src/resolve/resolved-dns-rr.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2014 Lennart Poettering
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21  ***/
  22
  23 #include <netinet/in.h>
  24
  25 #include "bitmap.h"
  26 #include "dns-type.h"
  27 #include "hashmap.h"
  28 #include "in-addr-util.h"
  29 #include "list.h"
  30 #include "string-util.h"
  31
  32 typedef struct DnsResourceKey DnsResourceKey;
  33 typedef struct DnsResourceRecord DnsResourceRecord;
  34 typedef struct DnsTxtItem DnsTxtItem;
  35
  36 /* DNSKEY RR flags */
  37 #define DNSKEY_FLAG_SEP      (UINT16_C(1) << 0)
  38 #define DNSKEY_FLAG_REVOKE   (UINT16_C(1) << 7)
  39 #define DNSKEY_FLAG_ZONE_KEY (UINT16_C(1) << 8)
  40
  41 /* mDNS RR flags */
  42 #define MDNS_RR_CACHE_FLUSH  (UINT16_C(1) << 15)
  43
  44 /* DNSSEC algorithm identifiers, see
  45  * http://tools.ietf.org/html/rfc4034#appendix-A.1 and
  46  * https://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */
  47 enum {
  48         DNSSEC_ALGORITHM_RSAMD5 = 1,
  49         DNSSEC_ALGORITHM_DH,
  50         DNSSEC_ALGORITHM_DSA,
  51         DNSSEC_ALGORITHM_ECC,
  52         DNSSEC_ALGORITHM_RSASHA1,
  53         DNSSEC_ALGORITHM_DSA_NSEC3_SHA1,
  54         DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1,
  55         DNSSEC_ALGORITHM_RSASHA256 = 8,        /* RFC 5702 */
  56         DNSSEC_ALGORITHM_RSASHA512 = 10,       /* RFC 5702 */
  57         DNSSEC_ALGORITHM_ECC_GOST = 12,        /* RFC 5933 */
  58         DNSSEC_ALGORITHM_ECDSAP256SHA256 = 13, /* RFC 6605 */
  59         DNSSEC_ALGORITHM_ECDSAP384SHA384 = 14, /* RFC 6605 */
  60         DNSSEC_ALGORITHM_INDIRECT = 252,
  61         DNSSEC_ALGORITHM_PRIVATEDNS,
  62         DNSSEC_ALGORITHM_PRIVATEOID,
  63         _DNSSEC_ALGORITHM_MAX_DEFINED
  64 };
  65
  66 /* DNSSEC digest identifiers, see
  67  * https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */
  68 enum {
  69         DNSSEC_DIGEST_SHA1 = 1,
  70         DNSSEC_DIGEST_SHA256 = 2,              /* RFC 4509 */
  71         DNSSEC_DIGEST_GOST_R_34_11_94 = 3,     /* RFC 5933 */
  72         DNSSEC_DIGEST_SHA384 = 4,              /* RFC 6605 */
  73         _DNSSEC_DIGEST_MAX_DEFINED
  74 };
  75
  76 /* DNSSEC NSEC3 hash algorithms, see
  77  * https://www.iana.org/assignments/dnssec-nsec3-parameters/dnssec-nsec3-parameters.xhtml */
  78 enum {
  79         NSEC3_ALGORITHM_SHA1 = 1,
  80         _NSEC3_ALGORITHM_MAX_DEFINED
  81 };
  82
  83 struct DnsResourceKey {
  84         unsigned n_ref; /* (unsigned -1) for const keys, see below */
  85         uint16_t class, type;
  86         char *_name; /* don't access directly, use dns_resource_key_name()! */
  87 };
  88
  89 /* Creates a temporary resource key. This is only useful to quickly
  90  * look up something, without allocating a full DnsResourceKey object
  91  * for it. Note that it is not OK to take references to this kind of
  92  * resource key object. */
  93 #define DNS_RESOURCE_KEY_CONST(c, t, n)                 \
  94         ((DnsResourceKey) {                             \
  95                 .n_ref = (unsigned) -1,                 \
  96                 .class = c,                             \
  97                 .type = t,                              \
  98                 ._name = (char*) n,                     \
  99         })
 100
 101
 102 struct DnsTxtItem {
 103         size_t length;
 104         LIST_FIELDS(DnsTxtItem, items);
 105         uint8_t data[];
 106 };
 107
 108 struct DnsResourceRecord {
 109         unsigned n_ref;
 110         DnsResourceKey *key;
 111
 112         char *to_string;
 113
 114         uint32_t ttl;
 115         usec_t expiry; /* RRSIG signature expiry */
 116
 117         /* How many labels to strip to determine "signer" of the RRSIG (aka, the zone). -1 if not signed. */
 118         unsigned n_skip_labels_signer;
 119         /* How many labels to strip to determine "synthesizing source" of this RR, i.e. the wildcard's immediate parent. -1 if not signed. */
 120         unsigned n_skip_labels_source;
 121
 122         bool unparseable:1;
 123
 124         bool wire_format_canonical:1;
 125         void *wire_format;
 126         size_t wire_format_size;
 127         size_t wire_format_rdata_offset;
 128
 129         union {
 130                 struct {
 131                         void *data;
 132                         size_t data_size;
 133                 } generic, opt;
 134
 135                 struct {
 136                         uint16_t priority;
 137                         uint16_t weight;
 138                         uint16_t port;
