1 |
|
|
/* $OpenBSD: addrmatch.c,v 1.13 2016/09/21 16:55:42 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 <stdarg.h> |
29 |
|
|
|
30 |
|
|
#include "match.h" |
31 |
|
|
#include "log.h" |
32 |
|
|
|
33 |
|
|
struct xaddr { |
34 |
|
|
sa_family_t af; |
35 |
|
|
union { |
36 |
|
|
struct in_addr v4; |
37 |
|
|
struct in6_addr v6; |
38 |
|
|
u_int8_t addr8[16]; |
39 |
|
|
u_int32_t addr32[4]; |
40 |
|
|
} xa; /* 128-bit address */ |
41 |
|
|
u_int32_t scope_id; /* iface scope id for v6 */ |
42 |
|
|
#define v4 xa.v4 |
43 |
|
|
#define v6 xa.v6 |
44 |
|
|
#define addr8 xa.addr8 |
45 |
|
|
#define addr32 xa.addr32 |
46 |
|
|
}; |
47 |
|
|
|
48 |
|
|
static int |
49 |
|
|
addr_unicast_masklen(int af) |
50 |
|
|
{ |
51 |
|
|
switch (af) { |
52 |
|
|
case AF_INET: |
53 |
|
|
return 32; |
54 |
|
|
case AF_INET6: |
55 |
|
|
return 128; |
56 |
|
|
default: |
57 |
|
|
return -1; |
58 |
|
|
} |
59 |
|
|
} |
60 |
|
|
|
61 |
|
|
static inline int |
62 |
|
|
masklen_valid(int af, u_int masklen) |
63 |
|
|
{ |
64 |
|
|
switch (af) { |
65 |
|
|
case AF_INET: |
66 |
|
|
return masklen <= 32 ? 0 : -1; |
67 |
|
|
case AF_INET6: |
68 |
|
|
return masklen <= 128 ? 0 : -1; |
69 |
|
|
default: |
70 |
|
|
return -1; |
71 |
|
|
} |
72 |
|
|
} |
73 |
|
|
|
74 |
|
|
/* |
75 |
|
|
* Convert struct sockaddr to struct xaddr |
76 |
|
|
* Returns 0 on success, -1 on failure. |
77 |
|
|
*/ |
78 |
|
|
static int |
79 |
|
|
addr_sa_to_xaddr(struct sockaddr *sa, socklen_t slen, struct xaddr *xa) |
80 |
|
|
{ |
81 |
|
|
struct sockaddr_in *in4 = (struct sockaddr_in *)sa; |
82 |
|
|
struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)sa; |
83 |
|
|
|
84 |
|
|
memset(xa, '\0', sizeof(*xa)); |
85 |
|
|
|
86 |
|
|
switch (sa->sa_family) { |
87 |
|
|
case AF_INET: |
88 |
|
|
if (slen < (socklen_t)sizeof(*in4)) |
89 |
|
|
return -1; |
90 |
|
|
xa->af = AF_INET; |
91 |
|
|
memcpy(&xa->v4, &in4->sin_addr, sizeof(xa->v4)); |
92 |
|
|
break; |
93 |
|
|
case AF_INET6: |
94 |
|
|
if (slen < (socklen_t)sizeof(*in6)) |
95 |
|
|
return -1; |
96 |
|
|
xa->af = AF_INET6; |
97 |
|
|
memcpy(&xa->v6, &in6->sin6_addr, sizeof(xa->v6)); |
98 |
|
|
xa->scope_id = in6->sin6_scope_id; |
99 |
|
|
break; |
100 |
|
|
default: |
101 |
|
|
return -1; |
102 |
|
|
} |
103 |
|
|
|
104 |
|
|
return 0; |
105 |
|
|
} |
106 |
|
|
|
107 |
|
|
/* |
108 |
|
|
* Calculate a netmask of length 'l' for address family 'af' and |
109 |
|
|
* store it in 'n'. |
110 |
|
|
* Returns 0 on success, -1 on failure. |
111 |
|
|
*/ |
112 |
|
