src/resolve/resolved-dns-rr.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   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 "resolved-dns-domain.h"
  23 #include "resolved-dns-rr.h"
  24
  25 DnsResourceKey* dns_resource_key_new(uint16_t class, uint16_t type, const char *name) {
  26         DnsResourceKey *k;
  27         size_t l;
  28
  29         assert(name);
  30
  31         l = strlen(name);
  32         k = malloc0(sizeof(DnsResourceKey) + l + 1);
  33         if (!k)
  34                 return NULL;
  35
  36         k->n_ref = 1;
  37         k->class = class;
  38         k->type = type;
  39
  40         strcpy((char*) k + sizeof(DnsResourceKey), name);
  41
  42         return k;
  43 }
  44
  45 DnsResourceKey* dns_resource_key_new_consume(uint16_t class, uint16_t type, char *name) {
  46         DnsResourceKey *k;
  47
  48         assert(name);
  49
  50         k = new0(DnsResourceKey, 1);
  51         if (!k)
  52                 return NULL;
  53
  54         k->n_ref = 1;
  55         k->class = class;
  56         k->type = type;
  57         k->_name = name;
  58
  59         return k;
  60 }
  61
  62 DnsResourceKey* dns_resource_key_ref(DnsResourceKey *k) {
  63
  64         if (!k)
  65                 return NULL;
  66
  67         assert(k->n_ref > 0);
  68         k->n_ref++;
  69
  70         return k;
  71 }
  72
  73 DnsResourceKey* dns_resource_key_unref(DnsResourceKey *k) {
  74         if (!k)
  75                 return NULL;
  76
  77         assert(k->n_ref > 0);
  78
  79         if (k->n_ref == 1) {
  80                 free(k->_name);
  81                 free(k);
  82         } else
  83                 k->n_ref--;
  84
  85         return NULL;
  86 }
  87
  88 int dns_resource_key_equal(const DnsResourceKey *a, const DnsResourceKey *b) {
  89         int r;
  90
  91         r = dns_name_equal(DNS_RESOURCE_KEY_NAME(a), DNS_RESOURCE_KEY_NAME(b));
  92         if (r <= 0)
  93                 return r;
  94
  95         if (a->class != b->class)
  96                 return 0;
  97
  98         if (a->type != b->type)
  99                 return 0;
 100
 101         return 1;
 102 }
 103
 104 int dns_resource_key_match_rr(const DnsResourceKey *key, const DnsResourceRecord *rr) {
 105         assert(key);
 106         assert(rr);
 107
 108         if (rr->key->class != key->class && key->class != DNS_CLASS_ANY)
 109                 return 0;
 110
 111         if (rr->key->type != key->type && key->type != DNS_TYPE_ANY)
 112                 return 0;
 113
 114         return dns_name_equal(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key));
 115 }
 116
 117 int dns_resource_key_match_cname(const DnsResourceKey *key, const DnsResourceRecord *rr) {
 118         assert(key);
 119         assert(rr);
 120
 121         if (rr->key->class != key->class && key->class != DNS_CLASS_ANY)
 122                 return 0;
 123
 124         if (rr->key->type != DNS_TYPE_CNAME)
 125                 return 0;
 126
 127         return dns_name_equal(DNS_RESOURCE_KEY_NAME(rr->key), DNS_RESOURCE_KEY_NAME(key));
 128 }
 129
 130 unsigned long dns_resource_key_hash_func(const void *i, const uint8_t hash_key[HASH_KEY_SIZE]) {
 131         const DnsResourceKey *k = i;
 132         unsigned long ul;
 133
 134         ul = dns_name_hash_func(DNS_RESOURCE_KEY_NAME(k), hash_key);
 135         ul = ul * hash_key[0] + ul + k->class;
 136         ul = ul * hash_key[1] + ul + k->type;
 137
 138         return ul;
 139 }
 140
 141 int dns_resource_key_compare_func(const void *a, const void *b) {
 142         const DnsResourceKey *x = a, *y = b;
 143         int ret;
 144
