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 1.19 2008/03/07 11:34:20 sephe 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_container *ifac;
 340
 341                 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
 342                         struct ifaddr *ifa = ifac->ifa;
 343
 344                         if (ifa->ifa_addr == NULL)
 345                                 continue;
 346                         if (ifa->ifa_addr->sa_family != AF_INET6)
 347                                 continue;
 348                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
 349                             &(((struct sockaddr_in6 *)
 350                             (ifa->ifa_addr))->sin6_addr)))
 351                                 continue;
 352                         return(1);
 353                 }
 354                 return(0);
 355         }
 356         return(1);
 357 }
 358
 359 static void
 360 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
 361         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
 362 {
 363         static int counter;
 364         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
 365         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
 366         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
 367         int count;
 368         char *action;
 369         char action2[32], proto[102], name[18];
 370         int len;
 371
 372         count = f ? f->fw_pcnt : ++counter;
 373         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
 374                 return;
 375
 376         /* Print command name */
 377         ksnprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
 378
 379         action = action2;
 380         if (!f)
 381                 action = "Refuse";
 382         else {
 383                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 384                 case IPV6_FW_F_DENY:
 385                         action = "Deny";
 386                         break;
 387                 case IPV6_FW_F_REJECT:
 388                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
 389                                 action = "Reset";
 390                         else
 391                                 action = "Unreach";
 392                         break;
 393                 case IPV6_FW_F_ACCEPT:
 394                         action = "Accept";
 395                         break;
 396                 case IPV6_FW_F_COUNT:
 397                         action = "Count";
 398                         break;
 399                 case IPV6_FW_F_DIVERT:
 400                         ksnprintf(SNPARGS(action2, 0), "Divert %d",
 401                             f->fw_divert_port);
 402                         break;
 403                 case IPV6_FW_F_TEE:
 404                         ksnprintf(SNPARGS(action2, 0), "Tee %d",
 405                             f->fw_divert_port);
 406                         break;
 407                 case IPV6_FW_F_SKIPTO:
 408                         ksnprintf(SNPARGS(action2, 0), "SkipTo %d",
 409                             f->fw_skipto_rule);
 410                         break;
 411                 default:
 412                         action = "UNKNOWN";
 413                         break;
 414                 }
 415         }
 416
 417         switch (nxt) {
 418         case IPPROTO_TCP:
 419                 len = ksnprintf(SNPARGS(proto, 0), "TCP [%s]",
 420                     ip6_sprintf(&ip6->ip6_src));
 421                 if (off > 0)
 422                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
 423                             ntohs(tcp6->th_sport));
 424                 else
 425                         len += ksnprintf(SNPARGS(proto, len), " ");
 426                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 427                     ip6_sprintf(&ip6->ip6_dst));
 428                 if (off > 0)
 429                         ksnprintf(SNPARGS(proto, len), ":%d",
 430                             ntohs(tcp6->th_dport));
 431                 break;
 432         case IPPROTO_UDP:
 433                 len = ksnprintf(SNPARGS(proto, 0), "UDP [%s]",
 434                     ip6_sprintf(&ip6->ip6_src));
 435                 if (off > 0)
 436                         len += ksnprintf(SNPARGS(proto, len), ":%d ",
 437                             ntohs(udp->uh_sport));
 438                 else
 439                     len += ksnprintf(SNPARGS(proto, len), " ");
 440                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 441                     ip6_sprintf(&ip6->ip6_dst));
 442                 if (off > 0)
 443                         ksnprintf(SNPARGS(proto, len), ":%d",
 444                             ntohs(udp->uh_dport));
 445                 break;
 446         case IPPROTO_ICMPV6:
 447                 if (off > 0)
 448                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
 449                             icmp6->icmp6_type, icmp6->icmp6_code);
 450                 else
 451                         len = ksnprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
 452                 len += ksnprintf(SNPARGS(proto, len), "[%s]",
 453                     ip6_sprintf(&ip6->ip6_src));
 454                 ksnprintf(SNPARGS(proto, len), " [%s]",
 455                     ip6_sprintf(&ip6->ip6_dst));
 456                 break;
 457         default:
 458                 len = ksnprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
 459                     ip6_sprintf(&ip6->ip6_src));
 460                 ksnprintf(SNPARGS(proto, len), " [%s]",
 461                     ip6_sprintf(&ip6->ip6_dst));
