xref: /freebsd/lib/libc/resolv/res_mkquery.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*
2  * Portions Copyright (C) 2004, 2005, 2008  Internet Systems Consortium, Inc. ("ISC")
3  * Portions Copyright (C) 1996, 1997, 1988, 1999, 2001, 2003  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /*
19  * Copyright (c) 1985, 1993
20  *    The Regents of the University of California.  All rights reserved.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the above copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 4. Neither the name of the University nor the names of its contributors
31  *    may be used to endorse or promote products derived from this software
32  *    without specific prior written permission.
33  *
34  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
35  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44  * SUCH DAMAGE.
45  */
46 
47 /*
48  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
49  *
50  * Permission to use, copy, modify, and distribute this software for any
51  * purpose with or without fee is hereby granted, provided that the above
52  * copyright notice and this permission notice appear in all copies, and that
53  * the name of Digital Equipment Corporation not be used in advertising or
54  * publicity pertaining to distribution of the document or software without
55  * specific, written prior permission.
56  *
57  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
58  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
59  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
60  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
61  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
62  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
63  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
64  * SOFTWARE.
65  */
66 
67 #if defined(LIBC_SCCS) && !defined(lint)
68 static const char sccsid[] = "@(#)res_mkquery.c	8.1 (Berkeley) 6/4/93";
69 static const char rcsid[] = "$Id: res_mkquery.c,v 1.10 2008/12/11 09:59:00 marka Exp $";
70 #endif /* LIBC_SCCS and not lint */
71 #include <sys/cdefs.h>
72 __FBSDID("$FreeBSD$");
73 
74 #include "port_before.h"
75 #include <sys/types.h>
76 #include <sys/param.h>
77 #include <netinet/in.h>
78 #include <arpa/nameser.h>
79 #include <netdb.h>
80 #include <resolv.h>
81 #include <stdio.h>
82 #include <string.h>
83 #include "port_after.h"
84 
85 /* Options.  Leave them on. */
86 #ifndef	DEBUG
87 #define	DEBUG
88 #endif
89 
90 extern const char *_res_opcodes[];
91 
92 /*%
93  * Form all types of queries.
94  * Returns the size of the result or -1.
95  */
96 int
97 res_nmkquery(res_state statp,
98 	     int op,			/*!< opcode of query  */
99 	     const char *dname,		/*!< domain name  */
100 	     int class, int type,	/*!< class and type of query  */
101 	     const u_char *data,	/*!< resource record data  */
102 	     int datalen,		/*!< length of data  */
103 	     const u_char *newrr_in,	/*!< new rr for modify or append  */
104 	     u_char *buf,		/*!< buffer to put query  */
105 	     int buflen)		/*!< size of buffer  */
106 {
107 	HEADER *hp;
108 	u_char *cp, *ep;
109 	int n;
110 	u_char *dnptrs[20], **dpp, **lastdnptr;
111 
112 	UNUSED(newrr_in);
113 
114 #ifdef DEBUG
115 	if (statp->options & RES_DEBUG)
116 		printf(";; res_nmkquery(%s, %s, %s, %s)\n",
117 		       _res_opcodes[op], dname, p_class(class), p_type(type));
118 #endif
119 	/*
120 	 * Initialize header fields.
121 	 */
122 	if ((buf == NULL) || (buflen < HFIXEDSZ))
123 		return (-1);
124 	memset(buf, 0, HFIXEDSZ);
125 	hp = (HEADER *) buf;
126 	statp->id = res_nrandomid(statp);
127 	hp->id = htons(statp->id);
128 	hp->opcode = op;
129 	hp->rd = (statp->options & RES_RECURSE) != 0U;
130 	hp->rcode = NOERROR;
131 	cp = buf + HFIXEDSZ;
132 	ep = buf + buflen;
133 	dpp = dnptrs;
134 	*dpp++ = buf;
135 	*dpp++ = NULL;
136 	lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
137 	/*
138 	 * perform opcode specific processing
139 	 */
140 	switch (op) {
141 	case QUERY:	/*FALLTHROUGH*/
142 	case NS_NOTIFY_OP:
143 		if (ep - cp < QFIXEDSZ)
144 			return (-1);
145 		if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
146 		    lastdnptr)) < 0)
147 			return (-1);
148 		cp += n;
149 		ns_put16(type, cp);
150 		cp += INT16SZ;
151 		ns_put16(class, cp);
152 		cp += INT16SZ;
153 		hp->qdcount = htons(1);
154 		if (op == QUERY || data == NULL)
155 			break;
156 		/*
157 		 * Make an additional record for completion domain.
