xref: /freebsd/sys/netpfil/ipfw/nat64/nat64stl_control.c (revision 38c63bdc46252d4d8cd313dff4183ec4546d26d9)
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/param.h>
31 #include <sys/systm.h>
32 #include <sys/counter.h>
33 #include <sys/errno.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/module.h>
39 #include <sys/rmlock.h>
40 #include <sys/rwlock.h>
41 #include <sys/socket.h>
42 #include <sys/sockopt.h>
43 #include <sys/queue.h>
44 #include <sys/syslog.h>
45 #include <sys/sysctl.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/pfil.h>
50 #include <net/route.h>
51 #include <net/vnet.h>
52 
53 #include <netinet/in.h>
54 #include <netinet/ip_var.h>
55 #include <netinet/ip_fw.h>
56 #include <netinet6/in6_var.h>
57 #include <netinet6/ip6_var.h>
58 #include <netinet6/ip_fw_nat64.h>
59 
60 #include <netpfil/ipfw/ip_fw_private.h>
61 
62 #include "nat64stl.h"
63 
64 VNET_DEFINE(uint16_t, nat64stl_eid) = 0;
65 
66 static struct nat64stl_cfg *nat64stl_alloc_config(const char *name,
67     uint8_t set);
68 static void nat64stl_free_config(struct nat64stl_cfg *cfg);
69 static struct nat64stl_cfg *nat64stl_find(struct namedobj_instance *ni,
70     const char *name, uint8_t set);
71 
72 static struct nat64stl_cfg *
73 nat64stl_alloc_config(const char *name, uint8_t set)
74 {
75 	struct nat64stl_cfg *cfg;
76 
77 	cfg = malloc(sizeof(struct nat64stl_cfg), M_IPFW, M_WAITOK | M_ZERO);
78 	COUNTER_ARRAY_ALLOC(cfg->base.stats.cnt, NAT64STATS, M_WAITOK);
79 	cfg->no.name = cfg->name;
80 	cfg->no.etlv = IPFW_TLV_NAT64STL_NAME;
81 	cfg->no.set = set;
82 	strlcpy(cfg->name, name, sizeof(cfg->name));
83 	return (cfg);
84 }
85 
86 static void
87 nat64stl_free_config(struct nat64stl_cfg *cfg)
88 {
89 
90 	COUNTER_ARRAY_FREE(cfg->base.stats.cnt, NAT64STATS);
91 	free(cfg, M_IPFW);
92 }
93 
94 static void
95 nat64stl_export_config(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
96     ipfw_nat64stl_cfg *uc)
97 {
98 	struct named_object *no;
99 
100 	uc->prefix6 = cfg->base.plat_prefix;
101 	uc->plen6 = cfg->base.plat_plen;
102 	uc->flags = cfg->base.flags & NAT64STL_FLAGSMASK;
103 	uc->set = cfg->no.set;
104 	strlcpy(uc->name, cfg->no.name, sizeof(uc->name));
105 
106 	no = ipfw_objhash_lookup_table_kidx(ch, cfg->map64);
107 	ipfw_export_obj_ntlv(no, &uc->ntlv6);
108 	no = ipfw_objhash_lookup_table_kidx(ch, cfg->map46);
109 	ipfw_export_obj_ntlv(no, &uc->ntlv4);
110 }
111 
112 struct nat64stl_dump_arg {
113 	struct ip_fw_chain *ch;
114 	struct sockopt_data *sd;
115 };
116 
117 static int
118 export_config_cb(struct namedobj_instance *ni, struct named_object *no,
119     void *arg)
120 {
121 	struct nat64stl_dump_arg *da = (struct nat64stl_dump_arg *)arg;
122 	ipfw_nat64stl_cfg *uc;
123 
124 	uc = (ipfw_nat64stl_cfg *)ipfw_get_sopt_space(da->sd, sizeof(*uc));
125 	nat64stl_export_config(da->ch, (struct nat64stl_cfg *)no, uc);
126 	return (0);
127 }
128 
129 static struct nat64stl_cfg *
130 nat64stl_find(struct namedobj_instance *ni, const char *name, uint8_t set)
131 {
132 	struct nat64stl_cfg *cfg;
133 
134 	cfg = (struct nat64stl_cfg *)ipfw_objhash_lookup_name_type(ni, set,
135 	    IPFW_TLV_NAT64STL_NAME, name);
136 
137 	return (cfg);
138 }
139 
140 static int
141 nat64stl_create_internal(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
142     ipfw_nat64stl_cfg *i)
143 {
144 
145 	IPFW_UH_WLOCK_ASSERT(ch);
146 
147 	if (ipfw_objhash_alloc_idx(CHAIN_TO_SRV(ch), &cfg->no.kidx) != 0)
148 		return (ENOSPC);
149 	cfg->base.flags |= NAT64STL_KIDX;
150 
151 	if (ipfw_ref_table(ch, &i->ntlv4, &cfg->map46) != 0)
152 		return (EINVAL);
153 	cfg->base.flags |= NAT64STL_46T;
154 
155 	if (ipfw_ref_table(ch, &i->ntlv6, &cfg->map64) != 0)
156 		return (EINVAL);
157 	cfg->base.flags |= NAT64STL_64T;
158 
159 	ipfw_objhash_add(CHAIN_TO_SRV(ch), &cfg->no);
160 
161 	return (0);
162 }
163 
164 /*
165  * Creates new nat64 instance.
