ip_fw_sockopt.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
 * Copyright (c) 2014-2025 Yandex LLC
 * Copyright (c) 2014 Alexander V. Chernikov
 *
 * Supported by: Valeria Paoli
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
/*
 * Control socket and rule management routines for ipfw.
 * Control is currently implemented via IP_FW3 setsockopt() code.
 */

#include "opt_ipfw.h"
#include "opt_inet.h"
#ifndef INET
#error IPFIREWALL requires INET.
#endif /* INET */
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>	/* struct m_tag used by nested headers */
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/rmlock.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/fnv_hash.h>
#include <net/if.h>
#include <net/route.h>
#include <net/vnet.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>

#include <netinet/in.h>
#include <netinet/ip_var.h> /* hooks */
#include <netinet/ip_fw.h>

#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/ip_fw_table.h>

#ifdef MAC
#include <security/mac/mac_framework.h>
#endif

static enum ipfw_opcheck_result
check_opcode_compat_nop(ipfw_insn **pcmd, int *plen,
    struct rule_check_info *ci)
{
	/* Compatibility code is not registered */
	return (FAILED);
}

static ipfw_check_opcode_t check_opcode_f = check_opcode_compat_nop;

static int check_ipfw_rule_body(ipfw_insn *cmd, int cmd_len,
    struct rule_check_info *ci);
static int rewrite_rule_uidx(struct ip_fw_chain *chain,
    struct rule_check_info *ci);

struct namedobj_instance {
	struct namedobjects_head	*names;
	struct namedobjects_head	*values;
	uint32_t nn_size;		/* names hash size */
	uint32_t nv_size;		/* number hash size */
	u_long *idx_mask;		/* used items bitmask */
	uint32_t max_blocks;		/* number of "long" blocks in bitmask */
	uint32_t count;			/* number of items */
	uint16_t free_off[IPFW_MAX_SETS];	/* first possible free offset */
	objhash_hash_f	*hash_f;
	objhash_cmp_f	*cmp_f;
};
#define	BLOCK_ITEMS	(8 * sizeof(u_long))	/* Number of items for ffsl() */

static uint32_t objhash_hash_name(struct namedobj_instance *ni,
    const void *key, uint32_t kopt);
static uint32_t objhash_hash_idx(struct namedobj_instance *ni, uint32_t val);
static int objhash_cmp_name(struct named_object *no, const void *name,
    uint32_t set);

MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");

/* ctl3 handler data */
static struct mtx ctl3_lock;
#define	CTL3_LOCK_INIT()	mtx_init(&ctl3_lock, "ctl3_lock", NULL, MTX_DEF)
#define	CTL3_LOCK_DESTROY()	mtx_destroy(&ctl3_lock)
#define	CTL3_LOCK()		mtx_lock(&ctl3_lock)
#define	CTL3_UNLOCK()		mtx_unlock(&ctl3_lock)

static struct ipfw_sopt_handler *ctl3_handlers;
static size_t ctl3_hsize;
static uint64_t ctl3_refct, ctl3_gencnt;
#define	CTL3_SMALLBUF	4096			/* small page-size write buffer */
#define	CTL3_LARGEBUF	(16 * 1024 * 1024)	/* handle large rulesets */

static int ipfw_flush_sopt_data(struct sockopt_data *sd);

static sopt_handler_f dump_config, add_rules, del_rules, clear_rules,
    move_rules, manage_sets, dump_soptcodes, dump_srvobjects,
    manage_skiptocache;

static struct ipfw_sopt_handler scodes[] = {
    { IP_FW_XGET,		IP_FW3_OPVER, HDIR_GET, dump_config },
    { IP_FW_XADD,		IP_FW3_OPVER, HDIR_BOTH, add_rules },
    { IP_FW_XDEL,		IP_FW3_OPVER, HDIR_BOTH, del_rules },
    { IP_FW_XZERO,		IP_FW3_OPVER, HDIR_SET, clear_rules },
    { IP_FW_XRESETLOG,		IP_FW3_OPVER, HDIR_SET, clear_rules },
    { IP_FW_XMOVE,		IP_FW3_OPVER, HDIR_SET, move_rules },
    { IP_FW_SET_SWAP,		IP_FW3_OPVER, HDIR_SET, manage_sets },
    { IP_FW_SET_MOVE,		IP_FW3_OPVER, HDIR_SET, manage_sets },
    { IP_FW_SET_ENABLE,		IP_FW3_OPVER, HDIR_SET, manage_sets },
    { IP_FW_DUMP_SOPTCODES,	IP_FW3_OPVER, HDIR_GET, dump_soptcodes },
    { IP_FW_DUMP_SRVOBJECTS,	IP_FW3_OPVER, HDIR_GET, dump_srvobjects },
    { IP_FW_SKIPTO_CACHE,	IP_FW3_OPVER, HDIR_BOTH, manage_skiptocache },
};

static struct opcode_obj_rewrite *find_op_rw(ipfw_insn *cmd,
    uint32_t *puidx, uint8_t *ptype);
static int ref_rule_objects(struct ip_fw_chain *ch, struct ip_fw *rule,
    struct rule_check_info *ci, struct obj_idx *oib, struct tid_info *ti);
static int ref_opcode_object(struct ip_fw_chain *ch, ipfw_insn *cmd,
    struct tid_info *ti, struct obj_idx *pidx, int *unresolved);
static void unref_rule_objects(struct ip_fw_chain *chain, struct ip_fw *rule);
static void unref_oib_objects(struct ip_fw_chain *ch, ipfw_insn *cmd,
    struct obj_idx *oib, struct obj_idx *end);
static int export_objhash_ntlv(struct namedobj_instance *ni, uint32_t kidx,
    struct sockopt_data *sd);

/*
 * Opcode object rewriter variables
 */
struct opcode_obj_rewrite *ctl3_rewriters;
static size_t ctl3_rsize;

/*
 * static variables followed by global ones
 */

VNET_DEFINE_STATIC(uma_zone_t, ipfw_cntr_zone);
#define	V_ipfw_cntr_zone		VNET(ipfw_cntr_zone)

void
ipfw_init_counters(void)
{

	V_ipfw_cntr_zone = uma_zcreate("IPFW counters",
	    IPFW_RULE_CNTR_SIZE, NULL, NULL, NULL, NULL,
	    UMA_ALIGN_PTR, UMA_ZONE_PCPU);
}

void
ipfw_destroy_counters(void)
{

	uma_zdestroy(V_ipfw_cntr_zone);
}

struct ip_fw *
ipfw_alloc_rule(struct ip_fw_chain *chain, size_t rulesize)
{
	struct ip_fw *rule;

	rule = malloc(rulesize, M_IPFW, M_WAITOK | M_ZERO);
	rule->cntr = uma_zalloc_pcpu(V_ipfw_cntr_zone, M_WAITOK | M_ZERO);
	rule->refcnt = 1;

	return (rule);
}

void
ipfw_free_rule(struct ip_fw *rule)
{

	/*
	 * We don't release refcnt here, since this function
	 * can be called without any locks held. The caller
	 * must release reference under IPFW_UH_WLOCK, and then
	 * call this function if refcount becomes 1.
	 */
	if (rule->refcnt > 1)
		return;
	uma_zfree_pcpu(V_ipfw_cntr_zone, rule->cntr);
	free(rule, M_IPFW);
}

/*
 * Find the smallest rule >= key, id.
 * We could use bsearch but it is so simple that we code it directly
 */
int
ipfw_find_rule(struct ip_fw_chain *chain, uint32_t key, uint32_t id)
{
	int i, lo, hi;
	struct ip_fw *r;

  	for (lo = 0, hi = chain->n_rules - 1; lo < hi;) {
		i = (lo + hi) / 2;
		r = chain->map[i];
		if (r->rulenum < key)
			lo = i + 1;	/* continue from the next one */
		else if (r->rulenum > key)
			hi = i;		/* this might be good */
		else if (r->id < id)
			lo = i + 1;	/* continue from the next one */
		else /* r->id >= id */
			hi = i;		/* this might be good */
	}
	return hi;
}

/*
 * Builds skipto cache on rule set @map.
 */
static void
update_skipto_cache(struct ip_fw_chain *chain, struct ip_fw **map)
{
	uint32_t *smap, rulenum;
	int i, mi;

	IPFW_UH_WLOCK_ASSERT(chain);

	mi = 0;
	rulenum = map[mi]->rulenum;
	smap = chain->idxmap_back;

	if (smap == NULL)
		return;

	for (i = 0; i <= IPFW_DEFAULT_RULE; i++) {
		smap[i] = mi;
		/* Use the same rule index until i < rulenum */
		if (i != rulenum || i == IPFW_DEFAULT_RULE)
			continue;
		/* Find next rule with num > i */
		rulenum = map[++mi]->rulenum;
		while (rulenum == i)
			rulenum = map[++mi]->rulenum;
	}
}

/*
 * Swaps prepared (backup) index with current one.
 */
static void
swap_skipto_cache(struct ip_fw_chain *chain)
{
	uint32_t *map;

	IPFW_UH_WLOCK_ASSERT(chain);
	IPFW_WLOCK_ASSERT(chain);

	map = chain->idxmap;
	chain->idxmap = chain->idxmap_back;
	chain->idxmap_back = map;
}

/*
 * Allocate and initialize skipto cache.
 */
void
ipfw_init_skipto_cache(struct ip_fw_chain *chain)
{
	uint32_t *idxmap, *idxmap_back;

	idxmap = malloc((IPFW_DEFAULT_RULE + 1) * sizeof(uint32_t),
	    M_IPFW, M_WAITOK | M_ZERO);
	idxmap_back = malloc((IPFW_DEFAULT_RULE + 1) * sizeof(uint32_t),
	    M_IPFW, M_WAITOK | M_ZERO);

	/*
	 * Note we may be called at any time after initialization,
	 * for example, on first skipto rule, so we need to
	 * provide valid chain->idxmap on return
	 */

	IPFW_UH_WLOCK(chain);
	if (chain->idxmap != NULL) {
		IPFW_UH_WUNLOCK(chain);
		free(idxmap, M_IPFW);
		free(idxmap_back, M_IPFW);
		return;
	}

	/* Set backup pointer first to permit building cache */
	chain->idxmap_back = idxmap_back;
	if (V_skipto_cache != 0)
		update_skipto_cache(chain, chain->map);
	IPFW_WLOCK(chain);
	/* It is now safe to set chain->idxmap ptr */
	chain->idxmap = idxmap;
	swap_skipto_cache(chain);
	IPFW_WUNLOCK(chain);
	IPFW_UH_WUNLOCK(chain);
}

/*
 * Destroys skipto cache.
 */
void
ipfw_destroy_skipto_cache(struct ip_fw_chain *chain)
{
	free(chain->idxmap, M_IPFW);
	free(chain->idxmap_back, M_IPFW);
}

/*
 * allocate a new map, returns the chain locked. extra is the number
 * of entries to add or delete.
 */
static struct ip_fw **
get_map(struct ip_fw_chain *chain, int extra, int locked)
{

	for (;;) {
		struct ip_fw **map;
		u_int i, mflags;

		mflags = M_ZERO | ((locked != 0) ? M_NOWAIT : M_WAITOK);

		i = chain->n_rules + extra;
		map = malloc(i * sizeof(struct ip_fw *), M_IPFW, mflags);
		if (map == NULL) {
			printf("%s: cannot allocate map\n", __FUNCTION__);
			return NULL;
		}
		if (!locked)
			IPFW_UH_WLOCK(chain);
		if (i >= chain->n_rules + extra) /* good */
			return map;
		/* otherwise we lost the race, free and retry */
		if (!locked)
			IPFW_UH_WUNLOCK(chain);
		free(map, M_IPFW);
	}
}

/*
 * swap the maps. It is supposed to be called with IPFW_UH_WLOCK
 */
static struct ip_fw **
swap_map(struct ip_fw_chain *chain, struct ip_fw **new_map, int new_len)
{
	struct ip_fw **old_map;

	IPFW_WLOCK(chain);
	chain->id++;
	chain->n_rules = new_len;
	old_map = chain->map;
	chain->map = new_map;
	swap_skipto_cache(chain);
	IPFW_WUNLOCK(chain);
	return old_map;
}

static void
export_cntr1_base(struct ip_fw *krule, struct ip_fw_bcounter *cntr)
{
	struct timeval boottime;

	cntr->size = sizeof(*cntr);

	if (krule->cntr != NULL) {
		cntr->pcnt = counter_u64_fetch(krule->cntr);
		cntr->bcnt = counter_u64_fetch(krule->cntr + 1);
		cntr->timestamp = krule->timestamp;
	}
	if (cntr->timestamp > 0) {
		getboottime(&boottime);
		cntr->timestamp += boottime.tv_sec;
	}
}

/*
 * Export rule into v1 format (Current).
 * Layout:
 * [ ipfw_obj_tlv(IPFW_TLV_RULE_ENT)
 *     [ ip_fw_rule ] OR
 *     [ ip_fw_bcounter ip_fw_rule] (depends on rcntrs).
 * ]
 * Assume @data is zeroed.
 */
static void
export_rule1(struct ip_fw *krule, caddr_t data, int len, int rcntrs)
{
	struct ip_fw_bcounter *cntr;
	struct ip_fw_rule *urule;
	ipfw_obj_tlv *tlv;

	/* Fill in TLV header */
	tlv = (ipfw_obj_tlv *)data;
	tlv->type = IPFW_TLV_RULE_ENT;
	tlv->length = len;

	if (rcntrs != 0) {
		/* Copy counters */
		cntr = (struct ip_fw_bcounter *)(tlv + 1);
		urule = (struct ip_fw_rule *)(cntr + 1);
		export_cntr1_base(krule, cntr);
	} else
		urule = (struct ip_fw_rule *)(tlv + 1);

	/* copy header */
	urule->act_ofs = krule->act_ofs;
	urule->cmd_len = krule->cmd_len;
	urule->rulenum = krule->rulenum;
	urule->set = krule->set;
	urule->flags = krule->flags;
	urule->id = krule->id;

