xref: /freebsd/sbin/pfctl/pf_ruleset.c (revision 32e86a82)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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  *	$OpenBSD: pf_ruleset.c,v 1.2 2008/12/18 15:31:37 dhill Exp $
37  */
38 
39 #include <sys/param.h>
40 #include <sys/socket.h>
41 #include <sys/mbuf.h>
42 
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #include <netinet/tcp.h>
47 
48 #include <net/if.h>
49 #include <net/vnet.h>
50 #include <net/pfvar.h>
51 
52 #ifdef INET6
53 #include <netinet/ip6.h>
54 #endif /* INET6 */
55 
56 #include <arpa/inet.h>
57 #include <errno.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #define rs_malloc(x)		 calloc(1, x)
62 #define rs_free(x)		 free(x)
63 
64 #include "pfctl.h"
65 #include "pfctl_parser.h"
66 
67 #ifdef PFDEBUG
68 #include <sys/stdarg.h>
69 #define DPFPRINTF(format, x...)	fprintf(stderr, format , ##x)
70 #else
71 #define DPFPRINTF(format, x...)	((void)0)
72 #endif /* PFDEBUG */
73 
74 struct pfctl_anchor_global	 pf_anchors;
75 extern struct pfctl_anchor	 pf_main_anchor;
76 extern struct pfctl_eth_anchor	 pf_eth_main_anchor;
77 #undef V_pf_anchors
78 #define V_pf_anchors		 pf_anchors
79 #undef pf_main_ruleset
80 #define pf_main_ruleset		 pf_main_anchor.ruleset
81 
82 static __inline int		pf_anchor_compare(struct pfctl_anchor *,
83 				    struct pfctl_anchor *);
84 static struct pfctl_anchor	*pf_find_anchor(const char *);
85 
86 RB_GENERATE(pfctl_anchor_global, pfctl_anchor, entry_global,
87     pf_anchor_compare);
88 RB_GENERATE(pfctl_anchor_node, pfctl_anchor, entry_node, pf_anchor_compare);
89 
90 static __inline int
pf_anchor_compare(struct pfctl_anchor * a,struct pfctl_anchor * b)91 pf_anchor_compare(struct pfctl_anchor *a, struct pfctl_anchor *b)
92 {
93 	int c = strcmp(a->path, b->path);
94 
95 	return (c ? (c < 0 ? -1 : 1) : 0);
96 }
97 
98 int
pf_get_ruleset_number(u_int8_t action)99 pf_get_ruleset_number(u_int8_t action)
100 {
101 	switch (action) {
102 	case PF_SCRUB:
103 	case PF_NOSCRUB:
104 		return (PF_RULESET_SCRUB);
105 		break;
106 	case PF_PASS:
107 	case PF_DROP:
108 	case PF_MATCH:
109 		return (PF_RULESET_FILTER);
110 		break;
111 	case PF_NAT:
112 	case PF_NONAT:
113 		return (PF_RULESET_NAT);
114 		break;
115 	case PF_BINAT:
116 	case PF_NOBINAT:
117 		return (PF_RULESET_BINAT);
118 		break;
119 	case PF_RDR:
120 	case PF_NORDR:
121 		return (PF_RULESET_RDR);
122 		break;
123 	default:
124 		return (PF_RULESET_MAX);
125 		break;
126 	}
127 }
128 
129 void
pf_init_ruleset(struct pfctl_ruleset * ruleset)130 pf_init_ruleset(struct pfctl_ruleset *ruleset)
131 {
132 	int	i;
133 
134 	memset(ruleset, 0, sizeof(struct pfctl_ruleset));
135 	for (i = 0; i < PF_RULESET_MAX; i++) {
136 		TAILQ_INIT(&ruleset->rules[i].queues[0]);
137 		TAILQ_INIT(&ruleset->rules[i].queues[1]);
138 		ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
139 		ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
140 	}
141 }
142 
143 static struct pfctl_anchor *
pf_find_anchor(const char * path)144 pf_find_anchor(const char *path)
145 {
146 	struct pfctl_anchor	*key, *found;
147 
148 	key = (struct pfctl_anchor *)rs_malloc(sizeof(*key));
149 	if (key == NULL)
150 		return (NULL);
151 	strlcpy(key->path, path, sizeof(key->path));
152 	found = RB_FIND(pfctl_anchor_global, &V_pf_anchors, key);
153 	rs_free(key);
154 	return (found);
155 }
156 
157 struct pfctl_ruleset *
pf_find_ruleset(const char * path)158 pf_find_ruleset(const char *path)
159 {
160 	struct pfctl_anchor	*anchor;
161 
162 	while (*path == '/')
163 		path++;
164 	if (!*path)
165 		return (&pf_main_ruleset);
166 	anchor = pf_find_anchor(path);
