1 /* $OpenBSD: addr.c,v 1.7 2023/03/27 03:31:05 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
addr_unicast_masklen(int af)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
masklen_valid(int af,u_int masklen)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
addr_xaddr_to_sa(const struct xaddr * xa,struct sockaddr * sa,socklen_t * len,u_int16_t port)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
addr_sa_to_xaddr(struct sockaddr * sa,socklen_t slen,struct xaddr * xa)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
addr_invert(struct xaddr * n)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
addr_netmask(int af,u_int l,struct xaddr * n)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
addr_hostmask(int af,u_int l,struct xaddr * n)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
addr_and(struct xaddr * dst,const struct xaddr * a,const struct xaddr * b)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
addr_or(struct xaddr * dst,const struct xaddr * a,const struct xaddr * b)231 addr_or(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
232 {
233 int i;
234
235 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
236 return (-1);
237
238 memcpy(dst, a, sizeof(*dst));
239 switch (a->af) {
240 case AF_INET:
241 dst->v4.s_addr |= b->v4.s_addr;
242 return (0);
243 case AF_INET6:
244 for (i = 0; i < 4; i++)
245 dst->addr32[i] |= b->addr32[i];
246 return (0);
247 default:
248 return (-1);
249 }
250 }
251
252 int
addr_cmp(const struct xaddr * a,const struct xaddr * b)253 addr_cmp(const struct xaddr *a, const struct xaddr *b)
254 {
255 int i;
256
257 if (a->af != b->af)
258 return (a->af == AF_INET6 ? 1 : -1);
259
260 switch (a->af) {
261 case AF_INET:
262 /*
263 * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is
264 * too big to fit into a signed int
265 */
266 if (a->v4.s_addr == b->v4.s_addr)
267 return 0;
268 return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1);
269 case AF_INET6:
270 /*
271 * Do this a byte at a time to avoid the above issue and
272 * any endian problems
273 */
274 for (i = 0; i < 16; i++)
275 if (a->addr8[i] - b->addr8[i] != 0)
276 return (a->addr8[i] - b->addr8[i]);
277 if (a->scope_id == b->scope_id)
278 return (0);
279 return (a->scope_id > b->scope_id ? 1 : -1);
280 default:
281 return (-1);
282 }
283 }
284
285 int
addr_is_all0s(const struct xaddr * a)286 addr_is_all0s(const struct xaddr *a)
287 {
288 int i;
289
290 switch (a->af) {
291 case AF_INET:
292 return (a->v4.s_addr == 0 ? 0 : -1);
293 case AF_INET6:
294 for (i = 0; i < 4; i++)
295 if (a->addr32[i] != 0)
296 return -1;
297 return 0;
298 default:
299 return -1;
300 }
301 }
302
303 /* Increment the specified address. Note, does not do overflow checking */
304 void
addr_increment(struct xaddr * a)305 addr_increment(struct xaddr *a)
306 {
307 int i;
308 uint32_t n;
309
310 switch (a->af) {
311 case AF_INET:
312 a->v4.s_addr = htonl(ntohl(a->v4.s_addr) + 1);
313 break;
314 case AF_INET6:
315 for (i = 0; i < 4; i++) {
316 /* Increment with carry */
317 n = ntohl(a->addr32[3 - i]) + 1;
318 a->addr32[3 - i] = htonl(n);
319 if (n != 0)
320 break;
321 }
322 break;
323 }
324 }
325
326 /*
327 * Test whether host portion of address 'a', as determined by 'masklen'
328 * is all zeros.
329 * Returns 0 if host portion of address is all-zeros,
330 * -1 if not all zeros or on failure.
331 */
332 int
addr_host_is_all0s(const struct xaddr * a,u_int masklen)333 addr_host_is_all0s(const struct xaddr *a, u_int masklen)
334 {
335 struct xaddr tmp_addr, tmp_mask, tmp_result;
336
337 memcpy(&tmp_addr, a, sizeof(tmp_addr));
338 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
339 return -1;
340 if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
341 return -1;
342 return addr_is_all0s(&tmp_result);
343 }
344
345 #if 0
346 int
347 addr_host_to_all0s(struct xaddr *a, u_int masklen)
348 {
349 struct xaddr tmp_mask;
350
351 if (addr_netmask(a->af, masklen, &tmp_mask) == -1)
352 return (-1);
353 if (addr_and(a, a, &tmp_mask) == -1)
354 return (-1);
355 return (0);
356 }
357 #endif
358
359 int
addr_host_to_all1s(struct xaddr * a,u_int masklen)360 addr_host_to_all1s(struct xaddr *a, u_int masklen)
361 {
362 struct xaddr tmp_mask;
363
364 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
365 return (-1);
366 if (addr_or(a, a, &tmp_mask) == -1)
367 return (-1);
368 return (0);
369 }
370
371 /*
372 * Parse string address 'p' into 'n'.
