exactmatch.bess

# Copyright (c) 2014-2016, The Regents of the University of California.
# Copyright (c) 2016-2017, Nefeli Networks, Inc.
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import scapy.all as scapy
import socket

def aton(ip):
    return socket.inet_aton(ip)

# Craft a packet with the specified IP addresses
def gen_packet(proto, src_ip, dst_ip):
    eth = scapy.Ether(src='02:1e:67:9f:4d:ae', dst='06:16:3e:1b:72:32')
    ip = scapy.IP(src=src_ip, dst=dst_ip)
    udp = proto(sport=10001, dport=10002)
    payload = 'helloworld'
    pkt = eth/ip/udp/payload
    return bytes(pkt)

packets = [gen_packet(scapy.UDP, '172.16.100.1', '10.0.0.1'),
           gen_packet(scapy.UDP, '172.12.55.99', '12.34.56.78'),
           gen_packet(scapy.UDP, '172.12.55.99', '10.0.0.1'),
           gen_packet(scapy.UDP, '172.16.100.1', '12.34.56.78'),
           gen_packet(scapy.TCP, '172.12.55.99', '12.34.56.78'),
           gen_packet(scapy.UDP, '192.168.1.123', '12.34.56.78'),
          ]

# L4 protocol and source/destination IP addresses
em::ExactMatch(fields=[{'offset':23, 'num_bytes':1},
                       {'offset':26, 'num_bytes':4},
                       {'offset':30, 'num_bytes':4}])

Source() -> Rewrite(templates=packets) -> em

em:0 -> Sink()
em:1 -> Sink()
em:2 -> Sink()
em:5 -> Sink()   # used as default gate

em.add(fields=[{'value_int':17}, {'value_bin':aton('172.16.100.1')}, {'value_bin':aton('10.0.0.1')}], gate=0)
em.add(fields=[{'value_int':6}, {'value_bin':aton('172.12.55.99')}, {'value_bin':aton('12.34.56.78')}], gate=1)
em.add(fields=[{'value_int':17}, {'value_bin':aton('172.12.55.99')}, {'value_bin':aton('12.34.56.78')}], gate=2)

# delete test
em.add(fields=[{'value_bin':b'\x11'}, {'value_bin':aton('192.168.1.123')}, {'value_bin':aton('12.34.56.78')}], gate=3)
em.delete(fields=[{'value_bin':b'\x11'}, {'value_bin':aton('192.168.1.123')}, {'value_bin':aton('12.34.56.78')}])

em.set_default_gate(gate=5)