git.sesse.net Git - vlc/blob - 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 #include <fcntl.h>
  42
  43 #ifdef HAVE_SYS_TIME_H
  44 #    include <sys/time.h>
  45 #endif
  46
  47 #ifdef HAVE_UNISTD_H
  48 #   include <unistd.h>
  49 #endif
  50 #ifdef HAVE_POLL
  51 #   include <poll.h>
  52 #endif
  53
  54 #include <vlc_network.h>
  55 #include <vlc_url.h>
  56 #include <vlc_vlm.h>
  57
  58 #define READ_MODE_PWD 1
  59 #define READ_MODE_CMD 2
  60 #define WRITE_MODE_PWD 3 // when we write the word "Password:"
  61 #define WRITE_MODE_CMD 4
  62
  63 /* telnet commands */
  64 #define TEL_WILL    251
  65 #define TEL_WONT    252
  66 #define TEL_DO      253
  67 #define TEL_DONT    254
  68 #define TEL_IAC     255
  69 #define TEL_ECHO    1
  70
  71 /*****************************************************************************
  72  * Module descriptor
  73  *****************************************************************************/
  74 static int  Open ( vlc_object_t * );
  75 static void Close( vlc_object_t * );
  76
  77 #define TELNETHOST_TEXT N_( "Host" )
  78 #define TELNETHOST_LONGTEXT N_( "This is the host on which the " \
  79     "interface will listen. It defaults to all network interfaces (0.0.0.0)." \
  80     " If you want this interface to be available only on the local " \
  81     "machine, enter \"127.0.0.1\"." )
  82 #define TELNETPORT_TEXT N_( "Port" )
  83 #define TELNETPORT_LONGTEXT N_( "This is the TCP port on which this " \
  84     "interface will listen. It defaults to 4212." )
  85 #define TELNETPORT_DEFAULT 4212
  86 #define TELNETPWD_TEXT N_( "Password" )
  87 #define TELNETPWD_LONGTEXT N_( "A single administration password is used " \
  88     "to protect this interface. The default value is \"admin\"." )
  89 #define TELNETPWD_DEFAULT "admin"
  90
  91 vlc_module_begin ()
  92     set_shortname( "Telnet" )
  93     set_category( CAT_INTERFACE )
  94     set_subcategory( SUBCAT_INTERFACE_CONTROL )
  95     add_string( "telnet-host", "", NULL, TELNETHOST_TEXT,
  96                  TELNETHOST_LONGTEXT, true )
  97     add_integer( "telnet-port", TELNETPORT_DEFAULT, NULL, TELNETPORT_TEXT,
  98                  TELNETPORT_LONGTEXT, true )
  99     add_password( "telnet-password", TELNETPWD_DEFAULT, NULL, TELNETPWD_TEXT,
 100                 TELNETPWD_LONGTEXT, true )
 101     set_description( N_("VLM remote control interface") )
 102     add_category_hint( "VLM", NULL, false )
 103     set_capability( "interface", 0 )
 104     set_callbacks( Open , Close )
 105 vlc_module_end ()
 106
 107 /*****************************************************************************
 108  * Local prototypes.
 109  *****************************************************************************/
 110 static void Run( intf_thread_t * );
 111
 112 typedef struct
 113 {
 114     int        i_mode; /* read or write */
 115     int        fd;
 116     char       buffer_read[1000]; // 1000 byte per command should be sufficient
 117     char      *buffer_write;
 118     char      *p_buffer_read;
 119     char      *p_buffer_write; // the position in the buffer
 120     int        i_buffer_write; // the number of byte we still have to send
 121     int        i_tel_cmd; // for specific telnet commands
 122
 123 } telnet_client_t;
 124
 125 static char *MessageToString( vlm_message_t *, int );
 126 static void Write_message( telnet_client_t *, vlm_message_t *, const char *, int );
 127
 128 struct intf_sys_t
 129 {
 130    telnet_client_t **clients;
 131    int             i_clients;
 132    int             *pi_fd;
 133    vlm_t           *mediatheque;
 134 };
 135
 136 /*
 137  * getPort: Decide which port to use. There are two possibilities to
 138  * specify a port: integrated in the --telnet-host option with :PORT
 139  * or using the --telnet-port option. The --telnet-port option has
 140  * precedence.
