-- minetest.lua -- Packet dissector for the UDP-based Minetest protocol -- Copy this to $HOME/.wireshark/plugins/ -- -- Minetest -- Copyright (C) 2011 celeron55, Perttu Ahola <celeron55@gmail.com> -- -- This program is free software; you can redistribute it and/or modify -- it under the terms of the GNU General Public License as published by -- the Free Software Foundation; either version 2 of the License, or -- (at your option) any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License along -- with this program; if not, write to the Free Software Foundation, Inc., -- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. -- -- Wireshark documentation: -- https://web.archive.org/web/20170711121726/https://www.wireshark.org/docs/wsdg_html_chunked/lua_module_Proto.html -- https://web.archive.org/web/20170711121844/https://www.wireshark.org/docs/wsdg_html_chunked/lua_module_Tree.html -- https://web.archive.org/web/20170711121917/https://www.wireshark.org/docs/wsdg_html_chunked/lua_module_Tvb.html -- Table of Contents: -- Part 1: Utility functions -- Part 2: Client command dissectors (TOSERVER_*) -- Part 3: Server command dissectors (TOCLIENT_*) -- Part 4: Wrapper protocol subdissectors -- Part 5: Wrapper protocol main dissector -- Part 6: Utility functions part 2 ----------------------- -- Part 1 -- -- Utility functions -- ----------------------- -- Creates two ProtoFields to hold a length and variable-length text content -- lentype must be either "uint16" or "uint32" function minetest_field_helper(lentype, name, abbr) local f_textlen = ProtoField[lentype](name .. "len", abbr .. " (length)", base.DEC) local f_text = ProtoField.string(name, abbr) return f_textlen, f_text end -------------------------------------------- -- Part 2 -- -- Client command dissectors (TOSERVER_*) -- -------------------------------------------- minetest_client_commands = {} minetest_client_obsolete = {} -- TOSERVER_INIT do local abbr = "minetest.client.init_" local f_ser_fmt = ProtoField.uint8(abbr.."ser_version", "Maximum serialization format version", base.DEC) local f_comp_modes = ProtoField.uint16(abbr.."compression", "Supported compression modes", base.DEC, { [0] = "No compression" }) local f_proto_min = ProtoField.uint16(abbr.."proto_min", "Minimum protocol version", base.DEC) local f_proto_max = ProtoField.uint16(abbr.."_proto_max", "Maximum protocol version", base.DEC) local f_player_namelen, f_player_name = minetest_field_helper("uint16", abbr.."player_name", "Player Name") minetest_client_commands[0x02] = { "INIT", -- Command name 11, -- Minimum message length including code { f_ser_fmt, -- List of fields [optional] f_comp_modes, f_proto_min, f_proto_max, f_player_namelen, f_player_name }, function(buffer, pinfo, tree, t) -- Dissector function [optional] t:add(f_ser_fmt, buffer(2,1)) t:add(f_comp_modes, buffer(3,2)) t:add(f_proto_min, buffer(5,2)) t:add(f_proto_max, buffer(7,2)) minetest_decode_helper_ascii(buffer, t, "uint16", 9, f_player_namelen, f_player_name) end } end -- TOSERVER_INIT_LEGACY (obsolete) minetest_client_commands[0x10] = { "INIT_LEGACY", 53 } minetest_client_obsolete[0x10] = true -- TOSERVER_INIT2 do local f_langlen, f_lang = minetest_field_helper("uint16", "minetest.client.init2_language", "Language Code") minetest_client_commands[0x11] = { "INIT2", 2, { f_langlen, f_lang }, function(buffer, pinfo, tree, t) minetest_decode_helper_ascii(buffer, t, "uint16", 2, f_langlen, f_lang) end } end -- TOSERVER_MODCHANNEL_JOIN minetest_client_commands[0x17] = { "MODCHANNEL_JOIN", 2 } -- TOSERVER_MODCHANNEL_LEAVE minetest_client_commands[0x18] = { "MODCHANNEL_LEAVE", 2 } -- TOSERVER_MODCHANNEL_MSG minetest_client_commands[0x19] = { "MODCHANNEL_MSG", 2 } -- TOSERVER_GETBLOCK (obsolete) minetest_client_commands[0x20] = { "GETBLOCK", 2 } minetest_client_obsolete[0x20] = true -- TOSERVER_ADDNODE (obsolete) minetest_client_commands[0x21] = { "ADDNODE", 2 } minetest_client_obsolete[0x21] = true -- TOSERVER_REMOVENODE (obsolete) minetest_client_commands[0x22] = { "REMOVENODE", 2 } minetest_client_obsolete[0x22] = true -- TOSERVER_PLAYERPOS do local abbr = "minetest.client.playerpos_" local f_x = ProtoField.int32(abbr.."x", "Position X", base.DEC) local f_y = ProtoField.int32(abbr.."y", "Position Y", base.DEC) local f_z = ProtoField.int32(abbr.."z", "Position Z", base.DEC) local f_speed_x = ProtoField.int32(abbr.."speed_x", "Speed X", base.DEC) local f_speed_y = ProtoField.int32(abbr.."speed_y", "Speed Y", base.DEC) local f_speed_z = ProtoField.int32(abbr.."speed_z", "Speed Z", base.DEC) local f_pitch = ProtoField.int32(abbr.."pitch", "Pitch", base.DEC) local f_yaw = ProtoField.int32(abbr.."yaw", "Yaw", base.DEC) local f_key_pressed = ProtoField.bytes(abbr.."key_pressed", "Pressed keys") local f_fov = ProtoField.uint8(abbr.."fov", "FOV", base.DEC) local f_wanted_range = ProtoField.uint8(abbr.."wanted_range", "Requested view range", base.DEC) minetest_client_commands[0x23] = { "PLAYERPOS", 34, { f_x, f_y, f_z, f_speed_x, f_speed_y, f_speed_z, f_pitch, f_yaw, f_key_pressed, f_fov, f_wanted_range }, function(buffer, pinfo, tree, t) t:add(f_x, buffer(2,4)) t:add(f_y, buffer(6,4)) t:add(f_z, buffer(10,4)) t:add(f_speed_x, buffer(14,4)) t:add(f_speed_y, buffer(18,4)) t:add(f_speed_z, buffer(22,4)) t:add(f_pitch, buffer(26,4)) t:add(f_yaw, buffer(30,4)) t:add(f_key_pressed, buffer(34,4)) t:add(f_fov, buffer(38,1)) t:add(f_wanted_range, buffer(39,1)) end } end -- TOSERVER_GOTBLOCKS do local f_count = ProtoField.uint8("minetest.client.gotblocks_count", "Count", base.DEC) local f_block = ProtoField.bytes("minetest.client.gotblocks_block", "Block", base.NONE) local f_x = ProtoField.int16("minetest.client.gotblocks_x", "Block position X", base.DEC) local f_y = ProtoField.int16("minetest.client.gotblocks_y", "Block position Y", base.DEC) local f_z = ProtoField.int16("minetest.client.gotblocks_z", "Block position Z", base.DEC) minetest_client_commands[0x24] = { "GOTBLOCKS", 3, { f_count, f_block, f_x, f_y, f_z }, function(buffer, pinfo, tree, t) t:add(f_count, buffer(2,1)) local count = buffer(2,1):uint() if minetest_check_length(buffer, 3 + 6*count, t) then pinfo.cols.info:append(" * " .. count) local index for index = 0, count - 1 do local pos = 3 + 6*index local t2 = t:add(f_block, buffer(pos, 6)) t2:set_text("Block, X: " .. buffer(pos, 2):int() .. ", Y: " .. buffer(pos + 2, 2):int() .. ", Z: " .. buffer(pos + 4, 2):int()) t2:add(f_x, buffer(pos, 2)) t2:add(f_y, buffer(pos + 2, 2)) t2:add(f_z, buffer(pos + 4, 2)) end end end } end -- TOSERVER_DELETEDBLOCKS do local f_count = ProtoField.uint8("minetest.client.deletedblocks_count", "Count", base.DEC) local f_block = ProtoField.bytes("minetest.client.deletedblocks_block", "Block", base.NONE) local f_x = ProtoField.int16("minetest.client.deletedblocks_x", "Block position X", base.DEC) local f_y = ProtoField.int16("minetest.client.deletedblocks_y", "Block position Y", base.DEC) local f_z = ProtoField.int16("minetest.client.deletedblocks_z", "Block position Z", base.DEC) minetest_client_commands[0x25] = { "DELETEDBLOCKS", 3, { f_count, f_block, f_x, f_y, f_z }, function(buffer, pinfo, tree, t) t:add(f_count, buffer(2,1)) local count = buffer(2,1):uint() if minetest_check_length(buffer, 3 + 6*count, t) then pinfo.cols.info:append(" * " .. count) local index for index = 0, count - 1 do local pos = 3 + 6*index local t2 = t:add(f_block, buffer(pos, 6)) t2:set_text("Block, X: " .. buffer(pos, 2):int() .. ", Y: " .. buffer(pos + 2, 2):int() .. ", Z: " .. buffer(pos + 4, 2):int()) t2:add(f_x, buffer(pos, 2)) t2:add(f_y, buffer(pos + 2, 2)) t2:add(f_z, buffer(pos + 4, 2)) end end end } end -- TOSERVER_ADDNODE_FROM_INVENTORY (obsolete) minetest_client_commands[0x26] = { "ADDNODE_FROM_INVENTORY", 2 } minetest_client_obsolete[0x26] = true -- TOSERVER_CLICK_OBJECT (obsolete) minetest_client_commands[0x27] = { "CLICK_OBJECT", 2 } minetest_client_obsolete[0x27] = true -- TOSERVER_GROUND_ACTION (obsolete) minetest_client_commands[0x28] = { "GROUND_ACTION", 2 } minetest_client_obsolete[0x28] = true -- TOSERVER_RELEASE (obsolete) minetest_client_commands[0x29] = { "RELEASE", 2 } minetest_client_obsolete[0x29] = true -- TOSERVER_SIGNTEXT (obsolete) minetest_client_commands[0x30] = { "SIGNTEXT", 2 } minetest_client_obsolete[0x30] = true -- TOSERVER_INVENTORY_ACTION do local f_action = ProtoField.string("minetest.client.inventory_action", "Action") minetest_client_commands[0x31] = { "INVENTORY_ACTION", 2, { f_action }, function(buffer, pinfo, tree, t) t:add(f_action, buffer(2, buffer:len() - 2)) end } end -- TOSERVER_CHAT_MESSAGE do local f_length = ProtoField.uint16("minetest.client.chat_message_length", "Length", base.DEC) local f_message = ProtoField.string("minetest.client.chat_message", "Message") minetest_client_commands[0x32] = { "CHAT_MESSAGE", 4, { f_length, f_message }, function(buffer, pinfo, tree, t) 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, buffer(4, textlen*2), buffer(4, textlen*2):ustring()) end end } end -- TOSERVER_SIGNNODETEXT (obsolete) minetest_client_commands[0x33] = { "SIGNNODETEXT", 2 } minetest_client_obsolete[0x33] = true -- TOSERVER_CLICK_ACTIVEOBJECT (obsolete) minetest_client_commands[0x34] = { "CLICK_ACTIVEOBJECT", 2 } minetest_client_obsolete[0x34] = true -- TOSERVER_DAMAGE do local f_amount = ProtoField.uint8("minetest.client.damage_amount", "Amount", base.DEC) minetest_client_commands[0x35] = { "DAMAGE", 3, { f_amount }, function(buffer, pinfo, tree, t) t:add(f_amount, buffer(2,1)) end } end -- TOSERVER_PASSWORD (obsolete) minetest_client_commands[0x36] = { "CLICK_ACTIVEOBJECT", 2 } minetest_client_obsolete[0x36] = true -- TOSERVER_PLAYERITEM do local f_item = ProtoField.uint16("minetest.client.playeritem_item", "Wielded item") minetest_client_commands[0x37] = { "PLAYERITEM", 4, { f_item }, function(buffer, pinfo, tree, t) t:add(f_item, buffer(2,2)) end } end -- TOSERVER_RESPAWN minetest_client_commands[0x38] = { "RESPAWN", 2 } -- TOSERVER_INTERACT do local abbr = "minetest.client.interact_" local vs_action = { [0] = "Start digging", [1] = "Stop digging", [2] = "Digging completed", [3] = "Place block or item", [4] = "Use item", [5] = "Activate held item", } local vs_pointed_type = { [0] = "Nothing", [1] = "Node", [2] = "Object", } local f_action = ProtoField.uint8(abbr.."action", "Action", base.DEC, vs_action) local f_item = ProtoField.uint16(abbr.."item", "Item Index", base.DEC) local f_plen = ProtoField.uint32(abbr.."plen", "Length of pointed thing", base.DEC) local f_pointed_version = ProtoField.uint8(abbr.."pointed_version", "Pointed Thing Version", base.DEC) local f_pointed_type = ProtoField.uint8(abbr.."pointed_version", "Pointed Thing Type", base.DEC, vs_pointed_type) local f_pointed_under_x = ProtoField.int16(abbr.."pointed_under_x", "Node position (under surface) X") local f_pointed_under_y = ProtoField.int16(abbr.."pointed_under_y", "Node position (under surface) Y") local f_pointed_under_z = ProtoField.int16(abbr.."pointed_under_z", "Node position (under surface) Z") local f_pointed_above_x = ProtoField.int16(abbr.."pointed_above_x", "Node position (above surface) X") local f_pointed_above_y = ProtoField.int16(abbr.."pointed_above_y", "Node position (above surface) Y") local f_pointed_above_z = ProtoField.int16(abbr.."pointed_above_z", "Node position (above surface) Z") local f_pointed_object_id = ProtoField.int16(abbr.."pointed_object_id", "Object ID") -- mising: additional playerpos data just like in TOSERVER_PLAYERPOS minetest_client_commands[0x39] = { "INTERACT", 11, { f_action, f_item, f_plen, f_pointed_version, f_pointed_type, f_pointed_under_x, f_pointed_under_y, f_pointed_under_z, f_pointed_above_x, f_pointed_above_y, f_pointed_above_z, f_pointed_object_id }, function(buffer, pinfo, tree, t) t:add(f_action, buffer(2,1)) t:add(f_item, buffer(3,2)) t:add(f_plen, buffer(5,4)) local plen = buffer(5,4):uint() if minetest_check_length(buffer, 9 + plen, t) then t:add(f_pointed_version, buffer(9,1)) t:add(f_pointed_type, buffer(10,1)) local ptype = buffer(10,1):uint() if ptype == 1 then -- Node t:add(f_pointed_under_x, buffer(11,2)) t:add(f_pointed_under_y, buffer(13,2)) t:add(f_pointed_under_z, buffer(15,2)) t:add(f_pointed_above_x, buffer(17,2)) t:add(f_pointed_above_y, buffer(19,2)) t:add(f_pointed_above_z, buffer(21,2)) elseif ptype == 2 then -- Object t:add(f_pointed_object_id, buffer(11,2)) end end end } end -- ... minetest_client_commands[0x3a] = { "REMOVED_SOUNDS", 2 } minetest_client_commands[0x3b] = { "NODEMETA_FIELDS", 2 } minetest_client_commands[0x3c] = { "INVENTORY_FIELDS", 2 } minetest_client_commands[0x40] = { "REQUEST_MEDIA", 2 } minetest_client_commands[0x41] = { "RECEIVED_MEDIA", 2 } -- TOSERVER_BREATH (obsolete) minetest_client_commands[0x42] = { "BREATH", 2 } minetest_client_obsolete[0x42] = true -- TOSERVER_CLIENT_READY do local abbr = "minetest.client.client_ready_" local f_major = ProtoField.uint8(abbr.."major","Version Major") local f_minor = ProtoField.uint8(abbr.."minor","Version Minor") local f_patch = ProtoField.uint8(abbr.."patch","Version Patch") local f_reserved = ProtoField.uint8(abbr.."reserved","Reserved") local f_versionlen, f_version = minetest_field_helper("uint16", abbr.."version", "Full Version String") local f_formspec_ver = ProtoField.uint16(abbr.."formspec_version", "Formspec API version") minetest_client_commands[0x43] = { "CLIENT_READY", 8, { f_major, f_minor, f_patch, f_reserved, f_versionlen, f_version, f_formspec_ver }, function(buffer, pinfo, tree, t) t:add(f_major, buffer(2,1)) t:add(f_minor, buffer(3,1)) t:add(f_patch, buffer(4,1)) t:add(f_reserved, buffer(5,1)) local off = minetest_decode_helper_ascii(buffer, t, "uint16", 6, f_versionlen, f_version) if off and minetest_check_length(buffer, off + 2, t) then t:add(f_formspec_ver, buffer(off,2)) end end } end -- ... minetest_client_commands[0x50] = { "FIRST_SRP", 2 } minetest_client_commands[0x51] = { "SRP_BYTES_A", 2 } minetest_client_commands[0x52] = { "SRP_BYTES_M", 2 } -------------------------------------------- -- Part 3 -- -- Server command dissectors (TOCLIENT_*) -- -------------------------------------------- minetest_server_commands = {} minetest_server_obsolete = {} -- TOCLIENT_HELLO do local abbr = "minetest.server.hello_" local f_ser_fmt = ProtoField.uint8(abbr.."ser_version", "Deployed serialization format version", base.DEC) local f_comp_mode = ProtoField.uint16(abbr.."compression", "Deployed compression mode", base.DEC, { [0] = "No compression" }) local f_proto = ProtoField.uint16(abbr.."proto", "Deployed protocol version", base.DEC) local f_auth_methods = ProtoField.bytes(abbr.."auth_modes", "Supported authentication modes") local f_legacy_namelen, f_legacy_name = minetest_field_helper("uint16", abbr.."legacy_name", "Legacy player name for hashing") minetest_server_commands[0x02] = { "HELLO", 13, { f_ser_fmt, f_comp_mode, f_proto, f_auth_methods, f_legacy_namelen, f_legacy_name }, function(buffer, pinfo, tree, t) t:add(f_ser_fmt, buffer(2,1)) t:add(f_comp_mode, buffer(3,2)) t:add(f_proto, buffer(5,2)) t:add(f_auth_methods, buffer(7,4)) minetest_decode_helper_ascii(buffer, t, "uint16", 11, f_legacy_namelen, f_legacy_name) end } end -- TOCLIENT_AUTH_ACCEPT do local abbr = "minetest.server.auth_accept_" local f_player_x = ProtoField.float(abbr.."player_x", "Player position X") local f_player_y = ProtoField.float(abbr.."player_y", "Player position Y") local f_player_z = ProtoField.float(abbr.."player_z", "Player