xref: /freebsd/lib/libc/resolv/res_mkupdate.c (revision d9f0ce31900a48d1a2bfc1c8c86f79d1e831451a)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1996-1999 by Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and 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
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /*! \file
19  * \brief
20  * Based on the Dynamic DNS reference implementation by Viraj Bais
21  * <viraj_bais@ccm.fm.intel.com>
22  */
23 
24 #if !defined(lint) && !defined(SABER)
25 static const char rcsid[] = "$Id: res_mkupdate.c,v 1.10 2008/12/11 09:59:00 marka Exp $";
26 #endif /* not lint */
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "port_before.h"
31 
32 #include <sys/types.h>
33 #include <sys/param.h>
34 
35 #include <netinet/in.h>
36 #include <arpa/nameser.h>
37 #include <arpa/inet.h>
38 
39 #include <errno.h>
40 #include <limits.h>
41 #include <netdb.h>
42 #include <resolv.h>
43 #include <res_update.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <ctype.h>
49 
50 #ifdef _LIBC
51 #include <isc/list.h>
52 #endif
53 
54 #include "port_after.h"
55 
56 /* Options.  Leave them on. */
57 #ifndef	DEBUG
58 #define	DEBUG
59 #endif
60 #define MAXPORT 1024
61 
62 static int getnum_str(u_char **, u_char *);
63 static int gethexnum_str(u_char **, u_char *);
64 static int getword_str(char *, int, u_char **, u_char *);
65 static int getstr_str(char *, int, u_char **, u_char *);
66 
67 #define ShrinkBuffer(x)  if ((buflen -= x) < 0) return (-2);
68 
69 /* Forward. */
70 
71 #ifdef _LIBC
72 static
73 #endif
74 int res_protocolnumber(const char *);
75 #ifdef _LIBC
76 static
77 #endif
78 int res_servicenumber(const char *);
79 
80 /*%
81  * Form update packets.
82  * Returns the size of the resulting packet if no error
83  *
84  * On error,
85  *	returns
86  *\li              -1 if error in reading a word/number in rdata
87  *		   portion for update packets
88  *\li		-2 if length of buffer passed is insufficient
89  *\li		-3 if zone section is not the first section in
90  *		   the linked list, or section order has a problem
91  *\li		-4 on a number overflow
92  *\li		-5 unknown operation or no records
93  */
94 int
95 res_nmkupdate(res_state statp, ns_updrec *rrecp_in, u_char *buf, int buflen) {
96 	ns_updrec *rrecp_start = rrecp_in;
97 	HEADER *hp;
98 	u_char *cp, *sp2, *startp, *endp;
99 	int n, i, soanum, multiline;
100 	ns_updrec *rrecp;
101 	struct in_addr ina;
102 	struct in6_addr in6a;
103         char buf2[MAXDNAME];
104 	u_char buf3[MAXDNAME];
105 	int section, numrrs = 0, counts[ns_s_max];
106 	u_int16_t rtype, rclass;
107 	u_int32_t n1, rttl;
108 	u_char *dnptrs[20], **dpp, **lastdnptr;
109 #ifndef _LIBC
110 	int siglen;
111 #endif
112 	int keylen, certlen;
113 
114 	/*
115 	 * Initialize header fields.
116 	 */
117 	if ((buf == NULL) || (buflen < HFIXEDSZ))
118 		return (-1);
119 	memset(buf, 0, HFIXEDSZ);
120 	hp = (HEADER *) buf;
121 	statp->id = res_nrandomid(statp);
122 	hp->id = htons(statp->id);
123 	hp->opcode = ns_o_update;
124 	hp->rcode = NOERROR;
125 	cp = buf + HFIXEDSZ;
126 	buflen -= HFIXEDSZ;
127 	dpp = dnptrs;
128 	*dpp++ = buf;
129 	*dpp++ = NULL;
130 	lastdnptr = dnptrs + nitems(dnptrs);
131 
132 	if (rrecp_start == NULL)
133 		return (-5);
134 	else if (rrecp_start->r_section != S_ZONE)
135 		return (-3);
136 
137 	memset(counts, 0, sizeof counts);
138 	for (rrecp = rrecp_start; rrecp; rrecp = NEXT(rrecp, r_glink)) {
139 		numrrs++;
140                 section = rrecp->r_section;
141 		if (section < 0 || section >= ns_s_max)
142 			return (-1);
143 		counts[section]++;
144 		for (i = section + 1; i < ns_s_max; i++)
145 			if (counts[i])
146 				return (-3);
147 		rtype = rrecp->r_type;
148 		rclass = rrecp->r_class;
149 		rttl = rrecp->r_ttl;
150 		/* overload class and type */