 141  * This code relies upon the fact the url.i_port is 0 if the :PORT
 142  * option is missing from --telnet-host.
 143  */
 144 static int getPort(intf_thread_t *p_intf, const vlc_url_t *url, int i_port)
 145 {
 146     if (i_port == TELNETPORT_DEFAULT && url->i_port != 0)
 147         i_port = url->i_port;
 148     if (url->i_port != 0 && url->i_port != i_port)
 149         // Print error if two different ports have been specified
 150         msg_Warn( p_intf, "ignoring port %d (using %d)", url->i_port, i_port );
 151     return i_port;
 152 }
 153
 154 /*****************************************************************************
 155  * Open: initialize dummy interface
 156  *****************************************************************************/
 157 static int Open( vlc_object_t *p_this )
 158 {
 159     intf_thread_t *p_intf = (intf_thread_t*) p_this;
 160     vlm_t *mediatheque;
 161     char *psz_address;
 162     vlc_url_t url;
 163     int i_telnetport;
 164
 165     if( !(mediatheque = vlm_New( p_intf )) )
 166     {
 167         msg_Err( p_intf, "cannot start VLM" );
 168         return VLC_EGENERIC;
 169     }
 170
 171     msg_Info( p_intf, "using the VLM interface plugin..." );
 172
 173     i_telnetport = var_InheritInteger( p_intf, "telnet-port" );
 174     psz_address  = var_InheritString( p_intf, "telnet-host" );
 175     vlc_UrlParse(&url, psz_address, 0);
 176     free( psz_address );
 177
 178     // There might be two ports given, resolve any potentially
 179     // conflict
 180     url.i_port = getPort(p_intf, &url, i_telnetport);
 181
 182     p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
 183     if( !p_intf->p_sys )
 184     {
 185         vlm_Delete( mediatheque );
 186         vlc_UrlClean( &url );
 187         return VLC_ENOMEM;
 188     }
 189     if( ( p_intf->p_sys->pi_fd = net_ListenTCP( p_intf, url.psz_host, url.i_port ) ) == NULL )
 190     {
 191         msg_Err( p_intf, "cannot listen for telnet" );
 192         vlm_Delete( mediatheque );
 193         vlc_UrlClean( &url );
 194         free( p_intf->p_sys );
 195         return VLC_EGENERIC;
 196     }
 197     msg_Info( p_intf,
 198               "telnet interface started on interface %s %d",
 199               url.psz_host, url.i_port );
 200
 201     p_intf->p_sys->i_clients   = 0;
 202     p_intf->p_sys->clients     = NULL;
 203     p_intf->p_sys->mediatheque = mediatheque;
 204     p_intf->pf_run = Run;
 205
 206     vlc_UrlClean( &url );
 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->buffer_write );
 224         free( cl );
 225     }
 226     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     char           *psz_password;
 242     unsigned        nlisten = 0;
 243
 244     for (const int *pfd = p_sys->pi_fd; *pfd != -1; pfd++)
 245         nlisten++; /* How many listening sockets do we have? */
 246
 247     /* FIXME: make sure config_* is cancel-safe */
 248     psz_password = var_InheritString( p_intf, "telnet-password" );
 249     vlc_cleanup_push( free, psz_password );
 250
 251     for( ;; )
 252     {
 253         unsigned ncli = p_sys->i_clients;
 254         struct pollfd ufd[ncli + nlisten];
 255
 256         for (unsigned i = 0; i < ncli; i++)
 257         {
 258             telnet_client_t *cl = p_sys->clients[i];
 259
 260             ufd[i].fd = cl->fd;
 261             if( (cl->i_mode == WRITE_MODE_PWD) || (cl->i_mode == WRITE_MODE_CMD) )
 262                 ufd[i].events = POLLOUT;
 263             else
 264                 ufd[i].events = POLLIN;
 265             ufd[i].revents = 0;
 266         }
 267
 268         for (unsigned i = 0; i < nlisten; i++)
 269         {
 270             ufd[ncli + i].fd = p_sys->pi_fd[i];
 271             ufd[ncli + i].events = POLLIN;
 272             ufd[ncli + i].revents = 0;
 273         }
 274
 275         switch (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1))
 276         {
 277             case -1:
 278                 if (net_errno != EINTR)
 279                 {
 280                     msg_Err (p_intf, "network poll error");
 281 #ifndef WIN32
 282                     pause ();  /* We are screwed! */
 283 #else
 284                     abort (); /* We are even more screwed! (no pause() in win32) */
 285 #endif
 286                     break;
