FreeBSD-5.3/sys/net/if_clone.c
/*
* Copyright (c) 1980, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)if.c 8.5 (Berkeley) 1/9/95
* $FreeBSD: src/sys/net/if_clone.c,v 1.2.2.1 2004/09/20 07:12:21 brooks Exp $
*/
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_clone.h>
#if 0
#include <net/if_dl.h>
#endif
#include <net/if_types.h>
#include <net/if_var.h>
#include <net/radix.h>
#include <net/route.h>
static void if_clone_free(struct if_clone *ifc);
static struct mtx if_cloners_mtx;
static int if_cloners_count;
LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);
#define IF_CLONERS_LOCK_INIT() \
mtx_init(&if_cloners_mtx, "if_cloners lock", NULL, MTX_DEF)
#define IF_CLONERS_LOCK_ASSERT() mtx_assert(&if_cloners_mtx, MA_OWNED)
#define IF_CLONERS_LOCK() mtx_lock(&if_cloners_mtx)
#define IF_CLONERS_UNLOCK() mtx_unlock(&if_cloners_mtx)
#define IF_CLONE_LOCK_INIT(ifc) \
mtx_init(&(ifc)->ifc_mtx, "if_clone lock", NULL, MTX_DEF)
#define IF_CLONE_LOCK_DESTROY(ifc) mtx_destroy(&(ifc)->ifc_mtx)
#define IF_CLONE_LOCK_ASSERT(ifc) mtx_assert(&(ifc)->ifc_mtx, MA_OWNED)
#define IF_CLONE_LOCK(ifc) mtx_lock(&(ifc)->ifc_mtx)
#define IF_CLONE_UNLOCK(ifc) mtx_unlock(&(ifc)->ifc_mtx)
#define IF_CLONE_ADDREF(ifc) \
do { \
IF_CLONE_LOCK(ifc); \
IF_CLONE_ADDREF_LOCKED(ifc); \
IF_CLONE_UNLOCK(ifc); \
} while (0)
#define IF_CLONE_ADDREF_LOCKED(ifc) \
do { \
IF_CLONE_LOCK_ASSERT(ifc); \
KASSERT((ifc)->ifc_refcnt >= 0, \
("negative refcnt %ld", (ifc)->ifc_refcnt)); \
(ifc)->ifc_refcnt++; \
} while (0)
#define IF_CLONE_REMREF(ifc) \
do { \
IF_CLONE_LOCK(ifc); \
IF_CLONE_REMREF_LOCKED(ifc); \
} while (0)
#define IF_CLONE_REMREF_LOCKED(ifc) \
do { \
IF_CLONE_LOCK_ASSERT(ifc); \
KASSERT((ifc)->ifc_refcnt > 0, \
("bogus refcnt %ld", (ifc)->ifc_refcnt)); \
if (--(ifc)->ifc_refcnt == 0) { \
IF_CLONE_UNLOCK(ifc); \
if_clone_free(ifc); \
} else { \
/* silently free the lock */ \
IF_CLONE_UNLOCK(ifc); \
} \
} while (0)
MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework");
void
if_clone_init(void)
{
IF_CLONERS_LOCK_INIT();
}
/*
* Create a clone network interface.
*/
int
if_clone_create(char *name, size_t len)
{
int err;
struct if_clone *ifc;
if (ifunit(name) != NULL)
return (EEXIST);
/* Try to find an applicable cloner for this request */
IF_CLONERS_LOCK();
LIST_FOREACH(ifc, &if_cloners, ifc_list) {
if (ifc->ifc_match(ifc, name)) {
IF_CLONE_ADDREF(ifc);
break;
}
}
IF_CLONERS_UNLOCK();
if (ifc == NULL)
return (EINVAL);
err = (*ifc->ifc_create)(ifc, name, len);
IF_CLONE_REMREF(ifc);
return (err);
}
/*
* Destroy a clone network interface.
