
threaded=self.threaded)
self.xmpp.add_event_handler('command_next',
self._handle_command_next,
threaded=self.threaded)
self.xmpp.add_event_handler('command_cancel',
self._handle_command_cancel,
threaded=self.threaded)
self.xmpp.add_event_handler('command_complete',
self._handle_command_complete,
threaded=self.threaded)
self.xmpp['xep_0030'].add_feature(Command.namespace)
def set_backend(self, db):
"""
Replace the default session storage dictionary with
a generic, external data storage mechanism.
The replacement backend must be able to interact through
the same syntax and interfaces as a normal dictionary.
Arguments:
db -- The new session storage mechanism.
"""
self.sessions = db
def prep_handlers(self, handlers, **kwargs):
"""
Prepare a list of functions for use by the backend service.
Intended to be replaced by the backend service as needed.
Arguments:
handlers -- A list of function pointers
**kwargs -- Any additional parameters required by the backend.
"""
pass
# =================================================================
# Server side (command provider) API
def add_command(self, jid=None, node=None, name='', handler=None):
"""
Make a new command available to external entities.
Access control may be implemented in the provided handler.
Command workflow is done across a sequence of command handlers. The
first handler is given the initial Iq stanza of the request in order
to support access control. Subsequent handlers are given only the
payload items of the command. All handlers will receive the command's
session data.
Arguments:
jid -- The JID that will expose the command.
node -- The node associated with the command.
name -- A human readable name for the command.
handler -- A function that will generate the response to the
initial command request, as well as enforcing any
access control policies.
"""
if jid is None:
jid = self.xmpp.boundjid
elif not isinstance(jid, JID):
jid = JID(jid)
item_jid = jid.full
# Client disco uses only the bare JID
if self.xmpp.is_component:
jid = jid.full
else:
jid = jid.bare
self.xmpp['xep_0030'].add_identity(category='automation',
itype='command-list',
name='Ad-Hoc commands',
node=Command.namespace,
jid=jid)
self.xmpp['xep_0030'].add_item(jid=item_jid,
name=name,
node=Command.namespace,
subnode=node,
ijid=jid)
self.xmpp['xep_0030'].add_identity(category='automation',
itype='command-node',
name=name,
node=node,
jid=jid)
self.xmpp['xep_0030'].add_feature(Command.namespace, None, jid)
self.commands[(item_jid, node)] = (name, handler)
def new_session(self):
"""Return a new session ID."""
return str(time.time()) + '-' + self.xmpp.new_id()
def _handle_command(self, iq):
"""Raise command events based on the command action."""
self.xmpp.event('command_%s' % iq['command']['action'], iq)
def _handle_command_start(self, iq):
"""
Process an initial request to execute a command.
Arguments:
iq -- The command execution request.
"""
sessionid = self.new_session()
node = iq['command']['node']
key = (iq['to'].full, node)
name, handler = self.commands.get(key, ('Not found', None))
if not handler:
log.debug('Command not found: %s, %s', key, self.commands)
initial_session = {'id': sessionid,
'from': iq['from'],
'to': iq['to'],
'node': node,
'payload': None,
'interfaces': '',
'payload_classes': None,
'notes': None,
'has_next': False,
'allow_complete': False,
'allow_prev': False,
'past': [],
'next': None,
'prev': None,
'cancel': None}
session = handler(iq, initial_session)
self._process_command_response(iq, session)
def _handle_command_next(self, iq):
"""
Process a request for the next step in the workflow
for a command with multiple steps.
Arguments:
iq -- The command continuation request.
"""
sessionid = iq['command']['sessionid']
session = self.sessions[sessionid]
handler = session['next']
interfaces = session['interfaces']
results = []
for stanza in iq['command']['substanzas']:
if stanza.plugin_attrib in interfaces:
results.append(stanza)
if len(results) == 1:
results = results[0]
session = handler(results, session)
self._process_command_response(iq, session)
def _process_command_response(self, iq, session):
"""
Generate a command reply stanza based on the
provided session data.
Arguments:
iq -- The command request stanza.
session -- A dictionary of relevant session data.
