sys/net/ip6fw/ip6_fw.c

   1 /*      $FreeBSD: src/sys/netinet6/ip6_fw.c,v 1.2.2.10 2003/08/03 17:52:54 ume Exp $    */
   2 /*      $DragonFly: src/sys/net/ip6fw/ip6_fw.c,v 1.18 2006/12/22 23:44:56 swildner Exp $        */
   3 /*      $KAME: ip6_fw.c,v 1.21 2001/01/24 01:25:32 itojun Exp $ */
   4
   5 /*
   6  * Copyright (C) 1998, 1999, 2000 and 2001 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1993 Daniel Boulet
  36  * Copyright (c) 1994 Ugen J.S.Antsilevich
  37  * Copyright (c) 1996 Alex Nash
  38  *
  39  * Redistribution and use in source forms, with and without modification,
  40  * are permitted provided that this entire comment appears intact.
  41  *
  42  * Redistribution in binary form may occur without any restrictions.
  43  * Obviously, it would be nice if you gave credit where credit is due
  44  * but requiring it would be too onerous.
  45  *
  46  * This software is provided ``AS IS'' without any warranties of any kind.
  47  */
  48
  49 /*
  50  * Implement IPv6 packet firewall
  51  */
  52
  53 #if !defined(KLD_MODULE)
  54 #include "opt_ip6fw.h"
  55 #include "opt_inet.h"
  56 #include "opt_inet6.h"
  57 #endif
  58
  59 #ifdef IP6DIVERT
  60 #error "NOT SUPPORTED IPV6 DIVERT"
  61 #endif
  62 #ifdef IP6FW_DIVERT_RESTART
  63 #error "NOT SUPPORTED IPV6 DIVERT"
  64 #endif
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/malloc.h>
  69 #include <sys/mbuf.h>
  70 #include <sys/queue.h>
  71 #include <sys/kernel.h>
  72 #include <sys/socket.h>
  73 #include <sys/socketvar.h>
  74 #include <sys/syslog.h>
  75 #include <sys/thread2.h>
  76 #include <sys/time.h>
  77 #include <net/if.h>
  78 #include <net/route.h>
  79 #include <netinet/in_systm.h>
  80 #include <netinet/in.h>
  81 #include <netinet/ip.h>
  82
  83 #include <netinet/ip6.h>
  84 #include <netinet6/ip6_var.h>
  85 #include <netinet6/in6_var.h>
  86 #include <netinet/icmp6.h>
  87
  88 #include <netinet/in_pcb.h>
  89
  90 #include "ip6_fw.h"
  91 #include <netinet/ip_var.h>
  92 #include <netinet/tcp.h>
  93 #include <netinet/tcp_seq.h>
  94 #include <netinet/tcp_timer.h>
  95 #include <netinet/tcp_var.h>
  96 #include <netinet/udp.h>
  97
  98 #include <sys/sysctl.h>
  99
 100 #include <net/net_osdep.h>
 101
 102 MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
 103
 104 static int fw6_debug = 1;
 105 #ifdef IPV6FIREWALL_VERBOSE
 106 static int fw6_verbose = 1;
 107 #else
 108 static int fw6_verbose = 0;
 109 #endif
 110 #ifdef IPV6FIREWALL_VERBOSE_LIMIT
 111 static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
 112 #else
 113 static int fw6_verbose_limit = 0;
 114 #endif
 115
 116 LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
 117
 118 #ifdef SYSCTL_NODE
 119 SYSCTL_DECL(_net_inet6_ip6);
 120 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 121 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW,
 122         &ip6_fw_enable, 0, "Enable ip6fw");
 123 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
 124 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw6_verbose, 0, "");
 125 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
 126 #endif
 127
 128 #define dprintf(a)      do {                                            \
 129                                 if (fw6_debug)                          \
 130                                         kprintf a;                      \
 131                         } while (0)
 132 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
 133
 134 static int      add_entry6 (struct ip6_fw_head *chainptr, struct ip6_fw *frwl);
 135 static int      del_entry6 (struct ip6_fw_head *chainptr, u_short number);
 136 static int      zero_entry6 (struct mbuf *m);
 137 static struct ip6_fw *check_ip6fw_struct (struct ip6_fw *m);
 138 static struct ip6_fw *check_ip6fw_mbuf (struct mbuf *fw);
 139 static int      ip6opts_match (struct ip6_hdr **ip6, struct ip6_fw *f,
 140                                    struct mbuf **m,
 141                                    int *off, int *nxt, u_short *offset);
 142 static int      port_match6 (u_short *portptr, int nports, u_short port,
 143                                 int range_flag);
 144 static int      tcp6flg_match (struct tcphdr *tcp6, struct ip6_fw *f);
 145 static int      icmp6type_match (struct icmp6_hdr *  icmp, struct ip6_fw * f);
 146 static void     ip6fw_report (struct ip6_fw *f, struct ip6_hdr *ip6,
 147                                 struct ifnet *rif, struct ifnet *oif, int off, int nxt);
 148
 149 static int      ip6_fw_chk (struct ip6_hdr **pip6,
 150                         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m);
 151 static int      ip6_fw_ctl (int stage, struct mbuf **mm);
 152
 153 static char err_prefix[] = "ip6_fw_ctl:";
 154
 155 /*
 156  * Returns 1 if the port is matched by the vector, 0 otherwise
 157  */
 158 static
 159 __inline int
 160 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
 161 {
 162         if (!nports)
 163                 return 1;
 164         if (range_flag) {
 165                 if (portptr[0] <= port && port <= portptr[1]) {
 166                         return 1;
 167                 }
 168                 nports -= 2;
 169                 portptr += 2;
 170         }
 171         while (nports-- > 0) {
 172                 if (*portptr++ == port) {
 173                         return 1;
 174                 }
 175         }
 176         return 0;
 177 }
 178
 179 static int
 180 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
 181 {
 182         u_char          flg_set, flg_clr;
 183
 184         /*
 185          * If an established connection is required, reject packets that
 186          * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
 187          * other flag requirements.