151 		if (section == S_PREREQ) {
152 			rttl = 0;
153 			switch (rrecp->r_opcode) {
154 			case YXDOMAIN:
155 				rclass = C_ANY;
156 				rtype = T_ANY;
157 				rrecp->r_size = 0;
158 				break;
159 			case NXDOMAIN:
160 				rclass = C_NONE;
161 				rtype = T_ANY;
162 				rrecp->r_size = 0;
163 				break;
164 			case NXRRSET:
165 				rclass = C_NONE;
166 				rrecp->r_size = 0;
167 				break;
168 			case YXRRSET:
169 				if (rrecp->r_size == 0)
170 					rclass = C_ANY;
171 				break;
172 			default:
173 				fprintf(stderr,
174 					"res_mkupdate: incorrect opcode: %d\n",
175 					rrecp->r_opcode);
176 				fflush(stderr);
177 				return (-1);
178 			}
179 		} else if (section == S_UPDATE) {
180 			switch (rrecp->r_opcode) {
181 			case DELETE:
182 				rclass = rrecp->r_size == 0 ? C_ANY : C_NONE;
183 				break;
184 			case ADD:
185 				break;
186 			default:
187 				fprintf(stderr,
188 					"res_mkupdate: incorrect opcode: %d\n",
189 					rrecp->r_opcode);
190 				fflush(stderr);
191 				return (-1);
192 			}
193 		}
194 
195 		/*
196 		 * XXX	appending default domain to owner name is omitted,
197 		 *	fqdn must be provided
198 		 */
199 		if ((n = dn_comp(rrecp->r_dname, cp, buflen, dnptrs,
200 				 lastdnptr)) < 0)
201 			return (-1);
202 		cp += n;
203 		ShrinkBuffer(n + 2*INT16SZ);
204 		PUTSHORT(rtype, cp);
205 		PUTSHORT(rclass, cp);
206 		if (section == S_ZONE) {
207 			if (numrrs != 1 || rrecp->r_type != T_SOA)
208 				return (-3);
209 			continue;
210 		}
211 		ShrinkBuffer(INT32SZ + INT16SZ);
212 		PUTLONG(rttl, cp);
213 		sp2 = cp;  /*%< save pointer to length byte */
214 		cp += INT16SZ;
215 		if (rrecp->r_size == 0) {
216 			if (section == S_UPDATE && rclass != C_ANY)
217 				return (-1);
218 			else {
219 				PUTSHORT(0, sp2);
220 				continue;
221 			}
222 		}
223 		startp = rrecp->r_data;
224 		endp = startp + rrecp->r_size - 1;
225 		/* XXX this should be done centrally. */
226 		switch (rrecp->r_type) {
227 		case T_A:
228 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
229 				return (-1);
230 			if (!inet_aton(buf2, &ina))
231 				return (-1);
232 			n1 = ntohl(ina.s_addr);
233 			ShrinkBuffer(INT32SZ);
234 			PUTLONG(n1, cp);
235 			break;
236 		case T_CNAME:
237 		case T_MB:
238 		case T_MG:
239 		case T_MR:
240 		case T_NS:
241 		case T_PTR:
242 		case ns_t_dname:
243 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
244 				return (-1);
245 			n = dn_comp(buf2, cp, buflen, dnptrs, lastdnptr);
246 			if (n < 0)
247 				return (-1);
248 			cp += n;
249 			ShrinkBuffer(n);
250 			break;
251 		case T_MINFO:
252 		case T_SOA:
253 		case T_RP:
254 			for (i = 0; i < 2; i++) {
255 				if (!getword_str(buf2, sizeof buf2, &startp,
256 						 endp))
257 				return (-1);
258 				n = dn_comp(buf2, cp, buflen,
259 					    dnptrs, lastdnptr);
260 				if (n < 0)
261 					return (-1);
262 				cp += n;
263 				ShrinkBuffer(n);
264 			}
265 			if (rrecp->r_type == T_SOA) {
266 				ShrinkBuffer(5 * INT32SZ);
267 				while (isspace(*startp) || !*startp)
268 					startp++;
269 				if (*startp == '(') {
270 					multiline = 1;
271 					startp++;
272 				} else
273 					multiline = 0;
274 				/* serial, refresh, retry, expire, minimum */
275 				for (i = 0; i < 5; i++) {
276 					soanum = getnum_str(&startp, endp);
277 					if (soanum < 0)
278 						return (-1);
279 					PUTLONG(soanum, cp);
280 				}
281 				if (multiline) {
282 					while (isspace(*startp) || !*startp)
283 						startp++;
284 					if (*startp != ')')
285 						return (-1);
286 				}
287 			}
288 			break;
289 		case T_MX:
290 		case T_AFSDB:
291 		case T_RT:
292 			n = getnum_str(&startp, endp);
293 			if (n < 0)
294 				return (-1);
295 			ShrinkBuffer(INT16SZ);
296 			PUTSHORT(n, cp);
297 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
