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/* $NetBSD: npf_conf.c,v 1.5 2013/11/22 00:25:51 rmind Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This material is based upon work partially supported by The
* NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* NPF config loading mechanism.
*
* There are few main operations on the config:
* 1) Read access which is primarily from the npf_packet_handler() et al.
* 2) Write access on particular set, mainly rule or table updates.
* 3) Deletion of the config, which is done during the reload operation.
*
* Synchronisation
*
* For (1) case, passive serialisation is used to allow concurrent
* access to the configuration set (ruleset, etc). It guarantees
* that the config will not be destroyed while accessing it.
*
* Writers, i.e. cases (2) and (3) use mutual exclusion and when
* necessary writer-side barrier of the passive serialisation.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: npf_conf.c,v 1.5 2013/11/22 00:25:51 rmind Exp $");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/atomic.h>
#include <sys/kmem.h>
#include <sys/pserialize.h>
#include <sys/mutex.h>
#include "npf_impl.h"
typedef struct {
npf_ruleset_t * n_rules;
npf_tableset_t * n_tables;
npf_ruleset_t * n_nat_rules;
npf_rprocset_t * n_rprocs;
prop_dictionary_t n_dict;
bool n_default_pass;
} npf_config_t;
static npf_config_t * npf_config __cacheline_aligned;
static kmutex_t npf_config_lock __cacheline_aligned;
static pserialize_t npf_config_psz __cacheline_aligned;
void
npf_config_init(void)
{
prop_dictionary_t dict;
npf_ruleset_t *rlset, *nset;
npf_rprocset_t *rpset;
npf_tableset_t *tset;
mutex_init(&npf_config_lock, MUTEX_DEFAULT, IPL_SOFTNET);
npf_config_psz = pserialize_create();
/* Load the empty configuration. */
dict = prop_dictionary_create();
tset = npf_tableset_create(0);
rpset = npf_rprocset_create();
rlset = npf_ruleset_create(0);
nset = npf_ruleset_create(0);
npf_config_reload(dict, rlset, tset, nset, rpset, true);
KASSERT(npf_config != NULL);
}
static void
npf_config_destroy(npf_config_t *nc)
{
prop_object_release(nc->n_dict);
npf_ruleset_destroy(nc->n_rules);
npf_ruleset_destroy(nc->n_nat_rules);
npf_rprocset_destroy(nc->n_rprocs);
npf_tableset_destroy(nc->n_tables);
kmem_free(nc, sizeof(npf_config_t));
}
void
npf_config_fini(void)
{
mutex_enter(&npf_config_lock);
pserialize_perform(npf_config_psz);
npf_ifmap_flush();
mutex_exit(&npf_config_lock);
npf_config_destroy(npf_config);
pserialize_destroy(npf_config_psz);
mutex_destroy(&npf_config_lock);
}
/*
* npf_config_reload: the main routine performing configuration reload.
* Performs the necessary synchronisation and destroys the old config.
*/
void
npf_config_reload(prop_dictionary_t dict, npf_ruleset_t *rset,
npf_tableset_t *tset, npf_ruleset_t *nset, npf_rprocset_t *rpset,
bool flush)
{
npf_config_t *nc, *onc;
nc = kmem_zalloc(sizeof(npf_config_t), KM_SLEEP);
nc->n_rules = rset;
nc->n_tables = tset;
nc->n_nat_rules = nset;
nc->n_rprocs = rpset;
nc->n_dict = dict;
nc->n_default_pass = flush;
/*
* Acquire the lock and perform the first phase:
* - Scan and use existing dynamic tables, reload only static.
* - Scan and use matching NAT policies to preserve the connections.
*/
mutex_enter(&npf_config_lock);
if ((onc = npf_config) != NULL) {
npf_ruleset_reload(rset, onc->n_rules);
npf_tableset_reload(tset, onc->n_tables);
npf_ruleset_natreload(nset, onc->n_nat_rules);
}
/*
* Set the new config and release the lock.
*/
membar_sync();
npf_config = nc;
if (onc == NULL) {
/* Initial load, done. */
npf_ifmap_flush();
mutex_exit(&npf_config_lock);
return;
}
/* Synchronise: drain all references. */
pserialize_perform(npf_config_psz);
if (flush) {
npf_ifmap_flush();
}
/* Sync the config proplib data. */
npf_tableset_syncdict(tset, dict);
mutex_exit(&npf_config_lock);
/* Finally, it is safe to destroy the old config. */
npf_config_destroy(onc);
}
/*
* Writer-side exclusive locking.
*/
void
npf_config_enter(void)
{
mutex_enter(&npf_config_lock);
}
void
npf_config_exit(void)
{
mutex_exit(&npf_config_lock);
}
bool
npf_config_locked_p(void)
{
return mutex_owned(&npf_config_lock);
}
void
npf_config_sync(void)
{
KASSERT(npf_config_locked_p());
pserialize_perform(npf_config_psz);
}
/*
* Reader-side synchronisation routines.
*/
int
npf_config_read_enter(void)
{
return pserialize_read_enter();
}
void
npf_config_read_exit(int s)
{
pserialize_read_exit(s);
}
/*
* Accessors.
*/
npf_ruleset_t *
npf_config_ruleset(void)
{
return npf_config->n_rules;
}
npf_ruleset_t *
npf_config_natset(void)
{
return npf_config->n_nat_rules;
}
npf_tableset_t *
npf_config_tableset(void)
{
return npf_config->n_tables;
}
prop_dictionary_t
npf_config_dict(void)
{
return npf_config->n_dict;
}
bool
npf_default_pass(void)
{
return npf_config->n_default_pass;
}
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