xref: /dragonfly/sys/net/ip6fw/ip6_fw.c (revision 1de703da)
1 /*	$FreeBSD: src/sys/netinet6/ip6_fw.c,v 1.2.2.9 2002/04/28 05:40:27 suz Exp $	*/
2 /*	$DragonFly: src/sys/net/ip6fw/ip6_fw.c,v 1.2 2003/06/17 04:28:52 dillon Exp $	*/
3 /*	$KAME: ip6_fw.c,v 1.21 2001/01/24 01:25:32 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1998, 1999, 2000 and 2001 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
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  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1993 Daniel Boulet
36  * Copyright (c) 1994 Ugen J.S.Antsilevich
37  * Copyright (c) 1996 Alex Nash
38  *
39  * Redistribution and use in source forms, with and without modification,
40  * are permitted provided that this entire comment appears intact.
41  *
42  * Redistribution in binary form may occur without any restrictions.
43  * Obviously, it would be nice if you gave credit where credit is due
44  * but requiring it would be too onerous.
45  *
46  * This software is provided ``AS IS'' without any warranties of any kind.
47  */
48 
49 /*
50  * Implement IPv6 packet firewall
51  */
52 
53 #if !defined(KLD_MODULE)
54 #include "opt_ip6fw.h"
55 #include "opt_inet.h"
56 #include "opt_inet6.h"
57 #endif
58 
59 #ifdef IP6DIVERT
60 #error "NOT SUPPORTED IPV6 DIVERT"
61 #endif
62 #ifdef IP6FW_DIVERT_RESTART
63 #error "NOT SUPPORTED IPV6 DIVERT"
64 #endif
65 
66 #include <sys/param.h>
67 #include <sys/systm.h>
68 #include <sys/malloc.h>
69 #include <sys/mbuf.h>
70 #include <sys/queue.h>
71 #include <sys/kernel.h>
72 #include <sys/socket.h>
73 #include <sys/socketvar.h>
74 #include <sys/syslog.h>
75 #include <sys/time.h>
76 #include <net/if.h>
77 #include <net/route.h>
78 #include <netinet/in_systm.h>
79 #include <netinet/in.h>
80 #include <netinet/ip.h>
81 
82 #include <netinet/ip6.h>
83 #include <netinet6/ip6_var.h>
84 #include <netinet6/in6_var.h>
85 #include <netinet/icmp6.h>
86 
87 #include <netinet/in_pcb.h>
88 
89 #include <netinet6/ip6_fw.h>
90 #include <netinet/ip_var.h>
91 #include <netinet/tcp.h>
92 #include <netinet/tcp_seq.h>
93 #include <netinet/tcp_timer.h>
94 #include <netinet/tcp_var.h>
95 #include <netinet/udp.h>
96 
97 #include <sys/sysctl.h>
98 
99 #include <net/net_osdep.h>
100 
101 MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
102 
103 static int fw6_debug = 1;
104 #ifdef IPV6FIREWALL_VERBOSE
105 static int fw6_verbose = 1;
106 #else
107 static int fw6_verbose = 0;
108 #endif
109 #ifdef IPV6FIREWALL_VERBOSE_LIMIT
110 static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
111 #else
112 static int fw6_verbose_limit = 0;
113 #endif
114 
115 LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
116 
117 #ifdef SYSCTL_NODE
118 SYSCTL_DECL(_net_inet6_ip6);
119 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
120 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW,
121 	&ip6_fw_enable, 0, "Enable ip6fw");
122 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
123 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw6_verbose, 0, "");
124 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
125 #endif
126 
127 #define dprintf(a)	do {						\
128 				if (fw6_debug)				\
129 					printf a;			\
130 			} while (0)
131 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
132 
133 static int	add_entry6 __P((struct ip6_fw_head *chainptr, struct ip6_fw *frwl));
134 static int	del_entry6 __P((struct ip6_fw_head *chainptr, u_short number));
135 static int	zero_entry6 __P((struct mbuf *m));
136 static struct ip6_fw *check_ip6fw_struct __P((struct ip6_fw *m));
137 static struct ip6_fw *check_ip6fw_mbuf __P((struct mbuf *fw));
138 static int	ip6opts_match __P((struct ip6_hdr **ip6, struct ip6_fw *f,
139 				   struct mbuf **m,
140 				   int *off, int *nxt, u_short *offset));
141 static int	port_match6 __P((u_short *portptr, int nports, u_short port,
142 				int range_flag));
143 static int	tcp6flg_match __P((struct tcphdr *tcp6, struct ip6_fw *f));
144 static int	icmp6type_match __P((struct icmp6_hdr *  icmp, struct ip6_fw * f));
145 static void	ip6fw_report __P((struct ip6_fw *f, struct ip6_hdr *ip6,
146 				struct ifnet *rif, struct ifnet *oif, int off, int nxt));
147 
148 static int	ip6_fw_chk __P((struct ip6_hdr **pip6,
149 			struct ifnet *oif, u_int16_t *cookie, struct mbuf **m));
150 static int	ip6_fw_ctl __P((int stage, struct mbuf **mm));
151 
152 static char err_prefix[] = "ip6_fw_ctl:";
153 
154 /*
155  * Returns 1 if the port is matched by the vector, 0 otherwise
156  */
157 static
158 __inline int
159 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
160 {
161 	if (!nports)
162 		return 1;
163 	if (range_flag) {
164 		if (portptr[0] <= port && port <= portptr[1]) {
165 			return 1;
166 		}
167 		nports -= 2;
168 		portptr += 2;
169 	}
170 	while (nports-- > 0) {
171 		if (*portptr++ == port) {
172 			return 1;
173 		}
174 	}
175 	return 0;
176 }
177 
178 static int
179 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
180 {
181 	u_char		flg_set, flg_clr;
182 
183 	/*
184 	 * If an established connection is required, reject packets that
185 	 * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
186 	 * other flag requirements.
