lat

int parser::packet_len (int fd)
{
    ssize_t a;
    unsigned char pkt_type;
    static const int lengths[] = {131, 1, 1, 1028, 7, 9, 8, 74, 10, 7, 5, 4, 2, 66, 65, 2, 0};

    a = recv(fd, &pkt_type, 1, MSG_PEEK);
    if (a < 1)
        return -1;

    if (pkt_type > 0x0F)
        return -1;

    return lengths[pkt_type];
}