xref: /freebsd/contrib/ldns/zone.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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, ldns_rr_list *list)
48 {
49 	return ldns_rr_list_cat(ldns_zone_rrs(z), list);
50 
51 }
52 
53 bool
54 ldns_zone_push_rr(ldns_zone *z, ldns_rr *rr)
55 {
56 	return ldns_rr_list_push_rr( ldns_zone_rrs(z), rr);
57 }
58 
59 
60 /*
61  * Get the list of glue records in a zone
62  * XXX: there should be a way for this to return error, other than NULL,
63  *      since NULL is a valid return
64  */
65 ldns_rr_list *
66 ldns_zone_glue_rr_list(const ldns_zone *z)
67 {
68 	/* when do we find glue? It means we find an IP address
69 	 * (AAAA/A) for a nameserver listed in the zone
70 	 *
71 	 * Alg used here:
72 	 * first find all the zonecuts (NS records)
73 	 * find all the AAAA or A records (can be done it the
74 	 * above loop).
75 	 *
76 	 * Check if the aaaa/a list are subdomains under the
77 	 * NS domains.
78 	 * If yes -> glue, if no -> not glue
79 	 */
80 
81 	ldns_rr_list *zone_cuts;
82 	ldns_rr_list *addr;
83 	ldns_rr_list *glue;
84 	ldns_rr *r, *ns, *a;
85 	ldns_rdf *dname_a, *ns_owner;
86 	size_t i,j;
87 
88 	zone_cuts = NULL;
89 	addr = NULL;
90 	glue = NULL;
91 
92 	/* we cannot determine glue in a 'zone' without a SOA */
93 	if (!ldns_zone_soa(z)) {
94 		return NULL;
95 	}
96 
97 	zone_cuts = ldns_rr_list_new();
98 	if (!zone_cuts) goto memory_error;
99 	addr = ldns_rr_list_new();
100 	if (!addr) goto memory_error;
101 	glue = ldns_rr_list_new();
102 	if (!glue) goto memory_error;
103 
104 	for(i = 0; i < ldns_zone_rr_count(z); i++) {
105 		r = ldns_rr_list_rr(ldns_zone_rrs(z), i);
106 		if (ldns_rr_get_type(r) == LDNS_RR_TYPE_A ||
107 				ldns_rr_get_type(r) == LDNS_RR_TYPE_AAAA) {
108 			/* possibly glue */
109 			if (!ldns_rr_list_push_rr(addr, r)) goto memory_error;
110 			continue;
111 		}
112 		if (ldns_rr_get_type(r) == LDNS_RR_TYPE_NS) {
113 			/* multiple zones will end up here -
114 			 * for now; not a problem
115 			 */
116 			/* don't add NS records for the current zone itself */
117 			if (ldns_rdf_compare(ldns_rr_owner(r),
118 						ldns_rr_owner(ldns_zone_soa(z))) != 0) {
119 				if (!ldns_rr_list_push_rr(zone_cuts, r)) goto memory_error;
120 			}
121 			continue;
122 		}
123 	}
124 
125 	/* will sorting make it quicker ?? */
126 	for(i = 0; i < ldns_rr_list_rr_count(zone_cuts); i++) {
127 		ns = ldns_rr_list_rr(zone_cuts, i);
128 		ns_owner = ldns_rr_owner(ns);
129 
130 		for(j = 0; j < ldns_rr_list_rr_count(addr); j++) {
131 			a = ldns_rr_list_rr(addr, j);
132 			dname_a = ldns_rr_owner(a);
133 
134 			if (ldns_dname_is_subdomain(dname_a, ns_owner) ||
135 				ldns_dname_compare(dname_a, ns_owner) == 0) {
136 				/* GLUE! */
137 				if (!ldns_rr_list_push_rr(glue, a)) goto memory_error;
138 			}
139 		}
140 	}
141 
142 	ldns_rr_list_free(addr);
143 	ldns_rr_list_free(zone_cuts);
144 
145 	if (ldns_rr_list_rr_count(glue) == 0) {
146 		ldns_rr_list_free(glue);
147 		return NULL;
148 	} else {
149 		return glue;
150 	}
151 
152 memory_error:
153 	if (zone_cuts) {
154 		LDNS_FREE(zone_cuts);
155 	}
156 	if (addr) {
157 		ldns_rr_list_free(addr);
158 	}
159 	if (glue) {
160 		ldns_rr_list_free(glue);
161 	}
162 	return NULL;
163 }
164 
165 ldns_zone *
166 ldns_zone_new(void)
167 {
168 	ldns_zone *z;
169 
170 	z = LDNS_MALLOC(ldns_zone);
171 	if (!z) {
172 		return NULL;