	/* Copy opcodes */
	memcpy(urule->cmd, krule->cmd, krule->cmd_len * sizeof(uint32_t));
}

/*
 * Add new rule(s) to the list possibly creating rule number for each.
 * Update the rule_number in the input struct so the caller knows it as well.
 * Must be called without IPFW_UH held
 */
int
ipfw_commit_rules(struct ip_fw_chain *chain, struct rule_check_info *rci,
    int count)
{
	int error, i, insert_before, tcount, rule_idx, last_rule_idx;
	uint32_t rulenum;
	struct rule_check_info *ci;
	struct ip_fw *krule;
	struct ip_fw **map;	/* the new array of pointers */

	/* Check if we need to do table/obj index remap */
	tcount = 0;
	for (ci = rci, i = 0; i < count; ci++, i++) {
		if (ci->object_opcodes == 0)
			continue;

		/*
		 * Rule has some object opcodes.
		 * We need to find (and create non-existing)
		 * kernel objects, and reference existing ones.
		 */
		error = rewrite_rule_uidx(chain, ci);
		if (error != 0) {

			/*
			 * rewrite failed, state for current rule
			 * has been reverted. Check if we need to
			 * revert more.
			 */
			if (tcount > 0) {

				/*
				 * We have some more table rules
				 * we need to rollback.
				 */

				IPFW_UH_WLOCK(chain);
				while (ci != rci) {
					ci--;
					if (ci->object_opcodes == 0)
						continue;
					unref_rule_objects(chain,ci->krule);

				}
				IPFW_UH_WUNLOCK(chain);

			}

			return (error);
		}

		tcount++;
	}

	/* get_map returns with IPFW_UH_WLOCK if successful */
	map = get_map(chain, count, 0 /* not locked */);
	if (map == NULL) {
		if (tcount > 0) {
			/* Unbind tables */
			IPFW_UH_WLOCK(chain);
			for (ci = rci, i = 0; i < count; ci++, i++) {
				if (ci->object_opcodes == 0)
					continue;

				unref_rule_objects(chain, ci->krule);
			}
			IPFW_UH_WUNLOCK(chain);
		}

		return (ENOSPC);
	}

	if (V_autoinc_step < 1)
		V_autoinc_step = 1;
	else if (V_autoinc_step > 1000)
		V_autoinc_step = 1000;

	last_rule_idx = 0;
	for (ci = rci, i = 0; i < count; ci++, i++) {
		krule = ci->krule;
		rulenum = krule->rulenum;

		krule->id = chain->id + 1;

		/* find the insertion point, we will insert before */
		insert_before = rulenum ? rulenum + 1 : IPFW_DEFAULT_RULE;
		rule_idx = ipfw_find_rule(chain, insert_before, 0);
		/* duplicate the previous part */
		if (last_rule_idx < rule_idx)
			bcopy(chain->map + last_rule_idx, map + last_rule_idx + i,
			    (rule_idx - last_rule_idx) * sizeof(struct ip_fw *));
		last_rule_idx = rule_idx;
		map[rule_idx + i] = krule;
		if (rulenum == 0) {
			/* Compute rule number and write it back */
			rulenum = rule_idx + i > 0 ? map[rule_idx + i - 1]->rulenum : 0;
			if (rulenum < IPFW_DEFAULT_RULE - V_autoinc_step)
				rulenum += V_autoinc_step;
			krule->rulenum = rulenum;
			/* Save number to userland rule */
			memcpy((char *)ci->urule + ci->urule_numoff, &rulenum,
			    sizeof(rulenum));
		}
	}

	/* duplicate the remaining part, we always have the default rule */
	bcopy(chain->map + last_rule_idx, map + last_rule_idx + count,
	    (chain->n_rules - last_rule_idx) * sizeof(struct ip_fw *));

	if (V_skipto_cache != 0)
		update_skipto_cache(chain, map);
	map = swap_map(chain, map, chain->n_rules + count);
	IPFW_UH_WUNLOCK(chain);
	if (map)
		free(map, M_IPFW);
	return (0);
}

int
ipfw_add_protected_rule(struct ip_fw_chain *chain, struct ip_fw *rule,
    int locked)
{
	struct ip_fw **map;

	map = get_map(chain, 1, locked);
	if (map == NULL)
		return (ENOMEM);
	if (chain->n_rules > 0)
		bcopy(chain->map, map,
		    chain->n_rules * sizeof(struct ip_fw *));
	map[chain->n_rules] = rule;
	rule->rulenum = IPFW_DEFAULT_RULE;
	rule->set = RESVD_SET;
	rule->id = chain->id + 1;
	/* We add rule in the end of chain, no need to update skipto cache */
	map = swap_map(chain, map, chain->n_rules + 1);
	IPFW_UH_WUNLOCK(chain);
	free(map, M_IPFW);
	return (0);
}

/*
 * Adds @rule to the list of rules to reap
 */
void
ipfw_reap_add(struct ip_fw_chain *chain, struct ip_fw **head,
    struct ip_fw *rule)
{

	IPFW_UH_WLOCK_ASSERT(chain);

	/* Unlink rule from everywhere */
	unref_rule_objects(chain, rule);

	rule->next = *head;
	*head = rule;
}

/*
 * Reclaim storage associated with a list of rules.  This is
 * typically the list created using remove_rule.
 * A NULL pointer on input is handled correctly.
 */
void
ipfw_reap_rules(struct ip_fw *head)
{
	struct ip_fw *rule;

	while ((rule = head) != NULL) {
		head = head->next;
		ipfw_free_rule(rule);
	}
}

/*
 * Rules to keep are
 *	(default || reserved || !match_set || !match_number)
 * where
 *   default ::= (rule->rulenum == IPFW_DEFAULT_RULE)
 *	// the default rule is always protected
 *
 *   reserved ::= (cmd == 0 && n == 0 && rule->set == RESVD_SET)
 *	// RESVD_SET is protected only if cmd == 0 and n == 0 ("ipfw flush")
 *
 *   match_set ::= (cmd == 0 || rule->set == set)
 *	// set number is ignored for cmd == 0
 *
 *   match_number ::= (cmd == 1 || n == 0 || n == rule->rulenum)
 *	// number is ignored for cmd == 1 or n == 0
 *
 */
int
ipfw_match_range(struct ip_fw *rule, ipfw_range_tlv *rt)
{

	/* Don't match default rule for modification queries */
	if (rule->rulenum == IPFW_DEFAULT_RULE &&
	    (rt->flags & IPFW_RCFLAG_DEFAULT) == 0)
		return (0);

	/* Don't match rules in reserved set for flush requests */
	if ((rt->flags & IPFW_RCFLAG_ALL) != 0 && rule->set == RESVD_SET)
		return (0);

	/* If we're filtering by set, don't match other sets */
	if ((rt->flags & IPFW_RCFLAG_SET) != 0 && rule->set != rt->set)
		return (0);

	if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 &&
	    (rule->rulenum < rt->start_rule || rule->rulenum > rt->end_rule))
		return (0);

	return (1);
}

struct manage_sets_args {
	uint32_t	set;
	uint8_t		new_set;
};

static int
swap_sets_cb(struct namedobj_instance *ni, struct named_object *no,
    void *arg)
{
	struct manage_sets_args *args;

	args = (struct manage_sets_args *)arg;
	if (no->set == (uint8_t)args->set)
		no->set = args->new_set;
	else if (no->set == args->new_set)
		no->set = (uint8_t)args->set;
	return (0);
}

static int
move_sets_cb(struct namedobj_instance *ni, struct named_object *no,
    void *arg)
{
	struct manage_sets_args *args;

	args = (struct manage_sets_args *)arg;
	if (no->set == (uint8_t)args->set)
		no->set = args->new_set;
	return (0);
}

static int
test_sets_cb(struct namedobj_instance *ni, struct named_object *no,
    void *arg)
{
	struct manage_sets_args *args;

	args = (struct manage_sets_args *)arg;
	if (no->set != (uint8_t)args->set)
		return (0);
	if (ipfw_objhash_lookup_name_type(ni, args->new_set,
	    no->etlv, no->name) != NULL)
		return (EEXIST);
	return (0);
}

/*
 * Generic function to handler moving and swapping sets.
 */
int
ipfw_obj_manage_sets(struct namedobj_instance *ni, uint16_t type,
    uint32_t set, uint8_t new_set, enum ipfw_sets_cmd cmd)
{
	struct manage_sets_args args;
	struct named_object *no;

	args.set = set;
	args.new_set = new_set;
	switch (cmd) {
	case SWAP_ALL:
		return (ipfw_objhash_foreach_type(ni, swap_sets_cb,
		    &args, type));
	case TEST_ALL:
		return (ipfw_objhash_foreach_type(ni, test_sets_cb,
		    &args, type));
	case MOVE_ALL:
		return (ipfw_objhash_foreach_type(ni, move_sets_cb,
		    &args, type));
	case COUNT_ONE:
		/*
		 * @set used to pass kidx.
		 * When @new_set is zero - reset object counter,
		 * otherwise increment it.
		 */
		no = ipfw_objhash_lookup_kidx(ni, set);
		if (new_set != 0)
			no->ocnt++;
		else
			no->ocnt = 0;
		return (0);
	case TEST_ONE:
		/* @set used to pass kidx */
		no = ipfw_objhash_lookup_kidx(ni, set);
		/*
		 * First check number of references:
		 * when it differs, this mean other rules are holding
		 * reference to given object, so it is not possible to
		 * change its set. Note that refcnt may account references
		 * to some going-to-be-added rules. Since we don't know
		 * their numbers (and even if they will be added) it is
		 * perfectly OK to return error here.
		 */
		if (no->ocnt != no->refcnt)
			return (EBUSY);
		if (ipfw_objhash_lookup_name_type(ni, new_set, type,
		    no->name) != NULL)
			return (EEXIST);
		return (0);
	case MOVE_ONE:
		/* @set used to pass kidx */
		no = ipfw_objhash_lookup_kidx(ni, set);
		no->set = new_set;
		return (0);
	}
	return (EINVAL);
}

/*
 * Delete rules matching range @rt.
 * Saves number of deleted rules in @ndel.
 *
 * Returns 0 on success.
 */
int
delete_range(struct ip_fw_chain *chain, ipfw_range_tlv *rt, int *ndel)
{
	struct ip_fw *reap, *rule, **map;
	uint32_t end, start;
	int i, n, ndyn, ofs;

	reap = NULL;
	IPFW_UH_WLOCK(chain);	/* arbitrate writers */

	/*
	 * Stage 1: Determine range to inspect.
	 * Range is half-inclusive, e.g [start, end).
	 */
	start = 0;
	end = chain->n_rules - 1;

	if ((rt->flags & IPFW_RCFLAG_RANGE) != 0) {
		start = ipfw_find_rule(chain, rt->start_rule, 0);

		if (rt->end_rule >= IPFW_DEFAULT_RULE)
			rt->end_rule = IPFW_DEFAULT_RULE - 1;
		end = ipfw_find_rule(chain, rt->end_rule, UINT32_MAX);
	}

	if (rt->flags & IPFW_RCFLAG_DYNAMIC) {
		/*
		 * Requested deleting only for dynamic states.
		 */
		*ndel = 0;
		ipfw_expire_dyn_states(chain, rt);
		IPFW_UH_WUNLOCK(chain);
		return (0);
	}

	/* Allocate new map of the same size */
	map = get_map(chain, 0, 1 /* locked */);
	if (map == NULL) {
		IPFW_UH_WUNLOCK(chain);
		return (ENOMEM);
	}

	n = 0;
	ndyn = 0;
	ofs = start;
	/* 1. bcopy the initial part of the map */
	if (start > 0)
		bcopy(chain->map, map, start * sizeof(struct ip_fw *));
	/* 2. copy active rules between start and end */
	for (i = start; i < end; i++) {
		rule = chain->map[i];
		if (ipfw_match_range(rule, rt) == 0) {
			map[ofs++] = rule;
			continue;
		}

		n++;
		if (ipfw_is_dyn_rule(rule) != 0)
			ndyn++;
	}
	/* 3. copy the final part of the map */
	bcopy(chain->map + end, map + ofs,
		(chain->n_rules - end) * sizeof(struct ip_fw *));
	/* 4. recalculate skipto cache */
	update_skipto_cache(chain, map);
	/* 5. swap the maps (under UH_WLOCK + WHLOCK) */
	map = swap_map(chain, map, chain->n_rules - n);
	/* 6. Remove all dynamic states originated by deleted rules */
	if (ndyn > 0)
		ipfw_expire_dyn_states(chain, rt);
	/* 7. now remove the rules deleted from the old map */
	for (i = start; i < end; i++) {
		rule = map[i];
		if (ipfw_match_range(rule, rt) == 0)
			continue;
		ipfw_reap_add(chain, &reap, rule);
	}
	IPFW_UH_WUNLOCK(chain);

	ipfw_reap_rules(reap);
	if (map != NULL)
		free(map, M_IPFW);
	*ndel = n;
	return (0);
}

static int
move_objects(struct ip_fw_chain *ch, ipfw_range_tlv *rt)
{
	struct opcode_obj_rewrite *rw;
	struct ip_fw *rule;
	ipfw_insn *cmd;
	uint32_t kidx;
	int cmdlen, i, l, c;

	IPFW_UH_WLOCK_ASSERT(ch);

