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