e390a13cdc29eacf0cee41abdb2c356388ed7710
[vlc.git] / modules / control / telnet.c
1 /*****************************************************************************
2  * telnet.c: VLM interface plugin
3  *****************************************************************************
4  * Copyright (C) 2000-2006 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Simon Latapie <garf@videolan.org>
8  *          Laurent Aimar <fenrir@videolan.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23  *****************************************************************************/
24
25 /*****************************************************************************
26  * Preamble
27  *****************************************************************************/
28 #include <stdlib.h>                                      /* malloc(), free() */
29
30 #include <vlc/vlc.h>
31 #include <vlc_interface.h>
32 #include <vlc_input.h>
33
34 #include <sys/stat.h>
35
36 #include <errno.h>
37 #include <fcntl.h>
38
39 #ifdef HAVE_SYS_TIME_H
40 #    include <sys/time.h>
41 #endif
42
43 #ifdef HAVE_UNISTD_H
44 #   include <unistd.h>
45 #endif
46
47 #include <vlc_network.h>
48 #include <vlc_url.h>
49 #include <vlc_vlm.h>
50
51 #define READ_MODE_PWD 1
52 #define READ_MODE_CMD 2
53 #define WRITE_MODE_PWD 3 // when we write the word "Password:"
54 #define WRITE_MODE_CMD 4
55
56 /* telnet commands */
57 #define TEL_WILL    251
58 #define TEL_WONT    252
59 #define TEL_DO      253
60 #define TEL_DONT    254
61 #define TEL_IAC     255
62 #define TEL_ECHO    1
63
64 /*****************************************************************************
65  * Module descriptor
66  *****************************************************************************/
67 static int  Open ( vlc_object_t * );
68 static void Close( vlc_object_t * );
69
70 #define TELNETHOST_TEXT N_( "Host" )
71 #define TELNETHOST_LONGTEXT N_( "This is the host on which the " \
72     "interface will listen. It defaults to all network interfaces (0.0.0.0)." \
73     " If you want this interface to be available only on the local " \
74     "machine, enter \"127.0.0.1\"." )
75 #define TELNETPORT_TEXT N_( "Port" )
76 #define TELNETPORT_LONGTEXT N_( "This is the TCP port on which this " \
77     "interface will listen. It defaults to 4212." )
78 #define TELNETPORT_DEFAULT 4212
79 #define TELNETPWD_TEXT N_( "Password" )
80 #define TELNETPWD_LONGTEXT N_( "A single administration password is used " \
81     "to protect this interface. The default value is \"admin\"." )
82 #define TELNETPWD_DEFAULT "admin"
83
84 vlc_module_begin();
85     set_shortname( "Telnet" );
86     set_category( CAT_INTERFACE );
87     set_subcategory( SUBCAT_INTERFACE_CONTROL );
88     add_string( "telnet-host", "", NULL, TELNETHOST_TEXT,
89                  TELNETHOST_LONGTEXT, VLC_TRUE );
90     add_integer( "telnet-port", TELNETPORT_DEFAULT, NULL, TELNETPORT_TEXT,
91                  TELNETPORT_LONGTEXT, VLC_TRUE );
92     add_string( "telnet-password", TELNETPWD_DEFAULT, NULL, TELNETPWD_TEXT,
93                 TELNETPWD_LONGTEXT, VLC_TRUE );
94     set_description( _("VLM remote control interface") );
95     add_category_hint( "VLM", NULL, VLC_FALSE );
96     set_capability( "interface", 0 );
97     set_callbacks( Open , Close );
98 vlc_module_end();
99
100 /*****************************************************************************
101  * Local prototypes.
102  *****************************************************************************/
103 static void Run( intf_thread_t * );
104
105 typedef struct
106 {
107     int        i_mode; /* read or write */
108     int        fd;
109     char       buffer_read[1000]; // 1000 byte per command should be sufficient
110     char      *buffer_write;
111     char      *p_buffer_read;
112     char      *p_buffer_write; // the position in the buffer
113     int        i_buffer_write; // the number of byte we still have to send
114     int        i_tel_cmd; // for specific telnet commands
115
116 } telnet_client_t;
117
118 static char *MessageToString( vlm_message_t *, int );
119 static void Write_message( telnet_client_t *, vlm_message_t *, char *, int );
120
121 struct intf_sys_t
122 {
123    telnet_client_t **clients;
124    int             i_clients;
125    int             *pi_fd;
126    vlm_t           *mediatheque;
127 };
128
129 /*
130  * getPort: Decide which port to use. There are two possibilities to
131  * specify a port: integrated in the --telnet-host option with :PORT
132  * or using the --telnet-port option. The --telnet-port option has
133  * precedence.
134  * This code relies upon the fact the url.i_port is 0 if the :PORT
135  * option is missing from --telnet-host.
