The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/ip6_fw.c

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    1 /*      $FreeBSD: releng/5.4/sys/netinet6/ip6_fw.c 141090 2005-01-31 23:27:04Z imp $    */
    2 /*      $KAME: ip6_fw.c,v 1.21 2001/01/24 01:25:32 itojun Exp $ */
    3 
    4 /*-
    5  * Copyright (C) 1998, 1999, 2000 and 2001 WIDE Project.
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. Neither the name of the project nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  */
   32 
   33 /*-
   34  * Copyright (c) 1993 Daniel Boulet
   35  * Copyright (c) 1994 Ugen J.S.Antsilevich
   36  * Copyright (c) 1996 Alex Nash
   37  *
   38  * Redistribution and use in source forms, with and without modification,
   39  * are permitted provided that this entire comment appears intact.
   40  *
   41  * Redistribution in binary form may occur without any restrictions.
   42  * Obviously, it would be nice if you gave credit where credit is due
   43  * but requiring it would be too onerous.
   44  *
   45  * This software is provided ``AS IS'' without any warranties of any kind.
   46  */
   47 
   48 /*
   49  * Implement IPv6 packet firewall
   50  */
   51 
   52 #if !defined(KLD_MODULE)
   53 #include "opt_ip6fw.h"
   54 #include "opt_inet.h"
   55 #include "opt_inet6.h"
   56 #endif
   57 
   58 #ifdef IP6DIVERT
   59 #error "NOT SUPPORTED IPV6 DIVERT"
   60 #endif
   61 #ifdef IP6FW_DIVERT_RESTART
   62 #error "NOT SUPPORTED IPV6 DIVERT"
   63 #endif
   64 
   65 #include <sys/param.h>
   66 #include <sys/systm.h>
   67 #include <sys/malloc.h>
   68 #include <sys/mbuf.h>
   69 #include <sys/queue.h>
   70 #include <sys/kernel.h>
   71 #include <sys/module.h>
   72 #include <sys/socket.h>
   73 #include <sys/socketvar.h>
   74 #include <sys/syslog.h>
   75 #include <sys/time.h>
   76 #include <net/if.h>
   77 #include <net/route.h>
   78 #include <netinet/in_systm.h>
   79 #include <netinet/in.h>
   80 #include <netinet/ip.h>
   81 
   82 #include <netinet/ip6.h>
   83 #include <netinet6/ip6_var.h>
   84 #include <netinet6/in6_var.h>
   85 #include <netinet/icmp6.h>
   86 
   87 #include <netinet/in_pcb.h>
   88 
   89 #include <netinet6/ip6_fw.h>
   90 #include <netinet/ip_var.h>
   91 #include <netinet/tcp.h>
   92 #include <netinet/tcp_seq.h>
   93 #include <netinet/tcp_timer.h>
   94 #include <netinet/tcp_var.h>
   95 #include <netinet/udp.h>
   96 
   97 #include <sys/sysctl.h>
   98 
   99 #include <net/net_osdep.h>
  100 
  101 MALLOC_DEFINE(M_IP6FW, "Ip6Fw/Ip6Acct", "Ip6Fw/Ip6Acct chain's");
  102 
  103 static int fw6_debug = 1;
  104 #ifdef IPV6FIREWALL_VERBOSE
  105 static int fw6_verbose = 1;
  106 #else
  107 static int fw6_verbose = 0;
  108 #endif
  109 #ifdef IPV6FIREWALL_VERBOSE_LIMIT
  110 static int fw6_verbose_limit = IPV6FIREWALL_VERBOSE_LIMIT;
  111 #else
  112 static int fw6_verbose_limit = 0;
  113 #endif
  114 
  115 static LIST_HEAD (ip6_fw_head, ip6_fw_chain) ip6_fw_chain;
  116 
  117 #ifdef SYSCTL_NODE
  118 SYSCTL_DECL(_net_inet6_ip6);
  119 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW | CTLFLAG_SECURE,
  120     0, "Firewall");
  121 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, enable, CTLFLAG_RW | CTLFLAG_SECURE,
  122         &ip6_fw_enable, 0, "Enable ip6fw");
  123 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, debug, CTLFLAG_RW, &fw6_debug, 0, "");
  124 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose, CTLFLAG_RW | CTLFLAG_SECURE,
  125     &fw6_verbose, 0, "");
  126 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, verbose_limit, CTLFLAG_RW, &fw6_verbose_limit, 0, "");
  127 #endif
  128 
  129 #define dprintf(a)      do {                                            \
  130                                 if (fw6_debug)                          \
  131                                         printf a;                       \
  132                         } while (/*CONSTCOND*/ 0)
  133 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
  134 
  135 static int      add_entry6 __P((struct ip6_fw_head *chainptr, struct ip6_fw *frwl));
  136 static int      del_entry6 __P((struct ip6_fw_head *chainptr, u_short number));
  137 static int      zero_entry6 __P((struct mbuf *m));
  138 static struct ip6_fw *check_ip6fw_struct __P((struct ip6_fw *m));
  139 static struct ip6_fw *check_ip6fw_mbuf __P((struct mbuf *fw));
  140 static int      ip6opts_match __P((struct ip6_hdr **ip6, struct ip6_fw *f,
  141                                    struct mbuf **m,
  142                                    int *off, int *nxt, u_short *offset));
  143 static int      port_match6 __P((u_short *portptr, int nports, u_short port,
  144                                 int range_flag));
  145 static int      tcp6flg_match __P((struct tcphdr *tcp6, struct ip6_fw *f));
  146 static int      icmp6type_match __P((struct icmp6_hdr *  icmp, struct ip6_fw * f));
  147 static void     ip6fw_report __P((struct ip6_fw *f, struct ip6_hdr *ip6,
  148                                 struct ifnet *rif, struct ifnet *oif, int off, int nxt));
  149 
  150 static int      ip6_fw_chk __P((struct ip6_hdr **pip6,
  151                         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m));
  152 static int      ip6_fw_ctl __P((int stage, struct mbuf **mm));
  153 
  154 static char err_prefix[] = "ip6_fw_ctl:";
  155 
  156 /*
  157  * Returns 1 if the port is matched by the vector, 0 otherwise
  158  */
  159 static
  160 __inline
  161 int
  162 port_match6(u_short *portptr, int nports, u_short port, int range_flag)
  163 {
  164         if (!nports)
  165                 return 1;
  166         if (range_flag) {
  167                 if (portptr[0] <= port && port <= portptr[1]) {
  168                         return 1;
  169                 }
  170                 nports -= 2;
  171                 portptr += 2;
  172         }
  173         while (nports-- > 0) {
  174                 if (*portptr++ == port) {
  175                         return 1;
  176                 }
  177         }
  178         return 0;
  179 }
  180 
  181 static int
  182 tcp6flg_match(struct tcphdr *tcp6, struct ip6_fw *f)
  183 {
  184         u_char          flg_set, flg_clr;
  185 
  186         /*
  187          * If an established connection is required, reject packets that
  188          * have only SYN of RST|ACK|SYN set.  Otherwise, fall through to
  189          * other flag requirements.
