ca8b94ee4fb5d8548ec1243cb058c29a9a1e21cd
[dragonfly.git] / sys / net / ip6fw / ip6_fw.c
1 /*      $FreeBSD: src/sys/netinet6/ip6_fw.c,v 1.2.2.10 2003/08/03 17:52:54 ume Exp $    */
2 /*      $DragonFly: src/sys/net/ip6fw/ip6_fw.c,v 1.19 2008/03/07 11:34:20 sephe 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/thread2.h>
76 #include <sys/time.h>
77 #include <net/if.h>
78 #include <net/route.h>
79 #include <netinet/in_systm.h>
80 #include <netinet/in.h>
81 #include <netinet/ip.h>
82
83 #include <netinet/ip6.h>
84 #include <netinet6/ip6_var.h>
85 #include <netinet6/in6_var.h>
86 #include <netinet/icmp6.h>
87
88 #include <netinet/in_pcb.h>
89
90 #include "ip6_fw.h"
91 #include <netinet/ip_var.h>
92 #include <netinet/tcp.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/udp.h>
97
98 #include <sys/sysctl.h>
99
100 #include <net/net_osdep.h>
101
102 MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
103
104 static int fw6_debug = 1;
105 #ifdef IPV6FIREWALL_VERBOSE
106 static int fw6_verbose = 1;
107 #else
108 static int fw6_verbose = 0;
109 #endif
110 #ifdef IPV6FIREWALL_VERBOSE_LIMIT
111 static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
112 #else
113 static int fw6_verbose_limit = 0;
114 #endif
115
116 LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
117
118 #ifdef SYSCTL_NODE
119 SYSCTL_DECL(_net_inet6_ip6);
120 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
121 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW,
122         &ip6_fw_enable, 0, "Enable ip6fw");
123 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
124 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw6_verbose, 0, "");
125 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
126 #endif
127
128 #define dprintf(a)      do {                                            \
129                                 if (fw6_debug)                          \
130                                         kprintf a;                      \
131                         } while (0)
132 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
133
134 static int      add_entry6 (struct ip6_fw_head *chainptr, struct ip6_fw *frwl);
135 static int      del_entry6 (struct ip6_fw_head *chainptr, u_short number);
136 static int      zero_entry6 (struct mbuf *m);
137 static struct ip6_fw *check_ip6fw_struct (struct ip6_fw *m);
138 static struct ip6_fw *check_ip6fw_mbuf (struct mbuf *fw);
139 static int      ip6opts_match (struct ip6_hdr **ip6, struct ip6_fw *f,
140                                    struct mbuf **m,
141                                    int *off, int *nxt, u_short *offset);
142 static int      port_match6 (u_short *portptr, int nports, u_short port,
143                                 int range_flag);
144 static int      tcp6flg_match (struct tcphdr *tcp6, struct ip6_fw *f);
145 static int      icmp6type_match (struct icmp6_hdr *  icmp, struct ip6_fw * f);
146 static void     ip6fw_report (struct ip6_fw *f, struct ip6_hdr *ip6,
147                                 struct ifnet *rif, struct ifnet *oif, int off, int nxt);
148
149 static int      ip6_fw_chk (struct ip6_hdr **pip6,
150                         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m);
151 static int      ip6_fw_ctl (int stage, struct mbuf **mm);
152
153 static char err_prefix[] = "ip6_fw_ctl:";
154
155 /*
156  * Returns 1 if the port is matched by the vector, 0 otherwise
157  */
158 static
159 __inline int
160 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
161 {
162         if (!nports)
163                 return 1;
164         if (range_flag) {
165                 if (portptr[0] <= port && port <= portptr[1]) {
166                         return 1;
167                 }
168                 nports -= 2;
169                 portptr += 2;
170         }
171         while (nports-- > 0) {
172                 if (*portptr++ == port) {
173                         return 1;
174                 }
175         }
176         return 0;
177 }
178
179 static int
180 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
181 {
182         u_char          flg_set, flg_clr;
183         
184         /*
185          * If an established connection is required, reject packets that
186          * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
187          * other flag requirements.
