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: stable/12/sbin/pfctl/pf_ruleset.c 370252 2021-07-31 13:05:35Z kp $");
41
42 #include <sys/param.h>
43 #include <sys/socket.h>
44 #include <sys/mbuf.h>
45
46 #include <netinet/in.h>
47 #include <netinet/in_systm.h>
48 #include <netinet/ip.h>
49 #include <netinet/tcp.h>
50
51 #include <net/if.h>
52 #include <net/vnet.h>
53 #include <net/pfvar.h>
54
55 #ifdef INET6
56 #include <netinet/ip6.h>
57 #endif /* INET6 */
58
59 #include <arpa/inet.h>
60 #include <errno.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #define rs_malloc(x) calloc(1, x)
65 #define rs_free(x) free(x)
66
67 #include "pfctl.h"
68
69 #ifdef PFDEBUG
70 #include <sys/stdarg.h>
71 #define DPFPRINTF(format, x...) fprintf(stderr, format , ##x)
72 #else
73 #define DPFPRINTF(format, x...) ((void)0)
74 #endif /* PFDEBUG */
75
76 struct pfctl_anchor_global pf_anchors;
77 struct pfctl_anchor pf_main_anchor;
78 #undef V_pf_anchors
79 #define V_pf_anchors pf_anchors
80 #undef pf_main_ruleset
81 #define pf_main_ruleset pf_main_anchor.ruleset
82
83 static __inline int pf_anchor_compare(struct pfctl_anchor *,
84 struct pfctl_anchor *);
85 static struct pfctl_anchor *pf_find_anchor(const char *);
86
87 RB_GENERATE(pfctl_anchor_global, pfctl_anchor, entry_global,
88 pf_anchor_compare);
89 RB_GENERATE(pfctl_anchor_node, pfctl_anchor, entry_node, pf_anchor_compare);
90
91 static __inline int
pf_anchor_compare(struct pfctl_anchor * a,struct pfctl_anchor * b)92 pf_anchor_compare(struct pfctl_anchor *a, struct pfctl_anchor *b)
93 {
94 int c = strcmp(a->path, b->path);
95
96 return (c ? (c < 0 ? -1 : 1) : 0);
97 }
98
99 int
pf_get_ruleset_number(u_int8_t action)100 pf_get_ruleset_number(u_int8_t action)
101 {
102 switch (action) {
103 case PF_SCRUB:
104 case PF_NOSCRUB:
105 return (PF_RULESET_SCRUB);
106 break;
107 case PF_PASS:
108 case PF_DROP:
109 case PF_MATCH:
110 return (PF_RULESET_FILTER);
111 break;
112 case PF_NAT:
113 case PF_NONAT:
114 return (PF_RULESET_NAT);
115 break;
116 case PF_BINAT:
117 case PF_NOBINAT:
118 return (PF_RULESET_BINAT);
119 break;
120 case PF_RDR:
121 case PF_NORDR:
122 return (PF_RULESET_RDR);
123 break;
124 default:
125 return (PF_RULESET_MAX);
126 break;
127 }
128 }
129
130 void
pf_init_ruleset(struct pfctl_ruleset * ruleset)131 pf_init_ruleset(struct pfctl_ruleset *ruleset)
132 {
133 int i;
134
135 memset(ruleset, 0, sizeof(struct pfctl_ruleset));
136 for (i = 0; i < PF_RULESET_MAX; i++) {
137 TAILQ_INIT(&ruleset->rules[i].queues[0]);
138 TAILQ_INIT(&ruleset->rules[i].queues[1]);
139 ruleset->rules[i].active.ptr = &ruleset->rules[i].queues[0];
140 ruleset->rules[i].inactive.ptr = &ruleset->rules[i].queues[1];
141 }
142 }
143
144 static struct pfctl_anchor *
pf_find_anchor(const char * path)145 pf_find_anchor(const char *path)
146 {
147 struct pfctl_anchor *key, *found;
148
149 key = (struct pfctl_anchor *)rs_malloc(sizeof(*key));
150 if (key == NULL)
151 return (NULL);
152 strlcpy(key->path, path, sizeof(key->path));
153 found = RB_FIND(pfctl_anchor_global, &V_pf_anchors, key);
154 rs_free(key);
155 return (found);
156 }
157
158 struct pfctl_ruleset *
pf_find_ruleset(const char * path)159 pf_find_ruleset(const char *path)
160 {
161 struct pfctl_anchor *anchor;
162
163 while (*path == '/')
164 path++;
165 if (!*path)
166 return (&pf_main_ruleset);
167 anchor = pf_find_anchor(path);
168 if (anchor == NULL)
169 return (NULL);
170 else
171 return (&anchor->ruleset);
172 }
173
174 struct pfctl_ruleset *
pf_find_or_create_ruleset(const char * path)175 pf_find_or_create_ruleset(const char *path)
176 {
177 char *p, *q, *r;
178 struct pfctl_ruleset *ruleset;
179 struct pfctl_anchor *anchor = NULL, *dup, *parent = NULL;
180
181 if (path[0] == 0)
182 return (&pf_main_ruleset);
183 while (*path == '/')
184 path++;
185 ruleset = pf_find_ruleset(path);
186 if (ruleset != NULL)
187 return (ruleset);
188 p = (char *)rs_malloc(MAXPATHLEN);
189 if (p == NULL)
190 return (NULL);
191 strlcpy(p, path, MAXPATHLEN);
192 while (parent == NULL && (q = strrchr(p, '/')) != NULL) {
193 *q = 0;
194 if ((ruleset = pf_find_ruleset(p)) != NULL) {
195 parent = ruleset->anchor;
196 break;
197 }
