The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_fw2.c

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    1 /*-
    2  * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
    3  *
    4  * Redistribution and use in source and binary forms, with or without
    5  * modification, are permitted provided that the following conditions
    6  * are met:
    7  * 1. Redistributions of source code must retain the above copyright
    8  *    notice, this list of conditions and the following disclaimer.
    9  * 2. Redistributions in binary form must reproduce the above copyright
   10  *    notice, this list of conditions and the following disclaimer in the
   11  *    documentation and/or other materials provided with the distribution.
   12  *
   13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   23  * SUCH DAMAGE.
   24  *
   25  * $FreeBSD: releng/6.1/sys/netinet/ip_fw2.c 156494 2006-03-09 13:42:44Z glebius $
   26  */
   27 
   28 #define        DEB(x)
   29 #define        DDB(x) x
   30 
   31 /*
   32  * Implement IP packet firewall (new version)
   33  */
   34 
   35 #if !defined(KLD_MODULE)
   36 #include "opt_ipfw.h"
   37 #include "opt_ip6fw.h"
   38 #include "opt_ipdn.h"
   39 #include "opt_inet.h"
   40 #ifndef INET
   41 #error IPFIREWALL requires INET.
   42 #endif /* INET */
   43 #endif
   44 #include "opt_inet6.h"
   45 #include "opt_ipsec.h"
   46 
   47 #include <sys/param.h>
   48 #include <sys/systm.h>
   49 #include <sys/condvar.h>
   50 #include <sys/malloc.h>
   51 #include <sys/mbuf.h>
   52 #include <sys/kernel.h>
   53 #include <sys/jail.h>
   54 #include <sys/module.h>
   55 #include <sys/proc.h>
   56 #include <sys/socket.h>
   57 #include <sys/socketvar.h>
   58 #include <sys/sysctl.h>
   59 #include <sys/syslog.h>
   60 #include <sys/ucred.h>
   61 #include <net/if.h>
   62 #include <net/radix.h>
   63 #include <net/route.h>
   64 #include <netinet/in.h>
   65 #include <netinet/in_systm.h>
   66 #include <netinet/in_var.h>
   67 #include <netinet/in_pcb.h>
   68 #include <netinet/ip.h>
   69 #include <netinet/ip_var.h>
   70 #include <netinet/ip_icmp.h>
   71 #include <netinet/ip_fw.h>
   72 #include <netinet/ip_divert.h>
   73 #include <netinet/ip_dummynet.h>
   74 #include <netinet/tcp.h>
   75 #include <netinet/tcp_timer.h>
   76 #include <netinet/tcp_var.h>
   77 #include <netinet/tcpip.h>
   78 #include <netinet/udp.h>
   79 #include <netinet/udp_var.h>
   80 
   81 #include <netgraph/ng_ipfw.h>
   82 
   83 #include <altq/if_altq.h>
   84 
   85 #ifdef IPSEC
   86 #include <netinet6/ipsec.h>
   87 #endif
   88 
   89 #include <netinet/ip6.h>
   90 #include <netinet/icmp6.h>
   91 #ifdef INET6
   92 #include <netinet6/scope6_var.h>
   93 #endif
   94 
   95 #include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
   96 
   97 #include <machine/in_cksum.h>   /* XXX for in_cksum */
   98 
   99 /*
  100  * set_disable contains one bit per set value (0..31).
  101  * If the bit is set, all rules with the corresponding set
  102  * are disabled. Set RESVD_SET(31) is reserved for the default rule
  103  * and rules that are not deleted by the flush command,
  104  * and CANNOT be disabled.
  105  * Rules in set RESVD_SET can only be deleted explicitly.
  106  */
  107 static u_int32_t set_disable;
  108 
  109 static int fw_verbose;
  110 static int verbose_limit;
  111 
  112 static struct callout ipfw_timeout;
  113 static uma_zone_t ipfw_dyn_rule_zone;
  114 #define IPFW_DEFAULT_RULE       65535
  115 
  116 /*
  117  * Data structure to cache our ucred related
  118  * information. This structure only gets used if
  119  * the user specified UID/GID based constraints in
  120  * a firewall rule.
  121  */
  122 struct ip_fw_ugid {
  123         gid_t           fw_groups[NGROUPS];
  124         int             fw_ngroups;
  125         uid_t           fw_uid;
  126         int             fw_prid;
  127 };
  128 
  129 #define IPFW_TABLES_MAX         128
  130 struct ip_fw_chain {
  131         struct ip_fw    *rules;         /* list of rules */
  132         struct ip_fw    *reap;          /* list of rules to reap */
  133         struct radix_node_head *tables[IPFW_TABLES_MAX];
  134         struct mtx      mtx;            /* lock guarding rule list */
  135         int             busy_count;     /* busy count for rw locks */
  136         int             want_write;
  137         struct cv       cv;
  138 };
  139 #define IPFW_LOCK_INIT(_chain) \
  140         mtx_init(&(_chain)->mtx, "IPFW static rules", NULL, \
  141                 MTX_DEF | MTX_RECURSE)
  142 #define IPFW_LOCK_DESTROY(_chain)       mtx_destroy(&(_chain)->mtx)
  143 #define IPFW_WLOCK_ASSERT(_chain)       do {                            \
  144         mtx_assert(&(_chain)->mtx, MA_OWNED);                           \
  145         NET_ASSERT_GIANT();                                             \
  146 } while (0)
  147 
  148 static __inline void
  149 IPFW_RLOCK(struct ip_fw_chain *chain)
  150 {
  151         mtx_lock(&chain->mtx);
  152         chain->busy_count++;
  153         mtx_unlock(&chain->mtx);
  154 }
  155 
  156 static __inline void
  157 IPFW_RUNLOCK(struct ip_fw_chain *chain)
  158 {
  159         mtx_lock(&chain->mtx);
  160         chain->busy_count--;
  161         if (chain->busy_count == 0 && chain->want_write)
  162                 cv_signal(&chain->cv);
  163         mtx_unlock(&chain->mtx);
  164 }
  165 
  166 static __inline void
  167 IPFW_WLOCK(struct ip_fw_chain *chain)
  168 {
  169         mtx_lock(&chain->mtx);
  170         chain->want_write++;
  171         while (chain->busy_count > 0)
  172                 cv_wait(&chain->cv, &chain->mtx);
  173 }
  174 
  175 static __inline void
  176 IPFW_WUNLOCK(struct ip_fw_chain *chain)
  177 {
  178         chain->want_write--;
  179         cv_signal(&chain->cv);
  180         mtx_unlock(&chain->mtx);
  181 }
  182 
  183 /*
  184  * list of rules for layer 3
  185  */
  186 static struct ip_fw_chain layer3_chain;
  187 
  188 MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
  189 MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables");
  190 
  191 struct table_entry {
  192         struct radix_node       rn[2];
  193         struct sockaddr_in      addr, mask;
  194         u_int32_t               value;
  195 };
  196 
  197 static int fw_debug = 1;
  198 static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
  199 
  200 #ifdef SYSCTL_NODE
  201 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
  202 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable,
  203     CTLFLAG_RW | CTLFLAG_SECURE3,
  204     &fw_enable, 0, "Enable ipfw");
  205 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW,
  206     &autoinc_step, 0, "Rule number autincrement step");
  207 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
  208     CTLFLAG_RW | CTLFLAG_SECURE3,
  209     &fw_one_pass, 0,
  210     "Only do a single pass through ipfw when using dummynet(4)");
  211 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
  212     &fw_debug, 0, "Enable printing of debug ip_fw statements");
  213 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose,
  214     CTLFLAG_RW | CTLFLAG_SECURE3,
  215     &fw_verbose, 0, "Log matches to ipfw rules");
  216 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
  217     &verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
  218 
  219 /*
  220  * Description of dynamic rules.
  221  *
  222  * Dynamic rules are stored in lists accessed through a hash table
  223  * (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
  224  * be modified through the sysctl variable dyn_buckets which is
  225  * updated when the table becomes empty.
  226  *
  227  * XXX currently there is only one list, ipfw_dyn.
  228  *
  229  * When a packet is received, its address fields are first masked
  230  * with the mask defined for the rule, then hashed, then matched
  231  * against the entries in the corresponding list.
  232  * Dynamic rules can be used for different purposes:
  233  *  + stateful rules;
  234  *  + enforcing limits on the number of sessions;
  235  *  + in-kernel NAT (not implemented yet)
  236  *
  237  * The lifetime of dynamic rules is regulated by dyn_*_lifetime,
  238  * measured in seconds and depending on the flags.
  239  *
  240  * The total number of dynamic rules is stored in dyn_count.
  241  * The max number of dynamic rules is dyn_max. When we reach
  242  * the maximum number of rules we do not create anymore. This is
  243  * done to avoid consuming too much memory, but also too much
  244  * time when searching on each packet (ideally, we should try instead
  245  * to put a limit on the length of the list on each bucket...).
  246  *
  247  * Each dynamic rule holds a pointer to the parent ipfw rule so
  248  * we know what action to perform. Dynamic rules are removed when
  249  * the parent rule is deleted. XXX we should make them survive.
  250  *
  251  * There are some limitations with dynamic rules -- we do not
  252  * obey the 'randomized match', and we do not do multiple
  253  * passes through the firewall. XXX check the latter!!!
  254  */
  255 static ipfw_dyn_rule **ipfw_dyn_v = NULL;
  256 static u_int32_t dyn_buckets = 256; /* must be power of 2 */
  257 static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */
  258 
  259 static struct mtx ipfw_dyn_mtx;         /* mutex guarding dynamic rules */
  260 #define IPFW_DYN_LOCK_INIT() \
  261         mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF)
  262 #define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx)
  263 #define IPFW_DYN_LOCK()         mtx_lock(&ipfw_dyn_mtx)
  264 #define IPFW_DYN_UNLOCK()       mtx_unlock(&ipfw_dyn_mtx)
  265 #define IPFW_DYN_LOCK_ASSERT()  mtx_assert(&ipfw_dyn_mtx, MA_OWNED)
  266 
  267 /*
  268  * Timeouts for various events in handing dynamic rules.
  269  */
  270 static u_int32_t dyn_ack_lifetime = 300;
  271 static u_int32_t dyn_syn_lifetime = 20;
  272 static u_int32_t dyn_fin_lifetime = 1;
  273 static u_int32_t dyn_rst_lifetime = 1;
  274 static u_int32_t dyn_udp_lifetime = 10;
  275 static u_int32_t dyn_short_lifetime = 5;
  276 
  277 /*
  278  * Keepalives are sent if dyn_keepalive is set. They are sent every
  279  * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
  280  * seconds of lifetime of a rule.
  281  * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
  282  * than dyn_keepalive_period.
  283  */
  284 
  285 static u_int32_t dyn_keepalive_interval = 20;
  286 static u_int32_t dyn_keepalive_period = 5;
  287 static u_int32_t dyn_keepalive = 1;     /* do send keepalives */
  288 
  289 static u_int32_t static_count;  /* # of static rules */
  290 static u_int32_t static_len;    /* size in bytes of static rules */
  291 static u_int32_t dyn_count;             /* # of dynamic rules */
  292 static u_int32_t dyn_max = 4096;        /* max # of dynamic rules */
  293 
  294 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
  295     &dyn_buckets, 0, "Number of dyn. buckets");
  296 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
  297     &curr_dyn_buckets, 0, "Current Number of dyn. buckets");
  298 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
  299     &dyn_count, 0, "Number of dyn. rules");
  300 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
  301     &dyn_max, 0, "Max number of dyn. rules");
  302 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
  303     &static_count, 0, "Number of static rules");
  304 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
  305     &dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
  306 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
  307     &dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
  308 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
  309     &dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
  310 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
  311     &dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
  312 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
  313     &dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
  314 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
  315     &dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
  316 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
  317     &dyn_keepalive, 0, "Enable keepalives for dyn. rules");
  318 
  319 #ifdef INET6
  320 /*
  321  * IPv6 specific variables
  322  */
  323 SYSCTL_DECL(_net_inet6_ip6);
  324 
  325 static struct sysctl_ctx_list ip6_fw_sysctl_ctx;
  326 static struct sysctl_oid *ip6_fw_sysctl_tree;
  327 #endif /* INET6 */
  328 #endif /* SYSCTL_NODE */
  329 
  330 static int fw_deny_unknown_exthdrs = 1;
  331 
  332 
  333 /*
  334  * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
  335  * Other macros just cast void * into the appropriate type
  336  */
  337 #define L3HDR(T, ip)    ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
  338 #define TCP(p)          ((struct tcphdr *)(p))
  339 #define UDP(p)          ((struct udphdr *)(p))
  340 #define ICMP(p)         ((struct icmphdr *)(p))
  341 #define ICMP6(p)        ((struct icmp6_hdr *)(p))
  342 
  343 static __inline int
  344 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
  345 {
  346         int type = icmp->icmp_type;
  347 
  348         return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
  349 }
  350 
  351 #define TT      ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
  352     (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
  353 
  354 static int
  355 is_icmp_query(struct icmphdr *icmp)
  356 {
  357         int type = icmp->icmp_type;
  358 
  359         return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
  360 }
  361 #undef TT
  362 
  363 /*
  364  * The following checks use two arrays of 8 or 16 bits to store the
  365  * bits that we want set or clear, respectively. They are in the
  366  * low and high half of cmd->arg1 or cmd->d[0].
  367  *
  368  * We scan options and store the bits we find set. We succeed if
  369  *
  370  *      (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
  371  *
  372  * The code is sometimes optimized not to store additional variables.
  373  */
  374 
  375 static int
  376 flags_match(ipfw_insn *cmd, u_int8_t bits)
  377 {
  378         u_char want_clear;
  379         bits = ~bits;
  380 
  381         if ( ((cmd->arg1 & 0xff) & bits) != 0)
  382                 return 0; /* some bits we want set were clear */
  383         want_clear = (cmd->arg1 >> 8) & 0xff;
  384         if ( (want_clear & bits) != want_clear)
  385                 return 0; /* some bits we want clear were set */
  386         return 1;
  387 }
  388 
  389 static int
  390 ipopts_match(struct ip *ip, ipfw_insn *cmd)
  391 {
  392         int optlen, bits = 0;
  393         u_char *cp = (u_char *)(ip + 1);
  394         int x = (ip->ip_hl << 2) - sizeof (struct ip);
  395 
  396         for (; x > 0; x -= optlen, cp += optlen) {
  397                 int opt = cp[IPOPT_OPTVAL];
  398 
  399                 if (opt == IPOPT_EOL)
  400                         break;
  401                 if (opt == IPOPT_NOP)
  402                         optlen = 1;
  403                 else {
  404                         optlen = cp[IPOPT_OLEN];
  405                         if (optlen <= 0 || optlen > x)
  406                                 return 0; /* invalid or truncated */
  407                 }
  408                 switch (opt) {
  409 
  410                 default:
  411                         break;
  412 
  413                 case IPOPT_LSRR:
  414                         bits |= IP_FW_IPOPT_LSRR;
  415                         break;
  416 
  417                 case IPOPT_SSRR:
  418                         bits |= IP_FW_IPOPT_SSRR;
  419                         break;
  420 
  421                 case IPOPT_RR:
  422                         bits |= IP_FW_IPOPT_RR;
  423                         break;
  424 
  425                 case IPOPT_TS:
  426                         bits |= IP_FW_IPOPT_TS;
  427                         break;
  428                 }
  429         }
  430         return (flags_match(cmd, bits));
  431 }
  432 
  433 static int
  434 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
  435 {
  436         int optlen, bits = 0;
  437         u_char *cp = (u_char *)(tcp + 1);
  438         int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
  439 
  440         for (; x > 0; x -= optlen, cp += optlen) {
  441                 int opt = cp[0];
  442                 if (opt == TCPOPT_EOL)
  443                         break;
  444                 if (opt == TCPOPT_NOP)
  445                         optlen = 1;
  446                 else {
  447                         optlen = cp[1];
  448                         if (optlen <= 0)
  449                                 break;
  450                 }
  451 
  452                 switch (opt) {
  453 
  454                 default:
  455                         break;
  456 
  457                 case TCPOPT_MAXSEG:
  458                         bits |= IP_FW_TCPOPT_MSS;
  459                         break;
  460 
  461                 case TCPOPT_WINDOW:
  462                         bits |= IP_FW_TCPOPT_WINDOW;
  463                         break;
  464 
  465                 case TCPOPT_SACK_PERMITTED:
  466                 case TCPOPT_SACK:
  467                         bits |= IP_FW_TCPOPT_SACK;
  468                         break;
  469 
  470                 case TCPOPT_TIMESTAMP:
  471                         bits |= IP_FW_TCPOPT_TS;
  472                         break;
  473 
  474                 }
  475         }
  476         return (flags_match(cmd, bits));
  477 }
  478 
  479 static int
  480 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
  481 {
  482         if (ifp == NULL)        /* no iface with this packet, match fails */
  483                 return 0;
  484         /* Check by name or by IP address */
  485         if (cmd->name[0] != '\0') { /* match by name */
  486                 /* Check name */
  487                 if (cmd->p.glob) {
  488                         if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
  489                                 return(1);
  490                 } else {
  491                         if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
  492                                 return(1);
  493                 }
  494         } else {
  495                 struct ifaddr *ia;
  496 
  497                 /* XXX lock? */
  498                 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
  499                         if (ia->ifa_addr == NULL)
  500                                 continue;
  501                         if (ia->ifa_addr->sa_family != AF_INET)
  502                                 continue;
  503                         if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
  504                             (ia->ifa_addr))->sin_addr.s_addr)
  505                                 return(1);      /* match */
  506                 }
  507         }
  508         return(0);      /* no match, fail ... */
  509 }
  510 
  511 /*
  512  * The verify_path function checks if a route to the src exists and
  513  * if it is reachable via ifp (when provided).
  514  * 
  515  * The 'verrevpath' option checks that the interface that an IP packet
  516  * arrives on is the same interface that traffic destined for the
  517  * packet's source address would be routed out of.  The 'versrcreach'
  518  * option just checks that the source address is reachable via any route
  519  * (except default) in the routing table.  These two are a measure to block
  520  * forged packets.  This is also commonly known as "anti-spoofing" or Unicast
  521  * Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
  522  * is purposely reminiscent of the Cisco IOS command,
  523  *
  524  *   ip verify unicast reverse-path
  525  *   ip verify unicast source reachable-via any
  526  *
  527  * which implements the same functionality. But note that syntax is
  528  * misleading. The check may be performed on all IP packets whether unicast,
  529  * multicast, or broadcast.
  530  */
  531 static int
  532 verify_path(struct in_addr src, struct ifnet *ifp)
  533 {
  534         struct route ro;
  535         struct sockaddr_in *dst;
  536 
  537         bzero(&ro, sizeof(ro));
  538 
  539         dst = (struct sockaddr_in *)&(ro.ro_dst);
  540         dst->sin_family = AF_INET;
  541         dst->sin_len = sizeof(*dst);
  542         dst->sin_addr = src;
  543         rtalloc_ign(&ro, RTF_CLONING);
  544 
  545         if (ro.ro_rt == NULL)
  546                 return 0;
  547 
  548         /*
  549          * If ifp is provided, check for equality with rtentry.
  550          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
  551          * in order to pass packets injected back by if_simloop():
  552          * if useloopback == 1 routing entry (via lo0) for our own address
  553          * may exist, so we need to handle routing assymetry.
  554          */
  555         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
  556                 RTFREE(ro.ro_rt);
  557                 return 0;
  558         }
  559 
  560         /* if no ifp provided, check if rtentry is not default route */
  561         if (ifp == NULL &&
  562              satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
  563                 RTFREE(ro.ro_rt);
  564                 return 0;
  565         }
  566 
  567         /* or if this is a blackhole/reject route */
  568         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
  569                 RTFREE(ro.ro_rt);
  570                 return 0;
  571         }
  572 
  573         /* found valid route */
  574         RTFREE(ro.ro_rt);
  575         return 1;
  576 }
  577 
  578 #ifdef INET6
  579 /*
  580  * ipv6 specific rules here...
