1 /* $NetBSD: npf_rproc.c,v 1.10 2014/05/19 18:45:51 jakllsch Exp $ */ 2 3 /*- 4 * Copyright (c) 2009-2013 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 extension and rule procedure interface. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD"); 38 39 #include <sys/param.h> 40 #include <sys/types.h> 41 42 #include <sys/atomic.h> 43 #include <sys/kmem.h> 44 #include <sys/mutex.h> 45 #include <sys/module.h> 46 47 #include "npf_impl.h" 48 49 #define EXT_NAME_LEN 32 50 51 typedef struct npf_ext { 52 char ext_callname[EXT_NAME_LEN]; 53 LIST_ENTRY(npf_ext) ext_entry; 54 const npf_ext_ops_t * ext_ops; 55 unsigned ext_refcnt; 56 } npf_ext_t; 57 58 struct npf_rprocset { 59 LIST_HEAD(, npf_rproc) rps_list; 60 }; 61 62 #define RPROC_NAME_LEN 32 63 #define RPROC_EXT_COUNT 16 64 65 struct npf_rproc { 66 /* Flags and reference count. */ 67 uint32_t rp_flags; 68 u_int rp_refcnt; 69 70 /* Associated extensions and their metadata . */ 71 unsigned rp_ext_count; 72 npf_ext_t * rp_ext[RPROC_EXT_COUNT]; 73 void * rp_ext_meta[RPROC_EXT_COUNT]; 74 75 /* Name of the procedure and list entry. */ 76 char rp_name[RPROC_NAME_LEN]; 77 LIST_ENTRY(npf_rproc) rp_entry; 78 }; 79 80 static LIST_HEAD(, npf_ext) ext_list __cacheline_aligned; 81 static kmutex_t ext_lock __cacheline_aligned; 82 83 void 84 npf_ext_sysinit(void) 85 { 86 mutex_init(&ext_lock, MUTEX_DEFAULT, IPL_NONE); 87 LIST_INIT(&ext_list); 88 } 89 90 void 91 npf_ext_sysfini(void) 92 { 93 KASSERT(LIST_EMPTY(&ext_list)); 94 mutex_destroy(&ext_lock); 95 } 96 97 /* 98 * NPF extension management for the rule procedures. 99 */ 100 101 static const char npf_ext_prefix[] = "npf_ext_"; 102 #define NPF_EXT_PREFLEN (sizeof(npf_ext_prefix) - 1) 103 104 static npf_ext_t * 105 npf_ext_lookup(const char *name, bool autoload) 106 { 107 npf_ext_t *ext; 108 char modname[RPROC_NAME_LEN + NPF_EXT_PREFLEN]; 109 int error; 110 111 KASSERT(mutex_owned(&ext_lock)); 112 113 again: 114 LIST_FOREACH(ext, &ext_list, ext_entry) 115 if (strcmp(ext->ext_callname, name) == 0) 116 break; 117 118 if (ext != NULL || !autoload) 119 return ext; 120 121 mutex_exit(&ext_lock); 122 autoload = false; 123 snprintf(modname, sizeof(modname), "%s%s", npf_ext_prefix, name); 124 error = module_autoload(modname, MODULE_CLASS_MISC); 125 mutex_enter(&ext_lock); 126 127 if (error) 128 return NULL; 129 goto again; 130 } 131 132 void * 133 npf_ext_register(const char *name, const npf_ext_ops_t *ops) 134 { 135 npf_ext_t *ext; 136 137 ext = kmem_zalloc(sizeof(npf_ext_t), KM_SLEEP); 138 strlcpy(ext->ext_callname, name, EXT_NAME_LEN); 139 ext->ext_ops = ops; 140 141 mutex_enter(&ext_lock); 142 if (npf_ext_lookup(name, false)) { 143 mutex_exit(&ext_lock); 144 kmem_free(ext, sizeof(npf_ext_t)); 145 return NULL; 146 } 147 LIST_INSERT_HEAD(&ext_list, ext, ext_entry); 148 mutex_exit(&ext_lock); 149 150 return (void *)ext; 151 } 152 153 int 154 npf_ext_unregister(void *extid) 155 { 156 npf_ext_t *ext = extid; 157 158 /* 159 * Check if in-use first (re-check with the lock held). 160 */ 161 if (ext->ext_refcnt) { 162 return EBUSY; 163 } 164 165 mutex_enter(&ext_lock); 166 if (ext->ext_refcnt) { 167 mutex_exit(&ext_lock); 168 return EBUSY; 169 } 170 KASSERT(npf_ext_lookup(ext->ext_callname, false)); 171 LIST_REMOVE(ext, ext_entry); 172 mutex_exit(&ext_lock); 173 174 kmem_free(ext, sizeof(npf_ext_t)); 175 return 0; 176 } 177 178 int 179 npf_ext_construct(const char *name, npf_rproc_t *rp, prop_dictionary_t params) 180 { 181 const npf_ext_ops_t *extops; 182 npf_ext_t *ext; 183 unsigned i; 184 int error; 185 186 if (rp->rp_ext_count >= RPROC_EXT_COUNT) { 187 return ENOSPC; 188 } 189 190 mutex_enter(&ext_lock); 191 ext = npf_ext_lookup(name, true); 192 if (ext) { 193 atomic_inc_uint(&ext->ext_refcnt); 194 } 195 mutex_exit(&ext_lock); 196 197 if (!ext) { 198 return ENOENT; 199 } 200 201 extops = ext->ext_ops; 202 KASSERT(extops != NULL); 203 204 error = extops->ctor(rp, params); 205 if (error) { 206 atomic_dec_uint(&ext->ext_refcnt); 207 return error; 208 } 209 i = rp->rp_ext_count++; 210 rp->rp_ext[i] = ext; 211 return 0; 212 } 213 214 /* 215 * Rule procedure management. 