 188          */
 189         if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
 190             ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
 191             IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
 192                 return 0;
 193
 194         flg_set = tcp6->th_flags & f->fw_tcpf;
 195         flg_clr = tcp6->th_flags & f->fw_tcpnf;
 196
 197         if (flg_set != f->fw_tcpf)
 198                 return 0;
 199         if (flg_clr)
 200                 return 0;
 201
 202         return 1;
 203 }
 204
 205 static int
 206 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
 207 {
 208         int type;
 209
 210         if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
 211                 return(1);
 212
 213         type = icmp6->icmp6_type;
 214
 215         /* check for matching type in the bitmap */
 216         if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
 217                 (f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
 218                 (1U << (type % (8 * sizeof(unsigned))))))
 219                 return(1);
 220
 221         return(0); /* no match */
 222 }
 223
 224 static int
 225 is_icmp6_query(struct ip6_hdr *ip6, int off)
 226 {
 227         const struct icmp6_hdr *icmp6;
 228         int icmp6_type;
 229
 230         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 231         icmp6_type = icmp6->icmp6_type;
 232
 233         if (icmp6_type == ICMP6_ECHO_REQUEST ||
 234             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 235             icmp6_type == ICMP6_WRUREQUEST ||
 236             icmp6_type == ICMP6_FQDN_QUERY ||
 237             icmp6_type == ICMP6_NI_QUERY)
 238                 return(1);
 239
 240         return(0);
 241 }
 242
 243 static int
 244 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
 245               int *off, int *nxt, u_short *offset)
 246 {
 247         int len;
 248         struct ip6_hdr *ip6 = *pip6;
 249         struct ip6_ext *ip6e;
 250         u_char  opts, nopts, nopts_sve;
 251
 252         opts = f->fw_ip6opt;
 253         nopts = nopts_sve = f->fw_ip6nopt;
 254
 255         *nxt = ip6->ip6_nxt;
 256         *off = sizeof(struct ip6_hdr);
 257         len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
 258         while (*off < len) {
 259                 ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
 260                 if ((*m)->m_len < *off + sizeof(*ip6e))
 261                         goto opts_check;        /* XXX */
 262
 263                 switch(*nxt) {
 264                 case IPPROTO_FRAGMENT:
 265                         if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
 266                                 struct ip6_frag *ip6f;
 267
 268                                 ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
 269                                 *offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
 270                         }
 271                         opts &= ~IPV6_FW_IP6OPT_FRAG;
 272                         nopts &= ~IPV6_FW_IP6OPT_FRAG;
 273                         *off += sizeof(struct ip6_frag);
 274                         break;
 275                 case IPPROTO_AH:
 276                         opts &= ~IPV6_FW_IP6OPT_AH;
 277                         nopts &= ~IPV6_FW_IP6OPT_AH;
 278                         *off += (ip6e->ip6e_len + 2) << 2;
 279                         break;
 280                 default:
 281                         switch (*nxt) {
 282                         case IPPROTO_HOPOPTS:
 283                                 opts &= ~IPV6_FW_IP6OPT_HOPOPT;
 284                                 nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
 285                                 break;
 286                         case IPPROTO_ROUTING:
 287                                 opts &= ~IPV6_FW_IP6OPT_ROUTE;
 288                                 nopts &= ~IPV6_FW_IP6OPT_ROUTE;
 289                                 break;
 290                         case IPPROTO_ESP:
 291                                 opts &= ~IPV6_FW_IP6OPT_ESP;
 292                                 nopts &= ~IPV6_FW_IP6OPT_ESP;
 293                                 goto opts_check;
 294                         case IPPROTO_NONE:
 295                                 opts &= ~IPV6_FW_IP6OPT_NONXT;
 296                                 nopts &= ~IPV6_FW_IP6OPT_NONXT;
 297                                 goto opts_check;
 298                         case IPPROTO_DSTOPTS:
 299                                 opts &= ~IPV6_FW_IP6OPT_OPTS;
 300                                 nopts &= ~IPV6_FW_IP6OPT_OPTS;
 301                                 break;
 302                         default:
 303                                 goto opts_check;
 304                         }
 305                         *off += (ip6e->ip6e_len + 1) << 3;
 306                         break;
 307                 }
 308                 *nxt = ip6e->ip6e_nxt;
 309
 310         }
 311  opts_check:
 312         if (f->fw_ip6opt == f->fw_ip6nopt)      /* XXX */
 313                 return 1;
 314
 315         if (opts == 0 && nopts == nopts_sve)
 316                 return 1;
 317         else
 318                 return 0;
 319 }
 320
 321 static
 322 __inline int
 323 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
 324 {
 325         /* Check by name or by IP address */
 326         if (byname) {
 327                 /* Check name */
 328                 if (ifu->fu_via_if.glob) {
 329                         if (kfnmatch(ifu->fu_via_if.name, ifp->if_xname, 0)
 330                             == FNM_NOMATCH)
 331                                 return(0);
 332                 } else {
 333                         if (strncmp(ifp->if_xname, ifu->fu_via_if.name,
 334                             IP6FW_IFNLEN) != 0)
