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#include <net/vnet.h>
53
54static void	if_clone_free(struct if_clone *ifc);
55static int	if_clone_createif(struct if_clone *ifc, char *name, size_t len,
56		    caddr_t params);
57
58static struct mtx	if_cloners_mtx;
59static VNET_DEFINE(int, if_cloners_count);
60VNET_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
115static MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework");
116
117void
118vnet_if_clone_init(void)
119{
120
121	LIST_INIT(&V_if_cloners);
122}
123
124void
125if_clone_init(void)
126{
127
128	IF_CLONERS_LOCK_INIT();
129}
130
131/*
132 * Lookup and create a clone network interface.
133 */
134int
135if_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 */
167static int
168if_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 */
196int
197if_clone_destroy(const char *name)
198{
199	int err;
200	struct if_clone *ifc;
201	struct ifnet *ifp;
202
203	ifp = ifunit_ref(name);
204	if (ifp == NULL)
205		return (ENXIO);
206
207	/* Find the cloner for this interface */
208	IF_CLONERS_LOCK();
209	LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
210		if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) {
211			break;
212		}
213	}
214#ifdef VIMAGE
215	if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) {
216		CURVNET_SET_QUIET(vnet0);
217		LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
218			if (ifc->ifc_match(ifc, name))
219				break;
220		}
221		CURVNET_RESTORE();
222	}
223#endif
224	IF_CLONERS_UNLOCK();
225	if (ifc == NULL) {
226		if_rele(ifp);
227		return (EINVAL);
228	}
229
230	err = if_clone_destroyif(ifc, ifp);
231	if_rele(ifp);
232	return err;
233}
234
235/*
236 * Destroy a clone network interface.
237 */
238int
239if_clone_destroyif(struct if_clone *ifc, struct ifnet *ifp)
240{
241	int err;
242	struct ifnet *ifcifp;
243
244	if (ifc->ifc_destroy == NULL)
245		return(EOPNOTSUPP);
246
247	/*
248	 * Given that the cloned ifnet might be attached to a different
249	 * vnet from where its cloner was registered, we have to
250	 * switch to the vnet context of the target vnet.
251	 */
252	CURVNET_SET_QUIET(ifp->if_vnet);
253
254	IF_CLONE_LOCK(ifc);
255	LIST_FOREACH(ifcifp, &ifc->ifc_iflist, if_clones) {
256		if (ifcifp == ifp) {
257			IFC_IFLIST_REMOVE(ifc, ifp);
258			break;
259		}
260	}
261	IF_CLONE_UNLOCK(ifc);
262	if (ifcifp == NULL) {
263		CURVNET_RESTORE();
264		return (ENXIO);		/* ifp is not on the list. */
265	}
266
267	if_delgroup(ifp, ifc->ifc_name);
268
269	err =  (*ifc->ifc_destroy)(ifc, ifp);
270
271	if (err != 0) {
272		if_addgroup(ifp, ifc->ifc_name);
273
274		IF_CLONE_LOCK(ifc);
275		IFC_IFLIST_INSERT(ifc, ifp);
276		IF_CLONE_UNLOCK(ifc);
277	}
278	CURVNET_RESTORE();
279	return (err);
280}
281
282/*
283 * Register a network interface cloner.
284 */
285void
286if_clone_attach(struct if_clone *ifc)
287{
288	int len, maxclone;
289
290	/*
291	 * Compute bitmap size and allocate it.
292	 */
293	maxclone = ifc->ifc_maxunit + 1;
294	len = maxclone >> 3;
295	if ((len << 3) < maxclone)
296		len++;
297	ifc->ifc_units = malloc(len, M_CLONE, M_WAITOK | M_ZERO);
298	ifc->ifc_bmlen = len;
299	IF_CLONE_LOCK_INIT(ifc);
300	IF_CLONE_ADDREF(ifc);
301
302	IF_CLONERS_LOCK();
303	LIST_INSERT_HEAD(&V_if_cloners, ifc, ifc_list);
304	V_if_cloners_count++;
305	IF_CLONERS_UNLOCK();
306
307	LIST_INIT(&ifc->ifc_iflist);
308
309	if (ifc->ifc_attach != NULL)
310		(*ifc->ifc_attach)(ifc);
311	EVENTHANDLER_INVOKE(if_clone_event, ifc);
312}
313
314/*
315 * Unregister a network interface cloner.
