xref: /dragonfly/sys/net/ip6fw/ip6_fw.c (revision 31524921)
1 /*	$FreeBSD: src/sys/netinet6/ip6_fw.c,v 1.2.2.10 2003/08/03 17:52:54 ume Exp $	*/
2 /*	$KAME: ip6_fw.c,v 1.21 2001/01/24 01:25:32 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1998, 1999, 2000 and 2001 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1993 Daniel Boulet
35  * Copyright (c) 1994 Ugen J.S.Antsilevich
36  * Copyright (c) 1996 Alex Nash
37  *
38  * Redistribution and use in source forms, with and without modification,
39  * are permitted provided that this entire comment appears intact.
40  *
41  * Redistribution in binary form may occur without any restrictions.
42  * Obviously, it would be nice if you gave credit where credit is due
43  * but requiring it would be too onerous.
44  *
45  * This software is provided ``AS IS'' without any warranties of any kind.
46  */
47 
48 /*
49  * Implement IPv6 packet firewall
50  */
51 
52 #if !defined(KLD_MODULE)
53 #include "opt_ip6fw.h"
54 #include "opt_inet.h"
55 #include "opt_inet6.h"
56 #endif
57 
58 #ifdef IP6DIVERT
59 #error "NOT SUPPORTED IPV6 DIVERT"
60 #endif
61 #ifdef IP6FW_DIVERT_RESTART
62 #error "NOT SUPPORTED IPV6 DIVERT"
63 #endif
64 
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/malloc.h>
68 #include <sys/mbuf.h>
69 #include <sys/queue.h>
70 #include <sys/kernel.h>
71 #include <sys/socket.h>
72 #include <sys/socketvar.h>
73 #include <sys/syslog.h>
74 #include <sys/thread2.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 "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 					kprintf a;			\
130 			} while (0)
131 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
132 
133 static int	add_entry6 (struct ip6_fw_head *chainptr, struct ip6_fw *frwl);
134 static int	del_entry6 (struct ip6_fw_head *chainptr, u_short number);
135 static int	zero_entry6 (struct mbuf *m);
136 static struct ip6_fw *check_ip6fw_struct (struct ip6_fw *m);
137 static struct ip6_fw *check_ip6fw_mbuf (struct mbuf *fw);
138 static int	ip6opts_match (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 (u_short *portptr, int nports, u_short port,
142 				int range_flag);
143 static int	tcp6flg_match (struct tcphdr *tcp6, struct ip6_fw *f);
144 static int	icmp6type_match (struct icmp6_hdr *  icmp, struct ip6_fw * f);
145 static void	ip6fw_report (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 (struct ip6_hdr **pip6,
149 			struct ifnet *oif, u_int16_t *cookie, struct mbuf **m);
150 static int	ip6_fw_ctl (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 __inline int
158 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
159 {
160 	if (!nports)
161 		return 1;
162 	if (range_flag) {
163 		if (portptr[0] <= port && port <= portptr[1]) {
164 			return 1;
165 		}
166 		nports -= 2;
167 		portptr += 2;
168 	}
169 	while (nports-- > 0) {
170 		if (*portptr++ == port) {
171 			return 1;
172 		}
173 	}
174 	return 0;
175 }
176 
177 static int
178 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
179 {
180 	u_char		flg_set, flg_clr;
181 
182 	/*
183 	 * If an established connection is required, reject packets that
184 	 * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
185 	 * other flag requirements.
186 	 */
187 	if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
188 	    ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
189 	    IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
190 		return 0;
191 
192 	flg_set = tcp6->th_flags & f->fw_tcpf;
193 	flg_clr = tcp6->th_flags & f->fw_tcpnf;
194 
195 	if (flg_set != f->fw_tcpf)
196 		return 0;
197 	if (flg_clr)
198 		return 0;
199 
200 	return 1;
201 }
202 
203 static int
204 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
205 {
206 	int type;
207 
208 	if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
209 		return(1);
210 
211 	type = icmp6->icmp6_type;
212 
213 	/* check for matching type in the bitmap */
214 	if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
215 		(f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
216 		(1U << (type % (8 * sizeof(unsigned))))))
217 		return(1);
218 
219 	return(0); /* no match */
220 }
221 
222 static int
223 is_icmp6_query(struct ip6_hdr *ip6, int off)
224 {
225 	const struct icmp6_hdr *icmp6;
226 	int icmp6_type;
227 
228 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
229 	icmp6_type = icmp6->icmp6_type;
230 
