1 /*- 2 * Copyright (c) 2013 The NetBSD Foundation, Inc. 3 * All rights reserved. 4 * 5 * This material is based upon work partially supported by The 6 * NetBSD Foundation under a contract with Mindaugas Rasiukevicius. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * NPF config loading mechanism. 32 * 33 * There are few main operations on the config: 34 * 1) Read access which is primarily from the npf_packet_handler() et al. 35 * 2) Write access on particular set, mainly rule or table updates. 36 * 3) Deletion of the config, which is done during the reload operation. 37 * 38 * Synchronisation 39 * 40 * For (1) case, passive serialisation is used to allow concurrent 41 * access to the configuration set (ruleset, etc). It guarantees 42 * that the config will not be destroyed while accessing it. 43 * 44 * Writers, i.e. cases (2) and (3) use mutual exclusion and when 45 * necessary writer-side barrier of the passive serialisation. 46 */ 47 48 #ifdef _KERNEL 49 #include <sys/cdefs.h> 50 __KERNEL_RCSID(0, "$NetBSD: npf_conf.c,v 1.15 2019/08/25 13:21:03 rmind Exp $"); 51 52 #include <sys/param.h> 53 #include <sys/types.h> 54 55 #include <sys/atomic.h> 56 #include <sys/kmem.h> 57 #include <sys/mutex.h> 58 #endif 59 60 #include "npf_impl.h" 61 #include "npf_conn.h" 62 63 void 64 npf_config_init(npf_t *npf) 65 { 66 npf_config_t *nc; 67 68 mutex_init(&npf->config_lock, MUTEX_DEFAULT, IPL_SOFTNET); 69 nc = npf_config_create(); 70 71 /* 72 * Load an empty configuration. 73 */ 74 nc->ruleset = npf_ruleset_create(0); 75 nc->nat_ruleset = npf_ruleset_create(0); 76 nc->rule_procs = npf_rprocset_create(); 77 nc->tableset = npf_tableset_create(0); 78 nc->default_pass = true; 79 80 npf_config_load(npf, nc, NULL, true); 81 KASSERT(npf->config != NULL); 82 } 83 84 npf_config_t * 85 npf_config_create(void) 86 { 87 return kmem_zalloc(sizeof(npf_config_t), KM_SLEEP); 88 } 89 90 void 91 npf_config_destroy(npf_config_t *nc) 92 { 93 /* 94 * Note: the rulesets must be destroyed first, in order to drop 95 * any references to the tableset. 96 */ 97 npf_ruleset_destroy(nc->ruleset); 98 npf_ruleset_destroy(nc->nat_ruleset); 99 npf_rprocset_destroy(nc->rule_procs); 100 npf_tableset_destroy(nc->tableset); 101 kmem_free(nc, sizeof(npf_config_t)); 102 } 103 104 void 105 npf_config_fini(npf_t *npf) 106 { 107 npf_conndb_t *cd = npf_conndb_create(); 108 109 /* Flush the connections. */ 110 mutex_enter(&npf->config_lock); 111 npf_conn_tracking(npf, false); 112 npf_ebr_full_sync(npf->ebr); 113 npf_conn_load(npf, cd, false); 114 npf_ifmap_flush(npf); 115 mutex_exit(&npf->config_lock); 116 117 npf_config_destroy(npf->config); 118 mutex_destroy(&npf->config_lock); 119 } 120 121 /* 122 * npf_config_load: the main routine performing configuration load. 123 * Performs the necessary synchronisation and destroys the old config. 124 */ 125 void 126 npf_config_load(npf_t *npf, npf_config_t *nc, npf_conndb_t *conns, bool flush) 127 { 128 const bool load = conns != NULL; 129 npf_config_t *onc; 130 131 nc->default_pass = flush; 132 133 /* 134 * Acquire the lock and perform the first phase: 135 * - Scan and use existing dynamic tables, reload only static. 