187 	 */
188 	if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
189 	    ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
190 	    IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
191 		return 0;
192 
193 	flg_set = tcp6->th_flags & f->fw_tcpf;
194 	flg_clr = tcp6->th_flags & f->fw_tcpnf;
195 
196 	if (flg_set != f->fw_tcpf)
197 		return 0;
198 	if (flg_clr)
199 		return 0;
200 
201 	return 1;
202 }
203 
204 static int
205 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
206 {
207 	int type;
208 
209 	if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
210 		return(1);
211 
212 	type = icmp6->icmp6_type;
213 
214 	/* check for matching type in the bitmap */
215 	if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
216 		(f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
217 		(1U << (type % (8 * sizeof(unsigned))))))
218 		return(1);
219 
220 	return(0); /* no match */
221 }
222 
223 static int
224 is_icmp6_query(struct ip6_hdr *ip6, int off)
225 {
226 	const struct icmp6_hdr *icmp6;
227 	int icmp6_type;
228 
229 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
230 	icmp6_type = icmp6->icmp6_type;
231 
232 	if (icmp6_type == ICMP6_ECHO_REQUEST ||
233 	    icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
234 	    icmp6_type == ICMP6_WRUREQUEST ||
235 	    icmp6_type == ICMP6_FQDN_QUERY ||
236 	    icmp6_type == ICMP6_NI_QUERY)
237 		return(1);
238 
239 	return(0);
240 }
241 
242 static int
243 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
244 	      int *off, int *nxt, u_short *offset)
245 {
246 	int len;
247 	struct ip6_hdr *ip6 = *pip6;
248 	struct ip6_ext *ip6e;
249 	u_char	opts, nopts, nopts_sve;
250 
251 	opts = f->fw_ip6opt;
252 	nopts = nopts_sve = f->fw_ip6nopt;
253 
254 	*nxt = ip6->ip6_nxt;
255 	*off = sizeof(struct ip6_hdr);
256 	len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
257 	while (*off < len) {
258 		ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
259 		if ((*m)->m_len < *off + sizeof(*ip6e))
260 			goto opts_check;	/* XXX */
261 
262 		switch(*nxt) {
263 		case IPPROTO_FRAGMENT:
264 			if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
265 				struct ip6_frag *ip6f;
266 
267 				ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
268 				*offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
269 			}
270 			opts &= ~IPV6_FW_IP6OPT_FRAG;
271 			nopts &= ~IPV6_FW_IP6OPT_FRAG;
272 			*off += sizeof(struct ip6_frag);
273 			break;
274 		case IPPROTO_AH:
275 			opts &= ~IPV6_FW_IP6OPT_AH;
276 			nopts &= ~IPV6_FW_IP6OPT_AH;
277 			*off += (ip6e->ip6e_len + 2) << 2;
278 			break;
279 		default:
280 			switch (*nxt) {
281 			case IPPROTO_HOPOPTS:
282 				opts &= ~IPV6_FW_IP6OPT_HOPOPT;
283 				nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
284 				break;
285 			case IPPROTO_ROUTING:
286 				opts &= ~IPV6_FW_IP6OPT_ROUTE;
287 				nopts &= ~IPV6_FW_IP6OPT_ROUTE;
288 				break;
289 			case IPPROTO_ESP:
290 				opts &= ~IPV6_FW_IP6OPT_ESP;
291 				nopts &= ~IPV6_FW_IP6OPT_ESP;
292 				break;
293 			case IPPROTO_NONE:
294 				opts &= ~IPV6_FW_IP6OPT_NONXT;
295 				nopts &= ~IPV6_FW_IP6OPT_NONXT;
296 				goto opts_check;
297 				break;
298 			case IPPROTO_DSTOPTS:
299 				opts &= ~IPV6_FW_IP6OPT_OPTS;
300 				nopts &= ~IPV6_FW_IP6OPT_OPTS;
301 				break;
302 			default:
303 				goto opts_check;
304 				break;
305 			}
306 			*off += (ip6e->ip6e_len + 1) << 3;
307 			break;
308 		}
309 		*nxt = ip6e->ip6e_nxt;
310 
311 	}
312  opts_check:
313 	if (f->fw_ip6opt == f->fw_ip6nopt)	/* XXX */
314 		return 1;
315 
316 	if (opts == 0 && nopts == nopts_sve)
317 		return 1;
318 	else
319 		return 0;
320 }
321 
322 static
323 __inline int
324 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
325 {
326 	/* Check by name or by IP address */
327 	if (byname) {
328 		/* Check unit number (-1 is wildcard) */
329 		if (ifu->fu_via_if.unit != -1
330 		    && ifp->if_unit != ifu->fu_via_if.unit)
331 			return(0);
332 		/* Check name */
333 		if (strncmp(ifp->if_name, ifu->fu_via_if.name, IP6FW_IFNLEN))
334 			return(0);
335 		return(1);
336 	} else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {	/* Zero == wildcard */
337 		struct ifaddr *ia;
338 
339 		for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next)
340 		{
341 
342 			if (ia->ifa_addr == NULL)
343 				continue;
344 			if (ia->ifa_addr->sa_family != AF_INET6)
345 				continue;
346 			if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
347 			    &(((struct sockaddr_in6 *)
348 			    (ia->ifa_addr))->sin6_addr)))
