madwifi/net80211/ieee80211_acl.c

313 lines
7.6 KiB
C

/*-
* Copyright (c) 2004-2005 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.
*
* $Id$
*/
#ifndef EXPORT_SYMTAB
#define EXPORT_SYMTAB
#endif
/*
* 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).
*/
#if !defined(AUTOCONF_INCLUDED) && !defined(CONFIG_LOCALVERSION)
#include <linux/config.h>
#endif
#include <linux/version.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include "if_media.h"
#include <net80211/ieee80211_var.h>
enum {
ACL_POLICY_OPEN = 0, /* open, don't check ACLs */
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 ACLs */
ATH_LIST_HEAD(, acl) as_hash[ACL_HASHSIZE];
};
/* 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 void acl_free_all_locked(struct aclstate *);
static int
acl_attach(struct ieee80211vap *vap)
{
struct aclstate *as;
_MOD_INC_USE(THIS_MODULE, return 0);
MALLOC(as, struct aclstate *, sizeof(struct aclstate),
M_DEVBUF, M_NOWAIT | M_ZERO);
if (as == NULL) {
_MOD_DEC_USE(THIS_MODULE);
return 0;
}
ACL_LOCK_INIT(as, "acl");
TAILQ_INIT(&as->as_list);
as->as_policy = ACL_POLICY_OPEN;
vap->iv_as = as;
return 1;
}
static void
acl_detach(struct ieee80211vap *vap)
{
struct aclstate *as = vap->iv_as;
ACL_LOCK(as);
acl_free_all_locked(as);
ACL_UNLOCK(as);
vap->iv_as = NULL;
ACL_LOCK_DESTROY(as);
FREE(as, M_DEVBUF);
_MOD_DEC_USE(THIS_MODULE);
}
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)
{
TAILQ_REMOVE(&as->as_list, acl, acl_list);
LIST_REMOVE(acl, acl_hash);
FREE(acl, M_80211_ACL);
}
static int
acl_check(struct ieee80211vap *vap, const u_int8_t mac[IEEE80211_ADDR_LEN])
{
struct aclstate *as = vap->iv_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 ieee80211vap *vap, const u_int8_t mac[IEEE80211_ADDR_LEN])
{
struct aclstate *as = vap->iv_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(vap, IEEE80211_MSG_ACL,
"ACL: add " MAC_FMT " failed, no memory\n", MAC_ADDR(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_EARLY(as);
FREE(new, M_80211_ACL);
IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
"ACL: add " MAC_FMT " failed, already present\n",
MAC_ADDR(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(vap, IEEE80211_MSG_ACL,
"ACL: add " MAC_FMT "\n", MAC_ADDR(mac));
return 0;
}
static int
acl_remove(struct ieee80211vap *vap, const u_int8_t mac[IEEE80211_ADDR_LEN])
{
struct aclstate *as = vap->iv_as;
struct acl *acl;
ACL_LOCK(as);
acl = _find_acl(as, mac);
if (acl != NULL)
_acl_free(as, acl);
ACL_UNLOCK(as);
IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
"ACL: remove " MAC_FMT "%s\n", MAC_ADDR(mac),
acl == NULL ? ", not present" : "");
return (acl == NULL ? ENOENT : 0);
}
static void
acl_free_all_locked(struct aclstate *as)
{
struct acl *acl;
ACL_LOCK_ASSERT(as);
while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
_acl_free(as, acl);
}
static int
acl_free_all(struct ieee80211vap *vap)
{
struct aclstate *as = vap->iv_as;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
ACL_LOCK(as);
acl_free_all_locked(vap->iv_as);
ACL_UNLOCK(as);
return 0;
}
static int
acl_setpolicy(struct ieee80211vap *vap, int policy)
{
struct aclstate *as = vap->iv_as;
IEEE80211_DPRINTF(vap, 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 ieee80211vap *vap)
{
struct aclstate *as = vap->iv_as;
return as->as_policy;
}
/*
* Module glue.
*/
MODULE_AUTHOR("Errno Consulting, Sam Leffler");
MODULE_DESCRIPTION("802.11 wireless support: MAC-based ACL policy");
#ifdef MODULE_LICENSE
MODULE_LICENSE("Dual BSD/GPL");
#endif
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,
};
static int __init
init_ieee80211_acl(void)
{
ieee80211_aclator_register(&mac);
return 0;
}
module_init(init_ieee80211_acl);
static void __exit
exit_ieee80211_acl(void)
{
ieee80211_aclator_unregister(&mac);
}
module_exit(exit_ieee80211_acl);