 335                                 return(0);
 336                 }
 337                 return(1);
 338         } else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {        /* Zero == wildcard */
 339                 struct ifaddr *ifa;
 340
 341                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 342                         if (ifa->ifa_addr == NULL)
 343                                 continue;
 344                         if (ifa->ifa_addr->sa_family != AF_INET6)
 345                                 continue;
 346                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
 347                             &(((struct sockaddr_in6 *)
 348                             (ifa->ifa_addr))->sin6_addr)))
 349                                 continue;
 350                         return(1);
 351                 }
 352                 return(0);
 353         }
 354         return(1);
 355 }
 356
 357 static void
 358 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
 359         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
 360 {
 361         static int counter;
 362         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
 363         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
 364         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
 365         int count;
 366         char *action;
 367         char action2[32], proto[102], name[18];
 368         int len;
 369
 370         count = f ? f->fw_pcnt : ++counter;
 371         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
 372                 return;
 373
 374         /* Print command name */
 375         ksnprintf(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                         ksnprintf(SNPARGS(action2, 0), "Divert %d",
 399                             f->fw_divert_port);
 400                         break;
 401                 case IPV6_FW_F_TEE:
 402                         ksnprintf(SNPARGS(action2, 0), "Tee %d",
 403                             f->fw_divert_port);
 404                         break;
 405                 case IPV6_FW_F_SKIPTO:
 406                         ksnprintf(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 = ksnprintf(SNPARGS(proto, 0), "TCP [%s]",
 418                     ip6_sprintf(&ip6->ip6_src));
 419                 if (off > 0)
 420                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
 421                             ntohs(tcp6->th_sport));
 422                 else
 423                         len += ksnprintf(SNPARGS(proto, len), " ");
 424                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 425                     ip6_sprintf(&ip6->ip6_dst));
 426                 if (off > 0)
 427                         ksnprintf(SNPARGS(proto, len), ":%d",
 428                             ntohs(tcp6->th_dport));
 429                 break;
 430         case IPPROTO_UDP:
 431                 len = ksnprintf(SNPARGS(proto, 0), "UDP [%s]",
 432                     ip6_sprintf(&ip6->ip6_src));
 433                 if (off > 0)
 434                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
 435                             ntohs(udp->uh_sport));
 436                 else
 437                     len += ksnprintf(SNPARGS(proto, len), " ");
 438                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 439                     ip6_sprintf(&ip6->ip6_dst));
 440                 if (off > 0)
 441                         ksnprintf(SNPARGS(proto, len), ":%d",
 442                             ntohs(udp->uh_dport));
 443                 break;
 444         case IPPROTO_ICMPV6:
 445                 if (off > 0)
 446                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
 447                             icmp6->icmp6_type, icmp6->icmp6_code);
 448                 else
 449                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
 450                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 451                     ip6_sprintf(&ip6->ip6_src));
 452                 ksnprintf(SNPARGS(proto, len), " [%s]",
 453                     ip6_sprintf(&ip6->ip6_dst));
 454                 break;
 455         default:
 456                 len = ksnprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
 457                     ip6_sprintf(&ip6->ip6_src));
 458                 ksnprintf(SNPARGS(proto, len), " [%s]",
 459                     ip6_sprintf(&ip6->ip6_dst));
 460                 break;
 461         }
 462
 463         if (oif)
 464                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
 465                     name, action, proto, if_name(oif));
 466         else if (rif)
 467                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
 468                     name, action, proto, if_name(rif));
 469         else
 470                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
 471                     name, action, proto);
 472         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
 473             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
 474                 f ? f->fw_number : -1);
 475 }
 476
 477 /*
 478  * Parameters:
 479  *
 480  *      ip      Pointer to packet header (struct ip6_hdr *)
 481  *      hlen    Packet header length
 482  *      oif     Outgoing interface, or NULL if packet is incoming
 483  * #ifndef IP6FW_DIVERT_RESTART
 484  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
 485  * #else
 486  *      *cookie Skip up to the first rule past this rule number;
 487  * #endif
 488  *      *m      The packet; we set to NULL when/if we nuke it.
 489  *
 490  * Return value:
 491  *
 492  *      0       The packet is to be accepted and routed normally OR
 493  *              the packet was denied/rejected and has been dropped;
 494  *              in the latter case, *m is equal to NULL upon return.