position Z") local f_map_seed = ProtoField.uint64(abbr.."map_seed", "Map seed") local f_send_interval = ProtoField.float(abbr.."send_interval", "Recommended send interval") local f_sudo_auth_methods = ProtoField.bytes(abbr.."sudo_auth_methods", "Supported auth methods for sudo mode") minetest_server_commands[0x03] = { "AUTH_ACCEPT", 30, { f_player_x, f_player_y, f_player_z, f_map_seed, f_send_interval, f_sudo_auth_methods }, function(buffer, pinfo, tree, t) t:add(f_player_x, buffer(2,4)) t:add(f_player_y, buffer(6,4)) t:add(f_player_z, buffer(10,4)) t:add(f_map_seed, buffer(14,8)) t:add(f_send_interval, buffer(22,4)) t:add(f_sudo_auth_methods, buffer(26,4)) end } end -- ... minetest_server_commands[0x04] = {"ACCEPT_SUDO_MODE", 2} minetest_server_commands[0x05] = {"DENY_SUDO_MODE", 2} minetest_server_commands[0x0A] = {"ACCESS_DENIED", 2} -- TOCLIENT_INIT (obsolete) minetest_server_commands[0x10] = { "INIT", 2 } minetest_server_obsolete[0x10] = true -- TOCLIENT_BLOCKDATA do local f_x = ProtoField.int16("minetest.server.blockdata_x", "Block position X", base.DEC) local f_y = ProtoField.int16("minetest.server.blockdata_y", "Block position Y", base.DEC) local f_z = ProtoField.int16("minetest.server.blockdata_z", "Block position Z", base.DEC) local f_data = ProtoField.bytes("minetest.server.blockdata_block", "Serialized MapBlock") minetest_server_commands[0x20] = { "BLOCKDATA", 8, { f_x, f_y, f_z, f_data }, function(buffer, pinfo, tree, t) t:add(f_x, buffer(2,2)) t:add(f_y, buffer(4,2)) t:add(f_z, buffer(6,2)) t:add(f_data, buffer(8, buffer:len() - 8)) end } end -- TOCLIENT_ADDNODE do local f_x = ProtoField.int16("minetest.server.addnode_x", "Position X", base.DEC) local f_y = ProtoField.int16("minetest.server.addnode_y", "Position Y", base.DEC) local f_z = ProtoField.int16("minetest.server.addnode_z", "Position Z", base.DEC) local f_data = ProtoField.bytes("minetest.server.addnode_node", "Serialized MapNode") minetest_server_commands[0x21] = { "ADDNODE", 8, { f_x, f_y, f_z, f_data }, function(buffer, pinfo, tree, t) t:add(f_x, buffer(2,2)) t:add(f_y, buffer(4,2)) t:add(f_z, buffer(6,2)) t:add(f_data, buffer(8, buffer:len() - 8)) end } end -- TOCLIENT_REMOVENODE do local f_x = ProtoField.int16("minetest.server.removenode_x", "Position X", base.DEC) local f_y = ProtoField.int16("minetest.server.removenode_y", "Position Y", base.DEC) local f_z = ProtoField.int16("minetest.server.removenode_z", "Position Z", base.DEC) minetest_server_commands[0x22] = { "REMOVENODE", 8, { f_x, f_y, f_z }, function(buffer, pinfo, tree, t) t:add(f_x, buffer(2,2)) t:add(f_y, buffer(4,2)) t:add(f_z, buffer(6,2)) end } end -- TOCLIENT_PLAYERPOS (obsolete) minetest_server_commands[0x23] = { "PLAYERPOS", 2 } minetest_server_obsolete[0x23] = true -- TOCLIENT_PLAYERINFO (obsolete) minetest_server_commands[0x24] = { "PLAYERINFO", 2 } minetest_server_obsolete[0x24] = true -- TOCLIENT_OPT_BLOCK_NOT_FOUND (obsolete) minetest_server_commands[0x25] = { "OPT_BLOCK_NOT_FOUND", 2 } minetest_server_obsolete[0x25] = true -- TOCLIENT_SECTORMETA (obsolete) minetest_server_commands[0x26] = { "SECTORMETA", 2 } minetest_server_obsolete[0x26] = true -- TOCLIENT_INVENTORY do local f_inventory = ProtoField.string("minetest.server.inventory", "Inventory") minetest_server_commands[0x27] = { "INVENTORY", 2, { f_inventory }, function(buffer, pinfo, tree, t) t:add(f_inventory, buffer(2, buffer:len() - 2)) end } end -- TOCLIENT_OBJECTDATA (obsolete) minetest_server_commands[0x28] = { "OBJECTDATA", 2 } minetest_server_obsolete[0x28] = true -- TOCLIENT_TIME_OF_DAY do local f_time = ProtoField.uint16("minetest.server.time_of_day", "Time", base.DEC) local f_time_speed = ProtoField.float("minetest.server.time_speed", "Time Speed", base.DEC) minetest_server_commands[0x29] = { "TIME_OF_DAY", 4, { f_time, f_time_speed }, function(buffer, pinfo, tree, t) t:add(f_time, buffer(2,2)) t:add(f_time_speed, buffer(4,4)) end } end -- TOCLIENT_CSM_RESTRICTION_FLAGS minetest_server_commands[0x2a] = { "CSM_RESTRICTION_FLAGS", 2 } -- TOCLIENT_PLAYER_SPEED minetest_server_commands[0x2b] = { "PLAYER_SPEED", 2 } -- TOCLIENT_CHAT_MESSAGE do local abbr = "minetest.server.chat_message_" local vs_type = { [0] = "Raw", [1] = "Normal", [2] = "Announce", [3] = "System", } local f_version = ProtoField.uint8(abbr.."version", "Version") local f_type = ProtoField.uint8(abbr.."type", "Message Type", base.DEC, vs_type) local f_senderlen, f_sender = minetest_field_helper("uint16", abbr.."sender", "Message sender") local f_messagelen, f_message = minetest_field_helper("uint16", abbr:sub(1,-2), "Message") minetest_server_commands[0x2f] = { "CHAT_MESSAGE", 8, { f_version, f_type, f_senderlen, f_sender, f_messagelen, f_message }, function(buffer, pinfo, tree, t) t:add(f_version, buffer(2,1)) t:add(f_type, buffer(3,1)) local off = 4 off = minetest_decode_helper_utf16(buffer, t, "uint16", off, f_senderlen, f_sender) if off then off = minetest_decode_helper_utf16(buffer, t, "uint16", off, f_messagelen, f_message) end end } end -- TOCLIENT_CHAT_MESSAGE_OLD (obsolete) minetest_server_commands[0x30] = { "CHAT_MESSAGE_OLD", 2 } minetest_server_obsolete[0x30] = true -- TOCLIENT_ACTIVE_OBJECT_REMOVE_ADD do local f_removed_count = ProtoField.uint16( "minetest.server.active_object_remove_add_removed_count", "Count of removed objects", base.DEC) local f_removed = ProtoField.bytes( "minetest.server.active_object_remove_add_removed", "Removed object") local f_removed_id = ProtoField.uint16( "minetest.server.active_object_remove_add_removed_id", "ID", base.DEC) local f_added_count = ProtoField.uint16( "minetest.server.active_object_remove_add_added_count", "Count of added objects", base.DEC) local f_added = ProtoField.bytes( "minetest.server.active_object_remove_add_added", "Added object") local f_added_id = ProtoField.uint16( "minetest.server.active_object_remove_add_added_id", "ID", base.DEC) local f_added_type = ProtoField.uint8( "minetest.server.active_object_remove_add_added_type", "Type", base.DEC) local f_added_init_length = ProtoField.uint32( "minetest.server.active_object_remove_add_added_init_length", "Initialization data length", base.DEC) local f_added_init_data = ProtoField.bytes( "minetest.server.active_object_remove_add_added_init_data", "Initialization data") minetest_server_commands[0x31] = { "ACTIVE_OBJECT_REMOVE_ADD", 6, { f_removed_count, f_removed, f_removed_id, f_added_count, f_added, f_added_id, f_added_type, f_added_init_length, f_added_init_data }, function(buffer, pinfo, tree, t) local t2, index, pos local removed_count_pos = 2 local removed_count = buffer(removed_count_pos, 2):uint() t:add(f_removed_count, buffer(removed_count_pos, 2)) local added_count_pos = removed_count_pos + 2 + 2 * removed_count if not minetest_check_length(buffer, added_count_pos + 2, t) then return end -- Loop through removed active objects for index = 0, removed_count - 1 do pos = removed_count_pos + 2 + 2 * index t2 = t:add(f_removed, buffer(pos, 2)) t2:set_text("Removed object, ID = " .. buffer(pos, 2):uint()) t2:add(f_removed_id, buffer(pos, 2)) end local added_count = buffer(added_count_pos, 2):uint() t:add(f_added_count, buffer(added_count_pos, 2)) -- Loop through added active objects pos = added_count_pos + 2 for index = 0, added_count - 1 do if not minetest_check_length(buffer, pos + 7, t) then return end local init_length = buffer(pos + 3, 4):uint() if not minetest_check_length(buffer, pos + 7 + init_length, t) then return end t2 = t:add(f_added, buffer(pos, 7 + init_length)) t2:set_text("Added object, ID = " .. buffer(pos, 2):uint()) t2:add(f_added_id, buffer(pos, 2)) t2:add(f_added_type, buffer(pos + 2, 1)) t2:add(f_added_init_length, buffer(pos + 3, 4)) t2:add(f_added_init_data, buffer(pos + 7, init_length)) pos = pos + 7 + init_length end pinfo.cols.info:append(" * " .. (removed_count + added_count)) end } end -- TOCLIENT_ACTIVE_OBJECT_MESSAGES do local f_object_count = ProtoField.uint16( "minetest.server.active_object_messages_object_count", "Count of objects", base.DEC) local f_object = ProtoField.bytes( "minetest.server.active_object_messages_object", "Object") local f_object_id = ProtoField.uint16( "minetest.server.active_object_messages_id", "ID", base.DEC) local f_message_length = ProtoField.uint16( "minetest.server.active_object_messages_message_length", "Message length", base.DEC) local f_message = ProtoField.bytes( "minetest.server.active_object_messages_message", "Message") minetest_server_commands[0x32] = { "ACTIVE_OBJECT_MESSAGES", 2, { f_object_count, f_object, f_object_id, f_message_length, f_message }, function(buffer, pinfo, tree, t) local t2, count, pos, message_length count = 0 pos = 2 while pos < buffer:len() do if not minetest_check_length(buffer, pos + 4, t) then return end message_length = buffer(pos + 2, 2):uint() if not minetest_check_length(buffer, pos + 4 + message_length, t) then return end count = count + 1 pos = pos + 4 + message_length end pinfo.cols.info:append(" * " .. count) t:add(f_object_count, count):set_generated() pos = 2 while pos < buffer:len() do message_length = buffer(pos + 2, 2):uint() t2 = t:add(f_object, buffer(pos, 4 + message_length)) t2:set_text("Object, ID = " .. buffer(pos, 2):uint()) t2:add(f_object_id, buffer(pos, 2)) t2:add(f_message_length, buffer(pos + 2, 2)) t2:add(f_message, buffer(pos + 4, message_length)) pos = pos + 4 + message_length end end } end -- TOCLIENT_HP do local f_hp = ProtoField.uint16("minetest.server.hp", "Health points", base.DEC) minetest_server_commands[0x33] = { "HP", 4, { f_hp }, function(buffer, pinfo, tree, t) t:add(f_hp, buffer(2,2)) end } end -- TOCLIENT_MOVE_PLAYER do local abbr = "minetest.server.move_player_" local f_x = ProtoField.float(abbr.."x", "Position X") local f_y = ProtoField.float(abbr.."y", "Position Y") local f_z = ProtoField.float(abbr.."z", "Position Z") local f_pitch = ProtoField.float(abbr.."