sd.lua

-- File : sd.lua
-- Who  : x-Felix-x
-- Based on: https://github.com/jamores/eth-ws-someip/blob/master/sd.lua
-- What : SD-over-SOMEIP dissector, called heuristically from SOMEIP

-- bitwise ops helpers
local band, bor = bit.band, bit.bor
local lshift, rshift = bit.lshift, bit.rshift
local tohex = bit.tohex

-- SD protocol
p_sd = Proto("sd", "SD")

local f_flags       = ProtoField.uint8("sd.flags", "Flags", base.HEX)
local f_res         = ProtoField.uint24("sd.res", "Reserved", base.HEX)
local f_ents_len    = ProtoField.uint32("sd.len_ent", "LengthEntries", base.HEX)
local f_ents        = ProtoField.bytes("sd.ent", "EntriesArray")
local f_opts_len    = ProtoField.uint32("sd.len_opt", "LengthOptions", base.HEX)
local f_opts        = ProtoField.bytes("sd.opt", "OptionsArray")

p_sd.fields = {f_flags, f_res, f_ents_len, f_ents, f_opts_len, f_opts}

function p_sd.dissector(buf, pinfo, root)
    pinfo.cols.protocol = "SOME/IP-SD"

    -- create subtree
    local subtree = root:add(p_sd, buf(0))

    -- add protocol fields to subtree
    local offset = 0
    
    -- Flags
    subtree:add(f_flags, buf(offset, 1))
    offset = offset + 1
    -- Reserved
    subtree:add(f_res, buf(offset, 3))
    offset = offset + 3

    -- Entries length
    local e_len = buf(offset, 4):uint()
    subtree:add(f_ents_len, buf(offset, 4))
    offset = offset + 4
    -- Entries
    --e_tree = subtree:add(f_ents,buf(offset,e_len))
    e_tree = subtree:add("EntriesArray")
    Dissector.get("sd_entries"):call(buf(offset - 4):tvb(), pinfo, e_tree)
    offset = offset + e_len

    -- Options length
    local o_len = buf(offset, 4):uint()
    subtree:add(f_opts_len, buf(offset, 4))
    offset = offset + 4
    -- Options
    --o_tree = subtree:add(f_ents,buf(offset,o_len))
    o_tree = subtree:add("OptionsArray")
    Dissector.get("sd_options"):call(buf(offset - 4):tvb(), pinfo, o_tree)
    offset = offset + o_len

end