tcp.c

VLC Player Source Code

int __net_Accept( vlc_object_t *p_this, int *pi_fd, mtime_t i_wait )
{
    int timeout = (i_wait < 0) ? -1 : i_wait / 1000;
    int evfd = vlc_object_waitpipe (p_this);

    if (evfd == -1)
        return -1;

    assert( pi_fd != NULL );

    for (;;)
    {
        unsigned n = 0;
        while (pi_fd[n] != -1)
            n++;
        struct pollfd ufd[n + 1];

        /* Initialize file descriptor set */
        for (unsigned i = 0; i <= n; i++)
        {
            ufd[i].fd = (i < n) ? pi_fd[i] : evfd;
            ufd[i].events = POLLIN;
            ufd[i].revents = 0;
        }
        if (evfd == -1)
            n--; /* avoid EBADF */

        switch (poll (ufd, n, timeout))
        {
            case -1:
                if (net_errno == EINTR)
                    continue;
                msg_Err (p_this, "poll error: %m");
                return -1;
            case 0:
                errno = ETIMEDOUT;
                return -1;
        }

        if (ufd[n].revents)
        {
            errno = EINTR;
            break;
        }

        for (unsigned i = 0; i < n; i++)
        {
            if (ufd[i].revents == 0)
                continue;

            int sfd = ufd[i].fd;
            int fd = net_AcceptSingle (p_this, sfd);
            if (fd == -1)
                continue;

            /*
             * Move listening socket to the end to let the others in the
             * set a chance next time.
             */
            memmove (pi_fd + i, pi_fd + i + 1, n - (i + 1));
            pi_fd[n - 1] = sfd;
            return fd;
        }
    }
    return -1;
}


/*****************************************************************************
 * SocksNegotiate:
 *****************************************************************************
 * Negotiate authentication with a SOCKS server.
 *****************************************************************************/
static int SocksNegotiate( vlc_object_t *p_obj,
                           int fd, int i_socks_version,
                           const char *psz_socks_user,
                           const char *psz_socks_passwd )
{
    uint8_t buffer[128+2*256];
    int i_len;
    bool b_auth = false;

    if( i_socks_version != 5 )
        return VLC_SUCCESS;

    /* We negotiate authentication */

    if( ( psz_socks_user == NULL ) && ( psz_socks_passwd == NULL ) )
        b_auth = true;

    buffer[0] = i_socks_version;    /* SOCKS version */
    if( b_auth )
    {
        buffer[1] = 2;                  /* Number of methods */
        buffer[2] = 0x00;               /* - No auth required */
        buffer[3] = 0x02;               /* - USer/Password */
        i_len = 4;
    }
    else
    {
        buffer[1] = 1;                  /* Number of methods */
        buffer[2] = 0x00;               /* - No auth required */
        i_len = 3;
    }

    if( net_Write( p_obj, fd, NULL, buffer, i_len ) != i_len )
        return VLC_EGENERIC;
    if( net_Read( p_obj, fd, NULL, buffer, 2, true ) != 2 )
        return VLC_EGENERIC;

    msg_Dbg( p_obj, "socks: v=%d method=%x", buffer[0], buffer[1] );

    if( buffer[1] == 0x00 )
    {
        msg_Dbg( p_obj, "socks: no authentication required" );
    }
    else if( buffer[1] == 0x02 )
    {
        int i_len1 = __MIN( strlen(psz_socks_user), 255 );
        int i_len2 = __MIN( strlen(psz_socks_passwd), 255 );
        msg_Dbg( p_obj, "socks: username/password authentication" );

        /* XXX: we don't support user/pwd > 255 (truncated)*/
        buffer[0] = i_socks_version;        /* Version */
        buffer[1] = i_len1;                 /* User length */
        memcpy( &buffer[2], psz_socks_user, i_len1 );
        buffer[2+i_len1] = i_len2;          /* Password length */
        memcpy( &buffer[2+i_len1+1], psz_socks_passwd, i_len2 );

        i_len = 3 + i_len1 + i_len2;

        if( net_Write( p_obj, fd, NULL, buffer, i_len ) != i_len )
            return VLC_EGENERIC;

        if( net_Read( p_obj, fd, NULL, buffer, 2, true ) != 2 )
            return VLC_EGENERIC;

