xref: /freebsd/lib/libc/resolv/res_mkquery.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
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 #if defined(LIBC_SCCS) && !defined(lint)
70 static const char sccsid[] = "@(#)res_mkquery.c	8.1 (Berkeley) 6/4/93";
71 static const char rcsid[] = "$Id: res_mkquery.c,v 1.10 2008/12/11 09:59:00 marka Exp $";
72 #endif /* LIBC_SCCS and not lint */
73 #include "port_before.h"
74 #include <sys/param.h>
75 #include <netinet/in.h>
76 #include <arpa/nameser.h>
77 #include <netdb.h>
78 #include <resolv.h>
79 #include <stdio.h>
80 #include <string.h>
81 #include "port_after.h"
82 
83 /* Options.  Leave them on. */
84 #ifndef	DEBUG
85 #define	DEBUG
86 #endif
87 
88 extern const char *_res_opcodes[];
89 
90 /*%
91  * Form all types of queries.
92  * Returns the size of the result or -1.
93  */
94 int
95 res_nmkquery(res_state statp,
96 	     int op,			/*!< opcode of query  */
97 	     const char *dname,		/*!< domain name  */
98 	     int class, int type,	/*!< class and type of query  */
99 	     const u_char *data,	/*!< resource record data  */
100 	     int datalen,		/*!< length of data  */
101 	     const u_char *newrr_in,	/*!< new rr for modify or append  */
102 	     u_char *buf,		/*!< buffer to put query  */
103 	     int buflen)		/*!< size of buffer  */
104 {
105 	HEADER *hp;
106 	u_char *cp, *ep;
107 	int n;
108 	u_char *dnptrs[20], **dpp, **lastdnptr;
109 
110 	UNUSED(newrr_in);
111 
112 #ifdef DEBUG
113 	if (statp->options & RES_DEBUG)
114 		printf(";; res_nmkquery(%s, %s, %s, %s)\n",
115 		       _res_opcodes[op], dname, p_class(class), p_type(type));
116 #endif
117 	/*
118 	 * Initialize header fields.
119 	 */
120 	if ((buf == NULL) || (buflen < HFIXEDSZ))
121 		return (-1);
122 	memset(buf, 0, HFIXEDSZ);
123 	hp = (HEADER *) buf;
124 	statp->id = res_nrandomid(statp);
125 	hp->id = htons(statp->id);
126 	hp->opcode = op;
127 	hp->rd = (statp->options & RES_RECURSE) != 0U;
128 	hp->rcode = NOERROR;
129 	cp = buf + HFIXEDSZ;
130 	ep = buf + buflen;
131 	dpp = dnptrs;
132 	*dpp++ = buf;
133 	*dpp++ = NULL;
134 	lastdnptr = dnptrs + nitems(dnptrs);
135 	/*
136 	 * perform opcode specific processing
137 	 */
138 	switch (op) {
139 	case QUERY:	/*FALLTHROUGH*/
140 	case NS_NOTIFY_OP:
141 		if (ep - cp < QFIXEDSZ)
142 			return (-1);
143 		if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
144 		    lastdnptr)) < 0)
145 			return (-1);
146 		cp += n;
147 		ns_put16(type, cp);
148 		cp += INT16SZ;
149 		ns_put16(class, cp);
150 		cp += INT16SZ;
151 		hp->qdcount = htons(1);
152 		if (op == QUERY || data == NULL)
153 			break;
154 		/*
155 		 * Make an additional record for completion domain.