298 				return (-1);
299 			n = dn_comp(buf2, cp, buflen, dnptrs, lastdnptr);
300 			if (n < 0)
301 				return (-1);
302 			cp += n;
303 			ShrinkBuffer(n);
304 			break;
305 		case T_SRV:
306 			n = getnum_str(&startp, endp);
307 			if (n < 0)
308 				return (-1);
309 			ShrinkBuffer(INT16SZ);
310 			PUTSHORT(n, cp);
311 
312 			n = getnum_str(&startp, endp);
313 			if (n < 0)
314 				return (-1);
315 			ShrinkBuffer(INT16SZ);
316 			PUTSHORT(n, cp);
317 
318 			n = getnum_str(&startp, endp);
319 			if (n < 0)
320 				return (-1);
321 			ShrinkBuffer(INT16SZ);
322 			PUTSHORT(n, cp);
323 
324 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
325 				return (-1);
326 			n = dn_comp(buf2, cp, buflen, NULL, NULL);
327 			if (n < 0)
328 				return (-1);
329 			cp += n;
330 			ShrinkBuffer(n);
331 			break;
332 		case T_PX:
333 			n = getnum_str(&startp, endp);
334 			if (n < 0)
335 				return (-1);
336 			PUTSHORT(n, cp);
337 			ShrinkBuffer(INT16SZ);
338 			for (i = 0; i < 2; i++) {
339 				if (!getword_str(buf2, sizeof buf2, &startp,
340 						 endp))
341 					return (-1);
342 				n = dn_comp(buf2, cp, buflen, dnptrs,
343 					    lastdnptr);
344 				if (n < 0)
345 					return (-1);
346 				cp += n;
347 				ShrinkBuffer(n);
348 			}
349 			break;
350 		case T_WKS: {
351 			char bm[MAXPORT/8];
352 			unsigned int maxbm = 0;
353 
354 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
355 				return (-1);
356 			if (!inet_aton(buf2, &ina))
357 				return (-1);
358 			n1 = ntohl(ina.s_addr);
359 			ShrinkBuffer(INT32SZ);
360 			PUTLONG(n1, cp);
361 
362 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
363 				return (-1);
364 			if ((i = res_protocolnumber(buf2)) < 0)
365 				return (-1);
366 			ShrinkBuffer(1);
367 			*cp++ = i & 0xff;
368 
369 			for (i = 0; i < MAXPORT/8 ; i++)
370 				bm[i] = 0;
371 
372 			while (getword_str(buf2, sizeof buf2, &startp, endp)) {
373 				if ((n = res_servicenumber(buf2)) <= 0)
374 					return (-1);
375 
376 				if (n < MAXPORT) {
377 					bm[n/8] |= (0x80>>(n%8));
378 					if ((unsigned)n > maxbm)
379 						maxbm = n;
380 				} else
381 					return (-1);
382 			}
383 			maxbm = maxbm/8 + 1;
384 			ShrinkBuffer(maxbm);
385 			memcpy(cp, bm, maxbm);
386 			cp += maxbm;
387 			break;
388 		}
389 		case T_HINFO:
390 			for (i = 0; i < 2; i++) {
391 				if ((n = getstr_str(buf2, sizeof buf2,
392 						&startp, endp)) < 0)
393 					return (-1);
394 				if (n > 255)
395 					return (-1);
396 				ShrinkBuffer(n+1);
397 				*cp++ = n;
398 				memcpy(cp, buf2, n);
399 				cp += n;
400 			}
401 			break;
402 		case T_TXT:
403 			for (;;) {
404 				if ((n = getstr_str(buf2, sizeof buf2,
405 						&startp, endp)) < 0) {
406 					if (cp != (sp2 + INT16SZ))
407 						break;
408 					return (-1);
409 				}
410 				if (n > 255)
411 					return (-1);
412 				ShrinkBuffer(n+1);
413 				*cp++ = n;
414 				memcpy(cp, buf2, n);
415 				cp += n;
416 			}
417 			break;
418 		case T_X25:
419 			/* RFC1183 */
420 			if ((n = getstr_str(buf2, sizeof buf2, &startp,
421 					 endp)) < 0)
422 				return (-1);
423 			if (n > 255)
424 				return (-1);
425 			ShrinkBuffer(n+1);
426 			*cp++ = n;
427 			memcpy(cp, buf2, n);
428 			cp += n;
429 			break;
430 		case T_ISDN:
431 			/* RFC1183 */
432 			if ((n = getstr_str(buf2, sizeof buf2, &startp,
433 					 endp)) < 0)
434 				return (-1);
435 			if ((n > 255) || (n == 0))
436 				return (-1);
437 			ShrinkBuffer(n+1);
438 			*cp++ = n;
439 			memcpy(cp, buf2, n);
440 			cp += n;
441 			if ((n = getstr_str(buf2, sizeof buf2, &startp,
442 					 endp)) < 0)
443 				n = 0;
444 			if (n > 255)
445 				return (-1);
446 			ShrinkBuffer(n+1);
447 			*cp++ = n;
448 			memcpy(cp, buf2, n);
449 			cp += n;
450 			break;
451 		case T_NSAP:
452 			if ((n = inet_nsap_addr((char *)startp, (u_char *)buf2, sizeof(buf2))) != 0) {
