1/*-
2 * SPDX-License-Identifier: (ISC AND BSD-3-Clause)
3 *
4 * Portions Copyright (C) 2004, 2005, 2008  Internet Systems Consortium, Inc. ("ISC")
5 * Portions Copyright (C) 1996, 1997, 1988, 1999, 2001, 2003  Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17 * PERFORMANCE OF THIS SOFTWARE.
18 */
19
20/*-
21 * Copyright (c) 1985, 1993
22 *    The Regents of the University of California.  All rights reserved.
23 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 * 1. Redistributions of source code must retain the above copyright
28 *    notice, this list of conditions and the following disclaimer.
29 * 2. Redistributions in binary form must reproduce the above copyright
30 *    notice, this list of conditions and the following disclaimer in the
31 *    documentation and/or other materials provided with the distribution.
32 * 3. Neither the name of the University nor the names of its contributors
33 *    may be used to endorse or promote products derived from this software
34 *    without specific prior written permission.
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
37 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
40 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 * SUCH DAMAGE.
47 */
48
49/*
50 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
51 *
52 * Permission to use, copy, modify, and distribute this software for any
53 * purpose with or without fee is hereby granted, provided that the above
54 * copyright notice and this permission notice appear in all copies, and that
55 * the name of Digital Equipment Corporation not be used in advertising or
56 * publicity pertaining to distribution of the document or software without
57 * specific, written prior permission.
58 *
59 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
60 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
61 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
62 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
63 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
64 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
65 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
66 * SOFTWARE.
67 */
68
69#include "port_before.h"
70#include <sys/param.h>
71#include <netinet/in.h>
72#include <arpa/nameser.h>
73#include <netdb.h>
74#include <resolv.h>
75#include <stdio.h>
76#include <string.h>
77#include "port_after.h"
78
79/* Options.  Leave them on. */
80#ifndef	DEBUG
81#define	DEBUG
82#endif
83
84extern const char *_res_opcodes[];
85
86/*%
87 * Form all types of queries.
88 * Returns the size of the result or -1.
89 */
90int
91res_nmkquery(res_state statp,
92	     int op,			/*!< opcode of query  */
93	     const char *dname,		/*!< domain name  */
94	     int class, int type,	/*!< class and type of query  */
95	     const u_char *data,	/*!< resource record data  */
96	     int datalen,		/*!< length of data  */
97	     const u_char *newrr_in,	/*!< new rr for modify or append  */
98	     u_char *buf,		/*!< buffer to put query  */
99	     int buflen)		/*!< size of buffer  */
100{
101	HEADER *hp;
102	u_char *cp, *ep;
103	int n;
104	u_char *dnptrs[20], **dpp, **lastdnptr;
105
106	UNUSED(newrr_in);
107
108#ifdef DEBUG
109	if (statp->options & RES_DEBUG)
110		printf(";; res_nmkquery(%s, %s, %s, %s)\n",
111		       _res_opcodes[op], dname, p_class(class), p_type(type));
112#endif
113	/*
114	 * Initialize header fields.
115	 */
116	if ((buf == NULL) || (buflen < HFIXEDSZ))
117		return (-1);
118	memset(buf, 0, HFIXEDSZ);
119	hp = (HEADER *) buf;
120	statp->id = res_nrandomid(statp);
121	hp->id = htons(statp->id);
122	hp->opcode = op;
123	hp->rd = (statp->options & RES_RECURSE) != 0U;
124	hp->rcode = NOERROR;
125	cp = buf + HFIXEDSZ;
126	ep = buf + buflen;
127	dpp = dnptrs;
128	*dpp++ = buf;
129	*dpp++ = NULL;
130	lastdnptr = dnptrs + nitems(dnptrs);
131	/*
132	 * perform opcode specific processing
133	 */
134	switch (op) {
135	case QUERY:	/*FALLTHROUGH*/
136	case NS_NOTIFY_OP:
137		if (ep - cp < QFIXEDSZ)
138			return (-1);
139		if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
140		    lastdnptr)) < 0)
141			return (-1);
142		cp += n;
143		ns_put16(type, cp);
144		cp += INT16SZ;
145		ns_put16(class, cp);
146		cp += INT16SZ;
147		hp->qdcount = htons(1);
148		if (op == QUERY || data == NULL)
149			break;
150		/*
151		 * Make an additional record for completion domain.
