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1 | /* $OpenBSD: addrmatch.c,v 1.4 2008/12/10 03:55:20 stevesk 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 | #include <stdarg.h> | |
31 | ||
32 | #include "match.h" | |
33 | #include "log.h" | |
34 | #include "xmalloc.h" | |
35 | ||
36 | struct 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 | ||
51 | static int | |
52 | addr_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 | ||
64 | static inline int | |
65 | masklen_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 | */ | |
81 | static int | |
82 | addr_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)); | |
101 | #ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_SCOPE_ID | |
102 | xa->scope_id = in6->sin6_scope_id; | |
103 | #endif | |
104 | 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 | */ | |
117 | static int | |
118 | addr_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 | */ | |
148 | static int | |
149 | addr_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 | */ | |
175 | static int | |
176 | addr_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 | */ | |
204 | static int | |
205 | addr_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 | */ | |
232 | static int | |
233 | addr_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 | */ | |
258 | static int | |
259 | addr_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 | */ | |
270 | static int | |
271 | addr_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 | */ | |
294 | static int | |
295 | addr_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 | */ | |
311 | static int | |
312 | addr_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 | ||
348 | static int | |
349 | addr_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. | |
372 | * Returns -1 on negated match found (never returned when addr == NULL). | |
373 | * Returns -2 on invalid list entry. | |
374 | */ | |
375 | int | |
376 | addr_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') { | |
394 | ret = -2; | |
395 | 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); | |
402 | ret = -2; | |
403 | break; | |
404 | } else if (r == 0) { | |
405 | if (addr != NULL && addr_netmatch(&try_addr, | |
406 | &match_addr, masklen) == 0) { | |
407 | foundit: | |
408 | if (neg) { | |
409 | ret = -1; | |
410 | 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 | } | |
421 | xfree(o); | |
422 | ||
423 | return ret; | |
424 | } |