  190          */
  191         if ((f->fw_ipflg & IPV6_FW_IF_TCPEST) &&
  192             ((tcp6->th_flags & (IPV6_FW_TCPF_RST | IPV6_FW_TCPF_ACK |
  193             IPV6_FW_TCPF_SYN)) == IPV6_FW_TCPF_SYN))
  194                 return 0;
  195 
  196         flg_set = tcp6->th_flags & f->fw_tcpf;
  197         flg_clr = tcp6->th_flags & f->fw_tcpnf;
  198 
  199         if (flg_set != f->fw_tcpf)
  200                 return 0;
  201         if (flg_clr)
  202                 return 0;
  203 
  204         return 1;
  205 }
  206 
  207 static int
  208 icmp6type_match(struct icmp6_hdr *icmp6, struct ip6_fw *f)
  209 {
  210         int type;
  211 
  212         if (!(f->fw_flg & IPV6_FW_F_ICMPBIT))
  213                 return (1);
  214 
  215         type = icmp6->icmp6_type;
  216 
  217         /* check for matching type in the bitmap */
  218         if (type < IPV6_FW_ICMPTYPES_DIM * sizeof(unsigned) * 8 &&
  219                 (f->fw_icmp6types[type / (sizeof(unsigned) * 8)] &
  220                 (1U << (type % (8 * sizeof(unsigned))))))
  221                 return (1);
  222 
  223         return (0); /* no match */
  224 }
  225 
  226 static int
  227 is_icmp6_query(struct ip6_hdr *ip6, int off)
  228 {
  229         const struct icmp6_hdr *icmp6;
  230         int icmp6_type;
  231 
  232         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
  233         icmp6_type = icmp6->icmp6_type;
  234 
  235         if (icmp6_type == ICMP6_ECHO_REQUEST ||
  236             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
  237             icmp6_type == ICMP6_WRUREQUEST ||
  238             icmp6_type == ICMP6_FQDN_QUERY ||
  239             icmp6_type == ICMP6_NI_QUERY)
  240                 return (1);
  241 
  242         return (0);
  243 }
  244 
  245 static int
  246 ip6opts_match(struct ip6_hdr **pip6, struct ip6_fw *f, struct mbuf **m,
  247               int *off, int *nxt, u_short *offset)
  248 {
  249         int len;
  250         struct ip6_hdr *ip6 = *pip6;
  251         struct ip6_ext *ip6e;
  252         u_char  opts, nopts, nopts_sve;
  253 
  254         opts = f->fw_ip6opt;
  255         nopts = nopts_sve = f->fw_ip6nopt;
  256 
  257         *nxt = ip6->ip6_nxt;
  258         *off = sizeof(struct ip6_hdr);
  259         len = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr);
  260         while (*off < len) {
  261                 ip6e = (struct ip6_ext *)((caddr_t) ip6 + *off);
  262                 if ((*m)->m_len < *off + sizeof(*ip6e))
  263                         goto opts_check;        /* XXX */
  264 
  265                 switch (*nxt) {
  266                 case IPPROTO_FRAGMENT:
  267                         if ((*m)->m_len >= *off + sizeof(struct ip6_frag)) {
  268                                 struct ip6_frag *ip6f;
  269 
  270                                 ip6f = (struct ip6_frag *) ((caddr_t)ip6 + *off);
  271                                 *offset = ip6f->ip6f_offlg & IP6F_OFF_MASK;
  272                         }
  273                         opts &= ~IPV6_FW_IP6OPT_FRAG;
  274                         nopts &= ~IPV6_FW_IP6OPT_FRAG;
  275                         *off += sizeof(struct ip6_frag);
  276                         break;
  277                 case IPPROTO_AH:
  278                         opts &= ~IPV6_FW_IP6OPT_AH;
  279                         nopts &= ~IPV6_FW_IP6OPT_AH;
  280                         *off += (ip6e->ip6e_len + 2) << 2;
  281                         break;
  282                 default:
  283                         switch (*nxt) {
  284                         case IPPROTO_HOPOPTS:
  285                                 opts &= ~IPV6_FW_IP6OPT_HOPOPT;
  286                                 nopts &= ~IPV6_FW_IP6OPT_HOPOPT;
  287                                 break;
  288                         case IPPROTO_ROUTING:
  289                                 opts &= ~IPV6_FW_IP6OPT_ROUTE;
  290                                 nopts &= ~IPV6_FW_IP6OPT_ROUTE;
  291                                 break;
  292                         case IPPROTO_ESP:
  293                                 opts &= ~IPV6_FW_IP6OPT_ESP;
  294                                 nopts &= ~IPV6_FW_IP6OPT_ESP;
  295                                 goto opts_check;
  296                         case IPPROTO_NONE:
  297                                 opts &= ~IPV6_FW_IP6OPT_NONXT;
  298                                 nopts &= ~IPV6_FW_IP6OPT_NONXT;
  299                                 goto opts_check;
  300                         case IPPROTO_DSTOPTS:
  301                                 opts &= ~IPV6_FW_IP6OPT_OPTS;
  302                                 nopts &= ~IPV6_FW_IP6OPT_OPTS;
  303                                 break;
  304                         default:
  305                                 goto opts_check;
  306                         }
  307                         *off += (ip6e->ip6e_len + 1) << 3;
  308                         break;
  309                 }
  310                 *nxt = ip6e->ip6e_nxt;
  311 
  312         }
  313  opts_check:
  314         if (f->fw_ip6opt == f->fw_ip6nopt)      /* XXX */
  315                 return 1;
  316 
  317         if (opts == 0 && nopts == nopts_sve)
  318                 return 1;
  319         else
  320                 return 0;
  321 }
  322 
  323 static
  324 __inline
  325 int
  326 iface_match(struct ifnet *ifp, union ip6_fw_if *ifu, int byname)
  327 {
  328         /* Check by name or by IP address */
  329         if (byname) {
  330                 /* Check name */
  331                 if (ifu->fu_via_if.glob) {
  332                         if (fnmatch(ifu->fu_via_if.name, ifp->if_xname, 0)
  333                             == FNM_NOMATCH)
  334                                 return(0);
  335                 } else {
  336                         if (strncmp(ifp->if_xname, ifu->fu_via_if.name,
  337                             IP6FW_IFNLEN) != 0)
  338                                 return(0);
  339                 }
  340                 return(1);
  341         } else if (!IN6_IS_ADDR_UNSPECIFIED(&ifu->fu_via_ip6)) {        /* Zero == wildcard */
  342                 struct ifaddr *ia;
  343 
  344                 for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) {
  345 
  346                         if (ia->ifa_addr == NULL)
  347                                 continue;
  348                         if (ia->ifa_addr->sa_family != AF_INET6)
  349                                 continue;
  350                         if (!IN6_ARE_ADDR_EQUAL(&ifu->fu_via_ip6,
  351                             &(((struct sockaddr_in6 *)
