BIO_CMSG_ALLOC_LEN
mh->Control.len = BIO_CMSG_ALLOC_LEN;
mh->msg_controllen = msg->local != NULL ? BIO_CMSG_ALLOC_LEN : 0;
unsigned char control[BIO_MAX_MSGS_PER_CALL][BIO_CMSG_ALLOC_LEN];
unsigned char control[BIO_CMSG_ALLOC_LEN];
unsigned char control[BIO_CMSG_ALLOC_LEN];
unsigned char control[BIO_MAX_MSGS_PER_CALL][BIO_CMSG_ALLOC_LEN];
unsigned char control[BIO_CMSG_ALLOC_LEN];
unsigned char control[BIO_CMSG_ALLOC_LEN];