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
65VNET_DEFINE(uint16_t, nat64clat_eid) = 0;
66
67static struct nat64clat_cfg *nat64clat_alloc_config(const char *name,
68    uint8_t set);
69static void nat64clat_free_config(struct nat64clat_cfg *cfg);
70static struct nat64clat_cfg *nat64clat_find(struct namedobj_instance *ni,
71    const char *name, uint8_t set);
72
73static struct nat64clat_cfg *
74nat64clat_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
87static void
88nat64clat_free_config(struct nat64clat_cfg *cfg)
89{
90
91	COUNTER_ARRAY_FREE(cfg->base.stats.cnt, NAT64STATS);
92	free(cfg, M_IPFW);
93}
94
95static void
96nat64clat_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
108struct nat64clat_dump_arg {
109	struct ip_fw_chain *ch;
110	struct sockopt_data *sd;
111};
112
113static int
114export_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
125static struct nat64clat_cfg *
126nat64clat_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 */
143static int
144nat64clat_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 */
214static int
215nat64clat_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
298static void
299nat64clat_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 */
315static int
316nat64clat_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 */
357static int
358nat64clat_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)
392static void
393export_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 */
417static int
418nat64clat_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 */
464static int
465nat64clat_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
489static 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
498static int
499nat64clat_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
513static void
514nat64clat_update_arg1(ipfw_insn *cmd, uint16_t idx)
515{
516
517	cmd->arg1 = idx;
518}
519
520static int
521nat64clat_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
531static struct named_object *
532nat64clat_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
545static int
546nat64clat_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
554static 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
566static int
567destroy_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
581int
582nat64clat_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
593void
594nat64clat_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