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():
self._drop(event)
return False
if event.port not in SWITCH_PORT_LIST:
self._drop(event)
return False
if packet.dst.isMulticast():
self._packet_out(event)
return False
outport = get_the_other_port(event.port)
if outport == event.port:
mylog(
"Same port for packet from %s -> %s on %s. Drop." % (packet.src, packet.dst, outport),
dpidToStr(event.dpid),
)
self._drop(event)
return False
return True
def _handle_PacketIn(self, event):
"""
Handles packet in messages from the switch to implement above algorithm.
"""
try:
return self._handle_pkt_in_helper(event)
except Exception:
mylog("*" * 80)
mylog("Pkt_in crashed:", traceback.format_exc())
def _packet_out(self, event):
""" Floods the packet """
if event.ofp.buffer_id == -1:
mylog("Not flooding unbuffered packet on", dpidToStr(event.dpid))
return
msg = of.ofp_packet_out()
msg.actions.append(of.ofp_action_output(port=get_the_other_port(event.port)))
msg.buffer_id = event.ofp.buffer_id
msg.in_port = event.port
self.connection.send(msg)
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 _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)
