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 /*      $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/socket.h>
  72 #include <sys/socketvar.h>
  73 #include <sys/syslog.h>
  74 #include <sys/thread2.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 "ip6_fw.h"
  90 #include <netinet/ip_var.h>
  91 #include <netinet/tcp.h>
  92 #include <netinet/tcp_seq.h>
  93 #include <netinet/tcp_timer.h>
  94 #include <netinet/tcp_var.h>
  95 #include <netinet/udp.h>
  96
  97 #include <sys/sysctl.h>
  98
  99 #include <net/net_osdep.h>
 100
 101 MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
 102
 103 static int fw6_debug = 1;
 104 #ifdef IPV6FIREWALL_VERBOSE
 105 static int fw6_verbose = 1;
 106 #else
 107 static int fw6_verbose = 0;
 108 #endif
 109 #ifdef IPV6FIREWALL_VERBOSE_LIMIT
 110 static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
 111 #else
 112 static int fw6_verbose_limit = 0;
 113 #endif
 114
 115 LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
 116
 117 #ifdef SYSCTL_NODE
 118 SYSCTL_DECL(_net_inet6_ip6);
 119 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
 120 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW,
 121         &ip6_fw_enable, 0, "Enable ip6fw");
 122 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
 123 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW, &fw6_verbose, 0, "");
 124 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
 125 #endif
 126
 127 #define dprintf(a)      do {                                            \
 128                                 if (fw6_debug)                          \
 129                                         kprintf a;                      \
 130                         } while (0)
 131 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
 132
 133 static int      add_entry6 (struct ip6_fw_head *chainptr, struct ip6_fw *frwl);
 134 static int      del_entry6 (struct ip6_fw_head *chainptr, u_short number);
 135 static int      zero_entry6 (struct mbuf *m);
 136 static struct ip6_fw *check_ip6fw_struct (struct ip6_fw *m);
 137 static struct ip6_fw *check_ip6fw_mbuf (struct mbuf *fw);
 138 static int      ip6opts_match (struct ip6_hdr **ip6, struct ip6_fw *f,
 139                                    struct mbuf **m,
 140                                    int *off, int *nxt, u_short *offset);
 141 static int      port_match6 (u_short *portptr, int nports, u_short port,
 142                                 int range_flag);
 143 static int      tcp6flg_match (struct tcphdr *tcp6, struct ip6_fw *f);
 144 static int      icmp6type_match (struct icmp6_hdr *  icmp, struct ip6_fw * f);
 145 static void     ip6fw_report (struct ip6_fw *f, struct ip6_hdr *ip6,
 146                                 struct ifnet *rif, struct ifnet *oif, int off, int nxt);
 147
 148 static int      ip6_fw_chk (struct ip6_hdr **pip6,
 149                         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m);
 150 static int      ip6_fw_ctl (int stage, struct mbuf **mm);
 151
 152 static char err_prefix[] = "ip6_fw_ctl:";
 153
 154 /*
 155  * Returns 1 if the port is matched by the vector, 0 otherwise
 156  */
 157 static
 158 __inline int
 159 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
 160 {
 161         if (!nports)
 162                 return 1;
 163         if (range_flag) {
 164                 if (portptr[0] <= port && port <= portptr[1]) {
 165                         return 1;
 166                 }
 167                 nports -= 2;
 168                 portptr += 2;
 169         }
 170         while (nports-- > 0) {
 171                 if (*portptr++ == port) {
 172                         return 1;
 173                 }
 174         }
 175         return 0;
 176 }
 177
 178 static int
 179 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
 180 {
 181         u_char          flg_set, flg_clr;
 182
 183         /*
 184          * If an established connection is required, reject packets that
 185          * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
 186          * other flag requirements.
