sap.c

VLC Player Source Code

    }

    for( i = 0 ; i< p_sd->p_sys->i_announces ; i++ )
    {
        sap_announce_t * p_announce = p_sd->p_sys->pp_announces[i];
        /* FIXME: slow */
        /* FIXME: we create a new announce each time the sdp changes */
        if( IsSameSession( p_announce->p_sdp, p_sdp ) )
        {
            /* We don't support delete announcement as they can easily
             * Be used to highjack an announcement by a third party.
             * Intead we cleverly implement Implicit Announcement removal.
             *
             * if( b_need_delete )
             *    RemoveAnnounce( p_sd, p_sd->p_sys->pp_announces[i]);
             * else
             */

            if( !b_need_delete )
            {
                /* No need to go after six, as we start to trust the
                 * average period at six */
                if( p_announce->i_period_trust <= 5 )
                    p_announce->i_period_trust++;

                /* Compute the average period */
                mtime_t now = mdate();
                p_announce->i_period = (p_announce->i_period + (now - p_announce->i_last)) / 2;
                p_announce->i_last = now;
            }
            FreeSDP( p_sdp ); p_sdp = NULL;
            return VLC_SUCCESS;
        }
    }

    CreateAnnounce( p_sd, i_hash, p_sdp );

    FREENULL (decomp);
    return VLC_SUCCESS;
}

sap_announce_t *CreateAnnounce( services_discovery_t *p_sd, uint16_t i_hash,
                                sdp_t *p_sdp )
{
    input_item_t *p_input;
    const char *psz_value;
    sap_announce_t *p_sap = (sap_announce_t *)malloc(
                                        sizeof(sap_announce_t ) );
    services_discovery_sys_t *p_sys;
    if( p_sap == NULL )
        return NULL;

    p_sys = p_sd->p_sys;

    p_sap->i_last = mdate();
    p_sap->i_period = 0;
    p_sap->i_period_trust = 0;
    p_sap->i_hash = i_hash;
    p_sap->p_sdp = p_sdp;

    /* Released in RemoveAnnounce */
    p_input = input_item_NewWithType( VLC_OBJECT(p_sd),
                                     p_sap->p_sdp->psz_uri,
                                     p_sdp->psz_sessionname,
                                     0, NULL, -1, ITEM_TYPE_NET );
    p_sap->p_item = p_input;
    if( !p_input )
    {
        free( p_sap );
        return NULL;
    }

    if( p_sys->b_timeshift )
        input_item_AddOption( p_input, ":access-filter=timeshift" );

    psz_value = GetAttribute( p_sap->p_sdp->pp_attributes, p_sap->p_sdp->i_attributes, "tool" );
    if( psz_value != NULL )
    {
        input_item_AddInfo( p_input, _("Session"), _("Tool"), "%s", psz_value );
    }
    if( strcmp( p_sdp->username, "-" ) )
    {
        input_item_AddInfo( p_input, _("Session"), _("User"), "%s",
                           p_sdp->username );
    }

    /* Handle group */
    if (p_sap->p_sdp->mediac >= 1)
        psz_value = FindAttribute (p_sap->p_sdp, 0, "x-plgroup");
    else
        psz_value = GetAttribute( p_sap->p_sdp->pp_attributes, p_sap->p_sdp->i_attributes, "x-plgroup" );

    services_discovery_AddItem( p_sd, p_input, psz_value /* category name */ );

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

    return p_sap;
}


static const char *FindAttribute (const sdp_t *sdp, unsigned media,
                                  const char *name)
{
    /* Look for media attribute, and fallback to session */
    return GetAttribute (sdp->mediav[media].pp_attributes,
                         sdp->mediav[media].i_attributes, name)
        ?: GetAttribute (sdp->pp_attributes, sdp->i_attributes, name);
}