349 				continue;
350 			return(1);
351 		}
352 		return(0);
353 	}
354 	return(1);
355 }
356 
357 static void
358 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
359 	struct ifnet *rif, struct ifnet *oif, int off, int nxt)
360 {
361 	static int counter;
362 	struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
363 	struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
364 	struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
365 	int count;
366 	char *action;
367 	char action2[32], proto[102], name[18];
368 	int len;
369 
370 	count = f ? f->fw_pcnt : ++counter;
371 	if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
372 		return;
373 
374 	/* Print command name */
375 	snprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
376 
377 	action = action2;
378 	if (!f)
379 		action = "Refuse";
380 	else {
381 		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
382 		case IPV6_FW_F_DENY:
383 			action = "Deny";
384 			break;
385 		case IPV6_FW_F_REJECT:
386 			if (f->fw_reject_code == IPV6_FW_REJECT_RST)
387 				action = "Reset";
388 			else
389 				action = "Unreach";
390 			break;
391 		case IPV6_FW_F_ACCEPT:
392 			action = "Accept";
393 			break;
394 		case IPV6_FW_F_COUNT:
395 			action = "Count";
396 			break;
397 		case IPV6_FW_F_DIVERT:
398 			snprintf(SNPARGS(action2, 0), "Divert %d",
399 			    f->fw_divert_port);
400 			break;
401 		case IPV6_FW_F_TEE:
402 			snprintf(SNPARGS(action2, 0), "Tee %d",
403 			    f->fw_divert_port);
404 			break;
405 		case IPV6_FW_F_SKIPTO:
406 			snprintf(SNPARGS(action2, 0), "SkipTo %d",
407 			    f->fw_skipto_rule);
408 			break;
409 		default:
410 			action = "UNKNOWN";
411 			break;
412 		}
413 	}
414 
415 	switch (nxt) {
416 	case IPPROTO_TCP:
417 		len = snprintf(SNPARGS(proto, 0), "TCP [%s]",
418 		    ip6_sprintf(&ip6->ip6_src));
419 		if (off > 0)
420 			len += snprintf(SNPARGS(proto, len), ":%d ",
421 			    ntohs(tcp6->th_sport));
422 		else
423 			len += snprintf(SNPARGS(proto, len), " ");
424 		len += snprintf(SNPARGS(proto, len), "[%s]",
425 		    ip6_sprintf(&ip6->ip6_dst));
426 		if (off > 0)
427 			snprintf(SNPARGS(proto, len), ":%d",
428 			    ntohs(tcp6->th_dport));
429 		break;
430 	case IPPROTO_UDP:
431 		len = snprintf(SNPARGS(proto, 0), "UDP [%s]",
432 		    ip6_sprintf(&ip6->ip6_src));
433 		if (off > 0)
434 			len += snprintf(SNPARGS(proto, len), ":%d ",
435 			    ntohs(udp->uh_sport));
436 		else
437 		    len += snprintf(SNPARGS(proto, len), " ");
438 		len += snprintf(SNPARGS(proto, len), "[%s]",
439 		    ip6_sprintf(&ip6->ip6_dst));
440 		if (off > 0)
441 			snprintf(SNPARGS(proto, len), ":%d",
442 			    ntohs(udp->uh_dport));
443 		break;
444 	case IPPROTO_ICMPV6:
445 		if (off > 0)
446 			len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
447 			    icmp6->icmp6_type, icmp6->icmp6_code);
448 		else
449 			len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
450 		len += snprintf(SNPARGS(proto, len), "[%s]",
451 		    ip6_sprintf(&ip6->ip6_src));
452 		snprintf(SNPARGS(proto, len), " [%s]",
453 		    ip6_sprintf(&ip6->ip6_dst));
454 		break;
455 	default:
456 		len = snprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
457 		    ip6_sprintf(&ip6->ip6_src));
458 		snprintf(SNPARGS(proto, len), " [%s]",
459 		    ip6_sprintf(&ip6->ip6_dst));
460 		break;
461 	}
462 
463 	if (oif)
464 		log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
465 		    name, action, proto, if_name(oif));
466 	else if (rif)
467 		log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
468 		    name, action, proto, if_name(rif));
469 	else
470 		log(LOG_SECURITY | LOG_INFO, "%s %s %s",
471 		    name, action, proto);
472 	if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
473 	    log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
474 		f ? f->fw_number : -1);
475 }
476 
477 /*
478  * Parameters:
479  *
480  *	ip	Pointer to packet header (struct ip6_hdr *)
481  *	hlen	Packet header length
482  *	oif	Outgoing interface, or NULL if packet is incoming
483  * #ifndef IP6FW_DIVERT_RESTART
484  *	*cookie	Ignore all divert/tee rules to this port (if non-zero)
485  * #else
486  *	*cookie Skip up to the first rule past this rule number;
487  * #endif
488  *	*m	The packet; we set to NULL when/if we nuke it.
489  *
490  * Return value:
491  *
492  *	0	The packet is to be accepted and routed normally OR
493  *      	the packet was denied/rejected and has been dropped;
494  *		in the latter case, *m is equal to NULL upon return.
