udp.c

VLC Player Source Code

#endif

/**
 * IP-agnostic multicast join,
 * with fallback to old APIs, and fallback from SSM to ASM.
 */
static int
net_SourceSubscribe (vlc_object_t *obj, int fd,
                     const struct sockaddr *src, socklen_t srclen,
                     const struct sockaddr *grp, socklen_t grplen)
{
    int level, iid = 0;

    char *iface = var_CreateGetNonEmptyString (obj, "miface");
    if (iface != NULL)
    {
        iid = if_nametoindex (iface);
        if (iid == 0)
        {
            msg_Err (obj, "invalid multicast interface: %s", iface);
            free (iface);
            return -1;
        }
        free (iface);
    }

    switch (grp->sa_family)
    {
#ifdef AF_INET6
        case AF_INET6:
            level = SOL_IPV6;
            if (((const struct sockaddr_in6 *)grp)->sin6_scope_id)
                iid = ((const struct sockaddr_in6 *)grp)->sin6_scope_id;
            break;
#endif

        case AF_INET:
            level = SOL_IP;
            break;

        default:
            errno = EAFNOSUPPORT;
            return -1;
    }

    if (src != NULL)
        switch (src->sa_family)
        {
#ifdef AF_INET6
            case AF_INET6:
                if (memcmp (&((const struct sockaddr_in6 *)src)->sin6_addr,
                            &in6addr_any, sizeof (in6addr_any)) == 0)
                    src = NULL;
            break;
#endif

            case AF_INET:
                if (((const struct sockaddr_in *)src)->sin_addr.s_addr
                     == INADDR_ANY)
                    src = NULL;
                break;
        }


    /* Agnostic ASM/SSM multicast join */
#ifdef MCAST_JOIN_SOURCE_GROUP
    union
    {
        struct group_req gr;
        struct group_source_req gsr;
    } opt;
    socklen_t optlen;

    memset (&opt, 0, sizeof (opt));

    if (src != NULL)
    {
        if ((grplen > sizeof (opt.gsr.gsr_group))
         || (srclen > sizeof (opt.gsr.gsr_source)))
            return -1;

        opt.gsr.gsr_interface = iid;
        memcpy (&opt.gsr.gsr_source, src, srclen);
        memcpy (&opt.gsr.gsr_group,  grp, grplen);
        optlen = sizeof (opt.gsr);
    }
    else
    {
        if (grplen > sizeof (opt.gr.gr_group))
            return -1;

        opt.gr.gr_interface = iid;
        memcpy (&opt.gr.gr_group, grp, grplen);
        optlen = sizeof (opt.gr);
    }

    msg_Dbg (obj, "Multicast %sgroup join request", src ? "source " : "");

    if (setsockopt (fd, level,
                    src ? MCAST_JOIN_SOURCE_GROUP : MCAST_JOIN_GROUP,
                    (void *)&opt, optlen) == 0)
        return 0;
#endif

    /* Fallback to IPv-specific APIs */
    if ((src != NULL) && (src->sa_family != grp->sa_family))
        return -1;

    switch (grp->sa_family)
    {
        case AF_INET:
            if ((grplen < sizeof (struct sockaddr_in))
             || ((src != NULL) && (srclen < sizeof (struct sockaddr_in))))
                return -1;

            if (net_IPv4Join (obj, fd, (const struct sockaddr_in *)src,
                              (const struct sockaddr_in *)grp) == 0)
                return 0;
            break;

#ifdef AF_INET6
        case AF_INET6:
            if ((grplen < sizeof (struct sockaddr_in6))
             || ((src != NULL) && (srclen < sizeof (struct sockaddr_in6))))
                return -1;

            /* IPv6-specific SSM API does not exist. So if we're here
             * it means IPv6 SSM is not supported on this OS and we
             * directly fallback to ASM */

            if (net_IPv6Join (obj, fd, (const struct sockaddr_in6 *)grp) == 0)
                return 0;
            break;
#endif
    }

    msg_Err (obj, "Multicast group join error (%m)");

    if (src != NULL)
    {
        msg_Warn (obj, "Trying ASM instead of SSM...");
        return net_Subscribe (obj, fd, grp, grplen);
    }

    msg_Err (obj, "Multicast not supported");
    return -1;
}


int net_Subscribe (vlc_object_t *obj, int fd,
                   const struct sockaddr *addr, socklen_t addrlen)
{
    return net_SourceSubscribe (obj, fd, NULL, 0, addr, addrlen);
}