 495  *      port    Divert the packet to port.
 496  */
 497
 498 static int
 499 ip6_fw_chk(struct ip6_hdr **pip6,
 500         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
 501 {
 502         struct ip6_fw_chain *chain;
 503         struct ip6_fw *rule = NULL;
 504         struct ip6_hdr *ip6 = *pip6;
 505         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
 506         u_short offset = 0;
 507         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
 508         u_short src_port, dst_port;
 509 #ifdef  IP6FW_DIVERT_RESTART
 510         u_int16_t skipto = *cookie;
 511 #else
 512         u_int16_t ignport = ntohs(*cookie);
 513 #endif
 514
 515         *cookie = 0;
 516         /*
 517          * Go down the chain, looking for enlightment
 518          * #ifdef IP6FW_DIVERT_RESTART
 519          * If we've been asked to start at a given rule immediatly, do so.
 520          * #endif
 521          */
 522         chain = LIST_FIRST(&ip6_fw_chain);
 523 #ifdef IP6FW_DIVERT_RESTART
 524         if (skipto) {
 525                 if (skipto >= 65535)
 526                         goto dropit;
 527                 while (chain && (chain->rule->fw_number <= skipto)) {
 528                         chain = LIST_NEXT(chain, chain);
 529                 }
 530                 if (! chain) goto dropit;
 531         }
 532 #endif /* IP6FW_DIVERT_RESTART */
 533         for (; chain; chain = LIST_NEXT(chain, chain)) {
 534                 struct ip6_fw *const f = chain->rule;
 535
 536                 if (oif) {
 537                         /* Check direction outbound */
 538                         if (!(f->fw_flg & IPV6_FW_F_OUT))
 539                                 continue;
 540                 } else {
 541                         /* Check direction inbound */
 542                         if (!(f->fw_flg & IPV6_FW_F_IN))
 543                                 continue;
 544                 }
 545
 546 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
 547         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
 548         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
 549         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
 550         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
 551
 552                 /* If src-addr doesn't match, not this rule. */
 553                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
 554                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
 555                         continue;
 556
 557                 /* If dest-addr doesn't match, not this rule. */
 558                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
 559                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
 560                         continue;
 561
 562 #undef IN6_ARE_ADDR_MASKEQUAL
 563                 /* Interface check */
 564                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 565                         struct ifnet *const iface = oif ? oif : rif;
 566
 567                         /* Backwards compatibility hack for "via" */
 568                         if (!iface || !iface_match(iface,
 569                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
 570                                 continue;
 571                 } else {
 572                         /* Check receive interface */
 573                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
 574                             && (!rif || !iface_match(rif,
 575                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
 576                                 continue;
 577                         /* Check outgoing interface */
 578                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
 579                             && (!oif || !iface_match(oif,
 580                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
 581                                 continue;
 582                 }
 583
 584                 /* Check IP options */
 585                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
 586                         continue;
 587
 588                 /* Fragments */
 589                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
 590                         continue;
 591
 592                 /* Check protocol; if wildcard, match */
 593                 if (f->fw_prot == IPPROTO_IPV6)
 594                         goto got_match;
 595
 596                 /* If different, don't match */
 597                 if (nxt != f->fw_prot)
 598                         continue;
 599
 600 #define PULLUP_TO(len)  do {                                            \
 601                             if ((*m)->m_len < (len)                     \
 602                                 && (*m = m_pullup(*m, (len))) == 0) {   \
 603                                     goto dropit;                        \
 604                             }                                           \
 605                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
 606                         } while (0)
 607
 608                 /* Protocol specific checks */
 609                 switch (nxt) {
 610                 case IPPROTO_TCP:
 611                     {
 612                         struct tcphdr *tcp6;
 613
 614                         if (offset == 1) {      /* cf. RFC 1858 */
 615                                 PULLUP_TO(off + 4); /* XXX ? */
 616                                 goto bogusfrag;
 617                         }
 618                         if (offset != 0) {
 619                                 /*
 620                                  * TCP flags and ports aren't available in this
 621                                  * packet -- if this rule specified either one,
 622                                  * we consider the rule a non-match.
 623                                  */
 624                                 if (f->fw_nports != 0 ||
 625                                     f->fw_tcpf != f->fw_tcpnf)
 626                                         continue;
 627
 628                                 break;
 629                         }
 630                         PULLUP_TO(off + 14);
 631                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
 632                         if (((f->fw_tcpf != f->fw_tcpnf) ||
 633                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
 634                            !tcp6flg_match(tcp6, f))
 635                                 continue;
 636                         src_port = ntohs(tcp6->th_sport);
 637                         dst_port = ntohs(tcp6->th_dport);
 638                         goto check_ports;
 639                     }
 640
 641                 case IPPROTO_UDP:
 642                     {
 643                         struct udphdr *udp;
 644
 645                         if (offset != 0) {
 646                                 /*
 647                                  * Port specification is unavailable -- if this
 648                                  * rule specifies a port, we consider the rule
 649                                  * a non-match.