453 				ShrinkBuffer(n);
454 				memcpy(cp, buf2, n);
455 				cp += n;
456 			} else {
457 				return (-1);
458 			}
459 			break;
460 		case T_LOC:
461 			if ((n = loc_aton((char *)startp, (u_char *)buf2)) != 0) {
462 				ShrinkBuffer(n);
463 				memcpy(cp, buf2, n);
464 				cp += n;
465 			} else
466 				return (-1);
467 			break;
468 		case ns_t_sig:
469 #ifdef _LIBC
470 			return (-1);
471 #else
472 		    {
473 			int sig_type, success, dateerror;
474 			u_int32_t exptime, timesigned;
475 
476 			/* type */
477 			if ((n = getword_str(buf2, sizeof buf2,
478 					     &startp, endp)) < 0)
479 				return (-1);
480 			sig_type = sym_ston(__p_type_syms, buf2, &success);
481 			if (!success || sig_type == ns_t_any)
482 				return (-1);
483 			ShrinkBuffer(INT16SZ);
484 			PUTSHORT(sig_type, cp);
485 			/* alg */
486 			n = getnum_str(&startp, endp);
487 			if (n < 0)
488 				return (-1);
489 			ShrinkBuffer(1);
490 			*cp++ = n;
491 			/* labels */
492 			n = getnum_str(&startp, endp);
493 			if (n <= 0 || n > 255)
494 				return (-1);
495 			ShrinkBuffer(1);
496 			*cp++ = n;
497 			/* ottl  & expire */
498 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
499 				return (-1);
500 			exptime = ns_datetosecs(buf2, &dateerror);
501 			if (!dateerror) {
502 				ShrinkBuffer(INT32SZ);
503 				PUTLONG(rttl, cp);
504 			}
505 			else {
506 				char *ulendp;
507 				u_int32_t ottl;
508 
509 				errno = 0;
510 				ottl = strtoul(buf2, &ulendp, 10);
511 				if (errno != 0 ||
512 				    (ulendp != NULL && *ulendp != '\0'))
513 					return (-1);
514 				ShrinkBuffer(INT32SZ);
515 				PUTLONG(ottl, cp);
516 				if (!getword_str(buf2, sizeof buf2, &startp,
517 						 endp))
518 					return (-1);
519 				exptime = ns_datetosecs(buf2, &dateerror);
520 				if (dateerror)
521 					return (-1);
522 			}
523 			/* expire */
524 			ShrinkBuffer(INT32SZ);
525 			PUTLONG(exptime, cp);
526 			/* timesigned */
527 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
528 				return (-1);
529 			timesigned = ns_datetosecs(buf2, &dateerror);
530 			if (!dateerror) {
531 				ShrinkBuffer(INT32SZ);
532 				PUTLONG(timesigned, cp);
533 			}
534 			else
535 				return (-1);
536 			/* footprint */
537 			n = getnum_str(&startp, endp);
538 			if (n < 0)
539 				return (-1);
540 			ShrinkBuffer(INT16SZ);
541 			PUTSHORT(n, cp);
542 			/* signer name */
543 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
544 				return (-1);
545 			n = dn_comp(buf2, cp, buflen, dnptrs, lastdnptr);
546 			if (n < 0)
547 				return (-1);
548 			cp += n;
549 			ShrinkBuffer(n);
550 			/* sig */
551 			if ((n = getword_str(buf2, sizeof buf2,
552 					     &startp, endp)) < 0)
553 				return (-1);
554 			siglen = b64_pton(buf2, buf3, sizeof(buf3));
555 			if (siglen < 0)
556 				return (-1);
557 			ShrinkBuffer(siglen);
558 			memcpy(cp, buf3, siglen);
559 			cp += siglen;
560 			break;
561 		    }
562 #endif
563 		case ns_t_key:
564 			/* flags */
565 			n = gethexnum_str(&startp, endp);
566 			if (n < 0)
567 				return (-1);
568 			ShrinkBuffer(INT16SZ);
569 			PUTSHORT(n, cp);
570 			/* proto */
571 			n = getnum_str(&startp, endp);
572 			if (n < 0)
573 				return (-1);
574 			ShrinkBuffer(1);
575 			*cp++ = n;
576 			/* alg */
577 			n = getnum_str(&startp, endp);
578 			if (n < 0)
579 				return (-1);
580 			ShrinkBuffer(1);
581 			*cp++ = n;
582 			/* key */
583 			if ((n = getword_str(buf2, sizeof buf2,
584 					     &startp, endp)) < 0)
585 				return (-1);
586 			keylen = b64_pton(buf2, buf3, sizeof(buf3));
587 			if (keylen < 0)
588 				return (-1);
589 			ShrinkBuffer(keylen);
590 			memcpy(cp, buf3, keylen);
591 			cp += keylen;
592 			break;
593 		case ns_t_nxt:
594 		    {
595 			int success, nxt_type;
596 			u_char data[32];
