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=([],[]))
flow_indx = h3.dst_port - start_port
if received_on_port == EXT_PORT and flow_emap.has_idx(flow_indx):
internal_flow = flow_emap.get_key(flow_indx)
flow_emap.refresh_idx(flow_indx, now)
if (internal_flow.dip == h2.saddr and
internal_flow.dp == h3.src_port and
internal_flow.prot == h2.npid):
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:
pass
else: # packet from the internal network
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
pass