src/basic/in-addr-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <arpa/inet.h>
   4 #include <endian.h>
   5 #include <errno.h>
   6 #include <net/if.h>
   7 #include <stdint.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10
  11 #include "alloc-util.h"
  12 #include "errno-util.h"
  13 #include "in-addr-util.h"
  14 #include "macro.h"
  15 #include "parse-util.h"
  16 #include "random-util.h"
  17 #include "string-util.h"
  18 #include "strxcpyx.h"
  19 #include "util.h"
  20
  21 bool in4_addr_is_null(const struct in_addr *a) {
  22         assert(a);
  23
  24         return a->s_addr == 0;
  25 }
  26
  27 int in_addr_is_null(int family, const union in_addr_union *u) {
  28         assert(u);
  29
  30         if (family == AF_INET)
  31                 return in4_addr_is_null(&u->in);
  32
  33         if (family == AF_INET6)
  34                 return IN6_IS_ADDR_UNSPECIFIED(&u->in6);
  35
  36         return -EAFNOSUPPORT;
  37 }
  38
  39 bool in4_addr_is_link_local(const struct in_addr *a) {
  40         assert(a);
  41
  42         return (be32toh(a->s_addr) & UINT32_C(0xFFFF0000)) == (UINT32_C(169) << 24 | UINT32_C(254) << 16);
  43 }
  44
  45 int in_addr_is_link_local(int family, const union in_addr_union *u) {
  46         assert(u);
  47
  48         if (family == AF_INET)
  49                 return in4_addr_is_link_local(&u->in);
  50
  51         if (family == AF_INET6)
  52                 return IN6_IS_ADDR_LINKLOCAL(&u->in6);
  53
  54         return -EAFNOSUPPORT;
  55 }
  56
  57 bool in6_addr_is_link_local_all_nodes(const struct in6_addr *a) {
  58         assert(a);
  59
  60         /* ff02::1 */
  61         return be32toh(a->s6_addr32[0]) == UINT32_C(0xff020000) &&
  62                 a->s6_addr32[1] == 0 &&
  63                 a->s6_addr32[2] == 0 &&
  64                 be32toh(a->s6_addr32[3]) == UINT32_C(0x00000001);
  65 }
  66
  67 int in_addr_is_multicast(int family, const union in_addr_union *u) {
  68         assert(u);
  69
  70         if (family == AF_INET)
  71                 return IN_MULTICAST(be32toh(u->in.s_addr));
  72
  73         if (family == AF_INET6)
  74                 return IN6_IS_ADDR_MULTICAST(&u->in6);
  75
  76         return -EAFNOSUPPORT;
  77 }
  78
  79 bool in4_addr_is_localhost(const struct in_addr *a) {
  80         assert(a);
  81
  82         /* All of 127.x.x.x is localhost. */
  83         return (be32toh(a->s_addr) & UINT32_C(0xFF000000)) == UINT32_C(127) << 24;
  84 }
  85
  86 bool in4_addr_is_non_local(const struct in_addr *a) {
  87         /* Whether the address is not null and not localhost.
  88          *
  89          * As such, it is suitable to configure as DNS/NTP server from DHCP. */
  90         return !in4_addr_is_null(a) &&
  91                !in4_addr_is_localhost(a);
  92 }
  93
  94 int in_addr_is_localhost(int family, const union in_addr_union *u) {
  95         assert(u);
  96
  97         if (family == AF_INET)
  98                 return in4_addr_is_localhost(&u->in);
  99
 100         if (family == AF_INET6)
 101                 return IN6_IS_ADDR_LOOPBACK(&u->in6);
 102
 103         return -EAFNOSUPPORT;
 104 }
 105
 106 bool in4_addr_equal(const struct in_addr *a, const struct in_addr *b) {
 107         assert(a);
 108         assert(b);
 109
 110         return a->s_addr == b->s_addr;
 111 }
 112
 113 int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b) {
 114         assert(a);
 115         assert(b);
 116
 117         if (family == AF_INET)
 118                 return in4_addr_equal(&a->in, &b->in);
 119
 120         if (family == AF_INET6)
 121                 return IN6_ARE_ADDR_EQUAL(&a->in6, &b->in6);
 122
 123         return -EAFNOSUPPORT;
 124 }
 125
 126 int in_addr_prefix_intersect(
 127                 int family,
 128                 const union in_addr_union *a,
 129                 unsigned aprefixlen,
 130                 const union in_addr_union *b,
 131                 unsigned bprefixlen) {
 132
 133         unsigned m;
 134
 135         assert(a);
 136         assert(b);
 137
 138         /* Checks whether there are any addresses that are in both
 139          * networks */
 140
 141         m = MIN(aprefixlen, bprefixlen);
 142
 143         if (family == AF_INET) {
 144                 uint32_t x, nm;
 145
 146                 x = be32toh(a->in.s_addr ^ b->in.s_addr);
