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/eventhandler.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/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/netisr.h>
51#include <net/pfil.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 <netinet/ip6.h>
58#include <netinet/icmp6.h>
59#include <netinet6/in6_var.h>
60#include <netinet6/ip6_var.h>
61
62#include <netpfil/ipfw/ip_fw_private.h>
63#include <netpfil/ipfw/nptv6/nptv6.h>
64
65VNET_DEFINE_STATIC(uint16_t, nptv6_eid) = 0;
66#define	V_nptv6_eid	VNET(nptv6_eid)
67#define	IPFW_TLV_NPTV6_NAME	IPFW_TLV_EACTION_NAME(V_nptv6_eid)
68
69static eventhandler_tag nptv6_ifaddr_event;
70
71static struct nptv6_cfg *nptv6_alloc_config(const char *name, uint8_t set);
72static void nptv6_free_config(struct nptv6_cfg *cfg);
73static struct nptv6_cfg *nptv6_find(struct namedobj_instance *ni,
74    const char *name, uint8_t set);
75static int nptv6_rewrite_internal(struct nptv6_cfg *cfg, struct mbuf **mp,
76    int offset);
77static int nptv6_rewrite_external(struct nptv6_cfg *cfg, struct mbuf **mp,
78    int offset);
79
80#define	NPTV6_LOOKUP(chain, cmd)	\
81    (struct nptv6_cfg *)SRV_OBJECT((chain), (cmd)->arg1)
82
83#ifndef IN6_MASK_ADDR
84#define IN6_MASK_ADDR(a, m)	do { \
85	(a)->s6_addr32[0] &= (m)->s6_addr32[0]; \
86	(a)->s6_addr32[1] &= (m)->s6_addr32[1]; \
87	(a)->s6_addr32[2] &= (m)->s6_addr32[2]; \
88	(a)->s6_addr32[3] &= (m)->s6_addr32[3]; \
89} while (0)
90#endif
91#ifndef IN6_ARE_MASKED_ADDR_EQUAL
92#define IN6_ARE_MASKED_ADDR_EQUAL(d, a, m)	(	\
93	(((d)->s6_addr32[0] ^ (a)->s6_addr32[0]) & (m)->s6_addr32[0]) == 0 && \
94	(((d)->s6_addr32[1] ^ (a)->s6_addr32[1]) & (m)->s6_addr32[1]) == 0 && \
95	(((d)->s6_addr32[2] ^ (a)->s6_addr32[2]) & (m)->s6_addr32[2]) == 0 && \
96	(((d)->s6_addr32[3] ^ (a)->s6_addr32[3]) & (m)->s6_addr32[3]) == 0 )
97#endif
98
99#if 0
100#define	NPTV6_DEBUG(fmt, ...)	do {			\
101	printf("%s: " fmt "\n", __func__, ## __VA_ARGS__);	\
102} while (0)
103#define	NPTV6_IPDEBUG(fmt, ...)	do {			\
104	char _s[INET6_ADDRSTRLEN], _d[INET6_ADDRSTRLEN];	\
105	printf("%s: " fmt "\n", __func__, ## __VA_ARGS__);	\
106} while (0)
107#else
108#define	NPTV6_DEBUG(fmt, ...)
109#define	NPTV6_IPDEBUG(fmt, ...)
110#endif
111
112static int
113nptv6_getlasthdr(struct nptv6_cfg *cfg, struct mbuf *m, int *offset)
114{
115	struct ip6_hdr *ip6;
116	struct ip6_hbh *hbh;
117	int proto, hlen;
118
119	hlen = (offset == NULL) ? 0: *offset;
120	if (m->m_len < hlen)
121		return (-1);
122	ip6 = mtodo(m, hlen);
123	hlen += sizeof(*ip6);
124	proto = ip6->ip6_nxt;
125	while (proto == IPPROTO_HOPOPTS || proto == IPPROTO_ROUTING ||
126	    proto == IPPROTO_DSTOPTS) {
127		hbh = mtodo(m, hlen);
128		if (m->m_len < hlen)
129			return (-1);
130		proto = hbh->ip6h_nxt;
131		hlen += (hbh->ip6h_len + 1) << 3;
132	}
133	if (offset != NULL)
134		*offset = hlen;
135	return (proto);
136}
137
138static int
139nptv6_translate_icmpv6(struct nptv6_cfg *cfg, struct mbuf **mp, int offset)
140{
141	struct icmp6_hdr *icmp6;
142	struct ip6_hdr *ip6;
143	struct mbuf *m;
144
145	m = *mp;
146	if (offset > m->m_len)
147		return (-1);
148	icmp6 = mtodo(m, offset);
149	NPTV6_DEBUG("ICMPv6 type %d", icmp6->icmp6_type);
150	switch (icmp6->icmp6_type) {
151	case ICMP6_DST_UNREACH:
152	case ICMP6_PACKET_TOO_BIG:
153	case ICMP6_TIME_EXCEEDED:
154	case ICMP6_PARAM_PROB:
155		break;
156	case ICMP6_ECHO_REQUEST:
157	case ICMP6_ECHO_REPLY:
158		/* nothing to translate */
159		return (0);
160	default:
161		/*
162		 * XXX: We can add some checks to not translate NDP and MLD
163		 * messages. Currently user must explicitly allow these message
164		 * types, otherwise packets will be dropped.