188          */
189         if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
190             ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
191             IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
192                 return 0;
193
194         flg_set = tcp6->th_flags & f->fw_tcpf;
195         flg_clr = tcp6->th_flags & f->fw_tcpnf;
196
197         if (flg_set != f->fw_tcpf)
198                 return 0;
199         if (flg_clr)
200                 return 0;
201
202         return 1;
203 }
204
205 static int
206 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
207 {
208         int type;
209
210         if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
211                 return(1);
212
213         type = icmp6->icmp6_type;
214
215         /* check for matching type in the bitmap */
216         if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
217                 (f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
218                 (1U << (type % (8 * sizeof(unsigned))))))
219                 return(1);
220
221         return(0); /* no match */
222 }
223
224 static int
225 is_icmp6_query(struct ip6_hdr *ip6, int off)
226 {
227         const struct icmp6_hdr *icmp6;
228         int icmp6_type;
229
230         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
231         icmp6_type = icmp6->icmp6_type;
232
233         if (icmp6_type == ICMP6_ECHO_REQUEST ||
234             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
235             icmp6_type == ICMP6_WRUREQUEST ||
236             icmp6_type == ICMP6_FQDN_QUERY ||
237             icmp6_type == ICMP6_NI_QUERY)
238                 return(1);
239
240         return(0);
241 }
242
243 static int
244 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
245               int *off, int *nxt, u_short *offset)
246 {
247         int len;
248         struct ip6_hdr *ip6 = *pip6;
249         struct ip6_ext *ip6e;
250         u_char  opts, nopts, nopts_sve;
251
252         opts = f->fw_ip6opt;
253         nopts = nopts_sve = f->fw_ip6nopt;
254
255         *nxt = ip6->ip6_nxt;
256         *off = sizeof(struct ip6_hdr);
257         len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
258         while (*off < len) {
259                 ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
260                 if ((*m)->m_len < *off + sizeof(*ip6e))
261                         goto opts_check;        /* XXX */
262
263                 switch(*nxt) {
264                 case IPPROTO_FRAGMENT:
265                         if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
266                                 struct ip6_frag *ip6f;
267
268                                 ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
269                                 *offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
270                         }
271                         opts &= ~IPV6_FW_IP6OPT_FRAG;
272                         nopts &= ~IPV6_FW_IP6OPT_FRAG;
273                         *off += sizeof(struct ip6_frag);
274                         break;
275                 case IPPROTO_AH:
276                         opts &= ~IPV6_FW_IP6OPT_AH;
277                         nopts &= ~IPV6_FW_IP6OPT_AH;
278                         *off += (ip6e->ip6e_len + 2) << 2;
279                         break;
280                 default:
281                         switch (*nxt) {
282                         case IPPROTO_HOPOPTS:
283                                 opts &= ~IPV6_FW_IP6OPT_HOPOPT;
284                                 nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
285                                 break;
286                         case IPPROTO_ROUTING:
287                                 opts &= ~IPV6_FW_IP6OPT_ROUTE;
288                                 nopts &= ~IPV6_FW_IP6OPT_ROUTE;
289                                 break;
290                         case IPPROTO_ESP:
291                                 opts &= ~IPV6_FW_IP6OPT_ESP;
292                                 nopts &= ~IPV6_FW_IP6OPT_ESP;
293                                 goto opts_check;
294                         case IPPROTO_NONE:
295                                 opts &= ~IPV6_FW_IP6OPT_NONXT;
296                                 nopts &= ~IPV6_FW_IP6OPT_NONXT;
297                                 goto opts_check;
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                         }
305                         *off += (ip6e->ip6e_len + 1) << 3;
306                         break;
307                 }
308                 *nxt = ip6e->ip6e_nxt;
309
310         }
311  opts_check:
312         if (f->fw_ip6opt == f->fw_ip6nopt)      /* XXX */
313                 return 1;
314
315         if (opts == 0 && nopts == nopts_sve)
316                 return 1;
317         else
318                 return 0;
319 }
320
321 static
322 __inline int
323 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
324 {
325         /* Check by name or by IP address */
326         if (byname) {
327                 /* Check name */
328                 if (ifu->fu_via_if.glob) {
329                         if (kfnmatch(ifu->fu_via_if.name, ifp->if_xname, 0)
330                             == FNM_NOMATCH)
331                                 return(0);
332                 } else {
333                         if (strncmp(ifp->if_xname, ifu->fu_via_if.name,
334                             IP6FW_IFNLEN) != 0)
335                                 return(0);
336                 }
337                 return(1);
338         } else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {        /* Zero == wildcard */
339                 struct ifaddr_container *ifac;
340
341                 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
342                         struct ifaddr *ifa = ifac->ifa;
343
344                         if (ifa->ifa_addr == NULL)
345                                 continue;
346                         if (ifa->ifa_addr->sa_family != AF_INET6)
347                                 continue;
348                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
349                             &(((struct sockaddr_in6 *)
350                             (ifa->ifa_addr))->sin6_addr)))
351                                 continue;
352                         return(1);
353                 }
354                 return(0);
355         }
356         return(1);
357 }
358
359 static void
360 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
361         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
362 {
363         static int counter;
364         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