  352                             (ia->ifa_addr))->sin6_addr)))
  353                                 continue;
  354                         return (1);
  355                 }
  356                 return (0);
  357         }
  358         return (1);
  359 }
  360 
  361 static void
  362 ip6fw_report(struct ip6_fw *f, struct ip6_hdr *ip6,
  363         struct ifnet *rif, struct ifnet *oif, int off, int nxt)
  364 {
  365         static int counter;
  366         struct tcphdr *const tcp6 = (struct tcphdr *) ((caddr_t) ip6+ off);
  367         struct udphdr *const udp = (struct udphdr *) ((caddr_t) ip6+ off);
  368         struct icmp6_hdr *const icmp6 = (struct icmp6_hdr *) ((caddr_t) ip6+ off);
  369         int count;
  370         char *action;
  371         char action2[32], proto[102], name[18];
  372         int len;
  373 
  374         count = f ? f->fw_pcnt : ++counter;
  375         if (fw6_verbose_limit != 0 && count > fw6_verbose_limit)
  376                 return;
  377 
  378         /* Print command name */
  379         snprintf(SNPARGS(name, 0), "ip6fw: %d", f ? f->fw_number : -1);
  380 
  381         action = action2;
  382         if (!f)
  383                 action = "Refuse";
  384         else {
  385                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
  386                 case IPV6_FW_F_DENY:
  387                         action = "Deny";
  388                         break;
  389                 case IPV6_FW_F_REJECT:
  390                         if (f->fw_reject_code == IPV6_FW_REJECT_RST)
  391                                 action = "Reset";
  392                         else
  393                                 action = "Unreach";
  394                         break;
  395                 case IPV6_FW_F_ACCEPT:
  396                         action = "Accept";
  397                         break;
  398                 case IPV6_FW_F_COUNT:
  399                         action = "Count";
  400                         break;
  401                 case IPV6_FW_F_DIVERT:
  402                         snprintf(SNPARGS(action2, 0), "Divert %d",
  403                             f->fw_divert_port);
  404                         break;
  405                 case IPV6_FW_F_TEE:
  406                         snprintf(SNPARGS(action2, 0), "Tee %d",
  407                             f->fw_divert_port);
  408                         break;
  409                 case IPV6_FW_F_SKIPTO:
  410                         snprintf(SNPARGS(action2, 0), "SkipTo %d",
  411                             f->fw_skipto_rule);
  412                         break;
  413                 default:
  414                         action = "UNKNOWN";
  415                         break;
  416                 }
  417         }
  418 
  419         switch (nxt) {
  420         case IPPROTO_TCP:
  421                 len = snprintf(SNPARGS(proto, 0), "TCP [%s]",
  422                     ip6_sprintf(&ip6->ip6_src));
  423                 if (off > 0)
  424                         len += snprintf(SNPARGS(proto, len), ":%d ",
  425                             ntohs(tcp6->th_sport));
  426                 else
  427                         len += snprintf(SNPARGS(proto, len), " ");
  428                 len += snprintf(SNPARGS(proto, len), "[%s]",
  429                     ip6_sprintf(&ip6->ip6_dst));
  430                 if (off > 0)
  431                         snprintf(SNPARGS(proto, len), ":%d",
  432                             ntohs(tcp6->th_dport));
  433                 break;
  434         case IPPROTO_UDP:
  435                 len = snprintf(SNPARGS(proto, 0), "UDP [%s]",
  436                     ip6_sprintf(&ip6->ip6_src));
  437                 if (off > 0)
  438                         len += snprintf(SNPARGS(proto, len), ":%d ",
  439                             ntohs(udp->uh_sport));
  440                 else
  441                     len += snprintf(SNPARGS(proto, len), " ");
  442                 len += snprintf(SNPARGS(proto, len), "[%s]",
  443                     ip6_sprintf(&ip6->ip6_dst));
  444                 if (off > 0)
  445                         snprintf(SNPARGS(proto, len), ":%d",
  446                             ntohs(udp->uh_dport));
  447                 break;
  448         case IPPROTO_ICMPV6:
  449                 if (off > 0)
  450                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP:%u.%u ",
  451                             icmp6->icmp6_type, icmp6->icmp6_code);
  452                 else
  453                         len = snprintf(SNPARGS(proto, 0), "IPV6-ICMP ");
  454                 len += snprintf(SNPARGS(proto, len), "[%s]",
  455                     ip6_sprintf(&ip6->ip6_src));
  456                 snprintf(SNPARGS(proto, len), " [%s]",
  457                     ip6_sprintf(&ip6->ip6_dst));
  458                 break;
  459         default:
  460                 len = snprintf(SNPARGS(proto, 0), "P:%d [%s]", nxt,
  461                     ip6_sprintf(&ip6->ip6_src));
  462                 snprintf(SNPARGS(proto, len), " [%s]",
  463                     ip6_sprintf(&ip6->ip6_dst));
  464                 break;
  465         }
  466 
  467         if (oif)
  468                 log(LOG_SECURITY | LOG_INFO, "%s %s %s out via %s\n",
  469                     name, action, proto, if_name(oif));
  470         else if (rif)
  471                 log(LOG_SECURITY | LOG_INFO, "%s %s %s in via %s\n",
  472                     name, action, proto, if_name(rif));
  473         else
  474                 log(LOG_SECURITY | LOG_INFO, "%s %s %s",
  475                     name, action, proto);
  476         if (fw6_verbose_limit != 0 && count == fw6_verbose_limit)
  477             log(LOG_SECURITY | LOG_INFO, "ip6fw: limit reached on entry %d\n",
  478                 f ? f->fw_number : -1);
  479 }
  480 
  481 /*
  482  * Parameters:
  483  *
  484  *      ip      Pointer to packet header (struct ip6_hdr *)
  485  *      hlen    Packet header length
  486  *      oif     Outgoing interface, or NULL if packet is incoming
  487  * #ifndef IP6FW_DIVERT_RESTART
  488  *      *cookie Ignore all divert/tee rules to this port (if non-zero)
  489  * #else
  490  *      *cookie Skip up to the first rule past this rule number;
  491  * #endif
  492  *      *m      The packet; we set to NULL when/if we nuke it.
  493  *
  494  * Return value:
  495  *
  496  *      0       The packet is to be accepted and routed normally OR
  497  *              the packet was denied/rejected and has been dropped;
  498  *              in the latter case, *m is equal to NULL upon return.
  499  *      port    Divert the packet to port.