167 	if (anchor == NULL)
168 		return (NULL);
169 	else
170 		return (&anchor->ruleset);
171 }
172 
173 struct pfctl_ruleset *
pf_find_or_create_ruleset(const char * path)174 pf_find_or_create_ruleset(const char *path)
175 {
176 	char			*p, *q, *r;
177 	struct pfctl_ruleset	*ruleset;
178 	struct pfctl_anchor	*anchor = NULL, *dup, *parent = NULL;
179 
180 	if (path[0] == 0)
181 		return (&pf_main_ruleset);
182 	while (*path == '/')
183 		path++;
184 	ruleset = pf_find_ruleset(path);
185 	if (ruleset != NULL)
186 		return (ruleset);
187 	p = (char *)rs_malloc(MAXPATHLEN);
188 	if (p == NULL)
189 		return (NULL);
190 	strlcpy(p, path, MAXPATHLEN);
191 	while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
192 		*q = 0;
193 		if ((ruleset = pf_find_ruleset(p)) != NULL) {
194 			parent = ruleset->anchor;
195 			break;
196 		}
197 	}
198 	if (q == NULL)
199 		q = p;
200 	else
201 		q++;
202 	strlcpy(p, path, MAXPATHLEN);
203 	if (!*q) {
204 		rs_free(p);
205 		return (NULL);
206 	}
207 	while ((r = strchr(q, '/')) != NULL || *q) {
208 		if (r != NULL)
209 			*r = 0;
210 		if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
211 		    (parent != NULL && strlen(parent->path) >=
212 		    MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
213 			rs_free(p);
214 			return (NULL);
215 		}
216 		anchor = (struct pfctl_anchor *)rs_malloc(sizeof(*anchor));
217 		if (anchor == NULL) {
218 			rs_free(p);
219 			return (NULL);
220 		}
221 		RB_INIT(&anchor->children);
222 		strlcpy(anchor->name, q, sizeof(anchor->name));
223 		if (parent != NULL) {
224 			strlcpy(anchor->path, parent->path,
225 			    sizeof(anchor->path));
226 			strlcat(anchor->path, "/", sizeof(anchor->path));
227 		}
228 		strlcat(anchor->path, anchor->name, sizeof(anchor->path));
229 		if ((dup = RB_INSERT(pfctl_anchor_global, &V_pf_anchors, anchor)) !=
230 		    NULL) {
231 			printf("pf_find_or_create_ruleset: RB_INSERT1 "
232 			    "'%s' '%s' collides with '%s' '%s'\n",
233 			    anchor->path, anchor->name, dup->path, dup->name);
234 			rs_free(anchor);
235 			rs_free(p);
236 			return (NULL);
237 		}
238 		if (parent != NULL) {
239 			anchor->parent = parent;
240 			if ((dup = RB_INSERT(pfctl_anchor_node, &parent->children,
241 			    anchor)) != NULL) {
242 				printf("pf_find_or_create_ruleset: "
243 				    "RB_INSERT2 '%s' '%s' collides with "
244 				    "'%s' '%s'\n", anchor->path, anchor->name,
245 				    dup->path, dup->name);
246 				RB_REMOVE(pfctl_anchor_global, &V_pf_anchors,
247 				    anchor);
248 				rs_free(anchor);
249 				rs_free(p);
250 				return (NULL);
251 			}
252 		}
253 		pf_init_ruleset(&anchor->ruleset);
254 		anchor->ruleset.anchor = anchor;
255 		parent = anchor;
256 		if (r != NULL)
257 			q = r + 1;
258 		else
259 			*q = 0;
260 	}
261 	rs_free(p);
262 	return (&anchor->ruleset);
263 }
264 
265 void
pf_remove_if_empty_ruleset(struct pfctl_ruleset * ruleset)266 pf_remove_if_empty_ruleset(struct pfctl_ruleset *ruleset)
267 {
268 	struct pfctl_anchor	*parent;
269 	int			 i;
270 
271 	while (ruleset != NULL) {
272 		if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
273 		    !RB_EMPTY(&ruleset->anchor->children) ||
274 		    ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
275 		    ruleset->topen)
276 			return;
277 		for (i = 0; i < PF_RULESET_MAX; ++i)
278 			if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
279 			    !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
280 			    ruleset->rules[i].inactive.open)
281 				return;
282 		RB_REMOVE(pfctl_anchor_global, &V_pf_anchors, ruleset->anchor);
283 		if ((parent = ruleset->anchor->parent) != NULL)
