/usr/lib/python3/dist-packages/nbxmpp/smacks.py is in python3-nbxmpp 0.6.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 | from .protocol import Acks
from .protocol import NS_STREAM_MGMT
from .transports_nb import CONNECTED, CONNECTING, DISCONNECTED, DISCONNECTING
import logging
log = logging.getLogger('nbxmpp.smacks')
class Smacks(object):
"""
This is Smacks is the Stream Management class. It takes care of requesting
and sending acks. Also, it keeps track of the unhandled outgoing stanzas.
The dispatcher has to be able to access this class to increment the
number of handled stanzas
"""
def __init__(self, con):
self.con = con # Connection object
self.out_h = 0 # Outgoing stanzas handled
self.in_h = 0 # Incoming stanzas handled
self.last_sent_in_h = 0 # Last acked stanza.
self.uqueue = [] # Unhandled stanzas queue
self.old_uqueue = [] # Unhandled stanzas queue of the last session
self.session_id = None
self.resumption = False # If server supports resume
# Max number of stanzas in queue before making a request
#be more agressive here (every message must be acked), this creates fewer message duplicates on failed resume)
self.max_queue = 0
self._owner = None
self.resuming = False
self.enabled = False # If SM is enabled
self.location = None
self.failed_resume = False # If last resuming attempt failed
self.supports_sm = False # If server supports sm
def set_owner(self, owner):
self._owner = owner
# Register handlers
owner.Dispatcher.RegisterNamespace(NS_STREAM_MGMT)
owner.Dispatcher.RegisterHandler('enabled', self._neg_response,
xmlns=NS_STREAM_MGMT)
owner.Dispatcher.RegisterHandler('r', self.send_ack,
xmlns=NS_STREAM_MGMT)
owner.Dispatcher.RegisterHandler('a', self.check_ack,
xmlns=NS_STREAM_MGMT)
owner.Dispatcher.RegisterHandler('resumed', self.check_resume,
xmlns=NS_STREAM_MGMT)
owner.Dispatcher.RegisterHandler('failed', self.error_handling,
xmlns=NS_STREAM_MGMT)
def _neg_response(self, disp, stanza):
r = stanza.getAttr('resume')
log.info("Session resumption: %s" % r)
if r == 'true' or r == 'True' or r == '1':
self.resumption = True
self.session_id = stanza.getAttr('id')
if r == 'false' or r == 'False' or r == '0':
self.negociate(False)
l = stanza.getAttr('location')
if l:
self.location = l
if self.failed_resume:
self.con._discover_server_at_connection(self.con.connection)
self.failed_resume = False
def negociate(self, resume=True):
# Every time we attempt to negociate, we must erase all previous info
# about any previous session
log.debug("Clearing smacks uqueue")
self.uqueue = []
self.in_h = 0
self.last_sent_in_h = 0
self.out_h = 0
self.session_id = None
self.enabled = True
stanza = Acks()
stanza.buildEnable(resume)
self._owner.Connection.send(stanza, now=True)
def resend_queue(self):
"""
Resends unsent stanzas when a new session is established.
This way there won't be any lost outgoing messages even on failed smacks resumes (but message duplicates are possible).
If your server supports revision 1.5 of smacks then even message duplicates are eliminated here :)
"""
if self.old_uqueue:
log.info('Session resumption failed, replaying %s stanzas anyways...' % len(self.old_uqueue))
for i in self.old_uqueue:
self._owner.Dispatcher.send(i, False) #use this send so that our stanzas actually increment out_h
self.old_uqueue = []
def resume_request(self):
if not self.session_id:
self.resuming = False
log.error('Attempted to resume without a valid session id ')
return
#save old messages in an extra "queue" to avoid race conditions and to make it possible to replay stanzas even when resuming fails
#add messages here (instead of overwriting) so that repeated connection errors don't delete unacked stanzas (uqueue should be empty in this case anyways)
self.old_uqueue += self.uqueue
self.uqueue = []
resume = Acks()
resume.buildResume(self.in_h, self.session_id)
self.last_sent_in_h = self.in_h
self._owner.Connection.send(resume, False)
def send_ack(self, disp=None, stanza=None):
ack = Acks()
ack.buildAnswer(self.in_h)
self.last_sent_in_h = self.in_h
self._owner.Connection.send(ack, False)
def send_closing_ack(self):
if self._owner.Connection.get_state() != DISCONNECTING:
log.error("Not allowed to send closing smacks ack when not disconnecting!")
return
ack = Acks()
ack.buildAnswer(self.in_h)
self.last_sent_in_h = self.in_h
self._owner.Connection.send(ack, True)
def request_ack(self):
r = Acks()
r.buildRequest()
self._owner.Connection.send(r, False)
def check_ack(self, disp, stanza):
"""
Checks if the number of stanzas sent are the same as the
number of stanzas received by the server. Pops stanzas that were
handled by the server from the queue.
