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 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 IF_CLONE_ADDREF(ifc); 128 break; 129 } 130 } 131 IF_CLONERS_UNLOCK(); 132 133 if (ifc == NULL) 134 return (EINVAL); 135 136 err = (*ifc->ifc_create)(ifc, name, len); 137 IF_CLONE_REMREF(ifc); 138 return (err); 139 } 140 141 /* 142 * Destroy a clone network interface. 143 */ 144 int 145 if_clone_destroy(const char *name) 146 { 147 int err; 148 struct if_clone *ifc; 149 struct ifnet *ifp; 150 151 ifp = ifunit(name); 152 if (ifp == NULL) 153 return (ENXIO); 154 155 /* Find the cloner for this interface */ 156 IF_CLONERS_LOCK(); 157 LIST_FOREACH(ifc, &if_cloners, ifc_list) { 158 if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) { 159 IF_CLONE_ADDREF(ifc); 160 break; 161 } 162 } 163 IF_CLONERS_UNLOCK(); 164 if (ifc == NULL) 165 return (EINVAL); 166 167 if (ifc->ifc_destroy == NULL) { 168 err = EOPNOTSUPP; 169 goto done; 170 } 171 172 err = (*ifc->ifc_destroy)(ifc, ifp); 173 174 done: 175 IF_CLONE_REMREF(ifc); 176 return (err); 177 } 178 179 /* 180 * Register a network interface cloner. 181 */ 182 void 183 if_clone_attach(struct if_clone *ifc) 184 { 185 int len, maxclone; 186 187 /* 188 * Compute bitmap size and allocate it. 189 */ 190 maxclone = ifc->ifc_maxunit + 1; 191 len = maxclone >> 3; 192 if ((len << 3) < maxclone) 193 len++; 194 ifc->ifc_units = malloc(len, M_CLONE, M_WAITOK | M_ZERO); 195 ifc->ifc_bmlen = len; 196 IF_CLONE_LOCK_INIT(ifc); 197 IF_CLONE_ADDREF(ifc); 198 199 IF_CLONERS_LOCK(); 200 LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list); 201 if_cloners_count++; 202 IF_CLONERS_UNLOCK(); 203 204 if (ifc->ifc_attach != NULL) 205 (*ifc->ifc_attach)(ifc); 206 EVENTHANDLER_INVOKE(if_clone_event, ifc); 207 } 208 209 /* 210 * Unregister a network interface cloner. 211 */ 212 void 213 if_clone_detach(struct if_clone *ifc) 214 { 215 216 IF_CLONERS_LOCK(); 217 LIST_REMOVE(ifc, ifc_list); 218 if_cloners_count--; 219 IF_CLONERS_UNLOCK(); 220 221 IF_CLONE_REMREF(ifc); 222 } 223 224 static void 225 if_clone_free(struct if_clone *ifc) 226 { 227 228 IF_CLONE_LOCK_DESTROY(ifc); 229 free(ifc->ifc_units, M_CLONE); 230 } 231 232 /* 233 * Provide list of interface cloners to userspace. 234 */ 235 int 236 if_clone_list(struct if_clonereq *ifcr) 237 { 238 char *buf, *dst, *outbuf = NULL; 239 struct if_clone *ifc; 240 int buf_count, count, err = 0; 241 242 IF_CLONERS_LOCK(); 243 /* 244 * Set our internal output buffer size. We could end up not 245 * reporting a cloner that is added between the unlock and lock 246 * below, but that's not a major problem. Not caping our 247 * allocation to the number of cloners actually in the system 248 * could be because that would let arbitrary users cause us to 249 * allocate abritrary amounts of kernel memory. 250 */ 251 buf_count = (if_cloners_count < ifcr->ifcr_count) ? 252 if_cloners_count : ifcr->ifcr_count; 253 IF_CLONERS_UNLOCK(); 254 255 outbuf = malloc(IFNAMSIZ*buf_count, M_CLONE, M_WAITOK | M_ZERO); 256 257 IF_CLONERS_LOCK(); 258 259 ifcr->ifcr_total = if_cloners_count; 260 if ((dst = ifcr->ifcr_buffer) == NULL) { 261 /* Just asking how many there are. */ 262 goto done; 263 } 264 265 if (ifcr->ifcr_count < 0) { 266 err = EINVAL; 267 goto done; 268 } 269 270 count = (if_cloners_count < buf_count) ? 271 if_cloners_count : buf_count; 272 273 for (ifc = LIST_FIRST(&if_cloners), buf = outbuf; 274 ifc != NULL && count != 0; 275 ifc = LIST_NEXT(ifc, ifc_list), count--, buf += IFNAMSIZ) { 276 strlcpy(buf, ifc->ifc_name, IFNAMSIZ); 277 } 278 279 done: 280 IF_CLONERS_UNLOCK(); 281 if (err == 0) 282 err = copyout(outbuf, dst, buf_count*IFNAMSIZ); 283 if (outbuf != NULL) 284 free(outbuf, M_CLONE); 285 return (err); 286 } 287 288 /* 289 * A utility function to extract unit numbers from interface names of 290 * the form name###. 291 * 292 * Returns 0 on success and an error on failure. 