284 			RB_REMOVE(pfctl_anchor_node, &parent->children,
285 			    ruleset->anchor);
286 		rs_free(ruleset->anchor);
287 		if (parent == NULL)
288 			return;
289 		ruleset = &parent->ruleset;
290 	}
291 }
292 
293 void
pf_remove_if_empty_eth_ruleset(struct pfctl_eth_ruleset * ruleset)294 pf_remove_if_empty_eth_ruleset(struct pfctl_eth_ruleset *ruleset)
295 {
296 	struct pfctl_eth_anchor	*parent;
297 
298 	return;
299 	while (ruleset != NULL) {
300 		if (ruleset == &pf_eth_main_anchor.ruleset ||
301 		    ruleset->anchor == NULL || ruleset->anchor->refcnt > 0)
302 			return;
303 		if (!TAILQ_EMPTY(&ruleset->rules))
304 			return;
305 		rs_free(ruleset->anchor);
306 		if (parent == NULL)
307 			return;
308 		ruleset = &parent->ruleset;
309 	}
310 }
311 
312 void
pf_init_eth_ruleset(struct pfctl_eth_ruleset * ruleset)313 pf_init_eth_ruleset(struct pfctl_eth_ruleset *ruleset)
314 {
315 
316 	memset(ruleset, 0, sizeof(*ruleset));
317 	TAILQ_INIT(&ruleset->rules);
318 }
319 
320 
321 static struct pfctl_eth_anchor*
_pf_find_eth_anchor(struct pfctl_eth_anchor * anchor,const char * path)322 _pf_find_eth_anchor(struct pfctl_eth_anchor *anchor, const char *path)
323 {
324 	struct pfctl_eth_rule	*r;
325 	struct pfctl_eth_anchor	*a;
326 
327 	if (strcmp(path, anchor->path) == 0)
328 		return (anchor);
329 
330 	TAILQ_FOREACH(r, &anchor->ruleset.rules, entries) {
331 		if (! r->anchor)
332 			continue;
333 
334 		/* Step into anchor */
335 		a = _pf_find_eth_anchor(r->anchor, path);
336 		if (a)
337 			return (a);
338 	}
339 
340 	return (NULL);
341 }
342 
343 static struct pfctl_eth_anchor*
pf_find_eth_anchor(const char * path)344 pf_find_eth_anchor(const char *path)
345 {
346 	return (_pf_find_eth_anchor(&pf_eth_main_anchor, path));
347 }
348 
349 static struct pfctl_eth_ruleset*
pf_find_eth_ruleset(const char * path)350 pf_find_eth_ruleset(const char *path)
351 {
352 	struct pfctl_eth_anchor	*anchor;
353 
354 	while (*path == '/')
355 		path++;
356 	if (!*path)
357 		return (&pf_eth_main_anchor.ruleset);
358 	anchor = pf_find_eth_anchor(path);
359 	if (anchor == NULL)
360 		return (NULL);
361 	else
362 		return (&anchor->ruleset);
363 }
364 
365 struct pfctl_eth_ruleset *
pf_find_or_create_eth_ruleset(const char * path)366 pf_find_or_create_eth_ruleset(const char *path)
367 {
368 	char				*p, *q, *r;
369 	struct pfctl_eth_ruleset	*ruleset;
370 	struct pfctl_eth_anchor		*anchor = NULL, *parent = NULL;
371 
372 	if (path[0] == 0)
373 		return (&pf_eth_main_anchor.ruleset);
374 	while (*path == '/')
375 		path++;
376 	ruleset = pf_find_eth_ruleset(path);
377 	if (ruleset != NULL)
378 		return (ruleset);
379 	p = (char *)rs_malloc(MAXPATHLEN);
380 	if (p == NULL)
381 		return (NULL);
382 	strlcpy(p, path, MAXPATHLEN);
383 	while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
384 		*q = 0;
385 		if ((ruleset = pf_find_eth_ruleset(p)) != NULL) {
386 			parent = ruleset->anchor;
387 			break;
388 		}
389 	}
390 	if (q == NULL)
391 		q = p;
392 	else
393 		q++;
394 	strlcpy(p, path, MAXPATHLEN);
395 	if (!*q) {
396 		rs_free(p);
397 		return (NULL);
398 	}
399 	while ((r = strchr(q, '/')) != NULL || *q) {
400 		if (r != NULL)
401 			*r = 0;
402 		if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
403 		    (parent != NULL && strlen(parent->path) >=
404 		    MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
405 			rs_free(p);
406 			return (NULL);
407 		}
408 		anchor = (struct pfctl_eth_anchor *)rs_malloc(sizeof(*anchor));
409 		if (anchor == NULL) {
410 			rs_free(p);
411 			return (NULL);
412 		}
413 		strlcpy(anchor->name, q, sizeof(anchor->name));
