blob: fb6de92e777bf2a680d977b514195776a59d024b [file] [log] [blame]
Darren Tuckera627d422013-06-02 07:31:17 +10001/* $OpenBSD: addrmatch.c,v 1.7 2013/05/17 00:13:13 djm 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;
Damien Miller0a80ca12010-02-27 07:55:05 +1100129 if (l == 0)
130 return 0;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000131 n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff);
132 return 0;
133 case AF_INET6:
134 n->af = AF_INET6;
135 for (i = 0; i < 4 && l >= 32; i++, l -= 32)
136 n->addr32[i] = 0xffffffffU;
137 if (i < 4 && l != 0)
138 n->addr32[i] = htonl((0xffffffff << (32 - l)) &
139 0xffffffff);
140 return 0;
141 default:
142 return -1;
143 }
144}
145
146/*
147 * Perform logical AND of addresses 'a' and 'b', storing result in 'dst'.
148 * Returns 0 on success, -1 on failure.
149 */
150static int
151addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b)
152{
153 int i;
154
155 if (dst == NULL || a == NULL || b == NULL || a->af != b->af)
156 return -1;
157
158 memcpy(dst, a, sizeof(*dst));
159 switch (a->af) {
160 case AF_INET:
161 dst->v4.s_addr &= b->v4.s_addr;
162 return 0;
163 case AF_INET6:
164 dst->scope_id = a->scope_id;
165 for (i = 0; i < 4; i++)
166 dst->addr32[i] &= b->addr32[i];
167 return 0;
168 default:
169 return -1;
170 }
171}
172
173/*
174 * Compare addresses 'a' and 'b'
175 * Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b)
176 */
177static int
178addr_cmp(const struct xaddr *a, const struct xaddr *b)
179{
180 int i;
181
182 if (a->af != b->af)
183 return a->af == AF_INET6 ? 1 : -1;
184
185 switch (a->af) {
186 case AF_INET:
187 if (a->v4.s_addr == b->v4.s_addr)
188 return 0;
189 return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1;
190 case AF_INET6:
191 for (i = 0; i < 16; i++)
192 if (a->addr8[i] - b->addr8[i] != 0)
193 return a->addr8[i] > b->addr8[i] ? 1 : -1;
194 if (a->scope_id == b->scope_id)
195 return 0;
196 return a->scope_id > b->scope_id ? 1 : -1;
197 default:
198 return -1;
199 }
200}
201
202/*
203 * Parse string address 'p' into 'n'
204 * Returns 0 on success, -1 on failure.
205 */
206static int
207addr_pton(const char *p, struct xaddr *n)
208{
209 struct addrinfo hints, *ai;
210
211 memset(&hints, '\0', sizeof(hints));
212 hints.ai_flags = AI_NUMERICHOST;
213
214 if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0)
215 return -1;
216
217 if (ai == NULL || ai->ai_addr == NULL)
218 return -1;
219
220 if (n != NULL &&
221 addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) {
222 freeaddrinfo(ai);
223 return -1;
224 }
225
226 freeaddrinfo(ai);
227 return 0;
228}
229
230/*
231 * Perform bitwise negation of address
232 * Returns 0 on success, -1 on failure.
233 */
234static int
235addr_invert(struct xaddr *n)
236{
237 int i;
238
239 if (n == NULL)
240 return (-1);
241
242 switch (n->af) {
243 case AF_INET:
244 n->v4.s_addr = ~n->v4.s_addr;
245 return (0);
246 case AF_INET6:
247 for (i = 0; i < 4; i++)
248 n->addr32[i] = ~n->addr32[i];
249 return (0);
250 default:
251 return (-1);
252 }
253}
254
255/*
256 * Calculate a netmask of length 'l' for address family 'af' and
257 * store it in 'n'.
258 * Returns 0 on success, -1 on failure.
259 */
260static int
261addr_hostmask(int af, u_int l, struct xaddr *n)
262{
263 if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1)
264 return (-1);
265 return (0);
266}
267
268/*
269 * Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::)
270 * Returns 0 on if address is all-zeros, -1 if not all zeros or on failure.