365         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
366         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
367         int count;
368         char *action;
369         char action2[32], proto[102], name[18];
370         int len;
371
372         count = f ? f->fw_pcnt : ++counter;
373         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
374                 return;
375
376         /* Print command name */
377         ksnprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
378
379         action = action2;
380         if (!f)
381                 action = "Refuse";
382         else {
383                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
384                 case IPV6_FW_F_DENY:
385                         action = "Deny";
386                         break;
387                 case IPV6_FW_F_REJECT:
388                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
389                                 action = "Reset";
390                         else
391                                 action = "Unreach";
392                         break;
393                 case IPV6_FW_F_ACCEPT:
394                         action = "Accept";
395                         break;
396                 case IPV6_FW_F_COUNT:
397                         action = "Count";
398                         break;
399                 case IPV6_FW_F_DIVERT:
400                         ksnprintf(SNPARGS(action2, 0), "Divert %d",
401                             f->fw_divert_port);
402                         break;
403                 case IPV6_FW_F_TEE:
404                         ksnprintf(SNPARGS(action2, 0), "Tee %d",
405                             f->fw_divert_port);
406                         break;
407                 case IPV6_FW_F_SKIPTO:
408                         ksnprintf(SNPARGS(action2, 0), "SkipTo %d",
409                             f->fw_skipto_rule);
410                         break;
411                 default:        
412                         action = "UNKNOWN";
413                         break;
414                 }
415         }
416
417         switch (nxt) {
418         case IPPROTO_TCP:
419                 len = ksnprintf(SNPARGS(proto, 0), "TCP [%s]",
420                     ip6_sprintf(&ip6->ip6_src));
421                 if (off > 0)
422                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
423                             ntohs(tcp6->th_sport));
424                 else
425                         len += ksnprintf(SNPARGS(proto, len), " ");
426                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
427                     ip6_sprintf(&ip6->ip6_dst));
428                 if (off > 0)
429                         ksnprintf(SNPARGS(proto, len), ":%d",
430                             ntohs(tcp6->th_dport));
431                 break;
432         case IPPROTO_UDP:
433                 len = ksnprintf(SNPARGS(proto, 0), "UDP [%s]",
434                     ip6_sprintf(&ip6->ip6_src));
435                 if (off > 0)
436                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
437                             ntohs(udp->uh_sport));
438                 else
439                     len += ksnprintf(SNPARGS(proto, len), " ");
440                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
441                     ip6_sprintf(&ip6->ip6_dst));
442                 if (off > 0)
443                         ksnprintf(SNPARGS(proto, len), ":%d",
444                             ntohs(udp->uh_dport));
445                 break;
446         case IPPROTO_ICMPV6:
447                 if (off > 0)
448                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
449                             icmp6->icmp6_type, icmp6->icmp6_code);
450                 else
451                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
452                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
453                     ip6_sprintf(&ip6->ip6_src));
454                 ksnprintf(SNPARGS(proto, len), " [%s]",
455                     ip6_sprintf(&ip6->ip6_dst));
456                 break;
457         default:
458                 len = ksnprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
459                     ip6_sprintf(&ip6->ip6_src));
460                 ksnprintf(SNPARGS(proto, len), " [%s]",
461                     ip6_sprintf(&ip6->ip6_dst));
462                 break;
463         }
464
465         if (oif)
466                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
467                     name, action, proto, if_name(oif));
468         else if (rif)
469                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
470                     name, action, proto, if_name(rif));
471         else
472                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
473                     name, action, proto);
474         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
475             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
476                 f ? f->fw_number : -1);
477 }
478
479 /*
480  * Parameters:
481  *
482  *      ip      Pointer to packet header (struct ip6_hdr *)
483  *      hlen    Packet header length
484  *      oif     Outgoing interface, or NULL if packet is incoming
485  * #ifndef IP6FW_DIVERT_RESTART
486  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
487  * #else
488  *      *cookie Skip up to the first rule past this rule number;
489  * #endif
490  *      *m      The packet; we set to NULL when/if we nuke it.
491  *
492  * Return value:
493  *
494  *      0       The packet is to be accepted and routed normally OR
495  *              the packet was denied/rejected and has been dropped;
496  *              in the latter case, *m is equal to NULL upon return.
497  *      port    Divert the packet to port.
498  */
499
500 static int
501 ip6_fw_chk(struct ip6_hdr **pip6,
502         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
503 {
504         struct ip6_fw_chain *chain;
505         struct ip6_fw *rule = NULL;
506         struct ip6_hdr *ip6 = *pip6;
507         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
508         u_short offset = 0;
509         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
510         u_short src_port, dst_port;
511 #ifdef  IP6FW_DIVERT_RESTART
512         u_int16_t skipto = *cookie;
513 #else
514         u_int16_t ignport = ntohs(*cookie);
515 #endif
516
517         *cookie = 0;
518         /*
519          * Go down the chain, looking for enlightment
520          * #ifdef IP6FW_DIVERT_RESTART
521          * If we've been asked to start at a given rule immediatly, do so.
