freebsd-skq/sys/net80211/ieee80211_acl.c
2004-12-31 20:39:41 +00:00

302 lines
7.5 KiB
C

/*-
* Copyright (c) 2004 Sam Leffler, Errno Consulting
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* IEEE 802.11 MAC ACL support.
*
* When this module is loaded the sender address of each received
* frame is passed to the iac_check method and the module indicates
* if the frame should be accepted or rejected. If the policy is
* set to ACL_POLICY_OPEN then all frames are accepted w/o checking
* the address. Otherwise, the address is looked up in the database
* and if found the frame is either accepted (ACL_POLICY_ALLOW)
* or rejected (ACL_POLICY_DENT).
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#include <net/route.h>
#include <net80211/ieee80211_var.h>
enum {
ACL_POLICY_OPEN = 0, /* open, don't check ACL's */
ACL_POLICY_ALLOW = 1, /* allow traffic from MAC */
ACL_POLICY_DENY = 2, /* deny traffic from MAC */
};
#define ACL_HASHSIZE 32
struct acl {
TAILQ_ENTRY(acl) acl_list;
LIST_ENTRY(acl) acl_hash;
u_int8_t acl_macaddr[IEEE80211_ADDR_LEN];
};
struct aclstate {
acl_lock_t as_lock;
int as_policy;
TAILQ_HEAD(, acl) as_list; /* list of all ACL's */
LIST_HEAD(, acl) as_hash[ACL_HASHSIZE];
struct ieee80211com *as_ic;
};
/* simple hash is enough for variation of macaddr */
#define ACL_HASH(addr) \
(((const u_int8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
static int acl_free_all(struct ieee80211com *);
static int
acl_attach(struct ieee80211com *ic)
{
struct aclstate *as;
MALLOC(as, struct aclstate *, sizeof(struct aclstate),
M_DEVBUF, M_NOWAIT | M_ZERO);
if (as == NULL)
return 0;
ACL_LOCK_INIT(as, "acl");
TAILQ_INIT(&as->as_list);
as->as_policy = ACL_POLICY_OPEN;
as->as_ic = ic;
ic->ic_as = as;
return 1;
}
static void
acl_detach(struct ieee80211com *ic)
{
struct aclstate *as = ic->ic_as;
acl_free_all(ic);
ic->ic_as = NULL;
ACL_LOCK_DESTROY(as);
FREE(as, M_DEVBUF);
}
static __inline struct acl *
_find_acl(struct aclstate *as, const u_int8_t *macaddr)
{
struct acl *acl;
int hash;
hash = ACL_HASH(macaddr);
LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
return acl;
}
return NULL;
}
static void
_acl_free(struct aclstate *as, struct acl *acl)
{
ACL_LOCK_ASSERT(as);
TAILQ_REMOVE(&as->as_list, acl, acl_list);
LIST_REMOVE(acl, acl_hash);
FREE(acl, M_80211_ACL);
}
static int
acl_check(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
{
struct aclstate *as = ic->ic_as;
switch (as->as_policy) {
case ACL_POLICY_OPEN:
return 1;
case ACL_POLICY_ALLOW:
return _find_acl(as, mac) != NULL;
case ACL_POLICY_DENY:
return _find_acl(as, mac) == NULL;
}
return 0; /* should not happen */
}
static int
acl_add(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
{
struct aclstate *as = ic->ic_as;
struct acl *acl, *new;
int hash;
MALLOC(new, struct acl *, sizeof(struct acl), M_80211_ACL, M_NOWAIT | M_ZERO);
if (new == NULL) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
"ACL: add %s failed, no memory\n", ether_sprintf(mac));
/* XXX statistic */
return ENOMEM;
}
ACL_LOCK(as);
hash = ACL_HASH(mac);
LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
ACL_UNLOCK(as);
FREE(new, M_80211_ACL);
IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
"ACL: add %s failed, already present\n",
ether_sprintf(mac));
return EEXIST;
}
}
IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
ACL_UNLOCK(as);
IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
"ACL: add %s\n", ether_sprintf(mac));
return 0;
}
static int
acl_remove(struct ieee80211com *ic, const u_int8_t mac[IEEE80211_ADDR_LEN])
{
struct aclstate *as = ic->ic_as;
struct acl *acl;
ACL_LOCK(as);
acl = _find_acl(as, mac);
if (acl != NULL)
_acl_free(as, acl);
ACL_UNLOCK(as);
IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
"ACL: remove %s%s\n", ether_sprintf(mac),
acl == NULL ? ", not present" : "");
return (acl == NULL ? ENOENT : 0);
}
static int
acl_free_all(struct ieee80211com *ic)
{
struct aclstate *as = ic->ic_as;
struct acl *acl;
IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
ACL_LOCK(as);
while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
_acl_free(as, acl);
ACL_UNLOCK(as);
return 0;
}
static int
acl_setpolicy(struct ieee80211com *ic, int policy)
{
struct aclstate *as = ic->ic_as;
IEEE80211_DPRINTF(ic, IEEE80211_MSG_ACL,
"ACL: set policy to %u\n", policy);
switch (policy) {
case IEEE80211_MACCMD_POLICY_OPEN:
as->as_policy = ACL_POLICY_OPEN;
break;
case IEEE80211_MACCMD_POLICY_ALLOW:
as->as_policy = ACL_POLICY_ALLOW;
break;
case IEEE80211_MACCMD_POLICY_DENY:
as->as_policy = ACL_POLICY_DENY;
break;
default:
return EINVAL;
}
return 0;
}
static int
acl_getpolicy(struct ieee80211com *ic)
{
struct aclstate *as = ic->ic_as;
return as->as_policy;
}
static const struct ieee80211_aclator mac = {
.iac_name = "mac",
.iac_attach = acl_attach,
.iac_detach = acl_detach,
.iac_check = acl_check,
.iac_add = acl_add,
.iac_remove = acl_remove,
.iac_flush = acl_free_all,
.iac_setpolicy = acl_setpolicy,
.iac_getpolicy = acl_getpolicy,
};
/*
* Module glue.
*/
static int
wlan_acl_modevent(module_t mod, int type, void *unused)
{
switch (type) {
case MOD_LOAD:
if (bootverbose)
printf("wlan: <802.11 MAC ACL support>\n");
ieee80211_aclator_register(&mac);
return 0;
case MOD_UNLOAD:
ieee80211_aclator_unregister(&mac);
return 0;
}
return EINVAL;
}
static moduledata_t wlan_acl_mod = {
"wlan_acl",
wlan_acl_modevent,
0
};
DECLARE_MODULE(wlan_acl, wlan_acl_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
MODULE_VERSION(wlan_acl, 1);
MODULE_DEPEND(wlan_acl, wlan, 1, 1, 1);