xref: /freebsd/sys/netpfil/pf/pf_ruleset.c (revision e8d8bef961a50d4dc22501cde4fb9fb0be1b2532)
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/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include <sys/param.h>
43 #include <sys/socket.h>
44 #include <sys/systm.h>
45 #include <sys/refcount.h>
46 #include <sys/mbuf.h>
47 
48 #include <netinet/in.h>
49 #include <netinet/in_systm.h>
50 #include <netinet/ip.h>
51 #include <netinet/tcp.h>
52 
53 #include <net/if.h>
54 #include <net/vnet.h>
55 #include <net/pfvar.h>
56 
57 #ifdef INET6
58 #include <netinet/ip6.h>
59 #endif /* INET6 */
60 
61 #ifndef _KERNEL
62 #error "Kernel only file. Please use sbin/pfctl/pf_ruleset.c instead."
63 #endif
64 
65 #define DPFPRINTF(format, x...)				\
66 	if (V_pf_status.debug >= PF_DEBUG_NOISY)	\
67 		printf(format , ##x)
68 #define rs_malloc(x)		malloc(x, M_TEMP, M_NOWAIT|M_ZERO)
69 #define rs_free(x)		free(x, M_TEMP)
70 
71 VNET_DEFINE(struct pf_kanchor_global,	pf_anchors);
72 VNET_DEFINE(struct pf_kanchor,		pf_main_anchor);
73 
74 static __inline int		pf_kanchor_compare(struct pf_kanchor *,
75 				    struct pf_kanchor *);
76 static struct pf_kanchor	*pf_find_kanchor(const char *);
77 
78 RB_GENERATE(pf_kanchor_global, pf_kanchor, entry_global, pf_kanchor_compare);
79 RB_GENERATE(pf_kanchor_node, pf_kanchor, entry_node, pf_kanchor_compare);
80 
81 static __inline int
82 pf_kanchor_compare(struct pf_kanchor *a, struct pf_kanchor *b)
83 {
84 	int c = strcmp(a->path, b->path);
85 
86 	return (c ? (c < 0 ? -1 : 1) : 0);
87 }
88 
89 int
90 pf_get_ruleset_number(u_int8_t action)
91 {
92 	switch (action) {
93 	case PF_SCRUB:
94 	case PF_NOSCRUB:
95 		return (PF_RULESET_SCRUB);
96 		break;
97 	case PF_PASS:
98 	case PF_DROP:
99 		return (PF_RULESET_FILTER);
100 		break;
101 	case PF_NAT:
102 	case PF_NONAT:
103 		return (PF_RULESET_NAT);
104 		break;
105 	case PF_BINAT:
106 	case PF_NOBINAT:
107 		return (PF_RULESET_BINAT);
108 		break;
109 	case PF_RDR:
110 	case PF_NORDR:
111 		return (PF_RULESET_RDR);
112 		break;
113 	default:
114 		return (PF_RULESET_MAX);
115 		break;
116 	}
117 }
118 
119 static struct pf_kanchor *
120 pf_find_kanchor(const char *path)
121 {
122 	struct pf_kanchor	*key, *found;
123 
124 	key = (struct pf_kanchor *)rs_malloc(sizeof(*key));
125 	if (key == NULL)
126 		return (NULL);
127 	strlcpy(key->path, path, sizeof(key->path));
128 	found = RB_FIND(pf_kanchor_global, &V_pf_anchors, key);
129 	rs_free(key);
130 	return (found);
131 }
132 
133 void
134 pf_init_kruleset(struct pf_kruleset *ruleset)
135 {
136 	int	i;
137 
138 	memset(ruleset, 0, sizeof(struct pf_kruleset));
139 	for (i = 0; i < PF_RULESET_MAX; i++) {
140 		TAILQ_INIT(&ruleset->rules[i].queues[0]);
141 		TAILQ_INIT(&ruleset->rules[i].queues[1]);
142 		ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
143 		ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
144 	}
145 }
146 
147 struct pf_kruleset *
148 pf_find_kruleset(const char *path)
149 {
150 	struct pf_kanchor	*anchor;
151 
152 	while (*path == '/')
153 		path++;
154 	if (!*path)
155 		return (&pf_main_ruleset);
156 	anchor = pf_find_kanchor(path);
157 	if (anchor == NULL)
158 		return (NULL);
159 	else
160 		return (&anchor->ruleset);
161 }
162 
163 struct pf_kruleset *
164 pf_find_or_create_kruleset(const char *path)
165 {
166 	char			*p, *q, *r;
167 	struct pf_kruleset	*ruleset;
168 	struct pf_kanchor	*anchor = NULL, *dup, *parent = NULL;
169 
170 	if (path[0] == 0)
171 		return (&pf_main_ruleset);
172 	while (*path == '/')
173 		path++;
174 	ruleset = pf_find_kruleset(path);
175 	if (ruleset != NULL)
176 		return (ruleset);
177 	p = (char *)rs_malloc(MAXPATHLEN);
178 	if (p == NULL)
179 		return (NULL);
180 	strlcpy(p, path, MAXPATHLEN);
181 	while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