271 */
272static int
273addr_is_all0s(const struct xaddr *a)
274{
275 int i;
276
277 switch (a->af) {
278 case AF_INET:
279 return (a->v4.s_addr == 0 ? 0 : -1);
280 case AF_INET6:;
281 for (i = 0; i < 4; i++)
282 if (a->addr32[i] != 0)
283 return (-1);
284 return (0);
285 default:
286 return (-1);
287 }
288}
289
290/*
291 * Test whether host portion of address 'a', as determined by 'masklen'
292 * is all zeros.
293 * Returns 0 on if host portion of address is all-zeros,
294 * -1 if not all zeros or on failure.
295 */
296static int
297addr_host_is_all0s(const struct xaddr *a, u_int masklen)
298{
299 struct xaddr tmp_addr, tmp_mask, tmp_result;
300
301 memcpy(&tmp_addr, a, sizeof(tmp_addr));
302 if (addr_hostmask(a->af, masklen, &tmp_mask) == -1)
303 return (-1);
304 if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1)
305 return (-1);
306 return (addr_is_all0s(&tmp_result));
307}
308
309/*
310 * Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z).
311 * Return -1 on parse error, -2 on inconsistency or 0 on success.
312 */
313static int
314addr_pton_cidr(const char *p, struct xaddr *n, u_int *l)
315{
316 struct xaddr tmp;
317 long unsigned int masklen = 999;
318 char addrbuf[64], *mp, *cp;
319
320 /* Don't modify argument */
Damien Miller97f43bb2012-06-30 08:32:29 +1000321 if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf))
Darren Tucker7a3935d2008-06-10 22:59:10 +1000322 return -1;
323
324 if ((mp = strchr(addrbuf, '/')) != NULL) {
325 *mp = '\0';
326 mp++;
327 masklen = strtoul(mp, &cp, 10);
328 if (*mp == '\0' || *cp != '\0' || masklen > 128)
329 return -1;
330 }
331
332 if (addr_pton(addrbuf, &tmp) == -1)
333 return -1;
334
335 if (mp == NULL)
336 masklen = addr_unicast_masklen(tmp.af);
337 if (masklen_valid(tmp.af, masklen) == -1)
338 return -2;
339 if (addr_host_is_all0s(&tmp, masklen) != 0)
340 return -2;
341
342 if (n != NULL)
343 memcpy(n, &tmp, sizeof(*n));
344 if (l != NULL)
345 *l = masklen;
346
347 return 0;
348}
349
350static int
351addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen)
352{
353 struct xaddr tmp_mask, tmp_result;
354
355 if (host->af != net->af)
356 return -1;
357
358 if (addr_netmask(host->af, masklen, &tmp_mask) == -1)
359 return -1;
360 if (addr_and(&tmp_result, host, &tmp_mask) == -1)
361 return -1;
362 return addr_cmp(&tmp_result, net);
363}
364
365/*
366 * Match "addr" against list pattern list "_list", which may contain a
367 * mix of CIDR addresses and old-school wildcards.
368 *
369 * If addr is NULL, then no matching is performed, but _list is parsed
370 * and checked for well-formedness.
371 *
372 * Returns 1 on match found (never returned when addr == NULL).
373 * Returns 0 on if no match found, or no errors found when addr == NULL.
Darren Tucker896ad5a2008-06-11 09:34:46 +1000374 * Returns -1 on negated match found (never returned when addr == NULL).
375 * Returns -2 on invalid list entry.
