1 /*- 2 * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org> 3 * Copyright (c) 1980, 1986, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 4. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * @(#)if.c 8.5 (Berkeley) 1/9/95 31 * $FreeBSD$ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/malloc.h> 36 #include <sys/limits.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/kernel.h> 40 #include <sys/systm.h> 41 #include <sys/types.h> 42 #include <sys/socket.h> 43 44 #include <net/if.h> 45 #include <net/if_clone.h> 46 #include <net/if_var.h> 47 #include <net/radix.h> 48 #include <net/route.h> 49 #include <net/vnet.h> 50 51 /* Current IF_MAXUNIT expands maximum to 5 characters. */ 52 #define IFCLOSIZ (IFNAMSIZ - 5) 53 54 /* 55 * Structure describing a `cloning' interface. 56 * 57 * List of locks 58 * (c) const until freeing 59 * (d) driver specific data, may need external protection. 60 * (e) locked by if_cloners_mtx 61 * (i) locked by ifc_mtx mtx 62 */ 63 struct if_clone { 64 char ifc_name[IFCLOSIZ]; /* (c) Name of device, e.g. `gif' */ 65 struct unrhdr *ifc_unrhdr; /* (c) alloc_unr(9) header */ 66 int ifc_maxunit; /* (c) maximum unit number */ 67 long ifc_refcnt; /* (i) Reference count. */ 68 LIST_HEAD(, ifnet) ifc_iflist; /* (i) List of cloned interfaces */ 69 struct mtx ifc_mtx; /* Mutex to protect members. */ 70 71 enum { SIMPLE, ADVANCED } ifc_type; /* (c) */ 72 73 /* (c) Driver specific cloning functions. Called with no locks held. */ 74 union { 75 struct { /* advanced cloner */ 76 ifc_match_t *_ifc_match; 77 ifc_create_t *_ifc_create; 78 ifc_destroy_t *_ifc_destroy; 79 } A; 80 struct { /* simple cloner */ 81 ifcs_create_t *_ifcs_create; 82 ifcs_destroy_t *_ifcs_destroy; 83 int _ifcs_minifs; /* minimum ifs */ 84 85 } S; 86 } U; 87 #define ifc_match U.A._ifc_match 88 #define ifc_create U.A._ifc_create 89 #define ifc_destroy U.A._ifc_destroy 90 #define ifcs_create U.S._ifcs_create 91 #define ifcs_destroy U.S._ifcs_destroy 92 #define ifcs_minifs U.S._ifcs_minifs 93 94 LIST_ENTRY(if_clone) ifc_list; /* (e) On list of cloners */ 95 }; 96 97 static void if_clone_free(struct if_clone *ifc); 98 static int if_clone_createif(struct if_clone *ifc, char *name, size_t len, 99 caddr_t params); 100 101 static int ifc_simple_match(struct if_clone *, const char *); 102 static int ifc_simple_create(struct if_clone *, char *, size_t, caddr_t); 103 static int ifc_simple_destroy(struct if_clone *, struct ifnet *); 104 105 static struct mtx if_cloners_mtx; 106 static VNET_DEFINE(int, if_cloners_count); 107 VNET_DEFINE(LIST_HEAD(, if_clone), if_cloners); 108 109 #define V_if_cloners_count VNET(if_cloners_count) 110 #define V_if_cloners VNET(if_cloners) 111 112 #define IF_CLONERS_LOCK_INIT() \ 113 mtx_init(&if_cloners_mtx, "if_cloners lock", NULL, MTX_DEF) 114 #define IF_CLONERS_LOCK_ASSERT() mtx_assert(&if_cloners_mtx, MA_OWNED) 115 #define IF_CLONERS_LOCK() mtx_lock(&if_cloners_mtx) 116 #define IF_CLONERS_UNLOCK() mtx_unlock(&if_cloners_mtx) 117 118 #define IF_CLONE_LOCK_INIT(ifc) \ 119 mtx_init(&(ifc)->ifc_mtx, "if_clone lock", NULL, MTX_DEF) 120 #define IF_CLONE_LOCK_DESTROY(ifc) mtx_destroy(&(ifc)->ifc_mtx) 121 #define IF_CLONE_LOCK_ASSERT(ifc) mtx_assert(&(ifc)->ifc_mtx, MA_OWNED) 122 #define IF_CLONE_LOCK(ifc) mtx_lock(&(ifc)->ifc_mtx) 