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1/* $OpenBSD: addr.c,v 1.9 2024/10/18 04:30:09 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 <sys/types.h>
20#include <sys/socket.h>
21#include <netinet/in.h>
22#include <arpa/inet.h>
23
24#include <netdb.h>
25#include <string.h>
26#include <stdlib.h>
27#include <stdio.h>
28#include <limits.h>
29
30#include "addr.h"
31
32#define _SA(x) ((struct sockaddr *)(x))
33
34static int
35addr_unicast_masklen(int af)
36{
37 switch (af) {
38 case AF_INET:
39 return 32;
40 case AF_INET6:
41 return 128;
42 default:
43 return -1;
44 }
45}
46
47static inline int
48masklen_valid(int af, u_int masklen)
49{
50 switch (af) {
51 case AF_INET:
52 return masklen <= 32 ? 0 : -1;
53 case AF_INET6:
54 return masklen <= 128 ? 0 : -1;
55 default:
56 return -1;
57 }
58}
59
60static int
61addr_xaddr_to_sa(const struct xaddr *xa, struct sockaddr *sa, socklen_t *len,
62 u_int16_t port)
63{
64 struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
65 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
66
67 if (xa == NULL || sa == NULL || len == NULL)
68 return -1;
69
70 switch (xa->af) {
71 case AF_INET:
72 if (*len < sizeof(*in4))
73 return -1;
74 memset(sa, '\0', sizeof(*in4));
75 *len = sizeof(*in4);
76#ifdef SOCK_HAS_LEN
77 in4->sin_len = sizeof(*in4);
78#endif
79 in4->sin_family = AF_INET;
80 in4->sin_port = htons(port);
81 memcpy(&in4->sin_addr, &xa->v4, sizeof(in4->sin_addr));
82 break;
83 case AF_INET6:
84 if (*len < sizeof(*in6))
85 return -1;
86 memset(sa, '\0', sizeof(*in6));
87 *len = sizeof(*in6);
88#ifdef SOCK_HAS_LEN
89 in6->sin6_len = sizeof(*in6);
90#endif
91 in6->sin6_family = AF_INET6;
92 in6->sin6_port = htons(port);
93 memcpy(&in6->sin6_addr, &xa->v6, sizeof(in6->sin6_addr));
94 in6->sin6_scope_id = xa->scope_id;
95 break;
96 default:
97 return -1;
98 }
99 return 0;
100}
101
102/*
103 * Convert struct sockaddr to struct xaddr
104 * Returns 0 on success, -1 on failure.
105 */
106int
107addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa)
108{
109 struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
110 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
111
112 memset(xa, '\0', sizeof(*xa));
113
114 switch (sa->sa_family) {
115 case AF_INET:
116 if (slen < (socklen_t)sizeof(*in4))
117 return -1;
118 xa->af = AF_INET;
119 memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4));
120 break;
121 case AF_INET6:
122 if (slen < (socklen_t)sizeof(*in6))
123 return -1;
124 xa->af = AF_INET6;
125 memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6));
126#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
127 xa->scope_id = in6->sin6_scope_id;
128#endif
129 break;
130 default:
131 return -1;
132 }
133
134 return 0;
135}
136
137static int
138addr_invert(struct xaddr *n)
139{
140 int i;
141
142 if (n == NULL)
143 return -1;
144
145 switch (n->af) {
146 case AF_INET:
147 n->v4.s_addr = ~n->v4.s_addr;
148 return 0;
149 case AF_INET6:
150 for (i = 0; i < 4; i++)
151 n->addr32[i] = ~n->addr32[i];
152 return 0;
153 default:
154 return -1;
155 }
156}
157
158/*
159 * Calculate a netmask of length 'l' for address family 'af' and
160 * store it in 'n'.
161 * Returns 0 on success, -1 on failure.
