sap.c

video linux conference

/*****************************************************************************
 * CloseDemux: Close the demuxer
 *****************************************************************************/
static void CloseDemux( vlc_object_t *p_this )
{

}

/*****************************************************************************
 * Run: main SAP thread
 *****************************************************************************
 * Listens to SAP packets, and sends them to packet_handle
 *****************************************************************************/
#define MAX_SAP_BUFFER 5000

static void Run( services_discovery_t *p_sd )
{
    int i;

    /* read SAP packets */
    while( !p_sd->b_die )
    {
        int i_read;
        uint8_t p_buffer[MAX_SAP_BUFFER + 1];

        i_read = net_Select( p_sd, p_sd->p_sys->pi_fd, NULL,
                             p_sd->p_sys->i_fd, p_buffer,
                             MAX_SAP_BUFFER, 500000 );

        /* Check for items that need deletion */
        for( i = 0; i < p_sd->p_sys->i_announces; i++ )
        {
            mtime_t i_timeout = ( mtime_t ) 1000000 * p_sd->p_sys->i_timeout;

            if( mdate() - p_sd->p_sys->pp_announces[i]->i_last > i_timeout )
            {
                struct sap_announce_t *p_announce;
                p_announce = p_sd->p_sys->pp_announces[i];

                /* Remove the playlist item */
                playlist_LockDelete( p_sd->p_sys->p_playlist,
                                     p_announce->i_item_id );

                /* Remove the sap_announce from the array */
                REMOVE_ELEM( p_sd->p_sys->pp_announces,
                           p_sd->p_sys->i_announces, i );

                free( p_announce );
            }
        }

        /* Minimum length is > 6 */
        if( i_read <= 6 )
        {
            if( i_read < 0 )
            {
                msg_Warn( p_sd, "socket read error" );
            }
            continue;
        }

        p_buffer[i_read] = '\0';

        /* Parse the packet */
        ParseSAP( p_sd, p_buffer, i_read );
    }
}

/**********************************************************************
 * Demux: reads and demuxes data packets
 * Return -1 if error, 0 if EOF, 1 else
 **********************************************************************/
static int Demux( demux_t *p_demux )
{
    sdp_t *p_sdp = p_demux->p_sys->p_sdp;
    playlist_t *p_playlist;

    p_playlist = (playlist_t *)vlc_object_find( p_demux, VLC_OBJECT_PLAYLIST,
                                               FIND_ANYWHERE );

    p_playlist->status.p_item->i_flags |= PLAYLIST_DEL_FLAG;

    playlist_Add( p_playlist, p_sdp->psz_uri, p_sdp->psz_sessionname,
                 PLAYLIST_APPEND, PLAYLIST_END );

    vlc_object_release( p_playlist );
    if( p_sdp ) FreeSDP( p_sdp );

    return VLC_SUCCESS;
}

static int Control( demux_t *p_demux, int i_query, va_list args )
{
    return VLC_EGENERIC;
}

/**************************************************************
 * Local functions
 **************************************************************/

/* i_read is at least > 6 */
static int ParseSAP( services_discovery_t *p_sd, uint8_t *p_buffer, int i_read )
{
    int                 i_version, i_address_type, i_hash, i;
    uint8_t             *psz_sdp;
    uint8_t             *psz_initial_sdp;
    sdp_t               *p_sdp;
    vlc_bool_t          b_compressed;
    vlc_bool_t          b_need_delete = VLC_FALSE;
#ifdef HAVE_ZLIB_H
    int                 i_decompressed_size;
    uint8_t             *p_decompressed_buffer;
#endif
    uint8_t             *psz_foo;

    /* First, check the sap announce is correct */
    i_version = p_buffer[0] >> 5;
    if( i_version != 1 )
    {
       msg_Dbg( p_sd, "strange sap version %d found", i_version );
    }

    i_address_type = p_buffer[0] & 0x10;

    if( (p_buffer[0] & 0x08) != 0 )
    {
        msg_Dbg( p_sd, "reserved bit incorrectly set" );
        return VLC_EGENERIC;
    }

    if( (p_buffer[0] & 0x04) != 0 )
    {
        msg_Dbg( p_sd, "session deletion packet" );
        b_need_delete = VLC_TRUE;
    }

    if( p_buffer[0] & 0x02  )
    {
        msg_Dbg( p_sd, "encrypted packet, unsupported" );
        return VLC_EGENERIC;
    }

    b_compressed = p_buffer[0] & 0x01;

    i_hash = ( p_buffer[2] << 8 ) + p_buffer[3];

    if( p_sd->p_sys->b_strict && i_hash == 0 )
    {
        msg_Dbg( p_sd, "strict mode, discarding announce with null id hash");
        return VLC_EGENERIC;
    }

    psz_sdp  = &p_buffer[4];
    psz_initial_sdp = psz_sdp;

    if( i_address_type == 0 ) /* ipv4 source address */
    {
        psz_sdp += 4;
        if( i_read <= 9 )
        {
            msg_Warn( p_sd, "too short SAP packet\n" );
            return VLC_EGENERIC;
        }
    }
    else /* ipv6 source address */
    {
        psz_sdp += 16;
        if( i_read <= 21 )
        {
            msg_Warn( p_sd, "too short SAP packet\n" );
            return VLC_EGENERIC;
        }
    }

