1 /* $OpenBSD: pf_ruleset.c,v 1.2 2008/12/18 15:31:37 dhill Exp $ */
2
3 /*
4 * Copyright (c) 2001 Daniel Hartmeier
5 * Copyright (c) 2002,2003 Henning Brauer
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * - Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * - Redistributions in binary form must reproduce the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer in the documentation and/or other materials provided
17 * with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
27 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
29 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 *
32 * Effort sponsored in part by the Defense Advanced Research Projects
33 * Agency (DARPA) and Air Force Research Laboratory, Air Force
34 * Materiel Command, USAF, under agreement number F30602-01-2-0537.
35 *
36 */
37
38 #ifdef __FreeBSD__
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD: stable/9/sys/contrib/pf/net/pf_ruleset.c 223637 2011-06-28 11:57:25Z bz $");
41 #endif
42
43 #include <sys/param.h>
44 #include <sys/socket.h>
45 #ifdef _KERNEL
46 # include <sys/systm.h>
47 #endif /* _KERNEL */
48 #include <sys/mbuf.h>
49
50 #include <netinet/in.h>
51 #include <netinet/in_systm.h>
52 #include <netinet/ip.h>
53 #include <netinet/tcp.h>
54
55 #include <net/if.h>
56 #include <net/pfvar.h>
57
58 #ifdef INET6
59 #include <netinet/ip6.h>
60 #endif /* INET6 */
61
62
63 #ifdef _KERNEL
64 #ifdef __FreeBSD__
65 #define DPFPRINTF(format, x...) \
66 if (V_pf_status.debug >= PF_DEBUG_NOISY) \
67 printf(format , ##x)
68 #else
69 #define DPFPRINTF(format, x...) \
70 if (pf_status.debug >= PF_DEBUG_NOISY) \
71 printf(format , ##x)
72 #endif
73 #ifdef __FreeBSD__
74 #define rs_malloc(x) malloc(x, M_TEMP, M_NOWAIT|M_ZERO)
75 #else
76 #define rs_malloc(x) malloc(x, M_TEMP, M_WAITOK|M_CANFAIL|M_ZERO)
77 #endif
78 #define rs_free(x) free(x, M_TEMP)
79
80 #else
81 /* Userland equivalents so we can lend code to pfctl et al. */
82
83 #include <arpa/inet.h>
84 #include <errno.h>
85 #include <stdio.h>
86 #include <stdlib.h>
87 #include <string.h>
88 #define rs_malloc(x) calloc(1, x)
89 #define rs_free(x) free(x)
90
91 #ifdef PFDEBUG
92 #include <sys/stdarg.h>
93 #define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
94 #else
95 #define DPFPRINTF(format, x...) ((void)0)
96 #endif /* PFDEBUG */
97 #endif /* _KERNEL */
98
99 #if defined(__FreeBSD__) && !defined(_KERNEL)
100 #undef V_pf_anchors
101 #define V_pf_anchors pf_anchors
102
103 #undef pf_main_ruleset
104 #define pf_main_ruleset pf_main_anchor.ruleset
105 #endif
106
107 #if defined(__FreeBSD__) && defined(_KERNEL)
108 VNET_DEFINE(struct pf_anchor_global, pf_anchors);
109 VNET_DEFINE(struct pf_anchor, pf_main_anchor);
110 #else
111 struct pf_anchor_global pf_anchors;
112 struct pf_anchor pf_main_anchor;
113 #endif
114
115 static __inline int pf_anchor_compare(struct pf_anchor *, struct pf_anchor *);
116
117 RB_GENERATE(pf_anchor_global, pf_anchor, entry_global, pf_anchor_compare);
118 RB_GENERATE(pf_anchor_node, pf_anchor, entry_node, pf_anchor_compare);
119
120 static __inline int
pf_anchor_compare(struct pf_anchor * a,struct pf_anchor * b)121 pf_anchor_compare(struct pf_anchor *a, struct pf_anchor *b)
122 {
123 int c = strcmp(a->path, b->path);
124
125 return (c ? (c < 0 ? -1 : 1) : 0);
126 }
127
128 int
pf_get_ruleset_number(u_int8_t action)129 pf_get_ruleset_number(u_int8_t action)
130 {
131 switch (action) {
132 case PF_SCRUB:
133 case PF_NOSCRUB:
134 return (PF_RULESET_SCRUB);
135 break;
136 case PF_PASS:
137 case PF_DROP:
138 return (PF_RULESET_FILTER);
139 break;
140 case PF_NAT:
141 case PF_NONAT:
142 return (PF_RULESET_NAT);
143 break;
144 case PF_BINAT:
145 case PF_NOBINAT:
146 return (PF_RULESET_BINAT);
147 break;
148 case PF_RDR:
149 case PF_NORDR:
150 return (PF_RULESET_RDR);
151 break;
152 default:
153 return (PF_RULESET_MAX);
154 break;
155 }
156 }
157
158 void
pf_init_ruleset(struct pf_ruleset * ruleset)159 pf_init_ruleset(struct pf_ruleset *ruleset)
160 {
161 int i;
162
163 memset(ruleset, 0, sizeof(struct pf_ruleset));
