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 <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_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 /* Crypto key length in bytes. */
  51 #define SRT_KEY_LENGTH_TEXT N_("Crypto key length in bytes")
  52 #define SRT_DEFAULT_KEY_LENGTH 16
  53 static const int srt_key_lengths[] = {
  54     16, 24, 32,
  55 };
  56
  57 static const char *const srt_key_length_names[] = {
  58     N_("16 bytes"), N_("24 bytes"), N_("32 bytes"),
  59 };
  60
  61 struct sout_access_out_sys_t
  62 {
  63     SRTSOCKET     sock;
  64     int           i_poll_id;
  65     int           i_poll_timeout;
  66     int           i_latency;
  67     size_t        i_chunk_size;
  68     int           i_pipe_fds[2];
  69 };
  70
  71 static void srt_wait_interrupted(void *p_data)
  72 {
  73     sout_access_out_t *p_access = p_data;
  74     sout_access_out_sys_t *p_sys = p_access->p_sys;
  75     msg_Dbg( p_access, "Waking up srt_epoll_wait");
  76     if ( write( p_sys->i_pipe_fds[1], &( bool ) { true }, sizeof( bool ) ) < 0 )
  77     {
  78         msg_Err( p_access, "Failed to send data to event fd");
  79     }
  80 }
  81
  82 static ssize_t Write( sout_access_out_t *p_access, block_t *p_buffer )
  83 {
  84     sout_access_out_sys_t *p_sys = p_access->p_sys;
  85     int i_len = 0;
  86
  87     vlc_interrupt_register( srt_wait_interrupted, p_access);
  88
  89     while( p_buffer )
  90     {
  91         block_t *p_next;
  92
  93         i_len += p_buffer->i_buffer;
  94
  95         while( p_buffer->i_buffer )
  96         {
  97             size_t i_write = __MIN( p_buffer->i_buffer, p_sys->i_chunk_size );
  98             SRTSOCKET ready[2];
  99
 100 retry:
 101             if ( srt_epoll_wait( p_sys->i_poll_id,
 102                 0, 0, ready, &(int){ 2 }, p_sys->i_poll_timeout,
 103                 &(int) { p_sys->i_pipe_fds[0] }, &(int) { 1 }, NULL, 0 ) == -1 )
 104             {
 105                 /* Assuming that timeout error is normal when SRT socket is connected. */
 106                 if ( srt_getlasterror( NULL ) == SRT_ETIMEOUT &&
 107                      srt_getsockstate( p_sys->sock ) == SRTS_CONNECTED )
 108                 {
 109                     srt_clearlasterror();
 110                     goto retry;
 111                 }
 112
 113                 i_len = VLC_EGENERIC;
 114                 goto out;
 115             }
 116
 117             bool cancel = 0;
 118             int ret = read( p_sys->i_pipe_fds[0], &cancel, sizeof( bool ) );
 119             if ( ret > 0 && cancel )
 120             {
 121                 msg_Dbg( p_access, "Cancelled running" );
 122                 i_len = 0;
 123                 goto out;
 124             }
 125
 126             if ( srt_sendmsg2( p_sys->sock, (char *)p_buffer->p_buffer, i_write, 0 ) == SRT_ERROR )
 127                 msg_Warn( p_access, "send error: %s", srt_getlasterror_str() );
 128
 129             p_buffer->p_buffer += i_write;
 130             p_buffer->i_buffer -= i_write;
 131         }
 132
 133         p_next = p_buffer->p_next;
 134         block_Release( p_buffer );
 135         p_buffer = p_next;
 136     }
 137
 138 out:
 139     vlc_interrupt_unregister();
 140     if ( i_len <= 0 ) block_ChainRelease( p_buffer );
 141     return i_len;
 142 }
 143
 144 static int Control( sout_access_out_t *p_access, int i_query, va_list args )
 145 {
 146     VLC_UNUSED (p_access);
 147
 148     int i_ret = VLC_SUCCESS;
 149
 150     switch( i_query )
 151     {
 152         case ACCESS_OUT_CONTROLS_PACE:
 153             *va_arg( args, bool * ) = false;
 154             break;
 155
 156         default:
 157             i_ret = VLC_EGENERIC;
 158             break;
 159     }
 160
 161     return i_ret;
 162 }
 163
 164 static int Open( vlc_object_t *p_this )
 165 {
 166     sout_access_out_t       *p_access = (sout_access_out_t*)p_this;
 167     sout_access_out_sys_t   *p_sys = NULL;
 168
 169     char                    *psz_dst_addr = NULL;
 170     int                      i_dst_port;
 171     int                      stat;
 172     char                    *psz_passphrase = NULL;
 173
 174     struct addrinfo hints = {
 175         .ai_socktype = SOCK_DGRAM,
 176     }, *res = NULL;
 177
 178     if (var_Create ( p_access, "dst-port", VLC_VAR_INTEGER )
 179      || var_Create ( p_access, "src-port", VLC_VAR_INTEGER )
 180      || var_Create ( p_access, "dst-addr", VLC_VAR_STRING )
 181      || var_Create ( p_access, "src-addr", VLC_VAR_STRING ) )
 182     {
 183          msg_Err( p_access, "Valid network information is required." );
 184         return VLC_ENOMEM;
 185     }
 186
 187     if( !( p_sys = malloc ( sizeof( *p_sys ) ) ) )
 188         return VLC_ENOMEM;
 189
 190     p_sys->i_chunk_size = var_InheritInteger( p_access, "chunk-size" );
 191     p_sys->i_poll_timeout = var_InheritInteger( p_access, "poll-timeout" );
 192     p_sys->i_latency = var_InheritInteger( p_access, "latency" );
 193     p_sys->i_poll_id = -1;
 194
 195     p_access->p_sys = p_sys;
 196
 197     psz_passphrase = var_InheritString( p_access, "passphrase" );
 198
 199     i_dst_port = SRT_DEFAULT_PORT;
 200     char *psz_parser = psz_dst_addr = strdup( p_access->psz_path );
 201     if( !psz_dst_addr )
 202     {
 203         free( p_sys );
 204         return VLC_ENOMEM;
 205     }
 206
 207     if (psz_parser[0] == '[')
 208         psz_parser = strchr (psz_parser, ']');
 209
 210     psz_parser = strchr (psz_parser ? psz_parser : psz_dst_addr, ':');
 211     if (psz_parser != NULL)
 212     {
 213         *psz_parser++ = '\0';
 214         i_dst_port = atoi (psz_parser);
 215     }
 216
 217     msg_Dbg( p_access, "Setting SRT socket (dest addresss: %s, port: %d).",
 218              psz_dst_addr, i_dst_port );
 219
 220     stat = vlc_getaddrinfo( psz_dst_addr, i_dst_port, &hints, &res );
 221     if ( stat )
 222     {
 223         msg_Err( p_access, "Cannot resolve [%s]:%d (reason: %s)",
 224                  psz_dst_addr,
 225                  i_dst_port,
 226                  gai_strerror( stat ) );
 227
 228         goto failed;
 229     }
 230
 231     p_sys->sock = srt_socket( res->ai_family, SOCK_DGRAM, 0 );
 232     if ( p_sys->sock == SRT_ERROR )
 233     {
 234         msg_Err( p_access, "Failed to open socket." );
 235         goto failed;
 236     }
 237
 238     /* Make SRT non-blocking */
 239     srt_setsockopt( p_sys->sock, 0, SRTO_SNDSYN, &(bool) { false }, sizeof( bool ) );
 240
 241     /* Make sure TSBPD mode is enable (SRT mode) */
 242     srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDMODE, &(int) { 1 }, sizeof( int ) );
 243
 244     /* This is an access_out so it is always a sender */
 245     srt_setsockopt( p_sys->sock, 0, SRTO_SENDER, &(int) { 1 }, sizeof( int ) );
 246
 247     /* Set latency */
 248     srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDDELAY, &p_sys->i_latency, sizeof( int ) );
 249
 250     if ( psz_passphrase != NULL && psz_passphrase[0] != '\0')
 251     {
 252         int i_key_length = var_InheritInteger( p_access, "key-length" );
