sys/net/ip6fw/ip6_fw.c

   1 /*      $FreeBSD: src/sys/netinet6/ip6_fw.c,v 1.2.2.9 2002/04/28 05:40:27 suz Exp $     */
   2 /*      $DragonFly: src/sys/net/ip6fw/ip6_fw.c,v 1.3 2003/07/29 12:51:30 hmp Exp $      */
   3 /*      $KAME: ip6_fw.c,v 1.21 2001/01/24 01:25:32 itojun Exp $ */
   4
   5 /*
   6  * Copyright (C) 1998, 1999, 2000 and 2001 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1993 Daniel Boulet
  36  * Copyright (c) 1994 Ugen J.S.Antsilevich
  37  * Copyright (c) 1996 Alex Nash
  38  *
  39  * Redistribution and use in source forms, with and without modification,
  40  * are permitted provided that this entire comment appears intact.
  41  *
  42  * Redistribution in binary form may occur without any restrictions.
  43  * Obviously, it would be nice if you gave credit where credit is due
  44  * but requiring it would be too onerous.
  45  *
  46  * This software is provided ``AS IS'' without any warranties of any kind.
  47  */
  48
  49 /*
  50  * Implement IPv6 packet firewall
  51  */
  52
  53 #if !defined(KLD_MODULE)
  54 #include "opt_ip6fw.h"
  55 #include "opt_inet.h"
  56 #include "opt_inet6.h"
  57 #endif
  58
  59 #ifdef IP6DIVERT
  60 #error "NOT SUPPORTED IPV6 DIVERT"
  61 #endif
  62 #ifdef IP6FW_DIVERT_RESTART
  63 #error "NOT SUPPORTED IPV6 DIVERT"
  64 #endif
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/malloc.h>
  69 #include <sys/mbuf.h>
  70 #include <sys/queue.h>
  71 #include <sys/kernel.h>
  72 #include <sys/socket.h>
  73 #include <sys/socketvar.h>
  74 #include <sys/syslog.h>
  75 #include <sys/time.h>
  76 #include <net/if.h>
  77 #include <net/route.h>
  78 #include <netinet/in_systm.h>
  79 #include <netinet/in.h>
  80 #include <netinet/ip.h>
  81
  82 #include <netinet/ip6.h>
  83 #include <netinet6/ip6_var.h>
  84 #include <netinet6/in6_var.h>
  85 #include <netinet/icmp6.h>
  86
  87 #include <netinet/in_pcb.h>
  88
  89 #include <netinet6/ip6_fw.h>
  90 #include <netinet/ip_var.h>
  91 #include <netinet/tcp.h>
  92 #include <netinet/tcp_seq.h>
  93 #include <netinet/tcp_timer.h>
  94 #include <netinet/tcp_var.h>
  95 #include <netinet/udp.h>
  96
  97 #include <sys/sysctl.h>
  98
  99 #include <net/net_osdep.h>
 100
 101 MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
 102
 103 static int fw6_debug = 1;
 104 #ifdef IPV6FIREWALL_VERBOSE
 105 static int fw6_verbose = 1;
 106 #else
 107 static int fw6_verbose = 0;
 108 #endif
 109 #ifdef IPV6FIREWALL_VERBOSE_LIMIT
 110 static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
 111 #else
 112 static int fw6_verbose_limit = 0;
 113 #endif
 114
 115 LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
 116
 117 #ifdef SYSCTL_NODE
 118 SYSCTL_DECL(_net_inet6_ip6);
 119 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 120 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW,
 121         &ip6_fw_enable, 0, "Enable ip6fw");
 122 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
 123 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw6_verbose, 0, "");
 124 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
 125 #endif
 126
 127 #define dprintf(a)      do {                                            \
 128                                 if (fw6_debug)                          \
 129                                         printf a;                       \
 130                         } while (0)
 131 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
 132
 133 static int      add_entry6 __P((struct ip6_fw_head *chainptr, struct ip6_fw *frwl));
 134 static int      del_entry6 __P((struct ip6_fw_head *chainptr, u_short number));
 135 static int      zero_entry6 __P((struct mbuf *m));
 136 static struct ip6_fw *check_ip6fw_struct __P((struct ip6_fw *m));
 137 static struct ip6_fw *check_ip6fw_mbuf __P((struct mbuf *fw));
 138 static int      ip6opts_match __P((struct ip6_hdr **ip6, struct ip6_fw *f,
 139                                    struct mbuf **m,
 140                                    int *off, int *nxt, u_short *offset));
 141 static int      port_match6 __P((u_short *portptr, int nports, u_short port,
 142                                 int range_flag));
 143 static int      tcp6flg_match __P((struct tcphdr *tcp6, struct ip6_fw *f));
 144 static int      icmp6type_match __P((struct icmp6_hdr *  icmp, struct ip6_fw * f));
 145 static void     ip6fw_report __P((struct ip6_fw *f, struct ip6_hdr *ip6,
 146                                 struct ifnet *rif, struct ifnet *oif, int off, int nxt));
 147
 148 static int      ip6_fw_chk __P((struct ip6_hdr **pip6,
 149                         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m));
 150 static int      ip6_fw_ctl __P((int stage, struct mbuf **mm));
 151
 152 static char err_prefix[] = "ip6_fw_ctl:";
 153
 154 /*
 155  * Returns 1 if the port is matched by the vector, 0 otherwise
 156  */
 157 static
 158 __inline int
 159 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
 160 {
 161         if (!nports)
 162                 return 1;
 163         if (range_flag) {
 164                 if (portptr[0] <= port && port <= portptr[1]) {
 165                         return 1;
 166                 }
 167                 nports -= 2;
 168                 portptr += 2;
 169         }
 170         while (nports-- > 0) {
 171                 if (*portptr++ == port) {
 172                         return 1;
 173                 }
 174         }
 175         return 0;
 176 }
 177
 178 static int
 179 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
 180 {
 181         u_char          flg_set, flg_clr;
 182
 183         /*
 184          * If an established connection is required, reject packets that
 185          * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
 186          * other flag requirements.