  500  */
  501 
  502 static int
  503 ip6_fw_chk(struct ip6_hdr **pip6,
  504         struct ifnet *oif, u_int16_t *cookie, struct mbuf **m)
  505 {
  506         struct ip6_fw_chain *chain;
  507         struct ip6_fw *rule = NULL;
  508         struct ip6_hdr *ip6 = *pip6;
  509         struct ifnet *const rif = (*m)->m_pkthdr.rcvif;
  510         u_short offset = 0;
  511         int off = sizeof(struct ip6_hdr), nxt = ip6->ip6_nxt;
  512         u_short src_port, dst_port;
  513 #ifdef  IP6FW_DIVERT_RESTART
  514         u_int16_t skipto = *cookie;
  515 #else
  516         u_int16_t ignport = ntohs(*cookie);
  517 #endif
  518 
  519         *cookie = 0;
  520         /*
  521          * Go down the chain, looking for enlightment
  522          * #ifdef IP6FW_DIVERT_RESTART
  523          * If we've been asked to start at a given rule immediatly, do so.
  524          * #endif
  525          */
  526         chain = LIST_FIRST(&ip6_fw_chain);
  527 #ifdef IP6FW_DIVERT_RESTART
  528         if (skipto) {
  529                 if (skipto >= 65535)
  530                         goto dropit;
  531                 while (chain && (chain->rule->fw_number <= skipto)) {
  532                         chain = LIST_NEXT(chain, chain);
  533                 }
  534                 if (! chain) goto dropit;
  535         }
  536 #endif /* IP6FW_DIVERT_RESTART */
  537         for (; chain; chain = LIST_NEXT(chain, chain)) {
  538                 struct ip6_fw *const f = chain->rule;
  539 
  540                 if (oif) {
  541                         /* Check direction outbound */
  542                         if (!(f->fw_flg & IPV6_FW_F_OUT))
  543                                 continue;
  544                 } else {
  545                         /* Check direction inbound */
  546                         if (!(f->fw_flg & IPV6_FW_F_IN))
  547                                 continue;
  548                 }
  549 
  550 #define IN6_ARE_ADDR_MASKEQUAL(x,y,z) (\
  551         (((x)->s6_addr32[0] & (y)->s6_addr32[0]) == (z)->s6_addr32[0]) && \
  552         (((x)->s6_addr32[1] & (y)->s6_addr32[1]) == (z)->s6_addr32[1]) && \
  553         (((x)->s6_addr32[2] & (y)->s6_addr32[2]) == (z)->s6_addr32[2]) && \
  554         (((x)->s6_addr32[3] & (y)->s6_addr32[3]) == (z)->s6_addr32[3]))
  555 
  556                 /* If src-addr doesn't match, not this rule. */
  557                 if (((f->fw_flg & IPV6_FW_F_INVSRC) != 0) ^
  558                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_src,&f->fw_smsk,&f->fw_src)))
  559                         continue;
  560 
  561                 /* If dest-addr doesn't match, not this rule. */
  562                 if (((f->fw_flg & IPV6_FW_F_INVDST) != 0) ^
  563                         (!IN6_ARE_ADDR_MASKEQUAL(&ip6->ip6_dst,&f->fw_dmsk,&f->fw_dst)))
  564                         continue;
  565 
  566 #undef IN6_ARE_ADDR_MASKEQUAL
  567                 /* Interface check */
  568                 if ((f->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
  569                         struct ifnet *const iface = oif ? oif : rif;
  570 
  571                         /* Backwards compatibility hack for "via" */
  572                         if (!iface || !iface_match(iface,
  573                             &f->fw_in_if, f->fw_flg & IPV6_FW_F_OIFNAME))
  574                                 continue;
  575                 } else {
  576                         /* Check receive interface */
  577                         if ((f->fw_flg & IPV6_FW_F_IIFACE)
  578                             && (!rif || !iface_match(rif,
  579                               &f->fw_in_if, f->fw_flg & IPV6_FW_F_IIFNAME)))
  580                                 continue;
  581                         /* Check outgoing interface */
  582                         if ((f->fw_flg & IPV6_FW_F_OIFACE)
  583                             && (!oif || !iface_match(oif,
  584                               &f->fw_out_if, f->fw_flg & IPV6_FW_F_OIFNAME)))
  585                                 continue;
  586                 }
  587 
  588                 /* Check IP options */
  589                 if (!ip6opts_match(&ip6, f, m, &off, &nxt, &offset))
  590                         continue;
  591 
  592                 /* Fragments */
  593                 if ((f->fw_flg & IPV6_FW_F_FRAG) && !offset)
  594                         continue;
  595 
  596                 /* Check protocol; if wildcard, match */
  597                 if (f->fw_prot == IPPROTO_IPV6)
  598                         goto got_match;
  599 
  600                 /* If different, don't match */
  601                 if (nxt != f->fw_prot)
  602                         continue;
  603 
  604 #define PULLUP_TO(len)  do {                                            \
  605                             if ((*m)->m_len < (len)                     \
  606                                 && (*m = m_pullup(*m, (len))) == 0) {   \
  607                                     goto dropit;                        \
  608                             }                                           \
  609                             *pip6 = ip6 = mtod(*m, struct ip6_hdr *);   \
  610                         } while (/*CONSTCOND*/ 0)
  611 
  612                 /* Protocol specific checks */
  613                 switch (nxt) {
  614                 case IPPROTO_TCP:
  615                     {
  616                         struct tcphdr *tcp6;
  617 
  618                         if (offset == 1) {      /* cf. RFC 1858 */
  619                                 PULLUP_TO(off + 4); /* XXX ? */
  620                                 goto bogusfrag;
  621                         }
  622                         if (offset != 0) {
  623                                 /*
  624                                  * TCP flags and ports aren't available in this
  625                                  * packet -- if this rule specified either one,
  626                                  * we consider the rule a non-match.
  627                                  */
  628                                 if (f->fw_nports != 0 ||
  629                                     f->fw_tcpf != f->fw_tcpnf)
  630                                         continue;
  631 
  632                                 break;
  633                         }
  634                         PULLUP_TO(off + 14);
  635                         tcp6 = (struct tcphdr *) ((caddr_t)ip6 + off);
  636                         if (((f->fw_tcpf != f->fw_tcpnf) ||
  637                            (f->fw_ipflg & IPV6_FW_IF_TCPEST))  &&
  638                            !tcp6flg_match(tcp6, f))
  639                                 continue;
  640                         src_port = ntohs(tcp6->th_sport);
  641                         dst_port = ntohs(tcp6->th_dport);
  642                         goto check_ports;
  643                     }
  644 
  645                 case IPPROTO_UDP:
  646                     {
  647                         struct udphdr *udp;
  648 
  649                         if (offset != 0) {
  650                                 /*
  651                                  * Port specification is unavailable -- if this
  652                                  * rule specifies a port, we consider the rule
  653                                  * a non-match.