	/* Stage 1: count number of references by given rules */
	for (c = 0, i = 0; i < ch->n_rules - 1; i++) {
		rule = ch->map[i];
		if (ipfw_match_range(rule, rt) == 0)
			continue;
		if (rule->set == rt->new_set) /* nothing to do */
			continue;
		/* Search opcodes with named objects */
		for (l = rule->cmd_len, cmdlen = 0, cmd = rule->cmd;
		    l > 0; l -= cmdlen, cmd += cmdlen) {
			cmdlen = F_LEN(cmd);
			rw = find_op_rw(cmd, &kidx, NULL);
			if (rw == NULL || rw->manage_sets == NULL)
				continue;
			/*
			 * When manage_sets() returns non-zero value to
			 * COUNT_ONE command, consider this as an object
			 * doesn't support sets (e.g. disabled with sysctl).
			 * So, skip checks for this object.
			 */
			if (rw->manage_sets(ch, kidx, 1, COUNT_ONE) != 0)
				continue;
			c++;
		}
	}
	if (c == 0) /* No objects found */
		return (0);
	/* Stage 2: verify "ownership" */
	for (c = 0, i = 0; (i < ch->n_rules - 1) && c == 0; i++) {
		rule = ch->map[i];
		if (ipfw_match_range(rule, rt) == 0)
			continue;
		if (rule->set == rt->new_set) /* nothing to do */
			continue;
		/* Search opcodes with named objects */
		for (l = rule->cmd_len, cmdlen = 0, cmd = rule->cmd;
		    l > 0 && c == 0; l -= cmdlen, cmd += cmdlen) {
			cmdlen = F_LEN(cmd);
			rw = find_op_rw(cmd, &kidx, NULL);
			if (rw == NULL || rw->manage_sets == NULL)
				continue;
			/* Test for ownership and conflicting names */
			c = rw->manage_sets(ch, kidx,
			    (uint8_t)rt->new_set, TEST_ONE);
		}
	}
	/* Stage 3: change set and cleanup */
	for (i = 0; i < ch->n_rules - 1; i++) {
		rule = ch->map[i];
		if (ipfw_match_range(rule, rt) == 0)
			continue;
		if (rule->set == rt->new_set) /* nothing to do */
			continue;
		/* Search opcodes with named objects */
		for (l = rule->cmd_len, cmdlen = 0, cmd = rule->cmd;
		    l > 0; l -= cmdlen, cmd += cmdlen) {
			cmdlen = F_LEN(cmd);
			rw = find_op_rw(cmd, &kidx, NULL);
			if (rw == NULL || rw->manage_sets == NULL)
				continue;
			/* cleanup object counter */
			rw->manage_sets(ch, kidx,
			    0 /* reset counter */, COUNT_ONE);
			if (c != 0)
				continue;
			/* change set */
			rw->manage_sets(ch, kidx,
			    (uint8_t)rt->new_set, MOVE_ONE);
		}
	}
	return (c);
}

/*
 * Changes set of given rule rannge @rt
 * with each other.
 *
 * Returns 0 on success.
 */
static int
move_range(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
{
	struct ip_fw *rule;
	int i;

	IPFW_UH_WLOCK(chain);

	/*
	 * Move rules with matching paramenerts to a new set.
	 * This one is much more complex. We have to ensure
	 * that all referenced tables (if any) are referenced
	 * by given rule subset only. Otherwise, we can't move
	 * them to new set and have to return error.
	 */
	if ((i = move_objects(chain, rt)) != 0) {
		IPFW_UH_WUNLOCK(chain);
		return (i);
	}

	/* XXX: We have to do swap holding WLOCK */
	for (i = 0; i < chain->n_rules; i++) {
		rule = chain->map[i];
		if (ipfw_match_range(rule, rt) == 0)
			continue;
		rule->set = rt->new_set;
	}

	IPFW_UH_WUNLOCK(chain);

	return (0);
}

/*
 * Returns pointer to action instruction, skips all possible rule
 * modifiers like O_LOG, O_TAG, O_ALTQ.
 */
ipfw_insn *
ipfw_get_action(struct ip_fw *rule)
{
	ipfw_insn *cmd;
	int l, cmdlen;

	cmd = ACTION_PTR(rule);
	l = rule->cmd_len - rule->act_ofs;
	while (l > 0) {
		switch (cmd->opcode) {
		case O_ALTQ:
		case O_LOG:
		case O_TAG:
			break;
		default:
			return (cmd);
		}
		cmdlen = F_LEN(cmd);
		l -= cmdlen;
		cmd += cmdlen;
	}
	panic("%s: rule (%p) has not action opcode", __func__, rule);
	return (NULL);
}

/*
 * Clear counters for a specific rule.
 * Normally run under IPFW_UH_RLOCK, but these are idempotent ops
 * so we only care that rules do not disappear.
 */
static void
clear_counters(struct ip_fw *rule, int log_only)
{
	ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);

	if (log_only == 0)
		IPFW_ZERO_RULE_COUNTER(rule);
	if (l->o.opcode == O_LOG)
		l->log_left = l->max_log;
}

/*
 * Flushes rules counters and/or log values on matching range.
 *
 * Returns number of items cleared.
 */
static int
clear_range(struct ip_fw_chain *chain, ipfw_range_tlv *rt, int log_only)
{
	struct ip_fw *rule;
	int num;
	int i;

	num = 0;
	rt->flags |= IPFW_RCFLAG_DEFAULT;

	IPFW_UH_WLOCK(chain);	/* arbitrate writers */
	for (i = 0; i < chain->n_rules; i++) {
		rule = chain->map[i];
		if (ipfw_match_range(rule, rt) == 0)
			continue;
		clear_counters(rule, log_only);
		num++;
	}
	IPFW_UH_WUNLOCK(chain);

	return (num);
}

static int
check_range_tlv(ipfw_range_tlv *rt)
{

	if (rt->head.length != sizeof(*rt))
		return (1);
	if (rt->start_rule > rt->end_rule)
		return (1);
	if (rt->set >= IPFW_MAX_SETS || rt->new_set >= IPFW_MAX_SETS)
		return (1);

	if ((rt->flags & IPFW_RCFLAG_USER) != rt->flags)
		return (1);

	return (0);
}

/*
 * Delete rules matching specified parameters
 * Data layout (v0)(current):
 * Request: [ ipfw_obj_header ipfw_range_tlv ]
 * Reply: [ ipfw_obj_header ipfw_range_tlv ]
 *
 * Saves number of deleted rules in ipfw_range_tlv->new_set.
 *
 * Returns 0 on success.
 */
static int
del_rules(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_range_header *rh;
	int error, ndel;

	if (sd->valsize != sizeof(*rh))
		return (EINVAL);

	rh = (ipfw_range_header *)ipfw_get_sopt_space(sd, sd->valsize);

	if (check_range_tlv(&rh->range) != 0)
		return (EINVAL);

	ndel = 0;
	if ((error = delete_range(chain, &rh->range, &ndel)) != 0)
		return (error);

	/* Save number of rules deleted */
	rh->range.new_set = ndel;
	return (0);
}

/*
 * Move rules/sets matching specified parameters
 * Data layout (v0)(current):
 * Request: [ ipfw_obj_header ipfw_range_tlv ]
 *
 * Returns 0 on success.
 */
static int
move_rules(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_range_header *rh;

	if (sd->valsize != sizeof(*rh))
		return (EINVAL);

	rh = (ipfw_range_header *)ipfw_get_sopt_space(sd, sd->valsize);

	if (check_range_tlv(&rh->range) != 0)
		return (EINVAL);

	return (move_range(chain, &rh->range));
}

/*
 * Clear rule accounting data matching specified parameters
 * Data layout (v0)(current):
 * Request: [ ipfw_obj_header ipfw_range_tlv ]
 * Reply: [ ipfw_obj_header ipfw_range_tlv ]
 *
 * Saves number of cleared rules in ipfw_range_tlv->new_set.
 *
 * Returns 0 on success.
 */
static int
clear_rules(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_range_header *rh;
	int log_only, num;
	char *msg;

	if (sd->valsize != sizeof(*rh))
		return (EINVAL);

	rh = (ipfw_range_header *)ipfw_get_sopt_space(sd, sd->valsize);

	if (check_range_tlv(&rh->range) != 0)
		return (EINVAL);

	log_only = (op3->opcode == IP_FW_XRESETLOG);

	num = clear_range(chain, &rh->range, log_only);

	if (rh->range.flags & IPFW_RCFLAG_ALL)
		msg = log_only ? "All logging counts reset" :
		    "Accounting cleared";
	else
		msg = log_only ? "logging count reset" : "cleared";

	if (V_fw_verbose) {
		int lev = LOG_SECURITY | LOG_NOTICE;
		log(lev, "ipfw: %s.\n", msg);
	}

	/* Save number of rules cleared */
	rh->range.new_set = num;
	return (0);
}

static void
enable_sets(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
{
	uint32_t v_set;

	IPFW_UH_WLOCK_ASSERT(chain);

	/* Change enabled/disabled sets mask */
	v_set = (V_set_disable | rt->set) & ~rt->new_set;
	v_set &= ~(1 << RESVD_SET); /* set RESVD_SET always enabled */
	IPFW_WLOCK(chain);
	V_set_disable = v_set;
	IPFW_WUNLOCK(chain);
}

static int
swap_sets(struct ip_fw_chain *chain, ipfw_range_tlv *rt, int mv)
{
	struct opcode_obj_rewrite *rw;
	struct ip_fw *rule;
	int i;

	IPFW_UH_WLOCK_ASSERT(chain);

	if (rt->set == rt->new_set) /* nothing to do */
		return (0);

	if (mv != 0) {
		/*
		 * Berfore moving the rules we need to check that
		 * there aren't any conflicting named objects.
		 */
		for (rw = ctl3_rewriters;
		    rw < ctl3_rewriters + ctl3_rsize; rw++) {
			if (rw->manage_sets == NULL)
				continue;
			i = rw->manage_sets(chain, (uint8_t)rt->set,
			    (uint8_t)rt->new_set, TEST_ALL);
			if (i != 0)
				return (EEXIST);
		}
	}
	/* Swap or move two sets */
	for (i = 0; i < chain->n_rules - 1; i++) {
		rule = chain->map[i];
		if (rule->set == (uint8_t)rt->set)
			rule->set = (uint8_t)rt->new_set;
		else if (rule->set == (uint8_t)rt->new_set && mv == 0)
			rule->set = (uint8_t)rt->set;
	}
	for (rw = ctl3_rewriters; rw < ctl3_rewriters + ctl3_rsize; rw++) {
		if (rw->manage_sets == NULL)
			continue;
		rw->manage_sets(chain, (uint8_t)rt->set,
		    (uint8_t)rt->new_set, mv != 0 ? MOVE_ALL: SWAP_ALL);
	}
	return (0);
}

/*
 * Swaps or moves set
 * Data layout (v0)(current):
 * Request: [ ipfw_obj_header ipfw_range_tlv ]
 *
 * Returns 0 on success.
 */
static int
manage_sets(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_range_header *rh;
	int ret;

	if (sd->valsize != sizeof(*rh))
		return (EINVAL);

	rh = (ipfw_range_header *)ipfw_get_sopt_space(sd, sd->valsize);

	if (rh->range.head.length != sizeof(ipfw_range_tlv))
		return (1);
	/* enable_sets() expects bitmasks. */
	if (op3->opcode != IP_FW_SET_ENABLE &&
	    (rh->range.set >= IPFW_MAX_SETS ||
	    rh->range.new_set >= IPFW_MAX_SETS))
		return (EINVAL);

	ret = 0;
	IPFW_UH_WLOCK(chain);
	switch (op3->opcode) {
	case IP_FW_SET_SWAP:
	case IP_FW_SET_MOVE:
		ret = swap_sets(chain, &rh->range,
		    op3->opcode == IP_FW_SET_MOVE);
		break;
	case IP_FW_SET_ENABLE:
		enable_sets(chain, &rh->range);
		break;
	}
	IPFW_UH_WUNLOCK(chain);

	return (ret);
}

/* Check rule format */
int
ipfw_check_rule(struct ip_fw_rule *rule, size_t size,
    struct rule_check_info *ci)
{
	int l;

	if (size < sizeof(*rule)) {
		printf("ipfw: rule too short\n");
		return (EINVAL);
	}

	/* Check for valid cmd_len */
	l = roundup2(RULESIZE(rule), sizeof(uint64_t));
	if (l != size) {
		printf("ipfw: size mismatch (have %zu want %d)\n", size, l);
		return (EINVAL);
	}
	if (rule->act_ofs >= rule->cmd_len) {
		printf("ipfw: bogus action offset (%u > %u)\n",
		    rule->act_ofs, rule->cmd_len - 1);
		return (EINVAL);
	}

	if (rule->rulenum > IPFW_DEFAULT_RULE - 1)
		return (EINVAL);

	return (check_ipfw_rule_body(rule->cmd, rule->cmd_len, ci));
}

#define	CHECK_TARG(a, c)	\
    ((a) == IP_FW_TARG && ((c)->flags & IPFW_RCIFLAG_HAS_STATE))

enum ipfw_opcheck_result
ipfw_check_opcode(ipfw_insn **pcmd, int *plen, struct rule_check_info *ci)
{
	ipfw_insn *cmd;
	size_t cmdlen;

	cmd = *pcmd;
	cmdlen = F_LEN(cmd);

	switch (cmd->opcode) {
	case O_PROBE_STATE:
	case O_KEEP_STATE:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_kidx))
			return (BAD_SIZE);
		ci->object_opcodes++;
		ci->flags |= IPFW_RCIFLAG_HAS_STATE;
		break;
	case O_PROTO:
	case O_IP_SRC_ME:
	case O_IP_DST_ME:
	case O_LAYER2:
	case O_IN:
	case O_FRAG:
	case O_DIVERTED:
	case O_IPOPT:
	case O_IPTOS:
	case O_IPPRECEDENCE:
	case O_IPVER:
	case O_SOCKARG:
	case O_TCPFLAGS:
	case O_TCPOPTS:
	case O_ESTAB:
	case O_VERREVPATH:
	case O_VERSRCREACH:
	case O_ANTISPOOF:
	case O_IPSEC:
#ifdef INET6
	case O_IP6_SRC_ME:
	case O_IP6_DST_ME:
	case O_EXT_HDR:
	case O_IP6:
#endif
	case O_IP4:
	case O_TAG:
	case O_SKIP_ACTION:
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		break;

	case O_EXTERNAL_ACTION:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_kidx))
			return (BAD_SIZE);

