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(struct work_struct *work);
  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_DELAYED_WORK(&auth->work, ieee80211softmac_auth_queue);
  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_delayed_work(&auth->work, 0);
  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(struct work_struct *work)
  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 = container_of(work, struct ieee80211softmac_auth_queue_item,
  81                             work.work);
  82         net = auth->net;
  83         mac = auth->mac;
  84
  85         if(auth->retry > 0) {
  86                 /* Switch to correct channel for this network */
  87                 mac->set_channel(mac->dev, net->channel);
  88
  89                 /* Lock and set flags */
  90                 spin_lock_irqsave(&mac->lock, flags);
  91                 if (unlikely(!mac->running)) {
  92                         /* Prevent reschedule on workqueue flush */
  93                         spin_unlock_irqrestore(&mac->lock, flags);
  94                         return;
  95                 }
  96                 net->authenticated = 0;
  97                 /* add a timeout call so we eventually give up waiting for an auth reply */
  98                 schedule_delayed_work(&auth->work, IEEE80211SOFTMAC_AUTH_TIMEOUT);
  99                 auth->retry--;
 100                 spin_unlock_irqrestore(&mac->lock, flags);
 101                 if (ieee80211softmac_send_mgt_frame(mac, auth->net, IEEE80211_STYPE_AUTH, auth->state))
 102                         dprintk(KERN_NOTICE PFX "Sending Authentication Request to "MAC_FMT" failed (this shouldn't happen, wait for the timeout).\n", MAC_ARG(net->bssid));
 103                 else
 104                         dprintk(KERN_NOTICE PFX "Sent Authentication Request to "MAC_FMT".\n", MAC_ARG(net->bssid));
 105                 return;
 106         }
 107
 108         printkl(KERN_WARNING PFX "Authentication timed out with "MAC_FMT"\n", MAC_ARG(net->bssid));
 109         /* Remove this item from the queue */
 110         spin_lock_irqsave(&mac->lock, flags);
 111         net->authenticating = 0;
 112         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_AUTH_TIMEOUT, net);
 113         cancel_delayed_work(&auth->work); /* just to make sure... */
 114         list_del(&auth->list);
 115         spin_unlock_irqrestore(&mac->lock, flags);
 116         /* Free it */
 117         kfree(auth);
 118 }
 119
 120 /* Sends a response to an auth challenge (for shared key auth). */
 121 static void
 122 ieee80211softmac_auth_challenge_response(struct work_struct *work)
 123 {
 124         struct ieee80211softmac_auth_queue_item *aq =
 125                 container_of(work, struct ieee80211softmac_auth_queue_item,
 126                              work.work);
 127
 128         /* Send our response */
 129         ieee80211softmac_send_mgt_frame(aq->mac, aq->net, IEEE80211_STYPE_AUTH, aq->state);
 130 }
 131
 132 /* Handle the auth response from the AP
 133  * This should be registered with ieee80211 as handle_auth
 134  */
 135 int
 136 ieee80211softmac_auth_resp(struct net_device *dev, struct ieee80211_auth *auth)
 137 {
 138
 139         struct list_head *list_ptr;
 140         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 141         struct ieee80211softmac_auth_queue_item *aq = NULL;
 142         struct ieee80211softmac_network *net = NULL;
 143         unsigned long flags;
 144         u8 * data;
 145
 146         if (unlikely(!mac->running))
 147                 return -ENODEV;
 148
 149         /* Find correct auth queue item */
 150         spin_lock_irqsave(&mac->lock, flags);
 151         list_for_each(list_ptr, &mac->auth_queue) {
 152                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 153                 net = aq->net;
 154                 if (!memcmp(net->bssid, auth->header.addr2, ETH_ALEN))
 155                         break;
 156                 else
 157                         aq = NULL;
 158         }
 159         spin_unlock_irqrestore(&mac->lock, flags);
 160
 161         /* Make sure that we've got an auth queue item for this request */
 162         if(aq == NULL)
 163         {
 164                 dprintkl(KERN_DEBUG PFX "Authentication response received from "MAC_FMT" but no queue item exists.\n", MAC_ARG(auth->header.addr2));
 165                 /* Error #? */
 166                 return -1;
 167         }
 168
 169         /* Check for out of order authentication */
 170         if(!net->authenticating)
 171         {
 172                 dprintkl(KERN_DEBUG PFX "Authentication response received from "MAC_FMT" but did not request authentication.\n",MAC_ARG(auth->header.addr2));
 173                 return -1;
 174         }
 175
 176         /* Parse the auth packet */
 177         switch(auth->algorithm) {
 178         case WLAN_AUTH_OPEN:
 179                 /* Check the status code of the response */
 180
 181                 switch(auth->status) {
 182                 case WLAN_STATUS_SUCCESS:
 183                         /* Update the status to Authenticated */
 184                         spin_lock_irqsave(&mac->lock, flags);
 185                         net->authenticating = 0;
 186                         net->authenticated = 1;
 187                         spin_unlock_irqrestore(&mac->lock, flags);
 188
 189                         /* Send event */
 190                         printkl(KERN_NOTICE PFX "Open Authentication completed with "MAC_FMT"\n", MAC_ARG(net->bssid));
 191                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 192                         break;