231 	if (icmp6_type == ICMP6_ECHO_REQUEST ||
232 	    icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
233 	    icmp6_type == ICMP6_WRUREQUEST ||
234 	    icmp6_type == ICMP6_FQDN_QUERY ||
235 	    icmp6_type == ICMP6_NI_QUERY)
236 		return(1);
237 
238 	return(0);
239 }
240 
241 static int
242 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
243 	      int *off, int *nxt, u_short *offset)
244 {
245 	int len;
246 	struct ip6_hdr *ip6 = *pip6;
247 	struct ip6_ext *ip6e;
248 	u_char	opts, nopts, nopts_sve;
249 
250 	opts = f->fw_ip6opt;
251 	nopts = nopts_sve = f->fw_ip6nopt;
252 
253 	*nxt = ip6->ip6_nxt;
254 	*off = sizeof(struct ip6_hdr);
255 	len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
256 	while (*off < len) {
257 		ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
258 		if ((*m)->m_len < *off + sizeof(*ip6e))
259 			goto opts_check;	/* XXX */
260 
261 		switch (*nxt) {
262 		case IPPROTO_FRAGMENT:
263 			if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
264 				struct ip6_frag *ip6f;
265 
266 				ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
267 				*offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
268 			}
269 			opts &= ~IPV6_FW_IP6OPT_FRAG;
270 			nopts &= ~IPV6_FW_IP6OPT_FRAG;
271 			*off += sizeof(struct ip6_frag);
272 			break;
273 		case IPPROTO_AH:
274 			opts &= ~IPV6_FW_IP6OPT_AH;
275 			nopts &= ~IPV6_FW_IP6OPT_AH;
276 			*off += (ip6e->ip6e_len + 2) << 2;
277 			break;
278 		default:
279 			switch (*nxt) {
280 			case IPPROTO_HOPOPTS:
281 				opts &= ~IPV6_FW_IP6OPT_HOPOPT;
282 				nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
283 				break;
284 			case IPPROTO_ROUTING:
285 				opts &= ~IPV6_FW_IP6OPT_ROUTE;
286 				nopts &= ~IPV6_FW_IP6OPT_ROUTE;
287 				break;
288 			case IPPROTO_ESP:
289 				opts &= ~IPV6_FW_IP6OPT_ESP;
290 				nopts &= ~IPV6_FW_IP6OPT_ESP;
291 				goto opts_check;
292 			case IPPROTO_NONE:
293 				opts &= ~IPV6_FW_IP6OPT_NONXT;
294 				nopts &= ~IPV6_FW_IP6OPT_NONXT;
295 				goto opts_check;
296 			case IPPROTO_DSTOPTS:
297 				opts &= ~IPV6_FW_IP6OPT_OPTS;
298 				nopts &= ~IPV6_FW_IP6OPT_OPTS;
299 				break;
300 			default:
301 				goto opts_check;
302 			}
303 			*off += (ip6e->ip6e_len + 1) << 3;
304 			break;
305 		}
306 		*nxt = ip6e->ip6e_nxt;
307 
308 	}
309  opts_check:
310 	if (f->fw_ip6opt == f->fw_ip6nopt)	/* XXX */
311 		return 1;
312 
313 	if (opts == 0 && nopts == nopts_sve)
314 		return 1;
315 	else
316 		return 0;
317 }
318 
319 static __inline int
320 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
321 {
322 	/* Check by name or by IP address */
323 	if (byname) {
324 		/* Check name */
325 		if (ifu->fu_via_if.glob) {
326 			if (kfnmatch(ifu->fu_via_if.name, ifp->if_xname, 0)
327 			    == FNM_NOMATCH)
328 				return(0);
329 		} else {
330 			if (strncmp(ifp->if_xname, ifu->fu_via_if.name,
331 			    IP6FW_IFNLEN) != 0)
332 				return(0);
333 		}
334 		return(1);
335 	} else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {	/* Zero == wildcard */
336 		struct ifaddr_container *ifac;
337 
338 		TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
339 			struct ifaddr *ifa = ifac->ifa;
340 
341 			if (ifa->ifa_addr == NULL)
342 				continue;
343 			if (ifa->ifa_addr->sa_family != AF_INET6)
344 				continue;
345 			if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
346 			    &(((struct sockaddr_in6 *)
347 			    (ifa->ifa_addr))->sin6_addr)))
348 				continue;
349 			return(1);
350 		}
351 		return(0);
352 	}
353 	return(1);
354 }
355 
356 static void
357 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
358 	struct ifnet *rif, struct ifnet *oif, int off, int nxt)
359 {
360 	static int counter;
361 	struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
362 	struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
363 	struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
364 	int count;
365 	char *action;
366 	char action2[32], proto[102], name[18];
367 	int len;
368 
369 	count = f ? f->fw_pcnt : ++counter;
370 	if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
371 		return;
372 
373 	/* Print command name */
374 	ksnprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
375 
376 	action = action2;
377 	if (!f)
378 		action = "Refuse";
379 	else {
380 		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
381 		case IPV6_FW_F_DENY:
382 			action = "Deny";
383 			break;
384 		case IPV6_FW_F_REJECT:
385 			if (f->fw_reject_code == IPV6_FW_REJECT_RST)
386 				action = "Reset";
387 			else
388 				action = "Unreach";
389 			break;
390 		case IPV6_FW_F_ACCEPT:
391 			action = "Accept";
392 			break;
393 		case IPV6_FW_F_COUNT:
394 			action = "Count";
395 			break;
396 		case IPV6_FW_F_DIVERT:
397 			ksnprintf(SNPARGS(action2, 0), "Divert %d",
398 			    f->fw_divert_port);
399 			break;
400 		case IPV6_FW_F_TEE:
401 			ksnprintf(SNPARGS(action2, 0), "Tee %d",
402 			    f->fw_divert_port);
403 			break;
404 		case IPV6_FW_F_SKIPTO:
405 			ksnprintf(SNPARGS(action2, 0), "SkipTo %d",
406 			    f->fw_skipto_rule);
407 			break;
408 		default:
409 			action = "UNKNOWN";
410 			break;
411 		}
412 	}
413 
414 	switch (nxt) {
415 	case IPPROTO_TCP:
416 		len = ksnprintf(SNPARGS(proto, 0), "TCP [%s]",
417 		    ip6_sprintf(&ip6->ip6_src));
418 		if (off > 0)
419 			len += ksnprintf(SNPARGS(proto, len), ":%d ",
420 			    ntohs(tcp6->th_sport));
421 		else
422 			len += ksnprintf(SNPARGS(proto, len), " ");
423 		len += ksnprintf(SNPARGS(proto, len), "[%s]",
424 		    ip6_sprintf(&ip6->ip6_dst));
425 		if (off > 0)
426 			ksnprintf(SNPARGS(proto, len), ":%d",
427 			    ntohs(tcp6->th_dport));
428 		break;
429 	case IPPROTO_UDP:
430 		len = ksnprintf(SNPARGS(proto, 0), "UDP [%s]",
431 		    ip6_sprintf(&ip6->ip6_src));
432 		if (off > 0)
433 			len += ksnprintf(SNPARGS(proto, len), ":%d ",
434 			    ntohs(udp->uh_sport));
435 		else
436 		    len += ksnprintf(SNPARGS(proto, len), " ");
437 		len += ksnprintf(SNPARGS(proto, len), "[%s]",
438 		    ip6_sprintf(&ip6->ip6_dst));
439 		if (off > 0)
440 			ksnprintf(SNPARGS(proto, len), ":%d",
441 			    ntohs(udp->uh_dport));
442 		break;
443 	case IPPROTO_ICMPV6:
444 		if (off > 0)
445 			len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
446 			    icmp6->icmp6_type, icmp6->icmp6_code);
447 		else
448 			len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
449 		len += ksnprintf(SNPARGS(proto, len), "[%s]",
450 		    ip6_sprintf(&ip6->ip6_src));
451 		ksnprintf(SNPARGS(proto, len), " [%s]",
452 		    ip6_sprintf(&ip6->ip6_dst));
453 		break;
454 	default:
455 		len = ksnprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
456 		    ip6_sprintf(&ip6->ip6_src));
457 		ksnprintf(SNPARGS(proto, len), " [%s]",
458 		    ip6_sprintf(&ip6->ip6_dst));
459 		break;
460 	}
461 
462 	if (oif)
463 		log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
464 		    name, action, proto, if_name(oif));
465 	else if (rif)
466 		log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
467 		    name, action, proto, if_name(rif));
468 	else
469 		log(LOG_SECURITY | LOG_INFO, "%s %s %s",
470 		    name, action, proto);
471 	if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
472 	    log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
473 		f ? f->fw_number : -1);
474 }
475 
476 /*
477  * Parameters:
478  *
479  *	ip	Pointer to packet header (struct ip6_hdr *)
480  *	hlen	Packet header length
481  *	oif	Outgoing interface, or NULL if packet is incoming
482  * #ifndef IP6FW_DIVERT_RESTART
483  *	*cookie	Ignore all divert/tee rules to this port (if non-zero)
484  * #else
485  *	*cookie Skip up to the first rule past this rule number;
486  * #endif
487  *	*m	The packet; we set to NULL when/if we nuke it.
488  *
489  * Return value:
490  *
491  *	0	The packet is to be accepted and routed normally OR
492  *      	the packet was denied/rejected and has been dropped;
493  *		in the latter case, *m is equal to NULL upon return.
494  *	port	Divert the packet to port.
495  */
496 
497 static int
498 ip6_fw_chk(struct ip6_hdr **pip6,
499 	struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
500 {
501 	struct ip6_fw_chain *chain;
502 	struct ip6_fw *rule = NULL;
503 	struct ip6_hdr *ip6 = *pip6;
504 	struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
505 	u_short offset = 0;
506 	int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
507 	u_short src_port, dst_port;
508 #ifdef	IP6FW_DIVERT_RESTART
509 	u_int16_t skipto = *cookie;
510 #else
511 	u_int16_t ignport = ntohs(*cookie);
512 #endif
513 
514 	*cookie = 0;
515 	/*
516 	 * Go down the chain, looking for enlightment
517 	 * #ifdef IP6FW_DIVERT_RESTART
518 	 * If we've been asked to start at a given rule immediatly, do so.
