1 /*
2  * Copyright (C) 2004, 2005, 2007, 2009, 2011-2015  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 1998-2002  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 /* $Id$ */
19 
20 /* Reviewed: Thu Mar 16 14:06:44 PST 2000 by gson */
21 
22 /* RFC2671 */
23 
24 #ifndef RDATA_GENERIC_OPT_41_C
25 #define RDATA_GENERIC_OPT_41_C
26 
27 #define RRTYPE_OPT_ATTRIBUTES (DNS_RDATATYPEATTR_SINGLETON | \
28 			       DNS_RDATATYPEATTR_META | \
29 			       DNS_RDATATYPEATTR_NOTQUESTION)
30 
31 static inline isc_result_t
fromtext_opt(ARGS_FROMTEXT)32 fromtext_opt(ARGS_FROMTEXT) {
33 	/*
34 	 * OPT records do not have a text format.
35 	 */
36 
37 	REQUIRE(type == dns_rdatatype_opt);
38 
39 	UNUSED(type);
40 	UNUSED(rdclass);
41 	UNUSED(lexer);
42 	UNUSED(origin);
43 	UNUSED(options);
44 	UNUSED(target);
45 	UNUSED(callbacks);
46 
47 	return (ISC_R_NOTIMPLEMENTED);
48 }
49 
50 static inline isc_result_t
totext_opt(ARGS_TOTEXT)51 totext_opt(ARGS_TOTEXT) {
52 	isc_region_t r;
53 	isc_region_t or;
54 	isc_uint16_t option;
55 	isc_uint16_t length;
56 	char buf[sizeof("64000 64000")];
57 
58 	/*
59 	 * OPT records do not have a text format.
60 	 */
61 
62 	REQUIRE(rdata->type == dns_rdatatype_opt);
63 
64 	dns_rdata_toregion(rdata, &r);
65 	while (r.length > 0) {
66 		option = uint16_fromregion(&r);
67 		isc_region_consume(&r, 2);
68 		length = uint16_fromregion(&r);
69 		isc_region_consume(&r, 2);
70 		sprintf(buf, "%u %u", option, length);
71 		RETERR(str_totext(buf, target));
72 		INSIST(r.length >= length);
73 		if (length > 0) {
74 			if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
75 				RETERR(str_totext(" (", target));
76 			RETERR(str_totext(tctx->linebreak, target));
77 			or = r;
78 			or.length = length;
79 			if (tctx->width == 0)   /* No splitting */
80 				RETERR(isc_base64_totext(&or, 60, "", target));
81 			else
82 				RETERR(isc_base64_totext(&or, tctx->width - 2,
83 							 tctx->linebreak,
84 							 target));
85 			isc_region_consume(&r, length);
86 			if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
87 				RETERR(str_totext(" )", target));
88 		}
89 		if (r.length > 0)
90 			RETERR(str_totext(" ", target));
91 	}
92 
93 	return (ISC_R_SUCCESS);
94 }
95 
96 static inline isc_result_t
fromwire_opt(ARGS_FROMWIRE)97 fromwire_opt(ARGS_FROMWIRE) {
98 	isc_region_t sregion;
99 	isc_region_t tregion;
100 	isc_uint16_t opt;
101 	isc_uint16_t length;
102 	unsigned int total;
103 
104 	REQUIRE(type == dns_rdatatype_opt);
105 
106 	UNUSED(type);
107 	UNUSED(rdclass);
108 	UNUSED(dctx);
109 	UNUSED(options);
110 
111 	isc_buffer_activeregion(source, &sregion);
112 	total = 0;
113 	while (sregion.length != 0) {
114 		if (sregion.length < 4)
115 			return (ISC_R_UNEXPECTEDEND);
116 		opt = uint16_fromregion(&sregion);
117 		isc_region_consume(&sregion, 2);
118 		length = uint16_fromregion(&sregion);
119 		isc_region_consume(&sregion, 2);
120 		total += 4;
121 		if (sregion.length < length)
122 			return (ISC_R_UNEXPECTEDEND);
123 		switch (opt) {
124 		case DNS_OPT_CLIENT_SUBNET: {
125 			isc_uint16_t family;
126 			isc_uint8_t addrlen;
127 			isc_uint8_t scope;
128 			isc_uint8_t addrbytes;
129 
130 			if (length < 4)
131 				return (DNS_R_OPTERR);
132 			family = uint16_fromregion(&sregion);
133 			isc_region_consume(&sregion, 2);
134 			addrlen = uint8_fromregion(&sregion);
135 			isc_region_consume(&sregion, 1);
136 			scope = uint8_fromregion(&sregion);
137 			isc_region_consume(&sregion, 1);
138 			switch (family) {
139 			case 1:
140 				if (addrlen > 32U || scope > 32U)
141 					return (DNS_R_OPTERR);
142 				break;
143 			case 2:
144 				if (addrlen > 128U || scope > 128U)
145 					return (DNS_R_OPTERR);
146 				break;
147 			default:
148 				return (DNS_R_OPTERR);
149 			}
150 			addrbytes = (addrlen + 7) / 8;
151 			if (addrbytes + 4 != length)
152 				return (DNS_R_OPTERR);
153 
154 			if (addrbytes != 0U && (addrlen % 8) != 0) {
155 				isc_uint8_t bits = ~0 << (8 - (addrlen % 8));
156 				bits &= sregion.base[addrbytes - 1];
157 				if (bits != sregion.base[addrbytes - 1])
158 					return (DNS_R_OPTERR);
159 			}
160 			isc_region_consume(&sregion, addrbytes);
161 			break;
162 		}
163 		case DNS_OPT_EXPIRE:
164 			/*
165 			 * Request has zero length.  Response is 32 bits.