    if( b_compressed )
    {
#ifdef HAVE_ZLIB_H
        i_decompressed_size = Decompress( psz_sdp,
                   &p_decompressed_buffer,i_read - ( psz_sdp - p_buffer ) );
        if( i_decompressed_size > 0 && i_decompressed_size < MAX_SAP_BUFFER )
        {
            memcpy( psz_sdp, p_decompressed_buffer, i_decompressed_size );
            psz_sdp[i_decompressed_size] = '\0';
            free( p_decompressed_buffer );
        }
#else
        msg_Warn( p_sd, "Ignoring compressed sap packet" );
        return VLC_EGENERIC;
#endif
    }

    /* Add the size of authentification info */
    if( i_read < p_buffer[1] + (psz_sdp - psz_initial_sdp ) )
    {
        msg_Warn( p_sd, "too short SAP packet\n");
        return VLC_EGENERIC;
    }
    psz_sdp += p_buffer[1];
    psz_foo = psz_sdp;

    /* Skip payload type */
    /* Handle announces without \0 between SAP and SDP */
    while( *psz_sdp != '\0' && ( psz_sdp[0] != 'v' && psz_sdp[1] != '=' ) )
    {
        if( psz_sdp - psz_initial_sdp >= i_read - 5 )
        {
            msg_Warn( p_sd, "empty SDP ?");
        }
        psz_sdp++;
    }

    if( *psz_sdp == '\0' )
    {
        psz_sdp++;
    }
    if( psz_sdp != psz_foo && strcasecmp( psz_foo, "application/sdp" ) )
    {
        msg_Dbg( p_sd, "unhandled content type: %s", psz_foo );        
    }
    if( psz_sdp -p_buffer >= i_read )
    {
        msg_Warn( p_sd, "package without content" );
        return VLC_EGENERIC;
    }

    /* Parse SDP info */
    p_sdp = ParseSDP( VLC_OBJECT(p_sd), psz_sdp );

    if( p_sdp == NULL )
    {
        return VLC_EGENERIC;
    }

    /* Decide whether we should add a playlist item for this SDP */
    /* Parse connection information (c= & m= ) */
    if( ParseConnection( VLC_OBJECT(p_sd), p_sdp ) )
    {
        p_sdp->psz_uri = NULL;
    }

    /* Multi-media or no-parse -> pass to LIVE.COM */
    if( p_sdp->i_media > 1 || ( p_sdp->i_media_type != 14 &&
                                p_sdp->i_media_type != 32 &&
                                p_sdp->i_media_type != 33) ||
        p_sd->p_sys->b_parse == VLC_FALSE )
    {
        if( p_sdp->psz_uri ) free( p_sdp->psz_uri );
        asprintf( &p_sdp->psz_uri, "sdp://%s", p_sdp->psz_sdp );
    }

    if( p_sdp->psz_uri == NULL ) return VLC_EGENERIC;

    for( i = 0 ; i< p_sd->p_sys->i_announces ; i++ )
    {
        /* FIXME: slow */
        /* FIXME: we create a new announce each time the sdp changes */
        if( IsSameSession( p_sd->p_sys->pp_announces[i]->p_sdp, p_sdp ) )
        {
            if( b_need_delete )
            {
                RemoveAnnounce( p_sd, p_sd->p_sys->pp_announces[i]);
                return VLC_SUCCESS;
            }
            else
            {
                p_sd->p_sys->pp_announces[i]->i_last = mdate();
                FreeSDP( p_sdp );
                return VLC_SUCCESS;
            }
        }
    }
    /* Add item */
    if( p_sdp->i_media > 1 )
    {
        msg_Dbg( p_sd, "passing to LIVE.COM" );
    }

    CreateAnnounce( p_sd, i_hash, p_sdp );

    return VLC_SUCCESS;
}

sap_announce_t *CreateAnnounce( services_discovery_t *p_sd, uint16_t i_hash,
                                sdp_t *p_sdp )
{
    playlist_item_t     *p_item, *p_child;
    char                *psz_value;
    sap_announce_t *p_sap = (sap_announce_t *)malloc(
                                        sizeof(sap_announce_t ) );

    psz_value = convert_from_utf8( p_sd, p_sdp->psz_sessionname );
    if( p_sap == NULL || psz_value == NULL )
    {
        FREE( p_sap );
        FREE( psz_value );
        return NULL;
    }
    p_sap->i_last = mdate();
    p_sap->i_hash = i_hash;
    p_sap->p_sdp = p_sdp;
    p_sap->i_item_id = -1;

