5aea30ef4b0d58cd1ad76cc980e40edc96d3770d
[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 1.13 2005/06/15 17:12:24 joerg 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                                         printf 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 (fnmatch(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 *ifa;
340
341                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
342                         if (ifa->ifa_addr == NULL)
343                                 continue;
344                         if (ifa->ifa_addr->sa_family != AF_INET6)
345                                 continue;
346                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
347                             &(((struct sockaddr_in6 *)
348                             (ifa->ifa_addr))->sin6_addr)))
349                                 continue;
350                         return(1);
351                 }
352                 return(0);
353         }
354         return(1);
355 }
356
357 static void
358 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
359         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
360 {
361         static int counter;
362         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
363         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
364         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
365         int count;
366         char *action;
367         char action2[32], proto[102], name[18];
368         int len;
369
370         count = f ? f->fw_pcnt : ++counter;
371         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
372                 return;
373
374         /* Print command name */
375         snprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
376
377         action = action2;
378         if (!f)
379                 action = "Refuse";
380         else {
381                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
382                 case IPV6_FW_F_DENY:
383                         action = "Deny";
384                         break;
385                 case IPV6_FW_F_REJECT:
386                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
387                                 action = "Reset";
388                         else
389                                 action = "Unreach";
390                         break;
391                 case IPV6_FW_F_ACCEPT:
392                         action = "Accept";
393                         break;
394                 case IPV6_FW_F_COUNT:
395                         action = "Count";
396                         break;
397                 case IPV6_FW_F_DIVERT:
398                         snprintf(SNPARGS(action2, 0), "Divert %d",
399                             f->fw_divert_port);
400                         break;
401                 case IPV6_FW_F_TEE:
402                         snprintf(SNPARGS(action2, 0), "Tee %d",
403                             f->fw_divert_port);
404                         break;
405                 case IPV6_FW_F_SKIPTO:
406                         snprintf(SNPARGS(action2, 0), "SkipTo %d",
407                             f->fw_skipto_rule);
408                         break;
409                 default:        
410                         action = "UNKNOWN";
411                         break;
412                 }
413         }
414
415         switch (nxt) {
416         case IPPROTO_TCP:
417                 len = snprintf(SNPARGS(proto, 0), "TCP [%s]",
418                     ip6_sprintf(&ip6->ip6_src));
419                 if (off > 0)
420                         len += snprintf(SNPARGS(proto, len), ":%d ",
421                             ntohs(tcp6->th_sport));
422                 else
423                         len += snprintf(SNPARGS(proto, len), " ");
424                 len += snprintf(SNPARGS(proto, len), "[%s]",
425                     ip6_sprintf(&ip6->ip6_dst));
426                 if (off > 0)
427                         snprintf(SNPARGS(proto, len), ":%d",
428                             ntohs(tcp6->th_dport));
429                 break;
430         case IPPROTO_UDP:
431                 len = snprintf(SNPARGS(proto, 0), "UDP [%s]",
432                     ip6_sprintf(&ip6->ip6_src));
433                 if (off > 0)
434                         len += snprintf(SNPARGS(proto, len), ":%d ",
435                             ntohs(udp->uh_sport));
436                 else
437                     len += snprintf(SNPARGS(proto, len), " ");
438                 len += snprintf(SNPARGS(proto, len), "[%s]",
439                     ip6_sprintf(&ip6->ip6_dst));
440                 if (off > 0)
441                         snprintf(SNPARGS(proto, len), ":%d",
442                             ntohs(udp->uh_dport));
443                 break;
444         case IPPROTO_ICMPV6:
445                 if (off > 0)
446                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
447                             icmp6->icmp6_type, icmp6->icmp6_code);
448                 else
449                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
450                 len += snprintf(SNPARGS(proto, len), "[%s]",
451                     ip6_sprintf(&ip6->ip6_src));
452                 snprintf(SNPARGS(proto, len), " [%s]",
453                     ip6_sprintf(&ip6->ip6_dst));
454                 break;
455         default:
456                 len = snprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
457                     ip6_sprintf(&ip6->ip6_src));
458                 snprintf(SNPARGS(proto, len), " [%s]",
459                     ip6_sprintf(&ip6->ip6_dst));
460                 break;
461         }
462
463         if (oif)
464                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
465                     name, action, proto, if_name(oif));
466         else if (rif)
467                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
468                     name, action, proto, if_name(rif));
469         else
470                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
471                     name, action, proto);
472         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
473             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
474                 f ? f->fw_number : -1);
475 }
476
477 /*
478  * Parameters:
479  *
480  *      ip      Pointer to packet header (struct ip6_hdr *)
481  *      hlen    Packet header length
482  *      oif     Outgoing interface, or NULL if packet is incoming
483  * #ifndef IP6FW_DIVERT_RESTART
484  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
485  * #else
486  *      *cookie Skip up to the first rule past this rule number;
487  * #endif
488  *      *m      The packet; we set to NULL when/if we nuke it.
