1 /*
2 * iterator/iter_priv.c - iterative resolver private address and domain store
3 *
4 * Copyright (c) 2008, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
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.
18 *
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.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 /**
37 * \file
38 *
39 * This file contains functions to assist the iterator module.
40 * Keep track of the private addresses and lookup fast.
41 */
42
43 #include "config.h"
44 #include "iterator/iter_priv.h"
45 #include "util/regional.h"
46 #include "util/log.h"
47 #include "util/config_file.h"
48 #include "util/data/dname.h"
49 #include "util/data/msgparse.h"
50 #include "util/net_help.h"
51 #include "util/storage/dnstree.h"
52 #include "sldns/str2wire.h"
53 #include "sldns/sbuffer.h"
54
priv_create(void)55 struct iter_priv* priv_create(void)
56 {
57 struct iter_priv* priv = (struct iter_priv*)calloc(1, sizeof(*priv));
58 if(!priv)
59 return NULL;
60 priv->region = regional_create();
61 if(!priv->region) {
62 priv_delete(priv);
63 return NULL;
64 }
65 addr_tree_init(&priv->a);
66 name_tree_init(&priv->n);
67 return priv;
68 }
69
priv_delete(struct iter_priv * priv)70 void priv_delete(struct iter_priv* priv)
71 {
72 if(!priv) return;
73 regional_destroy(priv->region);
74 free(priv);
75 }
76
77 /** Read private-addr declarations from config */
read_addrs(struct iter_priv * priv,struct config_file * cfg)78 static int read_addrs(struct iter_priv* priv, struct config_file* cfg)
79 {
80 /* parse addresses, report errors, insert into tree */
81 struct config_strlist* p;
82 struct addr_tree_node* n;
83 struct sockaddr_storage addr;
84 int net;
85 socklen_t addrlen;
86
87 for(p = cfg->private_address; p; p = p->next) {
88 log_assert(p->str);
89 if(!netblockstrtoaddr(p->str, UNBOUND_DNS_PORT, &addr,
90 &addrlen, &net)) {
91 log_err("cannot parse private-address: %s", p->str);
92 return 0;
93 }
94 n = (struct addr_tree_node*)regional_alloc(priv->region,
95 sizeof(*n));
96 if(!n) {
97 log_err("out of memory");
98 return 0;
99 }
100 if(!addr_tree_insert(&priv->a, n, &addr, addrlen, net)) {
101 verbose(VERB_QUERY, "ignoring duplicate "
102 "private-address: %s", p->str);
103 }
104 }
105 return 1;
106 }
107
108 /** Read private-domain declarations from config */
read_names(struct iter_priv * priv,struct config_file * cfg)109 static int read_names(struct iter_priv* priv, struct config_file* cfg)
110 {
111 /* parse names, report errors, insert into tree */
112 struct config_strlist* p;
113 struct name_tree_node* n;
114 uint8_t* nm, *nmr;
115 size_t nm_len;
116 int nm_labs;
117
118 for(p = cfg->private_domain; p; p = p->next) {
119 log_assert(p->str);
120 nm = sldns_str2wire_dname(p->str, &nm_len);
121 if(!nm) {
122 log_err("cannot parse private-domain: %s", p->str);
123 return 0;
124 }
125 nm_labs = dname_count_size_labels(nm, &nm_len);
126 nmr = (uint8_t*)regional_alloc_init(priv->region, nm, nm_len);
127 free(nm);
128 if(!nmr) {
129 log_err("out of memory");
130 return 0;
131 }
132 n = (struct name_tree_node*)regional_alloc(priv->region,
133 sizeof(*n));
134 if(!n) {
135 log_err("out of memory");
136 return 0;
137 }
138 if(!name_tree_insert(&priv->n, n, nmr, nm_len, nm_labs,
139 LDNS_RR_CLASS_IN)) {
140 verbose(VERB_QUERY, "ignoring duplicate "
141 "private-domain: %s", p->str);
142 }
143 }
144 return 1;
145 }
146
priv_apply_cfg(struct iter_priv * priv,struct config_file * cfg)147 int priv_apply_cfg(struct iter_priv* priv, struct config_file* cfg)
148 {
149 /* empty the current contents */
150 regional_free_all(priv->region);
151 addr_tree_init(&priv->a);
152 name_tree_init(&priv->n);
153
154 /* read new contents */
155 if(!read_addrs(priv, cfg))
156 return 0;
157 if(!read_names(priv, cfg))
158 return 0;
159
160 /* prepare for lookups */
161 addr_tree_init_parents(&priv->a);
162 name_tree_init_parents(&priv->n);
163 return 1;
164 }
165
166 /**
167 * See if an address is blocked.