  654                                  */
  655                                 if (f->fw_nports != 0)
  656                                         continue;
  657 
  658                                 break;
  659                         }
  660                         PULLUP_TO(off + 4);
  661                         udp = (struct udphdr *) ((caddr_t)ip6 + off);
  662                         src_port = ntohs(udp->uh_sport);
  663                         dst_port = ntohs(udp->uh_dport);
  664 check_ports:
  665                         if (!port_match6(&f->fw_pts[0],
  666                             IPV6_FW_GETNSRCP(f), src_port,
  667                             f->fw_flg & IPV6_FW_F_SRNG))
  668                                 continue;
  669                         if (!port_match6(&f->fw_pts[IPV6_FW_GETNSRCP(f)],
  670                             IPV6_FW_GETNDSTP(f), dst_port,
  671                             f->fw_flg & IPV6_FW_F_DRNG))
  672                                 continue;
  673                         break;
  674                     }
  675 
  676                 case IPPROTO_ICMPV6:
  677                     {
  678                         struct icmp6_hdr *icmp;
  679 
  680                         if (offset != 0)        /* Type isn't valid */
  681                                 break;
  682                         PULLUP_TO(off + 2);
  683                         icmp = (struct icmp6_hdr *) ((caddr_t)ip6 + off);
  684                         if (!icmp6type_match(icmp, f))
  685                                 continue;
  686                         break;
  687                     }
  688 #undef PULLUP_TO
  689 
  690 bogusfrag:
  691                         if (fw6_verbose)
  692                                 ip6fw_report(NULL, ip6, rif, oif, off, nxt);
  693                         goto dropit;
  694                 }
  695 
  696 got_match:
  697 #ifndef IP6FW_DIVERT_RESTART
  698                 /* Ignore divert/tee rule if socket port is "ignport" */
  699                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
  700                 case IPV6_FW_F_DIVERT:
  701                 case IPV6_FW_F_TEE:
  702                         if (f->fw_divert_port == ignport)
  703                                 continue;       /* ignore this rule */
  704                         break;
  705                 }
  706 
  707 #endif /* IP6FW_DIVERT_RESTART */
  708                 /* Update statistics */
  709                 f->fw_pcnt += 1;
  710                 f->fw_bcnt += ntohs(ip6->ip6_plen);
  711                 f->timestamp = time_second;
  712 
  713                 /* Log to console if desired */
  714                 if ((f->fw_flg & IPV6_FW_F_PRN) && fw6_verbose)
  715                         ip6fw_report(f, ip6, rif, oif, off, nxt);
  716 
  717                 /* Take appropriate action */
  718                 switch (f->fw_flg & IPV6_FW_F_COMMAND) {
  719                 case IPV6_FW_F_ACCEPT:
  720                         return (0);
  721                 case IPV6_FW_F_COUNT:
  722                         continue;
  723                 case IPV6_FW_F_DIVERT:
  724 #ifdef IP6FW_DIVERT_RESTART
  725                         *cookie = f->fw_number;
  726 #else
  727                         *cookie = htons(f->fw_divert_port);
  728 #endif /* IP6FW_DIVERT_RESTART */
  729                         return (f->fw_divert_port);
  730                 case IPV6_FW_F_TEE:
  731                         /*
  732                          * XXX someday tee packet here, but beware that you
  733                          * can't use m_copym() or m_copypacket() because
  734                          * the divert input routine modifies the mbuf
  735                          * (and these routines only increment reference
  736                          * counts in the case of mbuf clusters), so need
  737                          * to write custom routine.
  738                          */
  739                         continue;
  740                 case IPV6_FW_F_SKIPTO:
  741 #ifdef DIAGNOSTIC
  742                         while (chain->chain.le_next
  743                             && chain->chain.le_next->rule->fw_number
  744                                 < f->fw_skipto_rule)
  745 #else
  746                         while (chain->chain.le_next->rule->fw_number
  747                             < f->fw_skipto_rule)
  748 #endif
  749                                 chain = chain->chain.le_next;
  750                         continue;
  751                 }
  752 
  753                 /* Deny/reject this packet using this rule */
  754                 rule = f;
  755                 break;
  756         }
  757 
  758 #ifdef DIAGNOSTIC
  759         /* Rule 65535 should always be there and should always match */
  760         if (!chain)
  761                 panic("ip6_fw: chain");
  762 #endif
  763 
  764         /*
  765          * At this point, we're going to drop the packet.
  766          * Send a reject notice if all of the following are true:
  767          *
  768          * - The packet matched a reject rule
  769          * - The packet is not an ICMP packet, or is an ICMP query packet
  770          * - The packet is not a multicast or broadcast packet
  771          */
  772         if ((rule->fw_flg & IPV6_FW_F_COMMAND) == IPV6_FW_F_REJECT
  773             && (nxt != IPPROTO_ICMPV6 || is_icmp6_query(ip6, off))
  774             && !((*m)->m_flags & (M_BCAST|M_MCAST))
  775             && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  776                 switch (rule->fw_reject_code) {
  777                 case IPV6_FW_REJECT_RST:
  778 #if 1   /* not tested */
  779                   {
  780                         struct tcphdr *const tcp =
  781                                 (struct tcphdr *) ((caddr_t)ip6 + off);
  782                         struct {
  783                                 struct ip6_hdr ip6;
  784                                 struct tcphdr th;
  785                         } ti;
  786                         tcp_seq ack, seq;
  787                         int flags;
  788 
  789                         if (offset != 0 || (tcp->th_flags & TH_RST))
  790                                 break;
  791 
  792                         ti.ip6 = *ip6;
  793                         ti.th = *tcp;
  794                         ti.th.th_seq = ntohl(ti.th.th_seq);
  795                         ti.th.th_ack = ntohl(ti.th.th_ack);
  796                         ti.ip6.ip6_nxt = IPPROTO_TCP;
  797                         if (ti.th.th_flags & TH_ACK) {
  798                                 ack = 0;
  799                                 seq = ti.th.th_ack;
  800                                 flags = TH_RST;
  801                         } else {
  802                                 ack = ti.th.th_seq;
  803                                 if (((*m)->m_flags & M_PKTHDR) != 0) {
  804                                         ack += (*m)->m_pkthdr.len - off
  805                                                 - (ti.th.th_off << 2);
  806                                 } else if (ip6->ip6_plen) {
  807                                         ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
  808                                                 - off - (ti.th.th_off << 2);
  809                                 } else {
  810                                         m_freem(*m);
  811                                         *m = 0;
  812                                         break;
  813                                 }
  814                                 if (tcp->th_flags & TH_SYN)
  815                                         ack++;
  816                                 seq = 0;
  817                                 flags = TH_RST|TH_ACK;
  818                         }
  819                         bcopy(&ti, ip6, sizeof(ti));
  820                         tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
  821                                 *m, ack, seq, flags);
  822                         *m = NULL;
  823                         break;
  824                   }
  825 #endif
  826                 default:        /* Send an ICMP unreachable using code */
  827                         if (oif)
  828                                 (*m)->m_pkthdr.rcvif = oif;
  829                         icmp6_error(*m, ICMP6_DST_UNREACH,
  830                             rule->fw_reject_code, 0);
  831                         *m = NULL;
  832                         break;
  833                 }
  834         }
  835 
  836 dropit:
  837         /*
  838          * Finally, drop the packet.
