xref: /freebsd/sys/netpfil/ipfw/nptv6/nptv6.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * Copyright (c) 2016 Yandex LLC
3  * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
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/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/netisr.h>
50 #include <net/pfil.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 <netinet/ip6.h>
57 #include <netinet/icmp6.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/nptv6/nptv6.h>
63 
64 static VNET_DEFINE(uint16_t, nptv6_eid) = 0;
65 #define	V_nptv6_eid	VNET(nptv6_eid)
66 #define	IPFW_TLV_NPTV6_NAME	IPFW_TLV_EACTION_NAME(V_nptv6_eid)
67 
68 static struct nptv6_cfg *nptv6_alloc_config(const char *name, uint8_t set);
69 static void nptv6_free_config(struct nptv6_cfg *cfg);
70 static struct nptv6_cfg *nptv6_find(struct namedobj_instance *ni,
71     const char *name, uint8_t set);
72 static int nptv6_rewrite_internal(struct nptv6_cfg *cfg, struct mbuf **mp,
73     int offset);
74 static int nptv6_rewrite_external(struct nptv6_cfg *cfg, struct mbuf **mp,
75     int offset);
76 
77 #define	NPTV6_LOOKUP(chain, cmd)	\
78     (struct nptv6_cfg *)SRV_OBJECT((chain), (cmd)->arg1)
79 
80 #ifndef IN6_MASK_ADDR
81 #define IN6_MASK_ADDR(a, m)	do { \
82 	(a)->s6_addr32[0] &= (m)->s6_addr32[0]; \
83 	(a)->s6_addr32[1] &= (m)->s6_addr32[1]; \
84 	(a)->s6_addr32[2] &= (m)->s6_addr32[2]; \
85 	(a)->s6_addr32[3] &= (m)->s6_addr32[3]; \
86 } while (0)
87 #endif
88 #ifndef IN6_ARE_MASKED_ADDR_EQUAL
89 #define IN6_ARE_MASKED_ADDR_EQUAL(d, a, m)	(	\
90 	(((d)->s6_addr32[0] ^ (a)->s6_addr32[0]) & (m)->s6_addr32[0]) == 0 && \
91 	(((d)->s6_addr32[1] ^ (a)->s6_addr32[1]) & (m)->s6_addr32[1]) == 0 && \
92 	(((d)->s6_addr32[2] ^ (a)->s6_addr32[2]) & (m)->s6_addr32[2]) == 0 && \
93 	(((d)->s6_addr32[3] ^ (a)->s6_addr32[3]) & (m)->s6_addr32[3]) == 0 )
94 #endif
95 
96 #if 0
97 #define	NPTV6_DEBUG(fmt, ...)	do {			\
98 	printf("%s: " fmt "\n", __func__, ## __VA_ARGS__);	\
99 } while (0)
100 #define	NPTV6_IPDEBUG(fmt, ...)	do {			\
101 	char _s[INET6_ADDRSTRLEN], _d[INET6_ADDRSTRLEN];	\
102 	printf("%s: " fmt "\n", __func__, ## __VA_ARGS__);	\
103 } while (0)
104 #else
105 #define	NPTV6_DEBUG(fmt, ...)
106 #define	NPTV6_IPDEBUG(fmt, ...)
