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 #include <netinet6/ip_fw_nat64.h>
61 
62 #include <netpfil/ipfw/ip_fw_private.h>
63 
64 #include "nat64stl.h"
65 
66 VNET_DEFINE(uint16_t, nat64stl_eid) = 0;
67 
68 static struct nat64stl_cfg *nat64stl_alloc_config(const char *name,
69     uint8_t set);
70 static void nat64stl_free_config(struct nat64stl_cfg *cfg);
71 static struct nat64stl_cfg *nat64stl_find(struct namedobj_instance *ni,
72     const char *name, uint8_t set);
73 
74 static struct nat64stl_cfg *
75 nat64stl_alloc_config(const char *name, uint8_t set)
76 {
77 	struct nat64stl_cfg *cfg;
78 
79 	cfg = malloc(sizeof(struct nat64stl_cfg), M_IPFW, M_WAITOK | M_ZERO);
80 	COUNTER_ARRAY_ALLOC(cfg->base.stats.cnt, NAT64STATS, M_WAITOK);
81 	cfg->no.name = cfg->name;
82 	cfg->no.etlv = IPFW_TLV_NAT64STL_NAME;
83 	cfg->no.set = set;
84 	strlcpy(cfg->name, name, sizeof(cfg->name));
85 	return (cfg);
86 }
87 
88 static void
89 nat64stl_free_config(struct nat64stl_cfg *cfg)
90 {
91 
92 	COUNTER_ARRAY_FREE(cfg->base.stats.cnt, NAT64STATS);
93 	free(cfg, M_IPFW);
94 }
95 
96 static void
97 nat64stl_export_config(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
98     ipfw_nat64stl_cfg *uc)
99 {
100 	struct named_object *no;
101 
102 	uc->prefix6 = cfg->base.prefix6;
103 	uc->plen6 = cfg->base.plen6;
104 	uc->flags = cfg->base.flags & NAT64STL_FLAGSMASK;
105 	uc->set = cfg->no.set;
106 	strlcpy(uc->name, cfg->no.name, sizeof(uc->name));
107 
108 	no = ipfw_objhash_lookup_table_kidx(ch, cfg->map64);
109 	ipfw_export_obj_ntlv(no, &uc->ntlv6);
110 	no = ipfw_objhash_lookup_table_kidx(ch, cfg->map46);
111 	ipfw_export_obj_ntlv(no, &uc->ntlv4);
112 }
113 
114 struct nat64stl_dump_arg {
115 	struct ip_fw_chain *ch;
116 	struct sockopt_data *sd;
117 };
118 
119 static int
120 export_config_cb(struct namedobj_instance *ni, struct named_object *no,
121     void *arg)
122 {
123 	struct nat64stl_dump_arg *da = (struct nat64stl_dump_arg *)arg;
124 	ipfw_nat64stl_cfg *uc;
125 
126 	uc = (ipfw_nat64stl_cfg *)ipfw_get_sopt_space(da->sd, sizeof(*uc));
127 	nat64stl_export_config(da->ch, (struct nat64stl_cfg *)no, uc);
128 	return (0);
129 }
130 
131 static struct nat64stl_cfg *
132 nat64stl_find(struct namedobj_instance *ni, const char *name, uint8_t set)
133 {
134 	struct nat64stl_cfg *cfg;
135 
136 	cfg = (struct nat64stl_cfg *)ipfw_objhash_lookup_name_type(ni, set,
137 	    IPFW_TLV_NAT64STL_NAME, name);
138 
139 	return (cfg);
140 }
141 
142 
143 static int
144 nat64stl_create_internal(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
145     ipfw_nat64stl_cfg *i)
146 {
147 
148 	IPFW_UH_WLOCK_ASSERT(ch);
149 
150 	if (ipfw_objhash_alloc_idx(CHAIN_TO_SRV(ch), &cfg->no.kidx) != 0)
151 		return (ENOSPC);
152 	cfg->base.flags |= NAT64STL_KIDX;
153 
154 	if (ipfw_ref_table(ch, &i->ntlv4, &cfg->map46) != 0)
155 		return (EINVAL);
156 	cfg->base.flags |= NAT64STL_46T;
157 
158 	if (ipfw_ref_table(ch, &i->ntlv6, &cfg->map64) != 0)
159 		return (EINVAL);
160 	cfg->base.flags |= NAT64STL_64T;
161 
162 	ipfw_objhash_add(CHAIN_TO_SRV(ch), &cfg->no);
163 
164 	return (0);
165 }
166 
167 /*
168  * Creates new nat64 instance.
