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