1 /*
2 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6
7 /*
8 * Portions Copyright (C) 2004, 2005, 2008 Internet Systems Consortium, Inc. ("ISC")
9 * Portions Copyright (C) 1996, 1997, 1988, 1999, 2001, 2003 Internet Software Consortium.
10 *
11 * Permission to use, copy, modify, and/or distribute this software for any
12 * purpose with or without fee is hereby granted, provided that the above
13 * copyright notice and this permission notice appear in all copies.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
16 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
17 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
18 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
19 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
20 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
21 * PERFORMANCE OF THIS SOFTWARE.
22 */
23
24 /*
25 * Copyright (c) 1985, 1993
26 * The Regents of the University of California. All rights reserved.
27 *
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
30 * are met:
31 * 1. Redistributions of source code must retain the above copyright
32 * notice, this list of conditions and the following disclaimer.
33 * 2. Redistributions in binary form must reproduce the above copyright
34 * notice, this list of conditions and the following disclaimer in the
35 * documentation and/or other materials provided with the distribution.
36 * 3. All advertising materials mentioning features or use of this software
37 * must display the following acknowledgement:
38 * This product includes software developed by the University of
39 * California, Berkeley and its contributors.
40 * 4. Neither the name of the University nor the names of its contributors
41 * may be used to endorse or promote products derived from this software
42 * without specific prior written permission.
43 *
44 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
45 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
48 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54 * SUCH DAMAGE.
55 */
56
57 /*
58 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
59 *
60 * Permission to use, copy, modify, and distribute this software for any
61 * purpose with or without fee is hereby granted, provided that the above
62 * copyright notice and this permission notice appear in all copies, and that
63 * the name of Digital Equipment Corporation not be used in advertising or
64 * publicity pertaining to distribution of the document or software without
65 * specific, written prior permission.
66 *
67 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
68 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
69 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
70 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
71 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
72 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
73 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
74 * SOFTWARE.
75 */
76
77 #include "port_before.h"
78 #include <sys/types.h>
79 #include <sys/param.h>
80 #include <netinet/in.h>
81 #include <arpa/nameser.h>
82
83 #ifdef SUNW_CONFCHECK
84 #include <sys/socket.h>
85 #include <errno.h>
86 #include <sys/stat.h>
87 #endif /* SUNW_CONFCHECK */
88
89
90 #include <netdb.h>
91 #include <resolv.h>
92 #include <stdio.h>
93 #include <string.h>
94 #include "port_after.h"
95
96 /* Options. Leave them on. */
97 #define DEBUG
98
99 extern const char *_res_opcodes[];
100
101 #ifdef SUNW_CONFCHECK
102 static int _confcheck(res_state statp);
103 #endif /* SUNW_CONFCHECK */
104
105
106 /*%
107 * Form all types of queries.
108 * Returns the size of the result or -1.
109 */
110 int
res_nmkquery(res_state statp,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)111 res_nmkquery(res_state statp,
112 int op, /*!< opcode of query */
113 const char *dname, /*!< domain name */
114 int class, int type, /*!< class and type of query */
115 const u_char *data, /*!< resource record data */
116 int datalen, /*!< length of data */
117 const u_char *newrr_in, /*!< new rr for modify or append */
118 u_char *buf, /*!< buffer to put query */
119 int buflen) /*!< size of buffer */
120 {
121 register HEADER *hp;
122 register u_char *cp, *ep;
123 register int n;
124 u_char *dnptrs[20], **dpp, **lastdnptr;
125
126 UNUSED(newrr_in);
127
128 #ifdef DEBUG
129 if (statp->options & RES_DEBUG)
130 printf(";; res_nmkquery(%s, %s, %s, %s)\n",
131 _res_opcodes[op], dname, p_class(class), p_type(type));
132 #endif
133
134 #ifdef SUNW_CONFCHECK
135 /*
136 * 1247019, 1265838, and 4034368: Check to see if we can
137 * bailout quickly.