166  * Data layout (v0)(current):
167  * Request: [ ipfw_obj_lheader ipfw_nat64stl_cfg ]
168  *
169  * Returns 0 on success
170  */
171 static int
172 nat64stl_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
173     struct sockopt_data *sd)
174 {
175 	ipfw_obj_lheader *olh;
176 	ipfw_nat64stl_cfg *uc;
177 	struct namedobj_instance *ni;
178 	struct nat64stl_cfg *cfg;
179 	int error;
180 
181 	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
182 		return (EINVAL);
183 
184 	olh = (ipfw_obj_lheader *)sd->kbuf;
185 	uc = (ipfw_nat64stl_cfg *)(olh + 1);
186 
187 	if (ipfw_check_object_name_generic(uc->name) != 0)
188 		return (EINVAL);
189 	if (uc->set >= IPFW_MAX_SETS ||
190 	    nat64_check_prefix6(&uc->prefix6, uc->plen6) != 0)
191 		return (EINVAL);
192 
193 	/* XXX: check types of tables */
194 
195 	ni = CHAIN_TO_SRV(ch);
196 	error = 0;
197 
198 	IPFW_UH_RLOCK(ch);
199 	if (nat64stl_find(ni, uc->name, uc->set) != NULL) {
200 		IPFW_UH_RUNLOCK(ch);
201 		return (EEXIST);
202 	}
203 	IPFW_UH_RUNLOCK(ch);
204 
205 	cfg = nat64stl_alloc_config(uc->name, uc->set);
206 	cfg->base.plat_prefix = uc->prefix6;
207 	cfg->base.plat_plen = uc->plen6;
208 	cfg->base.flags = (uc->flags & NAT64STL_FLAGSMASK) | NAT64_PLATPFX;
209 	if (IN6_IS_ADDR_WKPFX(&cfg->base.plat_prefix))
210 		cfg->base.flags |= NAT64_WKPFX;
211 
212 	IPFW_UH_WLOCK(ch);
213 
214 	if (nat64stl_find(ni, uc->name, uc->set) != NULL) {
215 		IPFW_UH_WUNLOCK(ch);
216 		nat64stl_free_config(cfg);
217 		return (EEXIST);
218 	}
219 	error = nat64stl_create_internal(ch, cfg, uc);
220 	if (error == 0) {
221 		/* Okay, let's link data */
222 		SRV_OBJECT(ch, cfg->no.kidx) = cfg;
223 		IPFW_UH_WUNLOCK(ch);
224 		return (0);
225 	}
226 
227 	if (cfg->base.flags & NAT64STL_KIDX)
228 		ipfw_objhash_free_idx(ni, cfg->no.kidx);
229 	if (cfg->base.flags & NAT64STL_46T)
230 		ipfw_unref_table(ch, cfg->map46);
231 	if (cfg->base.flags & NAT64STL_64T)
232 		ipfw_unref_table(ch, cfg->map64);
233 
234 	IPFW_UH_WUNLOCK(ch);
235 	nat64stl_free_config(cfg);
236 	return (error);
237 }
238 
239 /*
240  * Change existing nat64stl instance configuration.