|
static int |
113 |
|
|
addr_netmask(int af, u_int l, struct xaddr *n) |
114 |
|
|
{ |
115 |
|
|
int i; |
116 |
|
|
|
117 |
|
|
if (masklen_valid(af, l) != 0 || n == NULL) |
118 |
|
|
return -1; |
119 |
|
|
|
120 |
|
|
memset(n, '\0', sizeof(*n)); |
121 |
|
|
switch (af) { |
122 |
|
|
case AF_INET: |
123 |
|
|
n->af = AF_INET; |
124 |
|
|
if (l == 0) |
125 |
|
|
return 0; |
126 |
|
|
n->v4.s_addr = htonl((0xffffffff << (32 - l)) & 0xffffffff); |
127 |
|
|
return 0; |
128 |
|
|
case AF_INET6: |
129 |
|
|
n->af = AF_INET6; |
130 |
|
|
for (i = 0; i < 4 && l >= 32; i++, l -= 32) |
131 |
|
|
n->addr32[i] = 0xffffffffU; |
132 |
|
|
if (i < 4 && l != 0) |
133 |
|
|
n->addr32[i] = htonl((0xffffffff << (32 - l)) & |
134 |
|
|
0xffffffff); |
135 |
|
|
return 0; |
136 |
|
|
default: |
137 |
|
|
return -1; |
138 |
|
|
} |
139 |
|
|
} |
140 |
|
|
|
141 |
|
|
/* |
142 |
|
|
* Perform logical AND of addresses 'a' and 'b', storing result in 'dst'. |
143 |
|
|
* Returns 0 on success, -1 on failure. |
144 |
|
|
*/ |
145 |
|
|
static int |
146 |
|
|
addr_and(struct xaddr *dst, const struct xaddr *a, const struct xaddr *b) |
147 |
|
|
{ |
148 |
|
|
int i; |
149 |
|
|
|
150 |
|
|
if (dst == NULL || a == NULL || b == NULL || a->af != b->af) |
151 |
|
|
return -1; |
152 |
|
|
|
153 |
|
|
memcpy(dst, a, sizeof(*dst)); |
154 |
|
|
switch (a->af) { |
155 |
|
|
case AF_INET: |
156 |
|
|
dst->v4.s_addr &= b->v4.s_addr; |
157 |
|
|
return 0; |
158 |
|
|
case AF_INET6: |
159 |
|
|
dst->scope_id = a->scope_id; |
160 |
|
|
for (i = 0; i < 4; i++) |
161 |
|
|
dst->addr32[i] &= b->addr32[i]; |
162 |
|
|
return 0; |
163 |
|
|
default: |
164 |
|
|
return -1; |
165 |
|
|
} |
166 |
|
|
} |
167 |
|
|
|
168 |
|
|
/* |
169 |
|
|
* Compare addresses 'a' and 'b' |
170 |
|
|
* Return 0 if addresses are identical, -1 if (a < b) or 1 if (a > b) |
171 |
|
|
*/ |
172 |
|
|
static int |
173 |
|
|
addr_cmp(const struct xaddr *a, const struct xaddr *b) |
174 |
|
|
{ |
175 |
|
|
int i; |
176 |
|
|
|
177 |
|
|
if (a->af != b->af) |
178 |
|
|
return a->af == AF_INET6 ? 1 : -1; |
179 |
|
|
|
180 |
|
|
switch (a->af) { |
181 |
|
|
case AF_INET: |
182 |
|
|
if (a->v4.s_addr == b->v4.s_addr) |
183 |
|
|
return 0; |
184 |
|
|
return ntohl(a->v4.s_addr) > ntohl(b->v4.s_addr) ? 1 : -1; |
185 |
|
|
case AF_INET6: |
186 |
|
|
for (i = 0; i < 16; i++) |
187 |
|
|
if (a->addr8[i] - b->addr8[i] != 0) |
188 |
|
|
return a->addr8[i] > b->addr8[i] ? 1 : -1; |
189 |
|
|
if (a->scope_id == b->scope_id) |
190 |
|
|
return 0; |
191 |