 187          */
 188         if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
 189             ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
 190             IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
 191                 return 0;
 192
 193         flg_set = tcp6->th_flags & f->fw_tcpf;
 194         flg_clr = tcp6->th_flags & f->fw_tcpnf;
 195
 196         if (flg_set != f->fw_tcpf)
 197                 return 0;
 198         if (flg_clr)
 199                 return 0;
 200
 201         return 1;
 202 }
 203
 204 static int
 205 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
 206 {
 207         int type;
 208
 209         if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
 210                 return(1);
 211
 212         type = icmp6->icmp6_type;
 213
 214         /* check for matching type in the bitmap */
 215         if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
 216                 (f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
 217                 (1U << (type % (8 * sizeof(unsigned))))))
 218                 return(1);
 219
 220         return(0); /* no match */
 221 }
 222
 223 static int
 224 is_icmp6_query(struct ip6_hdr *ip6, int off)
 225 {
 226         const struct icmp6_hdr *icmp6;
 227         int icmp6_type;
 228
 229         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 230         icmp6_type = icmp6->icmp6_type;
 231
 232         if (icmp6_type == ICMP6_ECHO_REQUEST ||
 233             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 234             icmp6_type == ICMP6_WRUREQUEST ||
 235             icmp6_type == ICMP6_FQDN_QUERY ||
 236             icmp6_type == ICMP6_NI_QUERY)
 237                 return(1);
 238
 239         return(0);
 240 }
 241
 242 static int
 243 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
 244               int *off, int *nxt, u_short *offset)
 245 {
 246         int len;
 247         struct ip6_hdr *ip6 = *pip6;
 248         struct ip6_ext *ip6e;
 249         u_char  opts, nopts, nopts_sve;
 250
 251         opts = f->fw_ip6opt;
 252         nopts = nopts_sve = f->fw_ip6nopt;
 253
 254         *nxt = ip6->ip6_nxt;
 255         *off = sizeof(struct ip6_hdr);
 256         len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
 257         while (*off < len) {
 258                 ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
 259                 if ((*m)->m_len < *off + sizeof(*ip6e))
 260                         goto opts_check;        /* XXX */
 261
 262                 switch(*nxt) {
 263                 case IPPROTO_FRAGMENT:
 264                         if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
 265                                 struct ip6_frag *ip6f;
 266
 267                                 ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
 268                                 *offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
 269                         }
 270                         opts &= ~IPV6_FW_IP6OPT_FRAG;
 271                         nopts &= ~IPV6_FW_IP6OPT_FRAG;
 272                         *off += sizeof(struct ip6_frag);
 273                         break;
 274                 case IPPROTO_AH:
 275                         opts &= ~IPV6_FW_IP6OPT_AH;
 276                         nopts &= ~IPV6_FW_IP6OPT_AH;
 277                         *off += (ip6e->ip6e_len + 2) << 2;
 278                         break;
 279                 default:
 280                         switch (*nxt) {
 281                         case IPPROTO_HOPOPTS:
 282                                 opts &= ~IPV6_FW_IP6OPT_HOPOPT;
 283                                 nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
 284                                 break;
 285                         case IPPROTO_ROUTING:
 286                                 opts &= ~IPV6_FW_IP6OPT_ROUTE;
 287                                 nopts &= ~IPV6_FW_IP6OPT_ROUTE;
 288                                 break;
 289                         case IPPROTO_ESP:
 290                                 opts &= ~IPV6_FW_IP6OPT_ESP;
 291                                 nopts &= ~IPV6_FW_IP6OPT_ESP;
 292                                 break;
 293                         case IPPROTO_NONE:
 294                                 opts &= ~IPV6_FW_IP6OPT_NONXT;
 295                                 nopts &= ~IPV6_FW_IP6OPT_NONXT;
 296                                 goto opts_check;
 297                                 break;
 298                         case IPPROTO_DSTOPTS:
 299                                 opts &= ~IPV6_FW_IP6OPT_OPTS;
 300                                 nopts &= ~IPV6_FW_IP6OPT_OPTS;
 301                                 break;
 302                         default:
 303                                 goto opts_check;
 304                                 break;
 305                         }
 306                         *off += (ip6e->ip6e_len + 1) << 3;
 307                         break;
 308                 }
 309                 *nxt = ip6e->ip6e_nxt;
 310
 311         }
 312  opts_check:
 313         if (f->fw_ip6opt == f->fw_ip6nopt)      /* XXX */
 314                 return 1;
 315
 316         if (opts == 0 && nopts == nopts_sve)
 317                 return 1;
 318         else
 319                 return 0;
 320 }
 321
 322 static
 323 __inline int
 324 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
 325 {
 326         /* Check by name or by IP address */
 327         if (byname) {
 328                 /* Check unit number (-1 is wildcard) */
 329                 if (ifu->fu_via_if.unit != -1
 330                     && ifp->if_unit != ifu->fu_via_if.unit)
 331                         return(0);
 332                 /* Check name */
 333                 if (strncmp(ifp->if_name, ifu->fu_via_if.name, IP6FW_IFNLEN))
 334                         return(0);
 335                 return(1);
 336         } else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {        /* Zero == wildcard */
 337                 struct ifaddr *ia;
 338
 339                 for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next)
 340                 {
 341
 342                         if (ia->ifa_addr == NULL)
 343                                 continue;
 344                         if (ia->ifa_addr->sa_family != AF_INET6)