 139                         char *name;
 140                 } srv;
 141
 142                 struct {
 143                         char *name;
 144                 } ptr, ns, cname, dname;
 145
 146                 struct {
 147                         char *cpu;
 148                         char *os;
 149                 } hinfo;
 150
 151                 struct {
 152                         DnsTxtItem *items;
 153                 } txt, spf;
 154
 155                 struct {
 156                         struct in_addr in_addr;
 157                 } a;
 158
 159                 struct {
 160                         struct in6_addr in6_addr;
 161                 } aaaa;
 162
 163                 struct {
 164                         char *mname;
 165                         char *rname;
 166                         uint32_t serial;
 167                         uint32_t refresh;
 168                         uint32_t retry;
 169                         uint32_t expire;
 170                         uint32_t minimum;
 171                 } soa;
 172
 173                 struct {
 174                         uint16_t priority;
 175                         char *exchange;
 176                 } mx;
 177
 178                 /* https://tools.ietf.org/html/rfc1876 */
 179                 struct {
 180                         uint8_t version;
 181                         uint8_t size;
 182                         uint8_t horiz_pre;
 183                         uint8_t vert_pre;
 184                         uint32_t latitude;
 185                         uint32_t longitude;
 186                         uint32_t altitude;
 187                 } loc;
 188
 189                 /* https://tools.ietf.org/html/rfc4255#section-3.1 */
 190                 struct {
 191                         uint8_t algorithm;
 192                         uint8_t fptype;
 193                         void *fingerprint;
 194                         size_t fingerprint_size;
 195                 } sshfp;
 196
 197                 /* http://tools.ietf.org/html/rfc4034#section-2.1 */
 198                 struct {
 199                         uint16_t flags;
 200                         uint8_t protocol;
 201                         uint8_t algorithm;
 202                         void* key;
 203                         size_t key_size;
 204                 } dnskey;
 205
 206                 /* http://tools.ietf.org/html/rfc4034#section-3.1 */
 207                 struct {
 208                         uint16_t type_covered;
 209                         uint8_t algorithm;
 210                         uint8_t labels;
 211                         uint32_t original_ttl;
 212                         uint32_t expiration;
 213                         uint32_t inception;
 214                         uint16_t key_tag;
 215                         char *signer;
 216                         void *signature;
 217                         size_t signature_size;
 218                 } rrsig;
 219
 220                 /* https://tools.ietf.org/html/rfc4034#section-4.1 */
 221                 struct {
 222                         char *next_domain_name;
 223                         Bitmap *types;
 224                 } nsec;
 225
 226                 /* https://tools.ietf.org/html/rfc4034#section-5.1 */
 227                 struct {
 228                         uint16_t key_tag;
 229                         uint8_t algorithm;
 230                         uint8_t digest_type;
 231                         void *digest;
 232                         size_t digest_size;
 233                 } ds;
 234
 235                 struct {
 236                         uint8_t algorithm;
 237                         uint8_t flags;
 238                         uint16_t iterations;
 239                         void *salt;
 240                         size_t salt_size;
 241                         void *next_hashed_name;
 242                         size_t next_hashed_name_size;
 243                         Bitmap *types;
 244                 } nsec3;
 245
 246                 /* https://tools.ietf.org/html/draft-ietf-dane-protocol-23 */
 247                 struct {
 248                         uint8_t cert_usage;
 249                         uint8_t selector;
 250                         uint8_t matching_type;
 251                         void *data;
 252                         size_t data_size;
 253                 } tlsa;
 254
 255                 /* https://tools.ietf.org/html/rfc6844 */
 256                 struct {
 257                         uint8_t flags;
 258                         char *tag;
 259                         void *value;