static int net_SetDSCP( int fd, uint8_t dscp )
{
    struct sockaddr_storage addr;
    if( getsockname( fd, (struct sockaddr *)&addr, &(socklen_t){ sizeof (addr) }) )
        return -1;

    int level, cmd;

    switch( addr.ss_family )
    {
#ifdef IPV6_TCLASS
        case AF_INET6:
            level = SOL_IPV6;
            cmd = IPV6_TCLASS;
            break;
#endif

        case AF_INET:
            level = SOL_IP;
            cmd = IP_TOS;
            break;

        default:
#ifdef ENOPROTOOPT
            errno = ENOPROTOOPT;
#endif
            return -1;
    }

    return setsockopt( fd, level, cmd, &(int){ dscp }, sizeof (int));
}


/*****************************************************************************
 * __net_ConnectDgram:
 *****************************************************************************
 * Open a datagram socket to send data to a defined destination, with an
 * optional hop limit.
 *****************************************************************************/
int __net_ConnectDgram( vlc_object_t *p_this, const char *psz_host, int i_port,
                        int i_hlim, int proto )
{
    struct addrinfo hints, *res, *ptr;
    int             i_val, i_handle = -1;
    bool      b_unreach = false;

    if( i_hlim < 1 )
        i_hlim = var_CreateGetInteger( p_this, "ttl" );

    memset( &hints, 0, sizeof( hints ) );
    hints.ai_socktype = SOCK_DGRAM;

    msg_Dbg( p_this, "net: connecting to [%s]:%d", psz_host, i_port );

    i_val = vlc_getaddrinfo( p_this, psz_host, i_port, &hints, &res );
    if( i_val )
    {
        msg_Err( p_this, "cannot resolve [%s]:%d : %s", psz_host, i_port,
                 vlc_gai_strerror( i_val ) );
        return -1;
    }

    for( ptr = res; ptr != NULL; ptr = ptr->ai_next )
    {
        char *str;
        int fd = net_Socket (p_this, ptr->ai_family, ptr->ai_socktype,
                             proto ?: ptr->ai_protocol);
        if (fd == -1)
            continue;

#if !defined( SYS_BEOS )
        /* Increase the receive buffer size to 1/2MB (8Mb/s during 1/2s)
        * to avoid packet loss caused by scheduling problems */
        setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &(int){ 0x80000 }, sizeof (int));
        setsockopt (fd, SOL_SOCKET, SO_SNDBUF, &(int){ 0x80000 }, sizeof (int));

        /* Allow broadcast sending */
        setsockopt (fd, SOL_SOCKET, SO_BROADCAST, &(int){ 1 }, sizeof (int));
#endif

        if( i_hlim > 0 )
            net_SetMcastHopLimit( p_this, fd, ptr->ai_family, i_hlim );

        str = var_CreateGetNonEmptyString (p_this, "miface");
        if (str != NULL)
        {
            net_SetMcastOut (p_this, fd, ptr->ai_family, str, NULL);
            free (str);
        }

        str = var_CreateGetNonEmptyString (p_this, "miface-addr");
        if (str != NULL)
        {
            net_SetMcastOut (p_this, fd, ptr->ai_family, NULL, str);
            free (str);
        }

        net_SetDSCP (fd, var_CreateGetInteger (p_this, "dscp"));

        if( connect( fd, ptr->ai_addr, ptr->ai_addrlen ) == 0 )
        {
            /* success */
            i_handle = fd;
            break;
        }

#if defined( WIN32 ) || defined( UNDER_CE )
        if( WSAGetLastError () == WSAENETUNREACH )
#else
        if( errno == ENETUNREACH )
#endif
            b_unreach = true;
        else
        {
            msg_Warn( p_this, "%s port %d : %m", psz_host, i_port);
            net_Close( fd );
            continue;
        }
    }

    vlc_freeaddrinfo( res );

    if( i_handle == -1 )
    {
        if( b_unreach )
            msg_Err( p_this, "Host %s port %d is unreachable", psz_host,
                     i_port );
        return -1;
    }

    return i_handle;
}


/*****************************************************************************
 * __net_OpenDgram:
 *****************************************************************************
 * OpenDgram a datagram socket and return a handle
 *****************************************************************************/
int __net_OpenDgram( vlc_object_t *obj, const char *psz_bind, int i_bind,
                     const char *psz_server, int i_server,
                     int family, int protocol )
{
    if ((psz_server == NULL) || (psz_server[0] == '\0'))
        return net_ListenSingle (obj, psz_bind, i_bind, family, protocol);

    msg_Dbg (obj, "net: connecting to [%s]:%d from [%s]:%d",
             psz_server, i_server, psz_bind, i_bind);

