Change ID field to use little-endian byte order (#4629)

* Change ID field to use little-endian byte order

* Add unit tests to verify encoding and decoding of Dot11 ID field

Author: satveerbrar

scapy/layers/dot11.py

@@ -730,7 +730,7 @@ class Dot11(Packet):
                        ["next_tbtt", "comp_ssid", "ano"]),
             lambda pkt: (pkt.type, pkt.subtype) == (3, 1)
         ),
-        ShortField("ID", 0),
+        LEShortField("ID", 0),
         _Dot11MacField("addr1", ETHER_ANY, 1),
         ConditionalField(
             _Dot11MacField("addr2", ETHER_ANY, 2),

test/scapy/layers/dot11.uts

@@ -18,6 +18,11 @@ len(dpl_ether) == 1 and Ether in dpl_ether[0]
 s = raw(Dot11())
 s == b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
 
+pkt = Dot11(ID=0x1205)
+raw_data = raw(pkt)
+expected = b'\x05\x12'
+assert raw_data[2:4] == b'\x05\x12', f"Encoded Dot11 ID field is {raw_data[2:4]}, expected {repr(expected)}."
+
 = Dot11 - dissection
 p = Dot11(s)
 Dot11 in p and p.addr3 == "00:00:00:00:00:00"
@@ -26,6 +31,10 @@ assert "DA" in p.address_meaning(1)
 assert "SA" in p.address_meaning(2)
 assert "BSSID" in p.address_meaning(3)
 
+pkt = b'\x00\x00\x05\x12\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+decoded_pkt = Dot11(pkt)
+assert decoded_pkt.ID == 0x1205, f"Decoded Dot11 ID field is {hex(decoded_pkt.ID)}, expected 0x1205."
+
 = Dot11QoS - build
 s = raw(Dot11()/Dot11QoS(Ack_Policy=1))
 assert s == b'\xc8\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 \x00'