Handle UTF-16 correctly in Wireshark dissector

diff --git a/util/wireshark/minetest.lua b/util/wireshark/minetest.lua
index dd0507c3e7d0083bca3e00769747d9ebce42c441..d954c7597b388f40b7964ae024894592fecfd3e5 100644 (file)
--- a/util/wireshark/minetest.lua
+++ b/util/wireshark/minetest.lua
@@ -299,7 +299,7 @@ do
                        t:add(f_length, buffer(2,2))
                        local textlen = buffer(2,2):uint()
                        if minetest_check_length(buffer, 4 + textlen*2, t) then
-                               t:add(f_message, minetest_convert_utf16(buffer(4, textlen*2), "Converted chat message"))
+                               t:add(f_message, buffer(4, textlen*2), buffer(4, textlen*2):ustring())
                        end
                end
        }
@@ -1379,35 +1379,6 @@ function minetest_check_length(tvb, min_len, t)
        end
 end
 
--- Takes a Tvb or TvbRange (i.e. part of a packet) that
--- contains a UTF-16 string and returns a TvbRange containing
--- string converted to ASCII. Any characters outside the range
--- 0x20 to 0x7e are replaced by a question mark.
--- Parameter: tvb: Tvb or TvbRange that contains the UTF-16 data
--- Parameter: name: will be the name of the newly created Tvb.
--- Returns: New TvbRange containing the ASCII string.
--- TODO: Handle surrogates (should only produce one question mark)
--- TODO: Remove this when Wireshark supports UTF-16 strings natively.
-function minetest_convert_utf16(tvb, name)
-       local hex, pos, char
-       hex = ""
-       for pos = 0, tvb:len() - 2, 2 do
-               char = tvb(pos, 2):uint()
-               if (char >= 0x20 and char <= 0x7e) or char == 0x0a then
-                       hex = hex .. string.format(" %02x", char)
-               else
-                       hex = hex .. " 3F"
-               end
-       end
-       if hex == "" then
-               -- This is a hack to avoid a failed assertion in tvbuff.c
-               -- (function: ensure_contiguous_no_exception)
-               return ByteArray.new("00"):tvb(name):range(0,0)
-       else
-               return ByteArray.new(hex):tvb(name):range()
-       end
-end
-
 -- Decodes a variable-length string as ASCII text
 -- t_textlen, t_text should be the ProtoFields created by minetest_field_helper
 --   alternatively t_text can be a ProtoField.string and t_textlen can be nil
@@ -1438,7 +1409,7 @@ function minetest_decode_helper_utf16(tvb, t, lentype, offset, f_textlen, f_text
        end
        local textlen = tvb(offset, n):uint() * 2
        if minetest_check_length(tvb, offset + n + textlen, t) then
-               t:add(f_text, minetest_convert_utf16(tvb(offset + n, textlen), "UTF-16 text"))
+               t:add(f_text, tvb(offset + n, textlen), tvb(offset + n, textlen):ustring())
                return offset + n + textlen
        end
 end