123 #define IF_CLONE_UNLOCK(ifc) mtx_unlock(&(ifc)->ifc_mtx) 124 125 #define IF_CLONE_ADDREF(ifc) \ 126 do { \ 127 IF_CLONE_LOCK(ifc); \ 128 IF_CLONE_ADDREF_LOCKED(ifc); \ 129 IF_CLONE_UNLOCK(ifc); \ 130 } while (0) 131 #define IF_CLONE_ADDREF_LOCKED(ifc) \ 132 do { \ 133 IF_CLONE_LOCK_ASSERT(ifc); \ 134 KASSERT((ifc)->ifc_refcnt >= 0, \ 135 ("negative refcnt %ld", (ifc)->ifc_refcnt)); \ 136 (ifc)->ifc_refcnt++; \ 137 } while (0) 138 #define IF_CLONE_REMREF(ifc) \ 139 do { \ 140 IF_CLONE_LOCK(ifc); \ 141 IF_CLONE_REMREF_LOCKED(ifc); \ 142 } while (0) 143 #define IF_CLONE_REMREF_LOCKED(ifc) \ 144 do { \ 145 IF_CLONE_LOCK_ASSERT(ifc); \ 146 KASSERT((ifc)->ifc_refcnt > 0, \ 147 ("bogus refcnt %ld", (ifc)->ifc_refcnt)); \ 148 if (--(ifc)->ifc_refcnt == 0) { \ 149 IF_CLONE_UNLOCK(ifc); \ 150 if_clone_free(ifc); \ 151 } else { \ 152 /* silently free the lock */ \ 153 IF_CLONE_UNLOCK(ifc); \ 154 } \ 155 } while (0) 156 157 #define IFC_IFLIST_INSERT(_ifc, _ifp) \ 158 LIST_INSERT_HEAD(&_ifc->ifc_iflist, _ifp, if_clones) 159 #define IFC_IFLIST_REMOVE(_ifc, _ifp) \ 160 LIST_REMOVE(_ifp, if_clones) 161 162 static MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework"); 163 164 void 165 vnet_if_clone_init(void) 166 { 167 168 LIST_INIT(&V_if_cloners); 169 } 170 171 void 172 if_clone_init(void) 173 { 174 175 IF_CLONERS_LOCK_INIT(); 176 } 177 178 /* 179 * Lookup and create a clone network interface. 180 */ 181 int 182 if_clone_create(char *name, size_t len, caddr_t params) 183 { 184 struct if_clone *ifc; 185 186 /* Try to find an applicable cloner for this request */ 187 IF_CLONERS_LOCK(); 188 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) 189 if (ifc->ifc_type == SIMPLE) { 190 if (ifc_simple_match(ifc, name)) 191 break; 192 } else { 193 if (ifc->ifc_match(ifc, name)) 194 break; 195 } 196 #ifdef VIMAGE 197 if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) { 198 CURVNET_SET_QUIET(vnet0); 199 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) 200 if (ifc->ifc_type == SIMPLE) { 201 if (ifc_simple_match(ifc, name)) 202 break; 203 } else { 204 if (ifc->ifc_match(ifc, name)) 205 break; 206 } 207 CURVNET_RESTORE(); 208 } 209 #endif 210 IF_CLONERS_UNLOCK(); 211 212 if (ifc == NULL) 213 return (EINVAL); 214 215 return (if_clone_createif(ifc, name, len, params)); 216 } 217 218 /* 219 * Create a clone network interface. 220 */ 221 static int 222 if_clone_createif(struct if_clone *ifc, char *name, size_t len, caddr_t params) 223 { 224 int err; 225 struct ifnet *ifp; 226 227 if (ifunit(name) != NULL) 228 return (EEXIST); 229 230 if (ifc->ifc_type == SIMPLE) 231 err = ifc_simple_create(ifc, name, len, params); 232 else 233 err = (*ifc->ifc_create)(ifc, name, len, params); 234 235 if (!err) { 236 ifp = ifunit(name); 237 if (ifp == NULL) 238 panic("%s: lookup failed for %s", __func__, name); 239 240 if_addgroup(ifp, ifc->ifc_name); 241 242 IF_CLONE_LOCK(ifc); 243 IFC_IFLIST_INSERT(ifc, ifp); 244 IF_CLONE_UNLOCK(ifc); 245 } 246 247 return (err); 248 } 249 250 /* 251 * Lookup and destroy a clone network interface. 