 145         ret = dns_name_compare_func(DNS_RESOURCE_KEY_NAME(x), DNS_RESOURCE_KEY_NAME(y));
 146         if (ret != 0)
 147                 return ret;
 148
 149         if (x->type < y->type)
 150                 return -1;
 151         if (x->type > y->type)
 152                 return 1;
 153
 154         if (x->class < y->class)
 155                 return -1;
 156         if (x->class > y->class)
 157                 return 1;
 158
 159         return 0;
 160 }
 161
 162 int dns_resource_key_to_string(const DnsResourceKey *key, char **ret) {
 163         char cbuf[DECIMAL_STR_MAX(uint16_t)], tbuf[DECIMAL_STR_MAX(uint16_t)];
 164         const char *c, *t;
 165         char *s;
 166
 167         c = dns_class_to_string(key->class);
 168         if (!c) {
 169                 sprintf(cbuf, "%i", key->class);
 170                 c = cbuf;
 171         }
 172
 173         t = dns_type_to_string(key->type);
 174         if (!t){
 175                 sprintf(tbuf, "%i", key->type);
 176                 t = tbuf;
 177         }
 178
 179         s = strjoin(DNS_RESOURCE_KEY_NAME(key), " ", c, " ", t, NULL);
 180         if (!s)
 181                 return -ENOMEM;
 182
 183         *ret = s;
 184         return 0;
 185 }
 186
 187 DnsResourceRecord* dns_resource_record_new(DnsResourceKey *key) {
 188         DnsResourceRecord *rr;
 189
 190         rr = new0(DnsResourceRecord, 1);
 191         if (!rr)
 192                 return NULL;
 193
 194         rr->n_ref = 1;
 195         rr->key = dns_resource_key_ref(key);
 196
 197         return rr;
 198 }
 199
 200 DnsResourceRecord* dns_resource_record_new_full(uint16_t class, uint16_t type, const char *name) {
 201         _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 202
 203         key = dns_resource_key_new(class, type, name);
 204         if (!key)
 205                 return NULL;
 206
 207         return dns_resource_record_new(key);
 208 }
 209
 210 DnsResourceRecord* dns_resource_record_ref(DnsResourceRecord *rr) {
 211         if (!rr)
 212                 return NULL;
 213
 214         assert(rr->n_ref > 0);
 215         rr->n_ref++;
 216
 217         return rr;
 218 }
 219
 220 DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr) {
 221         if (!rr)
 222                 return NULL;
 223
 224         assert(rr->n_ref > 0);
 225
 226         if (rr->n_ref > 1) {
 227                 rr->n_ref--;
 228                 return NULL;
 229         }
 230
 231         if (rr->key) {
 232                 if (IN_SET(rr->key->type, DNS_TYPE_PTR, DNS_TYPE_NS, DNS_TYPE_CNAME))
 233                         free(rr->ptr.name);
 234                 else if (rr->key->type == DNS_TYPE_HINFO) {
 235                         free(rr->hinfo.cpu);
 236                         free(rr->hinfo.os);
 237                 } else if (rr->key->type == DNS_TYPE_SOA) {
 238                         free(rr->soa.mname);
 239                         free(rr->soa.rname);
 240                 } else if (!IN_SET(rr->key->type, DNS_TYPE_A, DNS_TYPE_AAAA))
 241                         free(rr->generic.data);
 242
 243                 dns_resource_key_unref(rr->key);
 244         }
 245
 246         free(rr);
 247
 248         return NULL;
 249 }
 250
 251 int dns_resource_record_new_reverse(DnsResourceRecord **ret, int family, const union in_addr_union *address, const char *hostname) {
 252         _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 253         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
 254         _cleanup_free_ char *ptr = NULL;
 255         int r;
 256
 257         assert(ret);
 258         assert(address);
 259         assert(hostname);
 260
 261         r = dns_name_reverse(family, address, &ptr);