165		 */
166		return (-1);
167	}
168	offset += sizeof(*icmp6);
169	if (offset + sizeof(*ip6) > m->m_pkthdr.len)
170		return (-1);
171	if (offset + sizeof(*ip6) > m->m_len)
172		*mp = m = m_pullup(m, offset + sizeof(*ip6));
173	if (m == NULL)
174		return (-1);
175	ip6 = mtodo(m, offset);
176	NPTV6_IPDEBUG("offset %d, %s -> %s %d", offset,
177	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
178	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
179	    ip6->ip6_nxt);
180	if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_src,
181	    &cfg->external, &cfg->mask))
182		return (nptv6_rewrite_external(cfg, mp, offset));
183	else if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_dst,
184	    &cfg->internal, &cfg->mask))
185		return (nptv6_rewrite_internal(cfg, mp, offset));
186	/*
187	 * Addresses in the inner IPv6 header doesn't matched to
188	 * our prefixes.
189	 */
190	return (-1);
191}
192
193static int
194nptv6_search_index(struct nptv6_cfg *cfg, struct in6_addr *a)
195{
196	int idx;
197
198	if (cfg->flags & NPTV6_48PLEN)
199		return (3);
200
201	/* Search suitable word index for adjustment */
202	for (idx = 4; idx < 8; idx++)
203		if (a->s6_addr16[idx] != 0xffff)
204			break;
205	/*
206	 * RFC 6296 p3.7: If an NPTv6 Translator discovers a datagram with
207	 * an IID of all-zeros while performing address mapping, that
208	 * datagram MUST be dropped, and an ICMPv6 Parameter Problem error
209	 * SHOULD be generated.
210	 */
211	if (idx == 8 ||
212	    (a->s6_addr32[2] == 0 && a->s6_addr32[3] == 0))
213		return (-1);
214	return (idx);
215}
216
217static void
218nptv6_copy_addr(struct in6_addr *src, struct in6_addr *dst,
219    struct in6_addr *mask)
220{
221	int i;
222
223	for (i = 0; i < 8 && mask->s6_addr8[i] != 0; i++) {
224		dst->s6_addr8[i] &=  ~mask->s6_addr8[i];
225		dst->s6_addr8[i] |= src->s6_addr8[i] & mask->s6_addr8[i];
226	}
227}
228
229static int
230nptv6_rewrite_internal(struct nptv6_cfg *cfg, struct mbuf **mp, int offset)
231{
232	struct in6_addr *addr;
233	struct ip6_hdr *ip6;
234	int idx, proto;
235	uint16_t adj;
236
237	ip6 = mtodo(*mp, offset);
238	NPTV6_IPDEBUG("offset %d, %s -> %s %d", offset,
239	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
240	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
241	    ip6->ip6_nxt);
242	if (offset == 0)
243		addr = &ip6->ip6_src;
244	else {
245		/*
246		 * When we rewriting inner IPv6 header, we need to rewrite
247		 * destination address back to external prefix. The datagram in
248		 * the ICMPv6 payload should looks like it was send from
249		 * external prefix.
250		 */
251		addr = &ip6->ip6_dst;
252	}
253	idx = nptv6_search_index(cfg, addr);
254	if (idx < 0) {
255		/*
256		 * Do not send ICMPv6 error when offset isn't zero.
257		 * This means we are rewriting inner IPv6 header in the
258		 * ICMPv6 error message.
259		 */
260		if (offset == 0) {
261			icmp6_error2(*mp, ICMP6_DST_UNREACH,
262			    ICMP6_DST_UNREACH_ADDR, 0, (*mp)->m_pkthdr.rcvif);
263			*mp = NULL;
264		}
265		return (IP_FW_DENY);
266	}
267	adj = addr->s6_addr16[idx];
268	nptv6_copy_addr(&cfg->external, addr, &cfg->mask);
269	adj = cksum_add(adj, cfg->adjustment);
270	if (adj == 0xffff)
271		adj = 0;
272	addr->s6_addr16[idx] = adj;
273	if (offset == 0) {
274		/*
275		 * We may need to translate addresses in the inner IPv6
276		 * header for ICMPv6 error messages.