138 */
139 if (_confcheck(statp) == -1) {
140 RES_SET_H_ERRNO(statp, NO_RECOVERY);
141 return(-1);
142 }
143 #endif /* SUNW_CONFCHECK */
144
145 /*
146 * Initialize header fields.
147 */
148 if ((buf == NULL) || (buflen < HFIXEDSZ))
149 return (-1);
150 memset(buf, 0, HFIXEDSZ);
151 hp = (HEADER *) buf;
152 statp->id = res_nrandomid(statp);
153 hp->id = htons(statp->id);
154 hp->opcode = op;
155 hp->rd = (statp->options & RES_RECURSE) != 0U;
156 hp->rcode = NOERROR;
157 cp = buf + HFIXEDSZ;
158 ep = buf + buflen;
159 dpp = dnptrs;
160 *dpp++ = buf;
161 *dpp++ = NULL;
162 lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
163 /*
164 * perform opcode specific processing
165 */
166 switch (op) {
167 case QUERY: /*FALLTHROUGH*/
168 case NS_NOTIFY_OP:
169 if (ep - cp < QFIXEDSZ)
170 return (-1);
171 if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs,
172 lastdnptr)) < 0)
173 return (-1);
174 cp += n;
175 ns_put16(type, cp);
176 cp += INT16SZ;
177 ns_put16(class, cp);
178 cp += INT16SZ;
179 hp->qdcount = htons(1);
180 if (op == QUERY || data == NULL)
181 break;
182 /*
183 * Make an additional record for completion domain.
184 */
185 if ((ep - cp) < RRFIXEDSZ)
186 return (-1);
187 n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ,
188 dnptrs, lastdnptr);
189 if (n < 0)
190 return (-1);
191 cp += n;
192 ns_put16(T_NULL, cp);
193 cp += INT16SZ;
194 ns_put16(class, cp);
195 cp += INT16SZ;
196 ns_put32(0, cp);
197 cp += INT32SZ;
198 ns_put16(0, cp);
199 cp += INT16SZ;
200 hp->arcount = htons(1);
201 break;
202
203 case IQUERY:
204 /*
205 * Initialize answer section
206 */
207 if (ep - cp < 1 + RRFIXEDSZ + datalen)
208 return (-1);
209 *cp++ = '\0'; /*%< no domain name */
210 ns_put16(type, cp);
211 cp += INT16SZ;
212 ns_put16(class, cp);
213 cp += INT16SZ;
214 ns_put32(0, cp);
215 cp += INT32SZ;
216 ns_put16(datalen, cp);
217 cp += INT16SZ;
218 if (datalen) {
219 memcpy(cp, data, datalen);
220 cp += datalen;
221 }
222 hp->ancount = htons(1);
223 break;
224
225 default:
226 return (-1);
227 }
228 return (cp - buf);
229 }
230
231 #ifdef RES_USE_EDNS0
232 /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
233
234 int
res_nopt(res_state statp,int n0,u_char * buf,int buflen,int anslen)235 res_nopt(res_state statp,
236 int n0, /*%< current offset in buffer */
237 u_char *buf, /*%< buffer to put query */
238 int buflen, /*%< size of buffer */
239 int anslen) /*%< UDP answer buffer size */
240 {
241 register HEADER *hp;
242 register u_char *cp, *ep;
243 u_int16_t flags = 0;
244
245 #ifdef DEBUG
246 if ((statp->options & RES_DEBUG) != 0U)
247 printf(";; res_nopt()\n");
248 #endif
249
250 hp = (HEADER *) buf;
251 cp = buf + n0;
252 ep = buf + buflen;
253
254 if ((ep - cp) < 1 + RRFIXEDSZ)
255 return (-1);
256
257 *cp++ = 0; /*%< "." */
258 ns_put16(ns_t_opt, cp); /*%< TYPE */
259 cp += INT16SZ;
260 ns_put16(anslen & 0xffff, cp); /*%< CLASS = UDP payload size */
261 cp += INT16SZ;
262 *cp++ = NOERROR; /*%< extended RCODE */
263 *cp++ = 0; /*%< EDNS version */
264
265 if (statp->options & RES_USE_DNSSEC) {
266 #ifdef DEBUG
267 if (statp->options & RES_DEBUG)
268 printf(";; res_opt()... ENDS0 DNSSEC\n");
269 #endif
270 flags |= NS_OPT_DNSSEC_OK;
271 }
272 ns_put16(flags, cp);
273 cp += INT16SZ;
274
275 ns_put16(0U, cp); /*%< RDLEN */
276 cp += INT16SZ;
277
278 hp->arcount = htons(ntohs(hp->arcount) + 1);
279
280 return (cp - buf);
281 }
282
283 /*
284 * Construct variable data (RDATA) block for OPT psuedo-RR, append it
285 * to the buffer, then update the RDLEN field (previously set to zero by
286 * res_nopt()) with the new RDATA length.
