sys/netinet6/ip6_fw.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: ip6_fw.c,v 1.21 2001/01/24 01:25:32 itojun Exp $ */
   3
   4 /*-
   5  * Copyright (C) 1998, 1999, 2000 and 2001 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*-
  34  * Copyright (c) 1993 Daniel Boulet
  35  * Copyright (c) 1994 Ugen J.S.Antsilevich
  36  * Copyright (c) 1996 Alex Nash
  37  *
  38  * Redistribution and use in source forms, with and without modification,
  39  * are permitted provided that this entire comment appears intact.
  40  *
  41  * Redistribution in binary form may occur without any restrictions.
  42  * Obviously, it would be nice if you gave credit where credit is due
  43  * but requiring it would be too onerous.
  44  *
  45  * This software is provided ``AS IS'' without any warranties of any kind.
  46  */
  47
  48 /*
  49  * Implement IPv6 packet firewall
  50  */
  51
  52 #if !defined(KLD_MODULE)
  53 #include "opt_ip6fw.h"
  54 #include "opt_inet.h"
  55 #include "opt_inet6.h"
  56 #endif
  57
  58 #ifdef IP6DIVERT
  59 #error "NOT SUPPORTED IPV6 DIVERT"
  60 #endif
  61 #ifdef IP6FW_DIVERT_RESTART
  62 #error "NOT SUPPORTED IPV6 DIVERT"
  63 #endif
  64
  65 #include <sys/param.h>
  66 #include <sys/systm.h>
  67 #include <sys/malloc.h>
  68 #include <sys/mbuf.h>
  69 #include <sys/queue.h>
  70 #include <sys/kernel.h>
  71 #include <sys/module.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 static 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 | CTLFLAG_SECURE,
 120     0, "Firewall");
 121 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW | CTLFLAG_SECURE,
 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 | CTLFLAG_SECURE,
 125     &fw6_verbose, 0, "");
 126 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
 127 #endif
 128
 129 #define dprintf(a)      do {                                            \
 130                                 if (fw6_debug)                          \
 131                                         printf a;                       \
 132                         } while (/*CONSTCOND*/ 0)
 133 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
 134
 135 static int      add_entry6 __P((struct ip6_fw_head *chainptr, struct ip6_fw *frwl));
 136 static int      del_entry6 __P((struct ip6_fw_head *chainptr, u_short number));
 137 static int      zero_entry6 __P((struct mbuf *m));
 138 static struct ip6_fw *check_ip6fw_struct __P((struct ip6_fw *m));
 139 static struct ip6_fw *check_ip6fw_mbuf __P((struct mbuf *fw));
 140 static int      ip6opts_match __P((struct ip6_hdr **ip6, struct ip6_fw *f,
 141                                    struct mbuf **m,
 142                                    int *off, int *nxt, u_short *offset));
 143 static int      port_match6 __P((u_short *portptr, int nports, u_short port,
 144                                 int range_flag));
 145 static int      tcp6flg_match __P((struct tcphdr *tcp6, struct ip6_fw *f));
 146 static int      icmp6type_match __P((struct icmp6_hdr *  icmp, struct ip6_fw * f));
 147 static void     ip6fw_report __P((struct ip6_fw *f, struct ip6_hdr *ip6,
 148                                 struct ifnet *rif, struct ifnet *oif, int off, int nxt));
 149
 150 static int      ip6_fw_chk __P((struct ip6_hdr **pip6,
 151                         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m));
 152 static int      ip6_fw_ctl __P((int stage, struct mbuf **mm));
 153
 154 static char err_prefix[] = "ip6_fw_ctl:";
 155
 156 /*
 157  * Returns 1 if the port is matched by the vector, 0 otherwise
 158  */
 159 static
 160 __inline
 161 int
 162 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
 163 {
 164         if (!nports)
 165                 return 1;
 166         if (range_flag) {
 167                 if (portptr[0] <= port && port <= portptr[1]) {
 168                         return 1;
 169                 }
 170                 nports -= 2;
 171                 portptr += 2;
 172         }
 173         while (nports-- > 0) {
 174                 if (*portptr++ == port) {
 175                         return 1;
 176                 }
 177         }
 178         return 0;
 179 }
 180
 181 static int
 182 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
 183 {
 184         u_char          flg_set, flg_clr;
 185
 186         /*
 187          * If an established connection is required, reject packets that
 188          * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
 189          * other flag requirements.