/* Fill p_sdp->psz_uri */
static int ParseConnection( vlc_object_t *p_obj, sdp_t *p_sdp )
{
    if (p_sdp->mediac == 0)
    {
        msg_Dbg (p_obj, "Ignoring SDP with no media");
        return VLC_EGENERIC;
    }

    for (unsigned i = 1; i < p_sdp->mediac; i++)
    {
        if ((p_sdp->mediav[i].n_addr != p_sdp->mediav->n_addr)
         || (p_sdp->mediav[i].addrlen != p_sdp->mediav->addrlen)
         || memcmp (&p_sdp->mediav[i].addr, &p_sdp->mediav->addr,
                    p_sdp->mediav->addrlen))
        {
            msg_Dbg (p_obj, "Multiple media ports not supported -> live555");
            return VLC_EGENERIC;
        }
    }

    if (p_sdp->mediav->n_addr != 1)
    {
        msg_Dbg (p_obj, "Layered encoding not supported -> live555");
        return VLC_EGENERIC;
    }

    char psz_uri[1026];
    const char *host;
    int port;

    psz_uri[0] = '[';
    if (vlc_getnameinfo ((struct sockaddr *)&(p_sdp->mediav->addr),
                         p_sdp->mediav->addrlen, psz_uri + 1,
                         sizeof (psz_uri) - 2, &port, NI_NUMERICHOST))
        return VLC_EGENERIC;

    if (strchr (psz_uri + 1, ':'))
    {
        host = psz_uri;
        strcat (psz_uri, "]");
    }
    else
        host = psz_uri + 1;

    /* Parse m= field */
    char *sdp_proto = strdup (p_sdp->mediav[0].fmt);
    if (sdp_proto == NULL)
        return VLC_ENOMEM;

    char *subtype = strchr (sdp_proto, ' ');
    if (subtype == NULL)
    {
        msg_Dbg (p_obj, "missing SDP media subtype: %s", sdp_proto);
        free (sdp_proto);
        return VLC_EGENERIC;
    }
    else
    {
        *subtype++ = '\0';
        /* FIXME: check for multiple payload types in RTP/AVP case.
         * FIXME: check for "mpeg" subtype in raw udp case. */
        if (!strcasecmp (sdp_proto, "udp"))
            p_sdp->i_media_type = 33;
        else
            p_sdp->i_media_type = atoi (subtype);
    }

    /* RTP protocol, nul, VLC shortcut, nul, flags byte as follow:
     * 0x1: Connection-Oriented media. */
    static const char proto_match[] =
        "udp\0"             "udp\0\0"
        "RTP/AVP\0"         "rtp\0\0"
        "UDPLite/RTP/AVP\0" "udplite\0\0"
        "DCCP/RTP/AVP\0"    "dccp\0\1"
        "TCP/RTP/AVP\0"     "rtptcp\0\1"
        "\0";

    const char *vlc_proto = NULL;
    uint8_t flags = 0;
    for (const char *proto = proto_match; *proto;)
    {
        if (strcasecmp (proto, sdp_proto) == 0)
        {
            vlc_proto = proto + strlen (proto) + 1;
            flags = vlc_proto[strlen (vlc_proto) + 1];
            break;
        }
        proto += strlen (proto) + 1;
        proto += strlen (proto) + 2;
    }

    free (sdp_proto);
    if (vlc_proto == NULL)
    {
        msg_Dbg (p_obj, "unknown SDP media protocol: %s",
                 p_sdp->mediav[0].fmt);
        return VLC_EGENERIC;
    }

    if (flags & 1)
    {
        /* Connection-oriented media */
        const char *setup = FindAttribute (p_sdp, 0, "setup");
        if (setup == NULL)
            setup = "active"; /* default value */

        if (strcmp (setup, "actpass") && strcmp (setup, "passive"))
        {
            msg_Dbg (p_obj, "unsupported COMEDIA mode: %s", setup);
            return VLC_EGENERIC;
        }

        if (asprintf (&p_sdp->psz_uri, "%s://%s:%d", vlc_proto,
                      host, port) == -1)
            return VLC_ENOMEM;
    }
    else
    {
        /* Non-connected (normally multicast) media */

        char psz_source[258] = "";
        const char *sfilter = FindAttribute (p_sdp, 0, "source-filter");
        if (sfilter != NULL)
        {
            char psz_source_ip[256];
            unsigned ipv;