"""
sessionid = session['id']
payload = session['payload']
if not isinstance(payload, list):
payload = [payload]
session['interfaces'] = [item.plugin_attrib for item in payload]
session['payload_classes'] = [item.__class__ for item in payload]
self.sessions[sessionid] = session
for item in payload:
register_stanza_plugin(Command, item.__class__, iterable=True)
iq.reply()
iq['command']['node'] = session['node']
iq['command']['sessionid'] = session['id']
if session['next'] is None:
iq['command']['actions'] = []
iq['command']['status'] = 'completed'
elif session['has_next']:
actions = ['next']
if session['allow_complete']:
actions.append('complete')
if session['allow_prev']:
actions.append('prev')
iq['command']['actions'] = actions
iq['command']['status'] = 'executing'
else:
iq['command']['actions'] = ['complete']
iq['command']['status'] = 'executing'
iq['command']['notes'] = session['notes']
for item in payload:
iq['command'].append(item)
iq.send()
def _handle_command_cancel(self, iq):
"""
Process a request to cancel a command's execution.
Arguments:
iq -- The command cancellation request.
"""
node = iq['command']['node']
sessionid = iq['command']['sessionid']
session = self.sessions[sessionid]
handler = session['cancel']
if handler:
handler(iq, session)
try:
del self.sessions[sessionid]
except:
pass
iq.reply()
iq['command']['node'] = node
iq['command']['sessionid'] = sessionid
iq['command']['status'] = 'canceled'
iq['command']['notes'] = session['notes']
iq.send()
def _handle_command_complete(self, iq):
"""
Process a request to finish the execution of command
and terminate the workflow.
All data related to the command session will be removed.
Arguments:
iq -- The command completion request.
"""
node = iq['command']['node']
sessionid = iq['command']['sessionid']
session = self.sessions[sessionid]
handler = session['next']
interfaces = session['interfaces']
results = []
for stanza in iq['command']['substanzas']:
if stanza.plugin_attrib in interfaces:
results.append(stanza)
if len(results) == 1:
results = results[0]
if handler:
handler(results, session)
iq.reply()
iq['command']['node'] = node
iq['command']['sessionid'] = sessionid
iq['command']['actions'] = []
iq['command']['status'] = 'completed'
iq['command']['notes'] = session['notes']
iq.send()
del self.sessions[sessionid]
# =================================================================
# Client side (command user) API
def get_commands(self, jid, **kwargs):
"""
Return a list of commands provided by a given JID.
Arguments:
jid -- The JID to query for commands.
local -- If true, then the query is for a JID/node
combination handled by this Sleek instance and
no stanzas need to be sent.
Otherwise, a disco stanza must be sent to the
remove JID to retrieve the items.
ifrom -- Specifiy the sender's JID.
block -- If true, block and wait for the stanzas' reply.
timeout -- The time in seconds to block while waiting for
a reply. If None, then wait indefinitely.
callback -- Optional callback to execute when a reply is
received instead of blocking and waiting for
the reply.
iterator -- If True, return a result set iterator using
the XEP-0059 plugin, if the plugin is loaded.
Otherwise the parameter is ignored.
"""
return self.xmpp['xep_0030'].get_items(jid=jid,
node=Command.namespace,
**kwargs)
def send_command(self, jid, node, ifrom=None, action='execute',
payload=None, sessionid=None, flow=False, **kwargs):
"""
Create and send a command stanza, without using the provided
workflow management APIs.
Arguments:
jid -- The JID to send the command request or result.
node -- The node for the command.
ifrom -- Specify the sender's JID.
action -- May be one of: execute, cancel, complete,
or cancel.
payload -- Either a list of payload items, or a single
payload item such as a data form.
sessionid -- The current session's ID value.
flow -- If True, process the Iq result using the
command workflow methods contained in the
session instead of returning the response
stanza itself. Defaults to False.
block -- Specify if the send call will block until a
response is received, or a timeout occurs.
Defaults to True.
timeout -- The length of time (in seconds) to wait for a
response before exiting the send call
if blocking is used. Defaults to
sleekxmpp.xmlstream.RESPONSE_TIMEOUT
callback -- Optional reference to a stream handler
function. Will be executed when a reply
stanza is received if flow=False.
