crypto/openssh/addr.c

   1 /* $OpenBSD: addr.c,v 1.5 2022/04/29 04:55:07 djm Exp $ */
   2
   3 /*
   4  * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include "includes.h"
  20
  21 #include <sys/types.h>
  22 #include <sys/socket.h>
  23 #include <netinet/in.h>
  24 #include <arpa/inet.h>
  25
  26 #include <netdb.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30
  31 #include "addr.h"
  32
  33 #define _SA(x)  ((struct sockaddr *)(x))
  34
  35 int
  36 addr_unicast_masklen(int af)
  37 {
  38         switch (af) {
  39         case AF_INET:
  40                 return 32;
  41         case AF_INET6:
  42                 return 128;
  43         default:
  44                 return -1;
  45         }
  46 }
  47
  48 static inline int
  49 masklen_valid(int af, u_int masklen)
  50 {
  51         switch (af) {
  52         case AF_INET:
  53                 return masklen <= 32 ? 0 : -1;
  54         case AF_INET6:
  55                 return masklen <= 128 ? 0 : -1;
  56         default:
  57                 return -1;
  58         }
  59 }
  60
  61 int
  62 addr_xaddr_to_sa(const struct xaddr *xa, struct sockaddr *sa, socklen_t *len,
  63     u_int16_t port)
  64 {
  65         struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
  66         struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
  67
  68         if (xa == NULL || sa == NULL || len == NULL)
  69                 return -1;
  70
  71         switch (xa->af) {
  72         case AF_INET:
  73                 if (*len < sizeof(*in4))
  74                         return -1;
  75                 memset(sa, '\0', sizeof(*in4));
  76                 *len = sizeof(*in4);
  77 #ifdef SOCK_HAS_LEN
  78                 in4->sin_len = sizeof(*in4);
  79 #endif
  80                 in4->sin_family = AF_INET;
  81                 in4->sin_port = htons(port);
  82                 memcpy(&in4->sin_addr, &xa->v4, sizeof(in4->sin_addr));
  83                 break;
  84         case AF_INET6:
  85                 if (*len < sizeof(*in6))
  86                         return -1;
  87                 memset(sa, '\0', sizeof(*in6));
  88                 *len = sizeof(*in6);
  89 #ifdef SOCK_HAS_LEN
  90                 in6->sin6_len = sizeof(*in6);
  91 #endif
  92                 in6->sin6_family = AF_INET6;
  93                 in6->sin6_port = htons(port);
  94                 memcpy(&in6->sin6_addr, &xa->v6, sizeof(in6->sin6_addr));
  95 #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
  96                 in6->sin6_scope_id = xa->scope_id;
  97 #endif
  98                 break;
  99         default:
 100                 return -1;
 101         }
 102         return 0;
 103 }
 104
 105 /*
 106  * Convert struct sockaddr to struct xaddr
 107  * Returns 0 on success, -1 on failure.
 108  */
 109 int
 110 addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa)
 111 {
 112         struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
 113         struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
 114
 115         memset(xa, '\0', sizeof(*xa));
 116
 117         switch (sa->sa_family) {
 118         case AF_INET:
 119                 if (slen < (socklen_t)sizeof(*in4))
 120                         return -1;
 121                 xa->af = AF_INET;
 122                 memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4));
 123                 break;
 124         case AF_INET6:
 125                 if (slen < (socklen_t)sizeof(*in6))
 126                         return -1;
 127                 xa->af = AF_INET6;
 128                 memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6));
 129 #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
 130                 xa->scope_id = in6->sin6_scope_id;
 131 #endif
 132                 break;
 133         default:
 134                 return -1;
 135         }
 136
 137         return 0;
 138 }
 139
 140 int
 141 addr_invert(struct xaddr *n)
 142 {
 143         int i;
 144
 145         if (n == NULL)
 146                 return -1;
 147
 148         switch (n->af) {
 149         case AF_INET:
 150                 n->v4.s_addr = ~n->v4.s_addr;
 151                 return 0;
 152         case AF_INET6:
 153                 for (i = 0; i < 4; i++)
 154                         n->addr32[i] = ~n->addr32[i];
 155                 return 0;
 156         default:
 157                 return -1;
 158         }
 159 }
 160
 161 /*
 162  * Calculate a netmask of length 'l' for address family 'af' and
 163  * store it in 'n'.
