npf.c revision 1.7.2.6
1 /* $NetBSD: npf.c,v 1.7.2.6 2012/11/24 04:34:42 riz Exp $ */ 2 3 /*- 4 * Copyright (c) 2009-2012 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 main: dynamic load/initialisation and unload routines. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: npf.c,v 1.7.2.6 2012/11/24 04:34:42 riz Exp $"); 38 39 #include <sys/param.h> 40 #include <sys/types.h> 41 42 #include <sys/atomic.h> 43 #include <sys/conf.h> 44 #include <sys/kauth.h> 45 #include <sys/kmem.h> 46 #include <sys/lwp.h> 47 #include <sys/module.h> 48 #include <sys/percpu.h> 49 #include <sys/rwlock.h> 50 #include <sys/socketvar.h> 51 #include <sys/sysctl.h> 52 #include <sys/uio.h> 53 54 #include "npf_impl.h" 55 56 /* 57 * Module and device structures. 58 */ 59 MODULE(MODULE_CLASS_DRIVER, npf, NULL); 60 61 void npfattach(int); 62 63 static int npf_fini(void); 64 static int npf_dev_open(dev_t, int, int, lwp_t *); 65 static int npf_dev_close(dev_t, int, int, lwp_t *); 66 static int npf_dev_ioctl(dev_t, u_long, void *, int, lwp_t *); 67 static int npf_dev_poll(dev_t, int, lwp_t *); 68 static int npf_dev_read(dev_t, struct uio *, int); 69 70 typedef struct { 71 npf_ruleset_t * n_rules; 72 npf_tableset_t * n_tables; 73 npf_ruleset_t * n_nat_rules; 74 prop_dictionary_t n_dict; 75 bool n_default_pass; 76 } npf_core_t; 77 78 static void npf_core_destroy(npf_core_t *); 79 static int npfctl_stats(void *); 80 81 static krwlock_t npf_lock __cacheline_aligned; 82 static npf_core_t * npf_core __cacheline_aligned; 83 static percpu_t * npf_stats_percpu __read_mostly; 84 static struct sysctllog * npf_sysctl __read_mostly; 85 86 const struct cdevsw npf_cdevsw = { 87 npf_dev_open, npf_dev_close, npf_dev_read, nowrite, npf_dev_ioctl, 88 nostop, notty, npf_dev_poll, nommap, nokqfilter, D_OTHER | D_MPSAFE 89 }; 90 91 static int 92 npf_init(void) 93 { 94 #ifdef _MODULE 95 devmajor_t bmajor = NODEVMAJOR, cmajor = NODEVMAJOR; 96 #endif 97 npf_ruleset_t *rset, *nset; 98 npf_tableset_t *tset; 99 prop_dictionary_t dict; 100 int error = 0; 101 102 rw_init(&npf_lock); 103 npf_stats_percpu = percpu_alloc(NPF_STATS_SIZE); 104 npf_sysctl = NULL; 105 106 npf_tableset_sysinit(); 107 npf_session_sysinit(); 108 npf_nat_sysinit(); 109 npf_alg_sysinit(); 110 npf_ext_sysinit(); 111 112 /* Load empty configuration. */ 113 dict = prop_dictionary_create(); 114 rset = npf_ruleset_create(); 115 tset = npf_tableset_create(); 116 nset = npf_ruleset_create(); 117 npf_reload(dict, rset, tset, nset, true); 118 KASSERT(npf_core != NULL); 119 120 #ifdef _MODULE 121 /* Attach /dev/npf device. */ 122 error = devsw_attach("npf", NULL, &bmajor, &npf_cdevsw, &cmajor); 123 if (error) { 124 /* It will call devsw_detach(), which is safe. */ 125 (void)npf_fini(); 126 } 127 #endif 128 return error; 129 } 130 131 static int 132 npf_fini(void) 133 { 134 135 /* At first, detach device and remove pfil hooks. */ 136 #ifdef _MODULE 137 devsw_detach(NULL, &npf_cdevsw); 138 #endif 139 npf_pfil_unregister(); 140 141 /* Flush