152		 */
153		if ((ep - cp) < RRFIXEDSZ)
154			return (-1);
155		n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ,
156			    dnptrs, lastdnptr);
157		if (n < 0)
158			return (-1);
159		cp += n;
160		ns_put16(T_NULL, cp);
161		cp += INT16SZ;
162		ns_put16(class, cp);
163		cp += INT16SZ;
164		ns_put32(0, cp);
165		cp += INT32SZ;
166		ns_put16(0, cp);
167		cp += INT16SZ;
168		hp->arcount = htons(1);
169		break;
170
171	case IQUERY:
172		/*
173		 * Initialize answer section
174		 */
175		if (ep - cp < 1 + RRFIXEDSZ + datalen)
176			return (-1);
177		*cp++ = '\0';	/*%< no domain name */
178		ns_put16(type, cp);
179		cp += INT16SZ;
180		ns_put16(class, cp);
181		cp += INT16SZ;
182		ns_put32(0, cp);
183		cp += INT32SZ;
184		ns_put16(datalen, cp);
185		cp += INT16SZ;
186		if (datalen) {
187			memcpy(cp, data, datalen);
188			cp += datalen;
189		}
190		hp->ancount = htons(1);
191		break;
192
193	default:
194		return (-1);
195	}
196	return (cp - buf);
197}
198
199#ifdef RES_USE_EDNS0
200/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
201
202int
203res_nopt(res_state statp,
204	 int n0,		/*%< current offset in buffer */
205	 u_char *buf,		/*%< buffer to put query */
206	 int buflen,		/*%< size of buffer */
207	 int anslen)		/*%< UDP answer buffer size */
208{
209	HEADER *hp;
210	u_char *cp, *ep;
211	u_int16_t flags = 0;
212
213#ifdef DEBUG
214	if ((statp->options & RES_DEBUG) != 0U)
215		printf(";; res_nopt()\n");
216#endif
217
218	hp = (HEADER *) buf;
219	cp = buf + n0;
220	ep = buf + buflen;
221
222	if ((ep - cp) < 1 + RRFIXEDSZ)
223		return (-1);
224
225	*cp++ = 0;				/*%< "." */
226	ns_put16(ns_t_opt, cp);			/*%< TYPE */
227	cp += INT16SZ;
228	if (anslen > 0xffff)
229		anslen = 0xffff;		/* limit to 16bit value */
230	ns_put16(anslen & 0xffff, cp);		/*%< CLASS = UDP payload size */
231	cp += INT16SZ;
232	*cp++ = NOERROR;			/*%< extended RCODE */
233	*cp++ = 0;				/*%< EDNS version */
234
235	if (statp->options & RES_USE_DNSSEC) {
236#ifdef DEBUG
237		if (statp->options & RES_DEBUG)
238			printf(";; res_opt()... ENDS0 DNSSEC\n");
239#endif
240		flags |= NS_OPT_DNSSEC_OK;
241	}
242	ns_put16(flags, cp);
243	cp += INT16SZ;
244
245	ns_put16(0U, cp);			/*%< RDLEN */
246	cp += INT16SZ;
247
248	hp->arcount = htons(ntohs(hp->arcount) + 1);
249
250	return (cp - buf);
251}
252
253/*
254 * Construct variable data (RDATA) block for OPT pseudo-RR, append it
255 * to the buffer, then update the RDLEN field (previously set to zero by
256 * res_nopt()) with the new RDATA length.
257 */
258int
259res_nopt_rdata(res_state statp,
260	  int n0,	 	/*%< current offset in buffer */
261	  u_char *buf,	 	/*%< buffer to put query */
262	  int buflen,		/*%< size of buffer */
263	  u_char *rdata,	/*%< ptr to start of opt rdata */
264	  u_short code,		/*%< OPTION-CODE */
265	  u_short len,		/*%< OPTION-LENGTH */
266	  u_char *data)		/*%< OPTION_DATA */
267{
268	register u_char *cp, *ep;
269
270#ifdef DEBUG
271	if ((statp->options & RES_DEBUG) != 0U)
272		printf(";; res_nopt_rdata()\n");
273#endif
274
275	cp = buf + n0;
276	ep = buf + buflen;
277
278	if ((ep - cp) < (4 + len))
279		return (-1);
280
281	if (rdata < (buf + 2) || rdata >= ep)
282		return (-1);
283
284	ns_put16(code, cp);
285	cp += INT16SZ;
286
287	ns_put16(len, cp);
288	cp += INT16SZ;
289
290	memcpy(cp, data, len);
291	cp += len;
292
293	len = cp - rdata;
294	ns_put16(len, rdata - 2);	/* Update RDLEN field */
295
296	return (cp - buf);
297}
298#endif
299
300/*! \file */
301