share/lua/intf/telnet.lua

   1 --[==========================================================================[
   2  telnet.lua: VLM interface plugin
   3 --[==========================================================================[
   4  Copyright (C) 2007 the VideoLAN team
   5  $Id$
   6
   7  Authors: Antoine Cellerier <dionoea at videolan dot org>
   8
   9  This program is free software; you can redistribute it and/or modify
  10  it under the terms of the GNU General Public License as published by
  11  the Free Software Foundation; either version 2 of the License, or
  12  (at your option) any later version.
  13
  14  This program is distributed in the hope that it will be useful,
  15  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  GNU General Public License for more details.
  18
  19  You should have received a copy of the GNU General Public License
  20  along with this program; if not, write to the Free Software
  21  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22 --]==========================================================================]
  23
  24 description=
  25 [============================================================================[
  26  VLM Interface plugin
  27
  28  Copy (features wise) of the original VLC modules/control/telnet.c module.
  29
  30  Differences are:
  31     * it's in Lua
  32     * 'lock' command to lock the telnet promt
  33     * possibility to listen on different hosts including stdin
  34       for example:
  35         listen on stdin: vlc -I lua --lua-intf telnet --lua-config "telnet={host='*console'}"
  36         listen on stdin + 2 ports on localhost: vlc -I lua --lua-intf telnet --lua-config "telnet={hosts={'localhost:4212','localhost:5678','*console'}}"
  37
  38  Configuration options setable throught the --lua-config option are:
  39     * hosts: A list of hosts to listen on (see examples above).
  40     * host: A host to listen on. (won't be used if `hosts' is set)
  41     * password: The password used for remote clients.
  42     * prompt: The prompt.
  43 ]============================================================================]
  44
  45 require "host"
  46
  47 --[[ Some telnet command special characters ]]
  48 WILL = "\251" -- Indicates the desire to begin performing, or confirmation that you are now performing, the indicated option.
  49 WONT = "\252" -- Indicates the refusal to perform, or continue performing, the indicated option.
  50 DO   = "\253" -- Indicates the request that the other party perform, or confirmation that you are expecting the other party to perform, the indicated option.
  51 DONT = "\254" -- Indicates the demand that the other party stop performing, or confirmation that you are no longer expecting the other party to perform, the indicated option.
  52 IAC  = "\255" -- Interpret as command
  53
  54 ECHO = "\001"
  55
  56 --[[ Client status change callbacks ]]
  57 function on_password( client )
  58     if client.type == host.client_type.net then
  59         client:send( "Password: " ..IAC..WILL..ECHO )
  60     else
  61         -- no authentication needed on stdin
  62         client:switch_status( host.status.read )
  63     end
  64 end
  65 function on_read( client )
  66     client:send( config.prompt and tostring(config.prompt) or "> " )
  67 end
  68 function on_write( client )
  69 end
  70
  71 --[[ Misc functions ]]
  72 function telnet_commands( client )
  73     -- remove telnet command replies from the client's data
  74     client.buffer = string.gsub( client.buffer, IAC.."["..DO..DONT..WILL..WONT.."].", "" )
  75 end
  76
  77 function vlm_message_to_string(client,message,prefix)
  78     local prefix = prefix or ""
  79     if message.value then
  80         client:append(prefix .. message.name .. " : " .. message.value)
  81         return
  82     else
  83         client:append(prefix .. message.name)
  84         if message.children then
  85             for i,c in ipairs(message.children) do
  86                 vlm_message_to_string(client,c,prefix.."    ")
  87             end
  88         end
  89         return
  90     end
  91 end
  92
  93 --[[ Configure the host ]]
  94 h = host.host()
  95
  96 h.status_callbacks[host.status.password] = on_password
  97 h.status_callbacks[host.status.read] = on_read
  98 h.status_callbacks[host.status.write] = on_write
  99
 100 h:listen( config.hosts or config.host or "localhost:4212" )
 101 password = config.password or "admin"
 102
 103 --[[ Launch vlm ]]
 104 vlm = vlc.vlm()
 105
 106 --[[ Commands ]]
 107 function shutdown(client)
 108     h:broadcast("Shutting down.\r\n")
 109     vlc.msg.err("shutdown requested")
 110     vlc.misc.quit()
 111     return true
 112 end
 113 function logout(client)
 114     client:del()
 115     return true
 116 end
 117 function quit(client)
 118     if client.type == host.client_type.net then
 119         return logout(client)
 120     else
 121         return shutdown(client)
 122     end
 123 end
 124 function lock(client)
 125     client:send("\r\n")
 126     client:switch_status( host.status.password )
 127     client.buffer = ""
 128     return false
