higher.c revision 238104 
1/*
2 * higher.c
3 *
4 * Specify some higher level functions that would
5 * be usefull to would be developers
6 *
7 * a Net::DNS like library for C
8 *
9 * (c) NLnet Labs, 2004-2006
10 *
11 * See the file LICENSE for the license
12 */
13
14#include <ldns/config.h>
15
16#include <ldns/ldns.h>
17
18#ifdef HAVE_SSL
19#include <openssl/ssl.h>
20#include <openssl/sha.h>
21#endif /* HAVE_SSL */
22
23ldns_rr_list *
24ldns_get_rr_list_addr_by_name(ldns_resolver *res, ldns_rdf *name, ldns_rr_class c,
25		uint16_t flags)
26{
27	ldns_pkt *pkt;
28	ldns_rr_list *aaaa;
29	ldns_rr_list *a;
30	ldns_rr_list *result = NULL;
31	ldns_rr_list *hostsfilenames;
32	size_t i;
33	uint8_t ip6;
34
35	a = NULL;
36	aaaa = NULL;
37	result = NULL;
38
39	if (!res) {
40		return NULL;
41	}
42	if (ldns_rdf_get_type(name) != LDNS_RDF_TYPE_DNAME) {
43		return NULL;
44	}
45
46	ip6 = ldns_resolver_ip6(res); /* we use INET_ANY here, save
47					 what was there */
48
49	ldns_resolver_set_ip6(res, LDNS_RESOLV_INETANY);
50
51	hostsfilenames = ldns_get_rr_list_hosts_frm_file(NULL);
52	for (i = 0; i < ldns_rr_list_rr_count(hostsfilenames); i++) {
53		if (ldns_rdf_compare(name,
54					ldns_rr_owner(ldns_rr_list_rr(hostsfilenames,
55							i))) == 0) {
56			if (!result) {
57				result = ldns_rr_list_new();
58			}
59			ldns_rr_list_push_rr(result,
60					ldns_rr_clone(ldns_rr_list_rr(hostsfilenames, i)));
61		}
62	}
63	ldns_rr_list_deep_free(hostsfilenames);
64
65	if (result) {
66		return result;
67	}
68
69	/* add the RD flags, because we want an answer */
70	pkt = ldns_resolver_query(res, name, LDNS_RR_TYPE_AAAA, c, flags | LDNS_RD);
71	if (pkt) {
72		/* extract the data we need */
73		aaaa = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_AAAA,
74			LDNS_SECTION_ANSWER);
75		ldns_pkt_free(pkt);
76	}
77
78	pkt = ldns_resolver_query(res, name, LDNS_RR_TYPE_A, c, flags | LDNS_RD);
79	if (pkt) {
80		/* extract the data we need */
81		a = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_A, LDNS_SECTION_ANSWER);
82		ldns_pkt_free(pkt);
83	}
84	ldns_resolver_set_ip6(res, ip6);
85
86	if (aaaa && a) {
87		result = ldns_rr_list_cat_clone(aaaa, a);
88		ldns_rr_list_deep_free(aaaa);
89		ldns_rr_list_deep_free(a);
90		return result;
91	}
92
93	if (aaaa) {
94		result = ldns_rr_list_clone(aaaa);
95	}
96
97	if (a) {
98		result = ldns_rr_list_clone(a);
99	}
100
101	ldns_rr_list_deep_free(aaaa);
102	ldns_rr_list_deep_free(a);
103	return result;
104}
105
106ldns_rr_list *
107ldns_get_rr_list_name_by_addr(ldns_resolver *res, ldns_rdf *addr, ldns_rr_class c,
108		uint16_t flags)
109{
110	ldns_pkt *pkt;
111	ldns_rr_list *names;
112	ldns_rdf *name;
113
114	names = NULL;
115
116	if (!res || !addr) {
117		return NULL;
118	}
119
120	if (ldns_rdf_get_type(addr) != LDNS_RDF_TYPE_A &&
121			ldns_rdf_get_type(addr) != LDNS_RDF_TYPE_AAAA) {
122		return NULL;
123	}
124
125	name = ldns_rdf_address_reverse(addr);
126
127	/* add the RD flags, because we want an answer */
128	pkt = ldns_resolver_query(res, name, LDNS_RR_TYPE_PTR, c, flags | LDNS_RD);