		if (insntod(cmd, kidx)->kidx == 0)
			return (FAILED);
		ci->object_opcodes++;
		/*
		 * Do we have O_EXTERNAL_INSTANCE or O_EXTERNAL_DATA
		 * opcode?
		 */
		if (*plen != cmdlen) {
			*plen -= cmdlen;
			cmd += cmdlen;
			*pcmd = cmd;
			cmdlen = F_LEN(cmd);
			if (cmd->opcode == O_EXTERNAL_DATA)
				return (CHECK_ACTION);
			if (cmd->opcode != O_EXTERNAL_INSTANCE) {
				printf("ipfw: invalid opcode "
				    "next to external action %u\n",
				    cmd->opcode);
				return (FAILED);
			}
			if (cmdlen != F_INSN_SIZE(ipfw_insn_kidx))
				return (BAD_SIZE);
			if (insntod(cmd, kidx)->kidx == 0)
				return (FAILED);
			ci->object_opcodes++;
		}
		return (CHECK_ACTION);

	case O_FIB:
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		if (cmd->arg1 >= rt_numfibs) {
			printf("ipfw: invalid fib number %d\n",
				cmd->arg1);
			return (FAILED);
		}
		break;

	case O_SETFIB:
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		if ((cmd->arg1 != IP_FW_TARG) &&
		    ((cmd->arg1 & 0x7FFF) >= rt_numfibs)) {
			printf("ipfw: invalid fib number %d\n",
				cmd->arg1 & 0x7FFF);
			return (FAILED);
		}
		if (CHECK_TARG(cmd->arg1, ci))
			goto bad_targ;
		return (CHECK_ACTION);

	case O_UID:
	case O_GID:
	case O_JAIL:
	case O_IP_SRC:
	case O_IP_DST:
	case O_TCPSEQ:
	case O_TCPACK:
	case O_PROB:
	case O_ICMPTYPE:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
			return (BAD_SIZE);
		break;

	case O_LIMIT:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
			return (BAD_SIZE);
		ci->object_opcodes++;
		break;

	case O_LOG:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
			return (BAD_SIZE);
		insntod(cmd, log)->log_left = insntod(cmd, log)->max_log;
		break;

	case O_IP_SRC_MASK:
	case O_IP_DST_MASK:
		/* only odd command lengths */
		if ((cmdlen & 1) == 0)
			return (BAD_SIZE);
		break;

	case O_IP_SRC_SET:
	case O_IP_DST_SET:
		if (cmd->arg1 == 0 || cmd->arg1 > 256) {
			printf("ipfw: invalid set size %d\n",
				cmd->arg1);
			return (FAILED);
		}
		if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
		    (cmd->arg1+31)/32 )
			return (BAD_SIZE);
		break;

	case O_IP_SRC_LOOKUP:
	case O_IP_DST_LOOKUP:
	case O_IP_FLOW_LOOKUP:
	case O_MAC_SRC_LOOKUP:
	case O_MAC_DST_LOOKUP:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_kidx) &&
		    cmdlen != F_INSN_SIZE(ipfw_insn_table))
			return (BAD_SIZE);
		if (insntod(cmd, kidx)->kidx >= V_fw_tables_max) {
			printf("ipfw: invalid table index %u\n",
			    insntod(cmd, kidx)->kidx);
			return (FAILED);
		}
		ci->object_opcodes++;
		break;
	case O_MACADDR2:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
			return (BAD_SIZE);
		break;

	case O_NOP:
	case O_IPID:
	case O_IPTTL:
	case O_IPLEN:
	case O_TCPDATALEN:
	case O_TCPMSS:
	case O_TCPWIN:
	case O_TAGGED:
		if (cmdlen < 1 || cmdlen > 31)
			return (BAD_SIZE);
		break;

	case O_DSCP:
	case O_MARK:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 1)
			return (BAD_SIZE);
		break;

	case O_MAC_TYPE:
	case O_IP_SRCPORT:
	case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
		if (cmdlen < 2 || cmdlen > 31)
			return (BAD_SIZE);
		break;

	case O_RECV:
	case O_XMIT:
	case O_VIA:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
			return (BAD_SIZE);
		ci->object_opcodes++;
		break;

	case O_ALTQ:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_altq))
			return (BAD_SIZE);
		break;

	case O_PIPE:
	case O_QUEUE:
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		if (CHECK_TARG(cmd->arg1, ci))
			goto bad_targ;
		return (CHECK_ACTION);

	case O_FORWARD_IP:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
			return (BAD_SIZE);
		if (insntoc(cmd, sa)->sa.sin_addr.s_addr == INADDR_ANY &&
		    (ci->flags & IPFW_RCIFLAG_HAS_STATE))
			goto bad_targ;
		return (CHECK_ACTION);
#ifdef INET6
	case O_FORWARD_IP6:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_sa6))
			return (BAD_SIZE);
		return (CHECK_ACTION);
#endif /* INET6 */

	case O_DIVERT:
	case O_TEE:
		if (ip_divert_ptr == NULL)
			return (FAILED);
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		if (CHECK_TARG(cmd->arg1, ci))
			goto bad_targ;
		return (CHECK_ACTION);
	case O_NETGRAPH:
	case O_NGTEE:
		if (ng_ipfw_input_p == NULL)
			return (FAILED);
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		if (CHECK_TARG(cmd->arg1, ci))
			goto bad_targ;
		return (CHECK_ACTION);
	case O_NAT:
		if (!IPFW_NAT_LOADED)
			return (FAILED);
		if (cmdlen != F_INSN_SIZE(ipfw_insn_nat))
			return (BAD_SIZE);
		if (CHECK_TARG(cmd->arg1, ci))
			goto bad_targ;
		return (CHECK_ACTION);

	case O_SKIPTO:
	case O_CALLRETURN:
	case O_SETMARK:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
			return (BAD_SIZE);
		/* O_CALLRETURN + F_NOT means 'return' opcode. */
		if (cmd->opcode != O_CALLRETURN || (cmd->len & F_NOT) == 0) {
			if (CHECK_TARG(insntoc(cmd, u32)->d[0], ci))
				goto bad_targ;
		}
		return (CHECK_ACTION);

	case O_CHECK_STATE:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_kidx))
			return (BAD_SIZE);
		ci->object_opcodes++;
		return (CHECK_ACTION);

	case O_FORWARD_MAC: /* XXX not implemented yet */
	case O_COUNT:
	case O_ACCEPT:
	case O_DENY:
	case O_REJECT:
	case O_SETDSCP:
#ifdef INET6
	case O_UNREACH6:
#endif
	case O_REASS:
		if (cmdlen != F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		if (cmd->opcode == O_SETDSCP && CHECK_TARG(cmd->arg1, ci))
			goto bad_targ;
		return (CHECK_ACTION);
#ifdef INET6
	case O_IP6_SRC:
	case O_IP6_DST:
		if (cmdlen != F_INSN_SIZE(struct in6_addr) +
		    F_INSN_SIZE(ipfw_insn))
			return (BAD_SIZE);
		break;

	case O_FLOW6ID:
		if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
		    ((ipfw_insn_u32 *)cmd)->o.arg1)
			return (BAD_SIZE);
		break;

	case O_IP6_SRC_MASK:
	case O_IP6_DST_MASK:
		if ( !(cmdlen & 1) || cmdlen > 127)
			return (BAD_SIZE);
		break;
	case O_ICMP6TYPE:
		if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) )
			return (BAD_SIZE);
		break;
#endif

	default:
		switch (cmd->opcode) {
#ifndef INET6
		case O_IP6_SRC_ME:
		case O_IP6_DST_ME:
		case O_EXT_HDR:
		case O_IP6:
		case O_UNREACH6:
		case O_IP6_SRC:
		case O_IP6_DST:
		case O_FLOW6ID:
		case O_IP6_SRC_MASK:
		case O_IP6_DST_MASK:
		case O_ICMP6TYPE:
			printf("ipfw: no IPv6 support in kernel\n");
			return (FAILED);
#endif
		default:
			printf("ipfw: opcode %d: unknown opcode\n",
				cmd->opcode);
			return (FAILED);
		}
	}
	return (SUCCESS);
bad_targ:
	/*
	 * For dynamic states we can not correctly initialize tablearg value,
	 * because we don't go through rule's opcodes except rule action.
	 */
	printf("ipfw: tablearg is not allowed with dynamic states\n");
	return (FAILED);
}

static __noinline int
check_ipfw_rule_body(ipfw_insn *cmd, int cmd_len, struct rule_check_info *ci)
{
	int cmdlen, l;
	int have_action, ret;

	/*
	 * Now go for the individual checks. Very simple ones, basically only
	 * instruction sizes.
	 */
	have_action = 0;
	for (l = cmd_len; l > 0 ; l -= cmdlen, cmd += cmdlen) {
		cmdlen = F_LEN(cmd);
		if (cmdlen > l) {
			printf("ipfw: opcode %d: size truncated\n",
			    cmd->opcode);
			return (EINVAL);
		}
		if (ci->version != IP_FW3_OPVER)
			ret = (*check_opcode_f)(&cmd, &l, ci);
		else
			ret = ipfw_check_opcode(&cmd, &l, ci);

		if (ret == CHECK_ACTION) {
			if (have_action != 0) {
				printf("ipfw: opcode %d: multiple actions"
				    " not allowed\n", cmd->opcode);
				ret = FAILED;
			} else
				have_action = 1;

			if (l != F_LEN(cmd)) {
				printf("ipfw: opcode %d: action must be"
				    " last opcode\n", cmd->opcode);
				ret = FAILED;
			}
		}
		switch (ret) {
		case SUCCESS:
			continue;
		case BAD_SIZE:
			printf("ipfw: opcode %d: wrong size %d\n",
			    cmd->opcode, cmdlen);
			/* FALLTHROUGH */
		case FAILED:
			return (EINVAL);
		}
	}
	if (have_action == 0) {
		printf("ipfw: missing action\n");
		return (EINVAL);
	}
	return (0);
}

struct dump_args {
	uint32_t	b;	/* start rule */
	uint32_t	e;	/* end rule */
	uint32_t	rcount;	/* number of rules */
	uint32_t	rsize;	/* rules size */
	uint32_t	tcount;	/* number of tables */
	int		rcounters;	/* counters */
	uint32_t	*bmask;	/* index bitmask of used named objects */
};

void
ipfw_export_obj_ntlv(struct named_object *no, ipfw_obj_ntlv *ntlv)
{

	ntlv->head.type = no->etlv;
	ntlv->head.length = sizeof(*ntlv);
	ntlv->idx = no->kidx;
	strlcpy(ntlv->name, no->name, sizeof(ntlv->name));
}

/*
 * Export named object info in instance @ni, identified by @kidx
 * to ipfw_obj_ntlv. TLV is allocated from @sd space.
 *
 * Returns 0 on success.
 */
static int
export_objhash_ntlv(struct namedobj_instance *ni, uint32_t kidx,
    struct sockopt_data *sd)
{
	struct named_object *no;
	ipfw_obj_ntlv *ntlv;

	no = ipfw_objhash_lookup_kidx(ni, kidx);
	KASSERT(no != NULL, ("invalid object kernel index passed"));

	ntlv = (ipfw_obj_ntlv *)ipfw_get_sopt_space(sd, sizeof(*ntlv));
	if (ntlv == NULL)
		return (ENOMEM);

	ipfw_export_obj_ntlv(no, ntlv);
	return (0);
}

static int
export_named_objects(struct namedobj_instance *ni, struct dump_args *da,
    struct sockopt_data *sd)
{
	uint32_t i;
	int error;

	for (i = 0; i < IPFW_TABLES_MAX && da->tcount > 0; i++) {
		if ((da->bmask[i / 32] & (1 << (i % 32))) == 0)
			continue;
		if ((error = export_objhash_ntlv(ni, i, sd)) != 0)
			return (error);
		da->tcount--;
	}
	return (0);
}

static int
dump_named_objects(struct ip_fw_chain *ch, struct dump_args *da,
    struct sockopt_data *sd)
{
	ipfw_obj_ctlv *ctlv;
	int error;

	MPASS(da->tcount > 0);
	/* Header first */
	ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
	if (ctlv == NULL)
		return (ENOMEM);
	ctlv->head.type = IPFW_TLV_TBLNAME_LIST;
	ctlv->head.length = da->tcount * sizeof(ipfw_obj_ntlv) +
	    sizeof(*ctlv);
	ctlv->count = da->tcount;
	ctlv->objsize = sizeof(ipfw_obj_ntlv);

	/* Dump table names first (if any) */
	error = export_named_objects(ipfw_get_table_objhash(ch), da, sd);
	if (error != 0)
		return (error);
	/* Then dump another named objects */
	da->bmask += IPFW_TABLES_MAX / 32;
	return (export_named_objects(CHAIN_TO_SRV(ch), da, sd));
}

/*
 * Dumps static rules with table TLVs in buffer @sd.
 *
 * Returns 0 on success.
 */
static int
dump_static_rules(struct ip_fw_chain *chain, struct dump_args *da,
    struct sockopt_data *sd)
{
	ipfw_obj_ctlv *ctlv;
	struct ip_fw *krule;
	caddr_t dst;
	int i, l;

	/* Dump rules */
	ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
	if (ctlv == NULL)
		return (ENOMEM);
	ctlv->head.type = IPFW_TLV_RULE_LIST;
	ctlv->head.length = da->rsize + sizeof(*ctlv);
	ctlv->count = da->rcount;

	for (i = da->b; i < da->e; i++) {
		krule = chain->map[i];

		l = RULEUSIZE1(krule) + sizeof(ipfw_obj_tlv);
		if (da->rcounters != 0)
			l += sizeof(struct ip_fw_bcounter);
		dst = (caddr_t)ipfw_get_sopt_space(sd, l);
		if (dst == NULL)
			return (ENOMEM);

		export_rule1(krule, dst, l, da->rcounters);
	}

	return (0);
}

int
ipfw_mark_object_kidx(uint32_t *bmask, uint16_t etlv, uint32_t kidx)
{
	uint32_t bidx;