 164  * Returns 0 on success, -1 on failure.
 165  */
 166 int
 167 addr_netmask(int af, u_int l, struct xaddr *n)
 168 {
 169         int i;
 170
 171         if (masklen_valid(af, l) != 0 || n == NULL)
 172                 return -1;
 173
 174         memset(n, '\0', sizeof(*n));
 175         switch (af) {
 176         case AF_INET:
 177                 n->af = AF_INET;
 178                 if (l == 0)
 179                         return 0;
 180                 n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);
 181                 return 0;
 182         case AF_INET6:
 183                 n->af = AF_INET6;
 184                 for (i = 0; i < 4 && l >= 32; i++, l -= 32)
 185                         n->addr32[i] = 0xffffffffU;
 186                 if (i < 4 && l != 0)
 187                         n->addr32[i] = htonl((0xffffffff << (32 - l)) &
 188                             0xffffffff);
 189                 return 0;
 190         default:
 191                 return -1;
 192         }
 193 }
 194
 195 int
 196 addr_hostmask(int af, u_int l, struct xaddr *n)
 197 {
 198         if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)
 199                 return -1;
 200         return 0;
 201 }
 202
 203 /*
 204  * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.
 205  * Returns 0 on success, -1 on failure.
 206  */
 207 int
 208 addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
 209 {
 210         int i;
 211
 212         if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
 213                 return -1;
 214
 215         memcpy(dst, a, sizeof(*dst));
 216         switch (a->af) {
 217         case AF_INET:
 218                 dst->v4.s_addr &= b->v4.s_addr;
 219                 return 0;
 220         case AF_INET6:
 221                 dst->scope_id = a->scope_id;
 222                 for (i = 0; i < 4; i++)
 223                         dst->addr32[i] &= b->addr32[i];
 224                 return 0;
 225         default:
 226                 return -1;
 227         }
 228 }
 229
 230 int
 231 addr_cmp(const struct xaddr *a, const struct xaddr *b)
 232 {
 233         int i;
 234
 235         if (a->af != b->af)
 236                 return (a->af == AF_INET6 ? 1 : -1);
 237
 238         switch (a->af) {
 239         case AF_INET:
 240                 /*
 241                  * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is
 242                  * too big to fit into a signed int
 243                  */
 244                 if (a->v4.s_addr == b->v4.s_addr)
 245                         return 0;
 246                 return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1);
 247         case AF_INET6:
 248                 /*
 249                  * Do this a byte at a time to avoid the above issue and
 250                  * any endian problems
 251                  */
 252                 for (i = 0; i < 16; i++)
 253                         if (a->addr8[i] - b->addr8[i] != 0)
 254                                 return (a->addr8[i] - b->addr8[i]);
 255                 if (a->scope_id == b->scope_id)
 256                         return (0);
 257                 return (a->scope_id > b->scope_id ? 1 : -1);
 258         default:
 259                 return (-1);
 260         }
 261 }
 262
 263 int
 264 addr_is_all0s(const struct xaddr *a)
 265 {
 266         int i;
 267
 268         switch (a->af) {
 269         case AF_INET:
 270                 return (a->v4.s_addr == 0 ? 0 : -1);
 271         case AF_INET6:
 272                 for (i = 0; i < 4; i++)
 273                         if (a->addr32[i] != 0)
 274                                 return -1;
 275                 return 0;
 276         default:
 277                 return -1;
 278         }
 279 }
 280
 281 /*
 282  * Test whether host portion of address 'a', as determined by 'masklen'
 283  * is all zeros.
 284  * Returns 0 if host portion of address is all-zeros,
 285  * -1 if not all zeros or on failure.