 129 end
 130 function print_text(text)
 131     return function(client)
 132         client:append(string.gsub(text,"\r?\n","\r\n"))
 133         return true
 134     end
 135 end
 136 function help(client)
 137     client:append("    Telnet Specific Commands:")
 138     for c,t in pairs(commands) do
 139         client:append("        "..c.." : "..t.help)
 140     end
 141     return true
 142 end
 143 commands = {
 144     ["shutdown"]    = { func = shutdown, help = "shutdown VLC" },
 145     ["quit"]        = { func = quit, help = "logout from telnet/shutdown VLC from local shell" },
 146     ["logout"]      = { func = logout, help = "logout" },
 147     ["lock"]        = { func = lock, help = "lock the telnet prompt" },
 148     ["description"] = { func = print_text(description), help = "describe this module" },
 149     ["license"]     = { func = print_text(vlc.misc.license()), help = "print VLC's license message" },
 150     ["help"]        = { func = help, help = "show this help", dovlm = true },
 151     }
 152
 153 function client_command( client )
 154     local cmd = client.buffer
 155     client.buffer = ""
 156     if not commands[cmd] or not commands[cmd].func or commands[cmd].dovlm then
 157         -- if it's not an interface specific command, it has to be a VLM command
 158         local message, vlc_err = vlm:execute_command( cmd )
 159         vlm_message_to_string( client, message )
 160         if not commands[cmd] or not commands[cmd].func and not commands[cmd].dovlm then
 161             if vlc_err ~= 0 then client:append( "Type `help' for help." ) end
 162             return true
 163         end
 164     end
 165     ok, msg = pcall( commands[cmd].func, client )
 166     if not ok then
 167         client:append( "Error in `"..cmd.."' "..msg )
 168         return true
 169     end
 170     return msg
 171 end
 172
 173 --[[ The main loop ]]
 174 while not vlc.misc.should_die() do
 175     local w, r = h:accept_and_select()
 176
 177     -- Handle writes
 178     for _, client in pairs(w) do
 179         local len = client:send()
 180         client.buffer = string.sub(client.buffer,len+1)
 181         if client.buffer == "" then client:switch_status( host.status.read ) end
 182     end
 183
 184     -- Handle reads
 185     for _, client in pairs(r) do
 186         local str = string.gsub(client:recv(1000),"\r","\n")
 187         local done = false
 188
 189         -- the telnet client program has leave
 190         if not str then
 191             client.buffer = "quit"
 192             done = true
 193
 194         -- Caught a ^D
 195         elseif client.buffer == ""
 196            and ((client.type == host.client_type.stdio and str == "")
 197            or  (client.type == host.client_type.net and str == "\004")) then
 198             client.buffer = "quit"
 199             done = true
 200
 201         -- '\n' found: a command was sent
 202         elseif string.match(str,"\n") then
 203             client.buffer = client.buffer .. str
 204             done = true
 205
 206         -- The command is not finished yet
 207         else
 208             client.buffer = client.buffer .. str
 209         end
 210
 211         -- Some cleaning for telnet
 212         if client.type == host.client_type.net then
 213             telnet_commands( client )
 214         end
 215
 216         -- If a command must be parsed
 217         if done then
 218             -- loop on all commands (might have more than one commands seperated by '\n'
 219             local returned_values = ""
 220             while not (client.buffer == "") do
 221                 -- pick the first command
 222                 local commands = ""
 223                 if string.find(client.buffer, "\n") then
 224                     commands = string.sub(client.buffer, string.find(client.buffer, "\n") + 1)
 225                     client.buffer = string.sub(client.buffer, 0, string.find(client.buffer, "\n") - 1)
 226                 end
 227                 local cmd = client.buffer
 228
 229                 if client.status == host.status.password then
 230                     if client.buffer == password then
 231                         client:send( IAC..WONT..ECHO.."\r\nWelcome, Master\r\n" )
 232                         client.buffer = ""
 233                         client:switch_status( host.status.write )
 234                     else
 235                         client:send( "\r\nWrong password\r\nPassword: " )
 236                         client.buffer = ""
 237                     end
 238                 elseif client_command( client ) then
 239                     client:switch_status( host.status.write )
 240                     -- special case to exit the loop
 241                     if cmd == "quit" or cmd == "shutdown" then break end
 242                 end
 243                 returned_values = returned_values .. client.buffer
 244                 client.buffer = commands
 245             end
 246             vlc.msg.err("end of loop")
 247             client.buffer = returned_values
 248         end
 249     end
 250 end
 251
 252 --[[ Clean up ]]
 253 vlm = nil