 345                                 continue;
 346                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
 347                             &(((struct sockaddr_in6 *)
 348                             (ia->ifa_addr))->sin6_addr)))
 349                                 continue;
 350                         return(1);
 351                 }
 352                 return(0);
 353         }
 354         return(1);
 355 }
 356
 357 static void
 358 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
 359         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
 360 {
 361         static int counter;
 362         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
 363         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
 364         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
 365         int count;
 366         char *action;
 367         char action2[32], proto[102], name[18];
 368         int len;
 369
 370         count = f ? f->fw_pcnt : ++counter;
 371         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
 372                 return;
 373
 374         /* Print command name */
 375         snprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
 376
 377         action = action2;
 378         if (!f)
 379                 action = "Refuse";
 380         else {
 381                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 382                 case IPV6_FW_F_DENY:
 383                         action = "Deny";
 384                         break;
 385                 case IPV6_FW_F_REJECT:
 386                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
 387                                 action = "Reset";
 388                         else
 389                                 action = "Unreach";
 390                         break;
 391                 case IPV6_FW_F_ACCEPT:
 392                         action = "Accept";
 393                         break;
 394                 case IPV6_FW_F_COUNT:
 395                         action = "Count";
 396                         break;
 397                 case IPV6_FW_F_DIVERT:
 398                         snprintf(SNPARGS(action2, 0), "Divert %d",
 399                             f->fw_divert_port);
 400                         break;
 401                 case IPV6_FW_F_TEE:
 402                         snprintf(SNPARGS(action2, 0), "Tee %d",
 403                             f->fw_divert_port);
 404                         break;
 405                 case IPV6_FW_F_SKIPTO:
 406                         snprintf(SNPARGS(action2, 0), "SkipTo %d",
 407                             f->fw_skipto_rule);
 408                         break;
 409                 default:
 410                         action = "UNKNOWN";
 411                         break;
 412                 }
 413         }
 414
 415         switch (nxt) {
 416         case IPPROTO_TCP:
 417                 len = snprintf(SNPARGS(proto, 0), "TCP [%s]",
 418                     ip6_sprintf(&ip6->ip6_src));
 419                 if (off > 0)
 420                         len += snprintf(SNPARGS(proto, len), ":%d ",
 421                             ntohs(tcp6->th_sport));
 422                 else
 423                         len += snprintf(SNPARGS(proto, len), " ");
 424                 len += snprintf(SNPARGS(proto, len), "[%s]",
 425                     ip6_sprintf(&ip6->ip6_dst));
 426                 if (off > 0)
 427                         snprintf(SNPARGS(proto, len), ":%d",
 428                             ntohs(tcp6->th_dport));
 429                 break;
 430         case IPPROTO_UDP:
 431                 len = snprintf(SNPARGS(proto, 0), "UDP [%s]",
 432                     ip6_sprintf(&ip6->ip6_src));
 433                 if (off > 0)
 434                         len += snprintf(SNPARGS(proto, len), ":%d ",
 435                             ntohs(udp->uh_sport));
 436                 else
 437                     len += snprintf(SNPARGS(proto, len), " ");
 438                 len += snprintf(SNPARGS(proto, len), "[%s]",
 439                     ip6_sprintf(&ip6->ip6_dst));
 440                 if (off > 0)
 441                         snprintf(SNPARGS(proto, len), ":%d",
 442                             ntohs(udp->uh_dport));
 443                 break;
 444         case IPPROTO_ICMPV6:
 445                 if (off > 0)
 446                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
 447                             icmp6->icmp6_type, icmp6->icmp6_code);
 448                 else
 449                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
 450                 len += snprintf(SNPARGS(proto, len), "[%s]",
 451                     ip6_sprintf(&ip6->ip6_src));
 452                 snprintf(SNPARGS(proto, len), " [%s]",
 453                     ip6_sprintf(&ip6->ip6_dst));
 454                 break;
 455         default:
 456                 len = snprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
 457                     ip6_sprintf(&ip6->ip6_src));
 458                 snprintf(SNPARGS(proto, len), " [%s]",
 459                     ip6_sprintf(&ip6->ip6_dst));
 460                 break;
 461         }
 462
 463         if (oif)
 464                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
 465                     name, action, proto, if_name(oif));
 466         else if (rif)
 467                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
 468                     name, action, proto, if_name(rif));
 469         else
 470                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
 471                     name, action, proto);
 472         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
 473             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
 474                 f ? f->fw_number : -1);
 475 }
 476
 477 /*
 478  * Parameters:
 479  *
 480  *      ip      Pointer to packet header (struct ip6_hdr *)
 481  *      hlen    Packet header length
 482  *      oif     Outgoing interface, or NULL if packet is incoming
 483  * #ifndef IP6FW_DIVERT_RESTART
 484  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
 485  * #else
 486  *      *cookie Skip up to the first rule past this rule number;
 487  * #endif
 488  *      *m      The packet; we set to NULL when/if we nuke it.
