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 } \ 98 /* silently free the lock */ \ 99 IF_CLONE_UNLOCK(ifc); \ 100 } while (0) 101 102 MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework"); 103 104 void 105 if_clone_init(void) 106 { 107 IF_CLONERS_LOCK_INIT(); 108 } 109 110 /* 111 * Create a clone network interface. 112 */ 113 int 114 if_clone_create(char *name, size_t len) 115 { 116 int err; 117 struct if_clone *ifc; 118 119 if (ifunit(name) != NULL) 120 return (EEXIST); 121 122 /* Try to find an applicable cloner for this request */ 123 IF_CLONERS_LOCK(); 124 LIST_FOREACH(ifc, &if_cloners, ifc_list) { 125 if (ifc->ifc_match(ifc, name)) { 126 IF_CLONE_ADDREF(ifc); 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 IF_CLONE_REMREF(ifc); 137 return (err); 138 } 139 140 /* 141 * Destroy a clone network interface. 142 */ 143 int 144 if_clone_destroy(const char *name) 145 { 146 int err; 147 struct if_clone *ifc; 148 struct ifnet *ifp; 149 150 ifp = ifunit(name); 151 if (ifp == NULL) 152 return (ENXIO); 153 154 /* Find the cloner for this interface */ 155 IF_CLONERS_LOCK(); 156 LIST_FOREACH(ifc, &if_cloners, ifc_list) { 157 if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) { 158 IF_CLONE_ADDREF(ifc); 159 break; 160 } 161 } 162 IF_CLONERS_UNLOCK(); 163 if (ifc == NULL) 164 return (EINVAL); 165 166 if (ifc->ifc_destroy == NULL) { 167 err = EOPNOTSUPP; 168 goto done; 169 } 170 171 err = (*ifc->ifc_destroy)(ifc, ifp); 172 173 done: 174 IF_CLONE_REMREF(ifc); 175 return (err); 176 } 177 178 /* 179 * Register a network interface cloner. 180 */ 181 void 182 if_clone_attach(struct if_clone *ifc) 183 { 184 int len, maxclone; 185 186 /* 187 * Compute bitmap size and allocate it. 188 */ 189 maxclone = ifc->ifc_maxunit + 1; 190 len = maxclone >> 3; 191 if ((len << 3) < maxclone) 192 len++; 193 ifc->ifc_units = malloc(len, M_CLONE, M_WAITOK | M_ZERO); 194 ifc->ifc_bmlen = len; 195 IF_CLONE_LOCK_INIT(ifc); 196 IF_CLONE_ADDREF(ifc); 197 198 IF_CLONERS_LOCK(); 199 LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list); 200 if_cloners_count++; 201 IF_CLONERS_UNLOCK(); 202 203 if (ifc->ifc_attach != NULL) 204 (*ifc->ifc_attach)(ifc); 205 EVENTHANDLER_INVOKE(if_clone_event, ifc); 206 } 207 208 /* 209 * Unregister a network interface cloner. 210 */ 211 void 212 if_clone_detach(struct if_clone *ifc) 213 { 214 215 IF_CLONERS_LOCK(); 216 LIST_REMOVE(ifc, ifc_list); 217 if_cloners_count--; 218 IF_CLONERS_UNLOCK(); 219 220 IF_CLONE_REMREF(ifc); 221 } 222 223 static void 224 if_clone_free(struct if_clone *ifc) 225 { 226 227 IF_CLONE_LOCK_DESTROY(ifc); 228 free(ifc->ifc_units, M_CLONE); 229 } 230 231 /* 232 * Provide list of interface cloners to userspace. 233 */ 234 int 235 if_clone_list(struct if_clonereq *ifcr) 236 { 237 char outbuf[IFNAMSIZ], *dst; 238 struct if_clone *ifc; 239 int count, err = 0; 240 241 IF_CLONERS_LOCK(); 242 243 ifcr->ifcr_total = if_cloners_count; 244 if ((dst = ifcr->ifcr_buffer) == NULL) { 245 /* Just asking how many there are. */ 246 goto done; 247 } 248 249 if (ifcr->ifcr_count < 0) { 250 err = EINVAL; 251 goto done; 252 } 253 254 count = (if_cloners_count < ifcr->ifcr_count) ? 255 if_cloners_count : ifcr->ifcr_count; 256 257 for (ifc = LIST_FIRST(&if_cloners); ifc != NULL && count != 0; 258 ifc = LIST_NEXT(ifc, ifc_list), count--, dst += IFNAMSIZ) { 259 strlcpy(outbuf, ifc->ifc_name, IFNAMSIZ); 260 err = copyout(outbuf, dst, IFNAMSIZ); 261 if (err) 262 break; 263 } 264 265 done: 266 IF_CLONERS_UNLOCK(); 267 return (err); 268 } 269 270 /* 271 * A utility function to extract unit numbers from interface names of 272 * the form name###. 273 * 274 * Returns 0 on success and an error on failure. 