 462                 break;
 463         }
 464
 465         if (oif)
 466                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
 467                     name, action, proto, if_name(oif));
 468         else if (rif)
 469                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
 470                     name, action, proto, if_name(rif));
 471         else
 472                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
 473                     name, action, proto);
 474         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
 475             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
 476                 f ? f->fw_number : -1);
 477 }
 478
 479 /*
 480  * Parameters:
 481  *
 482  *      ip      Pointer to packet header (struct ip6_hdr *)
 483  *      hlen    Packet header length
 484  *      oif     Outgoing interface, or NULL if packet is incoming
 485  * #ifndef IP6FW_DIVERT_RESTART
 486  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
 487  * #else
 488  *      *cookie Skip up to the first rule past this rule number;
 489  * #endif
 490  *      *m      The packet; we set to NULL when/if we nuke it.
 491  *
 492  * Return value:
 493  *
 494  *      0       The packet is to be accepted and routed normally OR
 495  *              the packet was denied/rejected and has been dropped;
 496  *              in the latter case, *m is equal to NULL upon return.
 497  *      port    Divert the packet to port.
 498  */
 499
 500 static int
 501 ip6_fw_chk(struct ip6_hdr **pip6,
 502         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
 503 {
 504         struct ip6_fw_chain *chain;
 505         struct ip6_fw *rule = NULL;
 506         struct ip6_hdr *ip6 = *pip6;
 507         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
 508         u_short offset = 0;
 509         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
 510         u_short src_port, dst_port;
 511 #ifdef  IP6FW_DIVERT_RESTART
 512         u_int16_t skipto = *cookie;
 513 #else
 514         u_int16_t ignport = ntohs(*cookie);
 515 #endif
 516
 517         *cookie = 0;
 518         /*
 519          * Go down the chain, looking for enlightment
 520          * #ifdef IP6FW_DIVERT_RESTART
 521          * If we've been asked to start at a given rule immediatly, do so.
 522          * #endif
 523          */
 524         chain = LIST_FIRST(&ip6_fw_chain);
 525 #ifdef IP6FW_DIVERT_RESTART
 526         if (skipto) {
 527                 if (skipto >= 65535)
 528                         goto dropit;
 529                 while (chain && (chain->rule->fw_number <= skipto)) {
 530                         chain = LIST_NEXT(chain, chain);
 531                 }
 532                 if (! chain) goto dropit;
 533         }
 534 #endif /* IP6FW_DIVERT_RESTART */
 535         for (; chain; chain = LIST_NEXT(chain, chain)) {
 536                 struct ip6_fw *const f = chain->rule;
 537
 538                 if (oif) {
 539                         /* Check direction outbound */
 540                         if (!(f->fw_flg & IPV6_FW_F_OUT))
 541                                 continue;
 542                 } else {
 543                         /* Check direction inbound */
 544                         if (!(f->fw_flg & IPV6_FW_F_IN))
 545                                 continue;
 546                 }
 547
 548 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
 549         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
 550         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
 551         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
 552         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
 553
 554                 /* If src-addr doesn't match, not this rule. */
 555                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
 556                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
 557                         continue;
 558
 559                 /* If dest-addr doesn't match, not this rule. */
 560                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
 561                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
 562                         continue;
 563
 564 #undef IN6_ARE_ADDR_MASKEQUAL
 565                 /* Interface check */
 566                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 567                         struct ifnet *const iface = oif ? oif : rif;
 568
 569                         /* Backwards compatibility hack for "via" */
 570                         if (!iface || !iface_match(iface,
 571                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
 572                                 continue;
 573                 } else {
 574                         /* Check receive interface */
 575                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
 576                             && (!rif || !iface_match(rif,
 577                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
 578                                 continue;
 579                         /* Check outgoing interface */
 580                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
 581                             && (!oif || !iface_match(oif,
 582                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
 583                                 continue;
 584                 }
 585
 586                 /* Check IP options */
 587                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
 588                         continue;
 589
 590                 /* Fragments */