489  *
490  * Return value:
491  *
492  *      0       The packet is to be accepted and routed normally OR
493  *              the packet was denied/rejected and has been dropped;
494  *              in the latter case, *m is equal to NULL upon return.
495  *      port    Divert the packet to port.
496  */
497
498 static int
499 ip6_fw_chk(struct ip6_hdr **pip6,
500         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
501 {
502         struct ip6_fw_chain *chain;
503         struct ip6_fw *rule = NULL;
504         struct ip6_hdr *ip6 = *pip6;
505         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
506         u_short offset = 0;
507         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
508         u_short src_port, dst_port;
509 #ifdef  IP6FW_DIVERT_RESTART
510         u_int16_t skipto = *cookie;
511 #else
512         u_int16_t ignport = ntohs(*cookie);
513 #endif
514
515         *cookie = 0;
516         /*
517          * Go down the chain, looking for enlightment
518          * #ifdef IP6FW_DIVERT_RESTART
519          * If we've been asked to start at a given rule immediatly, do so.
520          * #endif
521          */
522         chain = LIST_FIRST(&ip6_fw_chain);
523 #ifdef IP6FW_DIVERT_RESTART
524         if (skipto) {
525                 if (skipto >= 65535)
526                         goto dropit;
527                 while (chain && (chain->rule->fw_number <= skipto)) {
528                         chain = LIST_NEXT(chain, chain);
529                 }
530                 if (! chain) goto dropit;
531         }
532 #endif /* IP6FW_DIVERT_RESTART */
533         for (; chain; chain = LIST_NEXT(chain, chain)) {
534                 struct ip6_fw *const f = chain->rule;
535
536                 if (oif) {
537                         /* Check direction outbound */
538                         if (!(f->fw_flg & IPV6_FW_F_OUT))
539                                 continue;
540                 } else {
541                         /* Check direction inbound */
542                         if (!(f->fw_flg & IPV6_FW_F_IN))
543                                 continue;
544                 }
545
546 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
547         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
548         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
549         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
550         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
551
552                 /* If src-addr doesn't match, not this rule. */
553                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
554                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
555                         continue;
556
557                 /* If dest-addr doesn't match, not this rule. */
558                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
559                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
560                         continue;
561
562 #undef IN6_ARE_ADDR_MASKEQUAL
563                 /* Interface check */
564                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
565                         struct ifnet *const iface = oif ? oif : rif;
566
567                         /* Backwards compatibility hack for "via" */
568                         if (!iface || !iface_match(iface,
569                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
570                                 continue;
571                 } else {
572                         /* Check receive interface */
573                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
574                             && (!rif || !iface_match(rif,
575                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
576                                 continue;
577                         /* Check outgoing interface */
578                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
579                             && (!oif || !iface_match(oif,
580                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
581                                 continue;
582                 }
583
584                 /* Check IP options */
585                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
586                         continue;
587
588                 /* Fragments */
589                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
590                         continue;
591
592                 /* Check protocol; if wildcard, match */
593                 if (f->fw_prot == IPPROTO_IPV6)
594                         goto got_match;
595
596                 /* If different, don't match */
597                 if (nxt != f->fw_prot)
598                         continue;
599
600 #define PULLUP_TO(len)  do {                                            \
601                             if ((*m)->m_len < (len)                     \
602                                 && (*m = m_pullup(*m, (len))) == 0) {   \
603                                     goto dropit;                        \
604                             }                                           \
605                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
606                         } while (0)
607
608                 /* Protocol specific checks */
609                 switch (nxt) {
610                 case IPPROTO_TCP:
611                     {
612                         struct tcphdr *tcp6;
613
614                         if (offset == 1) {      /* cf. RFC 1858 */
615                                 PULLUP_TO(off + 4); /* XXX ? */
616                                 goto bogusfrag;
617                         }
618                         if (offset != 0) {
619                                 /*
620                                  * TCP flags and ports aren't available in this
621                                  * packet -- if this rule specified either one,
622                                  * we consider the rule a non-match.