 147                 nm = (m == 0) ? 0 : 0xFFFFFFFFUL << (32 - m);
 148
 149                 return (x & nm) == 0;
 150         }
 151
 152         if (family == AF_INET6) {
 153                 unsigned i;
 154
 155                 if (m > 128)
 156                         m = 128;
 157
 158                 for (i = 0; i < 16; i++) {
 159                         uint8_t x, nm;
 160
 161                         x = a->in6.s6_addr[i] ^ b->in6.s6_addr[i];
 162
 163                         if (m < 8)
 164                                 nm = 0xFF << (8 - m);
 165                         else
 166                                 nm = 0xFF;
 167
 168                         if ((x & nm) != 0)
 169                                 return 0;
 170
 171                         if (m > 8)
 172                                 m -= 8;
 173                         else
 174                                 m = 0;
 175                 }
 176
 177                 return 1;
 178         }
 179
 180         return -EAFNOSUPPORT;
 181 }
 182
 183 int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen) {
 184         assert(u);
 185
 186         /* Increases the network part of an address by one. Returns
 187          * positive if that succeeds, or -ERANGE if this overflows. */
 188
 189         return in_addr_prefix_nth(family, u, prefixlen, 1);
 190 }
 191
 192 /*
 193  * Calculates the nth prefix of size prefixlen starting from the address denoted by u.
 194  *
 195  * On success 1 will be returned and the calculated prefix will be available in
 196  * u. In the case nth == 0 the input will be left unchanged and 1 will be returned.
 197  * In case the calculation cannot be performed (invalid prefix length,
 198  * overflows would occur) -ERANGE is returned. If the address family given isn't
 199  * supported -EAFNOSUPPORT will be returned.
 200  *
 201  *
 202  * Examples:
 203  *   - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 2), returns 1, writes 192.168.2.0 to u
 204  *   - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 0), returns 1, no data written
 205  *   - in_addr_prefix_nth(AF_INET, 255.255.255.0, 24, 1), returns -ERANGE, no data written
 206  *   - in_addr_prefix_nth(AF_INET, 255.255.255.0, 0, 1), returns -ERANGE, no data written
 207  *   - in_addr_prefix_nth(AF_INET6, 2001:db8, 64, 0xff00) returns 1, writes 2001:0db8:0000:ff00:: to u
 208  */
 209 int in_addr_prefix_nth(int family, union in_addr_union *u, unsigned prefixlen, uint64_t nth) {
 210         assert(u);
 211
 212         if (prefixlen <= 0)
 213                 return -ERANGE;
 214
 215         if (nth == 0)
 216                 return 1;
 217
 218         if (family == AF_INET) {
 219                 uint32_t c, n, t;
 220                 if (prefixlen > 32)
 221                         prefixlen = 32;
 222
 223                 c = be32toh(u->in.s_addr);
 224
 225                 t = nth << (32 - prefixlen);
 226
 227                 /* Check for wrap */
 228                 if (c > UINT32_MAX - t)
 229                         return -ERANGE;
 230
 231                 n = c + t;
 232
 233                 n &= UINT32_C(0xFFFFFFFF) << (32 - prefixlen);
 234                 u->in.s_addr = htobe32(n);
 235                 return 1;
 236         }
 237
 238         if (family == AF_INET6) {
 239                 struct in6_addr result = {};
 240                 uint8_t overflow = 0;
 241                 uint64_t delta;  /* this assumes that we only ever have to up to 1<<64 subnets */
 242                 unsigned start_byte = (prefixlen - 1) / 8;
 243
 244                 if (prefixlen > 128)
 245                         prefixlen = 128;
 246
 247                 /* First calculate what we have to add */
 248                 delta = nth << ((128 - prefixlen) % 8);
 249
 250                 for (unsigned i = 16; i > 0; i--) {
 251                         unsigned j = i - 1;
 252                         unsigned d = 0;
 253
 254                         if (j <= start_byte) {
 255                                 int16_t t;
 256
 257                                 d = delta & 0xFF;
 258                                 delta >>= 8;
 259
 260                                 t = u->in6.s6_addr[j] + d + overflow;
 261                                 overflow = t > UINT8_MAX ? t - UINT8_MAX : 0;
 262
 263                                 result.s6_addr[j] = (uint8_t)t;