158 		 */
159 		if ((ep - cp) < RRFIXEDSZ)
160 			return (-1);
161 		n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ,
162 			    dnptrs, lastdnptr);
163 		if (n < 0)
164 			return (-1);
165 		cp += n;
166 		ns_put16(T_NULL, cp);
167 		cp += INT16SZ;
168 		ns_put16(class, cp);
169 		cp += INT16SZ;
170 		ns_put32(0, cp);
171 		cp += INT32SZ;
172 		ns_put16(0, cp);
173 		cp += INT16SZ;
174 		hp->arcount = htons(1);
175 		break;
176 
177 	case IQUERY:
178 		/*
179 		 * Initialize answer section
180 		 */
181 		if (ep - cp < 1 + RRFIXEDSZ + datalen)
182 			return (-1);
183 		*cp++ = '\0';	/*%< no domain name */
184 		ns_put16(type, cp);
185 		cp += INT16SZ;
186 		ns_put16(class, cp);
187 		cp += INT16SZ;
188 		ns_put32(0, cp);
189 		cp += INT32SZ;
190 		ns_put16(datalen, cp);
191 		cp += INT16SZ;
192 		if (datalen) {
193 			memcpy(cp, data, datalen);
194 			cp += datalen;
195 		}
196 		hp->ancount = htons(1);
197 		break;
198 
199 	default:
200 		return (-1);
201 	}
202 	return (cp - buf);
203 }
204 
205 #ifdef RES_USE_EDNS0
206 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
207 
208 int
209 res_nopt(res_state statp,
210 	 int n0,		/*%< current offset in buffer */
211 	 u_char *buf,		/*%< buffer to put query */
212 	 int buflen,		/*%< size of buffer */
213 	 int anslen)		/*%< UDP answer buffer size */
214 {
215 	HEADER *hp;
216 	u_char *cp, *ep;
217 	u_int16_t flags = 0;
218 
219 #ifdef DEBUG
220 	if ((statp->options & RES_DEBUG) != 0U)
221 		printf(";; res_nopt()\n");
222 #endif
223 
224 	hp = (HEADER *) buf;
225 	cp = buf + n0;
226 	ep = buf + buflen;
227 
228 	if ((ep - cp) < 1 + RRFIXEDSZ)
229 		return (-1);
230 
231 	*cp++ = 0;				/*%< "." */
232 	ns_put16(ns_t_opt, cp);			/*%< TYPE */
233 	cp += INT16SZ;
234 	if (anslen > 0xffff)
235 		anslen = 0xffff;		/* limit to 16bit value */
236 	ns_put16(anslen & 0xffff, cp);		/*%< CLASS = UDP payload size */
237 	cp += INT16SZ;
238 	*cp++ = NOERROR;			/*%< extended RCODE */
239 	*cp++ = 0;				/*%< EDNS version */
240 
241 	if (statp->options & RES_USE_DNSSEC) {
242 #ifdef DEBUG
243 		if (statp->options & RES_DEBUG)
244 			printf(";; res_opt()... ENDS0 DNSSEC\n");
245 #endif
246 		flags |= NS_OPT_DNSSEC_OK;
247 	}
248 	ns_put16(flags, cp);
249 	cp += INT16SZ;
250 
251 	ns_put16(0U, cp);			/*%< RDLEN */
252 	cp += INT16SZ;
253 
254 	hp->arcount = htons(ntohs(hp->arcount) + 1);
255 
256 	return (cp - buf);
257 }
258 
259 /*
260  * Construct variable data (RDATA) block for OPT psuedo-RR, append it
261  * to the buffer, then update the RDLEN field (previously set to zero by
262  * res_nopt()) with the new RDATA length.
263  */
264 int
265 res_nopt_rdata(res_state statp,
266 	  int n0,	 	/*%< current offset in buffer */
267 	  u_char *buf,	 	/*%< buffer to put query */
268 	  int buflen,		/*%< size of buffer */
269 	  u_char *rdata,	/*%< ptr to start of opt rdata */
270 	  u_short code,		/*%< OPTION-CODE */
271 	  u_short len,		/*%< OPTION-LENGTH */
272 	  u_char *data)		/*%< OPTION_DATA */
273 {
274 	register u_char *cp, *ep;
275 
276 #ifdef DEBUG
277 	if ((statp->options & RES_DEBUG) != 0U)
278 		printf(";; res_nopt_rdata()\n");
279 #endif
280 
281 	cp = buf + n0;
282 	ep = buf + buflen;
283 
284 	if ((ep - cp) < (4 + len))
285 		return (-1);
286 
287 	if (rdata < (buf + 2) || rdata >= ep)
288 		return (-1);
289 
290 	ns_put16(code, cp);
291 	cp += INT16SZ;
292 
293 	ns_put16(len, cp);
294 	cp += INT16SZ;
295 
296 	memcpy(cp, data, len);
297 	cp += len;
298 
299 	len = cp - rdata;
300 	ns_put16(len, rdata - 2);	/* Update RDLEN field */
301 
302 	return (cp - buf);
303 }
304 #endif
305 
306 /*! \file */
307