dissectors/t937: dissect TEMP_STATUS messages

1 files changed, 30 insertions, 20 deletions

diff --git a/dissectors/t937.lua b/dissectors/t937.lua
index 9d37ba6..cec6e9a 100755
--- a/dissectors/t937.lua
+++ b/dissectors/t937.lua
@@ -18,7 +18,11 @@ proto.fields.fun = ProtoField.uint8("t937.function", "Function", base.HEX, FUN_T
 proto.fields.len = ProtoField.uint8("t937.length", "Data Length", base.HEX)

 proto.fields.checksum = ProtoField.uint16("t937.checksum", "Message Checksum", base.HEX)

 

-proto.fields.data = ProtoField.bytes("t937.data", "Data")

+proto.fields.temp1 = ProtoField.uint16("t937.temp1", "Chamber Temp 1", base.UNIT_STRING, {"°C"})

+proto.fields.temp2 = ProtoField.uint16("t937.temp2", "Chamber Temp 2", base.UNIT_STRING, {"°C"})

+proto.fields.temp3 = ProtoField.uint16("t937.temp3", "Control Board Temp", base.UNIT_STRING, {"°C"})

+

+proto.fields.data = ProtoField.bytes("t937.data", "Raw Data")

 

 local function try_dissect(bytes, pinfo, tree)

   -- minimum len is header + checksum

@@ -28,34 +32,40 @@ local function try_dissect(bytes, pinfo, tree)
   if bytes:len() < 4 + raw_len + 2 then return end

 

   local buffer = bytes:subset(0, 4+raw_len+2):tvb("T-937 Frame")

-  local address = buffer(0, 2)

-  local fun = buffer(2, 1)

-  local len = buffer(3, 1)

+  local sub = tree:add(proto, buffer())

+

+  local i = 0

+  sub:add_packet_field(proto.fields.addr, buffer(0, 2), ENC_BIG_ENDIAN)

+  local funf, fun, i = sub:add_packet_field(proto.fields.fun, buffer(2, 1), ENC_BIG_ENDIAN)

+  sub:add_packet_field(proto.fields.len, buffer(3, 1), ENC_BIG_ENDIAN)

   local data = buffer(4, raw_len)

-  local checksum = buffer(4+raw_len, 2)

+  sub:add_packet_field(proto.fields.data, data, ENC_BIG_ENDIAN)

+  local csf, cs = sub:add_packet_field(proto.fields.checksum, buffer(4+raw_len), ENC_BIG_ENDIAN)

 

   local sum = 0

   for i=0,4+raw_len-1 do

     sum = sum + buffer(i, 1):uint()

   end

 

-  pinfo.cols.info:set("T937 " .. (FUN_TABLE[fun:uint()] or ""))

-  pinfo.cols.dst:clear_fence()

-  pinfo.cols.dst:set(address:bytes():tohex())

-

-  local sub = tree:add(proto, buffer())

-  sub:add(proto.fields.addr, address)

-  sub:add(proto.fields.fun, fun)

-  sub:add(proto.fields.len, len)

-  sub:add(proto.fields.data, data)

-

-  local cs = sub:add(proto.fields.checksum, checksum)

-  if sum ~= checksum:uint() then

-    cs:add_proto_expert_info(proto.experts.checksum, string.format(

-      "expected 0x%04x, got 0x%04x", checksum:uint(), sum

+  if sum ~= cs then

+    csf:add_proto_expert_info(proto.experts.checksum, string.format(

+      "expected 0x%04x, got 0x%04x", cs, sum

     ))

   end

 

+  local fun_name = FUN_TABLE[fun]

+  pinfo.cols.info:set("T937 " .. (fun_name or ""))

+

+  if fun_name then

+    sub = sub:add(data, fun_name)

+  end

+

+  if fun_name == "TEMP_STATUS" then

+    sub:add(proto.fields.temp1, data(0,2))

+    sub:add(proto.fields.temp2, data(2,2))

+    sub:add(proto.fields.temp3, data(4,2))

+  end

+

   return buffer:len()

 end

 

@@ -106,9 +116,9 @@ function proto.dissector(_buf, pinfo, tree)
   while rest:len() > 0 do

     local ok, len = pcall(try_dissect, rest, pinfo, tree)

     if not ok then

-      print("GOT ERR", len, pinfo.number)

       state.error[pinfo.p2p_dir] = len

       state.last_number = pinfo.number

+      print(len)

       error(len)

     elseif not len then

       break