 262         if (r < 0)
 263                 return r;
 264
 265         key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, ptr);
 266         if (!key)
 267                 return -ENOMEM;
 268
 269         ptr = NULL;
 270
 271         rr = dns_resource_record_new(key);
 272         if (!rr)
 273                 return -ENOMEM;
 274
 275         rr->ptr.name = strdup(hostname);
 276         if (!rr->ptr.name)
 277                 return -ENOMEM;
 278
 279         *ret = rr;
 280         rr = NULL;
 281
 282         return 0;
 283 }
 284
 285 int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecord *b) {
 286         int r;
 287
 288         assert(a);
 289         assert(b);
 290
 291         r = dns_resource_key_equal(a->key, b->key);
 292         if (r <= 0)
 293                 return r;
 294
 295         switch (a->key->type) {
 296
 297         case DNS_TYPE_PTR:
 298         case DNS_TYPE_NS:
 299         case DNS_TYPE_CNAME:
 300                 return dns_name_equal(a->ptr.name, b->ptr.name);
 301
 302         case DNS_TYPE_HINFO:
 303                 return strcaseeq(a->hinfo.cpu, b->hinfo.cpu) &&
 304                        strcaseeq(a->hinfo.os, b->hinfo.os);
 305
 306         case DNS_TYPE_A:
 307                 return memcmp(&a->a.in_addr, &b->a.in_addr, sizeof(struct in_addr)) == 0;
 308
 309         case DNS_TYPE_AAAA:
 310                 return memcmp(&a->aaaa.in6_addr, &b->aaaa.in6_addr, sizeof(struct in6_addr)) == 0;
 311
 312         case DNS_TYPE_SOA:
 313                 r = dns_name_equal(a->soa.mname, b->soa.mname);
 314                 if (r <= 0)
 315                         return r;
 316                 r = dns_name_equal(a->soa.rname, b->soa.rname);
 317                 if (r <= 0)
 318                         return r;
 319
 320                 return a->soa.serial  == b->soa.serial &&
 321                        a->soa.refresh == b->soa.refresh &&
 322                        a->soa.retry   == b->soa.retry &&
 323                        a->soa.expire  == b->soa.expire &&
 324                        a->soa.minimum == b->soa.minimum;
 325         default:
 326                 return a->generic.size == b->generic.size &&
 327                         memcmp(a->generic.data, b->generic.data, a->generic.size) == 0;
 328         }
 329 }
 330
 331 int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) {
 332         _cleanup_free_ char *k = NULL;
 333         char *s;
 334         int r;
 335
 336         assert(rr);
 337
 338         r = dns_resource_key_to_string(rr->key, &k);
 339         if (r < 0)
 340                 return r;
 341
 342         switch (rr->key->type) {
 343
 344         case DNS_TYPE_PTR:
 345         case DNS_TYPE_NS:
 346         case DNS_TYPE_CNAME:
 347                 s = strjoin(k, " ", rr->ptr.name, NULL);
 348                 if (!s)
 349                         return -ENOMEM;
 350
 351                 break;
 352
 353         case DNS_TYPE_HINFO:
 354                 s = strjoin(k, " ", rr->hinfo.cpu, " ", rr->hinfo.os, NULL);
 355                 if (!s)
 356                         return -ENOMEM;
 357                 break;
 358
 359         case DNS_TYPE_A: {
 360                 _cleanup_free_ char *x = NULL;
 361
 362                 r = in_addr_to_string(AF_INET, (const union in_addr_union*) &rr->a.in_addr, &x);
 363                 if (r < 0)
 364                         return r;
 365
 366                 s = strjoin(k, " ", x, NULL);
 367                 if (!s)
 368                         return -ENOMEM;
 369                 break;
 370         }
 371
 372         case DNS_TYPE_AAAA: {
 373                 _cleanup_free_ char *x = NULL;
 374