107 #endif
108 
109 static int
110 nptv6_getlasthdr(struct nptv6_cfg *cfg, struct mbuf *m, int *offset)
111 {
112 	struct ip6_hdr *ip6;
113 	struct ip6_hbh *hbh;
114 	int proto, hlen;
115 
116 	hlen = (offset == NULL) ? 0: *offset;
117 	if (m->m_len < hlen)
118 		return (-1);
119 	ip6 = mtodo(m, hlen);
120 	hlen += sizeof(*ip6);
121 	proto = ip6->ip6_nxt;
122 	while (proto == IPPROTO_HOPOPTS || proto == IPPROTO_ROUTING ||
123 	    proto == IPPROTO_DSTOPTS) {
124 		hbh = mtodo(m, hlen);
125 		if (m->m_len < hlen)
126 			return (-1);
127 		proto = hbh->ip6h_nxt;
128 		hlen += (hbh->ip6h_len + 1) << 3;
129 	}
130 	if (offset != NULL)
131 		*offset = hlen;
132 	return (proto);
133 }
134 
135 static int
136 nptv6_translate_icmpv6(struct nptv6_cfg *cfg, struct mbuf **mp, int offset)
137 {
138 	struct icmp6_hdr *icmp6;
139 	struct ip6_hdr *ip6;
140 	struct mbuf *m;
141 
142 	m = *mp;
143 	if (offset > m->m_len)
144 		return (-1);
145 	icmp6 = mtodo(m, offset);
146 	NPTV6_DEBUG("ICMPv6 type %d", icmp6->icmp6_type);
147 	switch (icmp6->icmp6_type) {
148 	case ICMP6_DST_UNREACH:
149 	case ICMP6_PACKET_TOO_BIG:
150 	case ICMP6_TIME_EXCEEDED:
151 	case ICMP6_PARAM_PROB:
152 		break;
153 	case ICMP6_ECHO_REQUEST:
154 	case ICMP6_ECHO_REPLY:
155 		/* nothing to translate */
156 		return (0);
157 	default:
158 		/*
159 		 * XXX: We can add some checks to not translate NDP and MLD
160 		 * messages. Currently user must explicitly allow these message
161 		 * types, otherwise packets will be dropped.
162 		 */
163 		return (-1);
164 	}
165 	offset += sizeof(*icmp6);
166 	if (offset + sizeof(*ip6) > m->m_pkthdr.len)
167 		return (-1);
168 	if (offset + sizeof(*ip6) > m->m_len)
169 		*mp = m = m_pullup(m, offset + sizeof(*ip6));
170 	if (m == NULL)
171 		return (-1);
172 	ip6 = mtodo(m, offset);
173 	NPTV6_IPDEBUG("offset %d, %s -> %s %d", offset,
174 	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
175 	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
176 	    ip6->ip6_nxt);
177 	if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_src,
178 	    &cfg->external, &cfg->mask))
179 		return (nptv6_rewrite_external(cfg, mp, offset));
180 	else if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_dst,
181 	    &cfg->internal, &cfg->mask))
182 		return (nptv6_rewrite_internal(cfg, mp, offset));
183 	/*
184 	 * Addresses in the inner IPv6 header doesn't matched to
185 	 * our prefixes.
186 	 */
187 	return (-1);
188 }
189 
190 static int
191 nptv6_search_index(struct nptv6_cfg *cfg, struct in6_addr *a)
192 {
193 	int idx;
194 
195 	if (cfg->flags & NPTV6_48PLEN)
196 		return (3);
197 
198 	/* Search suitable word index for adjustment */
199 	for (idx = 4; idx < 8; idx++)
200 		if (a->s6_addr16[idx] != 0xffff)
201 			break;
202 	/*
203 	 * RFC 6296 p3.7: If an NPTv6 Translator discovers a datagram with
204 	 * an IID of all-zeros while performing address mapping, that
205 	 * datagram MUST be dropped, and an ICMPv6 Parameter Problem error
206 	 * SHOULD be generated.
207 	 */
208 	if (idx == 8 ||
209 	    (a->s6_addr32[2] == 0 && a->s6_addr32[3] == 0))
210 		return (-1);
211 	return (idx);
212 }
213 
214 static void
215 nptv6_copy_addr(struct in6_addr *src, struct in6_addr *dst,
216     struct in6_addr *mask)
217 {
218 	int i;
219 
220 	for (i = 0; i < 8 && mask->s6_addr8[i] != 0; i++) {
221 		dst->s6_addr8[i] &=  ~mask->s6_addr8[i];
222 		dst->s6_addr8[i] |= src->s6_addr8[i] & mask->s6_addr8[i];
223 	}
224 }
225 
226 static int
227 nptv6_rewrite_internal(struct nptv6_cfg *cfg, struct mbuf **mp, int offset)
228 {
229 	struct in6_addr *addr;
230 	struct ip6_hdr *ip6;
231 	int idx, proto;
232 	uint16_t adj;
233 
234 	ip6 = mtodo(*mp, offset);
235 	NPTV6_IPDEBUG("offset %d, %s -> %s %d", offset,
236 	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
237 	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
238 	    ip6->ip6_nxt);
239 	if (offset == 0)
240 		addr = &ip6->ip6_src;
241 	else {
242 		/*
243 		 * When we rewriting inner IPv6 header, we need to rewrite
244 		 * destination address back to external prefix. The datagram in
245 		 * the ICMPv6 payload should looks like it was send from
246 		 * external prefix.
