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

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    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2017-2018 Yandex LLC
    5  * Copyright (c) 2017-2018 Andrey V. Elsukov <ae@FreeBSD.org>
    6  * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  */
   29 
   30 #include <sys/cdefs.h>
   31 __FBSDID("$FreeBSD$");
   32 
   33 #include "opt_inet.h"
   34 #include "opt_inet6.h"
   35 #include "opt_ipfw.h"
   36 #ifndef INET
   37 #error IPFIREWALL requires INET.
   38 #endif /* INET */
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/hash.h>
   43 #include <sys/mbuf.h>
   44 #include <sys/kernel.h>
   45 #include <sys/lock.h>
   46 #include <sys/pcpu.h>
   47 #include <sys/queue.h>
   48 #include <sys/rmlock.h>
   49 #include <sys/smp.h>
   50 #include <sys/socket.h>
   51 #include <sys/sysctl.h>
   52 #include <sys/syslog.h>
   53 #include <net/ethernet.h>
   54 #include <net/if.h>
   55 #include <net/if_var.h>
   56 #include <net/vnet.h>
   57 
   58 #include <netinet/in.h>
   59 #include <netinet/ip.h>
   60 #include <netinet/ip_var.h>
   61 #include <netinet/ip_fw.h>
   62 #include <netinet/udp.h>
   63 #include <netinet/tcp.h>
   64 
   65 #include <netinet/ip6.h>        /* IN6_ARE_ADDR_EQUAL */
   66 #ifdef INET6
   67 #include <netinet6/in6_var.h>
   68 #include <netinet6/ip6_var.h>
   69 #include <netinet6/scope6_var.h>
   70 #endif
   71 
   72 #include <netpfil/ipfw/ip_fw_private.h>
   73 
   74 #include <machine/in_cksum.h>   /* XXX for in_cksum */
   75 
   76 #ifdef MAC
   77 #include <security/mac/mac_framework.h>
   78 #endif
   79 
   80 /*
   81  * Description of dynamic states.
   82  *
   83  * Dynamic states are stored in lists accessed through a hash tables
   84  * whose size is curr_dyn_buckets. This value can be modified through
   85  * the sysctl variable dyn_buckets.
   86  *
   87  * Currently there are four tables: dyn_ipv4, dyn_ipv6, dyn_ipv4_parent,
   88  * and dyn_ipv6_parent.
   89  *
   90  * When a packet is received, its address fields hashed, then matched
   91  * against the entries in the corresponding list by addr_type.
   92  * Dynamic states can be used for different purposes:
   93  *  + stateful rules;
   94  *  + enforcing limits on the number of sessions;
   95  *  + in-kernel NAT (not implemented yet)
   96  *
   97  * The lifetime of dynamic states is regulated by dyn_*_lifetime,
   98  * measured in seconds and depending on the flags.
   99  *
  100  * The total number of dynamic states is equal to UMA zone items count.
  101  * The max number of dynamic states is dyn_max. When we reach
  102  * the maximum number of rules we do not create anymore. This is
  103  * done to avoid consuming too much memory, but also too much
  104  * time when searching on each packet (ideally, we should try instead
  105  * to put a limit on the length of the list on each bucket...).
  106  *
  107  * Each state holds a pointer to the parent ipfw rule so we know what
  108  * action to perform. Dynamic rules are removed when the parent rule is
  109  * deleted.
  110  *
  111  * There are some limitations with dynamic rules -- we do not
  112  * obey the 'randomized match', and we do not do multiple
  113  * passes through the firewall. XXX check the latter!!!
  114  */
  115 
  116 /* By default use jenkins hash function */
  117 #define IPFIREWALL_JENKINSHASH
  118 
  119 #define DYN_COUNTER_INC(d, dir, pktlen) do {    \
  120         (d)->pcnt_ ## dir++;                    \
  121         (d)->bcnt_ ## dir += pktlen;            \
  122         } while (0)
  123 
  124 #define DYN_REFERENCED          0x01
  125 /*
  126  * DYN_REFERENCED flag is used to show that state keeps reference to named
  127  * object, and this reference should be released when state becomes expired.
  128  */
  129 
  130 struct dyn_data {
  131         void            *parent;        /* pointer to parent rule */
  132         uint32_t        chain_id;       /* cached ruleset id */
  133         uint32_t        f_pos;          /* cached rule index */
  134 
  135         uint32_t        hashval;        /* hash value used for hash resize */
  136         uint16_t        fibnum;         /* fib used to send keepalives */
  137         uint8_t         _pad[3];
  138         uint8_t         flags;          /* internal flags */
  139         uint16_t        rulenum;        /* parent rule number */
  140         uint32_t        ruleid;         /* parent rule id */
  141 
  142         uint32_t        state;          /* TCP session state and flags */
  143         uint32_t        ack_fwd;        /* most recent ACKs in forward */
  144         uint32_t        ack_rev;        /* and reverse direction (used */
  145                                         /* to generate keepalives) */
  146         uint32_t        sync;           /* synchronization time */
  147         uint32_t        expire;         /* expire time */
  148 
  149         uint64_t        pcnt_fwd;       /* bytes counter in forward */
  150         uint64_t        bcnt_fwd;       /* packets counter in forward */
  151         uint64_t        pcnt_rev;       /* bytes counter in reverse */
  152         uint64_t        bcnt_rev;       /* packets counter in reverse */
  153 };
  154 
  155 #define DPARENT_COUNT_DEC(p)    do {                    \
  156         MPASS(p->count > 0);                            \
  157         ck_pr_dec_32(&(p)->count);                      \
  158 } while (0)
  159 #define DPARENT_COUNT_INC(p)    ck_pr_inc_32(&(p)->count)
  160 #define DPARENT_COUNT(p)        ck_pr_load_32(&(p)->count)
  161 struct dyn_parent {
  162         void            *parent;        /* pointer to parent rule */
  163         uint32_t        count;          /* number of linked states */
  164         uint8_t         _pad[2];
  165         uint16_t        rulenum;        /* parent rule number */
  166         uint32_t        ruleid;         /* parent rule id */
  167         uint32_t        hashval;        /* hash value used for hash resize */
  168         uint32_t        expire;         /* expire time */
  169 };
  170 
  171 struct dyn_ipv4_state {
  172         uint8_t         type;           /* State type */
  173         uint8_t         proto;          /* UL Protocol */
  174         uint16_t        kidx;           /* named object index */
  175         uint16_t        sport, dport;   /* ULP source and destination ports */
  176         in_addr_t       src, dst;       /* IPv4 source and destination */
  177 
  178         union {
  179                 struct dyn_data *data;
  180                 struct dyn_parent *limit;
  181         };
  182         CK_SLIST_ENTRY(dyn_ipv4_state)  entry;
  183         SLIST_ENTRY(dyn_ipv4_state)     expired;
  184 };
  185 CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state);
  186 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4);
  187 VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4_parent);
  188 
  189 SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state);
  190 VNET_DEFINE_STATIC(struct dyn_ipv4_slist, dyn_expired_ipv4);
  191 #define V_dyn_ipv4                      VNET(dyn_ipv4)
  192 #define V_dyn_ipv4_parent               VNET(dyn_ipv4_parent)
  193 #define V_dyn_expired_ipv4              VNET(dyn_expired_ipv4)
  194 
  195 #ifdef INET6
  196 struct dyn_ipv6_state {
  197         uint8_t         type;           /* State type */
  198         uint8_t         proto;          /* UL Protocol */
  199         uint16_t        kidx;           /* named object index */
  200         uint16_t        sport, dport;   /* ULP source and destination ports */
  201         struct in6_addr src, dst;       /* IPv6 source and destination */
  202         uint32_t        zoneid;         /* IPv6 scope zone id */
  203         union {
  204                 struct dyn_data *data;
  205                 struct dyn_parent *limit;
  206         };
  207         CK_SLIST_ENTRY(dyn_ipv6_state)  entry;
  208         SLIST_ENTRY(dyn_ipv6_state)     expired;
  209 };
  210 CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state);
  211 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6);
  212 VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6_parent);
  213 
  214 SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state);
  215 VNET_DEFINE_STATIC(struct dyn_ipv6_slist, dyn_expired_ipv6);
  216 #define V_dyn_ipv6                      VNET(dyn_ipv6)
  217 #define V_dyn_ipv6_parent               VNET(dyn_ipv6_parent)
  218 #define V_dyn_expired_ipv6              VNET(dyn_expired_ipv6)
  219 #endif /* INET6 */
  220 
  221 /*
  222  * Per-CPU pointer indicates that specified state is currently in use
  223  * and must not be reclaimed by expiration callout.
  224  */
  225 static void **dyn_hp_cache;
  226 DPCPU_DEFINE_STATIC(void *, dyn_hp);
  227 #define DYNSTATE_GET(cpu)       ck_pr_load_ptr(DPCPU_ID_PTR((cpu), dyn_hp))
  228 #define DYNSTATE_PROTECT(v)     ck_pr_store_ptr(DPCPU_PTR(dyn_hp), (v))
  229 #define DYNSTATE_RELEASE()      DYNSTATE_PROTECT(NULL)
  230 #define DYNSTATE_CRITICAL_ENTER()       critical_enter()
  231 #define DYNSTATE_CRITICAL_EXIT()        do {    \
  232         DYNSTATE_RELEASE();                     \
  233         critical_exit();                        \
  234 } while (0);
  235 
  236 /*
  237  * We keep two version numbers, one is updated when new entry added to
  238  * the list. Second is updated when an entry deleted from the list.
  239  * Versions are updated under bucket lock.
  240  *
  241  * Bucket "add" version number is used to know, that in the time between
  242  * state lookup (i.e. ipfw_dyn_lookup_state()) and the followed state
  243  * creation (i.e. ipfw_dyn_install_state()) another concurrent thread did
  244  * not install some state in this bucket. Using this info we can avoid
  245  * additional state lookup, because we are sure that we will not install
  246  * the state twice.
  247  *
  248  * Also doing the tracking of bucket "del" version during lookup we can
  249  * be sure, that state entry was not unlinked and freed in time between
  250  * we read the state pointer and protect it with hazard pointer.
  251  *
  252  * An entry unlinked from CK list keeps unchanged until it is freed.
  253  * Unlinked entries are linked into expired lists using "expired" field.
  254  */
  255 
  256 /*
  257  * dyn_expire_lock is used to protect access to dyn_expired_xxx lists.
  258  * dyn_bucket_lock is used to get write access to lists in specific bucket.
  259  * Currently one dyn_bucket_lock is used for all ipv4, ipv4_parent, ipv6,
  260  * and ipv6_parent lists.
  261  */
  262 VNET_DEFINE_STATIC(struct mtx, dyn_expire_lock);
  263 VNET_DEFINE_STATIC(struct mtx *, dyn_bucket_lock);
  264 #define V_dyn_expire_lock               VNET(dyn_expire_lock)
  265 #define V_dyn_bucket_lock               VNET(dyn_bucket_lock)
  266 
  267 /*
  268  * Bucket's add/delete generation versions.
  269  */
  270 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_add);
  271 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_del);
  272 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_add);
  273 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_del);
  274 #define V_dyn_ipv4_add                  VNET(dyn_ipv4_add)
  275 #define V_dyn_ipv4_del                  VNET(dyn_ipv4_del)
  276 #define V_dyn_ipv4_parent_add           VNET(dyn_ipv4_parent_add)
  277 #define V_dyn_ipv4_parent_del           VNET(dyn_ipv4_parent_del)
  278 
  279 #ifdef INET6
  280 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_add);
  281 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_del);
  282 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_add);
  283 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_del);
  284 #define V_dyn_ipv6_add                  VNET(dyn_ipv6_add)
  285 #define V_dyn_ipv6_del                  VNET(dyn_ipv6_del)
  286 #define V_dyn_ipv6_parent_add           VNET(dyn_ipv6_parent_add)
  287 #define V_dyn_ipv6_parent_del           VNET(dyn_ipv6_parent_del)
  288 #endif /* INET6 */
  289 
  290 #define DYN_BUCKET(h, b)                ((h) & (b - 1))
  291 #define DYN_BUCKET_VERSION(b, v)        ck_pr_load_32(&V_dyn_ ## v[(b)])
  292 #define DYN_BUCKET_VERSION_BUMP(b, v)   ck_pr_inc_32(&V_dyn_ ## v[(b)])
  293 
  294 #define DYN_BUCKET_LOCK_INIT(lock, b)           \
  295     mtx_init(&lock[(b)], "IPFW dynamic bucket", NULL, MTX_DEF)
  296 #define DYN_BUCKET_LOCK_DESTROY(lock, b)        mtx_destroy(&lock[(b)])
  297 #define DYN_BUCKET_LOCK(b)      mtx_lock(&V_dyn_bucket_lock[(b)])
  298 #define DYN_BUCKET_UNLOCK(b)    mtx_unlock(&V_dyn_bucket_lock[(b)])
  299 #define DYN_BUCKET_ASSERT(b)    mtx_assert(&V_dyn_bucket_lock[(b)], MA_OWNED)
  300 
  301 #define DYN_EXPIRED_LOCK_INIT()         \
  302     mtx_init(&V_dyn_expire_lock, "IPFW expired states list", NULL, MTX_DEF)
  303 #define DYN_EXPIRED_LOCK_DESTROY()      mtx_destroy(&V_dyn_expire_lock)
  304 #define DYN_EXPIRED_LOCK()              mtx_lock(&V_dyn_expire_lock)
  305 #define DYN_EXPIRED_UNLOCK()            mtx_unlock(&V_dyn_expire_lock)
  306 
  307 VNET_DEFINE_STATIC(uint32_t, dyn_buckets_max);
  308 VNET_DEFINE_STATIC(uint32_t, curr_dyn_buckets);
  309 VNET_DEFINE_STATIC(struct callout, dyn_timeout);
  310 #define V_dyn_buckets_max               VNET(dyn_buckets_max)
  311 #define V_curr_dyn_buckets              VNET(curr_dyn_buckets)
  312 #define V_dyn_timeout                   VNET(dyn_timeout)
  313 
  314 /* Maximum length of states chain in a bucket */
  315 VNET_DEFINE_STATIC(uint32_t, curr_max_length);
  316 #define V_curr_max_length               VNET(curr_max_length)
  317 
  318 VNET_DEFINE_STATIC(uint32_t, dyn_keep_states);
  319 #define V_dyn_keep_states               VNET(dyn_keep_states)
  320 
  321 VNET_DEFINE_STATIC(uma_zone_t, dyn_data_zone);
  322 VNET_DEFINE_STATIC(uma_zone_t, dyn_parent_zone);
  323 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv4_zone);
  324 #ifdef INET6
  325 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv6_zone);
  326 #define V_dyn_ipv6_zone                 VNET(dyn_ipv6_zone)
  327 #endif /* INET6 */
  328 #define V_dyn_data_zone                 VNET(dyn_data_zone)
  329 #define V_dyn_parent_zone               VNET(dyn_parent_zone)
  330 #define V_dyn_ipv4_zone                 VNET(dyn_ipv4_zone)
  331 
  332 /*
  333  * Timeouts for various events in handing dynamic rules.
  334  */
  335 VNET_DEFINE_STATIC(uint32_t, dyn_ack_lifetime);
  336 VNET_DEFINE_STATIC(uint32_t, dyn_syn_lifetime);
  337 VNET_DEFINE_STATIC(uint32_t, dyn_fin_lifetime);
  338 VNET_DEFINE_STATIC(uint32_t, dyn_rst_lifetime);
  339 VNET_DEFINE_STATIC(uint32_t, dyn_udp_lifetime);
  340 VNET_DEFINE_STATIC(uint32_t, dyn_short_lifetime);
  341 
  342 #define V_dyn_ack_lifetime              VNET(dyn_ack_lifetime)
  343 #define V_dyn_syn_lifetime              VNET(dyn_syn_lifetime)
  344 #define V_dyn_fin_lifetime              VNET(dyn_fin_lifetime)
  345 #define V_dyn_rst_lifetime              VNET(dyn_rst_lifetime)
  346 #define V_dyn_udp_lifetime              VNET(dyn_udp_lifetime)
  347 #define V_dyn_short_lifetime            VNET(dyn_short_lifetime)
  348 
  349 /*
  350  * Keepalives are sent if dyn_keepalive is set. They are sent every
  351  * dyn_keepalive_period seconds, in the last dyn_keepalive_interval
  352  * seconds of lifetime of a rule.
