1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2015-2019 Yandex LLC
5  * Copyright (c) 2015 Alexander V. Chernikov <melifaro@FreeBSD.org>
6  * Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org>
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 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/counter.h>
34 #include <sys/errno.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/module.h>
40 #include <sys/rmlock.h>
41 #include <sys/rwlock.h>
42 #include <sys/socket.h>
43 #include <sys/sockopt.h>
44 #include <sys/queue.h>
45 #include <sys/syslog.h>
46 #include <sys/sysctl.h>
47 
48 #include <net/if.h>
49 #include <net/if_var.h>
50 #include <net/pfil.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 "nat64stl.h"
64 
65 VNET_DEFINE(uint16_t, nat64stl_eid) = 0;
66 
67 static struct nat64stl_cfg *nat64stl_alloc_config(const char *name,
68     uint8_t set);
69 static void nat64stl_free_config(struct nat64stl_cfg *cfg);
70 static struct nat64stl_cfg *nat64stl_find(struct namedobj_instance *ni,
71     const char *name, uint8_t set);
72 
73 static struct nat64stl_cfg *
74 nat64stl_alloc_config(const char *name, uint8_t set)
75 {
76 	struct nat64stl_cfg *cfg;
77 
78 	cfg = malloc(sizeof(struct nat64stl_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_NAT64STL_NAME;
82 	cfg->no.set = set;
83 	strlcpy(cfg->name, name, sizeof(cfg->name));
84 	return (cfg);
85 }
86 
87 static void
88 nat64stl_free_config(struct nat64stl_cfg *cfg)
89 {
90 
91 	COUNTER_ARRAY_FREE(cfg->base.stats.cnt, NAT64STATS);
92 	free(cfg, M_IPFW);
93 }
94 
95 static void
96 nat64stl_export_config(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
97     ipfw_nat64stl_cfg *uc)
98 {
99 	struct named_object *no;
100 
101 	uc->prefix6 = cfg->base.plat_prefix;
102 	uc->plen6 = cfg->base.plat_plen;
103 	uc->flags = cfg->base.flags & NAT64STL_FLAGSMASK;
104 	uc->set = cfg->no.set;
105 	strlcpy(uc->name, cfg->no.name, sizeof(uc->name));
106 
107 	no = ipfw_objhash_lookup_table_kidx(ch, cfg->map64);
108 	ipfw_export_obj_ntlv(no, &uc->ntlv6);
109 	no = ipfw_objhash_lookup_table_kidx(ch, cfg->map46);
110 	ipfw_export_obj_ntlv(no, &uc->ntlv4);
111 }
112 
113 struct nat64stl_dump_arg {
114 	struct ip_fw_chain *ch;
115 	struct sockopt_data *sd;
116 };
117 
118 static int
119 export_config_cb(struct namedobj_instance *ni, struct named_object *no,
120     void *arg)
121 {
122 	struct nat64stl_dump_arg *da = (struct nat64stl_dump_arg *)arg;
123 	ipfw_nat64stl_cfg *uc;
124 
125 	uc = (ipfw_nat64stl_cfg *)ipfw_get_sopt_space(da->sd, sizeof(*uc));
126 	nat64stl_export_config(da->ch, (struct nat64stl_cfg *)no, uc);
127 	return (0);
128 }
129 
130 static struct nat64stl_cfg *
131 nat64stl_find(struct namedobj_instance *ni, const char *name, uint8_t set)
132 {
133 	struct nat64stl_cfg *cfg;
134 
135 	cfg = (struct nat64stl_cfg *)ipfw_objhash_lookup_name_type(ni, set,
136 	    IPFW_TLV_NAT64STL_NAME, name);
137 
138 	return (cfg);
139 }
140 
141 static int
142 nat64stl_create_internal(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
143     ipfw_nat64stl_cfg *i)
144 {
145 
146 	IPFW_UH_WLOCK_ASSERT(ch);
147 
148 	if (ipfw_objhash_alloc_idx(CHAIN_TO_SRV(ch), &cfg->no.kidx) != 0)
149 		return (ENOSPC);
150 	cfg->base.flags |= NAT64STL_KIDX;
151 
152 	if (ipfw_ref_table(ch, &i->ntlv4, &cfg->map46) != 0)
153 		return (EINVAL);
154 	cfg->base.flags |= NAT64STL_46T;
155 
156 	if (ipfw_ref_table(ch, &i->ntlv6, &cfg->map64) != 0)
157 		return (EINVAL);
158 	cfg->base.flags |= NAT64STL_64T;
159 
160 	ipfw_objhash_add(CHAIN_TO_SRV(ch), &cfg->no);
161 
162 	return (0);
163 }
164 
165 /*
166  * Creates new nat64 instance.