	/*
	 * Maintain separate bitmasks for table and non-table objects.
	 */
	bidx = (etlv == IPFW_TLV_TBL_NAME) ? 0: IPFW_TABLES_MAX / 32;
	bidx += kidx / 32;
	if ((bmask[bidx] & (1 << (kidx % 32))) != 0)
		return (0);

	bmask[bidx] |= 1 << (kidx % 32);
	return (1);
}

/*
 * Marks every object index used in @rule with bit in @bmask.
 * Used to generate bitmask of referenced tables/objects for given ruleset
 * or its part.
 */
static void
mark_rule_objects(struct ip_fw_chain *ch, struct ip_fw *rule,
    struct dump_args *da)
{
	struct opcode_obj_rewrite *rw;
	ipfw_insn *cmd;
	uint32_t kidx;
	int cmdlen, l;
	uint8_t subtype;

	l = rule->cmd_len;
	cmd = rule->cmd;
	cmdlen = 0;
	for ( ;	l > 0 ; l -= cmdlen, cmd += cmdlen) {
		cmdlen = F_LEN(cmd);

		rw = find_op_rw(cmd, &kidx, &subtype);
		if (rw == NULL)
			continue;

		if (ipfw_mark_object_kidx(da->bmask, rw->etlv, kidx))
			da->tcount++;
	}
}

/*
 * Dumps requested objects data
 * Data layout (version 0)(current):
 * Request: [ ipfw_cfg_lheader ] + IPFW_CFG_GET_* flags
 *   size = ipfw_cfg_lheader.size
 * Reply: [ ipfw_cfg_lheader 
 *   [ ipfw_obj_ctlv(IPFW_TLV_TBL_LIST) ipfw_obj_ntlv x N ] (optional)
 *   [ ipfw_obj_ctlv(IPFW_TLV_RULE_LIST)
 *     ipfw_obj_tlv(IPFW_TLV_RULE_ENT) [ ip_fw_bcounter (optional) ip_fw_rule ]
 *   ] (optional)
 *   [ ipfw_obj_ctlv(IPFW_TLV_STATE_LIST) ipfw_obj_dyntlv x N ] (optional)
 * ]
 * * NOTE IPFW_TLV_STATE_LIST has the single valid field: objsize.
 * The rest (size, count) are set to zero and needs to be ignored.
 *
 * Returns 0 on success.
 */
static int
dump_config(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	struct dump_args da;
	ipfw_cfg_lheader *hdr;
	struct ip_fw *rule;
	size_t sz, rnum;
	uint32_t hdr_flags, *bmask;
	int error, i;

	hdr = (ipfw_cfg_lheader *)ipfw_get_sopt_header(sd, sizeof(*hdr));
	if (hdr == NULL)
		return (EINVAL);

	error = 0;
	bmask = NULL;
	memset(&da, 0, sizeof(da));
	/*
	 * Allocate needed state.
	 * Note we allocate 2xspace mask, for table & srv
	 */
	if (hdr->flags & (IPFW_CFG_GET_STATIC | IPFW_CFG_GET_STATES))
		da.bmask = bmask = malloc(
		    sizeof(uint32_t) * IPFW_TABLES_MAX * 2 / 32, M_TEMP,
		    M_WAITOK | M_ZERO);
	IPFW_UH_RLOCK(chain);

	/*
	 * STAGE 1: Determine size/count for objects in range.
	 * Prepare used tables bitmask.
	 */
	sz = sizeof(ipfw_cfg_lheader);
	da.e = chain->n_rules;

	if (hdr->end_rule != 0) {
		/* Handle custom range */
		if ((rnum = hdr->start_rule) > IPFW_DEFAULT_RULE)
			rnum = IPFW_DEFAULT_RULE;
		da.b = ipfw_find_rule(chain, rnum, 0);
		rnum = (hdr->end_rule < IPFW_DEFAULT_RULE) ?
		    hdr->end_rule + 1: IPFW_DEFAULT_RULE;
		da.e = ipfw_find_rule(chain, rnum, UINT32_MAX) + 1;
	}

	if (hdr->flags & IPFW_CFG_GET_STATIC) {
		for (i = da.b; i < da.e; i++) {
			rule = chain->map[i];
			da.rsize += RULEUSIZE1(rule) + sizeof(ipfw_obj_tlv);
			da.rcount++;
			/* Update bitmask of used objects for given range */
			mark_rule_objects(chain, rule, &da);
		}
		/* Add counters if requested */
		if (hdr->flags & IPFW_CFG_GET_COUNTERS) {
			da.rsize += sizeof(struct ip_fw_bcounter) * da.rcount;
			da.rcounters = 1;
		}
		sz += da.rsize + sizeof(ipfw_obj_ctlv);
	}

	if (hdr->flags & IPFW_CFG_GET_STATES) {
		sz += sizeof(ipfw_obj_ctlv) +
		    ipfw_dyn_get_count(bmask, &i) * sizeof(ipfw_obj_dyntlv);
		da.tcount += i;
	}

	if (da.tcount > 0)
		sz += da.tcount * sizeof(ipfw_obj_ntlv) +
		    sizeof(ipfw_obj_ctlv);

	/*
	 * Fill header anyway.
	 * Note we have to save header fields to stable storage
	 * buffer inside @sd can be flushed after dumping rules
	 */
	hdr->size = sz;
	hdr->set_mask = ~V_set_disable;
	hdr_flags = hdr->flags;
	hdr = NULL;

	if (sd->valsize < sz) {
		error = ENOMEM;
		goto cleanup;
	}

	/* STAGE2: Store actual data */
	if (da.tcount > 0) {
		error = dump_named_objects(chain, &da, sd);
		if (error != 0)
			goto cleanup;
	}

	if (hdr_flags & IPFW_CFG_GET_STATIC) {
		error = dump_static_rules(chain, &da, sd);
		if (error != 0)
			goto cleanup;
	}

	if (hdr_flags & IPFW_CFG_GET_STATES)
		error = ipfw_dump_states(chain, sd);

cleanup:
	IPFW_UH_RUNLOCK(chain);

	if (bmask != NULL)
		free(bmask, M_TEMP);

	return (error);
}

int
ipfw_check_object_name_generic(const char *name)
{
	int nsize;

	nsize = sizeof(((ipfw_obj_ntlv *)0)->name);
	if (strnlen(name, nsize) == nsize)
		return (EINVAL);
	if (name[0] == '\0')
		return (EINVAL);
	return (0);
}

/*
 * Creates non-existent objects referenced by rule.
 *
 * Return 0 on success.
 */
int
create_objects_compat(struct ip_fw_chain *ch, ipfw_insn *cmd,
    struct obj_idx *oib, struct obj_idx *pidx, struct tid_info *ti)
{
	struct opcode_obj_rewrite *rw;
	struct obj_idx *p;
	uint32_t kidx;
	int error;

	/*
	 * Compatibility stuff: do actual creation for non-existing,
	 * but referenced objects.
	 */
	for (p = oib; p < pidx; p++) {
		if (p->kidx != 0)
			continue;

		ti->uidx = p->uidx;
		ti->type = p->type;
		ti->atype = 0;

		rw = find_op_rw(cmd + p->off, NULL, NULL);
		KASSERT(rw != NULL, ("Unable to find handler for op %d",
		    (cmd + p->off)->opcode));

		if (rw->create_object == NULL)
			error = EOPNOTSUPP;
		else
			error = rw->create_object(ch, ti, &kidx);
		if (error == 0) {
			p->kidx = kidx;
			continue;
		}

		/*
		 * Error happened. We have to rollback everything.
		 * Drop all already acquired references.
		 */
		IPFW_UH_WLOCK(ch);
		unref_oib_objects(ch, cmd, oib, pidx);
		IPFW_UH_WUNLOCK(ch);

		return (error);
	}

	return (0);
}

/*
 * Unreferences all already-referenced objects in given @cmd rule,
 * using information in @oib.
 *
 * Used to rollback partially converted rule on error.
 */
static void
unref_oib_objects(struct ip_fw_chain *ch, ipfw_insn *cmd, struct obj_idx *oib,
    struct obj_idx *end)
{
	struct opcode_obj_rewrite *rw;
	struct named_object *no;
	struct obj_idx *p;

	IPFW_UH_WLOCK_ASSERT(ch);

	for (p = oib; p < end; p++) {
		if (p->kidx == 0)
			continue;

		rw = find_op_rw(cmd + p->off, NULL, NULL);
		KASSERT(rw != NULL, ("Unable to find handler for op %d",
		    (cmd + p->off)->opcode));

		/* Find & unref by existing idx */
		no = rw->find_bykidx(ch, p->kidx);
		KASSERT(no != NULL, ("Ref'd object %d disappeared", p->kidx));
		no->refcnt--;
	}
}

/*
 * Remove references from every object used in @rule.
 * Used at rule removal code.
 */
static void
unref_rule_objects(struct ip_fw_chain *ch, struct ip_fw *rule)
{
	struct opcode_obj_rewrite *rw;
	struct named_object *no;
	ipfw_insn *cmd;
	uint32_t kidx;
	int cmdlen, l;
	uint8_t subtype;

	IPFW_UH_WLOCK_ASSERT(ch);

	l = rule->cmd_len;
	cmd = rule->cmd;
	cmdlen = 0;
	for ( ;	l > 0 ; l -= cmdlen, cmd += cmdlen) {
		cmdlen = F_LEN(cmd);

		rw = find_op_rw(cmd, &kidx, &subtype);
		if (rw == NULL)
			continue;
		no = rw->find_bykidx(ch, kidx);

		KASSERT(no != NULL, ("object id %d not found", kidx));
		KASSERT(no->subtype == subtype,
		    ("wrong type %d (%d) for object id %d",
		    no->subtype, subtype, kidx));
		KASSERT(no->refcnt > 0, ("refcount for object %d is %d",
		    kidx, no->refcnt));

		if (no->refcnt == 1 && rw->destroy_object != NULL)
			rw->destroy_object(ch, no);
		else
			no->refcnt--;
	}
}

/*
 * Find and reference object (if any) stored in instruction @cmd.
 *
 * Saves object info in @pidx, sets
 *  - @unresolved to 1 if object should exists but not found
 *
 * Returns non-zero value in case of error.
 */
static int
ref_opcode_object(struct ip_fw_chain *ch, ipfw_insn *cmd, struct tid_info *ti,
    struct obj_idx *pidx, int *unresolved)
{
	struct named_object *no;
	struct opcode_obj_rewrite *rw;
	int error;

	/* Check if this opcode is candidate for rewrite */
	rw = find_op_rw(cmd, &ti->uidx, &ti->type);
	if (rw == NULL)
		return (0);

	/* Need to rewrite. Save necessary fields */
	pidx->uidx = ti->uidx;
	pidx->type = ti->type;

	/* Try to find referenced kernel object */
	error = rw->find_byname(ch, ti, &no);
	if (error != 0)
		return (error);
	if (no == NULL) {
		/*
		 * Report about unresolved object for automaic
		 * creation.
		 */
		*unresolved = 1;
		return (0);
	}

	/*
	 * Object is already exist.
	 * Its subtype should match with expected value.
	 */
	if (ti->type != no->subtype)
		return (EINVAL);

	/* Bump refcount and update kidx. */
	no->refcnt++;
	rw->update(cmd, no->kidx);
	return (0);
}

/*
 * Finds and bumps refcount for objects referenced by given @rule.
 * Auto-creates non-existing tables.
 * Fills in @oib array with userland/kernel indexes.
 *
 * Returns 0 on success.
 */
static int
ref_rule_objects(struct ip_fw_chain *ch, struct ip_fw *rule,
    struct rule_check_info *ci, struct obj_idx *oib, struct tid_info *ti)
{
	struct obj_idx *pidx;
	ipfw_insn *cmd;
	int cmdlen, error, l, unresolved;

	pidx = oib;
	l = rule->cmd_len;
	cmd = rule->cmd;
	cmdlen = 0;
	error = 0;

	IPFW_UH_WLOCK(ch);

	/* Increase refcount on each existing referenced table. */
	for ( ;	l > 0 ; l -= cmdlen, cmd += cmdlen) {
		cmdlen = F_LEN(cmd);
		unresolved = 0;

		error = ref_opcode_object(ch, cmd, ti, pidx, &unresolved);
		if (error != 0)
			break;
		/*
		 * Compatibility stuff for old clients:
		 * prepare to automaitcally create non-existing objects.
		 */
		if (unresolved != 0) {
			pidx->off = rule->cmd_len - l;
			pidx++;
		}
	}

	if (error != 0) {
		/* Unref everything we have already done */
		unref_oib_objects(ch, rule->cmd, oib, pidx);
		IPFW_UH_WUNLOCK(ch);
		return (error);
	}
	IPFW_UH_WUNLOCK(ch);

	/* Perform auto-creation for non-existing objects */
	if (pidx != oib)
		error = create_objects_compat(ch, rule->cmd, oib, pidx, ti);

	/* Calculate real number of dynamic objects */
	ci->object_opcodes = (uint16_t)(pidx - oib);

	return (error);
}

/*
 * Checks is opcode is referencing table of appropriate type.
 * Adds reference count for found table if true.
 * Rewrites user-supplied opcode values with kernel ones.
 *
 * Returns 0 on success and appropriate error code otherwise.
 */
static int
rewrite_rule_uidx(struct ip_fw_chain *chain, struct rule_check_info *ci)
{
	int error;
	ipfw_insn *cmd;
	struct obj_idx *p, *pidx_first, *pidx_last;
	struct tid_info ti;

	/*
	 * Prepare an array for storing opcode indices.
	 * Use stack allocation by default.
	 */
	if (ci->object_opcodes <= (sizeof(ci->obuf)/sizeof(ci->obuf[0]))) {
		/* Stack */
		pidx_first = ci->obuf;
	} else
		pidx_first = malloc(
		    ci->object_opcodes * sizeof(struct obj_idx),
		    M_IPFW, M_WAITOK | M_ZERO);

	error = 0;
	memset(&ti, 0, sizeof(ti));

	/* Use set rule is assigned to. */
	ti.set = ci->krule->set;
	if (ci->ctlv != NULL) {
		ti.tlvs = (void *)(ci->ctlv + 1);
		ti.tlen = ci->ctlv->head.length - sizeof(ipfw_obj_ctlv);
	}