623                                  */
624                                 if (f->fw_nports != 0 ||
625                                     f->fw_tcpf != f->fw_tcpnf)
626                                         continue;
627
628                                 break;
629                         }
630                         PULLUP_TO(off + 14);
631                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
632                         if (((f->fw_tcpf != f->fw_tcpnf) ||
633                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
634                            !tcp6flg_match(tcp6, f))
635                                 continue;
636                         src_port = ntohs(tcp6->th_sport);
637                         dst_port = ntohs(tcp6->th_dport);
638                         goto check_ports;
639                     }
640
641                 case IPPROTO_UDP:
642                     {
643                         struct udphdr *udp;
644
645                         if (offset != 0) {
646                                 /*
647                                  * Port specification is unavailable -- if this
648                                  * rule specifies a port, we consider the rule
649                                  * a non-match.
650                                  */
651                                 if (f->fw_nports != 0)
652                                         continue;
653
654                                 break;
655                         }
656                         PULLUP_TO(off + 4);
657                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
658                         src_port = ntohs(udp->uh_sport);
659                         dst_port = ntohs(udp->uh_dport);
660 check_ports:
661                         if (!port_match6(&f->fw_pts[0],
662                             IPV6_FW_GETNSRCP(f), src_port,
663                             f->fw_flg & IPV6_FW_F_SRNG))
664                                 continue;
665                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
666                             IPV6_FW_GETNDSTP(f), dst_port,
667                             f->fw_flg & IPV6_FW_F_DRNG))
668                                 continue;
669                         break;
670                     }
671
672                 case IPPROTO_ICMPV6:
673                     {
674                         struct icmp6_hdr *icmp;
675
676                         if (offset != 0)        /* Type isn't valid */
677                                 break;
678                         PULLUP_TO(off + 2);
679                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
680                         if (!icmp6type_match(icmp, f))
681                                 continue;
682                         break;
683                     }
684 #undef PULLUP_TO
685
686 bogusfrag:
687                         if (fw6_verbose)
688                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
689                         goto dropit;
690                 }
691
692 got_match:
693 #ifndef IP6FW_DIVERT_RESTART
694                 /* Ignore divert/tee rule if socket port is "ignport" */
695                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
696                 case IPV6_FW_F_DIVERT:
697                 case IPV6_FW_F_TEE:
698                         if (f->fw_divert_port == ignport)
699                                 continue;       /* ignore this rule */
700                         break;
701                 }
702
703 #endif /* IP6FW_DIVERT_RESTART */
704                 /* Update statistics */
705                 f->fw_pcnt += 1;
706                 f->fw_bcnt += ntohs(ip6->ip6_plen);
707                 f->timestamp = time_second;
708
709                 /* Log to console if desired */
710                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
711                         ip6fw_report(f, ip6, rif, oif, off, nxt);
712
713                 /* Take appropriate action */
714                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
715                 case IPV6_FW_F_ACCEPT:
716                         return(0);
717                 case IPV6_FW_F_COUNT:
718                         continue;
719                 case IPV6_FW_F_DIVERT:
720 #ifdef IP6FW_DIVERT_RESTART
721                         *cookie = f->fw_number;
722 #else
723                         *cookie = htons(f->fw_divert_port);
724 #endif /* IP6FW_DIVERT_RESTART */
725                         return(f->fw_divert_port);
726                 case IPV6_FW_F_TEE:
727                         /*
728                          * XXX someday tee packet here, but beware that you
729                          * can't use m_copym() or m_copypacket() because
730                          * the divert input routine modifies the mbuf
731                          * (and these routines only increment reference
732                          * counts in the case of mbuf clusters), so need
733                          * to write custom routine.
