modules/access_output/srt.c

   1 /*****************************************************************************
   2  * srt.c: SRT (Secure Reliable Transport) output 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 <sys/eventfd.h>
  29 #include <sys/epoll.h>
  30
  31 #include <vlc_common.h>
  32 #include <vlc_interrupt.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_sout.h>
  35 #include <vlc_block.h>
  36 #include <vlc_network.h>
  37
  38 #include <srt/srt.h>
  39
  40 /* libsrt defines default packet size as 1316 internally
  41  * so srt module takes same value. */
  42 #define SRT_DEFAULT_CHUNK_SIZE 1316
  43 /* libsrt tutorial uses 9000 as a default binding port */
  44 #define SRT_DEFAULT_PORT 9000
  45 /* The default timeout is -1 (infinite) */
  46 #define SRT_DEFAULT_POLL_TIMEOUT 100
  47 /* The default latency is 125
  48  * which uses srt library internally */
  49 #define SRT_DEFAULT_LATENCY 125
  50
  51 struct sout_access_out_sys_t
  52 {
  53     SRTSOCKET     sock;
  54     int           i_poll_id;
  55     int           i_poll_timeout;
  56     int           i_latency;
  57     size_t        i_chunk_size;
  58     int           i_event_fd;
  59 };
  60
  61 static void srt_wait_interrupted(void *p_data)
  62 {
  63     sout_access_out_t *p_access = p_data;
  64     sout_access_out_sys_t *p_sys = p_access->p_sys;
  65     msg_Dbg( p_access, "Waking up srt_epoll_wait");
  66     if ( write( p_sys->i_event_fd, &( bool ) { true }, sizeof( bool ) ) < 0 )
  67     {
  68         msg_Err( p_access, "Failed to send data to event fd");
  69     }
  70 }
  71
  72 static ssize_t Write( sout_access_out_t *p_access, block_t *p_buffer )
  73 {
  74     sout_access_out_sys_t *p_sys = p_access->p_sys;
  75     int i_len = 0;
  76
  77     vlc_interrupt_register( srt_wait_interrupted, p_access);
  78
  79     while( p_buffer )
  80     {
  81         block_t *p_next;
  82
  83         i_len += p_buffer->i_buffer;
  84
  85         while( p_buffer->i_buffer )
  86         {
  87             size_t i_write = __MIN( p_buffer->i_buffer, p_sys->i_chunk_size );
  88             SRTSOCKET ready[2];
  89
  90             struct epoll_event event[1] = { 0 };
  91 retry:
  92             if ( srt_epoll_wait( p_sys->i_poll_id,
  93                 0, 0, ready, &(int){ 2 }, p_sys->i_poll_timeout,
  94                 &(int) { p_sys->i_event_fd }, &(int) { 1 }, 0, 0 ) == -1 )
  95             {
  96                 /* Assuming that timeout error is normal when SRT socket is connected. */
  97                 if ( srt_getlasterror( NULL ) == SRT_ETIMEOUT &&
  98                      srt_getsockstate( p_sys->sock ) == SRTS_CONNECTED )
  99                 {
 100                     srt_clearlasterror();
 101                     goto retry;
 102                 }
 103
 104                 i_len = VLC_EGENERIC;
 105                 goto out;
 106             }
 107
 108             if ( event[0].events & EPOLLIN )
 109             {
 110                 bool cancel = 0;
 111                 int ret = read( event[0].data.fd, &cancel, sizeof( bool ) );
 112                 if ( ret < 0 )
 113                 {
 114                     goto retry;
 115                 }
 116
 117                 if ( cancel )
 118                 {
 119                     msg_Dbg( p_access, "Cancelled running" );
 120                     i_len = 0;
 121                     goto out;