 187          */
 188         if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
 189             ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
 190             IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
 191                 return 0;
 192
 193         flg_set = tcp6->th_flags & f->fw_tcpf;
 194         flg_clr = tcp6->th_flags & f->fw_tcpnf;
 195
 196         if (flg_set != f->fw_tcpf)
 197                 return 0;
 198         if (flg_clr)
 199                 return 0;
 200
 201         return 1;
 202 }
 203
 204 static int
 205 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
 206 {
 207         int type;
 208
 209         if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
 210                 return(1);
 211
 212         type = icmp6->icmp6_type;
 213
 214         /* check for matching type in the bitmap */
 215         if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
 216                 (f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
 217                 (1U << (type % (8 * sizeof(unsigned))))))
 218                 return(1);
 219
 220         return(0); /* no match */
 221 }
 222
 223 static int
 224 is_icmp6_query(struct ip6_hdr *ip6, int off)
 225 {
 226         const struct icmp6_hdr *icmp6;
 227         int icmp6_type;
 228
 229         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 230         icmp6_type = icmp6->icmp6_type;
 231
 232         if (icmp6_type == ICMP6_ECHO_REQUEST ||
 233             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
 234             icmp6_type == ICMP6_WRUREQUEST ||
 235             icmp6_type == ICMP6_FQDN_QUERY ||
 236             icmp6_type == ICMP6_NI_QUERY)
 237                 return(1);
 238
 239         return(0);
 240 }
 241
 242 static int
 243 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
 244               int *off, int *nxt, u_short *offset)
 245 {
 246         int len;
 247         struct ip6_hdr *ip6 = *pip6;
 248         struct ip6_ext *ip6e;
 249         u_char  opts, nopts, nopts_sve;
 250
 251         opts = f->fw_ip6opt;
 252         nopts = nopts_sve = f->fw_ip6nopt;
 253
 254         *nxt = ip6->ip6_nxt;
 255         *off = sizeof(struct ip6_hdr);
 256         len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
 257         while (*off < len) {
 258                 ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
 259                 if ((*m)->m_len < *off + sizeof(*ip6e))
 260                         goto opts_check;        /* XXX */
 261
 262                 switch(*nxt) {
 263                 case IPPROTO_FRAGMENT:
 264                         if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
 265                                 struct ip6_frag *ip6f;
 266
 267                                 ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
 268                                 *offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
 269                         }
 270                         opts &= ~IPV6_FW_IP6OPT_FRAG;
 271                         nopts &= ~IPV6_FW_IP6OPT_FRAG;
 272                         *off += sizeof(struct ip6_frag);
 273                         break;
 274                 case IPPROTO_AH:
 275                         opts &= ~IPV6_FW_IP6OPT_AH;
 276                         nopts &= ~IPV6_FW_IP6OPT_AH;
 277                         *off += (ip6e->ip6e_len + 2) << 2;
 278                         break;
 279                 default:
 280                         switch (*nxt) {
 281                         case IPPROTO_HOPOPTS:
 282                                 opts &= ~IPV6_FW_IP6OPT_HOPOPT;
 283                                 nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
 284                                 break;
 285                         case IPPROTO_ROUTING:
 286                                 opts &= ~IPV6_FW_IP6OPT_ROUTE;
 287                                 nopts &= ~IPV6_FW_IP6OPT_ROUTE;
 288                                 break;
 289                         case IPPROTO_ESP:
 290                                 opts &= ~IPV6_FW_IP6OPT_ESP;
 291                                 nopts &= ~IPV6_FW_IP6OPT_ESP;
 292                                 goto opts_check;
 293                         case IPPROTO_NONE:
 294                                 opts &= ~IPV6_FW_IP6OPT_NONXT;
 295                                 nopts &= ~IPV6_FW_IP6OPT_NONXT;
 296                                 goto opts_check;
 297                         case IPPROTO_DSTOPTS:
 298                                 opts &= ~IPV6_FW_IP6OPT_OPTS;
 299                                 nopts &= ~IPV6_FW_IP6OPT_OPTS;
 300                                 break;
 301                         default:
 302                                 goto opts_check;
 303                         }
 304                         *off += (ip6e->ip6e_len + 1) << 3;
 305                         break;
 306                 }
 307                 *nxt = ip6e->ip6e_nxt;
 308
 309         }
 310  opts_check:
 311         if (f->fw_ip6opt == f->fw_ip6nopt)      /* XXX */
 312                 return 1;
 313
 314         if (opts == 0 && nopts == nopts_sve)
 315                 return 1;
 316         else
 317                 return 0;
 318 }
 319
 320 static
 321 __inline int
 322 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
 323 {
 324         /* Check by name or by IP address */
 325         if (byname) {
 326                 /* Check name */
 327                 if (ifu->fu_via_if.glob) {
 328                         if (kfnmatch(ifu->fu_via_if.name, ifp->if_xname, 0)
 329                             == FNM_NOMATCH)
 330                                 return(0);
 331                 } else {
 332                         if (strncmp(ifp->if_xname, ifu->fu_via_if.name,
 333                             IP6FW_IFNLEN) != 0)
 334                                 return(0);
 335                 }
 336                 return(1);
 337         } else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {        /* Zero == wildcard */
 338                 struct ifaddr_container *ifac;
 339
 340                 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
 341                         struct ifaddr *ifa = ifac->ifa;
 342
 343                         if (ifa->ifa_addr == NULL)
 344                                 continue;
 345                         if (ifa->ifa_addr->sa_family != AF_INET6)
 346                                 continue;
 347                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
 348                             &(((struct sockaddr_in6 *)
 349                             (ifa->ifa_addr))->sin6_addr)))
 350                                 continue;
 351                         return(1);
 352                 }
 353                 return(0);
 354         }
 355         return(1);
 356 }
 357
 358 static void
 359 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
