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
35int
36addr_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
48static inline int
49masklen_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
61int
62addr_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 */
109int
110addr_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
140int
141addr_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 */
166int
167addr_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
195int
196addr_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 */
207int
208addr_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
230int
231addr_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
252int
253addr_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
285int
286addr_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 */
304void
305addr_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 */
332int
333addr_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
346int
347addr_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
359int
360addr_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 */
375int
376addr_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
404int
405addr_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
435int
436addr_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 */
456int
457addr_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
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}
507