FreeBSD/Linux Kernel Cross Reference
sys/net/if_clone.c
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: releng/8.0/sys/net/if_clone.c 196019 2009-08-01 19:26:27Z rwatson $
31 */
32
33 #include <sys/param.h>
34 #include <sys/malloc.h>
35 #include <sys/limits.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/kernel.h>
39 #include <sys/systm.h>
40 #include <sys/types.h>
41 #include <sys/socket.h>
42
43 #include <net/if.h>
44 #include <net/if_clone.h>
45 #if 0
46 #include <net/if_dl.h>
47 #endif
48 #include <net/if_types.h>
49 #include <net/if_var.h>
50 #include <net/radix.h>
51 #include <net/route.h>
52 #include <net/vnet.h>
53
54 static void if_clone_free(struct if_clone *ifc);
55 static int if_clone_createif(struct if_clone *ifc, char *name, size_t len,
56 caddr_t params);
57
58 static struct mtx if_cloners_mtx;
59 static VNET_DEFINE(int, if_cloners_count);
60 VNET_DEFINE(LIST_HEAD(, if_clone), if_cloners);
61
62 #define V_if_cloners_count VNET(if_cloners_count)
63 #define V_if_cloners VNET(if_cloners)
64
65 #define IF_CLONERS_LOCK_INIT() \
66 mtx_init(&if_cloners_mtx, "if_cloners lock", NULL, MTX_DEF)
67 #define IF_CLONERS_LOCK_ASSERT() mtx_assert(&if_cloners_mtx, MA_OWNED)
68 #define IF_CLONERS_LOCK() mtx_lock(&if_cloners_mtx)
69 #define IF_CLONERS_UNLOCK() mtx_unlock(&if_cloners_mtx)
70
71 #define IF_CLONE_LOCK_INIT(ifc) \
72 mtx_init(&(ifc)->ifc_mtx, "if_clone lock", NULL, MTX_DEF)
73 #define IF_CLONE_LOCK_DESTROY(ifc) mtx_destroy(&(ifc)->ifc_mtx)
74 #define IF_CLONE_LOCK_ASSERT(ifc) mtx_assert(&(ifc)->ifc_mtx, MA_OWNED)
75 #define IF_CLONE_LOCK(ifc) mtx_lock(&(ifc)->ifc_mtx)
76 #define IF_CLONE_UNLOCK(ifc) mtx_unlock(&(ifc)->ifc_mtx)
77
78 #define IF_CLONE_ADDREF(ifc) \
79 do { \
80 IF_CLONE_LOCK(ifc); \
81 IF_CLONE_ADDREF_LOCKED(ifc); \
82 IF_CLONE_UNLOCK(ifc); \
83 } while (0)
84 #define IF_CLONE_ADDREF_LOCKED(ifc) \
85 do { \
86 IF_CLONE_LOCK_ASSERT(ifc); \
87 KASSERT((ifc)->ifc_refcnt >= 0, \
88 ("negative refcnt %ld", (ifc)->ifc_refcnt)); \
89 (ifc)->ifc_refcnt++; \
90 } while (0)
91 #define IF_CLONE_REMREF(ifc) \
92 do { \
93 IF_CLONE_LOCK(ifc); \
94 IF_CLONE_REMREF_LOCKED(ifc); \
95 } while (0)
96 #define IF_CLONE_REMREF_LOCKED(ifc) \
97 do { \
98 IF_CLONE_LOCK_ASSERT(ifc); \
99 KASSERT((ifc)->ifc_refcnt > 0, \
100 ("bogus refcnt %ld", (ifc)->ifc_refcnt)); \
101 if (--(ifc)->ifc_refcnt == 0) { \
102 IF_CLONE_UNLOCK(ifc); \
103 if_clone_free(ifc); \
104 } else { \
105 /* silently free the lock */ \
106 IF_CLONE_UNLOCK(ifc); \
107 } \
108 } while (0)
109
110 #define IFC_IFLIST_INSERT(_ifc, _ifp) \
111 LIST_INSERT_HEAD(&_ifc->ifc_iflist, _ifp, if_clones)
112 #define IFC_IFLIST_REMOVE(_ifc, _ifp) \
113 LIST_REMOVE(_ifp, if_clones)
114
115 static MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework");
116
117 void
118 vnet_if_clone_init(void)
119 {
120
121 LIST_INIT(&V_if_cloners);
122 }
123
124 void
125 if_clone_init(void)
126 {
127
128 IF_CLONERS_LOCK_INIT();
129 }
130
131 /*
132 * Lookup and create a clone network interface.
