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
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_interface.h>
  36 #include <vlc_input.h>
  37
  38 #include <stdbool.h>
  39
  40 #include <errno.h>
  41
  42 #ifdef HAVE_UNISTD_H
  43 #   include <unistd.h>
  44 #endif
  45 #ifdef HAVE_POLL
  46 #   include <poll.h>
  47 #endif
  48
  49 #include <vlc_network.h>
  50 #include <vlc_url.h>
  51 #include <vlc_vlm.h>
  52
  53 #define READ_MODE_PWD 1
  54 #define READ_MODE_CMD 2
  55 #define WRITE_MODE_PWD 3 // when we write the word "Password:"
  56 #define WRITE_MODE_CMD 4
  57
  58 /* telnet commands */
  59 #define TEL_WILL    251
  60 #define TEL_WONT    252
  61 #define TEL_DO      253
  62 #define TEL_DONT    254
  63 #define TEL_IAC     255
  64 #define TEL_ECHO    1
  65
  66 /*****************************************************************************
  67  * Module descriptor
  68  *****************************************************************************/
  69 static int  Open ( vlc_object_t * );
  70 static void Close( vlc_object_t * );
  71
  72 #define TELNETHOST_TEXT N_( "Host" )
  73 #define TELNETHOST_LONGTEXT N_( "This is the host on which the " \
  74     "interface will listen. It defaults to all network interfaces (0.0.0.0)." \
  75     " If you want this interface to be available only on the local " \
  76     "machine, enter \"127.0.0.1\"." )
  77 #define TELNETPORT_TEXT N_( "Port" )
  78 #define TELNETPORT_LONGTEXT N_( "This is the TCP port on which this " \
  79     "interface will listen. It defaults to 4212." )
  80 #define TELNETPORT_DEFAULT 4212
  81 #define TELNETPWD_TEXT N_( "Password" )
  82 #define TELNETPWD_LONGTEXT N_( "A single administration password is used " \
  83     "to protect this interface. The default value is \"admin\"." )
  84 #define TELNETPWD_DEFAULT "admin"
  85
  86 vlc_module_begin ()
  87     set_shortname( "Telnet" )
  88     set_category( CAT_INTERFACE )
  89     set_subcategory( SUBCAT_INTERFACE_CONTROL )
  90     add_string( "telnet-host", "localhost", NULL, TELNETHOST_TEXT,
  91                  TELNETHOST_LONGTEXT, true )
  92     add_integer( "telnet-port", TELNETPORT_DEFAULT, NULL, TELNETPORT_TEXT,
  93                  TELNETPORT_LONGTEXT, true )
  94     add_password( "telnet-password", TELNETPWD_DEFAULT, NULL, TELNETPWD_TEXT,
  95                 TELNETPWD_LONGTEXT, true )
  96     set_description( N_("VLM remote control interface") )
  97     add_category_hint( "VLM", NULL, false )
  98     set_capability( "interface", 0 )
  99     set_callbacks( Open , Close )
 100 vlc_module_end ()
 101
 102 /*****************************************************************************
 103  * Local prototypes.
 104  *****************************************************************************/
 105 static void Run( intf_thread_t * );
 106
 107 typedef struct
 108 {
 109     int        i_mode; /* read or write */
 110     int        fd;
 111     char       buffer_read[1000]; // 1000 byte per command should be sufficient
 112     char      *buffer_write;
 113     char      *p_buffer_read;
 114     char      *p_buffer_write; // the position in the buffer
 115     int        i_buffer_write; // the number of byte we still have to send
 116     int        i_tel_cmd; // for specific telnet commands
 117
 118 } telnet_client_t;
 119
 120 static char *MessageToString( vlm_message_t *, int );
 121 static void Write_message( telnet_client_t *, vlm_message_t *, const char *, int );
 122
 123 struct intf_sys_t
 124 {
 125    telnet_client_t **clients;
 126    int             i_clients;
 127    int             *pi_fd;
 128    vlm_t           *mediatheque;
 129 };
 130
 131 /*
 132  * getPort: Decide which port to use. There are two possibilities to
 133  * specify a port: integrated in the --telnet-host option with :PORT
 134  * or using the --telnet-port option. The --telnet-port option has
 135  * precedence.
 136  * This code relies upon the fact the url.i_port is 0 if the :PORT
 137  * option is missing from --telnet-host.