    struct addrinfo hints, *loc, *rem;
    int val;

    memset (&hints, 0, sizeof (hints));
    hints.ai_family = family;
    hints.ai_socktype = SOCK_DGRAM;

    val = vlc_getaddrinfo (obj, psz_server, i_server, &hints, &rem);
    if (val)
    {
        msg_Err (obj, "cannot resolve %s port %d : %s", psz_bind, i_bind,
                 vlc_gai_strerror (val));
        return -1;
    }

    hints.ai_flags = AI_PASSIVE;
    val = vlc_getaddrinfo (obj, psz_bind, i_bind, &hints, &loc);
    if (val)
    {
        msg_Err (obj, "cannot resolve %s port %d : %s", psz_bind, i_bind,
                 vlc_gai_strerror (val));
        vlc_freeaddrinfo (rem);
        return -1;
    }

    for (struct addrinfo *ptr = loc; ptr != NULL; ptr = ptr->ai_next)
    {
        int fd = net_Socket (obj, ptr->ai_family, ptr->ai_socktype,
                             protocol ?: ptr->ai_protocol);
        if (fd == -1)
            continue; // usually, address family not supported

        fd = net_SetupDgramSocket( obj, fd, ptr );
        if( fd == -1 )
            continue;

        val = -1;
        for (struct addrinfo *ptr2 = rem; ptr2 != NULL; ptr2 = ptr2->ai_next)
        {
            if ((ptr2->ai_family != ptr->ai_family)
             || (ptr2->ai_socktype != ptr->ai_socktype)
             || (ptr2->ai_protocol != ptr->ai_protocol))
                continue;

            if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
              ? net_SourceSubscribe (obj, fd,
                                     ptr2->ai_addr, ptr2->ai_addrlen,
                                     ptr->ai_addr, ptr->ai_addrlen)
              : connect (fd, ptr2->ai_addr, ptr2->ai_addrlen))
            {
                msg_Err (obj, "cannot connect to %s port %d: %m",
                         psz_server, i_server);
                continue;
            }
            val = fd;
            break;
        }

        if (val != -1)
            break;

        net_Close (fd);
    }

    vlc_freeaddrinfo (rem);
    vlc_freeaddrinfo (loc);
    return val;
}


/**
 * net_SetCSCov:
 * Sets the send and receive checksum coverage of a socket:
 * @param fd socket
 * @param sendcov payload coverage of sent packets (bytes), -1 for full
 * @param recvcov minimum payload coverage of received packets, -1 for full
 */
int net_SetCSCov (int fd, int sendcov, int recvcov)
{
    int type;

    if (getsockopt (fd, SOL_SOCKET, SO_TYPE,
                    &type, &(socklen_t){ sizeof (type) }))
        return VLC_EGENERIC;

    switch (type)
    {
#ifdef UDPLITE_RECV_CSCOV
        case SOCK_DGRAM: /* UDP-Lite */
            if (sendcov == -1)
                sendcov = 0;
            else
                sendcov += 8; /* partial */
            if (setsockopt (fd, SOL_UDPLITE, UDPLITE_SEND_CSCOV, &sendcov,
                            sizeof (sendcov)))
                return VLC_EGENERIC;

            if (recvcov == -1)
                recvcov = 0;
            else
                recvcov += 8;
            if (setsockopt (fd, SOL_UDPLITE, UDPLITE_RECV_CSCOV,
                            &recvcov, sizeof (recvcov)))
                return VLC_EGENERIC;

            return VLC_SUCCESS;
#endif
#ifdef DCCP_SOCKOPT_SEND_CSCOV
        case SOCK_DCCP: /* DCCP and its ill-named socket type */
            if ((sendcov == -1) || (sendcov > 56))
                sendcov = 0;
            else
                sendcov = (sendcov + 3) / 4;
            if (setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_SEND_CSCOV,
                            &sendcov, sizeof (sendcov)))
                return VLC_EGENERIC;

            if ((recvcov == -1) || (recvcov > 56))
                recvcov = 0;
            else
                recvcov = (recvcov + 3) / 4;
            if (setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_RECV_CSCOV,
                            &recvcov, sizeof (recvcov)))
                return VLC_EGENERIC;

            return VLC_SUCCESS;
#endif
    }
#if !defined( UDPLITE_RECV_CSCOV ) && !defined( DCCP_SOCKOPT_SEND_CSCOV )
    VLC_UNUSED(sendcov);
    VLC_UNUSED(recvcov);
#endif

    return VLC_EGENERIC;
}