modules/access/srt.c

   1 /*****************************************************************************
   2  * srt.c: SRT (Secure Reliable Transport) input module
   3  *****************************************************************************
   4  * Copyright (C) 2017, Collabora Ltd.
   5  *
   6  * Authors: Justin Kim <justin.kim@collabora.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <errno.h>
  28 #include <fcntl.h>
  29
  30 #include <vlc_common.h>
  31 #include <vlc_interrupt.h>
  32 #include <vlc_fs.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_access.h>
  35
  36 #include <vlc_network.h>
  37 #include <vlc_url.h>
  38
  39 #include <srt/srt.h>
  40
  41 /* libsrt defines default packet size as 1316 internally
  42  * so srt module takes same value. */
  43 #define SRT_DEFAULT_CHUNK_SIZE 1316
  44 /* The default timeout is -1 (infinite) */
  45 #define SRT_DEFAULT_POLL_TIMEOUT -1
  46 /* The default latency is 125
  47  * which uses srt library internally */
  48 #define SRT_DEFAULT_LATENCY 125
  49 /* Crypto key length in bytes. */
  50 #define SRT_KEY_LENGTH_TEXT N_("Crypto key length in bytes")
  51 #define SRT_DEFAULT_KEY_LENGTH 16
  52 static const int srt_key_lengths[] = {
  53     16, 24, 32,
  54 };
  55
  56 static const char *const srt_key_length_names[] = {
  57     N_("16 bytes"), N_("24 bytes"), N_("32 bytes"),
  58 };
  59
  60 struct stream_sys_t
  61 {
  62     SRTSOCKET   sock;
  63     int         i_poll_id;
  64     int         i_poll_timeout;
  65     int         i_latency;
  66     size_t      i_chunk_size;
  67     int         i_pipe_fds[2];
  68 };
  69
  70 static void srt_wait_interrupted(void *p_data)
  71 {
  72     stream_t *p_stream = p_data;
  73     stream_sys_t *p_sys = p_stream->p_sys;
  74     msg_Dbg( p_stream, "Waking up srt_epoll_wait");
  75     if ( write( p_sys->i_pipe_fds[1], &( bool ) { true }, sizeof( bool ) ) < 0 )
  76     {
  77         msg_Err( p_stream, "Failed to send data to pipe");
  78     }
  79 }
  80
  81 static int Control(stream_t *p_stream, int i_query, va_list args)
  82 {
  83     int i_ret = VLC_SUCCESS;
  84
  85     switch( i_query )
  86     {
  87         case STREAM_CAN_SEEK:
  88         case STREAM_CAN_FASTSEEK:
  89         case STREAM_CAN_PAUSE:
  90         case STREAM_CAN_CONTROL_PACE:
  91             *va_arg( args, bool * ) = false;
  92             break;
  93         case STREAM_GET_PTS_DELAY:
  94             *va_arg( args, int64_t * ) = INT64_C(1000)
  95                    * var_InheritInteger(p_stream, "network-caching");
  96             break;
  97         default:
  98             i_ret = VLC_EGENERIC;
  99             break;
 100     }
 101
 102     return i_ret;
 103 }
 104
 105 static block_t *BlockSRT(stream_t *p_stream, bool *restrict eof)
 106 {
 107     stream_sys_t *p_sys = p_stream->p_sys;
 108
 109     block_t *pkt = block_Alloc( p_sys->i_chunk_size );
 110
 111     if ( unlikely( pkt == NULL ) )
 112     {
 113         return NULL;
 114     }
 115
 116     vlc_interrupt_register( srt_wait_interrupted, p_stream);
 117
 118     SRTSOCKET ready[2];
 119
 120     if ( srt_epoll_wait( p_sys->i_poll_id,
 121         ready, &(int) { 2 }, NULL, 0, p_sys->i_poll_timeout,
 122         &(int) { p_sys->i_pipe_fds[0] }, &(int) { 1 }, NULL, 0 ) == -1 )
 123     {
 124         int srt_err = srt_getlasterror( NULL );
 125
 126         /* Assuming that timeout error is normal when SRT socket is connected. */