	/* Reference all used tables and other objects */
	error = ref_rule_objects(chain, ci->krule, ci, pidx_first, &ti);
	if (error != 0)
		goto free;
	/*
	 * Note that ref_rule_objects() might have updated ci->object_opcodes
	 * to reflect actual number of object opcodes.
	 */

	/* Perform rewrite of remaining opcodes */
	p = pidx_first;
	pidx_last = pidx_first + ci->object_opcodes;
	for (p = pidx_first; p < pidx_last; p++) {
		cmd = ci->krule->cmd + p->off;
		update_opcode_kidx(cmd, p->kidx);
	}

free:
	if (pidx_first != ci->obuf)
		free(pidx_first, M_IPFW);

	return (error);
}

/*
 * Parses one or more rules from userland.
 * Data layout (version 1)(current):
 * Request:
 * [
 *   ip_fw3_opheader
 *   [ ipfw_obj_ctlv(IPFW_TLV_TBL_LIST) ipfw_obj_ntlv x N ] (optional *1)
 *   [ ipfw_obj_ctlv(IPFW_TLV_RULE_LIST) ip_fw x N ] (*2) (*3)
 * ]
 * Reply:
 * [
 *   ip_fw3_opheader
 *   [ ipfw_obj_ctlv(IPFW_TLV_TBL_LIST) ipfw_obj_ntlv x N ] (optional)
 *   [ ipfw_obj_ctlv(IPFW_TLV_RULE_LIST) ip_fw x N ]
 * ]
 *
 * Rules in reply are modified to store their actual ruleset number.
 *
 * (*1) TLVs inside IPFW_TLV_TBL_LIST needs to be sorted ascending
 * according to their idx field and there has to be no duplicates.
 * (*2) Numbered rules inside IPFW_TLV_RULE_LIST needs to be sorted ascending.
 * (*3) Each ip_fw structure needs to be aligned to u64 boundary.
 *
 * Returns 0 on success.
 */
static __noinline int
parse_rules_v1(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd, ipfw_obj_ctlv **prtlv,
    struct rule_check_info **pci)
{
	ipfw_obj_ctlv *ctlv, *rtlv, *tstate;
	ipfw_obj_ntlv *ntlv;
	struct rule_check_info *ci, *cbuf;
	struct ip_fw_rule *r;
	size_t count, clen, read, rsize;
	uint32_t idx, rulenum;
	int error;

	op3 = (ip_fw3_opheader *)ipfw_get_sopt_space(sd, sd->valsize);
	ctlv = (ipfw_obj_ctlv *)(op3 + 1);
	read = sizeof(ip_fw3_opheader);
	if (read + sizeof(*ctlv) > sd->valsize)
		return (EINVAL);

	rtlv = NULL;
	tstate = NULL;
	cbuf = NULL;
	/* Table names or other named objects. */
	if (ctlv->head.type == IPFW_TLV_TBLNAME_LIST) {
		/* Check size and alignment. */
		clen = ctlv->head.length;
		if (read + clen > sd->valsize || clen < sizeof(*ctlv) ||
		    (clen % sizeof(uint64_t)) != 0)
			return (EINVAL);
		/* Check for validness. */
		count = (ctlv->head.length - sizeof(*ctlv)) / sizeof(*ntlv);
		if (ctlv->count != count || ctlv->objsize != sizeof(*ntlv))
			return (EINVAL);
		/*
		 * Check each TLV.
		 * Ensure TLVs are sorted ascending and
		 * there are no duplicates.
		 */
		idx = 0;
		ntlv = (ipfw_obj_ntlv *)(ctlv + 1);
		while (count > 0) {
			if (ntlv->head.length != sizeof(ipfw_obj_ntlv))
				return (EINVAL);

			error = ipfw_check_object_name_generic(ntlv->name);
			if (error != 0)
				return (error);

			if (ntlv->idx <= idx)
				return (EINVAL);

			idx = ntlv->idx;
			count--;
			ntlv++;
		}

		tstate = ctlv;
		read += ctlv->head.length;
		ctlv = (ipfw_obj_ctlv *)((caddr_t)ctlv + ctlv->head.length);

		if (read + sizeof(*ctlv) > sd->valsize)
			return (EINVAL);
	}

	/* List of rules. */
	if (ctlv->head.type == IPFW_TLV_RULE_LIST) {
		clen = ctlv->head.length;
		if (read + clen > sd->valsize || clen < sizeof(*ctlv) ||
		    (clen % sizeof(uint64_t)) != 0)
			return (EINVAL);

		clen -= sizeof(*ctlv);
		if (ctlv->count == 0 ||
		    ctlv->count > clen / sizeof(struct ip_fw_rule))
			return (EINVAL);

		/* Allocate state for each rule */
		cbuf = malloc(ctlv->count * sizeof(struct rule_check_info),
		    M_TEMP, M_WAITOK | M_ZERO);

		/*
		 * Check each rule for validness.
		 * Ensure numbered rules are sorted ascending
		 * and properly aligned
		 */
		rulenum = 0;
		count = 0;
		error = 0;
		ci = cbuf;
		r = (struct ip_fw_rule *)(ctlv + 1);
		while (clen > 0) {
			rsize = RULEUSIZE1(r);
			if (rsize > clen || count > ctlv->count) {
				error = EINVAL;
				break;
			}
			ci->ctlv = tstate;
			ci->version = IP_FW3_OPVER;
			error = ipfw_check_rule(r, rsize, ci);
			if (error != 0)
				break;

			/* Check sorting */
			if (count != 0 && ((rulenum == 0) != (r->rulenum == 0) ||
			    r->rulenum < rulenum)) {
				printf("ipfw: wrong order: rulenum %u"
				    " vs %u\n", r->rulenum, rulenum);
				error = EINVAL;
				break;
			}
			rulenum = r->rulenum;
			ci->urule = (caddr_t)r;
			clen -= rsize;
			r = (struct ip_fw_rule *)((caddr_t)r + rsize);
			count++;
			ci++;
		}

		if (ctlv->count != count || error != 0) {
			free(cbuf, M_TEMP);
			return (EINVAL);
		}

		rtlv = ctlv;
		read += ctlv->head.length;
		ctlv = (ipfw_obj_ctlv *)((caddr_t)ctlv + ctlv->head.length);
	}

	if (read != sd->valsize || rtlv == NULL) {
		free(cbuf, M_TEMP);
		return (EINVAL);
	}

	*prtlv = rtlv;
	*pci = cbuf;
	return (0);
}

/*
 * Copy rule @urule from v1 userland format (current) to kernel @krule.
 */
static void
import_rule_v1(struct ip_fw_chain *chain, struct rule_check_info *ci)
{
	struct ip_fw_rule *urule;
	struct ip_fw *krule;

	urule = (struct ip_fw_rule *)ci->urule;
	krule = ci->krule = ipfw_alloc_rule(chain, RULEKSIZE1(urule));

	krule->act_ofs = urule->act_ofs;
	krule->cmd_len = urule->cmd_len;
	krule->rulenum = urule->rulenum;
	krule->set = urule->set;
	krule->flags = urule->flags;

	/* Save rulenum offset */
	ci->urule_numoff = offsetof(struct ip_fw_rule, rulenum);

	/* Copy opcodes */
	memcpy(krule->cmd, urule->cmd, krule->cmd_len * sizeof(uint32_t));
}

/*
 * Adds one or more rules to ipfw @chain.
 */
static int
add_rules(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_obj_ctlv *rtlv;
	struct rule_check_info *ci, *nci;
	int i, ret;

	/*
	 * Check rules buffer for validness.
	 */
	ret = parse_rules_v1(chain, op3, sd, &rtlv, &nci);
	if (ret != 0)
		return (ret);
	/*
	 * Allocate storage for the kernel representation of rules.
	 */
	for (i = 0, ci = nci; i < rtlv->count; i++, ci++)
		import_rule_v1(chain, ci);
	/*
	 * Try to add new rules to the chain.
	 */
	if ((ret = ipfw_commit_rules(chain, nci, rtlv->count)) != 0) {
		for (i = 0, ci = nci; i < rtlv->count; i++, ci++)
			ipfw_free_rule(ci->krule);
	}
	/* Cleanup after parse_rules() */
	free(nci, M_TEMP);
	return (ret);
}

/*
 * Lists all sopts currently registered.
 * Data layout (v1)(current):
 * Request: [ ipfw_obj_lheader ], size = ipfw_obj_lheader.size
 * Reply: [ ipfw_obj_lheader ipfw_sopt_info x N ]
 *
 * Returns 0 on success
 */
static int
dump_soptcodes(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	struct _ipfw_obj_lheader *olh;
	ipfw_sopt_info *i;
	struct ipfw_sopt_handler *sh;
	uint32_t count, n, size;

	olh = (struct _ipfw_obj_lheader *)ipfw_get_sopt_header(sd,
	    sizeof(*olh));
	if (olh == NULL)
		return (EINVAL);
	if (sd->valsize < olh->size)
		return (EINVAL);

	CTL3_LOCK();
	count = ctl3_hsize;
	size = count * sizeof(ipfw_sopt_info) + sizeof(ipfw_obj_lheader);

	/* Fill in header regadless of buffer size */
	olh->count = count;
	olh->objsize = sizeof(ipfw_sopt_info);

	if (size > olh->size) {
		olh->size = size;
		CTL3_UNLOCK();
		return (ENOMEM);
	}
	olh->size = size;

	for (n = 0; n < count; n++) {
		i = (ipfw_sopt_info *)ipfw_get_sopt_space(sd, sizeof(*i));
		KASSERT(i != NULL, ("previously checked buffer is not enough"));
		sh = &ctl3_handlers[n];
		i->opcode = sh->opcode;
		i->version = sh->version;
		i->refcnt = sh->refcnt;
	}
	CTL3_UNLOCK();

	return (0);
}

/*
 * Compares two opcodes.
 * Used both in qsort() and bsearch().
 *
 * Returns 0 if match is found.
 */
static int
compare_opcodes(const void *_a, const void *_b)
{
	const struct opcode_obj_rewrite *a, *b;

	a = (const struct opcode_obj_rewrite *)_a;
	b = (const struct opcode_obj_rewrite *)_b;

	if (a->opcode < b->opcode)
		return (-1);
	else if (a->opcode > b->opcode)
		return (1);

	return (0);
}

/*
 * XXX: Rewrite bsearch()
 */
static int
find_op_rw_range(uint16_t op, struct opcode_obj_rewrite **plo,
    struct opcode_obj_rewrite **phi)
{
	struct opcode_obj_rewrite *ctl3_max, *lo, *hi, h, *rw;

	memset(&h, 0, sizeof(h));
	h.opcode = op;

	rw = (struct opcode_obj_rewrite *)bsearch(&h, ctl3_rewriters,
	    ctl3_rsize, sizeof(h), compare_opcodes);
	if (rw == NULL)
		return (1);

	/* Find the first element matching the same opcode */
	lo = rw;
	for ( ; lo > ctl3_rewriters && (lo - 1)->opcode == op; lo--)
		;

	/* Find the last element matching the same opcode */
	hi = rw;
	ctl3_max = ctl3_rewriters + ctl3_rsize;
	for ( ; (hi + 1) < ctl3_max && (hi + 1)->opcode == op; hi++)
		;

	*plo = lo;
	*phi = hi;

	return (0);
}

/*
 * Finds opcode object rewriter based on @code.
 *
 * Returns pointer to handler or NULL.
 */
static struct opcode_obj_rewrite *
find_op_rw(ipfw_insn *cmd, uint32_t *puidx, uint8_t *ptype)
{
	struct opcode_obj_rewrite *rw, *lo, *hi;
	uint32_t uidx;
	uint8_t subtype;

	if (find_op_rw_range(cmd->opcode, &lo, &hi) != 0)
		return (NULL);

	for (rw = lo; rw <= hi; rw++) {
		if (rw->classifier(cmd, &uidx, &subtype) == 0) {
			if (puidx != NULL)
				*puidx = uidx;
			if (ptype != NULL)
				*ptype = subtype;
			return (rw);
		}
	}

	return (NULL);
}
int
classify_opcode_kidx(ipfw_insn *cmd, uint32_t *puidx)
{

	if (find_op_rw(cmd, puidx, NULL) == NULL)
		return (1);
	return (0);
}

void
update_opcode_kidx(ipfw_insn *cmd, uint32_t idx)
{
	struct opcode_obj_rewrite *rw;

	rw = find_op_rw(cmd, NULL, NULL);
	KASSERT(rw != NULL, ("No handler to update opcode %d", cmd->opcode));
	rw->update(cmd, idx);
}

void
ipfw_init_obj_rewriter(void)
{
	ctl3_rewriters = NULL;
	ctl3_rsize = 0;
}

void
ipfw_destroy_obj_rewriter(void)
{
	if (ctl3_rewriters != NULL)
		free(ctl3_rewriters, M_IPFW);
	ctl3_rewriters = NULL;
	ctl3_rsize = 0;
}

/*
 * Adds one or more opcode object rewrite handlers to the global array.
 * Function may sleep.
 */
void
ipfw_add_obj_rewriter(struct opcode_obj_rewrite *rw, size_t count)
{
	size_t sz;
	struct opcode_obj_rewrite *tmp;

	CTL3_LOCK();

	for (;;) {
		sz = ctl3_rsize + count;
		CTL3_UNLOCK();
		tmp = malloc(sizeof(*rw) * sz, M_IPFW, M_WAITOK | M_ZERO);
		CTL3_LOCK();
		if (ctl3_rsize + count <= sz)
			break;

		/* Retry */
		free(tmp, M_IPFW);
	}

	/* Merge old & new arrays */
	sz = ctl3_rsize + count;
	memcpy(tmp, ctl3_rewriters, ctl3_rsize * sizeof(*rw));
	memcpy(&tmp[ctl3_rsize], rw, count * sizeof(*rw));
	qsort(tmp, sz, sizeof(*rw), compare_opcodes);
	/* Switch new and free old */
	if (ctl3_rewriters != NULL)
		free(ctl3_rewriters, M_IPFW);
	ctl3_rewriters = tmp;
	ctl3_rsize = sz;