495  *	port	Divert the packet to port.
496  */
497 
498 static int
499 ip6_fw_chk(struct ip6_hdr **pip6,
500 	struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
501 {
502 	struct ip6_fw_chain *chain;
503 	struct ip6_fw *rule = NULL;
504 	struct ip6_hdr *ip6 = *pip6;
505 	struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
506 	u_short offset = 0;
507 	int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
508 	u_short src_port, dst_port;
509 #ifdef	IP6FW_DIVERT_RESTART
510 	u_int16_t skipto = *cookie;
511 #else
512 	u_int16_t ignport = ntohs(*cookie);
513 #endif
514 
515 	*cookie = 0;
516 	/*
517 	 * Go down the chain, looking for enlightment
518 	 * #ifdef IP6FW_DIVERT_RESTART
519 	 * If we've been asked to start at a given rule immediatly, do so.
520 	 * #endif
521 	 */
522 	chain = LIST_FIRST(&ip6_fw_chain);
523 #ifdef IP6FW_DIVERT_RESTART
524 	if (skipto) {
525 		if (skipto >= 65535)
526 			goto dropit;
527 		while (chain && (chain->rule->fw_number <= skipto)) {
528 			chain = LIST_NEXT(chain, chain);
529 		}
530 		if (! chain) goto dropit;
531 	}
532 #endif /* IP6FW_DIVERT_RESTART */
533 	for (; chain; chain = LIST_NEXT(chain, chain)) {
534 		struct ip6_fw *const f = chain->rule;
535 
536 		if (oif) {
537 			/* Check direction outbound */
538 			if (!(f->fw_flg & IPV6_FW_F_OUT))
539 				continue;
540 		} else {
541 			/* Check direction inbound */
542 			if (!(f->fw_flg & IPV6_FW_F_IN))
543 				continue;
544 		}
545 
546 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
547 	(((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
548 	(((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
549 	(((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
550 	(((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
551 
552 		/* If src-addr doesn't match, not this rule. */
553 		if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
554 			(!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
555 			continue;
556 
557 		/* If dest-addr doesn't match, not this rule. */
558 		if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
559 			(!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
560 			continue;
561 
562 #undef IN6_ARE_ADDR_MASKEQUAL
563 		/* Interface check */
564 		if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
565 			struct ifnet *const iface = oif ? oif : rif;
566 
567 			/* Backwards compatibility hack for "via" */
568 			if (!iface || !iface_match(iface,
569 			    &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
570 				continue;
571 		} else {
572 			/* Check receive interface */
573 			if ((f->fw_flg & IPV6_FW_F_IIFACE)
574 			    && (!rif || !iface_match(rif,
575 			      &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
576 				continue;
577 			/* Check outgoing interface */
578 			if ((f->fw_flg & IPV6_FW_F_OIFACE)
579 			    && (!oif || !iface_match(oif,
580 			      &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
581 				continue;
582 		}
583 
584 		/* Check IP options */
585 		if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
586 			continue;
587 
588 		/* Fragments */
589 		if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
590 			continue;
591 
592 		/* Check protocol; if wildcard, match */
593 		if (f->fw_prot == IPPROTO_IPV6)
594 			goto got_match;
595 
596 		/* If different, don't match */
597 		if (nxt != f->fw_prot)
598 			continue;
599 
600 #define PULLUP_TO(len)	do {						\
601 			    if ((*m)->m_len < (len)			\
602 				&& (*m = m_pullup(*m, (len))) == 0) {	\
603 				    goto dropit;			\
604 			    }						\
605 			    *pip6 = ip6 = mtod(*m, struct ip6_hdr *);	\
606 			} while (0)
607 
608 		/* Protocol specific checks */
609 		switch (nxt) {
610 		case IPPROTO_TCP:
611 		    {
612 			struct tcphdr *tcp6;
613 
614 			if (offset == 1) {	/* cf. RFC 1858 */
615 				PULLUP_TO(off + 4); /* XXX ? */
616 				goto bogusfrag;
617 			}
618 			if (offset != 0) {
619 				/*
620 				 * TCP flags and ports aren't available in this
621 				 * packet -- if this rule specified either one,
622 				 * we consider the rule a non-match.
623 				 */
624 				if (f->fw_nports != 0 ||
625 				    f->fw_tcpf != f->fw_tcpnf)
626 					continue;
627 
628 				break;
629 			}
630 			PULLUP_TO(off + 14);
631 			tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
632 			if (((f->fw_tcpf != f->fw_tcpnf) ||
633 			   (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
634 			   !tcp6flg_match(tcp6, f))
635 				continue;
636 			src_port = ntohs(tcp6->th_sport);
637 			dst_port = ntohs(tcp6->th_dport);
638 			goto check_ports;
639 		    }
640 
641 		case IPPROTO_UDP:
642 		    {
643 			struct udphdr *udp;
644 
645 			if (offset != 0) {
646 				/*
647 				 * Port specification is unavailable -- if this
648 				 * rule specifies a port, we consider the rule
649 				 * a non-match.