166 			 */
167 			if (length != 0 && length != 4)
168 				return (DNS_R_OPTERR);
169 			isc_region_consume(&sregion, length);
170 			break;
171 		case DNS_OPT_COOKIE:
172 			if (length != 8 && (length < 16 || length > 40))
173 				return (DNS_R_OPTERR);
174 			isc_region_consume(&sregion, length);
175 			break;
176 		default:
177 			isc_region_consume(&sregion, length);
178 			break;
179 		}
180 		total += length;
181 	}
182 
183 	isc_buffer_activeregion(source, &sregion);
184 	isc_buffer_availableregion(target, &tregion);
185 	if (tregion.length < total)
186 		return (ISC_R_NOSPACE);
187 	memmove(tregion.base, sregion.base, total);
188 	isc_buffer_forward(source, total);
189 	isc_buffer_add(target, total);
190 
191 	return (ISC_R_SUCCESS);
192 }
193 
194 static inline isc_result_t
towire_opt(ARGS_TOWIRE)195 towire_opt(ARGS_TOWIRE) {
196 
197 	REQUIRE(rdata->type == dns_rdatatype_opt);
198 
199 	UNUSED(cctx);
200 
201 	return (mem_tobuffer(target, rdata->data, rdata->length));
202 }
203 
204 static inline int
compare_opt(ARGS_COMPARE)205 compare_opt(ARGS_COMPARE) {
206 	isc_region_t r1;
207 	isc_region_t r2;
208 
209 	REQUIRE(rdata1->type == rdata2->type);
210 	REQUIRE(rdata1->rdclass == rdata2->rdclass);
211 	REQUIRE(rdata1->type == dns_rdatatype_opt);
212 
213 	dns_rdata_toregion(rdata1, &r1);
214 	dns_rdata_toregion(rdata2, &r2);
215 	return (isc_region_compare(&r1, &r2));
216 }
217 
218 static inline isc_result_t
fromstruct_opt(ARGS_FROMSTRUCT)219 fromstruct_opt(ARGS_FROMSTRUCT) {
220 	dns_rdata_opt_t *opt = source;
221 	isc_region_t region;
222 	isc_uint16_t length;
223 
224 	REQUIRE(type == dns_rdatatype_opt);
225 	REQUIRE(source != NULL);
226 	REQUIRE(opt->common.rdtype == type);
227 	REQUIRE(opt->common.rdclass == rdclass);
228 	REQUIRE(opt->options != NULL || opt->length == 0);
229 
230 	UNUSED(type);
231 	UNUSED(rdclass);
232 
233 	region.base = opt->options;
234 	region.length = opt->length;
235 	while (region.length >= 4) {
236 		isc_region_consume(&region, 2);	/* opt */
237 		length = uint16_fromregion(&region);
238 		isc_region_consume(&region, 2);
239 		if (region.length < length)
240 			return (ISC_R_UNEXPECTEDEND);
241 		isc_region_consume(&region, length);
242 	}
243 	if (region.length != 0)
244 		return (ISC_R_UNEXPECTEDEND);
245 
246 	return (mem_tobuffer(target, opt->options, opt->length));
247 }
248 
249 static inline isc_result_t
tostruct_opt(ARGS_TOSTRUCT)250 tostruct_opt(ARGS_TOSTRUCT) {
251 	dns_rdata_opt_t *opt = target;
252 	isc_region_t r;
253 
254 	REQUIRE(rdata->type == dns_rdatatype_opt);
255 	REQUIRE(target != NULL);
256 
257 	opt->common.rdclass = rdata->rdclass;
258 	opt->common.rdtype = rdata->type;
259 	ISC_LINK_INIT(&opt->common, link);
260 
261 	dns_rdata_toregion(rdata, &r);
262 	opt->length = r.length;
263 	opt->options = mem_maybedup(mctx, r.base, r.length);
264 	if (opt->options == NULL)
265 		return (ISC_R_NOMEMORY);
266 
267 	opt->offset = 0;
268 	opt->mctx = mctx;
269 	return (ISC_R_SUCCESS);
270 }
271 
272 static inline void
freestruct_opt(ARGS_FREESTRUCT)273 freestruct_opt(ARGS_FREESTRUCT) {
274 	dns_rdata_opt_t *opt = source;
275 
276 	REQUIRE(source != NULL);
277 	REQUIRE(opt->common.rdtype == dns_rdatatype_opt);
278 
279 	if (opt->mctx == NULL)
280 		return;
281 
282 	if (opt->options != NULL)
283 		isc_mem_free(opt->mctx, opt->options);
284 	opt->mctx = NULL;
285 }
286 
287 static inline isc_result_t
additionaldata_opt(ARGS_ADDLDATA)288 additionaldata_opt(ARGS_ADDLDATA) {
289 	REQUIRE(rdata->type == dns_rdatatype_opt);
290 
291 	UNUSED(rdata);
292 	UNUSED(add);
293 	UNUSED(arg);
294 
295 	return (ISC_R_SUCCESS);
296 }
297 
298 static inline isc_result_t
digest_opt(ARGS_DIGEST)299 digest_opt(ARGS_DIGEST) {
300 
301 	/*
302 	 * OPT records are not digested.
