if ((buflen -= QFIXEDSZ) < 0)
if (ep - cp < QFIXEDSZ)
res_mkquery(op, dname, class, type, data, datalen, newrr_in, buf, buflen)	int op;			/* opcode of query */	const char *dname;	/* domain name */	int class, 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;	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {		h_errno = NETDB_INTERNAL;		return (-1);	}#ifdef DEBUG	if (_res.options & RES_DEBUG)		printf(";; res_mkquery(%d, %s, %d, %d)\n",		       op, dname, class, type);#endif	/*	 * Initialize header fields.	 *	 * A special random number generator is used to create non predictable	 * and non repeating ids over a long period. It also avoids reuse	 * by switching between two distinct number cycles.	 */	if ((buf == NULL) || (buflen < HFIXEDSZ))		return (-1);	bzero(buf, HFIXEDSZ);	hp = (HEADER *) buf;	_res.id = res_randomid();	hp->id = htons(_res.id);	hp->opcode = op;	hp->rd = (_res.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) {			bcopy(data, cp, datalen);			cp += datalen;		}		hp->ancount = htons(1);		break;	default:		return (-1);	}	return (cp - buf);}