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 55struct 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 70void 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 */ 78static 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 */ 109static 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 147int 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 */ 173static int 174priv_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 */ 189static int 190priv_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 204size_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/** remove RR from msgparse RRset, return true if rrset is entirely bad */ 211static int 212remove_rr(const char* str, sldns_buffer* pkt, struct rrset_parse* rrset, 213 struct rr_parse* prev, struct rr_parse** rr, struct sockaddr_storage* addr, socklen_t addrlen) 214{ 215 if(verbosity >= VERB_QUERY && rrset->dname_len <= LDNS_MAX_DOMAINLEN && str) { 216 uint8_t buf[LDNS_MAX_DOMAINLEN+1]; 217 dname_pkt_copy(pkt, buf, rrset->dname); 218 log_name_addr(VERB_QUERY, str, buf, addr, addrlen); 219 } 220 if(prev) 221 prev->next = (*rr)->next; 222 else rrset->rr_first = (*rr)->next; 223 if(rrset->rr_last == *rr) 224 rrset->rr_last = prev; 225 rrset->rr_count --; 226 rrset->size -= (*rr)->size; 227 /* rr struct still exists, but is unlinked, so that in the for loop 228 * the rr->next works fine to continue. */ 229 return rrset->rr_count == 0; 230} 231 232int priv_rrset_bad(struct iter_priv* priv, sldns_buffer* pkt, 233 struct rrset_parse* rrset) 234{ 235 if(priv->a.count == 0) 236 return 0; /* there are no blocked addresses */ 237 238 /* see if it is a private name, that is allowed to have any */ 239 if(priv_lookup_name(priv, pkt, rrset->dname, rrset->dname_len, 240 ntohs(rrset->rrset_class))) { 241 return 0; 242 } else { 243 /* so its a public name, check the address */ 244 socklen_t len; 245 struct rr_parse* rr, *prev = NULL; 246 if(rrset->type == LDNS_RR_TYPE_A) { 247 struct sockaddr_storage addr; 248 struct sockaddr_in sa; 249 250 len = (socklen_t)sizeof(sa); 251 memset(&sa, 0, len); 252 sa.sin_family = AF_INET; 253 sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT); 254 for(rr = rrset->rr_first; rr; rr = rr->next) { 255 if(sldns_read_uint16(rr->ttl_data+4) 256 != INET_SIZE) { 257 prev = rr; 258 continue; 259 } 260 memmove(&sa.sin_addr, rr->ttl_data+4+2, 261 INET_SIZE); 262 memmove(&addr, &sa, len); 263 if(priv_lookup_addr(priv, &addr, len)) { 264 if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len)) 265 return 1; 266 continue; 267 } 268 prev = rr; 269 } 270 } else if(rrset->type == LDNS_RR_TYPE_AAAA) { 271 struct sockaddr_storage addr; 272 struct sockaddr_in6 sa; 273 len = (socklen_t)sizeof(sa); 274 memset(&sa, 0, len); 275 sa.sin6_family = AF_INET6; 276 sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT); 277 for(rr = rrset->rr_first; rr; rr = rr->next) { 278 if(sldns_read_uint16(rr->ttl_data+4) 279 != INET6_SIZE) { 280 prev = rr; 281 continue; 282 } 283 memmove(&sa.sin6_addr, rr->ttl_data+4+2, 284 INET6_SIZE); 285 memmove(&addr, &sa, len); 286 if(priv_lookup_addr(priv, &addr, len)) { 287 if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len)) 288 return 1; 289 continue; 290 } 291 prev = rr; 292 } 293 } 294 } 295 return 0; 296} 297