_pitch", "Pitch") local f_yaw = ProtoField.float(abbr.."yaw", "Yaw") minetest_server_commands[0x34] = { "MOVE_PLAYER", 22, { f_x, f_y, f_z, f_pitch, f_yaw, f_garbage }, function(buffer, pinfo, tree, t) t:add(f_x, buffer(2, 4)) t:add(f_y, buffer(6, 4)) t:add(f_z, buffer(10, 4)) t:add(f_pitch, buffer(14, 4)) t:add(f_yaw, buffer(18, 4)) end } end -- TOCLIENT_ACCESS_DENIED_LEGACY do local f_reason_length = ProtoField.uint16("minetest.server.access_denied_reason_length", "Reason length", base.DEC) local f_reason = ProtoField.string("minetest.server.access_denied_reason", "Reason") minetest_server_commands[0x35] = { "ACCESS_DENIED_LEGACY", 4, { f_reason_length, f_reason }, function(buffer, pinfo, tree, t) t:add(f_reason_length, buffer(2,2)) local reason_length = buffer(2,2):uint() if minetest_check_length(buffer, 4 + reason_length * 2, t) then t:add(f_reason, minetest_convert_utf16(buffer(4, reason_length * 2), "Converted reason message")) end end } end -- TOCLIENT_FOV minetest_server_commands[0x36] = { "FOV", 2 } -- TOCLIENT_DEATHSCREEN do local f_set_camera_point_target = ProtoField.bool( "minetest.server.deathscreen_set_camera_point_target", "Set camera point target") local f_camera_point_target_x = ProtoField.int32( "minetest.server.deathscreen_camera_point_target_x", "Camera point target X", base.DEC) local f_camera_point_target_y = ProtoField.int32( "minetest.server.deathscreen_camera_point_target_y", "Camera point target Y", base.DEC) local f_camera_point_target_z = ProtoField.int32( "minetest.server.deathscreen_camera_point_target_z", "Camera point target Z", base.DEC) minetest_server_commands[0x37] = { "DEATHSCREEN", 15, { f_set_camera_point_target, f_camera_point_target_x, f_camera_point_target_y, f_camera_point_target_z}, function(buffer, pinfo, tree, t) t:add(f_set_camera_point_target, buffer(2,1)) t:add(f_camera_point_target_x, buffer(3,4)) t:add(f_camera_point_target_y, buffer(7,4)) t:add(f_camera_point_target_z, buffer(11,4)) end } end -- TOCLIENT_MEDIA minetest_server_commands[0x38] = {"MEDIA", 2} -- TOCLIENT_TOOLDEF (obsolete) minetest_server_commands[0x39] = {"TOOLDEF", 2} minetest_server_obsolete[0x39] = true -- TOCLIENT_NODEDEF minetest_server_commands[0x3a] = {"NODEDEF", 2} -- TOCLIENT_CRAFTITEMDEF (obsolete) minetest_server_commands[0x3b] = {"CRAFTITEMDEF", 2} minetest_server_obsolete[0x3b] = true -- ... minetest_server_commands[0x3c] = {"ANNOUNCE_MEDIA", 2} minetest_server_commands[0x3d] = {"ITEMDEF", 2} minetest_server_commands[0x3f] = {"PLAY_SOUND", 2} minetest_server_commands[0x40] = {"STOP_SOUND", 2} minetest_server_commands[0x41] = {"PRIVILEGES", 2} minetest_server_commands[0x42] = {"INVENTORY_FORMSPEC", 2} minetest_server_commands[0x43] = {"DETACHED_INVENTORY", 2} minetest_server_commands[0x44] = {"SHOW_FORMSPEC", 2} minetest_server_commands[0x45] = {"MOVEMENT", 2} minetest_server_commands[0x46] = {"SPAWN_PARTICLE", 2} minetest_server_commands[0x47] = {"ADD_PARTICLE_SPAWNER", 2} -- TOCLIENT_DELETE_PARTICLESPAWNER_LEGACY (obsolete) minetest_server_commands[0x48] = {"DELETE_PARTICLESPAWNER_LEGACY", 2} minetest_server_obsolete[0x48] = true -- ... minetest_server_commands[0x49] = {"HUDADD", 2} minetest_server_commands[0x4a] = {"HUDRM", 2} minetest_server_commands[0x4b] = {"HUDCHANGE", 2} minetest_server_commands[0x4c] = {"HUD_SET_FLAGS", 2} minetest_server_commands[0x4d] = {"HUD_SET_PARAM", 2} minetest_server_commands[0x4e] = {"BREATH", 2} minetest_server_commands[0x4f] = {"SET_SKY", 2} minetest_server_commands[0x50] = {"OVERRIDE_DAY_NIGHT_RATIO", 2} minetest_server_commands[0x51] = {"LOCAL_PLAYER_ANIMATIONS", 2} minetest_server_commands[0x52] = {"EYE_OFFSET", 2} minetest_server_commands[0x53] = {"DELETE_PARTICLESPAWNER", 2} minetest_server_commands[0x54] = {"CLOUD_PARAMS", 2} minetest_server_commands[0x55] = {"FADE_SOUND", 2} -- TOCLIENT_UPDATE_PLAYER_LIST do local abbr = "minetest.server.update_player_list_" local vs_type = { [0] = "Init", [1] = "Add", [2] = "Remove", } local f_type = ProtoField.uint8(abbr.."type", "Type", base.DEC, vs_type) local f_count = ProtoField.uint16(abbr.."count", "Number of players", base.DEC) local f_name = ProtoField.string(abbr.."name", "Name") minetest_server_commands[0x56] = { "UPDATE_PLAYER_LIST", 5, { f_type, f_count, f_name }, function(buffer, pinfo, tree, t) t:add(f_type, buffer(2,1)) t:add(f_count, buffer(3,2)) local count = buffer(3,2):uint() local off = 5 for i = 1, count do if not minetest_check_length(buffer, off + 2, t) then return end off = minetest_decode_helper_ascii(buffer, t, "uint16", off, nil, f_name) if not off then return end end end } end -- ... minetest_server_commands[0x57] = {"MODCHANNEL_MSG", 2} minetest_server_commands[0x58] = {"MODCHANNEL_SIGNAL", 2} minetest_server_commands[0x59] = {"NODEMETA_CHANGED", 2} minetest_server_commands[0x5a] = {"SET_SUN", 2} minetest_server_commands[0x5b] = {"SET_MOON", 2} minetest_server_commands[0x5c] = {"SET_STARS", 2} minetest_server_commands[0x60] = {"SRP_BYTES_S_B", 2} minetest_server_commands[0x61] = {"FORMSPEC_PREPEND", 2} ------------------------------------ -- Part 4 -- -- Wrapper protocol subdissectors -- ------------------------------------ -- minetest.control dissector do local p_control = Proto("minetest.control", "Minetest Control") local vs_control_type = { [0] = "Ack", [1] = "Set Peer ID", [2] = "Ping", [3] = "Disco" } local f_control_type = ProtoField.uint8("minetest.control.type", "Control Type", base.DEC, vs_control_type) local f_control_ack = ProtoField.uint16("minetest.control.ack", "ACK sequence number", base.DEC) local f_control_peerid = ProtoField.uint8("minetest.control.peerid", "New peer ID", base.DEC) p_control.fields = { f_control_type, f_control_ack, f_control_peerid } local data_dissector = Dissector.get("data") function p_control.dissector(buffer, pinfo, tree) local t = tree:add(p_control, buffer(0,1)) t:add(f_control_type, buffer(0,1)) pinfo.cols.info = "Control message" local pos = 1 if buffer(0,1):uint() == 0 then pos = 3 t:set_len(3) t:add(f_control_ack, buffer(1,2)) pinfo.cols.info = "Ack " .. buffer(1,2):uint() elseif buffer(0,1):uint() == 1 then pos = 3 t:set_len(3) t:add(f_control_peerid, buffer(1,2)) pinfo.cols.info = "Set peer ID " .. buffer(1,2):uint() elseif buffer(0,1):uint() == 2 then pinfo.cols.info = "Ping" elseif buffer(0,1):uint() == 3 then pinfo.cols.info = "Disco" end data_dissector:call(buffer(pos):tvb(), pinfo, tree) end end -- minetest.client dissector -- minetest.server dissector -- Defines the minetest.client or minetest.server Proto. These two protocols -- are created by the same function because they are so similar. -- Parameter: proto: the Proto object -- Parameter: this_peer: "Client" or "Server" -- Parameter: other_peer: "Server" or "Client" -- Parameter: commands: table of command information, built above -- Parameter: obsolete: table of obsolete commands, built above function minetest_define_client_or_server_proto(is_client) -- Differences between minetest.client and minetest.server local proto_name, this_peer, other_peer, empty_message_info local commands, obsolete if is_client then proto_name = "minetest.client" this_peer = "Client" other_peer = "Server" empty_message_info = "Empty message / Connect" commands = minetest_client_commands -- defined in Part 2 obsolete = minetest_client_obsolete -- defined in Part 2 else proto_name = "minetest.server" this_peer = "Server" other_peer = "Client" empty_message_info = "Empty message" commands = minetest_server_commands -- defined in Part 3 obsolete = minetest_server_obsolete -- defined in Part 3 end -- Create the protocol object. local proto = Proto(proto_name, "Minetest " .. this_peer .. " to " .. other_peer) -- Create a table vs_command that maps command codes to command names. local vs_command = {} local code, command_info for code, command_info in pairs(commands) do local command_name = command_info[1] vs_command[code] = "TO" .. other_peer:upper() .. "_" .. command_name end -- Field definitions local f_command = ProtoField.uint16(proto_name .. ".command", "Command", base.HEX, vs_command) local f_empty = ProtoField.bool(proto_name .. ".empty", "Is empty", BASE_NONE) proto.fields = { f_command, f_empty } -- Add command-specific fields to the protocol for code, command_info in pairs(commands) do local command_fields = command_info[3] if command_fields ~= nil then for index, field in ipairs(command_fields) do assert(field ~= nil) table.insert(proto.fields, field) end end end -- minetest.client or minetest.server dissector function function proto.dissector(buffer, pinfo, tree) local t = tree:add(proto, buffer) pinfo.cols.info = this_peer if buffer:len() == 0 then -- Empty message. t:add(f_empty, 1):set_generated() pinfo.cols.info:append(": " .. empty_message_info) elseif minetest_check_length(buffer, 2, t) then -- Get the command code. t:add(f_command, buffer(0,2)) local code = buffer(0,2):uint() local command_info = commands[code] if command_info == nil then -- Error: Unknown command. pinfo.cols.info:append(": Unknown command") t:add_expert_info(PI_UNDECODED, PI_WARN, "Unknown " .. this_peer .. " to " .. other_peer .. " command") else -- Process a known command local command_name = command_info[1] local command_min_length = command_info[2] local command_fields = command_info[3] local command_dissector = command_info[4] if minetest_check_length(buffer, command_min_length, t) then pinfo.cols.info:append(": " .. command_name) if command_dissector ~= nil then command_dissector(buffer, pinfo, tree, t) end end if obsolete[code] then t:add_expert_info(PI_REQUEST_CODE, PI_WARN, "Obsolete command.") end end end end end minetest_define_client_or_server_proto(true) -- minetest.client minetest_define_client_or_server_proto(false) -- minetest.server -- minetest.split dissector do local p_split = Proto("minetest.split", "Minetest Split Message") local f_split_seq = ProtoField.uint16("minetest.split.seq", "Sequence number", base.DEC) local f_split_chunkcount = ProtoField.uint16("minetest.split.chunkcount", "Chunk count", base.DEC) local f_split_chunknum = ProtoField.uint16("minetest.split.chunknum", "Chunk number", base.DEC) local f_split_data = ProtoField.bytes("minetest.split.data", "Split message data") p_split.fields = { f_split_seq, f_split_chunkcount, f_split_chunknum, f_split_data } function p_split.dissector(buffer, pinfo, tree) local t = tree:add(p_split, buffer(0,6)) t:add(f_split_seq, buffer(0,2)) t:add(f_split_chunkcount, buffer(2,2)) t:add(f_split_chunknum, buffer(4,2)) t:add(f_split_data, buffer(6)) pinfo.cols.info:append(" " .. buffer(0,2):uint() .. " chunk " .. buffer(4,2):uint() .. "/" .. buffer(2,2):uint()) end end ------------------------------------- -- Part 5 -- -- Wrapper protocol main dissector -- ------------------------------------- -- minetest dissector do local p_minetest = Proto("minetest", "Minetest") local minetest_id = 0x4f457403 local vs_id = { [minetest_id] = "Valid" } local vs_peer = { [0] = "Inexistent", [1] = "Server" } local vs_type = { [0] = "Control", [1] = "Original", [2] = "Split", [3] = "Reliable" } local f_id = ProtoField.uint32("minetest.id", "ID", base.HEX, vs_id) local f_peer = ProtoField.uint16("minetest.peer", "Peer", base.DEC, vs_peer) local f_channel = ProtoField.uint8("minetest.channel", "Channel", base.DEC) local f_type = ProtoField.uint8("minetest.type", "Type", base.DEC, vs_type) local f_seq = ProtoField.uint16("minetest.seq", "Sequence number", base.DEC) local f_subtype = ProtoField.uint8("minetest.subtype", "Subtype", base.DEC, vs_type) p_minetest.fields = { f_id, f_peer, f_channel, f_type, f_seq, f_subtype } local data_dissector = Dissector.get("data") local control_dissector = Dissector.get("minetest.control") local client_dissector = Dissector.get("minetest.client") local server_dissector = Dissector.get("minetest.server") local split_dissector = Dissector.get("minetest.split") function p_minetest.dissector(buffer, pinfo, tree) -- Add Minetest tree item and verify the ID local t = tree:add(p_minetest, buffer(0,8)) t:add(f_id, buffer(0,4)) if buffer(0,4):uint() ~= minetest_id then t:add_expert_info(PI_UNDECODED, PI_WARN, "Invalid ID, this is not a Minetest packet") return end -- ID is valid, so replace packet's shown protocol pinfo.cols.protocol = "Minetest" pinfo.cols.info = "Minetest" -- Set the other header fields t:add(f_peer, buffer(4,2)) t:add(f_channel, buffer(6,1)) t:add(f_type, buffer(7,1)) t:set_text("Minetest, Peer: " .. buffer(4,2):uint() .. ", Channel: " .. buffer(6,1):uint()) local reliability_info if buffer(7,1):uint() == 3 then -- Reliable message reliability_info = "Seq=" .. buffer(8,2):uint() t:set_len(11) t:add(f_seq, buffer(8,2)) t:add(f_subtype, buffer(10,1)) pos = 10 else -- Unreliable message reliability_info = "Unrel" pos = 7 end if buffer(pos,1):uint() == 0 then -- Control message, possibly reliable control_dissector:call(buffer(pos+1):tvb(), pinfo, tree) elseif buffer(pos,1):uint() == 1 then -- Original message, possibly reliable if buffer(4,2):uint() == 1 then server_dissector:call(buffer(pos+1):tvb(), pinfo, tree) else client_dissector:call(buffer(pos+1):tvb(), pinfo, tree) end elseif buffer(pos,1):uint() == 2 then -- Split message, possibly reliable if buffer(4,2):uint() == 1 then pinfo.cols.info = "Server: Split message" else pinfo.cols.info = "Client: Split message" end split_dissector:call(buffer(pos+1):tvb(), pinfo, tree) elseif buffer(pos,1):uint() == 3 then -- Doubly reliable message?? t:add_expert_info(PI_MALFORMED, PI_ERROR, "Reliable message wrapped in reliable message") else data_dissector:call(buffer(pos+1):tvb(), pinfo, tree) end pinfo.cols.info:append(" (" .. reliability_info .. ")") end -- FIXME Is there a way to let the dissector table check if the first payload bytes are 0x4f457403? DissectorTable.get("udp.port"):add(30000, p_minetest) DissectorTable.get("udp.port"):add(30001, p_minetest) end ------------------------------ -- Part 6 -- -- Utility functions part 2 -- ------------------------------ -- Checks if a (sub-)Tvb is long enough to be further dissected. -- If it is long enough, sets the dissector tree item length to min_len -- and returns true. If it is not long enough, adds expert info to the -- dissector tree and returns false. -- Parameter: tvb: the Tvb -- Parameter: min_len: required minimum length -- Parameter: t: dissector tree item -- Returns: true if tvb:len() >= min_len, false otherwise function minetest_check_length(tvb, min_len, t) if tvb:len() >= min_len then t:set_len(min_len) return true -- TODO: check if other parts of -- the dissector could benefit from reported_length_remaining elseif tvb:reported_length_remaining() >= min_len then t:add_expert_info(PI_UNDECODED, PI_INFO, "Only part of this packet was captured, unable to decode.") return false else t:add_expert_info(PI_MALFORMED, PI_ERROR, "Message is too short") return false 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 -- lentype must be the type of the length field (as passed to minetest_field_helper) -- returns nil if length check failed function minetest_decode_helper_ascii(tvb, t, lentype, offset, f_textlen, f_text) local n = ({uint16 = 2, uint32 = 4})[lentype] assert(n) if f_textlen then t:add(f_textlen, tvb(offset, n)) end local textlen = tvb(offset, n):uint() if minetest_check_length(tvb, offset + n + textlen, t) then t:add(f_text, tvb(offset + n, textlen)) return offset + n + textlen end end -- Decodes a variable-length string as UTF-16 text -- (see minetest_decode_helper_ascii) function minetest_decode_helper_utf16(tvb, t, lentype, offset, f_textlen, f_text) local n = ({uint16 = 2, uint32 = 4})[lentype] assert(n) if f_textlen then t:add(f_textlen, tvb(offset, n)) end local textlen = tvb(offset, n):uint() * 2 if minetest_check_length(tvb, offset + n + textlen, t) then t:add(f_text, tvb(offset + n, textlen), tvb(offset + n, textlen):ustring()) return offset + n + textlen end end