from state import flow_emap
EXP_TIME = 10 * 1000
EXT_IP_ADDR = ext_ip
EXT_PORT = 1
if a_packet_received:
flow_emap.expire_all(now - EXP_TIME)
h3 = pop_header(tcpudp, on_mismatch=([], []))
h2 = pop_header(ipv4, on_mismatch=([], []))
h1 = pop_header(ether, on_mismatch=([], []))
internal_flow_id = FlowIdc(h3.src_port, h3.dst_port, h2.saddr, h2.daddr,
received_on_port, h2.npid)
if (received_on_port != EXT_PORT and not flow_emap.has(internal_flow_id)
and not flow_emap.full()):
idx = the_index_allocated
flow_emap.add(internal_flow_id, idx, now)
return ([EXT_PORT], [
ether(h1, saddr=..., daddr=...),
ipv4(h2, cksum=..., saddr=EXT_IP_ADDR),
tcpudp(h3, src_port=idx + start_port)
])
else:
pass
from state import flow_emap
EXP_TIME = 10 * 1000
EXT_PORT = 1
if a_packet_received:
flow_emap.expire_all(now - EXP_TIME)
h3 = pop_header(tcpudp, on_mismatch=([], []))
h2 = pop_header(ipv4, on_mismatch=([], []))
h1 = pop_header(ether, on_mismatch=([], []))
if received_on_port == EXT_PORT:
flow_indx = h3.dst_port - start_port
if flow_emap.has_idx(flow_indx): # Flow is present in the table
flow_emap.refresh_idx(flow_indx, now)
else: # packet from the internal network
internal_flow_id = FlowIdc(h3.src_port, h3.dst_port, h2.saddr, h2.daddr,
received_on_port, h2.npid)
if flow_emap.has(internal_flow_id): # flow present in the table
flow_emap.refresh_idx(flow_emap.get(internal_flow_id), now)
elif not flow_emap.full(): # No flow in the table, but some space
idx = the_index_allocated
flow_emap.add(internal_flow_id, idx, now)
if backend_ip_emap.has_idx(backend_id):
flow_emap.refresh_idx(flow_emap.get(packet_flow), now)
backend = backends.get(backend_id)
return ([backend.nic],
[ether(h1, saddr=..., daddr=backend.mac),
ipv4(h2, cksum=..., daddr=backend.ip),
tcpudp(h3)])
else:
flow_emap.erase(packet_flow)
alloc_flow_and_process_packet = True
else:
alloc_flow_and_process_packet = True
if alloc_flow_and_process_packet:
if backend_ip_emap.exists_with_cht(cht, _LoadBalancedFlow_hash(packet_flow)):
bknd = backend_ip_emap.choose_with_cht(cht, _LoadBalancedFlow_hash(packet_flow))
if not flow_emap.full():
idx = the_index_allocated
flow_emap.add(packet_flow, idx, now)
flow_id_to_backend_id.set(idx, bknd)
backend = backends.get(bknd)
return ([backend.nic],
[ether(h1, saddr=..., daddr=backend.mac),
ipv4(h2, cksum=..., daddr=backend.ip),
tcpudp(h3)])
else:
return ([],[])
else: # A heartbeat from a backend
bknd_addr = ip_addrc(h2.saddr)
if backend_ip_emap.has(bknd_addr):
backend_ip_emap.refresh_idx(backend_ip_emap.get(bknd_addr), now)
else:
if (internal_flow.dip != h2.saddr or
internal_flow.dp != h3.src_port or
internal_flow.prot != h2.npid):
return ([],[])
else:
return ([internal_flow.idev],
[ether(h1, saddr=..., daddr=...),
ipv4(h2, cksum=..., saddr=internal_flow.dip, daddr=internal_flow.sip),
tcpudp(src_port=internal_flow.dp, dst_port=internal_flow.sp)])
else:
return ([],[])
else: # packet from the internal network
internal_flow_id = FlowIdc(h3.src_port, h3.dst_port, h2.saddr, h2.daddr, received_on_port, h2.npid)
if flow_emap.has(internal_flow_id): # flow present in the table
idx = flow_emap.get(internal_flow_id)
flow_emap.refresh_idx(idx, now)
return ([EXT_PORT],
[ether(h1, saddr=..., daddr=...),
ipv4(h2, cksum=..., saddr=EXT_IP_ADDR),
tcpudp(h3, src_port=idx + start_port)])
else: # No flow in the table
if flow_emap.full(): # flowtable overflow
return ([],[])
else:
idx = the_index_allocated
flow_emap.add(internal_flow_id, idx, now)
return ([EXT_PORT],
[ether(h1, saddr=..., daddr=...),
ipv4(h2, cksum=..., saddr=EXT_IP_ADDR),
tcpudp(h3, src_port=idx + start_port)])