def add_tunnel(self, _bss_, _apn_):
"""
This method is called when new APN is discovered to connect it with all BSS stations via MAC Tunnels
Keyword arguments:
_bss_ -- usualy string representing BSS node in topology
_apn_ -- object of apn class representing APN in topology
"""
self.bss = _bss_
self.apn = _apn_
self.tid_out = get_tid()
self.tid_in = get_tid()
##Attempt to find path between the two nodes
##If no path is found, tunnel is added to INACTIVE_TUNNELS and is attempted to recreate next time
##when new link between forwarders is up
try:
self.path_out = topo.get_tunnel(self.bss, self.apn.name)
self.path_in = topo.get_tunnel(self.apn.name, self.bss)
except nx.NetworkXNoPath:
LOG.warning("Warning: Couldn't find path, network might not be converged yet. Retrying when next forwarder joins network.")
INACTIVE_TUNNELS.append(tunnel(self.bss,self.apn, self.tid_out, self.tid_in))
return
##Set forwarding rules for all but last forwarder on the way OUT
##On first forwarder on the way OUT these rules are placed into table MAC_TUNNEL_TABLE while on 'dumb' forwarders it goes to 0
dp = dpset.get(self.path_out[0].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=self.tid_out)
actions = [parser.OFPActionOutput(self.path_out[0].port_out)]
self.add_flow(dp, 300, match, actions, MAC_TUNNEL_TABLE)
##Rules for all 'dumb' forwardes on the way OUT
for node in self.path_out[1:-1]:
dp = dpset.get(node.dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=self.tid_out)
actions = [parser.OFPActionOutput(node.port_out)]
self.add_flow(dp, 300, match, actions, 0)
##Last forwarder on the way OUT needs to set eth_dst to eth_addr of APN otherwise it wont be processed
dp = dpset.get(self.path_out[-1].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=self.tid_out)
actions = [ parser.OFPActionSetField(eth_dst=self.apn.eth_addr), parser.OFPActionOutput(self.path_out[-1].port_out)]
self.add_flow(dp, 300, match, actions, 0)
##Here comes tunnel for way IN
##On first forwarder on the way IN these rules are placed into table MAC_TUNNEL_TABLE while on 'dumb' forwarders it goes to 0
dp = dpset.get(self.path_in[0].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=self.tid_in)
actions = [parser.OFPActionOutput(self.path_in[0].port_out)]
self.add_flow(dp, 300, match, actions, MAC_TUNNEL_TABLE)
##Rules for 'dumb' forwarders
for node in self.path_in[1:-1]:
dp = dpset.get(node.dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=self.tid_in)
actions = [parser.OFPActionOutput(node.port_out)]
self.add_flow(dp, 300, match, actions, 0)
##Last forwarder on the way IN sends packet to table #4 where it's matched based on active PDP CNTs
dp = dpset.get(self.path_in[-1].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=self.tid_in)
inst = [ parser.OFPInstructionGotoTable(OF_GPRS_TABLE_IN) ]
req = parser.OFPFlowMod(datapath=dp, priority=500, match=match, instructions=inst, table_id=0)
dp.send_msg(req)
ACTIVE_TUNNELS.append(tunnel(self.bss,self.apn, self.tid_out, self.tid_in, self.path_out, self.path_in))
LOG.debug('Tunnel between '+str(self.bss)+' and '+str(self.apn.name) + ' was set up.')
def retry_tunnels(self):
"""
This is very similar to add_tunnel method...I'm too tired to make and call
modified version of add_tunnel...
"""
##Search inactive tunels to see if any path can be resolved now, if yes...do the same thing as add_tunnel()
for inact_tunnel in INACTIVE_TUNNELS:
try:
self.path_out = topo.get_tunnel(inact_tunnel.bss, inact_tunnel.apn.name)
self.path_in = topo.get_tunnel(inact_tunnel.apn.name, inact_tunnel.bss)
except nx.NetworkXNoPath:
LOG.warning("Warning: Couldn't find path, network might not be converged yet. Retrying when next forwarder joins network...again...")
return
INACTIVE_TUNNELS.remove(inact_tunnel)
##Set forwarding rules for all but last forwarder on the way OUT
##On first forwarder on the way OUT these rules are placed into table MAC_TUNNEL_TABLE while on 'dumb' forwarders it goes to 0
dp = dpset.get(self.path_out[0].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=inact_tunnel.tid_out)
actions = [parser.OFPActionOutput(self.path_out[0].port_out)]
self.add_flow(dp, 300, match, actions, MAC_TUNNEL_TABLE)
##Rules for all 'dumb' forwardes on the way OUT
for node in self.path_out[1:-1]:
dp = dpset.get(node.dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=inact_tunnel.tid_out)
actions = [parser.OFPActionOutput(node.port_out)]
self.add_flow(dp, 300, match, actions, 0)
##Last forwarder on the way OUT needs to set eth_dst to eth_addr of APN otherwise it wont be processed
dp = dpset.get(self.path_out[-1].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=inact_tunnel.tid_out)
actions = [ parser.OFPActionSetField(eth_dst=inact_tunnel.apn.eth_addr), parser.OFPActionOutput(self.path_out[-1].port_out)]
self.add_flow(dp, 300, match, actions, 0)
##Here comes tunnel for the way IN
##On first forwarder on the way IN these rules are placed into table MAC_TUNNEL_TABLE while on 'dumb' forwarders it goes to 0
dp = dpset.get(self.path_in[0].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=inact_tunnel.tid_in)
actions = [parser.OFPActionOutput(self.path_in[0].port_out)]
self.add_flow(dp, 300, match, actions, MAC_TUNNEL_TABLE)
##Rules for all 'dumb' forwardes on the way IN
for node in self.path_in[1:-1]:
dp = dpset.get(node.dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=inact_tunnel.tid_in)
actions = [parser.OFPActionOutput(node.port_out)]
self.add_flow(dp, 300, match, actions, 0)
##Last forwarder on the way IN sends packet to table OF_GPRS_TABLE_IN where it's matched based on active PDP CNTs
dp = dpset.get(self.path_in[-1].dpid)
parser = dp.ofproto_parser
match = parser.OFPMatch(eth_dst=inact_tunnel.tid_in)
inst = [ parser.OFPInstructionGotoTable(OF_GPRS_TABLE_IN) ]
req = parser.OFPFlowMod(datapath=dp, priority=500, match=match, instructions=inst, table_id=0)
dp.send_msg(req)
ACTIVE_TUNNELS.append(tunnel(inact_tunnel.bss, inact_tunnel.apn, self.tid_out, self.tid_in, self.path_out, self.path_in))
LOG.debug('TOPO MNGR: Inactive tunnel between ' + str(inact_tunnel.bss) + ' and ' + str(inact_tunnel.apn.name) +' put into active state!')
