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 #include <sys/stat.h>
  40
  41 #include <errno.h>
  42 #include <fcntl.h>
  43
  44 #ifdef HAVE_SYS_TIME_H
  45 #    include <sys/time.h>
  46 #endif
  47
  48 #ifdef HAVE_UNISTD_H
  49 #   include <unistd.h>
  50 #endif
  51 #ifdef HAVE_POLL
  52 #   include <poll.h>
  53 #endif
  54
  55 #include <vlc_network.h>
  56 #include <vlc_url.h>
  57 #include <vlc_vlm.h>
  58
  59 #define READ_MODE_PWD 1
  60 #define READ_MODE_CMD 2
  61 #define WRITE_MODE_PWD 3 // when we write the word "Password:"
  62 #define WRITE_MODE_CMD 4
  63
  64 /* telnet commands */
  65 #define TEL_WILL    251
  66 #define TEL_WONT    252
  67 #define TEL_DO      253
  68 #define TEL_DONT    254
  69 #define TEL_IAC     255
  70 #define TEL_ECHO    1
  71
  72 /*****************************************************************************
  73  * Module descriptor
  74  *****************************************************************************/
  75 static int  Open ( vlc_object_t * );
  76 static void Close( vlc_object_t * );
  77
  78 #define TELNETHOST_TEXT N_( "Host" )
  79 #define TELNETHOST_LONGTEXT N_( "This is the host on which the " \
  80     "interface will listen. It defaults to all network interfaces (0.0.0.0)." \
  81     " If you want this interface to be available only on the local " \
  82     "machine, enter \"127.0.0.1\"." )
  83 #define TELNETPORT_TEXT N_( "Port" )
  84 #define TELNETPORT_LONGTEXT N_( "This is the TCP port on which this " \
  85     "interface will listen. It defaults to 4212." )
  86 #define TELNETPORT_DEFAULT 4212
  87 #define TELNETPWD_TEXT N_( "Password" )
  88 #define TELNETPWD_LONGTEXT N_( "A single administration password is used " \
  89     "to protect this interface. The default value is \"admin\"." )
  90 #define TELNETPWD_DEFAULT "admin"
  91
  92 vlc_module_begin ()
  93     set_shortname( "Telnet" )
  94     set_category( CAT_INTERFACE )
  95     set_subcategory( SUBCAT_INTERFACE_CONTROL )
  96     add_string( "telnet-host", "", NULL, TELNETHOST_TEXT,
  97                  TELNETHOST_LONGTEXT, true )
  98     add_integer( "telnet-port", TELNETPORT_DEFAULT, NULL, TELNETPORT_TEXT,
  99                  TELNETPORT_LONGTEXT, true )
 100     add_password( "telnet-password", TELNETPWD_DEFAULT, NULL, TELNETPWD_TEXT,
 101                 TELNETPWD_LONGTEXT, true )
 102     set_description( N_("VLM remote control interface") )
 103     add_category_hint( "VLM", NULL, false )
 104     set_capability( "interface", 0 )
 105     set_callbacks( Open , Close )
 106 vlc_module_end ()
 107
 108 /*****************************************************************************
 109  * Local prototypes.
 110  *****************************************************************************/
 111 static void Run( intf_thread_t * );
 112
 113 typedef struct
 114 {
 115     int        i_mode; /* read or write */
 116     int        fd;
 117     char       buffer_read[1000]; // 1000 byte per command should be sufficient
 118     char      *buffer_write;
 119     char      *p_buffer_read;
 120     char      *p_buffer_write; // the position in the buffer
 121     int        i_buffer_write; // the number of byte we still have to send
 122     int        i_tel_cmd; // for specific telnet commands
 123
 124 } telnet_client_t;
 125
 126 static char *MessageToString( vlm_message_t *, int );
 127 static void Write_message( telnet_client_t *, vlm_message_t *, const char *, int );
 128
 129 struct intf_sys_t
 130 {
 131    telnet_client_t **clients;
 132    int             i_clients;
 133    int             *pi_fd;
 134    vlm_t           *mediatheque;
 135 };
 136
 137 /*
 138  * getPort: Decide which port to use. There are two possibilities to
 139  * specify a port: integrated in the --telnet-host option with :PORT
 140  * or using the --telnet-port option. The --telnet-port option has
 141  * precedence.
 142  * This code relies upon the fact the url.i_port is 0 if the :PORT
 143  * option is missing from --telnet-host.
