def shared_outputs(policy1, policy2):
"""Try to find packet in output of policy1 and egress of slice2."""
p, q, pp = Consts("p q pp", Packet)
solv = Solver()
solv.add(output(policy1, p, pp))
solv.add(egress(policy2, q, pp))
if solv.check() == unsat:
return None
else:
return solv.model(), (p, pp), HEADER_INDEX
def shared_io(topo, policy1, policy2):
"""Try to find output of policy1 in the inputs of policy2."""
p, pp, q, qq = Consts("p pp q qq", Packet)
o = Int("o")
solv = Solver()
solv.add(output(policy1, p, pp))
solv.add(transfer(topo, pp, q))
solv.add(input(policy2, q, qq, o))
if solv.check() == unsat:
return None
else:
return solv.model(), (p, pp, q, qq), HEADER_INDEX