316 */
317void
318if_clone_detach(struct if_clone *ifc)
319{
320	struct ifc_simple_data *ifcs = ifc->ifc_data;
321
322	IF_CLONERS_LOCK();
323	LIST_REMOVE(ifc, ifc_list);
324	V_if_cloners_count--;
325	IF_CLONERS_UNLOCK();
326
327	/* Allow all simples to be destroyed */
328	if (ifc->ifc_attach == ifc_simple_attach)
329		ifcs->ifcs_minifs = 0;
330
331	/* destroy all interfaces for this cloner */
332	while (!LIST_EMPTY(&ifc->ifc_iflist))
333		if_clone_destroyif(ifc, LIST_FIRST(&ifc->ifc_iflist));
334
335	IF_CLONE_REMREF(ifc);
336}
337
338static void
339if_clone_free(struct if_clone *ifc)
340{
341	for (int bytoff = 0; bytoff < ifc->ifc_bmlen; bytoff++) {
342		KASSERT(ifc->ifc_units[bytoff] == 0x00,
343		    ("ifc_units[%d] is not empty", bytoff));
344	}
345
346	KASSERT(LIST_EMPTY(&ifc->ifc_iflist),
347	    ("%s: ifc_iflist not empty", __func__));
348
349	IF_CLONE_LOCK_DESTROY(ifc);
350	free(ifc->ifc_units, M_CLONE);
351}
352
353/*
354 * Provide list of interface cloners to userspace.
355 */
356int
357if_clone_list(struct if_clonereq *ifcr)
358{
359	char *buf, *dst, *outbuf = NULL;
360	struct if_clone *ifc;
361	int buf_count, count, err = 0;
362
363	if (ifcr->ifcr_count < 0)
364		return (EINVAL);
365
366	IF_CLONERS_LOCK();
367	/*
368	 * Set our internal output buffer size.  We could end up not
369	 * reporting a cloner that is added between the unlock and lock
370	 * below, but that's not a major problem.  Not caping our
371	 * allocation to the number of cloners actually in the system
372	 * could be because that would let arbitrary users cause us to
373	 * allocate abritrary amounts of kernel memory.
374	 */
375	buf_count = (V_if_cloners_count < ifcr->ifcr_count) ?
376	    V_if_cloners_count : ifcr->ifcr_count;
377	IF_CLONERS_UNLOCK();
378
379	outbuf = malloc(IFNAMSIZ*buf_count, M_CLONE, M_WAITOK | M_ZERO);
380
381	IF_CLONERS_LOCK();
382
383	ifcr->ifcr_total = V_if_cloners_count;
384	if ((dst = ifcr->ifcr_buffer) == NULL) {
385		/* Just asking how many there are. */
386		goto done;
387	}
388	count = (V_if_cloners_count < buf_count) ?
389	    V_if_cloners_count : buf_count;
390
391	for (ifc = LIST_FIRST(&V_if_cloners), buf = outbuf;
392	    ifc != NULL && count != 0;
393	    ifc = LIST_NEXT(ifc, ifc_list), count--, buf += IFNAMSIZ) {
394		strlcpy(buf, ifc->ifc_name, IFNAMSIZ);
395	}
396
397done:
398	IF_CLONERS_UNLOCK();
399	if (err == 0)
400		err = copyout(outbuf, dst, buf_count*IFNAMSIZ);
401	if (outbuf != NULL)
402		free(outbuf, M_CLONE);
403	return (err);
404}
405
406/*
407 * A utility function to extract unit numbers from interface names of
408 * the form name###.
409 *
410 * Returns 0 on success and an error on failure.
411 */
412int
413ifc_name2unit(const char *name, int *unit)
414{
415	const char	*cp;
416	int		cutoff = INT_MAX / 10;
417	int		cutlim = INT_MAX % 10;
418
419	for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++);
420	if (*cp == '\0') {
421		*unit = -1;
422	} else if (cp[0] == '0' && cp[1] != '\0') {
423		/* Disallow leading zeroes. */
424		return (EINVAL);
425	} else {
426		for (*unit = 0; *cp != '\0'; cp++) {
427			if (*cp < '0' || *cp > '9') {
428				/* Bogus unit number. */
429				return (EINVAL);
430			}
431			if (*unit > cutoff ||
432			    (*unit == cutoff && *cp - '0' > cutlim))
433				return (EINVAL);
434			*unit = (*unit * 10) + (*cp - '0');
435		}
436	}
437
438	return (0);
439}
440
441int
442ifc_alloc_unit(struct if_clone *ifc, int *unit)
443{
444	int wildcard, bytoff, bitoff;
445	int err = 0;
446
447	IF_CLONE_LOCK(ifc);
448
449	bytoff = bitoff = 0;
450	wildcard = (*unit < 0);
451	/*
452	 * Find a free unit if none was given.