 127         if ( srt_err == SRT_ETIMEOUT && srt_getsockstate( p_sys->sock ) == SRTS_CONNECTED )
 128         {
 129             goto skip;
 130         }
 131
 132         msg_Err( p_stream, "released poll wait (reason : %s)", srt_getlasterror_str() );
 133         goto endofstream;
 134     }
 135
 136     bool cancel = 0;
 137     int ret = read( p_sys->i_pipe_fds[0], &cancel, sizeof( bool ) );
 138     if ( ret > 0 && cancel )
 139     {
 140         msg_Dbg( p_stream, "Cancelled running" );
 141         goto endofstream;
 142     }
 143
 144     int stat = srt_recvmsg( p_sys->sock, (char *)pkt->p_buffer, p_sys->i_chunk_size );
 145
 146     if ( stat == SRT_ERROR )
 147     {
 148         msg_Err( p_stream, "failed to recevie SRT packet (reason: %s)", srt_getlasterror_str() );
 149         goto endofstream;
 150     }
 151
 152     pkt->i_buffer = stat;
 153     vlc_interrupt_unregister();
 154     return pkt;
 155
 156 endofstream:
 157     msg_Dbg( p_stream, "EOS");
 158    *eof = true;
 159 skip:
 160     block_Release(pkt);
 161     srt_clearlasterror();
 162     vlc_interrupt_unregister();
 163
 164     return NULL;
 165 }
 166
 167 static int Open(vlc_object_t *p_this)
 168 {
 169     stream_t     *p_stream = (stream_t*)p_this;
 170     stream_sys_t *p_sys = NULL;
 171     vlc_url_t     parsed_url = { 0 };
 172     struct addrinfo hints = {
 173         .ai_socktype = SOCK_DGRAM,
 174     }, *res = NULL;
 175     int stat;
 176
 177     char         *psz_passphrase = NULL;
 178
 179     p_sys = vlc_obj_malloc( p_this, sizeof( *p_sys ) );
 180     if( unlikely( p_sys == NULL ) )
 181         return VLC_ENOMEM;
 182
 183     if ( vlc_UrlParse( &parsed_url, p_stream->psz_url ) == -1 )
 184     {
 185         msg_Err( p_stream, "Failed to parse a given URL (%s)", p_stream->psz_url );
 186         goto failed;
 187     }
 188
 189     p_sys->i_chunk_size = var_InheritInteger( p_stream, "chunk-size" );
 190     p_sys->i_poll_timeout = var_InheritInteger( p_stream, "poll-timeout" );
 191     p_sys->i_latency = var_InheritInteger( p_stream, "latency" );
 192     p_sys->i_poll_id = -1;
 193     p_stream->p_sys = p_sys;
 194     p_stream->pf_block = BlockSRT;
 195     p_stream->pf_control = Control;
 196
 197     psz_passphrase = var_InheritString( p_stream, "passphrase" );
 198
 199     stat = vlc_getaddrinfo( parsed_url.psz_host, parsed_url.i_port, &hints, &res );
 200     if ( stat )
 201     {
 202         msg_Err( p_stream, "Cannot resolve [%s]:%d (reason: %s)",
 203                  parsed_url.psz_host,
 204                  parsed_url.i_port,
 205                  gai_strerror( stat ) );
 206
 207         goto failed;
 208     }
 209
 210     p_sys->sock = srt_socket( res->ai_family, SOCK_DGRAM, 0 );
 211     if ( p_sys->sock == SRT_ERROR )
 212     {
 213         msg_Err( p_stream, "Failed to open socket." );
 214         goto failed;
 215     }
 216
 217     /* Make SRT non-blocking */
 218     srt_setsockopt( p_sys->sock, 0, SRTO_SNDSYN, &(bool) { false }, sizeof( bool ) );
 219
 220     /* Make sure TSBPD mode is enable (SRT mode) */
 221     srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDMODE, &(int) { 1 }, sizeof( int ) );
 222
 223     /* Set latency */
 224     srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDDELAY, &p_sys->i_latency, sizeof( int ) );
 225
 226     if ( psz_passphrase != NULL && psz_passphrase[0] != '\0')
 227     {
 228         int i_key_length = var_InheritInteger( p_stream, "key-length" );