597 			int maxtype;
598 
599 			/* next name */
600 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
601 				return (-1);
602 			n = dn_comp(buf2, cp, buflen, NULL, NULL);
603 			if (n < 0)
604 				return (-1);
605 			cp += n;
606 			ShrinkBuffer(n);
607 			maxtype = 0;
608 			memset(data, 0, sizeof data);
609 			for (;;) {
610 				if (!getword_str(buf2, sizeof buf2, &startp,
611 						 endp))
612 					break;
613 				nxt_type = sym_ston(__p_type_syms, buf2,
614 						    &success);
615 				if (!success || !ns_t_rr_p(nxt_type))
616 					return (-1);
617 				NS_NXT_BIT_SET(nxt_type, data);
618 				if (nxt_type > maxtype)
619 					maxtype = nxt_type;
620 			}
621 			n = maxtype/NS_NXT_BITS+1;
622 			ShrinkBuffer(n);
623 			memcpy(cp, data, n);
624 			cp += n;
625 			break;
626 		    }
627 		case ns_t_cert:
628 			/* type */
629 			n = getnum_str(&startp, endp);
630 			if (n < 0)
631 				return (-1);
632 			ShrinkBuffer(INT16SZ);
633 			PUTSHORT(n, cp);
634 			/* key tag */
635 			n = getnum_str(&startp, endp);
636 			if (n < 0)
637 				return (-1);
638 			ShrinkBuffer(INT16SZ);
639 			PUTSHORT(n, cp);
640 			/* alg */
641 			n = getnum_str(&startp, endp);
642 			if (n < 0)
643 				return (-1);
644 			ShrinkBuffer(1);
645 			*cp++ = n;
646 			/* cert */
647 			if ((n = getword_str(buf2, sizeof buf2,
648 					     &startp, endp)) < 0)
649 				return (-1);
650 			certlen = b64_pton(buf2, buf3, sizeof(buf3));
651 			if (certlen < 0)
652 				return (-1);
653 			ShrinkBuffer(certlen);
654 			memcpy(cp, buf3, certlen);
655 			cp += certlen;
656 			break;
657 		case ns_t_aaaa:
658 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
659 				return (-1);
660 			if (inet_pton(AF_INET6, buf2, &in6a) <= 0)
661 				return (-1);
662 			ShrinkBuffer(NS_IN6ADDRSZ);
663 			memcpy(cp, &in6a, NS_IN6ADDRSZ);
664 			cp += NS_IN6ADDRSZ;
665 			break;
666 		case ns_t_naptr:
667 			/* Order Preference Flags Service Replacement Regexp */
668 			/* Order */
669 			n = getnum_str(&startp, endp);
670 			if (n < 0 || n > 65535)
671 				return (-1);
672 			ShrinkBuffer(INT16SZ);
673 			PUTSHORT(n, cp);
674 			/* Preference */
675 			n = getnum_str(&startp, endp);
676 			if (n < 0 || n > 65535)
677 				return (-1);
678 			ShrinkBuffer(INT16SZ);
679 			PUTSHORT(n, cp);
680 			/* Flags */
681 			if ((n = getstr_str(buf2, sizeof buf2,
682 					&startp, endp)) < 0) {
683 				return (-1);
684 			}
685 			if (n > 255)
686 				return (-1);
687 			ShrinkBuffer(n+1);
688 			*cp++ = n;
689 			memcpy(cp, buf2, n);
690 			cp += n;
691 			/* Service Classes */
692 			if ((n = getstr_str(buf2, sizeof buf2,
693 					&startp, endp)) < 0) {
694 				return (-1);
695 			}
696 			if (n > 255)
697 				return (-1);
698 			ShrinkBuffer(n+1);
699 			*cp++ = n;
700 			memcpy(cp, buf2, n);
701 			cp += n;
702 			/* Pattern */
703 			if ((n = getstr_str(buf2, sizeof buf2,
704 					&startp, endp)) < 0) {
705 				return (-1);
706 			}
707 			if (n > 255)
708 				return (-1);
709 			ShrinkBuffer(n+1);
710 			*cp++ = n;
711 			memcpy(cp, buf2, n);
712 			cp += n;
713 			/* Replacement */
714 			if (!getword_str(buf2, sizeof buf2, &startp, endp))
715 				return (-1);
716 			n = dn_comp(buf2, cp, buflen, NULL, NULL);
717 			if (n < 0)
718 				return (-1);
719 			cp += n;
720 			ShrinkBuffer(n);
721 			break;
722 		default:
723 			return (-1);
724 		} /*switch*/
725 		n = (u_int16_t)((cp - sp2) - INT16SZ);
726 		PUTSHORT(n, sp2);
727 	} /*for*/
728 
729 	hp->qdcount = htons(counts[0]);
730 	hp->ancount = htons(counts[1]);
731 	hp->nscount = htons(counts[2]);
732 	hp->arcount = htons(counts[3]);
733 	return (cp - buf);
734 }
735 
736 /*%
737  * Get a whitespace delimited word from a string (not file)
738  * into buf. modify the start pointer to point after the
739  * word in the string.
