net/ieee80211/softmac/ieee80211softmac_auth.c

   1 /*
   2  * This file contains the softmac's authentication logic.
   3  *
   4  * Copyright (c) 2005, 2006 Johannes Berg <johannes@sipsolutions.net>
   5  *                          Joseph Jezak <josejx@gentoo.org>
   6  *                          Larry Finger <Larry.Finger@lwfinger.net>
   7  *                          Danny van Dyk <kugelfang@gentoo.org>
   8  *                          Michael Buesch <mbuesch@freenet.de>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of version 2 of the GNU General Public License as
  12  * published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17  * more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  22  *
  23  * The full GNU General Public License is included in this distribution in the
  24  * file called COPYING.
  25  */
  26
  27 #include "ieee80211softmac_priv.h"
  28
  29 static void ieee80211softmac_auth_queue(void *data);
  30
  31 /* Queues an auth request to the desired AP */
  32 int
  33 ieee80211softmac_auth_req(struct ieee80211softmac_device *mac,
  34         struct ieee80211softmac_network *net)
  35 {
  36         struct ieee80211softmac_auth_queue_item *auth;
  37         unsigned long flags;
  38
  39         if (net->authenticating || net->authenticated)
  40                 return 0;
  41         net->authenticating = 1;
  42
  43         /* Add the network if it's not already added */
  44         ieee80211softmac_add_network(mac, net);
  45
  46         dprintk(KERN_NOTICE PFX "Queueing Authentication Request to "MAC_FMT"\n", MAC_ARG(net->bssid));
  47         /* Queue the auth request */
  48         auth = (struct ieee80211softmac_auth_queue_item *)
  49                 kmalloc(sizeof(struct ieee80211softmac_auth_queue_item), GFP_KERNEL);
  50         if(auth == NULL)
  51                 return -ENOMEM;
  52
  53         auth->net = net;
  54         auth->mac = mac;
  55         auth->retry = IEEE80211SOFTMAC_AUTH_RETRY_LIMIT;
  56         auth->state = IEEE80211SOFTMAC_AUTH_OPEN_REQUEST;
  57         INIT_WORK(&auth->work, &ieee80211softmac_auth_queue, (void *)auth);
  58
  59         /* Lock (for list) */
  60         spin_lock_irqsave(&mac->lock, flags);
  61
  62         /* add to list */
  63         list_add_tail(&auth->list, &mac->auth_queue);
  64         schedule_work(&auth->work);
  65         spin_unlock_irqrestore(&mac->lock, flags);
  66
  67         return 0;
  68 }
  69
  70
  71 /* Sends an auth request to the desired AP and handles timeouts */
  72 static void
  73 ieee80211softmac_auth_queue(void *data)
  74 {
  75         struct ieee80211softmac_device *mac;
  76         struct ieee80211softmac_auth_queue_item *auth;
  77         struct ieee80211softmac_network *net;
  78         unsigned long flags;
  79
  80         auth = (struct ieee80211softmac_auth_queue_item *)data;
  81         net = auth->net;
  82         mac = auth->mac;
  83
  84         if(auth->retry > 0) {
  85                 /* Switch to correct channel for this network */
  86                 mac->set_channel(mac->dev, net->channel);
  87
  88                 /* Lock and set flags */
  89                 spin_lock_irqsave(&mac->lock, flags);
  90                 if (unlikely(!mac->running)) {
  91                         /* Prevent reschedule on workqueue flush */
  92                         spin_unlock_irqrestore(&mac->lock, flags);
  93                         return;
  94                 }
  95                 net->authenticated = 0;
  96                 /* add a timeout call so we eventually give up waiting for an auth reply */
  97                 schedule_delayed_work(&auth->work, IEEE80211SOFTMAC_AUTH_TIMEOUT);
  98                 auth->retry--;
  99                 spin_unlock_irqrestore(&mac->lock, flags);
 100                 if (ieee80211softmac_send_mgt_frame(mac, auth->net, IEEE80211_STYPE_AUTH, auth->state))
 101                         dprintk(KERN_NOTICE PFX "Sending Authentication Request to "MAC_FMT" failed (this shouldn't happen, wait for the timeout).\n", MAC_ARG(net->bssid));
 102                 else
 103                         dprintk(KERN_NOTICE PFX "Sent Authentication Request to "MAC_FMT".\n", MAC_ARG(net->bssid));
 104                 return;
 105         }
 106
