xref: /netbsd-src/sys/net/npf/npf_ctl.c (revision 4817a0b0b8fe9612e8ebe21a9bf2d97b95038a97)
1 /*	$NetBSD: npf_ctl.c,v 1.4 2010/12/18 01:07:25 rmind Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009-2010 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This material is based upon work partially supported by The
8  * NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * NPF device control.
34  *
35  * Implementation of (re)loading, construction of tables and rules.
36  * NPF proplib(9) dictionary consumer.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: npf_ctl.c,v 1.4 2010/12/18 01:07:25 rmind Exp $");
41 
42 #include <sys/param.h>
43 #include <sys/conf.h>
44 #include <sys/kernel.h>
45 
46 #include <prop/proplib.h>
47 
48 #include "npf_ncode.h"
49 #include "npf_impl.h"
50 
51 /*
52  * npfctl_switch: enable or disable packet inspection.
53  */
54 int
55 npfctl_switch(void *data)
56 {
57 	const bool onoff = *(int *)data ? true : false;
58 	int error;
59 
60 	if (onoff) {
61 		/* Enable: add pfil hooks. */
62 		error = npf_register_pfil();
63 	} else {
64 		/* Disable: remove pfil hooks. */
65 		npf_unregister_pfil();
66 		error = 0;
67 	}
68 	return error;
69 }
70 
71 static int
72 npf_mk_tables(npf_tableset_t *tblset, prop_array_t tables)
73 {
74 	prop_object_iterator_t it;
75 	prop_dictionary_t tbldict;
76 	prop_object_t obj;
77 	int error = 0;
78 
79 	/* Tables - array. */
80 	if (prop_object_type(tables) != PROP_TYPE_ARRAY)
81 		return EINVAL;
82 
83 	it = prop_array_iterator(tables);
84 	while ((tbldict = prop_object_iterator_next(it)) != NULL) {
85 		prop_dictionary_t ent;
86 		prop_object_iterator_t eit;
87 		prop_array_t entries;
88 		npf_table_t *t;
89 		u_int tid;
90 		int type;
91 
92 		/* Table - dictionary. */
93 		if (prop_object_type(tbldict) != PROP_TYPE_DICTIONARY) {
94 			error = EINVAL;
95 			break;
96 		}
97 
98 		/* Table ID and type. */
99 		obj = prop_dictionary_get(tbldict, "id");
100 		tid = (u_int)prop_number_integer_value(obj);
101 		obj = prop_dictionary_get(tbldict, "type");
102 		type = (int)prop_number_integer_value(obj);
103 		/* Validate them. */
104 		error = npf_table_check(tblset, tid, type);
105 		if (error)
106 			break;
107 
108 		/* Create and insert the table. */
109 		t = npf_table_create(tid, type, 1024);	/* XXX */
110 		if (t == NULL) {
111 			error = ENOMEM;
112 			break;
113 		}
114 		error = npf_tableset_insert(tblset, t);
115 		KASSERT(error == 0);
116 
117 		/* Entries. */
118 		entries = prop_dictionary_get(tbldict, "entries");
119 		if (prop_object_type(entries) != PROP_TYPE_ARRAY) {
120 			error = EINVAL;
121 			break;
122 		}
123 		eit = prop_array_iterator(entries);
124 		while ((ent = prop_object_iterator_next(eit)) != NULL) {
125 			in_addr_t addr, mask;	/* XXX: IPv6 */
126 
127 			/* Address. */
128 			obj = prop_dictionary_get(ent, "addr");
129 			addr = (in_addr_t)prop_number_integer_value(obj);
130 			/* Mask. */
131 			obj = prop_dictionary_get(ent, "mask");
132 			mask = (in_addr_t)prop_number_integer_value(obj);
133 			/* Add a table entry. */
134 			error = npf_table_add_v4cidr(tblset, tid, addr, mask);
135 			if (error)
136 				break;
137 		}
138 		prop_object_iterator_release(eit);
139 		if (error)
140 			break;
141 	}
142 	prop_object_iterator_release(it);
143 	/*
144 	 * Note: in a case of error, caller will free the tableset.