*/
int
if_clone_destroy(const char *name)
{
int err;
struct if_clone *ifc;
struct ifnet *ifp;
ifp = ifunit(name);
if (ifp == NULL)
return (ENXIO);
/* Find the cloner for this interface */
IF_CLONERS_LOCK();
LIST_FOREACH(ifc, &if_cloners, ifc_list) {
if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) {
IF_CLONE_ADDREF(ifc);
break;
}
}
IF_CLONERS_UNLOCK();
if (ifc == NULL)
return (EINVAL);
if (ifc->ifc_destroy == NULL) {
err = EOPNOTSUPP;
goto done;
}
err = (*ifc->ifc_destroy)(ifc, ifp);
done:
IF_CLONE_REMREF(ifc);
return (err);
}
/*
* Register a network interface cloner.
*/
void
if_clone_attach(struct if_clone *ifc)
{
int len, maxclone;
/*
* Compute bitmap size and allocate it.
*/
maxclone = ifc->ifc_maxunit + 1;
len = maxclone >> 3;
if ((len << 3) < maxclone)
len++;
ifc->ifc_units = malloc(len, M_CLONE, M_WAITOK | M_ZERO);
ifc->ifc_bmlen = len;
IF_CLONE_LOCK_INIT(ifc);
IF_CLONE_ADDREF(ifc);
IF_CLONERS_LOCK();
LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list);
if_cloners_count++;
IF_CLONERS_UNLOCK();
if (ifc->ifc_attach != NULL)
(*ifc->ifc_attach)(ifc);
EVENTHANDLER_INVOKE(if_clone_event, ifc);
}
/*
* Unregister a network interface cloner.
*/
void
if_clone_detach(struct if_clone *ifc)
{
IF_CLONERS_LOCK();
LIST_REMOVE(ifc, ifc_list);
if_cloners_count--;
IF_CLONERS_UNLOCK();
IF_CLONE_REMREF(ifc);
}
static void
if_clone_free(struct if_clone *ifc)
{
IF_CLONE_LOCK_DESTROY(ifc);
free(ifc->ifc_units, M_CLONE);
}
/*
* Provide list of interface cloners to userspace.
*/
int
if_clone_list(struct if_clonereq *ifcr)
{
char *buf, *dst, *outbuf = NULL;
struct if_clone *ifc;
int buf_count, count, err = 0;
IF_CLONERS_LOCK();
/*
* Set our internal output buffer size. We could end up not
* reporting a cloner that is added between the unlock and lock
* below, but that's not a major problem. Not caping our
* allocation to the number of cloners actually in the system
* could be because that would let arbitrary users cause us to
* allocate abritrary amounts of kernel memory.
*/
buf_count = (if_cloners_count < ifcr->ifcr_count) ?
if_cloners_count : ifcr->ifcr_count;
IF_CLONERS_UNLOCK();
outbuf = malloc(IFNAMSIZ*buf_count, M_CLONE, M_WAITOK | M_ZERO);
IF_CLONERS_LOCK();
ifcr->ifcr_total = if_cloners_count;
if ((dst = ifcr->ifcr_buffer) == NULL) {
/* Just asking how many there are. */
goto done;
}
if (ifcr->ifcr_count < 0) {
err = EINVAL;
goto done;
}
count = (if_cloners_count < buf_count) ?
if_cloners_count : buf_count;
for (ifc = LIST_FIRST(&if_cloners), buf = outbuf;
ifc != NULL && count != 0;
ifc = LIST_NEXT(ifc, ifc_list), count--, buf += IFNAMSIZ) {
strlcpy(buf, ifc->ifc_name, IFNAMSIZ);
}
done:
IF_CLONERS_UNLOCK();
if (err == 0)
err = copyout(outbuf, dst, buf_count*IFNAMSIZ);
if (outbuf != NULL)
free(outbuf, M_CLONE);
return (err);
}
/*
* A utility function to extract unit numbers from interface names of
* the form name###.
*
* Returns 0 on success and an error on failure.
*/
int
ifc_name2unit(const char *name, int *unit)
{
const char *cp;
for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++);
if (*cp == '\0') {
*unit = -1;
} else {
for (*unit = 0; *cp != '\0'; cp++) {
if (*cp < '0' || *cp > '9') {
/* Bogus unit number. */
return (EINVAL);
}
*unit = (*unit * 10) + (*cp - '0');
}
}
return (0);
}
int
ifc_alloc_unit(struct if_clone *ifc, int *unit)
{
int wildcard, bytoff, bitoff;
int err = 0;
IF_CLONE_LOCK(ifc);
bytoff = bitoff = 0;
wildcard = (*unit < 0);
/*
* Find a free unit if none was given.