  581  */
  582 static __inline int
  583 icmp6type_match (int type, ipfw_insn_u32 *cmd)
  584 {
  585         return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
  586 }
  587 
  588 static int
  589 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
  590 {
  591         int i;
  592         for (i=0; i <= cmd->o.arg1; ++i )
  593                 if (curr_flow == cmd->d[i] )
  594                         return 1;
  595         return 0;
  596 }
  597 
  598 /* support for IP6_*_ME opcodes */
  599 static int
  600 search_ip6_addr_net (struct in6_addr * ip6_addr)
  601 {
  602         struct ifnet *mdc;
  603         struct ifaddr *mdc2;
  604         struct in6_ifaddr *fdm;
  605         struct in6_addr copia;
  606 
  607         TAILQ_FOREACH(mdc, &ifnet, if_link)
  608                 for (mdc2 = mdc->if_addrlist.tqh_first; mdc2;
  609                     mdc2 = mdc2->ifa_list.tqe_next) {
  610                         if (!mdc2->ifa_addr)
  611                                 continue;
  612                         if (mdc2->ifa_addr->sa_family == AF_INET6) {
  613                                 fdm = (struct in6_ifaddr *)mdc2;
  614                                 copia = fdm->ia_addr.sin6_addr;
  615                                 /* need for leaving scope_id in the sock_addr */
  616                                 in6_clearscope(&copia);
  617                                 if (IN6_ARE_ADDR_EQUAL(ip6_addr, &copia))
  618                                         return 1;
  619                         }
  620                 }
  621         return 0;
  622 }
  623 
  624 static int
  625 verify_path6(struct in6_addr *src, struct ifnet *ifp)
  626 {
  627         struct route_in6 ro;
  628         struct sockaddr_in6 *dst;
  629 
  630         bzero(&ro, sizeof(ro));
  631 
  632         dst = (struct sockaddr_in6 * )&(ro.ro_dst);
  633         dst->sin6_family = AF_INET6;
  634         dst->sin6_len = sizeof(*dst);
  635         dst->sin6_addr = *src;
  636         rtalloc_ign((struct route *)&ro, RTF_CLONING);
  637 
  638         if (ro.ro_rt == NULL)
  639                 return 0;
  640 
  641         /* 
  642          * if ifp is provided, check for equality with rtentry
  643          * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
  644          * to support the case of sending packets to an address of our own.
  645          * (where the former interface is the first argument of if_simloop()
  646          *  (=ifp), the latter is lo0)
  647          */
  648         if (ifp != NULL && ro.ro_rt->rt_ifa->ifa_ifp != ifp) {
  649                 RTFREE(ro.ro_rt);
  650                 return 0;
  651         }
  652 
  653         /* if no ifp provided, check if rtentry is not default route */
  654         if (ifp == NULL &&
  655             IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(ro.ro_rt))->sin6_addr)) {
  656                 RTFREE(ro.ro_rt);
  657                 return 0;
  658         }
  659 
  660         /* or if this is a blackhole/reject route */
  661         if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
  662                 RTFREE(ro.ro_rt);
  663                 return 0;
  664         }
  665 
  666         /* found valid route */
  667         RTFREE(ro.ro_rt);
  668         return 1;
  669 
  670 }
  671 static __inline int
  672 hash_packet6(struct ipfw_flow_id *id)
  673 {
  674         u_int32_t i;
  675         i = (id->dst_ip6.__u6_addr.__u6_addr32[0]) ^
  676             (id->dst_ip6.__u6_addr.__u6_addr32[1]) ^
  677             (id->dst_ip6.__u6_addr.__u6_addr32[2]) ^
  678             (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^
  679             (id->dst_port) ^ (id->src_port) ^ (id->flow_id6);
  680         return i;
  681 }
  682 
  683 static int
  684 is_icmp6_query(int icmp6_type)
  685 {
  686         if ((icmp6_type <= ICMP6_MAXTYPE) &&
  687             (icmp6_type == ICMP6_ECHO_REQUEST ||
  688             icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
  689             icmp6_type == ICMP6_WRUREQUEST ||
  690             icmp6_type == ICMP6_FQDN_QUERY ||
  691             icmp6_type == ICMP6_NI_QUERY))
  692                 return (1);
  693 
  694         return (0);
  695 }
  696 
  697 static void
  698 send_reject6(struct ip_fw_args *args, int code, u_short offset, u_int hlen)
  699 {
  700         if (code == ICMP6_UNREACH_RST && offset == 0 &&
  701             args->f_id.proto == IPPROTO_TCP) {
  702                 struct ip6_hdr *ip6;
  703                 struct tcphdr *tcp;
  704                 tcp_seq ack, seq;
  705                 int flags;
  706                 struct {
  707                         struct ip6_hdr ip6;
  708                         struct tcphdr th;
  709                 } ti;
  710 
  711                 if (args->m->m_len < (hlen+sizeof(struct tcphdr))) {
  712                         args->m = m_pullup(args->m, hlen+sizeof(struct tcphdr));
  713                         if (args->m == NULL)
  714                                 return;
  715                 }
  716 
  717                 ip6 = mtod(args->m, struct ip6_hdr *);
  718                 tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen);
  719 
  720                 if ((tcp->th_flags & TH_RST) != 0) {
  721                         m_freem(args->m);
  722                         return;
  723                 }
  724 
  725                 ti.ip6 = *ip6;
  726                 ti.th = *tcp;
  727                 ti.th.th_seq = ntohl(ti.th.th_seq);
  728                 ti.th.th_ack = ntohl(ti.th.th_ack);
  729                 ti.ip6.ip6_nxt = IPPROTO_TCP;
  730 
  731                 if (ti.th.th_flags & TH_ACK) {
  732                         ack = 0;
  733                         seq = ti.th.th_ack;
  734                         flags = TH_RST;
  735                 } else {
  736                         ack = ti.th.th_seq;
  737                         if (((args->m)->m_flags & M_PKTHDR) != 0) {
  738                                 ack += (args->m)->m_pkthdr.len - hlen
  739                                         - (ti.th.th_off << 2);
  740                         } else if (ip6->ip6_plen) {
  741                                 ack += ntohs(ip6->ip6_plen) + sizeof(*ip6)
  742                                         - hlen - (ti.th.th_off << 2);
  743                         } else {
  744                                 m_freem(args->m);
  745                                 return;
  746                         }
  747                         if (tcp->th_flags & TH_SYN)
  748                                 ack++;
  749                         seq = 0;
  750                         flags = TH_RST|TH_ACK;
  751                 }
  752                 bcopy(&ti, ip6, sizeof(ti));
  753                 tcp_respond(NULL, ip6, (struct tcphdr *)(ip6 + 1),
  754                         args->m, ack, seq, flags);
  755 
  756         } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
  757                 icmp6_error(args->m, ICMP6_DST_UNREACH, code, 0);
  758 
  759         } else
  760                 m_freem(args->m);
  761 
  762         args->m = NULL;
  763 }
  764 
  765 #endif /* INET6 */
  766 
  767 static u_int64_t norule_counter;        /* counter for ipfw_log(NULL...) */
  768 
  769 #define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
  770 #define SNP(buf) buf, sizeof(buf)
  771 
  772 /*
  773  * We enter here when we have a rule with O_LOG.
  774  * XXX this function alone takes about 2Kbytes of code!
  775  */
  776 static void
  777 ipfw_log(struct ip_fw *f, u_int hlen, struct ip_fw_args *args,
  778         struct mbuf *m, struct ifnet *oif, u_short offset)
  779 {
  780         struct ether_header *eh = args->eh;
  781         char *action;
  782         int limit_reached = 0;
  783         char action2[40], proto[128], fragment[32];
  784 
  785         fragment[0] = '\0';
  786         proto[0] = '\0';
  787 
  788         if (f == NULL) {        /* bogus pkt */
  789                 if (verbose_limit != 0 && norule_counter >= verbose_limit)
  790                         return;
  791                 norule_counter++;
  792                 if (norule_counter == verbose_limit)
  793                         limit_reached = verbose_limit;
  794                 action = "Refuse";
  795         } else {        /* O_LOG is the first action, find the real one */
  796                 ipfw_insn *cmd = ACTION_PTR(f);
  797                 ipfw_insn_log *l = (ipfw_insn_log *)cmd;
  798 
  799                 if (l->max_log != 0 && l->log_left == 0)
  800                         return;
  801                 l->log_left--;
  802                 if (l->log_left == 0)
  803                         limit_reached = l->max_log;
  804                 cmd += F_LEN(cmd);      /* point to first action */
  805                 if (cmd->opcode == O_ALTQ) {
  806                         ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
  807 
  808                         snprintf(SNPARGS(action2, 0), "Altq %d",
  809                                 altq->qid);
  810                         cmd += F_LEN(cmd);
  811                 }
  812                 if (cmd->opcode == O_PROB)
  813                         cmd += F_LEN(cmd);
  814 
  815                 action = action2;
  816                 switch (cmd->opcode) {
  817                 case O_DENY:
  818                         action = "Deny";
  819                         break;
  820 
  821                 case O_REJECT:
  822                         if (cmd->arg1==ICMP_REJECT_RST)
  823                                 action = "Reset";
  824                         else if (cmd->arg1==ICMP_UNREACH_HOST)
  825                                 action = "Reject";
  826                         else
  827                                 snprintf(SNPARGS(action2, 0), "Unreach %d",
  828                                         cmd->arg1);
  829                         break;
  830 
  831                 case O_UNREACH6:
  832                         if (cmd->arg1==ICMP6_UNREACH_RST)
  833                                 action = "Reset";
  834                         else
  835                                 snprintf(SNPARGS(action2, 0), "Unreach %d",
  836                                         cmd->arg1);
  837                         break;
  838 
  839                 case O_ACCEPT:
  840                         action = "Accept";
  841                         break;
  842                 case O_COUNT:
  843                         action = "Count";
  844                         break;
  845                 case O_DIVERT:
  846                         snprintf(SNPARGS(action2, 0), "Divert %d",
  847                                 cmd->arg1);
  848                         break;
  849                 case O_TEE:
  850                         snprintf(SNPARGS(action2, 0), "Tee %d",
  851                                 cmd->arg1);
  852                         break;
  853                 case O_SKIPTO:
  854                         snprintf(SNPARGS(action2, 0), "SkipTo %d",
  855                                 cmd->arg1);
  856                         break;
  857                 case O_PIPE:
  858                         snprintf(SNPARGS(action2, 0), "Pipe %d",
  859                                 cmd->arg1);
  860                         break;
  861                 case O_QUEUE:
  862                         snprintf(SNPARGS(action2, 0), "Queue %d",
  863                                 cmd->arg1);
  864                         break;
  865                 case O_FORWARD_IP: {
  866                         ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
  867                         int len;
  868 
  869                         len = snprintf(SNPARGS(action2, 0), "Forward to %s",
  870                                 inet_ntoa(sa->sa.sin_addr));
  871                         if (sa->sa.sin_port)
  872                                 snprintf(SNPARGS(action2, len), ":%d",
  873                                     sa->sa.sin_port);
  874                         }
  875                         break;
  876                 case O_NETGRAPH:
  877                         snprintf(SNPARGS(action2, 0), "Netgraph %d",
  878                                 cmd->arg1);
  879                         break;
  880                 case O_NGTEE:
  881                         snprintf(SNPARGS(action2, 0), "Ngtee %d",
  882                                 cmd->arg1);
  883                         break;
  884                 default:
  885                         action = "UNKNOWN";
  886                         break;
  887                 }
  888         }
  889 
  890         if (hlen == 0) {        /* non-ip */
  891                 snprintf(SNPARGS(proto, 0), "MAC");
  892 
  893         } else {
  894                 int len;
  895                 char src[48], dst[48];
  896                 struct icmphdr *icmp;
  897                 struct tcphdr *tcp;
  898                 struct udphdr *udp;
  899                 /* Initialize to make compiler happy. */
  900                 struct ip *ip = NULL;
  901 #ifdef INET6
  902                 struct ip6_hdr *ip6 = NULL;
  903                 struct icmp6_hdr *icmp6;
  904 #endif
  905                 src[0] = '\0';
  906                 dst[0] = '\0';
  907 #ifdef INET6
  908                 if (args->f_id.addr_type == 6) {
  909                         snprintf(src, sizeof(src), "[%s]",
  910                             ip6_sprintf(&args->f_id.src_ip6));
  911                         snprintf(dst, sizeof(dst), "[%s]",
  912                             ip6_sprintf(&args->f_id.dst_ip6));
  913 
  914                         ip6 = (struct ip6_hdr *)mtod(m, struct ip6_hdr *);
  915                         tcp = (struct tcphdr *)(mtod(args->m, char *) + hlen);
  916                         udp = (struct udphdr *)(mtod(args->m, char *) + hlen);
  917                 } else
  918 #endif
  919                 {
  920                         ip = mtod(m, struct ip *);
  921                         tcp = L3HDR(struct tcphdr, ip);
  922                         udp = L3HDR(struct udphdr, ip);
  923 
  924                         inet_ntoa_r(ip->ip_src, src);
  925                         inet_ntoa_r(ip->ip_dst, dst);
  926                 }
  927 
  928                 switch (args->f_id.proto) {
  929                 case IPPROTO_TCP:
  930                         len = snprintf(SNPARGS(proto, 0), "TCP %s", src);
  931                         if (offset == 0)
  932                                 snprintf(SNPARGS(proto, len), ":%d %s:%d",
  933                                     ntohs(tcp->th_sport),
  934                                     dst,
  935                                     ntohs(tcp->th_dport));
  936                         else
  937                                 snprintf(SNPARGS(proto, len), " %s", dst);
  938                         break;
  939 
  940                 case IPPROTO_UDP:
  941                         len = snprintf(SNPARGS(proto, 0), "UDP %s", src);
  942                         if (offset == 0)
  943                                 snprintf(SNPARGS(proto, len), ":%d %s:%d",
  944                                     ntohs(udp->uh_sport),
  945                                     dst,
  946                                     ntohs(udp->uh_dport));
  947                         else
  948                                 snprintf(SNPARGS(proto, len), " %s", dst);
  949                         break;
  950 
  951                 case IPPROTO_ICMP:
  952                         icmp = L3HDR(struct icmphdr, ip);
  953                         if (offset == 0)
  954                                 len = snprintf(SNPARGS(proto, 0),
  955                                     "ICMP:%u.%u ",
  956                                     icmp->icmp_type, icmp->icmp_code);
  957                         else
  958                                 len = snprintf(SNPARGS(proto, 0), "ICMP ");
  959                         len += snprintf(SNPARGS(proto, len), "%s", src);
  960                         snprintf(SNPARGS(proto, len), " %s", dst);
  961                         break;
  962 #ifdef INET6
  963                 case IPPROTO_ICMPV6:
  964                         icmp6 = (struct icmp6_hdr *)(mtod(args->m, char *) + hlen);
  965                         if (offset == 0)
  966                                 len = snprintf(SNPARGS(proto, 0),
  967                                     "ICMPv6:%u.%u ",
  968                                     icmp6->icmp6_type, icmp6->icmp6_code);
  969                         else
  970                                 len = snprintf(SNPARGS(proto, 0), "ICMPv6 ");
  971                         len += snprintf(SNPARGS(proto, len), "%s", src);
  972                         snprintf(SNPARGS(proto, len), " %s", dst);
  973                         break;
  974 #endif
  975                 default:
  976                         len = snprintf(SNPARGS(proto, 0), "P:%d %s",
  977                             args->f_id.proto, src);
  978                         snprintf(SNPARGS(proto, len), " %s", dst);
  979                         break;
  980                 }
  981 
  982 #ifdef INET6
  983                 if (args->f_id.addr_type == 6) {
  984                         if (offset & (IP6F_OFF_MASK | IP6F_MORE_FRAG))
  985                                 snprintf(SNPARGS(fragment, 0),
  986                                     " (frag %08x:%d@%d%s)",
  987                                     args->f_id.frag_id6,
  988                                     ntohs(ip6->ip6_plen) - hlen,
  989                                     ntohs(offset & IP6F_OFF_MASK) << 3,
  990                                     (offset & IP6F_MORE_FRAG) ? "+" : "");
  991                 } else
  992 #endif
  993                 {
  994                         int ip_off, ip_len;
  995                         if (eh != NULL) { /* layer 2 packets are as on the wire */
  996                                 ip_off = ntohs(ip->ip_off);
  997                                 ip_len = ntohs(ip->ip_len);
  998                         } else {
  999                                 ip_off = ip->ip_off;
 1000                                 ip_len = ip->ip_len;
 1001                         }
 1002                         if (ip_off & (IP_MF | IP_OFFMASK))
 1003                                 snprintf(SNPARGS(fragment, 0),
 1004                                     " (frag %d:%d@%d%s)",
 1005                                     ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
 1006                                     offset << 3,
 1007                                     (ip_off & IP_MF) ? "+" : "");
 1008                 }
 1009         }
 1010         if (oif || m->m_pkthdr.rcvif)
 1011                 log(LOG_SECURITY | LOG_INFO,
 1012                     "ipfw: %d %s %s %s via %s%s\n",
 1013                     f ? f->rulenum : -1,
 1014                     action, proto, oif ? "out" : "in",
 1015                     oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
 1016                     fragment);
 1017         else
 1018                 log(LOG_SECURITY | LOG_INFO,
 1019                     "ipfw: %d %s %s [no if info]%s\n",
 1020                     f ? f->rulenum : -1,
 1021                     action, proto, fragment);
 1022         if (limit_reached)
 1023                 log(LOG_SECURITY | LOG_NOTICE,
 1024                     "ipfw: limit %d reached on entry %d\n",
 1025                     limit_reached, f ? f->rulenum : -1);
 1026 }
 1027 
 1028 /*
 1029  * IMPORTANT: the hash function for dynamic rules must be commutative
 1030  * in source and destination (ip,port), because rules are bidirectional
 1031  * and we want to find both in the same bucket.
 1032  */
 1033 static __inline int
 1034 hash_packet(struct ipfw_flow_id *id)
 1035 {
 1036         u_int32_t i;
 1037 
 1038 #ifdef INET6
 1039         if (IS_IP6_FLOW_ID(id)) 
 1040                 i = hash_packet6(id);
 1041         else
 1042 #endif /* INET6 */
 1043         i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
 1044         i &= (curr_dyn_buckets - 1);
 1045         return i;
 1046 }
 1047 
 1048 /**
 1049  * unlink a dynamic rule from a chain. prev is a pointer to
 1050  * the previous one, q is a pointer to the rule to delete,
 1051  * head is a pointer to the head of the queue.
 1052  * Modifies q and potentially also head.
 1053  */
 1054 #define UNLINK_DYN_RULE(prev, head, q) {                                \
 1055         ipfw_dyn_rule *old_q = q;                                       \
 1056                                                                         \
 1057         /* remove a refcount to the parent */                           \
 1058         if (q->dyn_type == O_LIMIT)                                     \
 1059                 q->parent->count--;                                     \
 1060         DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\
 1061                 (q->id.src_ip), (q->id.src_port),                       \
 1062                 (q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); )      \
 1063         if (prev != NULL)                                               \
 1064                 prev->next = q = q->next;                               \
 1065         else                                                            \
 1066                 head = q = q->next;                                     \
 1067         dyn_count--;                                                    \
 1068         uma_zfree(ipfw_dyn_rule_zone, old_q); }
 1069 
 1070 #define TIME_LEQ(a,b)       ((int)((a)-(b)) <= 0)
 1071 
 1072 /**
 1073  * Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
 1074  *
 1075  * If keep_me == NULL, rules are deleted even if not expired,
 1076  * otherwise only expired rules are removed.
 1077  *
 1078  * The value of the second parameter is also used to point to identify
 1079  * a rule we absolutely do not want to remove (e.g. because we are
 1080  * holding a reference to it -- this is the case with O_LIMIT_PARENT
 1081  * rules). The pointer is only used for comparison, so any non-null
 1082  * value will do.
 1083  */
 1084 static void
 1085 remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
 1086 {
 1087         static u_int32_t last_remove = 0;
 1088 
 1089 #define FORCE (keep_me == NULL)
 1090 
 1091         ipfw_dyn_rule *prev, *q;
 1092         int i, pass = 0, max_pass = 0;
 1093 
 1094         IPFW_DYN_LOCK_ASSERT();
 1095 
 1096         if (ipfw_dyn_v == NULL || dyn_count == 0)
 1097                 return;
 1098         /* do not expire more than once per second, it is useless */
 1099         if (!FORCE && last_remove == time_second)
 1100                 return;
 1101         last_remove = time_second;
 1102 
 1103         /*
 1104          * because O_LIMIT refer to parent rules, during the first pass only
 1105          * remove child and mark any pending LIMIT_PARENT, and remove
 1106          * them in a second pass.
 1107          */
 1108 next_pass:
 1109         for (i = 0 ; i < curr_dyn_buckets ; i++) {
 1110                 for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) {
 1111                         /*
 1112                          * Logic can become complex here, so we split tests.
 1113                          */
 1114                         if (q == keep_me)
 1115                                 goto next;
 1116                         if (rule != NULL && rule != q->rule)
 1117                                 goto next; /* not the one we are looking for */
 1118                         if (q->dyn_type == O_LIMIT_PARENT) {
 1119                                 /*
 1120                                  * handle parent in the second pass,
 1121                                  * record we need one.
