contrib/unbound/iterator/iter_priv.c

   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 }