blob: d39885b7bdeb1a08a3e26e1e51f335930441d84e [file] [log] [blame]
Damien Miller7375fe22009-01-28 16:16:00 +11001/* $OpenBSD: addrmatch.c,v 1.4 2008/12/10 03:55:20 stevesk Exp $ */
Darren Tucker7a3935d2008-06-10 22:59:10 +10002
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#include <stdarg.h>
31
32#include "match.h"
33#include "log.h"
Damien Miller7375fe22009-01-28 16:16:00 +110034#include "xmalloc.h"
Darren Tucker7a3935d2008-06-10 22:59:10 +100035
36struct xaddr {
37 sa_family_t af;
38 union {
39 struct in_addr v4;
40 struct in6_addr v6;
41 u_int8_t addr8[16];
42 u_int32_t addr32[4];
43 } xa; /* 128-bit address */
44 u_int32_t scope_id; /* iface scope id for v6 */
45#define v4 xa.v4
46#define v6 xa.v6
47#define addr8 xa.addr8
48#define addr32 xa.addr32
49};
50
51static int
52addr_unicast_masklen(int af)
53{
54 switch (af) {
55 case AF_INET:
56 return 32;
57 case AF_INET6:
58 return 128;
59 default:
60 return -1;
61 }
62}
63
64static inline int
65masklen_valid(int af, u_int masklen)
66{
67 switch (af) {
68 case AF_INET:
69 return masklen <= 32 ? 0 : -1;
70 case AF_INET6:
71 return masklen <= 128 ? 0 : -1;
72 default:
73 return -1;
74 }
75}
76
77/*
78 * Convert struct sockaddr to struct xaddr
79 * Returns 0 on success, -1 on failure.
80 */
81static int
82addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa)
83{
84 struct sockaddr_in *in4 = (struct sockaddr_in *)sa;
85 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa;
86
87 memset(xa, '\0', sizeof(*xa));
88
89 switch (sa->sa_family) {
90 case AF_INET:
91 if (slen < sizeof(*in4))
92 return -1;
93 xa->af = AF_INET;
94 memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4));
95 break;
96 case AF_INET6:
97 if (slen < sizeof(*in6))
98 return -1;
99 xa->af = AF_INET6;
100 memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6));
Tim Rice0f4d2c02008-11-18 21:26:41 -0800101#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID
Darren Tucker7a3935d2008-06-10 22:59:10 +1000102 xa->scope_id = in6->sin6_scope_id;
Tim Rice0f4d2c02008-11-18 21:26:41 -0800103#endif
Darren Tucker7a3935d2008-06-10 22:59:10 +1000104 break;
105 default:
106 return -1;
107 }
108
109 return 0;
110}
111
112/*
113 * Calculate a netmask of length 'l' for address family 'af' and
114 * store it in 'n'.
115 * Returns 0 on success, -1 on failure.
116 */
117static int
118addr_netmask(int af, u_int l, struct xaddr *n)
119{
120 int i;
121
122 if (masklen_valid(af, l) != 0 || n == NULL)
123 return -1;
124
125 memset(n, '\0', sizeof(*n));
126 switch (af) {
127 case AF_INET:
128 n->af = AF_INET;
129 n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);
130 return 0;
131 case AF_INET6:
132 n->af = AF_INET6;
133 for (i = 0; i < 4 && l >= 32; i++, l -= 32)
134 n->addr32[i] = 0xffffffffU;
135 if (i < 4 && l != 0)
136 n->addr32[i] = htonl((0xffffffff << (32 - l)) &
137 0xffffffff);
138 return 0;
139 default:
140 return -1;
141 }
142}
143
144/*
145 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.
146 * Returns 0 on success, -1 on failure.
