1 files changed, 50 insertions, 0 deletions
diff --git a/wireshark/rxhdr.lua b/wireshark/rxhdr.lua
new file mode 100644
index 0000000..3924603
--- /dev/null
+++ b/wireshark/rxhdr.lua
@@ -0,0 +1,50 @@
+require "util"
+
+local p = Proto("rxhdr", "Hardware RX header")
+
+-- based off <https://www.problemkaputt.de/gbatek.htm#dswifihardwareheaders>
+
+p.fields.unknown = ProtoField.bytes("rxhdr.unknown", "Unknown")
+
+p.fields.flags = ProtoField.new("Flags", "rxhdr.flags", ftypes.BYTES)
+p.fields.flag_type = ProtoField.uint16("rxhdr.flags.type", "Frame type", base.DEC, nil, bits(0, 4))
+p.fields.flag_more = ProtoField.bool("rxhdr.flags.more", "More fragments", base.DEC, nil, bits(8))
+
+p.fields.new = ProtoField.bool("rxhdr.new", "New frame")
+p.fields.magic = ProtoField.bytes("rxhdr.magic", "Magic")
+p.fields.channel = ProtoField.uint8("rxhdr.channel", "802.11 channel")
+
+p.fields.rate = ProtoField.uint16("rxhdr.rate", "Transfer rate", base.HEX, {
+	[0x0a] = "1 Mbit/s",
+	[0x14] = "2 Mbit/s",
+})
+p.fields.length = ProtoField.uint16("rxhdr.len", "Remaining message length")
+
+local ieee_dissector = Dissector.get("ieee")
+
+function p.dissector(buffer, pinfo, tree)
+	local header_size = 12
+	-- check buffer size
+	if buffer:len() < header_size then return 0 end
+
+	local subtree = tree:add(p, buffer(0, header_size), string.format("%s: %d bytes", p.description, header_size))
+
+	local flags_tree = subtree:add(p.fields.flags, buffer(0x00, 2))
+		flags_tree:add_le(p.fields.flag_type, buffer(0x00, 2))
+		flags_tree:add_le(p.fields.flag_more, buffer(0x00, 2))
+
+	subtree:add(p.fields.unknown, buffer(0x02, 2))
+	subtree:add(p.fields.unknown, buffer(0x04, 2))
+
+	subtree:add_le(p.fields.rate, buffer(0x06, 2))
+	subtree:add_le(p.fields.length, buffer(0x08, 2))
+	local length = buffer(0x08, 2):le_uint()
+
+	-- pretty wireshark shit
+	pinfo.cols.protocol = p.name
+
+	ieee_dissector:call(buffer(header_size, length):tvb(), pinfo, tree)
+
+	return header_size
+end
+