 122                 }
 123             }
 124
 125             if ( srt_sendmsg2( p_sys->sock, (char *)p_buffer->p_buffer, i_write, 0 ) == SRT_ERROR )
 126                 msg_Warn( p_access, "send error: %s", srt_getlasterror_str() );
 127
 128             p_buffer->p_buffer += i_write;
 129             p_buffer->i_buffer -= i_write;
 130         }
 131
 132         p_next = p_buffer->p_next;
 133         block_Release( p_buffer );
 134         p_buffer = p_next;
 135     }
 136
 137 out:
 138     vlc_interrupt_unregister();
 139     if ( i_len <= 0 ) block_ChainRelease( p_buffer );
 140     return i_len;
 141 }
 142
 143 static int Control( sout_access_out_t *p_access, int i_query, va_list args )
 144 {
 145     sout_access_out_sys_t *p_sys = p_access->p_sys;
 146     int i_ret = VLC_SUCCESS;
 147
 148     switch( i_query )
 149     {
 150         case ACCESS_OUT_CONTROLS_PACE:
 151             *va_arg( args, bool * ) = false;
 152             break;
 153
 154         default:
 155             i_ret = VLC_EGENERIC;
 156             break;
 157     }
 158
 159     return i_ret;
 160 }
 161
 162 static int Open( vlc_object_t *p_this )
 163 {
 164     sout_access_out_t       *p_access = (sout_access_out_t*)p_this;
 165     sout_access_out_sys_t   *p_sys = NULL;
 166
 167     char                    *psz_dst_addr = NULL;
 168     int                      i_dst_port;
 169     int                      stat;
 170
 171     struct addrinfo hints = {
 172         .ai_socktype = SOCK_DGRAM,
 173     }, *res = NULL;
 174
 175     if (var_Create ( p_access, "dst-port", VLC_VAR_INTEGER )
 176      || var_Create ( p_access, "src-port", VLC_VAR_INTEGER )
 177      || var_Create ( p_access, "dst-addr", VLC_VAR_STRING )
 178      || var_Create ( p_access, "src-addr", VLC_VAR_STRING ) )
 179     {
 180          msg_Err( p_access, "Valid network information is required." );
 181         return VLC_ENOMEM;
 182     }
 183
 184     if( !( p_sys = malloc ( sizeof( *p_sys ) ) ) )
 185         return VLC_ENOMEM;
 186
 187     p_sys->i_chunk_size = var_InheritInteger( p_access, "chunk-size" );
 188     p_sys->i_poll_timeout = var_InheritInteger( p_access, "poll-timeout" );
 189     p_sys->i_latency = var_InheritInteger( p_access, "latency" );
 190     p_sys->i_poll_id = -1;
 191     p_sys->i_event_fd = -1;
 192
 193     p_access->p_sys = p_sys;
 194
 195     i_dst_port = SRT_DEFAULT_PORT;
 196     char *psz_parser = psz_dst_addr = strdup( p_access->psz_path );
 197     if( !psz_dst_addr )
 198     {
 199         free( p_sys );
 200         return VLC_ENOMEM;
 201     }
 202
 203     if (psz_parser[0] == '[')
 204         psz_parser = strchr (psz_parser, ']');
 205
 206     psz_parser = strchr (psz_parser ? psz_parser : psz_dst_addr, ':');
 207     if (psz_parser != NULL)
 208     {
 209         *psz_parser++ = '\0';
 210         i_dst_port = atoi (psz_parser);
 211     }
 212
 213     msg_Dbg( p_access, "Setting SRT socket (dest addresss: %s, port: %d).",
 214              psz_dst_addr, i_dst_port );
 215
 216     stat = vlc_getaddrinfo( psz_dst_addr, i_dst_port, &hints, &res );
 217     if ( stat )
 218     {
 219         msg_Err( p_access, "Cannot resolve [%s]:%d (reason: %s)",
 220                  psz_dst_addr,
 221                  i_dst_port,
 222                  gai_strerror( stat ) );
 223
 224         goto failed;
 225     }
 226