147 */
148static int
149addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
150{
151 int i;
152
153 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
154 return -1;
155
156 memcpy(dst, a, sizeof(*dst));
157 switch (a->af) {
158 case AF_INET:
159 dst->v4.s_addr &= b->v4.s_addr;
160 return 0;
161 case AF_INET6:
162 dst->scope_id = a->scope_id;
163 for (i = 0; i < 4; i++)
164 dst->addr32[i] &= b->addr32[i];
165 return 0;
166 default:
167 return -1;
168 }
169}
170
171/*
172 * Compare addresses 'a' and 'b'
173 * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b)
174 */
175static int
176addr_cmp(const struct xaddr *a, const struct xaddr *b)
177{
178 int i;
179
180 if (a->af != b->af)
181 return a->af == AF_INET6 ? 1 : -1;
182
183 switch (a->af) {
184 case AF_INET:
185 if (a->v4.s_addr == b->v4.s_addr)
186 return 0;
187 return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1;
188 case AF_INET6:
189 for (i = 0; i < 16; i++)
190 if (a->addr8[i] - b->addr8[i] != 0)
191 return a->addr8[i] > b->addr8[i] ? 1 : -1;
192 if (a->scope_id == b->scope_id)
193 return 0;
194 return a->scope_id > b->scope_id ? 1 : -1;
195 default:
196 return -1;
197 }
198}
199
200/*
201 * Parse string address 'p' into 'n'
202 * Returns 0 on success, -1 on failure.
203 */
204static int
205addr_pton(const char *p, struct xaddr *n)
206{
207 struct addrinfo hints, *ai;
208
209 memset(&hints, '\0', sizeof(hints));
210 hints.ai_flags = AI_NUMERICHOST;
211
212 if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
213 return -1;
214
215 if (ai == NULL || ai->ai_addr == NULL)
216 return -1;
217
218 if (n != NULL &&
219 addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) {
220 freeaddrinfo(ai);
221 return -1;
222 }
223
224 freeaddrinfo(ai);
225 return 0;
226}
227
228/*
229 * Perform bitwise negation of address
230 * Returns 0 on success, -1 on failure.
231 */
232static int
233addr_invert(struct xaddr *n)
234{
235 int i;
236
237 if (n == NULL)
238 return (-1);
239
240 switch (n->af) {
241 case AF_INET:
242 n->v4.s_addr = ~n->v4.s_addr;
243 return (0);
244 case AF_INET6:
245 for (i = 0; i < 4; i++)
246 n->addr32[i] = ~n->addr32[i];
247 return (0);
248 default:
249 return (-1);
250 }
251}
252
253/*
254 * Calculate a netmask of length 'l' for address family 'af' and
255 * store it in 'n'.
256 * Returns 0 on success, -1 on failure.
257 */
258static int
259addr_hostmask(int af, u_int l, struct xaddr *n)
260{
261 if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)
262 return (-1);
263 return (0);
264}
265
266/*
267 * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::)
268 * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure.
269 */
270static int
271addr_is_all0s(const struct xaddr *a)
272{
273 int i;
274
275 switch (a->af) {
276 case AF_INET:
277 return (a->v4.s_addr == 0 ? 0 : -1);
278 case AF_INET6:;
279 for (i = 0; i < 4; i++)
280 if (a->addr32[i] != 0)
281 return (-1);
282 return (0);
283 default:
284 return (-1);
285 }
286}
287
288/*
289 * Test whether host portion of address 'a', as determined by 'masklen'
290 * is all zeros.
291 * Returns 0 on if host portion of address is all-zeros,
292 * -1 if not all zeros or on failure.
293 */
294static int
295addr_host_is_all0s(const struct xaddr *a, u_int masklen)
296{
297 struct xaddr tmp_addr, tmp_mask, tmp_result;
298
299 memcpy(&tmp_addr, a, sizeof(tmp_addr));
300 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
301 return (-1);
302 if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
303 return (-1);
304 return (addr_is_all0s(&tmp_result));
305}
306
307/*
308 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
309 * Return -1 on parse error, -2 on inconsistency or 0 on success.