 264                         } else
 265                                 result.s6_addr[j] = u->in6.s6_addr[j];
 266                 }
 267
 268                 if (overflow || delta != 0)
 269                         return -ERANGE;
 270
 271                 u->in6 = result;
 272                 return 1;
 273         }
 274
 275         return -EAFNOSUPPORT;
 276 }
 277
 278 int in_addr_random_prefix(
 279                 int family,
 280                 union in_addr_union *u,
 281                 unsigned prefixlen_fixed_part,
 282                 unsigned prefixlen) {
 283
 284         assert(u);
 285
 286         /* Random network part of an address by one. */
 287
 288         if (prefixlen <= 0)
 289                 return 0;
 290
 291         if (family == AF_INET) {
 292                 uint32_t c, n;
 293
 294                 if (prefixlen_fixed_part > 32)
 295                         prefixlen_fixed_part = 32;
 296                 if (prefixlen > 32)
 297                         prefixlen = 32;
 298                 if (prefixlen_fixed_part >= prefixlen)
 299                         return -EINVAL;
 300
 301                 c = be32toh(u->in.s_addr);
 302                 c &= ((UINT32_C(1) << prefixlen_fixed_part) - 1) << (32 - prefixlen_fixed_part);
 303
 304                 random_bytes(&n, sizeof(n));
 305                 n &= ((UINT32_C(1) << (prefixlen - prefixlen_fixed_part)) - 1) << (32 - prefixlen);
 306
 307                 u->in.s_addr = htobe32(n | c);
 308                 return 1;
 309         }
 310
 311         if (family == AF_INET6) {
 312                 struct in6_addr n;
 313                 unsigned i, j;
 314
 315                 if (prefixlen_fixed_part > 128)
 316                         prefixlen_fixed_part = 128;
 317                 if (prefixlen > 128)
 318                         prefixlen = 128;
 319                 if (prefixlen_fixed_part >= prefixlen)
 320                         return -EINVAL;
 321
 322                 random_bytes(&n, sizeof(n));
 323
 324                 for (i = 0; i < 16; i++) {
 325                         uint8_t mask_fixed_part = 0, mask = 0;
 326
 327                         if (i < (prefixlen_fixed_part + 7) / 8) {
 328                                 if (i < prefixlen_fixed_part / 8)
 329                                         mask_fixed_part = 0xffu;
 330                                 else {
 331                                         j = prefixlen_fixed_part % 8;
 332                                         mask_fixed_part = ((UINT8_C(1) << (j + 1)) - 1) << (8 - j);
 333                                 }
 334                         }
 335
 336                         if (i < (prefixlen + 7) / 8) {
 337                                 if (i < prefixlen / 8)
 338                                         mask = 0xffu ^ mask_fixed_part;
 339                                 else {
 340                                         j = prefixlen % 8;
 341                                         mask = (((UINT8_C(1) << (j + 1)) - 1) << (8 - j)) ^ mask_fixed_part;
 342                                 }
 343                         }
 344
 345                         u->in6.s6_addr[i] &= mask_fixed_part;
 346                         u->in6.s6_addr[i] |= n.s6_addr[i] & mask;
 347                 }
 348
 349                 return 1;
 350         }
 351
 352         return -EAFNOSUPPORT;
 353 }
 354
 355 int in_addr_to_string(int family, const union in_addr_union *u, char **ret) {
 356         _cleanup_free_ char *x = NULL;
 357         size_t l;
 358
 359         assert(u);
 360         assert(ret);
 361
 362         if (family == AF_INET)
 363                 l = INET_ADDRSTRLEN;
 364         else if (family == AF_INET6)
 365                 l = INET6_ADDRSTRLEN;
 366         else
 367                 return -EAFNOSUPPORT;
 368
 369         x = new(char, l);
 370         if (!x)
 371                 return -ENOMEM;
 372
 373         errno = 0;
 374         if (!inet_ntop(family, u, x, l))
 375                 return errno_or_else(EINVAL);
 376
 377         *ret = TAKE_PTR(x);
 378         return 0;
 379 }
 380
 381 int in_addr_prefix_to_string(int family, const union in_addr_union *u, unsigned prefixlen, char **ret) {
 382         _cleanup_free_ char *x = NULL;
 383         char *p;
 384         size_t l;
 385
 386         assert(u);