650 				 */
651 				if (f->fw_nports != 0)
652 					continue;
653 
654 				break;
655 			}
656 			PULLUP_TO(off + 4);
657 			udp = (struct udphdr *) ((caddr_t)ip6 + off);
658 			src_port = ntohs(udp->uh_sport);
659 			dst_port = ntohs(udp->uh_dport);
660 check_ports:
661 			if (!port_match6(&f->fw_pts[0],
662 			    IPV6_FW_GETNSRCP(f), src_port,
663 			    f->fw_flg & IPV6_FW_F_SRNG))
664 				continue;
665 			if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
666 			    IPV6_FW_GETNDSTP(f), dst_port,
667 			    f->fw_flg & IPV6_FW_F_DRNG))
668 				continue;
669 			break;
670 		    }
671 
672 		case IPPROTO_ICMPV6:
673 		    {
674 			struct icmp6_hdr *icmp;
675 
676 			if (offset != 0)	/* Type isn't valid */
677 				break;
678 			PULLUP_TO(off + 2);
679 			icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
680 			if (!icmp6type_match(icmp, f))
681 				continue;
682 			break;
683 		    }
684 #undef PULLUP_TO
685 
686 bogusfrag:
687 			if (fw6_verbose)
688 				ip6fw_report(NULL, ip6, rif, oif, off, nxt);
689 			goto dropit;
690 		}
691 
692 got_match:
693 #ifndef IP6FW_DIVERT_RESTART
694 		/* Ignore divert/tee rule if socket port is "ignport" */
695 		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
696 		case IPV6_FW_F_DIVERT:
697 		case IPV6_FW_F_TEE:
698 			if (f->fw_divert_port == ignport)
699 				continue;       /* ignore this rule */
700 			break;
701 		}
702 
703 #endif /* IP6FW_DIVERT_RESTART */
704 		/* Update statistics */
705 		f->fw_pcnt += 1;
706 		f->fw_bcnt += ntohs(ip6->ip6_plen);
707 		f->timestamp = time_second;
708 
709 		/* Log to console if desired */
710 		if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
711 			ip6fw_report(f, ip6, rif, oif, off, nxt);
712 
713 		/* Take appropriate action */
714 		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
715 		case IPV6_FW_F_ACCEPT:
716 			return(0);
717 		case IPV6_FW_F_COUNT:
718 			continue;
719 		case IPV6_FW_F_DIVERT:
720 #ifdef IP6FW_DIVERT_RESTART
721 			*cookie = f->fw_number;
722 #else
723 			*cookie = htons(f->fw_divert_port);
724 #endif /* IP6FW_DIVERT_RESTART */
725 			return(f->fw_divert_port);
726 		case IPV6_FW_F_TEE:
727 			/*
728 			 * XXX someday tee packet here, but beware that you
729 			 * can't use m_copym() or m_copypacket() because
730 			 * the divert input routine modifies the mbuf
731 			 * (and these routines only increment reference
732 			 * counts in the case of mbuf clusters), so need
733 			 * to write custom routine.
734 			 */
735 			continue;
736 		case IPV6_FW_F_SKIPTO:
737 #ifdef DIAGNOSTIC
738 			while (chain->chain.le_next
739 			    && chain->chain.le_next->rule->fw_number
740 				< f->fw_skipto_rule)
741 #else
742 			while (chain->chain.le_next->rule->fw_number
743 			    < f->fw_skipto_rule)
744 #endif
745 				chain = chain->chain.le_next;
746 			continue;
747 		}
748 
749 		/* Deny/reject this packet using this rule */
750 		rule = f;
751 		break;
752 	}
753 
754 #ifdef DIAGNOSTIC
755 	/* Rule 65535 should always be there and should always match */
756 	if (!chain)
757 		panic("ip6_fw: chain");
758 #endif
759 
760 	/*
761 	 * At this point, we're going to drop the packet.
762 	 * Send a reject notice if all of the following are true:
763 	 *
764 	 * - The packet matched a reject rule
765 	 * - The packet is not an ICMP packet, or is an ICMP query packet
766 	 * - The packet is not a multicast or broadcast packet
767 	 */
768 	if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
769 	    && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
770 	    && !((*m)->m_flags & (M_BCAST|M_MCAST))
771 	    && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
772 		switch (rule->fw_reject_code) {
773 		case IPV6_FW_REJECT_RST:
774 		  {
775 			struct tcphdr *const tcp =
776 				(struct tcphdr *) ((caddr_t)ip6 + off);
777 			struct {
778 				struct ip6_hdr ip6;
779 				struct tcphdr th;
780 			} ti;
781 			tcp_seq ack, seq;
782 			int flags;
783 
784 			if (offset != 0 || (tcp->th_flags & TH_RST))
785 				break;
786 
787 			ti.ip6 = *ip6;
788 			ti.th = *tcp;
789 			NTOHL(ti.th.th_seq);
790 			NTOHL(ti.th.th_ack);
791 			ti.ip6.ip6_nxt = IPPROTO_TCP;
792 			if (ti.th.th_flags & TH_ACK) {
793 				ack = 0;
794 				seq = ti.th.th_ack;
795 				flags = TH_RST;
796 			} else {
797 				ack = ti.th.th_seq;
798 				if (((*m)->m_flags & M_PKTHDR) != 0) {
799 					ack += (*m)->m_pkthdr.len - off
800 						- (ti.th.th_off << 2);
801 				} else if (ip6->ip6_plen) {
802 					ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
803 						- off - (ti.th.th_off << 2);
804 				} else {
805 					m_freem(*m);
806 					*m = 0;
807 					break;
808 				}
809 				seq = 0;
810 				flags = TH_RST|TH_ACK;
811 			}
812 			bcopy(&ti, ip6, sizeof(ti));
813 			tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
814 				*m, ack, seq, flags);
815 			*m = NULL;
816 			break;
817 		  }
818 		default:	/* Send an ICMP unreachable using code */
819 			if (oif)
820 				(*m)->m_pkthdr.rcvif = oif;
821 			icmp6_error(*m, ICMP6_DST_UNREACH,
822 			    rule->fw_reject_code, 0);
823 			*m = NULL;
824 			break;
825 		}
826 	}
827 
828 dropit:
829 	/*
830 	 * Finally, drop the packet.