all sessions, destroy configuration (ruleset, etc). */ 142 npf_session_tracking(false); 143 npf_core_destroy(npf_core); 144 145 /* Finally, safe to destroy the subsystems. */ 146 npf_ext_sysfini(); 147 npf_alg_sysfini(); 148 npf_nat_sysfini(); 149 npf_session_sysfini(); 150 npf_tableset_sysfini(); 151 152 if (npf_sysctl) { 153 sysctl_teardown(&npf_sysctl); 154 } 155 percpu_free(npf_stats_percpu, NPF_STATS_SIZE); 156 rw_destroy(&npf_lock); 157 158 return 0; 159 } 160 161 /* 162 * Module interface. 163 */ 164 static int 165 npf_modcmd(modcmd_t cmd, void *arg) 166 { 167 168 switch (cmd) { 169 case MODULE_CMD_INIT: 170 return npf_init(); 171 case MODULE_CMD_FINI: 172 return npf_fini(); 173 case MODULE_CMD_AUTOUNLOAD: 174 if (npf_autounload_p()) { 175 return EBUSY; 176 } 177 break; 178 default: 179 return ENOTTY; 180 } 181 return 0; 182 } 183 184 void 185 npfattach(int nunits) 186 { 187 188 /* Void. */ 189 } 190 191 static int 192 npf_dev_open(dev_t dev, int flag, int mode, lwp_t *l) 193 { 194 195 /* Available only for super-user. */ 196 if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL)) { 197 return EPERM; 198 } 199 return 0; 200 } 201 202 static int 203 npf_dev_close(dev_t dev, int flag, int mode, lwp_t *l) 204 { 205 206 return 0; 207 } 208 209 static int 210 npf_dev_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 211 { 212 int error; 213 214 /* Available only for super-user. */ 215 if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL)) { 216 return EPERM; 217 } 218 219 switch (cmd) { 220 case IOC_NPF_VERSION: 221 *(int *)data = NPF_VERSION; 222 error = 0; 223 break; 224 case IOC_NPF_SWITCH: 225 error = npfctl_switch(data); 226 break; 227 case IOC_NPF_RELOAD: 228 error = npfctl_reload(cmd, data); 229 break; 230 case IOC_NPF_GETCONF: 231 error = npfctl_getconf(cmd, data); 232 break; 233 case IOC_NPF_TABLE: 234 error = npfctl_table(data); 235 break; 236 case IOC_NPF_STATS: 237 error = npfctl_stats(data); 238 break; 239 case IOC_NPF_SESSIONS_SAVE: 240 error = npfctl_sessions_save(cmd, data); 241 break; 242 case IOC_NPF_SESSIONS_LOAD: 243 error = npfctl_sessions_load(cmd, data); 244 break; 245 case IOC_NPF_UPDATE_RULE: 246 error = npfctl_update_rule(cmd, data); 247 break; 248 default: 249 error = ENOTTY; 250 break; 251 } 252 return error; 253 } 254 255 static int 256 npf_dev_poll(dev_t dev, int events, lwp_t *l) 257 { 258 259 return ENOTSUP; 260 } 261 262 static int 263 npf_dev_read(dev_t dev, struct uio *uio, int flag) 264 { 265 266 return ENOTSUP; 267 } 268 269 /* 270 * NPF core loading/reloading/unloading mechanism. 271 */ 272 273 static void 274 npf_core_destroy(npf_core_t *nc) 275 { 276 277 prop_object_release(nc->n_dict); 278 npf_ruleset_destroy(nc->n_rules); 279 npf_ruleset_destroy(nc->n_nat_rules); 280 npf_tableset_destroy(nc->n_tables); 281 kmem_free(nc, sizeof(npf_core_t)); 282 } 283 284 /* 285 * npf_reload: atomically load new ruleset, tableset and NAT policies. 286 * Then destroy old (unloaded) structures. 