1 /*
2  * Copyright (c) 1985, 1993
3  *    The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  * 	This product includes software developed by the University of
16  * 	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
36  *
37  * Permission to use, copy, modify, and distribute this software for any
38  * purpose with or without fee is hereby granted, provided that the above
39  * copyright notice and this permission notice appear in all copies, and that
40  * the name of Digital Equipment Corporation not be used in advertising or
41  * publicity pertaining to distribution of the document or software without
42  * specific, written prior permission.
43  *
44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
51  * SOFTWARE.
52  */
53 
54 /*
55  * Portions Copyright (c) 1996 by Internet Software Consortium.
56  *
57  * Permission to use, copy, modify, and distribute this software for any
58  * purpose with or without fee is hereby granted, provided that the above
59  * copyright notice and this permission notice appear in all copies.
60  *
61  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
62  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
63  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
64  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
65  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
66  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
67  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
68  * SOFTWARE.
69  */
70 
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static char sccsid[] = "@(#)res_mkquery.c	8.1 (Berkeley) 6/4/93";
73 static char orig_rcsid[] = "From: Id: res_mkquery.c,v 8.9 1997/04/24 22:22:36 vixie Exp $";
74 #endif /* LIBC_SCCS and not lint */
75 #include <sys/cdefs.h>
76 #include <sys/types.h>
77 #include <machine/endian.h>
78 
79 #include <sys/types.h>
80 #include <sys/param.h>
81 #include <netinet/in.h>
82 #include <arpa/nameser.h>
83 #include <netdb.h>
84 #include <resolv.h>
85 #include <stdio.h>
86 #include <string.h>
87 
88 #include "res_config.h"
89 
90 /*
91  * Form all types of queries.
92  * Returns the size of the result or -1.
93  */
94 int
res_mkquery(op,dname,class,type,data,datalen,newrr_in,buf,buflen)95 res_mkquery(op, dname, class, type, data, datalen, newrr_in, buf, buflen)
96 	int op;			/* opcode of query */
97 	const char *dname;	/* domain name */
98 	int class, 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;
107 	int n;
108 	u_char *dnptrs[20], **dpp, **lastdnptr;
109 
110 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
111 		h_errno = NETDB_INTERNAL;
112 		return (-1);
113 	}
114 #ifdef DEBUG
115 	if (_res.options & RES_DEBUG)
116 		printf(";; res_mkquery(%d, %s, %d, %d)\n",
117 		       op, dname, class, 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 	hp->id = htons(++_res.id);
127 	hp->opcode = op;
128 	hp->rd = (_res.options & RES_RECURSE) != 0;
129 	hp->rcode = NOERROR;
130 	cp = buf + HFIXEDSZ;
131 	buflen -= HFIXEDSZ;
132 	dpp = dnptrs;
133 	*dpp++ = buf;
134 	*dpp++ = NULL;
135 	lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
136 	/*
137 	 * perform opcode specific processing
138 	 */
139 	switch (op) {
140 	case QUERY:	/*FALLTHROUGH*/
141 	case NS_NOTIFY_OP:
142 		if ((buflen -= QFIXEDSZ) < 0)
143 			return (-1);
144 		if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
145 			return (-1);
146 		cp += n;
147 		buflen -= n;
148 		__putshort(type, cp);
149 		cp += INT16SZ;
150 		__putshort(class, cp);
151 		cp += INT16SZ;
152 		hp->qdcount = htons(1);
153 		if (op == QUERY || data == NULL)
154 			break;
155 		/*
156 		 * Make an additional record for completion domain.
157 		 */
158 		buflen -= RRFIXEDSZ;
159 		n = dn_comp((char *)data, cp, buflen, dnptrs, lastdnptr);
160 		if (n < 0)
161 			return (-1);
162 		cp += n;
163 		buflen -= n;
164 		__putshort(T_NULL, cp);
165 		cp += INT16SZ;
166 		__putshort(class, cp);
167 		cp += INT16SZ;
168 		__putlong(0, cp);
169 		cp += INT32SZ;
170 		__putshort(0, cp);
171 		cp += INT16SZ;
172 		hp->arcount = htons(1);
173 		break;
174 
175 	case IQUERY:
176 		/*
177 		 * Initialize answer section
178 		 */
179 		if (buflen < 1 + RRFIXEDSZ + datalen)
180 			return (-1);
181 		*cp++ = '\0';	/* no domain name */
182 		__putshort(type, cp);
183 		cp += INT16SZ;
184 		__putshort(class, cp);
185 		cp += INT16SZ;
186 		__putlong(0, cp);
187 		cp += INT32SZ;
188 		__putshort(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 /*
204  * Weak aliases for applications that use certain private entry points,
205  * and fail to include <resolv.h>.
206  */
207 #undef res_mkquery
208 __weak_reference(__res_mkquery, res_mkquery);
209 
210 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
211 int
res_opt(n0,buf,buflen,anslen)212 res_opt(n0, buf, buflen, anslen)
213 	int n0;
214 	u_char *buf;		/* buffer to put query */
215 	int buflen;		/* size of buffer */
216 	int anslen;		/* answer buffer length */
217 {
218 	HEADER *hp;
219 	u_char *cp;
220 
221 	hp = (HEADER *) buf;
222 	cp = buf + n0;
223 	buflen -= n0;
224 
225 	if (buflen < 1 + RRFIXEDSZ)
226 		return -1;
227 
228 	*cp++ = 0;	/* "." */
229 	buflen--;
230 
231 	__putshort(T_OPT, cp);	/* TYPE */
232 	cp += INT16SZ;
233 	__putshort(anslen & 0xffff, cp);	/* CLASS = UDP payload size */
234 	cp += INT16SZ;
235 	*cp++ = NOERROR;	/* extended RCODE */
236 	*cp++ = 0;		/* EDNS version */
237 	__putshort(0, cp);	/* MBZ */
238 	cp += INT16SZ;
239 	__putshort(0, cp);	/* RDLEN */
240 	cp += INT16SZ;
241 	hp->arcount = htons(ntohs(hp->arcount) + 1);
242 	buflen -= RRFIXEDSZ;
243 
244 	return cp - buf;
245 }
246