|
|
return a->scope_id > b->scope_id ? 1 : -1; |
192 |
|
|
default: |
193 |
|
|
return -1; |
194 |
|
|
} |
195 |
|
|
} |
196 |
|
|
|
197 |
|
|
/* |
198 |
|
|
* Parse string address 'p' into 'n' |
199 |
|
|
* Returns 0 on success, -1 on failure. |
200 |
|
|
*/ |
201 |
|
|
static int |
202 |
|
|
addr_pton(const char *p, struct xaddr *n) |
203 |
|
|
{ |
204 |
|
|
struct addrinfo hints, *ai; |
205 |
|
|
|
206 |
|
|
memset(&hints, '\0', sizeof(hints)); |
207 |
|
|
hints.ai_flags = AI_NUMERICHOST; |
208 |
|
|
|
209 |
|
|
if (p == NULL || getaddrinfo(p, NULL, &hints, &ai) != 0) |
210 |
|
|
return -1; |
211 |
|
|
|
212 |
|
|
if (ai == NULL || ai->ai_addr == NULL) |
213 |
|
|
return -1; |
214 |
|
|
|
215 |
|
|
if (n != NULL && |
216 |
|
|
addr_sa_to_xaddr(ai->ai_addr, ai->ai_addrlen, n) == -1) { |
217 |
|
|
freeaddrinfo(ai); |
218 |
|
|
return -1; |
219 |
|
|
} |
220 |
|
|
|
221 |
|
|
freeaddrinfo(ai); |
222 |
|
|
return 0; |
223 |
|
|
} |
224 |
|
|
|
225 |
|
|
/* |
226 |
|
|
* Perform bitwise negation of address |
227 |
|
|
* Returns 0 on success, -1 on failure. |
228 |
|
|
*/ |
229 |
|
|
static int |
230 |
|
|
addr_invert(struct xaddr *n) |
231 |
|
|
{ |
232 |
|
|
int i; |
233 |
|
|
|
234 |
|
|
if (n == NULL) |
235 |
|
|
return (-1); |
236 |
|
|
|
237 |
|
|
switch (n->af) { |
238 |
|
|
case AF_INET: |
239 |
|
|
n->v4.s_addr = ~n->v4.s_addr; |
240 |
|
|
return (0); |
241 |
|
|
case AF_INET6: |
242 |
|
|
for (i = 0; i < 4; i++) |
243 |
|
|
n->addr32[i] = ~n->addr32[i]; |
244 |
|
|
return (0); |
245 |
|
|
default: |
246 |
|
|
return (-1); |
247 |
|
|
} |
248 |
|
|
} |
249 |
|
|
|
250 |
|
|
/* |
251 |
|
|
* Calculate a netmask of length 'l' for address family 'af' and |
252 |
|
|
* store it in 'n'. |
253 |
|
|
* Returns 0 on success, -1 on failure. |
254 |
|
|
*/ |
255 |
|
|
static int |
256 |
|
|
addr_hostmask(int af, u_int l, struct xaddr *n) |
257 |
|
|
{ |
258 |
|
|
if (addr_netmask(af, l, n) == -1 || addr_invert(n) == -1) |
259 |
|
|
return (-1); |
260 |
|
|
return (0); |
261 |
|
|
} |
262 |
|
|
|
263 |
|
|
/* |
264 |
|
|
* Test whether address 'a' is all zeros (i.e. 0.0.0.0 or ::) |
265 |
|
|
* Returns 0 on if address is all-zeros, -1 if not all zeros or on failure. |
266 |
|
|
*/ |
267 |
|
|
static int |
268 |
|
|
addr_is_all0s(const struct xaddr *a) |
269 |
|
|
{ |
270 |
|
|
int i; |
271 |
|
|
|
272 |
|
|
switch (a->af) { |
273 |
|
|
case AF_INET: |
274 |
|
|
return (a->v4.s_addr == 0 ? 0 : -1); |
275 |
|
|
case AF_INET6:; |
276 |
|
|
for (i = 0; i < 4; i++) |
277 |