734                          */
735                         continue;
736                 case IPV6_FW_F_SKIPTO:
737 #ifdef DIAGNOSTIC
738                         while (chain->chain.le_next
739                             && chain->chain.le_next->rule->fw_number
740                                 < f->fw_skipto_rule)
741 #else
742                         while (chain->chain.le_next->rule->fw_number
743                             < f->fw_skipto_rule)
744 #endif
745                                 chain = chain->chain.le_next;
746                         continue;
747                 }
748
749                 /* Deny/reject this packet using this rule */
750                 rule = f;
751                 break;
752         }
753
754 #ifdef DIAGNOSTIC
755         /* Rule 65535 should always be there and should always match */
756         if (!chain)
757                 panic("ip6_fw: chain");
758 #endif
759
760         /*
761          * At this point, we're going to drop the packet.
762          * Send a reject notice if all of the following are true:
763          *
764          * - The packet matched a reject rule
765          * - The packet is not an ICMP packet, or is an ICMP query packet
766          * - The packet is not a multicast or broadcast packet
767          */
768         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
769             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
770             && !((*m)->m_flags & (M_BCAST|M_MCAST))
771             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
772                 switch (rule->fw_reject_code) {
773                 case IPV6_FW_REJECT_RST:
774                   {
775                         struct tcphdr *const tcp =
776                                 (struct tcphdr *) ((caddr_t)ip6 + off);
777                         struct {
778                                 struct ip6_hdr ip6;
779                                 struct tcphdr th;
780                         } ti;
781                         tcp_seq ack, seq;
782                         int flags;
783
784                         if (offset != 0 || (tcp->th_flags & TH_RST))
785                                 break;
786
787                         ti.ip6 = *ip6;
788                         ti.th = *tcp;
789                         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 = 0;
807                                         break;
808                                 }
809                                 seq = 0;
810                                 flags = TH_RST|TH_ACK;
811                         }
812                         bcopy(&ti, ip6, sizeof(ti));
813                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
814                                 *m, ack, seq, flags);
815                         *m = NULL;
816                         break;
817                   }
818                 default:        /* Send an ICMP unreachable using code */
819                         if (oif)
820                                 (*m)->m_pkthdr.rcvif = oif;
821                         icmp6_error(*m, ICMP6_DST_UNREACH,
822                             rule->fw_reject_code, 0);
823                         *m = NULL;
824                         break;
825                 }
826         }
827
828 dropit:
829         /*
830          * Finally, drop the packet.
831          */
832         if (*m) {
833                 m_freem(*m);
834                 *m = NULL;
835         }
836         return(0);
837 }
838
839 static int
840 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
841 {
842         struct ip6_fw *ftmp = 0;
843         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
844         u_short nbr = 0;
845
846         fwc = malloc(sizeof *fwc, M_IP6FW, M_INTWAIT);
847         ftmp = malloc(sizeof *ftmp, M_IP6FW, M_INTWAIT);
848
849         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
850         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
851         ftmp->fw_pcnt = 0L;
852         ftmp->fw_bcnt = 0L;
853         fwc->rule = ftmp;
854         
855         crit_enter();
856
857         if (!chainptr->lh_first) {
858                 LIST_INSERT_HEAD(chainptr, fwc, chain);
859                 crit_exit();
860                 return(0);
861         } else if (ftmp->fw_number == (u_short)-1) {
862                 if (fwc)  free(fwc, M_IP6FW);
863                 if (ftmp) free(ftmp, M_IP6FW);
864                 crit_exit();
865                 dprintf(("%s bad rule number\n", err_prefix));
866                 return (EINVAL);
867         }
868
869         /* If entry number is 0, find highest numbered rule and add 100 */
870         if (ftmp->fw_number == 0) {
871                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
872                         if (fcp->rule->fw_number != (u_short)-1)
873                                 nbr = fcp->rule->fw_number;
874                         else
875                                 break;
876                 }
877                 if (nbr < (u_short)-1 - 100)
878                         nbr += 100;
879                 ftmp->fw_number = nbr;
880         }
881
882         /* Got a valid number; now insert it, keeping the list ordered */
883         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
884                 if (fcp->rule->fw_number > ftmp->fw_number) {
885                         if (fcpl) {
886                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
887                         } else {
888                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
889                         }
890                         break;
891                 } else {