 144  */
 145 static int getPort(intf_thread_t *p_intf, const vlc_url_t *url, int i_port)
 146 {
 147     if (i_port == TELNETPORT_DEFAULT && url->i_port != 0)
 148         i_port = url->i_port;
 149     if (url->i_port != 0 && url->i_port != i_port)
 150         // Print error if two different ports have been specified
 151         msg_Warn( p_intf, "ignoring port %d (using %d)", url->i_port, i_port );
 152     return i_port;
 153 }
 154
 155 /*****************************************************************************
 156  * Open: initialize dummy interface
 157  *****************************************************************************/
 158 static int Open( vlc_object_t *p_this )
 159 {
 160     intf_thread_t *p_intf = (intf_thread_t*) p_this;
 161     vlm_t *mediatheque;
 162     char *psz_address;
 163     vlc_url_t url;
 164     int i_telnetport;
 165
 166     if( !(mediatheque = vlm_New( p_intf )) )
 167     {
 168         msg_Err( p_intf, "cannot start VLM" );
 169         return VLC_EGENERIC;
 170     }
 171
 172     msg_Info( p_intf, "using the VLM interface plugin..." );
 173
 174     i_telnetport = config_GetInt( p_intf, "telnet-port" );
 175     psz_address  = config_GetPsz( p_intf, "telnet-host" );
 176
 177     vlc_UrlParse(&url, psz_address, 0);
 178     free( psz_address );
 179
 180     // There might be two ports given, resolve any potentially
 181     // conflict
 182     url.i_port = getPort(p_intf, &url, i_telnetport);
 183
 184     p_intf->p_sys = malloc( sizeof( intf_sys_t ) );
 185     if( !p_intf->p_sys )
 186     {
 187         vlm_Delete( mediatheque );
 188         vlc_UrlClean( &url );
 189         return VLC_ENOMEM;
 190     }
 191     if( ( p_intf->p_sys->pi_fd = net_ListenTCP( p_intf, url.psz_host, url.i_port ) ) == NULL )
 192     {
 193         msg_Err( p_intf, "cannot listen for telnet" );
 194         vlm_Delete( mediatheque );
 195         vlc_UrlClean( &url );
 196         free( p_intf->p_sys );
 197         return VLC_EGENERIC;
 198     }
 199     msg_Info( p_intf,
 200               "telnet interface started on interface %s %d",
 201               url.psz_host, url.i_port );
 202
 203     p_intf->p_sys->i_clients   = 0;
 204     p_intf->p_sys->clients     = NULL;
 205     p_intf->p_sys->mediatheque = mediatheque;
 206     p_intf->pf_run = Run;
 207
 208     vlc_UrlClean( &url );
 209     return VLC_SUCCESS;
 210 }
 211
 212 /*****************************************************************************
 213  * Close:
 214  *****************************************************************************/
 215 static void Close( vlc_object_t *p_this )
 216 {
 217     intf_thread_t *p_intf = (intf_thread_t*)p_this;
 218     intf_sys_t    *p_sys  = p_intf->p_sys;
 219     int i;
 220
 221     for( i = 0; i < p_sys->i_clients; i++ )
 222     {
 223         telnet_client_t *cl = p_sys->clients[i];
 224         net_Close( cl->fd );
 225         free( cl->buffer_write );
 226         free( cl );
 227     }
 228     free( p_sys->clients );
 229
 230     net_ListenClose( p_sys->pi_fd );
 231
 232     vlm_Delete( p_sys->mediatheque );
 233
 234     free( p_sys );
 235 }
 236
 237 /*****************************************************************************
 238  * Run: main loop
 239  *****************************************************************************/
 240 static void Run( intf_thread_t *p_intf )
 241 {
 242     intf_sys_t     *p_sys = p_intf->p_sys;
 243     char           *psz_password;
 244     unsigned        nlisten = 0;
 245
 246     for (const int *pfd = p_sys->pi_fd; *pfd != -1; pfd++)
 247         nlisten++; /* How many listening sockets do we have? */
 248
 249     /* FIXME: make sure config_* is cancel-safe */
 250     psz_password = config_GetPsz( p_intf, "telnet-password" );
 251     vlc_cleanup_push( free, psz_password );
 252
 253     for( ;; )
 254     {
 255         unsigned ncli = p_sys->i_clients;
 256         struct pollfd ufd[ncli + nlisten];
 257
 258         for (unsigned i = 0; i < ncli; i++)
 259         {
 260             telnet_client_t *cl = p_sys->clients[i];
 261
 262             ufd[i].fd = cl->fd;
 263             if( (cl->i_mode == WRITE_MODE_PWD) || (cl->i_mode == WRITE_MODE_CMD) )
 264                 ufd[i].events = POLLOUT;
 265             else
 266                 ufd[i].events = POLLIN;
 267             ufd[i].revents = 0;
 268         }
 269
 270         for (unsigned i = 0; i < nlisten; i++)
 271         {
 272             ufd[ncli + i].fd = p_sys->pi_fd[i];