 591                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
 592                         continue;
 593
 594                 /* Check protocol; if wildcard, match */
 595                 if (f->fw_prot == IPPROTO_IPV6)
 596                         goto got_match;
 597
 598                 /* If different, don't match */
 599                 if (nxt != f->fw_prot)
 600                         continue;
 601
 602 #define PULLUP_TO(len)  do {                                            \
 603                             if ((*m)->m_len < (len)                     \
 604                                 && (*m = m_pullup(*m, (len))) == 0) {   \
 605                                     goto dropit;                        \
 606                             }                                           \
 607                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
 608                         } while (0)
 609
 610                 /* Protocol specific checks */
 611                 switch (nxt) {
 612                 case IPPROTO_TCP:
 613                     {
 614                         struct tcphdr *tcp6;
 615
 616                         if (offset == 1) {      /* cf. RFC 1858 */
 617                                 PULLUP_TO(off + 4); /* XXX ? */
 618                                 goto bogusfrag;
 619                         }
 620                         if (offset != 0) {
 621                                 /*
 622                                  * TCP flags and ports aren't available in this
 623                                  * packet -- if this rule specified either one,
 624                                  * we consider the rule a non-match.
 625                                  */
 626                                 if (f->fw_nports != 0 ||
 627                                     f->fw_tcpf != f->fw_tcpnf)
 628                                         continue;
 629
 630                                 break;
 631                         }
 632                         PULLUP_TO(off + 14);
 633                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
 634                         if (((f->fw_tcpf != f->fw_tcpnf) ||
 635                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
 636                            !tcp6flg_match(tcp6, f))
 637                                 continue;
 638                         src_port = ntohs(tcp6->th_sport);
 639                         dst_port = ntohs(tcp6->th_dport);
 640                         goto check_ports;
 641                     }
 642
 643                 case IPPROTO_UDP:
 644                     {
 645                         struct udphdr *udp;
 646
 647                         if (offset != 0) {
 648                                 /*
 649                                  * Port specification is unavailable -- if this
 650                                  * rule specifies a port, we consider the rule
 651                                  * a non-match.
 652                                  */
 653                                 if (f->fw_nports != 0)
 654                                         continue;
 655
 656                                 break;
 657                         }
 658                         PULLUP_TO(off + 4);
 659                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
 660                         src_port = ntohs(udp->uh_sport);
 661                         dst_port = ntohs(udp->uh_dport);
 662 check_ports:
 663                         if (!port_match6(&f->fw_pts[0],
 664                             IPV6_FW_GETNSRCP(f), src_port,
 665                             f->fw_flg & IPV6_FW_F_SRNG))
 666                                 continue;
 667                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
 668                             IPV6_FW_GETNDSTP(f), dst_port,
 669                             f->fw_flg & IPV6_FW_F_DRNG))
 670                                 continue;
 671                         break;
 672                     }
 673
 674                 case IPPROTO_ICMPV6:
 675                     {
 676                         struct icmp6_hdr *icmp;
 677
 678                         if (offset != 0)        /* Type isn't valid */
 679                                 break;
 680                         PULLUP_TO(off + 2);
 681                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
 682                         if (!icmp6type_match(icmp, f))
 683                                 continue;
 684                         break;
 685                     }
 686 #undef PULLUP_TO
 687
 688 bogusfrag:
 689                         if (fw6_verbose)
 690                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
 691                         goto dropit;
 692                 }
 693
 694 got_match:
 695 #ifndef IP6FW_DIVERT_RESTART
 696                 /* Ignore divert/tee rule if socket port is "ignport" */
 697                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 698                 case IPV6_FW_F_DIVERT:
 699                 case IPV6_FW_F_TEE:
 700                         if (f->fw_divert_port == ignport)
 701                                 continue;       /* ignore this rule */
 702                         break;
 703                 }
 704
 705 #endif /* IP6FW_DIVERT_RESTART */
 706                 /* Update statistics */
 707                 f->fw_pcnt += 1;
 708                 f->fw_bcnt += ntohs(ip6->ip6_plen);
 709                 f->timestamp = time_second;
 710
 711                 /* Log to console if desired */
 712                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
