1 /* $NetBSD: addr.c,v 1.8 2025/04/09 15:49:31 christos Exp $ */
2 /* $OpenBSD: addr.c,v 1.9 2024/10/18 04:30:09 djm Exp $ */
3
4 /*
5 * Copyright (c) 2004-2008 Damien Miller <djm@mindrot.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #include "includes.h"
21 __RCSID("$NetBSD: addr.c,v 1.8 2025/04/09 15:49:31 christos Exp $");
22
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <netinet/in.h>
26 #include <arpa/inet.h>
27
28 #include <netdb.h>
29 #include <string.h>
30 #include <stdlib.h>
31 #include <stdio.h>
32 #include <limits.h>
33
34 #include "addr.h"
35
36 #define _SA(x) ((struct sockaddr *)(x))
37
38 static int
addr_unicast_masklen(int af)39 addr_unicast_masklen(int af)
40 {
41 switch (af) {
42 case AF_INET:
43 return 32;
44 case AF_INET6:
45 return 128;
46 default:
47 return -1;
48 }
49 }
50
51 static inline int
masklen_valid(int af,u_int masklen)52 masklen_valid(int af, u_int masklen)
53 {
54 switch (af) {
55 case AF_INET:
56 return masklen <= 32 ? 0 : -1;
57 case AF_INET6:
58 return masklen <= 128 ? 0 : -1;
59 default:
60 return -1;
61 }
62 }
63
64 static int
addr_xaddr_to_sa(const struct xaddr * xa,struct sockaddr * sa,socklen_t * len,u_int16_t port)65 addr_xaddr_to_sa(const struct xaddr *xa, struct sockaddr *sa, socklen_t *len,
66 u_int16_t port)
67 {
68 struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
69 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
70
71 if (xa == NULL || sa == NULL || len == NULL)
72 return -1;
73
74 switch (xa->af) {
75 case AF_INET:
76 if (*len < sizeof(*in4))
77 return -1;
78 memset(sa, '\0', sizeof(*in4));
79 *len = sizeof(*in4);
80 #ifdef SOCK_HAS_LEN
81 in4->sin_len = sizeof(*in4);
82 #endif
83 in4->sin_family = AF_INET;
84 in4->sin_port = htons(port);
85 memcpy(&in4->sin_addr, &xa->v4, sizeof(in4->sin_addr));
86 break;
87 case AF_INET6:
88 if (*len < sizeof(*in6))
89 return -1;
90 memset(sa, '\0', sizeof(*in6));
91 *len = sizeof(*in6);
92 #ifdef SOCK_HAS_LEN
93 in6->sin6_len = sizeof(*in6);
94 #endif
95 in6->sin6_family = AF_INET6;
96 in6->sin6_port = htons(port);
97 memcpy(&in6->sin6_addr, &xa->v6, sizeof(in6->sin6_addr));
98 in6->sin6_scope_id = xa->scope_id;
99 break;
100 default:
101 return -1;
102 }
103 return 0;
104 }
105
106 /*
107 * Convert struct sockaddr to struct xaddr
108 * Returns 0 on success, -1 on failure.
109 */
110 int
addr_sa_to_xaddr(struct sockaddr * sa,socklen_t slen,struct xaddr * xa)111 addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa)
112 {
113 struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
114 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
115
116 memset(xa, '\0', sizeof(*xa));
117
118 switch (sa->sa_family) {
119 case AF_INET:
120 if (slen < (socklen_t)sizeof(*in4))
121 return -1;
122 xa->af = AF_INET;
123 memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4));
124 break;
125 case AF_INET6:
126 if (slen < (socklen_t)sizeof(*in6))
127 return -1;
128 xa->af = AF_INET6;
129 memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6));
130 #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
131 xa->scope_id = in6->sin6_scope_id;
132 #endif
133 break;
134 default:
135 return -1;
136 }
137
138 return 0;
139 }
140
141 static int
addr_invert(struct xaddr * n)142 addr_invert(struct xaddr *n)
143 {
144 int i;
145
146 if (n == NULL)
147 return -1;
148
149 switch (n->af) {
150 case AF_INET:
151 n->v4.s_addr = ~n->v4.s_addr;
152 return 0;
153 case AF_INET6:
154 for (i = 0; i < 4; i++)
155 n->addr32[i] = ~n->addr32[i];
156 return 0;
157 default:
158 return -1;
159 }
160 }
161
162 /*
163 * Calculate a netmask of length 'l' for address family 'af' and
164 * store it in 'n'.
165 * Returns 0 on success, -1 on failure.