            if (sscanf (sfilter, " incl IN IP%u %*s %255s ", &ipv,
                        psz_source_ip) == 2)
            {
                /* According to RFC4570, FQDNs can be used for source-filters,
                 * but -seriously- this is impractical */
                switch (ipv)
                {
#ifdef AF_INET6
                    case 6:
                    {
                        struct in6_addr addr;
                        if ((inet_pton (AF_INET6, psz_source_ip, &addr) > 0)
                        && (inet_ntop (AF_INET6, &addr, psz_source + 1,
                                        sizeof (psz_source) - 2) != NULL))
                        {
                            psz_source[0] = '[';
                            psz_source[strlen (psz_source)] = ']';
                        }
                        break;
                    }
#endif
                    case 4:
                    {
                        struct in_addr addr;
                        if ((inet_pton (AF_INET, psz_source_ip, &addr) > 0)
                        && (inet_ntop (AF_INET, &addr, psz_source,
                                        sizeof (psz_source)) == NULL))
                            *psz_source = '\0';
                        break;
                    }
                }
            }
        }

        if (asprintf (&p_sdp->psz_uri, "%s://%s@%s:%i", vlc_proto, psz_source,
                     host, port) == -1)
            return VLC_ENOMEM;
    }

    return VLC_SUCCESS;
}


static int ParseSDPConnection (const char *str, struct sockaddr_storage *addr,
                               socklen_t *addrlen, unsigned *number)
{
    char host[60];
    unsigned fam, n1, n2;

    int res = sscanf (str, "IN IP%u %59[^/]/%u/%u", &fam, host, &n1, &n2);
    if (res < 2)
        return -1;

    switch (fam)
    {
#ifdef AF_INET6
        case 6:
            addr->ss_family = AF_INET6;
# ifdef HAVE_SA_LEN
            addr->ss_len =
# endif
           *addrlen = sizeof (struct sockaddr_in6);

            if (inet_pton (AF_INET6, host,
                           &((struct sockaddr_in6 *)addr)->sin6_addr) <= 0)
                return -1;

            *number = (res >= 3) ? n1 : 1;
            break;
#endif

        case 4:
            addr->ss_family = AF_INET;
# ifdef HAVE_SA_LEN
            addr->ss_len =
# endif
           *addrlen = sizeof (struct sockaddr_in);

            if (inet_pton (AF_INET, host,
                           &((struct sockaddr_in *)addr)->sin_addr) <= 0)
                return -1;

            *number = (res >= 4) ? n2 : 1;
            break;

        default:
            return -1;
    }
    return 0;
}


/***********************************************************************
 * ParseSDP : SDP parsing
 * *********************************************************************
 * Validate SDP and parse all fields
 ***********************************************************************/
static sdp_t *ParseSDP (vlc_object_t *p_obj, const char *psz_sdp)
{
    if( psz_sdp == NULL )
        return NULL;

    sdp_t *p_sdp = calloc (1, sizeof (*p_sdp));
    if (p_sdp == NULL)
        return NULL;

    char expect = 'V';
    struct sockaddr_storage glob_addr;
    memset (&glob_addr, 0, sizeof (glob_addr));
    socklen_t glob_len = 0;
    unsigned glob_count = 1;
    int port = 0;

    /* TODO: use iconv and charset attribute instead of EnsureUTF8 */
    while (*psz_sdp)
    {
        /* Extract one line */
        char *eol = strchr (psz_sdp, '\n');
        size_t linelen = eol ? (size_t)(eol - psz_sdp) : strlen (psz_sdp);
        char line[linelen + 1];
        memcpy (line, psz_sdp, linelen);
        line[linelen] = '\0';

        psz_sdp += linelen + 1;

        /* Remove carriage return if present */
        eol = strchr (line, '\r');
        if (eol != NULL)
        {
            linelen = eol - line;
            line[linelen] = '\0';
        }

        /* Validate line */
        char cat = line[0], *data = line + 2;
        if (!cat || (strchr ("vosiuepcbtrzkam", cat) == NULL))
        {
            /* MUST ignore SDP with unknown line type */
            msg_Dbg (p_obj, "unknown SDP line type: 0x%02x", (int)cat);
            goto error;
        }
        if (line[1] != '=')
        {
            msg_Dbg (p_obj, "invalid SDP line: %s", line);
            goto error;
        }

        assert (linelen >= 2);

        /* SDP parsing state machine
         * We INTERNALLY use uppercase for session, lowercase for media
         */
        switch (expect)
        {
            /* Session description */
            case 'V':
                expect = 'O';
                if (cat != 'v')
                {
                    msg_Dbg (p_obj, "missing SDP version");