247 		 */
248 		addr = &ip6->ip6_dst;
249 	}
250 	idx = nptv6_search_index(cfg, addr);
251 	if (idx < 0) {
252 		/*
253 		 * Do not send ICMPv6 error when offset isn't zero.
254 		 * This means we are rewriting inner IPv6 header in the
255 		 * ICMPv6 error message.
256 		 */
257 		if (offset == 0) {
258 			icmp6_error2(*mp, ICMP6_DST_UNREACH,
259 			    ICMP6_DST_UNREACH_ADDR, 0, (*mp)->m_pkthdr.rcvif);
260 			*mp = NULL;
261 		}
262 		return (IP_FW_DENY);
263 	}
264 	adj = addr->s6_addr16[idx];
265 	nptv6_copy_addr(&cfg->external, addr, &cfg->mask);
266 	adj = cksum_add(adj, cfg->adjustment);
267 	if (adj == 0xffff)
268 		adj = 0;
269 	addr->s6_addr16[idx] = adj;
270 	if (offset == 0) {
271 		/*
272 		 * We may need to translate addresses in the inner IPv6
273 		 * header for ICMPv6 error messages.
274 		 */
275 		proto = nptv6_getlasthdr(cfg, *mp, &offset);
276 		if (proto < 0 || (proto == IPPROTO_ICMPV6 &&
277 		    nptv6_translate_icmpv6(cfg, mp, offset) != 0))
278 			return (IP_FW_DENY);
279 		NPTV6STAT_INC(cfg, in2ex);
280 	}
281 	return (0);
282 }
283 
284 static int
285 nptv6_rewrite_external(struct nptv6_cfg *cfg, struct mbuf **mp, int offset)
286 {
287 	struct in6_addr *addr;
288 	struct ip6_hdr *ip6;
289 	int idx, proto;
290 	uint16_t adj;
291 
292 	ip6 = mtodo(*mp, offset);
293 	NPTV6_IPDEBUG("offset %d, %s -> %s %d", offset,
294 	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
295 	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
296 	    ip6->ip6_nxt);
297 	if (offset == 0)
298 		addr = &ip6->ip6_dst;
299 	else {
300 		/*
301 		 * When we rewriting inner IPv6 header, we need to rewrite
302 		 * source address back to internal prefix. The datagram in
303 		 * the ICMPv6 payload should looks like it was send from
304 		 * internal prefix.
305 		 */
306 		addr = &ip6->ip6_src;
307 	}
308 	idx = nptv6_search_index(cfg, addr);
309 	if (idx < 0) {
310 		/*
311 		 * Do not send ICMPv6 error when offset isn't zero.
312 		 * This means we are rewriting inner IPv6 header in the
313 		 * ICMPv6 error message.
314 		 */
315 		if (offset == 0) {
316 			icmp6_error2(*mp, ICMP6_DST_UNREACH,
317 			    ICMP6_DST_UNREACH_ADDR, 0, (*mp)->m_pkthdr.rcvif);
318 			*mp = NULL;
319 		}
320 		return (IP_FW_DENY);
321 	}
322 	adj = addr->s6_addr16[idx];
323 	nptv6_copy_addr(&cfg->internal, addr, &cfg->mask);
324 	adj = cksum_add(adj, ~cfg->adjustment);
325 	if (adj == 0xffff)
326 		adj = 0;
327 	addr->s6_addr16[idx] = adj;
328 	if (offset == 0) {
329 		/*
330 		 * We may need to translate addresses in the inner IPv6
331 		 * header for ICMPv6 error messages.
332 		 */
333 		proto = nptv6_getlasthdr(cfg, *mp, &offset);
334 		if (proto < 0 || (proto == IPPROTO_ICMPV6 &&
335 		    nptv6_translate_icmpv6(cfg, mp, offset) != 0))
336 			return (IP_FW_DENY);
337 		NPTV6STAT_INC(cfg, ex2in);
338 	}
339 	return (0);
340 }
341 
342 /*
343  * ipfw external action handler.