136  */
137 static int getPort(intf_thread_t *p_intf, vlc_url_t url, int i_port)
138 {
139     // Print error if two different ports have been specified
140     if (url.i_port != 0  &&
141         i_port != TELNETPORT_DEFAULT &&
142         url.i_port != i_port )
143     {
144         msg_Err( p_intf, "ignoring port %d and using %d", url.i_port,
145                  i_port);
146     }
147     if (i_port != TELNETPORT_DEFAULT)
148     {
149         return i_port;
150     }
151     if (url.i_port != 0)
152     {
153          return url.i_port;
154     }
155     return i_port;
156 }
157
158 /*****************************************************************************
159  * Open: initialize dummy interface
160  *****************************************************************************/
161 static int Open( vlc_object_t *p_this )
162 {
163     intf_thread_t *p_intf = (intf_thread_t*) p_this;
164     vlm_t *mediatheque;
165     char *psz_address;
166     vlc_url_t url;
167     int i_telnetport;
168
169     if( !(mediatheque = vlm_New( p_intf )) )
170     {
171         msg_Err( p_intf, "cannot start VLM" );
172         return VLC_EGENERIC;
173     }
174
175     msg_Info( p_intf, "using the VLM interface plugin..." );
176
177     i_telnetport = config_GetInt( p_intf, "telnet-port" );
178     psz_address  = config_GetPsz( p_intf, "telnet-host" );
179
180     vlc_UrlParse(&url, psz_address, 0);
181
182     // There might be two ports given, resolve any potentially
183     // conflict
184     url.i_port = getPort(p_intf, url, i_telnetport);
185
186     p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
187     if( ( p_intf->p_sys->pi_fd = net_ListenTCP( p_intf, url.psz_host, url.i_port ) )
188                 == NULL )
189     {
190         msg_Err( p_intf, "cannot listen for telnet" );
191         vlc_UrlClean(&url);
192         free( psz_address );
193         free( p_intf->p_sys );
194         return VLC_EGENERIC;
195     }
196     msg_Info( p_intf,
197               "telnet interface started on interface %s %d",
198               url.psz_host, url.i_port );
199
200     p_intf->p_sys->i_clients   = 0;
201     p_intf->p_sys->clients     = NULL;
202     p_intf->p_sys->mediatheque = mediatheque;
203     p_intf->pf_run = Run;
204
205     vlc_UrlClean(&url);
206     free( psz_address );
207     return VLC_SUCCESS;
208 }
209
210 /*****************************************************************************
211  * Close:
212  *****************************************************************************/
213 static void Close( vlc_object_t *p_this )
214 {
215     intf_thread_t *p_intf = (intf_thread_t*)p_this;
216     intf_sys_t    *p_sys  = p_intf->p_sys;
217     int i;
218
219     for( i = 0; i < p_sys->i_clients; i++ )
220     {
221         telnet_client_t *cl = p_sys->clients[i];
222         net_Close( cl->fd );
223         free( cl );
224         p_sys->clients[i] = NULL;
225     }
226     if( p_sys->clients != NULL ) free( p_sys->clients );
227
228     net_ListenClose( p_sys->pi_fd );
229
230     vlm_Delete( p_sys->mediatheque );
231
232     free( p_sys );
233 }
234
235 /*****************************************************************************
236  * Run: main loop
237  *****************************************************************************/
238 static void Run( intf_thread_t *p_intf )
239 {
240     intf_sys_t     *p_sys = p_intf->p_sys;
241     struct timeval  timeout;
242     char           *psz_password;
243
244     psz_password = config_GetPsz( p_intf, "telnet-password" );
245
246     while( !intf_ShouldDie( p_intf ) )
247     {
248         fd_set fds_read, fds_write;
249         int    i_handle_max = 0;
250         int    i_ret, i_len, fd, i;
251
252         /* if a new client wants to communicate */
253         fd = net_Accept( p_intf, p_sys->pi_fd, p_sys->i_clients > 0 ? 0 : -1 );
254         if( fd != -1 )
255         {
256             telnet_client_t *cl = malloc( sizeof( telnet_client_t ));
257             if( cl )
258             {
259                 memset( cl, 0, sizeof(telnet_client_t) );
260                 cl->i_tel_cmd = 0;
261                 cl->fd = fd;
262                 cl->buffer_write = NULL;
263                 cl->p_buffer_write = cl->buffer_write;
264                 Write_message( cl, NULL,
265                                "Password: \xff\xfb\x01" , WRITE_MODE_PWD );
266
267                 TAB_APPEND( p_sys->i_clients, p_sys->clients, cl );
268             }
269             else
270             {
271                 net_Close( fd );
272                 continue;
273             }
274         }
275
276         /* to do a proper select */
277         FD_ZERO( &fds_read );
278         FD_ZERO( &fds_write );
279
280         for( i = 0 ; i < p_sys->i_clients ; i++ )
281         {
282             telnet_client_t *cl = p_sys->clients[i];
283
284             if( (cl->i_mode == WRITE_MODE_PWD) || (cl->i_mode == WRITE_MODE_CMD) )
285             {
286                 FD_SET( cl->fd , &fds_write );
287             }