 489  *
 490  * Return value:
 491  *
 492  *      0       The packet is to be accepted and routed normally OR
 493  *              the packet was denied/rejected and has been dropped;
 494  *              in the latter case, *m is equal to NULL upon return.
 495  *      port    Divert the packet to port.
 496  */
 497
 498 static int
 499 ip6_fw_chk(struct ip6_hdr **pip6,
 500         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
 501 {
 502         struct ip6_fw_chain *chain;
 503         struct ip6_fw *rule = NULL;
 504         struct ip6_hdr *ip6 = *pip6;
 505         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
 506         u_short offset = 0;
 507         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
 508         u_short src_port, dst_port;
 509 #ifdef  IP6FW_DIVERT_RESTART
 510         u_int16_t skipto = *cookie;
 511 #else
 512         u_int16_t ignport = ntohs(*cookie);
 513 #endif
 514
 515         *cookie = 0;
 516         /*
 517          * Go down the chain, looking for enlightment
 518          * #ifdef IP6FW_DIVERT_RESTART
 519          * If we've been asked to start at a given rule immediatly, do so.
 520          * #endif
 521          */
 522         chain = LIST_FIRST(&ip6_fw_chain);
 523 #ifdef IP6FW_DIVERT_RESTART
 524         if (skipto) {
 525                 if (skipto >= 65535)
 526                         goto dropit;
 527                 while (chain && (chain->rule->fw_number <= skipto)) {
 528                         chain = LIST_NEXT(chain, chain);
 529                 }
 530                 if (! chain) goto dropit;
 531         }
 532 #endif /* IP6FW_DIVERT_RESTART */
 533         for (; chain; chain = LIST_NEXT(chain, chain)) {
 534                 struct ip6_fw *const f = chain->rule;
 535
 536                 if (oif) {
 537                         /* Check direction outbound */
 538                         if (!(f->fw_flg & IPV6_FW_F_OUT))
 539                                 continue;
 540                 } else {
 541                         /* Check direction inbound */
 542                         if (!(f->fw_flg & IPV6_FW_F_IN))
 543                                 continue;
 544                 }
 545
 546 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
 547         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
 548         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
 549         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
 550         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
 551
 552                 /* If src-addr doesn't match, not this rule. */
 553                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
 554                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
 555                         continue;
 556
 557                 /* If dest-addr doesn't match, not this rule. */
 558                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
 559                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
 560                         continue;
 561
 562 #undef IN6_ARE_ADDR_MASKEQUAL
 563                 /* Interface check */
 564                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 565                         struct ifnet *const iface = oif ? oif : rif;
 566
 567                         /* Backwards compatibility hack for "via" */
 568                         if (!iface || !iface_match(iface,
 569                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
 570                                 continue;
 571                 } else {
 572                         /* Check receive interface */
 573                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
 574                             && (!rif || !iface_match(rif,
 575                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
 576                                 continue;
 577                         /* Check outgoing interface */
 578                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
 579                             && (!oif || !iface_match(oif,
 580                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
 581                                 continue;
 582                 }
 583
 584                 /* Check IP options */
 585                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
 586                         continue;
 587
 588                 /* Fragments */
 589                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
 590                         continue;
 591
 592                 /* Check protocol; if wildcard, match */
 593                 if (f->fw_prot == IPPROTO_IPV6)
 594                         goto got_match;
 595
 596                 /* If different, don't match */
 597                 if (nxt != f->fw_prot)
 598                         continue;
 599
 600 #define PULLUP_TO(len)  do {                                            \
 601                             if ((*m)->m_len < (len)                     \
 602                                 && (*m = m_pullup(*m, (len))) == 0) {   \
 603                                     goto dropit;                        \
 604                             }                                           \
 605                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
 606                         } while (0)
 607
 608                 /* Protocol specific checks */
 609                 switch (nxt) {
 610                 case IPPROTO_TCP:
 611                     {
 612                         struct tcphdr *tcp6;
 613
 614                         if (offset == 1) {      /* cf. RFC 1858 */
 615                                 PULLUP_TO(off + 4); /* XXX ? */
 616                                 goto bogusfrag;
 617                         }
 618                         if (offset != 0) {
 619                                 /*
 620                                  * TCP flags and ports aren't available in this
 621                                  * packet -- if this rule specified either one,
 622                                  * we consider the rule a non-match.
 623                                  */
 624                                 if (f->fw_nports != 0 ||
 625                                     f->fw_tcpf != f->fw_tcpnf)
 626                                         continue;
 627
 628                                 break;
 629                         }
 630                         PULLUP_TO(off + 14);
 631                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
 632                         if (((f->fw_tcpf != f->fw_tcpnf) ||
 633                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
 634                            !tcp6flg_match(tcp6, f))
 635                                 continue;
 636                         src_port = ntohs(tcp6->th_sport);
 637                         dst_port = ntohs(tcp6->th_dport);
 638                         goto check_ports;
 639                     }
 640
 641                 case IPPROTO_UDP:
 642                     {
 643                         struct udphdr *udp;
 644
 645                         if (offset != 0) {
 646                                 /*
 647                                  * Port specification is unavailable -- if this
 648                                  * rule specifies a port, we consider the rule
 649                                  * a non-match.