133 */
134 int
135 if_clone_create(char *name, size_t len, caddr_t params)
136 {
137 struct if_clone *ifc;
138
139 /* Try to find an applicable cloner for this request */
140 IF_CLONERS_LOCK();
141 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
142 if (ifc->ifc_match(ifc, name)) {
143 break;
144 }
145 }
146 #ifdef VIMAGE
147 if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) {
148 CURVNET_SET_QUIET(vnet0);
149 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
150 if (ifc->ifc_match(ifc, name))
151 break;
152 }
153 CURVNET_RESTORE();
154 }
155 #endif
156 IF_CLONERS_UNLOCK();
157
158 if (ifc == NULL)
159 return (EINVAL);
160
161 return (if_clone_createif(ifc, name, len, params));
162 }
163
164 /*
165 * Create a clone network interface.
166 */
167 static int
168 if_clone_createif(struct if_clone *ifc, char *name, size_t len, caddr_t params)
169 {
170 int err;
171 struct ifnet *ifp;
172
173 if (ifunit(name) != NULL)
174 return (EEXIST);
175
176 err = (*ifc->ifc_create)(ifc, name, len, params);
177
178 if (!err) {
179 ifp = ifunit(name);
180 if (ifp == NULL)
181 panic("%s: lookup failed for %s", __func__, name);
182
183 if_addgroup(ifp, ifc->ifc_name);
184
185 IF_CLONE_LOCK(ifc);
186 IFC_IFLIST_INSERT(ifc, ifp);
187 IF_CLONE_UNLOCK(ifc);
188 }
189
190 return (err);
191 }
192
193 /*
194 * Lookup and destroy a clone network interface.
195 */
196 int
197 if_clone_destroy(const char *name)
198 {
199 struct if_clone *ifc;
200 struct ifnet *ifp;
201
202 ifp = ifunit(name);
203 if (ifp == NULL)
204 return (ENXIO);
205
206 /* Find the cloner for this interface */
207 IF_CLONERS_LOCK();
208 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
209 if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) {
210 break;
211 }
212 }
213 #ifdef VIMAGE
214 if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) {
215 CURVNET_SET_QUIET(vnet0);
216 LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
217 if (ifc->ifc_match(ifc, name))
218 break;
219 }
220 CURVNET_RESTORE();
221 }
222 #endif
223 IF_CLONERS_UNLOCK();
224 if (ifc == NULL)
225 return (EINVAL);
226
227 return (if_clone_destroyif(ifc, ifp));
228 }
229
230 /*
231 * Destroy a clone network interface.
232 */
233 int
234 if_clone_destroyif(struct if_clone *ifc, struct ifnet *ifp)
235 {
236 int err;
237
238 if (ifc->ifc_destroy == NULL)
239 return(EOPNOTSUPP);
240
241 /*
242 * Given that the cloned ifnet might be attached to a different
243 * vnet from where its cloner was registered, we have to
244 * switch to the vnet context of the target vnet.
245 */
246 CURVNET_SET_QUIET(ifp->if_vnet);
247
248 IF_CLONE_LOCK(ifc);
249 IFC_IFLIST_REMOVE(ifc, ifp);
250 IF_CLONE_UNLOCK(ifc);
251
252 if_delgroup(ifp, ifc->ifc_name);
253
254 err = (*ifc->ifc_destroy)(ifc, ifp);
255
256 if (err != 0) {
257 if_addgroup(ifp, ifc->ifc_name);
258
259 IF_CLONE_LOCK(ifc);
260 IFC_IFLIST_INSERT(ifc, ifp);
261 IF_CLONE_UNLOCK(ifc);
262 }
263 CURVNET_RESTORE();
264 return (err);
265 }
266
267 /*
268 * Register a network interface cloner.
269 */
270 void
271 if_clone_attach(struct if_clone *ifc)
272 {
273 int len, maxclone;
274
275 /*
276 * Compute bitmap size and allocate it.
277 */
278 maxclone = ifc->ifc_maxunit + 1;
279 len = maxclone >> 3;
280 if ((len << 3) < maxclone)
281 len++;
282 ifc->ifc_units = malloc(len, M_CLONE, M_WAITOK | M_ZERO);
283 ifc->ifc_bmlen = len;
284 IF_CLONE_LOCK_INIT(ifc);
285 IF_CLONE_ADDREF(ifc);
286
287 IF_CLONERS_LOCK();
288 LIST_INSERT_HEAD(&V_if_cloners, ifc, ifc_list);
289 V_if_cloners_count++;
290 IF_CLONERS_UNLOCK();
291
292 LIST_INIT(&ifc->ifc_iflist);
293
294 if (ifc->ifc_attach != NULL)
295 (*ifc->ifc_attach)(ifc);
296 EVENTHANDLER_INVOKE(if_clone_event, ifc);
297 }
298
299 /*
300 * Unregister a network interface cloner.