 713                         ip6fw_report(f, ip6, rif, oif, off, nxt);
 714
 715                 /* Take appropriate action */
 716                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
 717                 case IPV6_FW_F_ACCEPT:
 718                         return(0);
 719                 case IPV6_FW_F_COUNT:
 720                         continue;
 721                 case IPV6_FW_F_DIVERT:
 722 #ifdef IP6FW_DIVERT_RESTART
 723                         *cookie = f->fw_number;
 724 #else
 725                         *cookie = htons(f->fw_divert_port);
 726 #endif /* IP6FW_DIVERT_RESTART */
 727                         return(f->fw_divert_port);
 728                 case IPV6_FW_F_TEE:
 729                         /*
 730                          * XXX someday tee packet here, but beware that you
 731                          * can't use m_copym() or m_copypacket() because
 732                          * the divert input routine modifies the mbuf
 733                          * (and these routines only increment reference
 734                          * counts in the case of mbuf clusters), so need
 735                          * to write custom routine.
 736                          */
 737                         continue;
 738                 case IPV6_FW_F_SKIPTO:
 739 #ifdef DIAGNOSTIC
 740                         while (chain->chain.le_next
 741                             && chain->chain.le_next->rule->fw_number
 742                                 < f->fw_skipto_rule)
 743 #else
 744                         while (chain->chain.le_next->rule->fw_number
 745                             < f->fw_skipto_rule)
 746 #endif
 747                                 chain = chain->chain.le_next;
 748                         continue;
 749                 }
 750
 751                 /* Deny/reject this packet using this rule */
 752                 rule = f;
 753                 break;
 754         }
 755
 756 #ifdef DIAGNOSTIC
 757         /* Rule 65535 should always be there and should always match */
 758         if (!chain)
 759                 panic("ip6_fw: chain");
 760 #endif
 761
 762         /*
 763          * At this point, we're going to drop the packet.
 764          * Send a reject notice if all of the following are true:
 765          *
 766          * - The packet matched a reject rule
 767          * - The packet is not an ICMP packet, or is an ICMP query packet
 768          * - The packet is not a multicast or broadcast packet
 769          */
 770         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
 771             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
 772             && !((*m)->m_flags & (M_BCAST|M_MCAST))
 773             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 774                 switch (rule->fw_reject_code) {
 775                 case IPV6_FW_REJECT_RST:
 776                   {
 777                         struct tcphdr *const tcp =
 778                                 (struct tcphdr *) ((caddr_t)ip6 + off);
 779                         struct {
 780                                 struct ip6_hdr ip6;
 781                                 struct tcphdr th;
 782                         } ti;
 783                         tcp_seq ack, seq;
 784                         int flags;
 785
 786                         if (offset != 0 || (tcp->th_flags & TH_RST))
 787                                 break;
 788
 789                         ti.ip6 = *ip6;
 790                         ti.th = *tcp;
 791                         ti.th.th_seq = ntohl(ti.th.th_seq);
 792                         ti.th.th_ack = ntohl(ti.th.th_ack);
 793                         ti.ip6.ip6_nxt = IPPROTO_TCP;
 794                         if (ti.th.th_flags & TH_ACK) {
 795                                 ack = 0;
 796                                 seq = ti.th.th_ack;
 797                                 flags = TH_RST;
 798                         } else {
 799                                 ack = ti.th.th_seq;
 800                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
 801                                         ack += (*m)->m_pkthdr.len - off
 802                                                 - (ti.th.th_off << 2);
 803                                 } else if (ip6->ip6_plen) {
 804                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
 805                                                 - off - (ti.th.th_off << 2);
 806                                 } else {
 807                                         m_freem(*m);
 808                                         *m = 0;
 809                                         break;
 810                                 }
 811                                 seq = 0;
 812                                 flags = TH_RST|TH_ACK;
 813                         }
 814                         bcopy(&ti, ip6, sizeof(ti));
 815                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
 816                                 *m, ack, seq, flags);
 817                         *m = NULL;
 818                         break;
 819                   }
 820                 default:        /* Send an ICMP unreachable using code */
 821                         if (oif)
 822                                 (*m)->m_pkthdr.rcvif = oif;
 823                         icmp6_error(*m, ICMP6_DST_UNREACH,
 824                             rule->fw_reject_code, 0);
 825                         *m = NULL;
 826                         break;
 827                 }
 828         }
 829
 830 dropit:
 831         /*
 832          * Finally, drop the packet.