344  */
345 static int
346 ipfw_nptv6(struct ip_fw_chain *chain, struct ip_fw_args *args,
347     ipfw_insn *cmd, int *done)
348 {
349 	struct ip6_hdr *ip6;
350 	struct nptv6_cfg *cfg;
351 	ipfw_insn *icmd;
352 	int ret;
353 
354 	*done = 0; /* try next rule if not matched */
355 	ret = IP_FW_DENY;
356 	icmd = cmd + 1;
357 	if (cmd->opcode != O_EXTERNAL_ACTION ||
358 	    cmd->arg1 != V_nptv6_eid ||
359 	    icmd->opcode != O_EXTERNAL_INSTANCE ||
360 	    (cfg = NPTV6_LOOKUP(chain, icmd)) == NULL)
361 		return (ret);
362 	/*
363 	 * We need act as router, so when forwarding is disabled -
364 	 * do nothing.
365 	 */
366 	if (V_ip6_forwarding == 0 || args->f_id.addr_type != 6)
367 		return (ret);
368 	/*
369 	 * NOTE: we expect ipfw_chk() did m_pullup() up to upper level
370 	 * protocol's headers. Also we skip some checks, that ip6_input(),
371 	 * ip6_forward(), ip6_fastfwd() and ipfw_chk() already did.
372 	 */
373 	ip6 = mtod(args->m, struct ip6_hdr *);
374 	NPTV6_IPDEBUG("eid %u, oid %u, %s -> %s %d",
375 	    cmd->arg1, icmd->arg1,
376 	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
377 	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
378 	    ip6->ip6_nxt);
379 	if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_src,
380 	    &cfg->internal, &cfg->mask)) {
381 		/*
382 		 * XXX: Do not translate packets when both src and dst
383 		 * are from internal prefix.
384 		 */
385 		if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_dst,
386 		    &cfg->internal, &cfg->mask))
387 			return (ret);
388 		ret = nptv6_rewrite_internal(cfg, &args->m, 0);
389 	} else if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_dst,
390 	    &cfg->external, &cfg->mask))
391 		ret = nptv6_rewrite_external(cfg, &args->m, 0);
392 	else
393 		return (ret);
394 	/*
395 	 * If address wasn't rewrited - free mbuf and terminate the search.
396 	 */
397 	if (ret != 0) {
398 		if (args->m != NULL) {
399 			m_freem(args->m);
400 			args->m = NULL; /* mark mbuf as consumed */
401 		}
402 		NPTV6STAT_INC(cfg, dropped);
403 		*done = 1;
404 	} else {
405 		/* Terminate the search if one_pass is set */
406 		*done = V_fw_one_pass;
407 		/* Update args->f_id when one_pass is off */
408 		if (*done == 0) {
409 			ip6 = mtod(args->m, struct ip6_hdr *);
410 			args->f_id.src_ip6 = ip6->ip6_src;
411 			args->f_id.dst_ip6 = ip6->ip6_dst;
412 		}
413 	}
414 	return (ret);
415 }
416 
417 static struct nptv6_cfg *
418 nptv6_alloc_config(const char *name, uint8_t set)
419 {
420 	struct nptv6_cfg *cfg;
421 
422 	cfg = malloc(sizeof(struct nptv6_cfg), M_IPFW, M_WAITOK | M_ZERO);
423 	COUNTER_ARRAY_ALLOC(cfg->stats, NPTV6STATS, M_WAITOK);
424 	cfg->no.name = cfg->name;
425 	cfg->no.etlv = IPFW_TLV_NPTV6_NAME;
426 	cfg->no.set = set;
427 	strlcpy(cfg->name, name, sizeof(cfg->name));
428 	return (cfg);
429 }
430 
431 static void
432 nptv6_free_config(struct nptv6_cfg *cfg)
433 {
434 
435 	COUNTER_ARRAY_FREE(cfg->stats, NPTV6STATS);
436 	free(cfg, M_IPFW);
437 }
438 
439 static void
440 nptv6_export_config(struct ip_fw_chain *ch, struct nptv6_cfg *cfg,
441     ipfw_nptv6_cfg *uc)
442 {
443 
444 	uc->internal = cfg->internal;
445 	uc->external = cfg->external;
446 	uc->plen = cfg->plen;
447 	uc->flags = cfg->flags & NPTV6_FLAGSMASK;
448 	uc->set = cfg->no.set;
449 	strlcpy(uc->name, cfg->no.name, sizeof(uc->name));
450 }
451 
452 struct nptv6_dump_arg {
453 	struct ip_fw_chain *ch;