  839          */
  840         if (*m) {
  841                 m_freem(*m);
  842                 *m = NULL;
  843         }
  844         return (0);
  845 }
  846 
  847 static int
  848 add_entry6(struct ip6_fw_head *chainptr, struct ip6_fw *frwl)
  849 {
  850         struct ip6_fw *ftmp = 0;
  851         struct ip6_fw_chain *fwc = 0, *fcp, *fcpl = 0;
  852         u_short nbr = 0;
  853         int s;
  854 
  855         fwc = malloc(sizeof *fwc, M_IP6FW, M_NOWAIT);
  856         ftmp = malloc(sizeof *ftmp, M_IP6FW, M_NOWAIT);
  857         if (!fwc || !ftmp) {
  858                 dprintf(("%s malloc said no\n", err_prefix));
  859                 if (fwc)  free(fwc, M_IP6FW);
  860                 if (ftmp) free(ftmp, M_IP6FW);
  861                 return (ENOSPC);
  862         }
  863 
  864         bcopy(frwl, ftmp, sizeof(struct ip6_fw));
  865         ftmp->fw_in_if.fu_via_if.name[IP6FW_IFNLEN - 1] = '\0';
  866         ftmp->fw_pcnt = 0L;
  867         ftmp->fw_bcnt = 0L;
  868         fwc->rule = ftmp;
  869 
  870         s = splnet();
  871 
  872         if (!chainptr->lh_first) {
  873                 LIST_INSERT_HEAD(chainptr, fwc, chain);
  874                 splx(s);
  875                 return (0);
  876         } else if (ftmp->fw_number == (u_short)-1) {
  877                 if (fwc)  free(fwc, M_IP6FW);
  878                 if (ftmp) free(ftmp, M_IP6FW);
  879                 splx(s);
  880                 dprintf(("%s bad rule number\n", err_prefix));
  881                 return (EINVAL);
  882         }
  883 
  884         /* If entry number is 0, find highest numbered rule and add 100 */
  885         if (ftmp->fw_number == 0) {
  886                 for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
  887                         if (fcp->rule->fw_number != (u_short)-1)
  888                                 nbr = fcp->rule->fw_number;
  889                         else
  890                                 break;
  891                 }
  892                 if (nbr < (u_short)-1 - 100)
  893                         nbr += 100;
  894                 ftmp->fw_number = nbr;
  895         }
  896 
  897         /* Got a valid number; now insert it, keeping the list ordered */
  898         for (fcp = chainptr->lh_first; fcp; fcp = fcp->chain.le_next) {
  899                 if (fcp->rule->fw_number > ftmp->fw_number) {
  900                         if (fcpl) {
  901                                 LIST_INSERT_AFTER(fcpl, fwc, chain);
  902                         } else {
  903                                 LIST_INSERT_HEAD(chainptr, fwc, chain);
  904                         }
  905                         break;
  906                 } else {
  907                         fcpl = fcp;
  908                 }
  909         }
  910 
  911         splx(s);
  912         return (0);
  913 }
  914 
  915 static int
  916 del_entry6(struct ip6_fw_head *chainptr, u_short number)
  917 {
  918         struct ip6_fw_chain *fcp;
  919         int s;
  920 
  921         s = splnet();
  922 
  923         fcp = chainptr->lh_first;
  924         if (number != (u_short)-1) {
  925                 for (; fcp; fcp = fcp->chain.le_next) {
  926                         if (fcp->rule->fw_number == number) {
  927                                 LIST_REMOVE(fcp, chain);
  928                                 splx(s);
  929                                 free(fcp->rule, M_IP6FW);
  930                                 free(fcp, M_IP6FW);
  931                                 return 0;
  932                         }
  933                 }
  934         }
  935 
  936         splx(s);
  937         return (EINVAL);
  938 }
  939 
  940 static int
  941 zero_entry6(struct mbuf *m)
  942 {
  943         struct ip6_fw *frwl;
  944         struct ip6_fw_chain *fcp;
  945         int s;
  946 
  947         if (m && m->m_len != 0) {
  948                 if (m->m_len != sizeof(struct ip6_fw))
  949                         return (EINVAL);
  950                 frwl = mtod(m, struct ip6_fw *);
  951         }
  952         else
  953                 frwl = NULL;
  954 
  955         /*
  956          *      It's possible to insert multiple chain entries with the
  957          *      same number, so we don't stop after finding the first
  958          *      match if zeroing a specific entry.
  959          */
  960         s = splnet();
  961         for (fcp = ip6_fw_chain.lh_first; fcp; fcp = fcp->chain.le_next)
  962                 if (!frwl || frwl->fw_number == fcp->rule->fw_number) {
  963                         fcp->rule->fw_bcnt = fcp->rule->fw_pcnt = 0;
  964                         fcp->rule->timestamp = 0;
  965                 }
  966         splx(s);
  967 
  968         if (fw6_verbose) {
  969                 if (frwl)
  970                         log(LOG_SECURITY | LOG_NOTICE,
  971                             "ip6fw: Entry %d cleared.\n", frwl->fw_number);
  972                 else
  973                         log(LOG_SECURITY | LOG_NOTICE,
  974                             "ip6fw: Accounting cleared.\n");
  975         }
  976 
  977         return (0);
  978 }
  979 
  980 static struct ip6_fw *
  981 check_ip6fw_mbuf(struct mbuf *m)
  982 {
  983         /* Check length */
  984         if (m->m_len != sizeof(struct ip6_fw)) {
  985                 dprintf(("%s len=%d, want %zu\n", err_prefix, m->m_len,
  986                     sizeof(struct ip6_fw)));
  987                 return (NULL);
  988         }
  989         return (check_ip6fw_struct(mtod(m, struct ip6_fw *)));
  990 }
  991 
  992 static struct ip6_fw *
  993 check_ip6fw_struct(struct ip6_fw *frwl)
  994 {
  995         /* Check for invalid flag bits */
  996         if ((frwl->fw_flg & ~IPV6_FW_F_MASK) != 0) {
  997                 dprintf(("%s undefined flag bits set (flags=%x)\n",
  998                     err_prefix, frwl->fw_flg));
  999                 return (NULL);
 1000         }
 1001         /* Must apply to incoming or outgoing (or both) */
 1002         if (!(frwl->fw_flg & (IPV6_FW_F_IN | IPV6_FW_F_OUT))) {
 1003                 dprintf(("%s neither in nor out\n", err_prefix));
 1004                 return (NULL);
 1005         }
 1006         /* Empty interface name is no good */
 1007         if (((frwl->fw_flg & IPV6_FW_F_IIFNAME)
 1008               && !*frwl->fw_in_if.fu_via_if.name)