216 */ 217 218 npf_rprocset_t * 219 npf_rprocset_create(void) 220 { 221 npf_rprocset_t *rpset; 222 223 rpset = kmem_zalloc(sizeof(npf_rprocset_t), KM_SLEEP); 224 LIST_INIT(&rpset->rps_list); 225 return rpset; 226 } 227 228 void 229 npf_rprocset_destroy(npf_rprocset_t *rpset) 230 { 231 npf_rproc_t *rp; 232 233 while ((rp = LIST_FIRST(&rpset->rps_list)) != NULL) { 234 LIST_REMOVE(rp, rp_entry); 235 npf_rproc_release(rp); 236 } 237 kmem_free(rpset, sizeof(npf_rprocset_t)); 238 } 239 240 /* 241 * npf_rproc_lookup: find a rule procedure by the name. 242 */ 243 npf_rproc_t * 244 npf_rprocset_lookup(npf_rprocset_t *rpset, const char *name) 245 { 246 npf_rproc_t *rp; 247 248 LIST_FOREACH(rp, &rpset->rps_list, rp_entry) { 249 if (strncmp(rp->rp_name, name, RPROC_NAME_LEN) == 0) 250 break; 251 } 252 return rp; 253 } 254 255 /* 256 * npf_rproc_insert: insert a new rule procedure into the set. 257 */ 258 void 259 npf_rprocset_insert(npf_rprocset_t *rpset, npf_rproc_t *rp) 260 { 261 LIST_INSERT_HEAD(&rpset->rps_list, rp, rp_entry); 262 } 263 264 /* 265 * npf_rproc_create: construct a new rule procedure, lookup and associate 266 * the extension calls with it. 267 */ 268 npf_rproc_t * 269 npf_rproc_create(prop_dictionary_t rpdict) 270 { 271 const char *name; 272 npf_rproc_t *rp; 273 274 if (!prop_dictionary_get_cstring_nocopy(rpdict, "name", &name)) { 275 return NULL; 276 } 277 278 rp = kmem_intr_zalloc(sizeof(npf_rproc_t), KM_SLEEP); 279 rp->rp_refcnt = 1; 280 281 strlcpy(rp->rp_name, name, RPROC_NAME_LEN); 282 prop_dictionary_get_uint32(rpdict, "flags", &rp->rp_flags); 283 return rp; 284 } 285 286 /* 287 * npf_rproc_acquire: acquire the reference on the rule procedure. 288 */ 289 void 290 npf_rproc_acquire(npf_rproc_t *rp) 291 { 292 atomic_inc_uint(&rp->rp_refcnt); 293 } 294 295 /* 296 * npf_rproc_release: drop the reference count and destroy the rule 297 * procedure on the last reference. 298 */ 299 void 300 npf_rproc_release(npf_rproc_t *rp) 301 { 302 303 KASSERT(rp->rp_refcnt > 0); 304 if (atomic_dec_uint_nv(&rp->rp_refcnt) != 0) { 305 return; 306 } 307 /* XXXintr */ 308 for (unsigned i = 0; i < rp->rp_ext_count; i++) { 309 npf_ext_t *ext = rp->rp_ext[i]; 310 const npf_ext_ops_t *extops = ext->ext_ops; 311 312 extops->dtor(rp, rp->rp_ext_meta[i]); 313 atomic_dec_uint(&ext->ext_refcnt); 314 } 315 kmem_intr_free(rp, sizeof(npf_rproc_t)); 316 } 317 318 void 319 npf_rproc_assign(npf_rproc_t *rp, void *params) 320 { 321 unsigned i = rp->rp_ext_count; 322 323 /* Note: params may be NULL. */ 324 KASSERT(i < RPROC_EXT_COUNT); 325 rp->rp_ext_meta[i] = params; 326 } 327 328 /* 329 * npf_rproc_run: run the rule procedure by executing each extension call. 330 * 331 * => Reference on the rule procedure must be held. 332 */ 333 bool 334 npf_rproc_run(npf_cache_t *npc, nbuf_t *nbuf, npf_rproc_t *rp, int *decision) 335 { 336 const unsigned extcount = rp->rp_ext_count; 337 338 KASSERT(!nbuf_flag_p(nbuf, NBUF_DATAREF_RESET)); 339 KASSERT(rp->rp_refcnt > 0); 340 341 for (unsigned i = 0; i < extcount; i++) { 342 const npf_ext_t *ext = rp->rp_ext[i]; 343 const npf_ext_ops_t *extops = ext->ext_ops; 344 345 KASSERT(ext->ext_refcnt > 0); 346 if (!extops->proc(npc, nbuf, rp->rp_ext_meta[i], decision)) { 347 return false; 348 } 349 350 if (nbuf_flag_p(nbuf, NBUF_DATAREF_RESET)) { 351 npf_recache(npc, nbuf); 352 } 353 } 354 355 return true; 356 } 357