	CTL3_UNLOCK();
}

/*
 * Removes one or more object rewrite handlers from the global array.
 */
int
ipfw_del_obj_rewriter(struct opcode_obj_rewrite *rw, size_t count)
{
	size_t sz;
	struct opcode_obj_rewrite *ctl3_max, *ktmp, *lo, *hi;
	int i;

	CTL3_LOCK();

	for (i = 0; i < count; i++) {
		if (find_op_rw_range(rw[i].opcode, &lo, &hi) != 0)
			continue;

		for (ktmp = lo; ktmp <= hi; ktmp++) {
			if (ktmp->classifier != rw[i].classifier)
				continue;

			ctl3_max = ctl3_rewriters + ctl3_rsize;
			sz = (ctl3_max - (ktmp + 1)) * sizeof(*ktmp);
			memmove(ktmp, ktmp + 1, sz);
			ctl3_rsize--;
			break;
		}
	}

	if (ctl3_rsize == 0) {
		if (ctl3_rewriters != NULL)
			free(ctl3_rewriters, M_IPFW);
		ctl3_rewriters = NULL;
	}

	CTL3_UNLOCK();

	return (0);
}

static int
export_objhash_ntlv_internal(struct namedobj_instance *ni,
    struct named_object *no, void *arg)
{
	struct sockopt_data *sd;
	ipfw_obj_ntlv *ntlv;

	sd = (struct sockopt_data *)arg;
	ntlv = (ipfw_obj_ntlv *)ipfw_get_sopt_space(sd, sizeof(*ntlv));
	if (ntlv == NULL)
		return (ENOMEM);
	ipfw_export_obj_ntlv(no, ntlv);
	return (0);
}

/*
 * Lists all service objects.
 * Data layout (v0)(current):
 * Request: [ ipfw_obj_lheader ] size = ipfw_obj_lheader.size
 * Reply: [ ipfw_obj_lheader [ ipfw_obj_ntlv x N ] (optional) ]
 * Returns 0 on success
 */
static int
dump_srvobjects(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_obj_lheader *hdr;
	int count;

	hdr = (ipfw_obj_lheader *)ipfw_get_sopt_header(sd, sizeof(*hdr));
	if (hdr == NULL)
		return (EINVAL);

	IPFW_UH_RLOCK(chain);
	count = ipfw_objhash_count(CHAIN_TO_SRV(chain));
	hdr->size = sizeof(ipfw_obj_lheader) + count * sizeof(ipfw_obj_ntlv);
	if (sd->valsize < hdr->size) {
		IPFW_UH_RUNLOCK(chain);
		return (ENOMEM);
	}
	hdr->count = count;
	hdr->objsize = sizeof(ipfw_obj_ntlv);
	if (count > 0)
		ipfw_objhash_foreach(CHAIN_TO_SRV(chain),
		    export_objhash_ntlv_internal, sd);
	IPFW_UH_RUNLOCK(chain);
	return (0);
}

void
ipfw_enable_skipto_cache(struct ip_fw_chain *chain)
{

	IPFW_UH_WLOCK_ASSERT(chain);
	update_skipto_cache(chain, chain->map);

	IPFW_WLOCK(chain);
	swap_skipto_cache(chain);
	V_skipto_cache = 1;
	IPFW_WUNLOCK(chain);
}

/*
 * Enables or disable skipto cache.
 * Request: [ ipfw_cmd_header ] size = ipfw_cmd_header.size
 * Reply: [ ipfw_cmd_header ]
 * Returns 0 on success
 */
static int
manage_skiptocache(struct ip_fw_chain *chain, ip_fw3_opheader *op3,
    struct sockopt_data *sd)
{
	ipfw_cmd_header *hdr;

	if (sd->valsize != sizeof(*hdr))
		return (EINVAL);

	hdr = (ipfw_cmd_header *)ipfw_get_sopt_space(sd, sd->valsize);
	if (hdr->cmd != SKIPTO_CACHE_DISABLE &&
	    hdr->cmd != SKIPTO_CACHE_ENABLE)
		return (EOPNOTSUPP);

	IPFW_UH_WLOCK(chain);
	if (hdr->cmd != V_skipto_cache) {
		if (hdr->cmd == SKIPTO_CACHE_ENABLE)
			ipfw_enable_skipto_cache(chain);
		V_skipto_cache = hdr->cmd;
	}
	IPFW_UH_WUNLOCK(chain);
	return (0);
}

/*
 * Compares two sopt handlers (code, version and handler ptr).
 * Used both as qsort() and bsearch().
 * Does not compare handler for latter case.
 *
 * Returns 0 if match is found.
 */
static int
compare_sh(const void *_a, const void *_b)
{
	const struct ipfw_sopt_handler *a, *b;

	a = (const struct ipfw_sopt_handler *)_a;
	b = (const struct ipfw_sopt_handler *)_b;

	if (a->opcode < b->opcode)
		return (-1);
	else if (a->opcode > b->opcode)
		return (1);

	if (a->version < b->version)
		return (-1);
	else if (a->version > b->version)
		return (1);

	/* bsearch helper */
	if (a->handler == NULL)
		return (0);

	if ((uintptr_t)a->handler < (uintptr_t)b->handler)
		return (-1);
	else if ((uintptr_t)a->handler > (uintptr_t)b->handler)
		return (1);

	return (0);
}

/*
 * Finds sopt handler based on @code and @version.
 *
 * Returns pointer to handler or NULL.
 */
static struct ipfw_sopt_handler *
find_sh(uint16_t code, uint8_t version, sopt_handler_f *handler)
{
	struct ipfw_sopt_handler *sh, h;

	memset(&h, 0, sizeof(h));
	h.opcode = code;
	h.version = version;
	h.handler = handler;

	sh = (struct ipfw_sopt_handler *)bsearch(&h, ctl3_handlers,
	    ctl3_hsize, sizeof(h), compare_sh);

	return (sh);
}

static int
find_ref_sh(uint16_t opcode, uint8_t version, struct ipfw_sopt_handler *psh)
{
	struct ipfw_sopt_handler *sh;

	CTL3_LOCK();
	if ((sh = find_sh(opcode, version, NULL)) == NULL) {
		CTL3_UNLOCK();
		printf("ipfw: ipfw_ctl3 invalid option %d""v""%d\n",
		    opcode, version);
		return (EINVAL);
	}
	sh->refcnt++;
	ctl3_refct++;
	/* Copy handler data to requested buffer */
	*psh = *sh; 
	CTL3_UNLOCK();

	return (0);
}

static void
find_unref_sh(struct ipfw_sopt_handler *psh)
{
	struct ipfw_sopt_handler *sh;

	CTL3_LOCK();
	sh = find_sh(psh->opcode, psh->version, NULL);
	KASSERT(sh != NULL, ("ctl3 handler disappeared"));
	sh->refcnt--;
	ctl3_refct--;
	CTL3_UNLOCK();
}

void
ipfw_init_sopt_handler(void)
{
	CTL3_LOCK_INIT();
	IPFW_ADD_SOPT_HANDLER(1, scodes);
}

void
ipfw_destroy_sopt_handler(void)
{
	IPFW_DEL_SOPT_HANDLER(1, scodes);
	CTL3_LOCK_DESTROY();
}

void
ipfw_register_compat(ipfw_check_opcode_t f)
{
	check_opcode_f = f;
}

void
ipfw_unregister_compat(void)
{
	check_opcode_f = check_opcode_compat_nop;
}

/*
 * Adds one or more sockopt handlers to the global array.
 * Function may sleep.
 */
void
ipfw_add_sopt_handler(struct ipfw_sopt_handler *sh, size_t count)
{
	size_t sz;
	struct ipfw_sopt_handler *tmp;

	CTL3_LOCK();

	for (;;) {
		sz = ctl3_hsize + count;
		CTL3_UNLOCK();
		tmp = malloc(sizeof(*sh) * sz, M_IPFW, M_WAITOK | M_ZERO);
		CTL3_LOCK();
		if (ctl3_hsize + count <= sz)
			break;

		/* Retry */
		free(tmp, M_IPFW);
	}

	/* Merge old & new arrays */
	sz = ctl3_hsize + count;
	memcpy(tmp, ctl3_handlers, ctl3_hsize * sizeof(*sh));
	memcpy(&tmp[ctl3_hsize], sh, count * sizeof(*sh));
	qsort(tmp, sz, sizeof(*sh), compare_sh);
	/* Switch new and free old */
	if (ctl3_handlers != NULL)
		free(ctl3_handlers, M_IPFW);
	ctl3_handlers = tmp;
	ctl3_hsize = sz;
	ctl3_gencnt++;

	CTL3_UNLOCK();
}

/*
 * Removes one or more sockopt handlers from the global array.
 */
int
ipfw_del_sopt_handler(struct ipfw_sopt_handler *sh, size_t count)
{
	size_t sz;
	struct ipfw_sopt_handler *tmp, *h;
	int i;

	CTL3_LOCK();

	for (i = 0; i < count; i++) {
		tmp = &sh[i];
		h = find_sh(tmp->opcode, tmp->version, tmp->handler);
		if (h == NULL)
			continue;

		sz = (ctl3_handlers + ctl3_hsize - (h + 1)) * sizeof(*h);
		memmove(h, h + 1, sz);
		ctl3_hsize--;
	}

	if (ctl3_hsize == 0) {
		if (ctl3_handlers != NULL)
			free(ctl3_handlers, M_IPFW);
		ctl3_handlers = NULL;
	}

	ctl3_gencnt++;

	CTL3_UNLOCK();

	return (0);
}

/*
 * Writes data accumulated in @sd to sockopt buffer.
 * Zeroes internal @sd buffer.
 */
static int
ipfw_flush_sopt_data(struct sockopt_data *sd)
{
	struct sockopt *sopt;
	int error;
	size_t sz;

	sz = sd->koff;
	if (sz == 0)
		return (0);

	sopt = sd->sopt;

	if (sopt->sopt_dir == SOPT_GET) {
		error = copyout(sd->kbuf, sopt->sopt_val, sz);
		if (error != 0)
			return (error);
	}

	memset(sd->kbuf, 0, sd->ksize);
	sd->ktotal += sz;
	sd->koff = 0;
	if (sd->ktotal + sd->ksize < sd->valsize)
		sd->kavail = sd->ksize;
	else
		sd->kavail = sd->valsize - sd->ktotal;

	/* Update sopt buffer data */
	sopt->sopt_valsize = sd->ktotal;
	sopt->sopt_val = sd->sopt_val + sd->ktotal;

	return (0);
}

/*
 * Ensures that @sd buffer has contiguous @neeeded number of
 * bytes.
 *
 * Returns pointer to requested space or NULL.
 */
caddr_t
ipfw_get_sopt_space(struct sockopt_data *sd, size_t needed)
{
	int error;
	caddr_t addr;

	if (sd->kavail < needed) {
		/*
		 * Flush data and try another time.
		 */
		error = ipfw_flush_sopt_data(sd);

		if (sd->kavail < needed || error != 0)
			return (NULL);
	}

	addr = sd->kbuf + sd->koff;
	sd->koff += needed;
	sd->kavail -= needed;
	return (addr);
}

/*
 * Requests @needed contiguous bytes from @sd buffer.
 * Function is used to notify subsystem that we are
 * interesed in first @needed bytes (request header)
 * and the rest buffer can be safely zeroed.
 *
 * Returns pointer to requested space or NULL.
 */
caddr_t
ipfw_get_sopt_header(struct sockopt_data *sd, size_t needed)
{
	caddr_t addr;

	if ((addr = ipfw_get_sopt_space(sd, needed)) == NULL)
		return (NULL);

	if (sd->kavail > 0)
		memset(sd->kbuf + sd->koff, 0, sd->kavail);

	return (addr);
}

/*
 * New sockopt handler.
 */
int
ipfw_ctl3(struct sockopt *sopt)
{
	int error, locked;
	size_t size, valsize;
	struct ip_fw_chain *chain;
	char xbuf[256];
	struct sockopt_data sdata;
	struct ipfw_sopt_handler h;
	ip_fw3_opheader *op3 = NULL;

	error = priv_check(sopt->sopt_td, PRIV_NETINET_IPFW);
	if (error != 0)
		return (error);

	if (sopt->sopt_name != IP_FW3)
		return (EOPNOTSUPP);

	chain = &V_layer3_chain;
	error = 0;

	/* Save original valsize before it is altered via sooptcopyin() */
	valsize = sopt->sopt_valsize;
	memset(&sdata, 0, sizeof(sdata));
	/* Read op3 header first to determine actual operation */
	op3 = (ip_fw3_opheader *)xbuf;
	error = sooptcopyin(sopt, op3, sizeof(*op3), sizeof(*op3));
	if (error != 0)
		return (error);
	sopt->sopt_valsize = valsize;

	/*
	 * Find and reference command.
	 */
	error = find_ref_sh(op3->opcode, op3->version, &h);
	if (error != 0)
		return (error);

	/*
	 * Disallow modifications in really-really secure mode, but still allow
	 * the logging counters to be reset.
	 */
	if ((h.dir & HDIR_SET) != 0 && h.opcode != IP_FW_XRESETLOG) {
		error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
		if (error != 0) {
			find_unref_sh(&h);
			return (error);
		}
	}

	/*
	 * Fill in sockopt_data structure that may be useful for
	 * IP_FW3 get requests.
	 */
	locked = 0;
	if (valsize <= sizeof(xbuf)) {
		/* use on-stack buffer */
		sdata.kbuf = xbuf;
		sdata.ksize = sizeof(xbuf);
		sdata.kavail = valsize;
	} else {
		/*
		 * Determine opcode type/buffer size:
		 * allocate sliding-window buf for data export or
		 * contiguous buffer for special ops.
		 */
		if ((h.dir & HDIR_SET) != 0) {
			/* Set request. Allocate contigous buffer. */
			if (valsize > CTL3_LARGEBUF) {
				find_unref_sh(&h);
				return (EFBIG);
			}

			size = valsize;
		} else {
			/* Get request. Allocate sliding window buffer */
			size = (valsize<CTL3_SMALLBUF) ? valsize:CTL3_SMALLBUF;

			if (size < valsize) {
				/* We have to wire user buffer */
				error = vslock(sopt->sopt_val, valsize);
				if (error != 0)
					return (error);
				locked = 1;
			}
		}

		sdata.kbuf = malloc(size, M_TEMP, M_WAITOK | M_ZERO);
		sdata.ksize = size;
		sdata.kavail = size;
	}

	sdata.sopt = sopt;
	sdata.sopt_val = sopt->sopt_val;
	sdata.valsize = valsize;