 190          */
 191         if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
 192             ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
 193             IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
 194                 return 0;
 195
 196         flg_set = tcp6->th_flags & f->fw_tcpf;
 197         flg_clr = tcp6->th_flags & f->fw_tcpnf;
 198
 199         if (flg_set != f->fw_tcpf)
 200                 return 0;
 201         if (flg_clr)
 202                 return 0;
 203
 204         return 1;
 205 }
 206
 207 static int
 208 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
 209 {
 210         int type;
 211
 212         if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
 213                 return (1);
 214
 215         type = icmp6->icmp6_type;
 216
 217         /* check for matching type in the bitmap */
 218         if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
 219                 (f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
 220                 (1U << (type % (8 * sizeof(unsigned))))))
 221                 return (1);
 222
 223         return (0); /* no match */
 224 }
 225
 226 static int
 227 is_icmp6_query(struct ip6_hdr *ip6, int off)
 228 {
 229         const struct icmp6_hdr *icmp6;
 230         int icmp6_type;
 231
 232         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 233         icmp6_type = icmp6->icmp6_type;
 234
 235         if (icmp6_type == ICMP6_ECHO_REQUEST ||
 236             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 237             icmp6_type == ICMP6_WRUREQUEST ||
 238             icmp6_type == ICMP6_FQDN_QUERY ||
 239             icmp6_type == ICMP6_NI_QUERY)
 240                 return (1);
 241
 242         return (0);
 243 }
 244
 245 static int
 246 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
 247               int *off, int *nxt, u_short *offset)
 248 {
 249         int len;
 250         struct ip6_hdr *ip6 = *pip6;
 251         struct ip6_ext *ip6e;
 252         u_char  opts, nopts, nopts_sve;
 253
 254         opts = f->fw_ip6opt;
 255         nopts = nopts_sve = f->fw_ip6nopt;
 256
 257         *nxt = ip6->ip6_nxt;
 258         *off = sizeof(struct ip6_hdr);
 259         len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
 260         while (*off < len) {
 261                 ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
 262                 if ((*m)->m_len < *off + sizeof(*ip6e))
 263                         goto opts_check;        /* XXX */
 264
 265                 switch (*nxt) {
 266                 case IPPROTO_FRAGMENT:
 267                         if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
 268                                 struct ip6_frag *ip6f;
 269
 270                                 ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
 271                                 *offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
 272                         }
 273                         opts &= ~IPV6_FW_IP6OPT_FRAG;
 274                         nopts &= ~IPV6_FW_IP6OPT_FRAG;
 275                         *off += sizeof(struct ip6_frag);
 276                         break;
 277                 case IPPROTO_AH:
 278                         opts &= ~IPV6_FW_IP6OPT_AH;
 279                         nopts &= ~IPV6_FW_IP6OPT_AH;
 280                         *off += (ip6e->ip6e_len + 2) << 2;
 281                         break;
 282                 default:
 283                         switch (*nxt) {
 284                         case IPPROTO_HOPOPTS:
 285                                 opts &= ~IPV6_FW_IP6OPT_HOPOPT;
 286                                 nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
 287                                 break;
 288                         case IPPROTO_ROUTING:
 289                                 opts &= ~IPV6_FW_IP6OPT_ROUTE;
 290                                 nopts &= ~IPV6_FW_IP6OPT_ROUTE;
 291                                 break;
 292                         case IPPROTO_ESP:
 293                                 opts &= ~IPV6_FW_IP6OPT_ESP;
 294                                 nopts &= ~IPV6_FW_IP6OPT_ESP;
 295                                 goto opts_check;
 296                         case IPPROTO_NONE:
 297                                 opts &= ~IPV6_FW_IP6OPT_NONXT;
 298                                 nopts &= ~IPV6_FW_IP6OPT_NONXT;
 299                                 goto opts_check;
 300                         case IPPROTO_DSTOPTS:
 301                                 opts &= ~IPV6_FW_IP6OPT_OPTS;
 302                                 nopts &= ~IPV6_FW_IP6OPT_OPTS;
 303                                 break;
 304                         default:
 305                                 goto opts_check;
 306                         }
 307                         *off += (ip6e->ip6e_len + 1) << 3;
 308                         break;
 309                 }
 310                 *nxt = ip6e->ip6e_nxt;
 311
 312         }
 313  opts_check:
 314         if (f->fw_ip6opt == f->fw_ip6nopt)      /* XXX */
 315                 return 1;
 316
 317         if (opts == 0 && nopts == nopts_sve)
 318                 return 1;
 319         else
 320                 return 0;
 321 }
 322
 323 static
 324 __inline
 325 int
 326 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
 327 {
 328         /* Check by name or by IP address */
 329         if (byname) {
 330                 /* Check name */
 331                 if (ifu->fu_via_if.glob) {
 332                         if (fnmatch(ifu->fu_via_if.name, ifp->if_xname, 0)
 333                             == FNM_NOMATCH)
 334                                 return(0);
 335                 } else {
 336                         if (strncmp(ifp->if_xname, ifu->fu_via_if.name,
 337                             IP6FW_IFNLEN) != 0)
 338                                 return(0);
 339                 }
 340                 return(1);
 341         } else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {        /* Zero == wildcard */
 342                 struct ifaddr *ia;
 343
 344                 for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) {
 345
 346                         if (ia->ifa_addr == NULL)
 347                                 continue;
 348                         if (ia->ifa_addr->sa_family != AF_INET6)
 349                                 continue;
 350                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
 351                             &(((struct sockaddr_in6 *)
 352                             (ia->ifa_addr))->sin6_addr)))
 353                                 continue;
 354                         return (1);
 355                 }
 356                 return (0);
 357         }
 358         return (1);
 359 }
 360
 361 static void
 362 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
 363         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