 833          */
 834         if (*m) {
 835                 m_freem(*m);
 836                 *m = NULL;
 837         }
 838         return(0);
 839 }
 840
 841 static int
 842 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
 843 {
 844         struct ip6_fw *ftmp = 0;
 845         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
 846         u_short nbr = 0;
 847
 848         fwc = kmalloc(sizeof *fwc, M_IP6FW, M_INTWAIT);
 849         ftmp = kmalloc(sizeof *ftmp, M_IP6FW, M_INTWAIT);
 850
 851         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
 852         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
 853         ftmp->fw_pcnt = 0L;
 854         ftmp->fw_bcnt = 0L;
 855         fwc->rule = ftmp;
 856
 857         crit_enter();
 858
 859         if (!chainptr->lh_first) {
 860                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 861                 crit_exit();
 862                 return(0);
 863         } else if (ftmp->fw_number == (u_short)-1) {
 864                 if (fwc)  kfree(fwc, M_IP6FW);
 865                 if (ftmp) kfree(ftmp, M_IP6FW);
 866                 crit_exit();
 867                 dprintf(("%s bad rule number\n", err_prefix));
 868                 return (EINVAL);
 869         }
 870
 871         /* If entry number is 0, find highest numbered rule and add 100 */
 872         if (ftmp->fw_number == 0) {
 873                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 874                         if (fcp->rule->fw_number != (u_short)-1)
 875                                 nbr = fcp->rule->fw_number;
 876                         else
 877                                 break;
 878                 }
 879                 if (nbr < (u_short)-1 - 100)
 880                         nbr += 100;
 881                 ftmp->fw_number = nbr;
 882         }
 883
 884         /* Got a valid number; now insert it, keeping the list ordered */
 885         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
 886                 if (fcp->rule->fw_number > ftmp->fw_number) {
 887                         if (fcpl) {
 888                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
 889                         } else {
 890                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
 891                         }
 892                         break;
 893                 } else {
 894                         fcpl = fcp;
 895                 }
 896         }
 897
 898         crit_exit();
 899         return (0);
 900 }
 901
 902 static int
 903 del_entry6(struct ip6_fw_head *chainptr, u_short number)
 904 {
 905         struct ip6_fw_chain *fcp;
 906
 907         crit_enter();
 908
 909         fcp = chainptr->lh_first;
 910         if (number != (u_short)-1) {
 911                 for (; fcp; fcp = fcp->chain.le_next) {
 912                         if (fcp->rule->fw_number == number) {
 913                                 LIST_REMOVE(fcp, chain);
 914                                 crit_exit();
 915                                 kfree(fcp->rule, M_IP6FW);
 916                                 kfree(fcp, M_IP6FW);
 917                                 return 0;
 918                         }
 919                 }
 920         }
 921
 922         crit_exit();
 923         return (EINVAL);
 924 }
 925
 926 static int
 927 zero_entry6(struct mbuf *m)
 928 {
 929         struct ip6_fw *frwl;
 930         struct ip6_fw_chain *fcp;
 931
 932         if (m && m->m_len != 0) {
 933                 if (m->m_len != sizeof(struct ip6_fw))
 934                         return(EINVAL);
 935                 frwl = mtod(m, struct ip6_fw *);
 936         }
 937         else
 938                 frwl = NULL;
 939
 940         /*
 941          *      It's possible to insert multiple chain entries with the
 942          *      same number, so we don't stop after finding the first
 943          *      match if zeroing a specific entry.