166 */
167 int
addr_netmask(int af,u_int l,struct xaddr * n)168 addr_netmask(int af, u_int l, struct xaddr *n)
169 {
170 int i;
171
172 if (masklen_valid(af, l) != 0 || n == NULL)
173 return -1;
174
175 memset(n, '\0', sizeof(*n));
176 switch (af) {
177 case AF_INET:
178 n->af = AF_INET;
179 if (l == 0)
180 return 0;
181 n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);
182 return 0;
183 case AF_INET6:
184 n->af = AF_INET6;
185 for (i = 0; i < 4 && l >= 32; i++, l -= 32)
186 n->addr32[i] = 0xffffffffU;
187 if (i < 4 && l != 0)
188 n->addr32[i] = htonl((0xffffffff << (32 - l)) &
189 0xffffffff);
190 return 0;
191 default:
192 return -1;
193 }
194 }
195
196 static int
addr_hostmask(int af,u_int l,struct xaddr * n)197 addr_hostmask(int af, u_int l, struct xaddr *n)
198 {
199 if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)
200 return -1;
201 return 0;
202 }
203
204 /*
205 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.
206 * Returns 0 on success, -1 on failure.
207 */
208 int
addr_and(struct xaddr * dst,const struct xaddr * a,const struct xaddr * b)209 addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
210 {
211 int i;
212
213 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
214 return -1;
215
216 memcpy(dst, a, sizeof(*dst));
217 switch (a->af) {
218 case AF_INET:
219 dst->v4.s_addr &= b->v4.s_addr;
220 return 0;
221 case AF_INET6:
222 dst->scope_id = a->scope_id;
223 for (i = 0; i < 4; i++)
224 dst->addr32[i] &= b->addr32[i];
225 return 0;
226 default:
227 return -1;
228 }
229 }
230
231 static int
addr_or(struct xaddr * dst,const struct xaddr * a,const struct xaddr * b)232 addr_or(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
233 {
234 int i;
235
236 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
237 return (-1);
238
239 memcpy(dst, a, sizeof(*dst));
240 switch (a->af) {
241 case AF_INET:
242 dst->v4.s_addr |= b->v4.s_addr;
243 return (0);
244 case AF_INET6:
245 for (i = 0; i < 4; i++)
246 dst->addr32[i] |= b->addr32[i];
247 return (0);
248 default:
249 return (-1);
250 }
251 }
252
253 int
addr_cmp(const struct xaddr * a,const struct xaddr * b)254 addr_cmp(const struct xaddr *a, const struct xaddr *b)
255 {
256 int i;
257
258 if (a->af != b->af)
259 return (a->af == AF_INET6 ? 1 : -1);
260
261 switch (a->af) {
262 case AF_INET:
263 /*
264 * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is
265 * too big to fit into a signed int
266 */
267 if (a->v4.s_addr == b->v4.s_addr)
268 return 0;
269 return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1);
270 case AF_INET6:
271 /*
272 * Do this a byte at a time to avoid the above issue and
273 * any endian problems
274 */
275 for (i = 0; i < 16; i++)
276 if (a->addr8[i] - b->addr8[i] != 0)
277 return (a->addr8[i] - b->addr8[i]);
278 if (a->scope_id == b->scope_id)
279 return (0);
280 return (a->scope_id > b->scope_id ? 1 : -1);
281 default:
282 return (-1);
283 }
284 }
285
286 static int
addr_is_all0s(const struct xaddr * a)287 addr_is_all0s(const struct xaddr *a)
288 {
289 int i;
290
291 switch (a->af) {
292 case AF_INET:
293 return (a->v4.s_addr == 0 ? 0 : -1);
294 case AF_INET6:
295 for (i = 0; i < 4; i++)
296 if (a->addr32[i] != 0)
297 return -1;
298 return 0;
299 default:
300 return -1;
301 }
302 }
303
304 /* Increment the specified address. Note, does not do overflow checking */
305 void
addr_increment(struct xaddr * a)306 addr_increment(struct xaddr *a)
307 {
308 int i;
309 uint32_t n;
310
311 switch (a->af) {
312 case AF_INET:
313 a->v4.s_addr = htonl(ntohl(a->v4.s_addr) + 1);
314 break;
315 case AF_INET6:
316 for (i = 0; i < 4; i++) {
317 /* Increment with carry */
318 n = ntohl(a->addr32[3 - i]) + 1;
319 a->addr32[3 - i] = htonl(n);
320 if (n != 0)
321 break;
322 }
323 break;
324 }
325 }
326
327 /*
328 * Test whether host portion of address 'a', as determined by 'masklen'
329 * is all zeros.
330 * Returns 0 if host portion of address is all-zeros,
331 * -1 if not all zeros or on failure.