 253         srt_setsockopt( p_sys->sock, 0, SRTO_PASSPHRASE,
 254             psz_passphrase, strlen( psz_passphrase ) );
 255         srt_setsockopt( p_sys->sock, 0, SRTO_PBKEYLEN,
 256             &i_key_length, sizeof( int ) );
 257     }
 258
 259     p_sys->i_poll_id = srt_epoll_create();
 260     if ( p_sys->i_poll_id == -1 )
 261     {
 262         msg_Err( p_access, "Failed to create poll id for SRT socket (reason: %s)",
 263                  srt_getlasterror_str() );
 264
 265         goto failed;
 266     }
 267
 268     if ( vlc_pipe( p_sys->i_pipe_fds ) != 0 )
 269     {
 270         msg_Err( p_access, "Failed to create pipe fds." );
 271         goto failed;
 272     }
 273     fcntl( p_sys->i_pipe_fds[0], F_SETFL, O_NONBLOCK | fcntl( p_sys->i_pipe_fds[0], F_GETFL ) );
 274
 275     srt_epoll_add_usock( p_sys->i_poll_id, p_sys->sock, &(int) { SRT_EPOLL_OUT });
 276     srt_setsockopt( p_sys->sock, 0, SRTO_SENDER, &(int) { 1 }, sizeof(int) );
 277
 278     srt_epoll_add_ssock( p_sys->i_poll_id, p_sys->i_pipe_fds[0], &(int) { SRT_EPOLL_IN } );
 279
 280     stat = srt_connect( p_sys->sock, res->ai_addr, sizeof (struct sockaddr));
 281     if ( stat == SRT_ERROR )
 282     {
 283         msg_Err( p_access, "Failed to connect to server (reason: %s)",
 284                  srt_getlasterror_str() );
 285         goto failed;
 286     }
 287
 288     p_access->pf_write = Write;
 289     p_access->pf_control = Control;
 290
 291     free( psz_passphrase );
 292     free( psz_dst_addr );
 293     freeaddrinfo( res );
 294
 295     return VLC_SUCCESS;
 296
 297 failed:
 298     free( psz_passphrase );
 299
 300     if ( psz_dst_addr != NULL)
 301         free( psz_dst_addr );
 302
 303     if ( res != NULL )
 304         freeaddrinfo( res );
 305
 306     vlc_close( p_sys->i_pipe_fds[0] );
 307     vlc_close( p_sys->i_pipe_fds[1] );
 308
 309     if ( p_sys != NULL )
 310     {
 311         if ( p_sys->i_poll_id != -1 ) srt_epoll_release( p_sys->i_poll_id );
 312         if ( p_sys->sock != -1 ) srt_close( p_sys->sock );
 313
 314         free( p_sys );
 315     }
 316
 317     return VLC_EGENERIC;
 318 }
 319
 320 static void Close( vlc_object_t * p_this )
 321 {
 322     sout_access_out_t     *p_access = (sout_access_out_t*)p_this;
 323     sout_access_out_sys_t *p_sys = p_access->p_sys;
 324
 325     srt_epoll_release( p_sys->i_poll_id );
 326     srt_close( p_sys->sock );
 327
 328     vlc_close( p_sys->i_pipe_fds[0] );
 329     vlc_close( p_sys->i_pipe_fds[1] );
 330
 331     free( p_sys );
 332 }
 333
 334 /* Module descriptor */
 335 vlc_module_begin()
 336     set_shortname( N_("SRT") )
 337     set_description( N_("SRT stream output") )
 338     set_category( CAT_SOUT )
 339     set_subcategory( SUBCAT_SOUT_ACO )
 340
 341     add_integer( "chunk-size", SRT_DEFAULT_CHUNK_SIZE,
 342             N_("SRT chunk size (bytes)"), NULL, true )
 343     add_integer( "poll-timeout", SRT_DEFAULT_POLL_TIMEOUT,
 344             N_("Return poll wait after timeout milliseconds (-1 = infinite)"), NULL, true )
 345     add_integer( "latency", SRT_DEFAULT_LATENCY, N_("SRT latency (ms)"), NULL, true )
 346     add_password( "passphrase", "", N_("Password for stream encryption"), NULL, false )
 347     add_integer( "key-length", SRT_DEFAULT_KEY_LENGTH,
 348             SRT_KEY_LENGTH_TEXT, SRT_KEY_LENGTH_TEXT, false )
 349         change_integer_list( srt_key_lengths, srt_key_length_names )
 350
 351     set_capability( "sout access", 0 )
 352     add_shortcut( "srt" )
 353
 354     set_callbacks( Open, Close )
 355 vlc_module_end ()