 364 {
 365         static int counter;
 366         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
 367         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
 368         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
 369         int count;
 370         char *action;
 371         char action2[32], proto[102], name[18];
 372         int len;
 373
 374         count = f ? f->fw_pcnt : ++counter;
 375         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
 376                 return;
 377
 378         /* Print command name */
 379         snprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
 380
 381         action = action2;
 382         if (!f)
 383                 action = "Refuse";
 384         else {
 385                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 386                 case IPV6_FW_F_DENY:
 387                         action = "Deny";
 388                         break;
 389                 case IPV6_FW_F_REJECT:
 390                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
 391                                 action = "Reset";
 392                         else
 393                                 action = "Unreach";
 394                         break;
 395                 case IPV6_FW_F_ACCEPT:
 396                         action = "Accept";
 397                         break;
 398                 case IPV6_FW_F_COUNT:
 399                         action = "Count";
 400                         break;
 401                 case IPV6_FW_F_DIVERT:
 402                         snprintf(SNPARGS(action2, 0), "Divert %d",
 403                             f->fw_divert_port);
 404                         break;
 405                 case IPV6_FW_F_TEE:
 406                         snprintf(SNPARGS(action2, 0), "Tee %d",
 407                             f->fw_divert_port);
 408                         break;
 409                 case IPV6_FW_F_SKIPTO:
 410                         snprintf(SNPARGS(action2, 0), "SkipTo %d",
 411                             f->fw_skipto_rule);
 412                         break;
 413                 default:
 414                         action = "UNKNOWN";
 415                         break;
 416                 }
 417         }
 418
 419         switch (nxt) {
 420         case IPPROTO_TCP:
 421                 len = snprintf(SNPARGS(proto, 0), "TCP [%s]",
 422                     ip6_sprintf(&ip6->ip6_src));
 423                 if (off > 0)
 424                         len += snprintf(SNPARGS(proto, len), ":%d ",
 425                             ntohs(tcp6->th_sport));
 426                 else
 427                         len += snprintf(SNPARGS(proto, len), " ");
 428                 len += snprintf(SNPARGS(proto, len), "[%s]",
 429                     ip6_sprintf(&ip6->ip6_dst));
 430                 if (off > 0)
 431                         snprintf(SNPARGS(proto, len), ":%d",
 432                             ntohs(tcp6->th_dport));
 433                 break;
 434         case IPPROTO_UDP:
 435                 len = snprintf(SNPARGS(proto, 0), "UDP [%s]",
 436                     ip6_sprintf(&ip6->ip6_src));
 437                 if (off > 0)
 438                         len += snprintf(SNPARGS(proto, len), ":%d ",
 439                             ntohs(udp->uh_sport));
 440                 else
 441                     len += snprintf(SNPARGS(proto, len), " ");
 442                 len += snprintf(SNPARGS(proto, len), "[%s]",
 443                     ip6_sprintf(&ip6->ip6_dst));
 444                 if (off > 0)
 445                         snprintf(SNPARGS(proto, len), ":%d",
 446                             ntohs(udp->uh_dport));
 447                 break;
 448         case IPPROTO_ICMPV6:
 449                 if (off > 0)
 450                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
 451                             icmp6->icmp6_type, icmp6->icmp6_code);
 452                 else
 453                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
 454                 len += snprintf(SNPARGS(proto, len), "[%s]",
 455                     ip6_sprintf(&ip6->ip6_src));
 456                 snprintf(SNPARGS(proto, len), " [%s]",
 457                     ip6_sprintf(&ip6->ip6_dst));
 458                 break;
 459         default:
 460                 len = snprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
 461                     ip6_sprintf(&ip6->ip6_src));
 462                 snprintf(SNPARGS(proto, len), " [%s]",
 463                     ip6_sprintf(&ip6->ip6_dst));
 464                 break;
 465         }
 466
 467         if (oif)
 468                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
 469                     name, action, proto, if_name(oif));
 470         else if (rif)
 471                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
 472                     name, action, proto, if_name(rif));
 473         else
 474                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
 475                     name, action, proto);
 476         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
 477             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
 478                 f ? f->fw_number : -1);
 479 }
 480
 481 /*
 482  * Parameters:
 483  *
 484  *      ip      Pointer to packet header (struct ip6_hdr *)
 485  *      hlen    Packet header length
 486  *      oif     Outgoing interface, or NULL if packet is incoming
 487  * #ifndef IP6FW_DIVERT_RESTART
 488  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
 489  * #else
 490  *      *cookie Skip up to the first rule past this rule number;
 491  * #endif
 492  *      *m      The packet; we set to NULL when/if we nuke it.
 493  *
 494  * Return value:
 495  *
 496  *      0       The packet is to be accepted and routed normally OR
 497  *              the packet was denied/rejected and has been dropped;
 498  *              in the latter case, *m is equal to NULL upon return.
 499  *      port    Divert the packet to port.
 500  */
 501
 502 static int
 503 ip6_fw_chk(struct ip6_hdr **pip6,
 504         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
 505 {
 506         struct ip6_fw_chain *chain;
 507         struct ip6_fw *rule = NULL;
 508         struct ip6_hdr *ip6 = *pip6;
 509         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
 510         u_short offset = 0;
 511         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
 512         u_short src_port, dst_port;
 513 #ifdef  IP6FW_DIVERT_RESTART
 514         u_int16_t skipto = *cookie;
 515 #else
 516         u_int16_t ignport = ntohs(*cookie);
 517 #endif
 518
 519         *cookie = 0;
 520         /*
 521          * Go down the chain, looking for enlightment
 522          * #ifdef IP6FW_DIVERT_RESTART
 523          * If we've been asked to start at a given rule immediatly, do so.
