xref: /freebsd/sys/netpfil/ipfw/nat64/nat64stl_control.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc)
1 /*-
2  * Copyright (c) 2015-2016 Yandex LLC
3  * Copyright (c) 2015-2016 Andrey V. Elsukov <ae@FreeBSD.org>
4  * Copyright (c) 2015 Alexander V. Chernikov <melifaro@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/counter.h>
35 #include <sys/errno.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/module.h>
41 #include <sys/rmlock.h>
42 #include <sys/rwlock.h>
43 #include <sys/socket.h>
44 #include <sys/sockopt.h>
45 #include <sys/queue.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/pfil.h>
52 #include <net/route.h>
53 #include <net/vnet.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/ip_var.h>
57 #include <netinet/ip_fw.h>
58 #include <netinet6/in6_var.h>
59 #include <netinet6/ip6_var.h>
60 
61 #include <netpfil/ipfw/ip_fw_private.h>
62 #include <netpfil/ipfw/nat64/ip_fw_nat64.h>
63 #include <netpfil/ipfw/nat64/nat64stl.h>
64 #include <netinet6/ip_fw_nat64.h>
65 
66 VNET_DEFINE(uint16_t, nat64stl_eid) = 0;
67 
68 static struct nat64stl_cfg *nat64stl_alloc_config(const char *name, 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->stats.stats, 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->stats.stats, 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->prefix6;
102 	uc->plen6 = cfg->plen6;
103 	uc->flags = cfg->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 
142 static int
143 nat64stl_create_internal(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
144     ipfw_nat64stl_cfg *i)
145 {
146 
147 	IPFW_UH_WLOCK_ASSERT(ch);
148 
149 	if (ipfw_objhash_alloc_idx(CHAIN_TO_SRV(ch), &cfg->no.kidx) != 0)
150 		return (ENOSPC);
151 	cfg->flags |= NAT64STL_KIDX;
152 
153 	if (ipfw_ref_table(ch, &i->ntlv4, &cfg->map46) != 0)
154 		return (EINVAL);
155 	cfg->flags |= NAT64STL_46T;
156 
157 	if (ipfw_ref_table(ch, &i->ntlv6, &cfg->map64) != 0)
158 		return (EINVAL);
159 	cfg->flags |= NAT64STL_64T;
160 
161 	ipfw_objhash_add(CHAIN_TO_SRV(ch), &cfg->no);
162 
163 	return (0);
164 }
165 
166 /*
167  * Creates new nat64 instance.
168  * Data layout (v0)(current):
169  * Request: [ ipfw_obj_lheader ipfw_nat64stl_cfg ]
170  *
171  * Returns 0 on success
172  */
173 static int
174 nat64stl_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
175     struct sockopt_data *sd)
176 {
177 	ipfw_obj_lheader *olh;
178 	ipfw_nat64stl_cfg *uc;
179 	struct namedobj_instance *ni;
180 	struct nat64stl_cfg *cfg;
181 	int error;
182 
183 	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
184 		return (EINVAL);
185 
186 	olh = (ipfw_obj_lheader *)sd->kbuf;
187 	uc = (ipfw_nat64stl_cfg *)(olh + 1);
188 
189 	if (ipfw_check_object_name_generic(uc->name) != 0)
190 		return (EINVAL);
191 	if (!IN6_IS_ADDR_WKPFX(&uc->prefix6))
192 		return (EINVAL);
193 	if (uc->plen6 != 96 || uc->set >= IPFW_MAX_SETS)
194 		return (EINVAL);
195 
196 	/* XXX: check types of tables */
197 
198 	ni = CHAIN_TO_SRV(ch);
199 	error = 0;
200 
201 	IPFW_UH_RLOCK(ch);
202 	if (nat64stl_find(ni, uc->name, uc->set) != NULL) {
203 		IPFW_UH_RUNLOCK(ch);
204 		return (EEXIST);
205 	}
206 	IPFW_UH_RUNLOCK(ch);
207 
208 	cfg = nat64stl_alloc_config(uc->name, uc->set);
209 	cfg->prefix6 = uc->prefix6;
210 	cfg->plen6 = uc->plen6;
211 	cfg->flags = uc->flags & NAT64STL_FLAGSMASK;
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 		IPFW_WLOCK(ch);
224 		SRV_OBJECT(ch, cfg->no.kidx) = cfg;
225 		IPFW_WUNLOCK(ch);
226 
227 		IPFW_UH_WUNLOCK(ch);
228 		return (0);
229 	}
230 
231 	if (cfg->flags & NAT64STL_KIDX)
232 		ipfw_objhash_free_idx(ni, cfg->no.kidx);
233 	if (cfg->flags & NAT64STL_46T)
234 		ipfw_unref_table(ch, cfg->map46);
235 	if (cfg->flags & NAT64STL_64T)
236 		ipfw_unref_table(ch, cfg->map64);
237 
238 	IPFW_UH_WUNLOCK(ch);
239 	nat64stl_free_config(cfg);
240 	return (error);
241 }
242 
243 /*
244  * Change existing nat64stl instance configuration.