 944          */
 945         crit_enter();
 946         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
 947                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
 948                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
 949                         fcp->rule->timestamp = 0;
 950                 }
 951         crit_exit();
 952
 953         if (fw6_verbose) {
 954                 if (frwl)
 955                         log(LOG_SECURITY | LOG_NOTICE,
 956                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
 957                 else
 958                         log(LOG_SECURITY | LOG_NOTICE,
 959                             "ip6fw: Accounting cleared.\n");
 960         }
 961
 962         return(0);
 963 }
 964
 965 static struct ip6_fw *
 966 check_ip6fw_mbuf(struct mbuf *m)
 967 {
 968         /* Check length */
 969         if (m->m_len != sizeof(struct ip6_fw)) {
 970                 dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
 971                     sizeof(struct ip6_fw)));
 972                 return (NULL);
 973         }
 974         return(check_ip6fw_struct(mtod(m, struct ip6_fw *)));
 975 }
 976
 977 static struct ip6_fw *
 978 check_ip6fw_struct(struct ip6_fw *frwl)
 979 {
 980         /* Check for invalid flag bits */
 981         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
 982                 dprintf(("%s undefined flag bits set (flags=%x)\n",
 983                     err_prefix, frwl->fw_flg));
 984                 return (NULL);
 985         }
 986         /* Must apply to incoming or outgoing (or both) */
 987         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
 988                 dprintf(("%s neither in nor out\n", err_prefix));
 989                 return (NULL);
 990         }
 991         /* Empty interface name is no good */
 992         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
 993               && !*frwl->fw_in_if.fu_via_if.name)
 994             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
 995               && !*frwl->fw_out_if.fu_via_if.name)) {
 996                 dprintf(("%s empty interface name\n", err_prefix));
 997                 return (NULL);
 998         }
 999         /* Sanity check interface matching */
1000         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
1001                 ;               /* allow "via" backwards compatibility */
1002         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
1003             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
1004                 dprintf(("%s outgoing interface check on incoming\n",
1005                     err_prefix));
1006                 return (NULL);
1007         }
1008         /* Sanity check port ranges */
1009         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
1010                 dprintf(("%s src range set but n_src_p=%d\n",
1011                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
1012                 return (NULL);
1013         }
1014         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
1015                 dprintf(("%s dst range set but n_dst_p=%d\n",
1016                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
1017                 return (NULL);
1018         }
1019         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
1020                 dprintf(("%s too many ports (%d+%d)\n",
1021                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
1022                 return (NULL);
1023         }
1024         /*
1025          *      Protocols other than TCP/UDP don't use port range
1026          */
1027         if ((frwl->fw_prot != IPPROTO_TCP) &&
1028             (frwl->fw_prot != IPPROTO_UDP) &&
1029             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
1030                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
1031                     err_prefix));
1032                 return(NULL);
1033         }
1034
1035         /*
1036          *      Rather than modify the entry to make such entries work,
1037          *      we reject this rule and require user level utilities
1038          *      to enforce whatever policy they deem appropriate.
