def do_flow_mod(self, event=None):
"""
If the event is not specified, then issues a flow mod with random src
and dst ports; all the other fields will match against the trigger event
saved earlier. Does not issue pkt_out.
Otherwise, does a normal flow_mod.
"""
msg = of.ofp_flow_mod()
# Normal flow-mod
if event:
msg.match = of.ofp_match.from_packet(event.parse())
msg.actions.append(of.ofp_action_output(port=get_the_other_port(event.port)))
msg.buffer_id = event.ofp.buffer_id
# Save the trigger event for later matching.
if msg.match.tp_dst == TRIGGER_PORT:
with self.lock:
self.trigger_event = event
mylog('Received trigger event. Trigger event.parse() =', pretty_dict(dictify(event.parse())))
mylog('Installed flow:', pretty_dict(dictify(msg.match)))
# Special flow-mod that generates random source/dst ports.
else:
with self.lock:
assert self.trigger_event
trigger_packet = func_cache(self.trigger_event.parse)
msg.match = of.ofp_match.from_packet(trigger_packet)
msg.actions.append(of.ofp_action_output(port=get_the_other_port(self.trigger_event.port)))
msg.match.tp_dst = random.randint(10, 65000)
msg.match.tp_src = random.randint(10, 65000)
current_time = time.time()
with self.lock:
(count, start, _) = self.flow_mod_stat
if start is None: start = current_time
self.flow_mod_stat = (count + 1, start, current_time)
msg.idle_timeout = IDLE_TIMEOUT
msg.hard_timeout = HARD_TIMEOUT
if (not USE_LIMITER) or (USE_LIMITER and self.flow_mod_limiter.to_forward_packet()):
self._of_send(msg)
self.flow_mod_queue.put((current_time, event.parse()))
def _install_rule(self, event, packet, outport, tp_dst=None, idle_timeout=IDLE_TIMEOUT):
"""
Installs a rule for any incoming packet, doing what a learning switch
should do.
"""
msg = of.ofp_flow_mod()
msg.match = of.ofp_match.from_packet(packet)
msg.idle_timeout = idle_timeout
msg.hard_timeout = HARD_TIMEOUT
msg.actions.append(of.ofp_action_output(port=outport))
with exp_control.lock:
exp_control.flow_mod_count += 1
install_bogus_rules = exp_control.install_bogus_rules
# Install a rule with a randomly generated dest mac address that no
# one will ever match against.
if install_bogus_rules:
# mac_addr_list = ['0' + str(random.randint(1,9)) for _ in range(6)]
# msg.match.dl_src = EthAddr(':'.join(mac_addr_list))
msg.match.tp_dst = random.randint(10, 65000)
msg.match.tp_src = random.randint(10, 65000)
msg.buffer_id = event.ofp.buffer_id
mylog("Installing a bogus flow.")
# Create a rule that matches with the incoming packet. When buffer ID is
# specified, the flow mod command is automatically followed by a packet-
# out command.
elif tp_dst is None:
msg.buffer_id = event.ofp.buffer_id
with exp_control.lock:
exp_control.pkt_out_count += 1
mylog("installing flow for %s.%i -> %s.%i" % (packet.src, event.port, packet.dst, outport))
# Create a rule with a specific dest port.
else:
msg.match.tp_dst = tp_dst
mylog("Installing rule for tp_dst =", tp_dst)
current_time = time.time()
with exp_control.lock:
if exp_control.flow_mod_start_time is None:
exp_control.flow_mod_start_time = current_time
exp_control.flow_mod_end_time = current_time
mylog("Flow_mod:", pretty_dict(dictify(msg)))
self.connection.send(msg)
def _is_relevant_packet(self, event, packet):
"""
Sanity check to make sure we deal with experimental traffic only.
Otherwise, returns False.
"""
mylog('zzzz inport =', event.port)
if not self.transparent:
if packet.type == packet.LLDP_TYPE or packet.dst.isBridgeFiltered():
mylog('pkt_in: Rejected packet LLDP or BridgeFiltered:', packet, repr(packet), dictify(packet))
self._drop(event)
return False
if event.port not in SWITCH_PORT_LIST:
mylog('pkt_in: Rejected packet: invalid port', packet, repr(packet), dictify(packet))
self._drop(event)
return False
if packet.dst.isMulticast():
self.do_pkt_out(event)
return False
return True
def _handle_pkt_in_helper(self, event):
packet = event.parse()
current_time = time.time()
with exp_control.lock:
flow_stat_interval = exp_control.flow_stat_interval
# Obtain flow stats once in a while.
if flow_stat_interval:
if current_time - self.last_flow_stat_time > flow_stat_interval:
self.last_flow_stat_time = current_time
self.connection.send(of.ofp_stats_request(body=of.ofp_flow_stats_request()))
# There are just packets that we don't care.
if not self._is_relevant_packet(event, packet):
mylog("pkt_in: Rejected packet:", packet, repr(packet), dictify(packet))
return
# Throttle packet-in events if need be.
if exp_control.emulate_hp_switch:
if not self.limiter_pkt_in.to_forward_packet():
return
# Count packet-in events.
with exp_control.lock:
learning_switch = exp_control.learning
exp_control.pkt_in_count += 1
if exp_control.pkt_in_start_time is None:
exp_control.pkt_in_start_time = current_time
exp_control.pkt_in_end_time = current_time
# Count number of packet-out events if the switch does not install
# rules.
if not learning_switch:
with exp_control.lock:
exp_control.pkt_out_count += 1
self._drop(event)
return
outport = get_the_other_port(event.port)
# Throttle flow-mod events and pkt-out events if need be.
if exp_control.emulate_hp_switch:
if self.limiter_flow_mod.to_forward_packet():
# flow-mod and pkt-out at 50 pps
pass
else:
# pkt-out at 50 pps, so regardless, total pkt-out at 100 pps
if self.limiter_pkt_out.to_forward_packet():
self._packet_out(event)
return
# Automatically learns new flows, as a normal learning switch would do.
if exp_control.auto_install_rules:
self._install_rule(event, packet, outport)
return
# Manually install rules in the port range.
with exp_control.lock:
tp_dst_range = exp_control.manual_install_tp_dst_range[:]
gap_ms = exp_control.manual_install_gap_ms
for tp_dst in range(*tp_dst_range):
# Keep going until the exp_control client decides to stop it.
with exp_control.lock:
manual_active = exp_control.manual_install_active
if not manual_active:
break
self._install_rule(event, packet, outport, tp_dst)
time.sleep(gap_ms / 1000.0)