 360         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
 361 {
 362         static int counter;
 363         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
 364         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
 365         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
 366         int count;
 367         char *action;
 368         char action2[32], proto[102], name[18];
 369         int len;
 370
 371         count = f ? f->fw_pcnt : ++counter;
 372         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
 373                 return;
 374
 375         /* Print command name */
 376         ksnprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
 377
 378         action = action2;
 379         if (!f)
 380                 action = "Refuse";
 381         else {
 382                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 383                 case IPV6_FW_F_DENY:
 384                         action = "Deny";
 385                         break;
 386                 case IPV6_FW_F_REJECT:
 387                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
 388                                 action = "Reset";
 389                         else
 390                                 action = "Unreach";
 391                         break;
 392                 case IPV6_FW_F_ACCEPT:
 393                         action = "Accept";
 394                         break;
 395                 case IPV6_FW_F_COUNT:
 396                         action = "Count";
 397                         break;
 398                 case IPV6_FW_F_DIVERT:
 399                         ksnprintf(SNPARGS(action2, 0), "Divert %d",
 400                             f->fw_divert_port);
 401                         break;
 402                 case IPV6_FW_F_TEE:
 403                         ksnprintf(SNPARGS(action2, 0), "Tee %d",
 404                             f->fw_divert_port);
 405                         break;
 406                 case IPV6_FW_F_SKIPTO:
 407                         ksnprintf(SNPARGS(action2, 0), "SkipTo %d",
 408                             f->fw_skipto_rule);
 409                         break;
 410                 default:
 411                         action = "UNKNOWN";
 412                         break;
 413                 }
 414         }
 415
 416         switch (nxt) {
 417         case IPPROTO_TCP:
 418                 len = ksnprintf(SNPARGS(proto, 0), "TCP [%s]",
 419                     ip6_sprintf(&ip6->ip6_src));
 420                 if (off > 0)
 421                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
 422                             ntohs(tcp6->th_sport));
 423                 else
 424                         len += ksnprintf(SNPARGS(proto, len), " ");
 425                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 426                     ip6_sprintf(&ip6->ip6_dst));
 427                 if (off > 0)
 428                         ksnprintf(SNPARGS(proto, len), ":%d",
 429                             ntohs(tcp6->th_dport));
 430                 break;
 431         case IPPROTO_UDP:
 432                 len = ksnprintf(SNPARGS(proto, 0), "UDP [%s]",
 433                     ip6_sprintf(&ip6->ip6_src));
 434                 if (off > 0)
 435                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
 436                             ntohs(udp->uh_sport));
 437                 else
 438                     len += ksnprintf(SNPARGS(proto, len), " ");
 439                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 440                     ip6_sprintf(&ip6->ip6_dst));
 441                 if (off > 0)
 442                         ksnprintf(SNPARGS(proto, len), ":%d",
 443                             ntohs(udp->uh_dport));
 444                 break;
 445         case IPPROTO_ICMPV6:
 446                 if (off > 0)
 447                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
 448                             icmp6->icmp6_type, icmp6->icmp6_code);
 449                 else
 450                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
 451                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 452                     ip6_sprintf(&ip6->ip6_src));
 453                 ksnprintf(SNPARGS(proto, len), " [%s]",
 454                     ip6_sprintf(&ip6->ip6_dst));
 455                 break;
 456         default:
 457                 len = ksnprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
 458                     ip6_sprintf(&ip6->ip6_src));
 459                 ksnprintf(SNPARGS(proto, len), " [%s]",
 460                     ip6_sprintf(&ip6->ip6_dst));
 461                 break;
 462         }
 463
 464         if (oif)
 465                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
 466                     name, action, proto, if_name(oif));
 467         else if (rif)
 468                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
 469                     name, action, proto, if_name(rif));
 470         else
 471                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
 472                     name, action, proto);
 473         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
 474             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
 475                 f ? f->fw_number : -1);
 476 }
 477
 478 /*
 479  * Parameters:
 480  *
 481  *      ip      Pointer to packet header (struct ip6_hdr *)
 482  *      hlen    Packet header length
 483  *      oif     Outgoing interface, or NULL if packet is incoming
 484  * #ifndef IP6FW_DIVERT_RESTART
 485  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
 486  * #else
 487  *      *cookie Skip up to the first rule past this rule number;
 488  * #endif
 489  *      *m      The packet; we set to NULL when/if we nuke it.
 490  *
 491  * Return value:
 492  *
 493  *      0       The packet is to be accepted and routed normally OR
 494  *              the packet was denied/rejected and has been dropped;
 495  *              in the latter case, *m is equal to NULL upon return.
 496  *      port    Divert the packet to port.
 497  */
 498
 499 static int
 500 ip6_fw_chk(struct ip6_hdr **pip6,
 501         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
 502 {
 503         struct ip6_fw_chain *chain;
 504         struct ip6_fw *rule = NULL;
 505         struct ip6_hdr *ip6 = *pip6;
 506         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
 507         u_short offset = 0;
 508         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
 509         u_short src_port, dst_port;
 510 #ifdef  IP6FW_DIVERT_RESTART
 511         u_int16_t skipto = *cookie;
 512 #else
 513         u_int16_t ignport = ntohs(*cookie);
 514 #endif
 515
 516         *cookie = 0;
 517         /*
 518          * Go down the chain, looking for enlightment
 519          * #ifdef IP6FW_DIVERT_RESTART
 520          * If we've been asked to start at a given rule immediatly, do so.