740  */
741 static int
742 getword_str(char *buf, int size, u_char **startpp, u_char *endp) {
743         char *cp;
744         int c;
745 
746         for (cp = buf; *startpp <= endp; ) {
747                 c = **startpp;
748                 if (isspace(c) || c == '\0') {
749                         if (cp != buf) /*%< trailing whitespace */
750                                 break;
751                         else { /*%< leading whitespace */
752                                 (*startpp)++;
753                                 continue;
754                         }
755                 }
756                 (*startpp)++;
757                 if (cp >= buf+size-1)
758                         break;
759                 *cp++ = (u_char)c;
760         }
761         *cp = '\0';
762         return (cp != buf);
763 }
764 
765 /*%
766  * get a white spae delimited string from memory.  Process quoted strings
767  * and \\DDD escapes.  Return length or -1 on error.  Returned string may
768  * contain nulls.
769  */
770 static char digits[] = "0123456789";
771 static int
772 getstr_str(char *buf, int size, u_char **startpp, u_char *endp) {
773         char *cp;
774         int c, c1 = 0;
775 	int inquote = 0;
776 	int seen_quote = 0;
777 	int escape = 0;
778 	int dig = 0;
779 
780 	for (cp = buf; *startpp <= endp; ) {
781                 if ((c = **startpp) == '\0')
782 			break;
783 		/* leading white space */
784 		if ((cp == buf) && !seen_quote && isspace(c)) {
785 			(*startpp)++;
786 			continue;
787 		}
788 
789 		switch (c) {
790 		case '\\':
791 			if (!escape)  {
792 				escape = 1;
793 				dig = 0;
794 				c1 = 0;
795 				(*startpp)++;
796 				continue;
797 			}
798 			goto do_escape;
799 		case '"':
800 			if (!escape) {
801 				inquote = !inquote;
802 				seen_quote = 1;
803 				(*startpp)++;
804 				continue;
805 			}
806 			/* fall through */
807 		default:
808 		do_escape:
809 			if (escape) {
810 				switch (c) {
811 				case '0':
812 				case '1':
813 				case '2':
814 				case '3':
815 				case '4':
816 				case '5':
817 				case '6':
818 				case '7':
819 				case '8':
820 				case '9':
821 					c1 = c1 * 10 +
822 						(strchr(digits, c) - digits);
823 
824 					if (++dig == 3) {
825 						c = c1 &0xff;
826 						break;
827 					}
828 					(*startpp)++;
829 					continue;
830 				}
831 				escape = 0;
832 			} else if (!inquote && isspace(c))
833 				goto done;
834 			if (cp >= buf+size-1)
835 				goto done;
836 			*cp++ = (u_char)c;
837 			(*startpp)++;
838 		}
839 	}
840  done:
841 	*cp = '\0';
842 	return ((cp == buf)?  (seen_quote? 0: -1): (cp - buf));
843 }
844 
845 /*%
846  * Get a whitespace delimited base 16 number from a string (not file) into buf
847  * update the start pointer to point after the number in the string.
848  */
849 static int
850 gethexnum_str(u_char **startpp, u_char *endp) {
851         int c, n;
852         int seendigit = 0;
853         int m = 0;
854 
855 	if (*startpp + 2 >= endp || strncasecmp((char *)*startpp, "0x", 2) != 0)
856 		return getnum_str(startpp, endp);
857 	(*startpp)+=2;
858         for (n = 0; *startpp <= endp; ) {
859                 c = **startpp;
860                 if (isspace(c) || c == '\0') {
861                         if (seendigit) /*%< trailing whitespace */
862                                 break;
863                         else { /*%< leading whitespace */
864                                 (*startpp)++;
865                                 continue;
866                         }
867                 }
868                 if (c == ';') {
869                         while ((*startpp <= endp) &&
870 			       ((c = **startpp) != '\n'))
871 					(*startpp)++;
872                         if (seendigit)
873                                 break;
874                         continue;
875                 }
876                 if (!isxdigit(c)) {
877                         if (c == ')' && seendigit) {
878                                 (*startpp)--;
879                                 break;
880                         }
881 			return (-1);
882                 }
883                 (*startpp)++;
884 		if (isdigit(c))
885 	                n = n * 16 + (c - '0');
886 		else
887 			n = n * 16 + (tolower(c) - 'a' + 10);
888                 seendigit = 1;
889         }
890         return (n + m);
891 }
892 
893 /*%
894  * Get a whitespace delimited base 10 number from a string (not file) into buf
895  * update the start pointer to point after the number in the string.