 107         printkl(KERN_WARNING PFX "Authentication timed out with "MAC_FMT"\n", MAC_ARG(net->bssid));
 108         /* Remove this item from the queue */
 109         spin_lock_irqsave(&mac->lock, flags);
 110         net->authenticating = 0;
 111         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_AUTH_TIMEOUT, net);
 112         cancel_delayed_work(&auth->work); /* just to make sure... */
 113         list_del(&auth->list);
 114         spin_unlock_irqrestore(&mac->lock, flags);
 115         /* Free it */
 116         kfree(auth);
 117 }
 118
 119 /* Sends a response to an auth challenge (for shared key auth). */
 120 static void
 121 ieee80211softmac_auth_challenge_response(void *_aq)
 122 {
 123         struct ieee80211softmac_auth_queue_item *aq = _aq;
 124
 125         /* Send our response */
 126         ieee80211softmac_send_mgt_frame(aq->mac, aq->net, IEEE80211_STYPE_AUTH, aq->state);
 127 }
 128
 129 /* Handle the auth response from the AP
 130  * This should be registered with ieee80211 as handle_auth
 131  */
 132 int
 133 ieee80211softmac_auth_resp(struct net_device *dev, struct ieee80211_auth *auth)
 134 {
 135
 136         struct list_head *list_ptr;
 137         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 138         struct ieee80211softmac_auth_queue_item *aq = NULL;
 139         struct ieee80211softmac_network *net = NULL;
 140         unsigned long flags;
 141         u8 * data;
 142
 143         if (unlikely(!mac->running))
 144                 return -ENODEV;
 145
 146         /* Find correct auth queue item */
 147         spin_lock_irqsave(&mac->lock, flags);
 148         list_for_each(list_ptr, &mac->auth_queue) {
 149                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 150                 net = aq->net;
 151                 if (!memcmp(net->bssid, auth->header.addr2, ETH_ALEN))
 152                         break;
 153                 else
 154                         aq = NULL;
 155         }
 156         spin_unlock_irqrestore(&mac->lock, flags);
 157
 158         /* Make sure that we've got an auth queue item for this request */
 159         if(aq == NULL)
 160         {
 161                 printkl(KERN_DEBUG PFX "Authentication response received from "MAC_FMT" but no queue item exists.\n", MAC_ARG(auth->header.addr2));
 162                 /* Error #? */
 163                 return -1;
 164         }
 165
 166         /* Check for out of order authentication */
 167         if(!net->authenticating)
 168         {
 169                 printkl(KERN_DEBUG PFX "Authentication response received from "MAC_FMT" but did not request authentication.\n",MAC_ARG(auth->header.addr2));
 170                 return -1;
 171         }
 172
 173         /* Parse the auth packet */
 174         switch(auth->algorithm) {
 175         case WLAN_AUTH_OPEN:
 176                 /* Check the status code of the response */
 177
 178                 switch(auth->status) {
 179                 case WLAN_STATUS_SUCCESS:
 180                         /* Update the status to Authenticated */
 181                         spin_lock_irqsave(&mac->lock, flags);
 182                         net->authenticating = 0;
 183                         net->authenticated = 1;
 184                         spin_unlock_irqrestore(&mac->lock, flags);
 185
 186                         /* Send event */
 187                         printkl(KERN_NOTICE PFX "Open Authentication completed with "MAC_FMT"\n", MAC_ARG(net->bssid));
 188                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 189                         break;
 190                 default:
 191                         /* Lock and reset flags */
 192                         spin_lock_irqsave(&mac->lock, flags);
 193                         net->authenticated = 0;
 194                         net->authenticating = 0;
 195                         spin_unlock_irqrestore(&mac->lock, flags);
 196
 197                         printkl(KERN_NOTICE PFX "Open Authentication with "MAC_FMT" failed, error code: %i\n",
 198                                 MAC_ARG(net->bssid), le16_to_cpup(&auth->status));
 199                         /* Count the error? */
 200                         break;
 201                 }
 202                 goto free_aq;