  353  * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
  354  * than dyn_keepalive_period.
  355  */
  356 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_interval);
  357 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_period);
  358 VNET_DEFINE_STATIC(uint32_t, dyn_keepalive);
  359 VNET_DEFINE_STATIC(time_t, dyn_keepalive_last);
  360 
  361 #define V_dyn_keepalive_interval        VNET(dyn_keepalive_interval)
  362 #define V_dyn_keepalive_period          VNET(dyn_keepalive_period)
  363 #define V_dyn_keepalive                 VNET(dyn_keepalive)
  364 #define V_dyn_keepalive_last            VNET(dyn_keepalive_last)
  365 
  366 VNET_DEFINE_STATIC(uint32_t, dyn_max);          /* max # of dynamic states */
  367 VNET_DEFINE_STATIC(uint32_t, dyn_count);        /* number of states */
  368 VNET_DEFINE_STATIC(uint32_t, dyn_parent_max);   /* max # of parent states */
  369 VNET_DEFINE_STATIC(uint32_t, dyn_parent_count); /* number of parent states */
  370 
  371 #define V_dyn_max                       VNET(dyn_max)
  372 #define V_dyn_count                     VNET(dyn_count)
  373 #define V_dyn_parent_max                VNET(dyn_parent_max)
  374 #define V_dyn_parent_count              VNET(dyn_parent_count)
  375 
  376 #define DYN_COUNT_DEC(name)     do {                    \
  377         MPASS((V_ ## name) > 0);                        \
  378         ck_pr_dec_32(&(V_ ## name));                    \
  379 } while (0)
  380 #define DYN_COUNT_INC(name)     ck_pr_inc_32(&(V_ ## name))
  381 #define DYN_COUNT(name)         ck_pr_load_32(&(V_ ## name))
  382 
  383 static time_t last_log; /* Log ratelimiting */
  384 
  385 /*
  386  * Get/set maximum number of dynamic states in given VNET instance.
  387  */
  388 static int
  389 sysctl_dyn_max(SYSCTL_HANDLER_ARGS)
  390 {
  391         uint32_t nstates;
  392         int error;
  393 
  394         nstates = V_dyn_max;
  395         error = sysctl_handle_32(oidp, &nstates, 0, req);
  396         /* Read operation or some error */
  397         if ((error != 0) || (req->newptr == NULL))
  398                 return (error);
  399 
  400         V_dyn_max = nstates;
  401         uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
  402         return (0);
  403 }
  404 
  405 static int
  406 sysctl_dyn_parent_max(SYSCTL_HANDLER_ARGS)
  407 {
  408         uint32_t nstates;
  409         int error;
  410 
  411         nstates = V_dyn_parent_max;
  412         error = sysctl_handle_32(oidp, &nstates, 0, req);
  413         /* Read operation or some error */
  414         if ((error != 0) || (req->newptr == NULL))
  415                 return (error);
  416 
  417         V_dyn_parent_max = nstates;
  418         uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
  419         return (0);
  420 }
  421 
  422 static int
  423 sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS)
  424 {
  425         uint32_t nbuckets;
  426         int error;
  427 
  428         nbuckets = V_dyn_buckets_max;
  429         error = sysctl_handle_32(oidp, &nbuckets, 0, req);
  430         /* Read operation or some error */
  431         if ((error != 0) || (req->newptr == NULL))
  432                 return (error);
  433 
  434         if (nbuckets > 256)
  435                 V_dyn_buckets_max = 1 << fls(nbuckets - 1);
  436         else
  437                 return (EINVAL);
  438         return (0);
  439 }
  440 
  441 SYSCTL_DECL(_net_inet_ip_fw);
  442 
  443 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_count,
  444     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_count), 0,
  445     "Current number of dynamic states.");
  446 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_parent_count,
  447     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_parent_count), 0,
  448     "Current number of parent states. ");
  449 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets,
  450     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0,
  451     "Current number of buckets for states hash table.");
  452 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_max_length,
  453     CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_max_length), 0,
  454     "Current maximum length of states chains in hash buckets.");
  455 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets,
  456     CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
  457     0, 0, sysctl_dyn_buckets, "IU",
  458     "Max number of buckets for dynamic states hash table.");
  459 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max,
  460     CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
  461     0, 0, sysctl_dyn_max, "IU",
  462     "Max number of dynamic states.");
  463 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_parent_max,
  464     CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
  465     0, 0, sysctl_dyn_parent_max, "IU",
  466     "Max number of parent dynamic states.");
  467 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime,
  468     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0,
  469     "Lifetime of dynamic states for TCP ACK.");
  470 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime,
  471     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0,
  472     "Lifetime of dynamic states for TCP SYN.");
  473 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime,
  474     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0,
  475     "Lifetime of dynamic states for TCP FIN.");
  476 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime,
  477     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0,
  478     "Lifetime of dynamic states for TCP RST.");
  479 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime,
  480     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0,
  481     "Lifetime of dynamic states for UDP.");
  482 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime,
  483     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0,
  484     "Lifetime of dynamic states for other situations.");
  485 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keepalive,
  486     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0,
  487     "Enable keepalives for dynamic states.");
  488 SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keep_states,
  489     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0,
  490     "Do not flush dynamic states on rule deletion");
  491 
  492 #ifdef IPFIREWALL_DYNDEBUG
  493 #define DYN_DEBUG(fmt, ...)     do {                    \
  494         printf("%s: " fmt "\n", __func__, __VA_ARGS__); \
  495 } while (0)
  496 #else
  497 #define DYN_DEBUG(fmt, ...)
  498 #endif /* !IPFIREWALL_DYNDEBUG */
  499 
  500 #ifdef INET6
  501 /* Functions to work with IPv6 states */
  502 static struct dyn_ipv6_state *dyn_lookup_ipv6_state(
  503     const struct ipfw_flow_id *, uint32_t, const void *,
  504     struct ipfw_dyn_info *, int);
  505 static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *,
  506     uint32_t, const void *, int, uint32_t, uint16_t);
  507 static struct dyn_ipv6_state *dyn_alloc_ipv6_state(
  508     const struct ipfw_flow_id *, uint32_t, uint16_t, uint8_t);
  509 static int dyn_add_ipv6_state(void *, uint32_t, uint16_t,
  510     const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t,
  511     struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
  512 static void dyn_export_ipv6_state(const struct dyn_ipv6_state *,
  513     ipfw_dyn_rule *);
  514 
  515 static uint32_t dyn_getscopeid(const struct ip_fw_args *);
  516 static void dyn_make_keepalive_ipv6(struct mbuf *, const struct in6_addr *,
  517     const struct in6_addr *, uint32_t, uint32_t, uint32_t, uint16_t,
  518     uint16_t);
  519 static void dyn_enqueue_keepalive_ipv6(struct mbufq *,
  520     const struct dyn_ipv6_state *);
  521 static void dyn_send_keepalive_ipv6(struct ip_fw_chain *);
  522 
  523 static struct dyn_ipv6_state *dyn_lookup_ipv6_parent(
  524     const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
  525     uint32_t);
  526 static struct dyn_ipv6_state *dyn_lookup_ipv6_parent_locked(
  527     const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
  528     uint32_t);
  529 static struct dyn_ipv6_state *dyn_add_ipv6_parent(void *, uint32_t, uint16_t,
  530     const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t, uint16_t);
  531 #endif /* INET6 */
  532 
  533 /* Functions to work with limit states */
  534 static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t,
  535     struct ip_fw *, uint32_t, uint32_t, uint16_t);
  536 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent(
  537     const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
  538 static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked(
  539     const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
  540 static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint16_t,
  541     uint32_t);
  542 static struct dyn_ipv4_state *dyn_add_ipv4_parent(void *, uint32_t, uint16_t,
  543     const struct ipfw_flow_id *, uint32_t, uint32_t, uint16_t);
  544 
  545 static void dyn_tick(void *);
  546 static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *);
  547 static void dyn_free_states(struct ip_fw_chain *);
  548 static void dyn_export_parent(const struct dyn_parent *, uint16_t, uint8_t,
  549     ipfw_dyn_rule *);
  550 static void dyn_export_data(const struct dyn_data *, uint16_t, uint8_t,
  551     uint8_t, ipfw_dyn_rule *);
  552 static uint32_t dyn_update_tcp_state(struct dyn_data *,
  553     const struct ipfw_flow_id *, const struct tcphdr *, int);
  554 static void dyn_update_proto_state(struct dyn_data *,
  555     const struct ipfw_flow_id *, const void *, int, int);
  556 
  557 /* Functions to work with IPv4 states */
  558 struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *,
  559     const void *, struct ipfw_dyn_info *, int);
  560 static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *,
  561     const void *, int, uint32_t, uint16_t);
  562 static struct dyn_ipv4_state *dyn_alloc_ipv4_state(
  563     const struct ipfw_flow_id *, uint16_t, uint8_t);
  564 static int dyn_add_ipv4_state(void *, uint32_t, uint16_t,
  565     const struct ipfw_flow_id *, const void *, int, uint32_t,
  566     struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
  567 static void dyn_export_ipv4_state(const struct dyn_ipv4_state *,
  568     ipfw_dyn_rule *);
  569 
  570 /*
  571  * Named states support.
  572  */
  573 static char *default_state_name = "default";
  574 struct dyn_state_obj {
  575         struct named_object     no;
  576         char                    name[64];
  577 };
  578 
  579 #define DYN_STATE_OBJ(ch, cmd)  \
  580     ((struct dyn_state_obj *)SRV_OBJECT(ch, (cmd)->arg1))
  581 /*
  582  * Classifier callback.
  583  * Return 0 if opcode contains object that should be referenced
  584  * or rewritten.
  585  */
  586 static int
  587 dyn_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
  588 {
  589 
  590         DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
  591         /* Don't rewrite "check-state any" */
  592         if (cmd->arg1 == 0 &&
  593             cmd->opcode == O_CHECK_STATE)
  594                 return (1);
  595 
  596         *puidx = cmd->arg1;
  597         *ptype = 0;
  598         return (0);
  599 }
  600 
  601 static void
  602 dyn_update(ipfw_insn *cmd, uint16_t idx)
  603 {
  604 
  605         cmd->arg1 = idx;
  606         DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
  607 }
  608 
  609 static int
  610 dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
  611     struct named_object **pno)
  612 {
  613         ipfw_obj_ntlv *ntlv;
  614         const char *name;
  615 
  616         DYN_DEBUG("uidx %d", ti->uidx);
  617         if (ti->uidx != 0) {
  618                 if (ti->tlvs == NULL)
  619                         return (EINVAL);
  620                 /* Search ntlv in the buffer provided by user */
  621                 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
  622                     IPFW_TLV_STATE_NAME);
  623                 if (ntlv == NULL)
  624                         return (EINVAL);
  625                 name = ntlv->name;
  626         } else
  627                 name = default_state_name;
  628         /*
  629          * Search named object with corresponding name.
  630          * Since states objects are global - ignore the set value
  631          * and use zero instead.
  632          */
  633         *pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0,
  634             IPFW_TLV_STATE_NAME, name);
  635         /*
  636          * We always return success here.
  637          * The caller will check *pno and mark object as unresolved,
  638          * then it will automatically create "default" object.
  639          */
  640         return (0);
  641 }
  642 
  643 static struct named_object *
  644 dyn_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
  645 {
  646 
  647         DYN_DEBUG("kidx %d", idx);
  648         return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx));
  649 }
  650 
  651 static int
  652 dyn_create(struct ip_fw_chain *ch, struct tid_info *ti,
  653     uint16_t *pkidx)
  654 {
  655         struct namedobj_instance *ni;
  656         struct dyn_state_obj *obj;
  657         struct named_object *no;
  658         ipfw_obj_ntlv *ntlv;
  659         char *name;
  660 
  661         DYN_DEBUG("uidx %d", ti->uidx);
  662         if (ti->uidx != 0) {
  663                 if (ti->tlvs == NULL)
  664                         return (EINVAL);
  665                 ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
  666                     IPFW_TLV_STATE_NAME);
  667                 if (ntlv == NULL)
  668                         return (EINVAL);
  669                 name = ntlv->name;
  670         } else
  671                 name = default_state_name;
  672 
  673         ni = CHAIN_TO_SRV(ch);
  674         obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO);
  675         obj->no.name = obj->name;
  676         obj->no.etlv = IPFW_TLV_STATE_NAME;
  677         strlcpy(obj->name, name, sizeof(obj->name));
  678 
  679         IPFW_UH_WLOCK(ch);
  680         no = ipfw_objhash_lookup_name_type(ni, 0,
  681             IPFW_TLV_STATE_NAME, name);
  682         if (no != NULL) {
  683                 /*
  684                  * Object is already created.
  685                  * Just return its kidx and bump refcount.
  686                  */
  687                 *pkidx = no->kidx;
  688                 no->refcnt++;
  689                 IPFW_UH_WUNLOCK(ch);
  690                 free(obj, M_IPFW);
  691                 DYN_DEBUG("\tfound kidx %d", *pkidx);
  692                 return (0);
  693         }
  694         if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) {
  695                 DYN_DEBUG("\talloc_idx failed for %s", name);
  696                 IPFW_UH_WUNLOCK(ch);
  697                 free(obj, M_IPFW);
  698                 return (ENOSPC);
  699         }
  700         ipfw_objhash_add(ni, &obj->no);
  701         SRV_OBJECT(ch, obj->no.kidx) = obj;
  702         obj->no.refcnt++;
  703         *pkidx = obj->no.kidx;
  704         IPFW_UH_WUNLOCK(ch);
  705         DYN_DEBUG("\tcreated kidx %d", *pkidx);
  706         return (0);
  707 }
  708 
  709 static void
  710 dyn_destroy(struct ip_fw_chain *ch, struct named_object *no)
  711 {
  712         struct dyn_state_obj *obj;
  713 
  714         IPFW_UH_WLOCK_ASSERT(ch);
  715 
  716         KASSERT(no->etlv == IPFW_TLV_STATE_NAME,
  717             ("%s: wrong object type %u", __func__, no->etlv));
  718         KASSERT(no->refcnt == 1,
  719             ("Destroying object '%s' (type %u, idx %u) with refcnt %u",
  720             no->name, no->etlv, no->kidx, no->refcnt));
  721         DYN_DEBUG("kidx %d", no->kidx);
  722         obj = SRV_OBJECT(ch, no->kidx);
  723         SRV_OBJECT(ch, no->kidx) = NULL;
  724         ipfw_objhash_del(CHAIN_TO_SRV(ch), no);
  725         ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx);
  726 
  727         free(obj, M_IPFW);
  728 }
  729 
  730 static struct opcode_obj_rewrite dyn_opcodes[] = {
  731         {
  732                 O_KEEP_STATE, IPFW_TLV_STATE_NAME,
  733                 dyn_classify, dyn_update,
  734                 dyn_findbyname, dyn_findbykidx,
  735                 dyn_create, dyn_destroy
  736         },
  737         {
  738                 O_CHECK_STATE, IPFW_TLV_STATE_NAME,
  739                 dyn_classify, dyn_update,
  740                 dyn_findbyname, dyn_findbykidx,
  741                 dyn_create, dyn_destroy
  742         },
  743         {
  744                 O_PROBE_STATE, IPFW_TLV_STATE_NAME,
  745                 dyn_classify, dyn_update,
  746                 dyn_findbyname, dyn_findbykidx,
  747                 dyn_create, dyn_destroy
  748         },
  749         {
  750                 O_LIMIT, IPFW_TLV_STATE_NAME,
  751                 dyn_classify, dyn_update,
  752                 dyn_findbyname, dyn_findbykidx,
  753                 dyn_create, dyn_destroy
  754         },
  755 };
  756 
  757 /*
  758  * IMPORTANT: the hash function for dynamic rules must be commutative
  759  * in source and destination (ip,port), because rules are bidirectional
  760  * and we want to find both in the same bucket.