	/*
	 * Copy either all request (if valsize < bsize_max)
	 * or first bsize_max bytes to guarantee most consumers
	 * that all necessary data has been copied).
	 * Anyway, copy not less than sizeof(ip_fw3_opheader).
	 */
	if ((error = sooptcopyin(sopt, sdata.kbuf, sdata.ksize,
	    sizeof(ip_fw3_opheader))) != 0)
		return (error);
	op3 = (ip_fw3_opheader *)sdata.kbuf;

	/* Finally, run handler */
	error = h.handler(chain, op3, &sdata);
	find_unref_sh(&h);

	/* Flush state and free buffers */
	if (error == 0)
		error = ipfw_flush_sopt_data(&sdata);
	else
		ipfw_flush_sopt_data(&sdata);

	if (locked != 0)
		vsunlock(sdata.sopt_val, valsize);

	/* Restore original pointer and set number of bytes written */
	sopt->sopt_val = sdata.sopt_val;
	sopt->sopt_valsize = sdata.ktotal;
	if (sdata.kbuf != xbuf)
		free(sdata.kbuf, M_TEMP);

	return (error);
}

/*
 * Named object api
 *
 */

void
ipfw_init_srv(struct ip_fw_chain *ch)
{
	ch->srvmap = ipfw_objhash_create(IPFW_OBJECTS_DEFAULT,
	    DEFAULT_OBJHASH_SIZE);
	ch->srvstate = malloc(sizeof(void *) * IPFW_OBJECTS_DEFAULT,
	    M_IPFW, M_WAITOK | M_ZERO);
}

void
ipfw_destroy_srv(struct ip_fw_chain *ch)
{
	free(ch->srvstate, M_IPFW);
	ipfw_objhash_destroy(ch->srvmap);
}

/*
 * Allocate new bitmask which can be used to enlarge/shrink
 * named instance index.
 */
void
ipfw_objhash_bitmap_alloc(uint32_t items, void **idx, int *pblocks)
{
	size_t size;
	int max_blocks;
	u_long *idx_mask;

	KASSERT((items % BLOCK_ITEMS) == 0,
	   ("bitmask size needs to power of 2 and greater or equal to %zu",
	    BLOCK_ITEMS));

	max_blocks = items / BLOCK_ITEMS;
	size = items / 8;
	idx_mask = malloc(size * IPFW_MAX_SETS, M_IPFW, M_WAITOK);
	/* Mark all as free */
	memset(idx_mask, 0xFF, size * IPFW_MAX_SETS);
	*idx_mask &= ~(u_long)1; /* Skip index 0 */

	*idx = idx_mask;
	*pblocks = max_blocks;
}

/*
 * Copy current bitmask index to new one.
 */
void
ipfw_objhash_bitmap_merge(struct namedobj_instance *ni, void **idx, int *blocks)
{
	int old_blocks, new_blocks;
	u_long *old_idx, *new_idx;
	int i;

	old_idx = ni->idx_mask;
	old_blocks = ni->max_blocks;
	new_idx = *idx;
	new_blocks = *blocks;

	for (i = 0; i < IPFW_MAX_SETS; i++) {
		memcpy(&new_idx[new_blocks * i], &old_idx[old_blocks * i],
		    old_blocks * sizeof(u_long));
	}
}

/*
 * Swaps current @ni index with new one.
 */
void
ipfw_objhash_bitmap_swap(struct namedobj_instance *ni, void **idx, int *blocks)
{
	int old_blocks;
	u_long *old_idx;

	old_idx = ni->idx_mask;
	old_blocks = ni->max_blocks;

	ni->idx_mask = *idx;
	ni->max_blocks = *blocks;

	/* Save old values */
	*idx = old_idx;
	*blocks = old_blocks;
}

void
ipfw_objhash_bitmap_free(void *idx, int blocks)
{
	free(idx, M_IPFW);
}

/*
 * Creates named hash instance.
 * Must be called without holding any locks.
 * Return pointer to new instance.
 */
struct namedobj_instance *
ipfw_objhash_create(uint32_t items, size_t hash_size)
{
	struct namedobj_instance *ni;
	int i;
	size_t size;

	size = sizeof(struct namedobj_instance) +
	    sizeof(struct namedobjects_head) * hash_size +
	    sizeof(struct namedobjects_head) * hash_size;

	ni = malloc(size, M_IPFW, M_WAITOK | M_ZERO);
	ni->nn_size = hash_size;
	ni->nv_size = hash_size;

	ni->names = (struct namedobjects_head *)(ni +1);
	ni->values = &ni->names[ni->nn_size];

	for (i = 0; i < ni->nn_size; i++)
		TAILQ_INIT(&ni->names[i]);

	for (i = 0; i < ni->nv_size; i++)
		TAILQ_INIT(&ni->values[i]);

	/* Set default hashing/comparison functions */
	ni->hash_f = objhash_hash_name;
	ni->cmp_f = objhash_cmp_name;

	/* Allocate bitmask separately due to possible resize */
	ipfw_objhash_bitmap_alloc(items, (void*)&ni->idx_mask, &ni->max_blocks);

	return (ni);
}

void
ipfw_objhash_destroy(struct namedobj_instance *ni)
{
	free(ni->idx_mask, M_IPFW);
	free(ni, M_IPFW);
}

void
ipfw_objhash_set_funcs(struct namedobj_instance *ni, objhash_hash_f *hash_f,
    objhash_cmp_f *cmp_f)
{

	ni->hash_f = hash_f;
	ni->cmp_f = cmp_f;
}

static uint32_t
objhash_hash_name(struct namedobj_instance *ni, const void *name, uint32_t set)
{

	return (fnv_32_str((const char *)name, FNV1_32_INIT));
}

static int
objhash_cmp_name(struct named_object *no, const void *name, uint32_t set)
{

	if ((strcmp(no->name, (const char *)name) == 0) && (no->set == set))
		return (0);

	return (1);
}

static uint32_t
objhash_hash_idx(struct namedobj_instance *ni, uint32_t val)
{
	uint32_t v;

	v = val % (ni->nv_size - 1);

	return (v);
}

struct named_object *
ipfw_objhash_lookup_name(struct namedobj_instance *ni, uint32_t set,
    const char *name)
{
	struct named_object *no;
	uint32_t hash;

	hash = ni->hash_f(ni, name, set) % ni->nn_size;

	TAILQ_FOREACH(no, &ni->names[hash], nn_next) {
		if (ni->cmp_f(no, name, set) == 0)
			return (no);
	}

	return (NULL);
}

/*
 * Find named object by @uid.
 * Check @tlvs for valid data inside.
 *
 * Returns pointer to found TLV or NULL.
 */
ipfw_obj_ntlv *
ipfw_find_name_tlv_type(void *tlvs, int len, uint32_t uidx, uint32_t etlv)
{
	ipfw_obj_ntlv *ntlv;
	uintptr_t pa, pe;
	int l;

	pa = (uintptr_t)tlvs;
	pe = pa + len;
	l = 0;
	for (; pa < pe; pa += l) {
		ntlv = (ipfw_obj_ntlv *)pa;
		l = ntlv->head.length;

		if (l != sizeof(*ntlv))
			return (NULL);

		if (ntlv->idx != uidx)
			continue;
		/*
		 * When userland has specified zero TLV type, do
		 * not compare it with eltv. In some cases userland
		 * doesn't know what type should it have. Use only
		 * uidx and name for search named_object.
		 */
		if (ntlv->head.type != 0 &&
		    ntlv->head.type != (uint16_t)etlv)
			continue;

		if (ipfw_check_object_name_generic(ntlv->name) != 0)
			return (NULL);

		return (ntlv);
	}

	return (NULL);
}

/*
 * Finds object config based on either legacy index
 * or name in ntlv.
 * Note @ti structure contains unchecked data from userland.
 *
 * Returns 0 in success and fills in @pno with found config
 */
int
ipfw_objhash_find_type(struct namedobj_instance *ni, struct tid_info *ti,
    uint32_t etlv, struct named_object **pno)
{
	char *name;
	ipfw_obj_ntlv *ntlv;
	uint32_t set;

	if (ti->tlvs == NULL)
		return (EINVAL);

	ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx, etlv);
	if (ntlv == NULL)
		return (EINVAL);
	name = ntlv->name;

	/*
	 * Use set provided by @ti instead of @ntlv one.
	 * This is needed due to different sets behavior
	 * controlled by V_fw_tables_sets.
	 */
	set = ti->set;
	*pno = ipfw_objhash_lookup_name(ni, set, name);
	if (*pno == NULL)
		return (ESRCH);
	return (0);
}

/*
 * Find named object by name, considering also its TLV type.
 */
struct named_object *
ipfw_objhash_lookup_name_type(struct namedobj_instance *ni, uint32_t set,
    uint32_t type, const char *name)
{
	struct named_object *no;
	uint32_t hash;

	hash = ni->hash_f(ni, name, set) % ni->nn_size;

	TAILQ_FOREACH(no, &ni->names[hash], nn_next) {
		if (ni->cmp_f(no, name, set) == 0 &&
		    no->etlv == (uint16_t)type)
			return (no);
	}

	return (NULL);
}

struct named_object *
ipfw_objhash_lookup_kidx(struct namedobj_instance *ni, uint32_t kidx)
{
	struct named_object *no;
	uint32_t hash;

	hash = objhash_hash_idx(ni, kidx);

	TAILQ_FOREACH(no, &ni->values[hash], nv_next) {
		if (no->kidx == kidx)
			return (no);
	}

	return (NULL);
}

int
ipfw_objhash_same_name(struct namedobj_instance *ni, struct named_object *a,
    struct named_object *b)
{

	if ((strcmp(a->name, b->name) == 0) && a->set == b->set)
		return (1);

	return (0);
}

void
ipfw_objhash_add(struct namedobj_instance *ni, struct named_object *no)
{
	uint32_t hash;

	hash = ni->hash_f(ni, no->name, no->set) % ni->nn_size;
	TAILQ_INSERT_HEAD(&ni->names[hash], no, nn_next);

	hash = objhash_hash_idx(ni, no->kidx);
	TAILQ_INSERT_HEAD(&ni->values[hash], no, nv_next);

	ni->count++;
}

void
ipfw_objhash_del(struct namedobj_instance *ni, struct named_object *no)
{
	uint32_t hash;

	hash = ni->hash_f(ni, no->name, no->set) % ni->nn_size;
	TAILQ_REMOVE(&ni->names[hash], no, nn_next);

	hash = objhash_hash_idx(ni, no->kidx);
	TAILQ_REMOVE(&ni->values[hash], no, nv_next);

	ni->count--;
}

uint32_t
ipfw_objhash_count(struct namedobj_instance *ni)
{

	return (ni->count);
}

uint32_t
ipfw_objhash_count_type(struct namedobj_instance *ni, uint16_t type)
{
	struct named_object *no;
	uint32_t count;
	int i;

	count = 0;
	for (i = 0; i < ni->nn_size; i++) {
		TAILQ_FOREACH(no, &ni->names[i], nn_next) {
			if (no->etlv == type)
				count++;
		}
	}
	return (count);
}

/*
 * Runs @func for each found named object.
 * It is safe to delete objects from callback
 */
int
ipfw_objhash_foreach(struct namedobj_instance *ni, objhash_cb_t *f, void *arg)
{
	struct named_object *no, *no_tmp;
	int i, ret;

	for (i = 0; i < ni->nn_size; i++) {
		TAILQ_FOREACH_SAFE(no, &ni->names[i], nn_next, no_tmp) {
			ret = f(ni, no, arg);
			if (ret != 0)
				return (ret);
		}
	}
	return (0);
}

/*
 * Runs @f for each found named object with type @type.
 * It is safe to delete objects from callback
 */
int
ipfw_objhash_foreach_type(struct namedobj_instance *ni, objhash_cb_t *f,
    void *arg, uint16_t type)
{
	struct named_object *no, *no_tmp;
	int i, ret;

	for (i = 0; i < ni->nn_size; i++) {
		TAILQ_FOREACH_SAFE(no, &ni->names[i], nn_next, no_tmp) {
			if (no->etlv != type)
				continue;
			ret = f(ni, no, arg);
			if (ret != 0)
				return (ret);
		}
	}
	return (0);
}

/*
 * Removes index from given set.
 * Returns 0 on success.
 */
int
ipfw_objhash_free_idx(struct namedobj_instance *ni, uint32_t idx)
{
	u_long *mask;
	int i, v;

	i = idx / BLOCK_ITEMS;
	v = idx % BLOCK_ITEMS;

	if (i >= ni->max_blocks)
		return (1);

	mask = &ni->idx_mask[i];

	if ((*mask & ((u_long)1 << v)) != 0)
		return (1);

	/* Mark as free */
	*mask |= (u_long)1 << v;

	/* Update free offset */
	if (ni->free_off[0] > i)
		ni->free_off[0] = i;

	return (0);
}

/*
 * Allocate new index in given instance and stores in in @pidx.
 * Returns 0 on success.
 */
int
ipfw_objhash_alloc_idx(void *n, uint32_t *pidx)
{
	struct namedobj_instance *ni;
	u_long *mask;
	int i, off, v;

	ni = (struct namedobj_instance *)n;

	off = ni->free_off[0];
	mask = &ni->idx_mask[off];

	for (i = off; i < ni->max_blocks; i++, mask++) {
		if ((v = ffsl(*mask)) == 0)
			continue;

		/* Mark as busy */
		*mask &= ~ ((u_long)1 << (v - 1));

		ni->free_off[0] = i;
		
		v = BLOCK_ITEMS * i + v - 1;

		*pidx = v;
		return (0);
	}

	return (1);
}

/* end of file */