 203                 break;
 204         case WLAN_AUTH_SHARED_KEY:
 205                 /* Figure out where we are in the process */
 206                 switch(auth->transaction) {
 207                 case IEEE80211SOFTMAC_AUTH_SHARED_CHALLENGE:
 208                         /* Check to make sure we have a challenge IE */
 209                         data = (u8 *)auth->info_element;
 210                         if (*data++ != MFIE_TYPE_CHALLENGE) {
 211                                 printkl(KERN_NOTICE PFX "Shared Key Authentication failed due to a missing challenge.\n");
 212                                 break;
 213                         }
 214                         /* Save the challenge */
 215                         spin_lock_irqsave(&mac->lock, flags);
 216                         net->challenge_len = *data++;
 217                         if (net->challenge_len > WLAN_AUTH_CHALLENGE_LEN)
 218                                 net->challenge_len = WLAN_AUTH_CHALLENGE_LEN;
 219                         if (net->challenge != NULL)
 220                                 kfree(net->challenge);
 221                         net->challenge = kmalloc(net->challenge_len, GFP_ATOMIC);
 222                         memcpy(net->challenge, data, net->challenge_len);
 223                         aq->state = IEEE80211SOFTMAC_AUTH_SHARED_RESPONSE;
 224
 225                         /* We reuse the work struct from the auth request here.
 226                          * It is safe to do so as each one is per-request, and
 227                          * at this point (dealing with authentication response)
 228                          * we have obviously already sent the initial auth
 229                          * request. */
 230                         cancel_delayed_work(&aq->work);
 231                         INIT_WORK(&aq->work, &ieee80211softmac_auth_challenge_response, (void *)aq);
 232                         schedule_work(&aq->work);
 233                         spin_unlock_irqrestore(&mac->lock, flags);
 234                         return 0;
 235                 case IEEE80211SOFTMAC_AUTH_SHARED_PASS:
 236                         kfree(net->challenge);
 237                         net->challenge = NULL;
 238                         net->challenge_len = 0;
 239                         /* Check the status code of the response */
 240                         switch(auth->status) {
 241                         case WLAN_STATUS_SUCCESS:
 242                                 /* Update the status to Authenticated */
 243                                 spin_lock_irqsave(&mac->lock, flags);
 244                                 net->authenticating = 0;
 245                                 net->authenticated = 1;
 246                                 spin_unlock_irqrestore(&mac->lock, flags);
 247                                 printkl(KERN_NOTICE PFX "Shared Key Authentication completed with "MAC_FMT"\n",
 248                                         MAC_ARG(net->bssid));
 249                                 ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 250                                 break;
 251                         default:
 252                                 printkl(KERN_NOTICE PFX "Shared Key Authentication with "MAC_FMT" failed, error code: %i\n",
 253                                         MAC_ARG(net->bssid), le16_to_cpup(&auth->status));
 254                                 /* Lock and reset flags */
 255                                 spin_lock_irqsave(&mac->lock, flags);
 256                                 net->authenticating = 0;
 257                                 net->authenticated = 0;
 258                                 spin_unlock_irqrestore(&mac->lock, flags);
 259                                 /* Count the error? */
 260                                 break;
 261                         }
 262                         goto free_aq;
 263                         break;
 264                 default:
 265                         printkl(KERN_WARNING PFX "Unhandled Authentication Step: %i\n", auth->transaction);
 266                         break;
 267                 }
 268                 goto free_aq;
 269                 break;
 270         default:
 271                 /* ERROR */
 272                 goto free_aq;
