random_time_bits = (tv.tv_sec << 8) ^ tv.tv_usec;
randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
res_nmkquery(res_state statp,	     int op,			/* opcode of query */	     const char *dname,		/* domain name */	     int class, int type,	/* class and type of query */	     const u_char *data,	/* resource record data */	     int datalen,		/* length of data */	     const u_char *newrr_in,	/* new rr for modify or append */	     u_char *buf,		/* buffer to put query */	     int buflen)		/* size of buffer */{	register HEADER *hp;	register u_char *cp;	register int n;	u_char *dnptrs[20], **dpp, **lastdnptr;#ifdef DEBUG	if (statp->options & RES_DEBUG)		printf(";; res_nmkquery(%s, %s, %s, %s)\n",		       _res_opcodes[op], dname, p_class(class), p_type(type));#endif	/*	 * Initialize header fields.	 */	if ((buf == NULL) || (buflen < HFIXEDSZ))		return (-1);	memset(buf, 0, HFIXEDSZ);	hp = (HEADER *) buf;	/* We randomize the IDs every time.  The old code just	   incremented by one after the initial randomization which	   still predictable if the application does multiple	   requests.  */#if 0	hp->id = htons(++statp->id);#else	hp->id = htons(statp->id);	int randombits;	do	  {#ifdef RANDOM_BITS	    RANDOM_BITS (randombits);#else	    struct timeval tv;	    __gettimeofday (&tv, NULL);	    random_time_bits = (tv.tv_sec << 8) ^ tv.tv_usec;#endif	  }	while (randombits == 0);	statp->id = (statp->id + randombits) & 0xffff;#endif	hp->opcode = op;	hp->rd = (statp->options & RES_RECURSE) != 0;	hp->rcode = NOERROR;	cp = buf + HFIXEDSZ;	buflen -= HFIXEDSZ;	dpp = dnptrs;	*dpp++ = buf;	*dpp++ = NULL;	lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];	/*	 * perform opcode specific processing	 */	switch (op) {	case QUERY:	/*FALLTHROUGH*/	case NS_NOTIFY_OP:		if ((buflen -= QFIXEDSZ) < 0)			return (-1);		if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)			return (-1);		cp += n;		buflen -= n;		__putshort(type, cp);		cp += INT16SZ;		__putshort(class, cp);		cp += INT16SZ;		hp->qdcount = htons(1);		if (op == QUERY || data == NULL)			break;		/*		 * Make an additional record for completion domain.		 */		buflen -= RRFIXEDSZ;		n = dn_comp((char *)data, cp, buflen, dnptrs, lastdnptr);		if (n < 0)			return (-1);		cp += n;		buflen -= n;		__putshort(T_NULL, cp);		cp += INT16SZ;		__putshort(class, cp);		cp += INT16SZ;		__putlong(0, cp);		cp += INT32SZ;		__putshort(0, cp);		cp += INT16SZ;		hp->arcount = htons(1);		break;	case IQUERY:		/*		 * Initialize answer section		 */		if (buflen < 1 + RRFIXEDSZ + datalen)			return (-1);		*cp++ = '\0';	/* no domain name */		__putshort(type, cp);		cp += INT16SZ;		__putshort(class, cp);		cp += INT16SZ;		__putlong(0, cp);		cp += INT32SZ;		__putshort(datalen, cp);		cp += INT16SZ;		if (datalen) {			memcpy(cp, data, datalen);			cp += datalen;		}		hp->ancount = htons(1);		break;	default:		return (-1);	}	return (cp - buf);}