198 }
199 if (q == NULL)
200 q = p;
201 else
202 q++;
203 strlcpy(p, path, MAXPATHLEN);
204 if (!*q) {
205 rs_free(p);
206 return (NULL);
207 }
208 while ((r = strchr(q, '/')) != NULL || *q) {
209 if (r != NULL)
210 *r = 0;
211 if (!*q || strlen(q) >= PF_ANCHOR_NAME_SIZE ||
212 (parent != NULL && strlen(parent->path) >=
213 MAXPATHLEN - PF_ANCHOR_NAME_SIZE - 1)) {
214 rs_free(p);
215 return (NULL);
216 }
217 anchor = (struct pfctl_anchor *)rs_malloc(sizeof(*anchor));
218 if (anchor == NULL) {
219 rs_free(p);
220 return (NULL);
221 }
222 RB_INIT(&anchor->children);
223 strlcpy(anchor->name, q, sizeof(anchor->name));
224 if (parent != NULL) {
225 strlcpy(anchor->path, parent->path,
226 sizeof(anchor->path));
227 strlcat(anchor->path, "/", sizeof(anchor->path));
228 }
229 strlcat(anchor->path, anchor->name, sizeof(anchor->path));
230 if ((dup = RB_INSERT(pfctl_anchor_global, &V_pf_anchors, anchor)) !=
231 NULL) {
232 printf("pf_find_or_create_ruleset: RB_INSERT1 "
233 "'%s' '%s' collides with '%s' '%s'\n",
234 anchor->path, anchor->name, dup->path, dup->name);
235 rs_free(anchor);
236 rs_free(p);
237 return (NULL);
238 }
239 if (parent != NULL) {
240 anchor->parent = parent;
241 if ((dup = RB_INSERT(pfctl_anchor_node, &parent->children,
242 anchor)) != NULL) {
243 printf("pf_find_or_create_ruleset: "
244 "RB_INSERT2 '%s' '%s' collides with "
245 "'%s' '%s'\n", anchor->path, anchor->name,
246 dup->path, dup->name);
247 RB_REMOVE(pfctl_anchor_global, &V_pf_anchors,
248 anchor);
249 rs_free(anchor);
250 rs_free(p);
251 return (NULL);
252 }
253 }
254 pf_init_ruleset(&anchor->ruleset);
255 anchor->ruleset.anchor = anchor;
256 parent = anchor;
257 if (r != NULL)
258 q = r + 1;
259 else
260 *q = 0;
261 }
262 rs_free(p);
263 return (&anchor->ruleset);
264 }
265
266 void
pf_remove_if_empty_ruleset(struct pfctl_ruleset * ruleset)267 pf_remove_if_empty_ruleset(struct pfctl_ruleset *ruleset)
268 {
269 struct pfctl_anchor *parent;
270 int i;
271
272 while (ruleset != NULL) {
273 if (ruleset == &pf_main_ruleset || ruleset->anchor == NULL ||
274 !RB_EMPTY(&ruleset->anchor->children) ||
275 ruleset->anchor->refcnt > 0 || ruleset->tables > 0 ||
276 ruleset->topen)
277 return;
278 for (i = 0; i < PF_RULESET_MAX; ++i)
279 if (!TAILQ_EMPTY(ruleset->rules[i].active.ptr) ||
280 !TAILQ_EMPTY(ruleset->rules[i].inactive.ptr) ||
281 ruleset->rules[i].inactive.open)
282 return;
283 RB_REMOVE(pfctl_anchor_global, &V_pf_anchors, ruleset->anchor);
284 if ((parent = ruleset->anchor->parent) != NULL)
285 RB_REMOVE(pfctl_anchor_node, &parent->children,
286 ruleset->anchor);
287 rs_free(ruleset->anchor);
288 if (parent == NULL)
289 return;
290 ruleset = &parent->ruleset;
291 }
292 }
293 int
pfctl_anchor_setup(struct pfctl_rule * r,const struct pfctl_ruleset * s,const char * name)294 pfctl_anchor_setup(struct pfctl_rule *r, const struct pfctl_ruleset *s,
295 const char *name)
296 {
297 char *p, *path;
298 struct pfctl_ruleset *ruleset;
299
300 r->anchor = NULL;
301 r->anchor_relative = 0;
302 r->anchor_wildcard = 0;
303 if (!name[0])
304 return (0);
305 path = (char *)rs_malloc(MAXPATHLEN);
306 if (path == NULL)
307 return (1);
308 if (name[0] == '/')
309 strlcpy(path, name + 1, MAXPATHLEN);
310 else {
311 /* relative path */
312 r->anchor_relative = 1;
313 if (s->anchor == NULL || !s->anchor->path[0])
314 path[0] = 0;
315 else
316 strlcpy(path, s->anchor->path, MAXPATHLEN);
317 while (name[0] == '.' && name[1] == '.' && name[2] == '/') {
318 if (!path[0]) {
319 printf("pfctl_anchor_setup: .. beyond root\n");
320 rs_free(path);
321 return (1);
322 }
323 if ((p = strrchr(path, '/')) != NULL)
324 *p = 0;
325 else
326 path[0] = 0;
327 r->anchor_relative++;
328 name += 3;
329 }
330 if (path[0])
331 strlcat(path, "/", MAXPATHLEN);
332 strlcat(path, name, MAXPATHLEN);
333 }
334 if ((p = strrchr(path, '/')) != NULL && !strcmp(p, "/*")) {
335 r->anchor_wildcard = 1;
336 *p = 0;
337 }
338 ruleset = pf_find_or_create_ruleset(path);
339 rs_free(path);
340 if (ruleset == NULL || ruleset->anchor == NULL) {
341 printf("pfctl_anchor_setup: ruleset\n");
342 return (1);
343 }
344 r->anchor = ruleset->anchor;
345 r->anchor->refcnt++;
346 return (0);
347 }
348