2 * iterator/iter_fwd.c - iterative resolver module forward zones.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
39 * This file contains functions to assist the iterator module.
40 * Keep track of forward zones and config settings.
43 #include <ldns/rdata.h>
44 #include <ldns/dname.h>
46 #include "iterator/iter_fwd.h"
47 #include "iterator/iter_delegpt.h"
49 #include "util/config_file.h"
50 #include "util/net_help.h"
51 #include "util/data/dname.h"
54 fwd_cmp(const void* k1, const void* k2)
57 struct iter_forward_zone* n1 = (struct iter_forward_zone*)k1;
58 struct iter_forward_zone* n2 = (struct iter_forward_zone*)k2;
59 if(n1->dclass != n2->dclass) {
60 if(n1->dclass < n2->dclass)
64 return dname_lab_cmp(n1->name, n1->namelabs, n2->name, n2->namelabs,
71 struct iter_forwards* fwd = (struct iter_forwards*)calloc(1,
72 sizeof(struct iter_forwards));
78 static void fwd_zone_free(struct iter_forward_zone* n)
81 delegpt_free_mlc(n->dp);
86 static void delfwdnode(rbnode_t* n, void* ATTR_UNUSED(arg))
88 struct iter_forward_zone* node = (struct iter_forward_zone*)n;
92 static void fwd_del_tree(struct iter_forwards* fwd)
95 traverse_postorder(fwd->tree, &delfwdnode, NULL);
100 forwards_delete(struct iter_forwards* fwd)
108 /** insert info into forward structure */
110 forwards_insert_data(struct iter_forwards* fwd, uint16_t c, uint8_t* nm,
111 size_t nmlen, int nmlabs, struct delegpt* dp)
113 struct iter_forward_zone* node = (struct iter_forward_zone*)malloc(
114 sizeof(struct iter_forward_zone));
116 delegpt_free_mlc(dp);
119 node->node.key = node;
121 node->name = memdup(nm, nmlen);
123 delegpt_free_mlc(dp);
127 node->namelen = nmlen;
128 node->namelabs = nmlabs;
130 if(!rbtree_insert(fwd->tree, &node->node)) {
133 log_err("duplicate forward zone %s ignored.", buf);
134 delegpt_free_mlc(dp);
141 /** insert new info into forward structure given dp */
143 forwards_insert(struct iter_forwards* fwd, uint16_t c, struct delegpt* dp)
145 return forwards_insert_data(fwd, c, dp->name, dp->namelen,
149 /** initialise parent pointers in the tree */
151 fwd_init_parents(struct iter_forwards* fwd)
153 struct iter_forward_zone* node, *prev = NULL, *p;
155 RBTREE_FOR(node, struct iter_forward_zone*, fwd->tree) {
157 if(!prev || prev->dclass != node->dclass) {
161 (void)dname_lab_cmp(prev->name, prev->namelabs, node->name,
162 node->namelabs, &m); /* we know prev is smaller */
163 /* sort order like: . com. bla.com. zwb.com. net. */
164 /* find the previous, or parent-parent-parent */
165 for(p = prev; p; p = p->parent)
166 /* looking for name with few labels, a parent */
167 if(p->namelabs <= m) {
168 /* ==: since prev matched m, this is closest*/
169 /* <: prev matches more, but is not a parent,
170 * this one is a (grand)parent */
179 static struct delegpt*
180 read_fwds_name(struct config_stub* s)
185 log_err("forward zone without a name (use name \".\" to forward everything)");
188 rdf = ldns_dname_new_frm_str(s->name);
190 log_err("cannot parse forward zone name %s", s->name);
193 if(!(dp=delegpt_create_mlc(ldns_rdf_data(rdf)))) {
194 ldns_rdf_deep_free(rdf);
195 log_err("out of memory");
198 ldns_rdf_deep_free(rdf);
202 /** set fwd host names */
204 read_fwds_host(struct config_stub* s, struct delegpt* dp)
206 struct config_strlist* p;
208 for(p = s->hosts; p; p = p->next) {
210 rdf = ldns_dname_new_frm_str(p->str);
212 log_err("cannot parse forward %s server name: '%s'",
216 if(!delegpt_add_ns_mlc(dp, ldns_rdf_data(rdf), 0)) {
217 ldns_rdf_deep_free(rdf);
218 log_err("out of memory");
221 ldns_rdf_deep_free(rdf);
226 /** set fwd server addresses */
228 read_fwds_addr(struct config_stub* s, struct delegpt* dp)
230 struct config_strlist* p;
231 struct sockaddr_storage addr;
233 for(p = s->addrs; p; p = p->next) {
235 if(!extstrtoaddr(p->str, &addr, &addrlen)) {
236 log_err("cannot parse forward %s ip address: '%s'",
240 if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) {
241 log_err("out of memory");
248 /** read forwards config */
250 read_forwards(struct iter_forwards* fwd, struct config_file* cfg)
252 struct config_stub* s;
253 for(s = cfg->forwards; s; s = s->next) {
255 if(!(dp=read_fwds_name(s)))
257 if(!read_fwds_host(s, dp) || !read_fwds_addr(s, dp)) {
258 delegpt_free_mlc(dp);
261 /* set flag that parent side NS information is included.
