sap.c

VLC Player Source Code

            }

            if( ipv4 == 0 )
            {
                msg_Err( p_sap, "Out-of-scope multicast address "
                         "not supported by SAP" );
                vlc_object_unlock( p_sap );
                return VLC_EGENERIC;
            }

            ((struct sockaddr_in *)&addr)->sin_addr.s_addr = htonl( ipv4 );
            break;
        }

        default:
            vlc_object_unlock( p_sap );
            msg_Err( p_sap, "Address family %d not supported by SAP",
                     addr.ss_family );
            return VLC_EGENERIC;
    }

    i = vlc_getnameinfo( (struct sockaddr *)&addr, addrlen,
                         psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );

    if( i )
    {
        vlc_object_unlock( p_sap );
        msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
        return VLC_EGENERIC;
    }

    msg_Dbg( p_sap, "using SAP address: %s", psz_addr);

    /* XXX: Check for dupes */
    p_sap_session = (sap_session_t*)malloc(sizeof(sap_session_t));
    p_sap_session->p_sd = p_session;
    p_sap_session->p_address = NULL;

    /* Add the address to the buffer */
    for( i = 0; i < p_sap->i_addresses; i++)
    {
        if( !strcmp( psz_addr, p_sap->pp_addresses[i]->psz_address ) )
        {
            p_sap_session->p_address = p_sap->pp_addresses[i];
            break;
        }
    }

    if( p_sap_session->p_address == NULL )
    {
        sap_address_t *p_address = (sap_address_t *)
                                    malloc( sizeof(sap_address_t) );
        if( !p_address )
        {
            vlc_object_unlock( p_sap );
            return VLC_ENOMEM;
        }
        p_address->psz_address = strdup( psz_addr );
        p_address->i_wfd = net_ConnectUDP( VLC_OBJECT(p_sap), psz_addr, SAP_PORT, 255 );
        if( p_address->i_wfd != -1 )
        {
            shutdown( p_address->i_wfd, SHUT_RD );
            p_address->origlen = sizeof (p_address->orig);
            getsockname (p_address->i_wfd, (struct sockaddr *)&p_address->orig,
                         &p_address->origlen);
        }

        if( p_sap->b_control == true )
        {
            p_address->i_rfd = net_ListenUDP1( (vlc_object_t*)p_sap, psz_addr, SAP_PORT );
            if( p_address->i_rfd != -1 )
                shutdown( p_address->i_rfd, SHUT_WR );
            p_address->i_buff = 0;
            p_address->b_enabled = true;
            p_address->b_ready = false;
            p_address->i_limit = 10000; /* 10000 bps */
            p_address->t1 = 0;
        }
        else
        {
            p_address->b_enabled = true;
            p_address->b_ready = true;
            p_address->i_interval = config_GetInt( p_sap,"sap-interval");
            p_address->i_rfd = -1;
        }

        if( p_address->i_wfd == -1 || (p_address->i_rfd == -1
                                        && p_sap->b_control ) )
        {
            msg_Warn( p_sap, "disabling address" );
            p_address->b_enabled = false;
        }

        INSERT_ELEM( p_sap->pp_addresses,
                     p_sap->i_addresses,
                     p_sap->i_addresses,
                     p_address );
        p_sap_session->p_address = p_address;
    }

    memcpy (&p_session->orig, &p_sap_session->p_address->orig,
             p_session->origlen = p_sap_session->p_address->origlen);

    size_t headsize = 20;
    switch (p_session->orig.ss_family)
    {
#ifdef AF_INET6
        case AF_INET6:
            headsize += 16;
            break;
#endif
        case AF_INET:
            headsize += 4;
            break;
        default:
            msg_Err( p_sap, "Address family %d not supported by SAP",
                     addr.ss_family );
            vlc_object_unlock( p_sap );
            return VLC_EGENERIC;
    }

    /* If needed, build the SDP */
    assert( p_session->psz_sdp != NULL );

    p_sap_session->i_last = 0;
    p_sap_session->i_length = headsize + strlen (p_session->psz_sdp);
    p_sap_session->psz_data = malloc (p_sap_session->i_length + 1);
    if (p_sap_session->psz_data == NULL)
    {
        free (p_session->psz_sdp);
        vlc_object_unlock( p_sap );
        return VLC_ENOMEM;
    }

    /* Build the SAP Headers */
    uint8_t *psz_head = p_sap_session->psz_data;