129	if (pkt) {
130		/* extract the data we need */
131		names = ldns_pkt_rr_list_by_type(pkt,
132				LDNS_RR_TYPE_PTR, LDNS_SECTION_ANSWER);
133	}
134	return names;
135}
136
137/* read a line, put it in a buffer, parse the buffer */
138ldns_rr_list *
139ldns_get_rr_list_hosts_frm_fp(FILE *fp)
140{
141	return ldns_get_rr_list_hosts_frm_fp_l(fp, NULL);
142}
143
144ldns_rr_list *
145ldns_get_rr_list_hosts_frm_fp_l(FILE *fp, int *line_nr)
146{
147	ssize_t i, j;
148	size_t cnt;
149	char *line;
150	char *word;
151	char *addr;
152	char *rr_str;
153	ldns_buffer *linebuf;
154	ldns_rr *rr;
155	ldns_rr_list *list;
156	ldns_rdf *tmp;
157	bool ip6;
158	ldns_status parse_result;
159
160	line = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
161	word = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
162	addr = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
163	rr_str = LDNS_XMALLOC(char, LDNS_MAX_LINELEN + 1);
164	ip6 = false;
165	list = ldns_rr_list_new();
166	rr = NULL;
167	if(!line || !word || !addr || !rr_str || !list) {
168		LDNS_FREE(line);
169		LDNS_FREE(word);
170		LDNS_FREE(addr);
171		LDNS_FREE(rr_str);
172		ldns_rr_list_free(list);
173		return NULL;
174	}
175
176	for(i = ldns_fget_token_l(fp, line, "\n", LDNS_MAX_LINELEN, line_nr);
177			i > 0; i = ldns_fget_token_l(fp, line, "\n", LDNS_MAX_LINELEN, line_nr)) {
178		/* # is comment */
179		if (line[0] == '#') {
180			continue;
181		}
182		/* put it in a buffer for further processing */
183		linebuf = LDNS_MALLOC(ldns_buffer);
184		if(!linebuf) {
185			LDNS_FREE(line);
186			LDNS_FREE(word);
187			LDNS_FREE(addr);
188			LDNS_FREE(rr_str);
189			ldns_rr_list_deep_free(list);
190			return NULL;
191		}
192
193		ldns_buffer_new_frm_data(linebuf, line, (size_t) i);
194		for(cnt = 0, j = ldns_bget_token(linebuf, word, LDNS_PARSE_NO_NL, LDNS_MAX_LINELEN);
195				j > 0;
196				j = ldns_bget_token(linebuf, word, LDNS_PARSE_NO_NL, LDNS_MAX_LINELEN), cnt++) {
197			if (cnt == 0) {
198				/* the address */
199				if ((tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_AAAA,
200								word))) {
201					/* ip6 */
202					ldns_rdf_deep_free(tmp);
203					ip6 = true;
204				} else {
205					if ((tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_A,
206									word))) {
207						/* ip4 */
208						ldns_rdf_deep_free(tmp);
209						ip6 = false;
210					} else {
211						/* kaput */
212						break;
213					}
214				}
215				(void)strlcpy(addr, word, LDNS_MAX_LINELEN+1);
216			} else {
217				/* la al la la */
218				if (ip6) {
219					snprintf(rr_str, LDNS_MAX_LINELEN,
220						"%s IN AAAA %s", word, addr);
221				} else {
222					snprintf(rr_str, LDNS_MAX_LINELEN,
223						"%s IN A %s", word, addr);
224				}
225				parse_result = ldns_rr_new_frm_str(&rr, rr_str, 0, NULL, NULL);
226				if (parse_result == LDNS_STATUS_OK && ldns_rr_owner(rr) && ldns_rr_rd_count(rr) > 0) {
227					ldns_rr_list_push_rr(list, ldns_rr_clone(rr));
228				}
229				ldns_rr_free(rr);
230			}
231		}
