def handle_read (self):
datagram, peer = self.recvfrom (pns_datagram_size)
if peer == None:
assert None == self.log ('nop', 'debug')
return
if self.pns_joined.has_key (peer):
# in circle question ...
self.pns_joined[peer].pns_question (datagram, peer)
return
if self.pns_accepted.has_key (peer[0]):
# question from a new peer accepted at right
self.pns_accepted[peer[0]].pns_question (
datagram, peer
)
return
# out of circle
model = list (netstring.decode (datagram))
if (
len (model) != 2 or # TODO: ? 3 instead ?
model[0] == '' or
not public_names.valid_utf8 (model[0])
):
# log and drop invalid out-of-circle question ...
self.log (
'invalid-peer ip="%s"' % peer[0], 'error'
)
return
# if subscribed, joined ...
if self.pns_peer.pns_subscribed.has_key (model[0]):
self.pns_peer.pns_subscribed[
model[0]
].pns_joined (peer)
return
# not subscribed, resolve a PIRP answer >>>
if not self.pns_peers.has_key (peer):
self.pns_peer.pns_resolution.pns_udp_pirp (
model[0], peer
)
def pns_answer (self, datagram, peer):
# handle in-circle and out-of-circle answers
if datagram.startswith ('0:,'):
if not self.pns_right:
# out-of-circle
model = list (netstring.decode (datagram))
if (
len (model) == 3 and
model[1] == '' and
ip_peer.is_ip (model[2])
):
# bounce to join left or right of L
self.pns_join (model[2])
return
assert None == self.log (
datagram, 'invalid-command-answer'
)
self.pns_quit ()
return
if datagram.startswith (self.PNS_SP):
# handle protocol statement
model = list (netstring.decode (datagram))
if not (len (model) == 3 and (
model[2] == '' or ip_peer.is_ip (model[2])
)):
assert None == self.log (
datagram, 'invalid-protocol-answer'
)
self.pns_quit ()
return
if self.pns_right:
# in-circle, quitted at left!
return
# out-of-circle
if model[2]:
# accept questions from R
self.pns_peer.pns_udp.pns_accepted[
model[2]
] = self
else:
# root join
self.pns_in_circle (peer)
return
# validate answer
model = list (netstring.decode (datagram))
if (
(len (model[0]) + len (model[1]) + len (
'%d%d' % (len (model[0]), len (model[1]))
)) > 512
or not public_names.valid_utf8 (
model[0], self.pns_horizon
)
):
assert None == self.log (
datagram, 'invalid-question'
)
self.pns_quit ()
return
sp = netstring.encode (model[:2])
if (
self.pns_buffer.has_key (sp) and
not self.pns_statements.has_key (sp)
):
# buffered not stated, drop
assert None == self.log (datagram, 'drop')
return
# echo to all subscribers
model.append (self.pns_name)
self.pns_tcp_continue (model, '!')
if self.pns_statements.get (sp) == model[2]:
# answer circled, clear the statement, do not relay
del self.pns_statements [sp]
assert None == self.log (datagram, 'circle')
return
# relay right
self.pns_sendto_right (
netstring.encode (model), self.pns_right
)
if (
model[1] == '' and
self.pns_peer.pns_subscribed.has_key (model[0])
):
# protocol answer, let the named circle handle it
if self.pns_peer.self.pns_peer.pns_subscribed[
model[0]
].pns_protocol_answer (model[2]):
return
# resolve ...
self.pns_peer.pns_resolution.pns_udp_answer (model)
def pns_question (self, datagram, peer):
# handle in-circle question
if datagram.startswith ('0:,'):
# command: quit right
model = list (netstring.decode (datagram))
if len (model) == 2 and ip_peer.is_ip (model[1]):
self.pns_quit_right (model[1])
return
assert None == self.log (
datagram, 'invalid-protocol-command'
)
self.pns_quitted ()
return
if datagram.startswith (self.PNS_SP):
# protocol question for this circle
if self.pns_right:
# in-circle, forward quit and then close
self.sendto (self.PNS_SP, (
self.pns_left, 3534
))
self.pns_quitted ()
elif self.pns_left:
# ? joining
pass
else:
# ? accept
pass
return
# validate question
model = list (netstring.decode (datagram))
if (len (model) != 2 or not public_names.valid_utf8 (
model[0], self.pns_horizon
)):
assert None == self.log (
datagram, 'invalid-question'
)
# TODO: ban IP addresses that send invalid datagrams!
self.pns_quit ()
return
sp = netstring.encode (model)
if (
self.pns_buffer.get (sp) == '' and
not self.pns_statements.has_key (sp)
):
# buffered not stated, drop
assert None == self.log (datagram, 'drop')
return
# echo the statement to the PNS/TCP subscribers
model.append ('')
model.append (self.pns_name)
self.pns_tcp_continue (model, '?')
if self.pns_statements.get (sp) == '':
# question circled, clear the statement, do not relay
del self.pns_statements[sp]
assert None == self.log (datagram, 'circle')
return
# relay left
self.sendto (sp, (self.pns_left, 3534))
if (
model[1] == '' and
self.pns_peer.pns_subscribed.has_key (model[0])
):
# protocol question for a subscribed circle, bounce
# this peer's IP address as the answer.
left = self.pns_peer.pns_udp.addr[0]
self.pns_sendto_right (
'%s%d:%s' % (sp, len(left), left),
self.pns_right
)
return
# resolve ...
self.pns_peer.pns_resolution.pns_udp_question (model)