301 */
302 void
303 if_clone_detach(struct if_clone *ifc)
304 {
305 struct ifc_simple_data *ifcs = ifc->ifc_data;
306
307 IF_CLONERS_LOCK();
308 LIST_REMOVE(ifc, ifc_list);
309 V_if_cloners_count--;
310 IF_CLONERS_UNLOCK();
311
312 /* Allow all simples to be destroyed */
313 if (ifc->ifc_attach == ifc_simple_attach)
314 ifcs->ifcs_minifs = 0;
315
316 /* destroy all interfaces for this cloner */
317 while (!LIST_EMPTY(&ifc->ifc_iflist))
318 if_clone_destroyif(ifc, LIST_FIRST(&ifc->ifc_iflist));
319
320 IF_CLONE_REMREF(ifc);
321 }
322
323 static void
324 if_clone_free(struct if_clone *ifc)
325 {
326 for (int bytoff = 0; bytoff < ifc->ifc_bmlen; bytoff++) {
327 KASSERT(ifc->ifc_units[bytoff] == 0x00,
328 ("ifc_units[%d] is not empty", bytoff));
329 }
330
331 KASSERT(LIST_EMPTY(&ifc->ifc_iflist),
332 ("%s: ifc_iflist not empty", __func__));
333
334 IF_CLONE_LOCK_DESTROY(ifc);
335 free(ifc->ifc_units, M_CLONE);
336 }
337
338 /*
339 * Provide list of interface cloners to userspace.
340 */
341 int
342 if_clone_list(struct if_clonereq *ifcr)
343 {
344 char *buf, *dst, *outbuf = NULL;
345 struct if_clone *ifc;
346 int buf_count, count, err = 0;
347
348 if (ifcr->ifcr_count < 0)
349 return (EINVAL);
350
351 IF_CLONERS_LOCK();
352 /*
353 * Set our internal output buffer size. We could end up not
354 * reporting a cloner that is added between the unlock and lock
355 * below, but that's not a major problem. Not caping our
356 * allocation to the number of cloners actually in the system
357 * could be because that would let arbitrary users cause us to
358 * allocate abritrary amounts of kernel memory.
359 */
360 buf_count = (V_if_cloners_count < ifcr->ifcr_count) ?
361 V_if_cloners_count : ifcr->ifcr_count;
362 IF_CLONERS_UNLOCK();
363
364 outbuf = malloc(IFNAMSIZ*buf_count, M_CLONE, M_WAITOK | M_ZERO);
365
366 IF_CLONERS_LOCK();
367
368 ifcr->ifcr_total = V_if_cloners_count;
369 if ((dst = ifcr->ifcr_buffer) == NULL) {
370 /* Just asking how many there are. */
371 goto done;
372 }
373 count = (V_if_cloners_count < buf_count) ?
374 V_if_cloners_count : buf_count;
375
376 for (ifc = LIST_FIRST(&V_if_cloners), buf = outbuf;
377 ifc != NULL && count != 0;
378 ifc = LIST_NEXT(ifc, ifc_list), count--, buf += IFNAMSIZ) {
379 strlcpy(buf, ifc->ifc_name, IFNAMSIZ);
380 }
381
382 done:
383 IF_CLONERS_UNLOCK();
384 if (err == 0)
385 err = copyout(outbuf, dst, buf_count*IFNAMSIZ);
386 if (outbuf != NULL)
387 free(outbuf, M_CLONE);
388 return (err);
389 }
390
391 /*
392 * A utility function to extract unit numbers from interface names of
393 * the form name###.
394 *
395 * Returns 0 on success and an error on failure.
396 */
397 int
398 ifc_name2unit(const char *name, int *unit)
399 {
400 const char *cp;
401 int cutoff = INT_MAX / 10;
402 int cutlim = INT_MAX % 10;
403
404 for (cp = name; *cp != '\0' && (*cp < '' || *cp > '9'); cp++);
405 if (*cp == '\0') {
406 *unit = -1;
407 } else if (cp[0] == '' && cp[1] != '\0') {
408 /* Disallow leading zeroes. */
409 return (EINVAL);
410 } else {
411 for (*unit = 0; *cp != '\0'; cp++) {
412 if (*cp < '' || *cp > '9') {
413 /* Bogus unit number. */
414 return (EINVAL);
415 }
416 if (*unit > cutoff ||
417 (*unit == cutoff && *cp - '' > cutlim))
418 return (EINVAL);
419 *unit = (*unit * 10) + (*cp - '');
420 }
421 }
422
423 return (0);
424 }
425
426 int
427 ifc_alloc_unit(struct if_clone *ifc, int *unit)
428 {
429 int wildcard, bytoff, bitoff;
430 int err = 0;
431
432 IF_CLONE_LOCK(ifc);
433
434 bytoff = bitoff = 0;
435 wildcard = (*unit < 0);
436 /*
437 * Find a free unit if none was given.