293 */ 294 int 295 ifc_name2unit(const char *name, int *unit) 296 { 297 const char *cp; 298 299 for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++); 300 if (*cp == '\0') { 301 *unit = -1; 302 } else { 303 for (*unit = 0; *cp != '\0'; cp++) { 304 if (*cp < '0' || *cp > '9') { 305 /* Bogus unit number. */ 306 return (EINVAL); 307 } 308 *unit = (*unit * 10) + (*cp - '0'); 309 } 310 } 311 312 return (0); 313 } 314 315 int 316 ifc_alloc_unit(struct if_clone *ifc, int *unit) 317 { 318 int wildcard, bytoff, bitoff; 319 int err = 0; 320 321 IF_CLONE_LOCK(ifc); 322 323 bytoff = bitoff = 0; 324 wildcard = (*unit < 0); 325 /* 326 * Find a free unit if none was given. 327 */ 328 if (wildcard) { 329 while ((bytoff < ifc->ifc_bmlen) 330 && (ifc->ifc_units[bytoff] == 0xff)) 331 bytoff++; 332 if (bytoff >= ifc->ifc_bmlen) { 333 err = ENOSPC; 334 goto done; 335 } 336 while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) 337 bitoff++; 338 *unit = (bytoff << 3) + bitoff; 339 } 340 341 if (*unit > ifc->ifc_maxunit) { 342 err = ENOSPC; 343 goto done; 344 } 345 346 if (!wildcard) { 347 bytoff = *unit >> 3; 348 bitoff = *unit - (bytoff << 3); 349 } 350 351 if((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) { 352 err = EEXIST; 353 goto done; 354 } 355 /* 356 * Allocate the unit in the bitmap. 357 */ 358 ifc->ifc_units[bytoff] |= (1 << bitoff); 359 360 done: 361 IF_CLONE_UNLOCK(ifc); 362 return (err); 363 } 364 365 void 366 ifc_free_unit(struct if_clone *ifc, int unit) 367 { 368 int bytoff, bitoff; 369 370 371 /* 372 * Compute offset in the bitmap and deallocate the unit. 373 */ 374 bytoff = unit >> 3; 375 bitoff = unit - (bytoff << 3); 376 377 IF_CLONE_LOCK(ifc); 378 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0, 379 ("%s: bit is already cleared", __func__)); 380 ifc->ifc_units[bytoff] &= ~(1 << bitoff); 381 IF_CLONE_UNLOCK(ifc); 382 } 383 384 void 385 ifc_simple_attach(struct if_clone *ifc) 386 { 387 int err; 388 int unit; 389 char name[IFNAMSIZ]; 390 struct ifc_simple_data *ifcs = ifc->ifc_data; 391 392 KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit, 393 ("%s: %s requested more units then allowed (%d > %d)", 394 __func__, ifc->ifc_name, ifcs->ifcs_minifs, 395 ifc->ifc_maxunit + 1)); 396 397 for (unit = 0; unit < ifcs->ifcs_minifs; unit++) { 398 snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit); 399 err = (*ifc->ifc_create)(ifc, name, IFNAMSIZ); 400 KASSERT(err == 0, 401 ("%s: failed to create required interface %s", 402 __func__, name)); 403 } 404 } 405 406 int 407 ifc_simple_match(struct if_clone *ifc, const char *name) 408 { 409 const char *cp; 410 int i; 411 412 /* Match the name */ 413 for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) { 414 if (ifc->ifc_name[i] != *cp) 415 return (0); 416 } 417 418 /* Make sure there's a unit number or nothing after the name */ 419 for (; *cp != '\0'; cp++) { 420 if (*cp < '0' || *cp > '9') 421 return (0); 422 } 423 424 return (1); 425 } 426 427 int 428 ifc_simple_create(struct if_clone *ifc, char *name, size_t len) 429 { 430 char *dp; 431 int wildcard; 432 int unit; 433 int err; 434 struct ifc_simple_data *ifcs = ifc->ifc_data; 435 436 err = ifc_name2unit(name, &unit); 437 if (err != 0) 438 return (err); 439 440 wildcard = (unit < 0); 441 442 err = ifc_alloc_unit(ifc, &unit); 443 if (err != 0) 444 return (err); 445 446 err = ifcs->ifcs_create(ifc, unit); 447 if (err != 0) { 448 ifc_free_unit(ifc, unit); 449 return (err); 450 } 451 452 /* In the wildcard case, we need to update the name. */ 453 if (wildcard) { 454 for (dp = name; *dp != '\0'; dp++); 455 if (snprintf(dp, len - (dp-name), "%d", unit) > 456 len - (dp-name) - 1) { 457 /* 458 * This can only be a programmer error and 459 * there's no straightforward way to recover if 460 * it happens. 461 */ 462 panic("if_clone_create(): interface name too long"); 463 } 464 465 } 466 467 return (0); 468 } 469 470 int 471 ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp) 472 { 473 int unit; 474 struct ifc_simple_data *ifcs = ifc->ifc_data; 475 476 unit = ifp->if_dunit; 477 478 if (unit < ifcs->ifcs_minifs) 479 return (EINVAL); 480 481 ifcs->ifcs_destroy(ifp); 482 483 ifc_free_unit(ifc, unit); 484 485 return (0); 486 } 487