 1009             || ((frwl->fw_flg & IPV6_FW_F_OIFNAME)
 1010               && !*frwl->fw_out_if.fu_via_if.name)) {
 1011                 dprintf(("%s empty interface name\n", err_prefix));
 1012                 return (NULL);
 1013         }
 1014         /* Sanity check interface matching */
 1015         if ((frwl->fw_flg & IF6_FW_F_VIAHACK) == IF6_FW_F_VIAHACK) {
 1016                 ;               /* allow "via" backwards compatibility */
 1017         } else if ((frwl->fw_flg & IPV6_FW_F_IN)
 1018             && (frwl->fw_flg & IPV6_FW_F_OIFACE)) {
 1019                 dprintf(("%s outgoing interface check on incoming\n",
 1020                     err_prefix));
 1021                 return (NULL);
 1022         }
 1023         /* Sanity check port ranges */
 1024         if ((frwl->fw_flg & IPV6_FW_F_SRNG) && IPV6_FW_GETNSRCP(frwl) < 2) {
 1025                 dprintf(("%s src range set but n_src_p=%d\n",
 1026                     err_prefix, IPV6_FW_GETNSRCP(frwl)));
 1027                 return (NULL);
 1028         }
 1029         if ((frwl->fw_flg & IPV6_FW_F_DRNG) && IPV6_FW_GETNDSTP(frwl) < 2) {
 1030                 dprintf(("%s dst range set but n_dst_p=%d\n",
 1031                     err_prefix, IPV6_FW_GETNDSTP(frwl)));
 1032                 return (NULL);
 1033         }
 1034         if (IPV6_FW_GETNSRCP(frwl) + IPV6_FW_GETNDSTP(frwl) > IPV6_FW_MAX_PORTS) {
 1035                 dprintf(("%s too many ports (%d+%d)\n",
 1036                     err_prefix, IPV6_FW_GETNSRCP(frwl), IPV6_FW_GETNDSTP(frwl)));
 1037                 return (NULL);
 1038         }
 1039         /*
 1040          *      Protocols other than TCP/UDP don't use port range
 1041          */
 1042         if ((frwl->fw_prot != IPPROTO_TCP) &&
 1043             (frwl->fw_prot != IPPROTO_UDP) &&
 1044             (IPV6_FW_GETNSRCP(frwl) || IPV6_FW_GETNDSTP(frwl))) {
 1045                 dprintf(("%s port(s) specified for non TCP/UDP rule\n",
 1046                     err_prefix));
 1047                 return (NULL);
 1048         }
 1049 
 1050         /*
 1051          *      Rather than modify the entry to make such entries work,
 1052          *      we reject this rule and require user level utilities
 1053          *      to enforce whatever policy they deem appropriate.
 1054          */
 1055         if ((frwl->fw_src.s6_addr32[0] & (~frwl->fw_smsk.s6_addr32[0])) ||
 1056                 (frwl->fw_src.s6_addr32[1] & (~frwl->fw_smsk.s6_addr32[1])) ||
 1057                 (frwl->fw_src.s6_addr32[2] & (~frwl->fw_smsk.s6_addr32[2])) ||
 1058                 (frwl->fw_src.s6_addr32[3] & (~frwl->fw_smsk.s6_addr32[3])) ||
 1059                 (frwl->fw_dst.s6_addr32[0] & (~frwl->fw_dmsk.s6_addr32[0])) ||
 1060                 (frwl->fw_dst.s6_addr32[1] & (~frwl->fw_dmsk.s6_addr32[1])) ||
 1061                 (frwl->fw_dst.s6_addr32[2] & (~frwl->fw_dmsk.s6_addr32[2])) ||
 1062                 (frwl->fw_dst.s6_addr32[3] & (~frwl->fw_dmsk.s6_addr32[3]))) {
 1063                 dprintf(("%s rule never matches\n", err_prefix));
 1064                 return (NULL);
 1065         }
 1066 
 1067         if ((frwl->fw_flg & IPV6_FW_F_FRAG) &&
 1068                 (frwl->fw_prot == IPPROTO_UDP || frwl->fw_prot == IPPROTO_TCP)) {
 1069                 if (frwl->fw_nports) {
 1070                         dprintf(("%s cannot mix 'frag' and ports\n", err_prefix));
 1071                         return (NULL);
 1072                 }
 1073                 if (frwl->fw_prot == IPPROTO_TCP &&
 1074                         frwl->fw_tcpf != frwl->fw_tcpnf) {
 1075                         dprintf(("%s cannot mix 'frag' with TCP flags\n", err_prefix));
 1076                         return (NULL);
 1077                 }
 1078         }
 1079 
 1080         /* Check command specific stuff */
 1081         switch (frwl->fw_flg & IPV6_FW_F_COMMAND)
 1082         {
 1083         case IPV6_FW_F_REJECT:
 1084                 if (frwl->fw_reject_code >= 0x100
 1085                     && !(frwl->fw_prot == IPPROTO_TCP
 1086                       && frwl->fw_reject_code == IPV6_FW_REJECT_RST)) {
 1087                         dprintf(("%s unknown reject code\n", err_prefix));
 1088                         return (NULL);
 1089                 }
 1090                 break;
 1091         case IPV6_FW_F_DIVERT:          /* Diverting to port zero is invalid */
 1092         case IPV6_FW_F_TEE:
 1093                 if (frwl->fw_divert_port == 0) {
 1094                         dprintf(("%s can't divert to port 0\n", err_prefix));
 1095                         return (NULL);
 1096                 }
 1097                 break;
 1098         case IPV6_FW_F_DENY:
 1099         case IPV6_FW_F_ACCEPT:
 1100         case IPV6_FW_F_COUNT:
 1101         case IPV6_FW_F_SKIPTO:
 1102                 break;
 1103         default:
 1104                 dprintf(("%s invalid command\n", err_prefix));
 1105                 return (NULL);
 1106         }
 1107 
 1108         return frwl;
 1109 }
 1110 
 1111 static int
 1112 ip6_fw_ctl(int stage, struct mbuf **mm)
 1113 {
 1114         int error;
 1115         struct mbuf *m;
 1116 
 1117         if (stage == IPV6_FW_GET) {
 1118                 struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
 1119                 *mm = m = m_get(M_TRYWAIT, MT_DATA); /* XXX */
 1120                 if (!m)
 1121                         return (ENOBUFS);
 1122                 if (sizeof *(fcp->rule) > MLEN) {
 1123                         MCLGET(m, M_TRYWAIT);
 1124                         if ((m->m_flags & M_EXT) == 0) {
 1125                                 m_free(m);
 1126                                 return (ENOBUFS);
 1127                         }
 1128                 }
 1129                 for (; fcp; fcp = fcp->chain.le_next) {
 1130                         bcopy(fcp->rule, m->m_data, sizeof *(fcp->rule));
 1131                         m->m_len = sizeof *(fcp->rule);
 1132                         m->m_next = m_get(M_TRYWAIT, MT_DATA); /* XXX */
 1133                         if (!m->m_next) {
 1134                                 m_freem(*mm);
 1135                                 return (ENOBUFS);
 1136                         }
 1137                         m = m->m_next;
 1138                         if (sizeof *(fcp->rule) > MLEN) {