 524          * #endif
 525          */
 526         chain = LIST_FIRST(&ip6_fw_chain);
 527 #ifdef IP6FW_DIVERT_RESTART
 528         if (skipto) {
 529                 if (skipto >= 65535)
 530                         goto dropit;
 531                 while (chain && (chain->rule->fw_number <= skipto)) {
 532                         chain = LIST_NEXT(chain, chain);
 533                 }
 534                 if (! chain) goto dropit;
 535         }
 536 #endif /* IP6FW_DIVERT_RESTART */
 537         for (; chain; chain = LIST_NEXT(chain, chain)) {
 538                 struct ip6_fw *const f = chain->rule;
 539
 540                 if (oif) {
 541                         /* Check direction outbound */
 542                         if (!(f->fw_flg & IPV6_FW_F_OUT))
 543                                 continue;
 544                 } else {
 545                         /* Check direction inbound */
 546                         if (!(f->fw_flg & IPV6_FW_F_IN))
 547                                 continue;
 548                 }
 549
 550 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
 551         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
 552         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
 553         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
 554         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
 555
 556                 /* If src-addr doesn't match, not this rule. */
 557                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
 558                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
 559                         continue;
 560
 561                 /* If dest-addr doesn't match, not this rule. */
 562                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
 563                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
 564                         continue;
 565
 566 #undef IN6_ARE_ADDR_MASKEQUAL
 567                 /* Interface check */
 568                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 569                         struct ifnet *const iface = oif ? oif : rif;
 570
 571                         /* Backwards compatibility hack for "via" */
 572                         if (!iface || !iface_match(iface,
 573                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
 574                                 continue;
 575                 } else {
 576                         /* Check receive interface */
 577                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
 578                             && (!rif || !iface_match(rif,
 579                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
 580                                 continue;
 581                         /* Check outgoing interface */
 582                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
 583                             && (!oif || !iface_match(oif,
 584                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
 585                                 continue;
 586                 }
 587
 588                 /* Check IP options */
 589                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
 590                         continue;
 591
 592                 /* Fragments */
 593                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
 594                         continue;
 595
 596                 /* Check protocol; if wildcard, match */
 597                 if (f->fw_prot == IPPROTO_IPV6)
 598                         goto got_match;
 599
 600                 /* If different, don't match */
 601                 if (nxt != f->fw_prot)
 602                         continue;
 603
 604 #define PULLUP_TO(len)  do {                                            \
 605                             if ((*m)->m_len < (len)                     \
 606                                 && (*m = m_pullup(*m, (len))) == 0) {   \
 607                                     goto dropit;                        \
 608                             }                                           \
 609                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
 610                         } while (/*CONSTCOND*/ 0)
 611
 612                 /* Protocol specific checks */
 613                 switch (nxt) {
 614                 case IPPROTO_TCP:
 615                     {
 616                         struct tcphdr *tcp6;
 617
 618                         if (offset == 1) {      /* cf. RFC 1858 */
 619                                 PULLUP_TO(off + 4); /* XXX ? */
 620                                 goto bogusfrag;
 621                         }
 622                         if (offset != 0) {
 623                                 /*
 624                                  * TCP flags and ports aren't available in this
 625                                  * packet -- if this rule specified either one,
 626                                  * we consider the rule a non-match.
 627                                  */
 628                                 if (f->fw_nports != 0 ||
 629                                     f->fw_tcpf != f->fw_tcpnf)
 630                                         continue;
 631
 632                                 break;
 633                         }
 634                         PULLUP_TO(off + 14);
 635                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
 636                         if (((f->fw_tcpf != f->fw_tcpnf) ||
 637                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
 638                            !tcp6flg_match(tcp6, f))
 639                                 continue;
 640                         src_port = ntohs(tcp6->th_sport);
 641                         dst_port = ntohs(tcp6->th_dport);
 642                         goto check_ports;
 643                     }
 644
 645                 case IPPROTO_UDP:
 646                     {
 647                         struct udphdr *udp;
 648
 649                         if (offset != 0) {
 650                                 /*
 651                                  * Port specification is unavailable -- if this
 652                                  * rule specifies a port, we consider the rule
 653                                  * a non-match.