454 	struct sockopt_data *sd;
455 };
456 
457 static int
458 export_config_cb(struct namedobj_instance *ni, struct named_object *no,
459     void *arg)
460 {
461 	struct nptv6_dump_arg *da = (struct nptv6_dump_arg *)arg;
462 	ipfw_nptv6_cfg *uc;
463 
464 	uc = (ipfw_nptv6_cfg *)ipfw_get_sopt_space(da->sd, sizeof(*uc));
465 	nptv6_export_config(da->ch, (struct nptv6_cfg *)no, uc);
466 	return (0);
467 }
468 
469 static struct nptv6_cfg *
470 nptv6_find(struct namedobj_instance *ni, const char *name, uint8_t set)
471 {
472 	struct nptv6_cfg *cfg;
473 
474 	cfg = (struct nptv6_cfg *)ipfw_objhash_lookup_name_type(ni, set,
475 	    IPFW_TLV_NPTV6_NAME, name);
476 
477 	return (cfg);
478 }
479 
480 static void
481 nptv6_calculate_adjustment(struct nptv6_cfg *cfg)
482 {
483 	uint16_t i, e;
484 	uint16_t *p;
485 
486 	/* Calculate checksum of internal prefix */
487 	for (i = 0, p = (uint16_t *)&cfg->internal;
488 	    p < (uint16_t *)(&cfg->internal + 1); p++)
489 		i = cksum_add(i, *p);
490 
491 	/* Calculate checksum of external prefix */
492 	for (e = 0, p = (uint16_t *)&cfg->external;
493 	    p < (uint16_t *)(&cfg->external + 1); p++)
494 		e = cksum_add(e, *p);
495 
496 	/* Adjustment value for Int->Ext direction */
497 	cfg->adjustment = cksum_add(~e, i);
498 }
499 
500 /*
501  * Creates new NPTv6 instance.
502  * Data layout (v0)(current):
503  * Request: [ ipfw_obj_lheader ipfw_nptv6_cfg ]
504  *
505  * Returns 0 on success
506  */
507 static int
508 nptv6_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
509     struct sockopt_data *sd)
510 {
511 	struct in6_addr mask;
512 	ipfw_obj_lheader *olh;
513 	ipfw_nptv6_cfg *uc;
514 	struct namedobj_instance *ni;
515 	struct nptv6_cfg *cfg;
516 
517 	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
518 		return (EINVAL);
519 
520 	olh = (ipfw_obj_lheader *)sd->kbuf;
521 	uc = (ipfw_nptv6_cfg *)(olh + 1);
522 	if (ipfw_check_object_name_generic(uc->name) != 0)
523 		return (EINVAL);
524 	if (uc->plen < 8 || uc->plen > 64 || uc->set >= IPFW_MAX_SETS)
525 		return (EINVAL);
526 	if (IN6_IS_ADDR_MULTICAST(&uc->internal) ||
527 	    IN6_IS_ADDR_MULTICAST(&uc->external) ||
528 	    IN6_IS_ADDR_UNSPECIFIED(&uc->internal) ||
529 	    IN6_IS_ADDR_UNSPECIFIED(&uc->external) ||
530 	    IN6_IS_ADDR_LINKLOCAL(&uc->internal) ||
531 	    IN6_IS_ADDR_LINKLOCAL(&uc->external))
532 		return (EINVAL);
533 	in6_prefixlen2mask(&mask, uc->plen);
534 	if (IN6_ARE_MASKED_ADDR_EQUAL(&uc->internal, &uc->external, &mask))
535 		return (EINVAL);
536 
537 	ni = CHAIN_TO_SRV(ch);
538 	IPFW_UH_RLOCK(ch);
539 	if (nptv6_find(ni, uc->name, uc->set) != NULL) {
540 		IPFW_UH_RUNLOCK(ch);
541 		return (EEXIST);
542 	}
543 	IPFW_UH_RUNLOCK(ch);
544 
545 	cfg = nptv6_alloc_config(uc->name, uc->set);
546 	cfg->plen = uc->plen;
547 	if (cfg->plen <= 48)
548 		cfg->flags |= NPTV6_48PLEN;
549 	cfg->internal = uc->internal;
550 	cfg->external = uc->external;
551 	cfg->mask = mask;
552 	IN6_MASK_ADDR(&cfg->internal, &mask);
553 	IN6_MASK_ADDR(&cfg->external, &mask);
554 	nptv6_calculate_adjustment(cfg);
555 
556 	IPFW_UH_WLOCK(ch);
557 	if (ipfw_objhash_alloc_idx(ni, &cfg->no.kidx) != 0) {
558 		IPFW_UH_WUNLOCK(ch);
559 		nptv6_free_config(cfg);
560 		return (ENOSPC);
561 	}
562 	ipfw_objhash_add(ni, &cfg->no);
563 	SRV_OBJECT(ch, cfg->no.kidx) = cfg;
564 	IPFW_UH_WUNLOCK(ch);
565 	return (0);
566 }
567 
568 /*
569  * Destroys NPTv6 instance.