831 	 */
832 	if (*m) {
833 		m_freem(*m);
834 		*m = NULL;
835 	}
836 	return(0);
837 }
838 
839 static int
840 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
841 {
842 	struct ip6_fw *ftmp = 0;
843 	struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
844 	u_short nbr = 0;
845 	int s;
846 
847 	fwc = malloc(sizeof *fwc, M_IP6FW, M_DONTWAIT);
848 	ftmp = malloc(sizeof *ftmp, M_IP6FW, M_DONTWAIT);
849 	if (!fwc || !ftmp) {
850 		dprintf(("%s malloc said no\n", err_prefix));
851 		if (fwc)  free(fwc, M_IP6FW);
852 		if (ftmp) free(ftmp, M_IP6FW);
853 		return (ENOSPC);
854 	}
855 
856 	bcopy(frwl, ftmp, sizeof(struct ip6_fw));
857 	ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
858 	ftmp->fw_pcnt = 0L;
859 	ftmp->fw_bcnt = 0L;
860 	fwc->rule = ftmp;
861 
862 	s = splnet();
863 
864 	if (!chainptr->lh_first) {
865 		LIST_INSERT_HEAD(chainptr, fwc, chain);
866 		splx(s);
867 		return(0);
868         } else if (ftmp->fw_number == (u_short)-1) {
869 		if (fwc)  free(fwc, M_IP6FW);
870 		if (ftmp) free(ftmp, M_IP6FW);
871 		splx(s);
872 		dprintf(("%s bad rule number\n", err_prefix));
873 		return (EINVAL);
874         }
875 
876 	/* If entry number is 0, find highest numbered rule and add 100 */
877 	if (ftmp->fw_number == 0) {
878 		for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
879 			if (fcp->rule->fw_number != (u_short)-1)
880 				nbr = fcp->rule->fw_number;
881 			else
882 				break;
883 		}
884 		if (nbr < (u_short)-1 - 100)
885 			nbr += 100;
886 		ftmp->fw_number = nbr;
887 	}
888 
889 	/* Got a valid number; now insert it, keeping the list ordered */
890 	for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
891 		if (fcp->rule->fw_number > ftmp->fw_number) {
892 			if (fcpl) {
893 				LIST_INSERT_AFTER(fcpl, fwc, chain);
894 			} else {
895 				LIST_INSERT_HEAD(chainptr, fwc, chain);
896 			}
897 			break;
898 		} else {
899 			fcpl = fcp;
900 		}
901 	}
902 
903 	splx(s);
904 	return (0);
905 }
906 
907 static int
908 del_entry6(struct ip6_fw_head *chainptr, u_short number)
909 {
910 	struct ip6_fw_chain *fcp;
911 	int s;
912 
913 	s = splnet();
914 
915 	fcp = chainptr->lh_first;
916 	if (number != (u_short)-1) {
917 		for (; fcp; fcp = fcp->chain.le_next) {
918 			if (fcp->rule->fw_number == number) {
919 				LIST_REMOVE(fcp, chain);
920 				splx(s);
921 				free(fcp->rule, M_IP6FW);
922 				free(fcp, M_IP6FW);
923 				return 0;
924 			}
925 		}
926 	}
927 
928 	splx(s);
929 	return (EINVAL);
930 }
931 
932 static int
933 zero_entry6(struct mbuf *m)
934 {
935 	struct ip6_fw *frwl;
936 	struct ip6_fw_chain *fcp;
937 	int s;
938 
939 	if (m && m->m_len != 0) {
940 		if (m->m_len != sizeof(struct ip6_fw))
941 			return(EINVAL);
942 		frwl = mtod(m, struct ip6_fw *);
943 	}
944 	else
945 		frwl = NULL;
946 
947 	/*
948 	 *	It's possible to insert multiple chain entries with the
949 	 *	same number, so we don't stop after finding the first
950 	 *	match if zeroing a specific entry.