245  * Data layout (v0)(current):
246  * Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
247  * Reply: [ ipfw_obj_header ipfw_nat64stl_cfg ]
248  *
249  * Returns 0 on success
250  */
251 static int
252 nat64stl_config(struct ip_fw_chain *ch, ip_fw3_opheader *op,
253     struct sockopt_data *sd)
254 {
255 	ipfw_obj_header *oh;
256 	ipfw_nat64stl_cfg *uc;
257 	struct nat64stl_cfg *cfg;
258 	struct namedobj_instance *ni;
259 
260 	if (sd->valsize != sizeof(*oh) + sizeof(*uc))
261 		return (EINVAL);
262 
263 	oh = (ipfw_obj_header *)ipfw_get_sopt_space(sd,
264 	    sizeof(*oh) + sizeof(*uc));
265 	uc = (ipfw_nat64stl_cfg *)(oh + 1);
266 
267 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
268 	    oh->ntlv.set >= IPFW_MAX_SETS)
269 		return (EINVAL);
270 
271 	ni = CHAIN_TO_SRV(ch);
272 	if (sd->sopt->sopt_dir == SOPT_GET) {
273 		IPFW_UH_RLOCK(ch);
274 		cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
275 		if (cfg == NULL) {
276 			IPFW_UH_RUNLOCK(ch);
277 			return (EEXIST);
278 		}
279 		nat64stl_export_config(ch, cfg, uc);
280 		IPFW_UH_RUNLOCK(ch);
281 		return (0);
282 	}
283 
284 	IPFW_UH_WLOCK(ch);
285 	cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
286 	if (cfg == NULL) {
287 		IPFW_UH_WUNLOCK(ch);
288 		return (EEXIST);
289 	}
290 
291 	/*
292 	 * For now allow to change only following values:
293 	 *  flags.
294 	 */
295 
296 	cfg->flags = uc->flags & NAT64STL_FLAGSMASK;
297 	IPFW_UH_WUNLOCK(ch);
298 	return (0);
299 }
300 
301 static void
302 nat64stl_detach_config(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg)
303 {
304 
305 	IPFW_UH_WLOCK_ASSERT(ch);
306 
307 	ipfw_objhash_del(CHAIN_TO_SRV(ch), &cfg->no);
308 	ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), cfg->no.kidx);
309 	ipfw_unref_table(ch, cfg->map46);
310 	ipfw_unref_table(ch, cfg->map64);
311 }
312 
313 /*
314  * Destroys nat64 instance.
315  * Data layout (v0)(current):
316  * Request: [ ipfw_obj_header ]
317  *
318  * Returns 0 on success
319  */
320 static int
321 nat64stl_destroy(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
322     struct sockopt_data *sd)
323 {
324 	ipfw_obj_header *oh;
325 	struct nat64stl_cfg *cfg;
326 
327 	if (sd->valsize != sizeof(*oh))
328 		return (EINVAL);
329 
330 	oh = (ipfw_obj_header *)sd->kbuf;
331 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0)
332 		return (EINVAL);
333 
334 	IPFW_UH_WLOCK(ch);
335 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
336 	if (cfg == NULL) {
337 		IPFW_UH_WUNLOCK(ch);
338 		return (ESRCH);
339 	}
340 	if (cfg->no.refcnt > 0) {
341 		IPFW_UH_WUNLOCK(ch);
342 		return (EBUSY);
343 	}
344 
345 	IPFW_WLOCK(ch);
346 	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
347 	IPFW_WUNLOCK(ch);
348 
349 	nat64stl_detach_config(ch, cfg);
350 	IPFW_UH_WUNLOCK(ch);
351 
352 	nat64stl_free_config(cfg);
353 	return (0);
354 }
355 
356 /*
357  * Lists all nat64stl instances currently available in kernel.
