Add filterable expert info for Lua

This adds the ability for a Lua script to register expert info fields,
similar to C-code dissectors. This change also removes the need for
the expert_add_info_format_internal() function. Existing Lua scripts
do not have to change, because the existing expert info function
uses the internal "_ws.lua" protocol instead of nothing; but using
the new functionality provides more benefits since it correctly
registers the expert info fields to the dissector's protocol.

The test suite was amended to generate both old and new forms.

Change-Id: Ib5ae74e927cfa81312baf7b04ff4104b0b4f936e
Reviewed-on: https://code.wireshark.org/review/830
Reviewed-by: Evan Huus <eapache@gmail.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 29 insertions, 1 deletions

diff --git a/test/lua/proto.lua b/test/lua/proto.lua
index 9b159e65a3..157c4b2a9c 100644
--- a/test/lua/proto.lua
+++ b/test/lua/proto.lua
@@ -289,6 +289,24 @@ function dns.init()
 end
 
 ----------------------------------------
+-- create some expert info fields
+local ef_query     = ProtoExpert.new("mydns.query.expert", "DNS query message",
+                                     expert.group.REQUEST_CODE, expert.severity.CHAT)
+local ef_response  = ProtoExpert.new("mydns.response.expert", "DNS response message",
+                                     expert.group.RESPONSE_CODE, expert.severity.CHAT)
+local ef_ultimate  = ProtoExpert.new("mydns.response.ultimate.expert", "DNS answer to life, the universe, and everything",
+                                     expert.group.COMMENTS_GROUP, expert.severity.NOTE)
+-- some error expert info's
+local ef_too_short = ProtoExpert.new("mydns.too_short.expert", "DNS message too short",
+                                     expert.group.MALFORMED, expert.severity.ERROR)
+local ef_bad_query = ProtoExpert.new("mydns.query.missing.expert", "DNS query missing or malformed",
+                                     expert.group.MALFORMED, expert.severity.WARN)
+
+-- register them
+dns.experts = { ef_query, ef_too_short, ef_bad_query, ef_response, ef_ultimate }
+
+
+----------------------------------------
 -- we don't just want to display our protocol's fields, we want to access the value of some of them too!
 -- There are several ways to do that.  One is to just parse the buffer contents in Lua code to find
 -- the values.  But since ProtoFields actually do the parsing for us, and can be retrieved using Field
@@ -391,7 +409,17 @@ function dns.dissector(tvbuf,pktinfo,root)
     local flag_tree = tree:add(pf_flags, flagrange)
         -- I'm indenting this for calarity, because it's adding to the flag's child-tree
         -- let's add the type of message (query vs. response)
-        flag_tree:add(pf_flag_response, flagrange)
+        local query_flag_tree = flag_tree:add(pf_flag_response, flagrange)
+
+        -- let's also add an expert info about it
+        if isResponse() then
+            query_flag_tree:add_proto_expert_info(ef_response, "It's a response!")
+            if transid == 42 then
+                tree:add_tvb_expert_info(ef_ultimate, tvbuf:range(0,2))
+            end
+        else
+            query_flag_tree:add_proto_expert_info(ef_query)
+        end
 
         -- we now know if it's a response or query, so let's put that in the
         -- GUI packet row, in the INFO column cell