303 	 */
304 
305 	REQUIRE(rdata->type == dns_rdatatype_opt);
306 
307 	UNUSED(rdata);
308 	UNUSED(digest);
309 	UNUSED(arg);
310 
311 	return (ISC_R_NOTIMPLEMENTED);
312 }
313 
314 static inline isc_boolean_t
checkowner_opt(ARGS_CHECKOWNER)315 checkowner_opt(ARGS_CHECKOWNER) {
316 
317 	REQUIRE(type == dns_rdatatype_opt);
318 
319 	UNUSED(type);
320 	UNUSED(rdclass);
321 	UNUSED(wildcard);
322 
323 	return (dns_name_equal(name, dns_rootname));
324 }
325 
326 static inline isc_boolean_t
checknames_opt(ARGS_CHECKNAMES)327 checknames_opt(ARGS_CHECKNAMES) {
328 
329 	REQUIRE(rdata->type == dns_rdatatype_opt);
330 
331 	UNUSED(rdata);
332 	UNUSED(owner);
333 	UNUSED(bad);
334 
335 	return (ISC_TRUE);
336 }
337 
338 static inline int
casecompare_opt(ARGS_COMPARE)339 casecompare_opt(ARGS_COMPARE) {
340 	return (compare_opt(rdata1, rdata2));
341 }
342 
343 isc_result_t
dns_rdata_opt_first(dns_rdata_opt_t * opt)344 dns_rdata_opt_first(dns_rdata_opt_t *opt) {
345 
346 	REQUIRE(opt != NULL);
347 	REQUIRE(opt->common.rdtype == dns_rdatatype_opt);
348 	REQUIRE(opt->options != NULL || opt->length == 0);
349 
350 	if (opt->length == 0)
351 		return (ISC_R_NOMORE);
352 
353 	opt->offset = 0;
354 	return (ISC_R_SUCCESS);
355 }
356 
357 isc_result_t
dns_rdata_opt_next(dns_rdata_opt_t * opt)358 dns_rdata_opt_next(dns_rdata_opt_t *opt) {
359 	isc_region_t r;
360 	isc_uint16_t length;
361 
362 	REQUIRE(opt != NULL);
363 	REQUIRE(opt->common.rdtype == dns_rdatatype_opt);
364 	REQUIRE(opt->options != NULL && opt->length != 0);
365 	REQUIRE(opt->offset < opt->length);
366 
367 	INSIST(opt->offset + 4 <= opt->length);
368 	r.base = opt->options + opt->offset + 2;
369 	r.length = opt->length - opt->offset - 2;
370 	length = uint16_fromregion(&r);
371 	INSIST(opt->offset + 4 + length <= opt->length);
372 	opt->offset = opt->offset + 4 + length;
373 	if (opt->offset == opt->length)
374 		return (ISC_R_NOMORE);
375 	return (ISC_R_SUCCESS);
376 }
377 
378 isc_result_t
dns_rdata_opt_current(dns_rdata_opt_t * opt,dns_rdata_opt_opcode_t * opcode)379 dns_rdata_opt_current(dns_rdata_opt_t *opt, dns_rdata_opt_opcode_t *opcode) {
380 	isc_region_t r;
381 
382 	REQUIRE(opt != NULL);
383 	REQUIRE(opcode != NULL);
384 	REQUIRE(opt->common.rdtype == dns_rdatatype_opt);
385 	REQUIRE(opt->options != NULL);
386 	REQUIRE(opt->offset < opt->length);
387 
388 	INSIST(opt->offset + 4 <= opt->length);
389 	r.base = opt->options + opt->offset;
390 	r.length = opt->length - opt->offset;
391 
392 	opcode->opcode = uint16_fromregion(&r);
393 	isc_region_consume(&r, 2);
394 	opcode->length = uint16_fromregion(&r);
395 	isc_region_consume(&r, 2);
396 	opcode->data = r.base;
397 	INSIST(opt->offset + 4 + opcode->length <= opt->length);
398 
399 	return (ISC_R_SUCCESS);
400 }
401 
402 #endif	/* RDATA_GENERIC_OPT_41_C */
403