896  */
897 static int
898 getnum_str(u_char **startpp, u_char *endp) {
899         int c, n;
900         int seendigit = 0;
901         int m = 0;
902 
903         for (n = 0; *startpp <= endp; ) {
904                 c = **startpp;
905                 if (isspace(c) || c == '\0') {
906                         if (seendigit) /*%< trailing whitespace */
907                                 break;
908                         else { /*%< leading whitespace */
909                                 (*startpp)++;
910                                 continue;
911                         }
912                 }
913                 if (c == ';') {
914                         while ((*startpp <= endp) &&
915 			       ((c = **startpp) != '\n'))
916 					(*startpp)++;
917                         if (seendigit)
918                                 break;
919                         continue;
920                 }
921                 if (!isdigit(c)) {
922                         if (c == ')' && seendigit) {
923                                 (*startpp)--;
924                                 break;
925                         }
926 			return (-1);
927                 }
928                 (*startpp)++;
929                 n = n * 10 + (c - '0');
930                 seendigit = 1;
931         }
932         return (n + m);
933 }
934 
935 /*%
936  * Allocate a resource record buffer & save rr info.
937  */
938 ns_updrec *
939 res_mkupdrec(int section, const char *dname,
940 	     u_int class, u_int type, u_long ttl) {
941 	ns_updrec *rrecp = (ns_updrec *)calloc(1, sizeof(ns_updrec));
942 
943 	if (!rrecp || !(rrecp->r_dname = strdup(dname))) {
944 		if (rrecp)
945 			free((char *)rrecp);
946 		return (NULL);
947 	}
948 	INIT_LINK(rrecp, r_link);
949 	INIT_LINK(rrecp, r_glink);
950  	rrecp->r_class = (ns_class)class;
951 	rrecp->r_type = (ns_type)type;
952 	rrecp->r_ttl = ttl;
953 	rrecp->r_section = (ns_sect)section;
954 	return (rrecp);
955 }
956 
957 /*%
958  * Free a resource record buffer created by res_mkupdrec.
959  */
960 void
961 res_freeupdrec(ns_updrec *rrecp) {
962 	/* Note: freeing r_dp is the caller's responsibility. */
963 	if (rrecp->r_dname != NULL)
964 		free(rrecp->r_dname);
965 	free(rrecp);
966 }
967 
968 struct valuelist {
969 	struct valuelist *	next;
970 	struct valuelist *	prev;
971 	char *			name;
972 	char *			proto;
973 	int			port;
974 };
975 static struct valuelist *servicelist, *protolist;
976 
977 static void
978 res_buildservicelist(void) {
979 	struct servent *sp;
980 	struct valuelist *slp;
981 
982 #ifdef MAYBE_HESIOD
983 	setservent(0);
984 #else
985 	setservent(1);
986 #endif
987 	while ((sp = getservent()) != NULL) {
988 		slp = (struct valuelist *)malloc(sizeof(struct valuelist));
989 		if (!slp)
990 			break;
991 		slp->name = strdup(sp->s_name);
992 		slp->proto = strdup(sp->s_proto);
993 		if ((slp->name == NULL) || (slp->proto == NULL)) {
994 			if (slp->name) free(slp->name);
995 			if (slp->proto) free(slp->proto);
996 			free(slp);
997 			break;
998 		}
999 		slp->port = ntohs((u_int16_t)sp->s_port);  /*%< host byt order */
1000 		slp->next = servicelist;
1001 		slp->prev = NULL;
1002 		if (servicelist)
1003 			servicelist->prev = slp;
1004 		servicelist = slp;
1005 	}
1006 	endservent();
1007 }
1008 
1009 #ifndef _LIBC
1010 void
1011 res_destroyservicelist() {
1012 	struct valuelist *slp, *slp_next;
1013 
1014 	for (slp = servicelist; slp != NULL; slp = slp_next) {
1015 		slp_next = slp->next;
1016 		free(slp->name);
1017 		free(slp->proto);
1018 		free(slp);
1019 	}
1020 	servicelist = (struct valuelist *)0;
1021 }
1022 #endif
1023 
1024 #ifdef _LIBC
1025 static
1026 #endif
1027 void
1028 res_buildprotolist(void) {
1029 	struct protoent *pp;
1030 	struct valuelist *slp;
1031 
1032 #ifdef MAYBE_HESIOD
1033 	setprotoent(0);
1034 #else
1035 	setprotoent(1);
1036 #endif
1037 	while ((pp = getprotoent()) != NULL) {
1038 		slp = (struct valuelist *)malloc(sizeof(struct valuelist));
1039 		if (!slp)
1040 			break;
1041 		slp->name = strdup(pp->p_name);
1042 		if (slp->name == NULL) {
1043 			free(slp);
1044 			break;
1045 		}
1046 		slp->port = pp->p_proto;	/*%< host byte order */
1047 		slp->next = protolist;
1048 		slp->prev = NULL;
1049 		if (protolist)
1050 			protolist->prev = slp;
1051 		protolist = slp;
1052 	}
1053 	endprotoent();
1054 }
1055 
1056 #ifndef _LIBC
1057 void
1058 res_destroyprotolist(void) {
1059 	struct valuelist *plp, *plp_next;
1060 
1061 	for (plp = protolist; plp != NULL; plp = plp_next) {
1062 		plp_next = plp->next;
1063 		free(plp->name);
1064 		free(plp);
1065 	}
1066 	protolist = (struct valuelist *)0;
1067 }
1068 #endif
1069 
1070 static int
1071 findservice(const char *s, struct valuelist **list) {
1072 	struct valuelist *lp = *list;
1073 	int n;
1074 
1075 	for (; lp != NULL; lp = lp->next)
1076 		if (strcasecmp(lp->name, s) == 0) {
1077 			if (lp != *list) {
1078 				lp->prev->next = lp->next;
1079 				if (lp->next)
1080 					lp->next->prev = lp->prev;
1081 				(*list)->prev = lp;
1082 				lp->next = *list;
1083 				*list = lp;
1084 			}
1085 			return (lp->port);	/*%< host byte order */
1086 		}
1087 	if (sscanf(s, "%d", &n) != 1 || n <= 0)
1088 		n = -1;
1089 	return (n);
1090 }
1091 
1092 /*%
1093  * Convert service name or (ascii) number to int.
