1 /*- 2 * Copyright (c) 1980, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)if.c 8.5 (Berkeley) 1/9/95 30 * $FreeBSD$ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/malloc.h> 35 #include <sys/lock.h> 36 #include <sys/mutex.h> 37 #include <sys/kernel.h> 38 #include <sys/systm.h> 39 #include <sys/types.h> 40 #include <sys/socket.h> 41 42 #include <net/if.h> 43 #include <net/if_clone.h> 44 #if 0 45 #include <net/if_dl.h> 46 #endif 47 #include <net/if_types.h> 48 #include <net/if_var.h> 49 #include <net/radix.h> 50 #include <net/route.h> 51 52 static void if_clone_free(struct if_clone *ifc); 53 54 static struct mtx if_cloners_mtx; 55 static int if_cloners_count; 56 LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners); 57 58 #define IF_CLONERS_LOCK_INIT() \ 59 mtx_init(&if_cloners_mtx, "if_cloners lock", NULL, MTX_DEF) 60 #define IF_CLONERS_LOCK_ASSERT() mtx_assert(&if_cloners_mtx, MA_OWNED) 61 #define IF_CLONERS_LOCK() mtx_lock(&if_cloners_mtx) 62 #define IF_CLONERS_UNLOCK() mtx_unlock(&if_cloners_mtx) 63 64 #define IF_CLONE_LOCK_INIT(ifc) \ 65 mtx_init(&(ifc)->ifc_mtx, "if_clone lock", NULL, MTX_DEF) 66 #define IF_CLONE_LOCK_DESTROY(ifc) mtx_destroy(&(ifc)->ifc_mtx) 67 #define IF_CLONE_LOCK_ASSERT(ifc) mtx_assert(&(ifc)->ifc_mtx, MA_OWNED) 68 #define IF_CLONE_LOCK(ifc) mtx_lock(&(ifc)->ifc_mtx) 69 #define IF_CLONE_UNLOCK(ifc) mtx_unlock(&(ifc)->ifc_mtx) 70 71 #define IF_CLONE_ADDREF(ifc) \ 72 do { \ 73 IF_CLONE_LOCK(ifc); \ 74 IF_CLONE_ADDREF_LOCKED(ifc); \ 75 IF_CLONE_UNLOCK(ifc); \ 76 } while (0) 77 #define IF_CLONE_ADDREF_LOCKED(ifc) \ 78 do { \ 79 IF_CLONE_LOCK_ASSERT(ifc); \ 80 KASSERT((ifc)->ifc_refcnt >= 0, \ 81 ("negative refcnt %ld", (ifc)->ifc_refcnt)); \ 82 (ifc)->ifc_refcnt++; \ 83 } while (0) 84 #define IF_CLONE_REMREF(ifc) \ 85 do { \ 86 IF_CLONE_LOCK(ifc); \ 87 IF_CLONE_REMREF_LOCKED(ifc); \ 88 } while (0) 89 #define IF_CLONE_REMREF_LOCKED(ifc) \ 90 do { \ 91 IF_CLONE_LOCK_ASSERT(ifc); \ 92 KASSERT((ifc)->ifc_refcnt > 0, \ 93 ("bogus refcnt %ld", (ifc)->ifc_refcnt)); \ 94 if (--(ifc)->ifc_refcnt == 0) { \ 95 IF_CLONE_UNLOCK(ifc); \ 96 if_clone_free(ifc); \ 97 } else { \ 98 /* silently free the lock */ \ 99 IF_CLONE_UNLOCK(ifc); \ 100 } \ 101 } while (0) 102 103 static MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework"); 104 105 void 106 if_clone_init(void) 107 { 108 IF_CLONERS_LOCK_INIT(); 109 } 110 111 /* 112 * Create a clone network interface. 113 */ 114 int 115 if_clone_create(char *name, size_t len) 116 { 117 int err; 118 struct if_clone *ifc; 119 120 if (ifunit(name) != NULL) 121 return (EEXIST); 122 123 /* Try to find an applicable cloner for this request */ 124 IF_CLONERS_LOCK(); 125 LIST_FOREACH(ifc, &if_cloners, ifc_list) { 126 if (ifc->ifc_match(ifc, name)) { 127 break; 128 } 129 } 130 IF_CLONERS_UNLOCK(); 131 132 if (ifc == NULL) 133 return (EINVAL); 134 135 err = (*ifc->ifc_create)(ifc, name, len); 136 return (err); 137 } 138 139 /* 140 * Destroy a clone network interface. 141 */ 142 int 143 if_clone_destroy(const char *name) 144 { 145 int err; 146 struct if_clone *ifc; 147 struct ifnet *ifp; 148 149 ifp = ifunit(name); 150 if (ifp == NULL) 151 return (ENXIO); 152 153 /* Find the cloner for this interface */ 154 IF_CLONERS_LOCK(); 155 LIST_FOREACH(ifc, &if_cloners, ifc_list) { 156 if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) { 157 break; 158 } 159 } 160 IF_CLONERS_UNLOCK(); 161 if (ifc == NULL) 162 return (EINVAL); 163 164 if (ifc->ifc_destroy == NULL) { 165 err = EOPNOTSUPP; 166 goto done; 167 } 168 169 err = (*ifc->ifc_destroy)(ifc, ifp); 170 171 done: 172 return (err); 173 } 174 175 /* 176 * Register a network interface cloner. 