1/* $NetBSD: npf_conf.c,v 1.1 2013/02/09 03:35:31 rmind Exp $ */ 2 3/*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This material is based upon work partially supported by The 8 * NetBSD Foundation under a contract with Mindaugas Rasiukevicius. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32/* 33 * NPF config loading mechanism. 34 * 35 * There are few main operations on the config: 36 * 1) Read access which is primarily from the npf_packet_handler() et al. 37 * 2) Write access on particular set, mainly rule or table updates. 38 * 3) Deletion of the config, which is done during the reload operation. 39 * 40 * Synchronisation 41 * 42 * For (1) case, passive serialisation is used to allow concurrent 43 * access to the configuration set (ruleset, etc). It guarantees 44 * that the config will not be destroyed while accessing it. 45 * 46 * Writers, i.e. cases (2) and (3) use mutual exclusion and when 47 * necessary writer-side barrier of the passive serialisation. 48 */ 49 50#include <sys/cdefs.h> 51__KERNEL_RCSID(0, "$NetBSD: npf_conf.c,v 1.1 2013/02/09 03:35:31 rmind Exp $"); 52 53#include <sys/param.h> 54#include <sys/types.h> 55 56#include <sys/atomic.h> 57#include <sys/kmem.h> 58#include <sys/pserialize.h> 59#include <sys/mutex.h> 60 61#include "npf_impl.h" 62 63typedef struct { 64 npf_ruleset_t * n_rules; 65 npf_tableset_t * n_tables; 66 npf_ruleset_t * n_nat_rules; 67 npf_rprocset_t * n_rprocs; 68 prop_dictionary_t n_dict; 69 bool n_default_pass; 70} npf_config_t; 71 72static npf_config_t * npf_config __cacheline_aligned; 73static kmutex_t npf_config_lock __cacheline_aligned; 74static pserialize_t npf_config_psz __cacheline_aligned; 75 76void 77npf_config_init(void) 78{ 79 prop_dictionary_t dict; 80 npf_ruleset_t *rlset, *nset; 81 npf_rprocset_t *rpset; 82 npf_tableset_t *tset; 83 84 mutex_init(&npf_config_lock, MUTEX_DEFAULT, IPL_SOFTNET); 85 npf_config_psz = pserialize_create(); 86 87 /* Load the empty configuration. */ 88 dict = prop_dictionary_create(); 89 tset = npf_tableset_create(); 90 rpset = npf_rprocset_create(); 91 rlset = npf_ruleset_create(0); 92 nset = npf_ruleset_create(0); 93 npf_config_reload(dict, rlset, tset, nset, rpset, true); 94 KASSERT(npf_config != NULL); 95} 96 97static void 98npf_config_destroy(npf_config_t *nc) 99{ 100 prop_object_release(nc->n_dict); 101 npf_ruleset_destroy(nc->n_rules); 102 npf_ruleset_destroy(nc->n_nat_rules); 103 npf_rprocset_destroy(nc->n_rprocs); 104 npf_tableset_destroy(nc->n_tables); 105 kmem_free(nc, sizeof(npf_config_t)); 106} 107 108void 109npf_config_fini(void) 110{ 111 npf_config_destroy(npf_config); 112 pserialize_destroy(npf_config_psz); 113 mutex_destroy(&npf_config_lock); 114} 115 116/* 117 * npf_config_reload: the main routine performing configuration reload. 118 * Performs the necessary synchronisation and destroys the old config. 119 */ 120void 121npf_config_reload(prop_dictionary_t dict, npf_ruleset_t *rset, 122 npf_tableset_t *tset, npf_ruleset_t *nset, npf_rprocset_t *rpset, 123 bool flush) 124{ 125 npf_config_t *nc, *onc; 126 127 nc = kmem_zalloc(sizeof(npf_config_t), KM_SLEEP); 128 nc->n_rules = rset; 129 nc->n_tables = tset; 130 nc->n_nat_rules = nset; 131 nc->n_rprocs = rpset; 132 nc->n_dict = dict; 133 nc->n_default_pass = flush; 134 135 /* 136 * Acquire the lock and perform the first phase: 137 * - Scan and use existing dynamic tables, reload only static. 138 * - Scan and use matching NAT policies to preserve the connections. 139 */ 140 mutex_enter(&npf_config_lock); 141 if ((onc = npf_config) != NULL) { 142 npf_ruleset_reload(rset, onc->n_rules); 143 npf_tableset_reload(tset, onc->n_tables); 144 npf_ruleset_natreload(nset, onc->n_nat_rules); 145 } 146 147 /* 148 * Set the new config and release the lock. 149 */ 150 membar_sync(); 151 npf_config = nc; 152 if (onc == NULL) { 153 /* Initial load, done. */ 154 mutex_exit(&npf_config_lock); 155 return; 156 } 157 158 /* Synchronise: drain all references. */ 159 pserialize_perform(npf_config_psz); 160 mutex_exit(&npf_config_lock); 161 162 /* Finally, it is safe to destroy the old config. */ 163 npf_config_destroy(onc); 164} 165 166/* 167 * Writer-side exclusive locking. 168 */ 169 170void 171npf_config_enter(void) 172{ 173 mutex_enter(&npf_config_lock); 174} 175 176void 177npf_config_exit(void) 178{ 179 mutex_exit(&npf_config_lock); 180} 181 182bool 183npf_config_locked_p(void) 184{ 185 return mutex_owned(&npf_config_lock); 186} 187 188void 189npf_config_sync(void) 190{ 191 KASSERT(npf_config_locked_p()); 192 pserialize_perform(npf_config_psz); 193} 194 195/* 196 * Reader-side synchronisation routines. 197 */ 198 199int 200npf_config_read_enter(void) 201{ 202 return pserialize_read_enter(); 203} 204 205void 206npf_config_read_exit(int s) 207{ 208 pserialize_read_exit(s); 209} 210 211/* 212 * Accessors. 213 */ 214 215npf_ruleset_t * 216npf_config_ruleset(void) 217{ 218 return npf_config->n_rules; 219} 220 221npf_ruleset_t * 222npf_config_natset(void) 223{ 224 return npf_config->n_nat_rules; 225} 226 227npf_tableset_t * 228npf_config_tableset(void) 229{ 230 return npf_config->n_tables; 231} 232 233prop_dictionary_t 234npf_config_dict(void) 235{ 236 return npf_config->n_dict; 237} 238 239bool 240npf_default_pass(void) 241{ 242 return npf_config->n_default_pass; 243} 244