570  * Data layout (v0)(current):
571  * Request: [ ipfw_obj_header ]
572  *
573  * Returns 0 on success
574  */
575 static int
576 nptv6_destroy(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
577     struct sockopt_data *sd)
578 {
579 	ipfw_obj_header *oh;
580 	struct nptv6_cfg *cfg;
581 
582 	if (sd->valsize != sizeof(*oh))
583 		return (EINVAL);
584 
585 	oh = (ipfw_obj_header *)sd->kbuf;
586 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0)
587 		return (EINVAL);
588 
589 	IPFW_UH_WLOCK(ch);
590 	cfg = nptv6_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
591 	if (cfg == NULL) {
592 		IPFW_UH_WUNLOCK(ch);
593 		return (ESRCH);
594 	}
595 	if (cfg->no.refcnt > 0) {
596 		IPFW_UH_WUNLOCK(ch);
597 		return (EBUSY);
598 	}
599 
600 	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
601 	ipfw_objhash_del(CHAIN_TO_SRV(ch), &cfg->no);
602 	ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), cfg->no.kidx);
603 	IPFW_UH_WUNLOCK(ch);
604 
605 	nptv6_free_config(cfg);
606 	return (0);
607 }
608 
609 /*
610  * Get or change nptv6 instance config.
611  * Request: [ ipfw_obj_header [ ipfw_nptv6_cfg ] ]
612  */
613 static int
614 nptv6_config(struct ip_fw_chain *chain, ip_fw3_opheader *op,
615     struct sockopt_data *sd)
616 {
617 
618 	return (EOPNOTSUPP);
619 }
620 
621 /*
622  * Lists all NPTv6 instances currently available in kernel.
623  * Data layout (v0)(current):
624  * Request: [ ipfw_obj_lheader ]
625  * Reply: [ ipfw_obj_lheader ipfw_nptv6_cfg x N ]
626  *
627  * Returns 0 on success
628  */
629 static int
630 nptv6_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
631     struct sockopt_data *sd)
632 {
633 	ipfw_obj_lheader *olh;
634 	struct nptv6_dump_arg da;
635 
636 	/* Check minimum header size */
637 	if (sd->valsize < sizeof(ipfw_obj_lheader))
638 		return (EINVAL);
639 
640 	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
641 
642 	IPFW_UH_RLOCK(ch);
643 	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
644 	    IPFW_TLV_NPTV6_NAME);
645 	olh->objsize = sizeof(ipfw_nptv6_cfg);
646 	olh->size = sizeof(*olh) + olh->count * olh->objsize;
647 
648 	if (sd->valsize < olh->size) {
649 		IPFW_UH_RUNLOCK(ch);
650 		return (ENOMEM);
651 	}
652 	memset(&da, 0, sizeof(da));
653 	da.ch = ch;
654 	da.sd = sd;
655 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
656 	    &da, IPFW_TLV_NPTV6_NAME);
657 	IPFW_UH_RUNLOCK(ch);
658 
659 	return (0);
660 }
661 
662 #define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
663 	(_stats)->_field = NPTV6STAT_FETCH(_cfg, _field)
664 static void
665 export_stats(struct ip_fw_chain *ch, struct nptv6_cfg *cfg,
666     struct ipfw_nptv6_stats *stats)
667 {
668 
669 	__COPY_STAT_FIELD(cfg, stats, in2ex);
670 	__COPY_STAT_FIELD(cfg, stats, ex2in);
671 	__COPY_STAT_FIELD(cfg, stats, dropped);
672 }
673 
674 /*
675  * Get NPTv6 statistics.
