Add 802.11 HE Operation Info

[middleendian]

• 802.11ax-2021 9.4.2.249
• Add unit test

AI-Assisted: yes (Codex)

PR 0001: Dot11 Element ID Extension and HE Operation

Scope:

• Adds Dot11EltExtension dispatch for Element ID 255.
• Adds Dot11EltExtensionGeneric for unknown or unsupported extension IDs.
• Adds Dot11EltHEOperation for Extended ID 36.
• Adds Dot11HE6GOperationInfo when the HE Operation element indicates that
  6 GHz operation information is present.
• Adds focused test/scapy/layers/dot11.uts tests for generic, short, HE, and
  HE 6 GHz extended elements.

Spec references used in code comments:

• IEEE Std 802.11ax-2021, 9.4.2.1 and Table 9-92: Element ID Extension.
• IEEE Std 802.11ax-2021, 9.4.2.249: HE Operation element.
• IEEE Std 802.11ax-2021, Figure 9-788k: 6 GHz Operation Information field.

Intentional partial support:

• Element ID Extension is a registry for many 802.11 information elements. This
  patch does not try to implement all of them.
• Unknown and unsupported extension IDs intentionally remain
  Dot11EltExtensionGeneric.
• EHT Operation and Multi-Link are left for separate follow-up patches so this
  first PR is reviewable on its own.

Focused test command used:

test/run_tests -t test/scapy/layers/dot11.uts -n 57-61 -F

Result:

PASSED=5 FAILED=0

Full dot11 suite note:

• A full test/scapy/layers/dot11.uts run reached and passed the existing
  tests up through Dot11EltVHTOperation in isolation before I interrupted it
  in this local environment because it was taking longer than expected.
  The focused tests for this patch passed.

[gpotter2]

You should be able to use a dictionary that is automatically registered based on the subclasses ext_ID. Like what was done in

scapy/scapy/layers/dot11.py

Lines 1059 to 1074 in fda6032

	@classmethod
	def register_variant(cls, id=None):
	id = id or cls.ID.default
	if id not in cls.registered_ies:
	cls.registered_ies[id] = cls
	@classmethod
	def dispatch_hook(cls, _pkt=None, *args, **kargs):
	if _pkt:
	_id = ord(_pkt[:1])
	idcls = cls.registered_ies.get(_id, cls)
	if idcls.dispatch_hook != cls.dispatch_hook:
	# Vendor has its own dispatch_hook
	return idcls.dispatch_hook(_pkt=_pkt, *args, **kargs)
	cls = idcls
	return cls