453	 */
454	if (wildcard) {
455		while ((bytoff < ifc->ifc_bmlen)
456		    && (ifc->ifc_units[bytoff] == 0xff))
457			bytoff++;
458		if (bytoff >= ifc->ifc_bmlen) {
459			err = ENOSPC;
460			goto done;
461		}
462		while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0)
463			bitoff++;
464		*unit = (bytoff << 3) + bitoff;
465	}
466
467	if (*unit > ifc->ifc_maxunit) {
468		err = ENOSPC;
469		goto done;
470	}
471
472	if (!wildcard) {
473		bytoff = *unit >> 3;
474		bitoff = *unit - (bytoff << 3);
475	}
476
477	if((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) {
478		err = EEXIST;
479		goto done;
480	}
481	/*
482	 * Allocate the unit in the bitmap.
483	 */
484	KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) == 0,
485	    ("%s: bit is already set", __func__));
486	ifc->ifc_units[bytoff] |= (1 << bitoff);
487	IF_CLONE_ADDREF_LOCKED(ifc);
488
489done:
490	IF_CLONE_UNLOCK(ifc);
491	return (err);
492}
493
494void
495ifc_free_unit(struct if_clone *ifc, int unit)
496{
497	int bytoff, bitoff;
498
499
500	/*
501	 * Compute offset in the bitmap and deallocate the unit.
502	 */
503	bytoff = unit >> 3;
504	bitoff = unit - (bytoff << 3);
505
506	IF_CLONE_LOCK(ifc);
507	KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0,
508	    ("%s: bit is already cleared", __func__));
509	ifc->ifc_units[bytoff] &= ~(1 << bitoff);
510	IF_CLONE_REMREF_LOCKED(ifc);	/* releases lock */
511}
512
513void
514ifc_simple_attach(struct if_clone *ifc)
515{
516	int err;
517	int unit;
518	char name[IFNAMSIZ];
519	struct ifc_simple_data *ifcs = ifc->ifc_data;
520
521	KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit,
522	    ("%s: %s requested more units than allowed (%d > %d)",
523	    __func__, ifc->ifc_name, ifcs->ifcs_minifs,
524	    ifc->ifc_maxunit + 1));
525
526	for (unit = 0; unit < ifcs->ifcs_minifs; unit++) {
527		snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit);
528		err = if_clone_createif(ifc, name, IFNAMSIZ, NULL);
529		KASSERT(err == 0,
530		    ("%s: failed to create required interface %s",
531		    __func__, name));
532	}
533}
534
535int
536ifc_simple_match(struct if_clone *ifc, const char *name)
537{
538	const char *cp;
539	int i;
540
541	/* Match the name */
542	for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) {
543		if (ifc->ifc_name[i] != *cp)
544			return (0);
545	}
546
547	/* Make sure there's a unit number or nothing after the name */
548	for (; *cp != '\0'; cp++) {
549		if (*cp < '0' || *cp > '9')
550			return (0);
551	}
552
553	return (1);
554}
555
556int
557ifc_simple_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
558{
559	char *dp;
560	int wildcard;
561	int unit;
562	int err;
563	struct ifc_simple_data *ifcs = ifc->ifc_data;
564
565	err = ifc_name2unit(name, &unit);
566	if (err != 0)
567		return (err);
568
569	wildcard = (unit < 0);
570
571	err = ifc_alloc_unit(ifc, &unit);
572	if (err != 0)
573		return (err);
574
575	err = ifcs->ifcs_create(ifc, unit, params);
576	if (err != 0) {
577		ifc_free_unit(ifc, unit);
578		return (err);
579	}
580
581	/* In the wildcard case, we need to update the name. */
582	if (wildcard) {
583		for (dp = name; *dp != '\0'; dp++);
584		if (snprintf(dp, len - (dp-name), "%d", unit) >
585		    len - (dp-name) - 1) {
586			/*
587			 * This can only be a programmer error and
588			 * there's no straightforward way to recover if
589			 * it happens.
590			 */
591			panic("if_clone_create(): interface name too long");
592		}
593
594	}
595
596	return (0);
597}
598
599int
600ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp)
601{
602	int unit;
603	struct ifc_simple_data *ifcs = ifc->ifc_data;
604
605	unit = ifp->if_dunit;
606
607	if (unit < ifcs->ifcs_minifs)
608		return (EINVAL);
609
610	ifcs->ifcs_destroy(ifp);
611
612	ifc_free_unit(ifc, unit);
613
614	return (0);
615}
616