438 */
439 if (wildcard) {
440 while ((bytoff < ifc->ifc_bmlen)
441 && (ifc->ifc_units[bytoff] == 0xff))
442 bytoff++;
443 if (bytoff >= ifc->ifc_bmlen) {
444 err = ENOSPC;
445 goto done;
446 }
447 while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0)
448 bitoff++;
449 *unit = (bytoff << 3) + bitoff;
450 }
451
452 if (*unit > ifc->ifc_maxunit) {
453 err = ENOSPC;
454 goto done;
455 }
456
457 if (!wildcard) {
458 bytoff = *unit >> 3;
459 bitoff = *unit - (bytoff << 3);
460 }
461
462 if((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) {
463 err = EEXIST;
464 goto done;
465 }
466 /*
467 * Allocate the unit in the bitmap.
468 */
469 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) == 0,
470 ("%s: bit is already set", __func__));
471 ifc->ifc_units[bytoff] |= (1 << bitoff);
472 IF_CLONE_ADDREF_LOCKED(ifc);
473
474 done:
475 IF_CLONE_UNLOCK(ifc);
476 return (err);
477 }
478
479 void
480 ifc_free_unit(struct if_clone *ifc, int unit)
481 {
482 int bytoff, bitoff;
483
484
485 /*
486 * Compute offset in the bitmap and deallocate the unit.
487 */
488 bytoff = unit >> 3;
489 bitoff = unit - (bytoff << 3);
490
491 IF_CLONE_LOCK(ifc);
492 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0,
493 ("%s: bit is already cleared", __func__));
494 ifc->ifc_units[bytoff] &= ~(1 << bitoff);
495 IF_CLONE_REMREF_LOCKED(ifc); /* releases lock */
496 }
497
498 void
499 ifc_simple_attach(struct if_clone *ifc)
500 {
501 int err;
502 int unit;
503 char name[IFNAMSIZ];
504 struct ifc_simple_data *ifcs = ifc->ifc_data;
505
506 KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit,
507 ("%s: %s requested more units than allowed (%d > %d)",
508 __func__, ifc->ifc_name, ifcs->ifcs_minifs,
509 ifc->ifc_maxunit + 1));
510
511 for (unit = 0; unit < ifcs->ifcs_minifs; unit++) {
512 snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit);
513 err = if_clone_createif(ifc, name, IFNAMSIZ, NULL);
514 KASSERT(err == 0,
515 ("%s: failed to create required interface %s",
516 __func__, name));
517 }
518 }
519
520 int
521 ifc_simple_match(struct if_clone *ifc, const char *name)
522 {
523 const char *cp;
524 int i;
525
526 /* Match the name */
527 for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) {
528 if (ifc->ifc_name[i] != *cp)
529 return (0);
530 }
531
532 /* Make sure there's a unit number or nothing after the name */
533 for (; *cp != '\0'; cp++) {
534 if (*cp < '' || *cp > '9')
535 return (0);
536 }
537
538 return (1);
539 }
540
541 int
542 ifc_simple_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
543 {
544 char *dp;
545 int wildcard;
546 int unit;
547 int err;
548 struct ifc_simple_data *ifcs = ifc->ifc_data;
549
550 err = ifc_name2unit(name, &unit);
551 if (err != 0)
552 return (err);
553
554 wildcard = (unit < 0);
555
556 err = ifc_alloc_unit(ifc, &unit);
557 if (err != 0)
558 return (err);
559
560 err = ifcs->ifcs_create(ifc, unit, params);
561 if (err != 0) {
562 ifc_free_unit(ifc, unit);
563 return (err);
564 }
565
566 /* In the wildcard case, we need to update the name. */
567 if (wildcard) {
568 for (dp = name; *dp != '\0'; dp++);
569 if (snprintf(dp, len - (dp-name), "%d", unit) >
570 len - (dp-name) - 1) {
571 /*
572 * This can only be a programmer error and
573 * there's no straightforward way to recover if
574 * it happens.
575 */
576 panic("if_clone_create(): interface name too long");
577 }
578
579 }
580
581 return (0);
582 }
583
584 int
585 ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp)
586 {
587 int unit;
588 struct ifc_simple_data *ifcs = ifc->ifc_data;
589
590 unit = ifp->if_dunit;
591
592 if (unit < ifcs->ifcs_minifs)
593 return (EINVAL);
594
595 ifcs->ifcs_destroy(ifp);
596
597 ifc_free_unit(ifc, unit);
598
599 return (0);
600 }
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