145 	 */
146 	return error;
147 }
148 
149 static int
150 npf_mk_singlerule(prop_dictionary_t rldict,
151     npf_ruleset_t *rlset, npf_rule_t **parent)
152 {
153 	npf_rule_t *rl;
154 	prop_object_t obj;
155 	size_t nc_size;
156 	void *nc;
157 
158 	/* Rule - dictionary. */
159 	if (prop_object_type(rldict) != PROP_TYPE_DICTIONARY)
160 		return EINVAL;
161 
162 	/* N-code (binary data). */
163 	obj = prop_dictionary_get(rldict, "ncode");
164 	if (obj) {
165 		const void *ncptr;
166 		int npf_err, errat;
167 
168 		/*
169 		 * Allocate, copy and validate n-code. XXX: Inefficient.
170 		 */
171 		ncptr = prop_data_data_nocopy(obj);
172 		nc_size = prop_data_size(obj);
173 		if (ncptr == NULL || nc_size > NPF_NCODE_LIMIT) {
174 			return EINVAL;
175 		}
176 		nc = npf_ncode_alloc(nc_size);
177 		if (nc == NULL) {
178 			return EINVAL;
179 		}
180 		memcpy(nc, ncptr, nc_size);
181 		npf_err = npf_ncode_validate(nc, nc_size, &errat);
182 		if (npf_err) {
183 			npf_ncode_free(nc, nc_size);
184 			/* TODO: return error details via proplib */
185 			return EINVAL;
186 		}
187 	} else {
188 		/* No n-code. */
189 		nc = NULL;
190 		nc_size = 0;
191 	}
192 
193 	/* Allocate and setup NPF rule. */
194 	rl = npf_rule_alloc(rldict, nc, nc_size);
195 	if (rl == NULL) {
196 		if (nc) {
197 			npf_ncode_free(nc, nc_size);	/* XXX */
198 		}
199 		return ENOMEM;
200 	}
201 	npf_ruleset_insert(rlset, rl);
202 	if (parent) {
203 		*parent = rl;
204 	}
205 	return 0;
206 }
207 
208 static int
209 npf_mk_rules(npf_ruleset_t *rlset, prop_array_t rules)
210 {
211 	prop_object_iterator_t it;
212 	prop_dictionary_t rldict;
213 	int error;
214 
215 	/* Ruleset - array. */
216 	if (prop_object_type(rules) != PROP_TYPE_ARRAY)
217 		return EINVAL;
218 
219 	error = 0;
220 	it = prop_array_iterator(rules);
221 	while ((rldict = prop_object_iterator_next(it)) != NULL) {
222 		prop_object_iterator_t sit;
223 		prop_array_t subrules;
224 		prop_dictionary_t srldict;
225 		npf_rule_t *myrl;
226 
227 		/* Generate a single rule. */
228 		error = npf_mk_singlerule(rldict, rlset, &myrl);
229 		if (error)
230 			break;
231 
232 		/* Check for subrules. */
233 		subrules = prop_dictionary_get(rldict, "subrules");
234 		if (subrules == NULL) {
235 			/* No subrules, next.. */
236 			continue;
237 		}
238 		/* Generate subrules, if any. */
239 		if (prop_object_type(subrules) != PROP_TYPE_ARRAY) {
240 			error = EINVAL;
241 			break;
242 		}
243 		sit = prop_array_iterator(subrules);
244 		while ((srldict = prop_object_iterator_next(sit)) != NULL) {
245 			/* For subrule, pass ruleset pointer of parent. */
246 			error = npf_mk_singlerule(srldict,
247 			    npf_rule_subset(myrl), NULL);
248 			if (error)
249 				break;
250 		}
251 		prop_object_iterator_release(sit);
252 		if (error)
253 			break;
254 	}
255 	prop_object_iterator_release(it);
256 	/*
257 	 * Note: in a case of error, caller will free the ruleset.