 521          * #endif
 522          */
 523         chain = LIST_FIRST(&ip6_fw_chain);
 524 #ifdef IP6FW_DIVERT_RESTART
 525         if (skipto) {
 526                 if (skipto >= 65535)
 527                         goto dropit;
 528                 while (chain && (chain->rule->fw_number <= skipto)) {
 529                         chain = LIST_NEXT(chain, chain);
 530                 }
 531                 if (! chain) goto dropit;
 532         }
 533 #endif /* IP6FW_DIVERT_RESTART */
 534         for (; chain; chain = LIST_NEXT(chain, chain)) {
 535                 struct ip6_fw *const f = chain->rule;
 536
 537                 if (oif) {
 538                         /* Check direction outbound */
 539                         if (!(f->fw_flg & IPV6_FW_F_OUT))
 540                                 continue;
 541                 } else {
 542                         /* Check direction inbound */
 543                         if (!(f->fw_flg & IPV6_FW_F_IN))
 544                                 continue;
 545                 }
 546
 547 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
 548         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
 549         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
 550         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
 551         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
 552
 553                 /* If src-addr doesn't match, not this rule. */
 554                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
 555                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
 556                         continue;
 557
 558                 /* If dest-addr doesn't match, not this rule. */
 559                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
 560                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
 561                         continue;
 562
 563 #undef IN6_ARE_ADDR_MASKEQUAL
 564                 /* Interface check */
 565                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 566                         struct ifnet *const iface = oif ? oif : rif;
 567
 568                         /* Backwards compatibility hack for "via" */
 569                         if (!iface || !iface_match(iface,
 570                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
 571                                 continue;
 572                 } else {
 573                         /* Check receive interface */
 574                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
 575                             && (!rif || !iface_match(rif,
 576                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
 577                                 continue;
 578                         /* Check outgoing interface */
 579                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
 580                             && (!oif || !iface_match(oif,
 581                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
 582                                 continue;
 583                 }
 584
 585                 /* Check IP options */
 586                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
 587                         continue;
 588
 589                 /* Fragments */
 590                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
 591                         continue;
 592
 593                 /* Check protocol; if wildcard, match */
 594                 if (f->fw_prot == IPPROTO_IPV6)
 595                         goto got_match;
 596
 597                 /* If different, don't match */
 598                 if (nxt != f->fw_prot)
 599                         continue;
 600
 601 #define PULLUP_TO(len)  do {                                            \
 602                             if ((*m)->m_len < (len)                     \
 603                                 && (*m = m_pullup(*m, (len))) == 0) {   \
 604                                     goto dropit;                        \
 605                             }                                           \
 606                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
 607                         } while (0)
 608
 609                 /* Protocol specific checks */
 610                 switch (nxt) {
 611                 case IPPROTO_TCP:
 612                     {
 613                         struct tcphdr *tcp6;
 614
 615                         if (offset == 1) {      /* cf. RFC 1858 */
 616                                 PULLUP_TO(off + 4); /* XXX ? */
 617                                 goto bogusfrag;
 618                         }
 619                         if (offset != 0) {
 620                                 /*
 621                                  * TCP flags and ports aren't available in this
 622                                  * packet -- if this rule specified either one,
 623                                  * we consider the rule a non-match.
 624                                  */
 625                                 if (f->fw_nports != 0 ||
 626                                     f->fw_tcpf != f->fw_tcpnf)
 627                                         continue;
 628
 629                                 break;
 630                         }
 631                         PULLUP_TO(off + 14);
 632                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
 633                         if (((f->fw_tcpf != f->fw_tcpnf) ||
 634                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
 635                            !tcp6flg_match(tcp6, f))
 636                                 continue;
 637                         src_port = ntohs(tcp6->th_sport);
 638                         dst_port = ntohs(tcp6->th_dport);
 639                         goto check_ports;
 640                     }
 641
 642                 case IPPROTO_UDP:
 643                     {
 644                         struct udphdr *udp;
 645
 646                         if (offset != 0) {
 647                                 /*
 648                                  * Port specification is unavailable -- if this
 649                                  * rule specifies a port, we consider the rule
 650                                  * a non-match.