373 * Returns 0 on success, -1 on failure.
374 */
375 int
addr_pton(const char * p,struct xaddr * n)376 addr_pton(const char *p, struct xaddr *n)
377 {
378 struct addrinfo hints, *ai;
379
380 memset(&hints, '\0', sizeof(hints));
381 hints.ai_flags = AI_NUMERICHOST;
382
383 if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
384 return -1;
385
386 if (ai == NULL)
387 return -1;
388
389 if (ai->ai_addr == NULL) {
390 freeaddrinfo(ai);
391 return -1;
392 }
393
394 if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen,
395 n) == -1) {
396 freeaddrinfo(ai);
397 return -1;
398 }
399
400 freeaddrinfo(ai);
401 return 0;
402 }
403
404 int
addr_sa_pton(const char * h,const char * s,struct sockaddr * sa,socklen_t slen)405 addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen)
406 {
407 struct addrinfo hints, *ai;
408
409 memset(&hints, '\0', sizeof(hints));
410 hints.ai_flags = AI_NUMERICHOST;
411
412 if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0)
413 return -1;
414
415 if (ai == NULL)
416 return -1;
417
418 if (ai->ai_addr == NULL) {
419 freeaddrinfo(ai);
420 return -1;
421 }
422
423 if (sa != NULL) {
424 if (slen < ai->ai_addrlen) {
425 freeaddrinfo(ai);
426 return -1;
427 }
428 memcpy(sa, &ai->ai_addr, ai->ai_addrlen);
429 }
430
431 freeaddrinfo(ai);
432 return 0;
433 }
434
435 int
addr_ntop(const struct xaddr * n,char * p,size_t len)436 addr_ntop(const struct xaddr *n, char *p, size_t len)
437 {
438 struct sockaddr_storage ss;
439 socklen_t slen = sizeof(ss);
440
441 if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1)
442 return -1;
443 if (p == NULL || len == 0)
444 return -1;
445 if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0,
446 NI_NUMERICHOST) != 0)
447 return -1;
448
449 return 0;
450 }
451
452 /*
453 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
454 * Return -1 on parse error, -2 on inconsistency or 0 on success.
455 */
456 int
addr_pton_cidr(const char * p,struct xaddr * n,u_int * l)457 addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
458 {
459 struct xaddr tmp;
460 long unsigned int masklen = 999;
461 char addrbuf[64], *mp, *cp;
462
463 /* Don't modify argument */
464 if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf))
465 return -1;
466
467 if ((mp = strchr(addrbuf, '/')) != NULL) {
468 *mp = '\0';
469 mp++;
470 masklen = strtoul(mp, &cp, 10);
471 if (*mp < '0' || *mp > '9' || *cp != '\0' || masklen > 128)
472 return -1;
473 }
474
475 if (addr_pton(addrbuf, &tmp) == -1)
476 return -1;
477
478 if (mp == NULL)
479 masklen = addr_unicast_masklen(tmp.af);
480 if (masklen_valid(tmp.af, masklen) == -1)
481 return -2;
482 if (addr_host_is_all0s(&tmp, masklen) != 0)
483 return -2;
484
485 if (n != NULL)
486 memcpy(n, &tmp, sizeof(*n));
487 if (l != NULL)
488 *l = masklen;
489
490 return 0;
491 }
492
493 int
addr_netmatch(const struct xaddr * host,const struct xaddr * net,u_int masklen)494 addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)
495 {
496 struct xaddr tmp_mask, tmp_result;
497
498 if (host->af != net->af)
499 return -1;
500
501 if (addr_netmask(host->af, masklen, &tmp_mask) == -1)
502 return -1;
503 if (addr_and(&tmp_result, host, &tmp_mask) == -1)
504 return -1;
505 return addr_cmp(&tmp_result, net);
506 }
507