275 */ 276 int 277 ifc_name2unit(const char *name, int *unit) 278 { 279 const char *cp; 280 281 for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++); 282 if (*cp == '\0') { 283 *unit = -1; 284 } else { 285 for (*unit = 0; *cp != '\0'; cp++) { 286 if (*cp < '0' || *cp > '9') { 287 /* Bogus unit number. */ 288 return (EINVAL); 289 } 290 *unit = (*unit * 10) + (*cp - '0'); 291 } 292 } 293 294 return (0); 295 } 296 297 int 298 ifc_alloc_unit(struct if_clone *ifc, int *unit) 299 { 300 int wildcard, bytoff, bitoff; 301 int err = 0; 302 303 IF_CLONE_LOCK(ifc); 304 305 bytoff = bitoff = 0; 306 wildcard = (*unit < 0); 307 /* 308 * Find a free unit if none was given. 309 */ 310 if (wildcard) { 311 while ((bytoff < ifc->ifc_bmlen) 312 && (ifc->ifc_units[bytoff] == 0xff)) 313 bytoff++; 314 if (bytoff >= ifc->ifc_bmlen) { 315 err = ENOSPC; 316 goto done; 317 } 318 while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) 319 bitoff++; 320 *unit = (bytoff << 3) + bitoff; 321 } 322 323 if (*unit > ifc->ifc_maxunit) { 324 err = ENOSPC; 325 goto done; 326 } 327 328 if (!wildcard) { 329 bytoff = *unit >> 3; 330 bitoff = *unit - (bytoff << 3); 331 } 332 333 if((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) { 334 err = EEXIST; 335 goto done; 336 } 337 /* 338 * Allocate the unit in the bitmap. 339 */ 340 ifc->ifc_units[bytoff] |= (1 << bitoff); 341 342 done: 343 IF_CLONE_UNLOCK(ifc); 344 return (err); 345 } 346 347 void 348 ifc_free_unit(struct if_clone *ifc, int unit) 349 { 350 int bytoff, bitoff; 351 352 353 /* 354 * Compute offset in the bitmap and deallocate the unit. 355 */ 356 bytoff = unit >> 3; 357 bitoff = unit - (bytoff << 3); 358 359 IF_CLONE_LOCK(ifc); 360 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0, 361 ("%s: bit is already cleared", __func__)); 362 ifc->ifc_units[bytoff] &= ~(1 << bitoff); 363 IF_CLONE_UNLOCK(ifc); 364 } 365 366 void 367 ifc_simple_attach(struct if_clone *ifc) 368 { 369 int err; 370 int unit; 371 char name[IFNAMSIZ]; 372 struct ifc_simple_data *ifcs = ifc->ifc_data; 373 374 KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit, 375 ("%s: %s requested more units then allowed (%d > %d)", 376 __func__, ifc->ifc_name, ifcs->ifcs_minifs, 377 ifc->ifc_maxunit + 1)); 378 379 for (unit = 0; unit < ifcs->ifcs_minifs; unit++) { 380 snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit); 381 err = (*ifc->ifc_create)(ifc, name, IFNAMSIZ); 382 KASSERT(err == 0, 383 ("%s: failed to create required interface %s", 384 __func__, name)); 385 } 386 } 387 388 int 389 ifc_simple_match(struct if_clone *ifc, const char *name) 390 { 391 const char *cp; 392 int i; 393 394 /* Match the name */ 395 for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) { 396 if (ifc->ifc_name[i] != *cp) 397 return (0); 398 } 399 400 /* Make sure there's a unit number or nothing after the name */ 401 for (; *cp != '\0'; cp++) { 402 if (*cp < '0' || *cp > '9') 403 return (0); 404 } 405 406 return (1); 407 } 408 409 int 410 ifc_simple_create(struct if_clone *ifc, char *name, size_t len) 411 { 412 char *dp; 413 int wildcard; 414 int unit; 415 int err; 416 struct ifc_simple_data *ifcs = ifc->ifc_data; 417 418 err = ifc_name2unit(name, &unit); 419 if (err != 0) 420 return (err); 421 422 wildcard = (unit < 0); 423 424 err = ifc_alloc_unit(ifc, &unit); 425 if (err != 0) 426 return (err); 427 428 err = ifcs->ifcs_create(ifc, unit); 429 if (err != 0) { 430 ifc_free_unit(ifc, unit); 431 return (err); 432 } 433 434 /* In the wildcard case, we need to update the name. */ 435 if (wildcard) { 436 for (dp = name; *dp != '\0'; dp++); 437 if (snprintf(dp, len - (dp-name), "%d", unit) > 438 len - (dp-name) - 1) { 439 /* 440 * This can only be a programmer error and 441 * there's no straightforward way to recover if 442 * it happens. 443 */ 444 panic("if_clone_create(): interface name too long"); 445 } 446 447 } 448 449 return (0); 450 } 451 452 int 453 ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp) 454 { 455 int unit; 456 struct ifc_simple_data *ifcs = ifc->ifc_data; 457 458 unit = ifp->if_dunit; 459 460 if (unit < ifcs->ifcs_minifs) 461 return (EINVAL); 462 463 ifcs->ifcs_destroy(ifp); 464 465 ifc_free_unit(ifc, unit); 466 467 return (0); 468 } 469