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 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. 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 <ldns/dname.h> 45 #include "iterator/iter_priv.h" 46 #include "util/regional.h" 47 #include "util/log.h" 48 #include "util/config_file.h" 49 #include "util/data/dname.h" 50 #include "util/data/msgparse.h" 51 #include "util/net_help.h" 52 #include "util/storage/dnstree.h" 53 54 struct iter_priv* priv_create(void) 55 { 56 struct iter_priv* priv = (struct iter_priv*)calloc(1, sizeof(*priv)); 57 if(!priv) 58 return NULL; 59 priv->region = regional_create(); 60 if(!priv->region) { 61 priv_delete(priv); 62 return NULL; 63 } 64 addr_tree_init(&priv->a); 65 name_tree_init(&priv->n); 66 return priv; 67 } 68 69 void priv_delete(struct iter_priv* priv) 70 { 71 if(!priv) return; 72 regional_destroy(priv->region); 73 free(priv); 74 } 75 76 /** Read private-addr declarations from config */ 77 static int read_addrs(struct iter_priv* priv, struct config_file* cfg) 78 { 79 /* parse addresses, report errors, insert into tree */ 80 struct config_strlist* p; 81 struct addr_tree_node* n; 82 struct sockaddr_storage addr; 83 int net; 84 socklen_t addrlen; 85 86 for(p = cfg->private_address; p; p = p->next) { 87 log_assert(p->str); 88 if(!netblockstrtoaddr(p->str, UNBOUND_DNS_PORT, &addr, 89 &addrlen, &net)) { 90 log_err("cannot parse private-address: %s", p->str); 91 return 0; 92 } 93 n = (struct addr_tree_node*)regional_alloc(priv->region, 94 sizeof(*n)); 95 if(!n) { 96 log_err("out of memory"); 97 return 0; 98 } 99 if(!addr_tree_insert(&priv->a, n, &addr, addrlen, net)) { 100 verbose(VERB_QUERY, "ignoring duplicate " 101 "private-address: %s", p->str); 102 } 103 } 104 return 1; 105 } 106 107 /** Read private-domain declarations from config */ 108 static int read_names(struct iter_priv* priv, struct config_file* cfg) 109 { 110 /* parse names, report errors, insert into tree */ 111 struct config_strlist* p; 112 struct name_tree_node* n; 113 uint8_t* nm; 114 size_t nm_len; 115 int nm_labs; 116 ldns_rdf* rdf; 117 118 for(p = cfg->private_domain; p; p = p->next) { 119 log_assert(p->str); 120 rdf = ldns_dname_new_frm_str(p->str); 121 if(!rdf) { 122 log_err("cannot parse private-domain: %s", p->str); 123 return 0; 124 } 125 nm = ldns_rdf_data(rdf); 126 nm_labs = dname_count_size_labels(nm, &nm_len); 127 nm = (uint8_t*)regional_alloc_init(priv->region, nm, nm_len); 128 ldns_rdf_deep_free(rdf); 129 if(!nm) { 130 log_err("out of memory"); 131 return 0; 132 } 133 n = (struct name_tree_node*)regional_alloc(priv->region, 134 sizeof(*n)); 135 if(!n) { 136 log_err("out of memory"); 137 return 0; 138 } 139 if(!name_tree_insert(&priv->n, n, nm, nm_len, nm_labs, 140 LDNS_RR_CLASS_IN)) { 141 verbose(VERB_QUERY, "ignoring duplicate " 142 "private-domain: %s", p->str); 143 } 144 } 145 return 1; 146 } 147 148 int priv_apply_cfg(struct iter_priv* priv, struct config_file* cfg) 149 { 150 /* empty the current contents */ 151 regional_free_all(priv->region); 152 addr_tree_init(&priv->a); 153 name_tree_init(&priv->n); 154 155 /* read new contents */ 156 if(!read_addrs(priv, cfg)) 157 return 0; 158 if(!read_names(priv, cfg)) 159 return 0; 160 161 /* prepare for lookups */ 162 addr_tree_init_parents(&priv->a); 163 name_tree_init_parents(&priv->n); 164 return 1; 165 } 166 167 /** 168 * See if an address is blocked. 