 387         assert(ret);
 388
 389         if (family == AF_INET)
 390                 l = INET_ADDRSTRLEN + 3;
 391         else if (family == AF_INET6)
 392                 l = INET6_ADDRSTRLEN + 4;
 393         else
 394                 return -EAFNOSUPPORT;
 395
 396         if (prefixlen > FAMILY_ADDRESS_SIZE(family) * 8)
 397                 return -EINVAL;
 398
 399         x = new(char, l);
 400         if (!x)
 401                 return -ENOMEM;
 402
 403         errno = 0;
 404         if (!inet_ntop(family, u, x, l))
 405                 return errno_or_else(EINVAL);
 406
 407         p = x + strlen(x);
 408         l -= strlen(x);
 409         (void) strpcpyf(&p, l, "/%u", prefixlen);
 410
 411         *ret = TAKE_PTR(x);
 412         return 0;
 413 }
 414
 415 int in_addr_port_ifindex_name_to_string(int family, const union in_addr_union *u, uint16_t port, int ifindex, const char *server_name, char **ret) {
 416         _cleanup_free_ char *ip_str = NULL, *x = NULL;
 417         int r;
 418
 419         assert(IN_SET(family, AF_INET, AF_INET6));
 420         assert(u);
 421         assert(ret);
 422
 423         /* Much like in_addr_to_string(), but optionally appends the zone interface index to the address, to properly
 424          * handle IPv6 link-local addresses. */
 425
 426         r = in_addr_to_string(family, u, &ip_str);
 427         if (r < 0)
 428                 return r;
 429
 430         if (family == AF_INET6) {
 431                 r = in_addr_is_link_local(family, u);
 432                 if (r < 0)
 433                         return r;
 434                 if (r == 0)
 435                         ifindex = 0;
 436         } else
 437                 ifindex = 0; /* For IPv4 address, ifindex is always ignored. */
 438
 439         if (port == 0 && ifindex == 0 && isempty(server_name)) {
 440                 *ret = TAKE_PTR(ip_str);
 441                 return 0;
 442         }
 443
 444         const char *separator = isempty(server_name) ? "" : "#";
 445         server_name = strempty(server_name);
 446
 447         if (port > 0) {
 448                 if (family == AF_INET6) {
 449                         if (ifindex > 0)
 450                                 r = asprintf(&x, "[%s]:%"PRIu16"%%%i%s%s", ip_str, port, ifindex, separator, server_name);
 451                         else
 452                                 r = asprintf(&x, "[%s]:%"PRIu16"%s%s", ip_str, port, separator, server_name);
 453                 } else
 454                         r = asprintf(&x, "%s:%"PRIu16"%s%s", ip_str, port, separator, server_name);
 455         } else {
 456                 if (ifindex > 0)
 457                         r = asprintf(&x, "%s%%%i%s%s", ip_str, ifindex, separator, server_name);
 458                 else {
 459                         x = strjoin(ip_str, separator, server_name);
 460                         r = x ? 0 : -ENOMEM;
 461                 }
 462         }
 463         if (r < 0)
 464                 return -ENOMEM;
 465
 466         *ret = TAKE_PTR(x);
 467         return 0;
 468 }
 469
 470 int in_addr_from_string(int family, const char *s, union in_addr_union *ret) {
 471         union in_addr_union buffer;
 472         assert(s);
 473
 474         if (!IN_SET(family, AF_INET, AF_INET6))
 475                 return -EAFNOSUPPORT;
 476
 477         errno = 0;
 478         if (inet_pton(family, s, ret ?: &buffer) <= 0)
 479                 return errno_or_else(EINVAL);
 480
 481         return 0;
 482 }
 483
 484 int in_addr_from_string_auto(const char *s, int *ret_family, union in_addr_union *ret) {
 485         int r;
 486
 487         assert(s);
 488
 489         r = in_addr_from_string(AF_INET, s, ret);
 490         if (r >= 0) {
 491                 if (ret_family)
 492                         *ret_family = AF_INET;
 493                 return 0;
 494         }
 495
 496         r = in_addr_from_string(AF_INET6, s, ret);
 497         if (r >= 0) {
 498                 if (ret_family)
 499                         *ret_family = AF_INET6;
 500                 return 0;
 501         }
 502
 503         return -EINVAL;
 504 }
 505
 506 unsigned char in4_addr_netmask_to_prefixlen(const struct in_addr *addr) {
 507         assert(addr);
 508
 509         return 32U - u32ctz(be32toh(addr->s_addr));
 510 }
 511