 375                 r = in_addr_to_string(AF_INET6, (const union in_addr_union*) &rr->aaaa.in6_addr, &x);
 376                 if (r < 0)
 377                         return r;
 378
 379                 s = strjoin(k, " ", x, NULL);
 380                 if (!s)
 381                         return -ENOMEM;
 382                 break;
 383         }
 384
 385         case DNS_TYPE_SOA:
 386                 r = asprintf(&s, "%s %s %s %u %u %u %u %u",
 387                              k,
 388                              strna(rr->soa.mname),
 389                              strna(rr->soa.rname),
 390                              rr->soa.serial,
 391                              rr->soa.refresh,
 392                              rr->soa.retry,
 393                              rr->soa.expire,
 394                              rr->soa.minimum);
 395                 if (r < 0)
 396                         return -ENOMEM;
 397                 break;
 398
 399         default: {
 400                 _cleanup_free_ char *x = NULL;
 401
 402                 x = hexmem(rr->generic.data, rr->generic.size);
 403                 if (!x)
 404                         return -ENOMEM;
 405
 406                 s = strjoin(k, " ", x, NULL);
 407                 if (!s)
 408                         return -ENOMEM;
 409                 break;
 410         }}
 411
 412         *ret = s;
 413         return 0;
 414 }
 415
 416 const char *dns_class_to_string(uint16_t class) {
 417
 418         switch (class) {
 419
 420         case DNS_CLASS_IN:
 421                 return "IN";
 422
 423         case DNS_CLASS_ANY:
 424                 return "ANY";
 425         }
 426
 427         return NULL;
 428 }
 429
 430 int dns_class_from_string(const char *s, uint16_t *class) {
 431         assert(s);
 432         assert(class);
 433
 434         if (strcaseeq(s, "IN"))
 435                 *class = DNS_CLASS_IN;
 436         else if (strcaseeq(s, "ANY"))
 437                 *class = DNS_TYPE_ANY;
 438         else
 439                 return -EINVAL;
 440
 441         return 0;
 442 }
 443
 444 static const struct {
 445         uint16_t type;
 446         const char *name;
 447 } dns_types[] = {
 448         { DNS_TYPE_A,     "A"     },
 449         { DNS_TYPE_NS,    "NS"    },
 450         { DNS_TYPE_CNAME, "CNAME" },
 451         { DNS_TYPE_SOA,   "SOA"   },
 452         { DNS_TYPE_PTR,   "PTR"   },
 453         { DNS_TYPE_HINFO, "HINFO" },
 454         { DNS_TYPE_MX,    "MX"    },
 455         { DNS_TYPE_TXT,   "TXT"   },
 456         { DNS_TYPE_AAAA,  "AAAA"  },
 457         { DNS_TYPE_SRV,   "SRV"   },
 458         { DNS_TYPE_SSHFP, "SSHFP" },
 459         { DNS_TYPE_DNAME, "DNAME" },
 460         { DNS_TYPE_ANY,   "ANY"   },
 461         { DNS_TYPE_OPT,   "OPT"   },
 462         { DNS_TYPE_TKEY,  "TKEY"  },
 463         { DNS_TYPE_TSIG,  "TSIG"  },
 464         { DNS_TYPE_IXFR,  "IXFR"  },
 465         { DNS_TYPE_AXFR,  "AXFR"  },
 466 };
 467
 468
 469 const char *dns_type_to_string(uint16_t type) {
 470         unsigned i;
 471
 472         for (i = 0; i < ELEMENTSOF(dns_types); i++)
 473                 if (dns_types[i].type == type)
 474                         return dns_types[i].name;
 475
 476         return NULL;
 477 }
 478
 479 int dns_type_from_string(const char *s, uint16_t *type) {
 480         unsigned i;
 481
 482         assert(s);
 483         assert(type);
 484
 485         for (i = 0; i < ELEMENTSOF(dns_types); i++)
 486                 if (strcaseeq(dns_types[i].name, s)) {
 487                         *type = dns_types[i].type;
 488                         return 0;
 489                 }
 490
 491         return -EINVAL;
 492 }