167  * Data layout (v0)(current):
168  * Request: [ ipfw_obj_lheader ipfw_nat64stl_cfg ]
169  *
170  * Returns 0 on success
171  */
172 static int
173 nat64stl_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
174     struct sockopt_data *sd)
175 {
176 	ipfw_obj_lheader *olh;
177 	ipfw_nat64stl_cfg *uc;
178 	struct namedobj_instance *ni;
179 	struct nat64stl_cfg *cfg;
180 	int error;
181 
182 	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
183 		return (EINVAL);
184 
185 	olh = (ipfw_obj_lheader *)sd->kbuf;
186 	uc = (ipfw_nat64stl_cfg *)(olh + 1);
187 
188 	if (ipfw_check_object_name_generic(uc->name) != 0)
189 		return (EINVAL);
190 	if (uc->set >= IPFW_MAX_SETS ||
191 	    nat64_check_prefix6(&uc->prefix6, uc->plen6) != 0)
192 		return (EINVAL);
193 
194 	/* XXX: check types of tables */
195 
196 	ni = CHAIN_TO_SRV(ch);
197 	error = 0;
198 
199 	IPFW_UH_RLOCK(ch);
200 	if (nat64stl_find(ni, uc->name, uc->set) != NULL) {
201 		IPFW_UH_RUNLOCK(ch);
202 		return (EEXIST);
203 	}
204 	IPFW_UH_RUNLOCK(ch);
205 
206 	cfg = nat64stl_alloc_config(uc->name, uc->set);
207 	cfg->base.plat_prefix = uc->prefix6;
208 	cfg->base.plat_plen = uc->plen6;
209 	cfg->base.flags = (uc->flags & NAT64STL_FLAGSMASK) | NAT64_PLATPFX;
210 	if (IN6_IS_ADDR_WKPFX(&cfg->base.plat_prefix))
211 		cfg->base.flags |= NAT64_WKPFX;
212 
213 	IPFW_UH_WLOCK(ch);
214 
215 	if (nat64stl_find(ni, uc->name, uc->set) != NULL) {
216 		IPFW_UH_WUNLOCK(ch);
217 		nat64stl_free_config(cfg);
218 		return (EEXIST);
219 	}
220 	error = nat64stl_create_internal(ch, cfg, uc);
221 	if (error == 0) {
222 		/* Okay, let's link data */
223 		SRV_OBJECT(ch, cfg->no.kidx) = cfg;
224 		IPFW_UH_WUNLOCK(ch);
225 		return (0);
226 	}
227 
228 	if (cfg->base.flags & NAT64STL_KIDX)
229 		ipfw_objhash_free_idx(ni, cfg->no.kidx);
230 	if (cfg->base.flags & NAT64STL_46T)
231 		ipfw_unref_table(ch, cfg->map46);
232 	if (cfg->base.flags & NAT64STL_64T)
233 		ipfw_unref_table(ch, cfg->map64);
234 
235 	IPFW_UH_WUNLOCK(ch);
236 	nat64stl_free_config(cfg);
237 	return (error);
238 }
239 
240 /*
241  * Change existing nat64stl instance configuration.