  761  */
  762 #ifndef IPFIREWALL_JENKINSHASH
  763 static __inline uint32_t
  764 hash_packet(const struct ipfw_flow_id *id)
  765 {
  766         uint32_t i;
  767 
  768 #ifdef INET6
  769         if (IS_IP6_FLOW_ID(id))
  770                 i = ntohl((id->dst_ip6.__u6_addr.__u6_addr32[2]) ^
  771                     (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^
  772                     (id->src_ip6.__u6_addr.__u6_addr32[2]) ^
  773                     (id->src_ip6.__u6_addr.__u6_addr32[3]));
  774         else
  775 #endif /* INET6 */
  776         i = (id->dst_ip) ^ (id->src_ip);
  777         i ^= (id->dst_port) ^ (id->src_port);
  778         return (i);
  779 }
  780 
  781 static __inline uint32_t
  782 hash_parent(const struct ipfw_flow_id *id, const void *rule)
  783 {
  784 
  785         return (hash_packet(id) ^ ((uintptr_t)rule));
  786 }
  787 
  788 #else /* IPFIREWALL_JENKINSHASH */
  789 
  790 VNET_DEFINE_STATIC(uint32_t, dyn_hashseed);
  791 #define V_dyn_hashseed          VNET(dyn_hashseed)
  792 
  793 static __inline int
  794 addrcmp4(const struct ipfw_flow_id *id)
  795 {
  796 
  797         if (id->src_ip < id->dst_ip)
  798                 return (0);
  799         if (id->src_ip > id->dst_ip)
  800                 return (1);
  801         if (id->src_port <= id->dst_port)
  802                 return (0);
  803         return (1);
  804 }
  805 
  806 #ifdef INET6
  807 static __inline int
  808 addrcmp6(const struct ipfw_flow_id *id)
  809 {
  810         int ret;
  811 
  812         ret = memcmp(&id->src_ip6, &id->dst_ip6, sizeof(struct in6_addr));
  813         if (ret < 0)
  814                 return (0);
  815         if (ret > 0)
  816                 return (1);
  817         if (id->src_port <= id->dst_port)
  818                 return (0);
  819         return (1);
  820 }
  821 
  822 static __inline uint32_t
  823 hash_packet6(const struct ipfw_flow_id *id)
  824 {
  825         struct tuple6 {
  826                 struct in6_addr addr[2];
  827                 uint16_t        port[2];
  828         } t6;
  829 
  830         if (addrcmp6(id) == 0) {
  831                 t6.addr[0] = id->src_ip6;
  832                 t6.addr[1] = id->dst_ip6;
  833                 t6.port[0] = id->src_port;
  834                 t6.port[1] = id->dst_port;
  835         } else {
  836                 t6.addr[0] = id->dst_ip6;
  837                 t6.addr[1] = id->src_ip6;
  838                 t6.port[0] = id->dst_port;
  839                 t6.port[1] = id->src_port;
  840         }
  841         return (jenkins_hash32((const uint32_t *)&t6,
  842             sizeof(t6) / sizeof(uint32_t), V_dyn_hashseed));
  843 }
  844 #endif
  845 
  846 static __inline uint32_t
  847 hash_packet(const struct ipfw_flow_id *id)
  848 {
  849         struct tuple4 {
  850                 in_addr_t       addr[2];
  851                 uint16_t        port[2];
  852         } t4;
  853 
  854         if (IS_IP4_FLOW_ID(id)) {
  855                 /* All fields are in host byte order */
  856                 if (addrcmp4(id) == 0) {
  857                         t4.addr[0] = id->src_ip;
  858                         t4.addr[1] = id->dst_ip;
  859                         t4.port[0] = id->src_port;
  860                         t4.port[1] = id->dst_port;
  861                 } else {
  862                         t4.addr[0] = id->dst_ip;
  863                         t4.addr[1] = id->src_ip;
  864                         t4.port[0] = id->dst_port;
  865                         t4.port[1] = id->src_port;
  866                 }
  867                 return (jenkins_hash32((const uint32_t *)&t4,
  868                     sizeof(t4) / sizeof(uint32_t), V_dyn_hashseed));
  869         } else
  870 #ifdef INET6
  871         if (IS_IP6_FLOW_ID(id))
  872                 return (hash_packet6(id));
  873 #endif
  874         return (0);
  875 }
  876 
  877 static __inline uint32_t
  878 hash_parent(const struct ipfw_flow_id *id, const void *rule)
  879 {
  880 
  881         return (jenkins_hash32((const uint32_t *)&rule,
  882             sizeof(rule) / sizeof(uint32_t), hash_packet(id)));
  883 }
  884 #endif /* IPFIREWALL_JENKINSHASH */
  885 
  886 /*
  887  * Print customizable flow id description via log(9) facility.
  888  */
  889 static void
  890 print_dyn_rule_flags(const struct ipfw_flow_id *id, int dyn_type,
  891     int log_flags, char *prefix, char *postfix)
  892 {
  893         struct in_addr da;
  894 #ifdef INET6
  895         char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
  896 #else
  897         char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN];
  898 #endif
  899 
  900 #ifdef INET6
  901         if (IS_IP6_FLOW_ID(id)) {
  902                 ip6_sprintf(src, &id->src_ip6);
  903                 ip6_sprintf(dst, &id->dst_ip6);
  904         } else
  905 #endif
  906         {
  907                 da.s_addr = htonl(id->src_ip);
  908                 inet_ntop(AF_INET, &da, src, sizeof(src));
  909                 da.s_addr = htonl(id->dst_ip);
  910                 inet_ntop(AF_INET, &da, dst, sizeof(dst));
  911         }
  912         log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n",
  913             prefix, dyn_type, src, id->src_port, dst,
  914             id->dst_port, V_dyn_count, postfix);
  915 }
  916 
  917 #define print_dyn_rule(id, dtype, prefix, postfix)      \
  918         print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix)
  919 
  920 #define TIME_LEQ(a,b)   ((int)((a)-(b)) <= 0)
  921 #define TIME_LE(a,b)    ((int)((a)-(b)) < 0)
  922 #define _SEQ_GE(a,b)    ((int)((a)-(b)) >= 0)
  923 #define BOTH_SYN        (TH_SYN | (TH_SYN << 8))
  924 #define BOTH_FIN        (TH_FIN | (TH_FIN << 8))
  925 #define TCP_FLAGS       (TH_FLAGS | (TH_FLAGS << 8))
  926 #define ACK_FWD         0x00010000      /* fwd ack seen */
  927 #define ACK_REV         0x00020000      /* rev ack seen */
  928 #define ACK_BOTH        (ACK_FWD | ACK_REV)
  929 
  930 static uint32_t
  931 dyn_update_tcp_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
  932     const struct tcphdr *tcp, int dir)
  933 {
  934         uint32_t ack, expire;
  935         uint32_t state, old;
  936         uint8_t th_flags;
  937 
  938         expire = data->expire;
  939         old = state = data->state;
  940         th_flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST);
  941         state |= (dir == MATCH_FORWARD) ? th_flags: (th_flags << 8);
  942         switch (state & TCP_FLAGS) {
  943         case TH_SYN:                    /* opening */
  944                 expire = time_uptime + V_dyn_syn_lifetime;
  945                 break;
  946 
  947         case BOTH_SYN:                  /* move to established */
  948         case BOTH_SYN | TH_FIN:         /* one side tries to close */
  949         case BOTH_SYN | (TH_FIN << 8):
  950                 if (tcp == NULL)
  951                         break;
  952                 ack = ntohl(tcp->th_ack);
  953                 if (dir == MATCH_FORWARD) {
  954                         if (data->ack_fwd == 0 ||
  955                             _SEQ_GE(ack, data->ack_fwd)) {
  956                                 state |= ACK_FWD;
  957                                 if (data->ack_fwd != ack)
  958                                         ck_pr_store_32(&data->ack_fwd, ack);
  959                         }
  960                 } else {
  961                         if (data->ack_rev == 0 ||
  962                             _SEQ_GE(ack, data->ack_rev)) {
  963                                 state |= ACK_REV;
  964                                 if (data->ack_rev != ack)
  965                                         ck_pr_store_32(&data->ack_rev, ack);
  966                         }
  967                 }
  968                 if ((state & ACK_BOTH) == ACK_BOTH) {
  969                         /*
  970                          * Set expire time to V_dyn_ack_lifetime only if
  971                          * we got ACKs for both directions.
  972                          * We use XOR here to avoid possible state
  973                          * overwriting in concurrent thread.
  974                          */
  975                         expire = time_uptime + V_dyn_ack_lifetime;
  976                         ck_pr_xor_32(&data->state, ACK_BOTH);
  977                 } else if ((data->state & ACK_BOTH) != (state & ACK_BOTH))
  978                         ck_pr_or_32(&data->state, state & ACK_BOTH);
  979                 break;
  980 
  981         case BOTH_SYN | BOTH_FIN:       /* both sides closed */
  982                 if (V_dyn_fin_lifetime >= V_dyn_keepalive_period)
  983                         V_dyn_fin_lifetime = V_dyn_keepalive_period - 1;
  984                 expire = time_uptime + V_dyn_fin_lifetime;
  985                 break;
  986 
  987         default:
  988                 if (V_dyn_keepalive != 0 &&
  989                     V_dyn_rst_lifetime >= V_dyn_keepalive_period)
  990                         V_dyn_rst_lifetime = V_dyn_keepalive_period - 1;
  991                 expire = time_uptime + V_dyn_rst_lifetime;
  992         }
  993         /* Save TCP state if it was changed */
  994         if ((state & TCP_FLAGS) != (old & TCP_FLAGS))
  995                 ck_pr_or_32(&data->state, state & TCP_FLAGS);
  996         return (expire);
  997 }
  998 
  999 /*
 1000  * Update ULP specific state.
 1001  * For TCP we keep sequence numbers and flags. For other protocols
 1002  * currently we update only expire time. Packets and bytes counters
 1003  * are also updated here.
 1004  */
 1005 static void
 1006 dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
 1007     const void *ulp, int pktlen, int dir)
 1008 {
 1009         uint32_t expire;
 1010 
 1011         /* NOTE: we are in critical section here. */
 1012         switch (pkt->proto) {
 1013         case IPPROTO_UDP:
 1014         case IPPROTO_UDPLITE:
 1015                 expire = time_uptime + V_dyn_udp_lifetime;
 1016                 break;
 1017         case IPPROTO_TCP:
 1018                 expire = dyn_update_tcp_state(data, pkt, ulp, dir);
 1019                 break;
 1020         default:
 1021                 expire = time_uptime + V_dyn_short_lifetime;
 1022         }
 1023         /*
 1024          * Expiration timer has the per-second granularity, no need to update
 1025          * it every time when state is matched.
 1026          */
 1027         if (data->expire != expire)
 1028                 ck_pr_store_32(&data->expire, expire);
 1029 
 1030         if (dir == MATCH_FORWARD)
 1031                 DYN_COUNTER_INC(data, fwd, pktlen);
 1032         else
 1033                 DYN_COUNTER_INC(data, rev, pktlen);
 1034 }
 1035 
 1036 /*
 1037  * Lookup IPv4 state.
 1038  * Must be called in critical section.
 1039  */
 1040 struct dyn_ipv4_state *
 1041 dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp,
 1042     struct ipfw_dyn_info *info, int pktlen)
 1043 {
 1044         struct dyn_ipv4_state *s;
 1045         uint32_t version, bucket;
 1046 
 1047         bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
 1048         info->version = DYN_BUCKET_VERSION(bucket, ipv4_add);
 1049 restart:
 1050         version = DYN_BUCKET_VERSION(bucket, ipv4_del);
 1051         CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
 1052                 DYNSTATE_PROTECT(s);
 1053                 if (version != DYN_BUCKET_VERSION(bucket, ipv4_del))
 1054                         goto restart;
 1055                 if (s->proto != pkt->proto)
 1056                         continue;
 1057                 if (info->kidx != 0 && s->kidx != info->kidx)
 1058                         continue;
 1059                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
 1060                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
 1061                         info->direction = MATCH_FORWARD;
 1062                         break;
 1063                 }
 1064                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
 1065                     s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
 1066                         info->direction = MATCH_REVERSE;
 1067                         break;
 1068                 }
 1069         }
 1070 
 1071         if (s != NULL)
 1072                 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
 1073                     info->direction);
 1074         return (s);
 1075 }
 1076 
 1077 /*
 1078  * Lookup IPv4 state.
 1079  * Simplifed version is used to check that matching state doesn't exist.
 1080  */
 1081 static int
 1082 dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt,
 1083     const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
 1084 {
 1085         struct dyn_ipv4_state *s;
 1086         int dir;
 1087 
 1088         dir = MATCH_NONE;
 1089         DYN_BUCKET_ASSERT(bucket);
 1090         CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
 1091                 if (s->proto != pkt->proto ||
 1092                     s->kidx != kidx)
 1093                         continue;
 1094                 if (s->sport == pkt->src_port &&
 1095                     s->dport == pkt->dst_port &&
 1096                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
 1097                         dir = MATCH_FORWARD;
 1098                         break;
 1099                 }
 1100                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
 1101                     s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
 1102                         dir = MATCH_REVERSE;
 1103                         break;
 1104                 }
 1105         }
 1106         if (s != NULL)
 1107                 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
 1108         return (s != NULL);
 1109 }
 1110 
 1111 struct dyn_ipv4_state *
 1112 dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule,
 1113     uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
 1114 {
 1115         struct dyn_ipv4_state *s;
 1116         uint32_t version, bucket;
 1117 
 1118         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1119 restart:
 1120         version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del);
 1121         CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
 1122                 DYNSTATE_PROTECT(s);
 1123                 if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del))
 1124                         goto restart;
 1125                 /*
 1126                  * NOTE: we do not need to check kidx, because parent rule
 1127                  * can not create states with different kidx.
 1128                  * And parent rule always created for forward direction.
 1129                  */
 1130                 if (s->limit->parent == rule &&
 1131                     s->limit->ruleid == ruleid &&
 1132                     s->limit->rulenum == rulenum &&
 1133                     s->proto == pkt->proto &&
 1134                     s->sport == pkt->src_port &&
 1135                     s->dport == pkt->dst_port &&
 1136                     s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
 1137                         if (s->limit->expire != time_uptime +
 1138                             V_dyn_short_lifetime)
 1139                                 ck_pr_store_32(&s->limit->expire,
 1140                                     time_uptime + V_dyn_short_lifetime);
 1141                         break;
 1142                 }
 1143         }
 1144         return (s);
 1145 }
 1146 
 1147 static struct dyn_ipv4_state *
 1148 dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt,
 1149     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
 1150 {
 1151         struct dyn_ipv4_state *s;
 1152 
 1153         DYN_BUCKET_ASSERT(bucket);
 1154         CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
 1155                 if (s->limit->parent == rule &&
 1156                     s->limit->ruleid == ruleid &&
 1157                     s->limit->rulenum == rulenum &&
 1158                     s->proto == pkt->proto &&
 1159                     s->sport == pkt->src_port &&
 1160                     s->dport == pkt->dst_port &&
 1161                     s->src == pkt->src_ip && s->dst == pkt->dst_ip)
 1162                         break;
 1163         }
 1164         return (s);
 1165 }
 1166 
 1167 #ifdef INET6
 1168 static uint32_t
 1169 dyn_getscopeid(const struct ip_fw_args *args)
 1170 {
 1171 
 1172         /*
 1173          * If source or destination address is an scopeid address, we need
 1174          * determine the scope zone id to resolve address scope ambiguity.
 1175          */
 1176         if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) ||
 1177             IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6))
 1178                 return (in6_getscopezone(args->ifp, IPV6_ADDR_SCOPE_LINKLOCAL));
 1179 
 1180         return (0);
 1181 }
 1182 
 1183 /*
 1184  * Lookup IPv6 state.
 1185  * Must be called in critical section.