519 	 * #endif
520 	 */
521 	chain = LIST_FIRST(&ip6_fw_chain);
522 #ifdef IP6FW_DIVERT_RESTART
523 	if (skipto) {
524 		if (skipto >= 65535)
525 			goto dropit;
526 		while (chain && (chain->rule->fw_number <= skipto)) {
527 			chain = LIST_NEXT(chain, chain);
528 		}
529 		if (! chain) goto dropit;
530 	}
531 #endif /* IP6FW_DIVERT_RESTART */
532 	for (; chain; chain = LIST_NEXT(chain, chain)) {
533 		struct ip6_fw *const f = chain->rule;
534 
535 		if (oif) {
536 			/* Check direction outbound */
537 			if (!(f->fw_flg & IPV6_FW_F_OUT))
538 				continue;
539 		} else {
540 			/* Check direction inbound */
541 			if (!(f->fw_flg & IPV6_FW_F_IN))
542 				continue;
543 		}
544 
545 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
546 	(((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
547 	(((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
548 	(((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
549 	(((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
550 
551 		/* If src-addr doesn't match, not this rule. */
552 		if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
553 			(!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
554 			continue;
555 
556 		/* If dest-addr doesn't match, not this rule. */
557 		if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
558 			(!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
559 			continue;
560 
561 #undef IN6_ARE_ADDR_MASKEQUAL
562 		/* Interface check */
563 		if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
564 			struct ifnet *const iface = oif ? oif : rif;
565 
566 			/* Backwards compatibility hack for "via" */
567 			if (!iface || !iface_match(iface,
568 			    &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
569 				continue;
570 		} else {
571 			/* Check receive interface */
572 			if ((f->fw_flg & IPV6_FW_F_IIFACE)
573 			    && (!rif || !iface_match(rif,
574 			      &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
575 				continue;
576 			/* Check outgoing interface */
577 			if ((f->fw_flg & IPV6_FW_F_OIFACE)
578 			    && (!oif || !iface_match(oif,
579 			      &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
580 				continue;
581 		}
582 
583 		/* Check IP options */
584 		if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
585 			continue;
586 
587 		/* Fragments */
588 		if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
589 			continue;
590 
591 		/* Check protocol; if wildcard, match */
592 		if (f->fw_prot == IPPROTO_IPV6)
593 			goto got_match;
594 
595 		/* If different, don't match */
596 		if (nxt != f->fw_prot)
597 			continue;
598 
599 #define PULLUP_TO(len)	do {						\
600 			    if ((*m)->m_len < (len)			\
601 				&& (*m = m_pullup(*m, (len))) == NULL) {\
602 				    goto dropit;			\
603 			    }						\
604 			    *pip6 = ip6 = mtod(*m, struct ip6_hdr *);	\
605 			} while (0)
606 
607 		/* Protocol specific checks */
608 		switch (nxt) {
609 		case IPPROTO_TCP:
610 		    {
611 			struct tcphdr *tcp6;
612 
613 			if (offset == 1) {	/* cf. RFC 1858 */
614 				PULLUP_TO(off + 4); /* XXX ? */
615 				goto bogusfrag;
616 			}
617 			if (offset != 0) {
618 				/*
619 				 * TCP flags and ports aren't available in this
620 				 * packet -- if this rule specified either one,
621 				 * we consider the rule a non-match.
622 				 */
623 				if (f->fw_nports != 0 ||
624 				    f->fw_tcpf != f->fw_tcpnf)
625 					continue;
626 
627 				break;
628 			}
629 			PULLUP_TO(off + 14);
630 			tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
631 			if (((f->fw_tcpf != f->fw_tcpnf) ||
632 			   (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
633 			   !tcp6flg_match(tcp6, f))
634 				continue;
635 			src_port = ntohs(tcp6->th_sport);
636 			dst_port = ntohs(tcp6->th_dport);
637 			goto check_ports;
638 		    }
639 
640 		case IPPROTO_UDP:
641 		    {
642 			struct udphdr *udp;
643 
644 			if (offset != 0) {
645 				/*
646 				 * Port specification is unavailable -- if this
647 				 * rule specifies a port, we consider the rule
648 				 * a non-match.