"""
h = stanza.getAttr('h')
if not h:
log.error('Server did not send h attribute')
return
h = int(h)
diff = self.out_h - h
if diff < 0:
log.error('Server and client number of stanzas handled mismatch (our h: %d, server h: %d, #queue: %d)' % (self.out_h, h, len(self.uqueue)))
while (len(self.uqueue)): #don't accumulate all messages in this case (they would otherwise all be resent on the next reconnect)
self.uqueue.pop(0)
elif len(self.uqueue) < diff:
log.error('Server and client number of stanzas handled mismatch (our h: %d, server h: %d, #queue: %d)' % (self.out_h, h, len(self.uqueue)))
else:
log.debug('Got ack for outgoing stanzas (our h: %d, server h: %d, #queue: %d), removing %d messages from queue...' % (self.out_h, h, len(self.uqueue), len(self.uqueue) - diff))
while (len(self.uqueue) > diff):
self.uqueue.pop(0)
def check_resume(self, disp, stanza):
"""
Checks if the number of stanzas sent are the same as the
number of stanzas received by the server. Resends stanzas not received
by the server in the last session.
"""
log.info("Session resumption succeeded")
h = stanza.getAttr('h')
if not h:
log.error('Server did not send h attribute')
return
h = int(h)
diff = self.out_h - h
if diff < 0:
log.error('Server and client number of stanzas handled mismatch on session resumption (our h: %d, server h: %d. #queue: %d)' % (self.out_h, h, len(self.old_uqueue)))
self.old_uqueue = [] #that's weird, but we don't resend this stanzas if the server says we don't need to
elif len(self.old_uqueue) < diff:
log.error('Server and client number of stanzas handled mismatch on session resumption (our h: %d, server h: %d, #queue: %d)' % (self.out_h, h, len(self.old_uqueue)))
else:
log.info('Removing %d already acked stanzas from old outgoing queue (our h: %d, server h: %d, #queue: %d, remaining in queue: %d)' % (len(self.old_uqueue) - diff, self.out_h, h, len(self.old_uqueue), diff))
while (len(self.old_uqueue) > diff):
self.old_uqueue.pop(0)
self.enabled = True
self.resuming = True
self.con.set_oldst()
if self.old_uqueue:
log.info('Session resumed, replaying %s stanzas...' % len(self.old_uqueue))
for i in self.old_uqueue:
self._owner.Connection.send(i, False)
self.old_uqueue = []
def error_handling(self, disp, stanza):
# If the server doesn't recognize previd, forget about resuming
# Ask for service discovery, etc..
if stanza.getTag('item-not-found'):
self.resuming = False
self.enabled = False
# we need to bind a resource
self._owner.NonBlockingBind.resuming = False
self._owner._on_auth_bind(None)
self.failed_resume = True
h = stanza.getAttr('h')
log.info('Session resumption failed (item-not-found), server h: %s' % str(h))
if not h:
return
#prepare old_queue to contain only unacked stanzas for later resend (which is happening after our session is established properly)
h = int(h)
diff = self.out_h - h
if diff < 0:
log.error('Server and client number of stanzas handled mismatch on session resumption (our h: %d, server h: %d, #queue: %d)' % (self.out_h, h, len(self.old_uqueue)))
self.old_uqueue = [] #that's weird, but we don't resend this stanzas if the server says we don't need to
elif len(self.old_uqueue) < diff:
log.error('Server and client number of stanzas handled mismatch on session resumption (our h: %d, server h: %d, #queue: %d)' % (self.out_h, h, len(self.old_uqueue)))
else:
log.info('Removing %d already acked stanzas from old outgoing queue (our h: %d, server h: %d, #queue: %d, remaining in queue: %d)' % (len(self.old_uqueue) - diff, self.out_h, h, len(self.old_uqueue), diff))
while (len(self.old_uqueue) > diff):
self.old_uqueue.pop(0)
return
# Doesn't support resumption
if stanza.getTag('feature-not-implemented'):
log.info('Session resumption failed (feature-not-implemented)')
self.negociate(False)
return
if stanza.getTag('unexpected-request'):
log.error('Gajim failed to negociate Stream Management')
self.enabled = False
return
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