 1186  */
 1187 static struct dyn_ipv6_state *
 1188 dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1189     const void *ulp, struct ipfw_dyn_info *info, int pktlen)
 1190 {
 1191         struct dyn_ipv6_state *s;
 1192         uint32_t version, bucket;
 1193 
 1194         bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
 1195         info->version = DYN_BUCKET_VERSION(bucket, ipv6_add);
 1196 restart:
 1197         version = DYN_BUCKET_VERSION(bucket, ipv6_del);
 1198         CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
 1199                 DYNSTATE_PROTECT(s);
 1200                 if (version != DYN_BUCKET_VERSION(bucket, ipv6_del))
 1201                         goto restart;
 1202                 if (s->proto != pkt->proto || s->zoneid != zoneid)
 1203                         continue;
 1204                 if (info->kidx != 0 && s->kidx != info->kidx)
 1205                         continue;
 1206                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
 1207                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
 1208                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
 1209                         info->direction = MATCH_FORWARD;
 1210                         break;
 1211                 }
 1212                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
 1213                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
 1214                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
 1215                         info->direction = MATCH_REVERSE;
 1216                         break;
 1217                 }
 1218         }
 1219         if (s != NULL)
 1220                 dyn_update_proto_state(s->data, pkt, ulp, pktlen,
 1221                     info->direction);
 1222         return (s);
 1223 }
 1224 
 1225 /*
 1226  * Lookup IPv6 state.
 1227  * Simplifed version is used to check that matching state doesn't exist.
 1228  */
 1229 static int
 1230 dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1231     const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
 1232 {
 1233         struct dyn_ipv6_state *s;
 1234         int dir;
 1235 
 1236         dir = MATCH_NONE;
 1237         DYN_BUCKET_ASSERT(bucket);
 1238         CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
 1239                 if (s->proto != pkt->proto || s->kidx != kidx ||
 1240                     s->zoneid != zoneid)
 1241                         continue;
 1242                 if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
 1243                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
 1244                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
 1245                         dir = MATCH_FORWARD;
 1246                         break;
 1247                 }
 1248                 if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
 1249                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
 1250                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
 1251                         dir = MATCH_REVERSE;
 1252                         break;
 1253                 }
 1254         }
 1255         if (s != NULL)
 1256                 dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
 1257         return (s != NULL);
 1258 }
 1259 
 1260 static struct dyn_ipv6_state *
 1261 dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1262     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
 1263 {
 1264         struct dyn_ipv6_state *s;
 1265         uint32_t version, bucket;
 1266 
 1267         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1268 restart:
 1269         version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del);
 1270         CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
 1271                 DYNSTATE_PROTECT(s);
 1272                 if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del))
 1273                         goto restart;
 1274                 /*
 1275                  * NOTE: we do not need to check kidx, because parent rule
 1276                  * can not create states with different kidx.
 1277                  * Also parent rule always created for forward direction.
 1278                  */
 1279                 if (s->limit->parent == rule &&
 1280                     s->limit->ruleid == ruleid &&
 1281                     s->limit->rulenum == rulenum &&
 1282                     s->proto == pkt->proto &&
 1283                     s->sport == pkt->src_port &&
 1284                     s->dport == pkt->dst_port && s->zoneid == zoneid &&
 1285                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
 1286                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
 1287                         if (s->limit->expire != time_uptime +
 1288                             V_dyn_short_lifetime)
 1289                                 ck_pr_store_32(&s->limit->expire,
 1290                                     time_uptime + V_dyn_short_lifetime);
 1291                         break;
 1292                 }
 1293         }
 1294         return (s);
 1295 }
 1296 
 1297 static struct dyn_ipv6_state *
 1298 dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1299     const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
 1300 {
 1301         struct dyn_ipv6_state *s;
 1302 
 1303         DYN_BUCKET_ASSERT(bucket);
 1304         CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
 1305                 if (s->limit->parent == rule &&
 1306                     s->limit->ruleid == ruleid &&
 1307                     s->limit->rulenum == rulenum &&
 1308                     s->proto == pkt->proto &&
 1309                     s->sport == pkt->src_port &&
 1310                     s->dport == pkt->dst_port && s->zoneid == zoneid &&
 1311                     IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
 1312                     IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6))
 1313                         break;
 1314         }
 1315         return (s);
 1316 }
 1317 
 1318 #endif /* INET6 */
 1319 
 1320 /*
 1321  * Lookup dynamic state.
 1322  *  pkt - filled by ipfw_chk() ipfw_flow_id;
 1323  *  ulp - determined by ipfw_chk() upper level protocol header;
 1324  *  dyn_info - info about matched state to return back;
 1325  * Returns pointer to state's parent rule and dyn_info. If there is
 1326  * no state, NULL is returned.
 1327  * On match ipfw_dyn_lookup() updates state's counters.
 1328  */
 1329 struct ip_fw *
 1330 ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp,
 1331     int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info)
 1332 {
 1333         struct dyn_data *data;
 1334         struct ip_fw *rule;
 1335 
 1336         IPFW_RLOCK_ASSERT(&V_layer3_chain);
 1337 
 1338         data = NULL;
 1339         rule = NULL;
 1340         info->kidx = cmd->arg1;
 1341         info->direction = MATCH_NONE;
 1342         info->hashval = hash_packet(&args->f_id);
 1343 
 1344         DYNSTATE_CRITICAL_ENTER();
 1345         if (IS_IP4_FLOW_ID(&args->f_id)) {
 1346                 struct dyn_ipv4_state *s;
 1347 
 1348                 s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen);
 1349                 if (s != NULL) {
 1350                         /*
 1351                          * Dynamic states are created using the same 5-tuple,
 1352                          * so it is assumed, that parent rule for O_LIMIT
 1353                          * state has the same address family.
 1354                          */
 1355                         data = s->data;
 1356                         if (s->type == O_LIMIT) {
 1357                                 s = data->parent;
 1358                                 rule = s->limit->parent;
 1359                         } else
 1360                                 rule = data->parent;
 1361                 }
 1362         }
 1363 #ifdef INET6
 1364         else if (IS_IP6_FLOW_ID(&args->f_id)) {
 1365                 struct dyn_ipv6_state *s;
 1366 
 1367                 s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args),
 1368                     ulp, info, pktlen);
 1369                 if (s != NULL) {
 1370                         data = s->data;
 1371                         if (s->type == O_LIMIT) {
 1372                                 s = data->parent;
 1373                                 rule = s->limit->parent;
 1374                         } else
 1375                                 rule = data->parent;
 1376                 }
 1377         }
 1378 #endif
 1379         if (data != NULL) {
 1380                 /*
 1381                  * If cached chain id is the same, we can avoid rule index
 1382                  * lookup. Otherwise do lookup and update chain_id and f_pos.
 1383                  * It is safe even if there is concurrent thread that want
 1384                  * update the same state, because chain->id can be changed
 1385                  * only under IPFW_WLOCK().
 1386                  */
 1387                 if (data->chain_id != V_layer3_chain.id) {
 1388                         data->f_pos = ipfw_find_rule(&V_layer3_chain,
 1389                             data->rulenum, data->ruleid);
 1390                         /*
 1391                          * Check that found state has not orphaned.
 1392                          * When chain->id being changed the parent
 1393                          * rule can be deleted. If found rule doesn't
 1394                          * match the parent pointer, consider this
 1395                          * result as MATCH_NONE and return NULL.
 1396                          *
 1397                          * This will lead to creation of new similar state
 1398                          * that will be added into head of this bucket.
 1399                          * And the state that we currently have matched
 1400                          * should be deleted by dyn_expire_states().
 1401                          *
 1402                          * In case when dyn_keep_states is enabled, return
 1403                          * pointer to deleted rule and f_pos value
 1404                          * corresponding to penultimate rule.
 1405                          * When we have enabled V_dyn_keep_states, states
 1406                          * that become orphaned will get the DYN_REFERENCED
 1407                          * flag and rule will keep around. So we can return
 1408                          * it. But since it is not in the rules map, we need
 1409                          * return such f_pos value, so after the state
 1410                          * handling if the search will continue, the next rule
 1411                          * will be the last one - the default rule.
 1412                          */
 1413                         if (V_layer3_chain.map[data->f_pos] == rule) {
 1414                                 data->chain_id = V_layer3_chain.id;
 1415                                 info->f_pos = data->f_pos;
 1416                         } else if (V_dyn_keep_states != 0) {
 1417                                 /*
 1418                                  * The original rule pointer is still usable.
 1419                                  * So, we return it, but f_pos need to be
 1420                                  * changed to point to the penultimate rule.
 1421                                  */
 1422                                 MPASS(V_layer3_chain.n_rules > 1);
 1423                                 data->chain_id = V_layer3_chain.id;
 1424                                 data->f_pos = V_layer3_chain.n_rules - 2;
 1425                                 info->f_pos = data->f_pos;
 1426                         } else {
 1427                                 rule = NULL;
 1428                                 info->direction = MATCH_NONE;
 1429                                 DYN_DEBUG("rule %p  [%u, %u] is considered "
 1430                                     "invalid in data %p", rule, data->ruleid,
 1431                                     data->rulenum, data);
 1432                                 /* info->f_pos doesn't matter here. */
 1433                         }
 1434                 } else
 1435                         info->f_pos = data->f_pos;
 1436         }
 1437         DYNSTATE_CRITICAL_EXIT();
 1438 #if 0
 1439         /*
 1440          * Return MATCH_NONE if parent rule is in disabled set.
 1441          * This will lead to creation of new similar state that
 1442          * will be added into head of this bucket.
 1443          *
 1444          * XXXAE: we need to be able update state's set when parent
 1445          *        rule set is changed.
 1446          */
 1447         if (rule != NULL && (V_set_disable & (1 << rule->set))) {
 1448                 rule = NULL;
 1449                 info->direction = MATCH_NONE;
 1450         }
 1451 #endif
 1452         return (rule);
 1453 }
 1454 
 1455 static struct dyn_parent *
 1456 dyn_alloc_parent(void *parent, uint32_t ruleid, uint16_t rulenum,
 1457     uint32_t hashval)
 1458 {
 1459         struct dyn_parent *limit;
 1460 
 1461         limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO);
 1462         if (limit == NULL) {
 1463                 if (last_log != time_uptime) {
 1464                         last_log = time_uptime;
 1465                         log(LOG_DEBUG,
 1466                             "ipfw: Cannot allocate parent dynamic state, "
 1467                             "consider increasing "
 1468                             "net.inet.ip.fw.dyn_parent_max\n");
 1469                 }
 1470                 return (NULL);
 1471         }
 1472 
 1473         limit->parent = parent;
 1474         limit->ruleid = ruleid;
 1475         limit->rulenum = rulenum;
 1476         limit->hashval = hashval;
 1477         limit->expire = time_uptime + V_dyn_short_lifetime;
 1478         return (limit);
 1479 }
 1480 
 1481 static struct dyn_data *
 1482 dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint16_t rulenum,
 1483     const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
 1484     uint32_t hashval, uint16_t fibnum)
 1485 {
 1486         struct dyn_data *data;
 1487 
 1488         data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO);
 1489         if (data == NULL) {
 1490                 if (last_log != time_uptime) {
 1491                         last_log = time_uptime;
 1492                         log(LOG_DEBUG,
 1493                             "ipfw: Cannot allocate dynamic state, "
 1494                             "consider increasing net.inet.ip.fw.dyn_max\n");
 1495                 }
 1496                 return (NULL);
 1497         }
 1498 
 1499         data->parent = parent;
 1500         data->ruleid = ruleid;
 1501         data->rulenum = rulenum;
 1502         data->fibnum = fibnum;
 1503         data->hashval = hashval;
 1504         data->expire = time_uptime + V_dyn_syn_lifetime;
 1505         dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD);
 1506         return (data);
 1507 }
 1508 
 1509 static struct dyn_ipv4_state *
 1510 dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint16_t kidx,
 1511     uint8_t type)
 1512 {
 1513         struct dyn_ipv4_state *s;
 1514 
 1515         s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO);
 1516         if (s == NULL)
 1517                 return (NULL);
 1518 
 1519         s->type = type;
 1520         s->kidx = kidx;
 1521         s->proto = pkt->proto;
 1522         s->sport = pkt->src_port;
 1523         s->dport = pkt->dst_port;
 1524         s->src = pkt->src_ip;
 1525         s->dst = pkt->dst_ip;
 1526         return (s);
 1527 }
 1528 
 1529 /*
 1530  * Add IPv4 parent state.
 1531  * Returns pointer to parent state. When it is not NULL we are in
 1532  * critical section and pointer protected by hazard pointer.
 1533  * When some error occurs, it returns NULL and exit from critical section
 1534  * is not needed.
 1535  */
 1536 static struct dyn_ipv4_state *
 1537 dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
 1538     const struct ipfw_flow_id *pkt, uint32_t hashval, uint32_t version,
 1539     uint16_t kidx)
 1540 {
 1541         struct dyn_ipv4_state *s;
 1542         struct dyn_parent *limit;
 1543         uint32_t bucket;
 1544 
 1545         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1546         DYN_BUCKET_LOCK(bucket);
 1547         if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) {
 1548                 /*
 1549                  * Bucket version has been changed since last lookup,
 1550                  * do lookup again to be sure that state does not exist.
 1551                  */
 1552                 s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid,
 1553                     rulenum, bucket);
 1554                 if (s != NULL) {
 1555                         /*
 1556                          * Simultaneous thread has already created this
 1557                          * state. Just return it.
 1558                          */
 1559                         DYNSTATE_CRITICAL_ENTER();
 1560                         DYNSTATE_PROTECT(s);
 1561                         DYN_BUCKET_UNLOCK(bucket);
 1562                         return (s);
 1563                 }
 1564         }
 1565 
 1566         limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval);
 1567         if (limit == NULL) {
 1568                 DYN_BUCKET_UNLOCK(bucket);
 1569                 return (NULL);
 1570         }
 1571 
 1572         s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT);
 1573         if (s == NULL) {
 1574                 DYN_BUCKET_UNLOCK(bucket);
 1575                 uma_zfree(V_dyn_parent_zone, limit);
 1576                 return (NULL);
 1577         }
 1578 
 1579         s->limit = limit;
 1580         CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry);
 1581         DYN_COUNT_INC(dyn_parent_count);
 1582         DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add);
 1583         DYNSTATE_CRITICAL_ENTER();
 1584         DYNSTATE_PROTECT(s);
 1585         DYN_BUCKET_UNLOCK(bucket);
 1586         return (s);
 1587 }
 1588 
 1589 static int
 1590 dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint16_t rulenum,
 1591     const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
 1592     uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum,
 1593     uint16_t kidx, uint8_t type)
 1594 {
 1595         struct dyn_ipv4_state *s;
 1596         void *data;
 1597         uint32_t bucket;
 1598 
 1599         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1600         DYN_BUCKET_LOCK(bucket);
 1601         if (info->direction == MATCH_UNKNOWN ||
 1602             info->kidx != kidx ||
 1603             info->hashval != hashval ||
 1604             info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) {
 1605                 /*
 1606                  * Bucket version has been changed since last lookup,
 1607                  * do lookup again to be sure that state does not exist.
 1608                  */
 1609                 if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen,
 1610                     bucket, kidx) != 0) {
 1611                         DYN_BUCKET_UNLOCK(bucket);
 1612                         return (EEXIST);
 1613                 }
 1614         }
 1615 
 1616         data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp,
 1617             pktlen, hashval, fibnum);
 1618         if (data == NULL) {
 1619                 DYN_BUCKET_UNLOCK(bucket);
 1620                 return (ENOMEM);
 1621         }
 1622 
 1623         s = dyn_alloc_ipv4_state(pkt, kidx, type);
 1624         if (s == NULL) {
 1625                 DYN_BUCKET_UNLOCK(bucket);
 1626                 uma_zfree(V_dyn_data_zone, data);
 1627                 return (ENOMEM);
 1628         }
 1629 
 1630         s->data = data;
 1631         CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry);
 1632         DYN_COUNT_INC(dyn_count);
 1633         DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add);
 1634         DYN_BUCKET_UNLOCK(bucket);
 1635         return (0);
 1636 }
 1637 
 1638 #ifdef INET6
 1639 static struct dyn_ipv6_state *
 1640 dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1641     uint16_t kidx, uint8_t type)
 1642 {
 1643         struct dyn_ipv6_state *s;
 1644 
 1645         s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO);
 1646         if (s == NULL)
 1647                 return (NULL);
 1648 
 1649         s->type = type;
 1650         s->kidx = kidx;
 1651         s->zoneid = zoneid;
 1652         s->proto = pkt->proto;
 1653         s->sport = pkt->src_port;
 1654         s->dport = pkt->dst_port;
 1655         s->src = pkt->src_ip6;
 1656         s->dst = pkt->dst_ip6;
 1657         return (s);
 1658 }
 1659 
 1660 /*
 1661  * Add IPv6 parent state.