 138  */
 139 static int getPort(intf_thread_t *p_intf, const vlc_url_t *url, int i_port)
 140 {
 141     if (i_port == TELNETPORT_DEFAULT && url->i_port != 0)
 142         i_port = url->i_port;
 143     if (url->i_port != 0 && url->i_port != i_port)
 144         // Print error if two different ports have been specified
 145         msg_Warn( p_intf, "ignoring port %d (using %d)", url->i_port, i_port );
 146     return i_port;
 147 }
 148
 149 /*****************************************************************************
 150  * Open: initialize dummy interface
 151  *****************************************************************************/
 152 static int Open( vlc_object_t *p_this )
 153 {
 154     intf_thread_t *p_intf = (intf_thread_t*) p_this;
 155     vlm_t *mediatheque;
 156     char *psz_address;
 157     vlc_url_t url;
 158     int i_telnetport;
 159
 160     if( !(mediatheque = vlm_New( p_intf )) )
 161     {
 162         msg_Err( p_intf, "cannot start VLM" );
 163         return VLC_EGENERIC;
 164     }
 165
 166     msg_Info( p_intf, "using the VLM interface plugin..." );
 167
 168     i_telnetport = var_InheritInteger( p_intf, "telnet-port" );
 169     psz_address  = var_InheritString( p_intf, "telnet-host" );
 170     vlc_UrlParse(&url, psz_address, 0);
 171     free( psz_address );
 172
 173     // There might be two ports given, resolve any potentially
 174     // conflict
 175     url.i_port = getPort(p_intf, &url, i_telnetport);
 176
 177     p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
 178     if( !p_intf->p_sys )
 179     {
 180         vlm_Delete( mediatheque );
 181         vlc_UrlClean( &url );
 182         return VLC_ENOMEM;
 183     }
 184     if( ( p_intf->p_sys->pi_fd = net_ListenTCP( p_intf, url.psz_host, url.i_port ) ) == NULL )
 185     {
 186         msg_Err( p_intf, "cannot listen for telnet" );
 187         vlm_Delete( mediatheque );
 188         vlc_UrlClean( &url );
 189         free( p_intf->p_sys );
 190         return VLC_EGENERIC;
 191     }
 192     msg_Info( p_intf,
 193               "telnet interface started on interface %s %d",
 194               url.psz_host, url.i_port );
 195
 196     p_intf->p_sys->i_clients   = 0;
 197     p_intf->p_sys->clients     = NULL;
 198     p_intf->p_sys->mediatheque = mediatheque;
 199     p_intf->pf_run = Run;
 200
 201     vlc_UrlClean( &url );
 202     return VLC_SUCCESS;
 203 }
 204
 205 /*****************************************************************************
 206  * Close:
 207  *****************************************************************************/
 208 static void Close( vlc_object_t *p_this )
 209 {
 210     intf_thread_t *p_intf = (intf_thread_t*)p_this;
 211     intf_sys_t    *p_sys  = p_intf->p_sys;
 212     int i;
 213
 214     for( i = 0; i < p_sys->i_clients; i++ )
 215     {
 216         telnet_client_t *cl = p_sys->clients[i];
 217         net_Close( cl->fd );
 218         free( cl->buffer_write );
 219         free( cl );
 220     }
 221     free( p_sys->clients );
 222
 223     net_ListenClose( p_sys->pi_fd );
 224
 225     vlm_Delete( p_sys->mediatheque );
 226
 227     free( p_sys );
 228 }
 229
 230 /*****************************************************************************
 231  * Run: main loop
 232  *****************************************************************************/
 233 static void Run( intf_thread_t *p_intf )
 234 {
 235     intf_sys_t     *p_sys = p_intf->p_sys;
 236     char           *psz_password;
 237     unsigned        nlisten = 0;
 238
 239     for (const int *pfd = p_sys->pi_fd; *pfd != -1; pfd++)
 240         nlisten++; /* How many listening sockets do we have? */
 241
 242     /* FIXME: make sure config_* is cancel-safe */
 243     psz_password = var_InheritString( p_intf, "telnet-password" );
 244     vlc_cleanup_push( free, psz_password );
 245
 246     for( ;; )
 247     {
 248         unsigned ncli = p_sys->i_clients;
 249         struct pollfd ufd[ncli + nlisten];
 250
 251         for (unsigned i = 0; i < ncli; i++)
 252         {
 253             telnet_client_t *cl = p_sys->clients[i];
 254
 255             ufd[i].fd = cl->fd;
 256             if( (cl->i_mode == WRITE_MODE_PWD) || (cl->i_mode == WRITE_MODE_CMD) )
 257                 ufd[i].events = POLLOUT;
 258             else
 259                 ufd[i].events = POLLIN;
 260             ufd[i].revents = 0;
 261         }
 262
 263         for (unsigned i = 0; i < nlisten; i++)
 264         {
 265             ufd[ncli + i].fd = p_sys->pi_fd[i];
