xref: /freebsd/sys/netpfil/ipfw/nat64/nat64clat_control.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2019 Yandex LLC
5  * Copyright (c) 2019 Andrey V. Elsukov <ae@FreeBSD.org>
6  * Copyright (c) 2019 Boris N. Lytochkin <lytboris@gmail.com>
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  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/counter.h>
36 #include <sys/errno.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/module.h>
42 #include <sys/rmlock.h>
43 #include <sys/rwlock.h>
44 #include <sys/socket.h>
45 #include <sys/sockopt.h>
46 #include <sys/syslog.h>
47 #include <sys/sysctl.h>
48 
49 #include <net/if.h>
50 #include <net/if_var.h>
51 #include <net/route.h>
52 #include <net/vnet.h>
53 
54 #include <netinet/in.h>
55 #include <netinet/ip_var.h>
56 #include <netinet/ip_fw.h>
57 #include <netinet6/in6_var.h>
58 #include <netinet6/ip6_var.h>
59 #include <netinet6/ip_fw_nat64.h>
60 
61 #include <netpfil/ipfw/ip_fw_private.h>
62 
63 #include "nat64clat.h"
64 
65 VNET_DEFINE(uint16_t, nat64clat_eid) = 0;
66 
67 static struct nat64clat_cfg *nat64clat_alloc_config(const char *name,
68     uint8_t set);
69 static void nat64clat_free_config(struct nat64clat_cfg *cfg);
70 static struct nat64clat_cfg *nat64clat_find(struct namedobj_instance *ni,
71     const char *name, uint8_t set);
72 
73 static struct nat64clat_cfg *
74 nat64clat_alloc_config(const char *name, uint8_t set)
75 {
76 	struct nat64clat_cfg *cfg;
77 
78 	cfg = malloc(sizeof(struct nat64clat_cfg), M_IPFW, M_WAITOK | M_ZERO);
79 	COUNTER_ARRAY_ALLOC(cfg->base.stats.cnt, NAT64STATS, M_WAITOK);
80 	cfg->no.name = cfg->name;
81 	cfg->no.etlv = IPFW_TLV_NAT64CLAT_NAME;
82 	cfg->no.set = set;
83 	strlcpy(cfg->name, name, sizeof(cfg->name));
84 	return (cfg);
85 }
86 
87 static void
88 nat64clat_free_config(struct nat64clat_cfg *cfg)
89 {
90 
91 	COUNTER_ARRAY_FREE(cfg->base.stats.cnt, NAT64STATS);
92 	free(cfg, M_IPFW);
93 }
94 
95 static void
96 nat64clat_export_config(struct ip_fw_chain *ch, struct nat64clat_cfg *cfg,
97     ipfw_nat64clat_cfg *uc)
98 {
99 	uc->plat_prefix = cfg->base.plat_prefix;
100 	uc->plat_plen = cfg->base.plat_plen;
101 	uc->clat_prefix = cfg->base.clat_prefix;
102 	uc->clat_plen = cfg->base.clat_plen;
103 	uc->flags = cfg->base.flags & NAT64CLAT_FLAGSMASK;
104 	uc->set = cfg->no.set;
105 	strlcpy(uc->name, cfg->no.name, sizeof(uc->name));
106 }
107 
108 struct nat64clat_dump_arg {
109 	struct ip_fw_chain *ch;
110 	struct sockopt_data *sd;
111 };
112 
113 static int
114 export_config_cb(struct namedobj_instance *ni, struct named_object *no,
115     void *arg)
116 {
117 	struct nat64clat_dump_arg *da = (struct nat64clat_dump_arg *)arg;
118 	ipfw_nat64clat_cfg *uc;
119 
120 	uc = (ipfw_nat64clat_cfg *)ipfw_get_sopt_space(da->sd, sizeof(*uc));
121 	nat64clat_export_config(da->ch, (struct nat64clat_cfg *)no, uc);
122 	return (0);
123 }
124 
125 static struct nat64clat_cfg *
126 nat64clat_find(struct namedobj_instance *ni, const char *name, uint8_t set)
127 {
128 	struct nat64clat_cfg *cfg;
129 
130 	cfg = (struct nat64clat_cfg *)ipfw_objhash_lookup_name_type(ni, set,
131 	    IPFW_TLV_NAT64CLAT_NAME, name);
132 
133 	return (cfg);
134 }
135 
136 /*
137  * Creates new consumer-side nat64 translator instance.