232		ldns_buffer_free(linebuf);
233	}
234	LDNS_FREE(line);
235	LDNS_FREE(word);
236	LDNS_FREE(addr);
237	LDNS_FREE(rr_str);
238	return list;
239}
240
241ldns_rr_list *
242ldns_get_rr_list_hosts_frm_file(char *filename)
243{
244	ldns_rr_list *names;
245	FILE *fp;
246
247	if (!filename) {
248                fp = fopen(LDNS_RESOLV_HOSTS, "r");
249
250        } else {
251                fp = fopen(filename, "r");
252        }
253        if (!fp) {
254                return NULL;
255        }
256
257	names = ldns_get_rr_list_hosts_frm_fp(fp);
258	fclose(fp);
259	return names;
260}
261
262uint16_t
263ldns_getaddrinfo(ldns_resolver *res, ldns_rdf *node, ldns_rr_class c,
264		ldns_rr_list **ret)
265{
266	ldns_rdf_type t;
267	uint16_t names_found;
268	ldns_resolver *r;
269	ldns_status s;
270
271	t = ldns_rdf_get_type(node);
272	names_found = 0;
273	r = res;
274
275	if (res == NULL) {
276		/* prepare a new resolver, using /etc/resolv.conf as a guide  */
277		s = ldns_resolver_new_frm_file(&r, NULL);
278		if (s != LDNS_STATUS_OK) {
279			return 0;
280		}
281	}
282
283	if (t == LDNS_RDF_TYPE_DNAME) {
284		/* we're asked to query for a name */
285		*ret = ldns_get_rr_list_addr_by_name(r, node, c, 0);
286		names_found = ldns_rr_list_rr_count(*ret);
287	}
288
289	if (t == LDNS_RDF_TYPE_A || t == LDNS_RDF_TYPE_AAAA) {
290		/* an address */
291		*ret = ldns_get_rr_list_name_by_addr(r, node, c, 0);
292		names_found = ldns_rr_list_rr_count(*ret);
293	}
294
295	if (res == NULL) {
296		ldns_resolver_deep_free(r);
297	}
298
299	return names_found;
300}
301
302bool
303ldns_nsec_type_check(ldns_rr *nsec, ldns_rr_type t)
304{
305	/* does the nsec cover the t given? */
306	/* copied from host2str.c line 465: ldns_rdf2buffer_str_nsec */
307        uint8_t window_block_nr;
308        uint8_t bitmap_length;
309        uint16_t type;
310        uint16_t pos = 0;
311        uint16_t bit_pos;
312	ldns_rdf *nsec_type_list = ldns_rr_rdf(nsec, 1);
313	uint8_t *data;
314
315	if (nsec_type_list == NULL) {
316		return false;
317	}
318	data  = ldns_rdf_data(nsec_type_list);
319
320	while(pos < ldns_rdf_size(nsec_type_list)) {
321		window_block_nr = data[pos];
322		bitmap_length = data[pos + 1];
323		pos += 2;
324
325		for (bit_pos = 0; bit_pos < (bitmap_length) * 8; bit_pos++) {
326			if (ldns_get_bit(&data[pos], bit_pos)) {
327				type = 256 * (uint16_t) window_block_nr + bit_pos;
328
329				if ((ldns_rr_type)type == t) {
330					/* we have a winner */
331					return true;
332				}
333			}
334		}
335		pos += (uint16_t) bitmap_length;
336	}
337	return false;
338}
339
340void
341ldns_print_rr_rdf(FILE *fp, ldns_rr *r, int rdfnum, ...)
342{
343	int16_t rdf;
344	ldns_rdf *rd;
345	va_list va_rdf;
346	va_start(va_rdf, rdfnum);
347
348	for (rdf = (int16_t)rdfnum; rdf != -1; rdf = (int16_t)va_arg(va_rdf, int))
349	{
350		rd = ldns_rr_rdf(r, rdf);
351		if (!rd) {
352			continue;
353		} else {
354			ldns_rdf_print(fp, rd);
355			fprintf(fp, " "); /* not sure if we want to do this */
356		}
357	}
358	va_end(va_rdf);
359}
360