 273                 break;
 274         }
 275         return 0;
 276 free_aq:
 277         /* Cancel the timeout */
 278         spin_lock_irqsave(&mac->lock, flags);
 279         cancel_delayed_work(&aq->work);
 280         /* Remove this item from the queue */
 281         list_del(&aq->list);
 282         spin_unlock_irqrestore(&mac->lock, flags);
 283
 284         /* Free it */
 285         kfree(aq);
 286         return 0;
 287 }
 288
 289 /*
 290  * Handle deauthorization
 291  */
 292 static void
 293 ieee80211softmac_deauth_from_net(struct ieee80211softmac_device *mac,
 294         struct ieee80211softmac_network *net)
 295 {
 296         struct ieee80211softmac_auth_queue_item *aq = NULL;
 297         struct list_head *list_ptr;
 298         unsigned long flags;
 299
 300         /* deauthentication implies disassociation */
 301         ieee80211softmac_disassoc(mac);
 302
 303         /* Lock and reset status flags */
 304         spin_lock_irqsave(&mac->lock, flags);
 305         net->authenticating = 0;
 306         net->authenticated = 0;
 307
 308         /* Find correct auth queue item, if it exists */
 309         list_for_each(list_ptr, &mac->auth_queue) {
 310                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 311                 if (!memcmp(net->bssid, aq->net->bssid, ETH_ALEN))
 312                         break;
 313                 else
 314                         aq = NULL;
 315         }
 316
 317         /* Cancel pending work */
 318         if(aq != NULL)
 319                 /* Not entirely safe?  What about running work? */
 320                 cancel_delayed_work(&aq->work);
 321
 322         /* Free our network ref */
 323         ieee80211softmac_del_network_locked(mac, net);
 324         if(net->challenge != NULL)
 325                 kfree(net->challenge);
 326         kfree(net);
 327
 328         /* can't transmit data right now... */
 329         netif_carrier_off(mac->dev);
 330         spin_unlock_irqrestore(&mac->lock, flags);
 331 }
 332
 333 /*
 334  * Sends a deauth request to the desired AP
 335  */
 336 int
 337 ieee80211softmac_deauth_req(struct ieee80211softmac_device *mac,
 338         struct ieee80211softmac_network *net, int reason)
 339 {
 340         int ret;
 341
 342         /* Make sure the network is authenticated */
 343         if (!net->authenticated)
 344         {
 345                 printkl(KERN_DEBUG PFX "Can't send deauthentication packet, network is not authenticated.\n");
 346                 /* Error okay? */
 347                 return -EPERM;
 348         }
 349
 350         /* Send the de-auth packet */
 351         if((ret = ieee80211softmac_send_mgt_frame(mac, net, IEEE80211_STYPE_DEAUTH, reason)))
 352                 return ret;
 353
 354         ieee80211softmac_deauth_from_net(mac, net);
 355         return 0;
 356 }
 357
 358 /*
 359  * This should be registered with ieee80211 as handle_deauth
 360  */
 361 int
 362 ieee80211softmac_deauth_resp(struct net_device *dev, struct ieee80211_deauth *deauth)
 363 {
 364
 365         struct ieee80211softmac_network *net = NULL;
 366         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 367
 368         if (unlikely(!mac->running))
 369                 return -ENODEV;
 370
 371         if (!deauth) {
 372                 dprintk("deauth without deauth packet. eek!\n");
 373                 return 0;
 374         }
 375
 376         net = ieee80211softmac_get_network_by_bssid(mac, deauth->header.addr2);
 377
 378         if (net == NULL) {
 379                 printkl(KERN_DEBUG PFX "Received deauthentication packet from "MAC_FMT", but that network is unknown.\n",
 380                         MAC_ARG(deauth->header.addr2));
 381                 return 0;
 382         }
 383
 384         /* Make sure the network is authenticated */
 385         if(!net->authenticated)
 386         {
 387                 printkl(KERN_DEBUG PFX "Can't perform deauthentication, network is not authenticated.\n");
 388                 /* Error okay? */
 389                 return -EPERM;
 390         }
 391
 392         ieee80211softmac_deauth_from_net(mac, net);
 393
 394         /* let's try to re-associate */
 395         schedule_work(&mac->associnfo.work);
 396         return 0;
 397 }