252 */ 253 int 254 if_clone_destroy(const char *name) 255 { 256 int err; 257 struct if_clone *ifc; 258 struct ifnet *ifp; 259 260 ifp = ifunit_ref(name); 261 if (ifp == NULL) 262 return (ENXIO); 263 264 /* Find the cloner for this interface */ 265 IF_CLONERS_LOCK(); 266 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) { 267 if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) { 268 break; 269 } 270 } 271 #ifdef VIMAGE 272 if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) { 273 CURVNET_SET_QUIET(vnet0); 274 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) 275 if (ifc->ifc_type == SIMPLE) { 276 if (ifc_simple_match(ifc, name)) 277 break; 278 } else { 279 if (ifc->ifc_match(ifc, name)) 280 break; 281 } 282 CURVNET_RESTORE(); 283 } 284 #endif 285 IF_CLONERS_UNLOCK(); 286 if (ifc == NULL) { 287 if_rele(ifp); 288 return (EINVAL); 289 } 290 291 err = if_clone_destroyif(ifc, ifp); 292 if_rele(ifp); 293 return err; 294 } 295 296 /* 297 * Destroy a clone network interface. 298 */ 299 int 300 if_clone_destroyif(struct if_clone *ifc, struct ifnet *ifp) 301 { 302 int err; 303 struct ifnet *ifcifp; 304 305 if (ifc->ifc_type == ADVANCED && ifc->ifc_destroy == NULL) 306 return(EOPNOTSUPP); 307 308 /* 309 * Given that the cloned ifnet might be attached to a different 310 * vnet from where its cloner was registered, we have to 311 * switch to the vnet context of the target vnet. 312 */ 313 CURVNET_SET_QUIET(ifp->if_vnet); 314 315 IF_CLONE_LOCK(ifc); 316 LIST_FOREACH(ifcifp, &ifc->ifc_iflist, if_clones) { 317 if (ifcifp == ifp) { 318 IFC_IFLIST_REMOVE(ifc, ifp); 319 break; 320 } 321 } 322 IF_CLONE_UNLOCK(ifc); 323 if (ifcifp == NULL) { 324 CURVNET_RESTORE(); 325 return (ENXIO); /* ifp is not on the list. */ 326 } 327 328 if_delgroup(ifp, ifc->ifc_name); 329 330 if (ifc->ifc_type == SIMPLE) 331 err = ifc_simple_destroy(ifc, ifp); 332 else 333 err = (*ifc->ifc_destroy)(ifc, ifp); 334 335 if (err != 0) { 336 if_addgroup(ifp, ifc->ifc_name); 337 338 IF_CLONE_LOCK(ifc); 339 IFC_IFLIST_INSERT(ifc, ifp); 340 IF_CLONE_UNLOCK(ifc); 341 } 342 CURVNET_RESTORE(); 343 return (err); 344 } 345 346 static struct if_clone * 347 if_clone_alloc(const char *name, int maxunit) 348 { 349 struct if_clone *ifc; 350 351 KASSERT(name != NULL, ("%s: no name\n", __func__)); 352 353 ifc = malloc(sizeof(struct if_clone), M_CLONE, M_WAITOK | M_ZERO); 354 strncpy(ifc->ifc_name, name, IFCLOSIZ-1); 355 IF_CLONE_LOCK_INIT(ifc); 356 IF_CLONE_ADDREF(ifc); 357 ifc->ifc_maxunit = maxunit ? maxunit : IF_MAXUNIT; 358 ifc->ifc_unrhdr = new_unrhdr(0, ifc->ifc_maxunit, &ifc->ifc_mtx); 359 LIST_INIT(&ifc->ifc_iflist); 360 361 return (ifc); 362 } 363 364 static int 365 if_clone_attach(struct if_clone *ifc) 366 { 367 struct if_clone *ifc1; 368 369 IF_CLONERS_LOCK(); 370 LIST_FOREACH(ifc1, &V_if_cloners, ifc_list) 371 if (strcmp(ifc->ifc_name, ifc1->ifc_name) == 0) { 372 IF_CLONERS_UNLOCK(); 373 IF_CLONE_REMREF(ifc); 374 return (EEXIST); 375 } 376 LIST_INSERT_HEAD(&V_if_cloners, ifc, ifc_list); 377 V_if_cloners_count++; 378 IF_CLONERS_UNLOCK(); 379 380 return (0); 381 } 382 383 struct if_clone * 384 if_clone_advanced(const char *name, u_int maxunit, ifc_match_t match, 385 ifc_create_t create, ifc_destroy_t destroy) 386 { 387 struct if_clone *ifc; 388 389 ifc = if_clone_alloc(name, maxunit); 390 ifc->ifc_type = ADVANCED; 391 ifc->ifc_match = match; 392 ifc->ifc_create = create; 393 ifc->ifc_destroy = destroy; 394 395 if (if_clone_attach(ifc) != 0) { 396 if_clone_free(ifc); 397 return (NULL); 398 } 399 400 