xref: /freebsd/contrib/ldns/zone.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /* zone.c
2  *
3  * Functions for ldns_zone structure
4  * a Net::DNS like library for C
5  *
6  * (c) NLnet Labs, 2005-2006
7  * See the file LICENSE for the license
8  */
9 #include <ldns/config.h>
10 
11 #include <ldns/ldns.h>
12 
13 #include <strings.h>
14 #include <limits.h>
15 
16 ldns_rr *
17 ldns_zone_soa(const ldns_zone *z)
18 {
19         return z->_soa;
20 }
21 
22 size_t
23 ldns_zone_rr_count(const ldns_zone *z)
24 {
25 	return ldns_rr_list_rr_count(z->_rrs);
26 }
27 
28 void
29 ldns_zone_set_soa(ldns_zone *z, ldns_rr *soa)
30 {
31 	z->_soa = soa;
32 }
33 
34 ldns_rr_list *
35 ldns_zone_rrs(const ldns_zone *z)
36 {
37 	return z->_rrs;
38 }
39 
40 void
41 ldns_zone_set_rrs(ldns_zone *z, ldns_rr_list *rrlist)
42 {
43 	z->_rrs = rrlist;
44 }
45 
46 bool
47 ldns_zone_push_rr_list(ldns_zone *z, const ldns_rr_list *list)
48 {
49 	return ldns_rr_list_cat(ldns_zone_rrs(z), list);
50 }
51 
52 bool
53 ldns_zone_push_rr(ldns_zone *z, ldns_rr *rr)
54 {
55 	return ldns_rr_list_push_rr(ldns_zone_rrs(z), rr);
56 }
57 
58 
59 /*
60  * Get the list of glue records in a zone
61  * XXX: there should be a way for this to return error, other than NULL,
62  *      since NULL is a valid return
63  */
64 ldns_rr_list *
65 ldns_zone_glue_rr_list(const ldns_zone *z)
66 {
67 	/* when do we find glue? It means we find an IP address
68 	 * (AAAA/A) for a nameserver listed in the zone
69 	 *
70 	 * Alg used here:
71 	 * first find all the zonecuts (NS records)
72 	 * find all the AAAA or A records (can be done it the
73 	 * above loop).
74 	 *
75 	 * Check if the aaaa/a list are subdomains under the
76 	 * NS domains.
77 	 * If yes -> glue, if no -> not glue
78 	 */
79 
80 	ldns_rr_list *zone_cuts;
81 	ldns_rr_list *addr;
82 	ldns_rr_list *glue;
83 	ldns_rr *r, *ns, *a;
84 	ldns_rdf *dname_a, *ns_owner;
85 	size_t i,j;
86 
87 	zone_cuts = NULL;
88 	addr = NULL;
89 	glue = NULL;
90 
91 	/* we cannot determine glue in a 'zone' without a SOA */
92 	if (!ldns_zone_soa(z)) {
93 		return NULL;
94 	}
95 
96 	zone_cuts = ldns_rr_list_new();
97 	if (!zone_cuts) goto memory_error;
98 	addr = ldns_rr_list_new();
99 	if (!addr) goto memory_error;
100 	glue = ldns_rr_list_new();
101 	if (!glue) goto memory_error;
102 
103 	for(i = 0; i < ldns_zone_rr_count(z); i++) {
104 		r = ldns_rr_list_rr(ldns_zone_rrs(z), i);
105 		if (ldns_rr_get_type(r) == LDNS_RR_TYPE_A ||
106 				ldns_rr_get_type(r) == LDNS_RR_TYPE_AAAA) {
107 			/* possibly glue */
108 			if (!ldns_rr_list_push_rr(addr, r)) goto memory_error;
109 			continue;
110 		}
111 		if (ldns_rr_get_type(r) == LDNS_RR_TYPE_NS) {
112 			/* multiple zones will end up here -
113 			 * for now; not a problem
114 			 */
115 			/* don't add NS records for the current zone itself */
116 			if (ldns_rdf_compare(ldns_rr_owner(r),
117 						ldns_rr_owner(ldns_zone_soa(z))) != 0) {
118 				if (!ldns_rr_list_push_rr(zone_cuts, r)) goto memory_error;
119 			}
120 			continue;
121 		}
122 	}
123 
124 	/* will sorting make it quicker ?? */
125 	for(i = 0; i < ldns_rr_list_rr_count(zone_cuts); i++) {
126 		ns = ldns_rr_list_rr(zone_cuts, i);
127 		ns_owner = ldns_rr_owner(ns);
128 
129 		for(j = 0; j < ldns_rr_list_rr_count(addr); j++) {
130 			a = ldns_rr_list_rr(addr, j);
131 			dname_a = ldns_rr_owner(a);
132 
133 			if (ldns_dname_is_subdomain(dname_a, ns_owner) ||
134 				ldns_dname_compare(dname_a, ns_owner) == 0) {
135 				/* GLUE! */
136 				if (!ldns_rr_list_push_rr(glue, a)) goto memory_error;
137 			}
138 		}
139 	}
140 
141 	ldns_rr_list_free(addr);
142 	ldns_rr_list_free(zone_cuts);
143 
144 	if (ldns_rr_list_rr_count(glue) == 0) {
145 		ldns_rr_list_free(glue);
146 		return NULL;
147 	} else {
148 		return glue;
