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freebsd/sys/net/if_clone.c
Robert Watson 530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00

601 lines
14 KiB
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
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/limits.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>
#include <net/vnet.h>
static void if_clone_free(struct if_clone *ifc);
static int if_clone_createif(struct if_clone *ifc, char *name, size_t len,
caddr_t params);
static struct mtx if_cloners_mtx;
static VNET_DEFINE(int, if_cloners_count);
VNET_DEFINE(LIST_HEAD(, if_clone), if_cloners);
#define V_if_cloners_count VNET(if_cloners_count)
#define V_if_cloners VNET(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)
#define IFC_IFLIST_INSERT(_ifc, _ifp) \
LIST_INSERT_HEAD(&_ifc->ifc_iflist, _ifp, if_clones)
#define IFC_IFLIST_REMOVE(_ifc, _ifp) \
LIST_REMOVE(_ifp, if_clones)
static MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework");
void
vnet_if_clone_init(void)
{
LIST_INIT(&V_if_cloners);
}
void
if_clone_init(void)
{
IF_CLONERS_LOCK_INIT();
}
/*
* Lookup and create a clone network interface.
*/
int
if_clone_create(char *name, size_t len, caddr_t params)
{
struct if_clone *ifc;
/* Try to find an applicable cloner for this request */
IF_CLONERS_LOCK();
LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
if (ifc->ifc_match(ifc, name)) {
break;
}
}
#ifdef VIMAGE
if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) {
CURVNET_SET_QUIET(vnet0);
LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
if (ifc->ifc_match(ifc, name))
break;
}
CURVNET_RESTORE();
}
#endif
IF_CLONERS_UNLOCK();
if (ifc == NULL)
return (EINVAL);
return (if_clone_createif(ifc, name, len, params));
}
/*
* Create a clone network interface.
*/
static int
if_clone_createif(struct if_clone *ifc, char *name, size_t len, caddr_t params)
{
int err;
struct ifnet *ifp;
if (ifunit(name) != NULL)
return (EEXIST);
err = (*ifc->ifc_create)(ifc, name, len, params);
if (!err) {
ifp = ifunit(name);
if (ifp == NULL)
panic("%s: lookup failed for %s", __func__, name);
if_addgroup(ifp, ifc->ifc_name);
IF_CLONE_LOCK(ifc);
IFC_IFLIST_INSERT(ifc, ifp);
IF_CLONE_UNLOCK(ifc);
}
return (err);
}
/*
* Lookup and destroy a clone network interface.
*/
int
if_clone_destroy(const char *name)
{
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, &V_if_cloners, ifc_list) {
if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) {
break;
}
}
#ifdef VIMAGE
if (ifc == NULL && !IS_DEFAULT_VNET(curvnet)) {
CURVNET_SET_QUIET(vnet0);
LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
if (ifc->ifc_match(ifc, name))
break;
}
CURVNET_RESTORE();
}
#endif
IF_CLONERS_UNLOCK();
if (ifc == NULL)
return (EINVAL);
return (if_clone_destroyif(ifc, ifp));
}
/*
* Destroy a clone network interface.
*/
int
if_clone_destroyif(struct if_clone *ifc, struct ifnet *ifp)
{
int err;
if (ifc->ifc_destroy == NULL)
return(EOPNOTSUPP);
/*
* Given that the cloned ifnet might be attached to a different
* vnet from where its cloner was registered, we have to
* switch to the vnet context of the target vnet.
*/
CURVNET_SET_QUIET(ifp->if_vnet);
IF_CLONE_LOCK(ifc);
IFC_IFLIST_REMOVE(ifc, ifp);
IF_CLONE_UNLOCK(ifc);
if_delgroup(ifp, ifc->ifc_name);
err = (*ifc->ifc_destroy)(ifc, ifp);
if (err != 0) {
if_addgroup(ifp, ifc->ifc_name);
IF_CLONE_LOCK(ifc);
IFC_IFLIST_INSERT(ifc, ifp);
IF_CLONE_UNLOCK(ifc);
}
CURVNET_RESTORE();
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(&V_if_cloners, ifc, ifc_list);
V_if_cloners_count++;
IF_CLONERS_UNLOCK();
LIST_INIT(&ifc->ifc_iflist);
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)
{
struct ifc_simple_data *ifcs = ifc->ifc_data;
IF_CLONERS_LOCK();
LIST_REMOVE(ifc, ifc_list);
V_if_cloners_count--;
IF_CLONERS_UNLOCK();
/* Allow all simples to be destroyed */
if (ifc->ifc_attach == ifc_simple_attach)
ifcs->ifcs_minifs = 0;
/* destroy all interfaces for this cloner */
while (!LIST_EMPTY(&ifc->ifc_iflist))
if_clone_destroyif(ifc, LIST_FIRST(&ifc->ifc_iflist));
IF_CLONE_REMREF(ifc);
}
static void
if_clone_free(struct if_clone *ifc)
{
for (int bytoff = 0; bytoff < ifc->ifc_bmlen; bytoff++) {
KASSERT(ifc->ifc_units[bytoff] == 0x00,
("ifc_units[%d] is not empty", bytoff));
}
KASSERT(LIST_EMPTY(&ifc->ifc_iflist),
("%s: ifc_iflist not empty", __func__));
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 (ifcr->ifcr_count < 0)
return (EINVAL);
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 = (V_if_cloners_count < ifcr->ifcr_count) ?
V_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 = V_if_cloners_count;
if ((dst = ifcr->ifcr_buffer) == NULL) {
/* Just asking how many there are. */
goto done;
}
count = (V_if_cloners_count < buf_count) ?
V_if_cloners_count : buf_count;
for (ifc = LIST_FIRST(&V_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;
int cutoff = INT_MAX / 10;
int cutlim = INT_MAX % 10;
for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++);
if (*cp == '\0') {
*unit = -1;
} else if (cp[0] == '0' && cp[1] != '\0') {
/* Disallow leading zeroes. */
return (EINVAL);
} else {
for (*unit = 0; *cp != '\0'; cp++) {
if (*cp < '0' || *cp > '9') {
/* Bogus unit number. */
return (EINVAL);
}
if (*unit > cutoff ||
(*unit == cutoff && *cp - '0' > cutlim))
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.
*/
KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) == 0,
("%s: bit is already set", __func__));
ifc->ifc_units[bytoff] |= (1 << bitoff);
IF_CLONE_ADDREF_LOCKED(ifc);
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_REMREF_LOCKED(ifc); /* releases lock */
}
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 than 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 = if_clone_createif(ifc, name, IFNAMSIZ, NULL);
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, caddr_t params)
{
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, params);
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);
}