 287                 }
 288             case 0:
 289                 continue;
 290         }
 291
 292         int canc = vlc_savecancel ();
 293         /* check if there is something to do with the socket */
 294         for (unsigned i = 0; i < ncli; i++)
 295         {
 296             telnet_client_t *cl = p_sys->clients[i];
 297
 298             if (ufd[i].revents & (POLLERR|POLLHUP))
 299             {
 300             drop:
 301                 net_Close( cl->fd );
 302                 TAB_REMOVE( p_intf->p_sys->i_clients ,
 303                             p_intf->p_sys->clients , cl );
 304                 free( cl->buffer_write );
 305                 free( cl );
 306                 continue;
 307             }
 308
 309             if (ufd[i].revents & POLLOUT && (cl->i_buffer_write > 0))
 310             {
 311                 ssize_t i_len;
 312
 313                 i_len = send( cl->fd, cl->p_buffer_write ,
 314                               cl->i_buffer_write, 0 );
 315                 if( i_len > 0 )
 316                 {
 317                     cl->p_buffer_write += i_len;
 318                     cl->i_buffer_write -= i_len;
 319                 }
 320             }
 321             if (ufd[i].revents & POLLIN)
 322             {
 323                 bool end = false;
 324                 ssize_t i_recv;
 325
 326                 while( ((i_recv=recv( cl->fd, cl->p_buffer_read, 1, 0 )) > 0) &&
 327                        ((cl->p_buffer_read - cl->buffer_read) < 999) )
 328                 {
 329                     switch( cl->i_tel_cmd )
 330                     {
 331                     case 0:
 332                         switch( *(uint8_t *)cl->p_buffer_read )
 333                         {
 334                         case '\r':
 335                             break;
 336                         case '\n':
 337                             *cl->p_buffer_read = '\n';
 338                             end = true;
 339                             break;
 340                         case TEL_IAC: // telnet specific command
 341                             cl->i_tel_cmd = 1;
 342                             cl->p_buffer_read++;
 343                             break;
 344                         default:
 345                             cl->p_buffer_read++;
 346                             break;
 347                         }
 348                         break;
 349                     case 1:
 350                         switch( *(uint8_t *)cl->p_buffer_read )
 351                         {
 352                         case TEL_WILL: case TEL_WONT:
 353                         case TEL_DO: case TEL_DONT:
 354                             cl->i_tel_cmd++;
 355                             cl->p_buffer_read++;
 356                             break;
 357                         default:
 358                             cl->i_tel_cmd = 0;
 359                             cl->p_buffer_read--;
 360                             break;
 361                         }
 362                         break;
 363                     case 2:
 364                         cl->i_tel_cmd = 0;
 365                         cl->p_buffer_read -= 2;
 366                         break;
 367                     }
 368
 369                     if( end ) break;
 370                 }
 371
 372                 if( (cl->p_buffer_read - cl->buffer_read) == 999 )
 373                 {
 374                     Write_message( cl, NULL, "Line too long\r\n",
 375                                    cl->i_mode + 2 );
 376                 }
 377
 378 #ifdef WIN32
 379                 if( i_recv <= 0 && WSAGetLastError() == WSAEWOULDBLOCK )
 380                 {
 381                     errno = EAGAIN;
 382                 }
 383 #endif
 384                 if( i_recv == 0 || ( i_recv == -1 && ( end || errno != EAGAIN ) ) )
 385                     goto drop;
 386             }
 387         }
 388
 389         /* and now we should bidouille the data we received / send */
 390         for(int i = 0 ; i < p_sys->i_clients ; i++ )
 391         {
 392             telnet_client_t *cl = p_sys->clients[i];
 393
 394             if( cl->i_mode >= WRITE_MODE_PWD && cl->i_buffer_write == 0 )
 395             {
 396                // we have finished to send