 1122                                  */
 1123                                 max_pass = 1;
 1124                                 if (pass == 0)
 1125                                         goto next;
 1126                                 if (FORCE && q->count != 0 ) {
 1127                                         /* XXX should not happen! */
 1128                                         printf("ipfw: OUCH! cannot remove rule,"
 1129                                              " count %d\n", q->count);
 1130                                 }
 1131                         } else {
 1132                                 if (!FORCE &&
 1133                                     !TIME_LEQ( q->expire, time_second ))
 1134                                         goto next;
 1135                         }
 1136              if (q->dyn_type != O_LIMIT_PARENT || !q->count) {
 1137                      UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
 1138                      continue;
 1139              }
 1140 next:
 1141                         prev=q;
 1142                         q=q->next;
 1143                 }
 1144         }
 1145         if (pass++ < max_pass)
 1146                 goto next_pass;
 1147 }
 1148 
 1149 
 1150 /**
 1151  * lookup a dynamic rule.
 1152  */
 1153 static ipfw_dyn_rule *
 1154 lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction,
 1155         struct tcphdr *tcp)
 1156 {
 1157         /*
 1158          * stateful ipfw extensions.
 1159          * Lookup into dynamic session queue
 1160          */
 1161 #define MATCH_REVERSE   0
 1162 #define MATCH_FORWARD   1
 1163 #define MATCH_NONE      2
 1164 #define MATCH_UNKNOWN   3
 1165         int i, dir = MATCH_NONE;
 1166         ipfw_dyn_rule *prev, *q=NULL;
 1167 
 1168         IPFW_DYN_LOCK_ASSERT();
 1169 
 1170         if (ipfw_dyn_v == NULL)
 1171                 goto done;      /* not found */
 1172         i = hash_packet( pkt );
 1173         for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) {
 1174                 if (q->dyn_type == O_LIMIT_PARENT && q->count)
 1175                         goto next;
 1176                 if (TIME_LEQ( q->expire, time_second)) { /* expire entry */
 1177                         UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
 1178                         continue;
 1179                 }
 1180                 if (pkt->proto == q->id.proto &&
 1181                     q->dyn_type != O_LIMIT_PARENT) {
 1182                         if (IS_IP6_FLOW_ID(pkt)) {
 1183                             if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6),
 1184                                 &(q->id.src_ip6)) &&
 1185                             IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6),
 1186                                 &(q->id.dst_ip6)) &&
 1187                             pkt->src_port == q->id.src_port &&
 1188                             pkt->dst_port == q->id.dst_port ) {
 1189                                 dir = MATCH_FORWARD;
 1190                                 break;
 1191                             }
 1192                             if (IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6),
 1193                                     &(q->id.dst_ip6)) &&
 1194                                 IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6),
 1195                                     &(q->id.src_ip6)) &&
 1196                                 pkt->src_port == q->id.dst_port &&
 1197                                 pkt->dst_port == q->id.src_port ) {
 1198                                     dir = MATCH_REVERSE;
 1199                                     break;
 1200                             }
 1201                         } else {
 1202                             if (pkt->src_ip == q->id.src_ip &&
 1203                                 pkt->dst_ip == q->id.dst_ip &&
 1204                                 pkt->src_port == q->id.src_port &&
 1205                                 pkt->dst_port == q->id.dst_port ) {
 1206                                     dir = MATCH_FORWARD;
 1207                                     break;
 1208                             }
 1209                             if (pkt->src_ip == q->id.dst_ip &&
 1210                                 pkt->dst_ip == q->id.src_ip &&
 1211                                 pkt->src_port == q->id.dst_port &&
 1212                                 pkt->dst_port == q->id.src_port ) {
 1213                                     dir = MATCH_REVERSE;
 1214                                     break;
 1215                             }
 1216                         }
 1217                 }
 1218 next:
 1219                 prev = q;
 1220                 q = q->next;
 1221         }
 1222         if (q == NULL)
 1223                 goto done; /* q = NULL, not found */
 1224 
 1225         if ( prev != NULL) { /* found and not in front */
 1226                 prev->next = q->next;
 1227                 q->next = ipfw_dyn_v[i];
 1228                 ipfw_dyn_v[i] = q;
 1229         }
 1230         if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
 1231                 u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
 1232 
 1233 #define BOTH_SYN        (TH_SYN | (TH_SYN << 8))
 1234 #define BOTH_FIN        (TH_FIN | (TH_FIN << 8))
 1235                 q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
 1236                 switch (q->state) {
 1237                 case TH_SYN:                            /* opening */
 1238                         q->expire = time_second + dyn_syn_lifetime;
 1239                         break;
 1240 
 1241                 case BOTH_SYN:                  /* move to established */
 1242                 case BOTH_SYN | TH_FIN :        /* one side tries to close */
 1243                 case BOTH_SYN | (TH_FIN << 8) :
 1244                         if (tcp) {
 1245 #define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0)
 1246                             u_int32_t ack = ntohl(tcp->th_ack);
 1247                             if (dir == MATCH_FORWARD) {
 1248                                 if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd))
 1249                                     q->ack_fwd = ack;
 1250                                 else { /* ignore out-of-sequence */
 1251                                     break;
 1252                                 }
 1253                             } else {
 1254                                 if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev))
 1255                                     q->ack_rev = ack;
 1256                                 else { /* ignore out-of-sequence */
 1257                                     break;
 1258                                 }
 1259                             }
 1260                         }
 1261                         q->expire = time_second + dyn_ack_lifetime;
 1262                         break;
 1263 
 1264                 case BOTH_SYN | BOTH_FIN:       /* both sides closed */
 1265                         if (dyn_fin_lifetime >= dyn_keepalive_period)
 1266                                 dyn_fin_lifetime = dyn_keepalive_period - 1;
 1267                         q->expire = time_second + dyn_fin_lifetime;
 1268                         break;
 1269 
 1270                 default:
 1271 #if 0
 1272                         /*
 1273                          * reset or some invalid combination, but can also
 1274                          * occur if we use keep-state the wrong way.
 1275                          */
 1276                         if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
 1277                                 printf("invalid state: 0x%x\n", q->state);
 1278 #endif
 1279                         if (dyn_rst_lifetime >= dyn_keepalive_period)
 1280                                 dyn_rst_lifetime = dyn_keepalive_period - 1;
 1281                         q->expire = time_second + dyn_rst_lifetime;
 1282                         break;
 1283                 }
 1284         } else if (pkt->proto == IPPROTO_UDP) {
 1285                 q->expire = time_second + dyn_udp_lifetime;
 1286         } else {
 1287                 /* other protocols */
 1288                 q->expire = time_second + dyn_short_lifetime;
 1289         }
 1290 done:
 1291         if (match_direction)
 1292                 *match_direction = dir;
 1293         return q;
 1294 }
 1295 
 1296 static ipfw_dyn_rule *
 1297 lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
 1298         struct tcphdr *tcp)
 1299 {
 1300         ipfw_dyn_rule *q;
 1301 
 1302         IPFW_DYN_LOCK();
 1303         q = lookup_dyn_rule_locked(pkt, match_direction, tcp);
 1304         if (q == NULL)
 1305                 IPFW_DYN_UNLOCK();
 1306         /* NB: return table locked when q is not NULL */
 1307         return q;
 1308 }
 1309 
 1310 static void
 1311 realloc_dynamic_table(void)
 1312 {
 1313         IPFW_DYN_LOCK_ASSERT();
 1314 
 1315         /*
 1316          * Try reallocation, make sure we have a power of 2 and do
 1317          * not allow more than 64k entries. In case of overflow,
 1318          * default to 1024.
 1319          */
 1320 
 1321         if (dyn_buckets > 65536)
 1322                 dyn_buckets = 1024;
 1323         if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */
 1324                 dyn_buckets = curr_dyn_buckets; /* reset */
 1325                 return;
 1326         }
 1327         curr_dyn_buckets = dyn_buckets;
 1328         if (ipfw_dyn_v != NULL)
 1329                 free(ipfw_dyn_v, M_IPFW);
 1330         for (;;) {
 1331                 ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
 1332                        M_IPFW, M_NOWAIT | M_ZERO);
 1333                 if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
 1334                         break;
 1335                 curr_dyn_buckets /= 2;
 1336         }
 1337 }
 1338 
 1339 /**
 1340  * Install state of type 'type' for a dynamic session.
 1341  * The hash table contains two type of rules:
 1342  * - regular rules (O_KEEP_STATE)
 1343  * - rules for sessions with limited number of sess per user
 1344  *   (O_LIMIT). When they are created, the parent is
 1345  *   increased by 1, and decreased on delete. In this case,
 1346  *   the third parameter is the parent rule and not the chain.
 1347  * - "parent" rules for the above (O_LIMIT_PARENT).
 1348  */
 1349 static ipfw_dyn_rule *
 1350 add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule)
 1351 {
 1352         ipfw_dyn_rule *r;
 1353         int i;
 1354 
 1355         IPFW_DYN_LOCK_ASSERT();
 1356 
 1357         if (ipfw_dyn_v == NULL ||
 1358             (dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
 1359                 realloc_dynamic_table();
 1360                 if (ipfw_dyn_v == NULL)
 1361                         return NULL; /* failed ! */
 1362         }
 1363         i = hash_packet(id);
 1364 
 1365         r = uma_zalloc(ipfw_dyn_rule_zone, M_NOWAIT | M_ZERO);
 1366         if (r == NULL) {
 1367                 printf ("ipfw: sorry cannot allocate state\n");
 1368                 return NULL;
 1369         }
 1370 
 1371         /* increase refcount on parent, and set pointer */
 1372         if (dyn_type == O_LIMIT) {
 1373                 ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
 1374                 if ( parent->dyn_type != O_LIMIT_PARENT)
 1375                         panic("invalid parent");
 1376                 parent->count++;
 1377                 r->parent = parent;
 1378                 rule = parent->rule;
 1379         }
 1380 
 1381         r->id = *id;
 1382         r->expire = time_second + dyn_syn_lifetime;
 1383         r->rule = rule;
 1384         r->dyn_type = dyn_type;
 1385         r->pcnt = r->bcnt = 0;
 1386         r->count = 0;
 1387 
 1388         r->bucket = i;
 1389         r->next = ipfw_dyn_v[i];
 1390         ipfw_dyn_v[i] = r;
 1391         dyn_count++;
 1392         DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
 1393            dyn_type,
 1394            (r->id.src_ip), (r->id.src_port),
 1395            (r->id.dst_ip), (r->id.dst_port),
 1396            dyn_count ); )
 1397         return r;
 1398 }
 1399 
 1400 /**
 1401  * lookup dynamic parent rule using pkt and rule as search keys.
 1402  * If the lookup fails, then install one.
 1403  */
 1404 static ipfw_dyn_rule *
 1405 lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
 1406 {
 1407         ipfw_dyn_rule *q;
 1408         int i;
 1409 
 1410         IPFW_DYN_LOCK_ASSERT();
 1411 
 1412         if (ipfw_dyn_v) {
 1413                 int is_v6 = IS_IP6_FLOW_ID(pkt);
 1414                 i = hash_packet( pkt );
 1415                 for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next)
 1416                         if (q->dyn_type == O_LIMIT_PARENT &&
 1417                             rule== q->rule &&
 1418                             pkt->proto == q->id.proto &&
 1419                             pkt->src_port == q->id.src_port &&
 1420                             pkt->dst_port == q->id.dst_port &&
 1421                             (
 1422                                 (is_v6 &&
 1423                                  IN6_ARE_ADDR_EQUAL(&(pkt->src_ip6),
 1424                                         &(q->id.src_ip6)) &&
 1425                                  IN6_ARE_ADDR_EQUAL(&(pkt->dst_ip6),
 1426                                         &(q->id.dst_ip6))) ||
 1427                                 (!is_v6 &&
 1428                                  pkt->src_ip == q->id.src_ip &&
 1429                                  pkt->dst_ip == q->id.dst_ip)
 1430                             )
 1431                         ) {
 1432                                 q->expire = time_second + dyn_short_lifetime;
 1433                                 DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);)
 1434                                 return q;
 1435                         }
 1436         }
 1437         return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
 1438 }
 1439 
 1440 /**
 1441  * Install dynamic state for rule type cmd->o.opcode
 1442  *
 1443  * Returns 1 (failure) if state is not installed because of errors or because
 1444  * session limitations are enforced.
 1445  */
 1446 static int
 1447 install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
 1448         struct ip_fw_args *args)
 1449 {
 1450         static int last_log;
 1451 
 1452         ipfw_dyn_rule *q;
 1453 
 1454         DEB(printf("ipfw: install state type %d 0x%08x %u -> 0x%08x %u\n",
 1455             cmd->o.opcode,
 1456             (args->f_id.src_ip), (args->f_id.src_port),
 1457             (args->f_id.dst_ip), (args->f_id.dst_port) );)
 1458 
 1459         IPFW_DYN_LOCK();
 1460 
 1461         q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL);
 1462 
 1463         if (q != NULL) { /* should never occur */
 1464                 if (last_log != time_second) {
 1465                         last_log = time_second;
 1466                         printf("ipfw: install_state: entry already present, done\n");
 1467                 }
 1468                 IPFW_DYN_UNLOCK();
 1469                 return 0;
 1470         }
 1471 
 1472         if (dyn_count >= dyn_max)
 1473                 /*
 1474                  * Run out of slots, try to remove any expired rule.
 1475                  */
 1476                 remove_dyn_rule(NULL, (ipfw_dyn_rule *)1);
 1477 
 1478         if (dyn_count >= dyn_max) {
 1479                 if (last_log != time_second) {
 1480                         last_log = time_second;
 1481                         printf("ipfw: install_state: Too many dynamic rules\n");
 1482                 }
 1483                 IPFW_DYN_UNLOCK();
 1484                 return 1; /* cannot install, notify caller */
 1485         }
 1486 
 1487         switch (cmd->o.opcode) {
 1488         case O_KEEP_STATE: /* bidir rule */
 1489                 add_dyn_rule(&args->f_id, O_KEEP_STATE, rule);
 1490                 break;
 1491 
 1492         case O_LIMIT: /* limit number of sessions */
 1493             {
 1494                 u_int16_t limit_mask = cmd->limit_mask;
 1495                 struct ipfw_flow_id id;
 1496                 ipfw_dyn_rule *parent;
 1497 
 1498                 DEB(printf("ipfw: installing dyn-limit rule %d\n",
 1499                     cmd->conn_limit);)
 1500 
 1501                 id.dst_ip = id.src_ip = 0;
 1502                 id.dst_port = id.src_port = 0;
 1503                 id.proto = args->f_id.proto;
 1504 
 1505                 if (IS_IP6_FLOW_ID (&(args->f_id))) {
 1506                         if (limit_mask & DYN_SRC_ADDR)
 1507                                 id.src_ip6 = args->f_id.src_ip6;
 1508                         if (limit_mask & DYN_DST_ADDR)
 1509                                 id.dst_ip6 = args->f_id.dst_ip6;
 1510                 } else {
 1511                         if (limit_mask & DYN_SRC_ADDR)
 1512                                 id.src_ip = args->f_id.src_ip;
 1513                         if (limit_mask & DYN_DST_ADDR)
 1514                                 id.dst_ip = args->f_id.dst_ip;
 1515                 }
 1516                 if (limit_mask & DYN_SRC_PORT)
 1517                         id.src_port = args->f_id.src_port;
 1518                 if (limit_mask & DYN_DST_PORT)
 1519                         id.dst_port = args->f_id.dst_port;
 1520                 parent = lookup_dyn_parent(&id, rule);
 1521                 if (parent == NULL) {
 1522                         printf("ipfw: add parent failed\n");
 1523                         IPFW_DYN_UNLOCK();
 1524                         return 1;
 1525                 }
 1526                 if (parent->count >= cmd->conn_limit) {
 1527                         /*
 1528                          * See if we can remove some expired rule.
 1529                          */
 1530                         remove_dyn_rule(rule, parent);
 1531                         if (parent->count >= cmd->conn_limit) {
 1532                                 if (fw_verbose && last_log != time_second) {
 1533                                         last_log = time_second;
 1534                                         log(LOG_SECURITY | LOG_DEBUG,
 1535                                             "drop session, too many entries\n");
 1536                                 }
 1537                                 IPFW_DYN_UNLOCK();
 1538                                 return 1;
 1539                         }
 1540                 }
 1541                 add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent);
 1542             }
 1543                 break;
 1544         default:
 1545                 printf("ipfw: unknown dynamic rule type %u\n", cmd->o.opcode);
 1546                 IPFW_DYN_UNLOCK();
 1547                 return 1;
 1548         }
 1549         lookup_dyn_rule_locked(&args->f_id, NULL, NULL); /* XXX just set lifetime */
 1550         IPFW_DYN_UNLOCK();
 1551         return 0;
 1552 }
 1553 
 1554 /*
 1555  * Generate a TCP packet, containing either a RST or a keepalive.
 1556  * When flags & TH_RST, we are sending a RST packet, because of a
 1557  * "reset" action matched the packet.
 1558  * Otherwise we are sending a keepalive, and flags & TH_
 1559  */
 1560 static struct mbuf *
 1561 send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags)
 1562 {
 1563         struct mbuf *m;
 1564         struct ip *ip;
 1565         struct tcphdr *tcp;
 1566 
 1567         MGETHDR(m, M_DONTWAIT, MT_HEADER);
 1568         if (m == 0)
 1569                 return (NULL);
 1570         m->m_pkthdr.rcvif = (struct ifnet *)0;
 1571         m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
 1572         m->m_data += max_linkhdr;
 1573 
 1574         ip = mtod(m, struct ip *);
 1575         bzero(ip, m->m_len);
 1576         tcp = (struct tcphdr *)(ip + 1); /* no IP options */
 1577         ip->ip_p = IPPROTO_TCP;
 1578         tcp->th_off = 5;
 1579         /*
 1580          * Assume we are sending a RST (or a keepalive in the reverse
 1581          * direction), swap src and destination addresses and ports.
 1582          */
 1583         ip->ip_src.s_addr = htonl(id->dst_ip);
 1584         ip->ip_dst.s_addr = htonl(id->src_ip);
 1585         tcp->th_sport = htons(id->dst_port);
 1586         tcp->th_dport = htons(id->src_port);
 1587         if (flags & TH_RST) {   /* we are sending a RST */
 1588                 if (flags & TH_ACK) {
 1589                         tcp->th_seq = htonl(ack);
 1590                         tcp->th_ack = htonl(0);
 1591                         tcp->th_flags = TH_RST;
 1592                 } else {
 1593                         if (flags & TH_SYN)
 1594                                 seq++;
 1595                         tcp->th_seq = htonl(0);
 1596                         tcp->th_ack = htonl(seq);
 1597                         tcp->th_flags = TH_RST | TH_ACK;
 1598                 }
 1599         } else {
 1600                 /*
 1601                  * We are sending a keepalive. flags & TH_SYN determines
 1602                  * the direction, forward if set, reverse if clear.
 1603                  * NOTE: seq and ack are always assumed to be correct
 1604                  * as set by the caller. This may be confusing...
 1605                  */
 1606                 if (flags & TH_SYN) {
 1607                         /*
 1608                          * we have to rewrite the correct addresses!
 1609                          */
 1610                         ip->ip_dst.s_addr = htonl(id->dst_ip);
 1611                         ip->ip_src.s_addr = htonl(id->src_ip);
 1612                         tcp->th_dport = htons(id->dst_port);
 1613                         tcp->th_sport = htons(id->src_port);
 1614                 }
 1615                 tcp->th_seq = htonl(seq);
 1616                 tcp->th_ack = htonl(ack);
 1617                 tcp->th_flags = TH_ACK;
 1618         }
 1619         /*
 1620          * set ip_len to the payload size so we can compute
 1621          * the tcp checksum on the pseudoheader
 1622          * XXX check this, could save a couple of words ?
 1623          */
 1624         ip->ip_len = htons(sizeof(struct tcphdr));
 1625         tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
 1626         /*
 1627          * now fill fields left out earlier
 1628          */
 1629         ip->ip_ttl = ip_defttl;
 1630         ip->ip_len = m->m_pkthdr.len;
 1631         m->m_flags |= M_SKIP_FIREWALL;
 1632         return (m);
 1633 }
 1634 
 1635 /*
 1636  * sends a reject message, consuming the mbuf passed as an argument.
 1637  */
 1638 static void
 1639 send_reject(struct ip_fw_args *args, int code, u_short offset, int ip_len)
 1640 {
 1641 
 1642         if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
 1643                 /* We need the IP header in host order for icmp_error(). */
 1644                 if (args->eh != NULL) {
 1645                         struct ip *ip = mtod(args->m, struct ip *);
 1646                         ip->ip_len = ntohs(ip->ip_len);
 1647                         ip->ip_off = ntohs(ip->ip_off);
 1648                 }
 1649                 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
 1650         } else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
 1651                 struct tcphdr *const tcp =
 1652                     L3HDR(struct tcphdr, mtod(args->m, struct ip *));
 1653                 if ( (tcp->th_flags & TH_RST) == 0) {
 1654                         struct mbuf *m;
 1655                         m = send_pkt(&(args->f_id), ntohl(tcp->th_seq),
 1656                                 ntohl(tcp->th_ack),
 1657                                 tcp->th_flags | TH_RST);
 1658                         if (m != NULL)
 1659                                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 1660                 }
 1661                 m_freem(args->m);
 1662         } else
 1663                 m_freem(args->m);
 1664         args->m = NULL;
 1665 }
 1666 
 1667 /**
 1668  *
 1669  * Given an ip_fw *, lookup_next_rule will return a pointer
 1670  * to the next rule, which can be either the jump
 1671  * target (for skipto instructions) or the next one in the list (in
 1672  * all other cases including a missing jump target).