 260                         size_t value_size;
 261                 } caa;
 262         };
 263 };
 264
 265 static inline const void* DNS_RESOURCE_RECORD_RDATA(DnsResourceRecord *rr) {
 266         if (!rr)
 267                 return NULL;
 268
 269         if (!rr->wire_format)
 270                 return NULL;
 271
 272         assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
 273         return (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset;
 274 }
 275
 276 static inline size_t DNS_RESOURCE_RECORD_RDATA_SIZE(DnsResourceRecord *rr) {
 277         if (!rr)
 278                 return 0;
 279         if (!rr->wire_format)
 280                 return 0;
 281
 282         assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
 283         return rr->wire_format_size - rr->wire_format_rdata_offset;
 284 }
 285
 286 static inline uint8_t DNS_RESOURCE_RECORD_OPT_VERSION_SUPPORTED(DnsResourceRecord *rr) {
 287         assert(rr);
 288         assert(rr->key->type == DNS_TYPE_OPT);
 289
 290         return ((rr->ttl >> 16) & 0xFF) == 0;
 291 }
 292
 293 DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name);
 294 DnsResourceKey* dns_resource_key_new_redirect(const DnsResourceKey *key, const DnsResourceRecord *cname);
 295 int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key, char *name);
 296 DnsResourceKey* dns_resource_key_new_consume(uint16_t class, uint16_t type, char *name);
 297 DnsResourceKey* dns_resource_key_ref(DnsResourceKey *key);
 298 DnsResourceKey* dns_resource_key_unref(DnsResourceKey *key);
 299 const char* dns_resource_key_name(const DnsResourceKey *key);
 300 bool dns_resource_key_is_address(const DnsResourceKey *key);
 301 int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b);
 302 int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr, const char *search_domain);
 303 int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain);
 304 int dns_resource_key_match_soa(const DnsResourceKey *key, const DnsResourceKey *soa);
 305
 306 /* _DNS_{CLASS,TYPE}_STRING_MAX include one byte for NUL, which we use for space instead below.
 307  * DNS_HOSTNAME_MAX does not include the NUL byte, so we need to add 1. */
 308 #define DNS_RESOURCE_KEY_STRING_MAX (_DNS_CLASS_STRING_MAX + _DNS_TYPE_STRING_MAX + DNS_HOSTNAME_MAX + 1)
 309
 310 char* dns_resource_key_to_string(const DnsResourceKey *key, char *buf, size_t buf_size);
 311 ssize_t dns_resource_record_payload(DnsResourceRecord *rr, void **out);
 312
 313 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceKey*, dns_resource_key_unref);
 314
 315 static inline bool dns_key_is_shared(const DnsResourceKey *key) {
 316         return IN_SET(key->type, DNS_TYPE_PTR);
 317 }
 318
 319 bool dns_resource_key_reduce(DnsResourceKey **a, DnsResourceKey **b);
 320
 321 DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key);
 322 DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, const char *name);
 323 DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr);
 324 DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr);
 325 int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name);
 326 int dns_resource_record_new_address(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name);
 327 int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b);
 328 const char* dns_resource_record_to_string(DnsResourceRecord *rr);
 329 DnsResourceRecord *dns_resource_record_copy(DnsResourceRecord *rr);
 330 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref);
 331
 332 int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical);
 333
 334 int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret);
 335 int dns_resource_record_source(DnsResourceRecord *rr, const char **ret);
 336 int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone);
 337 int dns_resource_record_is_synthetic(DnsResourceRecord *rr);
 338
 339 int dns_resource_record_clamp_ttl(DnsResourceRecord **rr, uint32_t max_ttl);
 340
 341 DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i);
 342 bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b);
 343 DnsTxtItem *dns_txt_item_copy(DnsTxtItem *i);
 344 int dns_txt_item_new_empty(DnsTxtItem **ret);
 345
 346 void dns_resource_record_hash_func(const void *i, struct siphash *state);
 347
 348 extern const struct hash_ops dns_resource_key_hash_ops;
 349 extern const struct hash_ops dns_resource_record_hash_ops;
 350
 351 int dnssec_algorithm_to_string_alloc(int i, char **ret);
 352 int dnssec_algorithm_from_string(const char *s) _pure_;
 353
 354 int dnssec_digest_to_string_alloc(int i, char **ret);
 355 int dnssec_digest_from_string(const char *s) _pure_;