 1662  * Returns pointer to parent state. When it is not NULL we are in
 1663  * critical section and pointer protected by hazard pointer.
 1664  * When some error occurs, it return NULL and exit from critical section
 1665  * is not needed.
 1666  */
 1667 static struct dyn_ipv6_state *
 1668 dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
 1669     const struct ipfw_flow_id *pkt, uint32_t zoneid, uint32_t hashval,
 1670     uint32_t version, uint16_t kidx)
 1671 {
 1672         struct dyn_ipv6_state *s;
 1673         struct dyn_parent *limit;
 1674         uint32_t bucket;
 1675 
 1676         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1677         DYN_BUCKET_LOCK(bucket);
 1678         if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) {
 1679                 /*
 1680                  * Bucket version has been changed since last lookup,
 1681                  * do lookup again to be sure that state does not exist.
 1682                  */
 1683                 s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid,
 1684                     rulenum, bucket);
 1685                 if (s != NULL) {
 1686                         /*
 1687                          * Simultaneous thread has already created this
 1688                          * state. Just return it.
 1689                          */
 1690                         DYNSTATE_CRITICAL_ENTER();
 1691                         DYNSTATE_PROTECT(s);
 1692                         DYN_BUCKET_UNLOCK(bucket);
 1693                         return (s);
 1694                 }
 1695         }
 1696 
 1697         limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval);
 1698         if (limit == NULL) {
 1699                 DYN_BUCKET_UNLOCK(bucket);
 1700                 return (NULL);
 1701         }
 1702 
 1703         s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT);
 1704         if (s == NULL) {
 1705                 DYN_BUCKET_UNLOCK(bucket);
 1706                 uma_zfree(V_dyn_parent_zone, limit);
 1707                 return (NULL);
 1708         }
 1709 
 1710         s->limit = limit;
 1711         CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry);
 1712         DYN_COUNT_INC(dyn_parent_count);
 1713         DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add);
 1714         DYNSTATE_CRITICAL_ENTER();
 1715         DYNSTATE_PROTECT(s);
 1716         DYN_BUCKET_UNLOCK(bucket);
 1717         return (s);
 1718 }
 1719 
 1720 static int
 1721 dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint16_t rulenum,
 1722     const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp,
 1723     int pktlen, uint32_t hashval, struct ipfw_dyn_info *info,
 1724     uint16_t fibnum, uint16_t kidx, uint8_t type)
 1725 {
 1726         struct dyn_ipv6_state *s;
 1727         struct dyn_data *data;
 1728         uint32_t bucket;
 1729 
 1730         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1731         DYN_BUCKET_LOCK(bucket);
 1732         if (info->direction == MATCH_UNKNOWN ||
 1733             info->kidx != kidx ||
 1734             info->hashval != hashval ||
 1735             info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) {
 1736                 /*
 1737                  * Bucket version has been changed since last lookup,
 1738                  * do lookup again to be sure that state does not exist.
 1739                  */
 1740                 if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen,
 1741                     bucket, kidx) != 0) {
 1742                         DYN_BUCKET_UNLOCK(bucket);
 1743                         return (EEXIST);
 1744                 }
 1745         }
 1746 
 1747         data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp,
 1748             pktlen, hashval, fibnum);
 1749         if (data == NULL) {
 1750                 DYN_BUCKET_UNLOCK(bucket);
 1751                 return (ENOMEM);
 1752         }
 1753 
 1754         s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type);
 1755         if (s == NULL) {
 1756                 DYN_BUCKET_UNLOCK(bucket);
 1757                 uma_zfree(V_dyn_data_zone, data);
 1758                 return (ENOMEM);
 1759         }
 1760 
 1761         s->data = data;
 1762         CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry);
 1763         DYN_COUNT_INC(dyn_count);
 1764         DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add);
 1765         DYN_BUCKET_UNLOCK(bucket);
 1766         return (0);
 1767 }
 1768 #endif /* INET6 */
 1769 
 1770 static void *
 1771 dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1772     struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint16_t kidx)
 1773 {
 1774         char sbuf[24];
 1775         struct dyn_parent *p;
 1776         void *ret;
 1777         uint32_t bucket, version;
 1778 
 1779         p = NULL;
 1780         ret = NULL;
 1781         bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
 1782         DYNSTATE_CRITICAL_ENTER();
 1783         if (IS_IP4_FLOW_ID(pkt)) {
 1784                 struct dyn_ipv4_state *s;
 1785 
 1786                 version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add);
 1787                 s = dyn_lookup_ipv4_parent(pkt, rule, rule->id,
 1788                     rule->rulenum, bucket);
 1789                 if (s == NULL) {
 1790                         /*
 1791                          * Exit from critical section because dyn_add_parent()
 1792                          * will acquire bucket lock.
 1793                          */
 1794                         DYNSTATE_CRITICAL_EXIT();
 1795 
 1796                         s = dyn_add_ipv4_parent(rule, rule->id,
 1797                             rule->rulenum, pkt, hashval, version, kidx);
 1798                         if (s == NULL)
 1799                                 return (NULL);
 1800                         /* Now we are in critical section again. */
 1801                 }
 1802                 ret = s;
 1803                 p = s->limit;
 1804         }
 1805 #ifdef INET6
 1806         else if (IS_IP6_FLOW_ID(pkt)) {
 1807                 struct dyn_ipv6_state *s;
 1808 
 1809                 version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add);
 1810                 s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id,
 1811                     rule->rulenum, bucket);
 1812                 if (s == NULL) {
 1813                         /*
 1814                          * Exit from critical section because dyn_add_parent()
 1815                          * can acquire bucket mutex.
 1816                          */
 1817                         DYNSTATE_CRITICAL_EXIT();
 1818 
 1819                         s = dyn_add_ipv6_parent(rule, rule->id,
 1820                             rule->rulenum, pkt, zoneid, hashval, version,
 1821                             kidx);
 1822                         if (s == NULL)
 1823                                 return (NULL);
 1824                         /* Now we are in critical section again. */
 1825                 }
 1826                 ret = s;
 1827                 p = s->limit;
 1828         }
 1829 #endif
 1830         else {
 1831                 DYNSTATE_CRITICAL_EXIT();
 1832                 return (NULL);
 1833         }
 1834 
 1835         /* Check the limit */
 1836         if (DPARENT_COUNT(p) >= limit) {
 1837                 DYNSTATE_CRITICAL_EXIT();
 1838                 if (V_fw_verbose && last_log != time_uptime) {
 1839                         last_log = time_uptime;
 1840                         snprintf(sbuf, sizeof(sbuf), "%u drop session",
 1841                             rule->rulenum);
 1842                         print_dyn_rule_flags(pkt, O_LIMIT,
 1843                             LOG_SECURITY | LOG_DEBUG, sbuf,
 1844                             "too many entries");
 1845                 }
 1846                 return (NULL);
 1847         }
 1848 
 1849         /* Take new session into account. */
 1850         DPARENT_COUNT_INC(p);
 1851         /*
 1852          * We must exit from critical section because the following code
 1853          * can acquire bucket mutex.
 1854          * We rely on the 'count' field. The state will not expire
 1855          * until it has some child states, i.e. 'count' field is not zero.
 1856          * Return state pointer, it will be used by child states as parent.
 1857          */
 1858         DYNSTATE_CRITICAL_EXIT();
 1859         return (ret);
 1860 }
 1861 
 1862 static int
 1863 dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
 1864     uint16_t fibnum, const void *ulp, int pktlen, struct ip_fw *rule,
 1865     struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask,
 1866     uint16_t kidx, uint8_t type)
 1867 {
 1868         struct ipfw_flow_id id;
 1869         uint32_t hashval, parent_hashval, ruleid, rulenum;
 1870         int ret;
 1871 
 1872         MPASS(type == O_LIMIT || type == O_KEEP_STATE);
 1873 
 1874         ruleid = rule->id;
 1875         rulenum = rule->rulenum;
 1876         if (type == O_LIMIT) {
 1877                 /* Create masked flow id and calculate bucket */
 1878                 id.addr_type = pkt->addr_type;
 1879                 id.proto = pkt->proto;
 1880                 id.fib = fibnum; /* unused */
 1881                 id.src_port = (limit_mask & DYN_SRC_PORT) ?
 1882                     pkt->src_port: 0;
 1883                 id.dst_port = (limit_mask & DYN_DST_PORT) ?
 1884                     pkt->dst_port: 0;
 1885                 if (IS_IP4_FLOW_ID(pkt)) {
 1886                         id.src_ip = (limit_mask & DYN_SRC_ADDR) ?
 1887                             pkt->src_ip: 0;
 1888                         id.dst_ip = (limit_mask & DYN_DST_ADDR) ?
 1889                             pkt->dst_ip: 0;
 1890                 }
 1891 #ifdef INET6
 1892                 else if (IS_IP6_FLOW_ID(pkt)) {
 1893                         if (limit_mask & DYN_SRC_ADDR)
 1894                                 id.src_ip6 = pkt->src_ip6;
 1895                         else
 1896                                 memset(&id.src_ip6, 0, sizeof(id.src_ip6));
 1897                         if (limit_mask & DYN_DST_ADDR)
 1898                                 id.dst_ip6 = pkt->dst_ip6;
 1899                         else
 1900                                 memset(&id.dst_ip6, 0, sizeof(id.dst_ip6));
 1901                 }
 1902 #endif
 1903                 else
 1904                         return (EAFNOSUPPORT);
 1905 
 1906                 parent_hashval = hash_parent(&id, rule);
 1907                 rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval,
 1908                     limit, kidx);
 1909                 if (rule == NULL) {
 1910 #if 0
 1911                         if (V_fw_verbose && last_log != time_uptime) {
 1912                                 last_log = time_uptime;
 1913                                 snprintf(sbuf, sizeof(sbuf),
 1914                                     "%u drop session", rule->rulenum);
 1915                         print_dyn_rule_flags(pkt, O_LIMIT,
 1916                             LOG_SECURITY | LOG_DEBUG, sbuf,
 1917                             "too many entries");
 1918                         }
 1919 #endif
 1920                         return (EACCES);
 1921                 }
 1922                 /*
 1923                  * Limit is not reached, create new state.
 1924                  * Now rule points to parent state.
 1925                  */
 1926         }
 1927 
 1928         hashval = hash_packet(pkt);
 1929         if (IS_IP4_FLOW_ID(pkt))
 1930                 ret = dyn_add_ipv4_state(rule, ruleid, rulenum, pkt,
 1931                     ulp, pktlen, hashval, info, fibnum, kidx, type);
 1932 #ifdef INET6
 1933         else if (IS_IP6_FLOW_ID(pkt))
 1934                 ret = dyn_add_ipv6_state(rule, ruleid, rulenum, pkt,
 1935                     zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type);
 1936 #endif /* INET6 */
 1937         else
 1938                 ret = EAFNOSUPPORT;
 1939 
 1940         if (type == O_LIMIT) {
 1941                 if (ret != 0) {
 1942                         /*
 1943                          * We failed to create child state for O_LIMIT
 1944                          * opcode. Since we already counted it in the parent,
 1945                          * we must revert counter back. The 'rule' points to
 1946                          * parent state, use it to get dyn_parent.
 1947                          *
 1948                          * XXXAE: it should be safe to use 'rule' pointer
 1949                          * without extra lookup, parent state is referenced
 1950                          * and should not be freed.
 1951                          */
 1952                         if (IS_IP4_FLOW_ID(&id))
 1953                                 DPARENT_COUNT_DEC(
 1954                                     ((struct dyn_ipv4_state *)rule)->limit);
 1955 #ifdef INET6
 1956                         else if (IS_IP6_FLOW_ID(&id))
 1957                                 DPARENT_COUNT_DEC(
 1958                                     ((struct dyn_ipv6_state *)rule)->limit);
 1959 #endif
 1960                 }
 1961         }
 1962         /*
 1963          * EEXIST means that simultaneous thread has created this
 1964          * state. Consider this as success.
 1965          *
 1966          * XXXAE: should we invalidate 'info' content here?
 1967          */
 1968         if (ret == EEXIST)
 1969                 return (0);
 1970         return (ret);
 1971 }
 1972 
 1973 /*
 1974  * Install dynamic state.
 1975  *  chain - ipfw's instance;
 1976  *  rule - the parent rule that installs the state;
 1977  *  cmd - opcode that installs the state;
 1978  *  args - ipfw arguments;
 1979  *  ulp - upper level protocol header;
 1980  *  pktlen - packet length;
 1981  *  info - dynamic state lookup info;
 1982  *  tablearg - tablearg id.
 1983  *
 1984  * Returns non-zero value (failure) if state is not installed because
 1985  * of errors or because session limitations are enforced.
 1986  */
 1987 int
 1988 ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule,
 1989     const ipfw_insn_limit *cmd, const struct ip_fw_args *args,
 1990     const void *ulp, int pktlen, struct ipfw_dyn_info *info,
 1991     uint32_t tablearg)
 1992 {
 1993         uint32_t limit;
 1994         uint16_t limit_mask;
 1995 
 1996         if (cmd->o.opcode == O_LIMIT) {
 1997                 limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit);
 1998                 limit_mask = cmd->limit_mask;
 1999         } else {
 2000                 limit = 0;
 2001                 limit_mask = 0;
 2002         }
 2003         return (dyn_install_state(&args->f_id,
 2004 #ifdef INET6
 2005             IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args):
 2006 #endif
 2007             0, M_GETFIB(args->m), ulp, pktlen, rule, info, limit,
 2008             limit_mask, cmd->o.arg1, cmd->o.opcode));
 2009 }
 2010 
 2011 /*
 2012  * Free safe to remove state entries from expired lists.
 2013  */
 2014 static void
 2015 dyn_free_states(struct ip_fw_chain *chain)
 2016 {
 2017         struct dyn_ipv4_state *s4, *s4n;
 2018 #ifdef INET6
 2019         struct dyn_ipv6_state *s6, *s6n;
 2020 #endif
 2021         int cached_count, i;
 2022 
 2023         /*
 2024          * We keep pointers to objects that are in use on each CPU
 2025          * in the per-cpu dyn_hp pointer. When object is going to be
 2026          * removed, first of it is unlinked from the corresponding
 2027          * list. This leads to changing of dyn_bucket_xxx_delver version.
 2028          * Unlinked objects is placed into corresponding dyn_expired_xxx
 2029          * list. Reader that is going to dereference object pointer checks
 2030          * dyn_bucket_xxx_delver version before and after storing pointer
 2031          * into dyn_hp. If version is the same, the object is protected
 2032          * from freeing and it is safe to dereference. Othervise reader
 2033          * tries to iterate list again from the beginning, but this object
 2034          * now unlinked and thus will not be accessible.
 2035          *
 2036          * Copy dyn_hp pointers for each CPU into dyn_hp_cache array.
 2037          * It does not matter that some pointer can be changed in
 2038          * time while we are copying. We need to check, that objects
 2039          * removed in the previous pass are not in use. And if dyn_hp
 2040          * pointer does not contain it in the time when we are copying,
 2041          * it will not appear there, because it is already unlinked.
 2042          * And for new pointers we will not free objects that will be
 2043          * unlinked in this pass.
 2044          */
 2045         cached_count = 0;
 2046         CPU_FOREACH(i) {
 2047                 dyn_hp_cache[cached_count] = DYNSTATE_GET(i);
 2048                 if (dyn_hp_cache[cached_count] != NULL)
 2049                         cached_count++;
 2050         }
 2051 
 2052         /*
 2053          * Free expired states that are safe to free.