    /* Create the playlist item here */
    p_item = playlist_ItemNew( p_sd, p_sap->p_sdp->psz_uri, psz_value );
    free( psz_value );

    if( !p_item )
    {
        free( p_sap );
        return NULL;
    }

    psz_value = GetAttribute( p_sap->p_sdp, "tool" );
    if( psz_value != NULL )
    {
        vlc_input_item_AddInfo( &p_item->input, _("Session"),
                                _("Tool"), psz_value );
    }
    if( strcmp( p_sdp->psz_username, "-" ) )
    {
        vlc_input_item_AddInfo( &p_item->input, _("Session"),
                                _("User"), p_sdp->psz_username );
    }

    psz_value = GetAttribute( p_sap->p_sdp, "x-plgroup" );

    if( psz_value == NULL )
    {
        psz_value = GetAttribute( p_sap->p_sdp, "plgroup" );
    }

    if( psz_value != NULL )
    {
        char *psz_grp = convert_from_utf8( p_sd, psz_value );

        if( psz_grp != NULL )
        {
            p_child = playlist_ChildSearchName( p_sd->p_sys->p_node,
                                                psz_grp );

            if( p_child == NULL )
            {
                p_child = playlist_NodeCreate( p_sd->p_sys->p_playlist,
                                               VIEW_CATEGORY, psz_grp,
                                               p_sd->p_sys->p_node );
                p_child->i_flags =~ PLAYLIST_SKIP_FLAG;
            }
            free( psz_grp );
        }
        else
        {
            msg_Err( p_sd, "out of memory");
            free( p_sap );
            return NULL;
        }
    }
    else
    {
        p_child = p_sd->p_sys->p_node;
    }

    p_item->i_flags &= ~PLAYLIST_SKIP_FLAG;
    p_item->i_flags &= ~PLAYLIST_SAVE_FLAG;

    playlist_NodeAddItem( p_sd->p_sys->p_playlist, p_item, VIEW_CATEGORY,
                              p_child, PLAYLIST_APPEND, PLAYLIST_END );

    p_sap->i_item_id = p_item->input.i_id;

    TAB_APPEND( p_sd->p_sys->i_announces,
                p_sd->p_sys->pp_announces, p_sap );

    return p_sap;
}

static char *GetAttribute( sdp_t *p_sdp, const char *psz_search )
{
    int i;

    for( i = 0 ; i< p_sdp->i_attributes; i++ )
    {
        if( !strncmp( p_sdp->pp_attributes[i]->psz_field, psz_search,
                      strlen( p_sdp->pp_attributes[i]->psz_field ) ) )
        {
            return p_sdp->pp_attributes[i]->psz_value;
        }
    }
    return NULL;
}


/* Fill p_sdp->psz_uri */
static int ParseConnection( vlc_object_t *p_obj, sdp_t *p_sdp )
{
    char *psz_eof;
    char *psz_parse;
    char *psz_uri = NULL;
    char *psz_proto = NULL;
    int i_port = 0;

    /* Parse c= field */
    if( p_sdp->psz_connection )
    {
        psz_parse = p_sdp->psz_connection;

        psz_eof = strchr( psz_parse, ' ' );

        if( psz_eof )
        {
            *psz_eof = '\0';
            psz_parse = psz_eof + 1;
        }
        else
        {
            msg_Warn( p_obj, "unable to parse c field (1)");
            return VLC_EGENERIC;
        }

        psz_eof = strchr( psz_parse, ' ' );

        if( psz_eof )
        {
            *psz_eof = '\0';
            if( !strncmp( psz_parse, "IP4", 3 ) )
            {
                p_sdp->i_in = 4;
            }
            else if( !strncmp( psz_parse, "IP6", 3 ) )
            {
                p_sdp->i_in = 6;
            }
            else
            {
                p_sdp->i_in = 0;
            }
            psz_parse = psz_eof + 1;
        }
        else
        {
            msg_Warn( p_obj, "unable to parse c field (2)");
            return VLC_EGENERIC;
        }

        psz_eof = strchr( psz_parse, '/' );

        if( psz_eof )
        {
            *psz_eof = 0;
        }
        else
        {
            msg_Dbg( p_obj, "incorrect c field, %s", p_sdp->psz_connection );
        }
        psz_uri = strdup( psz_parse );

    }

    /* Parse m= field */
    if( p_sdp->psz_media )
    {
        psz_parse = p_sdp->psz_media;

        psz_eof = strchr( psz_parse, ' ' );

        if( psz_eof )
        {
            *psz_eof = '\0';

            if( strncmp( psz_parse, "audio", 5 )  &&
                strncmp( psz_parse, "video",5 ) )
            {
                msg_Warn( p_obj, "unhandled media type -%s-", psz_parse );
                FREE( psz_uri );
                return VLC_EGENERIC;
            }

            psz_parse = psz_eof + 1;
        }
        else
        {
            msg_Warn( p_obj, "unable to parse m field (1)");
            FREE( psz_uri );
            return VLC_EGENERIC;
        }

        psz_eof = strchr( psz_parse, ' ' );

        if( psz_eof )
        {
            *psz_eof = '\0';

            /* FIXME : multiple port ! */
            i_port = atoi( psz_parse );

            if( i_port <= 0 || i_port >= 65536 )
            {
                msg_Warn( p_obj, "invalid transport port %i", i_port );
            }

            psz_parse = psz_eof + 1;