sys/netproto/802_11/wlan_acl/ieee80211_acl.c

   1 /*-
   2  * Copyright (c) 2004-2008 Sam Leffler, Errno Consulting
   3  * 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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  *
  25  * $FreeBSD: head/sys/net80211/ieee80211_acl.c 186302 2008-12-18 23:00:09Z sam $
  26  */
  27
  28 /*
  29  * IEEE 802.11 MAC ACL support.
  30  *
  31  * When this module is loaded the sender address of each auth mgt
  32  * frame is passed to the iac_check method and the module indicates
  33  * if the frame should be accepted or rejected.  If the policy is
  34  * set to ACL_POLICY_OPEN then all frames are accepted w/o checking
  35  * the address.  Otherwise, the address is looked up in the database
  36  * and if found the frame is either accepted (ACL_POLICY_ALLOW)
  37  * or rejected (ACL_POLICY_DENT).
  38  */
  39 #include "opt_wlan.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/kernel.h>
  43 #include <sys/systm.h>
  44 #include <sys/mbuf.h>
  45 #include <sys/module.h>
  46 #include <sys/queue.h>
  47
  48 #include <sys/socket.h>
  49
  50 #include <net/if.h>
  51 #include <net/if_media.h>
  52 #include <net/ethernet.h>
  53 #include <net/route.h>
  54
  55 #include <netproto/802_11/ieee80211_var.h>
  56
  57 enum {
  58         ACL_POLICY_OPEN         = 0,    /* open, don't check ACL's */
  59         ACL_POLICY_ALLOW        = 1,    /* allow traffic from MAC */
  60         ACL_POLICY_DENY         = 2,    /* deny traffic from MAC */
  61         /*
  62          * NB: ACL_POLICY_RADIUS must be the same value as
  63          *     IEEE80211_MACCMD_POLICY_RADIUS because of the way
  64          *     acl_getpolicy() works.
  65          */
  66         ACL_POLICY_RADIUS       = 7,    /* defer to RADIUS ACL server */
  67 };
  68
  69 #define ACL_HASHSIZE    32
  70
  71 struct acl {
  72         TAILQ_ENTRY(acl)        acl_list;
  73         LIST_ENTRY(acl)         acl_hash;
  74         uint8_t                 acl_macaddr[IEEE80211_ADDR_LEN];
  75 };
  76 struct aclstate {
  77         int                     as_policy;
  78         int                     as_nacls;
  79         TAILQ_HEAD(, acl)       as_list;        /* list of all ACL's */
  80         LIST_HEAD(, acl)        as_hash[ACL_HASHSIZE];
  81         struct ieee80211vap     *as_vap;
  82 };
  83
  84 /* simple hash is enough for variation of macaddr */
  85 #define ACL_HASH(addr)  \
  86         (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % ACL_HASHSIZE)
  87
  88 MALLOC_DEFINE(M_80211_ACL, "acl", "802.11 station acl");
  89
  90 static  int acl_free_all(struct ieee80211vap *);
  91
  92 /* number of references from net80211 layer */
  93 static  int nrefs = 0;
  94
  95 static int
  96 acl_attach(struct ieee80211vap *vap)
  97 {
  98         struct aclstate *as;
  99
 100         as = (struct aclstate *) kmalloc(sizeof(struct aclstate),
 101                 M_80211_ACL, M_INTWAIT | M_ZERO);
 102         if (as == NULL)
 103                 return 0;
 104         TAILQ_INIT(&as->as_list);
 105         as->as_policy = ACL_POLICY_OPEN;
 106         as->as_vap = vap;
 107         vap->iv_as = as;
 108         nrefs++;                        /* NB: we assume caller locking */
 109         return 1;
 110 }
 111
 112 static void
 113 acl_detach(struct ieee80211vap *vap)
 114 {
 115         struct aclstate *as = vap->iv_as;
 116
 117         KASSERT(nrefs > 0, ("imbalanced attach/detach"));
 118         nrefs--;                        /* NB: we assume caller locking */
 119
 120         acl_free_all(vap);
 121         vap->iv_as = NULL;
 122         kfree(as, M_80211_ACL);
 123 }
 124
 125 static __inline struct acl *
 126 _find_acl(struct aclstate *as, const uint8_t *macaddr)
 127 {
 128         struct acl *acl;
 129         int hash;
 130
 131         hash = ACL_HASH(macaddr);
 132         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 133                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, macaddr))
 134                         return acl;
 135         }
 136         return NULL;
 137 }
 138
 139 static void
 140 _acl_free(struct aclstate *as, struct acl *acl)
 141 {
 142
 143         TAILQ_REMOVE(&as->as_list, acl, acl_list);
 144         LIST_REMOVE(acl, acl_hash);
 145         kfree(acl, M_80211_ACL);
 146         as->as_nacls--;
 147 }
 148
 149 static int
 150 acl_check(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
 151 {
 152         struct aclstate *as = vap->iv_as;
 153
 154         switch (as->as_policy) {
 155         case ACL_POLICY_OPEN:
 156         case ACL_POLICY_RADIUS:
 157                 return 1;
 158         case ACL_POLICY_ALLOW:
 159                 return _find_acl(as, mac) != NULL;
 160         case ACL_POLICY_DENY:
 161                 return _find_acl(as, mac) == NULL;
 162         }
 163         return 0;               /* should not happen */
 164 }
 165
 166 static int
 167 acl_add(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
 168 {
 169         struct aclstate *as = vap->iv_as;
 170         struct acl *acl, *new;
 171         int hash;
 172
 173         new = (struct acl *) kmalloc(sizeof(struct acl), M_80211_ACL, M_INTWAIT | M_ZERO);
 174         if (new == NULL) {
 175                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 176                         "ACL: add %6D failed, no memory\n", mac, ":");