277		 */
278		proto = nptv6_getlasthdr(cfg, *mp, &offset);
279		if (proto < 0 || (proto == IPPROTO_ICMPV6 &&
280		    nptv6_translate_icmpv6(cfg, mp, offset) != 0))
281			return (IP_FW_DENY);
282		NPTV6STAT_INC(cfg, in2ex);
283	}
284	return (0);
285}
286
287static int
288nptv6_rewrite_external(struct nptv6_cfg *cfg, struct mbuf **mp, int offset)
289{
290	struct in6_addr *addr;
291	struct ip6_hdr *ip6;
292	int idx, proto;
293	uint16_t adj;
294
295	ip6 = mtodo(*mp, offset);
296	NPTV6_IPDEBUG("offset %d, %s -> %s %d", offset,
297	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
298	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
299	    ip6->ip6_nxt);
300	if (offset == 0)
301		addr = &ip6->ip6_dst;
302	else {
303		/*
304		 * When we rewriting inner IPv6 header, we need to rewrite
305		 * source address back to internal prefix. The datagram in
306		 * the ICMPv6 payload should looks like it was send from
307		 * internal prefix.
308		 */
309		addr = &ip6->ip6_src;
310	}
311	idx = nptv6_search_index(cfg, addr);
312	if (idx < 0) {
313		/*
314		 * Do not send ICMPv6 error when offset isn't zero.
315		 * This means we are rewriting inner IPv6 header in the
316		 * ICMPv6 error message.
317		 */
318		if (offset == 0) {
319			icmp6_error2(*mp, ICMP6_DST_UNREACH,
320			    ICMP6_DST_UNREACH_ADDR, 0, (*mp)->m_pkthdr.rcvif);
321			*mp = NULL;
322		}
323		return (IP_FW_DENY);
324	}
325	adj = addr->s6_addr16[idx];
326	nptv6_copy_addr(&cfg->internal, addr, &cfg->mask);
327	adj = cksum_add(adj, ~cfg->adjustment);
328	if (adj == 0xffff)
329		adj = 0;
330	addr->s6_addr16[idx] = adj;
331	if (offset == 0) {
332		/*
333		 * We may need to translate addresses in the inner IPv6
334		 * header for ICMPv6 error messages.
335		 */
336		proto = nptv6_getlasthdr(cfg, *mp, &offset);
337		if (proto < 0 || (proto == IPPROTO_ICMPV6 &&
338		    nptv6_translate_icmpv6(cfg, mp, offset) != 0))
339			return (IP_FW_DENY);
340		NPTV6STAT_INC(cfg, ex2in);
341	}
342	return (0);
343}
344
345/*
346 * ipfw external action handler.
347 */
348static int
349ipfw_nptv6(struct ip_fw_chain *chain, struct ip_fw_args *args,
350    ipfw_insn *cmd, int *done)
351{
352	struct ip6_hdr *ip6;
353	struct nptv6_cfg *cfg;
354	ipfw_insn *icmd;
355	int ret;
356
357	*done = 0; /* try next rule if not matched */
358	ret = IP_FW_DENY;
359	icmd = cmd + 1;
360	if (cmd->opcode != O_EXTERNAL_ACTION ||
361	    cmd->arg1 != V_nptv6_eid ||
362	    icmd->opcode != O_EXTERNAL_INSTANCE ||
363	    (cfg = NPTV6_LOOKUP(chain, icmd)) == NULL ||
364	    (cfg->flags & NPTV6_READY) == 0)
365		return (ret);
366	/*
367	 * We need act as router, so when forwarding is disabled -
368	 * do nothing.
369	 */
370	if (V_ip6_forwarding == 0 || args->f_id.addr_type != 6)
371		return (ret);
372	/*
373	 * NOTE: we expect ipfw_chk() did m_pullup() up to upper level
374	 * protocol's headers. Also we skip some checks, that ip6_input(),
375	 * ip6_forward(), ip6_fastfwd() and ipfw_chk() already did.
376	 */
377	ip6 = mtod(args->m, struct ip6_hdr *);
378	NPTV6_IPDEBUG("eid %u, oid %u, %s -> %s %d",
379	    cmd->arg1, icmd->arg1,
380	    inet_ntop(AF_INET6, &ip6->ip6_src, _s, sizeof(_s)),
381	    inet_ntop(AF_INET6, &ip6->ip6_dst, _d, sizeof(_d)),
382	    ip6->ip6_nxt);
383	if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_src,
384	    &cfg->internal, &cfg->mask)) {
385		/*
386		 * XXX: Do not translate packets when both src and dst
387		 * are from internal prefix.
388		 */
389		if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_dst,
390		    &cfg->internal, &cfg->mask))
391			return (ret);
392		ret = nptv6_rewrite_internal(cfg, &args->m, 0);
393	} else if (IN6_ARE_MASKED_ADDR_EQUAL(&ip6->ip6_dst,
394	    &cfg->external, &cfg->mask))
395		ret = nptv6_rewrite_external(cfg, &args->m, 0);
396	else
397		return (ret);
398	/*
399	 * If address wasn't rewrited - free mbuf and terminate the search.