 2054          * Check each entry from previous pass in the dyn_expired_xxx
 2055          * list, if pointer to the object is in the dyn_hp_cache array,
 2056          * keep it until next pass. Otherwise it is safe to free the
 2057          * object.
 2058          *
 2059          * XXXAE: optimize this to use SLIST_REMOVE_AFTER.
 2060          */
 2061 #define DYN_FREE_STATES(s, next, name)          do {                    \
 2062         s = SLIST_FIRST(&V_dyn_expired_ ## name);                       \
 2063         while (s != NULL) {                                             \
 2064                 next = SLIST_NEXT(s, expired);                          \
 2065                 for (i = 0; i < cached_count; i++)                      \
 2066                         if (dyn_hp_cache[i] == s)                       \
 2067                                 break;                                  \
 2068                 if (i == cached_count) {                                \
 2069                         if (s->type == O_LIMIT_PARENT &&                \
 2070                             s->limit->count != 0) {                     \
 2071                                 s = next;                               \
 2072                                 continue;                               \
 2073                         }                                               \
 2074                         SLIST_REMOVE(&V_dyn_expired_ ## name,           \
 2075                             s, dyn_ ## name ## _state, expired);        \
 2076                         if (s->type == O_LIMIT_PARENT)                  \
 2077                                 uma_zfree(V_dyn_parent_zone, s->limit); \
 2078                         else                                            \
 2079                                 uma_zfree(V_dyn_data_zone, s->data);    \
 2080                         uma_zfree(V_dyn_ ## name ## _zone, s);          \
 2081                 }                                                       \
 2082                 s = next;                                               \
 2083         }                                                               \
 2084 } while (0)
 2085 
 2086         /*
 2087          * Protect access to expired lists with DYN_EXPIRED_LOCK.
 2088          * Userland can invoke ipfw_expire_dyn_states() to delete
 2089          * specific states, this will lead to modification of expired
 2090          * lists.
 2091          *
 2092          * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use
 2093          *        IPFW_UH_WLOCK to protect access to these lists.
 2094          */
 2095         DYN_EXPIRED_LOCK();
 2096         DYN_FREE_STATES(s4, s4n, ipv4);
 2097 #ifdef INET6
 2098         DYN_FREE_STATES(s6, s6n, ipv6);
 2099 #endif
 2100         DYN_EXPIRED_UNLOCK();
 2101 #undef DYN_FREE_STATES
 2102 }
 2103 
 2104 /*
 2105  * Returns:
 2106  * 0 when state is not matched by specified range;
 2107  * 1 when state is matched by specified range;
 2108  * 2 when state is matched by specified range and requested deletion of
 2109  *   dynamic states.
 2110  */
 2111 static int
 2112 dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt)
 2113 {
 2114 
 2115         MPASS(rt != NULL);
 2116         /* flush all states */
 2117         if (rt->flags & IPFW_RCFLAG_ALL) {
 2118                 if (rt->flags & IPFW_RCFLAG_DYNAMIC)
 2119                         return (2); /* forced */
 2120                 return (1);
 2121         }
 2122         if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set)
 2123                 return (0);
 2124         if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 &&
 2125             (rulenum < rt->start_rule || rulenum > rt->end_rule))
 2126                 return (0);
 2127         if (rt->flags & IPFW_RCFLAG_DYNAMIC)
 2128                 return (2);
 2129         return (1);
 2130 }
 2131 
 2132 static void
 2133 dyn_acquire_rule(struct ip_fw_chain *ch, struct dyn_data *data,
 2134     struct ip_fw *rule, uint16_t kidx)
 2135 {
 2136         struct dyn_state_obj *obj;
 2137 
 2138         /*
 2139          * Do not acquire reference twice.
 2140          * This can happen when rule deletion executed for
 2141          * the same range, but different ruleset id.
 2142          */
 2143         if (data->flags & DYN_REFERENCED)
 2144                 return;
 2145 
 2146         IPFW_UH_WLOCK_ASSERT(ch);
 2147         MPASS(kidx != 0);
 2148 
 2149         data->flags |= DYN_REFERENCED;
 2150         /* Reference the named object */
 2151         obj = SRV_OBJECT(ch, kidx);
 2152         obj->no.refcnt++;
 2153         MPASS(obj->no.etlv == IPFW_TLV_STATE_NAME);
 2154 
 2155         /* Reference the parent rule */
 2156         rule->refcnt++;
 2157 }
 2158 
 2159 static void
 2160 dyn_release_rule(struct ip_fw_chain *ch, struct dyn_data *data,
 2161     struct ip_fw *rule, uint16_t kidx)
 2162 {
 2163         struct dyn_state_obj *obj;
 2164 
 2165         IPFW_UH_WLOCK_ASSERT(ch);
 2166         MPASS(kidx != 0);
 2167 
 2168         obj = SRV_OBJECT(ch, kidx);
 2169         if (obj->no.refcnt == 1)
 2170                 dyn_destroy(ch, &obj->no);
 2171         else
 2172                 obj->no.refcnt--;
 2173 
 2174         if (--rule->refcnt == 1)
 2175                 ipfw_free_rule(rule);
 2176 }
 2177 
 2178 /*
 2179  * We do not keep O_LIMIT_PARENT states when V_dyn_keep_states is enabled.
 2180  * O_LIMIT state is created when new connection is going to be established
 2181  * and there is no matching state. So, since the old parent rule was deleted
 2182  * we can't create new states with old parent, and thus we can not account
 2183  * new connections with already established connections, and can not do
 2184  * proper limiting.
 2185  */
 2186 static int
 2187 dyn_match_ipv4_state(struct ip_fw_chain *ch, struct dyn_ipv4_state *s,
 2188     const ipfw_range_tlv *rt)
 2189 {
 2190         struct ip_fw *rule;
 2191         int ret;
 2192 
 2193         if (s->type == O_LIMIT_PARENT) {
 2194                 rule = s->limit->parent;
 2195                 return (dyn_match_range(s->limit->rulenum, rule->set, rt));
 2196         }
 2197 
 2198         rule = s->data->parent;
 2199         if (s->type == O_LIMIT)
 2200                 rule = ((struct dyn_ipv4_state *)rule)->limit->parent;
 2201 
 2202         ret = dyn_match_range(s->data->rulenum, rule->set, rt);
 2203         if (ret == 0 || V_dyn_keep_states == 0 || ret > 1)
 2204                 return (ret);
 2205 
 2206         dyn_acquire_rule(ch, s->data, rule, s->kidx);
 2207         return (0);
 2208 }
 2209 
 2210 #ifdef INET6
 2211 static int
 2212 dyn_match_ipv6_state(struct ip_fw_chain *ch, struct dyn_ipv6_state *s,
 2213     const ipfw_range_tlv *rt)
 2214 {
 2215         struct ip_fw *rule;
 2216         int ret;
 2217 
 2218         if (s->type == O_LIMIT_PARENT) {
 2219                 rule = s->limit->parent;
 2220                 return (dyn_match_range(s->limit->rulenum, rule->set, rt));
 2221         }
 2222 
 2223         rule = s->data->parent;
 2224         if (s->type == O_LIMIT)
 2225                 rule = ((struct dyn_ipv6_state *)rule)->limit->parent;
 2226 
 2227         ret = dyn_match_range(s->data->rulenum, rule->set, rt);
 2228         if (ret == 0 || V_dyn_keep_states == 0 || ret > 1)
 2229                 return (ret);
 2230 
 2231         dyn_acquire_rule(ch, s->data, rule, s->kidx);
 2232         return (0);
 2233 }
 2234 #endif
 2235 
 2236 /*
 2237  * Unlink expired entries from states lists.
 2238  * @rt can be used to specify the range of states for deletion.
 2239  */
 2240 static void
 2241 dyn_expire_states(struct ip_fw_chain *ch, ipfw_range_tlv *rt)
 2242 {
 2243         struct dyn_ipv4_slist expired_ipv4;
 2244 #ifdef INET6
 2245         struct dyn_ipv6_slist expired_ipv6;
 2246         struct dyn_ipv6_state *s6, *s6n, *s6p;
 2247 #endif
 2248         struct dyn_ipv4_state *s4, *s4n, *s4p;
 2249         void *rule;
 2250         int bucket, removed, length, max_length;
 2251 
 2252         IPFW_UH_WLOCK_ASSERT(ch);
 2253 
 2254         /*
 2255          * Unlink expired states from each bucket.
 2256          * With acquired bucket lock iterate entries of each lists:
 2257          * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time
 2258          * and unlink entry from the list, link entry into temporary
 2259          * expired_xxx lists then bump "del" bucket version.
 2260          *
 2261          * When an entry is removed, corresponding states counter is
 2262          * decremented. If entry has O_LIMIT type, parent's reference
 2263          * counter is decremented.
 2264          *
 2265          * NOTE: this function can be called from userspace context
 2266          * when user deletes rules. In this case all matched states
 2267          * will be forcedly unlinked. O_LIMIT_PARENT states will be kept
 2268          * in the expired lists until reference counter become zero.
 2269          */
 2270 #define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra)  do {    \
 2271         length = 0;                                                     \
 2272         removed = 0;                                                    \
 2273         prev = NULL;                                                    \
 2274         s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]);                   \
 2275         while (s != NULL) {                                             \
 2276                 next = CK_SLIST_NEXT(s, entry);                         \
 2277                 if ((TIME_LEQ((s)->exp, time_uptime) && extra) ||       \
 2278                     (rt != NULL &&                                      \
 2279                      dyn_match_ ## af ## _state(ch, s, rt))) {          \
 2280                         if (prev != NULL)                               \
 2281                                 CK_SLIST_REMOVE_AFTER(prev, entry);     \
 2282                         else                                            \
 2283                                 CK_SLIST_REMOVE_HEAD(                   \
 2284                                     &V_dyn_ ## name [bucket], entry);   \
 2285                         removed++;                                      \
 2286                         SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \
 2287                         if (s->type == O_LIMIT_PARENT)                  \
 2288                                 DYN_COUNT_DEC(dyn_parent_count);        \
 2289                         else {                                          \
 2290                                 DYN_COUNT_DEC(dyn_count);               \
 2291                                 if (s->data->flags & DYN_REFERENCED) {  \
 2292                                         rule = s->data->parent;         \
 2293                                         if (s->type == O_LIMIT)         \
 2294                                                 rule = ((__typeof(s))   \
 2295                                                     rule)->limit->parent;\
 2296                                         dyn_release_rule(ch, s->data,   \
 2297                                             rule, s->kidx);             \
 2298                                 }                                       \
 2299                                 if (s->type == O_LIMIT) {               \
 2300                                         s = s->data->parent;            \
 2301                                         DPARENT_COUNT_DEC(s->limit);    \
 2302                                 }                                       \
 2303                         }                                               \
 2304                 } else {                                                \
 2305                         prev = s;                                       \
 2306                         length++;                                       \
 2307                 }                                                       \
 2308                 s = next;                                               \
 2309         }                                                               \
 2310         if (removed != 0)                                               \
 2311                 DYN_BUCKET_VERSION_BUMP(bucket, name ## _del);          \
 2312         if (length > max_length)                                \
 2313                 max_length = length;                            \
 2314 } while (0)
 2315 
 2316         SLIST_INIT(&expired_ipv4);
 2317 #ifdef INET6
 2318         SLIST_INIT(&expired_ipv6);
 2319 #endif
 2320         max_length = 0;
 2321         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 2322                 DYN_BUCKET_LOCK(bucket);
 2323                 DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1);
 2324                 DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4,
 2325                     ipv4_parent, (s4->limit->count == 0));
 2326 #ifdef INET6
 2327                 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1);
 2328                 DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6,
 2329                     ipv6_parent, (s6->limit->count == 0));
 2330 #endif
 2331                 DYN_BUCKET_UNLOCK(bucket);
 2332         }
 2333         /* Update curr_max_length for statistics. */
 2334         V_curr_max_length = max_length;
 2335         /*
 2336          * Concatenate temporary lists with global expired lists.
 2337          */
 2338         DYN_EXPIRED_LOCK();
 2339         SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4,
 2340             dyn_ipv4_state, expired);
 2341 #ifdef INET6
 2342         SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6,
 2343             dyn_ipv6_state, expired);
 2344 #endif
 2345         DYN_EXPIRED_UNLOCK();
 2346 #undef DYN_UNLINK_STATES
 2347 #undef DYN_UNREF_STATES
 2348 }
 2349 
 2350 static struct mbuf *
 2351 dyn_mgethdr(int len, uint16_t fibnum)
 2352 {
 2353         struct mbuf *m;
 2354 
 2355         m = m_gethdr(M_NOWAIT, MT_DATA);
 2356         if (m == NULL)
 2357                 return (NULL);
 2358 #ifdef MAC
 2359         mac_netinet_firewall_send(m);
 2360 #endif
 2361         M_SETFIB(m, fibnum);
 2362         m->m_data += max_linkhdr;
 2363         m->m_flags |= M_SKIP_FIREWALL;
 2364         m->m_len = m->m_pkthdr.len = len;
 2365         bzero(m->m_data, len);
 2366         return (m);
 2367 }
 2368 
 2369 static void
 2370 dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst,
 2371     uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport)
 2372 {
 2373         struct tcphdr *tcp;
 2374         struct ip *ip;
 2375 
 2376         ip = mtod(m, struct ip *);
 2377         ip->ip_v = 4;
 2378         ip->ip_hl = sizeof(*ip) >> 2;
 2379         ip->ip_tos = IPTOS_LOWDELAY;
 2380         ip->ip_len = htons(m->m_len);
 2381         ip->ip_off |= htons(IP_DF);
 2382         ip->ip_ttl = V_ip_defttl;
 2383         ip->ip_p = IPPROTO_TCP;
 2384         ip->ip_src.s_addr = htonl(src);
 2385         ip->ip_dst.s_addr = htonl(dst);
 2386 
 2387         tcp = mtodo(m, sizeof(struct ip));
 2388         tcp->th_sport = htons(sport);
 2389         tcp->th_dport = htons(dport);
 2390         tcp->th_off = sizeof(struct tcphdr) >> 2;
 2391         tcp->th_seq = htonl(seq);
 2392         tcp->th_ack = htonl(ack);
 2393         tcp->th_flags = TH_ACK;
 2394         tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
 2395             htons(sizeof(struct tcphdr) + IPPROTO_TCP));
 2396 
 2397         m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 2398         m->m_pkthdr.csum_flags = CSUM_TCP;
 2399 }
 2400 
 2401 static void
 2402 dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s)
 2403 {
 2404         struct mbuf *m;
 2405 
 2406         if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
 2407                 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
 2408                     s->data->fibnum);
 2409                 if (m != NULL) {
 2410                         dyn_make_keepalive_ipv4(m, s->dst, s->src,
 2411                             s->data->ack_fwd - 1, s->data->ack_rev,
 2412                             s->dport, s->sport);
 2413                         if (mbufq_enqueue(q, m)) {
 2414                                 m_freem(m);
 2415                                 log(LOG_DEBUG, "ipfw: limit for IPv4 "
 2416                                     "keepalive queue is reached.\n");
 2417                                 return;
 2418                         }
 2419                 }
 2420         }
 2421 
 2422         if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
 2423                 m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
 2424                     s->data->fibnum);
 2425                 if (m != NULL) {
 2426                         dyn_make_keepalive_ipv4(m, s->src, s->dst,
 2427                             s->data->ack_rev - 1, s->data->ack_fwd,
 2428                             s->sport, s->dport);
 2429                         if (mbufq_enqueue(q, m)) {
 2430                                 m_freem(m);
 2431                                 log(LOG_DEBUG, "ipfw: limit for IPv4 "
 2432                                     "keepalive queue is reached.\n");
 2433                                 return;
 2434                         }
 2435                 }
 2436         }
 2437 }
 2438 
 2439 /*
 2440  * Prepare and send keep-alive packets.
 2441  */
 2442 static void
 2443 dyn_send_keepalive_ipv4(struct ip_fw_chain *chain)
 2444 {
 2445         struct mbufq q;
 2446         struct mbuf *m;
 2447         struct dyn_ipv4_state *s;
 2448         uint32_t bucket;
 2449 
 2450         mbufq_init(&q, INT_MAX);
 2451         IPFW_UH_RLOCK(chain);
 2452         /*
 2453          * It is safe to not use hazard pointer and just do lockless
 2454          * access to the lists, because states entries can not be deleted
 2455          * while we hold IPFW_UH_RLOCK.