 650                                  */
 651                                 if (f->fw_nports != 0)
 652                                         continue;
 653
 654                                 break;
 655                         }
 656                         PULLUP_TO(off + 4);
 657                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
 658                         src_port = ntohs(udp->uh_sport);
 659                         dst_port = ntohs(udp->uh_dport);
 660 check_ports:
 661                         if (!port_match6(&f->fw_pts[0],
 662                             IPV6_FW_GETNSRCP(f), src_port,
 663                             f->fw_flg & IPV6_FW_F_SRNG))
 664                                 continue;
 665                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
 666                             IPV6_FW_GETNDSTP(f), dst_port,
 667                             f->fw_flg & IPV6_FW_F_DRNG))
 668                                 continue;
 669                         break;
 670                     }
 671
 672                 case IPPROTO_ICMPV6:
 673                     {
 674                         struct icmp6_hdr *icmp;
 675
 676                         if (offset != 0)        /* Type isn't valid */
 677                                 break;
 678                         PULLUP_TO(off + 2);
 679                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
 680                         if (!icmp6type_match(icmp, f))
 681                                 continue;
 682                         break;
 683                     }
 684 #undef PULLUP_TO
 685
 686 bogusfrag:
 687                         if (fw6_verbose)
 688                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
 689                         goto dropit;
 690                 }
 691
 692 got_match:
 693 #ifndef IP6FW_DIVERT_RESTART
 694                 /* Ignore divert/tee rule if socket port is "ignport" */
 695                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 696                 case IPV6_FW_F_DIVERT:
 697                 case IPV6_FW_F_TEE:
 698                         if (f->fw_divert_port == ignport)
 699                                 continue;       /* ignore this rule */
 700                         break;
 701                 }
 702
 703 #endif /* IP6FW_DIVERT_RESTART */
 704                 /* Update statistics */
 705                 f->fw_pcnt += 1;
 706                 f->fw_bcnt += ntohs(ip6->ip6_plen);
 707                 f->timestamp = time_second;
 708
 709                 /* Log to console if desired */
 710                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
 711                         ip6fw_report(f, ip6, rif, oif, off, nxt);
 712
 713                 /* Take appropriate action */
 714                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 715                 case IPV6_FW_F_ACCEPT:
 716                         return(0);
 717                 case IPV6_FW_F_COUNT:
 718                         continue;
 719                 case IPV6_FW_F_DIVERT:
 720 #ifdef IP6FW_DIVERT_RESTART
 721                         *cookie = f->fw_number;
 722 #else
 723                         *cookie = htons(f->fw_divert_port);
 724 #endif /* IP6FW_DIVERT_RESTART */
 725                         return(f->fw_divert_port);
 726                 case IPV6_FW_F_TEE:
 727                         /*
 728                          * XXX someday tee packet here, but beware that you
 729                          * can't use m_copym() or m_copypacket() because
 730                          * the divert input routine modifies the mbuf
 731                          * (and these routines only increment reference
 732                          * counts in the case of mbuf clusters), so need
 733                          * to write custom routine.
 734                          */
 735                         continue;
 736                 case IPV6_FW_F_SKIPTO:
 737 #ifdef DIAGNOSTIC
 738                         while (chain->chain.le_next
 739                             && chain->chain.le_next->rule->fw_number
 740                                 < f->fw_skipto_rule)
 741 #else
 742                         while (chain->chain.le_next->rule->fw_number
 743                             < f->fw_skipto_rule)
 744 #endif
 745                                 chain = chain->chain.le_next;
 746                         continue;
 747                 }
 748
 749                 /* Deny/reject this packet using this rule */
 750                 rule = f;
 751                 break;
 752         }
 753
 754 #ifdef DIAGNOSTIC
 755         /* Rule 65535 should always be there and should always match */
 756         if (!chain)
 757                 panic("ip6_fw: chain");
 758 #endif
 759
 760         /*
 761          * At this point, we're going to drop the packet.