*/
if (wildcard) {
while ((bytoff < ifc->ifc_bmlen)
&& (ifc->ifc_units[bytoff] == 0xff))
bytoff++;
if (bytoff >= ifc->ifc_bmlen) {
err = ENOSPC;
goto done;
}
while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0)
bitoff++;
*unit = (bytoff << 3) + bitoff;
}
if (*unit > ifc->ifc_maxunit) {
err = ENOSPC;
goto done;
}
if (!wildcard) {
bytoff = *unit >> 3;
bitoff = *unit - (bytoff << 3);
}
if((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0) {
err = EEXIST;
goto done;
}
/*
* Allocate the unit in the bitmap.
*/
ifc->ifc_units[bytoff] |= (1 << bitoff);
done:
IF_CLONE_UNLOCK(ifc);
return (err);
}
void
ifc_free_unit(struct if_clone *ifc, int unit)
{
int bytoff, bitoff;
/*
* Compute offset in the bitmap and deallocate the unit.
*/
bytoff = unit >> 3;
bitoff = unit - (bytoff << 3);
IF_CLONE_LOCK(ifc);
KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0,
("%s: bit is already cleared", __func__));
ifc->ifc_units[bytoff] &= ~(1 << bitoff);
IF_CLONE_UNLOCK(ifc);
}
void
ifc_simple_attach(struct if_clone *ifc)
{
int err;
int unit;
char name[IFNAMSIZ];
struct ifc_simple_data *ifcs = ifc->ifc_data;
KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit,
("%s: %s requested more units then allowed (%d > %d)",
__func__, ifc->ifc_name, ifcs->ifcs_minifs,
ifc->ifc_maxunit + 1));
for (unit = 0; unit < ifcs->ifcs_minifs; unit++) {
snprintf(name, IFNAMSIZ, "%s%d", ifc->ifc_name, unit);
err = (*ifc->ifc_create)(ifc, name, IFNAMSIZ);
KASSERT(err == 0,
("%s: failed to create required interface %s",
__func__, name));
}
}
int
ifc_simple_match(struct if_clone *ifc, const char *name)
{
const char *cp;
int i;
/* Match the name */
for (cp = name, i = 0; i < strlen(ifc->ifc_name); i++, cp++) {
if (ifc->ifc_name[i] != *cp)
return (0);
}
/* Make sure there's a unit number or nothing after the name */
for (; *cp != '\0'; cp++) {
if (*cp < '0' || *cp > '9')
return (0);
}
return (1);
}
int
ifc_simple_create(struct if_clone *ifc, char *name, size_t len)
{
char *dp;
int wildcard;
int unit;
int err;
struct ifc_simple_data *ifcs = ifc->ifc_data;
err = ifc_name2unit(name, &unit);
if (err != 0)
return (err);
wildcard = (unit < 0);
err = ifc_alloc_unit(ifc, &unit);
if (err != 0)
return (err);
err = ifcs->ifcs_create(ifc, unit);
if (err != 0) {
ifc_free_unit(ifc, unit);
return (err);
}
/* In the wildcard case, we need to update the name. */
if (wildcard) {
for (dp = name; *dp != '\0'; dp++);
if (snprintf(dp, len - (dp-name), "%d", unit) >
len - (dp-name) - 1) {
/*
* This can only be a programmer error and
* there's no straightforward way to recover if
* it happens.
*/
panic("if_clone_create(): interface name too long");
}
}
return (0);
}
int
ifc_simple_destroy(struct if_clone *ifc, struct ifnet *ifp)
{
int unit;
struct ifc_simple_data *ifcs = ifc->ifc_data;
unit = ifp->if_dunit;
if (unit < ifcs->ifcs_minifs)
return (EINVAL);
ifcs->ifcs_destroy(ifp);
ifc_free_unit(ifc, unit);
return (0);
}