 1673  * The result is also written in the "next_rule" field of the rule.
 1674  * Backward jumps are not allowed, so start looking from the next
 1675  * rule...
 1676  *
 1677  * This never returns NULL -- in case we do not have an exact match,
 1678  * the next rule is returned. When the ruleset is changed,
 1679  * pointers are flushed so we are always correct.
 1680  */
 1681 
 1682 static struct ip_fw *
 1683 lookup_next_rule(struct ip_fw *me)
 1684 {
 1685         struct ip_fw *rule = NULL;
 1686         ipfw_insn *cmd;
 1687 
 1688         /* look for action, in case it is a skipto */
 1689         cmd = ACTION_PTR(me);
 1690         if (cmd->opcode == O_LOG)
 1691                 cmd += F_LEN(cmd);
 1692         if (cmd->opcode == O_ALTQ)
 1693                 cmd += F_LEN(cmd);
 1694         if ( cmd->opcode == O_SKIPTO )
 1695                 for (rule = me->next; rule ; rule = rule->next)
 1696                         if (rule->rulenum >= cmd->arg1)
 1697                                 break;
 1698         if (rule == NULL)                       /* failure or not a skipto */
 1699                 rule = me->next;
 1700         me->next_rule = rule;
 1701         return rule;
 1702 }
 1703 
 1704 static int
 1705 add_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr,
 1706         uint8_t mlen, uint32_t value)
 1707 {
 1708         struct radix_node_head *rnh;
 1709         struct table_entry *ent;
 1710 
 1711         if (tbl >= IPFW_TABLES_MAX)
 1712                 return (EINVAL);
 1713         rnh = ch->tables[tbl];
 1714         ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO);
 1715         if (ent == NULL)
 1716                 return (ENOMEM);
 1717         ent->value = value;
 1718         ent->addr.sin_len = ent->mask.sin_len = 8;
 1719         ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0);
 1720         ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr;
 1721         IPFW_WLOCK(&layer3_chain);
 1722         if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) ==
 1723             NULL) {
 1724                 IPFW_WUNLOCK(&layer3_chain);
 1725                 free(ent, M_IPFW_TBL);
 1726                 return (EEXIST);
 1727         }
 1728         IPFW_WUNLOCK(&layer3_chain);
 1729         return (0);
 1730 }
 1731 
 1732 static int
 1733 del_table_entry(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr,
 1734         uint8_t mlen)
 1735 {
 1736         struct radix_node_head *rnh;
 1737         struct table_entry *ent;
 1738         struct sockaddr_in sa, mask;
 1739 
 1740         if (tbl >= IPFW_TABLES_MAX)
 1741                 return (EINVAL);
 1742         rnh = ch->tables[tbl];
 1743         sa.sin_len = mask.sin_len = 8;
 1744         mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0);
 1745         sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr;
 1746         IPFW_WLOCK(ch);
 1747         ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh);
 1748         if (ent == NULL) {
 1749                 IPFW_WUNLOCK(ch);
 1750                 return (ESRCH);
 1751         }
 1752         IPFW_WUNLOCK(ch);
 1753         free(ent, M_IPFW_TBL);
 1754         return (0);
 1755 }
 1756 
 1757 static int
 1758 flush_table_entry(struct radix_node *rn, void *arg)
 1759 {
 1760         struct radix_node_head * const rnh = arg;
 1761         struct table_entry *ent;
 1762 
 1763         ent = (struct table_entry *)
 1764             rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh);
 1765         if (ent != NULL)
 1766                 free(ent, M_IPFW_TBL);
 1767         return (0);
 1768 }
 1769 
 1770 static int
 1771 flush_table(struct ip_fw_chain *ch, uint16_t tbl)
 1772 {
 1773         struct radix_node_head *rnh;
 1774 
 1775         IPFW_WLOCK_ASSERT(ch);
 1776 
 1777         if (tbl >= IPFW_TABLES_MAX)
 1778                 return (EINVAL);
 1779         rnh = ch->tables[tbl];
 1780         KASSERT(rnh != NULL, ("NULL IPFW table"));
 1781         rnh->rnh_walktree(rnh, flush_table_entry, rnh);
 1782         return (0);
 1783 }
 1784 
 1785 static void
 1786 flush_tables(struct ip_fw_chain *ch)
 1787 {
 1788         uint16_t tbl;
 1789 
 1790         IPFW_WLOCK_ASSERT(ch);
 1791 
 1792         for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++)
 1793                 flush_table(ch, tbl);
 1794 }
 1795 
 1796 static int
 1797 init_tables(struct ip_fw_chain *ch)
 1798 { 
 1799         int i;
 1800         uint16_t j;
 1801 
 1802         for (i = 0; i < IPFW_TABLES_MAX; i++) {
 1803                 if (!rn_inithead((void **)&ch->tables[i], 32)) {
 1804                         for (j = 0; j < i; j++) {
 1805                                 (void) flush_table(ch, j);
 1806                         }
 1807                         return (ENOMEM);
 1808                 }
 1809         }
 1810         return (0);
 1811 }
 1812 
 1813 static int
 1814 lookup_table(struct ip_fw_chain *ch, uint16_t tbl, in_addr_t addr,
 1815         uint32_t *val)
 1816 {
 1817         struct radix_node_head *rnh;
 1818         struct table_entry *ent;
 1819         struct sockaddr_in sa;
 1820 
 1821         if (tbl >= IPFW_TABLES_MAX)
 1822                 return (0);
 1823         rnh = ch->tables[tbl];
 1824         sa.sin_len = 8;
 1825         sa.sin_addr.s_addr = addr;
 1826         ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh));
 1827         if (ent != NULL) {
 1828                 *val = ent->value;
 1829                 return (1);
 1830         }
 1831         return (0);
 1832 }
 1833 
 1834 static int
 1835 count_table_entry(struct radix_node *rn, void *arg)
 1836 {
 1837         u_int32_t * const cnt = arg;
 1838 
 1839         (*cnt)++;
 1840         return (0);
 1841 }
 1842 
 1843 static int
 1844 count_table(struct ip_fw_chain *ch, uint32_t tbl, uint32_t *cnt)
 1845 {
 1846         struct radix_node_head *rnh;
 1847 
 1848         if (tbl >= IPFW_TABLES_MAX)
 1849                 return (EINVAL);
 1850         rnh = ch->tables[tbl];
 1851         *cnt = 0;
 1852         rnh->rnh_walktree(rnh, count_table_entry, cnt);
 1853         return (0);
 1854 }
 1855 
 1856 static int
 1857 dump_table_entry(struct radix_node *rn, void *arg)
 1858 {
 1859         struct table_entry * const n = (struct table_entry *)rn;
 1860         ipfw_table * const tbl = arg;
 1861         ipfw_table_entry *ent;
 1862 
 1863         if (tbl->cnt == tbl->size)
 1864                 return (1);
 1865         ent = &tbl->ent[tbl->cnt];
 1866         ent->tbl = tbl->tbl;
 1867         if (in_nullhost(n->mask.sin_addr))
 1868                 ent->masklen = 0;
 1869         else
 1870                 ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr));
 1871         ent->addr = n->addr.sin_addr.s_addr;
 1872         ent->value = n->value;
 1873         tbl->cnt++;
 1874         return (0);
 1875 }
 1876 
 1877 static int
 1878 dump_table(struct ip_fw_chain *ch, ipfw_table *tbl)
 1879 {
 1880         struct radix_node_head *rnh;
 1881 
 1882         if (tbl->tbl >= IPFW_TABLES_MAX)
 1883                 return (EINVAL);
 1884         rnh = ch->tables[tbl->tbl];
 1885         tbl->cnt = 0;
 1886         rnh->rnh_walktree(rnh, dump_table_entry, tbl);
 1887         return (0);
 1888 }
 1889 
 1890 static void
 1891 fill_ugid_cache(struct inpcb *inp, struct ip_fw_ugid *ugp)
 1892 {
 1893         struct ucred *cr;
 1894 
 1895         if (inp->inp_socket != NULL) {
 1896                 cr = inp->inp_socket->so_cred;
 1897                 ugp->fw_prid = jailed(cr) ?
 1898                     cr->cr_prison->pr_id : -1;
 1899                 ugp->fw_uid = cr->cr_uid;
 1900                 ugp->fw_ngroups = cr->cr_ngroups;
 1901                 bcopy(cr->cr_groups, ugp->fw_groups,
 1902                     sizeof(ugp->fw_groups));
 1903         }
 1904 }
 1905 
 1906 static int
 1907 check_uidgid(ipfw_insn_u32 *insn,
 1908         int proto, struct ifnet *oif,
 1909         struct in_addr dst_ip, u_int16_t dst_port,
 1910         struct in_addr src_ip, u_int16_t src_port,
 1911         struct ip_fw_ugid *ugp, int *lookup, struct inpcb *inp)
 1912 {
 1913         struct inpcbinfo *pi;
 1914         int wildcard;
 1915         struct inpcb *pcb;
 1916         int match;
 1917         gid_t *gp;
 1918 
 1919         /*
 1920          * Check to see if the UDP or TCP stack supplied us with
 1921          * the PCB. If so, rather then holding a lock and looking
 1922          * up the PCB, we can use the one that was supplied.
 1923          */
 1924         if (inp && *lookup == 0) {
 1925                 INP_LOCK_ASSERT(inp);
 1926                 if (inp->inp_socket != NULL) {
 1927                         fill_ugid_cache(inp, ugp);
 1928                         *lookup = 1;
 1929                 }
 1930         }
 1931         /*
 1932          * If we have already been here and the packet has no
 1933          * PCB entry associated with it, then we can safely
 1934          * assume that this is a no match.
 1935          */
 1936         if (*lookup == -1)
 1937                 return (0);
 1938         if (proto == IPPROTO_TCP) {
 1939                 wildcard = 0;
 1940                 pi = &tcbinfo;
 1941         } else if (proto == IPPROTO_UDP) {
 1942                 wildcard = 1;
 1943                 pi = &udbinfo;
 1944         } else
 1945                 return 0;
 1946         match = 0;
 1947         if (*lookup == 0) {
 1948                 INP_INFO_RLOCK(pi);
 1949                 pcb =  (oif) ?
 1950                         in_pcblookup_hash(pi,
 1951                                 dst_ip, htons(dst_port),
 1952                                 src_ip, htons(src_port),
 1953                                 wildcard, oif) :
 1954                         in_pcblookup_hash(pi,
 1955                                 src_ip, htons(src_port),
 1956                                 dst_ip, htons(dst_port),
 1957                                 wildcard, NULL);
 1958                 if (pcb != NULL) {
 1959                         INP_LOCK(pcb);
 1960                         if (pcb->inp_socket != NULL) {
 1961                                 fill_ugid_cache(pcb, ugp);
 1962                                 *lookup = 1;
 1963                         }
 1964                         INP_UNLOCK(pcb);
 1965                 }
 1966                 INP_INFO_RUNLOCK(pi);
 1967                 if (*lookup == 0) {
 1968                         /*
 1969                          * If the lookup did not yield any results, there
 1970                          * is no sense in coming back and trying again. So
 1971                          * we can set lookup to -1 and ensure that we wont
 1972                          * bother the pcb system again.
 1973                          */
 1974                         *lookup = -1;
 1975                         return (0);
 1976                 }
 1977         } 
 1978         if (insn->o.opcode == O_UID)
 1979                 match = (ugp->fw_uid == (uid_t)insn->d[0]);
 1980         else if (insn->o.opcode == O_GID) {
 1981                 for (gp = ugp->fw_groups;
 1982                         gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++)
 1983                         if (*gp == (gid_t)insn->d[0]) {
 1984                                 match = 1;
 1985                                 break;
 1986                         }
 1987         } else if (insn->o.opcode == O_JAIL)
 1988                 match = (ugp->fw_prid == (int)insn->d[0]);
 1989         return match;
 1990 }
 1991 
 1992 /*
 1993  * The main check routine for the firewall.
 1994  *
 1995  * All arguments are in args so we can modify them and return them
 1996  * back to the caller.
 1997  *
 1998  * Parameters:
 1999  *
 2000  *      args->m (in/out) The packet; we set to NULL when/if we nuke it.
 2001  *              Starts with the IP header.
 2002  *      args->eh (in)   Mac header if present, or NULL for layer3 packet.
 2003  *      args->oif       Outgoing interface, or NULL if packet is incoming.
 2004  *              The incoming interface is in the mbuf. (in)
 2005  *      args->divert_rule (in/out)
 2006  *              Skip up to the first rule past this rule number;
 2007  *              upon return, non-zero port number for divert or tee.
 2008  *
 2009  *      args->rule      Pointer to the last matching rule (in/out)
 2010  *      args->next_hop  Socket we are forwarding to (out).
 2011  *      args->f_id      Addresses grabbed from the packet (out)
 2012  *      args->cookie    a cookie depending on rule action
 2013  *
 2014  * Return value:
 2015  *
 2016  *      IP_FW_PASS      the packet must be accepted
 2017  *      IP_FW_DENY      the packet must be dropped
 2018  *      IP_FW_DIVERT    divert packet, port in m_tag
 2019  *      IP_FW_TEE       tee packet, port in m_tag
 2020  *      IP_FW_DUMMYNET  to dummynet, pipe in args->cookie
 2021  *      IP_FW_NETGRAPH  into netgraph, cookie args->cookie
 2022  *
 2023  */
 2024 
 2025 int
 2026 ipfw_chk(struct ip_fw_args *args)
 2027 {
 2028         /*
 2029          * Local variables hold state during the processing of a packet.
 2030          *
 2031          * IMPORTANT NOTE: to speed up the processing of rules, there
 2032          * are some assumption on the values of the variables, which
 2033          * are documented here. Should you change them, please check
 2034          * the implementation of the various instructions to make sure
 2035          * that they still work.
 2036          *
 2037          * args->eh     The MAC header. It is non-null for a layer2
 2038          *      packet, it is NULL for a layer-3 packet.
 2039          *
 2040          * m | args->m  Pointer to the mbuf, as received from the caller.
 2041          *      It may change if ipfw_chk() does an m_pullup, or if it
 2042          *      consumes the packet because it calls send_reject().
 2043          *      XXX This has to change, so that ipfw_chk() never modifies
 2044          *      or consumes the buffer.
 2045          * ip   is simply an alias of the value of m, and it is kept
 2046          *      in sync with it (the packet is  supposed to start with
 2047          *      the ip header).
 2048          */
 2049         struct mbuf *m = args->m;
 2050         struct ip *ip = mtod(m, struct ip *);
 2051 
 2052         /*
 2053          * For rules which contain uid/gid or jail constraints, cache
 2054          * a copy of the users credentials after the pcb lookup has been
 2055          * executed. This will speed up the processing of rules with
 2056          * these types of constraints, as well as decrease contention
 2057          * on pcb related locks.
 2058          */
 2059         struct ip_fw_ugid fw_ugid_cache;
 2060         int ugid_lookup = 0;
 2061 
 2062         /*
 2063          * divinput_flags       If non-zero, set to the IP_FW_DIVERT_*_FLAG
 2064          *      associated with a packet input on a divert socket.  This
 2065          *      will allow to distinguish traffic and its direction when
 2066          *      it originates from a divert socket.
 2067          */
 2068         u_int divinput_flags = 0;
 2069 
 2070         /*
 2071          * oif | args->oif      If NULL, ipfw_chk has been called on the
 2072          *      inbound path (ether_input, bdg_forward, ip_input).
 2073          *      If non-NULL, ipfw_chk has been called on the outbound path
 2074          *      (ether_output, ip_output).
 2075          */
 2076         struct ifnet *oif = args->oif;
 2077 
 2078         struct ip_fw *f = NULL;         /* matching rule */
 2079         int retval = 0;
 2080 
 2081         /*
 2082          * hlen The length of the IP header.
 2083          */
 2084         u_int hlen = 0;         /* hlen >0 means we have an IP pkt */
 2085 
 2086         /*
 2087          * offset       The offset of a fragment. offset != 0 means that
 2088          *      we have a fragment at this offset of an IPv4 packet.
 2089          *      offset == 0 means that (if this is an IPv4 packet)
 2090          *      this is the first or only fragment.
 2091          *      For IPv6 offset == 0 means there is no Fragment Header. 
 2092          *      If offset != 0 for IPv6 always use correct mask to
 2093          *      get the correct offset because we add IP6F_MORE_FRAG
 2094          *      to be able to dectect the first fragment which would
 2095          *      otherwise have offset = 0.
 2096          */
 2097         u_short offset = 0;
 2098 
 2099         /*
 2100          * Local copies of addresses. They are only valid if we have
 2101          * an IP packet.
 2102          *
 2103          * proto        The protocol. Set to 0 for non-ip packets,
 2104          *      or to the protocol read from the packet otherwise.
 2105          *      proto != 0 means that we have an IPv4 packet.
 2106          *
 2107          * src_port, dst_port   port numbers, in HOST format. Only
 2108          *      valid for TCP and UDP packets.
 2109          *
 2110          * src_ip, dst_ip       ip addresses, in NETWORK format.
 2111          *      Only valid for IPv4 packets.
 2112          */
 2113         u_int8_t proto;
 2114         u_int16_t src_port = 0, dst_port = 0;   /* NOTE: host format    */
 2115         struct in_addr src_ip, dst_ip;          /* NOTE: network format */
 2116         u_int16_t ip_len=0;
 2117         int pktlen;
 2118 
 2119         /*
 2120          * dyn_dir = MATCH_UNKNOWN when rules unchecked,
 2121          *      MATCH_NONE when checked and not matched (q = NULL),
 2122          *      MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
 2123          */
 2124         int dyn_dir = MATCH_UNKNOWN;
 2125         ipfw_dyn_rule *q = NULL;
 2126         struct ip_fw_chain *chain = &layer3_chain;
 2127         struct m_tag *mtag;
 2128 
 2129         /*
 2130          * We store in ulp a pointer to the upper layer protocol header.
 2131          * In the ipv4 case this is easy to determine from the header,
 2132          * but for ipv6 we might have some additional headers in the middle.
 2133          * ulp is NULL if not found.
 2134          */
 2135         void *ulp = NULL;               /* upper layer protocol pointer. */
 2136         /* XXX ipv6 variables */
 2137         int is_ipv6 = 0;
 2138         u_int16_t ext_hd = 0;   /* bits vector for extension header filtering */
 2139         /* end of ipv6 variables */
 2140         int is_ipv4 = 0;
 2141 
 2142         if (m->m_flags & M_SKIP_FIREWALL)
 2143                 return (IP_FW_PASS);    /* accept */
 2144 
 2145         pktlen = m->m_pkthdr.len;
 2146         proto = args->f_id.proto = 0;   /* mark f_id invalid */
 2147                 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
 2148 
 2149 /*
 2150  * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
 2151  * then it sets p to point at the offset "len" in the mbuf. WARNING: the
 2152  * pointer might become stale after other pullups (but we never use it
 2153  * this way).