287 */
288 int
res_nopt_rdata(res_state statp,int n0,u_char * buf,int buflen,u_char * rdata,u_short code,u_short len,u_char * data)289 res_nopt_rdata(res_state statp,
290 int n0, /*%< current offset in buffer */
291 u_char *buf, /*%< buffer to put query */
292 int buflen, /*%< size of buffer */
293 u_char *rdata, /*%< ptr to start of opt rdata */
294 u_short code, /*%< OPTION-CODE */
295 u_short len, /*%< OPTION-LENGTH */
296 u_char *data) /*%< OPTION_DATA */
297 {
298 register u_char *cp, *ep;
299
300 #ifdef DEBUG
301 if ((statp->options & RES_DEBUG) != 0U)
302 printf(";; res_nopt_rdata()\n");
303 #endif
304
305 cp = buf + n0;
306 ep = buf + buflen;
307
308 if ((ep - cp) < (4 + len))
309 return (-1);
310
311 if (rdata < (buf + 2) || rdata >= ep)
312 return (-1);
313
314 ns_put16(code, cp);
315 cp += INT16SZ;
316
317 ns_put16(len, cp);
318 cp += INT16SZ;
319
320 memcpy(cp, data, len);
321 cp += len;
322
323 len = cp - rdata;
324 ns_put16(len, rdata - 2); /* Update RDLEN field */
325
326 return (cp - buf);
327 }
328 #endif
329
330 #ifdef SUNW_CONFCHECK
331
332 /*
333 * Time out quickly if there is no /etc/resolv.conf and a TCP connection
334 * to the local DNS server fails.
335 */
_confcheck(res_state statp)336 static int _confcheck(res_state statp)
337 {
338 int ns;
339 struct stat rc_stat;
340 struct sockaddr_in ns_sin;
341
342 /* First, we check to see if /etc/resolv.conf exists.
343 * If it doesn't, then it is likely that the localhost is
344 * the nameserver.
345 */
346 if (stat(_PATH_RESCONF, &rc_stat) == -1 && errno == ENOENT) {
347
348 /* Next, we check to see if _res.nsaddr is set to loopback.
349 * If it isn't, it has been altered by the application
350 * explicitly and we then want to bail with success.
351 */
352 if (statp->nsaddr.sin_addr.S_un.S_addr ==
353 htonl(INADDR_LOOPBACK)) {
354
355 /* Lastly, we try to connect to the TCP port of the
356 * nameserver. If this fails, then we know that
357 * DNS is misconfigured and we can quickly exit.
358 */
359 ns = socket(AF_INET, SOCK_STREAM, 0);
360 IN_SET_LOOPBACK_ADDR(&ns_sin);
361 ns_sin.sin_port = htons(NAMESERVER_PORT);
362 if (connect(ns, (struct sockaddr *) &ns_sin,
363 sizeof ns_sin) == -1) {
364 close(ns);
365 return(-1);
366 }
367 else {
368 close(ns);
369
370 return(0);
371 }
372 }
373
374 return(0);
375 }
376
377 return (0);
378 }
379 #endif /* SUNW_CONFCHECK */
380
381 /*! \file */
382