262 * Asking a (higher up) server on the internet is not useful */
263 /* the flag is turned off for 'forward-first' so that the
264 * last resort will ask for parent-side NS record and thus
265 * fallback to the internet name servers on a failure */
266 dp->has_parent_side_NS = (uint8_t)!s->isfirst;
267 verbose(VERB_QUERY, "Forward zone server list:");
268 delegpt_log(VERB_QUERY, dp);
269 if(!forwards_insert(fwd, LDNS_RR_CLASS_IN, dp))
275 /** insert a stub hole (if necessary) for stub name */
277 fwd_add_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm)
279 struct iter_forward_zone key;
283 key.namelabs = dname_count_size_labels(key.name, &key.namelen);
284 return forwards_insert_data(fwd, key.dclass, key.name,
285 key.namelen, key.namelabs, NULL);
288 /** make NULL entries for stubs */
290 make_stub_holes(struct iter_forwards* fwd, struct config_file* cfg)
292 struct config_stub* s;
293 for(s = cfg->stubs; s; s = s->next) {
294 ldns_rdf* rdf = ldns_dname_new_frm_str(s->name);
296 log_err("cannot parse stub name '%s'", s->name);
299 if(!fwd_add_stub_hole(fwd, LDNS_RR_CLASS_IN,
300 ldns_rdf_data(rdf))) {
301 ldns_rdf_deep_free(rdf);
302 log_err("out of memory");
305 ldns_rdf_deep_free(rdf);
311 forwards_apply_cfg(struct iter_forwards* fwd, struct config_file* cfg)
314 fwd->tree = rbtree_create(fwd_cmp);
318 /* read forward zones */
319 if(!read_forwards(fwd, cfg))
321 if(!make_stub_holes(fwd, cfg))
323 fwd_init_parents(fwd);
328 forwards_lookup(struct iter_forwards* fwd, uint8_t* qname, uint16_t qclass)
330 /* lookup the forward zone in the tree */
331 rbnode_t* res = NULL;
332 struct iter_forward_zone *result;
333 struct iter_forward_zone key;
337 key.namelabs = dname_count_size_labels(qname, &key.namelen);
338 if(rbtree_find_less_equal(fwd->tree, &key, &res)) {
340 result = (struct iter_forward_zone*)res;
342 /* smaller element (or no element) */
344 result = (struct iter_forward_zone*)res;
345 if(!result || result->dclass != qclass)
347 /* count number of labels matched */
348 (void)dname_lab_cmp(result->name, result->namelabs, key.name,
350 while(result) { /* go up until qname is subdomain of stub */
351 if(result->namelabs <= m)
353 result = result->parent;
362 forwards_lookup_root(struct iter_forwards* fwd, uint16_t qclass)
365 return forwards_lookup(fwd, &root, qclass);
369 forwards_next_root(struct iter_forwards* fwd, uint16_t* dclass)
371 struct iter_forward_zone key;
373 struct iter_forward_zone* p;
375 /* first root item is first item in tree */
376 n = rbtree_first(fwd->tree);
379 p = (struct iter_forward_zone*)n;
380 if(dname_is_root(p->name)) {
384 /* root not first item? search for higher items */
385 *dclass = p->dclass + 1;
386 return forwards_next_root(fwd, dclass);
388 /* find class n in tree, we may get a direct hit, or if we don't
389 * this is the last item of the previous class so rbtree_next() takes
390 * us to the next root (if any) */
392 key.name = (uint8_t*)"\000";
395 key.dclass = *dclass;
397 if(rbtree_find_less_equal(fwd->tree, &key, &n)) {
401 /* smaller element */
402 if(!n || n == RBTREE_NULL)
403 return 0; /* nothing found */
406 return 0; /* no higher */
407 p = (struct iter_forward_zone*)n;
408 if(dname_is_root(p->name)) {
412 /* not a root node, return next higher item */
413 *dclass = p->dclass+1;
414 return forwards_next_root(fwd, dclass);
419 forwards_get_mem(struct iter_forwards* fwd)
421 struct iter_forward_zone* p;
425 s = sizeof(*fwd) + sizeof(*fwd->tree);
426 RBTREE_FOR(p, struct iter_forward_zone*, fwd->tree) {
427 s += sizeof(*p) + p->namelen + delegpt_get_mem(p->dp);
432 static struct iter_forward_zone*
433 fwd_zone_find(struct iter_forwards* fwd, uint16_t c, uint8_t* nm)
435 struct iter_forward_zone key;
439 key.namelabs = dname_count_size_labels(nm, &key.namelen);
440 return (struct iter_forward_zone*)rbtree_search(fwd->tree, &key);
444 forwards_add_zone(struct iter_forwards* fwd, uint16_t c, struct delegpt* dp)
446 struct iter_forward_zone *z;
447 if((z=fwd_zone_find(fwd, c, dp->name)) != NULL) {
448 (void)rbtree_delete(fwd->tree, &z->node);
451 if(!forwards_insert(fwd, c, dp))
453 fwd_init_parents(fwd);
458 forwards_delete_zone(struct iter_forwards* fwd, uint16_t c, uint8_t* nm)
460 struct iter_forward_zone *z;
461 if(!(z=fwd_zone_find(fwd, c, nm)))
462 return; /* nothing to do */
463 (void)rbtree_delete(fwd->tree, &z->node);
465 fwd_init_parents(fwd);
469 forwards_add_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm)
471 if(!fwd_add_stub_hole(fwd, c, nm)) {
474 fwd_init_parents(fwd);
479 forwards_delete_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm)
481 struct iter_forward_zone *z;
482 if(!(z=fwd_zone_find(fwd, c, nm)))
483 return; /* nothing to do */
485 return; /* not a stub hole */
486 (void)rbtree_delete(fwd->tree, &z->node);
488 fwd_init_parents(fwd);