 654                                  */
 655                                 if (f->fw_nports != 0)
 656                                         continue;
 657
 658                                 break;
 659                         }
 660                         PULLUP_TO(off + 4);
 661                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
 662                         src_port = ntohs(udp->uh_sport);
 663                         dst_port = ntohs(udp->uh_dport);
 664 check_ports:
 665                         if (!port_match6(&f->fw_pts[0],
 666                             IPV6_FW_GETNSRCP(f), src_port,
 667                             f->fw_flg & IPV6_FW_F_SRNG))
 668                                 continue;
 669                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
 670                             IPV6_FW_GETNDSTP(f), dst_port,
 671                             f->fw_flg & IPV6_FW_F_DRNG))
 672                                 continue;
 673                         break;
 674                     }
 675
 676                 case IPPROTO_ICMPV6:
 677                     {
 678                         struct icmp6_hdr *icmp;
 679
 680                         if (offset != 0)        /* Type isn't valid */
 681                                 break;
 682                         PULLUP_TO(off + 2);
 683                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
 684                         if (!icmp6type_match(icmp, f))
 685                                 continue;
 686                         break;
 687                     }
 688 #undef PULLUP_TO
 689
 690 bogusfrag:
 691                         if (fw6_verbose)
 692                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
 693                         goto dropit;
 694                 }
 695
 696 got_match:
 697 #ifndef IP6FW_DIVERT_RESTART
 698                 /* Ignore divert/tee rule if socket port is "ignport" */
 699                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 700                 case IPV6_FW_F_DIVERT:
 701                 case IPV6_FW_F_TEE:
 702                         if (f->fw_divert_port == ignport)
 703                                 continue;       /* ignore this rule */
 704                         break;
 705                 }
 706
 707 #endif /* IP6FW_DIVERT_RESTART */
 708                 /* Update statistics */
 709                 f->fw_pcnt += 1;
 710                 f->fw_bcnt += ntohs(ip6->ip6_plen);
 711                 f->timestamp = time_second;
 712
 713                 /* Log to console if desired */
 714                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
 715                         ip6fw_report(f, ip6, rif, oif, off, nxt);
 716
 717                 /* Take appropriate action */
 718                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 719                 case IPV6_FW_F_ACCEPT:
 720                         return (0);
 721                 case IPV6_FW_F_COUNT:
 722                         continue;
 723                 case IPV6_FW_F_DIVERT:
 724 #ifdef IP6FW_DIVERT_RESTART
 725                         *cookie = f->fw_number;
 726 #else
 727                         *cookie = htons(f->fw_divert_port);
 728 #endif /* IP6FW_DIVERT_RESTART */
 729                         return (f->fw_divert_port);
 730                 case IPV6_FW_F_TEE:
 731                         /*
 732                          * XXX someday tee packet here, but beware that you
 733                          * can't use m_copym() or m_copypacket() because
 734                          * the divert input routine modifies the mbuf
 735                          * (and these routines only increment reference
 736                          * counts in the case of mbuf clusters), so need
 737                          * to write custom routine.
 738                          */
 739                         continue;
 740                 case IPV6_FW_F_SKIPTO:
 741 #ifdef DIAGNOSTIC
 742                         while (chain->chain.le_next
 743                             && chain->chain.le_next->rule->fw_number
 744                                 < f->fw_skipto_rule)
 745 #else
 746                         while (chain->chain.le_next->rule->fw_number
 747                             < f->fw_skipto_rule)
 748 #endif
 749                                 chain = chain->chain.le_next;
 750                         continue;
 751                 }
 752
 753                 /* Deny/reject this packet using this rule */
 754                 rule = f;
 755                 break;
 756         }
 757
 758 #ifdef DIAGNOSTIC
 759         /* Rule 65535 should always be there and should always match */
 760         if (!chain)
 761                 panic("ip6_fw: chain");
 762 #endif
 763
 764         /*
 765          * At this point, we're going to drop the packet.
 766          * Send a reject notice if all of the following are true:
 767          *
 768          * - The packet matched a reject rule
 769          * - The packet is not an ICMP packet, or is an ICMP query packet
 770          * - The packet is not a multicast or broadcast packet
 771          */
 772         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
 773             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
 774             && !((*m)->m_flags & (M_BCAST|M_MCAST))
 775             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 776                 switch (rule->fw_reject_code) {
 777                 case IPV6_FW_REJECT_RST:
 778 #if 1   /* not tested */
 779                   {
 780                         struct tcphdr *const tcp =
 781                                 (struct tcphdr *) ((caddr_t)ip6 + off);
 782                         struct {
 783                                 struct ip6_hdr ip6;
 784                                 struct tcphdr th;
 785                         } ti;
 786                         tcp_seq ack, seq;
 787                         int flags;
 788
 789                         if (offset != 0 || (tcp->th_flags & TH_RST))
 790                                 break;
 791
 792                         ti.ip6 = *ip6;
 793                         ti.th = *tcp;
 794                         ti.th.th_seq = ntohl(ti.th.th_seq);
 795                         ti.th.th_ack = ntohl(ti.th.th_ack);
 796                         ti.ip6.ip6_nxt = IPPROTO_TCP;
 797                         if (ti.th.th_flags & TH_ACK) {
 798                                 ack = 0;
 799                                 seq = ti.th.th_ack;
 800                                 flags = TH_RST;
 801                         } else {
 802                                 ack = ti.th.th_seq;
 803                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
 804                                         ack += (*m)->m_pkthdr.len - off
 805                                                 - (ti.th.th_off << 2);
 806                                 } else if (ip6->ip6_plen) {
 807                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
 808                                                 - off - (ti.th.th_off << 2);
 809                                 } else {
 810                                         m_freem(*m);
 811                                         *m = 0;
 812                                         break;
 813                                 }
 814                                 if (tcp->th_flags & TH_SYN)
 815                                         ack++;
 816                                 seq = 0;
 817                                 flags = TH_RST|TH_ACK;
 818                         }
 819                         bcopy(&ti, ip6, sizeof(ti));
 820                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
 821                                 *m, ack, seq, flags);
 822                         *m = NULL;
 823                         break;
 824                   }
 825 #endif
 826                 default:        /* Send an ICMP unreachable using code */
 827                         if (oif)
 828                                 (*m)->m_pkthdr.rcvif = oif;
 829                         icmp6_error(*m, ICMP6_DST_UNREACH,
 830                             rule->fw_reject_code, 0);
 831                         *m = NULL;
 832                         break;
 833                 }
 834         }
 835
 836 dropit:
 837         /*
 838          * Finally, drop the packet.