676  * Data layout (v0)(current):
677  * Request: [ ipfw_obj_header ]
678  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
679  *
680  * Returns 0 on success
681  */
682 static int
683 nptv6_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
684     struct sockopt_data *sd)
685 {
686 	struct ipfw_nptv6_stats stats;
687 	struct nptv6_cfg *cfg;
688 	ipfw_obj_header *oh;
689 	ipfw_obj_ctlv *ctlv;
690 	size_t sz;
691 
692 	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
693 	if (sd->valsize % sizeof(uint64_t))
694 		return (EINVAL);
695 	if (sd->valsize < sz)
696 		return (ENOMEM);
697 	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
698 	if (oh == NULL)
699 		return (EINVAL);
700 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
701 	    oh->ntlv.set >= IPFW_MAX_SETS)
702 		return (EINVAL);
703 	memset(&stats, 0, sizeof(stats));
704 
705 	IPFW_UH_RLOCK(ch);
706 	cfg = nptv6_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
707 	if (cfg == NULL) {
708 		IPFW_UH_RUNLOCK(ch);
709 		return (ESRCH);
710 	}
711 	export_stats(ch, cfg, &stats);
712 	IPFW_UH_RUNLOCK(ch);
713 
714 	ctlv = (ipfw_obj_ctlv *)(oh + 1);
715 	memset(ctlv, 0, sizeof(*ctlv));
716 	ctlv->head.type = IPFW_TLV_COUNTERS;
717 	ctlv->head.length = sz - sizeof(ipfw_obj_header);
718 	ctlv->count = sizeof(stats) / sizeof(uint64_t);
719 	ctlv->objsize = sizeof(uint64_t);
720 	ctlv->version = 1;
721 	memcpy(ctlv + 1, &stats, sizeof(stats));
722 	return (0);
723 }
724 
725 /*
726  * Reset NPTv6 statistics.
727  * Data layout (v0)(current):
728  * Request: [ ipfw_obj_header ]
729  *
730  * Returns 0 on success
731  */
732 static int
733 nptv6_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
734     struct sockopt_data *sd)
735 {
736 	struct nptv6_cfg *cfg;
737 	ipfw_obj_header *oh;
738 
739 	if (sd->valsize != sizeof(*oh))
740 		return (EINVAL);
741 	oh = (ipfw_obj_header *)sd->kbuf;
742 	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
743 	    oh->ntlv.set >= IPFW_MAX_SETS)
744 		return (EINVAL);
745 
746 	IPFW_UH_WLOCK(ch);
747 	cfg = nptv6_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
748 	if (cfg == NULL) {
749 		IPFW_UH_WUNLOCK(ch);
750 		return (ESRCH);
751 	}
752 	COUNTER_ARRAY_ZERO(cfg->stats, NPTV6STATS);
753 	IPFW_UH_WUNLOCK(ch);
754 	return (0);
755 }
756 
757 static struct ipfw_sopt_handler	scodes[] = {
758 	{ IP_FW_NPTV6_CREATE, 0,	HDIR_SET,	nptv6_create },
759 	{ IP_FW_NPTV6_DESTROY,0,	HDIR_SET,	nptv6_destroy },
760 	{ IP_FW_NPTV6_CONFIG, 0,	HDIR_BOTH,	nptv6_config },
761 	{ IP_FW_NPTV6_LIST,   0,	HDIR_GET,	nptv6_list },
762 	{ IP_FW_NPTV6_STATS,  0,	HDIR_GET,	nptv6_stats },
763 	{ IP_FW_NPTV6_RESET_STATS,0,	HDIR_SET,	nptv6_reset_stats },
764 };
765 
766 static int
767 nptv6_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
768 {
769 	ipfw_insn *icmd;
770 
771 	icmd = cmd - 1;
772 	NPTV6_DEBUG("opcode %d, arg1 %d, opcode0 %d, arg1 %d",
773 	    cmd->opcode, cmd->arg1, icmd->opcode, icmd->arg1);
774 	if (icmd->opcode != O_EXTERNAL_ACTION ||
775 	    icmd->arg1 != V_nptv6_eid)