 650                                  */
 651                                 if (f->fw_nports != 0)
 652                                         continue;
 653
 654                                 break;
 655                         }
 656                         PULLUP_TO(off + 4);
 657                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
 658                         src_port = ntohs(udp->uh_sport);
 659                         dst_port = ntohs(udp->uh_dport);
 660 check_ports:
 661                         if (!port_match6(&f->fw_pts[0],
 662                             IPV6_FW_GETNSRCP(f), src_port,
 663                             f->fw_flg & IPV6_FW_F_SRNG))
 664                                 continue;
 665                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
 666                             IPV6_FW_GETNDSTP(f), dst_port,
 667                             f->fw_flg & IPV6_FW_F_DRNG))
 668                                 continue;
 669                         break;
 670                     }
 671
 672                 case IPPROTO_ICMPV6:
 673                     {
 674                         struct icmp6_hdr *icmp;
 675
 676                         if (offset != 0)        /* Type isn't valid */
 677                                 break;
 678                         PULLUP_TO(off + 2);
 679                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
 680                         if (!icmp6type_match(icmp, f))
 681                                 continue;
 682                         break;
 683                     }
 684 #undef PULLUP_TO
 685
 686 bogusfrag:
 687                         if (fw6_verbose)
 688                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
 689                         goto dropit;
 690                 }
 691
 692 got_match:
 693 #ifndef IP6FW_DIVERT_RESTART
 694                 /* Ignore divert/tee rule if socket port is "ignport" */
 695                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 696                 case IPV6_FW_F_DIVERT:
 697                 case IPV6_FW_F_TEE:
 698                         if (f->fw_divert_port == ignport)
 699                                 continue;       /* ignore this rule */
 700                         break;
 701                 }
 702
 703 #endif /* IP6FW_DIVERT_RESTART */
 704                 /* Update statistics */
 705                 f->fw_pcnt += 1;
 706                 f->fw_bcnt += ntohs(ip6->ip6_plen);
 707                 f->timestamp = time_second;
 708
 709                 /* Log to console if desired */
 710                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
 711                         ip6fw_report(f, ip6, rif, oif, off, nxt);
 712
 713                 /* Take appropriate action */
 714                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 715                 case IPV6_FW_F_ACCEPT:
 716                         return(0);
 717                 case IPV6_FW_F_COUNT:
 718                         continue;
 719                 case IPV6_FW_F_DIVERT:
 720 #ifdef IP6FW_DIVERT_RESTART
 721                         *cookie = f->fw_number;
 722 #else
 723                         *cookie = htons(f->fw_divert_port);
 724 #endif /* IP6FW_DIVERT_RESTART */
 725                         return(f->fw_divert_port);
 726                 case IPV6_FW_F_TEE:
 727                         /*
 728                          * XXX someday tee packet here, but beware that you
 729                          * can't use m_copym() or m_copypacket() because
 730                          * the divert input routine modifies the mbuf
 731                          * (and these routines only increment reference
 732                          * counts in the case of mbuf clusters), so need
 733                          * to write custom routine.
 734                          */
 735                         continue;
 736                 case IPV6_FW_F_SKIPTO:
 737 #ifdef DIAGNOSTIC
 738                         while (chain->chain.le_next
 739                             && chain->chain.le_next->rule->fw_number
 740                                 < f->fw_skipto_rule)
 741 #else
 742                         while (chain->chain.le_next->rule->fw_number
 743                             < f->fw_skipto_rule)
 744 #endif
 745                                 chain = chain->chain.le_next;
 746                         continue;
 747                 }
 748
 749                 /* Deny/reject this packet using this rule */
 750                 rule = f;
 751                 break;
 752         }
 753
 754 #ifdef DIAGNOSTIC
 755         /* Rule 65535 should always be there and should always match */
 756         if (!chain)
 757                 panic("ip6_fw: chain");
 758 #endif
 759
 760         /*
 761          * At this point, we're going to drop the packet.
 762          * Send a reject notice if all of the following are true:
 763          *
 764          * - The packet matched a reject rule
 765          * - The packet is not an ICMP packet, or is an ICMP query packet
 766          * - The packet is not a multicast or broadcast packet
 767          */
 768         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
 769             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
 770             && !((*m)->m_flags & (M_BCAST|M_MCAST))
 771             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 772                 switch (rule->fw_reject_code) {
 773                 case IPV6_FW_REJECT_RST:
 774                   {
 775                         struct tcphdr *const tcp =
 776                                 (struct tcphdr *) ((caddr_t)ip6 + off);
 777                         struct {
 778                                 struct ip6_hdr ip6;
 779                                 struct tcphdr th;
 780                         } ti;
 781                         tcp_seq ack, seq;
 782                         int flags;
 783
 784                         if (offset != 0 || (tcp->th_flags & TH_RST))
 785                                 break;
 786
 787                         ti.ip6 = *ip6;
 788                         ti.th = *tcp;
 789                         ti.th.th_seq = ntohl(ti.th.th_seq);
 790                         ti.th.th_ack = ntohl(ti.th.th_ack);
 791                         ti.ip6.ip6_nxt = IPPROTO_TCP;
 792                         if (ti.th.th_flags & TH_ACK) {
 793                                 ack = 0;
 794                                 seq = ti.th.th_ack;
 795                                 flags = TH_RST;
 796                         } else {
 797                                 ack = ti.th.th_seq;
 798                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
 799                                         ack += (*m)->m_pkthdr.len - off
 800                                                 - (ti.th.th_off << 2);
 801                                 } else if (ip6->ip6_plen) {
 802                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
 803                                                 - off - (ti.th.th_off << 2);
 804                                 } else {
 805                                         m_freem(*m);
 806                                         *m = 0;
 807                                         break;
 808                                 }
 809                                 seq = 0;
 810                                 flags = TH_RST|TH_ACK;
 811                         }
 812                         bcopy(&ti, ip6, sizeof(ti));
 813                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
 814                                 *m, ack, seq, flags);
 815                         *m = NULL;
 816                         break;
 817                   }
 818                 default:        /* Send an ICMP unreachable using code */
 819                         if (oif)
 820                                 (*m)->m_pkthdr.rcvif = oif;
 821                         icmp6_error(*m, ICMP6_DST_UNREACH,
 822                             rule->fw_reject_code, 0);
 823                         *m = NULL;
 824                         break;
 825                 }
 826         }
 827
 828 dropit:
 829         /*
 830          * Finally, drop the packet.