649 				 */
650 				if (f->fw_nports != 0)
651 					continue;
652 
653 				break;
654 			}
655 			PULLUP_TO(off + 4);
656 			udp = (struct udphdr *) ((caddr_t)ip6 + off);
657 			src_port = ntohs(udp->uh_sport);
658 			dst_port = ntohs(udp->uh_dport);
659 check_ports:
660 			if (!port_match6(&f->fw_pts[0],
661 			    IPV6_FW_GETNSRCP(f), src_port,
662 			    f->fw_flg & IPV6_FW_F_SRNG))
663 				continue;
664 			if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
665 			    IPV6_FW_GETNDSTP(f), dst_port,
666 			    f->fw_flg & IPV6_FW_F_DRNG))
667 				continue;
668 			break;
669 		    }
670 
671 		case IPPROTO_ICMPV6:
672 		    {
673 			struct icmp6_hdr *icmp;
674 
675 			if (offset != 0)	/* Type isn't valid */
676 				break;
677 			PULLUP_TO(off + 2);
678 			icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
679 			if (!icmp6type_match(icmp, f))
680 				continue;
681 			break;
682 		    }
683 #undef PULLUP_TO
684 
685 bogusfrag:
686 			if (fw6_verbose)
687 				ip6fw_report(NULL, ip6, rif, oif, off, nxt);
688 			goto dropit;
689 		}
690 
691 got_match:
692 #ifndef IP6FW_DIVERT_RESTART
693 		/* Ignore divert/tee rule if socket port is "ignport" */
694 		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
695 		case IPV6_FW_F_DIVERT:
696 		case IPV6_FW_F_TEE:
697 			if (f->fw_divert_port == ignport)
698 				continue;       /* ignore this rule */
699 			break;
700 		}
701 
702 #endif /* IP6FW_DIVERT_RESTART */
703 		/* Update statistics */
704 		f->fw_pcnt += 1;
705 		f->fw_bcnt += ntohs(ip6->ip6_plen);
706 		f->timestamp = time_second;
707 
708 		/* Log to console if desired */
709 		if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
710 			ip6fw_report(f, ip6, rif, oif, off, nxt);
711 
712 		/* Take appropriate action */
713 		switch (f->fw_flg & IPV6_FW_F_COMMAND) {
714 		case IPV6_FW_F_ACCEPT:
715 			return(0);
716 		case IPV6_FW_F_COUNT:
717 			continue;
718 		case IPV6_FW_F_DIVERT:
719 #ifdef IP6FW_DIVERT_RESTART
720 			*cookie = f->fw_number;
721 #else
722 			*cookie = htons(f->fw_divert_port);
723 #endif /* IP6FW_DIVERT_RESTART */
724 			return(f->fw_divert_port);
725 		case IPV6_FW_F_TEE:
726 			/*
727 			 * XXX someday tee packet here, but beware that you
728 			 * can't use m_copym() or m_copypacket() because
729 			 * the divert input routine modifies the mbuf
730 			 * (and these routines only increment reference
731 			 * counts in the case of mbuf clusters), so need
732 			 * to write custom routine.
733 			 */
734 			continue;
735 		case IPV6_FW_F_SKIPTO:
736 #ifdef DIAGNOSTIC
737 			while (chain->chain.le_next
738 			    && chain->chain.le_next->rule->fw_number
739 				< f->fw_skipto_rule)
740 #else
741 			while (chain->chain.le_next->rule->fw_number
742 			    < f->fw_skipto_rule)
743 #endif
744 				chain = chain->chain.le_next;
745 			continue;
746 		}
747 
748 		/* Deny/reject this packet using this rule */
749 		rule = f;
750 		break;
751 	}
752 
753 #ifdef DIAGNOSTIC
754 	/* Rule 65535 should always be there and should always match */
755 	if (!chain)
756 		panic("ip6_fw: chain");
757 #endif
758 
759 	/*
760 	 * At this point, we're going to drop the packet.
761 	 * Send a reject notice if all of the following are true:
762 	 *
763 	 * - The packet matched a reject rule
764 	 * - The packet is not an ICMP packet, or is an ICMP query packet
765 	 * - The packet is not a multicast or broadcast packet
766 	 */
767 	if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
768 	    && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
769 	    && !((*m)->m_flags & (M_BCAST|M_MCAST))
770 	    && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
771 		switch (rule->fw_reject_code) {
772 		case IPV6_FW_REJECT_RST:
773 #if 1	/* not tested */
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 			ti.th.th_seq = ntohl(ti.th.th_seq);
790 			ti.th.th_ack = 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 = NULL;
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 #endif
819 		default:	/* Send an ICMP unreachable using code */
820 			if (oif)
821 				(*m)->m_pkthdr.rcvif = oif;
822 			icmp6_error(*m, ICMP6_DST_UNREACH,
823 			    rule->fw_reject_code, 0);
824 			*m = NULL;
825 			break;
826 		}
827 	}
828 
829 dropit:
830 	/*
831 	 * Finally, drop the packet.