164 for (i = 0; i < PF_RULESET_MAX; i++) {
165 TAILQ_INIT(&ruleset->rules[i].queues[0]);
166 TAILQ_INIT(&ruleset->rules[i].queues[1]);
167 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
168 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
169 }
170 }
171
172 struct pf_anchor *
pf_find_anchor(const char * path)173 pf_find_anchor(const char *path)
174 {
175 struct pf_anchor *key, *found;
176
177 key = (struct pf_anchor *)rs_malloc(sizeof(*key));
178 if (key == NULL)
179 return (NULL);
180 strlcpy(key->path, path, sizeof(key->path));
181 #ifdef __FreeBSD__
182 found = RB_FIND(pf_anchor_global, &V_pf_anchors, key);
183 #else
184 found = RB_FIND(pf_anchor_global, &pf_anchors, key);
185 #endif
186 rs_free(key);
187 return (found);
188 }
189
190 struct pf_ruleset *
pf_find_ruleset(const char * path)191 pf_find_ruleset(const char *path)
192 {
193 struct pf_anchor *anchor;
194
195 while (*path == '/')
196 path++;
197 if (!*path)
198 return (&pf_main_ruleset);
199 anchor = pf_find_anchor(path);
200 if (anchor == NULL)
201 return (NULL);
202 else
203 return (&anchor->ruleset);
204 }
205
206 struct pf_ruleset *
pf_find_or_create_ruleset(const char * path)207 pf_find_or_create_ruleset(const char *path)
208 {
209 char *p, *q, *r;
210 struct pf_ruleset *ruleset;
211 #ifdef __FreeBSD__
212 struct pf_anchor *anchor = NULL, *dup, *parent = NULL;
213 #else
214 struct pf_anchor *anchor, *dup, *parent = NULL;
215 #endif
216
217 if (path[0] == 0)
218 return (&pf_main_ruleset);
219 while (*path == '/')
220 path++;
221 ruleset = pf_find_ruleset(path);
222 if (ruleset != NULL)
223 return (ruleset);
224 p = (char *)rs_malloc(MAXPATHLEN);
225 if (p == NULL)
226 return (NULL);
227 strlcpy(p, path, MAXPATHLEN);
228 while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
229 *q = 0;
230 if ((ruleset = pf_find_ruleset(p)) != NULL) {
231 parent = ruleset->anchor;
232 break;
233 }
234 }
235 if (q == NULL)
236 q = p;
237 else
238 q++;
239 strlcpy(p, path, MAXPATHLEN);
240 if (!*q) {
241 rs_free(p);
242 return (NULL);
243 }
244 while ((r = strchr(q, '/')) != NULL || *q) {
245 if (r != NULL)
246 *r = 0;
247 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
248 (parent != NULL && strlen(parent->path) >=
249 MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
250 rs_free(p);
251 return (NULL);
252 }
253 anchor = (struct pf_anchor *)rs_malloc(sizeof(*anchor));
254 if (anchor == NULL) {
255 rs_free(p);
256 return (NULL);
257 }
258 RB_INIT(&anchor->children);
259 strlcpy(anchor->name, q, sizeof(anchor->name));
260 if (parent != NULL) {
261 strlcpy(anchor->path, parent->path,
262 sizeof(anchor->path));
263 strlcat(anchor->path, "/", sizeof(anchor->path));
264 }
265 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
266 #ifdef __FreeBSD__
267 if ((dup = RB_INSERT(pf_anchor_global, &V_pf_anchors, anchor)) !=
268 #else
269 if ((dup = RB_INSERT(pf_anchor_global, &pf_anchors, anchor)) !=
270 #endif
271 NULL) {
272 printf("pf_find_or_create_ruleset: RB_INSERT1 "
273 "'%s' '%s' collides with '%s' '%s'\n",
274 anchor->path, anchor->name, dup->path, dup->name);
275 rs_free(anchor);
276 rs_free(p);
277 return (NULL);
278 }
279 if (parent != NULL) {
280 anchor->parent = parent;
281 if ((dup = RB_INSERT(pf_anchor_node, &parent->children,
282 anchor)) != NULL) {
283 printf("pf_find_or_create_ruleset: "
284 "RB_INSERT2 '%s' '%s' collides with "
285 "'%s' '%s'\n", anchor->path, anchor->name,
286 dup->path, dup->name);
287 #ifdef __FreeBSD__
288 RB_REMOVE(pf_anchor_global, &V_pf_anchors,
289 #else
290 RB_REMOVE(pf_anchor_global, &pf_anchors,
291 #endif
292 anchor);
293 rs_free(anchor);
294 rs_free(p);
295 return (NULL);
296 }
297 }
298 pf_init_ruleset(&anchor->ruleset);
299 anchor->ruleset.anchor = anchor;
300 parent = anchor;
301 if (r != NULL)
302 q = r + 1;
303 else
304 *q = 0;
305 }
306 rs_free(p);
307 return (&anchor->ruleset);
308 }
309
310 void
pf_remove_if_empty_ruleset(struct pf_ruleset * ruleset)311 pf_remove_if_empty_ruleset(struct pf_ruleset *ruleset)
312 {