 273             ufd[ncli + i].events = POLLIN;
 274             ufd[ncli + i].revents = 0;
 275         }
 276
 277         switch (poll (ufd, sizeof (ufd) / sizeof (ufd[0]), -1))
 278         {
 279             case -1:
 280                 if (net_errno != EINTR)
 281                 {
 282                     msg_Err (p_intf, "network poll error");
 283 #ifndef WIN32
 284                     pause ();  /* We are screwed! */
 285 #else
 286                     abort (); /* We are even more screwed! (no pause() in win32) */
 287 #endif
 288                     break;
 289                 }
 290             case 0:
 291                 continue;
 292         }
 293
 294         int canc = vlc_savecancel ();
 295         /* check if there is something to do with the socket */
 296         for (unsigned i = 0; i < ncli; i++)
 297         {
 298             telnet_client_t *cl = p_sys->clients[i];
 299
 300             if (ufd[i].revents & (POLLERR|POLLHUP))
 301             {
 302             drop:
 303                 net_Close( cl->fd );
 304                 TAB_REMOVE( p_intf->p_sys->i_clients ,
 305                             p_intf->p_sys->clients , cl );
 306                 free( cl->buffer_write );
 307                 free( cl );
 308                 continue;
 309             }
 310
 311             if (ufd[i].revents & POLLOUT && (cl->i_buffer_write > 0))
 312             {
 313                 ssize_t i_len;
 314
 315                 i_len = send( cl->fd, cl->p_buffer_write ,
 316                               cl->i_buffer_write, 0 );
 317                 if( i_len > 0 )
 318                 {
 319                     cl->p_buffer_write += i_len;
 320                     cl->i_buffer_write -= i_len;
 321                 }
 322             }
 323             if (ufd[i].revents & POLLIN)
 324             {
 325                 bool end = false;
 326                 ssize_t i_recv;
 327
 328                 while( ((i_recv=recv( cl->fd, cl->p_buffer_read, 1, 0 )) > 0) &&
 329                        ((cl->p_buffer_read - cl->buffer_read) < 999) )
 330                 {
 331                     switch( cl->i_tel_cmd )
 332                     {
 333                     case 0:
 334                         switch( *(uint8_t *)cl->p_buffer_read )
 335                         {
 336                         case '\r':
 337                             break;
 338                         case '\n':
 339                             *cl->p_buffer_read = '\n';
 340                             end = true;
 341                             break;
 342                         case TEL_IAC: // telnet specific command
 343                             cl->i_tel_cmd = 1;
 344                             cl->p_buffer_read++;
 345                             break;
 346                         default:
 347                             cl->p_buffer_read++;
 348                             break;
 349                         }
 350                         break;
 351                     case 1:
 352                         switch( *(uint8_t *)cl->p_buffer_read )
 353                         {
 354                         case TEL_WILL: case TEL_WONT:
 355                         case TEL_DO: case TEL_DONT:
 356                             cl->i_tel_cmd++;
 357                             cl->p_buffer_read++;
 358                             break;
 359                         default:
 360                             cl->i_tel_cmd = 0;
 361                             cl->p_buffer_read--;
 362                             break;
 363                         }
 364                         break;
 365                     case 2:
 366                         cl->i_tel_cmd = 0;
 367                         cl->p_buffer_read -= 2;
 368                         break;
 369                     }
 370
 371                     if( end ) break;
 372                 }
 373
 374                 if( (cl->p_buffer_read - cl->buffer_read) == 999 )
 375                 {
 376                     Write_message( cl, NULL, "Line too long\r\n",
 377                                    cl->i_mode + 2 );
 378                 }
 379
 380 #ifdef WIN32
 381                 if( i_recv <= 0 && WSAGetLastError() == WSAEWOULDBLOCK )
 382                 {
 383                     errno = EAGAIN;
 384                 }
 385 #endif
 386                 if( i_recv == 0 || ( i_recv == -1 && ( end || errno != EAGAIN ) ) )
 387                     goto drop;