522          * #endif
523          */
524         chain = LIST_FIRST(&ip6_fw_chain);
525 #ifdef IP6FW_DIVERT_RESTART
526         if (skipto) {
527                 if (skipto >= 65535)
528                         goto dropit;
529                 while (chain && (chain->rule->fw_number <= skipto)) {
530                         chain = LIST_NEXT(chain, chain);
531                 }
532                 if (! chain) goto dropit;
533         }
534 #endif /* IP6FW_DIVERT_RESTART */
535         for (; chain; chain = LIST_NEXT(chain, chain)) {
536                 struct ip6_fw *const f = chain->rule;
537
538                 if (oif) {
539                         /* Check direction outbound */
540                         if (!(f->fw_flg & IPV6_FW_F_OUT))
541                                 continue;
542                 } else {
543                         /* Check direction inbound */
544                         if (!(f->fw_flg & IPV6_FW_F_IN))
545                                 continue;
546                 }
547
548 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
549         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
550         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
551         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
552         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
553
554                 /* If src-addr doesn't match, not this rule. */
555                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
556                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
557                         continue;
558
559                 /* If dest-addr doesn't match, not this rule. */
560                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
561                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
562                         continue;
563
564 #undef IN6_ARE_ADDR_MASKEQUAL
565                 /* Interface check */
566                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
567                         struct ifnet *const iface = oif ? oif : rif;
568
569                         /* Backwards compatibility hack for "via" */
570                         if (!iface || !iface_match(iface,
571                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
572                                 continue;
573                 } else {
574                         /* Check receive interface */
575                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
576                             && (!rif || !iface_match(rif,
577                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
578                                 continue;
579                         /* Check outgoing interface */
580                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
581                             && (!oif || !iface_match(oif,
582                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
583                                 continue;
584                 }
585
586                 /* Check IP options */
587                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
588                         continue;
589
590                 /* Fragments */
591                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
592                         continue;
593
594                 /* Check protocol; if wildcard, match */
595                 if (f->fw_prot == IPPROTO_IPV6)
596                         goto got_match;
597
598                 /* If different, don't match */
599                 if (nxt != f->fw_prot)
600                         continue;
601
602 #define PULLUP_TO(len)  do {                                            \
603                             if ((*m)->m_len < (len)                     \
604                                 && (*m = m_pullup(*m, (len))) == 0) {   \
605                                     goto dropit;                        \
606                             }                                           \
607                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
608                         } while (0)
609
610                 /* Protocol specific checks */
611                 switch (nxt) {
612                 case IPPROTO_TCP:
613                     {
614                         struct tcphdr *tcp6;
615
616                         if (offset == 1) {      /* cf. RFC 1858 */
617                                 PULLUP_TO(off + 4); /* XXX ? */
618                                 goto bogusfrag;
619                         }
620                         if (offset != 0) {
621                                 /*
622                                  * TCP flags and ports aren't available in this
623                                  * packet -- if this rule specified either one,
624                                  * we consider the rule a non-match.
625                                  */
626                                 if (f->fw_nports != 0 ||
627                                     f->fw_tcpf != f->fw_tcpnf)
628                                         continue;
629
630                                 break;
631                         }
632                         PULLUP_TO(off + 14);
633                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
634                         if (((f->fw_tcpf != f->fw_tcpnf) ||
635                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
636                            !tcp6flg_match(tcp6, f))
637                                 continue;
638                         src_port = ntohs(tcp6->th_sport);
639                         dst_port = ntohs(tcp6->th_dport);
640                         goto check_ports;
641                     }
642
643                 case IPPROTO_UDP:
644                     {
645                         struct udphdr *udp;
646
647                         if (offset != 0) {
648                                 /*
649                                  * Port specification is unavailable -- if this
650                                  * rule specifies a port, we consider the rule
651                                  * a non-match.