169  * Data layout (v0)(current):
170  * Request: [ ipfw_obj_lheader ipfw_nat64stl_cfg ]
171  *
172  * Returns 0 on success
173  */
174 static int
175 nat64stl_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
176     struct sockopt_data *sd)
177 {
178 	ipfw_obj_lheader *olh;
179 	ipfw_nat64stl_cfg *uc;
180 	struct namedobj_instance *ni;
181 	struct nat64stl_cfg *cfg;
182 	int error;
183 
184 	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
185 		return (EINVAL);
186 
187 	olh = (ipfw_obj_lheader *)sd->kbuf;
188 	uc = (ipfw_nat64stl_cfg *)(olh + 1);
189 
190 	if (ipfw_check_object_name_generic(uc->name) != 0)
191 		return (EINVAL);
192 	if (uc->set >= IPFW_MAX_SETS ||
193 	    nat64_check_prefix6(&uc->prefix6, uc->plen6) != 0)
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->base.prefix6 = uc->prefix6;
210 	cfg->base.plen6 = uc->plen6;
211 	cfg->base.flags = uc->flags & NAT64STL_FLAGSMASK;
212 	if (IN6_IS_ADDR_WKPFX(&cfg->base.prefix6))
213 		cfg->base.flags |= NAT64_WKPFX;
214 
215 	IPFW_UH_WLOCK(ch);
216 
217 	if (nat64stl_find(ni, uc->name, uc->set) != NULL) {
218 		IPFW_UH_WUNLOCK(ch);
219 		nat64stl_free_config(cfg);
220 		return (EEXIST);
221 	}
222 	error = nat64stl_create_internal(ch, cfg, uc);
223 	if (error == 0) {
224 		/* Okay, let's link data */
225 		SRV_OBJECT(ch, cfg->no.kidx) = cfg;
226 		IPFW_UH_WUNLOCK(ch);
227 		return (0);
228 	}
229 
230 	if (cfg->base.flags & NAT64STL_KIDX)
231 		ipfw_objhash_free_idx(ni, cfg->no.kidx);
232 	if (cfg->base.flags & NAT64STL_46T)
233 		ipfw_unref_table(ch, cfg->map46);
234 	if (cfg->base.flags & NAT64STL_64T)
235 		ipfw_unref_table(ch, cfg->map64);
236 
237 	IPFW_UH_WUNLOCK(ch);
238 	nat64stl_free_config(cfg);
239 	return (error);
240 }
241 
242 /*
243  * Change existing nat64stl instance configuration.
244  * Data layout (v0)(current):
245  * Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
246  * Reply: [ ipfw_obj_header ipfw_nat64stl_cfg ]
247  *
248  * Returns 0 on success
249  */
250 static int
251 nat64stl_config(struct ip_fw_chain *ch, ip_fw3_opheader *op,
252     struct sockopt_data *sd)
253 {
254 	ipfw_obj_header *oh;
255 	ipfw_nat64stl_cfg *uc;
256 	struct nat64stl_cfg *cfg;
257 	struct namedobj_instance *ni;
258 
259 	if (sd->valsize != sizeof(*oh) + sizeof(*uc))
260 		return (EINVAL);
261 
262 	oh = (ipfw_obj_header *)ipfw_get_sopt_space(sd,
263 	    sizeof(*oh) + sizeof(*uc));
264 	uc = (ipfw_nat64stl_cfg *)(oh + 1);
265 
266 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
267 	    oh->ntlv.set >= IPFW_MAX_SETS)
268 		return (EINVAL);
269 
270 	ni = CHAIN_TO_SRV(ch);
271 	if (sd->sopt->sopt_dir == SOPT_GET) {
272 		IPFW_UH_RLOCK(ch);
273 		cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
274 		if (cfg == NULL) {
275 			IPFW_UH_RUNLOCK(ch);
276 			return (EEXIST);
277 		}
278 		nat64stl_export_config(ch, cfg, uc);
279 		IPFW_UH_RUNLOCK(ch);
280 		return (0);
281 	}
282 
283 	IPFW_UH_WLOCK(ch);
284 	cfg = nat64stl_find(ni, oh->ntlv.name, oh->ntlv.set);
285 	if (cfg == NULL) {
286 		IPFW_UH_WUNLOCK(ch);
287 		return (EEXIST);
288 	}
289 
290 	/*
291 	 * For now allow to change only following values:
292 	 *  flags.
293 	 */
294 	cfg->base.flags &= ~NAT64STL_FLAGSMASK;
295 	cfg->base.flags |= uc->flags & NAT64STL_FLAGSMASK;
296 
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_reset_eaction_instance(ch, V_nat64stl_eid, cfg->no.kidx);
346 	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
347 	nat64stl_detach_config(ch, cfg);
348 	IPFW_UH_WUNLOCK(ch);
349 
350 	nat64stl_free_config(cfg);
351 	return (0);
352 }
353 
354 /*
355  * Lists all nat64stl instances currently available in kernel.