332 */
333 static int
addr_host_is_all0s(const struct xaddr * a,u_int masklen)334 addr_host_is_all0s(const struct xaddr *a, u_int masklen)
335 {
336 struct xaddr tmp_addr, tmp_mask, tmp_result;
337
338 memcpy(&tmp_addr, a, sizeof(tmp_addr));
339 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
340 return -1;
341 if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
342 return -1;
343 return addr_is_all0s(&tmp_result);
344 }
345
346 #if 0
347 static int
348 addr_host_to_all0s(struct xaddr *a, u_int masklen)
349 {
350 struct xaddr tmp_mask;
351
352 if (addr_netmask(a->af, masklen, &tmp_mask) == -1)
353 return (-1);
354 if (addr_and(a, a, &tmp_mask) == -1)
355 return (-1);
356 return (0);
357 }
358 #endif
359
360 int
addr_host_to_all1s(struct xaddr * a,u_int masklen)361 addr_host_to_all1s(struct xaddr *a, u_int masklen)
362 {
363 struct xaddr tmp_mask;
364
365 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
366 return (-1);
367 if (addr_or(a, a, &tmp_mask) == -1)
368 return (-1);
369 return (0);
370 }
371
372 /*
373 * Parse string address 'p' into 'n'.
374 * Returns 0 on success, -1 on failure.
375 */
376 int
addr_pton(const char * p,struct xaddr * n)377 addr_pton(const char *p, struct xaddr *n)
378 {
379 struct addrinfo hints, *ai;
380
381 memset(&hints, '\0', sizeof(hints));
382 hints.ai_flags = AI_NUMERICHOST;
383
384 if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
385 return -1;
386
387 if (ai == NULL)
388 return -1;
389
390 if (ai->ai_addr == NULL) {
391 freeaddrinfo(ai);
392 return -1;
393 }
394
395 if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen,
396 n) == -1) {
397 freeaddrinfo(ai);
398 return -1;
399 }
400
401 freeaddrinfo(ai);
402 return 0;
403 }
404
405 #if 0
406 static int
407 addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen)
408 {
409 struct addrinfo hints, *ai;
410
411 memset(&hints, '\0', sizeof(hints));
412 hints.ai_flags = AI_NUMERICHOST;
413
414 if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0)
415 return -1;
416
417 if (ai == NULL)
418 return -1;
419
420 if (ai->ai_addr == NULL) {
421 freeaddrinfo(ai);
422 return -1;
423 }
424
425 if (sa != NULL) {
426 if (slen < ai->ai_addrlen) {
427 freeaddrinfo(ai);
428 return -1;
429 }
430 memcpy(sa, &ai->ai_addr, ai->ai_addrlen);
431 }
432
433 freeaddrinfo(ai);
434 return 0;
435 }
436 #endif
437
438 int
addr_ntop(const struct xaddr * n,char * p,size_t len)439 addr_ntop(const struct xaddr *n, char *p, size_t len)
440 {
441 struct sockaddr_storage ss;
442 socklen_t slen = sizeof(ss);
443
444 if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1)
445 return -1;
446 if (p == NULL || len == 0)
447 return -1;
448 if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0,
449 NI_NUMERICHOST) != 0)
450 return -1;
451
452 return 0;
453 }
454
455 /*
456 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
457 * Return -1 on parse error, -2 on inconsistency or 0 on success.
458 */
459 int
addr_pton_cidr(const char * p,struct xaddr * n,u_int * l)460 addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
461 {
462 struct xaddr tmp;
463 u_int masklen = 999;
464 char addrbuf[64], *mp;
465 const char *errstr;
466
467 /* Don't modify argument */
468 if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf))
469 return -1;
470
471 if ((mp = strchr(addrbuf, '/')) != NULL) {
472 *mp = '\0';
473 mp++;
474 masklen = (u_int)strtonum(mp, 0, INT_MAX, &errstr);
475 if (errstr)
476 return -1;
477 }
478
479 if (addr_pton(addrbuf, &tmp) == -1)
480 return -1;
481
482 if (mp == NULL)
483 masklen = addr_unicast_masklen(tmp.af);
484 if (masklen_valid(tmp.af, masklen) == -1)
485 return -2;
486 if (addr_host_is_all0s(&tmp, masklen) != 0)
487 return -2;
488
489 if (n != NULL)
490 memcpy(n, &tmp, sizeof(*n));
491 if (l != NULL)
492 *l = masklen;
493
494 return 0;
495 }
496
497 int
addr_netmatch(const struct xaddr * host,const struct xaddr * net,u_int masklen)498 addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)
499 {
500 struct xaddr tmp_mask, tmp_result;
501
502 if (host->af != net->af)
503 return -1;
504
505 if (addr_netmask(host->af, masklen, &tmp_mask) == -1)
506 return -1;
507 if (addr_and(&tmp_result, host, &tmp_mask) == -1)
508 return -1;
509 return addr_cmp(&tmp_result, net);
510 }
511