258 	 */
259 	return error;
260 }
261 
262 static int
263 npf_mk_natlist(npf_ruleset_t *nset, prop_array_t natlist)
264 {
265 	prop_object_iterator_t it;
266 	prop_dictionary_t natdict;
267 	int error;
268 
269 	/* NAT policies - array. */
270 	if (prop_object_type(natlist) != PROP_TYPE_ARRAY)
271 		return EINVAL;
272 
273 	error = 0;
274 	it = prop_array_iterator(natlist);
275 	while ((natdict = prop_object_iterator_next(it)) != NULL) {
276 		npf_natpolicy_t *np;
277 		npf_rule_t *rl;
278 
279 		/* NAT policy - dictionary. */
280 		if (prop_object_type(natdict) != PROP_TYPE_DICTIONARY) {
281 			error = EINVAL;
282 			break;
283 		}
284 
285 		/*
286 		 * NAT policies are standard rules, plus additional
287 		 * information for translation.  Make a rule.
288 		 */
289 		error = npf_mk_singlerule(natdict, nset, &rl);
290 		if (error)
291 			break;
292 
293 		/* Allocate a new NAT policy and assign to the rule. */
294 		np = npf_nat_newpolicy(natdict);
295 		if (np == NULL) {
296 			npf_rule_free(rl);
297 			error = ENOMEM;
298 			break;
299 		}
300 		npf_rule_setnat(rl, np);
301 	}
302 	prop_object_iterator_release(it);
303 	/*
304 	 * Note: in a case of error, caller will free entire NAT ruleset
305 	 * with assigned NAT policies.
306 	 */
307 	return error;
308 }
309 
310 /*
311  * npfctl_reload: store passed data i.e. update settings, create passed
312  * tables, rules and atomically activate all them.
313  */
314 int
315 npfctl_reload(u_long cmd, void *data)
316 {
317 	const struct plistref *pref = data;
318 	npf_tableset_t *tblset = NULL;
319 	npf_ruleset_t *rlset = NULL;
320 	npf_ruleset_t *nset = NULL;
321 	prop_dictionary_t dict;
322 	prop_array_t natlist, tables, rules;
323 	int error;
324 
325 	/* Retrieve the dictionary. */
326 #ifdef _KERNEL
327 	error = prop_dictionary_copyin_ioctl(pref, cmd, &dict);
328 	if (error)
329 		return error;
330 #else
331 	dict = prop_dictionary_internalize_from_file(data);
332 	if (dict == NULL)
333 		return EINVAL;
334 #endif
335 	/* NAT policies. */
336 	nset = npf_ruleset_create();
337 	natlist = prop_dictionary_get(dict, "translation");
338 	error = npf_mk_natlist(nset, natlist);
339 	if (error)
340 		goto fail;
341 
342 	/* Tables. */
343 	tblset = npf_tableset_create();
344 	tables = prop_dictionary_get(dict, "tables");
345 	error = npf_mk_tables(tblset, tables);
346 	if (error)
347 		goto fail;
348 
349 	/* Rules. */
350 	rlset = npf_ruleset_create();
351 	rules = prop_dictionary_get(dict, "rules");
352 	error = npf_mk_rules(rlset, rules);
353 	if (error)
354 		goto fail;
355 
356 	/*
357 	 * Finally - reload ruleset, tableset and NAT policies.
358 	 * Operation will be performed as a single transaction.
359 	 */
360 	npf_reload(rlset, tblset, nset);
361 
362 	/* Done.  Since data is consumed now, we shall not destroy it. */
363 	tblset = NULL;
364 	rlset = NULL;
365 	nset = NULL;
366 fail:
367 	prop_object_release(dict);
368 	/*
369 	 * Note: destroy rulesets first, to drop references to the tableset.
370 	 */
371 	KASSERT(error == 0 || (nset || rlset || tblset));
372 	if (nset) {
373 		npf_ruleset_destroy(nset);
374 	}
375 	if (rlset) {
376 		npf_ruleset_destroy(rlset);
377 	}
378 	if (tblset) {
379 		npf_tableset_destroy(tblset);
380 	}
381 	return error;
382 }
383 
384 /*
385  * npfctl_sessions_save: construct a list of sessions and export for saving.