|
|
if (a->addr32[i] != 0) |
278 |
|
|
return (-1); |
279 |
|
|
return (0); |
280 |
|
|
default: |
281 |
|
|
return (-1); |
282 |
|
|
} |
283 |
|
|
} |
284 |
|
|
|
285 |
|
|
/* |
286 |
|
|
* Test whether host portion of address 'a', as determined by 'masklen' |
287 |
|
|
* is all zeros. |
288 |
|
|
* Returns 0 on if host portion of address is all-zeros, |
289 |
|
|
* -1 if not all zeros or on failure. |
290 |
|
|
*/ |
291 |
|
|
static int |
292 |
|
|
addr_host_is_all0s(const struct xaddr *a, u_int masklen) |
293 |
|
|
{ |
294 |
|
|
struct xaddr tmp_addr, tmp_mask, tmp_result; |
295 |
|
|
|
296 |
|
|
memcpy(&tmp_addr, a, sizeof(tmp_addr)); |
297 |
|
|
if (addr_hostmask(a->af, masklen, &tmp_mask) == -1) |
298 |
|
|
return (-1); |
299 |
|
|
if (addr_and(&tmp_result, &tmp_addr, &tmp_mask) == -1) |
300 |
|
|
return (-1); |
301 |
|
|
return (addr_is_all0s(&tmp_result)); |
302 |
|
|
} |
303 |
|
|
|
304 |
|
|
/* |
305 |
|
|
* Parse a CIDR address (x.x.x.x/y or xxxx:yyyy::/z). |
306 |
|
|
* Return -1 on parse error, -2 on inconsistency or 0 on success. |
307 |
|
|
*/ |
308 |
|
|
static int |
309 |
|
|
addr_pton_cidr(const char *p, struct xaddr *n, u_int *l) |
310 |
|
|
{ |
311 |
|
|
struct xaddr tmp; |
312 |
|
|
long unsigned int masklen = 999; |
313 |
|
|
char addrbuf[64], *mp, *cp; |
314 |
|
|
|
315 |
|
|
/* Don't modify argument */ |
316 |
|
|
if (p == NULL || strlcpy(addrbuf, p, sizeof(addrbuf)) >= sizeof(addrbuf)) |
317 |
|
|
return -1; |
318 |
|
|
|
319 |
|
|
if ((mp = strchr(addrbuf, '/')) != NULL) { |
320 |
|
|
*mp = '\0'; |
321 |
|
|
mp++; |
322 |
|
|
masklen = strtoul(mp, &cp, 10); |
323 |
|
|
if (*mp == '\0' || *cp != '\0' || masklen > 128) |
324 |
|
|
return -1; |
325 |
|
|
} |
326 |
|
|
|
327 |
|
|
if (addr_pton(addrbuf, &tmp) == -1) |
328 |
|
|
return -1; |
329 |
|
|
|
330 |
|
|
if (mp == NULL) |
331 |
|
|
masklen = addr_unicast_masklen(tmp.af); |
332 |
|
|
if (masklen_valid(tmp.af, masklen) == -1) |
333 |
|
|
return -2; |
334 |
|
|
if (addr_host_is_all0s(&tmp, masklen) != 0) |
335 |
|
|
return -2; |
336 |
|
|
|
337 |
|
|
if (n != NULL) |
338 |
|
|
memcpy(n, &tmp, sizeof(*n)); |
339 |
|
|
if (l != NULL) |
340 |
|
|
*l = masklen; |
341 |
|
|
|
342 |
|
|
return 0; |
343 |
|
|
} |
344 |
|
|
|
345 |
|
|
static int |
346 |
|
|
addr_netmatch(const struct xaddr *host, const struct xaddr *net, u_int masklen) |
347 |
|
|
{ |
348 |
|
|
struct xaddr tmp_mask, tmp_result; |
349 |
|
|
|
350 |
|
|
if (host->af != net->af) |
351 |
|
|
return -1; |
352 |
|
|
|
353 |
|
|