832 	 */
833 	if (*m) {
834 		m_freem(*m);
835 		*m = NULL;
836 	}
837 	return(0);
838 }
839 
840 static int
841 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
842 {
843 	struct ip6_fw *ftmp = NULL;
844 	struct ip6_fw_chain *fwc = NULL, *fcp, *fcpl = NULL;
845 	u_short nbr = 0;
846 
847 	fwc = kmalloc(sizeof *fwc, M_IP6FW, M_INTWAIT);
848 	ftmp = kmalloc(sizeof *ftmp, M_IP6FW, M_INTWAIT);
849 
850 	bcopy(frwl, ftmp, sizeof(struct ip6_fw));
851 	ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
852 	ftmp->fw_pcnt = 0L;
853 	ftmp->fw_bcnt = 0L;
854 	fwc->rule = ftmp;
855 
856 	crit_enter();
857 
858 	if (!chainptr->lh_first) {
859 		LIST_INSERT_HEAD(chainptr, fwc, chain);
860 		crit_exit();
861 		return(0);
862         } else if (ftmp->fw_number == (u_short)-1) {
863 		if (fwc)  kfree(fwc, M_IP6FW);
864 		if (ftmp) kfree(ftmp, M_IP6FW);
865 		crit_exit();
866 		dprintf(("%s bad rule number\n", err_prefix));
867 		return (EINVAL);
868         }
869 
870 	/* If entry number is 0, find highest numbered rule and add 100 */
871 	if (ftmp->fw_number == 0) {
872 		LIST_FOREACH(fcp, chainptr, chain) {
873 			if (fcp->rule->fw_number != (u_short)-1)
874 				nbr = fcp->rule->fw_number;
875 			else
876 				break;
877 		}
878 		if (nbr < (u_short)-1 - 100)
879 			nbr += 100;
880 		ftmp->fw_number = nbr;
881 	}
882 
883 	/* Got a valid number; now insert it, keeping the list ordered */
884 	LIST_FOREACH(fcp, chainptr, chain) {
885 		if (fcp->rule->fw_number > ftmp->fw_number) {
886 			if (fcpl) {
887 				LIST_INSERT_AFTER(fcpl, fwc, chain);
888 			} else {
889 				LIST_INSERT_HEAD(chainptr, fwc, chain);
890 			}
891 			break;
892 		} else {
893 			fcpl = fcp;
894 		}
895 	}
896 
897 	crit_exit();
898 	return (0);
899 }
900 
901 static int
902 del_entry6(struct ip6_fw_head *chainptr, u_short number)
903 {
904 	struct ip6_fw_chain *fcp;
905 
906 	crit_enter();
907 
908 	fcp = chainptr->lh_first;
909 	if (number != (u_short)-1) {
910 		for (; fcp; fcp = fcp->chain.le_next) {
911 			if (fcp->rule->fw_number == number) {
912 				LIST_REMOVE(fcp, chain);
913 				crit_exit();
914 				kfree(fcp->rule, M_IP6FW);
915 				kfree(fcp, M_IP6FW);
916 				return 0;
917 			}
918 		}
919 	}
920 
921 	crit_exit();
922 	return (EINVAL);
923 }
924 
925 static int
926 zero_entry6(struct mbuf *m)
927 {
928 	struct ip6_fw *frwl;
929 	struct ip6_fw_chain *fcp;
930 
931 	if (m && m->m_len != 0) {
932 		if (m->m_len != sizeof(struct ip6_fw))
933 			return(EINVAL);
934 		frwl = mtod(m, struct ip6_fw *);
935 	}
936 	else
937 		frwl = NULL;
938 
939 	/*
940 	 *	It's possible to insert multiple chain entries with the
941 	 *	same number, so we don't stop after finding the first
942 	 *	match if zeroing a specific entry.
943 	 */
944 	crit_enter();
945 	for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
946 		if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
947 			fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
948 			fcp->rule->timestamp = 0;
949 		}
950 	crit_exit();
951 
952 	if (fw6_verbose) {
953 		if (frwl)
954 			log(LOG_SECURITY | LOG_NOTICE,
955 			    "ip6fw: Entry %d cleared.\n", frwl->fw_number);
956 		else
957 			log(LOG_SECURITY | LOG_NOTICE,
958 			    "ip6fw: Accounting cleared.\n");
959 	}
960 
961 	return(0);
962 }
963 
964 static struct ip6_fw *
965 check_ip6fw_mbuf(struct mbuf *m)
966 {
967 	/* Check length */
968 	if (m->m_len != sizeof(struct ip6_fw)) {
969 		dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
970 			(int)sizeof(struct ip6_fw)));
971 		return (NULL);
972 	}
973 	return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
974 }
975 
976 static struct ip6_fw *
977 check_ip6fw_struct(struct ip6_fw *frwl)
978 {
979 	/* Check for invalid flag bits */
980 	if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
981 		dprintf(("%s undefined flag bits set (flags=%x)\n",
982 		    err_prefix, frwl->fw_flg));
983 		return (NULL);
984 	}
985 	/* Must apply to incoming or outgoing (or both) */
986 	if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
987 		dprintf(("%s neither in nor out\n", err_prefix));
988 		return (NULL);
989 	}
990 	/* Empty interface name is no good */
991 	if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
992 	      && !*frwl->fw_in_if.fu_via_if.name)
993 	    || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
994 	      && !*frwl->fw_out_if.fu_via_if.name)) {
995 		dprintf(("%s empty interface name\n", err_prefix));
996 		return (NULL);
997 	}
998 	/* Sanity check interface matching */
999 	if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1000 		;		/* allow "via" backwards compatibility */
1001 	} else if ((frwl->fw_flg & IPV6_FW_F_IN)
1002 	    && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1003 		dprintf(("%s outgoing interface check on incoming\n",
1004 		    err_prefix));
1005 		return (NULL);
1006 	}
1007 	/* Sanity check port ranges */
1008 	if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1009 		dprintf(("%s src range set but n_src_p=%d\n",
1010 		    err_prefix, IPV6_FW_GETNSRCP(frwl)));
1011 		return (NULL);
1012 	}
1013 	if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1014 		dprintf(("%s dst range set but n_dst_p=%d\n",
1015 		    err_prefix, IPV6_FW_GETNDSTP(frwl)));
1016 		return (NULL);
1017 	}
1018 	if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1019 		dprintf(("%s too many ports (%d+%d)\n",
1020 		    err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1021 		return (NULL);
1022 	}
1023 	/*
1024 	 *	Protocols other than TCP/UDP don't use port range
1025 	 */
1026 	if ((frwl->fw_prot != IPPROTO_TCP) &&
1027 	    (frwl->fw_prot != IPPROTO_UDP) &&
1028 	    (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1029 		dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1030 		    err_prefix));
1031 		return(NULL);
1032 	}
1033 
1034 	/*
1035 	 *	Rather than modify the entry to make such entries work,
1036 	 *	we reject this rule and require user level utilities
1037 	 *	to enforce whatever policy they deem appropriate.