169 * @param priv: structure for address storage. 170 * @param addr: address to check 171 * @param addrlen: length of addr. 172 * @return: true if the address must not be queried. false if unlisted. 173 */ 174 static int 175 priv_lookup_addr(struct iter_priv* priv, struct sockaddr_storage* addr, 176 socklen_t addrlen) 177 { 178 return addr_tree_lookup(&priv->a, addr, addrlen) != NULL; 179 } 180 181 /** 182 * See if a name is whitelisted. 183 * @param priv: structure for address storage. 184 * @param pkt: the packet (for compression ptrs). 185 * @param name: name to check. 186 * @param name_len: uncompressed length of the name to check. 187 * @param dclass: class to check. 188 * @return: true if the name is OK. false if unlisted. 189 */ 190 static int 191 priv_lookup_name(struct iter_priv* priv, ldns_buffer* pkt, 192 uint8_t* name, size_t name_len, uint16_t dclass) 193 { 194 size_t len; 195 uint8_t decomp[256]; 196 int labs; 197 if(name_len >= sizeof(decomp)) 198 return 0; 199 dname_pkt_copy(pkt, decomp, name); 200 labs = dname_count_size_labels(decomp, &len); 201 log_assert(name_len == len); 202 return name_tree_lookup(&priv->n, decomp, len, labs, dclass) != NULL; 203 } 204 205 size_t priv_get_mem(struct iter_priv* priv) 206 { 207 if(!priv) return 0; 208 return sizeof(*priv) + regional_get_mem(priv->region); 209 } 210 211 int priv_rrset_bad(struct iter_priv* priv, ldns_buffer* pkt, 212 struct rrset_parse* rrset) 213 { 214 if(priv->a.count == 0) 215 return 0; /* there are no blocked addresses */ 216 217 /* see if it is a private name, that is allowed to have any */ 218 if(priv_lookup_name(priv, pkt, rrset->dname, rrset->dname_len, 219 ntohs(rrset->rrset_class))) { 220 return 0; 221 } else { 222 /* so its a public name, check the address */ 223 socklen_t len; 224 struct rr_parse* rr; 225 if(rrset->type == LDNS_RR_TYPE_A) { 226 struct sockaddr_storage addr; 227 struct sockaddr_in sa; 228 229 len = (socklen_t)sizeof(sa); 230 memset(&sa, 0, len); 231 sa.sin_family = AF_INET; 232 sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); 233 for(rr = rrset->rr_first; rr; rr = rr->next) { 234 if(ldns_read_uint16(rr->ttl_data+4) 235 != INET_SIZE) 236 continue; 237 memmove(&sa.sin_addr, rr->ttl_data+4+2, 238 INET_SIZE); 239 memmove(&addr, &sa, len); 240 if(priv_lookup_addr(priv, &addr, len)) 241 return 1; 242 } 243 } else if(rrset->type == LDNS_RR_TYPE_AAAA) { 244 struct sockaddr_storage addr; 245 struct sockaddr_in6 sa; 246 len = (socklen_t)sizeof(sa); 247 memset(&sa, 0, len); 248 sa.sin6_family = AF_INET6; 249 sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); 250 for(rr = rrset->rr_first; rr; rr = rr->next) { 251 if(ldns_read_uint16(rr->ttl_data+4) 252 != INET6_SIZE) 253 continue; 254 memmove(&sa.sin6_addr, rr->ttl_data+4+2, 255 INET6_SIZE); 256 memmove(&addr, &sa, len); 257 if(priv_lookup_addr(priv, &addr, len)) 258 return 1; 259 } 260 } 261 } 262 return 0; 263 } 264