if (addr_netmask(host->af, masklen, &tmp_mask) == -1) |
354 |
|
|
return -1; |
355 |
|
|
if (addr_and(&tmp_result, host, &tmp_mask) == -1) |
356 |
|
|
return -1; |
357 |
|
|
return addr_cmp(&tmp_result, net); |
358 |
|
|
} |
359 |
|
|
|
360 |
|
|
/* |
361 |
|
|
* Match "addr" against list pattern list "_list", which may contain a |
362 |
|
|
* mix of CIDR addresses and old-school wildcards. |
363 |
|
|
* |
364 |
|
|
* If addr is NULL, then no matching is performed, but _list is parsed |
365 |
|
|
* and checked for well-formedness. |
366 |
|
|
* |
367 |
|
|
* Returns 1 on match found (never returned when addr == NULL). |
368 |
|
|
* Returns 0 on if no match found, or no errors found when addr == NULL. |
369 |
|
|
* Returns -1 on negated match found (never returned when addr == NULL). |
370 |
|
|
* Returns -2 on invalid list entry. |
371 |
|
|
*/ |
372 |
|
|
int |
373 |
|
|
addr_match_list(const char *addr, const char *_list) |
374 |
|
|
{ |
375 |
|
|
char *list, *cp, *o; |
376 |
|
|
struct xaddr try_addr, match_addr; |
377 |
|
|
u_int masklen, neg; |
378 |
|
|
int ret = 0, r; |
379 |
|
|
|
380 |
|
|
if (addr != NULL && addr_pton(addr, &try_addr) != 0) { |
381 |
|
|
debug2("%s: couldn't parse address %.100s", __func__, addr); |
382 |
|
|
return 0; |
383 |
|
|
} |
384 |
|
|
if ((o = list = strdup(_list)) == NULL) |
385 |
|
|
return -1; |
386 |
|
|
while ((cp = strsep(&list, ",")) != NULL) { |
387 |
|
|
neg = *cp == '!'; |
388 |
|
|
if (neg) |
389 |
|
|
cp++; |
390 |
|
|
if (*cp == '\0') { |
391 |
|
|
ret = -2; |
392 |
|
|
break; |
393 |
|
|
} |
394 |
|
|
/* Prefer CIDR address matching */ |
395 |
|
|
r = addr_pton_cidr(cp, &match_addr, &masklen); |
396 |
|
|
if (r == -2) { |
397 |
|
|
debug2("%s: inconsistent mask length for " |
398 |
|
|
"match network \"%.100s\"", __func__, cp); |
399 |
|
|
ret = -2; |
400 |
|
|
break; |
401 |
|
|
} else if (r == 0) { |
402 |
|
|
if (addr != NULL && addr_netmatch(&try_addr, |
403 |
|
|
&match_addr, masklen) == 0) { |
404 |
|
|
foundit: |
405 |
|
|
if (neg) { |
406 |
|
|
ret = -1; |
407 |
|
|
break; |
408 |
|
|
} |
409 |
|
|
ret = 1; |
410 |
|
|
} |
411 |
|
|
continue; |
412 |
|
|
} else { |
413 |
|
|
/* If CIDR parse failed, try wildcard string match */ |
414 |
|
|
if (addr != NULL && match_pattern(addr, cp) == 1) |
415 |
|
|
goto foundit; |
416 |
|
|
} |
417 |
|
|
} |
418 |
|
|
free(o); |
419 |
|
|
|
420 |
|
|
return ret; |
421 |
|
|
} |
422 |
|
|
|
423 |
|
|
/* |
424 |
|
|
* Match "addr" against list CIDR list "_list". Lexical wildcards and |