1038 	 */
1039 	if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1040 		(frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1041 		(frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1042 		(frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1043 		(frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1044 		(frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1045 		(frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1046 		(frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1047 		dprintf(("%s rule never matches\n", err_prefix));
1048 		return(NULL);
1049 	}
1050 
1051 	if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1052 		(frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1053 		if (frwl->fw_nports) {
1054 			dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1055 			return(NULL);
1056 		}
1057 		if (frwl->fw_prot == IPPROTO_TCP &&
1058 			frwl->fw_tcpf != frwl->fw_tcpnf) {
1059 			dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1060 			return(NULL);
1061 		}
1062 	}
1063 
1064 	/* Check command specific stuff */
1065 	switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1066 	{
1067 	case IPV6_FW_F_REJECT:
1068 		if (frwl->fw_reject_code >= 0x100
1069 		    && !(frwl->fw_prot == IPPROTO_TCP
1070 		      && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1071 			dprintf(("%s unknown reject code\n", err_prefix));
1072 			return(NULL);
1073 		}
1074 		break;
1075 	case IPV6_FW_F_DIVERT:		/* Diverting to port zero is invalid */
1076 	case IPV6_FW_F_TEE:
1077 		if (frwl->fw_divert_port == 0) {
1078 			dprintf(("%s can't divert to port 0\n", err_prefix));
1079 			return (NULL);
1080 		}
1081 		break;
1082 	case IPV6_FW_F_DENY:
1083 	case IPV6_FW_F_ACCEPT:
1084 	case IPV6_FW_F_COUNT:
1085 	case IPV6_FW_F_SKIPTO:
1086 		break;
1087 	default:
1088 		dprintf(("%s invalid command\n", err_prefix));
1089 		return(NULL);
1090 	}
1091 
1092 	return frwl;
1093 }
1094 
1095 static int
1096 ip6_fw_ctl(int stage, struct mbuf **mm)
1097 {
1098 	int error;
1099 	struct mbuf *m;
1100 
1101 	if (stage == IPV6_FW_GET) {
1102 		struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1103 		*mm = m = m_get(M_WAITOK, MT_DATA); /* XXX */
1104 		if (!m)
1105 			return(ENOBUFS);
1106 		if (sizeof *(fcp->rule) > MLEN) {
1107 			MCLGET(m, M_WAITOK);
1108 			if ((m->m_flags & M_EXT) == 0) {
1109 				m_free(m);
1110 				return(ENOBUFS);
1111 			}
1112 		}
1113 		for (; fcp; fcp = fcp->chain.le_next) {
1114 			bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1115 			m->m_len = sizeof *(fcp->rule);
1116 			m->m_next = m_get(M_WAITOK, MT_DATA); /* XXX */
1117 			if (!m->m_next) {
1118 				m_freem(*mm);
1119 				return(ENOBUFS);
1120 			}
1121 			m = m->m_next;
1122 			if (sizeof *(fcp->rule) > MLEN) {
1123 				MCLGET(m, M_WAITOK);
1124 				if ((m->m_flags & M_EXT) == 0) {
1125 					m_freem(*mm);
1126 					return(ENOBUFS);
1127 				}
1128 			}
1129 			m->m_len = 0;
1130 		}
1131 		return (0);
1132 	}
1133 	m = *mm;
1134 	/* only allow get calls if secure mode > 2 */
1135 	if (securelevel > 2) {
1136 		if (m) {
1137 			m_freem(m);
1138 			*mm = NULL;
1139 		}
1140 		return(EPERM);
1141 	}
1142 	if (stage == IPV6_FW_FLUSH) {
1143 		while (ip6_fw_chain.lh_first != NULL &&
1144 		    ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1145 			struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1146 			crit_enter();
1147 			LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1148 			crit_exit();
1149 			kfree(fcp->rule, M_IP6FW);
1150 			kfree(fcp, M_IP6FW);
1151 		}
1152 		if (m) {