358  * Data layout (v0)(current):
359  * Request: [ ipfw_obj_lheader ]
360  * Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
361  *
362  * Returns 0 on success
363  */
364 static int
365 nat64stl_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
366     struct sockopt_data *sd)
367 {
368 	ipfw_obj_lheader *olh;
369 	struct nat64stl_dump_arg da;
370 
371 	/* Check minimum header size */
372 	if (sd->valsize < sizeof(ipfw_obj_lheader))
373 		return (EINVAL);
374 
375 	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
376 
377 	IPFW_UH_RLOCK(ch);
378 	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
379 	    IPFW_TLV_NAT64STL_NAME);
380 	olh->objsize = sizeof(ipfw_nat64stl_cfg);
381 	olh->size = sizeof(*olh) + olh->count * olh->objsize;
382 
383 	if (sd->valsize < olh->size) {
384 		IPFW_UH_RUNLOCK(ch);
385 		return (ENOMEM);
386 	}
387 	memset(&da, 0, sizeof(da));
388 	da.ch = ch;
389 	da.sd = sd;
390 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
391 	    &da, IPFW_TLV_NAT64STL_NAME);
392 	IPFW_UH_RUNLOCK(ch);
393 
394 	return (0);
395 }
396 
397 #define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
398 	(_stats)->_field = NAT64STAT_FETCH(&(_cfg)->stats, _field)
399 static void
400 export_stats(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
401     struct ipfw_nat64stl_stats *stats)
402 {
403 
404 	__COPY_STAT_FIELD(cfg, stats, opcnt64);
405 	__COPY_STAT_FIELD(cfg, stats, opcnt46);
406 	__COPY_STAT_FIELD(cfg, stats, ofrags);
407 	__COPY_STAT_FIELD(cfg, stats, ifrags);
408 	__COPY_STAT_FIELD(cfg, stats, oerrors);
409 	__COPY_STAT_FIELD(cfg, stats, noroute4);
410 	__COPY_STAT_FIELD(cfg, stats, noroute6);
411 	__COPY_STAT_FIELD(cfg, stats, noproto);
412 	__COPY_STAT_FIELD(cfg, stats, nomem);
413 	__COPY_STAT_FIELD(cfg, stats, dropped);
414 }
415 
416 /*
417  * Get nat64stl statistics.
418  * Data layout (v0)(current):
419  * Request: [ ipfw_obj_header ]
420  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
421  *
422  * Returns 0 on success
423  */
424 static int
425 nat64stl_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
426     struct sockopt_data *sd)
427 {
428 	struct ipfw_nat64stl_stats stats;
429 	struct nat64stl_cfg *cfg;
430 	ipfw_obj_header *oh;
431 	ipfw_obj_ctlv *ctlv;
432 	size_t sz;
433 
434 	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
435 	if (sd->valsize % sizeof(uint64_t))
436 		return (EINVAL);
437 	if (sd->valsize < sz)
438 		return (ENOMEM);
439 	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
440 	if (oh == NULL)
441 		return (EINVAL);
442 	memset(&stats, 0, sizeof(stats));
443 
444 	IPFW_UH_RLOCK(ch);
445 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
446 	if (cfg == NULL) {
447 		IPFW_UH_RUNLOCK(ch);
448 		return (ESRCH);
449 	}
450 	export_stats(ch, cfg, &stats);
451 	IPFW_UH_RUNLOCK(ch);
452 
453 	ctlv = (ipfw_obj_ctlv *)(oh + 1);
454 	memset(ctlv, 0, sizeof(*ctlv));
455 	ctlv->head.type = IPFW_TLV_COUNTERS;
456 	ctlv->head.length = sz - sizeof(ipfw_obj_header);
457 	ctlv->count = sizeof(stats) / sizeof(uint64_t);
458 	ctlv->objsize = sizeof(uint64_t);
459 	ctlv->version = IPFW_NAT64_VERSION;
460 	memcpy(ctlv + 1, &stats, sizeof(stats));
461 	return (0);
462 }
463 
464 /*
465  * Reset nat64stl statistics.