138  * Data layout (v0)(current):
139  * Request: [ ipfw_obj_lheader ipfw_nat64clat_cfg ]
140  *
141  * Returns 0 on success
142  */
143 static int
144 nat64clat_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
145     struct sockopt_data *sd)
146 {
147 	ipfw_obj_lheader *olh;
148 	ipfw_nat64clat_cfg *uc;
149 	struct namedobj_instance *ni;
150 	struct nat64clat_cfg *cfg;
151 
152 	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
153 		return (EINVAL);
154 
155 	olh = (ipfw_obj_lheader *)sd->kbuf;
156 	uc = (ipfw_nat64clat_cfg *)(olh + 1);
157 
158 	if (ipfw_check_object_name_generic(uc->name) != 0)
159 		return (EINVAL);
160 
161 	if (uc->set >= IPFW_MAX_SETS ||
162 	    nat64_check_prefix6(&uc->plat_prefix, uc->plat_plen) != 0 ||
163 	    nat64_check_prefix6(&uc->clat_prefix, uc->clat_plen) != 0)
164 		return (EINVAL);
165 
166 	ni = CHAIN_TO_SRV(ch);
167 
168 	IPFW_UH_RLOCK(ch);
169 	if (nat64clat_find(ni, uc->name, uc->set) != NULL) {
170 		IPFW_UH_RUNLOCK(ch);
171 		return (EEXIST);
172 	}
173 	IPFW_UH_RUNLOCK(ch);
174 
175 	cfg = nat64clat_alloc_config(uc->name, uc->set);
176 	cfg->base.plat_prefix = uc->plat_prefix;
177 	cfg->base.plat_plen = uc->plat_plen;
178 	cfg->base.clat_prefix = uc->clat_prefix;
179 	cfg->base.clat_plen = uc->clat_plen;
180 	cfg->base.flags = (uc->flags & NAT64CLAT_FLAGSMASK) |
181 	    NAT64_CLATPFX | NAT64_PLATPFX;
182 	if (IN6_IS_ADDR_WKPFX(&cfg->base.plat_prefix))
183 		cfg->base.flags |= NAT64_WKPFX;
184 
185 	IPFW_UH_WLOCK(ch);
186 
187 	if (nat64clat_find(ni, uc->name, uc->set) != NULL) {
188 		IPFW_UH_WUNLOCK(ch);
189 		nat64clat_free_config(cfg);
190 		return (EEXIST);
191 	}
192 
193 	if (ipfw_objhash_alloc_idx(ni, &cfg->no.kidx) != 0) {
194 		IPFW_UH_WUNLOCK(ch);
195 		nat64clat_free_config(cfg);
196 		return (ENOSPC);
197 	}
198 	ipfw_objhash_add(CHAIN_TO_SRV(ch), &cfg->no);
199 	/* Okay, let's link data */
200 	SRV_OBJECT(ch, cfg->no.kidx) = cfg;
201 	IPFW_UH_WUNLOCK(ch);
202 
203 	return (0);
204 }
205 
206 /*
207  * Change existing nat64clat instance configuration.
208  * Data layout (v0)(current):
209  * Request: [ ipfw_obj_header ipfw_nat64clat_cfg ]
210  * Reply: [ ipfw_obj_header ipfw_nat64clat_cfg ]
211  *
212  * Returns 0 on success
213  */
214 static int
215 nat64clat_config(struct ip_fw_chain *ch, ip_fw3_opheader *op,
216     struct sockopt_data *sd)
217 {
218 	ipfw_obj_header *oh;
219 	ipfw_nat64clat_cfg *uc;
220 	struct nat64clat_cfg *cfg;
221 	struct namedobj_instance *ni;
222 	uint32_t flags;
223 
224 	if (sd->valsize != sizeof(*oh) + sizeof(*uc))
225 		return (EINVAL);
226 
227 	oh = (ipfw_obj_header *)ipfw_get_sopt_space(sd,
228 	    sizeof(*oh) + sizeof(*uc));
229 	uc = (ipfw_nat64clat_cfg *)(oh + 1);
230 
231 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
232 	    oh->ntlv.set >= IPFW_MAX_SETS)
233 		return (EINVAL);
234 
235 	ni = CHAIN_TO_SRV(ch);
236 	if (sd->sopt->sopt_dir == SOPT_GET) {
237 		IPFW_UH_RLOCK(ch);
238 		cfg = nat64clat_find(ni, oh->ntlv.name, oh->ntlv.set);
239 		if (cfg == NULL) {
240 			IPFW_UH_RUNLOCK(ch);
241 			return (ENOENT);
242 		}
243 		nat64clat_export_config(ch, cfg, uc);
244 		IPFW_UH_RUNLOCK(ch);
245 		return (0);
246 	}
247 
248 	IPFW_UH_WLOCK(ch);
249 	cfg = nat64clat_find(ni, oh->ntlv.name, oh->ntlv.set);
250 	if (cfg == NULL) {
251 		IPFW_UH_WUNLOCK(ch);
252 		return (ENOENT);
253 	}
254 
255 	/*
256 	 * For now allow to change only following values:
257 	 *  plat_prefix, plat_plen, clat_prefix, clat_plen, flags.