 229
 230         srt_setsockopt( p_sys->sock, 0, SRTO_PASSPHRASE,
 231             psz_passphrase, strlen( psz_passphrase ) );
 232         srt_setsockopt( p_sys->sock, 0, SRTO_PBKEYLEN,
 233             &i_key_length, sizeof( int ) );
 234     }
 235
 236     p_sys->i_poll_id = srt_epoll_create();
 237     if ( p_sys->i_poll_id == -1 )
 238     {
 239         msg_Err( p_stream, "Failed to create poll id for SRT socket." );
 240         goto failed;
 241     }
 242
 243     if ( vlc_pipe( p_sys->i_pipe_fds ) != 0 )
 244     {
 245         msg_Err( p_stream, "Failed to create pipe fds." );
 246         goto failed;
 247     }
 248
 249     fcntl( p_sys->i_pipe_fds[0], F_SETFL, O_NONBLOCK | fcntl( p_sys->i_pipe_fds[0], F_GETFL ) );
 250
 251     srt_epoll_add_usock( p_sys->i_poll_id, p_sys->sock, &(int) { SRT_EPOLL_IN } );
 252     srt_epoll_add_ssock( p_sys->i_poll_id, p_sys->i_pipe_fds[0], &(int) { SRT_EPOLL_IN } );
 253
 254     stat = srt_connect( p_sys->sock, res->ai_addr, sizeof (struct sockaddr) );
 255
 256     if ( stat == SRT_ERROR )
 257     {
 258         msg_Err( p_stream, "Failed to connect to server." );
 259         goto failed;
 260     }
 261
 262     vlc_UrlClean( &parsed_url );
 263     freeaddrinfo( res );
 264     free (psz_passphrase);
 265
 266     return VLC_SUCCESS;
 267
 268 failed:
 269
 270     if ( parsed_url.psz_host != NULL
 271       && parsed_url.psz_buffer != NULL)
 272     {
 273         vlc_UrlClean( &parsed_url );
 274     }
 275
 276     if ( res != NULL )
 277     {
 278         freeaddrinfo( res );
 279     }
 280
 281     vlc_close( p_sys->i_pipe_fds[0] );
 282     vlc_close( p_sys->i_pipe_fds[1] );
 283
 284     if ( p_sys->i_poll_id != -1 )
 285     {
 286         srt_epoll_release( p_sys->i_poll_id );
 287         p_sys->i_poll_id = -1;
 288     }
 289     srt_close( p_sys->sock );
 290
 291     free (psz_passphrase);
 292
 293     return VLC_EGENERIC;
 294 }
 295
 296 static void Close(vlc_object_t *p_this)
 297 {
 298     stream_t     *p_stream = (stream_t*)p_this;
 299     stream_sys_t *p_sys = p_stream->p_sys;
 300
 301     if ( p_sys->i_poll_id != -1 )
 302     {
 303         srt_epoll_release( p_sys->i_poll_id );
 304         p_sys->i_poll_id = -1;
 305     }
 306     msg_Dbg( p_stream, "closing server" );
 307     srt_close( p_sys->sock );
 308
 309     vlc_close( p_sys->i_pipe_fds[0] );
 310     vlc_close( p_sys->i_pipe_fds[1] );
 311 }
 312
 313 /* Module descriptor */
 314 vlc_module_begin ()
 315     set_shortname( N_("SRT") )
 316     set_description( N_("SRT input") )
 317     set_category( CAT_INPUT )
 318     set_subcategory( SUBCAT_INPUT_ACCESS )
 319
 320     add_integer( "chunk-size", SRT_DEFAULT_CHUNK_SIZE,
 321             N_("SRT chunk size (bytes)"), NULL, true )
 322     add_integer( "poll-timeout", SRT_DEFAULT_POLL_TIMEOUT,
 323             N_("Return poll wait after timeout milliseconds (-1 = infinite)"), NULL, true )
 324     add_integer( "latency", SRT_DEFAULT_LATENCY, N_("SRT latency (ms)"), NULL, true )
 325     add_password( "passphrase", "", N_("Password for stream encryption"), NULL, false )
 326     add_integer( "key-length", SRT_DEFAULT_KEY_LENGTH,
 327             SRT_KEY_LENGTH_TEXT, SRT_KEY_LENGTH_TEXT, false )
 328         change_integer_list( srt_key_lengths, srt_key_length_names )
 329
 330     set_capability( "access", 0 )
 331     add_shortcut( "srt" )
 332
 333     set_callbacks( Open, Close )
 334 vlc_module_end ()