 839          */
 840         if (*m) {
 841                 m_freem(*m);
 842                 *m = NULL;
 843         }
 844         return (0);
 845 }
 846
 847 static int
 848 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
 849 {
 850         struct ip6_fw *ftmp = 0;
 851         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
 852         u_short nbr = 0;
 853         int s;
 854
 855         fwc = malloc(sizeof *fwc, M_IP6FW, M_NOWAIT);
 856         ftmp = malloc(sizeof *ftmp, M_IP6FW, M_NOWAIT);
 857         if (!fwc || !ftmp) {
 858                 dprintf(("%s malloc said no\n", err_prefix));
 859                 if (fwc)  free(fwc, M_IP6FW);
 860                 if (ftmp) free(ftmp, M_IP6FW);
 861                 return (ENOSPC);
 862         }
 863
 864         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
 865         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
 866         ftmp->fw_pcnt = 0L;
 867         ftmp->fw_bcnt = 0L;
 868         fwc->rule = ftmp;
 869
 870         s = splnet();
 871
 872         if (!chainptr->lh_first) {
 873                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 874                 splx(s);
 875                 return (0);
 876         } else if (ftmp->fw_number == (u_short)-1) {
 877                 if (fwc)  free(fwc, M_IP6FW);
 878                 if (ftmp) free(ftmp, M_IP6FW);
 879                 splx(s);
 880                 dprintf(("%s bad rule number\n", err_prefix));
 881                 return (EINVAL);
 882         }
 883
 884         /* If entry number is 0, find highest numbered rule and add 100 */
 885         if (ftmp->fw_number == 0) {
 886                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 887                         if (fcp->rule->fw_number != (u_short)-1)
 888                                 nbr = fcp->rule->fw_number;
 889                         else
 890                                 break;
 891                 }
 892                 if (nbr < (u_short)-1 - 100)
 893                         nbr += 100;
 894                 ftmp->fw_number = nbr;
 895         }
 896
 897         /* Got a valid number; now insert it, keeping the list ordered */
 898         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 899                 if (fcp->rule->fw_number > ftmp->fw_number) {
 900                         if (fcpl) {
 901                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
 902                         } else {
 903                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 904                         }
 905                         break;
 906                 } else {
 907                         fcpl = fcp;
 908                 }
 909         }
 910
 911         splx(s);
 912         return (0);
 913 }
 914
 915 static int
 916 del_entry6(struct ip6_fw_head *chainptr, u_short number)
 917 {
 918         struct ip6_fw_chain *fcp;
 919         int s;
 920
 921         s = splnet();
 922
 923         fcp = chainptr->lh_first;
 924         if (number != (u_short)-1) {
 925                 for (; fcp; fcp = fcp->chain.le_next) {
 926                         if (fcp->rule->fw_number == number) {
 927                                 LIST_REMOVE(fcp, chain);
 928                                 splx(s);
 929                                 free(fcp->rule, M_IP6FW);
 930                                 free(fcp, M_IP6FW);
 931                                 return 0;
 932                         }
 933                 }
 934         }
 935
 936         splx(s);
 937         return (EINVAL);
 938 }
 939
 940 static int
 941 zero_entry6(struct mbuf *m)
 942 {
 943         struct ip6_fw *frwl;
 944         struct ip6_fw_chain *fcp;
 945         int s;
 946
 947         if (m && m->m_len != 0) {
 948                 if (m->m_len != sizeof(struct ip6_fw))
 949                         return (EINVAL);
 950                 frwl = mtod(m, struct ip6_fw *);
 951         }
 952         else
 953                 frwl = NULL;
 954
 955         /*
 956          *      It's possible to insert multiple chain entries with the
 957          *      same number, so we don't stop after finding the first
 958          *      match if zeroing a specific entry.