 651                                  */
 652                                 if (f->fw_nports != 0)
 653                                         continue;
 654
 655                                 break;
 656                         }
 657                         PULLUP_TO(off + 4);
 658                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
 659                         src_port = ntohs(udp->uh_sport);
 660                         dst_port = ntohs(udp->uh_dport);
 661 check_ports:
 662                         if (!port_match6(&f->fw_pts[0],
 663                             IPV6_FW_GETNSRCP(f), src_port,
 664                             f->fw_flg & IPV6_FW_F_SRNG))
 665                                 continue;
 666                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
 667                             IPV6_FW_GETNDSTP(f), dst_port,
 668                             f->fw_flg & IPV6_FW_F_DRNG))
 669                                 continue;
 670                         break;
 671                     }
 672
 673                 case IPPROTO_ICMPV6:
 674                     {
 675                         struct icmp6_hdr *icmp;
 676
 677                         if (offset != 0)        /* Type isn't valid */
 678                                 break;
 679                         PULLUP_TO(off + 2);
 680                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
 681                         if (!icmp6type_match(icmp, f))
 682                                 continue;
 683                         break;
 684                     }
 685 #undef PULLUP_TO
 686
 687 bogusfrag:
 688                         if (fw6_verbose)
 689                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
 690                         goto dropit;
 691                 }
 692
 693 got_match:
 694 #ifndef IP6FW_DIVERT_RESTART
 695                 /* Ignore divert/tee rule if socket port is "ignport" */
 696                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 697                 case IPV6_FW_F_DIVERT:
 698                 case IPV6_FW_F_TEE:
 699                         if (f->fw_divert_port == ignport)
 700                                 continue;       /* ignore this rule */
 701                         break;
 702                 }
 703
 704 #endif /* IP6FW_DIVERT_RESTART */
 705                 /* Update statistics */
 706                 f->fw_pcnt += 1;
 707                 f->fw_bcnt += ntohs(ip6->ip6_plen);
 708                 f->timestamp = time_second;
 709
 710                 /* Log to console if desired */
 711                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
 712                         ip6fw_report(f, ip6, rif, oif, off, nxt);
 713
 714                 /* Take appropriate action */
 715                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 716                 case IPV6_FW_F_ACCEPT:
 717                         return(0);
 718                 case IPV6_FW_F_COUNT:
 719                         continue;
 720                 case IPV6_FW_F_DIVERT:
 721 #ifdef IP6FW_DIVERT_RESTART
 722                         *cookie = f->fw_number;
 723 #else
 724                         *cookie = htons(f->fw_divert_port);
 725 #endif /* IP6FW_DIVERT_RESTART */
 726                         return(f->fw_divert_port);
 727                 case IPV6_FW_F_TEE:
 728                         /*
 729                          * XXX someday tee packet here, but beware that you
 730                          * can't use m_copym() or m_copypacket() because
 731                          * the divert input routine modifies the mbuf
 732                          * (and these routines only increment reference
 733                          * counts in the case of mbuf clusters), so need
 734                          * to write custom routine.
 735                          */
 736                         continue;
 737                 case IPV6_FW_F_SKIPTO:
 738 #ifdef DIAGNOSTIC
 739                         while (chain->chain.le_next
 740                             && chain->chain.le_next->rule->fw_number
 741                                 < f->fw_skipto_rule)
 742 #else
 743                         while (chain->chain.le_next->rule->fw_number
 744                             < f->fw_skipto_rule)
 745 #endif
 746                                 chain = chain->chain.le_next;
 747                         continue;
 748                 }
 749
 750                 /* Deny/reject this packet using this rule */
 751                 rule = f;
 752                 break;
 753         }
 754
 755 #ifdef DIAGNOSTIC
 756         /* Rule 65535 should always be there and should always match */
 757         if (!chain)
 758                 panic("ip6_fw: chain");
 759 #endif
 760
 761         /*
 762          * At this point, we're going to drop the packet.
 763          * Send a reject notice if all of the following are true:
 764          *
 765          * - The packet matched a reject rule
 766          * - The packet is not an ICMP packet, or is an ICMP query packet
 767          * - The packet is not a multicast or broadcast packet
 768          */
 769         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
 770             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
 771             && !((*m)->m_flags & (M_BCAST|M_MCAST))
 772             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 773                 switch (rule->fw_reject_code) {
 774                 case IPV6_FW_REJECT_RST:
 775                   {
 776                         struct tcphdr *const tcp =
 777                                 (struct tcphdr *) ((caddr_t)ip6 + off);
 778                         struct {
 779                                 struct ip6_hdr ip6;
 780                                 struct tcphdr th;
 781                         } ti;
 782                         tcp_seq ack, seq;
 783                         int flags;
 784
 785                         if (offset != 0 || (tcp->th_flags & TH_RST))
 786                                 break;
 787
 788                         ti.ip6 = *ip6;
 789                         ti.th = *tcp;
 790                         ti.th.th_seq = ntohl(ti.th.th_seq);
 791                         ti.th.th_ack = ntohl(ti.th.th_ack);
 792                         ti.ip6.ip6_nxt = IPPROTO_TCP;
 793                         if (ti.th.th_flags & TH_ACK) {
 794                                 ack = 0;
 795                                 seq = ti.th.th_ack;
 796                                 flags = TH_RST;
 797                         } else {
 798                                 ack = ti.th.th_seq;
 799                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
 800                                         ack += (*m)->m_pkthdr.len - off
 801                                                 - (ti.th.th_off << 2);
 802                                 } else if (ip6->ip6_plen) {
 803                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
 804                                                 - off - (ti.th.th_off << 2);
 805                                 } else {
 806                                         m_freem(*m);
 807                                         *m = NULL;
 808                                         break;
 809                                 }
 810                                 seq = 0;
 811                                 flags = TH_RST|TH_ACK;
 812                         }
 813                         bcopy(&ti, ip6, sizeof(ti));
 814                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
 815                                 *m, ack, seq, flags);
 816                         *m = NULL;
 817                         break;
 818                   }
 819                 default:        /* Send an ICMP unreachable using code */
 820                         if (oif)
 821                                 (*m)->m_pkthdr.rcvif = oif;
 822                         icmp6_error(*m, ICMP6_DST_UNREACH,
 823                             rule->fw_reject_code, 0);
 824                         *m = NULL;
 825                         break;
 826                 }
 827         }
 828
 829 dropit:
 830         /*
 831          * Finally, drop the packet.