136 * - Scan and use matching NAT policies to preserve the connections. 137 */ 138 mutex_enter(&npf->config_lock); 139 if ((onc = npf->config) != NULL) { 140 npf_ruleset_reload(npf, nc->ruleset, onc->ruleset, load); 141 npf_tableset_reload(npf, nc->tableset, onc->tableset); 142 npf_ruleset_reload(npf, nc->nat_ruleset, onc->nat_ruleset, load); 143 } 144 145 /* 146 * Set the new config and release the lock. 147 */ 148 membar_sync(); 149 npf->config = nc; 150 if (onc == NULL) { 151 /* Initial load, done. */ 152 npf_ifmap_flush(npf); 153 npf_conn_load(npf, conns, !flush); 154 mutex_exit(&npf->config_lock); 155 goto done; 156 } 157 158 /* 159 * If we are going to flush the connections or load the new ones, 160 * then disable the connection tracking for the grace period. 161 */ 162 if (flush || conns) { 163 npf_conn_tracking(npf, false); 164 } 165 166 /* Synchronise: drain all references. */ 167 npf_ebr_full_sync(npf->ebr); 168 if (flush) { 169 npf_portmap_flush(npf->portmap); 170 npf_ifmap_flush(npf); 171 } 172 173 /* 174 * G/C the existing connections and, if passed, load the new ones. 175 * If not flushing - enable the connection tracking. 176 */ 177 npf_conn_load(npf, conns, !flush); 178 mutex_exit(&npf->config_lock); 179 180 /* Finally, it is safe to destroy the old config. */ 181 npf_config_destroy(onc); 182 done: 183 /* Sync all interface address tables (can be done asynchronously). */ 184 npf_ifaddr_syncall(npf); 185 } 186 187 /* 188 * Writer-side exclusive locking. 189 */ 190 191 npf_config_t * 192 npf_config_enter(npf_t *npf) 193 { 194 mutex_enter(&npf->config_lock); 195 return npf->config; 196 } 197 198 void 199 npf_config_exit(npf_t *npf) 200 { 201 mutex_exit(&npf->config_lock); 202 } 203 204 bool 205 npf_config_locked_p(npf_t *npf) 206 { 207 return mutex_owned(&npf->config_lock); 208 } 209 210 void 211 npf_config_sync(npf_t *npf) 212 { 213 KASSERT(npf_config_locked_p(npf)); 214 npf_ebr_full_sync(npf->ebr); 215 } 216 217 /* 218 * Reader-side synchronisation routines. 219 */ 220 221 int 222 npf_config_read_enter(npf_t *npf) 223 { 224 return npf_ebr_enter(npf->ebr); 225 } 226 227 void 228 npf_config_read_exit(npf_t *npf, int s) 229 { 230 npf_ebr_exit(npf->ebr, s); 231 } 232 233 /* 234 * Accessors. 235 */ 236 237 npf_ruleset_t * 238 npf_config_ruleset(npf_t *npf) 239 { 240 KASSERT(npf_config_locked_p(npf) || npf_ebr_incrit_p(npf->ebr)); 241 return npf->config->ruleset; 242 } 243 244 npf_ruleset_t * 245 npf_config_natset(npf_t *npf) 246 { 247 KASSERT(npf_config_locked_p(npf) || npf_ebr_incrit_p(npf->ebr)); 248 return npf->config->nat_ruleset; 249 } 250 251 npf_tableset_t * 252 npf_config_tableset(npf_t *npf) 253 { 254 KASSERT(npf_config_locked_p(npf) || npf_ebr_incrit_p(npf->ebr)); 255 return npf->config->tableset; 256 } 257 258 bool 259 npf_default_pass(npf_t *npf) 260 { 261 KASSERT(npf_config_locked_p(npf) || npf_ebr_incrit_p(npf->ebr)); 262 return npf->config->default_pass; 263 } 264