def _check_remote_ifid(self, pcb: PathSegment) -> Optional[ISD_AS]:
Requires(Acc(pcb.State(), 1 / 20))
Ensures(Acc(pcb.State(), 1 / 20))
"""
Checkes whether any PCB markings have unset remote IFID values for
up/downstream ASes. This can happen during normal startup depending
on the timing of PCB propagation vs IFID keep-alives, but should
not happen once the infrastructure is settled.
Remote IFID is only allowed to be 0 if the corresponding ISD-AS is
0-0.
"""
asms = pcb.iter_asms()
for asm in asms:
Invariant(Forall(asms, lambda a: (Acc(a.State(), 1 / 4), [])))
pcbms = asm.iter_pcbms()
for pcbm in pcbms:
Invariant(Forall(pcbms, lambda p: (Acc(p.State(), 1 / 4), [])))
if (pcbm.inIA().to_int() and not Unfolding(
Acc(pcbm.State(), 1 / 8),
Unfolding(Acc(pcbm.p.State(), 1 / 16), pcbm.p.inIF))):
return pcbm.inIA()
if (pcbm.outIA().to_int() and not Unfolding(
Acc(pcbm.State(), 1 / 8),
Unfolding(Acc(pcbm.p.State(), 1 / 16), pcbm.p.outIF))):
return pcbm.outIA()
return None
def _setup(self):
asms = []
for i in range(3):
pcbm = create_mock_full({"hof()": "hof %d" % i})
asms.append(create_mock_full({"pcbm()": pcbm}))
inst = PathSegment(None)
inst.iter_asms = create_mock_full(return_value=asms)
return inst
def test_3(self, _):
asms = []
for i in range(3):
asms.append(
create_mock_full({"sig_pack()": bytes("asm %i" % i, "ascii")}))
inst = PathSegment(create_mock_full({"info": b"info"}))
inst.is_sibra = create_mock_full()
inst.iter_asms = create_mock_full(return_value=asms)
inst.sibra_ext = create_mock_full({"sig_pack()": b"sibraext"})
expected = b"".join(
[b"info", b"asm 0", b"asm 1", b"asm 2", b"sibraext"])
# Call
ntools.eq_(inst.sig_pack(3), expected)
def _check_unwanted_ases(
self, pcb: PathSegment) -> Optional[ISD_AS]: # pragma: no cover
Requires(Acc(pcb.State(), 1 / 20))
Requires(Acc(self.State(), 1 / 8))
Ensures(Acc(pcb.State(), 1 / 20))
Ensures(Acc(self.State(), 1 / 8))
"""
Checks whether any of the ASes in the path belong to the black list.
:param pcb: beacon to analyze.
:type pcb: :class:`PathSegment`
"""
asms = pcb.iter_asms()
for asm in asms:
Invariant(Forall(asms, lambda a: (Acc(a.State(), 1 / 4), [])))
Invariant(Acc(self.State(), 1 / 9))
Invariant(Acc(pcb.State(), 1 / 20))
isd_as = asm.isd_as()
Unfold(Acc(self.State(), 1 / 10))
if isd_as in self.unwanted_ases:
Fold(Acc(self.State(), 1 / 10))
return isd_as
Fold(Acc(self.State(), 1 / 10))