fix: repair LinuxSLL.set_addr() array type mismatch in zero-padding

[VoidChecksum]

Summary

LinuxSLL.set_addr() passes raw bytes to array.array.extend(), which is not guaranteed by the array API across Python versions and can raise TypeError.

Root cause: In set_addr(), the addr variable is an array.array('B', ...), but addr.extend(b'\0' * n) passes a bytes object. While some Python versions coerce bytes to array-compatible input in extend(), this is not guaranteed — the array documentation specifies that extend() accepts an iterable of the array's type, not arbitrary bytes.

Fix: Wrap the zero-padding bytes in array.array('B', ...) before passing to extend().

Reproduction

from impacket.ImpactPacket import LinuxSLL

sll = LinuxSLL()
sll.set_addr(b'\x01\x02')  # May raise TypeError during padding

Changes

impacket/ImpactPacket.py line 734:

 if len(addr) < 8:
-    addr.extend(b'\0' * (8 - len(addr)))
+    addr.extend(array.array('B', b'\0' * (8 - len(addr))))

Test plan

• set_addr(b'\x01\x02') — short address pads to 8 bytes without TypeError
• set_addr(b'\x01\x02\x03\x04\x05\x06\x07\x08') — full-length address, no padding path
• get_addr() round-trips correctly after set_addr()
• Consistent behavior across Python 3.10, 3.11, 3.12, 3.13

Fixes #2093

[Copilot]

Pull request overview

This PR updates LinuxSLL address padding logic in ImpactPacket.py by changing how zero-bytes are appended when the provided address is shorter than 8 bytes.

Changes:

• Adjusted LinuxSLL.set_addr() to extend the address buffer using an array.array('B', ...) wrapper around the padding bytes.

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