258 	 */
259 	flags = 0;
260 	if (uc->plat_plen != cfg->base.plat_plen ||
261 	    !IN6_ARE_ADDR_EQUAL(&uc->plat_prefix, &cfg->base.plat_prefix)) {
262 		if (nat64_check_prefix6(&uc->plat_prefix, uc->plat_plen) != 0) {
263 			IPFW_UH_WUNLOCK(ch);
264 			return (EINVAL);
265 		}
266 		flags |= NAT64_PLATPFX;
267 	}
268 
269 	if (uc->clat_plen != cfg->base.clat_plen ||
270 	    !IN6_ARE_ADDR_EQUAL(&uc->clat_prefix, &cfg->base.clat_prefix)) {
271 		if (nat64_check_prefix6(&uc->clat_prefix, uc->clat_plen) != 0) {
272 			IPFW_UH_WUNLOCK(ch);
273 			return (EINVAL);
274 		}
275 		flags |= NAT64_CLATPFX;
276 	}
277 
278 	if (flags != 0) {
279 		IPFW_WLOCK(ch);
280 		if (flags & NAT64_PLATPFX) {
281 			cfg->base.plat_prefix = uc->plat_prefix;
282 			cfg->base.plat_plen = uc->plat_plen;
283 		}
284 		if (flags & NAT64_CLATPFX) {
285 			cfg->base.clat_prefix = uc->clat_prefix;
286 			cfg->base.clat_plen = uc->clat_plen;
287 		}
288 		IPFW_WUNLOCK(ch);
289 	}
290 
291 	cfg->base.flags &= ~NAT64CLAT_FLAGSMASK;
292 	cfg->base.flags |= uc->flags & NAT64CLAT_FLAGSMASK;
293 
294 	IPFW_UH_WUNLOCK(ch);
295 	return (0);
296 }
297 
298 static void
299 nat64clat_detach_config(struct ip_fw_chain *ch, struct nat64clat_cfg *cfg)
300 {
301 
302 	IPFW_UH_WLOCK_ASSERT(ch);
303 
304 	ipfw_objhash_del(CHAIN_TO_SRV(ch), &cfg->no);
305 	ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), cfg->no.kidx);
306 }
307 
308 /*
309  * Destroys nat64 instance.
310  * Data layout (v0)(current):
311  * Request: [ ipfw_obj_header ]
312  *
313  * Returns 0 on success
314  */
315 static int
316 nat64clat_destroy(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
317     struct sockopt_data *sd)
318 {
319 	ipfw_obj_header *oh;
320 	struct nat64clat_cfg *cfg;
321 
322 	if (sd->valsize != sizeof(*oh))
323 		return (EINVAL);
324 
325 	oh = (ipfw_obj_header *)sd->kbuf;
326 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0)
327 		return (EINVAL);
328 
329 	IPFW_UH_WLOCK(ch);
330 	cfg = nat64clat_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
331 	if (cfg == NULL) {
332 		IPFW_UH_WUNLOCK(ch);
333 		return (ENOENT);
334 	}
335 	if (cfg->no.refcnt > 0) {
336 		IPFW_UH_WUNLOCK(ch);
337 		return (EBUSY);
338 	}
339 
340 	ipfw_reset_eaction_instance(ch, V_nat64clat_eid, cfg->no.kidx);
341 	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
342 	nat64clat_detach_config(ch, cfg);
343 	IPFW_UH_WUNLOCK(ch);
344 
345 	nat64clat_free_config(cfg);
346 	return (0);
347 }
348 
349 /*
350  * Lists all nat64clat instances currently available in kernel.