1039          */
1040         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
1041                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
1042                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
1043                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
1044                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
1045                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
1046                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
1047                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
1048                 dprintf(("%s rule never matches\n", err_prefix));
1049                 return(NULL);
1050         }
1051
1052         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
1053                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
1054                 if (frwl->fw_nports) {
1055                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
1056                         return(NULL);
1057                 }
1058                 if (frwl->fw_prot == IPPROTO_TCP &&
1059                         frwl->fw_tcpf != frwl->fw_tcpnf) {
1060                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
1061                         return(NULL);
1062                 }
1063         }
1064
1065         /* Check command specific stuff */
1066         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
1067         {
1068         case IPV6_FW_F_REJECT:
1069                 if (frwl->fw_reject_code >= 0x100
1070                     && !(frwl->fw_prot == IPPROTO_TCP
1071                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
1072                         dprintf(("%s unknown reject code\n", err_prefix));
1073                         return(NULL);
1074                 }
1075                 break;
1076         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
1077         case IPV6_FW_F_TEE:
1078                 if (frwl->fw_divert_port == 0) {
1079                         dprintf(("%s can't divert to port 0\n", err_prefix));
1080                         return (NULL);
1081                 }
1082                 break;
1083         case IPV6_FW_F_DENY:
1084         case IPV6_FW_F_ACCEPT:
1085         case IPV6_FW_F_COUNT:
1086         case IPV6_FW_F_SKIPTO:
1087                 break;
1088         default:
1089                 dprintf(("%s invalid command\n", err_prefix));
1090                 return(NULL);
1091         }
1092
1093         return frwl;
1094 }
1095
1096 static int
1097 ip6_fw_ctl(int stage, struct mbuf **mm)
1098 {
1099         int error;
1100         struct mbuf *m;
1101
1102         if (stage == IPV6_FW_GET) {
1103                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1104                 *mm = m = m_get(MB_WAIT, MT_DATA); /* XXX */
1105                 if (!m)
1106                         return(ENOBUFS);
1107                 if (sizeof *(fcp->rule) > MLEN) {
1108                         MCLGET(m, MB_WAIT);
1109                         if ((m->m_flags & M_EXT) == 0) {
1110                                 m_free(m);
1111                                 return(ENOBUFS);
1112                         }
1113                 }
1114                 for (; fcp; fcp = fcp->chain.le_next) {
1115                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
1116                         m->m_len = sizeof *(fcp->rule);
1117                         m->m_next = m_get(MB_WAIT, MT_DATA); /* XXX */
1118                         if (!m->m_next) {
1119                                 m_freem(*mm);
1120                                 return(ENOBUFS);
1121                         }
1122                         m = m->m_next;
1123                         if (sizeof *(fcp->rule) > MLEN) {
1124                                 MCLGET(m, MB_WAIT);
1125                                 if ((m->m_flags & M_EXT) == 0) {
1126                                         m_freem(*mm);
1127                                         return(ENOBUFS);
1128                                 }
1129                         }
1130                         m->m_len = 0;
1131                 }
1132                 return (0);
1133         }
1134         m = *mm;
1135         /* only allow get calls if secure mode > 2 */
1136         if (securelevel > 2) {
1137                 if (m) {
1138                         m_freem(m);
1139                         *mm = 0;
1140                 }
1141                 return(EPERM);
1142         }
1143         if (stage == IPV6_FW_FLUSH) {
1144                 while (ip6_fw_chain.lh_first != NULL &&
1145                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
1146                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
1147                         crit_enter();
1148                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
1149                         crit_exit();