 1139                                 MCLGET(m, M_TRYWAIT);
 1140                                 if ((m->m_flags & M_EXT) == 0) {
 1141                                         m_freem(*mm);
 1142                                         return (ENOBUFS);
 1143                                 }
 1144                         }
 1145                         m->m_len = 0;
 1146                 }
 1147                 return (0);
 1148         }
 1149         m = *mm;
 1150         /* only allow get calls if secure mode > 2 */
 1151         if (securelevel > 2) {
 1152                 if (m) {
 1153                         (void)m_freem(m);
 1154                         *mm = 0;
 1155                 }
 1156                 return (EPERM);
 1157         }
 1158         if (stage == IPV6_FW_FLUSH) {
 1159                 while (ip6_fw_chain.lh_first != NULL &&
 1160                     ip6_fw_chain.lh_first->rule->fw_number != (u_short)-1) {
 1161                         struct ip6_fw_chain *fcp = ip6_fw_chain.lh_first;
 1162                         int s = splnet();
 1163                         LIST_REMOVE(ip6_fw_chain.lh_first, chain);
 1164                         splx(s);
 1165                         free(fcp->rule, M_IP6FW);
 1166                         free(fcp, M_IP6FW);
 1167                 }
 1168                 if (m) {
 1169                         (void)m_freem(m);
 1170                         *mm = 0;
 1171                 }
 1172                 return (0);
 1173         }
 1174         if (stage == IPV6_FW_ZERO) {
 1175                 error = zero_entry6(m);
 1176                 if (m) {
 1177                         (void)m_freem(m);
 1178                         *mm = 0;
 1179                 }
 1180                 return (error);
 1181         }
 1182         if (m == NULL) {
 1183                 printf("%s NULL mbuf ptr\n", err_prefix);
 1184                 return (EINVAL);
 1185         }
 1186 
 1187         if (stage == IPV6_FW_ADD) {
 1188                 struct ip6_fw *frwl = check_ip6fw_mbuf(m);
 1189 
 1190                 if (!frwl)
 1191                         error = EINVAL;
 1192                 else
 1193                         error = add_entry6(&ip6_fw_chain, frwl);
 1194                 if (m) {
 1195                         (void)m_freem(m);
 1196                         *mm = 0;
 1197                 }
 1198                 return error;
 1199         }
 1200         if (stage == IPV6_FW_DEL) {
 1201                 if (m->m_len != sizeof(struct ip6_fw)) {
 1202                         dprintf(("%s len=%d, want %zu\n", err_prefix, m->m_len,
 1203                             sizeof(struct ip6_fw)));
 1204                         error = EINVAL;
 1205                 } else if (mtod(m, struct ip6_fw *)->fw_number == (u_short)-1) {
 1206                         dprintf(("%s can't delete rule 65535\n", err_prefix));
 1207                         error = EINVAL;
 1208                 } else
 1209                         error = del_entry6(&ip6_fw_chain,
 1210                             mtod(m, struct ip6_fw *)->fw_number);
 1211                 if (m) {
 1212                         (void)m_freem(m);
 1213                         *mm = 0;
 1214                 }
 1215                 return error;
 1216         }
 1217 
 1218         dprintf(("%s unknown request %d\n", err_prefix, stage));
 1219         if (m) {
 1220                 (void)m_freem(m);
 1221                 *mm = 0;
 1222         }
 1223         return (EINVAL);
 1224 }
 1225 
 1226 void
 1227 ip6_fw_init(void)
 1228 {
 1229         struct ip6_fw default_rule;
 1230 
 1231         ip6_fw_chk_ptr = ip6_fw_chk;
 1232         ip6_fw_ctl_ptr = ip6_fw_ctl;
 1233         LIST_INIT(&ip6_fw_chain);
 1234 
 1235         bzero(&default_rule, sizeof default_rule);
 1236         default_rule.fw_prot = IPPROTO_IPV6;
 1237         default_rule.fw_number = (u_short)-1;
 1238 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
 1239         default_rule.fw_flg |= IPV6_FW_F_ACCEPT;
 1240 #else
 1241         default_rule.fw_flg |= IPV6_FW_F_DENY;
 1242 #endif
 1243         default_rule.fw_flg |= IPV6_FW_F_IN | IPV6_FW_F_OUT;
 1244         if (check_ip6fw_struct(&default_rule) == NULL ||
 1245                 add_entry6(&ip6_fw_chain, &default_rule))
 1246                 panic(__FUNCTION__);
 1247 
 1248         printf("IPv6 packet filtering initialized, ");
 1249 #ifdef IPV6FIREWALL_DEFAULT_TO_ACCEPT
 1250         printf("default to accept, ");
 1251 #endif
 1252 #ifndef IPV6FIREWALL_VERBOSE
 1253         printf("logging disabled\n");
 1254 #else
 1255         if (fw6_verbose_limit == 0)
 1256                 printf("unlimited logging\n");
 1257         else
 1258                 printf("logging limited to %d packets/entry\n",
 1259                     fw6_verbose_limit);
 1260 #endif
 1261 }
 1262 
 1263 static ip6_fw_chk_t *old_chk_ptr;
 1264 static ip6_fw_ctl_t *old_ctl_ptr;
 1265 
 1266 static int
 1267 ip6fw_modevent(module_t mod, int type, void *unused)
 1268 {
 1269         int s;
 1270 
 1271         switch (type) {
 1272         case MOD_LOAD:
 1273                 s = splnet();
 1274 
 1275                 old_chk_ptr = ip6_fw_chk_ptr;
 1276                 old_ctl_ptr = ip6_fw_ctl_ptr;
 1277 
 1278                 ip6_fw_init();
 1279                 splx(s);
 1280                 return 0;
 1281         case MOD_UNLOAD:
 1282                 s = splnet();
 1283                 ip6_fw_chk_ptr =  old_chk_ptr;
 1284                 ip6_fw_ctl_ptr =  old_ctl_ptr;
 1285                 while (LIST_FIRST(&ip6_fw_chain) != NULL) {
 1286                         struct ip6_fw_chain *fcp = LIST_FIRST(&ip6_fw_chain);
 1287                         LIST_REMOVE(LIST_FIRST(&ip6_fw_chain), chain);
 1288                         free(fcp->rule, M_IP6FW);
 1289                         free(fcp, M_IP6FW);
 1290                 }
 1291 
 1292                 splx(s);
 1293                 printf("IPv6 firewall unloaded\n");
 1294                 return 0;
 1295         default:
 1296                 return EOPNOTSUPP;
 1297                 break;
 1298         }
 1299         return 0;
 1300 }
 1301 
 1302 static moduledata_t ip6fwmod = {
 1303         "ip6fw",
 1304         ip6fw_modevent,
 1305         0
 1306 };
 1307 DECLARE_MODULE(ip6fw, ip6fwmod, SI_SUB_PSEUDO, SI_ORDER_ANY);

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