177 */ 178 void 179 if_clone_attach(struct if_clone *ifc) 180 { 181 int len, maxclone; 182 183 /* 184 * Compute bitmap size and allocate it. 185 */ 186 maxclone = ifc->ifc_maxunit + 1; 187 len = maxclone >> 3; 188 if ((len << 3) < maxclone) 189 len++; 190 ifc->ifc_units = malloc(len, M_CLONE, M_WAITOK | M_ZERO); 191 ifc->ifc_bmlen = len; 192 IF_CLONE_LOCK_INIT(ifc); 193 IF_CLONE_ADDREF(ifc); 194 195 IF_CLONERS_LOCK(); 196 LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list); 197 if_cloners_count++; 198 IF_CLONERS_UNLOCK(); 199 200 if (ifc->ifc_attach != NULL) 201 (*ifc->ifc_attach)(ifc); 202 EVENTHANDLER_INVOKE(if_clone_event, ifc); 203 } 204 205 /* 206 * Unregister a network interface cloner. 207 */ 208 void 209 if_clone_detach(struct if_clone *ifc) 210 { 211 struct ifc_simple_data *ifcs = ifc->ifc_data; 212 213 IF_CLONERS_LOCK(); 214 LIST_REMOVE(ifc, ifc_list); 215 if_cloners_count--; 216 IF_CLONERS_UNLOCK(); 217 218 /* Allow all simples to be destroyed */ 219 if (ifc->ifc_attach == ifc_simple_attach) 220 ifcs->ifcs_minifs = 0; 221 222 IF_CLONE_REMREF(ifc); 223 } 224 225 static void 226 if_clone_free(struct if_clone *ifc) 227 { 228 for (int bytoff = 0; bytoff < ifc->ifc_bmlen; bytoff++) { 229 KASSERT(ifc->ifc_units[bytoff] == 0x00, 230 ("ifc_units[%d] is not empty", bytoff)); 231 } 232 233 IF_CLONE_LOCK_DESTROY(ifc); 234 free(ifc->ifc_units, M_CLONE); 235 } 236 237 /* 238 * Provide list of interface cloners to userspace. 239 */ 240 int 241 if_clone_list(struct if_clonereq *ifcr) 242 { 243 char *buf, *dst, *outbuf = NULL; 244 struct if_clone *ifc; 245 int buf_count, count, err = 0; 246 247 if (ifcr->ifcr_count < 0) 248 return (EINVAL); 249 250 IF_CLONERS_LOCK(); 251 /* 252 * Set our internal output buffer size. We could end up not 253 * reporting a cloner that is added between the unlock and lock 254 * below, but that's not a major problem. Not caping our 255 * allocation to the number of cloners actually in the system 256 * could be because that would let arbitrary users cause us to 257 * allocate abritrary amounts of kernel memory. 258 */ 259 buf_count = (if_cloners_count < ifcr->ifcr_count) ? 260 if_cloners_count : ifcr->ifcr_count; 261 IF_CLONERS_UNLOCK(); 262 263 outbuf = malloc(IFNAMSIZ*buf_count, M_CLONE, M_WAITOK | M_ZERO); 264 265 IF_CLONERS_LOCK(); 266 267 ifcr->ifcr_total = if_cloners_count; 268 if ((dst = ifcr->ifcr_buffer) == NULL) { 269 /* Just asking how many there are. */ 270 goto done; 271 } 272 count = (if_cloners_count < buf_count) ? 273 if_cloners_count : buf_count; 274 275 for (ifc = LIST_FIRST(&if_cloners), buf = outbuf; 276 ifc != NULL && count != 0; 277 ifc = LIST_NEXT(ifc, ifc_list), count--, buf += IFNAMSIZ) { 278 strlcpy(buf, ifc->ifc_name, IFNAMSIZ); 279 } 280 281 done: 282 IF_CLONERS_UNLOCK(); 283 if (err == 0) 284 err = copyout(outbuf, dst, buf_count*IFNAMSIZ); 285 if (outbuf != NULL) 286 free(outbuf, M_CLONE); 287 return (err); 288 } 289 290 /* 291 * A utility function to extract unit numbers from interface names of 292 * the form name###. 293 * 294 * Returns 0 on success and an error on failure. 295 */ 296 int 297 ifc_name2unit(const char *name, int *unit) 298 { 299 const char *cp; 300 301 for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++); 302 if (*cp == '\0') { 303 *unit = -1; 304 } else { 305 for (*unit = 0; *cp != '\0'; cp++) { 306 if (*cp < '0' || *cp > '9') { 307 /* Bogus unit number. */ 308 return (EINVAL); 309 } 310 *unit = (*unit * 10) + (*cp - '0'); 311 } 312 } 313 314 return (0); 315 } 316 317 int 318 ifc_alloc_unit(struct if_clone *ifc, int *unit) 319 { 320 int wildcard, bytoff, bitoff; 321 int err = 0; 322 323 IF_CLONE_LOCK(ifc); 324 325 bytoff = bitoff = 0; 326 wildcard = (*unit < 0); 327 /* 328 * Find a free unit if none was given. 