351  * Data layout (v0)(current):
352  * Request: [ ipfw_obj_lheader ]
353  * Reply: [ ipfw_obj_lheader ipfw_nat64clat_cfg x N ]
354  *
355  * Returns 0 on success
356  */
357 static int
358 nat64clat_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
359     struct sockopt_data *sd)
360 {
361 	ipfw_obj_lheader *olh;
362 	struct nat64clat_dump_arg da;
363 
364 	/* Check minimum header size */
365 	if (sd->valsize < sizeof(ipfw_obj_lheader))
366 		return (EINVAL);
367 
368 	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
369 
370 	IPFW_UH_RLOCK(ch);
371 	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
372 	    IPFW_TLV_NAT64CLAT_NAME);
373 	olh->objsize = sizeof(ipfw_nat64clat_cfg);
374 	olh->size = sizeof(*olh) + olh->count * olh->objsize;
375 
376 	if (sd->valsize < olh->size) {
377 		IPFW_UH_RUNLOCK(ch);
378 		return (ENOMEM);
379 	}
380 	memset(&da, 0, sizeof(da));
381 	da.ch = ch;
382 	da.sd = sd;
383 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
384 	    &da, IPFW_TLV_NAT64CLAT_NAME);
385 	IPFW_UH_RUNLOCK(ch);
386 
387 	return (0);
388 }
389 
390 #define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
391 	(_stats)->_field = NAT64STAT_FETCH(&(_cfg)->base.stats, _field)
392 static void
393 export_stats(struct ip_fw_chain *ch, struct nat64clat_cfg *cfg,
394     struct ipfw_nat64clat_stats *stats)
395 {
396 
397 	__COPY_STAT_FIELD(cfg, stats, opcnt64);
398 	__COPY_STAT_FIELD(cfg, stats, opcnt46);
399 	__COPY_STAT_FIELD(cfg, stats, ofrags);
400 	__COPY_STAT_FIELD(cfg, stats, ifrags);
401 	__COPY_STAT_FIELD(cfg, stats, oerrors);
402 	__COPY_STAT_FIELD(cfg, stats, noroute4);
403 	__COPY_STAT_FIELD(cfg, stats, noroute6);
404 	__COPY_STAT_FIELD(cfg, stats, noproto);
405 	__COPY_STAT_FIELD(cfg, stats, nomem);
406 	__COPY_STAT_FIELD(cfg, stats, dropped);
407 }
408 
409 /*
410  * Get nat64clat statistics.
411  * Data layout (v0)(current):
412  * Request: [ ipfw_obj_header ]
413  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
414  *
415  * Returns 0 on success
416  */
417 static int
418 nat64clat_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
419     struct sockopt_data *sd)
420 {
421 	struct ipfw_nat64clat_stats stats;
422 	struct nat64clat_cfg *cfg;
423 	ipfw_obj_header *oh;
424 	ipfw_obj_ctlv *ctlv;
425 	size_t sz;
426 
427 	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
428 	if (sd->valsize % sizeof(uint64_t))
429 		return (EINVAL);
430 	if (sd->valsize < sz)
431 		return (ENOMEM);
432 	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
433 	if (oh == NULL)
434 		return (EINVAL);
435 	memset(&stats, 0, sizeof(stats));
436 
437 	IPFW_UH_RLOCK(ch);
438 	cfg = nat64clat_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
439 	if (cfg == NULL) {
440 		IPFW_UH_RUNLOCK(ch);
441 		return (ENOENT);
442 	}
443 	export_stats(ch, cfg, &stats);
444 	IPFW_UH_RUNLOCK(ch);
445 
446 	ctlv = (ipfw_obj_ctlv *)(oh + 1);
447 	memset(ctlv, 0, sizeof(*ctlv));
448 	ctlv->head.type = IPFW_TLV_COUNTERS;
449 	ctlv->head.length = sz - sizeof(ipfw_obj_header);
450 	ctlv->count = sizeof(stats) / sizeof(uint64_t);
451 	ctlv->objsize = sizeof(uint64_t);
452 	ctlv->version = IPFW_NAT64_VERSION;
453 	memcpy(ctlv + 1, &stats, sizeof(stats));
454 	return (0);
455 }
456 
457 /*
458  * Reset nat64clat statistics.