    /* SAPv1, not encrypted, not compressed */
    psz_head[0] = 0x20;
    psz_head[1] = 0x00; /* No authentification length */

    i_hash = mdate();
    psz_head[2] = i_hash >> 8; /* Msg id hash */
    psz_head[3] = i_hash;      /* Msg id hash 2 */

    headsize = 4;
    switch (p_session->orig.ss_family)
    {
#ifdef AF_INET6
        case AF_INET6:
        {
            struct in6_addr *a6 =
                &((struct sockaddr_in6 *)&p_session->orig)->sin6_addr;
            memcpy (psz_head + headsize, a6, 16);
            psz_head[0] |= 0x10; /* IPv6 flag */
            headsize += 16;
            break;
        }
#endif
        case AF_INET:
        {
            uint32_t ipv4 =
                (((struct sockaddr_in *)&p_session->orig)->sin_addr.s_addr);
            memcpy (psz_head + headsize, &ipv4, 4);
            headsize += 4;
            break;
        }

    }

    memcpy (psz_head + headsize, "application/sdp", 16);
    headsize += 16;

    /* Build the final message */
    strcpy( (char *)psz_head + headsize, p_session->psz_sdp);

    /* Enqueue the announce */
    INSERT_ELEM( p_sap->pp_sessions,
                 p_sap->i_sessions,
                 p_sap->i_sessions,
                 p_sap_session );
    msg_Dbg( p_sap,"%i addresses, %i sessions",
                   p_sap->i_addresses,p_sap->i_sessions);

    vlc_object_unlock( p_sap );

    return VLC_SUCCESS;
}

/* Remove a SAP Announce */
static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
                             session_descriptor_t *p_session )
{
    int i;
    vlc_object_lock( p_sap );

    msg_Dbg( p_sap, "removing session %p from SAP", p_session);

    /* Dequeue the announce */
    for( i = 0; i< p_sap->i_sessions; i++)
    {
        if( p_session == p_sap->pp_sessions[i]->p_sd )
        {
            free( p_session->psz_sdp );
            sap_session_t *p_mysession = p_sap->pp_sessions[i];
            REMOVE_ELEM( p_sap->pp_sessions,
                         p_sap->i_sessions,
                         i );

            free( p_mysession->psz_data );
            free( p_mysession );
            break;
        }
    }

    /* XXX: Dequeue the address too if it is not used anymore
     * TODO: - address refcount
             - send a SAP deletion packet */

    msg_Dbg( p_sap,"%i announcements remaining", p_sap->i_sessions );

    vlc_object_unlock( p_sap );

    return VLC_SUCCESS;
}

static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
                                     sap_session_t *p_session )
{
    int i_ret;

    /* This announce has never been sent yet */
    if( p_session->i_last == 0 )
    {
        p_session->i_next = mdate()+ p_session->p_address->i_interval*1000000;
        p_session->i_last = 1;
        return VLC_SUCCESS;
    }

    if( p_session->i_next < mdate() )
    {
#ifdef EXTRA_DEBUG
        msg_Dbg( p_sap, "sending announce");
#endif
        i_ret = net_Write( p_sap, p_session->p_address->i_wfd, NULL,
                           p_session->psz_data,
                           p_session->i_length );
        if( i_ret != (int)p_session->i_length )
        {
            msg_Warn( p_sap, "SAP send failed on address %s (%i %i)",
                      p_session->p_address->psz_address,
                      i_ret, p_session->i_length );
        }
        p_session->i_last = p_session->i_next;
        p_session->i_next = p_session->i_last
                            + p_session->p_address->i_interval*1000000;
    }
    return VLC_SUCCESS;
}

static int ComputeRate( sap_address_t *p_address )
{
    uint8_t buffer[SAP_MAX_BUFFER];
    ssize_t i_tot = 0;
    mtime_t i_temp;
    int i_rate;

    if( p_address->t1 == 0 )
    {
        p_address->t1 = mdate();
        return VLC_SUCCESS;
    }
    for (;;)
    {
        /* Might be too slow if we have huge data */
        ssize_t i_read = recv( p_address->i_rfd, buffer, SAP_MAX_BUFFER, 0 );
        if (i_read == -1)
            break;
        i_tot += i_read;
    }

    i_temp = mdate();

    /* We calculate the rate every 5 seconds */
    if( i_temp - p_address->t1 < 5000000 )
    {
        p_address->i_buff += i_tot;
        return VLC_SUCCESS;
    }

    /* Bits/second */
    i_rate = (int)(8*1000000*((mtime_t)p_address->i_buff + (mtime_t)i_tot ) /
                        (i_temp - p_address->t1 ));

    p_address->i_limit = 10000;

    p_address->i_interval = ((1000*i_rate / p_address->i_limit) *
                            (MAX_INTERVAL - MIN_INTERVAL))/1000 + MIN_INTERVAL;

    if( p_address->i_interval > MAX_INTERVAL || p_address->i_interval < 0 )
    {
        p_address->i_interval = MAX_INTERVAL;
    }
#ifdef EXTRA_DEBUG
    msg_Dbg( p_sap,"%s:%i: rate=%i, interval = %i s",
             p_address->psz_address,SAP_PORT, i_rate, p_address->i_interval );
#endif

    p_address->b_ready = true;

    p_address->t1 = i_temp;
    p_address->i_buff = 0;

    return VLC_SUCCESS;
}