288             else
289             {
290                 FD_SET( cl->fd , &fds_read );
291             }
292             i_handle_max = __MAX( i_handle_max, cl->fd );
293         }
294
295         timeout.tv_sec = 0;
296         timeout.tv_usec = 500*1000;
297
298         i_ret = select( i_handle_max + 1, &fds_read, &fds_write, 0, &timeout );
299         if( (i_ret == -1) && (errno != EINTR) )
300         {
301             msg_Warn( p_intf, "cannot select sockets" );
302             msleep( 1000 );
303             continue;
304         }
305         else if( i_ret <= 0 )
306         {
307             continue;
308         }
309
310         /* check if there is something to do with the socket */
311         for( i = 0 ; i < p_sys->i_clients ; i++ )
312         {
313             telnet_client_t *cl = p_sys->clients[i];
314
315             if( FD_ISSET(cl->fd , &fds_write) && (cl->i_buffer_write > 0) )
316             {
317                 i_len = send( cl->fd, cl->p_buffer_write ,
318                               cl->i_buffer_write, 0 );
319                 if( i_len > 0 )
320                 {
321                     cl->p_buffer_write += i_len;
322                     cl->i_buffer_write -= i_len;
323                 }
324             }
325             else if( FD_ISSET( cl->fd, &fds_read) )
326             {
327                 int i_end = 0;
328                 int i_recv;
329
330                 while( ((i_recv=recv( cl->fd, cl->p_buffer_read, 1, 0 )) > 0) &&
331                        ((cl->p_buffer_read - cl->buffer_read) < 999) )
332                 {
333                     switch( cl->i_tel_cmd )
334                     {
335                     case 0:
336                         switch( *(uint8_t *)cl->p_buffer_read )
337                         {
338                         case '\r':
339                             break;
340                         case '\n':
341                             *cl->p_buffer_read = '\n';
342                             i_end = 1;
343                             break;
344                         case TEL_IAC: // telnet specific command
345                             cl->i_tel_cmd = 1;
346                             cl->p_buffer_read++;
347                             break;
348                         default:
349                             cl->p_buffer_read++;
350                             break;
351                         }
352                         break;
353                     case 1:
354                         switch( *(uint8_t *)cl->p_buffer_read )
355                         {
356                         case TEL_WILL: case TEL_WONT:
357                         case TEL_DO: case TEL_DONT:
358                             cl->i_tel_cmd++;
359                             cl->p_buffer_read++;
360                             break;
361                         default:
362                             cl->i_tel_cmd = 0;
363                             cl->p_buffer_read--;
364                             break;
365                         }
366                         break;
367                     case 2:
368                         cl->i_tel_cmd = 0;
369                         cl->p_buffer_read -= 2;
370                         break;
371                     }
372
373                     if( i_end != 0 ) break;
374                 }
375
376                 if( (cl->p_buffer_read - cl->buffer_read) == 999 )
377                 {
378                     Write_message( cl, NULL, "Line too long\r\n",
379                                    cl->i_mode + 2 );
380                 }
381
382                 if( i_recv == 0  || ( i_recv == -1 &&  errno != EAGAIN && errno != 0 ) )
383                 {
384                     net_Close( cl->fd );
385                     TAB_REMOVE( p_intf->p_sys->i_clients ,
386                                 p_intf->p_sys->clients , cl );
387                     free( cl );
388                 }
389             }
390         }
391
392         /* and now we should bidouille the data we received / send */
393         for( i = 0 ; i < p_sys->i_clients ; i++ )
394         {
395             telnet_client_t *cl = p_sys->clients[i];
396
397             if( cl->i_mode >= WRITE_MODE_PWD && cl->i_buffer_write == 0 )
398             {
399                // we have finished to send
400                cl->i_mode -= 2; // corresponding READ MODE
401             }
402             else if( cl->i_mode == READ_MODE_PWD &&
403                      *cl->p_buffer_read == '\n' )
404             {
405                 *cl->p_buffer_read = '\0';
406                 if( !psz_password || !strcmp( psz_password, cl->buffer_read ) )
407                 {
408                     Write_message( cl, NULL, "\xff\xfc\x01\r\nWelcome, "
409                                    "Master\r\n> ", WRITE_MODE_CMD );
410                 }
411                 else
412                 {
413                     /* wrong password */
414                     Write_message( cl, NULL,
415                                    "\r\nWrong password.\r\nPassword: ",