 2154  */
 2155 #define PULLUP_TO(len, p, T)                                            \
 2156 do {                                                                    \
 2157         int x = (len) + sizeof(T);                                      \
 2158         if ((m)->m_len < x) {                                           \
 2159                 args->m = m = m_pullup(m, x);                           \
 2160                 if (m == NULL)                                          \
 2161                         goto pullup_failed;                             \
 2162         }                                                               \
 2163         p = (mtod(m, char *) + (len));                                  \
 2164 } while (0)
 2165 
 2166         /* Identify IP packets and fill up variables. */
 2167         if (pktlen >= sizeof(struct ip6_hdr) &&
 2168             (args->eh == NULL || ntohs(args->eh->ether_type)==ETHERTYPE_IPV6) &&
 2169             mtod(m, struct ip *)->ip_v == 6) {
 2170                 is_ipv6 = 1;
 2171                 args->f_id.addr_type = 6;
 2172                 hlen = sizeof(struct ip6_hdr);
 2173                 proto = mtod(m, struct ip6_hdr *)->ip6_nxt;
 2174 
 2175                 /* Search extension headers to find upper layer protocols */
 2176                 while (ulp == NULL) {
 2177                         switch (proto) {
 2178                         case IPPROTO_ICMPV6:
 2179                                 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
 2180                                 args->f_id.flags = ICMP6(ulp)->icmp6_type;
 2181                                 break;
 2182 
 2183                         case IPPROTO_TCP:
 2184                                 PULLUP_TO(hlen, ulp, struct tcphdr);
 2185                                 dst_port = TCP(ulp)->th_dport;
 2186                                 src_port = TCP(ulp)->th_sport;
 2187                                 args->f_id.flags = TCP(ulp)->th_flags;
 2188                                 break;
 2189 
 2190                         case IPPROTO_UDP:
 2191                                 PULLUP_TO(hlen, ulp, struct udphdr);
 2192                                 dst_port = UDP(ulp)->uh_dport;
 2193                                 src_port = UDP(ulp)->uh_sport;
 2194                                 break;
 2195 
 2196                         case IPPROTO_HOPOPTS:   /* RFC 2460 */
 2197                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
 2198                                 ext_hd |= EXT_HOPOPTS;
 2199                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
 2200                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
 2201                                 ulp = NULL;
 2202                                 break;
 2203 
 2204                         case IPPROTO_ROUTING:   /* RFC 2460 */
 2205                                 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
 2206                                 if (((struct ip6_rthdr *)ulp)->ip6r_type != 0) {
 2207                                         printf("IPFW2: IPV6 - Unknown Routing "
 2208                                             "Header type(%d)\n",
 2209                                             ((struct ip6_rthdr *)ulp)->ip6r_type);
 2210                                         if (fw_deny_unknown_exthdrs)
 2211                                             return (IP_FW_DENY);
 2212                                         break;
 2213                                 }
 2214                                 ext_hd |= EXT_ROUTING;
 2215                                 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
 2216                                 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
 2217                                 ulp = NULL;
 2218                                 break;
 2219 
 2220                         case IPPROTO_FRAGMENT:  /* RFC 2460 */
 2221                                 PULLUP_TO(hlen, ulp, struct ip6_frag);
 2222                                 ext_hd |= EXT_FRAGMENT;
 2223                                 hlen += sizeof (struct ip6_frag);
 2224                                 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
 2225                                 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
 2226                                         IP6F_OFF_MASK;
 2227                                 /* Add IP6F_MORE_FRAG for offset of first
 2228                                  * fragment to be != 0. */
 2229                                 offset |= ((struct ip6_frag *)ulp)->ip6f_offlg &
 2230                                         IP6F_MORE_FRAG;
 2231                                 if (offset == 0) {
 2232                                         printf("IPFW2: IPV6 - Invalid Fragment "
 2233                                             "Header\n");
 2234                                         if (fw_deny_unknown_exthdrs)
 2235                                             return (IP_FW_DENY);
 2236                                         break;
 2237                                 }
 2238                                 args->f_id.frag_id6 =
 2239                                     ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
 2240                                 ulp = NULL;
 2241                                 break;
 2242 
 2243                         case IPPROTO_DSTOPTS:   /* RFC 2460 */
 2244                                 PULLUP_TO(hlen, ulp, struct ip6_hbh);
 2245                                 ext_hd |= EXT_DSTOPTS;
 2246                                 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
 2247                                 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
 2248                                 ulp = NULL;
 2249                                 break;
 2250 
 2251                         case IPPROTO_AH:        /* RFC 2402 */
 2252                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
 2253                                 ext_hd |= EXT_AH;
 2254                                 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
 2255                                 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
 2256                                 ulp = NULL;
 2257                                 break;
 2258 
 2259                         case IPPROTO_ESP:       /* RFC 2406 */
 2260                                 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
 2261                                 /* Anything past Seq# is variable length and
 2262                                  * data past this ext. header is encrypted. */
 2263                                 ext_hd |= EXT_ESP;
 2264                                 break;
 2265 
 2266                         case IPPROTO_NONE:      /* RFC 2460 */
 2267                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
 2268                                 /* Packet ends here. if ip6e_len!=0 octets
 2269                                  * must be ignored. */
 2270                                 break;
 2271 
 2272                         case IPPROTO_OSPFIGP:
 2273                                 /* XXX OSPF header check? */
 2274                                 PULLUP_TO(hlen, ulp, struct ip6_ext);
 2275                                 break;
 2276 
 2277                         default:
 2278                                 printf("IPFW2: IPV6 - Unknown Extension "
 2279                                     "Header(%d), ext_hd=%x\n", proto, ext_hd);
 2280                                 if (fw_deny_unknown_exthdrs)
 2281                                     return (IP_FW_DENY);
 2282                                 break;
 2283                         } /*switch */
 2284                 }
 2285                 args->f_id.src_ip6 = mtod(m,struct ip6_hdr *)->ip6_src;
 2286                 args->f_id.dst_ip6 = mtod(m,struct ip6_hdr *)->ip6_dst;
 2287                 args->f_id.src_ip = 0;
 2288                 args->f_id.dst_ip = 0;
 2289                 args->f_id.flow_id6 = ntohl(mtod(m, struct ip6_hdr *)->ip6_flow);
 2290         } else if (pktlen >= sizeof(struct ip) &&
 2291             (args->eh == NULL || ntohs(args->eh->ether_type) == ETHERTYPE_IP) &&
 2292             mtod(m, struct ip *)->ip_v == 4) {
 2293                 is_ipv4 = 1;
 2294                 ip = mtod(m, struct ip *);
 2295                 hlen = ip->ip_hl << 2;
 2296                 args->f_id.addr_type = 4;
 2297 
 2298                 /*
 2299                  * Collect parameters into local variables for faster matching.
 2300                  */
 2301                 proto = ip->ip_p;
 2302                 src_ip = ip->ip_src;
 2303                 dst_ip = ip->ip_dst;
 2304                 if (args->eh != NULL) { /* layer 2 packets are as on the wire */
 2305                         offset = ntohs(ip->ip_off) & IP_OFFMASK;
 2306                         ip_len = ntohs(ip->ip_len);
 2307                 } else {
 2308                         offset = ip->ip_off & IP_OFFMASK;
 2309                         ip_len = ip->ip_len;
 2310                 }
 2311                 pktlen = ip_len < pktlen ? ip_len : pktlen;
 2312 
 2313                 if (offset == 0) {
 2314                         switch (proto) {
 2315                         case IPPROTO_TCP:
 2316                                 PULLUP_TO(hlen, ulp, struct tcphdr);
 2317                                 dst_port = TCP(ulp)->th_dport;
 2318                                 src_port = TCP(ulp)->th_sport;
 2319                                 args->f_id.flags = TCP(ulp)->th_flags;
 2320                                 break;
 2321 
 2322                         case IPPROTO_UDP:
 2323                                 PULLUP_TO(hlen, ulp, struct udphdr);
 2324                                 dst_port = UDP(ulp)->uh_dport;
 2325                                 src_port = UDP(ulp)->uh_sport;
 2326                                 break;
 2327 
 2328                         case IPPROTO_ICMP:
 2329                                 PULLUP_TO(hlen, ulp, struct icmphdr);
 2330                                 args->f_id.flags = ICMP(ulp)->icmp_type;
 2331                                 break;
 2332 
 2333                         default:
 2334                                 break;
 2335                         }
 2336                 }
 2337 
 2338                 args->f_id.src_ip = ntohl(src_ip.s_addr);
 2339                 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
 2340         }
 2341 #undef PULLUP_TO
 2342         if (proto) { /* we may have port numbers, store them */
 2343                 args->f_id.proto = proto;
 2344                 args->f_id.src_port = src_port = ntohs(src_port);
 2345                 args->f_id.dst_port = dst_port = ntohs(dst_port);
 2346         }
 2347 
 2348         IPFW_RLOCK(chain);
 2349         mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL);
 2350         if (args->rule) {
 2351                 /*
 2352                  * Packet has already been tagged. Look for the next rule
 2353                  * to restart processing.
 2354                  *
 2355                  * If fw_one_pass != 0 then just accept it.
 2356                  * XXX should not happen here, but optimized out in
 2357                  * the caller.
 2358                  */
 2359                 if (fw_one_pass) {
 2360                         IPFW_RUNLOCK(chain);
 2361                         return (IP_FW_PASS);
 2362                 }
 2363 
 2364                 f = args->rule->next_rule;
 2365                 if (f == NULL)
 2366                         f = lookup_next_rule(args->rule);
 2367         } else {
 2368                 /*
 2369                  * Find the starting rule. It can be either the first
 2370                  * one, or the one after divert_rule if asked so.
 2371                  */
 2372                 int skipto = mtag ? divert_cookie(mtag) : 0;
 2373 
 2374                 f = chain->rules;
 2375                 if (args->eh == NULL && skipto != 0) {
 2376                         if (skipto >= IPFW_DEFAULT_RULE) {
 2377                                 IPFW_RUNLOCK(chain);
 2378                                 return (IP_FW_DENY); /* invalid */
 2379                         }
 2380                         while (f && f->rulenum <= skipto)
 2381                                 f = f->next;
 2382                         if (f == NULL) {        /* drop packet */
 2383                                 IPFW_RUNLOCK(chain);
 2384                                 return (IP_FW_DENY);
 2385                         }
 2386                 }
 2387         }
 2388         /* reset divert rule to avoid confusion later */
 2389         if (mtag) {
 2390                 divinput_flags = divert_info(mtag) &
 2391                     (IP_FW_DIVERT_OUTPUT_FLAG | IP_FW_DIVERT_LOOPBACK_FLAG);
 2392                 m_tag_delete(m, mtag);
 2393         }
 2394 
 2395         /*
 2396          * Now scan the rules, and parse microinstructions for each rule.
 2397          */
 2398         for (; f; f = f->next) {
 2399                 ipfw_insn *cmd;
 2400                 uint32_t tablearg = 0;
 2401                 int l, cmdlen, skip_or; /* skip rest of OR block */
 2402 
 2403 again:
 2404                 if (set_disable & (1 << f->set) )
 2405                         continue;
 2406 
 2407                 skip_or = 0;
 2408                 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
 2409                     l -= cmdlen, cmd += cmdlen) {
 2410                         int match;
 2411 
 2412                         /*
 2413                          * check_body is a jump target used when we find a
 2414                          * CHECK_STATE, and need to jump to the body of
 2415                          * the target rule.
 2416                          */
 2417 
 2418 check_body:
 2419                         cmdlen = F_LEN(cmd);
 2420                         /*
 2421                          * An OR block (insn_1 || .. || insn_n) has the
 2422                          * F_OR bit set in all but the last instruction.
 2423                          * The first match will set "skip_or", and cause
 2424                          * the following instructions to be skipped until
 2425                          * past the one with the F_OR bit clear.
 2426                          */
 2427                         if (skip_or) {          /* skip this instruction */
 2428                                 if ((cmd->len & F_OR) == 0)
 2429                                         skip_or = 0;    /* next one is good */
 2430                                 continue;
 2431                         }
 2432                         match = 0; /* set to 1 if we succeed */
 2433 
 2434                         switch (cmd->opcode) {
 2435                         /*
 2436                          * The first set of opcodes compares the packet's
 2437                          * fields with some pattern, setting 'match' if a
 2438                          * match is found. At the end of the loop there is
 2439                          * logic to deal with F_NOT and F_OR flags associated
 2440                          * with the opcode.
 2441                          */
 2442                         case O_NOP:
 2443                                 match = 1;
 2444                                 break;
 2445 
 2446                         case O_FORWARD_MAC:
 2447                                 printf("ipfw: opcode %d unimplemented\n",
 2448                                     cmd->opcode);
 2449                                 break;
 2450 
 2451                         case O_GID:
 2452                         case O_UID:
 2453                         case O_JAIL:
 2454                                 /*
 2455                                  * We only check offset == 0 && proto != 0,
 2456                                  * as this ensures that we have a
 2457                                  * packet with the ports info.
 2458                                  */
 2459                                 if (offset!=0)
 2460                                         break;
 2461                                 if (is_ipv6) /* XXX to be fixed later */
 2462                                         break;
 2463                                 if (proto == IPPROTO_TCP ||
 2464                                     proto == IPPROTO_UDP)
 2465                                         match = check_uidgid(
 2466                                                     (ipfw_insn_u32 *)cmd,
 2467                                                     proto, oif,
 2468                                                     dst_ip, dst_port,
 2469                                                     src_ip, src_port, &fw_ugid_cache,
 2470                                                     &ugid_lookup, args->inp);
 2471                                 break;
 2472 
 2473                         case O_RECV:
 2474                                 match = iface_match(m->m_pkthdr.rcvif,
 2475                                     (ipfw_insn_if *)cmd);
 2476                                 break;
 2477 
 2478                         case O_XMIT:
 2479                                 match = iface_match(oif, (ipfw_insn_if *)cmd);
 2480                                 break;
 2481 
 2482                         case O_VIA:
 2483                                 match = iface_match(oif ? oif :
 2484                                     m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
 2485                                 break;
 2486 
 2487                         case O_MACADDR2:
 2488                                 if (args->eh != NULL) { /* have MAC header */
 2489                                         u_int32_t *want = (u_int32_t *)
 2490                                                 ((ipfw_insn_mac *)cmd)->addr;
 2491                                         u_int32_t *mask = (u_int32_t *)
 2492                                                 ((ipfw_insn_mac *)cmd)->mask;
 2493                                         u_int32_t *hdr = (u_int32_t *)args->eh;
 2494 
 2495                                         match =
 2496                                             ( want[0] == (hdr[0] & mask[0]) &&
 2497                                               want[1] == (hdr[1] & mask[1]) &&
 2498                                               want[2] == (hdr[2] & mask[2]) );
 2499                                 }
 2500                                 break;
 2501 
 2502                         case O_MAC_TYPE:
 2503                                 if (args->eh != NULL) {
 2504                                         u_int16_t t =
 2505                                             ntohs(args->eh->ether_type);
 2506                                         u_int16_t *p =
 2507                                             ((ipfw_insn_u16 *)cmd)->ports;
 2508                                         int i;
 2509 
 2510                                         for (i = cmdlen - 1; !match && i>0;
 2511                                             i--, p += 2)
 2512                                                 match = (t>=p[0] && t<=p[1]);
 2513                                 }
 2514                                 break;
 2515 
 2516                         case O_FRAG:
 2517                                 match = (offset != 0);
 2518                                 break;
 2519 
 2520                         case O_IN:      /* "out" is "not in" */
 2521                                 match = (oif == NULL);
 2522                                 break;
 2523 
 2524                         case O_LAYER2:
 2525                                 match = (args->eh != NULL);
 2526                                 break;
 2527 
 2528                         case O_DIVERTED:
 2529                                 match = (cmd->arg1 & 1 && divinput_flags &
 2530                                     IP_FW_DIVERT_LOOPBACK_FLAG) ||
 2531                                         (cmd->arg1 & 2 && divinput_flags &
 2532                                     IP_FW_DIVERT_OUTPUT_FLAG);
 2533                                 break;
 2534 
 2535                         case O_PROTO:
 2536                                 /*
 2537                                  * We do not allow an arg of 0 so the
 2538                                  * check of "proto" only suffices.
 2539                                  */
 2540                                 match = (proto == cmd->arg1);
 2541                                 break;
 2542 
 2543                         case O_IP_SRC:
 2544                                 match = is_ipv4 &&
 2545                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
 2546                                     src_ip.s_addr);
 2547                                 break;
 2548 
 2549                         case O_IP_SRC_LOOKUP:
 2550                         case O_IP_DST_LOOKUP:
 2551                                 if (is_ipv4) {
 2552                                     uint32_t a =
 2553                                         (cmd->opcode == O_IP_DST_LOOKUP) ?
 2554                                             dst_ip.s_addr : src_ip.s_addr;
 2555                                     uint32_t v;
 2556 
 2557                                     match = lookup_table(chain, cmd->arg1, a,
 2558                                         &v);
 2559                                     if (!match)
 2560                                         break;
 2561                                     if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
 2562                                         match =
 2563                                             ((ipfw_insn_u32 *)cmd)->d[0] == v;
 2564                                     else
 2565                                         tablearg = v;
 2566                                 }
 2567                                 break;
 2568 
 2569                         case O_IP_SRC_MASK:
 2570                         case O_IP_DST_MASK:
 2571                                 if (is_ipv4) {
 2572                                     uint32_t a =
 2573                                         (cmd->opcode == O_IP_DST_MASK) ?
 2574                                             dst_ip.s_addr : src_ip.s_addr;
 2575                                     uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
 2576                                     int i = cmdlen-1;
 2577 
 2578                                     for (; !match && i>0; i-= 2, p+= 2)
 2579                                         match = (p[0] == (a & p[1]));
 2580                                 }
 2581                                 break;
 2582 
 2583                         case O_IP_SRC_ME:
 2584                                 if (is_ipv4) {
 2585                                         struct ifnet *tif;
 2586 
 2587                                         INADDR_TO_IFP(src_ip, tif);
 2588                                         match = (tif != NULL);
 2589                                 }
 2590                                 break;
 2591 
 2592                         case O_IP_DST_SET:
 2593                         case O_IP_SRC_SET:
 2594                                 if (is_ipv4) {
 2595                                         u_int32_t *d = (u_int32_t *)(cmd+1);
 2596                                         u_int32_t addr =
 2597                                             cmd->opcode == O_IP_DST_SET ?
 2598                                                 args->f_id.dst_ip :
 2599                                                 args->f_id.src_ip;
 2600 
 2601                                             if (addr < d[0])
 2602                                                     break;
 2603                                             addr -= d[0]; /* subtract base */
 2604                                             match = (addr < cmd->arg1) &&
 2605                                                 ( d[ 1 + (addr>>5)] &
 2606                                                   (1<<(addr & 0x1f)) );
 2607                                 }
 2608                                 break;
 2609 
 2610                         case O_IP_DST:
 2611                                 match = is_ipv4 &&
 2612                                     (((ipfw_insn_ip *)cmd)->addr.s_addr ==
 2613                                     dst_ip.s_addr);
 2614                                 break;
 2615 
 2616                         case O_IP_DST_ME:
 2617                                 if (is_ipv4) {
 2618                                         struct ifnet *tif;
 2619 
 2620                                         INADDR_TO_IFP(dst_ip, tif);
 2621                                         match = (tif != NULL);
 2622                                 }
 2623                                 break;
 2624 
 2625                         case O_IP_SRCPORT:
 2626                         case O_IP_DSTPORT:
 2627                                 /*
 2628                                  * offset == 0 && proto != 0 is enough
 2629                                  * to guarantee that we have a
 2630                                  * packet with port info.
 2631                                  */
 2632                                 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
 2633                                     && offset == 0) {
 2634                                         u_int16_t x =
 2635                                             (cmd->opcode == O_IP_SRCPORT) ?