 266             ufd[ncli + i].events = POLLIN;
 267             ufd[ncli + i].revents = 0;
 268         }
 269
 270         switch (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1))
 271         {
 272             case -1:
 273                 if (net_errno != EINTR)
 274                 {
 275                     msg_Err (p_intf, "network poll error");
 276 #ifndef WIN32
 277                     pause ();  /* We are screwed! */
 278 #else
 279                     abort (); /* We are even more screwed! (no pause() in win32) */
 280 #endif
 281                     break;
 282                 }
 283             case 0:
 284                 continue;
 285         }
 286
 287         int canc = vlc_savecancel ();
 288         /* check if there is something to do with the socket */
 289         for (unsigned i = 0; i < ncli; i++)
 290         {
 291             telnet_client_t *cl = p_sys->clients[i];
 292
 293             if (ufd[i].revents & (POLLERR|POLLHUP))
 294             {
 295             drop:
 296                 net_Close( cl->fd );
 297                 TAB_REMOVE( p_intf->p_sys->i_clients ,
 298                             p_intf->p_sys->clients , cl );
 299                 free( cl->buffer_write );
 300                 free( cl );
 301                 continue;
 302             }
 303
 304             if (ufd[i].revents & POLLOUT && (cl->i_buffer_write > 0))
 305             {
 306                 ssize_t i_len;
 307
 308                 i_len = send( cl->fd, cl->p_buffer_write ,
 309                               cl->i_buffer_write, 0 );
 310                 if( i_len > 0 )
 311                 {
 312                     cl->p_buffer_write += i_len;
 313                     cl->i_buffer_write -= i_len;
 314                 }
 315             }
 316             if (ufd[i].revents & POLLIN)
 317             {
 318                 bool end = false;
 319                 ssize_t i_recv;
 320
 321                 while( ((i_recv=recv( cl->fd, cl->p_buffer_read, 1, 0 )) > 0) &&
 322                        ((cl->p_buffer_read - cl->buffer_read) < 999) )
 323                 {
 324                     switch( cl->i_tel_cmd )
 325                     {
 326                     case 0:
 327                         switch( *(uint8_t *)cl->p_buffer_read )
 328                         {
 329                         case '\r':
 330                             break;
 331                         case '\n':
 332                             *cl->p_buffer_read = '\n';
 333                             end = true;
 334                             break;
 335                         case TEL_IAC: // telnet specific command
 336                             cl->i_tel_cmd = 1;
 337                             cl->p_buffer_read++;
 338                             break;
 339                         default:
 340                             cl->p_buffer_read++;
 341                             break;
 342                         }
 343                         break;
 344                     case 1:
 345                         switch( *(uint8_t *)cl->p_buffer_read )
 346                         {
 347                         case TEL_WILL: case TEL_WONT:
 348                         case TEL_DO: case TEL_DONT:
 349                             cl->i_tel_cmd++;
 350                             cl->p_buffer_read++;
 351                             break;
 352                         default:
 353                             cl->i_tel_cmd = 0;
 354                             cl->p_buffer_read--;
 355                             break;
 356                         }
 357                         break;
 358                     case 2:
 359                         cl->i_tel_cmd = 0;
 360                         cl->p_buffer_read -= 2;
 361                         break;
 362                     }
 363
 364                     if( end ) break;
 365                 }
 366
 367                 if( (cl->p_buffer_read - cl->buffer_read) == 999 )
 368                 {
 369                     Write_message( cl, NULL, "Line too long\r\n",
 370                                    cl->i_mode + 2 );
 371                 }
 372
 373 #ifdef WIN32
 374                 if( i_recv <= 0 && WSAGetLastError() == WSAEWOULDBLOCK )
 375                 {
 376                     errno = EAGAIN;
 377                 }
 378 #endif
 379                 if( i_recv == 0 || ( i_recv == -1 && ( end || errno != EAGAIN ) ) )
 380                     goto drop;