416                                    WRITE_MODE_PWD );
417                 }
418             }
419             else if( cl->i_mode == READ_MODE_CMD &&
420                      *cl->p_buffer_read == '\n' )
421             {
422                 /* ok, here is a command line */
423                 if( !strncmp( cl->buffer_read, "logout", 6 ) ||
424                     !strncmp( cl->buffer_read, "quit", 4 )  ||
425                     !strncmp( cl->buffer_read, "exit", 4 ) )
426                 {
427                     net_Close( cl->fd );
428                     TAB_REMOVE( p_intf->p_sys->i_clients ,
429                                 p_intf->p_sys->clients , cl );
430                     free( cl );
431                 }
432                 else if( !strncmp( cl->buffer_read, "shutdown", 8 ) )
433                 {
434                     msg_Err( p_intf, "shutdown requested" );
435                     p_intf->p_libvlc->b_die = VLC_TRUE;
436                 }
437                 else
438                 {
439                     vlm_message_t *message;
440
441                     /* create a standard string */
442                     *cl->p_buffer_read = '\0';
443
444                     vlm_ExecuteCommand( p_sys->mediatheque, cl->buffer_read,
445                                         &message );
446                     if( !strncmp( cl->buffer_read, "help", 4 ) )
447                     {
448                         vlm_message_t *p_my_help =
449                             vlm_MessageNew( "Telnet Specific Commands:", NULL );
450                         vlm_MessageAdd( p_my_help,
451                             vlm_MessageNew( "logout, quit, exit" , NULL ) );
452                         vlm_MessageAdd( p_my_help,
453                             vlm_MessageNew( "shutdown" , NULL ) );
454                         vlm_MessageAdd( message, p_my_help );
455                     }
456                     Write_message( cl, message, NULL, WRITE_MODE_CMD );
457                     vlm_MessageDelete( message );
458
459                 }
460             }
461         }
462     }
463     if( psz_password )
464         free( psz_password );
465 }
466
467 static void Write_message( telnet_client_t *client, vlm_message_t *message,
468                            char *string_message, int i_mode )
469 {
470     char *psz_message;
471
472     client->p_buffer_read = client->buffer_read;
473     (client->p_buffer_read)[0] = 0; // if (cl->p_buffer_read)[0] = '\n'
474     if( client->buffer_write ) free( client->buffer_write );
475
476     /* generate the psz_message string */
477     if( message )
478     {
479         /* ok, look for vlm_message_t */
480         psz_message = MessageToString( message, 0 );
481     }
482     else
483     {
484         /* it is a basic string_message */
485         psz_message = strdup( string_message );
486     }
487
488     client->buffer_write = client->p_buffer_write = psz_message;
489     client->i_buffer_write = strlen( psz_message );
490     client->i_mode = i_mode;
491 }
492
493 /* We need the level of the message to put a beautiful indentation.
494  * first level is 0 */
495 static char *MessageToString( vlm_message_t *message, int i_level )
496 {
497 #define STRING_CR "\r\n"
498 #define STRING_TAIL "> "
499
500     char *psz_message;
501     int i, i_message = sizeof( STRING_TAIL );
502
503     if( !message || !message->psz_name )
504     {
505         return strdup( STRING_CR STRING_TAIL );
506     }
507     else if( !i_level && !message->i_child && !message->psz_value  )
508     {
509         /* A command is successful. Don't write anything */
510         return strdup( /*STRING_CR*/ STRING_TAIL );
511     }
512
513     i_message += strlen( message->psz_name ) + i_level * sizeof( "    " ) + 1;
514     psz_message = malloc( i_message );
515     *psz_message = 0;
516     for( i = 0; i < i_level; i++ ) strcat( psz_message, "    " );
517     strcat( psz_message, message->psz_name );
518
519     if( message->psz_value )
520     {
521         i_message += sizeof( " : " ) + strlen( message->psz_value ) +
522             sizeof( STRING_CR );
523         psz_message = realloc( psz_message, i_message );
524         strcat( psz_message, " : " );
525         strcat( psz_message, message->psz_value );
526         strcat( psz_message, STRING_CR );
527     }
528     else
529     {
530         i_message += sizeof( STRING_CR );
531         psz_message = realloc( psz_message, i_message );
532         strcat( psz_message, STRING_CR );
533     }
534
535     for( i = 0; i < message->i_child; i++ )
536     {
537         char *child_message =
538             MessageToString( message->child[i], i_level + 1 );
539
540         i_message += strlen( child_message );
541         psz_message = realloc( psz_message, i_message );
542         strcat( psz_message, child_message );
543         free( child_message );
544     }
545
546     if( i_level == 0 ) strcat( psz_message, STRING_TAIL );
547
548     return psz_message;
549 }