 227     p_sys->sock = srt_socket( res->ai_family, SOCK_DGRAM, 0 );
 228     if ( p_sys->sock == SRT_ERROR )
 229     {
 230         msg_Err( p_access, "Failed to open socket." );
 231         goto failed;
 232     }
 233
 234     /* Make SRT non-blocking */
 235     srt_setsockopt( p_sys->sock, 0, SRTO_SNDSYN, &(bool) { false }, sizeof( bool ) );
 236
 237     /* Make sure TSBPD mode is enable (SRT mode) */
 238     srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDMODE, &(int) { 1 }, sizeof( int ) );
 239
 240     /* This is an access_out so it is always a sender */
 241     srt_setsockopt( p_sys->sock, 0, SRTO_SENDER, &(int) { 1 }, sizeof( int ) );
 242
 243     /* Set latency */
 244     srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDDELAY, &p_sys->i_latency, sizeof( int ) );
 245
 246     p_sys->i_poll_id = srt_epoll_create();
 247     if ( p_sys->i_poll_id == -1 )
 248     {
 249         msg_Err( p_access, "Failed to create poll id for SRT socket (reason: %s)",
 250                  srt_getlasterror_str() );
 251
 252         goto failed;
 253     }
 254
 255     srt_epoll_add_usock( p_sys->i_poll_id, p_sys->sock, &(int) { SRT_EPOLL_OUT });
 256     srt_setsockopt( p_sys->sock, 0, SRTO_SENDER, &(int) { 1 }, sizeof(int) );
 257
 258     p_sys->i_event_fd = eventfd( 0, EFD_NONBLOCK | EFD_CLOEXEC );
 259     srt_epoll_add_ssock( p_sys->i_poll_id, p_sys->i_event_fd, &(int) { EPOLLIN } );
 260
 261     stat = srt_connect( p_sys->sock, res->ai_addr, sizeof (struct sockaddr));
 262     if ( stat == SRT_ERROR )
 263     {
 264         msg_Err( p_access, "Failed to connect to server (reason: %s)",
 265                  srt_getlasterror_str() );
 266         goto failed;
 267     }
 268
 269     p_access->pf_write = Write;
 270     p_access->pf_control = Control;
 271
 272     free( psz_dst_addr );
 273     freeaddrinfo( res );
 274
 275     return VLC_SUCCESS;
 276
 277 failed:
 278     if ( psz_dst_addr != NULL)
 279         free( psz_dst_addr );
 280
 281     if ( res != NULL )
 282         freeaddrinfo( res );
 283
 284     if ( p_sys != NULL )
 285     {
 286         if ( p_sys->i_poll_id != -1 ) srt_epoll_release( p_sys->i_poll_id );
 287         if ( p_sys->sock != -1 ) srt_close( p_sys->sock );
 288         if ( p_sys->i_event_fd != -1 ) close( p_sys->i_event_fd );
 289
 290         free( p_sys );
 291     }
 292
 293     return VLC_EGENERIC;
 294 }
 295
 296 static void Close( vlc_object_t * p_this )
 297 {
 298     sout_access_out_t     *p_access = (sout_access_out_t*)p_this;
 299     sout_access_out_sys_t *p_sys = p_access->p_sys;
 300
 301     srt_epoll_release( p_sys->i_poll_id );
 302     srt_close( p_sys->sock );
 303
 304     if ( p_sys->i_event_fd != -1 )
 305     {
 306         close( p_sys->i_event_fd );
 307         p_sys->i_event_fd = -1;
 308     }
 309
 310     free( p_sys );
 311 }
 312
 313 /* Module descriptor */
 314 vlc_module_begin()
 315     set_shortname( N_("SRT") )
 316     set_description( N_("SRT stream output") )
 317     set_category( CAT_SOUT )
 318     set_subcategory( SUBCAT_SOUT_ACO )
 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 miliseconds (-1 = infinite)"), NULL, true )
 324     add_integer( "latency", SRT_DEFAULT_LATENCY, N_("SRT latency (ms)"), NULL, true )
 325
 326     set_capability( "sout access", 0 )
 327     add_shortcut( "srt" )
 328
 329     set_callbacks( Open, Close )
 330 vlc_module_end ()