466  * Data layout (v0)(current):
467  * Request: [ ipfw_obj_header ]
468  *
469  * Returns 0 on success
470  */
471 static int
472 nat64stl_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
473     struct sockopt_data *sd)
474 {
475 	struct nat64stl_cfg *cfg;
476 	ipfw_obj_header *oh;
477 
478 	if (sd->valsize != sizeof(*oh))
479 		return (EINVAL);
480 	oh = (ipfw_obj_header *)sd->kbuf;
481 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
482 	    oh->ntlv.set >= IPFW_MAX_SETS)
483 		return (EINVAL);
484 
485 	IPFW_UH_WLOCK(ch);
486 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
487 	if (cfg == NULL) {
488 		IPFW_UH_WUNLOCK(ch);
489 		return (ESRCH);
490 	}
491 	COUNTER_ARRAY_ZERO(cfg->stats.stats, NAT64STATS);
492 	IPFW_UH_WUNLOCK(ch);
493 	return (0);
494 }
495 
496 static struct ipfw_sopt_handler	scodes[] = {
497 
498 	{ IP_FW_NAT64STL_CREATE, 0,	HDIR_SET,	nat64stl_create },
499 	{ IP_FW_NAT64STL_DESTROY,0,	HDIR_SET,	nat64stl_destroy },
500 	{ IP_FW_NAT64STL_CONFIG, 0,	HDIR_BOTH,	nat64stl_config },
501 	{ IP_FW_NAT64STL_LIST,   0,	HDIR_GET,	nat64stl_list },
502 	{ IP_FW_NAT64STL_STATS,  0,	HDIR_GET,	nat64stl_stats },
503 	{ IP_FW_NAT64STL_RESET_STATS,0,	HDIR_SET,	nat64stl_reset_stats },
504 };
505 
506 static int
507 nat64stl_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
508 {
509 	ipfw_insn *icmd;
510 
511 	icmd = cmd - 1;
512 	if (icmd->opcode != O_EXTERNAL_ACTION ||
513 	    icmd->arg1 != V_nat64stl_eid)
514 		return (1);
515 
516 	*puidx = cmd->arg1;
517 	*ptype = 0;
518 	return (0);
519 }
520 
521 static void
522 nat64stl_update_arg1(ipfw_insn *cmd, uint16_t idx)
523 {
524 
525 	cmd->arg1 = idx;
526 }
527 
528 static int
529 nat64stl_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
530     struct named_object **pno)
531 {
532 	int err;
533 
534 	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
535 	    IPFW_TLV_NAT64STL_NAME, pno);
536 	return (err);
537 }
538 
539 static struct named_object *
540 nat64stl_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
541 {
542 	struct namedobj_instance *ni;
543 	struct named_object *no;
544 
545 	IPFW_UH_WLOCK_ASSERT(ch);
546 	ni = CHAIN_TO_SRV(ch);
547 	no = ipfw_objhash_lookup_kidx(ni, idx);
548 	KASSERT(no != NULL, ("NAT with index %d not found", idx));
549 
550 	return (no);
551 }
552 
553 static int
554 nat64stl_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
555     enum ipfw_sets_cmd cmd)
556 {
557 
558 	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NAT64STL_NAME,
559 	    set, new_set, cmd));
560 }
561 
562 static struct opcode_obj_rewrite opcodes[] = {
563 	{
564 		.opcode = O_EXTERNAL_INSTANCE,
565 		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
566 		.classifier = nat64stl_classify,
567 		.update = nat64stl_update_arg1,
568 		.find_byname = nat64stl_findbyname,
569 		.find_bykidx = nat64stl_findbykidx,
570 		.manage_sets = nat64stl_manage_sets,
571 	},
572 };
573 
574 static int
575 destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
576     void *arg)
577 {
578 	struct nat64stl_cfg *cfg;
579 	struct ip_fw_chain *ch;
580 
581 	ch = (struct ip_fw_chain *)arg;
582 	cfg = (struct nat64stl_cfg *)SRV_OBJECT(ch, no->kidx);
583 	SRV_OBJECT(ch, no->kidx) = NULL;
584 	nat64stl_detach_config(ch, cfg);
585 	nat64stl_free_config(cfg);
586 	return (0);
587 }
588 
589 int
590 nat64stl_init(struct ip_fw_chain *ch, int first)
591 {
592 
593 	V_nat64stl_eid = ipfw_add_eaction(ch, ipfw_nat64stl, "nat64stl");
594 	if (V_nat64stl_eid == 0)
595 		return (ENXIO);
596 	IPFW_ADD_SOPT_HANDLER(first, scodes);
597 	IPFW_ADD_OBJ_REWRITER(first, opcodes);
598 	return (0);
599 }
600 
601 void
602 nat64stl_uninit(struct ip_fw_chain *ch, int last)
603 {
604 
605 	IPFW_DEL_OBJ_REWRITER(last, opcodes);
606 	IPFW_DEL_SOPT_HANDLER(last, scodes);
607 	ipfw_del_eaction(ch, V_nat64stl_eid);
608 	/*
609 	 * Since we already have deregistered external action,
610 	 * our named objects become unaccessible via rules, because
611 	 * all rules were truncated by ipfw_del_eaction().
612 	 * So, we can unlink and destroy our named objects without holding
613 	 * IPFW_WLOCK().
614 	 */
615 	IPFW_UH_WLOCK(ch);
616 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
617 	    IPFW_TLV_NAT64STL_NAME);
618 	V_nat64stl_eid = 0;
619 	IPFW_UH_WUNLOCK(ch);
620 }
621 
622