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 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 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 */ 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 */ 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 } 146 147 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 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 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 } 203 204 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 } 209 210 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