149 	}
150 
151 memory_error:
152 	if (zone_cuts) {
153 		LDNS_FREE(zone_cuts);
154 	}
155 	if (addr) {
156 		ldns_rr_list_free(addr);
157 	}
158 	if (glue) {
159 		ldns_rr_list_free(glue);
160 	}
161 	return NULL;
162 }
163 
164 ldns_zone *
165 ldns_zone_new(void)
166 {
167 	ldns_zone *z;
168 
169 	z = LDNS_MALLOC(ldns_zone);
170 	if (!z) {
171 		return NULL;
172 	}
173 
174 	z->_rrs = ldns_rr_list_new();
175 	if (!z->_rrs) {
176 		LDNS_FREE(z);
177 		return NULL;
178 	}
179 	ldns_zone_set_soa(z, NULL);
180 	return z;
181 }
182 
183 /* we regocnize:
184  * $TTL, $ORIGIN
185  */
186 ldns_status
187 ldns_zone_new_frm_fp(ldns_zone **z, FILE *fp, const ldns_rdf *origin, uint32_t ttl, ldns_rr_class c)
188 {
189 	return ldns_zone_new_frm_fp_l(z, fp, origin, ttl, c, NULL);
190 }
191 
192 /* XXX: class is never used */
193 ldns_status
194 ldns_zone_new_frm_fp_l(ldns_zone **z, FILE *fp, const ldns_rdf *origin, uint32_t ttl,
195         ldns_rr_class ATTR_UNUSED(c), int *line_nr)
196 {
197 	ldns_zone *newzone;
198 	ldns_rr *rr;
199 	uint32_t my_ttl;
200 	ldns_rdf *my_origin;
201 	ldns_rdf *my_prev;
202 	bool soa_seen = false; 	/* 2 soa are an error */
203 	ldns_status s;
204 	ldns_status ret;
205 
206 	/* most cases of error are memory problems */
207 	ret = LDNS_STATUS_MEM_ERR;
208 
209 	newzone = NULL;
210 	my_origin = NULL;
211 	my_prev = NULL;
212 
213 	my_ttl    = ttl;
214 
215 	if (origin) {
216 		my_origin = ldns_rdf_clone(origin);
217 		if (!my_origin) goto error;
218 		/* also set the prev */
219 		my_prev   = ldns_rdf_clone(origin);
220 		if (!my_prev) goto error;
221 	}
222 
223 	newzone = ldns_zone_new();
224 	if (!newzone) goto error;
225 
226 	while(!feof(fp)) {
227 		s = ldns_rr_new_frm_fp_l(&rr, fp, &my_ttl, &my_origin, &my_prev, line_nr);
228 		switch (s) {
229 		case LDNS_STATUS_OK:
230 			if (ldns_rr_get_type(rr) == LDNS_RR_TYPE_SOA) {
231 				if (soa_seen) {
232 					/* second SOA
233 					 * just skip, maybe we want to say
234 					 * something??? */
235 					ldns_rr_free(rr);
236 					continue;
237 				}
238 				soa_seen = true;
239 				ldns_zone_set_soa(newzone, rr);
240 				/* set origin to soa if not specified */
241 				if (!my_origin) {
242 					my_origin = ldns_rdf_clone(ldns_rr_owner(rr));
243 				}
244 				continue;
245 			}
246 
247 			/* a normal RR - as sofar the DNS is normal */
248 			if (!ldns_zone_push_rr(newzone, rr)) goto error;
249 
250 		case LDNS_STATUS_SYNTAX_EMPTY:
251 			/* empty line was seen */
252 		case LDNS_STATUS_SYNTAX_TTL:
253 			/* the function set the ttl */
254 			break;
255 		case LDNS_STATUS_SYNTAX_ORIGIN:
256 			/* the function set the origin */
257 			break;
258 		case LDNS_STATUS_SYNTAX_INCLUDE:
259 			ret = LDNS_STATUS_SYNTAX_INCLUDE_ERR_NOTIMPL;
260 			break;
261 		default:
262 			ret = s;
263 			goto error;
264 		}
265 	}
266 
267 	if (my_origin) {
268 		ldns_rdf_deep_free(my_origin);
269 	}
270 	if (my_prev) {
271 		ldns_rdf_deep_free(my_prev);
272 	}
273 	if (z) {
274 		*z = newzone;
275 	} else {
276 		ldns_zone_free(newzone);
277 	}
278 
279 	return LDNS_STATUS_OK;
280 
281 error:
282 	if (my_origin) {
283 		ldns_rdf_deep_free(my_origin);
284 	}
285 	if (my_prev) {
286 		ldns_rdf_deep_free(my_prev);
287 	}
288 	if (newzone) {
289 		ldns_zone_free(newzone);
290 	}
291 	return ret;
292 }
293 
294 void
295 ldns_zone_sort(ldns_zone *zone)
296 {
297 	ldns_rr_list *zrr;
298 	assert(zone != NULL);
299 
300 	zrr = ldns_zone_rrs(zone);
301 	ldns_rr_list_sort(zrr);
302 }
303 
304 void
305 ldns_zone_free(ldns_zone *zone)
306 {
307 	ldns_rr_list_free(zone->_rrs);
308 	LDNS_FREE(zone);
309 }
310 
311 void
312 ldns_zone_deep_free(ldns_zone *zone)
313 {
314 	ldns_rr_free(zone->_soa);
315 	ldns_rr_list_deep_free(zone->_rrs);
316 	LDNS_FREE(zone);
317 }
318