 2456          */
 2457         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 2458                 CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
 2459                         /*
 2460                          * Only established TCP connections that will
 2461                          * become expired withing dyn_keepalive_interval.
 2462                          */
 2463                         if (s->proto != IPPROTO_TCP ||
 2464                             (s->data->state & BOTH_SYN) != BOTH_SYN ||
 2465                             TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
 2466                                 s->data->expire))
 2467                                 continue;
 2468                         dyn_enqueue_keepalive_ipv4(&q, s);
 2469                 }
 2470         }
 2471         IPFW_UH_RUNLOCK(chain);
 2472         while ((m = mbufq_dequeue(&q)) != NULL)
 2473                 ip_output(m, NULL, NULL, 0, NULL, NULL);
 2474 }
 2475 
 2476 #ifdef INET6
 2477 static void
 2478 dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src,
 2479     const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack,
 2480     uint16_t sport, uint16_t dport)
 2481 {
 2482         struct tcphdr *tcp;
 2483         struct ip6_hdr *ip6;
 2484 
 2485         ip6 = mtod(m, struct ip6_hdr *);
 2486         ip6->ip6_vfc |= IPV6_VERSION;
 2487         ip6->ip6_plen = htons(sizeof(struct tcphdr));
 2488         ip6->ip6_nxt = IPPROTO_TCP;
 2489         ip6->ip6_hlim = IPV6_DEFHLIM;
 2490         ip6->ip6_src = *src;
 2491         if (IN6_IS_ADDR_LINKLOCAL(src))
 2492                 ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff);
 2493         ip6->ip6_dst = *dst;
 2494         if (IN6_IS_ADDR_LINKLOCAL(dst))
 2495                 ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff);
 2496 
 2497         tcp = mtodo(m, sizeof(struct ip6_hdr));
 2498         tcp->th_sport = htons(sport);
 2499         tcp->th_dport = htons(dport);
 2500         tcp->th_off = sizeof(struct tcphdr) >> 2;
 2501         tcp->th_seq = htonl(seq);
 2502         tcp->th_ack = htonl(ack);
 2503         tcp->th_flags = TH_ACK;
 2504         tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr),
 2505             IPPROTO_TCP, 0);
 2506 
 2507         m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
 2508         m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
 2509 }
 2510 
 2511 static void
 2512 dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s)
 2513 {
 2514         struct mbuf *m;
 2515 
 2516         if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
 2517                 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
 2518                     sizeof(struct tcphdr), s->data->fibnum);
 2519                 if (m != NULL) {
 2520                         dyn_make_keepalive_ipv6(m, &s->dst, &s->src,
 2521                             s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev,
 2522                             s->dport, s->sport);
 2523                         if (mbufq_enqueue(q, m)) {
 2524                                 m_freem(m);
 2525                                 log(LOG_DEBUG, "ipfw: limit for IPv6 "
 2526                                     "keepalive queue is reached.\n");
 2527                                 return;
 2528                         }
 2529                 }
 2530         }
 2531 
 2532         if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
 2533                 m = dyn_mgethdr(sizeof(struct ip6_hdr) +
 2534                     sizeof(struct tcphdr), s->data->fibnum);
 2535                 if (m != NULL) {
 2536                         dyn_make_keepalive_ipv6(m, &s->src, &s->dst,
 2537                             s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd,
 2538                             s->sport, s->dport);
 2539                         if (mbufq_enqueue(q, m)) {
 2540                                 m_freem(m);
 2541                                 log(LOG_DEBUG, "ipfw: limit for IPv6 "
 2542                                     "keepalive queue is reached.\n");
 2543                                 return;
 2544                         }
 2545                 }
 2546         }
 2547 }
 2548 
 2549 static void
 2550 dyn_send_keepalive_ipv6(struct ip_fw_chain *chain)
 2551 {
 2552         struct mbufq q;
 2553         struct mbuf *m;
 2554         struct dyn_ipv6_state *s;
 2555         uint32_t bucket;
 2556 
 2557         mbufq_init(&q, INT_MAX);
 2558         IPFW_UH_RLOCK(chain);
 2559         /*
 2560          * It is safe to not use hazard pointer and just do lockless
 2561          * access to the lists, because states entries can not be deleted
 2562          * while we hold IPFW_UH_RLOCK.
 2563          */
 2564         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 2565                 CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
 2566                         /*
 2567                          * Only established TCP connections that will
 2568                          * become expired withing dyn_keepalive_interval.
 2569                          */
 2570                         if (s->proto != IPPROTO_TCP ||
 2571                             (s->data->state & BOTH_SYN) != BOTH_SYN ||
 2572                             TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
 2573                                 s->data->expire))
 2574                                 continue;
 2575                         dyn_enqueue_keepalive_ipv6(&q, s);
 2576                 }
 2577         }
 2578         IPFW_UH_RUNLOCK(chain);
 2579         while ((m = mbufq_dequeue(&q)) != NULL)
 2580                 ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 2581 }
 2582 #endif /* INET6 */
 2583 
 2584 static void
 2585 dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new, int flags)
 2586 {
 2587 #ifdef INET6
 2588         struct dyn_ipv6ck_slist *ipv6, *ipv6_parent;
 2589         uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del;
 2590         struct dyn_ipv6_state *s6;
 2591 #endif
 2592         struct dyn_ipv4ck_slist *ipv4, *ipv4_parent;
 2593         uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del;
 2594         struct dyn_ipv4_state *s4;
 2595         struct mtx *bucket_lock;
 2596         void *tmp;
 2597         uint32_t bucket;
 2598 
 2599         MPASS(powerof2(new));
 2600         DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new);
 2601         /*
 2602          * Allocate and initialize new lists.
 2603          */
 2604         bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW,
 2605             flags | M_ZERO);
 2606         if (bucket_lock == NULL)
 2607                 return;
 2608 
 2609         ipv4 = ipv4_parent = NULL;
 2610         ipv4_add = ipv4_del = ipv4_parent_add = ipv4_parent_del = NULL;
 2611 #ifdef INET6
 2612         ipv6 = ipv6_parent = NULL;
 2613         ipv6_add = ipv6_del = ipv6_parent_add = ipv6_parent_del = NULL;
 2614 #endif
 2615 
 2616         ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
 2617             flags | M_ZERO);
 2618         if (ipv4 == NULL)
 2619                 goto bad;
 2620         ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
 2621             flags | M_ZERO);
 2622         if (ipv4_parent == NULL)
 2623                 goto bad;
 2624         ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
 2625         if (ipv4_add == NULL)
 2626                 goto bad;
 2627         ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
 2628         if (ipv4_del == NULL)
 2629                 goto bad;
 2630         ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
 2631             flags | M_ZERO);
 2632         if (ipv4_parent_add == NULL)
 2633                 goto bad;
 2634         ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
 2635             flags | M_ZERO);
 2636         if (ipv4_parent_del == NULL)
 2637                 goto bad;
 2638 #ifdef INET6
 2639         ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
 2640             flags | M_ZERO);
 2641         if (ipv6 == NULL)
 2642                 goto bad;
 2643         ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
 2644             flags | M_ZERO);
 2645         if (ipv6_parent == NULL)
 2646                 goto bad;
 2647         ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
 2648         if (ipv6_add == NULL)
 2649                 goto bad;
 2650         ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO);
 2651         if (ipv6_del == NULL)
 2652                 goto bad;
 2653         ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
 2654             flags | M_ZERO);
 2655         if (ipv6_parent_add == NULL)
 2656                 goto bad;
 2657         ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
 2658             flags | M_ZERO);
 2659         if (ipv6_parent_del == NULL)
 2660                 goto bad;
 2661 #endif
 2662         for (bucket = 0; bucket < new; bucket++) {
 2663                 DYN_BUCKET_LOCK_INIT(bucket_lock, bucket);
 2664                 CK_SLIST_INIT(&ipv4[bucket]);
 2665                 CK_SLIST_INIT(&ipv4_parent[bucket]);
 2666 #ifdef INET6
 2667                 CK_SLIST_INIT(&ipv6[bucket]);
 2668                 CK_SLIST_INIT(&ipv6_parent[bucket]);
 2669 #endif
 2670         }
 2671 
 2672 #define DYN_RELINK_STATES(s, hval, i, head, ohead)      do {            \
 2673         while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) {     \
 2674                 CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry);       \
 2675                 CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)],   \
 2676                     s, entry);                                          \
 2677         }                                                               \
 2678 } while (0)
 2679         /*
 2680          * Prevent rules changing from userland.
 2681          */
 2682         IPFW_UH_WLOCK(chain);
 2683         /*
 2684          * Hold traffic processing until we finish resize to
 2685          * prevent access to states lists.
 2686          */
 2687         IPFW_WLOCK(chain);
 2688         /* Re-link all dynamic states */
 2689         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 2690                 DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4);
 2691                 DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent,
 2692                     ipv4_parent);
 2693 #ifdef INET6
 2694                 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6);
 2695                 DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent,
 2696                     ipv6_parent);
 2697 #endif
 2698         }
 2699 
 2700 #define DYN_SWAP_PTR(old, new, tmp)     do {            \
 2701         tmp = old;                                      \
 2702         old = new;                                      \
 2703         new = tmp;                                      \
 2704 } while (0)
 2705         /* Swap pointers */
 2706         DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp);
 2707         DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp);
 2708         DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp);
 2709         DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp);
 2710         DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp);
 2711         DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp);
 2712         DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp);
 2713 
 2714 #ifdef INET6
 2715         DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp);
 2716         DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp);
 2717         DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp);
 2718         DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp);
 2719         DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp);
 2720         DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp);
 2721 #endif
 2722         bucket = V_curr_dyn_buckets;
 2723         V_curr_dyn_buckets = new;
 2724 
 2725         IPFW_WUNLOCK(chain);
 2726         IPFW_UH_WUNLOCK(chain);
 2727 
 2728         /* Release old resources */
 2729         while (bucket-- != 0)
 2730                 DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket);
 2731 bad:
 2732         free(bucket_lock, M_IPFW);
 2733         free(ipv4, M_IPFW);
 2734         free(ipv4_parent, M_IPFW);
 2735         free(ipv4_add, M_IPFW);
 2736         free(ipv4_parent_add, M_IPFW);
 2737         free(ipv4_del, M_IPFW);
 2738         free(ipv4_parent_del, M_IPFW);
 2739 #ifdef INET6
 2740         free(ipv6, M_IPFW);
 2741         free(ipv6_parent, M_IPFW);
 2742         free(ipv6_add, M_IPFW);
 2743         free(ipv6_parent_add, M_IPFW);
 2744         free(ipv6_del, M_IPFW);
 2745         free(ipv6_parent_del, M_IPFW);
 2746 #endif
 2747 }
 2748 
 2749 /*
 2750  * This function is used to perform various maintenance
 2751  * on dynamic hash lists. Currently it is called every second.
 2752  */
 2753 static void
 2754 dyn_tick(void *vnetx)
 2755 {
 2756         struct epoch_tracker et;
 2757         uint32_t buckets;
 2758 
 2759         CURVNET_SET((struct vnet *)vnetx);
 2760         /*
 2761          * First free states unlinked in previous passes.
 2762          */
 2763         dyn_free_states(&V_layer3_chain);
 2764         /*
 2765          * Now unlink others expired states.
 2766          * We use IPFW_UH_WLOCK to avoid concurrent call of
 2767          * dyn_expire_states(). It is the only function that does
 2768          * deletion of state entries from states lists.
 2769          */
 2770         IPFW_UH_WLOCK(&V_layer3_chain);
 2771         dyn_expire_states(&V_layer3_chain, NULL);
 2772         IPFW_UH_WUNLOCK(&V_layer3_chain);
 2773         /*
 2774          * Send keepalives if they are enabled and the time has come.
 2775          */
 2776         if (V_dyn_keepalive != 0 &&
 2777             V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) {
 2778                 V_dyn_keepalive_last = time_uptime;
 2779                 NET_EPOCH_ENTER(et);
 2780                 dyn_send_keepalive_ipv4(&V_layer3_chain);
 2781 #ifdef INET6
 2782                 dyn_send_keepalive_ipv6(&V_layer3_chain);
 2783 #endif
 2784                 NET_EPOCH_EXIT(et);
 2785         }
 2786         /*
 2787          * Check if we need to resize the hash:
 2788          * if current number of states exceeds number of buckets in hash,
 2789          * and dyn_buckets_max permits to grow the number of buckets, then
 2790          * do it. Grow hash size to the minimum power of 2 which is bigger
 2791          * than current states count.
 2792          */
 2793         if (V_curr_dyn_buckets < V_dyn_buckets_max &&
 2794             (V_curr_dyn_buckets < V_dyn_count / 2 || (
 2795             V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) {
 2796                 buckets = 1 << fls(V_dyn_count);
 2797                 if (buckets > V_dyn_buckets_max)
 2798                         buckets = V_dyn_buckets_max;
 2799                 dyn_grow_hashtable(&V_layer3_chain, buckets, M_NOWAIT);
 2800         }
 2801 
 2802         callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0);
 2803         CURVNET_RESTORE();
 2804 }
 2805 
 2806 void
 2807 ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
 2808 {
 2809         /*
 2810          * Do not perform any checks if we currently have no dynamic states
 2811          */
 2812         if (V_dyn_count == 0)
 2813                 return;
 2814 
 2815         IPFW_UH_WLOCK_ASSERT(chain);
 2816         dyn_expire_states(chain, rt);
 2817 }
 2818 
 2819 /*
 2820  * Pass through all states and reset eaction for orphaned rules.
 2821  */
 2822 void
 2823 ipfw_dyn_reset_eaction(struct ip_fw_chain *ch, uint16_t eaction_id,
 2824     uint16_t default_id, uint16_t instance_id)
 2825 {
 2826 #ifdef INET6
 2827         struct dyn_ipv6_state *s6;
 2828 #endif
 2829         struct dyn_ipv4_state *s4;
 2830         struct ip_fw *rule;
 2831         uint32_t bucket;
 2832 
 2833 #define DYN_RESET_EACTION(s, h, b)                                      \
 2834         CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) {                   \
 2835                 if ((s->data->flags & DYN_REFERENCED) == 0)             \
 2836                         continue;                                       \
 2837                 rule = s->data->parent;                                 \
 2838                 if (s->type == O_LIMIT)                                 \
 2839                         rule = ((__typeof(s))rule)->limit->parent;      \
 2840                 ipfw_reset_eaction(ch, rule, eaction_id,                \
 2841                     default_id, instance_id);                           \
 2842         }
 2843 
 2844         IPFW_UH_WLOCK_ASSERT(ch);
 2845         if (V_dyn_count == 0)
 2846                 return;
 2847         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 2848                 DYN_RESET_EACTION(s4, ipv4, bucket);
 2849 #ifdef INET6
 2850                 DYN_RESET_EACTION(s6, ipv6, bucket);
 2851 #endif
 2852         }
 2853 }
 2854 
 2855 /*
 2856  * Returns size of dynamic states in legacy format
 2857  */
 2858 int
 2859 ipfw_dyn_len(void)
 2860 {
 2861 
 2862         return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule));
 2863 }
 2864 
 2865 /*
 2866  * Returns number of dynamic states.
 2867  * Marks every named object index used by dynamic states with bit in @bmask.
 2868  * Returns number of named objects accounted in bmask via @nocnt.
 2869  * Used by dump format v1 (current).