 762          * Send a reject notice if all of the following are true:
 763          *
 764          * - The packet matched a reject rule
 765          * - The packet is not an ICMP packet, or is an ICMP query packet
 766          * - The packet is not a multicast or broadcast packet
 767          */
 768         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
 769             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
 770             && !((*m)->m_flags & (M_BCAST|M_MCAST))
 771             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 772                 switch (rule->fw_reject_code) {
 773                 case IPV6_FW_REJECT_RST:
 774                   {
 775                         struct tcphdr *const tcp =
 776                                 (struct tcphdr *) ((caddr_t)ip6 + off);
 777                         struct {
 778                                 struct ip6_hdr ip6;
 779                                 struct tcphdr th;
 780                         } ti;
 781                         tcp_seq ack, seq;
 782                         int flags;
 783
 784                         if (offset != 0 || (tcp->th_flags & TH_RST))
 785                                 break;
 786
 787                         ti.ip6 = *ip6;
 788                         ti.th = *tcp;
 789                         NTOHL(ti.th.th_seq);
 790                         NTOHL(ti.th.th_ack);
 791                         ti.ip6.ip6_nxt = IPPROTO_TCP;
 792                         if (ti.th.th_flags & TH_ACK) {
 793                                 ack = 0;
 794                                 seq = ti.th.th_ack;
 795                                 flags = TH_RST;
 796                         } else {
 797                                 ack = ti.th.th_seq;
 798                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
 799                                         ack += (*m)->m_pkthdr.len - off
 800                                                 - (ti.th.th_off << 2);
 801                                 } else if (ip6->ip6_plen) {
 802                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
 803                                                 - off - (ti.th.th_off << 2);
 804                                 } else {
 805                                         m_freem(*m);
 806                                         *m = 0;
 807                                         break;
 808                                 }
 809                                 seq = 0;
 810                                 flags = TH_RST|TH_ACK;
 811                         }
 812                         bcopy(&ti, ip6, sizeof(ti));
 813                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
 814                                 *m, ack, seq, flags);
 815                         *m = NULL;
 816                         break;
 817                   }
 818                 default:        /* Send an ICMP unreachable using code */
 819                         if (oif)
 820                                 (*m)->m_pkthdr.rcvif = oif;
 821                         icmp6_error(*m, ICMP6_DST_UNREACH,
 822                             rule->fw_reject_code, 0);
 823                         *m = NULL;
 824                         break;
 825                 }
 826         }
 827
 828 dropit:
 829         /*
 830          * Finally, drop the packet.
 831          */
 832         if (*m) {
 833                 m_freem(*m);
 834                 *m = NULL;
 835         }
 836         return(0);
 837 }
 838
 839 static int
 840 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
 841 {
 842         struct ip6_fw *ftmp = 0;
 843         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
 844         u_short nbr = 0;
 845         int s;
 846
 847         fwc = malloc(sizeof *fwc, M_IP6FW, M_NOWAIT);
 848         ftmp = malloc(sizeof *ftmp, M_IP6FW, M_NOWAIT);
 849         if (!fwc || !ftmp) {
 850                 dprintf(("%s malloc said no\n", err_prefix));
 851                 if (fwc)  free(fwc, M_IP6FW);
 852                 if (ftmp) free(ftmp, M_IP6FW);
 853                 return (ENOSPC);
 854         }
 855
 856         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
 857         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
 858         ftmp->fw_pcnt = 0L;
 859         ftmp->fw_bcnt = 0L;
 860         fwc->rule = ftmp;
 861
 862         s = splnet();
 863
 864         if (!chainptr->lh_first) {
 865                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 866                 splx(s);
 867                 return(0);
 868         } else if (ftmp->fw_number == (u_short)-1) {
 869                 if (fwc)  free(fwc, M_IP6FW);
 870                 if (ftmp) free(ftmp, M_IP6FW);
 871                 splx(s);
 872                 dprintf(("%s bad rule number\n", err_prefix));
 873                 return (EINVAL);
 874         }
 875
 876         /* If entry number is 0, find highest numbered rule and add 100 */
 877         if (ftmp->fw_number == 0) {
 878                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 879                         if (fcp->rule->fw_number != (u_short)-1)
 880                                 nbr = fcp->rule->fw_number;
 881                         else
 882                                 break;
 883                 }
 884                 if (nbr < (u_short)-1 - 100)
 885                         nbr += 100;
 886                 ftmp->fw_number = nbr;
 887         }
 888
 889         /* Got a valid number; now insert it, keeping the list ordered */
 890         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 891                 if (fcp->rule->fw_number > ftmp->fw_number) {
 892                         if (fcpl) {
 893                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
 894                         } else {
 895                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 896                         }
 897                         break;
 898                 } else {
 899                         fcpl = fcp;
 900                 }
 901         }
 902
 903         splx(s);
 904         return (0);
 905 }
 906
 907 static int
 908 del_entry6(struct ip6_fw_head *chainptr, u_short number)
 909 {
 910         struct ip6_fw_chain *fcp;
 911         int s;
 912
 913         s = splnet();
 914
 915         fcp = chainptr->lh_first;
 916         if (number != (u_short)-1) {
 917                 for (; fcp; fcp = fcp->chain.le_next) {
 918                         if (fcp->rule->fw_number == number) {
 919                                 LIST_REMOVE(fcp, chain);
 920                                 splx(s);
 921                                 free(fcp->rule, M_IP6FW);
 922                                 free(fcp, M_IP6FW);
 923                                 return 0;
 924                         }
 925                 }
 926         }
 927
 928         splx(s);
 929         return (EINVAL);
 930 }
 931
 932 static int
 933 zero_entry6(struct mbuf *m)
 934 {
 935         struct ip6_fw *frwl;
 936         struct ip6_fw_chain *fcp;
 937         int s;
 938
 939         if (m && m->m_len != 0) {
 940                 if (m->m_len != sizeof(struct ip6_fw))
 941                         return(EINVAL);
 942                 frwl = mtod(m, struct ip6_fw *);
 943         }
 944         else
 945                 frwl = NULL;
 946
 947         /*
 948          *      It's possible to insert multiple chain entries with the
 949          *      same number, so we don't stop after finding the first
 950          *      match if zeroing a specific entry.