386  */
387 int
388 npfctl_sessions_save(u_long cmd, void *data)
389 {
390 	struct plistref *pref = data;
391 	prop_dictionary_t sesdict;
392 	prop_array_t selist, nplist;
393 	int error;
394 
395 	/* Create a dictionary and two lists. */
396 	sesdict = prop_dictionary_create();
397 	selist = prop_array_create();
398 	nplist = prop_array_create();
399 
400 	/* Save the sessions. */
401 	error = npf_session_save(selist, nplist);
402 	if (error) {
403 		goto fail;
404 	}
405 
406 	/* Set the session list, NAT policy list and export the dictionary. */
407 	prop_dictionary_set(sesdict, "session-list", selist);
408 	prop_dictionary_set(sesdict, "nat-policy-list", nplist);
409 #ifdef _KERNEL
410 	error = prop_dictionary_copyout_ioctl(pref, cmd, sesdict);
411 #else
412 	error = prop_dictionary_externalize_to_file(sesdict, data) ? 0 : errno;
413 #endif
414 fail:
415 	prop_object_release(sesdict);
416 	return error;
417 }
418 
419 /*
420  * npfctl_sessions_load: import a list of sessions, reconstruct them and load.
421  */
422 int
423 npfctl_sessions_load(u_long cmd, void *data)
424 {
425 	const struct plistref *pref = data;
426 	npf_sehash_t *sehasht = NULL;
427 	prop_dictionary_t sesdict, sedict;
428 	prop_object_iterator_t it;
429 	prop_array_t selist;
430 	int error;
431 
432 	/* Retrieve the dictionary containing session and NAT policy lists. */
433 #ifdef _KERNEL
434 	error = prop_dictionary_copyin_ioctl(pref, cmd, &sesdict);
435 	if (error)
436 		return error;
437 #else
438 	sesdict = prop_dictionary_internalize_from_file(data);
439 	if (sesdict == NULL)
440 		return EINVAL;
441 #endif
442 	/*
443 	 * Note: session objects contain the references to the NAT policy
444 	 * entries.  Therefore, no need to directly access it.
445 	 */
446 	selist = prop_dictionary_get(sesdict, "session-list");
447 	if (prop_object_type(selist) != PROP_TYPE_ARRAY) {
448 		error = EINVAL;
449 		goto fail;
450 	}
451 
452 	/* Create a session hash table. */
453 	sehasht = sess_htable_create();
454 	if (sehasht == NULL) {
455 		error = ENOMEM;
456 		goto fail;
457 	}
458 
459 	/*
460 	 * Iterate through and construct each session.
461 	 */
462 	error = 0;
463 	it = prop_array_iterator(selist);
464 	npf_core_enter();
465 	while ((sedict = prop_object_iterator_next(it)) != NULL) {
466 		/* Session - dictionary. */
467 		if (prop_object_type(sedict) != PROP_TYPE_DICTIONARY) {
468 			error = EINVAL;
469 			goto fail;
470 		}
471 		/* Construct and insert real session structure. */
472 		error = npf_session_restore(sehasht, sedict);
473 		if (error) {
474 			goto fail;
475 		}
476 	}
477 	npf_core_exit();
478 	sess_htable_reload(sehasht);
479 fail:
480 	prop_object_release(selist);
481 	if (error && sehasht) {
482 		/* Destroy session table. */
483 		sess_htable_destroy(sehasht);
484 	}
485 	return error;
486 }
487 
488 /*
489  * npfctl_table: add, remove or query entries in the specified table.
490  *
491  * For maximum performance, interface is avoiding proplib(3)'s overhead.
492  */
493 int
494 npfctl_table(void *data)
495 {
496 	npf_ioctl_table_t *nct = data;
497 	int error;
498 
499 	switch (nct->nct_action) {
500 	case NPF_IOCTL_TBLENT_ADD:
501 		error = npf_table_add_v4cidr(NULL, nct->nct_tid,
502 		    nct->nct_addr, nct->nct_mask);
503 		break;
504 	case NPF_IOCTL_TBLENT_REM:
505 		error = npf_table_rem_v4cidr(NULL, nct->nct_tid,
506 		    nct->nct_addr, nct->nct_mask);
507 		break;
508 	default:
509 		/* XXX */
510 		error = npf_table_match_v4addr(nct->nct_tid, nct->nct_addr);
511 		if (error) {
512 			error = EINVAL;
513 		}
514 	}
515 	return error;
516 }
517