892                         fcpl = fcp;
893                 }
894         }
895
896         crit_exit();
897         return (0);
898 }
899
900 static int
901 del_entry6(struct ip6_fw_head *chainptr, u_short number)
902 {
903         struct ip6_fw_chain *fcp;
904
905         crit_enter();
906
907         fcp = chainptr->lh_first;
908         if (number != (u_short)-1) {
909                 for (; fcp; fcp = fcp->chain.le_next) {
910                         if (fcp->rule->fw_number == number) {
911                                 LIST_REMOVE(fcp, chain);
912                                 crit_exit();
913                                 free(fcp->rule, M_IP6FW);
914                                 free(fcp, M_IP6FW);
915                                 return 0;
916                         }
917                 }
918         }
919
920         crit_exit();
921         return (EINVAL);
922 }
923
924 static int
925 zero_entry6(struct mbuf *m)
926 {
927         struct ip6_fw *frwl;
928         struct ip6_fw_chain *fcp;
929
930         if (m && m->m_len != 0) {
931                 if (m->m_len != sizeof(struct ip6_fw))
932                         return(EINVAL);
933                 frwl = mtod(m, struct ip6_fw *);
934         }
935         else
936                 frwl = NULL;
937
938         /*
939          *      It's possible to insert multiple chain entries with the
940          *      same number, so we don't stop after finding the first
941          *      match if zeroing a specific entry.
942          */
943         crit_enter();
944         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
945                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
946                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
947                         fcp->rule->timestamp = 0;
948                 }
949         crit_exit();
950
951         if (fw6_verbose) {
952                 if (frwl)
953                         log(LOG_SECURITY | LOG_NOTICE,
954                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
955                 else
956                         log(LOG_SECURITY | LOG_NOTICE,
957                             "ip6fw: Accounting cleared.\n");
958         }
959
960         return(0);
961 }
962
963 static struct ip6_fw *
964 check_ip6fw_mbuf(struct mbuf *m)
965 {
966         /* Check length */
967         if (m->m_len != sizeof(struct ip6_fw)) {
968                 dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
969                     sizeof(struct ip6_fw)));
970                 return (NULL);
971         }
972         return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
973 }
974
975 static struct ip6_fw *
976 check_ip6fw_struct(struct ip6_fw *frwl)
977 {
978         /* Check for invalid flag bits */
979         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
980                 dprintf(("%s undefined flag bits set (flags=%x)\n",
981                     err_prefix, frwl->fw_flg));
982                 return (NULL);
983         }
984         /* Must apply to incoming or outgoing (or both) */
985         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
986                 dprintf(("%s neither in nor out\n", err_prefix));
987                 return (NULL);
988         }
989         /* Empty interface name is no good */
990         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
991               && !*frwl->fw_in_if.fu_via_if.name)
992             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
993               && !*frwl->fw_out_if.fu_via_if.name)) {
994                 dprintf(("%s empty interface name\n", err_prefix));
995                 return (NULL);
996         }
997         /* Sanity check interface matching */
998         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
999                 ;               /* allow "via" backwards compatibility */
1000         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1001             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1002                 dprintf(("%s outgoing interface check on incoming\n",
1003                     err_prefix));
1004                 return (NULL);
1005         }
1006         /* Sanity check port ranges */
1007         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1008                 dprintf(("%s src range set but n_src_p=%d\n",
1009                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1010                 return (NULL);
1011         }
1012         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1013                 dprintf(("%s dst range set but n_dst_p=%d\n",
1014                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1015                 return (NULL);
1016         }
1017         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1018                 dprintf(("%s too many ports (%d+%d)\n",
1019                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1020                 return (NULL);
1021         }
1022         /*
1023          *      Protocols other than TCP/UDP don't use port range
1024          */
1025         if ((frwl->fw_prot != IPPROTO_TCP) &&
1026             (frwl->fw_prot != IPPROTO_UDP) &&
1027             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1028                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1029                     err_prefix));
1030                 return(NULL);
1031         }
1032
1033         /*
1034          *      Rather than modify the entry to make such entries work,
1035          *      we reject this rule and require user level utilities
1036          *      to enforce whatever policy they deem appropriate.