329 */ 330 if (wildcard) { 331 while ((bytoff < ifc->ifc_bmlen) 332 && (ifc->ifc_units[bytoff] == 0xff)) 333 bytoff++; 334 if (bytoff >= ifc->ifc_bmlen) { 335 err = ENOSPC; 336 goto done; 337 } 338 while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) 339 bitoff++; 340 *unit = (bytoff << 3) + bitoff; 341 } 342 343 if (*unit > ifc->ifc_maxunit) { 344 err = ENOSPC; 345 goto done; 346 } 347 348 if (!wildcard) { 349 bytoff = *unit >> 3; 350 bitoff = *unit - (bytoff << 3); 351 } 352 353 if((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) { 354 err = EEXIST; 355 goto done; 356 } 357 /* 358 * Allocate the unit in the bitmap. 359 */ 360 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) == 0, 361 ("%s: bit is already set", __func__)); 362 ifc->ifc_units[bytoff] |= (1 << bitoff); 363 IF_CLONE_ADDREF_LOCKED(ifc); 364 365 done: 366 IF_CLONE_UNLOCK(ifc); 367 return (err); 368 } 369 370 void 371 ifc_free_unit(struct if_clone *ifc, int unit) 372 { 373 int bytoff, bitoff; 374 375 376 /* 377 * Compute offset in the bitmap and deallocate the unit. 378 */ 379 bytoff = unit >> 3; 380 bitoff = unit - (bytoff << 3); 381 382 IF_CLONE_LOCK(ifc); 383 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0, 384 ("%s: bit is already cleared", __func__)); 385 ifc->ifc_units[bytoff] &= ~(1 << bitoff); 386 IF_CLONE_REMREF_LOCKED(ifc); /* releases lock */ 387 } 388 389 void 390 ifc_simple_attach(struct if_clone *ifc) 391 { 392 int err; 393 int unit; 394 char name[IFNAMSIZ]; 395 struct ifc_simple_data *ifcs = ifc->ifc_data; 396 397 KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit, 398 ("%s: %s requested more units then allowed (%d > %d)", 399 __func__, ifc->ifc_name, ifcs->ifcs_minifs, 400 ifc->ifc_maxunit + 1)); 401 402 for (unit = 0; unit < ifcs->ifcs_minifs; unit++) { 403 snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit); 404 err = (*ifc->ifc_create)(ifc, name, IFNAMSIZ); 405 KASSERT(err == 0, 406 ("%s: failed to create required interface %s", 407 __func__, name)); 408 } 409 } 410 411 int 412 ifc_simple_match(struct if_clone *ifc, const char *name) 413 { 414 const char *cp; 415 int i; 416 417 /* Match the name */ 418 for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) { 419 if (ifc->ifc_name[i] != *cp) 420 return (0); 421 } 422 423 /* Make sure there's a unit number or nothing after the name */ 424 for (; *cp != '\0'; cp++) { 425 if (*cp < '0' || *cp > '9') 426 return (0); 427 } 428 429 return (1); 430 } 431 432 int 433 ifc_simple_create(struct if_clone *ifc, char *name, size_t len) 434 { 435 char *dp; 436 int wildcard; 437 int unit; 438 int err; 439 struct ifc_simple_data *ifcs = ifc->ifc_data; 440 441 err = ifc_name2unit(name, &unit); 442 if (err != 0) 443 return (err); 444 445 wildcard = (unit < 0); 446 447 err = ifc_alloc_unit(ifc, &unit); 448 if (err != 0) 449 return (err); 450 451 err = ifcs->ifcs_create(ifc, unit); 452 if (err != 0) { 453 ifc_free_unit(ifc, unit); 454 return (err); 455 } 456 457 /* In the wildcard case, we need to update the name. */ 458 if (wildcard) { 459 for (dp = name; *dp != '\0'; dp++); 460 if (snprintf(dp, len - (dp-name), "%d", unit) > 461 len - (dp-name) - 1) { 462 /* 463 * This can only be a programmer error and 464 * there's no straightforward way to recover if 465 * it happens. 466 */ 467 panic("if_clone_create(): interface name too long"); 468 } 469 470 } 471 472 return (0); 473 } 474 475 int 476 ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp) 477 { 478 int unit; 479 struct ifc_simple_data *ifcs = ifc->ifc_data; 480 481 unit = ifp->if_dunit; 482 483 if (unit < ifcs->ifcs_minifs) 484 return (EINVAL); 485 486 ifcs->ifcs_destroy(ifp); 487 488 ifc_free_unit(ifc, unit); 489 490 return (0); 491 } 492