356  * Data layout (v0)(current):
357  * Request: [ ipfw_obj_lheader ]
358  * Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
359  *
360  * Returns 0 on success
361  */
362 static int
363 nat64stl_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
364     struct sockopt_data *sd)
365 {
366 	ipfw_obj_lheader *olh;
367 	struct nat64stl_dump_arg da;
368 
369 	/* Check minimum header size */
370 	if (sd->valsize < sizeof(ipfw_obj_lheader))
371 		return (EINVAL);
372 
373 	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
374 
375 	IPFW_UH_RLOCK(ch);
376 	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
377 	    IPFW_TLV_NAT64STL_NAME);
378 	olh->objsize = sizeof(ipfw_nat64stl_cfg);
379 	olh->size = sizeof(*olh) + olh->count * olh->objsize;
380 
381 	if (sd->valsize < olh->size) {
382 		IPFW_UH_RUNLOCK(ch);
383 		return (ENOMEM);
384 	}
385 	memset(&da, 0, sizeof(da));
386 	da.ch = ch;
387 	da.sd = sd;
388 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
389 	    &da, IPFW_TLV_NAT64STL_NAME);
390 	IPFW_UH_RUNLOCK(ch);
391 
392 	return (0);
393 }
394 
395 #define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
396 	(_stats)->_field = NAT64STAT_FETCH(&(_cfg)->base.stats, _field)
397 static void
398 export_stats(struct ip_fw_chain *ch, struct nat64stl_cfg *cfg,
399     struct ipfw_nat64stl_stats *stats)
400 {
401 
402 	__COPY_STAT_FIELD(cfg, stats, opcnt64);
403 	__COPY_STAT_FIELD(cfg, stats, opcnt46);
404 	__COPY_STAT_FIELD(cfg, stats, ofrags);
405 	__COPY_STAT_FIELD(cfg, stats, ifrags);
406 	__COPY_STAT_FIELD(cfg, stats, oerrors);
407 	__COPY_STAT_FIELD(cfg, stats, noroute4);
408 	__COPY_STAT_FIELD(cfg, stats, noroute6);
409 	__COPY_STAT_FIELD(cfg, stats, noproto);
410 	__COPY_STAT_FIELD(cfg, stats, nomem);
411 	__COPY_STAT_FIELD(cfg, stats, dropped);
412 }
413 
414 /*
415  * Get nat64stl statistics.
416  * Data layout (v0)(current):
417  * Request: [ ipfw_obj_header ]
418  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
419  *
420  * Returns 0 on success
421  */
422 static int
423 nat64stl_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
424     struct sockopt_data *sd)
425 {
426 	struct ipfw_nat64stl_stats stats;
427 	struct nat64stl_cfg *cfg;
428 	ipfw_obj_header *oh;
429 	ipfw_obj_ctlv *ctlv;
430 	size_t sz;
431 
432 	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
433 	if (sd->valsize % sizeof(uint64_t))
434 		return (EINVAL);
435 	if (sd->valsize < sz)
436 		return (ENOMEM);
437 	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
438 	if (oh == NULL)
439 		return (EINVAL);
440 	memset(&stats, 0, sizeof(stats));
441 
442 	IPFW_UH_RLOCK(ch);
443 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
444 	if (cfg == NULL) {
445 		IPFW_UH_RUNLOCK(ch);
446 		return (ESRCH);
447 	}
448 	export_stats(ch, cfg, &stats);
449 	IPFW_UH_RUNLOCK(ch);
450 
451 	ctlv = (ipfw_obj_ctlv *)(oh + 1);
452 	memset(ctlv, 0, sizeof(*ctlv));
453 	ctlv->head.type = IPFW_TLV_COUNTERS;
454 	ctlv->head.length = sz - sizeof(ipfw_obj_header);
455 	ctlv->count = sizeof(stats) / sizeof(uint64_t);
456 	ctlv->objsize = sizeof(uint64_t);
457 	ctlv->version = IPFW_NAT64_VERSION;
458 	memcpy(ctlv + 1, &stats, sizeof(stats));
459 	return (0);
460 }
461 
462 /*
463  * Reset nat64stl statistics.
