1 /** $MirOS: src/lib/libc/net/res_mkquery.c,v 1.4 2005/09/22 20:40:03 tg Exp $ */
2 /* $OpenBSD: res_mkquery.c,v 1.17 2005/08/06 20:30:04 espie Exp $ */
3
4 /*
5 * Copyright (c) 1985, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 * -
32 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
33 *
34 * Permission to use, copy, modify, and distribute this software for any
35 * purpose with or without fee is hereby granted, provided that the above
36 * copyright notice and this permission notice appear in all copies, and that
37 * the name of Digital Equipment Corporation not be used in advertising or
38 * publicity pertaining to distribution of the document or software without
39 * specific, written prior permission.
40 *
41 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
42 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
43 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
44 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
45 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
46 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
47 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
48 * SOFTWARE.
49 * -
50 * --Copyright--
51 */
52
53 #include <sys/param.h>
54 #include <netinet/in.h>
55 #include <arpa/nameser.h>
56
57 #include <stdio.h>
58 #include <netdb.h>
59 #include <resolv.h>
60 #include <string.h>
61
62 #include "thread_private.h"
63
64 __RCSID("$MirOS: src/lib/libc/net/res_mkquery.c,v 1.4 2005/09/22 20:40:03 tg Exp $");
65
66 /*
67 * Form all types of queries.
68 * Returns the size of the result or -1.
69 */
70 /* ARGSUSED */
71 int
res_mkquery(int op,const char * dname,int class,int type,const u_char * data,int datalen,const u_char * newrr_in,u_char * buf,int buflen)72 res_mkquery(int op,
73 const char *dname, /* opcode of query */
74 int class, /* domain name */
75 int type, /* class and type of query */
76 const u_char *data, /* resource record data */
77 int datalen, /* length of data */
78 const u_char *newrr_in, /* new rr for modify or append */
79 u_char *buf, /* buffer to put query */
80 int buflen) /* size of buffer */
81 {
82 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
83 HEADER *hp;
84 u_char *cp, *ep;
85 int n;
86 u_char *dnptrs[20], **dpp, **lastdnptr;
87
88 if (_res_init(0) == -1) {
89 h_errno = NETDB_INTERNAL;
90 return (-1);
91 }
92 #ifdef DEBUG
93 if (_resp->options & RES_DEBUG)
94 printf(";; res_mkquery(%d, %s, %d, %d)\n",
95 op, dname, class, type);
96 #endif
97 /*
98 * Initialize header fields.
99 *
100 * A special random number generator is used to create non predictable
101 * and non repeating ids over a long period. It also avoids reuse
102 * by switching between two distinct number cycles.
103 */
104
105 if ((buf == NULL) || (buflen < HFIXEDSZ))
106 return (-1);
107 memset(buf, 0, HFIXEDSZ);
108 hp = (HEADER *) buf;
109 _resp->id = res_randomid();
110 hp->id = htons(_resp->id);
111 hp->opcode = op;
112 hp->rd = (_resp->options & RES_RECURSE) != 0;
113 hp->rcode = NOERROR;
114 cp = buf + HFIXEDSZ;
115 ep = buf + buflen;
116 dpp = dnptrs;
117 *dpp++ = buf;
118 *dpp++ = NULL;
119 lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
120 /*
121 * perform opcode specific processing
122 */
123 switch (op) {
124 case QUERY: /*FALLTHROUGH*/
125 case NS_NOTIFY_OP:
126 if (ep - cp < QFIXEDSZ)
127 return (-1);
128 if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
129 lastdnptr)) < 0)
130 return (-1);
131 cp += n;
132 __putshort(type, cp);
133 cp += INT16SZ;
134 __putshort(class, cp);
135 cp += INT16SZ;
136 hp->qdcount = htons(1);
137 if (op == QUERY || data == NULL)
138 break;
139 /*
140 * Make an additional record for completion domain.
141 */
142 if (ep - cp < RRFIXEDSZ)
143 return (-1);
144 n = dn_comp((char *)data, cp, ep - cp - RRFIXEDSZ, dnptrs,
145 lastdnptr);
146 if (n < 0)
147 return (-1);
148 cp += n;
149 __putshort(T_NULL, cp);
150 cp += INT16SZ;
151 __putshort(class, cp);
152 cp += INT16SZ;
153 __putlong(0, cp);
154 cp += INT32SZ;
155 __putshort(0, cp);
156 cp += INT16SZ;
157 hp->arcount = htons(1);
158 break;
159
160 case IQUERY:
161 /*
162 * Initialize answer section
163 */
164 if (ep - cp < 1 + RRFIXEDSZ + datalen)
165 return (-1);
166 *cp++ = '\0'; /* no domain name */
167 __putshort(type, cp);
168 cp += INT16SZ;
169 __putshort(class, cp);
170 cp += INT16SZ;
171 __putlong(0, cp);
172 cp += INT32SZ;
173 __putshort(datalen, cp);
174 cp += INT16SZ;
175 if (datalen) {
176 memmove(cp, data, datalen);
177 cp += datalen;
178 }
179 hp->ancount = htons(1);
180 break;
181
182 default:
183 return (-1);
184 }
185 return (cp - buf);
186 }
187
188 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
189 int
res_opt(int n0,u_char * buf,int buflen,int anslen)190 res_opt(int n0,
191 u_char *buf, /* buffer to put query */
192 int buflen, /* size of buffer */
193 int anslen) /* answer buffer length */
194 {
195 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
196 HEADER *hp;
197 u_char *cp, *ep;
198
199 hp = (HEADER *) buf;
200 cp = buf + n0;
201 ep = buf + buflen;
202
203 if (ep - cp < 1 + RRFIXEDSZ)
204 return -1;
205
206 *cp++ = 0; /* "." */
207
208 __putshort(T_OPT, cp); /* TYPE */
209 cp += INT16SZ;
210 if (anslen > 0xffff)
211 anslen = 0xffff; /* limit to 16bit value */
212 __putshort(anslen & 0xffff, cp); /* CLASS = UDP payload size */
213 cp += INT16SZ;
214 *cp++ = NOERROR; /* extended RCODE */
215 *cp++ = 0; /* EDNS version */
216 if (_resp->options & RES_USE_DNSSEC) {
217 #ifdef DEBUG
218 if (_resp->options & RES_DEBUG)
219 printf(";; res_opt()... ENDS0 DNSSEC OK\n");
220 #endif /* DEBUG */
221 __putshort(DNS_MESSAGEEXTFLAG_DO, cp); /* EDNS Z field */
222 cp += INT16SZ;
223 } else {
224 __putshort(0, cp); /* EDNS Z field */
225 cp += INT16SZ;
226 }
227 __putshort(0, cp); /* RDLEN */
228 cp += INT16SZ;
229 hp->arcount = htons(ntohs(hp->arcount) + 1);
230
231 return cp - buf;
232 }
233