951 	 */
952 	s = splnet();
953 	for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
954 		if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
955 			fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
956 			fcp->rule->timestamp = 0;
957 		}
958 	splx(s);
959 
960 	if (fw6_verbose) {
961 		if (frwl)
962 			log(LOG_SECURITY | LOG_NOTICE,
963 			    "ip6fw: Entry %d cleared.\n", frwl->fw_number);
964 		else
965 			log(LOG_SECURITY | LOG_NOTICE,
966 			    "ip6fw: Accounting cleared.\n");
967 	}
968 
969 	return(0);
970 }
971 
972 static struct ip6_fw *
973 check_ip6fw_mbuf(struct mbuf *m)
974 {
975 	/* Check length */
976 	if (m->m_len != sizeof(struct ip6_fw)) {
977 		dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
978 		    sizeof(struct ip6_fw)));
979 		return (NULL);
980 	}
981 	return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
982 }
983 
984 static struct ip6_fw *
985 check_ip6fw_struct(struct ip6_fw *frwl)
986 {
987 	/* Check for invalid flag bits */
988 	if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
989 		dprintf(("%s undefined flag bits set (flags=%x)\n",
990 		    err_prefix, frwl->fw_flg));
991 		return (NULL);
992 	}
993 	/* Must apply to incoming or outgoing (or both) */
994 	if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
995 		dprintf(("%s neither in nor out\n", err_prefix));
996 		return (NULL);
997 	}
998 	/* Empty interface name is no good */
999 	if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
1000 	      && !*frwl->fw_in_if.fu_via_if.name)
1001 	    || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
1002 	      && !*frwl->fw_out_if.fu_via_if.name)) {
1003 		dprintf(("%s empty interface name\n", err_prefix));
1004 		return (NULL);
1005 	}
1006 	/* Sanity check interface matching */
1007 	if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1008 		;		/* allow "via" backwards compatibility */
1009 	} else if ((frwl->fw_flg & IPV6_FW_F_IN)
1010 	    && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1011 		dprintf(("%s outgoing interface check on incoming\n",
1012 		    err_prefix));
1013 		return (NULL);
1014 	}
1015 	/* Sanity check port ranges */
1016 	if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1017 		dprintf(("%s src range set but n_src_p=%d\n",
1018 		    err_prefix, IPV6_FW_GETNSRCP(frwl)));
1019 		return (NULL);
1020 	}
1021 	if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1022 		dprintf(("%s dst range set but n_dst_p=%d\n",
1023 		    err_prefix, IPV6_FW_GETNDSTP(frwl)));
1024 		return (NULL);
1025 	}
1026 	if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1027 		dprintf(("%s too many ports (%d+%d)\n",
1028 		    err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1029 		return (NULL);
1030 	}
1031 	/*
1032 	 *	Protocols other than TCP/UDP don't use port range
1033 	 */
1034 	if ((frwl->fw_prot != IPPROTO_TCP) &&
1035 	    (frwl->fw_prot != IPPROTO_UDP) &&
1036 	    (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1037 		dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1038 		    err_prefix));
1039 		return(NULL);
1040 	}
1041 
1042 	/*
1043 	 *	Rather than modify the entry to make such entries work,
1044 	 *	we reject this rule and require user level utilities
1045 	 *	to enforce whatever policy they deem appropriate.
1046 	 */
1047 	if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1048 		(frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1049 		(frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1050 		(frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1051 		(frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1052 		(frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1053 		(frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1054 		(frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1055 		dprintf(("%s rule never matches\n", err_prefix));
1056 		return(NULL);
1057 	}
1058 
1059 	if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1060 		(frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1061 		if (frwl->fw_nports) {
1062 			dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1063 			return(NULL);
1064 		}
1065 		if (frwl->fw_prot == IPPROTO_TCP &&
1066 			frwl->fw_tcpf != frwl->fw_tcpnf) {
1067 			dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1068 			return(NULL);
1069 		}
1070 	}
1071 
1072 	/* Check command specific stuff */
1073 	switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1074 	{
1075 	case IPV6_FW_F_REJECT:
1076 		if (frwl->fw_reject_code >= 0x100
1077 		    && !(frwl->fw_prot == IPPROTO_TCP
1078 		      && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1079 			dprintf(("%s unknown reject code\n", err_prefix));
1080 			return(NULL);
1081 		}
1082 		break;
1083 	case IPV6_FW_F_DIVERT:		/* Diverting to port zero is invalid */
1084 	case IPV6_FW_F_TEE:
1085 		if (frwl->fw_divert_port == 0) {
1086 			dprintf(("%s can't divert to port 0\n", err_prefix));
1087 			return (NULL);
1088 		}
1089 		break;
1090 	case IPV6_FW_F_DENY:
1091 	case IPV6_FW_F_ACCEPT:
1092 	case IPV6_FW_F_COUNT:
1093 	case IPV6_FW_F_SKIPTO:
1094 		break;
1095 	default:
1096 		dprintf(("%s invalid command\n", err_prefix));
1097 		return(NULL);
1098 	}
1099 
1100 	return frwl;
1101 }