313 struct pf_anchor *parent;
314 int i;
315
316 while (ruleset != NULL) {
317 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
318 !RB_EMPTY(&ruleset->anchor->children) ||
319 ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
320 ruleset->topen)
321 return;
322 for (i = 0; i < PF_RULESET_MAX; ++i)
323 if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
324 !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
325 ruleset->rules[i].inactive.open)
326 return;
327 #ifdef __FreeBSD__
328 RB_REMOVE(pf_anchor_global, &V_pf_anchors, ruleset->anchor);
329 #else
330 RB_REMOVE(pf_anchor_global, &pf_anchors, ruleset->anchor);
331 #endif
332 if ((parent = ruleset->anchor->parent) != NULL)
333 RB_REMOVE(pf_anchor_node, &parent->children,
334 ruleset->anchor);
335 rs_free(ruleset->anchor);
336 if (parent == NULL)
337 return;
338 ruleset = &parent->ruleset;
339 }
340 }
341
342 int
pf_anchor_setup(struct pf_rule * r,const struct pf_ruleset * s,const char * name)343 pf_anchor_setup(struct pf_rule *r, const struct pf_ruleset *s,
344 const char *name)
345 {
346 char *p, *path;
347 struct pf_ruleset *ruleset;
348
349 r->anchor = NULL;
350 r->anchor_relative = 0;
351 r->anchor_wildcard = 0;
352 if (!name[0])
353 return (0);
354 path = (char *)rs_malloc(MAXPATHLEN);
355 if (path == NULL)
356 return (1);
357 if (name[0] == '/')
358 strlcpy(path, name + 1, MAXPATHLEN);
359 else {
360 /* relative path */
361 r->anchor_relative = 1;
362 if (s->anchor == NULL || !s->anchor->path[0])
363 path[0] = 0;
364 else
365 strlcpy(path, s->anchor->path, MAXPATHLEN);
366 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
367 if (!path[0]) {
368 printf("pf_anchor_setup: .. beyond root\n");
369 rs_free(path);
370 return (1);
371 }
372 if ((p = strrchr(path, '/')) != NULL)
373 *p = 0;
374 else
375 path[0] = 0;
376 r->anchor_relative++;
377 name += 3;
378 }
379 if (path[0])
380 strlcat(path, "/", MAXPATHLEN);
381 strlcat(path, name, MAXPATHLEN);
382 }
383 if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
384 r->anchor_wildcard = 1;
385 *p = 0;
386 }
387 ruleset = pf_find_or_create_ruleset(path);
388 rs_free(path);
389 if (ruleset == NULL || ruleset->anchor == NULL) {
390 printf("pf_anchor_setup: ruleset\n");
391 return (1);
392 }
393 r->anchor = ruleset->anchor;
394 r->anchor->refcnt++;
395 return (0);
396 }
397
398 int
pf_anchor_copyout(const struct pf_ruleset * rs,const struct pf_rule * r,struct pfioc_rule * pr)399 pf_anchor_copyout(const struct pf_ruleset *rs, const struct pf_rule *r,
400 struct pfioc_rule *pr)
401 {
402 pr->anchor_call[0] = 0;
403 if (r->anchor == NULL)
404 return (0);
405 if (!r->anchor_relative) {
406 strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
407 strlcat(pr->anchor_call, r->anchor->path,
408 sizeof(pr->anchor_call));
409 } else {
410 char *a, *p;
411 int i;
412
413 a = (char *)rs_malloc(MAXPATHLEN);
414 if (a == NULL)
415 return (1);
416 if (rs->anchor == NULL)
417 a[0] = 0;
418 else
419 strlcpy(a, rs->anchor->path, MAXPATHLEN);
420 for (i = 1; i < r->anchor_relative; ++i) {
421 if ((p = strrchr(a, '/')) == NULL)
422 p = a;
423 *p = 0;
424 strlcat(pr->anchor_call, "../",
425 sizeof(pr->anchor_call));
426 }
427 if (strncmp(a, r->anchor->path, strlen(a))) {
428 printf("pf_anchor_copyout: '%s' '%s'\n", a,
429 r->anchor->path);
430 rs_free(a);
431 return (1);
432 }
433 if (strlen(r->anchor->path) > strlen(a))
434 strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
435 strlen(a) + 1 : 0), sizeof(pr->anchor_call));
436 rs_free(a);
437 }
438 if (r->anchor_wildcard)
439 strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
440 sizeof(pr->anchor_call));
441 return (0);
442 }
443
444 void
pf_anchor_remove(struct pf_rule * r)445 pf_anchor_remove(struct pf_rule *r)
446 {
447 if (r->anchor == NULL)
448 return;
449 if (r->anchor->refcnt <= 0) {
450 printf("pf_anchor_remove: broken refcount\n");
451 r->anchor = NULL;
452 return;
453 }
454 if (!--r->anchor->refcnt)
455 pf_remove_if_empty_ruleset(&r->anchor->ruleset);
456 r->anchor = NULL;
457 }
458