1037          */
1038         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1039                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1040                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1041                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1042                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1043                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1044                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1045                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1046                 dprintf(("%s rule never matches\n", err_prefix));
1047                 return(NULL);
1048         }
1049
1050         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1051                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1052                 if (frwl->fw_nports) {
1053                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1054                         return(NULL);
1055                 }
1056                 if (frwl->fw_prot == IPPROTO_TCP &&
1057                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1058                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1059                         return(NULL);
1060                 }
1061         }
1062
1063         /* Check command specific stuff */
1064         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1065         {
1066         case IPV6_FW_F_REJECT:
1067                 if (frwl->fw_reject_code >= 0x100
1068                     && !(frwl->fw_prot == IPPROTO_TCP
1069                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1070                         dprintf(("%s unknown reject code\n", err_prefix));
1071                         return(NULL);
1072                 }
1073                 break;
1074         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1075         case IPV6_FW_F_TEE:
1076                 if (frwl->fw_divert_port == 0) {
1077                         dprintf(("%s can't divert to port 0\n", err_prefix));
1078                         return (NULL);
1079                 }
1080                 break;
1081         case IPV6_FW_F_DENY:
1082         case IPV6_FW_F_ACCEPT:
1083         case IPV6_FW_F_COUNT:
1084         case IPV6_FW_F_SKIPTO:
1085                 break;
1086         default:
1087                 dprintf(("%s invalid command\n", err_prefix));
1088                 return(NULL);
1089         }
1090
1091         return frwl;
1092 }
1093
1094 static int
1095 ip6_fw_ctl(int stage, struct mbuf **mm)
1096 {
1097         int error;
1098         struct mbuf *m;
1099
1100         if (stage == IPV6_FW_GET) {
1101                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1102                 *mm = m = m_get(MB_WAIT, MT_DATA); /* XXX */
1103                 if (!m)
1104                         return(ENOBUFS);
1105                 if (sizeof *(fcp->rule) > MLEN) {
1106                         MCLGET(m, MB_WAIT);
1107                         if ((m->m_flags & M_EXT) == 0) {
1108                                 m_free(m);
1109                                 return(ENOBUFS);
1110                         }
1111                 }
1112                 for (; fcp; fcp = fcp->chain.le_next) {
1113                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1114                         m->m_len = sizeof *(fcp->rule);
1115                         m->m_next = m_get(MB_WAIT, MT_DATA); /* XXX */
1116                         if (!m->m_next) {
1117                                 m_freem(*mm);
1118                                 return(ENOBUFS);
1119                         }
1120                         m = m->m_next;
1121                         if (sizeof *(fcp->rule) > MLEN) {
1122                                 MCLGET(m, MB_WAIT);
1123                                 if ((m->m_flags & M_EXT) == 0) {
1124                                         m_freem(*mm);
1125                                         return(ENOBUFS);
1126                                 }
1127                         }
1128                         m->m_len = 0;
1129                 }
1130                 return (0);
1131         }
1132         m = *mm;
1133         /* only allow get calls if secure mode > 2 */
1134         if (securelevel > 2) {
1135                 if (m) {
1136                         (void)m_freem(m);
1137                         *mm = 0;
1138                 }
1139                 return(EPERM);
1140         }
1141         if (stage == IPV6_FW_FLUSH) {
1142                 while (ip6_fw_chain.lh_first != NULL &&
1143                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1144                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1145                         crit_enter();
1146                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1147                         crit_exit();
