src/resolve/resolved-dns-rr.h

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