162 */
163int
164addr_netmask(int af, u_int l, struct xaddr *n)
165{
166 int i;
167
168 if (masklen_valid(af, l) != 0 || n == NULL)
169 return -1;
170
171 memset(n, '\0', sizeof(*n));
172 switch (af) {
173 case AF_INET:
174 n->af = AF_INET;
175 if (l == 0)
176 return 0;
177 n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);
178 return 0;
179 case AF_INET6:
180 n->af = AF_INET6;
181 for (i = 0; i < 4 && l >= 32; i++, l -= 32)
182 n->addr32[i] = 0xffffffffU;
183 if (i < 4 && l != 0)
184 n->addr32[i] = htonl((0xffffffff << (32 - l)) &
185 0xffffffff);
186 return 0;
187 default:
188 return -1;
189 }
190}
191
192static int
193addr_hostmask(int af, u_int l, struct xaddr *n)
194{
195 if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)
196 return -1;
197 return 0;
198}
199
200/*
201 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.
202 * Returns 0 on success, -1 on failure.
203 */
204int
205addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
206{
207 int i;
208
209 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
210 return -1;
211
212 memcpy(dst, a, sizeof(*dst));
213 switch (a->af) {
214 case AF_INET:
215 dst->v4.s_addr &= b->v4.s_addr;
216 return 0;
217 case AF_INET6:
218 dst->scope_id = a->scope_id;
219 for (i = 0; i < 4; i++)
220 dst->addr32[i] &= b->addr32[i];
221 return 0;
222 default:
223 return -1;
224 }
225}
226
227static int
228addr_or(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
229{
230 int i;
231
232 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
233 return (-1);
234
235 memcpy(dst, a, sizeof(*dst));
236 switch (a->af) {
237 case AF_INET:
238 dst->v4.s_addr |= b->v4.s_addr;
239 return (0);
240 case AF_INET6:
241 for (i = 0; i < 4; i++)
242 dst->addr32[i] |= b->addr32[i];
243 return (0);
244 default:
245 return (-1);
246 }
247}
248
249int
250addr_cmp(const struct xaddr *a, const struct xaddr *b)
251{
252 int i;
253
254 if (a->af != b->af)
255 return (a->af == AF_INET6 ? 1 : -1);
256
257 switch (a->af) {
258 case AF_INET:
259 /*
260 * Can't just subtract here as 255.255.255.255 - 0.0.0.0 is
261 * too big to fit into a signed int
262 */
263 if (a->v4.s_addr == b->v4.s_addr)
264 return 0;
265 return (ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1);
266 case AF_INET6:
267 /*
268 * Do this a byte at a time to avoid the above issue and
269 * any endian problems
270 */
271 for (i = 0; i < 16; i++)
272 if (a->addr8[i] - b->addr8[i] != 0)
273 return (a->addr8[i] - b->addr8[i]);
274 if (a->scope_id == b->scope_id)
275 return (0);
276 return (a->scope_id > b->scope_id ? 1 : -1);
277 default:
278 return (-1);
279 }
280}
281
282static int
283addr_is_all0s(const struct xaddr *a)
284{
285 int i;
286
287 switch (a->af) {
288 case AF_INET:
289 return (a->v4.s_addr == 0 ? 0 : -1);
290 case AF_INET6:
291 for (i = 0; i < 4; i++)
292 if (a->addr32[i] != 0)
293 return -1;
294 return 0;
295 default:
296 return -1;
297 }
298}
299
300/* Increment the specified address. Note, does not do overflow checking */
301void
302addr_increment(struct xaddr *a)
303{
304 int i;
305 uint32_t n;
306
307 switch (a->af) {
308 case AF_INET:
309 a->v4.s_addr = htonl(ntohl(a->v4.s_addr) + 1);
310 break;
311 case AF_INET6:
312 for (i = 0; i < 4; i++) {
313 /* Increment with carry */
314 n = ntohl(a->addr32[3 - i]) + 1;
315 a->addr32[3 - i] = htonl(n);
316 if (n != 0)
317 break;
318 }
319 break;
320 }
321}
322
323/*
324 * Test whether host portion of address 'a', as determined by 'masklen'
325 * is all zeros.