652                                  */
653                                 if (f->fw_nports != 0)
654                                         continue;
655
656                                 break;
657                         }
658                         PULLUP_TO(off + 4);
659                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
660                         src_port = ntohs(udp->uh_sport);
661                         dst_port = ntohs(udp->uh_dport);
662 check_ports:
663                         if (!port_match6(&f->fw_pts[0],
664                             IPV6_FW_GETNSRCP(f), src_port,
665                             f->fw_flg & IPV6_FW_F_SRNG))
666                                 continue;
667                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
668                             IPV6_FW_GETNDSTP(f), dst_port,
669                             f->fw_flg & IPV6_FW_F_DRNG))
670                                 continue;
671                         break;
672                     }
673
674                 case IPPROTO_ICMPV6:
675                     {
676                         struct icmp6_hdr *icmp;
677
678                         if (offset != 0)        /* Type isn't valid */
679                                 break;
680                         PULLUP_TO(off + 2);
681                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
682                         if (!icmp6type_match(icmp, f))
683                                 continue;
684                         break;
685                     }
686 #undef PULLUP_TO
687
688 bogusfrag:
689                         if (fw6_verbose)
690                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
691                         goto dropit;
692                 }
693
694 got_match:
695 #ifndef IP6FW_DIVERT_RESTART
696                 /* Ignore divert/tee rule if socket port is "ignport" */
697                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
698                 case IPV6_FW_F_DIVERT:
699                 case IPV6_FW_F_TEE:
700                         if (f->fw_divert_port == ignport)
701                                 continue;       /* ignore this rule */
702                         break;
703                 }
704
705 #endif /* IP6FW_DIVERT_RESTART */
706                 /* Update statistics */
707                 f->fw_pcnt += 1;
708                 f->fw_bcnt += ntohs(ip6->ip6_plen);
709                 f->timestamp = time_second;
710
711                 /* Log to console if desired */
712                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
713                         ip6fw_report(f, ip6, rif, oif, off, nxt);
714
715                 /* Take appropriate action */
716                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
717                 case IPV6_FW_F_ACCEPT:
718                         return(0);
719                 case IPV6_FW_F_COUNT:
720                         continue;
721                 case IPV6_FW_F_DIVERT:
722 #ifdef IP6FW_DIVERT_RESTART
723                         *cookie = f->fw_number;
724 #else
725                         *cookie = htons(f->fw_divert_port);
726 #endif /* IP6FW_DIVERT_RESTART */
727                         return(f->fw_divert_port);
728                 case IPV6_FW_F_TEE:
729                         /*
730                          * XXX someday tee packet here, but beware that you
731                          * can't use m_copym() or m_copypacket() because
732                          * the divert input routine modifies the mbuf
733                          * (and these routines only increment reference
734                          * counts in the case of mbuf clusters), so need
735                          * to write custom routine.
736                          */
737                         continue;
738                 case IPV6_FW_F_SKIPTO:
739 #ifdef DIAGNOSTIC
740                         while (chain->chain.le_next
741                             && chain->chain.le_next->rule->fw_number
742                                 < f->fw_skipto_rule)
743 #else
744                         while (chain->chain.le_next->rule->fw_number
745                             < f->fw_skipto_rule)
746 #endif
747                                 chain = chain->chain.le_next;
748                         continue;
749                 }
750
751                 /* Deny/reject this packet using this rule */
752                 rule = f;
753                 break;
754         }
755
756 #ifdef DIAGNOSTIC
757         /* Rule 65535 should always be there and should always match */
758         if (!chain)
759                 panic("ip6_fw: chain");
760 #endif
761
762         /*
763          * At this point, we're going to drop the packet.
764          * Send a reject notice if all of the following are true:
765          *
766          * - The packet matched a reject rule
767          * - The packet is not an ICMP packet, or is an ICMP query packet
768          * - The packet is not a multicast or broadcast packet
769          */
770         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
771             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
772             && !((*m)->m_flags & (M_BCAST|M_MCAST))
773             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
774                 switch (rule->fw_reject_code) {
775                 case IPV6_FW_REJECT_RST:
776                   {
777                         struct tcphdr *const tcp =
778                                 (struct tcphdr *) ((caddr_t)ip6 + off);
779                         struct {
780                                 struct ip6_hdr ip6;
781                                 struct tcphdr th;
782                         } ti;
783                         tcp_seq ack, seq;
784                         int flags;
785
786                         if (offset != 0 || (tcp->th_flags & TH_RST))
787                                 break;
788
789                         ti.ip6 = *ip6;
790                         ti.th = *tcp;
791                         ti.th.th_seq = ntohl(ti.th.th_seq);
792                         ti.th.th_ack = ntohl(ti.th.th_ack);
793                         ti.ip6.ip6_nxt = IPPROTO_TCP;
794                         if (ti.th.th_flags & TH_ACK) {
795                                 ack = 0;
796                                 seq = ti.th.th_ack;
797                                 flags = TH_RST;
798                         } else {
799                                 ack = ti.th.th_seq;
800                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
801                                         ack += (*m)->m_pkthdr.len - off
802                                                 - (ti.th.th_off << 2);
803                                 } else if (ip6->ip6_plen) {
804                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
805                                                 - off - (ti.th.th_off << 2);
806                                 } else {
807                                         m_freem(*m);
808                                         *m = 0;
809                                         break;
810                                 }
811                                 seq = 0;
812                                 flags = TH_RST|TH_ACK;
813                         }
814                         bcopy(&ti, ip6, sizeof(ti));
815                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
816                                 *m, ack, seq, flags);
817                         *m = NULL;
818                         break;
819                   }
820                 default:        /* Send an ICMP unreachable using code */
821                         if (oif)
822                                 (*m)->m_pkthdr.rcvif = oif;
823                         icmp6_error(*m, ICMP6_DST_UNREACH,
824                             rule->fw_reject_code, 0);
825                         *m = NULL;
826                         break;
827                 }
828         }
829
830 dropit:
831         /*
832          * Finally, drop the packet.