1153 			m_freem(m);
1154 			*mm = NULL;
1155 		}
1156 		return (0);
1157 	}
1158 	if (stage == IPV6_FW_ZERO) {
1159 		error = zero_entry6(m);
1160 		if (m) {
1161 			m_freem(m);
1162 			*mm = NULL;
1163 		}
1164 		return (error);
1165 	}
1166 	if (m == NULL) {
1167 		kprintf("%s NULL mbuf ptr\n", err_prefix);
1168 		return (EINVAL);
1169 	}
1170 
1171 	if (stage == IPV6_FW_ADD) {
1172 		struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1173 
1174 		if (!frwl)
1175 			error = EINVAL;
1176 		else
1177 			error = add_entry6(&ip6_fw_chain, frwl);
1178 		if (m) {
1179 			m_freem(m);
1180 			*mm = NULL;
1181 		}
1182 		return error;
1183 	}
1184 	if (stage == IPV6_FW_DEL) {
1185 		if (m->m_len != sizeof(struct ip6_fw)) {
1186 			dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1187 				(int)sizeof(struct ip6_fw)));
1188 			error = EINVAL;
1189 		} else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1190 			dprintf(("%s can't delete rule 65535\n", err_prefix));
1191 			error = EINVAL;
1192 		} else
1193 			error = del_entry6(&ip6_fw_chain,
1194 			    mtod(m, struct ip6_fw *)->fw_number);
1195 		if (m) {
1196 			m_freem(m);
1197 			*mm = NULL;
1198 		}
1199 		return error;
1200 	}
1201 
1202 	dprintf(("%s unknown request %d\n", err_prefix, stage));
1203 	if (m) {
1204 		m_freem(m);
1205 		*mm = NULL;
1206 	}
1207 	return (EINVAL);
1208 }
1209 
1210 void
1211 ip6_fw_init(void)
1212 {
1213 	struct ip6_fw default_rule;
1214 
1215 	ip6_fw_chk_ptr = ip6_fw_chk;
1216 	ip6_fw_ctl_ptr = ip6_fw_ctl;
1217 	LIST_INIT(&ip6_fw_chain);
1218 
1219 	bzero(&default_rule, sizeof default_rule);
1220 	default_rule.fw_prot = IPPROTO_IPV6;
1221 	default_rule.fw_number = (u_short)-1;
1222 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1223 	default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1224 #else
1225 	default_rule.fw_flg |= IPV6_FW_F_DENY;
1226 #endif
1227 	default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1228 	if (check_ip6fw_struct(&default_rule) == NULL ||
1229 		add_entry6(&ip6_fw_chain, &default_rule))
1230 		panic(__func__);
1231 
1232 	kprintf("IPv6 packet filtering initialized, ");
1233 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1234 	kprintf("default to accept, ");
1235 #endif
1236 #ifndef IPV6FIREWALL_VERBOSE
1237 	kprintf("logging disabled\n");
1238 #else
1239 	if (fw6_verbose_limit == 0)
1240 		kprintf("unlimited logging\n");
1241 	else
1242 		kprintf("logging limited to %d packets/entry\n",
1243 		    fw6_verbose_limit);
1244 #endif
1245 }
1246 
1247 static ip6_fw_chk_t *old_chk_ptr;
1248 static ip6_fw_ctl_t *old_ctl_ptr;
1249 
1250 static int
1251 ip6fw_modevent(module_t mod, int type, void *unused)
1252 {
1253 	switch (type) {
1254 	case MOD_LOAD:
1255 		crit_enter();
1256 
1257 		old_chk_ptr = ip6_fw_chk_ptr;
1258 		old_ctl_ptr = ip6_fw_ctl_ptr;
1259 
1260 		ip6_fw_init();
1261 		crit_exit();
1262 		return 0;
1263 	case MOD_UNLOAD:
1264 		crit_enter();
1265 		ip6_fw_chk_ptr =  old_chk_ptr;
1266 		ip6_fw_ctl_ptr =  old_ctl_ptr;
1267 		while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1268 			struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1269 			LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1270 			kfree(fcp->rule, M_IP6FW);
1271 			kfree(fcp, M_IP6FW);
1272 		}
1273 
1274 		crit_exit();
1275 		kprintf("IPv6 firewall unloaded\n");
1276 		return 0;
1277 	default:
1278 		break;
1279 	}
1280 	return 0;
1281 }
1282 
1283 static moduledata_t ip6fwmod = {
1284 	"ip6fw",
1285 	ip6fw_modevent,
1286 	0
1287 };
1288 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
1289