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_ED25519 = 15,         /* RFC 8080 */
  61         DNSSEC_ALGORITHM_ED448 = 16,           /* RFC 8080 */
  62         DNSSEC_ALGORITHM_INDIRECT = 252,
  63         DNSSEC_ALGORITHM_PRIVATEDNS,
  64         DNSSEC_ALGORITHM_PRIVATEOID,
  65         _DNSSEC_ALGORITHM_MAX_DEFINED
  66 };
  67
  68 /* DNSSEC digest identifiers, see
  69  * https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */
  70 enum {
  71         DNSSEC_DIGEST_SHA1 = 1,
  72         DNSSEC_DIGEST_SHA256 = 2,              /* RFC 4509 */
  73         DNSSEC_DIGEST_GOST_R_34_11_94 = 3,     /* RFC 5933 */
  74         DNSSEC_DIGEST_SHA384 = 4,              /* RFC 6605 */
  75         _DNSSEC_DIGEST_MAX_DEFINED
  76 };
  77
  78 /* DNSSEC NSEC3 hash algorithms, see
  79  * https://www.iana.org/assignments/dnssec-nsec3-parameters/dnssec-nsec3-parameters.xhtml */
  80 enum {
  81         NSEC3_ALGORITHM_SHA1 = 1,
  82         _NSEC3_ALGORITHM_MAX_DEFINED
  83 };
  84
  85 struct DnsResourceKey {
  86         unsigned n_ref; /* (unsigned -1) for const keys, see below */
  87         uint16_t class, type;
  88         char *_name; /* don't access directly, use dns_resource_key_name()! */
  89 };
  90
  91 /* Creates a temporary resource key. This is only useful to quickly
  92  * look up something, without allocating a full DnsResourceKey object
  93  * for it. Note that it is not OK to take references to this kind of
  94  * resource key object. */
  95 #define DNS_RESOURCE_KEY_CONST(c, t, n)                 \
  96         ((DnsResourceKey) {                             \
  97                 .n_ref = (unsigned) -1,                 \
  98                 .class = c,                             \
  99                 .type = t,                              \
 100                 ._name = (char*) n,                     \
 101         })
 102
 103
 104 struct DnsTxtItem {
 105         size_t length;
 106         LIST_FIELDS(DnsTxtItem, items);
 107         uint8_t data[];
 108 };
 109
 110 struct DnsResourceRecord {
 111         unsigned n_ref;
 112         DnsResourceKey *key;
 113
 114         char *to_string;
 115
 116         uint32_t ttl;
 117         usec_t expiry; /* RRSIG signature expiry */
 118
 119         /* How many labels to strip to determine "signer" of the RRSIG (aka, the zone). -1 if not signed. */
 120         unsigned n_skip_labels_signer;
 121         /* How many labels to strip to determine "synthesizing source" of this RR, i.e. the wildcard's immediate parent. -1 if not signed. */
 122         unsigned n_skip_labels_source;
 123
 124         bool unparseable:1;
 125
 126         bool wire_format_canonical:1;
 127         void *wire_format;
 128         size_t wire_format_size;
 129         size_t wire_format_rdata_offset;
 130
 131         union {
 132                 struct {
 133                         void *data;
 134                         size_t data_size;
 135                 } generic, opt;
 136
 137                 struct {
 138                         uint16_t priority;
 139                         uint16_t weight;
 140                         uint16_t port;
 141                         char *name;
 142                 } srv;
 143
 144                 struct {
 145                         char *name;
 146                 } ptr, ns, cname, dname;
 147
 148                 struct {
 149                         char *cpu;
 150                         char *os;
 151                 } hinfo;
 152
 153                 struct {
 154                         DnsTxtItem *items;
 155                 } txt, spf;
 156
 157                 struct {
 158                         struct in_addr in_addr;
 159                 } a;
 160
 161                 struct {
 162                         struct in6_addr in6_addr;
 163                 } aaaa;
 164
 165                 struct {
 166                         char *mname;
 167                         char *rname;
 168                         uint32_t serial;
 169                         uint32_t refresh;
 170                         uint32_t retry;
 171                         uint32_t expire;
 172                         uint32_t minimum;
 173                 } soa;
 174