EVENTHANDLER_INVOKE(if_clone_event, ifc); 401 402 return (ifc); 403 } 404 405 struct if_clone * 406 if_clone_simple(const char *name, ifcs_create_t create, ifcs_destroy_t destroy, 407 u_int minifs) 408 { 409 struct if_clone *ifc; 410 u_int unit; 411 412 ifc = if_clone_alloc(name, 0); 413 ifc->ifc_type = SIMPLE; 414 ifc->ifcs_create = create; 415 ifc->ifcs_destroy = destroy; 416 ifc->ifcs_minifs = minifs; 417 418 if (if_clone_attach(ifc) != 0) { 419 if_clone_free(ifc); 420 return (NULL); 421 } 422 423 for (unit = 0; unit < minifs; unit++) { 424 char name[IFNAMSIZ]; 425 int error; 426 427 snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit); 428 error = if_clone_createif(ifc, name, IFNAMSIZ, NULL); 429 KASSERT(error == 0, 430 ("%s: failed to create required interface %s", 431 __func__, name)); 432 } 433 434 EVENTHANDLER_INVOKE(if_clone_event, ifc); 435 436 return (ifc); 437 } 438 439 /* 440 * Unregister a network interface cloner. 441 */ 442 void 443 if_clone_detach(struct if_clone *ifc) 444 { 445 446 IF_CLONERS_LOCK(); 447 LIST_REMOVE(ifc, ifc_list); 448 V_if_cloners_count--; 449 IF_CLONERS_UNLOCK(); 450 451 /* Allow all simples to be destroyed */ 452 if (ifc->ifc_type == SIMPLE) 453 ifc->ifcs_minifs = 0; 454 455 /* destroy all interfaces for this cloner */ 456 while (!LIST_EMPTY(&ifc->ifc_iflist)) 457 if_clone_destroyif(ifc, LIST_FIRST(&ifc->ifc_iflist)); 458 459 IF_CLONE_REMREF(ifc); 460 } 461 462 static void 463 if_clone_free(struct if_clone *ifc) 464 { 465 466 KASSERT(LIST_EMPTY(&ifc->ifc_iflist), 467 ("%s: ifc_iflist not empty", __func__)); 468 469 IF_CLONE_LOCK_DESTROY(ifc); 470 delete_unrhdr(ifc->ifc_unrhdr); 471 free(ifc, M_CLONE); 472 } 473 474 /* 475 * Provide list of interface cloners to userspace. 476 */ 477 int 478 if_clone_list(struct if_clonereq *ifcr) 479 { 480 char *buf, *dst, *outbuf = NULL; 481 struct if_clone *ifc; 482 int buf_count, count, err = 0; 483 484 if (ifcr->ifcr_count < 0) 485 return (EINVAL); 486 487 IF_CLONERS_LOCK(); 488 /* 489 * Set our internal output buffer size. We could end up not 490 * reporting a cloner that is added between the unlock and lock 491 * below, but that's not a major problem. Not caping our 492 * allocation to the number of cloners actually in the system 493 * could be because that would let arbitrary users cause us to 494 * allocate abritrary amounts of kernel memory. 495 */ 496 buf_count = (V_if_cloners_count < ifcr->ifcr_count) ? 497 V_if_cloners_count : ifcr->ifcr_count; 498 IF_CLONERS_UNLOCK(); 499 500 outbuf = malloc(IFNAMSIZ*buf_count, M_CLONE, M_WAITOK | M_ZERO); 501 502 IF_CLONERS_LOCK(); 503 504 ifcr->ifcr_total = V_if_cloners_count; 505 if ((dst = ifcr->ifcr_buffer) == NULL) { 506 /* Just asking how many there are. */ 507 goto done; 508 } 509 count = (V_if_cloners_count < buf_count) ? 510 V_if_cloners_count : buf_count; 511 512 for (ifc = LIST_FIRST(&V_if_cloners), buf = outbuf; 513 ifc != NULL && count != 0; 514 ifc = LIST_NEXT(ifc, ifc_list), count--, buf += IFNAMSIZ) { 515 strlcpy(buf, ifc->ifc_name, IFNAMSIZ); 516 } 517 518 done: 519 IF_CLONERS_UNLOCK(); 520 if (err == 0) 521 err = copyout(outbuf, dst, buf_count*IFNAMSIZ); 522 if (outbuf != NULL) 523 free(outbuf, M_CLONE); 524 return (err); 525 } 526 527 /* 528 * A utility function to extract unit numbers from interface names of 529 * the form name###. 