242  * Data layout (v0)(current):
243  * Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
244  * Reply: [ ipfw_obj_header ipfw_nat64stl_cfg ]
245  *
246  * Returns 0 on success
247  */
248 static int
249 nat64stl_config(struct ip_fw_chain *ch, ip_fw3_opheader *op,
250     struct sockopt_data *sd)
251 {
252 	ipfw_obj_header *oh;
253 	ipfw_nat64stl_cfg *uc;
254 	struct nat64stl_cfg *cfg;
255 	struct namedobj_instance *ni;
256 
257 	if (sd->valsize != sizeof(*oh) + sizeof(*uc))
258 		return (EINVAL);
259 
260 	oh = (ipfw_obj_header *)ipfw_get_sopt_space(sd,
261 	    sizeof(*oh) + sizeof(*uc));
262 	uc = (ipfw_nat64stl_cfg *)(oh + 1);
263 
264 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
265 	    oh->ntlv.set >= IPFW_MAX_SETS)
266 		return (EINVAL);
267 
268 	ni = CHAIN_TO_SRV(ch);
269 	if (sd->sopt->sopt_dir == SOPT_GET) {
270 		IPFW_UH_RLOCK(ch);
271 		cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
272 		if (cfg == NULL) {
273 			IPFW_UH_RUNLOCK(ch);
274 			return (EEXIST);
275 		}
276 		nat64stl_export_config(ch, cfg, uc);
277 		IPFW_UH_RUNLOCK(ch);
278 		return (0);
279 	}
280 
281 	IPFW_UH_WLOCK(ch);
282 	cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
283 	if (cfg == NULL) {
284 		IPFW_UH_WUNLOCK(ch);
285 		return (EEXIST);
286 	}
287 
288 	/*
289 	 * For now allow to change only following values:
290 	 *  flags.
291 	 */
292 	cfg->base.flags &= ~NAT64STL_FLAGSMASK;
293 	cfg->base.flags |= uc->flags & NAT64STL_FLAGSMASK;
294 
295 	IPFW_UH_WUNLOCK(ch);
296 	return (0);
297 }
298 
299 static void
300 nat64stl_detach_config(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg)
301 {
302 
303 	IPFW_UH_WLOCK_ASSERT(ch);
304 
305 	ipfw_objhash_del(CHAIN_TO_SRV(ch), &cfg->no);
306 	ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), cfg->no.kidx);
307 	ipfw_unref_table(ch, cfg->map46);
308 	ipfw_unref_table(ch, cfg->map64);
309 }
310 
311 /*
312  * Destroys nat64 instance.
313  * Data layout (v0)(current):
314  * Request: [ ipfw_obj_header ]
315  *
316  * Returns 0 on success
317  */
318 static int
319 nat64stl_destroy(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
320     struct sockopt_data *sd)
321 {
322 	ipfw_obj_header *oh;
323 	struct nat64stl_cfg *cfg;
324 
325 	if (sd->valsize != sizeof(*oh))
326 		return (EINVAL);
327 
328 	oh = (ipfw_obj_header *)sd->kbuf;
329 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0)
330 		return (EINVAL);
331 
332 	IPFW_UH_WLOCK(ch);
333 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
334 	if (cfg == NULL) {
335 		IPFW_UH_WUNLOCK(ch);
336 		return (ESRCH);
337 	}
338 	if (cfg->no.refcnt > 0) {
339 		IPFW_UH_WUNLOCK(ch);
340 		return (EBUSY);
341 	}
342 
343 	ipfw_reset_eaction_instance(ch, V_nat64stl_eid, cfg->no.kidx);
344 	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
345 	nat64stl_detach_config(ch, cfg);
346 	IPFW_UH_WUNLOCK(ch);
347 
348 	nat64stl_free_config(cfg);
349 	return (0);
350 }
351 
352 /*
353  * Lists all nat64stl instances currently available in kernel.