Darren Tucker7a3935d2008-06-10 22:59:10 +1000376 */
377int
378addr_match_list(const char *addr, const char *_list)
379{
380 char *list, *cp, *o;
381 struct xaddr try_addr, match_addr;
382 u_int masklen, neg;
383 int ret = 0, r;
384
385 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
386 debug2("%s: couldn't parse address %.100s", __func__, addr);
387 return 0;
388 }
389 if ((o = list = strdup(_list)) == NULL)
390 return -1;
391 while ((cp = strsep(&list, ",")) != NULL) {
392 neg = *cp == '!';
393 if (neg)
394 cp++;
395 if (*cp == '\0') {
Darren Tucker896ad5a2008-06-11 09:34:46 +1000396 ret = -2;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000397 break;
398 }
399 /* Prefer CIDR address matching */
400 r = addr_pton_cidr(cp, &match_addr, &masklen);
401 if (r == -2) {
402 error("Inconsistent mask length for "
403 "network \"%.100s\"", cp);
Darren Tucker896ad5a2008-06-11 09:34:46 +1000404 ret = -2;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000405 break;
406 } else if (r == 0) {
407 if (addr != NULL && addr_netmatch(&try_addr,
408 &match_addr, masklen) == 0) {
409 foundit:
410 if (neg) {
Darren Tucker896ad5a2008-06-11 09:34:46 +1000411 ret = -1;
Darren Tucker7a3935d2008-06-10 22:59:10 +1000412 break;
413 }
414 ret = 1;
415 }
416 continue;
417 } else {
418 /* If CIDR parse failed, try wildcard string match */
419 if (addr != NULL && match_pattern(addr, cp) == 1)
420 goto foundit;
421 }
422 }
Darren Tuckera627d422013-06-02 07:31:17 +1000423 free(o);
Darren Tucker7a3935d2008-06-10 22:59:10 +1000424
425 return ret;
426}
Damien Miller0a80ca12010-02-27 07:55:05 +1100427
428/*
429 * Match "addr" against list CIDR list "_list". Lexical wildcards and
430 * negation are not supported. If "addr" == NULL, will verify structure
431 * of "_list".
432 *
433 * Returns 1 on match found (never returned when addr == NULL).
434 * Returns 0 on if no match found, or no errors found when addr == NULL.
435 * Returns -1 on error
436 */
437int
438addr_match_cidr_list(const char *addr, const char *_list)
439{
440 char *list, *cp, *o;
441 struct xaddr try_addr, match_addr;
442 u_int masklen;
443 int ret = 0, r;
444
445 if (addr != NULL && addr_pton(addr, &try_addr) != 0) {
446 debug2("%s: couldn't parse address %.100s", __func__, addr);
447 return 0;
448 }
449 if ((o = list = strdup(_list)) == NULL)
450 return -1;
451 while ((cp = strsep(&list, ",")) != NULL) {
452 if (*cp == '\0') {
453 error("%s: empty entry in list \"%.100s\"",
454 __func__, o);
455 ret = -1;
456 break;
457 }
458
459 /*
460 * NB. This function is called in pre-auth with untrusted data,
461 * so be extra paranoid about junk reaching getaddrino (via
462 * addr_pton_cidr).
463 */
464
465 /* Stop junk from reaching getaddrinfo. +3 is for masklen */
466 if (strlen(cp) > INET6_ADDRSTRLEN + 3) {
467 error("%s: list entry \"%.100s\" too long",
468 __func__, cp);
469 ret = -1;
470 break;
471 }
472#define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/"
473 if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) {
474 error("%s: list entry \"%.100s\" contains invalid "
475 "characters", __func__, cp);
476 ret = -1;
477 }
478
479 /* Prefer CIDR address matching */
480 r = addr_pton_cidr(cp, &match_addr, &masklen);
481 if (r == -1) {
482 error("Invalid network entry \"%.100s\"", cp);
483 ret = -1;
484 break;
485 } else if (r == -2) {
486 error("Inconsistent mask length for "
487 "network \"%.100s\"", cp);
488 ret = -1;
489 break;
490 } else if (r == 0 && addr != NULL) {
491 if (addr_netmatch(&try_addr, &match_addr,
492 masklen) == 0)
493 ret = 1;
494 continue;
495 }
496 }
Darren Tuckera627d422013-06-02 07:31:17 +1000497 free(o);
Damien Miller0a80ca12010-02-27 07:55:05 +1100498
499 return ret;
500}