1148                         free(fcp->rule, M_IP6FW);
1149                         free(fcp, M_IP6FW);
1150                 }
1151                 if (m) {
1152                         (void)m_freem(m);
1153                         *mm = 0;
1154                 }
1155                 return (0);
1156         }
1157         if (stage == IPV6_FW_ZERO) {
1158                 error = zero_entry6(m);
1159                 if (m) {
1160                         (void)m_freem(m);
1161                         *mm = 0;
1162                 }
1163                 return (error);
1164         }
1165         if (m == NULL) {
1166                 printf("%s NULL mbuf ptr\n", err_prefix);
1167                 return (EINVAL);
1168         }
1169
1170         if (stage == IPV6_FW_ADD) {
1171                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1172
1173                 if (!frwl)
1174                         error = EINVAL;
1175                 else
1176                         error = add_entry6(&ip6_fw_chain, frwl);
1177                 if (m) {
1178                         (void)m_freem(m);
1179                         *mm = 0;
1180                 }
1181                 return error;
1182         }
1183         if (stage == IPV6_FW_DEL) {
1184                 if (m->m_len != sizeof(struct ip6_fw)) {
1185                         dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1186                             sizeof(struct ip6_fw)));
1187                         error = EINVAL;
1188                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1189                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1190                         error = EINVAL;
1191                 } else
1192                         error = del_entry6(&ip6_fw_chain,
1193                             mtod(m, struct ip6_fw *)->fw_number);
1194                 if (m) {
1195                         (void)m_freem(m);
1196                         *mm = 0;
1197                 }
1198                 return error;
1199         }
1200
1201         dprintf(("%s unknown request %d\n", err_prefix, stage));
1202         if (m) {
1203                 (void)m_freem(m);
1204                 *mm = 0;
1205         }
1206         return (EINVAL);
1207 }
1208
1209 void
1210 ip6_fw_init(void)
1211 {
1212         struct ip6_fw default_rule;
1213
1214         ip6_fw_chk_ptr = ip6_fw_chk;
1215         ip6_fw_ctl_ptr = ip6_fw_ctl;
1216         LIST_INIT(&ip6_fw_chain);
1217
1218         bzero(&default_rule, sizeof default_rule);
1219         default_rule.fw_prot = IPPROTO_IPV6;
1220         default_rule.fw_number = (u_short)-1;
1221 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1222         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1223 #else
1224         default_rule.fw_flg |= IPV6_FW_F_DENY;
1225 #endif
1226         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1227         if (check_ip6fw_struct(&default_rule) == NULL ||
1228                 add_entry6(&ip6_fw_chain, &default_rule))
1229                 panic(__func__);
1230
1231         printf("IPv6 packet filtering initialized, ");
1232 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1233         printf("default to accept, ");
1234 #endif
1235 #ifndef IPV6FIREWALL_VERBOSE
1236         printf("logging disabled\n");
1237 #else
1238         if (fw6_verbose_limit == 0)
1239                 printf("unlimited logging\n");
1240         else
1241                 printf("logging limited to %d packets/entry\n",
1242                     fw6_verbose_limit);
1243 #endif
1244 }
1245
1246 static ip6_fw_chk_t *old_chk_ptr;
1247 static ip6_fw_ctl_t *old_ctl_ptr;
1248
1249 static int
1250 ip6fw_modevent(module_t mod, int type, void *unused)
1251 {
1252         switch (type) {
1253         case MOD_LOAD:
1254                 crit_enter();
1255
1256                 old_chk_ptr = ip6_fw_chk_ptr;
1257                 old_ctl_ptr = ip6_fw_ctl_ptr;
1258
1259                 ip6_fw_init();
1260                 crit_exit();
1261                 return 0;
1262         case MOD_UNLOAD:
1263                 crit_enter();
1264                 ip6_fw_chk_ptr =  old_chk_ptr;
1265                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1266                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1267                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1268                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1269                         free(fcp->rule, M_IP6FW);
1270                         free(fcp, M_IP6FW);
1271                 }
1272
1273                 crit_exit();
1274                 printf("IPv6 firewall unloaded\n");
1275                 return 0;
1276         default:
1277                 break;
1278         }
1279         return 0;
1280 }
1281
1282 static moduledata_t ip6fwmod = {
1283         "ip6fw",
1284         ip6fw_modevent,
1285         0
1286 };
1287 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);