459  * Data layout (v0)(current):
460  * Request: [ ipfw_obj_header ]
461  *
462  * Returns 0 on success
463  */
464 static int
465 nat64clat_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
466     struct sockopt_data *sd)
467 {
468 	struct nat64clat_cfg *cfg;
469 	ipfw_obj_header *oh;
470 
471 	if (sd->valsize != sizeof(*oh))
472 		return (EINVAL);
473 	oh = (ipfw_obj_header *)sd->kbuf;
474 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
475 	    oh->ntlv.set >= IPFW_MAX_SETS)
476 		return (EINVAL);
477 
478 	IPFW_UH_WLOCK(ch);
479 	cfg = nat64clat_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
480 	if (cfg == NULL) {
481 		IPFW_UH_WUNLOCK(ch);
482 		return (ENOENT);
483 	}
484 	COUNTER_ARRAY_ZERO(cfg->base.stats.cnt, NAT64STATS);
485 	IPFW_UH_WUNLOCK(ch);
486 	return (0);
487 }
488 
489 static struct ipfw_sopt_handler	scodes[] = {
490 	{ IP_FW_NAT64CLAT_CREATE, 0,	HDIR_SET,	nat64clat_create },
491 	{ IP_FW_NAT64CLAT_DESTROY,0,	HDIR_SET,	nat64clat_destroy },
492 	{ IP_FW_NAT64CLAT_CONFIG, 0,	HDIR_BOTH,	nat64clat_config },
493 	{ IP_FW_NAT64CLAT_LIST,   0,	HDIR_GET,	nat64clat_list },
494 	{ IP_FW_NAT64CLAT_STATS,  0,	HDIR_GET,	nat64clat_stats },
495 	{ IP_FW_NAT64CLAT_RESET_STATS,0,	HDIR_SET,	nat64clat_reset_stats },
496 };
497 
498 static int
499 nat64clat_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
500 {
501 	ipfw_insn *icmd;
502 
503 	icmd = cmd - 1;
504 	if (icmd->opcode != O_EXTERNAL_ACTION ||
505 	    icmd->arg1 != V_nat64clat_eid)
506 		return (1);
507 
508 	*puidx = cmd->arg1;
509 	*ptype = 0;
510 	return (0);
511 }
512 
513 static void
514 nat64clat_update_arg1(ipfw_insn *cmd, uint16_t idx)
515 {
516 
517 	cmd->arg1 = idx;
518 }
519 
520 static int
521 nat64clat_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
522     struct named_object **pno)
523 {
524 	int err;
525 
526 	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
527 	    IPFW_TLV_NAT64CLAT_NAME, pno);
528 	return (err);
529 }
530 
531 static struct named_object *
532 nat64clat_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
533 {
534 	struct namedobj_instance *ni;
535 	struct named_object *no;
536 
537 	IPFW_UH_WLOCK_ASSERT(ch);
538 	ni = CHAIN_TO_SRV(ch);
539 	no = ipfw_objhash_lookup_kidx(ni, idx);
540 	KASSERT(no != NULL, ("NAT with index %d not found", idx));
541 
542 	return (no);
543 }
544 
545 static int
546 nat64clat_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
547     enum ipfw_sets_cmd cmd)
548 {
549 
550 	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NAT64CLAT_NAME,
551 	    set, new_set, cmd));
552 }
553 
554 static struct opcode_obj_rewrite opcodes[] = {
555 	{
556 		.opcode = O_EXTERNAL_INSTANCE,
557 		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
558 		.classifier = nat64clat_classify,
559 		.update = nat64clat_update_arg1,
560 		.find_byname = nat64clat_findbyname,
561 		.find_bykidx = nat64clat_findbykidx,
562 		.manage_sets = nat64clat_manage_sets,
563 	},
564 };
565 
566 static int
567 destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
568     void *arg)
569 {
570 	struct nat64clat_cfg *cfg;
571 	struct ip_fw_chain *ch;
572 
573 	ch = (struct ip_fw_chain *)arg;
574 	cfg = (struct nat64clat_cfg *)SRV_OBJECT(ch, no->kidx);
575 	SRV_OBJECT(ch, no->kidx) = NULL;
576 	nat64clat_detach_config(ch, cfg);
577 	nat64clat_free_config(cfg);
578 	return (0);
579 }
580 
581 int
582 nat64clat_init(struct ip_fw_chain *ch, int first)
583 {
584 
585 	V_nat64clat_eid = ipfw_add_eaction(ch, ipfw_nat64clat, "nat64clat");
586 	if (V_nat64clat_eid == 0)
587 		return (ENXIO);
588 	IPFW_ADD_SOPT_HANDLER(first, scodes);
589 	IPFW_ADD_OBJ_REWRITER(first, opcodes);
590 	return (0);
591 }
592 
593 void
594 nat64clat_uninit(struct ip_fw_chain *ch, int last)
595 {
596 
597 	IPFW_DEL_OBJ_REWRITER(last, opcodes);
598 	IPFW_DEL_SOPT_HANDLER(last, scodes);
599 	ipfw_del_eaction(ch, V_nat64clat_eid);
600 	/*
601 	 * Since we already have deregistered external action,
602 	 * our named objects become unaccessible via rules, because
603 	 * all rules were truncated by ipfw_del_eaction().
604 	 * So, we can unlink and destroy our named objects without holding
605 	 * IPFW_WLOCK().
606 	 */
607 	IPFW_UH_WLOCK(ch);
608 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
609 	    IPFW_TLV_NAT64CLAT_NAME);
610 	V_nat64clat_eid = 0;
611 	IPFW_UH_WUNLOCK(ch);
612 }
613