 832          */
 833         if (*m) {
 834                 m_freem(*m);
 835                 *m = NULL;
 836         }
 837         return(0);
 838 }
 839
 840 static int
 841 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
 842 {
 843         struct ip6_fw *ftmp = NULL;
 844         struct ip6_fw_chain *fwc = NULL, *fcp, *fcpl = NULL;
 845         u_short nbr = 0;
 846
 847         fwc = kmalloc(sizeof *fwc, M_IP6FW, M_INTWAIT);
 848         ftmp = kmalloc(sizeof *ftmp, M_IP6FW, M_INTWAIT);
 849
 850         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
 851         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
 852         ftmp->fw_pcnt = 0L;
 853         ftmp->fw_bcnt = 0L;
 854         fwc->rule = ftmp;
 855
 856         crit_enter();
 857
 858         if (!chainptr->lh_first) {
 859                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 860                 crit_exit();
 861                 return(0);
 862         } else if (ftmp->fw_number == (u_short)-1) {
 863                 if (fwc)  kfree(fwc, M_IP6FW);
 864                 if (ftmp) kfree(ftmp, M_IP6FW);
 865                 crit_exit();
 866                 dprintf(("%s bad rule number\n", err_prefix));
 867                 return (EINVAL);
 868         }
 869
 870         /* If entry number is 0, find highest numbered rule and add 100 */
 871         if (ftmp->fw_number == 0) {
 872                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 873                         if (fcp->rule->fw_number != (u_short)-1)
 874                                 nbr = fcp->rule->fw_number;
 875                         else
 876                                 break;
 877                 }
 878                 if (nbr < (u_short)-1 - 100)
 879                         nbr += 100;
 880                 ftmp->fw_number = nbr;
 881         }
 882
 883         /* Got a valid number; now insert it, keeping the list ordered */
 884         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 885                 if (fcp->rule->fw_number > ftmp->fw_number) {
 886                         if (fcpl) {
 887                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
 888                         } else {
 889                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 890                         }
 891                         break;
 892                 } else {
 893                         fcpl = fcp;
 894                 }
 895         }
 896
 897         crit_exit();
 898         return (0);
 899 }
 900
 901 static int
 902 del_entry6(struct ip6_fw_head *chainptr, u_short number)
 903 {
 904         struct ip6_fw_chain *fcp;
 905
 906         crit_enter();
 907
 908         fcp = chainptr->lh_first;
 909         if (number != (u_short)-1) {
 910                 for (; fcp; fcp = fcp->chain.le_next) {
 911                         if (fcp->rule->fw_number == number) {
 912                                 LIST_REMOVE(fcp, chain);
 913                                 crit_exit();
 914                                 kfree(fcp->rule, M_IP6FW);
 915                                 kfree(fcp, M_IP6FW);
 916                                 return 0;
 917                         }
 918                 }
 919         }
 920
 921         crit_exit();
 922         return (EINVAL);
 923 }
 924
 925 static int
 926 zero_entry6(struct mbuf *m)
 927 {
 928         struct ip6_fw *frwl;
 929         struct ip6_fw_chain *fcp;
 930
 931         if (m && m->m_len != 0) {
 932                 if (m->m_len != sizeof(struct ip6_fw))
 933                         return(EINVAL);
 934                 frwl = mtod(m, struct ip6_fw *);
 935         }
 936         else
 937                 frwl = NULL;
 938
 939         /*
 940          *      It's possible to insert multiple chain entries with the
 941          *      same number, so we don't stop after finding the first
 942          *      match if zeroing a specific entry.