 2636                                                 src_port : dst_port ;
 2637                                         u_int16_t *p =
 2638                                             ((ipfw_insn_u16 *)cmd)->ports;
 2639                                         int i;
 2640 
 2641                                         for (i = cmdlen - 1; !match && i>0;
 2642                                             i--, p += 2)
 2643                                                 match = (x>=p[0] && x<=p[1]);
 2644                                 }
 2645                                 break;
 2646 
 2647                         case O_ICMPTYPE:
 2648                                 match = (offset == 0 && proto==IPPROTO_ICMP &&
 2649                                     icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
 2650                                 break;
 2651 
 2652 #ifdef INET6
 2653                         case O_ICMP6TYPE:
 2654                                 match = is_ipv6 && offset == 0 &&
 2655                                     proto==IPPROTO_ICMPV6 &&
 2656                                     icmp6type_match(
 2657                                         ICMP6(ulp)->icmp6_type,
 2658                                         (ipfw_insn_u32 *)cmd);
 2659                                 break;
 2660 #endif /* INET6 */
 2661 
 2662                         case O_IPOPT:
 2663                                 match = (is_ipv4 &&
 2664                                     ipopts_match(mtod(m, struct ip *), cmd) );
 2665                                 break;
 2666 
 2667                         case O_IPVER:
 2668                                 match = (is_ipv4 &&
 2669                                     cmd->arg1 == mtod(m, struct ip *)->ip_v);
 2670                                 break;
 2671 
 2672                         case O_IPID:
 2673                         case O_IPLEN:
 2674                         case O_IPTTL:
 2675                                 if (is_ipv4) {  /* only for IP packets */
 2676                                     uint16_t x;
 2677                                     uint16_t *p;
 2678                                     int i;
 2679 
 2680                                     if (cmd->opcode == O_IPLEN)
 2681                                         x = ip_len;
 2682                                     else if (cmd->opcode == O_IPTTL)
 2683                                         x = mtod(m, struct ip *)->ip_ttl;
 2684                                     else /* must be IPID */
 2685                                         x = ntohs(mtod(m, struct ip *)->ip_id);
 2686                                     if (cmdlen == 1) {
 2687                                         match = (cmd->arg1 == x);
 2688                                         break;
 2689                                     }
 2690                                     /* otherwise we have ranges */
 2691                                     p = ((ipfw_insn_u16 *)cmd)->ports;
 2692                                     i = cmdlen - 1;
 2693                                     for (; !match && i>0; i--, p += 2)
 2694                                         match = (x >= p[0] && x <= p[1]);
 2695                                 }
 2696                                 break;
 2697 
 2698                         case O_IPPRECEDENCE:
 2699                                 match = (is_ipv4 &&
 2700                                     (cmd->arg1 == (mtod(m, struct ip *)->ip_tos & 0xe0)) );
 2701                                 break;
 2702 
 2703                         case O_IPTOS:
 2704                                 match = (is_ipv4 &&
 2705                                     flags_match(cmd, mtod(m, struct ip *)->ip_tos));
 2706                                 break;
 2707 
 2708                         case O_TCPDATALEN:
 2709                                 if (proto == IPPROTO_TCP && offset == 0) {
 2710                                     struct tcphdr *tcp;
 2711                                     uint16_t x;
 2712                                     uint16_t *p;
 2713                                     int i;
 2714 
 2715                                     tcp = TCP(ulp);
 2716                                     x = ip_len -
 2717                                         ((ip->ip_hl + tcp->th_off) << 2);
 2718                                     if (cmdlen == 1) {
 2719                                         match = (cmd->arg1 == x);
 2720                                         break;
 2721                                     }
 2722                                     /* otherwise we have ranges */
 2723                                     p = ((ipfw_insn_u16 *)cmd)->ports;
 2724                                     i = cmdlen - 1;
 2725                                     for (; !match && i>0; i--, p += 2)
 2726                                         match = (x >= p[0] && x <= p[1]);
 2727                                 }
 2728                                 break;
 2729 
 2730                         case O_TCPFLAGS:
 2731                                 match = (proto == IPPROTO_TCP && offset == 0 &&
 2732                                     flags_match(cmd, TCP(ulp)->th_flags));
 2733                                 break;
 2734 
 2735                         case O_TCPOPTS:
 2736                                 match = (proto == IPPROTO_TCP && offset == 0 &&
 2737                                     tcpopts_match(TCP(ulp), cmd));
 2738                                 break;
 2739 
 2740                         case O_TCPSEQ:
 2741                                 match = (proto == IPPROTO_TCP && offset == 0 &&
 2742                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
 2743                                         TCP(ulp)->th_seq);
 2744                                 break;
 2745 
 2746                         case O_TCPACK:
 2747                                 match = (proto == IPPROTO_TCP && offset == 0 &&
 2748                                     ((ipfw_insn_u32 *)cmd)->d[0] ==
 2749                                         TCP(ulp)->th_ack);
 2750                                 break;
 2751 
 2752                         case O_TCPWIN:
 2753                                 match = (proto == IPPROTO_TCP && offset == 0 &&
 2754                                     cmd->arg1 == TCP(ulp)->th_win);
 2755                                 break;
 2756 
 2757                         case O_ESTAB:
 2758                                 /* reject packets which have SYN only */
 2759                                 /* XXX should i also check for TH_ACK ? */
 2760                                 match = (proto == IPPROTO_TCP && offset == 0 &&
 2761                                     (TCP(ulp)->th_flags &
 2762                                      (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
 2763                                 break;
 2764 
 2765                         case O_ALTQ: {
 2766                                 struct altq_tag *at;
 2767                                 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
 2768 
 2769                                 match = 1;
 2770                                 mtag = m_tag_find(m, PACKET_TAG_PF_QID, NULL);
 2771                                 if (mtag != NULL)
 2772                                         break;
 2773                                 mtag = m_tag_get(PACKET_TAG_PF_QID,
 2774                                                 sizeof(struct altq_tag),
 2775                                                 M_NOWAIT);
 2776                                 if (mtag == NULL) {
 2777                                         /*
 2778                                          * Let the packet fall back to the
 2779                                          * default ALTQ.
 2780                                          */
 2781                                         break;
 2782                                 }
 2783                                 at = (struct altq_tag *)(mtag+1);
 2784                                 at->qid = altq->qid;
 2785                                 if (is_ipv4)
 2786                                         at->af = AF_INET;
 2787                                 else
 2788                                         at->af = AF_LINK;
 2789                                 at->hdr = ip;
 2790                                 m_tag_prepend(m, mtag);
 2791                                 break;
 2792                         }
 2793 
 2794                         case O_LOG:
 2795                                 if (fw_verbose)
 2796                                         ipfw_log(f, hlen, args, m, oif, offset);
 2797                                 match = 1;
 2798                                 break;
 2799 
 2800                         case O_PROB:
 2801                                 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
 2802                                 break;
 2803 
 2804                         case O_VERREVPATH:
 2805                                 /* Outgoing packets automatically pass/match */
 2806                                 match = ((oif != NULL) ||
 2807                                     (m->m_pkthdr.rcvif == NULL) ||
 2808                                     (
 2809 #ifdef INET6
 2810                                     is_ipv6 ?
 2811                                         verify_path6(&(args->f_id.src_ip6),
 2812                                             m->m_pkthdr.rcvif) :
 2813 #endif
 2814                                     verify_path(src_ip, m->m_pkthdr.rcvif)));
 2815                                 break;
 2816 
 2817                         case O_VERSRCREACH:
 2818                                 /* Outgoing packets automatically pass/match */
 2819                                 match = (hlen > 0 && ((oif != NULL) ||
 2820 #ifdef INET6
 2821                                     is_ipv6 ?
 2822                                         verify_path6(&(args->f_id.src_ip6),
 2823                                             NULL) :
 2824 #endif
 2825                                     verify_path(src_ip, NULL)));
 2826                                 break;
 2827 
 2828                         case O_ANTISPOOF:
 2829                                 /* Outgoing packets automatically pass/match */
 2830                                 if (oif == NULL && hlen > 0 &&
 2831                                     (  (is_ipv4 && in_localaddr(src_ip))
 2832 #ifdef INET6
 2833                                     || (is_ipv6 &&
 2834                                         in6_localaddr(&(args->f_id.src_ip6)))
 2835 #endif
 2836                                     ))
 2837                                         match =
 2838 #ifdef INET6
 2839                                             is_ipv6 ? verify_path6(
 2840                                                 &(args->f_id.src_ip6),
 2841                                                 m->m_pkthdr.rcvif) :
 2842 #endif
 2843                                             verify_path(src_ip,
 2844                                                 m->m_pkthdr.rcvif);
 2845                                 else
 2846                                         match = 1;
 2847                                 break;
 2848 
 2849                         case O_IPSEC:
 2850 #ifdef FAST_IPSEC
 2851                                 match = (m_tag_find(m,
 2852                                     PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
 2853 #endif
 2854 #ifdef IPSEC
 2855                                 match = (ipsec_getnhist(m) != 0);
 2856 #endif
 2857                                 /* otherwise no match */
 2858                                 break;
 2859 
 2860 #ifdef INET6
 2861                         case O_IP6_SRC:
 2862                                 match = is_ipv6 &&
 2863                                     IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
 2864                                     &((ipfw_insn_ip6 *)cmd)->addr6);
 2865                                 break;
 2866 
 2867                         case O_IP6_DST:
 2868                                 match = is_ipv6 &&
 2869                                 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
 2870                                     &((ipfw_insn_ip6 *)cmd)->addr6);
 2871                                 break;
 2872                         case O_IP6_SRC_MASK:
 2873                                 if (is_ipv6) {
 2874                                         ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd;
 2875                                         struct in6_addr p = args->f_id.src_ip6;
 2876 
 2877                                         APPLY_MASK(&p, &te->mask6);
 2878                                         match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p);
 2879                                 }
 2880                                 break;
 2881 
 2882                         case O_IP6_DST_MASK:
 2883                                 if (is_ipv6) {
 2884                                         ipfw_insn_ip6 *te = (ipfw_insn_ip6 *)cmd;
 2885                                         struct in6_addr p = args->f_id.dst_ip6;
 2886 
 2887                                         APPLY_MASK(&p, &te->mask6);
 2888                                         match = IN6_ARE_ADDR_EQUAL(&te->addr6, &p);
 2889                                 }
 2890                                 break;
 2891 
 2892                         case O_IP6_SRC_ME:
 2893                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.src_ip6);
 2894                                 break;
 2895 
 2896                         case O_IP6_DST_ME:
 2897                                 match= is_ipv6 && search_ip6_addr_net(&args->f_id.dst_ip6);
 2898                                 break;
 2899 
 2900                         case O_FLOW6ID:
 2901                                 match = is_ipv6 &&
 2902                                     flow6id_match(args->f_id.flow_id6,
 2903                                     (ipfw_insn_u32 *) cmd);
 2904                                 break;
 2905 
 2906                         case O_EXT_HDR:
 2907                                 match = is_ipv6 &&
 2908                                     (ext_hd & ((ipfw_insn *) cmd)->arg1);
 2909                                 break;
 2910 
 2911                         case O_IP6:
 2912                                 match = is_ipv6;
 2913                                 break;
 2914 #endif
 2915 
 2916                         case O_IP4:
 2917                                 match = is_ipv4;
 2918                                 break;
 2919 
 2920                         /*
 2921                          * The second set of opcodes represents 'actions',
 2922                          * i.e. the terminal part of a rule once the packet
 2923                          * matches all previous patterns.
 2924                          * Typically there is only one action for each rule,
 2925                          * and the opcode is stored at the end of the rule
 2926                          * (but there are exceptions -- see below).
 2927                          *
 2928                          * In general, here we set retval and terminate the
 2929                          * outer loop (would be a 'break 3' in some language,
 2930                          * but we need to do a 'goto done').
 2931                          *
 2932                          * Exceptions:
 2933                          * O_COUNT and O_SKIPTO actions:
 2934                          *   instead of terminating, we jump to the next rule
 2935                          *   ('goto next_rule', equivalent to a 'break 2'),
 2936                          *   or to the SKIPTO target ('goto again' after
 2937                          *   having set f, cmd and l), respectively.
 2938                          *
 2939                          * O_LOG and O_ALTQ action parameters:
 2940                          *   perform some action and set match = 1;
 2941                          *
 2942                          * O_LIMIT and O_KEEP_STATE: these opcodes are
 2943                          *   not real 'actions', and are stored right
 2944                          *   before the 'action' part of the rule.
 2945                          *   These opcodes try to install an entry in the
 2946                          *   state tables; if successful, we continue with
 2947                          *   the next opcode (match=1; break;), otherwise
 2948                          *   the packet *   must be dropped
 2949                          *   ('goto done' after setting retval);
 2950                          *
 2951                          * O_PROBE_STATE and O_CHECK_STATE: these opcodes
 2952                          *   cause a lookup of the state table, and a jump
 2953                          *   to the 'action' part of the parent rule
 2954                          *   ('goto check_body') if an entry is found, or
 2955                          *   (CHECK_STATE only) a jump to the next rule if
 2956                          *   the entry is not found ('goto next_rule').
 2957                          *   The result of the lookup is cached to make
 2958                          *   further instances of these opcodes are
 2959                          *   effectively NOPs.
 2960                          */
 2961                         case O_LIMIT:
 2962                         case O_KEEP_STATE:
 2963                                 if (install_state(f,
 2964                                     (ipfw_insn_limit *)cmd, args)) {
 2965                                         retval = IP_FW_DENY;
 2966                                         goto done; /* error/limit violation */
 2967                                 }
 2968                                 match = 1;
 2969                                 break;
 2970 
 2971                         case O_PROBE_STATE:
 2972                         case O_CHECK_STATE:
 2973                                 /*
 2974                                  * dynamic rules are checked at the first
 2975                                  * keep-state or check-state occurrence,
 2976                                  * with the result being stored in dyn_dir.
 2977                                  * The compiler introduces a PROBE_STATE
 2978                                  * instruction for us when we have a
 2979                                  * KEEP_STATE (because PROBE_STATE needs
 2980                                  * to be run first).
 2981                                  */
 2982                                 if (dyn_dir == MATCH_UNKNOWN &&
 2983                                     (q = lookup_dyn_rule(&args->f_id,
 2984                                      &dyn_dir, proto == IPPROTO_TCP ?
 2985                                         TCP(ulp) : NULL))
 2986                                         != NULL) {
 2987                                         /*
 2988                                          * Found dynamic entry, update stats
 2989                                          * and jump to the 'action' part of
 2990                                          * the parent rule.
 2991                                          */
 2992                                         q->pcnt++;
 2993                                         q->bcnt += pktlen;
 2994                                         f = q->rule;
 2995                                         cmd = ACTION_PTR(f);
 2996                                         l = f->cmd_len - f->act_ofs;
 2997                                         IPFW_DYN_UNLOCK();
 2998                                         goto check_body;
 2999                                 }
 3000                                 /*
 3001                                  * Dynamic entry not found. If CHECK_STATE,
 3002                                  * skip to next rule, if PROBE_STATE just
 3003                                  * ignore and continue with next opcode.
 3004                                  */
 3005                                 if (cmd->opcode == O_CHECK_STATE)
 3006                                         goto next_rule;
 3007                                 match = 1;
 3008                                 break;
 3009 
 3010                         case O_ACCEPT:
 3011                                 retval = 0;     /* accept */
 3012                                 goto done;
 3013 
 3014                         case O_PIPE:
 3015                         case O_QUEUE:
 3016                                 args->rule = f; /* report matching rule */
 3017                                 if (cmd->arg1 == IP_FW_TABLEARG)
 3018                                         args->cookie = tablearg;
 3019                                 else
 3020                                         args->cookie = cmd->arg1;
 3021                                 retval = IP_FW_DUMMYNET;
 3022                                 goto done;
 3023 
 3024                         case O_DIVERT:
 3025                         case O_TEE: {
 3026                                 struct divert_tag *dt;
 3027 
 3028                                 if (args->eh) /* not on layer 2 */
 3029                                         break;
 3030                                 mtag = m_tag_get(PACKET_TAG_DIVERT,
 3031                                                 sizeof(struct divert_tag),
 3032                                                 M_NOWAIT);
 3033                                 if (mtag == NULL) {
 3034                                         /* XXX statistic */
 3035                                         /* drop packet */
 3036                                         IPFW_RUNLOCK(chain);
 3037                                         return (IP_FW_DENY);
 3038                                 }
 3039                                 dt = (struct divert_tag *)(mtag+1);
 3040                                 dt->cookie = f->rulenum;
 3041                                 if (cmd->arg1 == IP_FW_TABLEARG)
 3042                                         dt->info = tablearg;
 3043                                 else
 3044                                         dt->info = cmd->arg1;
 3045                                 m_tag_prepend(m, mtag);
 3046                                 retval = (cmd->opcode == O_DIVERT) ?
 3047                                     IP_FW_DIVERT : IP_FW_TEE;
 3048                                 goto done;
 3049                         }
 3050 
 3051                         case O_COUNT:
 3052                         case O_SKIPTO:
 3053                                 f->pcnt++;      /* update stats */
 3054                                 f->bcnt += pktlen;
 3055                                 f->timestamp = time_second;
 3056                                 if (cmd->opcode == O_COUNT)
 3057                                         goto next_rule;
 3058                                 /* handle skipto */
 3059                                 if (f->next_rule == NULL)
 3060                                         lookup_next_rule(f);
 3061                                 f = f->next_rule;
 3062                                 goto again;
 3063 
 3064                         case O_REJECT:
 3065                                 /*
 3066                                  * Drop the packet and send a reject notice
 3067                                  * if the packet is not ICMP (or is an ICMP
 3068                                  * query), and it is not multicast/broadcast.
 3069                                  */
 3070                                 if (hlen > 0 && is_ipv4 && offset == 0 &&
 3071                                     (proto != IPPROTO_ICMP ||
 3072                                      is_icmp_query(ICMP(ulp))) &&
 3073                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
 3074                                     !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
 3075                                         send_reject(args, cmd->arg1,
 3076                                             offset,ip_len);
 3077                                         m = args->m;
 3078                                 }
 3079                                 /* FALLTHROUGH */
 3080 #ifdef INET6
 3081                         case O_UNREACH6:
 3082                                 if (hlen > 0 && is_ipv6 &&
 3083                                     (proto != IPPROTO_ICMPV6 ||
 3084                                      (is_icmp6_query(args->f_id.flags) == 1)) &&
 3085                                     !(m->m_flags & (M_BCAST|M_MCAST)) &&
 3086                                     !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
 3087                                         send_reject6(args, cmd->arg1,
 3088                                             offset, hlen);
 3089                                         m = args->m;
 3090                                 }
 3091                                 /* FALLTHROUGH */
 3092 #endif
 3093                         case O_DENY:
 3094                                 retval = IP_FW_DENY;
 3095                                 goto done;
 3096 
 3097                         case O_FORWARD_IP:
 3098                                 if (args->eh)   /* not valid on layer2 pkts */
 3099                                         break;
 3100                                 if (!q || dyn_dir == MATCH_FORWARD)
 3101                                         args->next_hop =
 3102                                             &((ipfw_insn_sa *)cmd)->sa;
 3103                                 retval = IP_FW_PASS;
 3104                                 goto done;
 3105 
 3106                         case O_NETGRAPH:
 3107                         case O_NGTEE:
 3108                                 args->rule = f; /* report matching rule */
 3109                                 if (cmd->arg1 == IP_FW_TABLEARG)
 3110                                         args->cookie = tablearg;
 3111                                 else
 3112                                         args->cookie = cmd->arg1;
 3113                                 retval = (cmd->opcode == O_NETGRAPH) ?
 3114                                     IP_FW_NETGRAPH : IP_FW_NGTEE;
 3115                                 goto done;
 3116 
 3117                         default:
 3118                                 panic("-- unknown opcode %d\n", cmd->opcode);
 3119                         } /* end of switch() on opcodes */
 3120 
 3121                         if (cmd->len & F_NOT)
 3122                                 match = !match;
 3123 
 3124                         if (match) {
 3125                                 if (cmd->len & F_OR)
 3126                                         skip_or = 1;
 3127                         } else {
 3128                                 if (!(cmd->len & F_OR)) /* not an OR block, */
 3129                                         break;          /* try next rule    */
 3130                         }
 3131 
 3132                 }       /* end of inner for, scan opcodes */
 3133 
 3134 next_rule:;             /* try next rule                */
 3135 
 3136         }               /* end of outer for, scan rules */
 3137         printf("ipfw: ouch!, skip past end of rules, denying packet\n");
 3138         IPFW_RUNLOCK(chain);
 3139         return (IP_FW_DENY);
 3140 
 3141 done:
 3142         /* Update statistics */
 3143         f->pcnt++;
 3144         f->bcnt += pktlen;
 3145         f->timestamp = time_second;
 3146         IPFW_RUNLOCK(chain);
 3147         return (retval);
 3148 
 3149 pullup_failed:
 3150         if (fw_verbose)
 3151                 printf("ipfw: pullup failed\n");
 3152         return (IP_FW_DENY);
 3153 }
 3154 
 3155 /*
 3156  * When a rule is added/deleted, clear the next_rule pointers in all rules.
 3157  * These will be reconstructed on the fly as packets are matched.
 3158  */
 3159 static void
 3160 flush_rule_ptrs(struct ip_fw_chain *chain)
 3161 {
 3162         struct ip_fw *rule;
 3163 
 3164         IPFW_WLOCK_ASSERT(chain);
 3165 
 3166         for (rule = chain->rules; rule; rule = rule->next)
 3167                 rule->next_rule = NULL;
 3168 }
 3169 
 3170 /*
 3171  * When pipes/queues are deleted, clear the "pipe_ptr" pointer to a given
 3172  * pipe/queue, or to all of them (match == NULL).
 3173  */
 3174 void
 3175 flush_pipe_ptrs(struct dn_flow_set *match)
 3176 {
 3177         struct ip_fw *rule;
 3178 
 3179         IPFW_WLOCK(&layer3_chain);
 3180         for (rule = layer3_chain.rules; rule; rule = rule->next) {
 3181                 ipfw_insn_pipe *cmd = (ipfw_insn_pipe *)ACTION_PTR(rule);
 3182 
 3183                 if (cmd->o.opcode != O_PIPE && cmd->o.opcode != O_QUEUE)
 3184                         continue;
 3185                 /*
 3186                  * XXX Use bcmp/bzero to handle pipe_ptr to overcome
 3187                  * possible alignment problems on 64-bit architectures.
 3188                  * This code is seldom used so we do not worry too
 3189                  * much about efficiency.
 3190                  */
 3191                 if (match == NULL ||
 3192                     !bcmp(&cmd->pipe_ptr, &match, sizeof(match)) )
 3193                         bzero(&cmd->pipe_ptr, sizeof(cmd->pipe_ptr));
 3194         }
 3195         IPFW_WUNLOCK(&layer3_chain);
 3196 }
 3197 
 3198 /*
 3199  * Add a new rule to the list. Copy the rule into a malloc'ed area, then
 3200  * possibly create a rule number and add the rule to the list.
 3201  * Update the rule_number in the input struct so the caller knows it as well.