1102 
1103 static int
1104 ip6_fw_ctl(int stage, struct mbuf **mm)
1105 {
1106 	int error;
1107 	struct mbuf *m;
1108 
1109 	if (stage == IPV6_FW_GET) {
1110 		struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1111 		*mm = m = m_get(M_WAIT, MT_DATA); /* XXX */
1112 		if (!m)
1113 			return(ENOBUFS);
1114 		if (sizeof *(fcp->rule) > MLEN) {
1115 			MCLGET(m, M_WAIT);
1116 			if ((m->m_flags & M_EXT) == 0) {
1117 				m_free(m);
1118 				return(ENOBUFS);
1119 			}
1120 		}
1121 		for (; fcp; fcp = fcp->chain.le_next) {
1122 			bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1123 			m->m_len = sizeof *(fcp->rule);
1124 			m->m_next = m_get(M_WAIT, MT_DATA); /* XXX */
1125 			if (!m->m_next) {
1126 				m_freem(*mm);
1127 				return(ENOBUFS);
1128 			}
1129 			m = m->m_next;
1130 			if (sizeof *(fcp->rule) > MLEN) {
1131 				MCLGET(m, M_WAIT);
1132 				if ((m->m_flags & M_EXT) == 0) {
1133 					m_freem(*mm);
1134 					return(ENOBUFS);
1135 				}
1136 			}
1137 			m->m_len = 0;
1138 		}
1139 		return (0);
1140 	}
1141 	m = *mm;
1142 	/* only allow get calls if secure mode > 2 */
1143 	if (securelevel > 2) {
1144 		if (m) {
1145 			(void)m_freem(m);
1146 			*mm = 0;
1147 		}
1148 		return(EPERM);
1149 	}
1150 	if (stage == IPV6_FW_FLUSH) {
1151 		while (ip6_fw_chain.lh_first != NULL &&
1152 		    ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1153 			struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1154 			int s = splnet();
1155 			LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1156 			splx(s);
1157 			free(fcp->rule, M_IP6FW);
1158 			free(fcp, M_IP6FW);
1159 		}
1160 		if (m) {
1161 			(void)m_freem(m);
1162 			*mm = 0;
1163 		}
1164 		return (0);
1165 	}
1166 	if (stage == IPV6_FW_ZERO) {
1167 		error = zero_entry6(m);
1168 		if (m) {
1169 			(void)m_freem(m);
1170 			*mm = 0;
1171 		}
1172 		return (error);
1173 	}
1174 	if (m == NULL) {
1175 		printf("%s NULL mbuf ptr\n", err_prefix);
1176 		return (EINVAL);
1177 	}
1178 
1179 	if (stage == IPV6_FW_ADD) {
1180 		struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1181 
1182 		if (!frwl)
1183 			error = EINVAL;
1184 		else
1185 			error = add_entry6(&ip6_fw_chain, frwl);
1186 		if (m) {
1187 			(void)m_freem(m);
1188 			*mm = 0;
1189 		}
1190 		return error;
1191 	}
1192 	if (stage == IPV6_FW_DEL) {
1193 		if (m->m_len != sizeof(struct ip6_fw)) {
1194 			dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1195 			    sizeof(struct ip6_fw)));
1196 			error = EINVAL;
1197 		} else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1198 			dprintf(("%s can't delete rule 65535\n", err_prefix));
1199 			error = EINVAL;
1200 		} else
1201 			error = del_entry6(&ip6_fw_chain,
1202 			    mtod(m, struct ip6_fw *)->fw_number);
1203 		if (m) {
1204 			(void)m_freem(m);
1205 			*mm = 0;
1206 		}
1207 		return error;
1208 	}
1209 
1210 	dprintf(("%s unknown request %d\n", err_prefix, stage));
1211 	if (m) {
1212 		(void)m_freem(m);
1213 		*mm = 0;
1214 	}
1215 	return (EINVAL);
1216 }
1217 
1218 void
1219 ip6_fw_init(void)
1220 {
1221 	struct ip6_fw default_rule;
1222 
1223 	ip6_fw_chk_ptr = ip6_fw_chk;
1224 	ip6_fw_ctl_ptr = ip6_fw_ctl;
1225 	LIST_INIT(&ip6_fw_chain);
1226 
1227 	bzero(&default_rule, sizeof default_rule);
1228 	default_rule.fw_prot = IPPROTO_IPV6;
1229 	default_rule.fw_number = (u_short)-1;
1230 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1231 	default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1232 #else
1233 	default_rule.fw_flg |= IPV6_FW_F_DENY;
1234 #endif
1235 	default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1236 	if (check_ip6fw_struct(&default_rule) == NULL ||
1237 		add_entry6(&ip6_fw_chain, &default_rule))
1238 		panic(__FUNCTION__);
1239 
1240 	printf("IPv6 packet filtering initialized, ");
1241 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1242 	printf("default to accept, ");
1243 #endif
1244 #ifndef IPV6FIREWALL_VERBOSE
1245 	printf("logging disabled\n");
1246 #else
1247 	if (fw6_verbose_limit == 0)
1248 		printf("unlimited logging\n");
1249 	else
1250 		printf("logging limited to %d packets/entry\n",
1251 		    fw6_verbose_limit);
1252 #endif
1253 }
1254 
1255 static ip6_fw_chk_t *old_chk_ptr;
1256 static ip6_fw_ctl_t *old_ctl_ptr;
1257 
1258 static int
1259 ip6fw_modevent(module_t mod, int type, void *unused)
1260 {
1261 	int s;
1262 
1263 	switch (type) {
1264 	case MOD_LOAD:
1265 		s = splnet();
1266 
1267 		old_chk_ptr = ip6_fw_chk_ptr;
1268 		old_ctl_ptr = ip6_fw_ctl_ptr;
1269 
1270 		ip6_fw_init();
1271 		splx(s);
1272 		return 0;
1273 	case MOD_UNLOAD:
1274 		s = splnet();
1275 		ip6_fw_chk_ptr =  old_chk_ptr;
1276 		ip6_fw_ctl_ptr =  old_ctl_ptr;
1277 		while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1278 			struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1279 			LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1280 			free(fcp->rule, M_IP6FW);
1281 			free(fcp, M_IP6FW);
1282 		}
1283 
1284 		splx(s);
1285 		printf("IPv6 firewall unloaded\n");
1286 		return 0;
1287 	default:
1288 		break;
1289 	}
1290 	return 0;
1291 }
1292 
1293 static moduledata_t ip6fwmod = {
1294 	"ip6fw",
1295 	ip6fw_modevent,
1296 	0
1297 };
1298 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
1299