 943          */
 944         crit_enter();
 945         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
 946                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
 947                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
 948                         fcp->rule->timestamp = 0;
 949                 }
 950         crit_exit();
 951
 952         if (fw6_verbose) {
 953                 if (frwl)
 954                         log(LOG_SECURITY | LOG_NOTICE,
 955                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
 956                 else
 957                         log(LOG_SECURITY | LOG_NOTICE,
 958                             "ip6fw: Accounting cleared.\n");
 959         }
 960
 961         return(0);
 962 }
 963
 964 static struct ip6_fw *
 965 check_ip6fw_mbuf(struct mbuf *m)
 966 {
 967         /* Check length */
 968         if (m->m_len != sizeof(struct ip6_fw)) {
 969                 dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
 970                         (int)sizeof(struct ip6_fw)));
 971                 return (NULL);
 972         }
 973         return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
 974 }
 975
 976 static struct ip6_fw *
 977 check_ip6fw_struct(struct ip6_fw *frwl)
 978 {
 979         /* Check for invalid flag bits */
 980         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
 981                 dprintf(("%s undefined flag bits set (flags=%x)\n",
 982                     err_prefix, frwl->fw_flg));
 983                 return (NULL);
 984         }
 985         /* Must apply to incoming or outgoing (or both) */
 986         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
 987                 dprintf(("%s neither in nor out\n", err_prefix));
 988                 return (NULL);
 989         }
 990         /* Empty interface name is no good */
 991         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
 992               && !*frwl->fw_in_if.fu_via_if.name)
 993             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
 994               && !*frwl->fw_out_if.fu_via_if.name)) {
 995                 dprintf(("%s empty interface name\n", err_prefix));
 996                 return (NULL);
 997         }
 998         /* Sanity check interface matching */
 999         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1000                 ;               /* allow "via" backwards compatibility */
1001         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1002             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1003                 dprintf(("%s outgoing interface check on incoming\n",
1004                     err_prefix));
1005                 return (NULL);
1006         }
1007         /* Sanity check port ranges */
1008         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1009                 dprintf(("%s src range set but n_src_p=%d\n",
1010                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1011                 return (NULL);
1012         }
1013         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1014                 dprintf(("%s dst range set but n_dst_p=%d\n",
1015                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1016                 return (NULL);
1017         }
1018         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1019                 dprintf(("%s too many ports (%d+%d)\n",
1020                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1021                 return (NULL);
1022         }
1023         /*
1024          *      Protocols other than TCP/UDP don't use port range
1025          */
1026         if ((frwl->fw_prot != IPPROTO_TCP) &&
1027             (frwl->fw_prot != IPPROTO_UDP) &&
1028             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1029                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1030                     err_prefix));
1031                 return(NULL);
1032         }
1033
1034         /*
1035          *      Rather than modify the entry to make such entries work,
1036          *      we reject this rule and require user level utilities
1037          *      to enforce whatever policy they deem appropriate.
1038          */
1039         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1040                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1041                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1042                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1043                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1044                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1045                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1046                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1047                 dprintf(("%s rule never matches\n", err_prefix));
1048                 return(NULL);
1049         }
1050
1051         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1052                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1053                 if (frwl->fw_nports) {
1054                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1055                         return(NULL);
1056                 }
1057                 if (frwl->fw_prot == IPPROTO_TCP &&
1058                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1059                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1060                         return(NULL);
1061                 }
1062         }
1063
1064         /* Check command specific stuff */
1065         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1066         {
1067         case IPV6_FW_F_REJECT:
1068                 if (frwl->fw_reject_code >= 0x100
1069                     && !(frwl->fw_prot == IPPROTO_TCP
1070                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1071                         dprintf(("%s unknown reject code\n", err_prefix));
1072                         return(NULL);
1073                 }
1074                 break;
1075         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1076         case IPV6_FW_F_TEE:
1077                 if (frwl->fw_divert_port == 0) {
1078                         dprintf(("%s can't divert to port 0\n", err_prefix));
1079                         return (NULL);
1080                 }
1081                 break;
1082         case IPV6_FW_F_DENY:
1083         case IPV6_FW_F_ACCEPT:
1084         case IPV6_FW_F_COUNT:
1085         case IPV6_FW_F_SKIPTO:
1086                 break;
1087         default:
1088                 dprintf(("%s invalid command\n", err_prefix));
1089                 return(NULL);
1090         }
1091
1092         return frwl;
1093 }
1094
1095 static int
1096 ip6_fw_ctl(int stage, struct mbuf **mm)
1097 {
1098         int error;
1099         struct mbuf *m;
1100
1101         if (stage == IPV6_FW_GET) {
1102                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1103                 *mm = m = m_get(MB_WAIT, MT_DATA); /* XXX */