 177                 /* XXX statistic */
 178                 return ENOMEM;
 179         }
 180
 181         hash = ACL_HASH(mac);
 182         LIST_FOREACH(acl, &as->as_hash[hash], acl_hash) {
 183                 if (IEEE80211_ADDR_EQ(acl->acl_macaddr, mac)) {
 184                         kfree(new, M_80211_ACL);
 185                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 186                                 "ACL: add %6D failed, already present\n",
 187                                 mac, ":");
 188                         return EEXIST;
 189                 }
 190         }
 191         IEEE80211_ADDR_COPY(new->acl_macaddr, mac);
 192         TAILQ_INSERT_TAIL(&as->as_list, new, acl_list);
 193         LIST_INSERT_HEAD(&as->as_hash[hash], new, acl_hash);
 194         as->as_nacls++;
 195
 196         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 197                 "ACL: add %6D\n", mac, ":");
 198         return 0;
 199 }
 200
 201 static int
 202 acl_remove(struct ieee80211vap *vap, const uint8_t mac[IEEE80211_ADDR_LEN])
 203 {
 204         struct aclstate *as = vap->iv_as;
 205         struct acl *acl;
 206
 207         acl = _find_acl(as, mac);
 208         if (acl != NULL)
 209                 _acl_free(as, acl);
 210
 211         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 212                 "ACL: remove %6D%s\n", mac, ":",
 213                 acl == NULL ? ", not present" : "");
 214
 215         return (acl == NULL ? ENOENT : 0);
 216 }
 217
 218 static int
 219 acl_free_all(struct ieee80211vap *vap)
 220 {
 221         struct aclstate *as = vap->iv_as;
 222         struct acl *acl;
 223
 224         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL, "ACL: %s\n", "free all");
 225
 226         while ((acl = TAILQ_FIRST(&as->as_list)) != NULL)
 227                 _acl_free(as, acl);
 228
 229         return 0;
 230 }
 231
 232 static int
 233 acl_setpolicy(struct ieee80211vap *vap, int policy)
 234 {
 235         struct aclstate *as = vap->iv_as;
 236
 237         IEEE80211_DPRINTF(vap, IEEE80211_MSG_ACL,
 238                 "ACL: set policy to %u\n", policy);
 239
 240         switch (policy) {
 241         case IEEE80211_MACCMD_POLICY_OPEN:
 242                 as->as_policy = ACL_POLICY_OPEN;
 243                 break;
 244         case IEEE80211_MACCMD_POLICY_ALLOW:
 245                 as->as_policy = ACL_POLICY_ALLOW;
 246                 break;
 247         case IEEE80211_MACCMD_POLICY_DENY:
 248                 as->as_policy = ACL_POLICY_DENY;
 249                 break;
 250         case IEEE80211_MACCMD_POLICY_RADIUS:
 251                 as->as_policy = ACL_POLICY_RADIUS;
 252                 break;
 253         default:
 254                 return EINVAL;
 255         }
 256         return 0;
 257 }
 258
 259 static int
 260 acl_getpolicy(struct ieee80211vap *vap)
 261 {
 262         struct aclstate *as = vap->iv_as;
 263
 264         return as->as_policy;
 265 }
 266
 267 static int
 268 acl_setioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
 269 {
 270
 271         return EINVAL;
 272 }
 273
 274 static int
 275 acl_getioctl(struct ieee80211vap *vap, struct ieee80211req *ireq)
 276 {
 277         struct aclstate *as = vap->iv_as;
 278         struct acl *acl;
 279         struct ieee80211req_maclist *ap;
 280         int error, space, i;
 281
 282         switch (ireq->i_val) {
 283         case IEEE80211_MACCMD_POLICY:
 284                 ireq->i_val = as->as_policy;
 285                 return 0;
 286         case IEEE80211_MACCMD_LIST:
 287                 space = as->as_nacls * IEEE80211_ADDR_LEN;
 288                 if (ireq->i_len == 0) {
 289                         ireq->i_len = space;    /* return required space */
 290                         return 0;               /* NB: must not error */
 291                 }
 292                 ap = (struct ieee80211req_maclist *) kmalloc(space,
 293                     M_TEMP, M_INTWAIT);
 294                 if (ap == NULL)
 295                         return ENOMEM;
 296                 i = 0;
 297                 TAILQ_FOREACH(acl, &as->as_list, acl_list) {
 298                         IEEE80211_ADDR_COPY(ap[i].ml_macaddr, acl->acl_macaddr);
 299                         i++;
 300                 }
 301                 if (ireq->i_len >= space) {
 302                         error = copyout(ap, ireq->i_data, space);
 303                         ireq->i_len = space;
 304                 } else
 305                         error = copyout(ap, ireq->i_data, ireq->i_len);
 306                 kfree(ap, M_TEMP);
 307                 return error;
 308         }
 309         return EINVAL;
 310 }
 311
 312 static const struct ieee80211_aclator mac = {
 313         .iac_name       = "mac",
 314         .iac_attach     = acl_attach,
 315         .iac_detach     = acl_detach,
 316         .iac_check      = acl_check,
 317         .iac_add        = acl_add,
 318         .iac_remove     = acl_remove,
 319         .iac_flush      = acl_free_all,
 320         .iac_setpolicy  = acl_setpolicy,
 321         .iac_getpolicy  = acl_getpolicy,
 322         .iac_setioctl   = acl_setioctl,
 323         .iac_getioctl   = acl_getioctl,
 324 };
 325 IEEE80211_ACL_MODULE(wlan_acl, mac, 1);