 286  */
 287 int
 288 addr_host_is_all0s(const struct xaddr *a, u_int masklen)
 289 {
 290         struct xaddr tmp_addr, tmp_mask, tmp_result;
 291
 292         memcpy(&tmp_addr, a, sizeof(tmp_addr));
 293         if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
 294                 return -1;
 295         if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
 296                 return -1;
 297         return addr_is_all0s(&tmp_result);
 298 }
 299
 300 /*
 301  * Parse string address 'p' into 'n'.
 302  * Returns 0 on success, -1 on failure.
 303  */
 304 int
 305 addr_pton(const char *p, struct xaddr *n)
 306 {
 307         struct addrinfo hints, *ai;
 308
 309         memset(&hints, '\0', sizeof(hints));
 310         hints.ai_flags = AI_NUMERICHOST;
 311
 312         if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
 313                 return -1;
 314
 315         if (ai == NULL)
 316                 return -1;
 317
 318         if (ai->ai_addr == NULL) {
 319                 freeaddrinfo(ai);
 320                 return -1;
 321         }
 322
 323         if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen,
 324             n) == -1) {
 325                 freeaddrinfo(ai);
 326                 return -1;
 327         }
 328
 329         freeaddrinfo(ai);
 330         return 0;
 331 }
 332
 333 int
 334 addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen)
 335 {
 336         struct addrinfo hints, *ai;
 337
 338         memset(&hints, '\0', sizeof(hints));
 339         hints.ai_flags = AI_NUMERICHOST;
 340
 341         if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0)
 342                 return -1;
 343
 344         if (ai == NULL)
 345                 return -1;
 346
 347         if (ai->ai_addr == NULL) {
 348                 freeaddrinfo(ai);
 349                 return -1;
 350         }
 351
 352         if (sa != NULL) {
 353                 if (slen < ai->ai_addrlen) {
 354                         freeaddrinfo(ai);
 355                         return -1;
 356                 }
 357                 memcpy(sa, &ai->ai_addr, ai->ai_addrlen);
 358         }
 359
 360         freeaddrinfo(ai);
 361         return 0;
 362 }
 363
 364 int
 365 addr_ntop(const struct xaddr *n, char *p, size_t len)
 366 {
 367         struct sockaddr_storage ss;
 368         socklen_t slen = sizeof(ss);
 369
 370         if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1)
 371                 return -1;
 372         if (p == NULL || len == 0)
 373                 return -1;
 374         if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0,
 375             NI_NUMERICHOST) == -1)
 376                 return -1;
 377
 378         return 0;
 379 }
 380
 381 /*
 382  * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
 383  * Return -1 on parse error, -2 on inconsistency or 0 on success.
 384  */
 385 int
 386 addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
 387 {
 388         struct xaddr tmp;
 389         long unsigned int masklen = 999;
 390         char addrbuf[64], *mp, *cp;
 391
 392         /* Don't modify argument */
 393         if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf))
 394                 return -1;
 395
 396         if ((mp = strchr(addrbuf, '/')) != NULL) {
 397                 *mp = '\0';
 398                 mp++;
 399                 masklen = strtoul(mp, &cp, 10);
 400                 if (*mp < '0' || *mp > '9' || *cp != '\0' || masklen > 128)
 401                         return -1;
 402         }
 403
 404         if (addr_pton(addrbuf, &tmp) == -1)
 405                 return -1;
 406
 407         if (mp == NULL)
 408                 masklen = addr_unicast_masklen(tmp.af);
 409         if (masklen_valid(tmp.af, masklen) == -1)
 410                 return -2;
 411         if (addr_host_is_all0s(&tmp, masklen) != 0)
 412                 return -2;
 413
 414         if (n != NULL)
 415                 memcpy(n, &tmp, sizeof(*n));
 416         if (l != NULL)
 417                 *l = masklen;
 418
 419         return 0;
 420 }
 421
 422 int
 423 addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)
 424 {
 425         struct xaddr tmp_mask, tmp_result;
 426
 427         if (host->af != net->af)
 428                 return -1;
 429
 430         if (addr_netmask(host->af, masklen, &tmp_mask) == -1)
 431                 return -1;
 432         if (addr_and(&tmp_result, host, &tmp_mask) == -1)
 433                 return -1;
 434         return addr_cmp(&tmp_result, net);
 435 }