400	 */
401	if (ret != 0) {
402		if (args->m != NULL) {
403			m_freem(args->m);
404			args->m = NULL; /* mark mbuf as consumed */
405		}
406		NPTV6STAT_INC(cfg, dropped);
407		*done = 1;
408	} else {
409		/* Terminate the search if one_pass is set */
410		*done = V_fw_one_pass;
411		/* Update args->f_id when one_pass is off */
412		if (*done == 0) {
413			ip6 = mtod(args->m, struct ip6_hdr *);
414			args->f_id.src_ip6 = ip6->ip6_src;
415			args->f_id.dst_ip6 = ip6->ip6_dst;
416		}
417	}
418	return (ret);
419}
420
421static struct nptv6_cfg *
422nptv6_alloc_config(const char *name, uint8_t set)
423{
424	struct nptv6_cfg *cfg;
425
426	cfg = malloc(sizeof(struct nptv6_cfg), M_IPFW, M_WAITOK | M_ZERO);
427	COUNTER_ARRAY_ALLOC(cfg->stats, NPTV6STATS, M_WAITOK);
428	cfg->no.name = cfg->name;
429	cfg->no.etlv = IPFW_TLV_NPTV6_NAME;
430	cfg->no.set = set;
431	strlcpy(cfg->name, name, sizeof(cfg->name));
432	return (cfg);
433}
434
435static void
436nptv6_free_config(struct nptv6_cfg *cfg)
437{
438
439	COUNTER_ARRAY_FREE(cfg->stats, NPTV6STATS);
440	free(cfg, M_IPFW);
441}
442
443static void
444nptv6_export_config(struct ip_fw_chain *ch, struct nptv6_cfg *cfg,
445    ipfw_nptv6_cfg *uc)
446{
447
448	uc->internal = cfg->internal;
449	if (cfg->flags & NPTV6_DYNAMIC_PREFIX)
450		memcpy(uc->if_name, cfg->if_name, IF_NAMESIZE);
451	else
452		uc->external = cfg->external;
453	uc->plen = cfg->plen;
454	uc->flags = cfg->flags & NPTV6_FLAGSMASK;
455	uc->set = cfg->no.set;
456	strlcpy(uc->name, cfg->no.name, sizeof(uc->name));
457}
458
459struct nptv6_dump_arg {
460	struct ip_fw_chain *ch;
461	struct sockopt_data *sd;
462};
463
464static int
465export_config_cb(struct namedobj_instance *ni, struct named_object *no,
466    void *arg)
467{
468	struct nptv6_dump_arg *da = (struct nptv6_dump_arg *)arg;
469	ipfw_nptv6_cfg *uc;
470
471	uc = (ipfw_nptv6_cfg *)ipfw_get_sopt_space(da->sd, sizeof(*uc));
472	nptv6_export_config(da->ch, (struct nptv6_cfg *)no, uc);
473	return (0);
474}
475
476static struct nptv6_cfg *
477nptv6_find(struct namedobj_instance *ni, const char *name, uint8_t set)
478{
479	struct nptv6_cfg *cfg;
480
481	cfg = (struct nptv6_cfg *)ipfw_objhash_lookup_name_type(ni, set,
482	    IPFW_TLV_NPTV6_NAME, name);
483
484	return (cfg);
485}
486
487static void
488nptv6_calculate_adjustment(struct nptv6_cfg *cfg)
489{
490	uint16_t i, e;
491	uint16_t *p;
492
493	/* Calculate checksum of internal prefix */
494	for (i = 0, p = (uint16_t *)&cfg->internal;
495	    p < (uint16_t *)(&cfg->internal + 1); p++)
496		i = cksum_add(i, *p);
497
498	/* Calculate checksum of external prefix */
499	for (e = 0, p = (uint16_t *)&cfg->external;
500	    p < (uint16_t *)(&cfg->external + 1); p++)
501		e = cksum_add(e, *p);
502
503	/* Adjustment value for Int->Ext direction */
504	cfg->adjustment = cksum_add(~e, i);
505}
506
507static int
508nptv6_check_prefix(const struct in6_addr *addr)
509{
510
511	if (IN6_IS_ADDR_MULTICAST(addr) ||
512	    IN6_IS_ADDR_LINKLOCAL(addr) ||
513	    IN6_IS_ADDR_LOOPBACK(addr) ||
514	    IN6_IS_ADDR_UNSPECIFIED(addr))
515		return (EINVAL);
516	return (0);
517}
518
519static void
520nptv6_set_external(struct nptv6_cfg *cfg, struct in6_addr *addr)
521{
522
523	cfg->external = *addr;
524	IN6_MASK_ADDR(&cfg->external, &cfg->mask);
525	nptv6_calculate_adjustment(cfg);
526	cfg->flags |= NPTV6_READY;
527}
528
529/*
530 * Try to determine what prefix to use as external for
531 * configured interface name.