354  * Data layout (v0)(current):
355  * Request: [ ipfw_obj_lheader ]
356  * Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
357  *
358  * Returns 0 on success
359  */
360 static int
361 nat64stl_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
362     struct sockopt_data *sd)
363 {
364 	ipfw_obj_lheader *olh;
365 	struct nat64stl_dump_arg da;
366 
367 	/* Check minimum header size */
368 	if (sd->valsize < sizeof(ipfw_obj_lheader))
369 		return (EINVAL);
370 
371 	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
372 
373 	IPFW_UH_RLOCK(ch);
374 	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
375 	    IPFW_TLV_NAT64STL_NAME);
376 	olh->objsize = sizeof(ipfw_nat64stl_cfg);
377 	olh->size = sizeof(*olh) + olh->count * olh->objsize;
378 
379 	if (sd->valsize < olh->size) {
380 		IPFW_UH_RUNLOCK(ch);
381 		return (ENOMEM);
382 	}
383 	memset(&da, 0, sizeof(da));
384 	da.ch = ch;
385 	da.sd = sd;
386 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
387 	    &da, IPFW_TLV_NAT64STL_NAME);
388 	IPFW_UH_RUNLOCK(ch);
389 
390 	return (0);
391 }
392 
393 #define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
394 	(_stats)->_field = NAT64STAT_FETCH(&(_cfg)->base.stats, _field)
395 static void
396 export_stats(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
397     struct ipfw_nat64stl_stats *stats)
398 {
399 
400 	__COPY_STAT_FIELD(cfg, stats, opcnt64);
401 	__COPY_STAT_FIELD(cfg, stats, opcnt46);
402 	__COPY_STAT_FIELD(cfg, stats, ofrags);
403 	__COPY_STAT_FIELD(cfg, stats, ifrags);
404 	__COPY_STAT_FIELD(cfg, stats, oerrors);
405 	__COPY_STAT_FIELD(cfg, stats, noroute4);
406 	__COPY_STAT_FIELD(cfg, stats, noroute6);
407 	__COPY_STAT_FIELD(cfg, stats, noproto);
408 	__COPY_STAT_FIELD(cfg, stats, nomem);
409 	__COPY_STAT_FIELD(cfg, stats, dropped);
410 }
411 
412 /*
413  * Get nat64stl statistics.
414  * Data layout (v0)(current):
415  * Request: [ ipfw_obj_header ]
416  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
417  *
418  * Returns 0 on success
419  */
420 static int
421 nat64stl_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
422     struct sockopt_data *sd)
423 {
424 	struct ipfw_nat64stl_stats stats;
425 	struct nat64stl_cfg *cfg;
426 	ipfw_obj_header *oh;
427 	ipfw_obj_ctlv *ctlv;
428 	size_t sz;
429 
430 	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
431 	if (sd->valsize % sizeof(uint64_t))
432 		return (EINVAL);
433 	if (sd->valsize < sz)
434 		return (ENOMEM);
435 	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
436 	if (oh == NULL)
437 		return (EINVAL);
438 	memset(&stats, 0, sizeof(stats));
439 
440 	IPFW_UH_RLOCK(ch);
441 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
442 	if (cfg == NULL) {
443 		IPFW_UH_RUNLOCK(ch);
444 		return (ESRCH);
445 	}
446 	export_stats(ch, cfg, &stats);
447 	IPFW_UH_RUNLOCK(ch);
448 
449 	ctlv = (ipfw_obj_ctlv *)(oh + 1);
450 	memset(ctlv, 0, sizeof(*ctlv));
451 	ctlv->head.type = IPFW_TLV_COUNTERS;
452 	ctlv->head.length = sz - sizeof(ipfw_obj_header);
453 	ctlv->count = sizeof(stats) / sizeof(uint64_t);
454 	ctlv->objsize = sizeof(uint64_t);
455 	ctlv->version = IPFW_NAT64_VERSION;
456 	memcpy(ctlv + 1, &stats, sizeof(stats));
457 	return (0);
458 }
459 
460 /*
461  * Reset nat64stl statistics.
462  * Data layout (v0)(current):
463  * Request: [ ipfw_obj_header ]
464  *
465  * Returns 0 on success
466  */
467 static int
468 nat64stl_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
469     struct sockopt_data *sd)
470 {
471 	struct nat64stl_cfg *cfg;
472 	ipfw_obj_header *oh;
473 
474 	if (sd->valsize != sizeof(*oh))
475 		return (EINVAL);
476 	oh = (ipfw_obj_header *)sd->kbuf;
477 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
478 	    oh->ntlv.set >= IPFW_MAX_SETS)
479 		return (EINVAL);
480 