 512 struct in_addr* in4_addr_prefixlen_to_netmask(struct in_addr *addr, unsigned char prefixlen) {
 513         assert(addr);
 514         assert(prefixlen <= 32);
 515
 516         /* Shifting beyond 32 is not defined, handle this specially. */
 517         if (prefixlen == 0)
 518                 addr->s_addr = 0;
 519         else
 520                 addr->s_addr = htobe32((0xffffffff << (32 - prefixlen)) & 0xffffffff);
 521
 522         return addr;
 523 }
 524
 525 int in4_addr_default_prefixlen(const struct in_addr *addr, unsigned char *prefixlen) {
 526         uint8_t msb_octet = *(uint8_t*) addr;
 527
 528         /* addr may not be aligned, so make sure we only access it byte-wise */
 529
 530         assert(addr);
 531         assert(prefixlen);
 532
 533         if (msb_octet < 128)
 534                 /* class A, leading bits: 0 */
 535                 *prefixlen = 8;
 536         else if (msb_octet < 192)
 537                 /* class B, leading bits 10 */
 538                 *prefixlen = 16;
 539         else if (msb_octet < 224)
 540                 /* class C, leading bits 110 */
 541                 *prefixlen = 24;
 542         else
 543                 /* class D or E, no default prefixlen */
 544                 return -ERANGE;
 545
 546         return 0;
 547 }
 548
 549 int in4_addr_default_subnet_mask(const struct in_addr *addr, struct in_addr *mask) {
 550         unsigned char prefixlen;
 551         int r;
 552
 553         assert(addr);
 554         assert(mask);
 555
 556         r = in4_addr_default_prefixlen(addr, &prefixlen);
 557         if (r < 0)
 558                 return r;
 559
 560         in4_addr_prefixlen_to_netmask(mask, prefixlen);
 561         return 0;
 562 }
 563
 564 int in_addr_mask(int family, union in_addr_union *addr, unsigned char prefixlen) {
 565         assert(addr);
 566
 567         if (family == AF_INET) {
 568                 struct in_addr mask;
 569
 570                 if (!in4_addr_prefixlen_to_netmask(&mask, prefixlen))
 571                         return -EINVAL;
 572
 573                 addr->in.s_addr &= mask.s_addr;
 574                 return 0;
 575         }
 576
 577         if (family == AF_INET6) {
 578                 unsigned i;
 579
 580                 for (i = 0; i < 16; i++) {
 581                         uint8_t mask;
 582
 583                         if (prefixlen >= 8) {
 584                                 mask = 0xFF;
 585                                 prefixlen -= 8;
 586                         } else {
 587                                 mask = 0xFF << (8 - prefixlen);
 588                                 prefixlen = 0;
 589                         }
 590
 591                         addr->in6.s6_addr[i] &= mask;
 592                 }
 593
 594                 return 0;
 595         }
 596
 597         return -EAFNOSUPPORT;
 598 }
 599
 600 int in_addr_prefix_covers(int family,
 601                           const union in_addr_union *prefix,
 602                           unsigned char prefixlen,
 603                           const union in_addr_union *address) {
 604
 605         union in_addr_union masked_prefix, masked_address;
 606         int r;
 607
 608         assert(prefix);
 609         assert(address);
 610
 611         masked_prefix = *prefix;
 612         r = in_addr_mask(family, &masked_prefix, prefixlen);
 613         if (r < 0)
 614                 return r;
 615
 616         masked_address = *address;
 617         r = in_addr_mask(family, &masked_address, prefixlen);
 618         if (r < 0)
 619                 return r;
 620
 621         return in_addr_equal(family, &masked_prefix, &masked_address);
 622 }
 623
 624 int in_addr_parse_prefixlen(int family, const char *p, unsigned char *ret) {
 625         uint8_t u;
 626         int r;
 627
 628         if (!IN_SET(family, AF_INET, AF_INET6))
 629                 return -EAFNOSUPPORT;
 630
 631         r = safe_atou8(p, &u);
 632         if (r < 0)
 633                 return r;
 634
 635         if (u > FAMILY_ADDRESS_SIZE(family) * 8)
 636                 return -ERANGE;
 637
 638         *ret = u;
 639         return 0;
 640 }
 641
 642 int in_addr_prefix_from_string(
 643                 const char *p,
 644                 int family,
 645                 union in_addr_union *ret_prefix,
 646                 unsigned char *ret_prefixlen) {
 647
 648         _cleanup_free_ char *str = NULL;