425 |
|
|
* negation are not supported. If "addr" == NULL, will verify structure |
426 |
|
|
* of "_list". |
427 |
|
|
* |
428 |
|
|
* Returns 1 on match found (never returned when addr == NULL). |
429 |
|
|
* Returns 0 on if no match found, or no errors found when addr == NULL. |
430 |
|
|
* Returns -1 on error |
431 |
|
|
*/ |
432 |
|
|
int |
433 |
|
|
addr_match_cidr_list(const char *addr, const char *_list) |
434 |
|
|
{ |
435 |
|
|
char *list, *cp, *o; |
436 |
|
|
struct xaddr try_addr, match_addr; |
437 |
|
|
u_int masklen; |
438 |
|
|
int ret = 0, r; |
439 |
|
|
|
440 |
|
|
if (addr != NULL && addr_pton(addr, &try_addr) != 0) { |
441 |
|
|
debug2("%s: couldn't parse address %.100s", __func__, addr); |
442 |
|
|
return 0; |
443 |
|
|
} |
444 |
|
|
if ((o = list = strdup(_list)) == NULL) |
445 |
|
|
return -1; |
446 |
|
|
while ((cp = strsep(&list, ",")) != NULL) { |
447 |
|
|
if (*cp == '\0') { |
448 |
|
|
error("%s: empty entry in list \"%.100s\"", |
449 |
|
|
__func__, o); |
450 |
|
|
ret = -1; |
451 |
|
|
break; |
452 |
|
|
} |
453 |
|
|
|
454 |
|
|
/* |
455 |
|
|
* NB. This function is called in pre-auth with untrusted data, |
456 |
|
|
* so be extra paranoid about junk reaching getaddrino (via |
457 |
|
|
* addr_pton_cidr). |
458 |
|
|
*/ |
459 |
|
|
|
460 |
|
|
/* Stop junk from reaching getaddrinfo. +3 is for masklen */ |
461 |
|
|
if (strlen(cp) > INET6_ADDRSTRLEN + 3) { |
462 |
|
|
error("%s: list entry \"%.100s\" too long", |
463 |
|
|
__func__, cp); |
464 |
|
|
ret = -1; |
465 |
|
|
break; |
466 |
|
|
} |
467 |
|
|
#define VALID_CIDR_CHARS "0123456789abcdefABCDEF.:/" |
468 |
|
|
if (strspn(cp, VALID_CIDR_CHARS) != strlen(cp)) { |
469 |
|
|
error("%s: list entry \"%.100s\" contains invalid " |
470 |
|
|
"characters", __func__, cp); |
471 |
|
|
ret = -1; |
472 |
|
|
} |
473 |
|
|
|
474 |
|
|
/* Prefer CIDR address matching */ |
475 |
|
|
r = addr_pton_cidr(cp, &match_addr, &masklen); |
476 |
|
|
if (r == -1) { |
477 |
|
|
error("Invalid network entry \"%.100s\"", cp); |
478 |
|
|
ret = -1; |
479 |
|
|
break; |
480 |
|
|
} else if (r == -2) { |
481 |
|
|
error("Inconsistent mask length for " |
482 |
|
|
"network \"%.100s\"", cp); |
483 |
|
|
ret = -1; |
484 |
|
|
break; |
485 |
|
|
} else if (r == 0 && addr != NULL) { |
486 |
|
|
if (addr_netmatch(&try_addr, &match_addr, |
487 |
|
|
masklen) == 0) |
488 |
|
|
ret = 1; |
489 |
|
|
continue; |
490 |
|
|
} |
491 |
|
|
} |
492 |
|
|
free(o); |
493 |
|
|
|
494 |
|
|
return ret; |
495 |
|
|
} |