1104                 if (!m)
1105                         return(ENOBUFS);
1106                 if (sizeof *(fcp->rule) > MLEN) {
1107                         MCLGET(m, MB_WAIT);
1108                         if ((m->m_flags & M_EXT) == 0) {
1109                                 m_free(m);
1110                                 return(ENOBUFS);
1111                         }
1112                 }
1113                 for (; fcp; fcp = fcp->chain.le_next) {
1114                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1115                         m->m_len = sizeof *(fcp->rule);
1116                         m->m_next = m_get(MB_WAIT, MT_DATA); /* XXX */
1117                         if (!m->m_next) {
1118                                 m_freem(*mm);
1119                                 return(ENOBUFS);
1120                         }
1121                         m = m->m_next;
1122                         if (sizeof *(fcp->rule) > MLEN) {
1123                                 MCLGET(m, MB_WAIT);
1124                                 if ((m->m_flags & M_EXT) == 0) {
1125                                         m_freem(*mm);
1126                                         return(ENOBUFS);
1127                                 }
1128                         }
1129                         m->m_len = 0;
1130                 }
1131                 return (0);
1132         }
1133         m = *mm;
1134         /* only allow get calls if secure mode > 2 */
1135         if (securelevel > 2) {
1136                 if (m) {
1137                         m_freem(m);
1138                         *mm = NULL;
1139                 }
1140                 return(EPERM);
1141         }
1142         if (stage == IPV6_FW_FLUSH) {
1143                 while (ip6_fw_chain.lh_first != NULL &&
1144                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1145                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1146                         crit_enter();
1147                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1148                         crit_exit();
1149                         kfree(fcp->rule, M_IP6FW);
1150                         kfree(fcp, M_IP6FW);
1151                 }
1152                 if (m) {
1153                         m_freem(m);
1154                         *mm = NULL;
1155                 }
1156                 return (0);
1157         }
1158         if (stage == IPV6_FW_ZERO) {
1159                 error = zero_entry6(m);
1160                 if (m) {
1161                         m_freem(m);
1162                         *mm = NULL;
1163                 }
1164                 return (error);
1165         }
1166         if (m == NULL) {
1167                 kprintf("%s NULL mbuf ptr\n", err_prefix);
1168                 return (EINVAL);
1169         }
1170
1171         if (stage == IPV6_FW_ADD) {
1172                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1173
1174                 if (!frwl)
1175                         error = EINVAL;
1176                 else
1177                         error = add_entry6(&ip6_fw_chain, frwl);
1178                 if (m) {
1179                         m_freem(m);
1180                         *mm = NULL;
1181                 }
1182                 return error;
1183         }
1184         if (stage == IPV6_FW_DEL) {
1185                 if (m->m_len != sizeof(struct ip6_fw)) {
1186                         dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1187                                 (int)sizeof(struct ip6_fw)));
1188                         error = EINVAL;
1189                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1190                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1191                         error = EINVAL;
1192                 } else
1193                         error = del_entry6(&ip6_fw_chain,
1194                             mtod(m, struct ip6_fw *)->fw_number);
1195                 if (m) {
1196                         m_freem(m);
1197                         *mm = NULL;
1198                 }
1199                 return error;
1200         }
1201
1202         dprintf(("%s unknown request %d\n", err_prefix, stage));
1203         if (m) {
1204                 m_freem(m);
1205                 *mm = NULL;
1206         }
1207         return (EINVAL);
1208 }
1209
1210 void
1211 ip6_fw_init(void)
1212 {
1213         struct ip6_fw default_rule;
1214
1215         ip6_fw_chk_ptr = ip6_fw_chk;
1216         ip6_fw_ctl_ptr = ip6_fw_ctl;
1217         LIST_INIT(&ip6_fw_chain);
1218
1219         bzero(&default_rule, sizeof default_rule);
1220         default_rule.fw_prot = IPPROTO_IPV6;
1221         default_rule.fw_number = (u_short)-1;
1222 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1223         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1224 #else
1225         default_rule.fw_flg |= IPV6_FW_F_DENY;
1226 #endif
1227         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1228         if (check_ip6fw_struct(&default_rule) == NULL ||
1229                 add_entry6(&ip6_fw_chain, &default_rule))
1230                 panic(__func__);
1231
1232         kprintf("IPv6 packet filtering initialized, ");
1233 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1234         kprintf("default to accept, ");
1235 #endif
1236 #ifndef IPV6FIREWALL_VERBOSE
1237         kprintf("logging disabled\n");
1238 #else
1239         if (fw6_verbose_limit == 0)
1240                 kprintf("unlimited logging\n");
1241         else
1242                 kprintf("logging limited to %d packets/entry\n",
1243                     fw6_verbose_limit);
1244 #endif
1245 }
1246
1247 static ip6_fw_chk_t *old_chk_ptr;
1248 static ip6_fw_ctl_t *old_ctl_ptr;
1249
1250 static int
1251 ip6fw_modevent(module_t mod, int type, void *unused)
1252 {
1253         switch (type) {
1254         case MOD_LOAD:
1255                 crit_enter();
1256
1257                 old_chk_ptr = ip6_fw_chk_ptr;
1258                 old_ctl_ptr = ip6_fw_ctl_ptr;
1259
1260                 ip6_fw_init();
1261                 crit_exit();
1262                 return 0;
1263         case MOD_UNLOAD:
1264                 crit_enter();
1265                 ip6_fw_chk_ptr =  old_chk_ptr;
1266                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1267                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1268                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1269                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1270                         kfree(fcp->rule, M_IP6FW);
1271                         kfree(fcp, M_IP6FW);
1272                 }
1273
1274                 crit_exit();
1275                 kprintf("IPv6 firewall unloaded\n");
1276                 return 0;
1277         default:
1278                 break;
1279         }
1280         return 0;
1281 }
1282
1283 static moduledata_t ip6fwmod = {
1284         "ip6fw",
1285         ip6fw_modevent,
1286         0
1287 };
1288 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);