host2wire.c revision 269257 
1/*
2 * host2wire.c
3 *
4 * conversion routines from the host to the wire format.
5 * This will usually just a re-ordering of the
6 * data (as we store it in network format)
7 *
8 * a Net::DNS like library for C
9 *
10 * (c) NLnet Labs, 2004-2006
11 *
12 * See the file LICENSE for the license
13 */
14
15#include <ldns/config.h>
16
17#include <ldns/ldns.h>
18
19/* TODO Jelte
20  add a pointer to a 'possiblecompression' structure
21  to all the needed functions?
22  something like an array of name, pointer values?
23  every dname part could be added to it
24*/
25
26ldns_status
27ldns_dname2buffer_wire(ldns_buffer *buffer, const ldns_rdf *name)
28{
29	if (ldns_buffer_reserve(buffer, ldns_rdf_size(name))) {
30		ldns_buffer_write(buffer, ldns_rdf_data(name), ldns_rdf_size(name));
31	}
32	return ldns_buffer_status(buffer);
33}
34
35ldns_status
36ldns_rdf2buffer_wire(ldns_buffer *buffer, const ldns_rdf *rdf)
37{
38	if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) {
39		ldns_buffer_write(buffer, ldns_rdf_data(rdf), ldns_rdf_size(rdf));
40	}
41	return ldns_buffer_status(buffer);
42}
43
44ldns_status
45ldns_rdf2buffer_wire_canonical(ldns_buffer *buffer, const ldns_rdf *rdf)
46{
47	size_t i;
48	uint8_t *rdf_data;
49
50	if (ldns_rdf_get_type(rdf) == LDNS_RDF_TYPE_DNAME) {
51		if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) {
52			rdf_data = ldns_rdf_data(rdf);
53			for (i = 0; i < ldns_rdf_size(rdf); i++) {
54				ldns_buffer_write_u8(buffer,
55				    (uint8_t) LDNS_DNAME_NORMALIZE((int)rdf_data[i]));
56			}
57		}
58	} else {
59		/* direct copy for all other types */
60		if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) {
61			ldns_buffer_write(buffer,
62						   ldns_rdf_data(rdf),
63						   ldns_rdf_size(rdf));
64		}
65	}
66	return ldns_buffer_status(buffer);
67}
68
69/* convert a rr list to wireformat */
70ldns_status
71ldns_rr_list2buffer_wire(ldns_buffer *buffer,const ldns_rr_list *rr_list)
72{
73	uint16_t rr_count;
74	uint16_t i;
75
76	rr_count = ldns_rr_list_rr_count(rr_list);
77	for(i = 0; i < rr_count; i++) {
78		(void)ldns_rr2buffer_wire(buffer, ldns_rr_list_rr(rr_list, i),
79					  LDNS_SECTION_ANY);
80	}
81	return ldns_buffer_status(buffer);
82}
83
84
85ldns_status
86ldns_rr2buffer_wire_canonical(ldns_buffer *buffer,
87						const ldns_rr *rr,
88						int section)
89{
90	uint16_t i;
91	uint16_t rdl_pos = 0;
92	bool pre_rfc3597 = false;
93	switch (ldns_rr_get_type(rr)) {
94	case LDNS_RR_TYPE_NS:
95	case LDNS_RR_TYPE_MD:
96	case LDNS_RR_TYPE_MF:
97	case LDNS_RR_TYPE_CNAME:
98	case LDNS_RR_TYPE_SOA:
99	case LDNS_RR_TYPE_MB:
100	case LDNS_RR_TYPE_MG:
101	case LDNS_RR_TYPE_MR:
102	case LDNS_RR_TYPE_PTR:
103	case LDNS_RR_TYPE_HINFO:
104	case LDNS_RR_TYPE_MINFO:
105	case LDNS_RR_TYPE_MX:
106	case LDNS_RR_TYPE_RP:
107	case LDNS_RR_TYPE_AFSDB:
108	case LDNS_RR_TYPE_RT:
109	case LDNS_RR_TYPE_SIG:
110	case LDNS_RR_TYPE_PX:
111	case LDNS_RR_TYPE_NXT:
112	case LDNS_RR_TYPE_NAPTR:
113	case LDNS_RR_TYPE_KX:
114	case LDNS_RR_TYPE_SRV:
115	case LDNS_RR_TYPE_DNAME:
116	case LDNS_RR_TYPE_A6:
117	case LDNS_RR_TYPE_RRSIG:
118		pre_rfc3597 = true;
119		break;
120	default:
121		break;
122	}
123
124	if (ldns_rr_owner(rr)) {
125		(void) ldns_rdf2buffer_wire_canonical(buffer, ldns_rr_owner(rr));
126	}
127
128	if (ldns_buffer_reserve(buffer, 4)) {
129		(void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr));
130		(void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr));
131	}
132
133	if (section != LDNS_SECTION_QUESTION) {
134		if (ldns_buffer_reserve(buffer, 6)) {
135			ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr));
136			/* remember pos for later */
137			rdl_pos = ldns_buffer_position(buffer);
138			ldns_buffer_write_u16(buffer, 0);
139		}
140		for (i = 0; i < ldns_rr_rd_count(rr); i++) {
141			if (pre_rfc3597) {
142				(void) ldns_rdf2buffer_wire_canonical(
