haslayer with conditional packet fields

[bsullivan19]

Brief description

haslayer returns true if a Packet has a ConditionalField(PacketField) even when the condition for the conditional field is false.

Scapy version

2.5.0

Python version

3.12.2

Operating system

Windows 10

Additional environment information

No response

How to reproduce

class FizzPacket(Packet):
    fields_desc = [IntField("fizz", 1)]

class BuzzPacket(Packet):
    fields_desc = [IntField("buzz", 1)]

class FooPacket(Packet):
    fields_desc = [IntField("foo", 0),
                   ConditionalField(PacketField("fizzp", FizzPacket(), FizzPacket), lambda p: p.foo == 1),
                   ConditionalField(PacketField("buzzp", BuzzPacket(), BuzzPacket), lambda p: p.foo == 2)]

>>> pkt = FooPacket(foo=1)
>>> pkt
<FooPacket  foo=1 fizzp=<FizzPacket  |> |>
>>> BuzzPacket in pkt
True

Actual result

No response

Expected result

Expected 'BuzzPacket in pkt' to return false because the condition for the field buzzp is false.

Related resources

No response

[gpotter2]

This isn't a supported behavior.

The supported ways are either:

• to test whether a field is None (when the condition is false)
• to check the condition yourself