833          */
834         if (*m) {
835                 m_freem(*m);
836                 *m = NULL;
837         }
838         return(0);
839 }
840
841 static int
842 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
843 {
844         struct ip6_fw *ftmp = 0;
845         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
846         u_short nbr = 0;
847
848         fwc = kmalloc(sizeof *fwc, M_IP6FW, M_INTWAIT);
849         ftmp = kmalloc(sizeof *ftmp, M_IP6FW, M_INTWAIT);
850
851         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
852         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
853         ftmp->fw_pcnt = 0L;
854         ftmp->fw_bcnt = 0L;
855         fwc->rule = ftmp;
856         
857         crit_enter();
858
859         if (!chainptr->lh_first) {
860                 LIST_INSERT_HEAD(chainptr, fwc, chain);
861                 crit_exit();
862                 return(0);
863         } else if (ftmp->fw_number == (u_short)-1) {
864                 if (fwc)  kfree(fwc, M_IP6FW);
865                 if (ftmp) kfree(ftmp, M_IP6FW);
866                 crit_exit();
867                 dprintf(("%s bad rule number\n", err_prefix));
868                 return (EINVAL);
869         }
870
871         /* If entry number is 0, find highest numbered rule and add 100 */
872         if (ftmp->fw_number == 0) {
873                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
874                         if (fcp->rule->fw_number != (u_short)-1)
875                                 nbr = fcp->rule->fw_number;
876                         else
877                                 break;
878                 }
879                 if (nbr < (u_short)-1 - 100)
880                         nbr += 100;
881                 ftmp->fw_number = nbr;
882         }
883
884         /* Got a valid number; now insert it, keeping the list ordered */
885         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
886                 if (fcp->rule->fw_number > ftmp->fw_number) {
887                         if (fcpl) {
888                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
889                         } else {
890                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
891                         }
892                         break;
893                 } else {
894                         fcpl = fcp;
895                 }
896         }
897
898         crit_exit();
899         return (0);
900 }
901
902 static int
903 del_entry6(struct ip6_fw_head *chainptr, u_short number)
904 {
905         struct ip6_fw_chain *fcp;
906
907         crit_enter();
908
909         fcp = chainptr->lh_first;
910         if (number != (u_short)-1) {
911                 for (; fcp; fcp = fcp->chain.le_next) {
912                         if (fcp->rule->fw_number == number) {
913                                 LIST_REMOVE(fcp, chain);
914                                 crit_exit();
915                                 kfree(fcp->rule, M_IP6FW);
916                                 kfree(fcp, M_IP6FW);
917                                 return 0;
918                         }
919                 }
920         }
921
922         crit_exit();
923         return (EINVAL);
924 }
925
926 static int
927 zero_entry6(struct mbuf *m)
928 {
929         struct ip6_fw *frwl;
930         struct ip6_fw_chain *fcp;
931
932         if (m && m->m_len != 0) {
933                 if (m->m_len != sizeof(struct ip6_fw))
934                         return(EINVAL);
935                 frwl = mtod(m, struct ip6_fw *);
936         }
937         else
938                 frwl = NULL;
939
940         /*
941          *      It's possible to insert multiple chain entries with the
942          *      same number, so we don't stop after finding the first
943          *      match if zeroing a specific entry.