310 */
311static int
312addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
313{
314 struct xaddr tmp;
315 long unsigned int masklen = 999;
316 char addrbuf[64], *mp, *cp;
317
318 /* Don't modify argument */
319 if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) > sizeof(addrbuf))
320 return -1;
321
322 if ((mp = strchr(addrbuf, '/')) != NULL) {
323 *mp = '\0';
324 mp++;
325 masklen = strtoul(mp, &cp, 10);
326 if (*mp == '\0' || *cp != '\0' || masklen > 128)
327 return -1;
328 }
329
330 if (addr_pton(addrbuf, &tmp) == -1)
331 return -1;
332
333 if (mp == NULL)
334 masklen = addr_unicast_masklen(tmp.af);
335 if (masklen_valid(tmp.af, masklen) == -1)
336 return -2;
337 if (addr_host_is_all0s(&tmp, masklen) != 0)
338 return -2;
339
340 if (n != NULL)
341 memcpy(n, &tmp, sizeof(*n));
342 if (l != NULL)
343 *l = masklen;
344
345 return 0;
346}
347
348static int
349addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)
350{
351 struct xaddr tmp_mask, tmp_result;
352
353 if (host->af != net->af)
354 return -1;
355
356 if (addr_netmask(host->af, masklen, &tmp_mask) == -1)
357 return -1;
358 if (addr_and(&tmp_result, host, &tmp_mask) == -1)
359 return -1;
360 return addr_cmp(&tmp_result, net);
361}
362
363/*
364 * Match "addr" against list pattern list "_list", which may contain a
365 * mix of CIDR addresses and old-school wildcards.
366 *
367 * If addr is NULL, then no matching is performed, but _list is parsed
368 * and checked for well-formedness.
369 *
370 * Returns 1 on match found (never returned when addr == NULL).
371 * Returns 0 on if no match found, or no errors found when addr == NULL.
Darren Tucker896ad5a2008-06-11 09:34:46 +1000372 * Returns -1 on negated match found (never returned when addr == NULL).
373 * Returns -2 on invalid list entry.
Darren Tucker7a3935d2008-06-10 22:59:10 +1000374 */
375int
376addr_match_list(const char *addr, const char *_list)
377{
378 char *list, *cp, *o;
379 struct xaddr try_addr, match_addr;
380 u_int masklen, neg;
381 int ret = 0, r;
382
383 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
384 debug2("%s: couldn't parse address %.100s", __func__, addr);
385 return 0;
386 }
387 if ((o = list = strdup(_list)) == NULL)
388 return -1;
389 while ((cp = strsep(&list, ",")) != NULL) {
390 neg = *cp == '!';
391 if (neg)
392 cp++;
393 if (*cp == '\0') {
Darren Tucker896ad5a2008-06-11 09:34:46 +1000394 ret = -2;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000395 break;
396 }
397 /* Prefer CIDR address matching */
398 r = addr_pton_cidr(cp, &match_addr, &masklen);
399 if (r == -2) {
400 error("Inconsistent mask length for "
401 "network \"%.100s\"", cp);
Darren Tucker896ad5a2008-06-11 09:34:46 +1000402 ret = -2;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000403 break;
404 } else if (r == 0) {
405 if (addr != NULL && addr_netmatch(&try_addr,
406 &match_addr, masklen) == 0) {
407 foundit:
408 if (neg) {
Darren Tucker896ad5a2008-06-11 09:34:46 +1000409 ret = -1;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000410 break;
411 }
412 ret = 1;
413 }
414 continue;
415 } else {
416 /* If CIDR parse failed, try wildcard string match */
417 if (addr != NULL && match_pattern(addr, cp) == 1)
418 goto foundit;
419 }
420 }
Damien Miller7375fe22009-01-28 16:16:00 +1100421 xfree(o);
Darren Tucker7a3935d2008-06-10 22:59:10 +1000422
423 return ret;
424}