 3202  */
 3203 static int
 3204 add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule)
 3205 {
 3206         struct ip_fw *rule, *f, *prev;
 3207         int l = RULESIZE(input_rule);
 3208 
 3209         if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE)
 3210                 return (EINVAL);
 3211 
 3212         rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO);
 3213         if (rule == NULL)
 3214                 return (ENOSPC);
 3215 
 3216         bcopy(input_rule, rule, l);
 3217 
 3218         rule->next = NULL;
 3219         rule->next_rule = NULL;
 3220 
 3221         rule->pcnt = 0;
 3222         rule->bcnt = 0;
 3223         rule->timestamp = 0;
 3224 
 3225         IPFW_WLOCK(chain);
 3226 
 3227         if (chain->rules == NULL) {     /* default rule */
 3228                 chain->rules = rule;
 3229                 goto done;
 3230         }
 3231 
 3232         /*
 3233          * If rulenum is 0, find highest numbered rule before the
 3234          * default rule, and add autoinc_step
 3235          */
 3236         if (autoinc_step < 1)
 3237                 autoinc_step = 1;
 3238         else if (autoinc_step > 1000)
 3239                 autoinc_step = 1000;
 3240         if (rule->rulenum == 0) {
 3241                 /*
 3242                  * locate the highest numbered rule before default
 3243                  */
 3244                 for (f = chain->rules; f; f = f->next) {
 3245                         if (f->rulenum == IPFW_DEFAULT_RULE)
 3246                                 break;
 3247                         rule->rulenum = f->rulenum;
 3248                 }
 3249                 if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step)
 3250                         rule->rulenum += autoinc_step;
 3251                 input_rule->rulenum = rule->rulenum;
 3252         }
 3253 
 3254         /*
 3255          * Now insert the new rule in the right place in the sorted list.
 3256          */
 3257         for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) {
 3258                 if (f->rulenum > rule->rulenum) { /* found the location */
 3259                         if (prev) {
 3260                                 rule->next = f;
 3261                                 prev->next = rule;
 3262                         } else { /* head insert */
 3263                                 rule->next = chain->rules;
 3264                                 chain->rules = rule;
 3265                         }
 3266                         break;
 3267                 }
 3268         }
 3269         flush_rule_ptrs(chain);
 3270 done:
 3271         static_count++;
 3272         static_len += l;
 3273         IPFW_WUNLOCK(chain);
 3274         DEB(printf("ipfw: installed rule %d, static count now %d\n",
 3275                 rule->rulenum, static_count);)
 3276         return (0);
 3277 }
 3278 
 3279 /**
 3280  * Remove a static rule (including derived * dynamic rules)
 3281  * and place it on the ``reap list'' for later reclamation.
 3282  * The caller is in charge of clearing rule pointers to avoid
 3283  * dangling pointers.
 3284  * @return a pointer to the next entry.
 3285  * Arguments are not checked, so they better be correct.
 3286  */
 3287 static struct ip_fw *
 3288 remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, struct ip_fw *prev)
 3289 {
 3290         struct ip_fw *n;
 3291         int l = RULESIZE(rule);
 3292 
 3293         IPFW_WLOCK_ASSERT(chain);
 3294 
 3295         n = rule->next;
 3296         IPFW_DYN_LOCK();
 3297         remove_dyn_rule(rule, NULL /* force removal */);
 3298         IPFW_DYN_UNLOCK();
 3299         if (prev == NULL)
 3300                 chain->rules = n;
 3301         else
 3302                 prev->next = n;
 3303         static_count--;
 3304         static_len -= l;
 3305 
 3306         rule->next = chain->reap;
 3307         chain->reap = rule;
 3308 
 3309         return n;
 3310 }
 3311 
 3312 /**
 3313  * Reclaim storage associated with a list of rules.  This is
 3314  * typically the list created using remove_rule.
 3315  */
 3316 static void
 3317 reap_rules(struct ip_fw *head)
 3318 {
 3319         struct ip_fw *rule;
 3320 
 3321         while ((rule = head) != NULL) {
 3322                 head = head->next;
 3323                 if (DUMMYNET_LOADED)
 3324                         ip_dn_ruledel_ptr(rule);
 3325                 free(rule, M_IPFW);
 3326         }
 3327 }
 3328 
 3329 /*
 3330  * Remove all rules from a chain (except rules in set RESVD_SET
 3331  * unless kill_default = 1).  The caller is responsible for
 3332  * reclaiming storage for the rules left in chain->reap.
 3333  */
 3334 static void
 3335 free_chain(struct ip_fw_chain *chain, int kill_default)
 3336 {
 3337         struct ip_fw *prev, *rule;
 3338 
 3339         IPFW_WLOCK_ASSERT(chain);
 3340 
 3341         flush_rule_ptrs(chain); /* more efficient to do outside the loop */
 3342         for (prev = NULL, rule = chain->rules; rule ; )
 3343                 if (kill_default || rule->set != RESVD_SET)
 3344                         rule = remove_rule(chain, rule, prev);
 3345                 else {
 3346                         prev = rule;
 3347                         rule = rule->next;
 3348                 }
 3349 }
 3350 
 3351 /**
 3352  * Remove all rules with given number, and also do set manipulation.
 3353  * Assumes chain != NULL && *chain != NULL.
 3354  *
 3355  * The argument is an u_int32_t. The low 16 bit are the rule or set number,
 3356  * the next 8 bits are the new set, the top 8 bits are the command:
 3357  *
 3358  *      0       delete rules with given number
 3359  *      1       delete rules with given set number
 3360  *      2       move rules with given number to new set
 3361  *      3       move rules with given set number to new set
 3362  *      4       swap sets with given numbers
 3363  */
 3364 static int
 3365 del_entry(struct ip_fw_chain *chain, u_int32_t arg)
 3366 {
 3367         struct ip_fw *prev = NULL, *rule;
 3368         u_int16_t rulenum;      /* rule or old_set */
 3369         u_int8_t cmd, new_set;
 3370 
 3371         rulenum = arg & 0xffff;
 3372         cmd = (arg >> 24) & 0xff;
 3373         new_set = (arg >> 16) & 0xff;
 3374 
 3375         if (cmd > 4)
 3376                 return EINVAL;
 3377         if (new_set > RESVD_SET)
 3378                 return EINVAL;
 3379         if (cmd == 0 || cmd == 2) {
 3380                 if (rulenum >= IPFW_DEFAULT_RULE)
 3381                         return EINVAL;
 3382         } else {
 3383                 if (rulenum > RESVD_SET)        /* old_set */
 3384                         return EINVAL;
 3385         }
 3386 
 3387         IPFW_WLOCK(chain);
 3388         rule = chain->rules;
 3389         chain->reap = NULL;
 3390         switch (cmd) {
 3391         case 0: /* delete rules with given number */
 3392                 /*
 3393                  * locate first rule to delete
 3394                  */
 3395                 for (; rule->rulenum < rulenum; prev = rule, rule = rule->next)
 3396                         ;
 3397                 if (rule->rulenum != rulenum) {
 3398                         IPFW_WUNLOCK(chain);
 3399                         return EINVAL;
 3400                 }
 3401 
 3402                 /*
 3403                  * flush pointers outside the loop, then delete all matching
 3404                  * rules. prev remains the same throughout the cycle.
 3405                  */
 3406                 flush_rule_ptrs(chain);
 3407                 while (rule->rulenum == rulenum)
 3408                         rule = remove_rule(chain, rule, prev);
 3409                 break;
 3410 
 3411         case 1: /* delete all rules with given set number */
 3412                 flush_rule_ptrs(chain);
 3413                 rule = chain->rules;
 3414                 while (rule->rulenum < IPFW_DEFAULT_RULE)
 3415                         if (rule->set == rulenum)
 3416                                 rule = remove_rule(chain, rule, prev);
 3417                         else {
 3418                                 prev = rule;
 3419                                 rule = rule->next;
 3420                         }
 3421                 break;
 3422 
 3423         case 2: /* move rules with given number to new set */
 3424                 rule = chain->rules;
 3425                 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next)
 3426                         if (rule->rulenum == rulenum)
 3427                                 rule->set = new_set;
 3428                 break;
 3429 
 3430         case 3: /* move rules with given set number to new set */
 3431                 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next)
 3432                         if (rule->set == rulenum)
 3433                                 rule->set = new_set;
 3434                 break;
 3435 
 3436         case 4: /* swap two sets */
 3437                 for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next)
 3438                         if (rule->set == rulenum)
 3439                                 rule->set = new_set;
 3440                         else if (rule->set == new_set)
 3441                                 rule->set = rulenum;
 3442                 break;
 3443         }
 3444         /*
 3445          * Look for rules to reclaim.  We grab the list before
 3446          * releasing the lock then reclaim them w/o the lock to
 3447          * avoid a LOR with dummynet.
 3448          */
 3449         rule = chain->reap;
 3450         chain->reap = NULL;
 3451         IPFW_WUNLOCK(chain);
 3452         if (rule)
 3453                 reap_rules(rule);
 3454         return 0;
 3455 }
 3456 
 3457 /*
 3458  * Clear counters for a specific rule.
 3459  * The enclosing "table" is assumed locked.
 3460  */
 3461 static void
 3462 clear_counters(struct ip_fw *rule, int log_only)
 3463 {
 3464         ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
 3465 
 3466         if (log_only == 0) {
 3467                 rule->bcnt = rule->pcnt = 0;
 3468                 rule->timestamp = 0;
 3469         }
 3470         if (l->o.opcode == O_LOG)
 3471                 l->log_left = l->max_log;
 3472 }
 3473 
 3474 /**
 3475  * Reset some or all counters on firewall rules.
 3476  * @arg frwl is null to clear all entries, or contains a specific
 3477  * rule number.
 3478  * @arg log_only is 1 if we only want to reset logs, zero otherwise.
 3479  */
 3480 static int
 3481 zero_entry(struct ip_fw_chain *chain, int rulenum, int log_only)
 3482 {
 3483         struct ip_fw *rule;
 3484         char *msg;
 3485 
 3486         IPFW_WLOCK(chain);
 3487         if (rulenum == 0) {
 3488                 norule_counter = 0;
 3489                 for (rule = chain->rules; rule; rule = rule->next)
 3490                         clear_counters(rule, log_only);
 3491                 msg = log_only ? "ipfw: All logging counts reset.\n" :
 3492                                 "ipfw: Accounting cleared.\n";
 3493         } else {
 3494                 int cleared = 0;
 3495                 /*
 3496                  * We can have multiple rules with the same number, so we
 3497                  * need to clear them all.
 3498                  */
 3499                 for (rule = chain->rules; rule; rule = rule->next)
 3500                         if (rule->rulenum == rulenum) {
 3501                                 while (rule && rule->rulenum == rulenum) {
 3502                                         clear_counters(rule, log_only);
 3503                                         rule = rule->next;
 3504                                 }
 3505                                 cleared = 1;
 3506                                 break;
 3507                         }
 3508                 if (!cleared) { /* we did not find any matching rules */
 3509                         IPFW_WUNLOCK(chain);
 3510                         return (EINVAL);
 3511                 }
 3512                 msg = log_only ? "ipfw: Entry %d logging count reset.\n" :
 3513                                 "ipfw: Entry %d cleared.\n";
 3514         }
 3515         IPFW_WUNLOCK(chain);
 3516 
 3517         if (fw_verbose)
 3518                 log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
 3519         return (0);
 3520 }
 3521 
 3522 /*
 3523  * Check validity of the structure before insert.
 3524  * Fortunately rules are simple, so this mostly need to check rule sizes.
 3525  */
 3526 static int
 3527 check_ipfw_struct(struct ip_fw *rule, int size)
 3528 {
 3529         int l, cmdlen = 0;
 3530         int have_action=0;
 3531         ipfw_insn *cmd;
 3532 
 3533         if (size < sizeof(*rule)) {
 3534                 printf("ipfw: rule too short\n");
 3535                 return (EINVAL);
 3536         }
 3537         /* first, check for valid size */
 3538         l = RULESIZE(rule);
 3539         if (l != size) {
 3540                 printf("ipfw: size mismatch (have %d want %d)\n", size, l);
 3541                 return (EINVAL);
 3542         }
 3543         if (rule->act_ofs >= rule->cmd_len) {
 3544                 printf("ipfw: bogus action offset (%u > %u)\n",
 3545                     rule->act_ofs, rule->cmd_len - 1);
 3546                 return (EINVAL);
 3547         }
 3548         /*
 3549          * Now go for the individual checks. Very simple ones, basically only
 3550          * instruction sizes.
 3551          */
 3552         for (l = rule->cmd_len, cmd = rule->cmd ;
 3553                         l > 0 ; l -= cmdlen, cmd += cmdlen) {
 3554                 cmdlen = F_LEN(cmd);
 3555                 if (cmdlen > l) {
 3556                         printf("ipfw: opcode %d size truncated\n",
 3557                             cmd->opcode);
 3558                         return EINVAL;
 3559                 }
 3560                 DEB(printf("ipfw: opcode %d\n", cmd->opcode);)
 3561                 switch (cmd->opcode) {
 3562                 case O_PROBE_STATE:
 3563                 case O_KEEP_STATE:
 3564                 case O_PROTO:
 3565                 case O_IP_SRC_ME:
 3566                 case O_IP_DST_ME:
 3567                 case O_LAYER2:
 3568                 case O_IN:
 3569                 case O_FRAG:
 3570                 case O_DIVERTED:
 3571                 case O_IPOPT:
 3572                 case O_IPTOS:
 3573                 case O_IPPRECEDENCE:
 3574                 case O_IPVER:
 3575                 case O_TCPWIN:
 3576                 case O_TCPFLAGS:
 3577                 case O_TCPOPTS:
 3578                 case O_ESTAB:
 3579                 case O_VERREVPATH:
 3580                 case O_VERSRCREACH:
 3581                 case O_ANTISPOOF:
 3582                 case O_IPSEC:
 3583 #ifdef INET6
 3584                 case O_IP6_SRC_ME:
 3585                 case O_IP6_DST_ME:
 3586                 case O_EXT_HDR:
 3587                 case O_IP6:
 3588 #endif
 3589                 case O_IP4:
 3590                         if (cmdlen != F_INSN_SIZE(ipfw_insn))
 3591                                 goto bad_size;
 3592                         break;
 3593 
 3594                 case O_UID:
 3595                 case O_GID:
 3596                 case O_JAIL:
 3597                 case O_IP_SRC:
 3598                 case O_IP_DST:
 3599                 case O_TCPSEQ:
 3600                 case O_TCPACK:
 3601                 case O_PROB:
 3602                 case O_ICMPTYPE:
 3603                         if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
 3604                                 goto bad_size;
 3605                         break;
 3606 
 3607                 case O_LIMIT:
 3608                         if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
 3609                                 goto bad_size;
 3610                         break;
 3611 
 3612                 case O_LOG:
 3613                         if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
 3614                                 goto bad_size;
 3615 
 3616                         ((ipfw_insn_log *)cmd)->log_left =
 3617                             ((ipfw_insn_log *)cmd)->max_log;
 3618 
 3619                         break;
 3620 
 3621                 case O_IP_SRC_MASK:
 3622                 case O_IP_DST_MASK:
 3623                         /* only odd command lengths */
 3624                         if ( !(cmdlen & 1) || cmdlen > 31)
 3625                                 goto bad_size;
 3626                         break;
 3627 
 3628                 case O_IP_SRC_SET:
 3629                 case O_IP_DST_SET:
 3630                         if (cmd->arg1 == 0 || cmd->arg1 > 256) {
 3631                                 printf("ipfw: invalid set size %d\n",
 3632                                         cmd->arg1);
 3633                                 return EINVAL;
 3634                         }
 3635                         if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
 3636                             (cmd->arg1+31)/32 )
 3637                                 goto bad_size;
 3638                         break;
 3639 
 3640                 case O_IP_SRC_LOOKUP:
 3641                 case O_IP_DST_LOOKUP:
 3642                         if (cmd->arg1 >= IPFW_TABLES_MAX) {
 3643                                 printf("ipfw: invalid table number %d\n",
 3644                                     cmd->arg1);
 3645                                 return (EINVAL);
 3646                         }
 3647                         if (cmdlen != F_INSN_SIZE(ipfw_insn) &&
 3648                             cmdlen != F_INSN_SIZE(ipfw_insn_u32))
 3649                                 goto bad_size;
 3650                         break;
 3651 
 3652                 case O_MACADDR2:
 3653                         if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
 3654                                 goto bad_size;
 3655                         break;
 3656 
 3657                 case O_NOP:
 3658                 case O_IPID:
 3659                 case O_IPTTL:
 3660                 case O_IPLEN:
 3661                 case O_TCPDATALEN:
 3662                         if (cmdlen < 1 || cmdlen > 31)
 3663                                 goto bad_size;
 3664                         break;
 3665 
 3666                 case O_MAC_TYPE:
 3667                 case O_IP_SRCPORT:
 3668                 case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
 3669                         if (cmdlen < 2 || cmdlen > 31)
 3670                                 goto bad_size;
 3671                         break;
 3672 
 3673                 case O_RECV:
 3674                 case O_XMIT:
 3675                 case O_VIA:
 3676                         if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
 3677                                 goto bad_size;
 3678                         break;
 3679 
 3680                 case O_ALTQ:
 3681                         if (cmdlen != F_INSN_SIZE(ipfw_insn_altq))
 3682                                 goto bad_size;
 3683                         break;
 3684 
 3685                 case O_PIPE:
 3686                 case O_QUEUE:
 3687                         if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
 3688                                 goto bad_size;
 3689                         goto check_action;
 3690 
 3691                 case O_FORWARD_IP:
 3692 #ifdef  IPFIREWALL_FORWARD
 3693                         if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
 3694                                 goto bad_size;
 3695                         goto check_action;
 3696 #else
 3697                         return EINVAL;
 3698 #endif
 3699 
 3700                 case O_DIVERT:
 3701                 case O_TEE:
 3702                         if (ip_divert_ptr == NULL)
 3703                                 return EINVAL;
 3704                         else
 3705                                 goto check_size;
 3706                 case O_NETGRAPH:
 3707                 case O_NGTEE:
 3708                         if (!NG_IPFW_LOADED)
 3709                                 return EINVAL;
 3710                         else
 3711                                 goto check_size;
 3712                 case O_FORWARD_MAC: /* XXX not implemented yet */
 3713                 case O_CHECK_STATE:
 3714                 case O_COUNT:
 3715                 case O_ACCEPT:
 3716                 case O_DENY:
 3717                 case O_REJECT:
 3718 #ifdef INET6
 3719                 case O_UNREACH6:
 3720 #endif
 3721                 case O_SKIPTO:
 3722 check_size:
 3723                         if (cmdlen != F_INSN_SIZE(ipfw_insn))
 3724                                 goto bad_size;
 3725 check_action:
 3726                         if (have_action) {
 3727                                 printf("ipfw: opcode %d, multiple actions"
 3728                                         " not allowed\n",
 3729                                         cmd->opcode);
 3730                                 return EINVAL;
 3731                         }
 3732                         have_action = 1;
 3733                         if (l != cmdlen) {
 3734                                 printf("ipfw: opcode %d, action must be"
 3735                                         " last opcode\n",
 3736                                         cmd->opcode);
 3737                                 return EINVAL;
 3738                         }
 3739                         break;
 3740 #ifdef INET6
 3741                 case O_IP6_SRC:
 3742                 case O_IP6_DST:
 3743                         if (cmdlen != F_INSN_SIZE(struct in6_addr) +
 3744                             F_INSN_SIZE(ipfw_insn))
 3745                                 goto bad_size;
 3746                         break;
 3747 
 3748                 case O_FLOW6ID:
 3749                         if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
 3750                             ((ipfw_insn_u32 *)cmd)->o.arg1)
 3751                                 goto bad_size;
 3752                         break;
 3753 
 3754                 case O_IP6_SRC_MASK:
 3755                 case O_IP6_DST_MASK:
 3756                         if ( !(cmdlen & 1) || cmdlen > 127)
 3757                                 goto bad_size;
 3758                         break;
 3759                 case O_ICMP6TYPE:
 3760                         if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) )
 3761                                 goto bad_size;
 3762                         break;
 3763 #endif
 3764 
 3765                 default:
 3766                         switch (cmd->opcode) {
 3767 #ifndef INET6
 3768                         case O_IP6_SRC_ME:
 3769                         case O_IP6_DST_ME:
 3770                         case O_EXT_HDR:
 3771                         case O_IP6:
 3772                         case O_UNREACH6:
 3773                         case O_IP6_SRC:
 3774                         case O_IP6_DST:
 3775                         case O_FLOW6ID:
 3776                         case O_IP6_SRC_MASK:
 3777                         case O_IP6_DST_MASK:
 3778                         case O_ICMP6TYPE:
 3779                                 printf("ipfw: no IPv6 support in kernel\n");
 3780                                 return EPROTONOSUPPORT;
 3781 #endif
 3782                         default:
 3783                                 printf("ipfw: opcode %d, unknown opcode\n",
 3784                                         cmd->opcode);
 3785                                 return EINVAL;
 3786                         }
 3787                 }
 3788         }
 3789         if (have_action == 0) {
 3790                 printf("ipfw: missing action\n");
 3791                 return EINVAL;
 3792         }
 3793         return 0;
 3794 
 3795 bad_size:
 3796         printf("ipfw: opcode %d size %d wrong\n",
 3797                 cmd->opcode, cmdlen);
 3798         return EINVAL;
 3799 }
 3800 
 3801 /*
 3802  * Copy the static and dynamic rules to the supplied buffer
 3803  * and return the amount of space actually used.