"""
iq = self.xmpp.Iq()
iq['type'] = 'set'
iq['to'] = jid
iq['from'] = ifrom
iq['command']['node'] = node
iq['command']['action'] = action
if sessionid is not None:
iq['command']['sessionid'] = sessionid
if payload is not None:
if not isinstance(payload, list):
payload = [payload]
for item in payload:
iq['command'].append(item)
if not flow:
return iq.send(**kwargs)
else:
if kwargs.get('block', True):
try:
result = iq.send(**kwargs)
except IqError as err:
result = err.iq
self._handle_command_result(result)
else:
iq.send(block=False, callback=self._handle_command_result)
def start_command(self, jid, node, session, ifrom=None, block=False):
"""
Initiate executing a command provided by a remote agent.
The default workflow provided is non-blocking, but a blocking
version may be used with block=True.
The provided session dictionary should contain:
next -- A handler for processing the command result.
error -- A handler for processing any error stanzas
generated by the request.
Arguments:
jid -- The JID to send the command request.
node -- The node for the desired command.
session -- A dictionary of relevant session data.
ifrom -- Optionally specify the sender's JID.
block -- If True, block execution until a result
is received. Defaults to False.
"""
session['jid'] = jid
session['node'] = node
session['timestamp'] = time.time()
session['payload'] = None
session['block'] = block
iq = self.xmpp.Iq()
iq['type'] = 'set'
iq['to'] = jid
iq['from'] = ifrom
session['from'] = ifrom
iq['command']['node'] = node
iq['command']['action'] = 'execute'
sessionid = 'client:pending_' + iq['id']
session['id'] = sessionid
self.sessions[sessionid] = session
if session['block']:
try:
result = iq.send(block=True)
except IqError as err:
result = err.iq
self._handle_command_result(result)
else:
iq.send(block=False, callback=self._handle_command_result)
def continue_command(self, session):
"""
Execute the next action of the command.
Arguments:
session -- All stored data relevant to the current
command session.
"""
sessionid = 'client:' + session['id']
self.sessions[sessionid] = session
self.send_command(session['jid'],
session['node'],
ifrom=session.get('from', None),
action='next',
payload=session.get('payload', None),
sessionid=session['id'],
flow=True,
block=session['block'])
def cancel_command(self, session):
"""
Cancel the execution of a command.
Arguments:
session -- All stored data relevant to the current
command session.
"""
sessionid = 'client:' + session['id']
self.sessions[sessionid] = session
self.send_command(session['jid'],
session['node'],
ifrom=session.get('from', None),
action='cancel',
payload=session.get('payload', None),
sessionid=session['id'],
flow=True,
block=session['block'])
def complete_command(self, session):
"""
Finish the execution of a command workflow.
Arguments:
session -- All stored data relevant to the current
command session.
"""
sessionid = 'client:' + session['id']
self.sessions[sessionid] = session
self.send_command(session['jid'],
session['node'],
ifrom=session.get('from', None),
action='complete',
payload=session.get('payload', None),
sessionid=session['id'],
flow=True,
block=session['block'])
def terminate_command(self, session):
"""
Delete a command's session after a command has completed
or an error has occured.
Arguments:
session -- All stored data relevant to the current
command session.
"""
try:
del self.sessions[session['id']]
except:
pass
def _handle_command_result(self, iq):
"""
Process the results of a command request.
Will execute the 'next' handler stored in the session
data, or the 'error' handler depending on the Iq's type.
Arguments:
iq -- The command response.
"""
sessionid = 'client:' + iq['command']['sessionid']
pending = False
if sessionid not in self.sessions:
pending = True
pendingid = 'client:pending_' + iq['id']
if pendingid not in self.sessions:
return
sessionid = pendingid
session = self.sessions[sessionid]
sessionid = 'client:' + iq['command']['sessionid']
session['id'] = iq['command']['sessionid']
self.sessions[sessionid] = session
if pending:
del self.sessions[pendingid]
handler_type = 'next'
if iq['type'] == 'error':
handler_type = 'error'
handler = session.get(handler_type, None)
if handler:
handler(iq, session)
elif iq['type'] == 'error':
self.terminate_command(session)
if iq['command']['status'] == 'completed':
self.terminate_command(session)