241  * Data layout (v0)(current):
242  * Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
243  * Reply: [ ipfw_obj_header ipfw_nat64stl_cfg ]
244  *
245  * Returns 0 on success
246  */
247 static int
248 nat64stl_config(struct ip_fw_chain *ch, ip_fw3_opheader *op,
249     struct sockopt_data *sd)
250 {
251 	ipfw_obj_header *oh;
252 	ipfw_nat64stl_cfg *uc;
253 	struct nat64stl_cfg *cfg;
254 	struct namedobj_instance *ni;
255 
256 	if (sd->valsize != sizeof(*oh) + sizeof(*uc))
257 		return (EINVAL);
258 
259 	oh = (ipfw_obj_header *)ipfw_get_sopt_space(sd,
260 	    sizeof(*oh) + sizeof(*uc));
261 	uc = (ipfw_nat64stl_cfg *)(oh + 1);
262 
263 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
264 	    oh->ntlv.set >= IPFW_MAX_SETS)
265 		return (EINVAL);
266 
267 	ni = CHAIN_TO_SRV(ch);
268 	if (sd->sopt->sopt_dir == SOPT_GET) {
269 		IPFW_UH_RLOCK(ch);
270 		cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
271 		if (cfg == NULL) {
272 			IPFW_UH_RUNLOCK(ch);
273 			return (EEXIST);
274 		}
275 		nat64stl_export_config(ch, cfg, uc);
276 		IPFW_UH_RUNLOCK(ch);
277 		return (0);
278 	}
279 
280 	IPFW_UH_WLOCK(ch);
281 	cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
282 	if (cfg == NULL) {
283 		IPFW_UH_WUNLOCK(ch);
284 		return (EEXIST);
285 	}
286 
287 	/*
288 	 * For now allow to change only following values:
289 	 *  flags.
290 	 */
291 	cfg->base.flags &= ~NAT64STL_FLAGSMASK;
292 	cfg->base.flags |= uc->flags & NAT64STL_FLAGSMASK;
293 
294 	IPFW_UH_WUNLOCK(ch);
295 	return (0);
296 }
297 
298 static void
299 nat64stl_detach_config(struct ip_fw_chain *ch, struct nat64stl_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 	ipfw_unref_table(ch, cfg->map46);
307 	ipfw_unref_table(ch, cfg->map64);
308 }
309 
310 /*
311  * Destroys nat64 instance.
312  * Data layout (v0)(current):
313  * Request: [ ipfw_obj_header ]
314  *
315  * Returns 0 on success
316  */
317 static int
318 nat64stl_destroy(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
319     struct sockopt_data *sd)
320 {
321 	ipfw_obj_header *oh;
322 	struct nat64stl_cfg *cfg;
323 
324 	if (sd->valsize != sizeof(*oh))
325 		return (EINVAL);
326 
327 	oh = (ipfw_obj_header *)sd->kbuf;
328 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0)
329 		return (EINVAL);
330 
331 	IPFW_UH_WLOCK(ch);
332 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
333 	if (cfg == NULL) {
334 		IPFW_UH_WUNLOCK(ch);
335 		return (ESRCH);
336 	}
337 	if (cfg->no.refcnt > 0) {
338 		IPFW_UH_WUNLOCK(ch);
339 		return (EBUSY);
340 	}
341 
342 	ipfw_reset_eaction_instance(ch, V_nat64stl_eid, cfg->no.kidx);
343 	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
344 	nat64stl_detach_config(ch, cfg);
345 	IPFW_UH_WUNLOCK(ch);
346 
347 	nat64stl_free_config(cfg);
348 	return (0);
349 }
350 
351 /*
352  * Lists all nat64stl instances currently available in kernel.
