1 /* $NetBSD: npf_conf.c,v 1.6 2014/05/30 23:26:06 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 1.6 2014/05/30 23:26:06 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 63 typedef 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 72 static npf_config_t * npf_config __cacheline_aligned; 73 static kmutex_t npf_config_lock __cacheline_aligned; 74 static pserialize_t npf_config_psz __cacheline_aligned; 75 76 void 77 npf_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(0); 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 97 static void 98 npf_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 } 107 108 void 109 npf_config_fini(void) 110 { 111 mutex_enter(&npf_config_lock); 112 pserialize_perform(npf_config_psz); 113 npf_ifmap_flush(); 114 mutex_exit(&npf_config_lock); 115 116 npf_config_destroy(npf_config); 117 pserialize_destroy(npf_config_psz); 118 mutex_destroy(&npf_config_lock); 119 } 120 121 /* 122 * npf_config_reload: the main routine performing configuration reload. 123 * Performs the necessary synchronisation and destroys the old config. 124 */ 125 void 126 npf_config_reload(prop_dictionary_t dict, npf_ruleset_t *rset, 127 npf_tableset_t *tset, npf_ruleset_t *nset, npf_rprocset_t *rpset, 128 bool flush) 129 { 130 npf_config_t *nc, *onc; 131 132 nc = kmem_zalloc(sizeof(npf_config_t), KM_SLEEP); 133 nc->n_rules = rset; 134 nc->n_tables = tset; 135 nc->n_nat_rules = nset; 136 nc->n_rprocs = rpset; 137 nc->n_dict = dict; 138 nc->n_default_pass = flush; 139 140 /* 141 * Acquire the lock and perform the first phase: 142 * - Scan and use existing dynamic tables, reload only static. 143 * - Scan and use matching NAT policies to preserve the connections. 144 */ 145 mutex_enter(&npf_config_lock); 146 if ((onc = npf_config) != NULL) { 147 npf_ruleset_reload(rset, onc->n_rules); 148 npf_tableset_reload(tset, onc->n_tables); 149 npf_ruleset_reload(nset, onc->n_nat_rules); 150 } 151 152 /* 153 * Set the new config and release the lock. 154 */ 155 membar_sync(); 156 npf_config = nc; 157 if (onc == NULL) { 158 /* Initial load, done. */ 159 npf_ifmap_flush(); 160 mutex_exit(&npf_config_lock); 161 return; 162 } 163 164 /* Synchronise: drain all references. */ 165 pserialize_perform(npf_config_psz); 166 if (flush) { 167 npf_ifmap_flush(); 168 } 169 170 /* Sync the config proplib data. */ 171 npf_tableset_syncdict(tset, dict); 172 mutex_exit(&npf_config_lock); 173 174 /* Finally, it is safe to destroy the old config. */ 175 npf_config_destroy(onc); 176 } 177 178 /* 179 * Writer-side exclusive locking. 180 */ 181 182 void 183 npf_config_enter(void) 184 { 185 mutex_enter(&npf_config_lock); 186 } 187 188 void 189 npf_config_exit(void) 190 { 191 mutex_exit(&npf_config_lock); 192 } 193 194 bool 195 npf_config_locked_p(void) 196 { 197 return mutex_owned(&npf_config_lock); 198 } 199 200 void 201 npf_config_sync(void) 202 { 203 KASSERT(npf_config_locked_p()); 204 pserialize_perform(npf_config_psz); 205 } 206 207 /* 208 * Reader-side synchronisation routines. 209 */ 210 211 int 212 npf_config_read_enter(void) 213 { 214 return pserialize_read_enter(); 215 } 216 217 void 218 npf_config_read_exit(int s) 219 { 220 pserialize_read_exit(s); 221 } 222 223 /* 224 * Accessors. 225 */ 226 227 npf_ruleset_t * 228 npf_config_ruleset(void) 229 { 230 return npf_config->n_rules; 231 } 232 233 npf_ruleset_t * 234 npf_config_natset(void) 235 { 236 return npf_config->n_nat_rules; 237 } 238 239 npf_tableset_t * 240 npf_config_tableset(void) 241 { 242 return npf_config->n_tables; 243 } 244 245 prop_dictionary_t 246 npf_config_dict(void) 247 { 248 return npf_config->n_dict; 249 } 250 251 bool 252 npf_default_pass(void) 253 { 254 return npf_config->n_default_pass; 255 } 256