 831          */
 832         if (*m) {
 833                 m_freem(*m);
 834                 *m = NULL;
 835         }
 836         return(0);
 837 }
 838
 839 static int
 840 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
 841 {
 842         struct ip6_fw *ftmp = 0;
 843         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
 844         u_short nbr = 0;
 845
 846         fwc = kmalloc(sizeof *fwc, M_IP6FW, M_INTWAIT);
 847         ftmp = kmalloc(sizeof *ftmp, M_IP6FW, M_INTWAIT);
 848
 849         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
 850         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
 851         ftmp->fw_pcnt = 0L;
 852         ftmp->fw_bcnt = 0L;
 853         fwc->rule = ftmp;
 854
 855         crit_enter();
 856
 857         if (!chainptr->lh_first) {
 858                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 859                 crit_exit();
 860                 return(0);
 861         } else if (ftmp->fw_number == (u_short)-1) {
 862                 if (fwc)  kfree(fwc, M_IP6FW);
 863                 if (ftmp) kfree(ftmp, M_IP6FW);
 864                 crit_exit();
 865                 dprintf(("%s bad rule number\n", err_prefix));
 866                 return (EINVAL);
 867         }
 868
 869         /* If entry number is 0, find highest numbered rule and add 100 */
 870         if (ftmp->fw_number == 0) {
 871                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 872                         if (fcp->rule->fw_number != (u_short)-1)
 873                                 nbr = fcp->rule->fw_number;
 874                         else
 875                                 break;
 876                 }
 877                 if (nbr < (u_short)-1 - 100)
 878                         nbr += 100;
 879                 ftmp->fw_number = nbr;
 880         }
 881
 882         /* Got a valid number; now insert it, keeping the list ordered */
 883         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 884                 if (fcp->rule->fw_number > ftmp->fw_number) {
 885                         if (fcpl) {
 886                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
 887                         } else {
 888                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 889                         }
 890                         break;
 891                 } else {
 892                         fcpl = fcp;
 893                 }
 894         }
 895
 896         crit_exit();
 897         return (0);
 898 }
 899
 900 static int
 901 del_entry6(struct ip6_fw_head *chainptr, u_short number)
 902 {
 903         struct ip6_fw_chain *fcp;
 904
 905         crit_enter();
 906
 907         fcp = chainptr->lh_first;
 908         if (number != (u_short)-1) {
 909                 for (; fcp; fcp = fcp->chain.le_next) {
 910                         if (fcp->rule->fw_number == number) {
 911                                 LIST_REMOVE(fcp, chain);
 912                                 crit_exit();
 913                                 kfree(fcp->rule, M_IP6FW);
 914                                 kfree(fcp, M_IP6FW);
 915                                 return 0;
 916                         }
 917                 }
 918         }
 919
 920         crit_exit();
 921         return (EINVAL);
 922 }
 923
 924 static int
 925 zero_entry6(struct mbuf *m)
 926 {
 927         struct ip6_fw *frwl;
 928         struct ip6_fw_chain *fcp;
 929
 930         if (m && m->m_len != 0) {
 931                 if (m->m_len != sizeof(struct ip6_fw))
 932                         return(EINVAL);
 933                 frwl = mtod(m, struct ip6_fw *);
 934         }
 935         else
 936                 frwl = NULL;
 937
 938         /*
 939          *      It's possible to insert multiple chain entries with the
 940          *      same number, so we don't stop after finding the first
 941          *      match if zeroing a specific entry.