 381             }
 382         }
 383
 384         /* and now we should bidouille the data we received / send */
 385         for(int i = 0 ; i < p_sys->i_clients ; i++ )
 386         {
 387             telnet_client_t *cl = p_sys->clients[i];
 388
 389             if( cl->i_mode >= WRITE_MODE_PWD && cl->i_buffer_write == 0 )
 390             {
 391                // we have finished to send
 392                cl->i_mode -= 2; // corresponding READ MODE
 393             }
 394             else if( cl->i_mode == READ_MODE_PWD &&
 395                      *cl->p_buffer_read == '\n' )
 396             {
 397                 *cl->p_buffer_read = '\0';
 398                 if( !psz_password || !strcmp( psz_password, cl->buffer_read ) )
 399                 {
 400                     Write_message( cl, NULL, "\xff\xfc\x01\r\nWelcome, "
 401                                    "Master\r\n> ", WRITE_MODE_CMD );
 402                 }
 403                 else
 404                 {
 405                     /* wrong password */
 406                     Write_message( cl, NULL,
 407                                    "\r\nWrong password.\r\nPassword: ",
 408                                    WRITE_MODE_PWD );
 409                 }
 410             }
 411             else if( cl->i_mode == READ_MODE_CMD &&
 412                      *cl->p_buffer_read == '\n' )
 413             {
 414                 /* ok, here is a command line */
 415                 if( !strncmp( cl->buffer_read, "logout", 6 ) ||
 416                     !strncmp( cl->buffer_read, "quit", 4 )  ||
 417                     !strncmp( cl->buffer_read, "exit", 4 ) )
 418                 {
 419                     net_Close( cl->fd );
 420                     TAB_REMOVE( p_intf->p_sys->i_clients ,
 421                                 p_intf->p_sys->clients , cl );
 422                     free( cl->buffer_write );
 423                     free( cl );
 424                 }
 425                 else if( !strncmp( cl->buffer_read, "shutdown", 8 ) )
 426                 {
 427                     msg_Err( p_intf, "shutdown requested" );
 428                     libvlc_Quit( p_intf->p_libvlc );
 429                 }
 430                 else if( *cl->buffer_read == '@'
 431                           && strchr( cl->buffer_read, ' ' ) )
 432                 {
 433                     /* Module specific commands (use same syntax as in the
 434                      * rc interface) */
 435                     char *psz_name = cl->buffer_read + 1;
 436                     char *psz_cmd, *psz_arg, *psz_msg;
 437                     int i_ret;
 438
 439                     psz_cmd = strchr( cl->buffer_read, ' ' );
 440                     *psz_cmd = '\0';  psz_cmd++;
 441                     if( ( psz_arg = strchr( psz_cmd, '\n' ) ) ) *psz_arg = '\0';
 442                     if( ( psz_arg = strchr( psz_cmd, '\r' ) ) ) *psz_arg = '\0';
 443                     if( ( psz_arg = strchr( psz_cmd, ' ' ) )
 444                         && *psz_arg )
 445                     {
 446                         *psz_arg = '\0';
 447                         psz_arg++;
 448                     }
 449
 450                     i_ret = var_Command( p_intf, psz_name, psz_cmd, psz_arg,
 451                                          &psz_msg );
 452
 453                     if( psz_msg )
 454                     {
 455                         vlm_message_t *message;
 456                         message = vlm_MessageNew( "Module command", "%s", psz_msg );
 457                         Write_message( cl, message, NULL, WRITE_MODE_CMD );
 458                         vlm_MessageDelete( message );
 459                         free( psz_msg );
 460                     }
 461                 }
 462                 else
 463                 {
 464                     vlm_message_t *message;
 465
 466                     /* create a standard string */
 467                     *cl->p_buffer_read = '\0';
 468
 469                     vlm_ExecuteCommand( p_sys->mediatheque, cl->buffer_read,
 470                                         &message );
 471                     if( !strncmp( cl->buffer_read, "help", 4 ) )
 472                     {
 473                         vlm_message_t *p_my_help =
 474                             vlm_MessageSimpleNew( "Telnet Specific Commands:" );
 475                         vlm_MessageAdd( p_my_help,
 476                             vlm_MessageSimpleNew( "logout, quit, exit" ) );