353  * Data layout (v0)(current):
354  * Request: [ ipfw_obj_lheader ]
355  * Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
356  *
357  * Returns 0 on success
358  */
359 static int
360 nat64stl_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
361     struct sockopt_data *sd)
362 {
363 	ipfw_obj_lheader *olh;
364 	struct nat64stl_dump_arg da;
365 
366 	/* Check minimum header size */
367 	if (sd->valsize < sizeof(ipfw_obj_lheader))
368 		return (EINVAL);
369 
370 	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
371 
372 	IPFW_UH_RLOCK(ch);
373 	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
374 	    IPFW_TLV_NAT64STL_NAME);
375 	olh->objsize = sizeof(ipfw_nat64stl_cfg);
376 	olh->size = sizeof(*olh) + olh->count * olh->objsize;
377 
378 	if (sd->valsize < olh->size) {
379 		IPFW_UH_RUNLOCK(ch);
380 		return (ENOMEM);
381 	}
382 	memset(&da, 0, sizeof(da));
383 	da.ch = ch;
384 	da.sd = sd;
385 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
386 	    &da, IPFW_TLV_NAT64STL_NAME);
387 	IPFW_UH_RUNLOCK(ch);
388 
389 	return (0);
390 }
391 
392 #define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
393 	(_stats)->_field = NAT64STAT_FETCH(&(_cfg)->base.stats, _field)
394 static void
395 export_stats(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
396     struct ipfw_nat64stl_stats *stats)
397 {
398 
399 	__COPY_STAT_FIELD(cfg, stats, opcnt64);
400 	__COPY_STAT_FIELD(cfg, stats, opcnt46);
401 	__COPY_STAT_FIELD(cfg, stats, ofrags);
402 	__COPY_STAT_FIELD(cfg, stats, ifrags);
403 	__COPY_STAT_FIELD(cfg, stats, oerrors);
404 	__COPY_STAT_FIELD(cfg, stats, noroute4);
405 	__COPY_STAT_FIELD(cfg, stats, noroute6);
406 	__COPY_STAT_FIELD(cfg, stats, noproto);
407 	__COPY_STAT_FIELD(cfg, stats, nomem);
408 	__COPY_STAT_FIELD(cfg, stats, dropped);
409 }
410 
411 /*
412  * Get nat64stl statistics.
413  * Data layout (v0)(current):
414  * Request: [ ipfw_obj_header ]
415  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
416  *
417  * Returns 0 on success
418  */
419 static int
420 nat64stl_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
421     struct sockopt_data *sd)
422 {
423 	struct ipfw_nat64stl_stats stats;
424 	struct nat64stl_cfg *cfg;
425 	ipfw_obj_header *oh;
426 	ipfw_obj_ctlv *ctlv;
427 	size_t sz;
428 
429 	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
430 	if (sd->valsize % sizeof(uint64_t))
431 		return (EINVAL);
432 	if (sd->valsize < sz)
433 		return (ENOMEM);
434 	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
435 	if (oh == NULL)
436 		return (EINVAL);
437 	memset(&stats, 0, sizeof(stats));
438 
439 	IPFW_UH_RLOCK(ch);
440 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
441 	if (cfg == NULL) {
442 		IPFW_UH_RUNLOCK(ch);
443 		return (ESRCH);
444 	}
445 	export_stats(ch, cfg, &stats);
446 	IPFW_UH_RUNLOCK(ch);
447 
448 	ctlv = (ipfw_obj_ctlv *)(oh + 1);
449 	memset(ctlv, 0, sizeof(*ctlv));
450 	ctlv->head.type = IPFW_TLV_COUNTERS;
451 	ctlv->head.length = sz - sizeof(ipfw_obj_header);
452 	ctlv->count = sizeof(stats) / sizeof(uint64_t);
453 	ctlv->objsize = sizeof(uint64_t);
454 	ctlv->version = IPFW_NAT64_VERSION;
455 	memcpy(ctlv + 1, &stats, sizeof(stats));
456 	return (0);
457 }
458 
459 /*
460  * Reset nat64stl statistics.