 942          */
 943         crit_enter();
 944         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
 945                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
 946                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
 947                         fcp->rule->timestamp = 0;
 948                 }
 949         crit_exit();
 950
 951         if (fw6_verbose) {
 952                 if (frwl)
 953                         log(LOG_SECURITY | LOG_NOTICE,
 954                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
 955                 else
 956                         log(LOG_SECURITY | LOG_NOTICE,
 957                             "ip6fw: Accounting cleared.\n");
 958         }
 959
 960         return(0);
 961 }
 962
 963 static struct ip6_fw *
 964 check_ip6fw_mbuf(struct mbuf *m)
 965 {
 966         /* Check length */
 967         if (m->m_len != sizeof(struct ip6_fw)) {
 968                 dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
 969                     sizeof(struct ip6_fw)));
 970                 return (NULL);
 971         }
 972         return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
 973 }
 974
 975 static struct ip6_fw *
 976 check_ip6fw_struct(struct ip6_fw *frwl)
 977 {
 978         /* Check for invalid flag bits */
 979         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
 980                 dprintf(("%s undefined flag bits set (flags=%x)\n",
 981                     err_prefix, frwl->fw_flg));
 982                 return (NULL);
 983         }
 984         /* Must apply to incoming or outgoing (or both) */
 985         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
 986                 dprintf(("%s neither in nor out\n", err_prefix));
 987                 return (NULL);
 988         }
 989         /* Empty interface name is no good */
 990         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
 991               && !*frwl->fw_in_if.fu_via_if.name)
 992             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
 993               && !*frwl->fw_out_if.fu_via_if.name)) {
 994                 dprintf(("%s empty interface name\n", err_prefix));
 995                 return (NULL);
 996         }
 997         /* Sanity check interface matching */
 998         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 999                 ;               /* allow "via" backwards compatibility */
1000         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1001             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1002                 dprintf(("%s outgoing interface check on incoming\n",
1003                     err_prefix));
1004                 return (NULL);
1005         }
1006         /* Sanity check port ranges */
1007         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1008                 dprintf(("%s src range set but n_src_p=%d\n",
1009                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1010                 return (NULL);
1011         }
1012         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1013                 dprintf(("%s dst range set but n_dst_p=%d\n",
1014                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1015                 return (NULL);
1016         }
1017         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1018                 dprintf(("%s too many ports (%d+%d)\n",
1019                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1020                 return (NULL);
1021         }
1022         /*
1023          *      Protocols other than TCP/UDP don't use port range
1024          */
1025         if ((frwl->fw_prot != IPPROTO_TCP) &&
1026             (frwl->fw_prot != IPPROTO_UDP) &&
1027             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1028                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1029                     err_prefix));
1030                 return(NULL);
1031         }
1032
1033         /*
1034          *      Rather than modify the entry to make such entries work,
1035          *      we reject this rule and require user level utilities
1036          *      to enforce whatever policy they deem appropriate.
1037          */
1038         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1039                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1040                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1041                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1042                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1043                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1044                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1045                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1046                 dprintf(("%s rule never matches\n", err_prefix));
1047                 return(NULL);
1048         }
1049
1050         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1051                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1052                 if (frwl->fw_nports) {
1053                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1054                         return(NULL);
1055                 }
1056                 if (frwl->fw_prot == IPPROTO_TCP &&
1057                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1058                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1059                         return(NULL);
1060                 }
1061         }
1062
1063         /* Check command specific stuff */
1064         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1065         {
1066         case IPV6_FW_F_REJECT:
1067                 if (frwl->fw_reject_code >= 0x100
1068                     && !(frwl->fw_prot == IPPROTO_TCP
1069                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1070                         dprintf(("%s unknown reject code\n", err_prefix));
1071                         return(NULL);
1072                 }
1073                 break;
1074         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1075         case IPV6_FW_F_TEE:
1076                 if (frwl->fw_divert_port == 0) {
1077                         dprintf(("%s can't divert to port 0\n", err_prefix));
1078                         return (NULL);
1079                 }
1080                 break;
1081         case IPV6_FW_F_DENY:
1082         case IPV6_FW_F_ACCEPT:
1083         case IPV6_FW_F_COUNT:
1084         case IPV6_FW_F_SKIPTO:
1085                 break;
1086         default:
1087                 dprintf(("%s invalid command\n", err_prefix));
1088                 return(NULL);
1089         }
1090
1091         return frwl;
1092 }
1093
1094 static int
1095 ip6_fw_ctl(int stage, struct mbuf **mm)
1096 {
1097         int error;
1098         struct mbuf *m;
1099
1100         if (stage == IPV6_FW_GET) {
1101                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1102                 *mm = m = m_get(MB_WAIT, MT_DATA); /* XXX */