 388             }
 389         }
 390
 391         /* and now we should bidouille the data we received / send */
 392         for(int i = 0 ; i < p_sys->i_clients ; i++ )
 393         {
 394             telnet_client_t *cl = p_sys->clients[i];
 395
 396             if( cl->i_mode >= WRITE_MODE_PWD && cl->i_buffer_write == 0 )
 397             {
 398                // we have finished to send
 399                cl->i_mode -= 2; // corresponding READ MODE
 400             }
 401             else if( cl->i_mode == READ_MODE_PWD &&
 402                      *cl->p_buffer_read == '\n' )
 403             {
 404                 *cl->p_buffer_read = '\0';
 405                 if( !psz_password || !strcmp( psz_password, cl->buffer_read ) )
 406                 {
 407                     Write_message( cl, NULL, "\xff\xfc\x01\r\nWelcome, "
 408                                    "Master\r\n> ", WRITE_MODE_CMD );
 409                 }
 410                 else
 411                 {
 412                     /* wrong password */
 413                     Write_message( cl, NULL,
 414                                    "\r\nWrong password.\r\nPassword: ",
 415                                    WRITE_MODE_PWD );
 416                 }
 417             }
 418             else if( cl->i_mode == READ_MODE_CMD &&
 419                      *cl->p_buffer_read == '\n' )
 420             {
 421                 /* ok, here is a command line */
 422                 if( !strncmp( cl->buffer_read, "logout", 6 ) ||
 423                     !strncmp( cl->buffer_read, "quit", 4 )  ||
 424                     !strncmp( cl->buffer_read, "exit", 4 ) )
 425                 {
 426                     net_Close( cl->fd );
 427                     TAB_REMOVE( p_intf->p_sys->i_clients ,
 428                                 p_intf->p_sys->clients , cl );
 429                     free( cl->buffer_write );
 430                     free( cl );
 431                 }
 432                 else if( !strncmp( cl->buffer_read, "shutdown", 8 ) )
 433                 {
 434                     msg_Err( p_intf, "shutdown requested" );
 435                     libvlc_Quit( p_intf->p_libvlc );
 436                 }
 437                 else if( *cl->buffer_read == '@'
 438                           && strchr( cl->buffer_read, ' ' ) )
 439                 {
 440                     /* Module specific commands (use same syntax as in the
 441                      * rc interface) */
 442                     char *psz_name = cl->buffer_read + 1;
 443                     char *psz_cmd, *psz_arg, *psz_msg;
 444                     int i_ret;
 445
 446                     psz_cmd = strchr( cl->buffer_read, ' ' );
 447                     *psz_cmd = '\0';  psz_cmd++;
 448                     if( ( psz_arg = strchr( psz_cmd, '\n' ) ) ) *psz_arg = '\0';
 449                     if( ( psz_arg = strchr( psz_cmd, '\r' ) ) ) *psz_arg = '\0';
 450                     if( ( psz_arg = strchr( psz_cmd, ' ' ) )
 451                         && *psz_arg )
 452                     {
 453                         *psz_arg = '\0';
 454                         psz_arg++;
 455                     }
 456
 457                     i_ret = var_Command( p_intf, psz_name, psz_cmd, psz_arg,
 458                                          &psz_msg );
 459
 460                     if( psz_msg )
 461                     {
 462                         vlm_message_t *message;
 463                         message = vlm_MessageNew( "Module command", "%s", psz_msg );
 464                         Write_message( cl, message, NULL, WRITE_MODE_CMD );
 465                         vlm_MessageDelete( message );
 466                         free( psz_msg );
 467                     }
 468                 }
 469                 else
 470                 {
 471                     vlm_message_t *message;
 472
 473                     /* create a standard string */
 474                     *cl->p_buffer_read = '\0';
 475
 476                     vlm_ExecuteCommand( p_sys->mediatheque, cl->buffer_read,
 477                                         &message );
 478                     if( !strncmp( cl->buffer_read, "help", 4 ) )
 479                     {
 480                         vlm_message_t *p_my_help =
 481                             vlm_MessageSimpleNew( "Telnet Specific Commands:" );
 482                         vlm_MessageAdd( p_my_help,
 483                             vlm_MessageSimpleNew( "logout, quit, exit" ) );