944          */
945         crit_enter();
946         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
947                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
948                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
949                         fcp->rule->timestamp = 0;
950                 }
951         crit_exit();
952
953         if (fw6_verbose) {
954                 if (frwl)
955                         log(LOG_SECURITY | LOG_NOTICE,
956                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
957                 else
958                         log(LOG_SECURITY | LOG_NOTICE,
959                             "ip6fw: Accounting cleared.\n");
960         }
961
962         return(0);
963 }
964
965 static struct ip6_fw *
966 check_ip6fw_mbuf(struct mbuf *m)
967 {
968         /* Check length */
969         if (m->m_len != sizeof(struct ip6_fw)) {
970                 dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
971                     sizeof(struct ip6_fw)));
972                 return (NULL);
973         }
974         return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
975 }
976
977 static struct ip6_fw *
978 check_ip6fw_struct(struct ip6_fw *frwl)
979 {
980         /* Check for invalid flag bits */
981         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
982                 dprintf(("%s undefined flag bits set (flags=%x)\n",
983                     err_prefix, frwl->fw_flg));
984                 return (NULL);
985         }
986         /* Must apply to incoming or outgoing (or both) */
987         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
988                 dprintf(("%s neither in nor out\n", err_prefix));
989                 return (NULL);
990         }
991         /* Empty interface name is no good */
992         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
993               && !*frwl->fw_in_if.fu_via_if.name)
994             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
995               && !*frwl->fw_out_if.fu_via_if.name)) {
996                 dprintf(("%s empty interface name\n", err_prefix));
997                 return (NULL);
998         }
999         /* Sanity check interface matching */
1000         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1001                 ;               /* allow "via" backwards compatibility */
1002         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1003             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1004                 dprintf(("%s outgoing interface check on incoming\n",
1005                     err_prefix));
1006                 return (NULL);
1007         }
1008         /* Sanity check port ranges */
1009         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1010                 dprintf(("%s src range set but n_src_p=%d\n",
1011                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1012                 return (NULL);
1013         }
1014         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1015                 dprintf(("%s dst range set but n_dst_p=%d\n",
1016                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1017                 return (NULL);
1018         }
1019         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1020                 dprintf(("%s too many ports (%d+%d)\n",
1021                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1022                 return (NULL);
1023         }
1024         /*
1025          *      Protocols other than TCP/UDP don't use port range
1026          */
1027         if ((frwl->fw_prot != IPPROTO_TCP) &&
1028             (frwl->fw_prot != IPPROTO_UDP) &&
1029             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1030                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1031                     err_prefix));
1032                 return(NULL);
1033         }
1034
1035         /*
1036          *      Rather than modify the entry to make such entries work,
1037          *      we reject this rule and require user level utilities
1038          *      to enforce whatever policy they deem appropriate.
1039          */
1040         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1041                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1042                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1043                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1044                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1045                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1046                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1047                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1048                 dprintf(("%s rule never matches\n", err_prefix));
1049                 return(NULL);
1050         }
1051
1052         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1053                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1054                 if (frwl->fw_nports) {
1055                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1056                         return(NULL);
1057                 }
1058                 if (frwl->fw_prot == IPPROTO_TCP &&
1059                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1060                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1061                         return(NULL);
1062                 }
1063         }
1064
1065         /* Check command specific stuff */
1066         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1067         {
1068         case IPV6_FW_F_REJECT:
1069                 if (frwl->fw_reject_code >= 0x100
1070                     && !(frwl->fw_prot == IPPROTO_TCP
1071                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1072                         dprintf(("%s unknown reject code\n", err_prefix));
1073                         return(NULL);
1074                 }
1075                 break;
1076         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1077         case IPV6_FW_F_TEE:
1078                 if (frwl->fw_divert_port == 0) {
1079                         dprintf(("%s can't divert to port 0\n", err_prefix));
1080                         return (NULL);
1081                 }
1082                 break;
1083         case IPV6_FW_F_DENY:
1084         case IPV6_FW_F_ACCEPT:
1085         case IPV6_FW_F_COUNT:
1086         case IPV6_FW_F_SKIPTO:
1087                 break;
1088         default:
1089                 dprintf(("%s invalid command\n", err_prefix));
1090                 return(NULL);
1091         }
1092
1093         return frwl;
1094 }
1095
1096 static int
1097 ip6_fw_ctl(int stage, struct mbuf **mm)
1098 {
1099         int error;
1100         struct mbuf *m;
1101
1102         if (stage == IPV6_FW_GET) {
1103                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1104                 *mm = m = m_get(MB_WAIT, MT_DATA); /* XXX */
1105                 if (!m)