461  * Data layout (v0)(current):
462  * Request: [ ipfw_obj_header ]
463  *
464  * Returns 0 on success
465  */
466 static int
467 nat64stl_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
468     struct sockopt_data *sd)
469 {
470 	struct nat64stl_cfg *cfg;
471 	ipfw_obj_header *oh;
472 
473 	if (sd->valsize != sizeof(*oh))
474 		return (EINVAL);
475 	oh = (ipfw_obj_header *)sd->kbuf;
476 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
477 	    oh->ntlv.set >= IPFW_MAX_SETS)
478 		return (EINVAL);
479 
480 	IPFW_UH_WLOCK(ch);
481 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
482 	if (cfg == NULL) {
483 		IPFW_UH_WUNLOCK(ch);
484 		return (ESRCH);
485 	}
486 	COUNTER_ARRAY_ZERO(cfg->base.stats.cnt, NAT64STATS);
487 	IPFW_UH_WUNLOCK(ch);
488 	return (0);
489 }
490 
491 static struct ipfw_sopt_handler	scodes[] = {
492 	{ IP_FW_NAT64STL_CREATE, 0,	HDIR_SET,	nat64stl_create },
493 	{ IP_FW_NAT64STL_DESTROY,0,	HDIR_SET,	nat64stl_destroy },
494 	{ IP_FW_NAT64STL_CONFIG, 0,	HDIR_BOTH,	nat64stl_config },
495 	{ IP_FW_NAT64STL_LIST,   0,	HDIR_GET,	nat64stl_list },
496 	{ IP_FW_NAT64STL_STATS,  0,	HDIR_GET,	nat64stl_stats },
497 	{ IP_FW_NAT64STL_RESET_STATS,0,	HDIR_SET,	nat64stl_reset_stats },
498 };
499 
500 static int
501 nat64stl_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
502 {
503 	ipfw_insn *icmd;
504 
505 	icmd = cmd - 1;
506 	if (icmd->opcode != O_EXTERNAL_ACTION ||
507 	    icmd->arg1 != V_nat64stl_eid)
508 		return (1);
509 
510 	*puidx = cmd->arg1;
511 	*ptype = 0;
512 	return (0);
513 }
514 
515 static void
516 nat64stl_update_arg1(ipfw_insn *cmd, uint16_t idx)
517 {
518 
519 	cmd->arg1 = idx;
520 }
521 
522 static int
523 nat64stl_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
524     struct named_object **pno)
525 {
526 	int err;
527 
528 	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
529 	    IPFW_TLV_NAT64STL_NAME, pno);
530 	return (err);
531 }
532 
533 static struct named_object *
534 nat64stl_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
535 {
536 	struct namedobj_instance *ni;
537 	struct named_object *no;
538 
539 	IPFW_UH_WLOCK_ASSERT(ch);
540 	ni = CHAIN_TO_SRV(ch);
541 	no = ipfw_objhash_lookup_kidx(ni, idx);
542 	KASSERT(no != NULL, ("NAT with index %d not found", idx));
543 
544 	return (no);
545 }
546 
547 static int
548 nat64stl_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
549     enum ipfw_sets_cmd cmd)
550 {
551 
552 	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NAT64STL_NAME,
553 	    set, new_set, cmd));
554 }
555 
556 static struct opcode_obj_rewrite opcodes[] = {
557 	{
558 		.opcode = O_EXTERNAL_INSTANCE,
559 		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
560 		.classifier = nat64stl_classify,
561 		.update = nat64stl_update_arg1,
562 		.find_byname = nat64stl_findbyname,
563 		.find_bykidx = nat64stl_findbykidx,
564 		.manage_sets = nat64stl_manage_sets,
565 	},
566 };
567 
568 static int
569 destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
570     void *arg)
571 {
572 	struct nat64stl_cfg *cfg;
573 	struct ip_fw_chain *ch;
574 
575 	ch = (struct ip_fw_chain *)arg;
576 	cfg = (struct nat64stl_cfg *)SRV_OBJECT(ch, no->kidx);
577 	SRV_OBJECT(ch, no->kidx) = NULL;
578 	nat64stl_detach_config(ch, cfg);
579 	nat64stl_free_config(cfg);
580 	return (0);
581 }
582 
583 int
584 nat64stl_init(struct ip_fw_chain *ch, int first)
585 {
586 
587 	V_nat64stl_eid = ipfw_add_eaction(ch, ipfw_nat64stl, "nat64stl");
588 	if (V_nat64stl_eid == 0)
589 		return (ENXIO);
590 	IPFW_ADD_SOPT_HANDLER(first, scodes);
591 	IPFW_ADD_OBJ_REWRITER(first, opcodes);
592 	return (0);
593 }
594 
595 void
596 nat64stl_uninit(struct ip_fw_chain *ch, int last)
597 {
598 
599 	IPFW_DEL_OBJ_REWRITER(last, opcodes);
600 	IPFW_DEL_SOPT_HANDLER(last, scodes);
601 	ipfw_del_eaction(ch, V_nat64stl_eid);
602 	/*
603 	 * Since we already have deregistered external action,
604 	 * our named objects become unaccessible via rules, because
605 	 * all rules were truncated by ipfw_del_eaction().
606 	 * So, we can unlink and destroy our named objects without holding
607 	 * IPFW_WLOCK().
608 	 */
609 	IPFW_UH_WLOCK(ch);
610 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
611 	    IPFW_TLV_NAT64STL_NAME);
612 	V_nat64stl_eid = 0;
613 	IPFW_UH_WUNLOCK(ch);
614 }
615