 959          */
 960         s = splnet();
 961         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
 962                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
 963                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
 964                         fcp->rule->timestamp = 0;
 965                 }
 966         splx(s);
 967
 968         if (fw6_verbose) {
 969                 if (frwl)
 970                         log(LOG_SECURITY | LOG_NOTICE,
 971                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
 972                 else
 973                         log(LOG_SECURITY | LOG_NOTICE,
 974                             "ip6fw: Accounting cleared.\n");
 975         }
 976
 977         return (0);
 978 }
 979
 980 static struct ip6_fw *
 981 check_ip6fw_mbuf(struct mbuf *m)
 982 {
 983         /* Check length */
 984         if (m->m_len != sizeof(struct ip6_fw)) {
 985                 dprintf(("%s len=%d, want %zu\n", err_prefix, m->m_len,
 986                     sizeof(struct ip6_fw)));
 987                 return (NULL);
 988         }
 989         return (check_ip6fw_struct(mtod(m, struct ip6_fw *)));
 990 }
 991
 992 static struct ip6_fw *
 993 check_ip6fw_struct(struct ip6_fw *frwl)
 994 {
 995         /* Check for invalid flag bits */
 996         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
 997                 dprintf(("%s undefined flag bits set (flags=%x)\n",
 998                     err_prefix, frwl->fw_flg));
 999                 return (NULL);
1000         }
1001         /* Must apply to incoming or outgoing (or both) */
1002         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
1003                 dprintf(("%s neither in nor out\n", err_prefix));
1004                 return (NULL);
1005         }
1006         /* Empty interface name is no good */
1007         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
1008               && !*frwl->fw_in_if.fu_via_if.name)
1009             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
1010               && !*frwl->fw_out_if.fu_via_if.name)) {
1011                 dprintf(("%s empty interface name\n", err_prefix));
1012                 return (NULL);
1013         }
1014         /* Sanity check interface matching */
1015         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1016                 ;               /* allow "via" backwards compatibility */
1017         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1018             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1019                 dprintf(("%s outgoing interface check on incoming\n",
1020                     err_prefix));
1021                 return (NULL);
1022         }
1023         /* Sanity check port ranges */
1024         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1025                 dprintf(("%s src range set but n_src_p=%d\n",
1026                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1027                 return (NULL);
1028         }
1029         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1030                 dprintf(("%s dst range set but n_dst_p=%d\n",
1031                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1032                 return (NULL);
1033         }
1034         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1035                 dprintf(("%s too many ports (%d+%d)\n",
1036                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1037                 return (NULL);
1038         }
1039         /*
1040          *      Protocols other than TCP/UDP don't use port range
1041          */
1042         if ((frwl->fw_prot != IPPROTO_TCP) &&
1043             (frwl->fw_prot != IPPROTO_UDP) &&
1044             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1045                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1046                     err_prefix));
1047                 return (NULL);
1048         }
1049
1050         /*
1051          *      Rather than modify the entry to make such entries work,
1052          *      we reject this rule and require user level utilities
1053          *      to enforce whatever policy they deem appropriate.
1054          */
1055         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1056                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1057                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1058                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1059                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1060                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1061                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1062                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1063                 dprintf(("%s rule never matches\n", err_prefix));
1064                 return (NULL);
1065         }
1066
1067         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1068                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1069                 if (frwl->fw_nports) {
1070                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1071                         return (NULL);
1072                 }
1073                 if (frwl->fw_prot == IPPROTO_TCP &&
1074                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1075                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1076                         return (NULL);
1077                 }
1078         }
1079
1080         /* Check command specific stuff */
1081         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1082         {
1083         case IPV6_FW_F_REJECT:
1084                 if (frwl->fw_reject_code >= 0x100
1085                     && !(frwl->fw_prot == IPPROTO_TCP
1086                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1087                         dprintf(("%s unknown reject code\n", err_prefix));
1088                         return (NULL);
1089                 }
1090                 break;
1091         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1092         case IPV6_FW_F_TEE:
1093                 if (frwl->fw_divert_port == 0) {
1094                         dprintf(("%s can't divert to port 0\n", err_prefix));
1095                         return (NULL);
1096                 }
1097                 break;
1098         case IPV6_FW_F_DENY:
1099         case IPV6_FW_F_ACCEPT:
1100         case IPV6_FW_F_COUNT:
1101         case IPV6_FW_F_SKIPTO:
1102                 break;
1103         default:
1104                 dprintf(("%s invalid command\n", err_prefix));
1105                 return (NULL);
1106         }
1107
1108         return frwl;
1109 }
1110
1111 static int
1112 ip6_fw_ctl(int stage, struct mbuf **mm)
1113 {
1114         int error;
1115         struct mbuf *m;
1116
1117         if (stage == IPV6_FW_GET) {
1118                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1119                 *mm = m = m_get(M_TRYWAIT, MT_DATA); /* XXX */
1120                 if (!m)