182 		*q = 0;
183 		if ((ruleset = pf_find_kruleset(p)) != NULL) {
184 			parent = ruleset->anchor;
185 			break;
186 		}
187 	}
188 	if (q == NULL)
189 		q = p;
190 	else
191 		q++;
192 	strlcpy(p, path, MAXPATHLEN);
193 	if (!*q) {
194 		rs_free(p);
195 		return (NULL);
196 	}
197 	while ((r = strchr(q, '/')) != NULL || *q) {
198 		if (r != NULL)
199 			*r = 0;
200 		if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
201 		    (parent != NULL && strlen(parent->path) >=
202 		    MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
203 			rs_free(p);
204 			return (NULL);
205 		}
206 		anchor = (struct pf_kanchor *)rs_malloc(sizeof(*anchor));
207 		if (anchor == NULL) {
208 			rs_free(p);
209 			return (NULL);
210 		}
211 		RB_INIT(&anchor->children);
212 		strlcpy(anchor->name, q, sizeof(anchor->name));
213 		if (parent != NULL) {
214 			strlcpy(anchor->path, parent->path,
215 			    sizeof(anchor->path));
216 			strlcat(anchor->path, "/", sizeof(anchor->path));
217 		}
218 		strlcat(anchor->path, anchor->name, sizeof(anchor->path));
219 		if ((dup = RB_INSERT(pf_kanchor_global, &V_pf_anchors, anchor)) !=
220 		    NULL) {
221 			printf("pf_find_or_create_ruleset: RB_INSERT1 "
222 			    "'%s' '%s' collides with '%s' '%s'\n",
223 			    anchor->path, anchor->name, dup->path, dup->name);
224 			rs_free(anchor);
225 			rs_free(p);
226 			return (NULL);
227 		}
228 		if (parent != NULL) {
229 			anchor->parent = parent;
230 			if ((dup = RB_INSERT(pf_kanchor_node, &parent->children,
231 			    anchor)) != NULL) {
232 				printf("pf_find_or_create_ruleset: "
233 				    "RB_INSERT2 '%s' '%s' collides with "
234 				    "'%s' '%s'\n", anchor->path, anchor->name,
235 				    dup->path, dup->name);
236 				RB_REMOVE(pf_kanchor_global, &V_pf_anchors,
237 				    anchor);
238 				rs_free(anchor);
239 				rs_free(p);
240 				return (NULL);
241 			}
242 		}
243 		pf_init_kruleset(&anchor->ruleset);
244 		anchor->ruleset.anchor = anchor;
245 		parent = anchor;
246 		if (r != NULL)
247 			q = r + 1;
248 		else
249 			*q = 0;
250 	}
251 	rs_free(p);
252 	return (&anchor->ruleset);
253 }
254 
255 void
256 pf_remove_if_empty_kruleset(struct pf_kruleset *ruleset)
257 {
258 	struct pf_kanchor	*parent;
259 	int			 i;
260 
261 	while (ruleset != NULL) {
262 		if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
263 		    !RB_EMPTY(&ruleset->anchor->children) ||
264 		    ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
265 		    ruleset->topen)
266 			return;
267 		for (i = 0; i < PF_RULESET_MAX; ++i)
268 			if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
269 			    !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
270 			    ruleset->rules[i].inactive.open)
271 				return;
272 		RB_REMOVE(pf_kanchor_global, &V_pf_anchors, ruleset->anchor);
273 		if ((parent = ruleset->anchor->parent) != NULL)
274 			RB_REMOVE(pf_kanchor_node, &parent->children,
275 			    ruleset->anchor);
276 		rs_free(ruleset->anchor);
277 		if (parent == NULL)
278 			return;
279 		ruleset = &parent->ruleset;
280 	}
281 }
282 
283 int
284 pf_kanchor_setup(struct pf_krule *r, const struct pf_kruleset *s,
285     const char *name)
286 {
287 	char			*p, *path;
288 	struct pf_kruleset	*ruleset;
289 
290 	r->anchor = NULL;
291 	r->anchor_relative = 0;
292 	r->anchor_wildcard = 0;
293 	if (!name[0])
294 		return (0);
295 	path = (char *)rs_malloc(MAXPATHLEN);
296 	if (path == NULL)
297 		return (1);
298 	if (name[0] == '/')
299 		strlcpy(path, name + 1, MAXPATHLEN);
300 	else {
301 		/* relative path */
302 		r->anchor_relative = 1;
303 		if (s->anchor == NULL || !s->anchor->path[0])
304 			path[0] = 0;
305 		else
306 			strlcpy(path, s->anchor->path, MAXPATHLEN);
307 		while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