 2870  */
 2871 uint32_t
 2872 ipfw_dyn_get_count(uint32_t *bmask, int *nocnt)
 2873 {
 2874 #ifdef INET6
 2875         struct dyn_ipv6_state *s6;
 2876 #endif
 2877         struct dyn_ipv4_state *s4;
 2878         uint32_t bucket;
 2879 
 2880 #define DYN_COUNT_OBJECTS(s, h, b)                                      \
 2881         CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) {                   \
 2882                 MPASS(s->kidx != 0);                                    \
 2883                 if (ipfw_mark_object_kidx(bmask, IPFW_TLV_STATE_NAME,   \
 2884                     s->kidx) != 0)                                      \
 2885                         (*nocnt)++;                                     \
 2886         }
 2887 
 2888         IPFW_UH_RLOCK_ASSERT(&V_layer3_chain);
 2889 
 2890         /* No need to pass through all the buckets. */
 2891         *nocnt = 0;
 2892         if (V_dyn_count + V_dyn_parent_count == 0)
 2893                 return (0);
 2894 
 2895         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 2896                 DYN_COUNT_OBJECTS(s4, ipv4, bucket);
 2897 #ifdef INET6
 2898                 DYN_COUNT_OBJECTS(s6, ipv6, bucket);
 2899 #endif
 2900         }
 2901 
 2902         return (V_dyn_count + V_dyn_parent_count);
 2903 }
 2904 
 2905 /*
 2906  * Check if rule contains at least one dynamic opcode.
 2907  *
 2908  * Returns 1 if such opcode is found, 0 otherwise.
 2909  */
 2910 int
 2911 ipfw_is_dyn_rule(struct ip_fw *rule)
 2912 {
 2913         int cmdlen, l;
 2914         ipfw_insn *cmd;
 2915 
 2916         l = rule->cmd_len;
 2917         cmd = rule->cmd;
 2918         cmdlen = 0;
 2919         for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) {
 2920                 cmdlen = F_LEN(cmd);
 2921 
 2922                 switch (cmd->opcode) {
 2923                 case O_LIMIT:
 2924                 case O_KEEP_STATE:
 2925                 case O_PROBE_STATE:
 2926                 case O_CHECK_STATE:
 2927                         return (1);
 2928                 }
 2929         }
 2930 
 2931         return (0);
 2932 }
 2933 
 2934 static void
 2935 dyn_export_parent(const struct dyn_parent *p, uint16_t kidx, uint8_t set,
 2936     ipfw_dyn_rule *dst)
 2937 {
 2938 
 2939         dst->dyn_type = O_LIMIT_PARENT;
 2940         dst->kidx = kidx;
 2941         dst->count = (uint16_t)DPARENT_COUNT(p);
 2942         dst->expire = TIME_LEQ(p->expire, time_uptime) ?  0:
 2943             p->expire - time_uptime;
 2944 
 2945         /* 'rule' is used to pass up the rule number and set */
 2946         memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum));
 2947 
 2948         /* store set number into high word of dst->rule pointer. */
 2949         memcpy((char *)&dst->rule + sizeof(p->rulenum), &set, sizeof(set));
 2950 
 2951         /* unused fields */
 2952         dst->pcnt = 0;
 2953         dst->bcnt = 0;
 2954         dst->parent = NULL;
 2955         dst->state = 0;
 2956         dst->ack_fwd = 0;
 2957         dst->ack_rev = 0;
 2958         dst->bucket = p->hashval;
 2959         /*
 2960          * The legacy userland code will interpret a NULL here as a marker
 2961          * for the last dynamic rule.
 2962          */
 2963         dst->next = (ipfw_dyn_rule *)1;
 2964 }
 2965 
 2966 static void
 2967 dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type,
 2968     uint8_t set, ipfw_dyn_rule *dst)
 2969 {
 2970 
 2971         dst->dyn_type = type;
 2972         dst->kidx = kidx;
 2973         dst->pcnt = data->pcnt_fwd + data->pcnt_rev;
 2974         dst->bcnt = data->bcnt_fwd + data->bcnt_rev;
 2975         dst->expire = TIME_LEQ(data->expire, time_uptime) ?  0:
 2976             data->expire - time_uptime;
 2977 
 2978         /* 'rule' is used to pass up the rule number and set */
 2979         memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum));
 2980 
 2981         /* store set number into high word of dst->rule pointer. */
 2982         memcpy((char *)&dst->rule + sizeof(data->rulenum), &set, sizeof(set));
 2983 
 2984         dst->state = data->state;
 2985         if (data->flags & DYN_REFERENCED)
 2986                 dst->state |= IPFW_DYN_ORPHANED;
 2987 
 2988         /* unused fields */
 2989         dst->parent = NULL;
 2990         dst->ack_fwd = data->ack_fwd;
 2991         dst->ack_rev = data->ack_rev;
 2992         dst->count = 0;
 2993         dst->bucket = data->hashval;
 2994         /*
 2995          * The legacy userland code will interpret a NULL here as a marker
 2996          * for the last dynamic rule.
 2997          */
 2998         dst->next = (ipfw_dyn_rule *)1;
 2999 }
 3000 
 3001 static void
 3002 dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst)
 3003 {
 3004         struct ip_fw *rule;
 3005 
 3006         switch (s->type) {
 3007         case O_LIMIT_PARENT:
 3008                 rule = s->limit->parent;
 3009                 dyn_export_parent(s->limit, s->kidx, rule->set, dst);
 3010                 break;
 3011         default:
 3012                 rule = s->data->parent;
 3013                 if (s->type == O_LIMIT)
 3014                         rule = ((struct dyn_ipv4_state *)rule)->limit->parent;
 3015                 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst);
 3016         }
 3017 
 3018         dst->id.dst_ip = s->dst;
 3019         dst->id.src_ip = s->src;
 3020         dst->id.dst_port = s->dport;
 3021         dst->id.src_port = s->sport;
 3022         dst->id.fib = s->data->fibnum;
 3023         dst->id.proto = s->proto;
 3024         dst->id._flags = 0;
 3025         dst->id.addr_type = 4;
 3026 
 3027         memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6));
 3028         memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6));
 3029         dst->id.flow_id6 = dst->id.extra = 0;
 3030 }
 3031 
 3032 #ifdef INET6
 3033 static void
 3034 dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst)
 3035 {
 3036         struct ip_fw *rule;
 3037 
 3038         switch (s->type) {
 3039         case O_LIMIT_PARENT:
 3040                 rule = s->limit->parent;
 3041                 dyn_export_parent(s->limit, s->kidx, rule->set, dst);
 3042                 break;
 3043         default:
 3044                 rule = s->data->parent;
 3045                 if (s->type == O_LIMIT)
 3046                         rule = ((struct dyn_ipv6_state *)rule)->limit->parent;
 3047                 dyn_export_data(s->data, s->kidx, s->type, rule->set, dst);
 3048         }
 3049 
 3050         dst->id.src_ip6 = s->src;
 3051         dst->id.dst_ip6 = s->dst;
 3052         dst->id.dst_port = s->dport;
 3053         dst->id.src_port = s->sport;
 3054         dst->id.fib = s->data->fibnum;
 3055         dst->id.proto = s->proto;
 3056         dst->id._flags = 0;
 3057         dst->id.addr_type = 6;
 3058 
 3059         dst->id.dst_ip = dst->id.src_ip = 0;
 3060         dst->id.flow_id6 = dst->id.extra = 0;
 3061 }
 3062 #endif /* INET6 */
 3063 
 3064 /*
 3065  * Fills the buffer given by @sd with dynamic states.
 3066  * Used by dump format v1 (current).
 3067  *
 3068  * Returns 0 on success.
 3069  */
 3070 int
 3071 ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd)
 3072 {
 3073 #ifdef INET6
 3074         struct dyn_ipv6_state *s6;
 3075 #endif
 3076         struct dyn_ipv4_state *s4;
 3077         ipfw_obj_dyntlv *dst, *last;
 3078         ipfw_obj_ctlv *ctlv;
 3079         uint32_t bucket;
 3080 
 3081         if (V_dyn_count == 0)
 3082                 return (0);
 3083 
 3084         /*
 3085          * IPFW_UH_RLOCK garantees that another userland request
 3086          * and callout thread will not delete entries from states
 3087          * lists.
 3088          */
 3089         IPFW_UH_RLOCK_ASSERT(chain);
 3090 
 3091         ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
 3092         if (ctlv == NULL)
 3093                 return (ENOMEM);
 3094         ctlv->head.type = IPFW_TLV_DYNSTATE_LIST;
 3095         ctlv->objsize = sizeof(ipfw_obj_dyntlv);
 3096         last = NULL;
 3097 
 3098 #define DYN_EXPORT_STATES(s, af, h, b)                          \
 3099         CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) {                   \
 3100                 dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd,        \
 3101                     sizeof(ipfw_obj_dyntlv));                           \
 3102                 if (dst == NULL)                                        \
 3103                         return (ENOMEM);                                \
 3104                 dyn_export_ ## af ## _state(s, &dst->state);            \
 3105                 dst->head.length = sizeof(ipfw_obj_dyntlv);             \
 3106                 dst->head.type = IPFW_TLV_DYN_ENT;                      \
 3107                 last = dst;                                             \
 3108         }
 3109 
 3110         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 3111                 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
 3112                 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
 3113 #ifdef INET6
 3114                 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
 3115                 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
 3116 #endif /* INET6 */
 3117         }
 3118 
 3119         /* mark last dynamic rule */
 3120         if (last != NULL)
 3121                 last->head.flags = IPFW_DF_LAST; /* XXX: unused */
 3122         return (0);
 3123 #undef DYN_EXPORT_STATES
 3124 }
 3125 
 3126 /*
 3127  * Fill given buffer with dynamic states (legacy format).
 3128  * IPFW_UH_RLOCK has to be held while calling.
 3129  */
 3130 void
 3131 ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep)
 3132 {
 3133 #ifdef INET6
 3134         struct dyn_ipv6_state *s6;
 3135 #endif
 3136         struct dyn_ipv4_state *s4;
 3137         ipfw_dyn_rule *p, *last = NULL;
 3138         char *bp;
 3139         uint32_t bucket;
 3140 
 3141         if (V_dyn_count == 0)
 3142                 return;
 3143         bp = *pbp;
 3144 
 3145         IPFW_UH_RLOCK_ASSERT(chain);
 3146 
 3147 #define DYN_EXPORT_STATES(s, af, head, b)                               \
 3148         CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) {                \
 3149                 if (bp + sizeof(*p) > ep)                               \
 3150                         break;                                          \
 3151                 p = (ipfw_dyn_rule *)bp;                                \
 3152                 dyn_export_ ## af ## _state(s, p);                      \
 3153                 last = p;                                               \
 3154                 bp += sizeof(*p);                                       \
 3155         }
 3156 
 3157         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 3158                 DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
 3159                 DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
 3160 #ifdef INET6
 3161                 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
 3162                 DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
 3163 #endif /* INET6 */
 3164         }
 3165 
 3166         if (last != NULL) /* mark last dynamic rule */
 3167                 last->next = NULL;
 3168         *pbp = bp;
 3169 #undef DYN_EXPORT_STATES
 3170 }
 3171 
 3172 void
 3173 ipfw_dyn_init(struct ip_fw_chain *chain)
 3174 {
 3175 
 3176 #ifdef IPFIREWALL_JENKINSHASH
 3177         V_dyn_hashseed = arc4random();
 3178 #endif
 3179         V_dyn_max = 16384;              /* max # of states */
 3180         V_dyn_parent_max = 4096;        /* max # of parent states */
 3181         V_dyn_buckets_max = 8192;       /* must be power of 2 */
 3182 
 3183         V_dyn_ack_lifetime = 300;
 3184         V_dyn_syn_lifetime = 20;
 3185         V_dyn_fin_lifetime = 1;
 3186         V_dyn_rst_lifetime = 1;
 3187         V_dyn_udp_lifetime = 10;
 3188         V_dyn_short_lifetime = 5;
 3189 
 3190         V_dyn_keepalive_interval = 20;
 3191         V_dyn_keepalive_period = 5;
 3192         V_dyn_keepalive = 1;            /* send keepalives */
 3193         V_dyn_keepalive_last = time_uptime;
 3194 
 3195         V_dyn_data_zone = uma_zcreate("IPFW dynamic states data",
 3196             sizeof(struct dyn_data), NULL, NULL, NULL, NULL,
 3197             UMA_ALIGN_PTR, 0);
 3198         uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
 3199 
 3200         V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states",
 3201             sizeof(struct dyn_parent), NULL, NULL, NULL, NULL,
 3202             UMA_ALIGN_PTR, 0);
 3203         uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
 3204 
 3205         SLIST_INIT(&V_dyn_expired_ipv4);
 3206         V_dyn_ipv4 = NULL;
 3207         V_dyn_ipv4_parent = NULL;
 3208         V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states",
 3209             sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL,
 3210             UMA_ALIGN_PTR, 0);
 3211 
 3212 #ifdef INET6
 3213         SLIST_INIT(&V_dyn_expired_ipv6);
 3214         V_dyn_ipv6 = NULL;
 3215         V_dyn_ipv6_parent = NULL;
 3216         V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states",
 3217             sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL,
 3218             UMA_ALIGN_PTR, 0);
 3219 #endif
 3220 
 3221         /* Initialize buckets. */
 3222         V_curr_dyn_buckets = 0;
 3223         V_dyn_bucket_lock = NULL;
 3224         dyn_grow_hashtable(chain, 256, M_WAITOK);
 3225 
 3226         if (IS_DEFAULT_VNET(curvnet))
 3227                 dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW,
 3228                     M_WAITOK | M_ZERO);
 3229 
 3230         DYN_EXPIRED_LOCK_INIT();
 3231         callout_init(&V_dyn_timeout, 1);
 3232         callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet);
 3233         IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
 3234 }
 3235 
 3236 void
 3237 ipfw_dyn_uninit(int pass)
 3238 {
 3239 #ifdef INET6
 3240         struct dyn_ipv6_state *s6;
 3241 #endif
 3242         struct dyn_ipv4_state *s4;
 3243         int bucket;
 3244 
 3245         if (pass == 0) {
 3246                 callout_drain(&V_dyn_timeout);
 3247                 return;
 3248         }
 3249         IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
 3250         DYN_EXPIRED_LOCK_DESTROY();
 3251 
 3252 #define DYN_FREE_STATES_FORCED(CK, s, af, name, en)     do {            \
 3253         while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) {      \
 3254                 CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en);   \
 3255                 if (s->type == O_LIMIT_PARENT)                          \
 3256                         uma_zfree(V_dyn_parent_zone, s->limit);         \
 3257                 else                                                    \
 3258                         uma_zfree(V_dyn_data_zone, s->data);            \
 3259                 uma_zfree(V_dyn_ ## af ## _zone, s);                    \
 3260         }                                                               \
 3261 } while (0)
 3262         for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
 3263                 DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket);
 3264 
 3265                 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry);
 3266                 DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket],
 3267                     entry);
 3268 #ifdef INET6
 3269                 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry);
 3270                 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket],
 3271                     entry);
 3272 #endif /* INET6 */
 3273         }
 3274         DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired);
 3275 #ifdef INET6
 3276         DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired);
 3277 #endif
 3278 #undef DYN_FREE_STATES_FORCED
 3279 
 3280         uma_zdestroy(V_dyn_ipv4_zone);
 3281         uma_zdestroy(V_dyn_data_zone);
 3282         uma_zdestroy(V_dyn_parent_zone);
 3283 #ifdef INET6
 3284         uma_zdestroy(V_dyn_ipv6_zone);
 3285         free(V_dyn_ipv6, M_IPFW);
 3286         free(V_dyn_ipv6_parent, M_IPFW);
 3287         free(V_dyn_ipv6_add, M_IPFW);
 3288         free(V_dyn_ipv6_parent_add, M_IPFW);
 3289         free(V_dyn_ipv6_del, M_IPFW);
 3290         free(V_dyn_ipv6_parent_del, M_IPFW);
 3291 #endif
 3292         free(V_dyn_bucket_lock, M_IPFW);
 3293         free(V_dyn_ipv4, M_IPFW);
 3294         free(V_dyn_ipv4_parent, M_IPFW);
 3295         free(V_dyn_ipv4_add, M_IPFW);
 3296         free(V_dyn_ipv4_parent_add, M_IPFW);
 3297         free(V_dyn_ipv4_del, M_IPFW);
 3298         free(V_dyn_ipv4_parent_del, M_IPFW);
 3299         if (IS_DEFAULT_VNET(curvnet))
 3300                 free(dyn_hp_cache, M_IPFW);
 3301 }

Cache object: 11c0fa87079ba5677b0a4c8ad287f057


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