156 		 */
157 		if ((ep - cp) < RRFIXEDSZ)
158 			return (-1);
159 		n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ,
160 			    dnptrs, lastdnptr);
161 		if (n < 0)
162 			return (-1);
163 		cp += n;
164 		ns_put16(T_NULL, cp);
165 		cp += INT16SZ;
166 		ns_put16(class, cp);
167 		cp += INT16SZ;
168 		ns_put32(0, cp);
169 		cp += INT32SZ;
170 		ns_put16(0, cp);
171 		cp += INT16SZ;
172 		hp->arcount = htons(1);
173 		break;
174 
175 	case IQUERY:
176 		/*
177 		 * Initialize answer section
178 		 */
179 		if (ep - cp < 1 + RRFIXEDSZ + datalen)
180 			return (-1);
181 		*cp++ = '\0';	/*%< no domain name */
182 		ns_put16(type, cp);
183 		cp += INT16SZ;
184 		ns_put16(class, cp);
185 		cp += INT16SZ;
186 		ns_put32(0, cp);
187 		cp += INT32SZ;
188 		ns_put16(datalen, cp);
189 		cp += INT16SZ;
190 		if (datalen) {
191 			memcpy(cp, data, datalen);
192 			cp += datalen;
193 		}
194 		hp->ancount = htons(1);
195 		break;
196 
197 	default:
198 		return (-1);
199 	}
200 	return (cp - buf);
201 }
202 
203 #ifdef RES_USE_EDNS0
204 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
205 
206 int
207 res_nopt(res_state statp,
208 	 int n0,		/*%< current offset in buffer */
209 	 u_char *buf,		/*%< buffer to put query */
210 	 int buflen,		/*%< size of buffer */
211 	 int anslen)		/*%< UDP answer buffer size */
212 {
213 	HEADER *hp;
214 	u_char *cp, *ep;
215 	u_int16_t flags = 0;
216 
217 #ifdef DEBUG
218 	if ((statp->options & RES_DEBUG) != 0U)
219 		printf(";; res_nopt()\n");
220 #endif
221 
222 	hp = (HEADER *) buf;
223 	cp = buf + n0;
224 	ep = buf + buflen;
225 
226 	if ((ep - cp) < 1 + RRFIXEDSZ)
227 		return (-1);
228 
229 	*cp++ = 0;				/*%< "." */
230 	ns_put16(ns_t_opt, cp);			/*%< TYPE */
231 	cp += INT16SZ;
232 	if (anslen > 0xffff)
233 		anslen = 0xffff;		/* limit to 16bit value */
234 	ns_put16(anslen & 0xffff, cp);		/*%< CLASS = UDP payload size */
235 	cp += INT16SZ;
236 	*cp++ = NOERROR;			/*%< extended RCODE */
237 	*cp++ = 0;				/*%< EDNS version */
238 
239 	if (statp->options & RES_USE_DNSSEC) {
240 #ifdef DEBUG
241 		if (statp->options & RES_DEBUG)
242 			printf(";; res_opt()... ENDS0 DNSSEC\n");
243 #endif
244 		flags |= NS_OPT_DNSSEC_OK;
245 	}
246 	ns_put16(flags, cp);
247 	cp += INT16SZ;
248 
249 	ns_put16(0U, cp);			/*%< RDLEN */
250 	cp += INT16SZ;
251 
252 	hp->arcount = htons(ntohs(hp->arcount) + 1);
253 
254 	return (cp - buf);
255 }
256 
257 /*
258  * Construct variable data (RDATA) block for OPT pseudo-RR, append it
259  * to the buffer, then update the RDLEN field (previously set to zero by
260  * res_nopt()) with the new RDATA length.
261  */
262 int
263 res_nopt_rdata(res_state statp,
264 	  int n0,	 	/*%< current offset in buffer */
265 	  u_char *buf,	 	/*%< buffer to put query */
266 	  int buflen,		/*%< size of buffer */
267 	  u_char *rdata,	/*%< ptr to start of opt rdata */
268 	  u_short code,		/*%< OPTION-CODE */
269 	  u_short len,		/*%< OPTION-LENGTH */
270 	  u_char *data)		/*%< OPTION_DATA */
271 {
272 	register u_char *cp, *ep;
273 
274 #ifdef DEBUG
275 	if ((statp->options & RES_DEBUG) != 0U)
276 		printf(";; res_nopt_rdata()\n");
277 #endif
278 
279 	cp = buf + n0;
280 	ep = buf + buflen;
281 
282 	if ((ep - cp) < (4 + len))
283 		return (-1);
284 
285 	if (rdata < (buf + 2) || rdata >= ep)
286 		return (-1);
287 
288 	ns_put16(code, cp);
289 	cp += INT16SZ;
290 
291 	ns_put16(len, cp);
292 	cp += INT16SZ;
293 
294 	memcpy(cp, data, len);
295 	cp += len;
296 
297 	len = cp - rdata;
298 	ns_put16(len, rdata - 2);	/* Update RDLEN field */
299 
300 	return (cp - buf);
301 }
302 #endif
303 
304 /*! \file */
305