lua/r8152.lua: add basic USB dissector for Realtek Ethernet adapter

Last modified at 2015-12-08

1 files changed, 73 insertions, 0 deletions

diff --git a/lua/r8152.lua b/lua/r8152.lua
new file mode 100644
index 0000000..4c6981e
--- /dev/null
+++ b/lua/r8152.lua
@@ -0,0 +1,73 @@
+-- Dissector for Realtek 8152 USB Ethernet adapter
+-- TODO interrupt dissection? (register accesses, etc.?)
+
+local r8152 = Proto("r8152", "Realtek 8152")
+
+local eth = Dissector.get("eth_withfcs")
+
+local usb_transfer_type = Field.new("usb.transfer_type")
+local usb_direction = Field.new("usb.endpoint_number.direction")
+
+r8152.fields.rx = ProtoField.bool("r8152.rx", "Receive Descriptor")
+r8152.fields.tx = ProtoField.bool("r8152.tx", "Transmit Descriptor")
+r8152.fields.opts = ProtoField.uint32("r8152.opts", "opts", base.HEX)
+r8152.fields.rx_len = ProtoField.uint16("r8152.rx_len", "Receive Length", base.DEC, nil, 0x7fff)
+
+function dissect_rx(tvb, pinfo, tree)
+    local i
+    local offset = 0
+    local opts1_tree = tree:add_le(r8152.fields.opts, tvb(offset, 4))
+    opts1_tree:add_le(r8152.fields.rx_len, tvb(offset, 4))
+    offset = offset + 4
+    for i = 2, 6 do
+        tree:add_le(r8152.fields.opts, tvb(offset, 4))
+        offset = offset + 4
+    end
+    return offset
+end
+
+function dissect_tx(tvb, pinfo, tree)
+    local i
+    local offset = 0
+    for i = 1, 2 do
+        tree:add_le(r8152.fields.opts, tvb(offset, 4))
+        offset = offset + 4
+    end
+    return offset
+end
+
+function r8152.dissector(tvb, pinfo, tree)
+    local offset
+    local transfer_type = usb_transfer_type().value
+    -- direction: OUT (0), IN (1)
+    local is_rx = usb_direction().value == 1
+
+    -- Process only bulk packets
+    if transfer_type ~= 3 then
+        return 0
+    end
+
+    pinfo.cols.protocol = r8152.name
+
+    local dissect_desc
+
+    local r8152_tree = tree:add(r8152, tvb)
+    local ti
+    if is_rx then
+        dissect_desc = dissect_rx
+        ti = r8152_tree:add(r8152.fields.rx, tvb(0, 24))
+    else
+        dissect_desc = dissect_tx
+        ti = r8152_tree:add(r8152.fields.tx, tvb(0, 8))
+    end
+    ti:set_generated(true)
+    offset = dissect_desc(tvb, pinfo, r8152_tree)
+    r8152_tree:set_len(offset)
+
+    eth(tvb(offset):tvb(), pinfo, tree)
+end
+
+function r8152.init()
+    local usb_product = DissectorTable.get("usb.product");
+    usb_product:add(0x0bda8153, r8152)
+end