10.2. Example of Dissector written in Lua
do
local p_multi = Proto("multi","MultiProto");
local vs_protos = {
[2] = "mtp2",
[3] = "mtp3",
[4] = "alcap",
[5] = "h248",
[6] = "ranap",
[7] = "rnsap",
[8] = "nbap"
}
local f_proto = ProtoField.uint8("multi.protocol","Protocol",base.DEC,vs_protos)
local f_dir = ProtoField.uint8("multi.direction","Direction",base.DEC,{ [1] = "incoming", [0] = "outgoing"})
local f_text = ProtoField.string("multi.text","Text")
p_multi.fields = { f_proto, f_dir, f_text }
local data_dis = Dissector.get("data")
local protos = {
[2] = Dissector.get("mtp2"),
[3] = Dissector.get("mtp3"),
[4] = Dissector.get("alcap"),
[5] = Dissector.get("h248"),
[6] = Dissector.get("ranap"),
[7] = Dissector.get("rnsap"),
[8] = Dissector.get("nbap"),
[9] = Dissector.get("rrc"),
[10] = DissectorTable.get("sctp.ppi"):get_dissector(3), -- m3ua
[11] = DissectorTable.get("ip.proto"):get_dissector(132), -- sctp
}
function p_multi.dissector(buf,pkt,root)
local t = root:add(p_multi,buf(0,2))
t:add(f_proto,buf(0,1))
t:add(f_dir,buf(1,1))
local proto_id = buf(0,1):uint()
local dissector = protos[proto_id]
if dissector ~= nil then
dissector:call(buf(2):tvb(),pkt,root)
elseif proto_id < 2 then
t:add(f_text,buf(2))
-- pkt.cols.info:set(buf(2,buf:len() - 3):string())
else
data_dis:call(buf(2):tvb(),pkt,root)
end
end
local wtap_encap_table = DissectorTable.get("wtap_encap")
local udp_encap_table = DissectorTable.get("udp.port")
wtap_encap_table:add(wtap.USER15,p_multi)
wtap_encap_table:add(wtap.USER12,p_multi)
udp_encap_table:add(7555,p_multi)
end