 484                         vlm_MessageAdd( p_my_help,
 485                             vlm_MessageSimpleNew( "shutdown" ) );
 486                         vlm_MessageAdd( p_my_help,
 487                             vlm_MessageSimpleNew( "@moduleinstance command argument" ) );
 488                         vlm_MessageAdd( message, p_my_help );
 489                     }
 490                     Write_message( cl, message, NULL, WRITE_MODE_CMD );
 491                     vlm_MessageDelete( message );
 492                 }
 493             }
 494         }
 495
 496         /* handle new connections */
 497         for (unsigned i = 0; i < nlisten; i++)
 498         {
 499             int fd;
 500
 501             if (ufd[ncli + i].revents == 0)
 502                 continue;
 503
 504             fd = net_AcceptSingle (VLC_OBJECT(p_intf), ufd[ncli + i].fd);
 505             if (fd == -1)
 506                 continue;
 507
 508             telnet_client_t *cl = calloc( 1, sizeof( telnet_client_t ));
 509             if (cl == NULL)
 510             {
 511                 net_Close (fd);
 512                 continue;
 513             }
 514
 515             cl->i_tel_cmd = 0;
 516             cl->fd = fd;
 517             cl->buffer_write = NULL;
 518             cl->p_buffer_write = cl->buffer_write;
 519             Write_message( cl, NULL,
 520                            "Password: \xff\xfb\x01" , WRITE_MODE_PWD );
 521             TAB_APPEND( p_sys->i_clients, p_sys->clients, cl );
 522         }
 523         vlc_restorecancel( canc );
 524     }
 525     vlc_cleanup_run ();
 526 }
 527
 528 static void Write_message( telnet_client_t *client, vlm_message_t *message,
 529                            const char *string_message, int i_mode )
 530 {
 531     char *psz_message;
 532
 533     client->p_buffer_read = client->buffer_read;
 534     (client->p_buffer_read)[0] = 0; // if (cl->p_buffer_read)[0] = '\n'
 535     free( client->buffer_write );
 536
 537     /* generate the psz_message string */
 538     if( message )
 539     {
 540         /* ok, look for vlm_message_t */
 541         psz_message = MessageToString( message, 0 );
 542     }
 543     else
 544     {
 545         /* it is a basic string_message */
 546         psz_message = strdup( string_message );
 547     }
 548
 549     client->buffer_write = client->p_buffer_write = psz_message;
 550     client->i_buffer_write = strlen( psz_message );
 551     client->i_mode = i_mode;
 552 }
 553
 554 /* We need the level of the message to put a beautiful indentation.
 555  * first level is 0 */
 556 static char *MessageToString( vlm_message_t *message, int i_level )
 557 {
 558 #define STRING_CR "\r\n"
 559 #define STRING_TAIL "> "
 560
 561     char *psz_message;
 562     int i, i_message = sizeof( STRING_TAIL );
 563
 564     if( !message || !message->psz_name )
 565     {
 566         return strdup( STRING_CR STRING_TAIL );
 567     }
 568     else if( !i_level && !message->i_child && !message->psz_value  )
 569     {
 570         /* A command is successful. Don't write anything */
 571         return strdup( /*STRING_CR*/ STRING_TAIL );
 572     }
 573
 574     i_message += strlen( message->psz_name ) + i_level * sizeof( "    " ) + 1;
 575     psz_message = xmalloc( i_message );
 576     *psz_message = 0;
 577     for( i = 0; i < i_level; i++ ) strcat( psz_message, "    " );
 578     strcat( psz_message, message->psz_name );
 579
 580     if( message->psz_value )
 581     {
 582         i_message += sizeof( " : " ) + strlen( message->psz_value ) +
 583             sizeof( STRING_CR );
 584         psz_message = xrealloc( psz_message, i_message );
 585         strcat( psz_message, " : " );
 586         strcat( psz_message, message->psz_value );
 587         strcat( psz_message, STRING_CR );
 588     }
 589     else
 590     {
 591         i_message += sizeof( STRING_CR );
 592         psz_message = xrealloc( psz_message, i_message );
 593         strcat( psz_message, STRING_CR );
 594     }
 595
 596     for( i = 0; i < message->i_child; i++ )
 597     {
 598         char *child_message =
 599             MessageToString( message->child[i], i_level + 1 );
 600
 601         i_message += strlen( child_message );
 602         psz_message = xrealloc( psz_message, i_message );
 603         strcat( psz_message, child_message );
 604         free( child_message );
 605     }
 606
 607     if( i_level == 0 ) strcat( psz_message, STRING_TAIL );
 608
 609     return psz_message;
 610 }