776 		return (1);
777 
778 	*puidx = cmd->arg1;
779 	*ptype = 0;
780 	return (0);
781 }
782 
783 static void
784 nptv6_update_arg1(ipfw_insn *cmd, uint16_t idx)
785 {
786 
787 	cmd->arg1 = idx;
788 	NPTV6_DEBUG("opcode %d, arg1 -> %d", cmd->opcode, cmd->arg1);
789 }
790 
791 static int
792 nptv6_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
793     struct named_object **pno)
794 {
795 	int err;
796 
797 	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
798 	    IPFW_TLV_NPTV6_NAME, pno);
799 	NPTV6_DEBUG("uidx %u, type %u, err %d", ti->uidx, ti->type, err);
800 	return (err);
801 }
802 
803 static struct named_object *
804 nptv6_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
805 {
806 	struct namedobj_instance *ni;
807 	struct named_object *no;
808 
809 	IPFW_UH_WLOCK_ASSERT(ch);
810 	ni = CHAIN_TO_SRV(ch);
811 	no = ipfw_objhash_lookup_kidx(ni, idx);
812 	KASSERT(no != NULL, ("NPT with index %d not found", idx));
813 
814 	NPTV6_DEBUG("kidx %u -> %s", idx, no->name);
815 	return (no);
816 }
817 
818 static int
819 nptv6_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
820     enum ipfw_sets_cmd cmd)
821 {
822 
823 	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NPTV6_NAME,
824 	    set, new_set, cmd));
825 }
826 
827 static struct opcode_obj_rewrite opcodes[] = {
828 	{
829 		.opcode	= O_EXTERNAL_INSTANCE,
830 		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
831 		.classifier = nptv6_classify,
832 		.update = nptv6_update_arg1,
833 		.find_byname = nptv6_findbyname,
834 		.find_bykidx = nptv6_findbykidx,
835 		.manage_sets = nptv6_manage_sets,
836 	},
837 };
838 
839 static int
840 destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
841     void *arg)
842 {
843 	struct nptv6_cfg *cfg;
844 	struct ip_fw_chain *ch;
845 
846 	ch = (struct ip_fw_chain *)arg;
847 	IPFW_UH_WLOCK_ASSERT(ch);
848 
849 	cfg = (struct nptv6_cfg *)SRV_OBJECT(ch, no->kidx);
850 	SRV_OBJECT(ch, no->kidx) = NULL;
851 	ipfw_objhash_del(ni, &cfg->no);
852 	ipfw_objhash_free_idx(ni, cfg->no.kidx);
853 	nptv6_free_config(cfg);
854 	return (0);
855 }
856 
857 int
858 nptv6_init(struct ip_fw_chain *ch, int first)
859 {
860 
861 	V_nptv6_eid = ipfw_add_eaction(ch, ipfw_nptv6, "nptv6");
862 	if (V_nptv6_eid == 0)
863 		return (ENXIO);
864 	IPFW_ADD_SOPT_HANDLER(first, scodes);
865 	IPFW_ADD_OBJ_REWRITER(first, opcodes);
866 	return (0);
867 }
868 
869 void
870 nptv6_uninit(struct ip_fw_chain *ch, int last)
871 {
872 
873 	IPFW_DEL_OBJ_REWRITER(last, opcodes);
874 	IPFW_DEL_SOPT_HANDLER(last, scodes);
875 	ipfw_del_eaction(ch, V_nptv6_eid);
876 	/*
877 	 * Since we already have deregistered external action,
878 	 * our named objects become unaccessible via rules, because
879 	 * all rules were truncated by ipfw_del_eaction().
880 	 * So, we can unlink and destroy our named objects without holding
881 	 * IPFW_WLOCK().
882 	 */
883 	IPFW_UH_WLOCK(ch);
884 	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
885 	    IPFW_TLV_NPTV6_NAME);
886 	V_nptv6_eid = 0;
887 	IPFW_UH_WUNLOCK(ch);
888 }
889 
890