532 */
533static void
534nptv6_find_prefix(struct ip_fw_chain *ch, struct nptv6_cfg *cfg,
535    struct ifnet *ifp)
536{
537	struct ifaddr *ifa;
538	struct in6_ifaddr *ia;
539
540	MPASS(cfg->flags & NPTV6_DYNAMIC_PREFIX);
541	IPFW_UH_WLOCK_ASSERT(ch);
542
543	if (ifp == NULL) {
544		ifp = ifunit_ref(cfg->if_name);
545		if (ifp == NULL)
546			return;
547	}
548	if_addr_rlock(ifp);
549	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
550		if (ifa->ifa_addr->sa_family != AF_INET6)
551			continue;
552		ia = (struct in6_ifaddr *)ifa;
553		if (nptv6_check_prefix(&ia->ia_addr.sin6_addr) ||
554		    IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
555		    &cfg->internal, &cfg->mask))
556			continue;
557		/* Suitable address is found. */
558		nptv6_set_external(cfg, &ia->ia_addr.sin6_addr);
559		break;
560	}
561	if_addr_runlock(ifp);
562	if_rele(ifp);
563}
564
565struct ifaddr_event_args {
566	struct ifnet *ifp;
567	const struct in6_addr *addr;
568	int event;
569};
570
571static int
572ifaddr_cb(struct namedobj_instance *ni, struct named_object *no,
573    void *arg)
574{
575	struct ifaddr_event_args *args;
576	struct ip_fw_chain *ch;
577	struct nptv6_cfg *cfg;
578
579	ch = &V_layer3_chain;
580	cfg = (struct nptv6_cfg *)SRV_OBJECT(ch, no->kidx);
581	if ((cfg->flags & NPTV6_DYNAMIC_PREFIX) == 0)
582		return (0);
583
584	args = arg;
585	/* If interface name doesn't match, ignore */
586	if (strncmp(args->ifp->if_xname, cfg->if_name, IF_NAMESIZE))
587		return (0);
588	if (args->ifp->if_flags & IFF_DYING) { /* XXX: is it possible? */
589		cfg->flags &= ~NPTV6_READY;
590		return (0);
591	}
592	if (args->event == IFADDR_EVENT_DEL) {
593		/* If instance is not ready, ignore */
594		if ((cfg->flags & NPTV6_READY) == 0)
595			return (0);
596		/* If address does not match the external prefix, ignore */
597		if (IN6_ARE_MASKED_ADDR_EQUAL(&cfg->external, args->addr,
598		    &cfg->mask) != 0)
599			return (0);
600		/* Otherwise clear READY flag */
601		cfg->flags &= ~NPTV6_READY;
602	} else {/* IFADDR_EVENT_ADD */
603		/* If instance is already ready, ignore */
604		if (cfg->flags & NPTV6_READY)
605			return (0);
606		/* If address is not suitable for prefix, ignore */
607		if (nptv6_check_prefix(args->addr) ||
608		    IN6_ARE_MASKED_ADDR_EQUAL(args->addr, &cfg->internal,
609		    &cfg->mask))
610			return (0);
611		/* FALLTHROUGH */
612	}
613	MPASS(!(cfg->flags & NPTV6_READY));
614	/* Try to determine the prefix */
615	if_ref(args->ifp);
616	nptv6_find_prefix(ch, cfg, args->ifp);
617	return (0);
618}
619
620static void
621nptv6_ifaddrevent_handler(void *arg __unused, struct ifnet *ifp,
622    struct ifaddr *ifa, int event)
623{
624	struct ifaddr_event_args args;
625	struct ip_fw_chain *ch;
626
627	if (ifa->ifa_addr->sa_family != AF_INET6)
628		return;
629
630	args.ifp = ifp;
631	args.addr = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
632	args.event = event;
633
634	ch = &V_layer3_chain;
635	IPFW_UH_WLOCK(ch);
636	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), ifaddr_cb, &args,
637	    IPFW_TLV_NPTV6_NAME);
638	IPFW_UH_WUNLOCK(ch);
639}
640
641/*
642 * Creates new NPTv6 instance.