        msg_Dbg( p_obj, "socks: v=%d status=%x", buffer[0], buffer[1] );
        if( buffer[1] != 0x00 )
        {
            msg_Err( p_obj, "socks: authentication rejected" );
            return VLC_EGENERIC;
        }
    }
    else
    {
        if( b_auth )
            msg_Err( p_obj, "socks: unsupported authentication method %x",
                     buffer[0] );
        else
            msg_Err( p_obj, "socks: authentification needed" );
        return VLC_EGENERIC;
    }

    return VLC_SUCCESS;
}

/*****************************************************************************
 * SocksHandshakeTCP:
 *****************************************************************************
 * Open a TCP connection using a SOCKS server and return a handle (RFC 1928)
 *****************************************************************************/
static int SocksHandshakeTCP( vlc_object_t *p_obj,
                              int fd,
                              int i_socks_version,
                              const char *psz_user, const char *psz_passwd,
                              const char *psz_host, int i_port )
{
    uint8_t buffer[128+2*256];

    if( i_socks_version != 4 && i_socks_version != 5 )
    {
        msg_Warn( p_obj, "invalid socks protocol version %d", i_socks_version );
        i_socks_version = 5;
    }

    if( i_socks_version == 5 &&
        SocksNegotiate( p_obj, fd, i_socks_version,
                        psz_user, psz_passwd ) )
        return VLC_EGENERIC;

    if( i_socks_version == 4 )
    {
        struct addrinfo hints, *p_res;

        /* v4 only support ipv4 */
        memset (&hints, 0, sizeof (hints));
        hints.ai_family = AF_INET;
        if( vlc_getaddrinfo( p_obj, psz_host, 0, &hints, &p_res ) )
            return VLC_EGENERIC;

        buffer[0] = i_socks_version;
        buffer[1] = 0x01;               /* CONNECT */
        SetWBE( &buffer[2], i_port );   /* Port */
        memcpy( &buffer[4],             /* Address */
                &((struct sockaddr_in *)(p_res->ai_addr))->sin_addr, 4 );
        vlc_freeaddrinfo( p_res );

        buffer[8] = 0;                  /* Empty user id */

        if( net_Write( p_obj, fd, NULL, buffer, 9 ) != 9 )
            return VLC_EGENERIC;
        if( net_Read( p_obj, fd, NULL, buffer, 8, true ) != 8 )
            return VLC_EGENERIC;

        msg_Dbg( p_obj, "socks: v=%d cd=%d",
                 buffer[0], buffer[1] );

        if( buffer[1] != 90 )
            return VLC_EGENERIC;
    }
    else if( i_socks_version == 5 )
    {
        int i_hlen = __MIN(strlen( psz_host ), 255);
        int i_len;

        buffer[0] = i_socks_version;    /* Version */
        buffer[1] = 0x01;               /* Cmd: connect */
        buffer[2] = 0x00;               /* Reserved */
        buffer[3] = 3;                  /* ATYP: for now domainname */

        buffer[4] = i_hlen;
        memcpy( &buffer[5], psz_host, i_hlen );
        SetWBE( &buffer[5+i_hlen], i_port );

        i_len = 5 + i_hlen + 2;


        if( net_Write( p_obj, fd, NULL, buffer, i_len ) != i_len )
            return VLC_EGENERIC;

        /* Read the header */
        if( net_Read( p_obj, fd, NULL, buffer, 5, true ) != 5 )
            return VLC_EGENERIC;

        msg_Dbg( p_obj, "socks: v=%d rep=%d atyp=%d",
                 buffer[0], buffer[1], buffer[3] );

        if( buffer[1] != 0x00 )
        {
            msg_Err( p_obj, "socks: CONNECT request failed\n" );
            return VLC_EGENERIC;
        }

        /* Read the remaining bytes */
        if( buffer[3] == 0x01 )
            i_len = 4-1 + 2;
        else if( buffer[3] == 0x03 )
            i_len = buffer[4] + 2;
        else if( buffer[3] == 0x04 )
            i_len = 16-1+2;
        else
            return VLC_EGENERIC;

        if( net_Read( p_obj, fd, NULL, buffer, i_len, true ) != i_len )
            return VLC_EGENERIC;
    }

    return VLC_SUCCESS;
}

void net_ListenClose( int *pi_fd )
{
    if( pi_fd != NULL )
    {
        int *pi;

        for( pi = pi_fd; *pi != -1; pi++ )
            net_Close( *pi );
        free( pi_fd );
    }
}