 3804  */
 3805 static size_t
 3806 ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space)
 3807 {
 3808         char *bp = buf;
 3809         char *ep = bp + space;
 3810         struct ip_fw *rule;
 3811         int i;
 3812 
 3813         /* XXX this can take a long time and locking will block packet flow */
 3814         IPFW_RLOCK(chain);
 3815         for (rule = chain->rules; rule ; rule = rule->next) {
 3816                 /*
 3817                  * Verify the entry fits in the buffer in case the
 3818                  * rules changed between calculating buffer space and
 3819                  * now.  This would be better done using a generation
 3820                  * number but should suffice for now.
 3821                  */
 3822                 i = RULESIZE(rule);
 3823                 if (bp + i <= ep) {
 3824                         bcopy(rule, bp, i);
 3825                         bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule),
 3826                             sizeof(set_disable));
 3827                         bp += i;
 3828                 }
 3829         }
 3830         IPFW_RUNLOCK(chain);
 3831         if (ipfw_dyn_v) {
 3832                 ipfw_dyn_rule *p, *last = NULL;
 3833 
 3834                 IPFW_DYN_LOCK();
 3835                 for (i = 0 ; i < curr_dyn_buckets; i++)
 3836                         for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) {
 3837                                 if (bp + sizeof *p <= ep) {
 3838                                         ipfw_dyn_rule *dst =
 3839                                                 (ipfw_dyn_rule *)bp;
 3840                                         bcopy(p, dst, sizeof *p);
 3841                                         bcopy(&(p->rule->rulenum), &(dst->rule),
 3842                                             sizeof(p->rule->rulenum));
 3843                                         /*
 3844                                          * store a non-null value in "next".
 3845                                          * The userland code will interpret a
 3846                                          * NULL here as a marker
 3847                                          * for the last dynamic rule.
 3848                                          */
 3849                                         bcopy(&dst, &dst->next, sizeof(dst));
 3850                                         last = dst;
 3851                                         dst->expire =
 3852                                             TIME_LEQ(dst->expire, time_second) ?
 3853                                                 0 : dst->expire - time_second ;
 3854                                         bp += sizeof(ipfw_dyn_rule);
 3855                                 }
 3856                         }
 3857                 IPFW_DYN_UNLOCK();
 3858                 if (last != NULL) /* mark last dynamic rule */
 3859                         bzero(&last->next, sizeof(last));
 3860         }
 3861         return (bp - (char *)buf);
 3862 }
 3863 
 3864 
 3865 /**
 3866  * {set|get}sockopt parser.
 3867  */
 3868 static int
 3869 ipfw_ctl(struct sockopt *sopt)
 3870 {
 3871 #define RULE_MAXSIZE    (256*sizeof(u_int32_t))
 3872         int error, rule_num;
 3873         size_t size;
 3874         struct ip_fw *buf, *rule;
 3875         u_int32_t rulenum[2];
 3876 
 3877         error = suser(sopt->sopt_td);
 3878         if (error)
 3879                 return (error);
 3880 
 3881         /*
 3882          * Disallow modifications in really-really secure mode, but still allow
 3883          * the logging counters to be reset.
 3884          */
 3885         if (sopt->sopt_name == IP_FW_ADD ||
 3886             (sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) {
 3887 #if __FreeBSD_version >= 500034
 3888                 error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
 3889                 if (error)
 3890                         return (error);
 3891 #else /* FreeBSD 4.x */
 3892                 if (securelevel >= 3)
 3893                         return (EPERM);
 3894 #endif
 3895         }
 3896 
 3897         error = 0;
 3898 
 3899         switch (sopt->sopt_name) {
 3900         case IP_FW_GET:
 3901                 /*
 3902                  * pass up a copy of the current rules. Static rules
 3903                  * come first (the last of which has number IPFW_DEFAULT_RULE),
 3904                  * followed by a possibly empty list of dynamic rule.
 3905                  * The last dynamic rule has NULL in the "next" field.
 3906                  *
 3907                  * Note that the calculated size is used to bound the
 3908                  * amount of data returned to the user.  The rule set may
 3909                  * change between calculating the size and returning the
 3910                  * data in which case we'll just return what fits.
 3911                  */
 3912                 size = static_len;      /* size of static rules */
 3913                 if (ipfw_dyn_v)         /* add size of dyn.rules */
 3914                         size += (dyn_count * sizeof(ipfw_dyn_rule));
 3915 
 3916                 /*
 3917                  * XXX todo: if the user passes a short length just to know
 3918                  * how much room is needed, do not bother filling up the
 3919                  * buffer, just jump to the sooptcopyout.
 3920                  */
 3921                 buf = malloc(size, M_TEMP, M_WAITOK);
 3922                 error = sooptcopyout(sopt, buf,
 3923                                 ipfw_getrules(&layer3_chain, buf, size));
 3924                 free(buf, M_TEMP);
 3925                 break;
 3926 
 3927         case IP_FW_FLUSH:
 3928                 /*
 3929                  * Normally we cannot release the lock on each iteration.
 3930                  * We could do it here only because we start from the head all
 3931                  * the times so there is no risk of missing some entries.
 3932                  * On the other hand, the risk is that we end up with
 3933                  * a very inconsistent ruleset, so better keep the lock
 3934                  * around the whole cycle.
 3935                  *
 3936                  * XXX this code can be improved by resetting the head of
 3937                  * the list to point to the default rule, and then freeing
 3938                  * the old list without the need for a lock.
 3939                  */
 3940 
 3941                 IPFW_WLOCK(&layer3_chain);
 3942                 layer3_chain.reap = NULL;
 3943                 free_chain(&layer3_chain, 0 /* keep default rule */);
 3944                 rule = layer3_chain.reap, layer3_chain.reap = NULL;
 3945                 IPFW_WUNLOCK(&layer3_chain);
 3946                 if (layer3_chain.reap != NULL)
 3947                         reap_rules(rule);
 3948                 break;
 3949 
 3950         case IP_FW_ADD:
 3951                 rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK);
 3952                 error = sooptcopyin(sopt, rule, RULE_MAXSIZE,
 3953                         sizeof(struct ip_fw) );
 3954                 if (error == 0)
 3955                         error = check_ipfw_struct(rule, sopt->sopt_valsize);
 3956                 if (error == 0) {
 3957                         error = add_rule(&layer3_chain, rule);
 3958                         size = RULESIZE(rule);
 3959                         if (!error && sopt->sopt_dir == SOPT_GET)
 3960                                 error = sooptcopyout(sopt, rule, size);
 3961                 }
 3962                 free(rule, M_TEMP);
 3963                 break;
 3964 
 3965         case IP_FW_DEL:
 3966                 /*
 3967                  * IP_FW_DEL is used for deleting single rules or sets,
 3968                  * and (ab)used to atomically manipulate sets. Argument size
 3969                  * is used to distinguish between the two:
 3970                  *    sizeof(u_int32_t)
 3971                  *      delete single rule or set of rules,
 3972                  *      or reassign rules (or sets) to a different set.
 3973                  *    2*sizeof(u_int32_t)
 3974                  *      atomic disable/enable sets.
 3975                  *      first u_int32_t contains sets to be disabled,
 3976                  *      second u_int32_t contains sets to be enabled.
 3977                  */
 3978                 error = sooptcopyin(sopt, rulenum,
 3979                         2*sizeof(u_int32_t), sizeof(u_int32_t));
 3980                 if (error)
 3981                         break;
 3982                 size = sopt->sopt_valsize;
 3983                 if (size == sizeof(u_int32_t))  /* delete or reassign */
 3984                         error = del_entry(&layer3_chain, rulenum[0]);
 3985                 else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */
 3986                         set_disable =
 3987                             (set_disable | rulenum[0]) & ~rulenum[1] &
 3988                             ~(1<<RESVD_SET); /* set RESVD_SET always enabled */
 3989                 else
 3990                         error = EINVAL;
 3991                 break;
 3992 
 3993         case IP_FW_ZERO:
 3994         case IP_FW_RESETLOG: /* argument is an int, the rule number */
 3995                 rule_num = 0;
 3996                 if (sopt->sopt_val != 0) {
 3997                     error = sooptcopyin(sopt, &rule_num,
 3998                             sizeof(int), sizeof(int));
 3999                     if (error)
 4000                         break;
 4001                 }
 4002                 error = zero_entry(&layer3_chain, rule_num,
 4003                         sopt->sopt_name == IP_FW_RESETLOG);
 4004                 break;
 4005 
 4006         case IP_FW_TABLE_ADD:
 4007                 {
 4008                         ipfw_table_entry ent;
 4009 
 4010                         error = sooptcopyin(sopt, &ent,
 4011                             sizeof(ent), sizeof(ent));
 4012                         if (error)
 4013                                 break;
 4014                         error = add_table_entry(&layer3_chain, ent.tbl,
 4015                             ent.addr, ent.masklen, ent.value);
 4016                 }
 4017                 break;
 4018 
 4019         case IP_FW_TABLE_DEL:
 4020                 {
 4021                         ipfw_table_entry ent;
 4022 
 4023                         error = sooptcopyin(sopt, &ent,
 4024                             sizeof(ent), sizeof(ent));
 4025                         if (error)
 4026                                 break;
 4027                         error = del_table_entry(&layer3_chain, ent.tbl,
 4028                             ent.addr, ent.masklen);
 4029                 }
 4030                 break;
 4031 
 4032         case IP_FW_TABLE_FLUSH:
 4033                 {
 4034                         u_int16_t tbl;
 4035 
 4036                         error = sooptcopyin(sopt, &tbl,
 4037                             sizeof(tbl), sizeof(tbl));
 4038                         if (error)
 4039                                 break;
 4040                         IPFW_WLOCK(&layer3_chain);
 4041                         error = flush_table(&layer3_chain, tbl);
 4042                         IPFW_WUNLOCK(&layer3_chain);
 4043                 }
 4044                 break;
 4045 
 4046         case IP_FW_TABLE_GETSIZE:
 4047                 {
 4048                         u_int32_t tbl, cnt;
 4049 
 4050                         if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl),
 4051                             sizeof(tbl))))
 4052                                 break;
 4053                         IPFW_RLOCK(&layer3_chain);
 4054                         error = count_table(&layer3_chain, tbl, &cnt);
 4055                         IPFW_RUNLOCK(&layer3_chain);
 4056                         if (error)
 4057                                 break;
 4058                         error = sooptcopyout(sopt, &cnt, sizeof(cnt));
 4059                 }
 4060                 break;
 4061 
 4062         case IP_FW_TABLE_LIST:
 4063                 {
 4064                         ipfw_table *tbl;
 4065 
 4066                         if (sopt->sopt_valsize < sizeof(*tbl)) {
 4067                                 error = EINVAL;
 4068                                 break;
 4069                         }
 4070                         size = sopt->sopt_valsize;
 4071                         tbl = malloc(size, M_TEMP, M_WAITOK);
 4072                         if (tbl == NULL) {
 4073                                 error = ENOMEM;
 4074                                 break;
 4075                         }
 4076                         error = sooptcopyin(sopt, tbl, size, sizeof(*tbl));
 4077                         if (error) {
 4078                                 free(tbl, M_TEMP);
 4079                                 break;
 4080                         }
 4081                         tbl->size = (size - sizeof(*tbl)) /
 4082                             sizeof(ipfw_table_entry);
 4083                         IPFW_RLOCK(&layer3_chain);
 4084                         error = dump_table(&layer3_chain, tbl);
 4085                         IPFW_RUNLOCK(&layer3_chain);
 4086                         if (error) {
 4087                                 free(tbl, M_TEMP);
 4088                                 break;
 4089                         }
 4090                         error = sooptcopyout(sopt, tbl, size);
 4091                         free(tbl, M_TEMP);
 4092                 }
 4093                 break;
 4094 
 4095         default:
 4096                 printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name);
 4097                 error = EINVAL;
 4098         }
 4099 
 4100         return (error);
 4101 #undef RULE_MAXSIZE
 4102 }
 4103 
 4104 /**
 4105  * dummynet needs a reference to the default rule, because rules can be
 4106  * deleted while packets hold a reference to them. When this happens,
 4107  * dummynet changes the reference to the default rule (it could well be a
 4108  * NULL pointer, but this way we do not need to check for the special
 4109  * case, plus here he have info on the default behaviour).
 4110  */
 4111 struct ip_fw *ip_fw_default_rule;
 4112 
 4113 /*
 4114  * This procedure is only used to handle keepalives. It is invoked
 4115  * every dyn_keepalive_period
 4116  */
 4117 static void
 4118 ipfw_tick(void * __unused unused)
 4119 {
 4120         struct mbuf *m0, *m, *mnext, **mtailp;
 4121         int i;
 4122         ipfw_dyn_rule *q;
 4123 
 4124         if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0)
 4125                 goto done;
 4126 
 4127         /*
 4128          * We make a chain of packets to go out here -- not deferring
 4129          * until after we drop the IPFW dynamic rule lock would result
 4130          * in a lock order reversal with the normal packet input -> ipfw
 4131          * call stack.
 4132          */
 4133         m0 = NULL;
 4134         mtailp = &m0;
 4135         IPFW_DYN_LOCK();
 4136         for (i = 0 ; i < curr_dyn_buckets ; i++) {
 4137                 for (q = ipfw_dyn_v[i] ; q ; q = q->next ) {
 4138                         if (q->dyn_type == O_LIMIT_PARENT)
 4139                                 continue;
 4140                         if (q->id.proto != IPPROTO_TCP)
 4141                                 continue;
 4142                         if ( (q->state & BOTH_SYN) != BOTH_SYN)
 4143                                 continue;
 4144                         if (TIME_LEQ( time_second+dyn_keepalive_interval,
 4145                             q->expire))
 4146                                 continue;       /* too early */
 4147                         if (TIME_LEQ(q->expire, time_second))
 4148                                 continue;       /* too late, rule expired */
 4149 
 4150                         *mtailp = send_pkt(&(q->id), q->ack_rev - 1,
 4151                                 q->ack_fwd, TH_SYN);
 4152                         if (*mtailp != NULL)
 4153                                 mtailp = &(*mtailp)->m_nextpkt;
 4154                         *mtailp = send_pkt(&(q->id), q->ack_fwd - 1,
 4155                                 q->ack_rev, 0);
 4156                         if (*mtailp != NULL)
 4157                                 mtailp = &(*mtailp)->m_nextpkt;
 4158                 }
 4159         }
 4160         IPFW_DYN_UNLOCK();
 4161         for (m = mnext = m0; m != NULL; m = mnext) {
 4162                 mnext = m->m_nextpkt;
 4163                 m->m_nextpkt = NULL;
 4164                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 4165         }
 4166 done:
 4167         callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL);
 4168 }
 4169 
 4170 int
 4171 ipfw_init(void)
 4172 {
 4173         struct ip_fw default_rule;
 4174         int error;
 4175 
 4176 #ifdef INET6
 4177         /* Setup IPv6 fw sysctl tree. */
 4178         sysctl_ctx_init(&ip6_fw_sysctl_ctx);
 4179         ip6_fw_sysctl_tree = SYSCTL_ADD_NODE(&ip6_fw_sysctl_ctx,
 4180                 SYSCTL_STATIC_CHILDREN(_net_inet6_ip6), OID_AUTO, "fw",
 4181                 CTLFLAG_RW | CTLFLAG_SECURE, 0, "Firewall");
 4182         SYSCTL_ADD_INT(&ip6_fw_sysctl_ctx, SYSCTL_CHILDREN(ip6_fw_sysctl_tree),
 4183                 OID_AUTO, "deny_unknown_exthdrs", CTLFLAG_RW | CTLFLAG_SECURE,
 4184                 &fw_deny_unknown_exthdrs, 0,
 4185                 "Deny packets with unknown IPv6 Extension Headers");
 4186 #endif
 4187 
 4188         layer3_chain.rules = NULL;
 4189         layer3_chain.want_write = 0;
 4190         layer3_chain.busy_count = 0;
 4191         cv_init(&layer3_chain.cv, "Condition variable for IPFW rw locks");
 4192         IPFW_LOCK_INIT(&layer3_chain);
 4193         ipfw_dyn_rule_zone = uma_zcreate("IPFW dynamic rule zone",
 4194             sizeof(ipfw_dyn_rule), NULL, NULL, NULL, NULL,
 4195             UMA_ALIGN_PTR, 0);
 4196         IPFW_DYN_LOCK_INIT();
 4197         callout_init(&ipfw_timeout, NET_CALLOUT_MPSAFE);
 4198 
 4199         bzero(&default_rule, sizeof default_rule);
 4200 
 4201         default_rule.act_ofs = 0;
 4202         default_rule.rulenum = IPFW_DEFAULT_RULE;
 4203         default_rule.cmd_len = 1;
 4204         default_rule.set = RESVD_SET;
 4205 
 4206         default_rule.cmd[0].len = 1;
 4207         default_rule.cmd[0].opcode =
 4208 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
 4209                                 1 ? O_ACCEPT :
 4210 #endif
 4211                                 O_DENY;
 4212 
 4213         error = add_rule(&layer3_chain, &default_rule);
 4214         if (error != 0) {
 4215                 printf("ipfw2: error %u initializing default rule "
 4216                         "(support disabled)\n", error);
 4217                 IPFW_DYN_LOCK_DESTROY();
 4218                 IPFW_LOCK_DESTROY(&layer3_chain);
 4219                 uma_zdestroy(ipfw_dyn_rule_zone);
 4220                 return (error);
 4221         }
 4222 
 4223         ip_fw_default_rule = layer3_chain.rules;
 4224         printf("ipfw2 (+ipv6) initialized, divert %s, "
 4225                 "rule-based forwarding "
 4226 #ifdef IPFIREWALL_FORWARD
 4227                 "enabled, "
 4228 #else
 4229                 "disabled, "
 4230 #endif
 4231                 "default to %s, logging ",
 4232 #ifdef IPDIVERT
 4233                 "enabled",
 4234 #else
 4235                 "loadable",
 4236 #endif
 4237                 default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny");
 4238 
 4239 #ifdef IPFIREWALL_VERBOSE
 4240         fw_verbose = 1;
 4241 #endif
 4242 #ifdef IPFIREWALL_VERBOSE_LIMIT
 4243         verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
 4244 #endif
 4245         if (fw_verbose == 0)
 4246                 printf("disabled\n");
 4247         else if (verbose_limit == 0)
 4248                 printf("unlimited\n");
 4249         else
 4250                 printf("limited to %d packets/entry by default\n",
 4251                     verbose_limit);
 4252 
 4253         error = init_tables(&layer3_chain);
 4254         if (error) {
 4255                 IPFW_DYN_LOCK_DESTROY();
 4256                 IPFW_LOCK_DESTROY(&layer3_chain);
 4257                 uma_zdestroy(ipfw_dyn_rule_zone);
 4258                 return (error);
 4259         }
 4260         ip_fw_ctl_ptr = ipfw_ctl;
 4261         ip_fw_chk_ptr = ipfw_chk;
 4262         callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL);
 4263 
 4264         return (0);
 4265 }
 4266 
 4267 void
 4268 ipfw_destroy(void)
 4269 {
 4270         struct ip_fw *reap;
 4271 
 4272         ip_fw_chk_ptr = NULL;
 4273         ip_fw_ctl_ptr = NULL;
 4274         callout_drain(&ipfw_timeout);
 4275         IPFW_WLOCK(&layer3_chain);
 4276         flush_tables(&layer3_chain);
 4277         layer3_chain.reap = NULL;
 4278         free_chain(&layer3_chain, 1 /* kill default rule */);
 4279         reap = layer3_chain.reap, layer3_chain.reap = NULL;
 4280         IPFW_WUNLOCK(&layer3_chain);
 4281         if (reap != NULL)
 4282                 reap_rules(reap);
 4283         IPFW_DYN_LOCK_DESTROY();
 4284         uma_zdestroy(ipfw_dyn_rule_zone);
 4285         IPFW_LOCK_DESTROY(&layer3_chain);
 4286 
 4287 #ifdef INET6
 4288         /* Free IPv6 fw sysctl tree. */
 4289         sysctl_ctx_free(&ip6_fw_sysctl_ctx);
 4290 #endif
 4291 
 4292         printf("IP firewall unloaded\n");
 4293 }

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