643 * Data layout (v0)(current):
644 * Request: [ ipfw_obj_lheader ipfw_nptv6_cfg ]
645 *
646 * Returns 0 on success
647 */
648static int
649nptv6_create(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
650    struct sockopt_data *sd)
651{
652	struct in6_addr mask;
653	ipfw_obj_lheader *olh;
654	ipfw_nptv6_cfg *uc;
655	struct namedobj_instance *ni;
656	struct nptv6_cfg *cfg;
657
658	if (sd->valsize != sizeof(*olh) + sizeof(*uc))
659		return (EINVAL);
660
661	olh = (ipfw_obj_lheader *)sd->kbuf;
662	uc = (ipfw_nptv6_cfg *)(olh + 1);
663	if (ipfw_check_object_name_generic(uc->name) != 0)
664		return (EINVAL);
665	if (uc->plen < 8 || uc->plen > 64 || uc->set >= IPFW_MAX_SETS)
666		return (EINVAL);
667	if (nptv6_check_prefix(&uc->internal))
668		return (EINVAL);
669	in6_prefixlen2mask(&mask, uc->plen);
670	if ((uc->flags & NPTV6_DYNAMIC_PREFIX) == 0 && (
671	    nptv6_check_prefix(&uc->external) ||
672	    IN6_ARE_MASKED_ADDR_EQUAL(&uc->external, &uc->internal, &mask)))
673		return (EINVAL);
674
675	ni = CHAIN_TO_SRV(ch);
676	IPFW_UH_RLOCK(ch);
677	if (nptv6_find(ni, uc->name, uc->set) != NULL) {
678		IPFW_UH_RUNLOCK(ch);
679		return (EEXIST);
680	}
681	IPFW_UH_RUNLOCK(ch);
682
683	cfg = nptv6_alloc_config(uc->name, uc->set);
684	cfg->plen = uc->plen;
685	cfg->flags = uc->flags & NPTV6_FLAGSMASK;
686	if (cfg->plen <= 48)
687		cfg->flags |= NPTV6_48PLEN;
688	cfg->mask = mask;
689	cfg->internal = uc->internal;
690	IN6_MASK_ADDR(&cfg->internal, &mask);
691	if (cfg->flags & NPTV6_DYNAMIC_PREFIX)
692		memcpy(cfg->if_name, uc->if_name, IF_NAMESIZE);
693	else
694		nptv6_set_external(cfg, &uc->external);
695
696	if ((uc->flags & NPTV6_DYNAMIC_PREFIX) != 0 &&
697	    nptv6_ifaddr_event == NULL)
698		nptv6_ifaddr_event = EVENTHANDLER_REGISTER(
699		    ifaddr_event_ext, nptv6_ifaddrevent_handler, NULL,
700		    EVENTHANDLER_PRI_ANY);
701
702	IPFW_UH_WLOCK(ch);
703	if (ipfw_objhash_alloc_idx(ni, &cfg->no.kidx) != 0) {
704		IPFW_UH_WUNLOCK(ch);
705		nptv6_free_config(cfg);
706		return (ENOSPC);
707	}
708	ipfw_objhash_add(ni, &cfg->no);
709	SRV_OBJECT(ch, cfg->no.kidx) = cfg;
710	if (cfg->flags & NPTV6_DYNAMIC_PREFIX)
711		nptv6_find_prefix(ch, cfg, NULL);
712	IPFW_UH_WUNLOCK(ch);
713
714	return (0);
715}
716
717/*
718 * Destroys NPTv6 instance.
719 * Data layout (v0)(current):
720 * Request: [ ipfw_obj_header ]
721 *
722 * Returns 0 on success
723 */
724static int
725nptv6_destroy(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
726    struct sockopt_data *sd)
727{
728	ipfw_obj_header *oh;
729	struct nptv6_cfg *cfg;
730
731	if (sd->valsize != sizeof(*oh))
732		return (EINVAL);
733
734	oh = (ipfw_obj_header *)sd->kbuf;
735	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0)
736		return (EINVAL);
737
738	IPFW_UH_WLOCK(ch);
739	cfg = nptv6_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
740	if (cfg == NULL) {
741		IPFW_UH_WUNLOCK(ch);
742		return (ESRCH);
743	}
744	if (cfg->no.refcnt > 0) {
745		IPFW_UH_WUNLOCK(ch);
746		return (EBUSY);
747	}
748
749	ipfw_reset_eaction_instance(ch, V_nptv6_eid, cfg->no.kidx);
750	SRV_OBJECT(ch, cfg->no.kidx) = NULL;
751	ipfw_objhash_del(CHAIN_TO_SRV(ch), &cfg->no);
752	ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), cfg->no.kidx);
753	IPFW_UH_WUNLOCK(ch);
754
755	nptv6_free_config(cfg);
756	return (0);
757}
758
759/*
760 * Get or change nptv6 instance config.
761 * Request: [ ipfw_obj_header [ ipfw_nptv6_cfg ] ]
762 */
763static int
764nptv6_config(struct ip_fw_chain *chain, ip_fw3_opheader *op,
765    struct sockopt_data *sd)
766{
767
768	return (EOPNOTSUPP);
769}
770
771/*
772 * Lists all NPTv6 instances currently available in kernel.