1150                         kfree(fcp->rule, M_IP6FW);
1151                         kfree(fcp, M_IP6FW);
1152                 }
1153                 if (m) {
1154                         m_freem(m);
1155                         *mm = 0;
1156                 }
1157                 return (0);
1158         }
1159         if (stage == IPV6_FW_ZERO) {
1160                 error = zero_entry6(m);
1161                 if (m) {
1162                         m_freem(m);
1163                         *mm = 0;
1164                 }
1165                 return (error);
1166         }
1167         if (m == NULL) {
1168                 kprintf("%s NULL mbuf ptr\n", err_prefix);
1169                 return (EINVAL);
1170         }
1171
1172         if (stage == IPV6_FW_ADD) {
1173                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
1174
1175                 if (!frwl)
1176                         error = EINVAL;
1177                 else
1178                         error = add_entry6(&ip6_fw_chain, frwl);
1179                 if (m) {
1180                         m_freem(m);
1181                         *mm = 0;
1182                 }
1183                 return error;
1184         }
1185         if (stage == IPV6_FW_DEL) {
1186                 if (m->m_len != sizeof(struct ip6_fw)) {
1187                         dprintf(("%s len=%d, want %d\n", err_prefix, m->m_len,
1188                             sizeof(struct ip6_fw)));
1189                         error = EINVAL;
1190                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
1191                         dprintf(("%s can't delete rule 65535\n", err_prefix));
1192                         error = EINVAL;
1193                 } else
1194                         error = del_entry6(&ip6_fw_chain,
1195                             mtod(m, struct ip6_fw *)->fw_number);
1196                 if (m) {
1197                         m_freem(m);
1198                         *mm = 0;
1199                 }
1200                 return error;
1201         }
1202
1203         dprintf(("%s unknown request %d\n", err_prefix, stage));
1204         if (m) {
1205                 m_freem(m);
1206                 *mm = 0;
1207         }
1208         return (EINVAL);
1209 }
1210
1211 void
1212 ip6_fw_init(void)
1213 {
1214         struct ip6_fw default_rule;
1215
1216         ip6_fw_chk_ptr = ip6_fw_chk;
1217         ip6_fw_ctl_ptr = ip6_fw_ctl;
1218         LIST_INIT(&ip6_fw_chain);
1219
1220         bzero(&default_rule, sizeof default_rule);
1221         default_rule.fw_prot = IPPROTO_IPV6;
1222         default_rule.fw_number = (u_short)-1;
1223 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1224         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
1225 #else
1226         default_rule.fw_flg |= IPV6_FW_F_DENY;
1227 #endif
1228         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
1229         if (check_ip6fw_struct(&default_rule) == NULL ||
1230                 add_entry6(&ip6_fw_chain, &default_rule))
1231                 panic(__func__);
1232
1233         kprintf("IPv6 packet filtering initialized, ");
1234 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
1235         kprintf("default to accept, ");
1236 #endif
1237 #ifndef IPV6FIREWALL_VERBOSE
1238         kprintf("logging disabled\n");
1239 #else
1240         if (fw6_verbose_limit == 0)
1241                 kprintf("unlimited logging\n");
1242         else
1243                 kprintf("logging limited to %d packets/entry\n",
1244                     fw6_verbose_limit);
1245 #endif
1246 }
1247
1248 static ip6_fw_chk_t *old_chk_ptr;
1249 static ip6_fw_ctl_t *old_ctl_ptr;
1250
1251 static int
1252 ip6fw_modevent(module_t mod, int type, void *unused)
1253 {
1254         switch (type) {
1255         case MOD_LOAD:
1256                 crit_enter();
1257
1258                 old_chk_ptr = ip6_fw_chk_ptr;
1259                 old_ctl_ptr = ip6_fw_ctl_ptr;
1260
1261                 ip6_fw_init();
1262                 crit_exit();
1263                 return 0;
1264         case MOD_UNLOAD:
1265                 crit_enter();
1266                 ip6_fw_chk_ptr =  old_chk_ptr;
1267                 ip6_fw_ctl_ptr =  old_ctl_ptr;
1268                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
1269                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
1270                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
1271                         kfree(fcp->rule, M_IP6FW);
1272                         kfree(fcp, M_IP6FW);
1273                 }
1274
1275                 crit_exit();
1276                 kprintf("IPv6 firewall unloaded\n");
1277                 return 0;
1278         default:
1279                 break;
1280         }
1281         return 0;
1282 }
1283
1284 static moduledata_t ip6fwmod = {
1285         "ip6fw",
1286         ip6fw_modevent,
1287         0
1288 };
1289 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);