 951          */
 952         s = splnet();
 953         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
 954                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
 955                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
 956                         fcp->rule->timestamp = 0;
 957                 }
 958         splx(s);
 959
 960         if (fw6_verbose) {
 961                 if (frwl)
 962                         log(LOG_SECURITY | LOG_NOTICE,
 963                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
 964                 else
 965                         log(LOG_SECURITY | LOG_NOTICE,
 966                             "ip6fw: Accounting cleared.\n");
 967         }
 968
 969         return(0);
 970 }
 971
 972 static struct ip6_fw *
 973 check_ip6fw_mbuf(struct mbuf *m)
 974 {
 975         /* Check length */
 976         if (m->m_len != sizeof(struct ip6_fw)) {
 977                 dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
 978                     sizeof(struct ip6_fw)));
 979                 return (NULL);
 980         }
 981         return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
 982 }
 983
 984 static struct ip6_fw *
 985 check_ip6fw_struct(struct ip6_fw *frwl)
 986 {
 987         /* Check for invalid flag bits */
 988         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
 989                 dprintf(("%s undefined flag bits set (flags=%x)\n",
 990                     err_prefix, frwl->fw_flg));
 991                 return (NULL);
 992         }
 993         /* Must apply to incoming or outgoing (or both) */
 994         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
 995                 dprintf(("%s neither in nor out\n", err_prefix));
 996                 return (NULL);
 997         }
 998         /* Empty interface name is no good */
 999         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
1000               && !*frwl->fw_in_if.fu_via_if.name)
1001             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
1002               && !*frwl->fw_out_if.fu_via_if.name)) {
1003                 dprintf(("%s empty interface name\n", err_prefix));
1004                 return (NULL);
1005         }
1006         /* Sanity check interface matching */
1007         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1008                 ;               /* allow "via" backwards compatibility */
1009         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1010             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1011                 dprintf(("%s outgoing interface check on incoming\n",
1012                     err_prefix));
1013                 return (NULL);
1014         }
1015         /* Sanity check port ranges */
1016         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1017                 dprintf(("%s src range set but n_src_p=%d\n",
1018                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1019                 return (NULL);
1020         }
1021         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1022                 dprintf(("%s dst range set but n_dst_p=%d\n",
1023                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1024                 return (NULL);
1025         }
1026         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1027                 dprintf(("%s too many ports (%d+%d)\n",
1028                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1029                 return (NULL);
1030         }
1031         /*
1032          *      Protocols other than TCP/UDP don't use port range
1033          */
1034         if ((frwl->fw_prot != IPPROTO_TCP) &&
1035             (frwl->fw_prot != IPPROTO_UDP) &&
1036             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1037                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1038                     err_prefix));
1039                 return(NULL);
1040         }
1041
1042         /*
1043          *      Rather than modify the entry to make such entries work,
1044          *      we reject this rule and require user level utilities
1045          *      to enforce whatever policy they deem appropriate.
1046          */
1047         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1048                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1049                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1050                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1051                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1052                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1053                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1054                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1055                 dprintf(("%s rule never matches\n", err_prefix));
1056                 return(NULL);
1057         }
1058
1059         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1060                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1061                 if (frwl->fw_nports) {
1062                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1063                         return(NULL);
1064                 }
1065                 if (frwl->fw_prot == IPPROTO_TCP &&
1066                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1067                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1068                         return(NULL);
1069                 }
1070         }
1071
1072         /* Check command specific stuff */
1073         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1074         {
1075         case IPV6_FW_F_REJECT:
1076                 if (frwl->fw_reject_code >= 0x100
1077                     && !(frwl->fw_prot == IPPROTO_TCP
1078                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1079                         dprintf(("%s unknown reject code\n", err_prefix));
1080                         return(NULL);
1081                 }
1082                 break;
1083         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1084         case IPV6_FW_F_TEE:
1085                 if (frwl->fw_divert_port == 0) {
1086                         dprintf(("%s can't divert to port 0\n", err_prefix));
1087                         return (NULL);
1088                 }
1089                 break;
1090         case IPV6_FW_F_DENY:
1091         case IPV6_FW_F_ACCEPT:
1092         case IPV6_FW_F_COUNT:
1093         case IPV6_FW_F_SKIPTO:
1094                 break;
1095         default:
1096                 dprintf(("%s invalid command\n", err_prefix));
1097                 return(NULL);
1098         }
1099
1100         return frwl;
1101 }
1102
1103 static int
1104 ip6_fw_ctl(int stage, struct mbuf **mm)
1105 {
1106         int error;
1107         struct mbuf *m;
1108
1109         if (stage == IPV6_FW_GET) {
1110                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1111                 *mm = m = m_get(M_WAIT, MT_DATA); /* XXX */
1112                 if (!m)