287 */ 288 void 289 npf_reload(prop_dictionary_t dict, npf_ruleset_t *rset, 290 npf_tableset_t *tset, npf_ruleset_t *nset, bool flush) 291 { 292 npf_core_t *nc, *onc; 293 294 /* Setup a new core structure. */ 295 nc = kmem_zalloc(sizeof(npf_core_t), KM_SLEEP); 296 nc->n_rules = rset; 297 nc->n_tables = tset; 298 nc->n_nat_rules = nset; 299 nc->n_dict = dict; 300 nc->n_default_pass = flush; 301 302 /* Lock and load the core structure. */ 303 rw_enter(&npf_lock, RW_WRITER); 304 onc = atomic_swap_ptr(&npf_core, nc); 305 if (onc) { 306 /* Reload only the static tables. */ 307 npf_tableset_reload(tset, onc->n_tables); 308 /* Reload only the necessary NAT policies. */ 309 npf_ruleset_natreload(nset, onc->n_nat_rules); 310 } 311 /* Unlock. Everything goes "live" now. */ 312 rw_exit(&npf_lock); 313 314 if (onc) { 315 /* Destroy unloaded structures. */ 316 npf_core_destroy(onc); 317 } 318 } 319 320 void 321 npf_core_enter(void) 322 { 323 rw_enter(&npf_lock, RW_READER); 324 } 325 326 npf_ruleset_t * 327 npf_core_ruleset(void) 328 { 329 KASSERT(rw_lock_held(&npf_lock)); 330 return npf_core->n_rules; 331 } 332 333 npf_ruleset_t * 334 npf_core_natset(void) 335 { 336 KASSERT(rw_lock_held(&npf_lock)); 337 return npf_core->n_nat_rules; 338 } 339 340 npf_tableset_t * 341 npf_core_tableset(void) 342 { 343 KASSERT(rw_lock_held(&npf_lock)); 344 return npf_core->n_tables; 345 } 346 347 void 348 npf_core_exit(void) 349 { 350 rw_exit(&npf_lock); 351 } 352 353 bool 354 npf_core_locked(void) 355 { 356 return rw_lock_held(&npf_lock); 357 } 358 359 prop_dictionary_t 360 npf_core_dict(void) 361 { 362 KASSERT(rw_lock_held(&npf_lock)); 363 return npf_core->n_dict; 364 } 365 366 bool 367 npf_default_pass(void) 368 { 369 KASSERT(rw_lock_held(&npf_lock)); 370 return npf_core->n_default_pass; 371 } 372 373 bool 374 npf_autounload_p(void) 375 { 376 return !npf_pfil_registered_p() && npf_default_pass(); 377 } 378 379 /* 380 * NPF statistics interface. 381 */ 382 383 void 384 npf_stats_inc(npf_stats_t st) 385 { 386 uint64_t *stats = percpu_getref(npf_stats_percpu); 387 stats[st]++; 388 percpu_putref(npf_stats_percpu); 389 } 390 391 void 392 npf_stats_dec(npf_stats_t st) 393 { 394 uint64_t *stats = percpu_getref(npf_stats_percpu); 395 stats[st]--; 396 percpu_putref(npf_stats_percpu); 397 } 398 399 static void 400 npf_stats_collect(void *mem, void *arg, struct cpu_info *ci) 401 { 402 uint64_t *percpu_stats = mem, *full_stats = arg; 403 int i; 404 405 for (i = 0; i < NPF_STATS_COUNT; i++) { 406 full_stats[i] += percpu_stats[i]; 407 } 408 } 409 410 /* 411 * npfctl_stats: export collected statistics. 412 */ 413 static int 414 npfctl_stats(void *data) 415 { 416 uint64_t *fullst, *uptr = *(uint64_t **)data; 417 int error; 418 419 fullst = kmem_zalloc(NPF_STATS_SIZE, KM_SLEEP); 420 percpu_foreach(npf_stats_percpu, npf_stats_collect, fullst); 421 error = copyout(fullst, uptr, NPF_STATS_SIZE); 422 kmem_free(fullst, NPF_STATS_SIZE); 423 return error; 424 } 425
Indexes created Wed Oct 22 13:09:56 GMT 2025