 175                 struct {
 176                         uint16_t priority;
 177                         char *exchange;
 178                 } mx;
 179
 180                 /* https://tools.ietf.org/html/rfc1876 */
 181                 struct {
 182                         uint8_t version;
 183                         uint8_t size;
 184                         uint8_t horiz_pre;
 185                         uint8_t vert_pre;
 186                         uint32_t latitude;
 187                         uint32_t longitude;
 188                         uint32_t altitude;
 189                 } loc;
 190
 191                 /* https://tools.ietf.org/html/rfc4255#section-3.1 */
 192                 struct {
 193                         uint8_t algorithm;
 194                         uint8_t fptype;
 195                         void *fingerprint;
 196                         size_t fingerprint_size;
 197                 } sshfp;
 198
 199                 /* http://tools.ietf.org/html/rfc4034#section-2.1 */
 200                 struct {
 201                         uint16_t flags;
 202                         uint8_t protocol;
 203                         uint8_t algorithm;
 204                         void* key;
 205                         size_t key_size;
 206                 } dnskey;
 207
 208                 /* http://tools.ietf.org/html/rfc4034#section-3.1 */
 209                 struct {
 210                         uint16_t type_covered;
 211                         uint8_t algorithm;
 212                         uint8_t labels;
 213                         uint32_t original_ttl;
 214                         uint32_t expiration;
 215                         uint32_t inception;
 216                         uint16_t key_tag;
 217                         char *signer;
 218                         void *signature;
 219                         size_t signature_size;
 220                 } rrsig;
 221
 222                 /* https://tools.ietf.org/html/rfc4034#section-4.1 */
 223                 struct {
 224                         char *next_domain_name;
 225                         Bitmap *types;
 226                 } nsec;
 227
 228                 /* https://tools.ietf.org/html/rfc4034#section-5.1 */
 229                 struct {
 230                         uint16_t key_tag;
 231                         uint8_t algorithm;
 232                         uint8_t digest_type;
 233                         void *digest;
 234                         size_t digest_size;
 235                 } ds;
 236
 237                 struct {
 238                         uint8_t algorithm;
 239                         uint8_t flags;
 240                         uint16_t iterations;
 241                         void *salt;
 242                         size_t salt_size;
 243                         void *next_hashed_name;
 244                         size_t next_hashed_name_size;
 245                         Bitmap *types;
 246                 } nsec3;
 247
 248                 /* https://tools.ietf.org/html/draft-ietf-dane-protocol-23 */
 249                 struct {
 250                         uint8_t cert_usage;
 251                         uint8_t selector;
 252                         uint8_t matching_type;
 253                         void *data;
 254                         size_t data_size;
 255                 } tlsa;
 256
 257                 /* https://tools.ietf.org/html/rfc6844 */
 258                 struct {
 259                         uint8_t flags;
 260                         char *tag;
 261                         void *value;
 262                         size_t value_size;
 263                 } caa;
 264         };
 265 };
 266
 267 static inline const void* DNS_RESOURCE_RECORD_RDATA(DnsResourceRecord *rr) {
 268         if (!rr)
 269                 return NULL;
 270
 271         if (!rr->wire_format)
 272                 return NULL;
 273
 274         assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
 275         return (uint8_t*) rr->wire_format + rr->wire_format_rdata_offset;
 276 }
 277
 278 static inline size_t DNS_RESOURCE_RECORD_RDATA_SIZE(DnsResourceRecord *rr) {
 279         if (!rr)
 280                 return 0;