143					buffer, ldns_rr_rdf(rr, i));
144			} else {
145				(void) ldns_rdf2buffer_wire(
146					buffer, ldns_rr_rdf(rr, i));
147			}
148		}
149		if (rdl_pos != 0) {
150			ldns_buffer_write_u16_at(buffer, rdl_pos,
151			                         ldns_buffer_position(buffer)
152		        	                   - rdl_pos - 2);
153		}
154	}
155	return ldns_buffer_status(buffer);
156}
157
158ldns_status
159ldns_rr2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr, int section)
160{
161	uint16_t i;
162	uint16_t rdl_pos = 0;
163
164	if (ldns_rr_owner(rr)) {
165		(void) ldns_dname2buffer_wire(buffer, ldns_rr_owner(rr));
166	}
167
168	if (ldns_buffer_reserve(buffer, 4)) {
169		(void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr));
170		(void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr));
171	}
172
173	if (section != LDNS_SECTION_QUESTION) {
174		if (ldns_buffer_reserve(buffer, 6)) {
175			ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr));
176			/* remember pos for later */
177			rdl_pos = ldns_buffer_position(buffer);
178			ldns_buffer_write_u16(buffer, 0);
179		}
180		for (i = 0; i < ldns_rr_rd_count(rr); i++) {
181			(void) ldns_rdf2buffer_wire(
182					buffer, ldns_rr_rdf(rr, i));
183		}
184		if (rdl_pos != 0) {
185			ldns_buffer_write_u16_at(buffer, rdl_pos,
186			                         ldns_buffer_position(buffer)
187		        	                   - rdl_pos - 2);
188		}
189	}
190	return ldns_buffer_status(buffer);
191}
192
193ldns_status
194ldns_rrsig2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr)
195{
196	uint16_t i;
197
198	/* it must be a sig RR */
199	if (ldns_rr_get_type(rr) != LDNS_RR_TYPE_RRSIG) {
200		return LDNS_STATUS_ERR;
201	}
202
203	/* Convert all the rdfs, except the actual signature data
204	 * rdf number 8  - the last, hence: -1 */
205	for (i = 0; i < ldns_rr_rd_count(rr) - 1; i++) {
206		(void) ldns_rdf2buffer_wire_canonical(buffer,
207				ldns_rr_rdf(rr, i));
208	}
209
210	return ldns_buffer_status(buffer);
211}
212
213ldns_status
214ldns_rr_rdata2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr)
215{
216	uint16_t i;
217	/* convert all the rdf's */
218	for (i = 0; i < ldns_rr_rd_count(rr); i++) {
219		(void) ldns_rdf2buffer_wire(buffer, ldns_rr_rdf(rr,i));
220	}
221	return ldns_buffer_status(buffer);
222}
223
224/*
225 * Copies the packet header data to the buffer in wire format
226 */
227static ldns_status
228ldns_hdr2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet)
229{
230	uint8_t flags;
231	uint16_t arcount;
232
233	if (ldns_buffer_reserve(buffer, 12)) {
234		ldns_buffer_write_u16(buffer, ldns_pkt_id(packet));
235
236		flags = ldns_pkt_qr(packet) << 7
237		        | ldns_pkt_get_opcode(packet) << 3
238		        | ldns_pkt_aa(packet) << 2
239		        | ldns_pkt_tc(packet) << 1 | ldns_pkt_rd(packet);
240		ldns_buffer_write_u8(buffer, flags);
241
242		flags = ldns_pkt_ra(packet) << 7
243		        /*| ldns_pkt_z(packet) << 6*/
244		        | ldns_pkt_ad(packet) << 5
245		        | ldns_pkt_cd(packet) << 4
246			| ldns_pkt_get_rcode(packet);
247		ldns_buffer_write_u8(buffer, flags);
248
249		ldns_buffer_write_u16(buffer, ldns_pkt_qdcount(packet));
250		ldns_buffer_write_u16(buffer, ldns_pkt_ancount(packet));
251		ldns_buffer_write_u16(buffer, ldns_pkt_nscount(packet));
252		/* add EDNS0 and TSIG to additional if they are there */
253		arcount = ldns_pkt_arcount(packet);
254		if (ldns_pkt_tsig(packet)) {
255			arcount++;
256		}
257		if (ldns_pkt_edns(packet)) {
258			arcount++;
259		}
260		ldns_buffer_write_u16(buffer, arcount);
261	}
262
263	return ldns_buffer_status(buffer);
264}
265
266ldns_status
267ldns_pkt2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet)
268{
269	ldns_rr_list *rr_list;
270	uint16_t i;
271
272	/* edns tmp vars */
273	ldns_rr *edns_rr;
274	uint8_t edata[4];
275