773 * Data layout (v0)(current):
774 * Request: [ ipfw_obj_lheader ]
775 * Reply: [ ipfw_obj_lheader ipfw_nptv6_cfg x N ]
776 *
777 * Returns 0 on success
778 */
779static int
780nptv6_list(struct ip_fw_chain *ch, ip_fw3_opheader *op3,
781    struct sockopt_data *sd)
782{
783	ipfw_obj_lheader *olh;
784	struct nptv6_dump_arg da;
785
786	/* Check minimum header size */
787	if (sd->valsize < sizeof(ipfw_obj_lheader))
788		return (EINVAL);
789
790	olh = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*olh));
791
792	IPFW_UH_RLOCK(ch);
793	olh->count = ipfw_objhash_count_type(CHAIN_TO_SRV(ch),
794	    IPFW_TLV_NPTV6_NAME);
795	olh->objsize = sizeof(ipfw_nptv6_cfg);
796	olh->size = sizeof(*olh) + olh->count * olh->objsize;
797
798	if (sd->valsize < olh->size) {
799		IPFW_UH_RUNLOCK(ch);
800		return (ENOMEM);
801	}
802	memset(&da, 0, sizeof(da));
803	da.ch = ch;
804	da.sd = sd;
805	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), export_config_cb,
806	    &da, IPFW_TLV_NPTV6_NAME);
807	IPFW_UH_RUNLOCK(ch);
808
809	return (0);
810}
811
812#define	__COPY_STAT_FIELD(_cfg, _stats, _field)	\
813	(_stats)->_field = NPTV6STAT_FETCH(_cfg, _field)
814static void
815export_stats(struct ip_fw_chain *ch, struct nptv6_cfg *cfg,
816    struct ipfw_nptv6_stats *stats)
817{
818
819	__COPY_STAT_FIELD(cfg, stats, in2ex);
820	__COPY_STAT_FIELD(cfg, stats, ex2in);
821	__COPY_STAT_FIELD(cfg, stats, dropped);
822}
823
824/*
825 * Get NPTv6 statistics.
826 * Data layout (v0)(current):
827 * Request: [ ipfw_obj_header ]
828 * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ]]
829 *
830 * Returns 0 on success
831 */
832static int
833nptv6_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
834    struct sockopt_data *sd)
835{
836	struct ipfw_nptv6_stats stats;
837	struct nptv6_cfg *cfg;
838	ipfw_obj_header *oh;
839	ipfw_obj_ctlv *ctlv;
840	size_t sz;
841
842	sz = sizeof(ipfw_obj_header) + sizeof(ipfw_obj_ctlv) + sizeof(stats);
843	if (sd->valsize % sizeof(uint64_t))
844		return (EINVAL);
845	if (sd->valsize < sz)
846		return (ENOMEM);
847	oh = (ipfw_obj_header *)ipfw_get_sopt_header(sd, sz);
848	if (oh == NULL)
849		return (EINVAL);
850	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
851	    oh->ntlv.set >= IPFW_MAX_SETS)
852		return (EINVAL);
853	memset(&stats, 0, sizeof(stats));
854
855	IPFW_UH_RLOCK(ch);
856	cfg = nptv6_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
857	if (cfg == NULL) {
858		IPFW_UH_RUNLOCK(ch);
859		return (ESRCH);
860	}
861	export_stats(ch, cfg, &stats);
862	IPFW_UH_RUNLOCK(ch);
863
864	ctlv = (ipfw_obj_ctlv *)(oh + 1);
865	memset(ctlv, 0, sizeof(*ctlv));
866	ctlv->head.type = IPFW_TLV_COUNTERS;
867	ctlv->head.length = sz - sizeof(ipfw_obj_header);
868	ctlv->count = sizeof(stats) / sizeof(uint64_t);
869	ctlv->objsize = sizeof(uint64_t);
870	ctlv->version = 1;
871	memcpy(ctlv + 1, &stats, sizeof(stats));
872	return (0);
873}
874
875/*
876 * Reset NPTv6 statistics.
877 * Data layout (v0)(current):
878 * Request: [ ipfw_obj_header ]
879 *
880 * Returns 0 on success
881 */
882static int
883nptv6_reset_stats(struct ip_fw_chain *ch, ip_fw3_opheader *op,
884    struct sockopt_data *sd)
885{
886	struct nptv6_cfg *cfg;
887	ipfw_obj_header *oh;
888
889	if (sd->valsize != sizeof(*oh))
890		return (EINVAL);
891	oh = (ipfw_obj_header *)sd->kbuf;
892	if (ipfw_check_object_name_generic(oh->ntlv.name) != 0 ||
893	    oh->ntlv.set >= IPFW_MAX_SETS)
894		return (EINVAL);
895
896	IPFW_UH_WLOCK(ch);
897	cfg = nptv6_find(CHAIN_TO_SRV(ch), oh->ntlv.name, oh->ntlv.set);
898	if (cfg == NULL) {
899		IPFW_UH_WUNLOCK(ch);
900		return (ESRCH);
901	}
902	COUNTER_ARRAY_ZERO(cfg->stats, NPTV6STATS);
903	IPFW_UH_WUNLOCK(ch);
904	return (0);
905}
906
907static struct ipfw_sopt_handler	scodes[] = {
908	{ IP_FW_NPTV6_CREATE, 0,	HDIR_SET,	nptv6_create },