 649         union in_addr_union buffer;
 650         const char *e, *l;
 651         unsigned char k;
 652         int r;
 653
 654         assert(p);
 655
 656         if (!IN_SET(family, AF_INET, AF_INET6))
 657                 return -EAFNOSUPPORT;
 658
 659         e = strchr(p, '/');
 660         if (e) {
 661                 str = strndup(p, e - p);
 662                 if (!str)
 663                         return -ENOMEM;
 664
 665                 l = str;
 666         } else
 667                 l = p;
 668
 669         r = in_addr_from_string(family, l, &buffer);
 670         if (r < 0)
 671                 return r;
 672
 673         if (e) {
 674                 r = in_addr_parse_prefixlen(family, e+1, &k);
 675                 if (r < 0)
 676                         return r;
 677         } else
 678                 k = FAMILY_ADDRESS_SIZE(family) * 8;
 679
 680         if (ret_prefix)
 681                 *ret_prefix = buffer;
 682         if (ret_prefixlen)
 683                 *ret_prefixlen = k;
 684
 685         return 0;
 686 }
 687
 688 int in_addr_prefix_from_string_auto_internal(
 689                 const char *p,
 690                 InAddrPrefixLenMode mode,
 691                 int *ret_family,
 692                 union in_addr_union *ret_prefix,
 693                 unsigned char *ret_prefixlen) {
 694
 695         _cleanup_free_ char *str = NULL;
 696         union in_addr_union buffer;
 697         const char *e, *l;
 698         unsigned char k;
 699         int family, r;
 700
 701         assert(p);
 702
 703         e = strchr(p, '/');
 704         if (e) {
 705                 str = strndup(p, e - p);
 706                 if (!str)
 707                         return -ENOMEM;
 708
 709                 l = str;
 710         } else
 711                 l = p;
 712
 713         r = in_addr_from_string_auto(l, &family, &buffer);
 714         if (r < 0)
 715                 return r;
 716
 717         if (e) {
 718                 r = in_addr_parse_prefixlen(family, e+1, &k);
 719                 if (r < 0)
 720                         return r;
 721         } else
 722                 switch (mode) {
 723                 case PREFIXLEN_FULL:
 724                         k = FAMILY_ADDRESS_SIZE(family) * 8;
 725                         break;
 726                 case PREFIXLEN_REFUSE:
 727                         return -ENOANO; /* To distinguish this error from others. */
 728                 case PREFIXLEN_LEGACY:
 729                         if (family == AF_INET) {
 730                                 r = in4_addr_default_prefixlen(&buffer.in, &k);
 731                                 if (r < 0)
 732                                         return r;
 733                         } else
 734                                 k = 0;
 735                         break;
 736                 default:
 737                         assert_not_reached("Invalid prefixlen mode");
 738                 }
 739
 740         if (ret_family)
 741                 *ret_family = family;
 742         if (ret_prefix)
 743                 *ret_prefix = buffer;
 744         if (ret_prefixlen)
 745                 *ret_prefixlen = k;
 746
 747         return 0;
 748
 749 }
 750
 751 static void in_addr_data_hash_func(const struct in_addr_data *a, struct siphash *state) {
 752         siphash24_compress(&a->family, sizeof(a->family), state);
 753         siphash24_compress(&a->address, FAMILY_ADDRESS_SIZE(a->family), state);
 754 }
 755
 756 static int in_addr_data_compare_func(const struct in_addr_data *x, const struct in_addr_data *y) {
 757         int r;
 758
 759         r = CMP(x->family, y->family);
 760         if (r != 0)
 761                 return r;
 762
 763         return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
 764 }
 765
 766 DEFINE_HASH_OPS(in_addr_data_hash_ops, struct in_addr_data, in_addr_data_hash_func, in_addr_data_compare_func);
 767
 768 void in6_addr_hash_func(const struct in6_addr *addr, struct siphash *state) {
 769         assert(addr);
 770
 771         siphash24_compress(addr, sizeof(*addr), state);
 772 }
 773
 774 int in6_addr_compare_func(const struct in6_addr *a, const struct in6_addr *b) {
 775         return memcmp(a, b, sizeof(*a));
 776 }
 777
 778 DEFINE_HASH_OPS(in6_addr_hash_ops, struct in6_addr, in6_addr_hash_func, in6_addr_compare_func);