1121                         return (ENOBUFS);
1122                 if (sizeof *(fcp->rule) > MLEN) {
1123                         MCLGET(m, M_TRYWAIT);
1124                         if ((m->m_flags & M_EXT) == 0) {
1125                                 m_free(m);
1126                                 return (ENOBUFS);
1127                         }
1128                 }
1129                 for (; fcp; fcp = fcp->chain.le_next) {
1130                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1131                         m->m_len = sizeof *(fcp->rule);
1132                         m->m_next = m_get(M_TRYWAIT, MT_DATA); /* XXX */
1133                         if (!m->m_next) {
1134                                 m_freem(*mm);
1135                                 return (ENOBUFS);
1136                         }
1137                         m = m->m_next;
1138                         if (sizeof *(fcp->rule) > MLEN) {
1139                                 MCLGET(m, M_TRYWAIT);
1140                                 if ((m->m_flags & M_EXT) == 0) {
1141                                         m_freem(*mm);
1142                                         return (ENOBUFS);
1143                                 }
1144                         }
1145                         m->m_len = 0;
1146                 }
1147                 return (0);
1148         }
1149         m = *mm;
1150         /* only allow get calls if secure mode > 2 */
1151         if (securelevel > 2) {
1152                 if (m) {
1153                         (void)m_freem(m);
1154                         *mm = 0;
1155                 }
1156                 return (EPERM);
1157         }
1158         if (stage == IPV6_FW_FLUSH) {
1159                 while (ip6_fw_chain.lh_first != NULL &&
1160                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1161                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1162                         int s = splnet();
1163                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1164                         splx(s);
1165                         free(fcp->rule, M_IP6FW);
1166                         free(fcp, M_IP6FW);
1167                 }
1168                 if (m) {
1169                         (void)m_freem(m);
1170                         *mm = 0;
1171                 }
1172                 return (0);
1173         }
1174         if (stage == IPV6_FW_ZERO) {
1175                 error = zero_entry6(m);
1176                 if (m) {
1177                         (void)m_freem(m);
1178                         *mm = 0;
1179                 }
1180                 return (error);
1181         }
1182         if (m == NULL) {
1183                 printf("%s NULL mbuf ptr\n", err_prefix);
1184                 return (EINVAL);
1185         }
1186
1187         if (stage == IPV6_FW_ADD) {
1188                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1189
1190                 if (!frwl)
1191                         error = EINVAL;
1192                 else
1193                         error = add_entry6(&ip6_fw_chain, frwl);
1194                 if (m) {
1195                         (void)m_freem(m);
1196                         *mm = 0;
1197                 }
1198                 return error;
1199         }
1200         if (stage == IPV6_FW_DEL) {
1201                 if (m->m_len != sizeof(struct ip6_fw)) {
1202                         dprintf(("%s len=%d, want %zu\n", err_prefix, m->m_len,
1203                             sizeof(struct ip6_fw)));
1204                         error = EINVAL;
1205                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1206                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1207                         error = EINVAL;
1208                 } else
1209                         error = del_entry6(&ip6_fw_chain,
1210                             mtod(m, struct ip6_fw *)->fw_number);
1211                 if (m) {
1212                         (void)m_freem(m);
1213                         *mm = 0;
1214                 }
1215                 return error;
1216         }
1217
1218         dprintf(("%s unknown request %d\n", err_prefix, stage));
1219         if (m) {
1220                 (void)m_freem(m);
1221                 *mm = 0;
1222         }
1223         return (EINVAL);
1224 }
1225
1226 void
1227 ip6_fw_init(void)
1228 {
1229         struct ip6_fw default_rule;
1230
1231         ip6_fw_chk_ptr = ip6_fw_chk;
1232         ip6_fw_ctl_ptr = ip6_fw_ctl;
1233         LIST_INIT(&ip6_fw_chain);
1234
1235         bzero(&default_rule, sizeof default_rule);
1236         default_rule.fw_prot = IPPROTO_IPV6;
1237         default_rule.fw_number = (u_short)-1;
1238 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1239         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1240 #else
1241         default_rule.fw_flg |= IPV6_FW_F_DENY;
1242 #endif
1243         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1244         if (check_ip6fw_struct(&default_rule) == NULL ||
1245                 add_entry6(&ip6_fw_chain, &default_rule))
1246                 panic(__func__);
1247
1248         printf("IPv6 packet filtering initialized, ");
1249 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1250         printf("default to accept, ");
1251 #endif
1252 #ifndef IPV6FIREWALL_VERBOSE
1253         printf("logging disabled\n");
1254 #else
1255         if (fw6_verbose_limit == 0)
1256                 printf("unlimited logging\n");
1257         else
1258                 printf("logging limited to %d packets/entry\n",
1259                     fw6_verbose_limit);
1260 #endif
1261 }
1262
1263 static ip6_fw_chk_t *old_chk_ptr;
1264 static ip6_fw_ctl_t *old_ctl_ptr;
1265
1266 static int
1267 ip6fw_modevent(module_t mod, int type, void *unused)
1268 {
1269         int s;
1270
1271         switch (type) {
1272         case MOD_LOAD:
1273                 s = splnet();
1274
1275                 old_chk_ptr = ip6_fw_chk_ptr;
1276                 old_ctl_ptr = ip6_fw_ctl_ptr;
1277
1278                 ip6_fw_init();
1279                 splx(s);
1280                 return 0;
1281         case MOD_UNLOAD:
1282                 s = splnet();
1283                 ip6_fw_chk_ptr =  old_chk_ptr;
1284                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1285                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1286                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1287                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1288                         free(fcp->rule, M_IP6FW);
1289                         free(fcp, M_IP6FW);
1290                 }
1291
1292                 splx(s);
1293                 printf("IPv6 firewall unloaded\n");
1294                 return 0;
1295         default:
1296                 return EOPNOTSUPP;
1297                 break;
1298         }
1299         return 0;
1300 }
1301
1302 static moduledata_t ip6fwmod = {
1303         "ip6fw",
1304         ip6fw_modevent,
1305         0
1306 };
1307 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);