464  * Data layout (v0)(current):
465  * Request: [ ipfw_obj_header ]
466  *
467  * Returns 0 on success
468  */
469 static int
470 nat64stl_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
471     struct sockopt_data *sd)
472 {
473 	struct nat64stl_cfg *cfg;
474 	ipfw_obj_header *oh;
475 
476 	if (sd->valsize != sizeof(*oh))
477 		return (EINVAL);
478 	oh = (ipfw_obj_header *)sd->kbuf;
479 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
480 	    oh->ntlv.set >= IPFW_MAX_SETS)
481 		return (EINVAL);
482 
483 	IPFW_UH_WLOCK(ch);
484 	cfg = nat64stl_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
485 	if (cfg == NULL) {
486 		IPFW_UH_WUNLOCK(ch);
487 		return (ESRCH);
488 	}
489 	COUNTER_ARRAY_ZERO(cfg->base.stats.cnt, NAT64STATS);
490 	IPFW_UH_WUNLOCK(ch);
491 	return (0);
492 }
493 
494 static struct ipfw_sopt_handler	scodes[] = {
495 
496 	{ IP_FW_NAT64STL_CREATE, 0,	HDIR_SET,	nat64stl_create },
497 	{ IP_FW_NAT64STL_DESTROY,0,	HDIR_SET,	nat64stl_destroy },
498 	{ IP_FW_NAT64STL_CONFIG, 0,	HDIR_BOTH,	nat64stl_config },
499 	{ IP_FW_NAT64STL_LIST,   0,	HDIR_GET,	nat64stl_list },
500 	{ IP_FW_NAT64STL_STATS,  0,	HDIR_GET,	nat64stl_stats },
501 	{ IP_FW_NAT64STL_RESET_STATS,0,	HDIR_SET,	nat64stl_reset_stats },
502 };
503 
504 static int
505 nat64stl_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
506 {
507 	ipfw_insn *icmd;
508 
509 	icmd = cmd - 1;
510 	if (icmd->opcode != O_EXTERNAL_ACTION ||
511 	    icmd->arg1 != V_nat64stl_eid)
512 		return (1);
513 
514 	*puidx = cmd->arg1;
515 	*ptype = 0;
516 	return (0);
517 }
518 
519 static void
520 nat64stl_update_arg1(ipfw_insn *cmd, uint16_t idx)
521 {
522 
523 	cmd->arg1 = idx;
524 }
525 
526 static int
527 nat64stl_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
528     struct named_object **pno)
529 {
530 	int err;
531 
532 	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
533 	    IPFW_TLV_NAT64STL_NAME, pno);
534 	return (err);
535 }
536 
537 static struct named_object *
538 nat64stl_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
539 {
540 	struct namedobj_instance *ni;
541 	struct named_object *no;
542 
543 	IPFW_UH_WLOCK_ASSERT(ch);
544 	ni = CHAIN_TO_SRV(ch);
545 	no = ipfw_objhash_lookup_kidx(ni, idx);
546 	KASSERT(no != NULL, ("NAT with index %d not found", idx));
547 
548 	return (no);
549 }
550 
551 static int
552 nat64stl_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
553     enum ipfw_sets_cmd cmd)
554 {
555 
556 	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NAT64STL_NAME,
557 	    set, new_set, cmd));
558 }
559 
560 static struct opcode_obj_rewrite opcodes[] = {
561 	{
562 		.opcode = O_EXTERNAL_INSTANCE,
563 		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
564 		.classifier = nat64stl_classify,
565 		.update = nat64stl_update_arg1,
566 		.find_byname = nat64stl_findbyname,
567 		.find_bykidx = nat64stl_findbykidx,
568 		.manage_sets = nat64stl_manage_sets,
569 	},
570 };
571 
572 static int
573 destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
574     void *arg)
575 {
576 	struct nat64stl_cfg *cfg;
577 	struct ip_fw_chain *ch;
578 
579 	ch = (struct ip_fw_chain *)arg;
580 	cfg = (struct nat64stl_cfg *)SRV_OBJECT(ch, no->kidx);
581 	SRV_OBJECT(ch, no->kidx) = NULL;
582 	nat64stl_detach_config(ch, cfg);
583 	nat64stl_free_config(cfg);
584 	return (0);
585 }
586 
587 int
588 nat64stl_init(struct ip_fw_chain *ch, int first)
589 {
590 
591 	V_nat64stl_eid = ipfw_add_eaction(ch, ipfw_nat64stl, "nat64stl");
592 	if (V_nat64stl_eid == 0)
593 		return (ENXIO);
594 	IPFW_ADD_SOPT_HANDLER(first, scodes);
595 	IPFW_ADD_OBJ_REWRITER(first, opcodes);
596 	return (0);
597 }
598 
599 void
600 nat64stl_uninit(struct ip_fw_chain *ch, int last)
601 {
602 
603 	IPFW_DEL_OBJ_REWRITER(last, opcodes);
604 	IPFW_DEL_SOPT_HANDLER(last, scodes);
605 	ipfw_del_eaction(ch, V_nat64stl_eid);
606 	/*
607 	 * Since we already have deregistered external action,
608 	 * our named objects become unaccessible via rules, because
609 	 * all rules were truncated by ipfw_del_eaction().
610 	 * So, we can unlink and destroy our named objects without holding
611 	 * IPFW_WLOCK().
612 	 */
613 	IPFW_UH_WLOCK(ch);
614 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
615 	    IPFW_TLV_NAT64STL_NAME);
616 	V_nat64stl_eid = 0;
617 	IPFW_UH_WUNLOCK(ch);
618 }
619 
620