276	(void) ldns_hdr2buffer_wire(buffer, packet);
277
278	rr_list = ldns_pkt_question(packet);
279	if (rr_list) {
280		for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
281			(void) ldns_rr2buffer_wire(buffer,
282			             ldns_rr_list_rr(rr_list, i), LDNS_SECTION_QUESTION);
283		}
284	}
285	rr_list = ldns_pkt_answer(packet);
286	if (rr_list) {
287		for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
288			(void) ldns_rr2buffer_wire(buffer,
289			             ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ANSWER);
290		}
291	}
292	rr_list = ldns_pkt_authority(packet);
293	if (rr_list) {
294		for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
295			(void) ldns_rr2buffer_wire(buffer,
296			             ldns_rr_list_rr(rr_list, i), LDNS_SECTION_AUTHORITY);
297		}
298	}
299	rr_list = ldns_pkt_additional(packet);
300	if (rr_list) {
301		for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
302			(void) ldns_rr2buffer_wire(buffer,
303			             ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ADDITIONAL);
304		}
305	}
306
307	/* add EDNS to additional if it is needed */
308	if (ldns_pkt_edns(packet)) {
309		edns_rr = ldns_rr_new();
310		if(!edns_rr) return LDNS_STATUS_MEM_ERR;
311		ldns_rr_set_owner(edns_rr,
312				ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, "."));
313		ldns_rr_set_type(edns_rr, LDNS_RR_TYPE_OPT);
314		ldns_rr_set_class(edns_rr, ldns_pkt_edns_udp_size(packet));
315		edata[0] = ldns_pkt_edns_extended_rcode(packet);
316		edata[1] = ldns_pkt_edns_version(packet);
317		ldns_write_uint16(&edata[2], ldns_pkt_edns_z(packet));
318		ldns_rr_set_ttl(edns_rr, ldns_read_uint32(edata));
319		/* don't forget to add the edns rdata (if any) */
320		if (packet->_edns_data)
321			ldns_rr_push_rdf (edns_rr, packet->_edns_data);
322		(void)ldns_rr2buffer_wire(buffer, edns_rr, LDNS_SECTION_ADDITIONAL);
323		/* take the edns rdata back out of the rr before we free rr */
324		if (packet->_edns_data)
325			(void)ldns_rr_pop_rdf (edns_rr);
326		ldns_rr_free(edns_rr);
327	}
328
329	/* add TSIG to additional if it is there */
330	if (ldns_pkt_tsig(packet)) {
331		(void) ldns_rr2buffer_wire(buffer,
332		                           ldns_pkt_tsig(packet), LDNS_SECTION_ADDITIONAL);
333	}
334
335	return LDNS_STATUS_OK;
336}
337
338ldns_status
339ldns_rdf2wire(uint8_t **dest, const ldns_rdf *rdf, size_t *result_size)
340{
341	ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN);
342	ldns_status status;
343	*result_size = 0;
344	*dest = NULL;
345	if(!buffer) return LDNS_STATUS_MEM_ERR;
346
347	status = ldns_rdf2buffer_wire(buffer, rdf);
348	if (status == LDNS_STATUS_OK) {
349		*result_size =  ldns_buffer_position(buffer);
350		*dest = (uint8_t *) ldns_buffer_export(buffer);
351	}
352	ldns_buffer_free(buffer);
353	return status;
354}
355
356ldns_status
357ldns_rr2wire(uint8_t **dest, const ldns_rr *rr, int section, size_t *result_size)
358{
359	ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN);
360	ldns_status status;
361	*result_size = 0;
362	*dest = NULL;
363	if(!buffer) return LDNS_STATUS_MEM_ERR;
364
365	status = ldns_rr2buffer_wire(buffer, rr, section);
366	if (status == LDNS_STATUS_OK) {
367		*result_size =  ldns_buffer_position(buffer);
368		*dest = (uint8_t *) ldns_buffer_export(buffer);
369	}
370	ldns_buffer_free(buffer);
371	return status;
372}
373
374ldns_status
375ldns_pkt2wire(uint8_t **dest, const ldns_pkt *packet, size_t *result_size)
376{
377	ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN);
378	ldns_status status;
379	*result_size = 0;
380	*dest = NULL;
381	if(!buffer) return LDNS_STATUS_MEM_ERR;
382
383	status = ldns_pkt2buffer_wire(buffer, packet);
384	if (status == LDNS_STATUS_OK) {
385		*result_size =  ldns_buffer_position(buffer);
386		*dest = (uint8_t *) ldns_buffer_export(buffer);
387	}
388	ldns_buffer_free(buffer);
389	return status;
390}
391