1094  */
1095 #ifdef _LIBC
1096 static
1097 #endif
1098 int
1099 res_servicenumber(const char *p) {
1100 	if (servicelist == (struct valuelist *)0)
1101 		res_buildservicelist();
1102 	return (findservice(p, &servicelist));
1103 }
1104 
1105 /*%
1106  * Convert protocol name or (ascii) number to int.
1107  */
1108 #ifdef _LIBC
1109 static
1110 #endif
1111 int
1112 res_protocolnumber(const char *p) {
1113 	if (protolist == (struct valuelist *)0)
1114 		res_buildprotolist();
1115 	return (findservice(p, &protolist));
1116 }
1117 
1118 #ifndef _LIBC
1119 static struct servent *
1120 cgetservbyport(u_int16_t port, const char *proto) {	/*%< Host byte order. */
1121 	struct valuelist **list = &servicelist;
1122 	struct valuelist *lp = *list;
1123 	static struct servent serv;
1124 
1125 	port = ntohs(port);
1126 	for (; lp != NULL; lp = lp->next) {
1127 		if (port != (u_int16_t)lp->port)	/*%< Host byte order. */
1128 			continue;
1129 		if (strcasecmp(lp->proto, proto) == 0) {
1130 			if (lp != *list) {
1131 				lp->prev->next = lp->next;
1132 				if (lp->next)
1133 					lp->next->prev = lp->prev;
1134 				(*list)->prev = lp;
1135 				lp->next = *list;
1136 				*list = lp;
1137 			}
1138 			serv.s_name = lp->name;
1139 			serv.s_port = htons((u_int16_t)lp->port);
1140 			serv.s_proto = lp->proto;
1141 			return (&serv);
1142 		}
1143 	}
1144 	return (0);
1145 }
1146 
1147 static struct protoent *
1148 cgetprotobynumber(int proto) {				/*%< Host byte order. */
1149 	struct valuelist **list = &protolist;
1150 	struct valuelist *lp = *list;
1151 	static struct protoent prot;
1152 
1153 	for (; lp != NULL; lp = lp->next)
1154 		if (lp->port == proto) {		/*%< Host byte order. */
1155 			if (lp != *list) {
1156 				lp->prev->next = lp->next;
1157 				if (lp->next)
1158 					lp->next->prev = lp->prev;
1159 				(*list)->prev = lp;
1160 				lp->next = *list;
1161 				*list = lp;
1162 			}
1163 			prot.p_name = lp->name;
1164 			prot.p_proto = lp->port;	/*%< Host byte order. */
1165 			return (&prot);
1166 		}
1167 	return (0);
1168 }
1169 
1170 const char *
1171 res_protocolname(int num) {
1172 	static char number[8];
1173 	struct protoent *pp;
1174 
1175 	if (protolist == (struct valuelist *)0)
1176 		res_buildprotolist();
1177 	pp = cgetprotobynumber(num);
1178 	if (pp == NULL)  {
1179 		(void) sprintf(number, "%d", num);
1180 		return (number);
1181 	}
1182 	return (pp->p_name);
1183 }
1184 
1185 const char *
1186 res_servicename(u_int16_t port, const char *proto) {	/*%< Host byte order. */
1187 	static char number[8];
1188 	struct servent *ss;
1189 
1190 	if (servicelist == (struct valuelist *)0)
1191 		res_buildservicelist();
1192 	ss = cgetservbyport(htons(port), proto);
1193 	if (ss == NULL)  {
1194 		(void) sprintf(number, "%d", port);
1195 		return (number);
1196 	}
1197 	return (ss->s_name);
1198 }
1199 #endif
1200