/*	$NetBSD: res_mkquery.c,v 1.6 2006/01/24 17:40:32 christos Exp $	*/

/*
 * Copyright (c) 1985, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 * 	This product includes software developed by the University of
 * 	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#ifdef notdef
static const char sccsid[] = "@(#)res_mkquery.c	8.1 (Berkeley) 6/4/93";
static const char rcsid[] = "Id: res_mkquery.c,v 1.1.2.2.4.2 2004/03/16 12:34:18 marka Exp";
#else
__RCSID("$NetBSD: res_mkquery.c,v 1.6 2006/01/24 17:40:32 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */


#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <netdb.h>
#ifdef ANDROID_CHANGES
#include "resolv_private.h"
#else
#include <resolv.h>
#endif
#include <stdio.h>
#include <string.h>

/* Options.  Leave them on. */
#ifndef DEBUG
#define DEBUG
#endif

#ifndef lint
#define UNUSED(a)	(void)&a
#else
#define UNUSED(a)	a = a
#endif

extern const char *_res_opcodes[];

/*
 * Form all types of queries.
 * Returns the size of the result or -1.
 */
int
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, *ep;
	register int n;
	u_char *dnptrs[20], **dpp, **lastdnptr;

	UNUSED(newrr_in);

#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 *)(void *)buf;
	hp->id = htons(res_randomid());
	hp->opcode = op;
	hp->rd = (statp->options & RES_RECURSE) != 0U;
	hp->ad = (statp->options & RES_USE_DNSSEC) != 0U;
	hp->rcode = NOERROR;
	cp = buf + HFIXEDSZ;
	ep = buf + buflen;
	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 (ep - cp < QFIXEDSZ)
			return (-1);
		if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
		    lastdnptr)) < 0)
			return (-1);
		cp += n;
		ns_put16(type, cp);
		cp += INT16SZ;
		ns_put16(class, cp);
		cp += INT16SZ;
		hp->qdcount = htons(1);
		if (op == QUERY || data == NULL)
			break;
		/*
		 * Make an additional record for completion domain.
		 */
		if ((ep - cp) < RRFIXEDSZ)
			return (-1);
		n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ,
			    dnptrs, lastdnptr);
		if (n < 0)
			return (-1);
		cp += n;
		ns_put16(T_NULL, cp);
		cp += INT16SZ;
		ns_put16(class, cp);
		cp += INT16SZ;
		ns_put32(0, cp);
		cp += INT32SZ;
		ns_put16(0, cp);
		cp += INT16SZ;
		hp->arcount = htons(1);
		break;

	case IQUERY:
		/*
		 * Initialize answer section
		 */
		if (ep - cp < 1 + RRFIXEDSZ + datalen)
			return (-1);
		*cp++ = '\0';	/* no domain name */
		ns_put16(type, cp);
		cp += INT16SZ;
		ns_put16(class, cp);
		cp += INT16SZ;
		ns_put32(0, cp);
		cp += INT32SZ;
		ns_put16(datalen, cp);
		cp += INT16SZ;
		if (datalen) {
			memcpy(cp, data, (size_t)datalen);
			cp += datalen;
		}
		hp->ancount = htons(1);
		break;

	default:
		return (-1);
	}
	return (cp - buf);
}

#ifdef RES_USE_EDNS0
/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
#ifndef T_OPT
#define T_OPT	41
#endif

int
res_nopt(res_state statp,
	 int n0,		/* current offset in buffer */
	 u_char *buf,		/* buffer to put query */
	 int buflen,		/* size of buffer */
	 int anslen)		/* UDP answer buffer size */
{
	register HEADER *hp;
	register u_char *cp, *ep;
	u_int16_t flags = 0;

#ifdef DEBUG
	if ((statp->options & RES_DEBUG) != 0U)
		printf(";; res_nopt()\n");
#endif

	hp = (HEADER *)(void *)buf;
	cp = buf + n0;
	ep = buf + buflen;

	if ((ep - cp) < 1 + RRFIXEDSZ)
		return (-1);

	*cp++ = 0;	/* "." */

	ns_put16(T_OPT, cp);	/* TYPE */
	cp += INT16SZ;
	if (anslen > 0xffff)
		anslen = 0xffff;
	ns_put16(anslen, cp);			/* CLASS = UDP payload size */
	cp += INT16SZ;
	*cp++ = NOERROR;	/* extended RCODE */
	*cp++ = 0;		/* EDNS version */
	if (statp->options & RES_USE_DNSSEC) {
#ifdef DEBUG
		if (statp->options & RES_DEBUG)
			printf(";; res_opt()... ENDS0 DNSSEC\n");
#endif
		flags |= NS_OPT_DNSSEC_OK;
	}
	ns_put16(flags, cp);
	cp += INT16SZ;
#ifdef EDNS0_PADDING
	{
		u_int16_t minlen = (cp - buf) + 3 * INT16SZ;
		u_int16_t extra = minlen % EDNS0_PADDING;
		u_int16_t padlen = (EDNS0_PADDING - extra) % EDNS0_PADDING;
		if (minlen > buflen) {
			return (-1);
		}
		padlen = MIN(padlen, buflen - minlen);
		ns_put16(padlen + 2 * INT16SZ, cp);	/* RDLEN */
		cp += INT16SZ;
		ns_put16(NS_OPT_PADDING, cp);	/* OPTION-CODE */
		cp += INT16SZ;
		ns_put16(padlen, cp);	/* OPTION-LENGTH */
		cp += INT16SZ;
		memset(cp, 0, padlen);
		cp += padlen;
	}
#else
	ns_put16(0, cp);	/* RDLEN */
	cp += INT16SZ;
#endif
	hp->arcount = htons(ntohs(hp->arcount) + 1);

	return (cp - buf);
}
#endif