1106                         return(ENOBUFS);
1107                 if (sizeof *(fcp->rule) > MLEN) {
1108                         MCLGET(m, MB_WAIT);
1109                         if ((m->m_flags & M_EXT) == 0) {
1110                                 m_free(m);
1111                                 return(ENOBUFS);
1112                         }
1113                 }
1114                 for (; fcp; fcp = fcp->chain.le_next) {
1115                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1116                         m->m_len = sizeof *(fcp->rule);
1117                         m->m_next = m_get(MB_WAIT, MT_DATA); /* XXX */
1118                         if (!m->m_next) {
1119                                 m_freem(*mm);
1120                                 return(ENOBUFS);
1121                         }
1122                         m = m->m_next;
1123                         if (sizeof *(fcp->rule) > MLEN) {
1124                                 MCLGET(m, MB_WAIT);
1125                                 if ((m->m_flags & M_EXT) == 0) {
1126                                         m_freem(*mm);
1127                                         return(ENOBUFS);
1128                                 }
1129                         }
1130                         m->m_len = 0;
1131                 }
1132                 return (0);
1133         }
1134         m = *mm;
1135         /* only allow get calls if secure mode > 2 */
1136         if (securelevel > 2) {
1137                 if (m) {
1138                         m_freem(m);
1139                         *mm = 0;
1140                 }
1141                 return(EPERM);
1142         }
1143         if (stage == IPV6_FW_FLUSH) {
1144                 while (ip6_fw_chain.lh_first != NULL &&
1145                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1146                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1147                         crit_enter();
1148                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1149                         crit_exit();
1150                         kfree(fcp->rule, M_IP6FW);
1151                         kfree(fcp, M_IP6FW);
1152                 }
1153                 if (m) {
1154                         m_freem(m);
1155                         *mm = 0;
1156                 }
1157                 return (0);
1158         }
1159         if (stage == IPV6_FW_ZERO) {
1160                 error = zero_entry6(m);
1161                 if (m) {
1162                         m_freem(m);
1163                         *mm = 0;
1164                 }
1165                 return (error);
1166         }
1167         if (m == NULL) {
1168                 kprintf("%s NULL mbuf ptr\n", err_prefix);
1169                 return (EINVAL);
1170         }
1171
1172         if (stage == IPV6_FW_ADD) {
1173                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1174
1175                 if (!frwl)
1176                         error = EINVAL;
1177                 else
1178                         error = add_entry6(&ip6_fw_chain, frwl);
1179                 if (m) {
1180                         m_freem(m);
1181                         *mm = 0;
1182                 }
1183                 return error;
1184         }
1185         if (stage == IPV6_FW_DEL) {
1186                 if (m->m_len != sizeof(struct ip6_fw)) {
1187                         dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1188                             sizeof(struct ip6_fw)));
1189                         error = EINVAL;
1190                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1191                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1192                         error = EINVAL;
1193                 } else
1194                         error = del_entry6(&ip6_fw_chain,
1195                             mtod(m, struct ip6_fw *)->fw_number);
1196                 if (m) {
1197                         m_freem(m);
1198                         *mm = 0;
1199                 }
1200                 return error;
1201         }
1202
1203         dprintf(("%s unknown request %d\n", err_prefix, stage));
1204         if (m) {
1205                 m_freem(m);
1206                 *mm = 0;
1207         }
1208         return (EINVAL);
1209 }
1210
1211 void
1212 ip6_fw_init(void)
1213 {
1214         struct ip6_fw default_rule;
1215
1216         ip6_fw_chk_ptr = ip6_fw_chk;
1217         ip6_fw_ctl_ptr = ip6_fw_ctl;
1218         LIST_INIT(&ip6_fw_chain);
1219
1220         bzero(&default_rule, sizeof default_rule);
1221         default_rule.fw_prot = IPPROTO_IPV6;
1222         default_rule.fw_number = (u_short)-1;
1223 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1224         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1225 #else
1226         default_rule.fw_flg |= IPV6_FW_F_DENY;
1227 #endif
1228         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1229         if (check_ip6fw_struct(&default_rule) == NULL ||
1230                 add_entry6(&ip6_fw_chain, &default_rule))
1231                 panic(__func__);
1232
1233         kprintf("IPv6 packet filtering initialized, ");
1234 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1235         kprintf("default to accept, ");
1236 #endif
1237 #ifndef IPV6FIREWALL_VERBOSE
1238         kprintf("logging disabled\n");
1239 #else
1240         if (fw6_verbose_limit == 0)
1241                 kprintf("unlimited logging\n");
1242         else
1243                 kprintf("logging limited to %d packets/entry\n",
1244                     fw6_verbose_limit);
1245 #endif
1246 }
1247
1248 static ip6_fw_chk_t *old_chk_ptr;
1249 static ip6_fw_ctl_t *old_ctl_ptr;
1250
1251 static int
1252 ip6fw_modevent(module_t mod, int type, void *unused)
1253 {
1254         switch (type) {
1255         case MOD_LOAD:
1256                 crit_enter();
1257
1258                 old_chk_ptr = ip6_fw_chk_ptr;
1259                 old_ctl_ptr = ip6_fw_ctl_ptr;
1260
1261                 ip6_fw_init();
1262                 crit_exit();
1263                 return 0;
1264         case MOD_UNLOAD:
1265                 crit_enter();
1266                 ip6_fw_chk_ptr =  old_chk_ptr;
1267                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1268                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1269                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1270                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1271                         kfree(fcp->rule, M_IP6FW);
1272                         kfree(fcp, M_IP6FW);
1273                 }
1274
1275                 crit_exit();
1276                 kprintf("IPv6 firewall unloaded\n");
1277                 return 0;
1278         default:
1279                 break;
1280         }
1281         return 0;
1282 }
1283
1284 static moduledata_t ip6fwmod = {
1285         "ip6fw",
1286         ip6fw_modevent,
1287         0
1288 };
1289 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);