326 * Returns 0 if host portion of address is all-zeros,
327 * -1 if not all zeros or on failure.
328 */
329static int
330addr_host_is_all0s(const struct xaddr *a, u_int masklen)
331{
332 struct xaddr tmp_addr, tmp_mask, tmp_result;
333
334 memcpy(&tmp_addr, a, sizeof(tmp_addr));
335 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
336 return -1;
337 if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
338 return -1;
339 return addr_is_all0s(&tmp_result);
340}
341
342#if 0
343static int
344addr_host_to_all0s(struct xaddr *a, u_int masklen)
345{
346 struct xaddr tmp_mask;
347
348 if (addr_netmask(a->af, masklen, &tmp_mask) == -1)
349 return (-1);
350 if (addr_and(a, a, &tmp_mask) == -1)
351 return (-1);
352 return (0);
353}
354#endif
355
356int
357addr_host_to_all1s(struct xaddr *a, u_int masklen)
358{
359 struct xaddr tmp_mask;
360
361 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
362 return (-1);
363 if (addr_or(a, a, &tmp_mask) == -1)
364 return (-1);
365 return (0);
366}
367
368/*
369 * Parse string address 'p' into 'n'.
370 * Returns 0 on success, -1 on failure.
371 */
372int
373addr_pton(const char *p, struct xaddr *n)
374{
375 struct addrinfo hints, *ai;
376
377 memset(&hints, '\0', sizeof(hints));
378 hints.ai_flags = AI_NUMERICHOST;
379
380 if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
381 return -1;
382
383 if (ai == NULL)
384 return -1;
385
386 if (ai->ai_addr == NULL) {
387 freeaddrinfo(ai);
388 return -1;
389 }
390
391 if (n != NULL && addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen,
392 n) == -1) {
393 freeaddrinfo(ai);
394 return -1;
395 }
396
397 freeaddrinfo(ai);
398 return 0;
399}
400
401#if 0
402static int
403addr_sa_pton(const char *h, const char *s, struct sockaddr *sa, socklen_t slen)
404{
405 struct addrinfo hints, *ai;
406
407 memset(&hints, '\0', sizeof(hints));
408 hints.ai_flags = AI_NUMERICHOST;
409
410 if (h == NULL || getaddrinfo(h, s, &hints, &ai) != 0)
411 return -1;
412
413 if (ai == NULL)
414 return -1;
415
416 if (ai->ai_addr == NULL) {
417 freeaddrinfo(ai);
418 return -1;
419 }
420
421 if (sa != NULL) {
422 if (slen < ai->ai_addrlen) {
423 freeaddrinfo(ai);
424 return -1;
425 }
426 memcpy(sa, &ai->ai_addr, ai->ai_addrlen);
427 }
428
429 freeaddrinfo(ai);
430 return 0;
431}
432#endif
433
434int
435addr_ntop(const struct xaddr *n, char *p, size_t len)
436{
437 struct sockaddr_storage ss;
438 socklen_t slen = sizeof(ss);
439
440 if (addr_xaddr_to_sa(n, _SA(&ss), &slen, 0) == -1)
441 return -1;
442 if (p == NULL || len == 0)
443 return -1;
444 if (getnameinfo(_SA(&ss), slen, p, len, NULL, 0,
445 NI_NUMERICHOST) != 0)
446 return -1;
447
448 return 0;
449}
450
451/*
452 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
453 * Return -1 on parse error, -2 on inconsistency or 0 on success.
454 */
455int
456addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
457{
458 struct xaddr tmp;
459 u_int masklen = 999;
460 char addrbuf[64], *mp;
461 const char *errstr;
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 = (u_int)strtonum(mp, 0, INT_MAX, &errstr);
471 if (errstr)
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
493int
494addr_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}