 397                cl->i_mode -= 2; // corresponding READ MODE
 398             }
 399             else if( cl->i_mode == READ_MODE_PWD &&
 400                      *cl->p_buffer_read == '\n' )
 401             {
 402                 *cl->p_buffer_read = '\0';
 403                 if( !psz_password || !strcmp( psz_password, cl->buffer_read ) )
 404                 {
 405                     Write_message( cl, NULL, "\xff\xfc\x01\r\nWelcome, "
 406                                    "Master\r\n> ", WRITE_MODE_CMD );
 407                 }
 408                 else
 409                 {
 410                     /* wrong password */
 411                     Write_message( cl, NULL,
 412                                    "\r\nWrong password.\r\nPassword: ",
 413                                    WRITE_MODE_PWD );
 414                 }
 415             }
 416             else if( cl->i_mode == READ_MODE_CMD &&
 417                      *cl->p_buffer_read == '\n' )
 418             {
 419                 /* ok, here is a command line */
 420                 if( !strncmp( cl->buffer_read, "logout", 6 ) ||
 421                     !strncmp( cl->buffer_read, "quit", 4 )  ||
 422                     !strncmp( cl->buffer_read, "exit", 4 ) )
 423                 {
 424                     net_Close( cl->fd );
 425                     TAB_REMOVE( p_intf->p_sys->i_clients ,
 426                                 p_intf->p_sys->clients , cl );
 427                     free( cl->buffer_write );
 428                     free( cl );
 429                 }
 430                 else if( !strncmp( cl->buffer_read, "shutdown", 8 ) )
 431                 {
 432                     msg_Err( p_intf, "shutdown requested" );
 433                     libvlc_Quit( p_intf->p_libvlc );
 434                 }
 435                 else if( *cl->buffer_read == '@'
 436                           && strchr( cl->buffer_read, ' ' ) )
 437                 {
 438                     /* Module specific commands (use same syntax as in the
 439                      * rc interface) */
 440                     char *psz_name = cl->buffer_read + 1;
 441                     char *psz_cmd, *psz_arg, *psz_msg;
 442                     int i_ret;
 443
 444                     psz_cmd = strchr( cl->buffer_read, ' ' );
 445                     *psz_cmd = '\0';  psz_cmd++;
 446                     if( ( psz_arg = strchr( psz_cmd, '\n' ) ) ) *psz_arg = '\0';
 447                     if( ( psz_arg = strchr( psz_cmd, '\r' ) ) ) *psz_arg = '\0';
 448                     if( ( psz_arg = strchr( psz_cmd, ' ' ) )
 449                         && *psz_arg )
 450                     {
 451                         *psz_arg = '\0';
 452                         psz_arg++;
 453                     }
 454
 455                     i_ret = var_Command( p_intf, psz_name, psz_cmd, psz_arg,
 456                                          &psz_msg );
 457
 458                     if( psz_msg )
 459                     {
 460                         vlm_message_t *message;
 461                         message = vlm_MessageNew( "Module command", "%s", psz_msg );
 462                         Write_message( cl, message, NULL, WRITE_MODE_CMD );
 463                         vlm_MessageDelete( message );
 464                         free( psz_msg );
 465                     }
 466                 }
 467                 else
 468                 {
 469                     vlm_message_t *message;
 470
 471                     /* create a standard string */
 472                     *cl->p_buffer_read = '\0';
 473
 474                     vlm_ExecuteCommand( p_sys->mediatheque, cl->buffer_read,
 475                                         &message );
 476                     if( !strncmp( cl->buffer_read, "help", 4 ) )
 477                     {
 478                         vlm_message_t *p_my_help =
 479                             vlm_MessageSimpleNew( "Telnet Specific Commands:" );
 480                         vlm_MessageAdd( p_my_help,
 481                             vlm_MessageSimpleNew( "logout, quit, exit" ) );
 482                         vlm_MessageAdd( p_my_help,
 483                             vlm_MessageSimpleNew( "shutdown" ) );
 484                         vlm_MessageAdd( p_my_help,