173 	}
174 
175 	z->_rrs = ldns_rr_list_new();
176 	if (!z->_rrs) {
177 		LDNS_FREE(z);
178 		return NULL;
179 	}
180 	ldns_zone_set_soa(z, NULL);
181 	return z;
182 }
183 
184 /* we regocnize:
185  * $TTL, $ORIGIN
186  */
187 ldns_status
188 ldns_zone_new_frm_fp(ldns_zone **z, FILE *fp, ldns_rdf *origin, uint32_t ttl, ldns_rr_class c)
189 {
190 	return ldns_zone_new_frm_fp_l(z, fp, origin, ttl, c, NULL);
191 }
192 
193 /* XXX: class is never used */
194 ldns_status
195 ldns_zone_new_frm_fp_l(ldns_zone **z, FILE *fp, ldns_rdf *origin, uint32_t ttl,
196         ldns_rr_class ATTR_UNUSED(c), int *line_nr)
197 {
198 	ldns_zone *newzone;
199 	ldns_rr *rr;
200 	uint32_t my_ttl;
201 	ldns_rdf *my_origin;
202 	ldns_rdf *my_prev;
203 	bool soa_seen = false; 	/* 2 soa are an error */
204 	ldns_status s;
205 	ldns_status ret;
206 
207 	/* most cases of error are memory problems */
208 	ret = LDNS_STATUS_MEM_ERR;
209 
210 	newzone = NULL;
211 	my_origin = NULL;
212 	my_prev = NULL;
213 
214 	my_ttl    = ttl;
215 
216 	if (origin) {
217 		my_origin = ldns_rdf_clone(origin);
218 		if (!my_origin) goto error;
219 		/* also set the prev */
220 		my_prev   = ldns_rdf_clone(origin);
221 		if (!my_prev) goto error;
222 	}
223 
224 	newzone = ldns_zone_new();
225 	if (!newzone) goto error;
226 
227 	while(!feof(fp)) {
228 		s = ldns_rr_new_frm_fp_l(&rr, fp, &my_ttl, &my_origin, &my_prev, line_nr);
229 		switch (s) {
230 		case LDNS_STATUS_OK:
231 			if (ldns_rr_get_type(rr) == LDNS_RR_TYPE_SOA) {
232 				if (soa_seen) {
233 					/* second SOA
234 					 * just skip, maybe we want to say
235 					 * something??? */
236 					ldns_rr_free(rr);
237 					continue;
238 				}
239 				soa_seen = true;
240 				ldns_zone_set_soa(newzone, rr);
241 				/* set origin to soa if not specified */
242 				if (!my_origin) {
243 					my_origin = ldns_rdf_clone(ldns_rr_owner(rr));
244 				}
245 				continue;
246 			}
247 
248 			/* a normal RR - as sofar the DNS is normal */
249 			if (!ldns_zone_push_rr(newzone, rr)) goto error;
250 
251 		case LDNS_STATUS_SYNTAX_EMPTY:
252 			/* empty line was seen */
253 		case LDNS_STATUS_SYNTAX_TTL:
254 			/* the function set the ttl */
255 			break;
256 		case LDNS_STATUS_SYNTAX_ORIGIN:
257 			/* the function set the origin */
258 			break;
259 		case LDNS_STATUS_SYNTAX_INCLUDE:
260 			ret = LDNS_STATUS_SYNTAX_INCLUDE_ERR_NOTIMPL;
261 			break;
262 		default:
263 			ret = s;
264 			goto error;
265 		}
266 	}
267 
268 	if (my_origin) {
269 		ldns_rdf_deep_free(my_origin);
270 	}
271 	if (my_prev) {
272 		ldns_rdf_deep_free(my_prev);
273 	}
274 	if (z) {
275 		*z = newzone;
276 	} else {
277 		ldns_zone_free(newzone);
278 	}
279 
280 	return LDNS_STATUS_OK;
281 
282 error:
283 	if (my_origin) {
284 		ldns_rdf_deep_free(my_origin);
285 	}
286 	if (my_prev) {
287 		ldns_rdf_deep_free(my_prev);
288 	}
289 	if (newzone) {
290 		ldns_zone_free(newzone);
291 	}
292 	return ret;
293 }
294 
295 void
296 ldns_zone_sort(ldns_zone *zone)
297 {
298 	ldns_rr_list *zrr;
299 	assert(zone != NULL);
300 
301 	zrr = ldns_zone_rrs(zone);
302 	ldns_rr_list_sort(zrr);
303 }
304 
305 void
306 ldns_zone_free(ldns_zone *zone)
307 {
308 	ldns_rr_list_free(zone->_rrs);
309 	LDNS_FREE(zone);
310 }
311 
312 void
313 ldns_zone_deep_free(ldns_zone *zone)
314 {
315 	ldns_rr_free(zone->_soa);
316 	ldns_rr_list_deep_free(zone->_rrs);
317 	LDNS_FREE(zone);
318 }
319