414 		if (parent != NULL) {
415 			strlcpy(anchor->path, parent->path,
416 			    sizeof(anchor->path));
417 			strlcat(anchor->path, "/", sizeof(anchor->path));
418 		}
419 		strlcat(anchor->path, anchor->name, sizeof(anchor->path));
420 		if (parent != NULL)
421 			anchor->parent = parent;
422 		pf_init_eth_ruleset(&anchor->ruleset);
423 		anchor->ruleset.anchor = anchor;
424 		parent = anchor;
425 		if (r != NULL)
426 			q = r + 1;
427 		else
428 			*q = 0;
429 	}
430 	rs_free(p);
431 	return (&anchor->ruleset);
432 }
433 
434 int
pfctl_anchor_setup(struct pfctl_rule * r,const struct pfctl_ruleset * s,const char * name)435 pfctl_anchor_setup(struct pfctl_rule *r, const struct pfctl_ruleset *s,
436     const char *name)
437 {
438 	char			*p, *path;
439 	struct pfctl_ruleset	*ruleset;
440 
441 	r->anchor = NULL;
442 	r->anchor_relative = 0;
443 	r->anchor_wildcard = 0;
444 	if (!name[0])
445 		return (0);
446 	path = (char *)rs_malloc(MAXPATHLEN);
447 	if (path == NULL)
448 		return (1);
449 	if (name[0] == '/')
450 		strlcpy(path, name + 1, MAXPATHLEN);
451 	else {
452 		/* relative path */
453 		r->anchor_relative = 1;
454 		if (s->anchor == NULL || !s->anchor->path[0])
455 			path[0] = 0;
456 		else
457 			strlcpy(path, s->anchor->path, MAXPATHLEN);
458 		while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
459 			if (!path[0]) {
460 				printf("pfctl_anchor_setup: .. beyond root\n");
461 				rs_free(path);
462 				return (1);
463 			}
464 			if ((p = strrchr(path, '/')) != NULL)
465 				*p = 0;
466 			else
467 				path[0] = 0;
468 			r->anchor_relative++;
469 			name += 3;
470 		}
471 		if (path[0])
472 			strlcat(path, "/", MAXPATHLEN);
473 		strlcat(path, name, MAXPATHLEN);
474 	}
475 	if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
476 		r->anchor_wildcard = 1;
477 		*p = 0;
478 	}
479 	ruleset = pf_find_or_create_ruleset(path);
480 	rs_free(path);
481 	if (ruleset == NULL || ruleset->anchor == NULL) {
482 		printf("pfctl_anchor_setup: ruleset\n");
483 		return (1);
484 	}
485 	r->anchor = ruleset->anchor;
486 	r->anchor->refcnt++;
487 	return (0);
488 }
489 
490 int
pfctl_eth_anchor_setup(struct pfctl * pf,struct pfctl_eth_rule * r,const struct pfctl_eth_ruleset * s,const char * name)491 pfctl_eth_anchor_setup(struct pfctl *pf, struct pfctl_eth_rule *r,
492     const struct pfctl_eth_ruleset *s, const char *name)
493 {
494 	char				*p, *path;
495 	struct pfctl_eth_ruleset	*ruleset;
496 
497 	r->anchor = NULL;
498 	if (!name[0])
499 		return (0);
500 	path = (char *)rs_malloc(MAXPATHLEN);
501 	if (path == NULL)
502 		return (1);
503 	if (name[0] == '/')
504 		strlcpy(path, name + 1, MAXPATHLEN);
505 	else {
506 		/* relative path */
507 		if (s->anchor == NULL || !s->anchor->path[0])
508 			path[0] = 0;
509 		else
510 			strlcpy(path, s->anchor->path, MAXPATHLEN);
511 		while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
512 			if (!path[0]) {
513 				printf("%s: .. beyond root\n", __func__);
514 				rs_free(path);
515 				return (1);
516 			}
517 			if ((p = strrchr(path, '/')) != NULL)
518 				*p = 0;
519 			else
520 				path[0] = 0;
521 			name += 3;
522 		}
523 		if (path[0])
524 			strlcat(path, "/", MAXPATHLEN);
525 		strlcat(path, name, MAXPATHLEN);
526 	}
527 	if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
528 		*p = 0;
529 	}
530 	ruleset = pf_find_or_create_eth_ruleset(path);
531 	rs_free(path);
532 	if (ruleset == NULL || ruleset->anchor == NULL) {
533 		printf("%s: ruleset\n", __func__);
534 		return (1);
535 	}
536 	r->anchor = ruleset->anchor;
537 	r->anchor->refcnt++;
538 	return (0);
539 }
540