 281         if (!rr->wire_format)
 282                 return 0;
 283
 284         assert(rr->wire_format_rdata_offset <= rr->wire_format_size);
 285         return rr->wire_format_size - rr->wire_format_rdata_offset;
 286 }
 287
 288 static inline uint8_t DNS_RESOURCE_RECORD_OPT_VERSION_SUPPORTED(DnsResourceRecord *rr) {
 289         assert(rr);
 290         assert(rr->key->type == DNS_TYPE_OPT);
 291
 292         return ((rr->ttl >> 16) & 0xFF) == 0;
 293 }
 294
 295 DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name);
 296 DnsResourceKey* dns_resource_key_new_redirect(const DnsResourceKey *key, const DnsResourceRecord *cname);
 297 int dns_resource_key_new_append_suffix(DnsResourceKey **ret, DnsResourceKey *key, char *name);
 298 DnsResourceKey* dns_resource_key_new_consume(uint16_t class, uint16_t type, char *name);
 299 DnsResourceKey* dns_resource_key_ref(DnsResourceKey *key);
 300 DnsResourceKey* dns_resource_key_unref(DnsResourceKey *key);
 301 const char* dns_resource_key_name(const DnsResourceKey *key);
 302 bool dns_resource_key_is_address(const DnsResourceKey *key);
 303 bool dns_resource_key_is_dnssd_ptr(const DnsResourceKey *key);
 304 int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b);
 305 int dns_resource_key_match_rr(const DnsResourceKey *key, DnsResourceRecord *rr, const char *search_domain);
 306 int dns_resource_key_match_cname_or_dname(const DnsResourceKey *key, const DnsResourceKey *cname, const char *search_domain);
 307 int dns_resource_key_match_soa(const DnsResourceKey *key, const DnsResourceKey *soa);
 308
 309 /* _DNS_{CLASS,TYPE}_STRING_MAX include one byte for NUL, which we use for space instead below.
 310  * DNS_HOSTNAME_MAX does not include the NUL byte, so we need to add 1. */
 311 #define DNS_RESOURCE_KEY_STRING_MAX (_DNS_CLASS_STRING_MAX + _DNS_TYPE_STRING_MAX + DNS_HOSTNAME_MAX + 1)
 312
 313 char* dns_resource_key_to_string(const DnsResourceKey *key, char *buf, size_t buf_size);
 314 ssize_t dns_resource_record_payload(DnsResourceRecord *rr, void **out);
 315
 316 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceKey*, dns_resource_key_unref);
 317
 318 static inline bool dns_key_is_shared(const DnsResourceKey *key) {
 319         return IN_SET(key->type, DNS_TYPE_PTR);
 320 }
 321
 322 bool dns_resource_key_reduce(DnsResourceKey **a, DnsResourceKey **b);
 323
 324 DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key);
 325 DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, const char *name);
 326 DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr);
 327 DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr);
 328 int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name);
 329 int dns_resource_record_new_address(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *name);
 330 int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b);
 331 const char* dns_resource_record_to_string(DnsResourceRecord *rr);
 332 DnsResourceRecord *dns_resource_record_copy(DnsResourceRecord *rr);
 333 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref);
 334
 335 int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical);
 336
 337 int dns_resource_record_signer(DnsResourceRecord *rr, const char **ret);
 338 int dns_resource_record_source(DnsResourceRecord *rr, const char **ret);
 339 int dns_resource_record_is_signer(DnsResourceRecord *rr, const char *zone);
 340 int dns_resource_record_is_synthetic(DnsResourceRecord *rr);
 341
 342 int dns_resource_record_clamp_ttl(DnsResourceRecord **rr, uint32_t max_ttl);
 343
 344 DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i);
 345 bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b);
 346 DnsTxtItem *dns_txt_item_copy(DnsTxtItem *i);
 347 int dns_txt_item_new_empty(DnsTxtItem **ret);
 348
 349 void dns_resource_record_hash_func(const void *i, struct siphash *state);
 350
 351 extern const struct hash_ops dns_resource_key_hash_ops;
 352 extern const struct hash_ops dns_resource_record_hash_ops;
 353
 354 int dnssec_algorithm_to_string_alloc(int i, char **ret);
 355 int dnssec_algorithm_from_string(const char *s) _pure_;
 356
 357 int dnssec_digest_to_string_alloc(int i, char **ret);
 358 int dnssec_digest_from_string(const char *s) _pure_;