1103                 if (!m)
1104                         return(ENOBUFS);
1105                 if (sizeof *(fcp->rule) > MLEN) {
1106                         MCLGET(m, MB_WAIT);
1107                         if ((m->m_flags & M_EXT) == 0) {
1108                                 m_free(m);
1109                                 return(ENOBUFS);
1110                         }
1111                 }
1112                 for (; fcp; fcp = fcp->chain.le_next) {
1113                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1114                         m->m_len = sizeof *(fcp->rule);
1115                         m->m_next = m_get(MB_WAIT, MT_DATA); /* XXX */
1116                         if (!m->m_next) {
1117                                 m_freem(*mm);
1118                                 return(ENOBUFS);
1119                         }
1120                         m = m->m_next;
1121                         if (sizeof *(fcp->rule) > MLEN) {
1122                                 MCLGET(m, MB_WAIT);
1123                                 if ((m->m_flags & M_EXT) == 0) {
1124                                         m_freem(*mm);
1125                                         return(ENOBUFS);
1126                                 }
1127                         }
1128                         m->m_len = 0;
1129                 }
1130                 return (0);
1131         }
1132         m = *mm;
1133         /* only allow get calls if secure mode > 2 */
1134         if (securelevel > 2) {
1135                 if (m) {
1136                         m_freem(m);
1137                         *mm = 0;
1138                 }
1139                 return(EPERM);
1140         }
1141         if (stage == IPV6_FW_FLUSH) {
1142                 while (ip6_fw_chain.lh_first != NULL &&
1143                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1144                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1145                         crit_enter();
1146                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1147                         crit_exit();
1148                         kfree(fcp->rule, M_IP6FW);
1149                         kfree(fcp, M_IP6FW);
1150                 }
1151                 if (m) {
1152                         m_freem(m);
1153                         *mm = 0;
1154                 }
1155                 return (0);
1156         }
1157         if (stage == IPV6_FW_ZERO) {
1158                 error = zero_entry6(m);
1159                 if (m) {
1160                         m_freem(m);
1161                         *mm = 0;
1162                 }
1163                 return (error);
1164         }
1165         if (m == NULL) {
1166                 kprintf("%s NULL mbuf ptr\n", err_prefix);
1167                 return (EINVAL);
1168         }
1169
1170         if (stage == IPV6_FW_ADD) {
1171                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1172
1173                 if (!frwl)
1174                         error = EINVAL;
1175                 else
1176                         error = add_entry6(&ip6_fw_chain, frwl);
1177                 if (m) {
1178                         m_freem(m);
1179                         *mm = 0;
1180                 }
1181                 return error;
1182         }
1183         if (stage == IPV6_FW_DEL) {
1184                 if (m->m_len != sizeof(struct ip6_fw)) {
1185                         dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1186                             sizeof(struct ip6_fw)));
1187                         error = EINVAL;
1188                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1189                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1190                         error = EINVAL;
1191                 } else
1192                         error = del_entry6(&ip6_fw_chain,
1193                             mtod(m, struct ip6_fw *)->fw_number);
1194                 if (m) {
1195                         m_freem(m);
1196                         *mm = 0;
1197                 }
1198                 return error;
1199         }
1200
1201         dprintf(("%s unknown request %d\n", err_prefix, stage));
1202         if (m) {
1203                 m_freem(m);
1204                 *mm = 0;
1205         }
1206         return (EINVAL);
1207 }
1208
1209 void
1210 ip6_fw_init(void)
1211 {
1212         struct ip6_fw default_rule;
1213
1214         ip6_fw_chk_ptr = ip6_fw_chk;
1215         ip6_fw_ctl_ptr = ip6_fw_ctl;
1216         LIST_INIT(&ip6_fw_chain);
1217
1218         bzero(&default_rule, sizeof default_rule);
1219         default_rule.fw_prot = IPPROTO_IPV6;
1220         default_rule.fw_number = (u_short)-1;
1221 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1222         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1223 #else
1224         default_rule.fw_flg |= IPV6_FW_F_DENY;
1225 #endif
1226         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1227         if (check_ip6fw_struct(&default_rule) == NULL ||
1228                 add_entry6(&ip6_fw_chain, &default_rule))
1229                 panic(__func__);
1230
1231         kprintf("IPv6 packet filtering initialized, ");
1232 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1233         kprintf("default to accept, ");
1234 #endif
1235 #ifndef IPV6FIREWALL_VERBOSE
1236         kprintf("logging disabled\n");
1237 #else
1238         if (fw6_verbose_limit == 0)
1239                 kprintf("unlimited logging\n");
1240         else
1241                 kprintf("logging limited to %d packets/entry\n",
1242                     fw6_verbose_limit);
1243 #endif
1244 }
1245
1246 static ip6_fw_chk_t *old_chk_ptr;
1247 static ip6_fw_ctl_t *old_ctl_ptr;
1248
1249 static int
1250 ip6fw_modevent(module_t mod, int type, void *unused)
1251 {
1252         switch (type) {
1253         case MOD_LOAD:
1254                 crit_enter();
1255
1256                 old_chk_ptr = ip6_fw_chk_ptr;
1257                 old_ctl_ptr = ip6_fw_ctl_ptr;
1258
1259                 ip6_fw_init();
1260                 crit_exit();
1261                 return 0;
1262         case MOD_UNLOAD:
1263                 crit_enter();
1264                 ip6_fw_chk_ptr =  old_chk_ptr;
1265                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1266                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1267                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1268                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1269                         kfree(fcp->rule, M_IP6FW);
1270                         kfree(fcp, M_IP6FW);
1271                 }
1272
1273                 crit_exit();
1274                 kprintf("IPv6 firewall unloaded\n");
1275                 return 0;
1276         default:
1277                 break;
1278         }
1279         return 0;
1280 }
1281
1282 static moduledata_t ip6fwmod = {
1283         "ip6fw",
1284         ip6fw_modevent,
1285         0
1286 };
1287 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);