1113                         return(ENOBUFS);
1114                 if (sizeof *(fcp->rule) > MLEN) {
1115                         MCLGET(m, M_WAIT);
1116                         if ((m->m_flags & M_EXT) == 0) {
1117                                 m_free(m);
1118                                 return(ENOBUFS);
1119                         }
1120                 }
1121                 for (; fcp; fcp = fcp->chain.le_next) {
1122                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1123                         m->m_len = sizeof *(fcp->rule);
1124                         m->m_next = m_get(M_WAIT, MT_DATA); /* XXX */
1125                         if (!m->m_next) {
1126                                 m_freem(*mm);
1127                                 return(ENOBUFS);
1128                         }
1129                         m = m->m_next;
1130                         if (sizeof *(fcp->rule) > MLEN) {
1131                                 MCLGET(m, M_WAIT);
1132                                 if ((m->m_flags & M_EXT) == 0) {
1133                                         m_freem(*mm);
1134                                         return(ENOBUFS);
1135                                 }
1136                         }
1137                         m->m_len = 0;
1138                 }
1139                 return (0);
1140         }
1141         m = *mm;
1142         /* only allow get calls if secure mode > 2 */
1143         if (securelevel > 2) {
1144                 if (m) {
1145                         (void)m_freem(m);
1146                         *mm = 0;
1147                 }
1148                 return(EPERM);
1149         }
1150         if (stage == IPV6_FW_FLUSH) {
1151                 while (ip6_fw_chain.lh_first != NULL &&
1152                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1153                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1154                         int s = splnet();
1155                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1156                         splx(s);
1157                         free(fcp->rule, M_IP6FW);
1158                         free(fcp, M_IP6FW);
1159                 }
1160                 if (m) {
1161                         (void)m_freem(m);
1162                         *mm = 0;
1163                 }
1164                 return (0);
1165         }
1166         if (stage == IPV6_FW_ZERO) {
1167                 error = zero_entry6(m);
1168                 if (m) {
1169                         (void)m_freem(m);
1170                         *mm = 0;
1171                 }
1172                 return (error);
1173         }
1174         if (m == NULL) {
1175                 printf("%s NULL mbuf ptr\n", err_prefix);
1176                 return (EINVAL);
1177         }
1178
1179         if (stage == IPV6_FW_ADD) {
1180                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1181
1182                 if (!frwl)
1183                         error = EINVAL;
1184                 else
1185                         error = add_entry6(&ip6_fw_chain, frwl);
1186                 if (m) {
1187                         (void)m_freem(m);
1188                         *mm = 0;
1189                 }
1190                 return error;
1191         }
1192         if (stage == IPV6_FW_DEL) {
1193                 if (m->m_len != sizeof(struct ip6_fw)) {
1194                         dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1195                             sizeof(struct ip6_fw)));
1196                         error = EINVAL;
1197                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1198                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1199                         error = EINVAL;
1200                 } else
1201                         error = del_entry6(&ip6_fw_chain,
1202                             mtod(m, struct ip6_fw *)->fw_number);
1203                 if (m) {
1204                         (void)m_freem(m);
1205                         *mm = 0;
1206                 }
1207                 return error;
1208         }
1209
1210         dprintf(("%s unknown request %d\n", err_prefix, stage));
1211         if (m) {
1212                 (void)m_freem(m);
1213                 *mm = 0;
1214         }
1215         return (EINVAL);
1216 }
1217
1218 void
1219 ip6_fw_init(void)
1220 {
1221         struct ip6_fw default_rule;
1222
1223         ip6_fw_chk_ptr = ip6_fw_chk;
1224         ip6_fw_ctl_ptr = ip6_fw_ctl;
1225         LIST_INIT(&ip6_fw_chain);
1226
1227         bzero(&default_rule, sizeof default_rule);
1228         default_rule.fw_prot = IPPROTO_IPV6;
1229         default_rule.fw_number = (u_short)-1;
1230 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1231         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1232 #else
1233         default_rule.fw_flg |= IPV6_FW_F_DENY;
1234 #endif
1235         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1236         if (check_ip6fw_struct(&default_rule) == NULL ||
1237                 add_entry6(&ip6_fw_chain, &default_rule))
1238                 panic(__FUNCTION__);
1239
1240         printf("IPv6 packet filtering initialized, ");
1241 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1242         printf("default to accept, ");
1243 #endif
1244 #ifndef IPV6FIREWALL_VERBOSE
1245         printf("logging disabled\n");
1246 #else
1247         if (fw6_verbose_limit == 0)
1248                 printf("unlimited logging\n");
1249         else
1250                 printf("logging limited to %d packets/entry\n",
1251                     fw6_verbose_limit);
1252 #endif
1253 }
1254
1255 static ip6_fw_chk_t *old_chk_ptr;
1256 static ip6_fw_ctl_t *old_ctl_ptr;
1257
1258 static int
1259 ip6fw_modevent(module_t mod, int type, void *unused)
1260 {
1261         int s;
1262
1263         switch (type) {
1264         case MOD_LOAD:
1265                 s = splnet();
1266
1267                 old_chk_ptr = ip6_fw_chk_ptr;
1268                 old_ctl_ptr = ip6_fw_ctl_ptr;
1269
1270                 ip6_fw_init();
1271                 splx(s);
1272                 return 0;
1273         case MOD_UNLOAD:
1274                 s = splnet();
1275                 ip6_fw_chk_ptr =  old_chk_ptr;
1276                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1277                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1278                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1279                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1280                         free(fcp->rule, M_IP6FW);
1281                         free(fcp, M_IP6FW);
1282                 }
1283
1284                 splx(s);
1285                 printf("IPv6 firewall unloaded\n");
1286                 return 0;
1287         default:
1288                 break;
1289         }
1290         return 0;
1291 }
1292
1293 static moduledata_t ip6fwmod = {
1294         "ip6fw",
1295         ip6fw_modevent,
1296         0
1297 };
1298 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);