530 * 531 * Returns 0 on success and an error on failure. 532 */ 533 int 534 ifc_name2unit(const char *name, int *unit) 535 { 536 const char *cp; 537 int cutoff = INT_MAX / 10; 538 int cutlim = INT_MAX % 10; 539 540 for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++); 541 if (*cp == '\0') { 542 *unit = -1; 543 } else if (cp[0] == '0' && cp[1] != '\0') { 544 /* Disallow leading zeroes. */ 545 return (EINVAL); 546 } else { 547 for (*unit = 0; *cp != '\0'; cp++) { 548 if (*cp < '0' || *cp > '9') { 549 /* Bogus unit number. */ 550 return (EINVAL); 551 } 552 if (*unit > cutoff || 553 (*unit == cutoff && *cp - '0' > cutlim)) 554 return (EINVAL); 555 *unit = (*unit * 10) + (*cp - '0'); 556 } 557 } 558 559 return (0); 560 } 561 562 int 563 ifc_alloc_unit(struct if_clone *ifc, int *unit) 564 { 565 char name[IFNAMSIZ]; 566 int wildcard; 567 568 wildcard = (*unit < 0); 569 retry: 570 if (*unit > ifc->ifc_maxunit) 571 return (ENOSPC); 572 if (*unit < 0) { 573 *unit = alloc_unr(ifc->ifc_unrhdr); 574 if (*unit == -1) 575 return (ENOSPC); 576 } else { 577 *unit = alloc_unr_specific(ifc->ifc_unrhdr, *unit); 578 if (*unit == -1) { 579 if (wildcard) { 580 (*unit)++; 581 goto retry; 582 } else 583 return (EEXIST); 584 } 585 } 586 587 snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, *unit); 588 if (ifunit(name) != NULL) { 589 free_unr(ifc->ifc_unrhdr, *unit); 590 if (wildcard) { 591 (*unit)++; 592 goto retry; 593 } else 594 return (EEXIST); 595 } 596 597 IF_CLONE_ADDREF(ifc); 598 599 return (0); 600 } 601 602 void 603 ifc_free_unit(struct if_clone *ifc, int unit) 604 { 605 606 free_unr(ifc->ifc_unrhdr, unit); 607 IF_CLONE_REMREF(ifc); 608 } 609 610 static int 611 ifc_simple_match(struct if_clone *ifc, const char *name) 612 { 613 const char *cp; 614 int i; 615 616 /* Match the name */ 617 for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) { 618 if (ifc->ifc_name[i] != *cp) 619 return (0); 620 } 621 622 /* Make sure there's a unit number or nothing after the name */ 623 for (; *cp != '\0'; cp++) { 624 if (*cp < '0' || *cp > '9') 625 return (0); 626 } 627 628 return (1); 629 } 630 631 static int 632 ifc_simple_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 633 { 634 char *dp; 635 int wildcard; 636 int unit; 637 int err; 638 639 err = ifc_name2unit(name, &unit); 640 if (err != 0) 641 return (err); 642 643 wildcard = (unit < 0); 644 645 err = ifc_alloc_unit(ifc, &unit); 646 if (err != 0) 647 return (err); 648 649 err = ifc->ifcs_create(ifc, unit, params); 650 if (err != 0) { 651 ifc_free_unit(ifc, unit); 652 return (err); 653 } 654 655 /* In the wildcard case, we need to update the name. */ 656 if (wildcard) { 657 for (dp = name; *dp != '\0'; dp++); 658 if (snprintf(dp, len - (dp-name), "%d", unit) > 659 len - (dp-name) - 1) { 660 /* 661 * This can only be a programmer error and 662 * there's no straightforward way to recover if 663 * it happens. 664 */ 665 panic("if_clone_create(): interface name too long"); 666 } 667 668 } 669 670 return (0); 671 } 672 673 static int 674 ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp) 675 { 676 int unit; 677 678 unit = ifp->if_dunit; 679 680 if (unit < ifc->ifcs_minifs) 681 return (EINVAL); 682 683 ifc->ifcs_destroy(ifp); 684 685 ifc_free_unit(ifc, unit); 686 687 return (0); 688 } 689