909	{ IP_FW_NPTV6_DESTROY,0,	HDIR_SET,	nptv6_destroy },
910	{ IP_FW_NPTV6_CONFIG, 0,	HDIR_BOTH,	nptv6_config },
911	{ IP_FW_NPTV6_LIST,   0,	HDIR_GET,	nptv6_list },
912	{ IP_FW_NPTV6_STATS,  0,	HDIR_GET,	nptv6_stats },
913	{ IP_FW_NPTV6_RESET_STATS,0,	HDIR_SET,	nptv6_reset_stats },
914};
915
916static int
917nptv6_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
918{
919	ipfw_insn *icmd;
920
921	icmd = cmd - 1;
922	NPTV6_DEBUG("opcode %d, arg1 %d, opcode0 %d, arg1 %d",
923	    cmd->opcode, cmd->arg1, icmd->opcode, icmd->arg1);
924	if (icmd->opcode != O_EXTERNAL_ACTION ||
925	    icmd->arg1 != V_nptv6_eid)
926		return (1);
927
928	*puidx = cmd->arg1;
929	*ptype = 0;
930	return (0);
931}
932
933static void
934nptv6_update_arg1(ipfw_insn *cmd, uint16_t idx)
935{
936
937	cmd->arg1 = idx;
938	NPTV6_DEBUG("opcode %d, arg1 -> %d", cmd->opcode, cmd->arg1);
939}
940
941static int
942nptv6_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
943    struct named_object **pno)
944{
945	int err;
946
947	err = ipfw_objhash_find_type(CHAIN_TO_SRV(ch), ti,
948	    IPFW_TLV_NPTV6_NAME, pno);
949	NPTV6_DEBUG("uidx %u, type %u, err %d", ti->uidx, ti->type, err);
950	return (err);
951}
952
953static struct named_object *
954nptv6_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
955{
956	struct namedobj_instance *ni;
957	struct named_object *no;
958
959	IPFW_UH_WLOCK_ASSERT(ch);
960	ni = CHAIN_TO_SRV(ch);
961	no = ipfw_objhash_lookup_kidx(ni, idx);
962	KASSERT(no != NULL, ("NPT with index %d not found", idx));
963
964	NPTV6_DEBUG("kidx %u -> %s", idx, no->name);
965	return (no);
966}
967
968static int
969nptv6_manage_sets(struct ip_fw_chain *ch, uint16_t set, uint8_t new_set,
970    enum ipfw_sets_cmd cmd)
971{
972
973	return (ipfw_obj_manage_sets(CHAIN_TO_SRV(ch), IPFW_TLV_NPTV6_NAME,
974	    set, new_set, cmd));
975}
976
977static struct opcode_obj_rewrite opcodes[] = {
978	{
979		.opcode	= O_EXTERNAL_INSTANCE,
980		.etlv = IPFW_TLV_EACTION /* just show it isn't table */,
981		.classifier = nptv6_classify,
982		.update = nptv6_update_arg1,
983		.find_byname = nptv6_findbyname,
984		.find_bykidx = nptv6_findbykidx,
985		.manage_sets = nptv6_manage_sets,
986	},
987};
988
989static int
990destroy_config_cb(struct namedobj_instance *ni, struct named_object *no,
991    void *arg)
992{
993	struct nptv6_cfg *cfg;
994	struct ip_fw_chain *ch;
995
996	ch = (struct ip_fw_chain *)arg;
997	IPFW_UH_WLOCK_ASSERT(ch);
998
999	cfg = (struct nptv6_cfg *)SRV_OBJECT(ch, no->kidx);
1000	SRV_OBJECT(ch, no->kidx) = NULL;
1001	ipfw_objhash_del(ni, &cfg->no);
1002	ipfw_objhash_free_idx(ni, cfg->no.kidx);
1003	nptv6_free_config(cfg);
1004	return (0);
1005}
1006
1007int
1008nptv6_init(struct ip_fw_chain *ch, int first)
1009{
1010
1011	V_nptv6_eid = ipfw_add_eaction(ch, ipfw_nptv6, "nptv6");
1012	if (V_nptv6_eid == 0)
1013		return (ENXIO);
1014	IPFW_ADD_SOPT_HANDLER(first, scodes);
1015	IPFW_ADD_OBJ_REWRITER(first, opcodes);
1016	return (0);
1017}
1018
1019void
1020nptv6_uninit(struct ip_fw_chain *ch, int last)
1021{
1022
1023	if (last && nptv6_ifaddr_event != NULL)
1024		EVENTHANDLER_DEREGISTER(ifaddr_event_ext, nptv6_ifaddr_event);
1025	IPFW_DEL_OBJ_REWRITER(last, opcodes);
1026	IPFW_DEL_SOPT_HANDLER(last, scodes);
1027	ipfw_del_eaction(ch, V_nptv6_eid);
1028	/*
1029	 * Since we already have deregistered external action,
1030	 * our named objects become unaccessible via rules, because
1031	 * all rules were truncated by ipfw_del_eaction().
1032	 * So, we can unlink and destroy our named objects without holding
1033	 * IPFW_WLOCK().
1034	 */
1035	IPFW_UH_WLOCK(ch);
1036	ipfw_objhash_foreach_type(CHAIN_TO_SRV(ch), destroy_config_cb, ch,
1037	    IPFW_TLV_NPTV6_NAME);
1038	V_nptv6_eid = 0;
1039	IPFW_UH_WUNLOCK(ch);
1040}
1041
1042