 477                         vlm_MessageAdd( p_my_help,
 478                             vlm_MessageSimpleNew( "shutdown" ) );
 479                         vlm_MessageAdd( p_my_help,
 480                             vlm_MessageSimpleNew( "@moduleinstance command argument" ) );
 481                         vlm_MessageAdd( message, p_my_help );
 482                     }
 483                     Write_message( cl, message, NULL, WRITE_MODE_CMD );
 484                     vlm_MessageDelete( message );
 485                 }
 486             }
 487         }
 488
 489         /* handle new connections */
 490         for (unsigned i = 0; i < nlisten; i++)
 491         {
 492             int fd;
 493
 494             if (ufd[ncli + i].revents == 0)
 495                 continue;
 496
 497             fd = net_AcceptSingle (VLC_OBJECT(p_intf), ufd[ncli + i].fd);
 498             if (fd == -1)
 499                 continue;
 500
 501             telnet_client_t *cl = calloc( 1, sizeof( telnet_client_t ));
 502             if (cl == NULL)
 503             {
 504                 net_Close (fd);
 505                 continue;
 506             }
 507
 508             cl->i_tel_cmd = 0;
 509             cl->fd = fd;
 510             cl->buffer_write = NULL;
 511             cl->p_buffer_write = cl->buffer_write;
 512             Write_message( cl, NULL,
 513                            "Password: \xff\xfb\x01" , WRITE_MODE_PWD );
 514             TAB_APPEND( p_sys->i_clients, p_sys->clients, cl );
 515         }
 516         vlc_restorecancel( canc );
 517     }
 518     vlc_cleanup_run ();
 519 }
 520
 521 static void Write_message( telnet_client_t *client, vlm_message_t *message,
 522                            const char *string_message, int i_mode )
 523 {
 524     char *psz_message;
 525
 526     client->p_buffer_read = client->buffer_read;
 527     (client->p_buffer_read)[0] = 0; // if (cl->p_buffer_read)[0] = '\n'
 528     free( client->buffer_write );
 529
 530     /* generate the psz_message string */
 531     if( message )
 532     {
 533         /* ok, look for vlm_message_t */
 534         psz_message = MessageToString( message, 0 );
 535     }
 536     else
 537     {
 538         /* it is a basic string_message */
 539         psz_message = strdup( string_message );
 540     }
 541
 542     client->buffer_write = client->p_buffer_write = psz_message;
 543     client->i_buffer_write = strlen( psz_message );
 544     client->i_mode = i_mode;
 545 }
 546
 547 /* We need the level of the message to put a beautiful indentation.
 548  * first level is 0 */
 549 static char *MessageToString( vlm_message_t *message, int i_level )
 550 {
 551 #define STRING_CR "\r\n"
 552 #define STRING_TAIL "> "
 553
 554     char *psz_message;
 555     int i, i_message = sizeof( STRING_TAIL );
 556
 557     if( !message || !message->psz_name )
 558     {
 559         return strdup( STRING_CR STRING_TAIL );
 560     }
 561     else if( !i_level && !message->i_child && !message->psz_value  )
 562     {
 563         /* A command is successful. Don't write anything */
 564         return strdup( /*STRING_CR*/ STRING_TAIL );
 565     }
 566
 567     i_message += strlen( message->psz_name ) + i_level * sizeof( "    " ) + 1;
 568     psz_message = xmalloc( i_message );
 569     *psz_message = 0;
 570     for( i = 0; i < i_level; i++ ) strcat( psz_message, "    " );
 571     strcat( psz_message, message->psz_name );
 572
 573     if( message->psz_value )
 574     {
 575         i_message += sizeof( " : " ) + strlen( message->psz_value ) +
 576             sizeof( STRING_CR );
 577         psz_message = xrealloc( psz_message, i_message );
 578         strcat( psz_message, " : " );
 579         strcat( psz_message, message->psz_value );
 580         strcat( psz_message, STRING_CR );
 581     }
 582     else
 583     {
 584         i_message += sizeof( STRING_CR );
 585         psz_message = xrealloc( psz_message, i_message );
 586         strcat( psz_message, STRING_CR );
 587     }
 588
 589     for( i = 0; i < message->i_child; i++ )
 590     {
 591         char *child_message =
 592             MessageToString( message->child[i], i_level + 1 );
 593
 594         i_message += strlen( child_message );
 595         psz_message = xrealloc( psz_message, i_message );
 596         strcat( psz_message, child_message );
 597         free( child_message );
 598     }
 599
 600     if( i_level == 0 ) strcat( psz_message, STRING_TAIL );
 601
 602     return psz_message;
 603 }