168 * @param priv: structure for address storage.
169 * @param addr: address to check
170 * @param addrlen: length of addr.
171 * @return: true if the address must not be queried. false if unlisted.
172 */
173 static int
priv_lookup_addr(struct iter_priv * priv,struct sockaddr_storage * addr,socklen_t addrlen)174 priv_lookup_addr(struct iter_priv* priv, struct sockaddr_storage* addr,
175 socklen_t addrlen)
176 {
177 return addr_tree_lookup(&priv->a, addr, addrlen) != NULL;
178 }
179
180 /**
181 * See if a name is whitelisted.
182 * @param priv: structure for address storage.
183 * @param pkt: the packet (for compression ptrs).
184 * @param name: name to check.
185 * @param name_len: uncompressed length of the name to check.
186 * @param dclass: class to check.
187 * @return: true if the name is OK. false if unlisted.
188 */
189 static int
priv_lookup_name(struct iter_priv * priv,sldns_buffer * pkt,uint8_t * name,size_t name_len,uint16_t dclass)190 priv_lookup_name(struct iter_priv* priv, sldns_buffer* pkt,
191 uint8_t* name, size_t name_len, uint16_t dclass)
192 {
193 size_t len;
194 uint8_t decomp[256];
195 int labs;
196 if(name_len >= sizeof(decomp))
197 return 0;
198 dname_pkt_copy(pkt, decomp, name);
199 labs = dname_count_size_labels(decomp, &len);
200 log_assert(name_len == len);
201 return name_tree_lookup(&priv->n, decomp, len, labs, dclass) != NULL;
202 }
203
priv_get_mem(struct iter_priv * priv)204 size_t priv_get_mem(struct iter_priv* priv)
205 {
206 if(!priv) return 0;
207 return sizeof(*priv) + regional_get_mem(priv->region);
208 }
209
priv_rrset_bad(struct iter_priv * priv,sldns_buffer * pkt,struct rrset_parse * rrset)210 int priv_rrset_bad(struct iter_priv* priv, sldns_buffer* pkt,
211 struct rrset_parse* rrset)
212 {
213 if(priv->a.count == 0)
214 return 0; /* there are no blocked addresses */
215
216 /* see if it is a private name, that is allowed to have any */
217 if(priv_lookup_name(priv, pkt, rrset->dname, rrset->dname_len,
218 ntohs(rrset->rrset_class))) {
219 return 0;
220 } else {
221 /* so its a public name, check the address */
222 socklen_t len;
223 struct rr_parse* rr, *prev = NULL;
224 if(rrset->type == LDNS_RR_TYPE_A) {
225 struct sockaddr_storage addr;
226 struct sockaddr_in sa;
227
228 len = (socklen_t)sizeof(sa);
229 memset(&sa, 0, len);
230 sa.sin_family = AF_INET;
231 sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT);
232 for(rr = rrset->rr_first; rr; rr = rr->next) {
233 if(sldns_read_uint16(rr->ttl_data+4)
234 != INET_SIZE) {
235 prev = rr;
236 continue;
237 }
238 memmove(&sa.sin_addr, rr->ttl_data+4+2,
239 INET_SIZE);
240 memmove(&addr, &sa, len);
241 if(priv_lookup_addr(priv, &addr, len)) {
242 if(msgparse_rrset_remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, rr, &addr, len))
243 return 1;
244 continue;
245 }
246 prev = rr;
247 }
248 } else if(rrset->type == LDNS_RR_TYPE_AAAA) {
249 struct sockaddr_storage addr;
250 struct sockaddr_in6 sa;
251 len = (socklen_t)sizeof(sa);
252 memset(&sa, 0, len);
253 sa.sin6_family = AF_INET6;
254 sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT);
255 for(rr = rrset->rr_first; rr; rr = rr->next) {
256 if(sldns_read_uint16(rr->ttl_data+4)
257 != INET6_SIZE) {
258 prev = rr;
259 continue;
260 }
261 memmove(&sa.sin6_addr, rr->ttl_data+4+2,
262 INET6_SIZE);
263 memmove(&addr, &sa, len);
264 if(priv_lookup_addr(priv, &addr, len)) {
265 if(msgparse_rrset_remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, rr, &addr, len))
266 return 1;
267 continue;
268 }
269 prev = rr;
270 }
271 }
272 }
273 return 0;
274 }
275