481 	IPFW_UH_WLOCK(ch);
482 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
483 	if (cfg == NULL) {
484 		IPFW_UH_WUNLOCK(ch);
485 		return (ESRCH);
486 	}
487 	COUNTER_ARRAY_ZERO(cfg->base.stats.cnt, NAT64STATS);
488 	IPFW_UH_WUNLOCK(ch);
489 	return (0);
490 }
491 
492 static struct ipfw_sopt_handler	scodes[] = {
493 	{ IP_FW_NAT64STL_CREATE, 0,	HDIR_SET,	nat64stl_create },
494 	{ IP_FW_NAT64STL_DESTROY,0,	HDIR_SET,	nat64stl_destroy },
495 	{ IP_FW_NAT64STL_CONFIG, 0,	HDIR_BOTH,	nat64stl_config },
496 	{ IP_FW_NAT64STL_LIST,   0,	HDIR_GET,	nat64stl_list },
497 	{ IP_FW_NAT64STL_STATS,  0,	HDIR_GET,	nat64stl_stats },
498 	{ IP_FW_NAT64STL_RESET_STATS,0,	HDIR_SET,	nat64stl_reset_stats },
499 };
500 
501 static int
502 nat64stl_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
503 {
504 	ipfw_insn *icmd;
505 
506 	icmd = cmd - 1;
507 	if (icmd->opcode != O_EXTERNAL_ACTION ||
508 	    icmd->arg1 != V_nat64stl_eid)
509 		return (1);
510 
511 	*puidx = cmd->arg1;
512 	*ptype = 0;
513 	return (0);
514 }
515 
516 static void
517 nat64stl_update_arg1(ipfw_insn *cmd, uint16_t idx)
518 {
519 
520 	cmd->arg1 = idx;
521 }
522 
523 static int
524 nat64stl_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
525     struct named_object **pno)
526 {
527 	int err;
528 
529 	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
530 	    IPFW_TLV_NAT64STL_NAME, pno);
531 	return (err);
532 }
533 
534 static struct named_object *
535 nat64stl_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
536 {
537 	struct namedobj_instance *ni;
538 	struct named_object *no;
539 
540 	IPFW_UH_WLOCK_ASSERT(ch);
541 	ni = CHAIN_TO_SRV(ch);
542 	no = ipfw_objhash_lookup_kidx(ni, idx);
543 	KASSERT(no != NULL, ("NAT with index %d not found", idx));
544 
545 	return (no);
546 }
547 
548 static int
549 nat64stl_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
550     enum ipfw_sets_cmd cmd)
551 {
552 
553 	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NAT64STL_NAME,
554 	    set, new_set, cmd));
555 }
556 
557 static struct opcode_obj_rewrite opcodes[] = {
558 	{
559 		.opcode = O_EXTERNAL_INSTANCE,
560 		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
561 		.classifier = nat64stl_classify,
562 		.update = nat64stl_update_arg1,
563 		.find_byname = nat64stl_findbyname,
564 		.find_bykidx = nat64stl_findbykidx,
565 		.manage_sets = nat64stl_manage_sets,
566 	},
567 };
568 
569 static int
570 destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
571     void *arg)
572 {
573 	struct nat64stl_cfg *cfg;
574 	struct ip_fw_chain *ch;
575 
576 	ch = (struct ip_fw_chain *)arg;
577 	cfg = (struct nat64stl_cfg *)SRV_OBJECT(ch, no->kidx);
578 	SRV_OBJECT(ch, no->kidx) = NULL;
579 	nat64stl_detach_config(ch, cfg);
580 	nat64stl_free_config(cfg);
581 	return (0);
582 }
583 
584 int
585 nat64stl_init(struct ip_fw_chain *ch, int first)
586 {
587 
588 	V_nat64stl_eid = ipfw_add_eaction(ch, ipfw_nat64stl, "nat64stl");
589 	if (V_nat64stl_eid == 0)
590 		return (ENXIO);
591 	IPFW_ADD_SOPT_HANDLER(first, scodes);
592 	IPFW_ADD_OBJ_REWRITER(first, opcodes);
593 	return (0);
594 }
595 
596 void
597 nat64stl_uninit(struct ip_fw_chain *ch, int last)
598 {
599 
600 	IPFW_DEL_OBJ_REWRITER(last, opcodes);
601 	IPFW_DEL_SOPT_HANDLER(last, scodes);
602 	ipfw_del_eaction(ch, V_nat64stl_eid);
603 	/*
604 	 * Since we already have deregistered external action,
605 	 * our named objects become unaccessible via rules, because
606 	 * all rules were truncated by ipfw_del_eaction().
607 	 * So, we can unlink and destroy our named objects without holding
608 	 * IPFW_WLOCK().
609 	 */
610 	IPFW_UH_WLOCK(ch);
611 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
612 	    IPFW_TLV_NAT64STL_NAME);
613 	V_nat64stl_eid = 0;
614 	IPFW_UH_WUNLOCK(ch);
615 }
616