308 			if (!path[0]) {
309 				DPFPRINTF("pf_anchor_setup: .. beyond root\n");
310 				rs_free(path);
311 				return (1);
312 			}
313 			if ((p = strrchr(path, '/')) != NULL)
314 				*p = 0;
315 			else
316 				path[0] = 0;
317 			r->anchor_relative++;
318 			name += 3;
319 		}
320 		if (path[0])
321 			strlcat(path, "/", MAXPATHLEN);
322 		strlcat(path, name, MAXPATHLEN);
323 	}
324 	if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
325 		r->anchor_wildcard = 1;
326 		*p = 0;
327 	}
328 	ruleset = pf_find_or_create_kruleset(path);
329 	rs_free(path);
330 	if (ruleset == NULL || ruleset->anchor == NULL) {
331 		DPFPRINTF("pf_anchor_setup: ruleset\n");
332 		return (1);
333 	}
334 	r->anchor = ruleset->anchor;
335 	r->anchor->refcnt++;
336 	return (0);
337 }
338 
339 int
340 pf_kanchor_nvcopyout(const struct pf_kruleset *rs, const struct pf_krule *r,
341     nvlist_t *nvl)
342 {
343 	char anchor_call[MAXPATHLEN] = { 0 };
344 
345 	if (r->anchor == NULL)
346 		goto done;
347 	if (!r->anchor_relative) {
348 		strlcpy(anchor_call, "/", sizeof(anchor_call));
349 		strlcat(anchor_call, r->anchor->path,
350 		    sizeof(anchor_call));
351 	} else {
352 		char	 a[MAXPATHLEN];
353 		char	*p;
354 		int	 i;
355 		if (rs->anchor == NULL)
356 			a[0] = 0;
357 		else
358 			strlcpy(a, rs->anchor->path, MAXPATHLEN);
359 		for (i = 1; i < r->anchor_relative; ++i) {
360 			if ((p = strrchr(a, '/')) == NULL)
361 				p = a;
362 			*p = 0;
363 			strlcat(anchor_call, "../",
364 			    sizeof(anchor_call));
365 		}
366 		if (strncmp(a, r->anchor->path, strlen(a))) {
367 			printf("pf_anchor_copyout: '%s' '%s'\n", a,
368 			    r->anchor->path);
369 			return (1);
370 		}
371 		if (strlen(r->anchor->path) > strlen(a))
372 			strlcat(anchor_call, r->anchor->path + (a[0] ?
373 			    strlen(a) + 1 : 0), sizeof(anchor_call));
374 
375 	}
376 	if (r->anchor_wildcard)
377 		strlcat(anchor_call, anchor_call[0] ? "/*" : "*",
378 		    sizeof(anchor_call));
379 
380 done:
381 	nvlist_add_string(nvl, "anchor_call", anchor_call);
382 
383 	return (0);
384 }
385 
386 int
387 pf_kanchor_copyout(const struct pf_kruleset *rs, const struct pf_krule *r,
388     struct pfioc_rule *pr)
389 {
390 	pr->anchor_call[0] = 0;
391 	if (r->anchor == NULL)
392 		return (0);
393 	if (!r->anchor_relative) {
394 		strlcpy(pr->anchor_call, "/", sizeof(pr->anchor_call));
395 		strlcat(pr->anchor_call, r->anchor->path,
396 		    sizeof(pr->anchor_call));
397 	} else {
398 		char	*a, *p;
399 		int	 i;
400 
401 		a = (char *)rs_malloc(MAXPATHLEN);
402 		if (a == NULL)
403 			return (1);
404 		if (rs->anchor == NULL)
405 			a[0] = 0;
406 		else
407 			strlcpy(a, rs->anchor->path, MAXPATHLEN);
408 		for (i = 1; i < r->anchor_relative; ++i) {
409 			if ((p = strrchr(a, '/')) == NULL)
410 				p = a;
411 			*p = 0;
412 			strlcat(pr->anchor_call, "../",
413 			    sizeof(pr->anchor_call));
414 		}
415 		if (strncmp(a, r->anchor->path, strlen(a))) {
416 			printf("pf_anchor_copyout: '%s' '%s'\n", a,
417 			    r->anchor->path);
418 			rs_free(a);
419 			return (1);
420 		}
421 		if (strlen(r->anchor->path) > strlen(a))
422 			strlcat(pr->anchor_call, r->anchor->path + (a[0] ?
423 			    strlen(a) + 1 : 0), sizeof(pr->anchor_call));
424 		rs_free(a);
425 	}
426 	if (r->anchor_wildcard)
427 		strlcat(pr->anchor_call, pr->anchor_call[0] ? "/*" : "*",
428 		    sizeof(pr->anchor_call));
429 	return (0);
430 }
431 
432 void
433 pf_kanchor_remove(struct pf_krule *r)
434 {
435 	if (r->anchor == NULL)
436 		return;
437 	if (r->anchor->refcnt <= 0) {
438 		printf("pf_anchor_remove: broken refcount\n");
439 		r->anchor = NULL;
440 		return;
441 	}
442 	if (!--r->anchor->refcnt)
443 		pf_remove_if_empty_kruleset(&r->anchor->ruleset);
444 	r->anchor = NULL;
445 }
446