 485                             vlm_MessageSimpleNew( "@moduleinstance command argument" ) );
 486                         vlm_MessageAdd( message, p_my_help );
 487                     }
 488                     Write_message( cl, message, NULL, WRITE_MODE_CMD );
 489                     vlm_MessageDelete( message );
 490                 }
 491             }
 492         }
 493
 494         /* handle new connections */
 495         for (unsigned i = 0; i < nlisten; i++)
 496         {
 497             int fd;
 498
 499             if (ufd[ncli + i].revents == 0)
 500                 continue;
 501
 502             fd = net_AcceptSingle (VLC_OBJECT(p_intf), ufd[ncli + i].fd);
 503             if (fd == -1)
 504                 continue;
 505
 506             telnet_client_t *cl = calloc( 1, sizeof( telnet_client_t ));
 507             if (cl == NULL)
 508             {
 509                 net_Close (fd);
 510                 continue;
 511             }
 512
 513             cl->i_tel_cmd = 0;
 514             cl->fd = fd;
 515             cl->buffer_write = NULL;
 516             cl->p_buffer_write = cl->buffer_write;
 517             Write_message( cl, NULL,
 518                            "Password: \xff\xfb\x01" , WRITE_MODE_PWD );
 519             TAB_APPEND( p_sys->i_clients, p_sys->clients, cl );
 520         }
 521         vlc_restorecancel( canc );
 522     }
 523     vlc_cleanup_run ();
 524 }
 525
 526 static void Write_message( telnet_client_t *client, vlm_message_t *message,
 527                            const char *string_message, int i_mode )
 528 {
 529     char *psz_message;
 530
 531     client->p_buffer_read = client->buffer_read;
 532     (client->p_buffer_read)[0] = 0; // if (cl->p_buffer_read)[0] = '\n'
 533     free( client->buffer_write );
 534
 535     /* generate the psz_message string */
 536     if( message )
 537     {
 538         /* ok, look for vlm_message_t */
 539         psz_message = MessageToString( message, 0 );
 540     }
 541     else
 542     {
 543         /* it is a basic string_message */
 544         psz_message = strdup( string_message );
 545     }
 546
 547     client->buffer_write = client->p_buffer_write = psz_message;
 548     client->i_buffer_write = strlen( psz_message );
 549     client->i_mode = i_mode;
 550 }
 551
 552 /* We need the level of the message to put a beautiful indentation.
 553  * first level is 0 */
 554 static char *MessageToString( vlm_message_t *message, int i_level )
 555 {
 556 #define STRING_CR "\r\n"
 557 #define STRING_TAIL "> "
 558
 559     char *psz_message;
 560     int i, i_message = sizeof( STRING_TAIL );
 561
 562     if( !message || !message->psz_name )
 563     {
 564         return strdup( STRING_CR STRING_TAIL );
 565     }
 566     else if( !i_level && !message->i_child && !message->psz_value  )
 567     {
 568         /* A command is successful. Don't write anything */
 569         return strdup( /*STRING_CR*/ STRING_TAIL );
 570     }
 571
 572     i_message += strlen( message->psz_name ) + i_level * sizeof( "    " ) + 1;
 573     psz_message = xmalloc( i_message );
 574     *psz_message = 0;
 575     for( i = 0; i < i_level; i++ ) strcat( psz_message, "    " );
 576     strcat( psz_message, message->psz_name );
 577
 578     if( message->psz_value )
 579     {
 580         i_message += sizeof( " : " ) + strlen( message->psz_value ) +
 581             sizeof( STRING_CR );
 582         psz_message = xrealloc( psz_message, i_message );
 583         strcat( psz_message, " : " );
 584         strcat( psz_message, message->psz_value );
 585         strcat( psz_message, STRING_CR );
 586     }
 587     else
 588     {
 589         i_message += sizeof( STRING_CR );
 590         psz_message = xrealloc( psz_message, i_message );
 591         strcat( psz_message, STRING_CR );
 592     }
 593
 594     for( i = 0; i < message->i_child; i++ )
 595     {
 596         char *child_message =
 597             MessageToString( message->child[i], i_level + 1 );
 598
 599         i_message += strlen( child_message );
 600         psz_message = xrealloc( psz_message, i_message );
 601         strcat( psz_message, child_message );
 602         free( child_message );
 603     }
 604
 605     if( i_level == 0 ) strcat( psz_message, STRING_TAIL );
 606
 607     return psz_message;
 608 }