 193                 default:
 194                         /* Lock and reset flags */
 195                         spin_lock_irqsave(&mac->lock, flags);
 196                         net->authenticated = 0;
 197                         net->authenticating = 0;
 198                         spin_unlock_irqrestore(&mac->lock, flags);
 199
 200                         printkl(KERN_NOTICE PFX "Open Authentication with "MAC_FMT" failed, error code: %i\n",
 201                                 MAC_ARG(net->bssid), le16_to_cpup(&auth->status));
 202                         /* Count the error? */
 203                         break;
 204                 }
 205                 goto free_aq;
 206                 break;
 207         case WLAN_AUTH_SHARED_KEY:
 208                 /* Figure out where we are in the process */
 209                 switch(auth->transaction) {
 210                 case IEEE80211SOFTMAC_AUTH_SHARED_CHALLENGE:
 211                         /* Check to make sure we have a challenge IE */
 212                         data = (u8 *)auth->info_element;
 213                         if (*data++ != MFIE_TYPE_CHALLENGE) {
 214                                 printkl(KERN_NOTICE PFX "Shared Key Authentication failed due to a missing challenge.\n");
 215                                 break;
 216                         }
 217                         /* Save the challenge */
 218                         spin_lock_irqsave(&mac->lock, flags);
 219                         net->challenge_len = *data++;
 220                         if (net->challenge_len > WLAN_AUTH_CHALLENGE_LEN)
 221                                 net->challenge_len = WLAN_AUTH_CHALLENGE_LEN;
 222                         kfree(net->challenge);
 223                         net->challenge = kmemdup(data, net->challenge_len,
 224                                                  GFP_ATOMIC);
 225                         if (net->challenge == NULL) {
 226                                 printkl(KERN_NOTICE PFX "Shared Key "
 227                                         "Authentication failed due to "
 228                                         "memory shortage.\n");
 229                                 spin_unlock_irqrestore(&mac->lock, flags);
 230                                 break;
 231                         }
 232                         aq->state = IEEE80211SOFTMAC_AUTH_SHARED_RESPONSE;
 233
 234                         /* We reuse the work struct from the auth request here.
 235                          * It is safe to do so as each one is per-request, and
 236                          * at this point (dealing with authentication response)
 237                          * we have obviously already sent the initial auth
 238                          * request. */
 239                         cancel_delayed_work(&aq->work);
 240                         INIT_DELAYED_WORK(&aq->work, &ieee80211softmac_auth_challenge_response);
 241                         schedule_delayed_work(&aq->work, 0);
 242                         spin_unlock_irqrestore(&mac->lock, flags);
 243                         return 0;
 244                 case IEEE80211SOFTMAC_AUTH_SHARED_PASS:
 245                         kfree(net->challenge);
 246                         net->challenge = NULL;
 247                         net->challenge_len = 0;
 248                         /* Check the status code of the response */
 249                         switch(auth->status) {
 250                         case WLAN_STATUS_SUCCESS:
 251                                 /* Update the status to Authenticated */
 252                                 spin_lock_irqsave(&mac->lock, flags);
 253                                 net->authenticating = 0;
 254                                 net->authenticated = 1;
 255                                 spin_unlock_irqrestore(&mac->lock, flags);
 256                                 printkl(KERN_NOTICE PFX "Shared Key Authentication completed with "MAC_FMT"\n",
 257                                         MAC_ARG(net->bssid));
 258                                 ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 259                                 break;
 260                         default:
 261                                 printkl(KERN_NOTICE PFX "Shared Key Authentication with "MAC_FMT" failed, error code: %i\n",
 262                                         MAC_ARG(net->bssid), le16_to_cpup(&auth->status));
 263                                 /* Lock and reset flags */
 264                                 spin_lock_irqsave(&mac->lock, flags);
 265                                 net->authenticating = 0;
 266                                 net->authenticated = 0;
 267                                 spin_unlock_irqrestore(&mac->lock, flags);
 268                                 /* Count the error? */
 269                                 break;
 270                         }
 271                         goto free_aq;
 272                         break;
 273                 default:
 274                         printkl(KERN_WARNING PFX "Unhandled Authentication Step: %i\n", auth->transaction);
 275                         break;
 276                 }
 277                 goto free_aq;
 278                 break;
 279         default:
 280                 /* ERROR */
 281                 goto free_aq;
 282                 break;
 283         }
 284         return 0;
 285 free_aq:
 286         /* Cancel the timeout */
 287         spin_lock_irqsave(&mac->lock, flags);
 288         cancel_delayed_work(&aq->work);
 289         /* Remove this item from the queue */
 290         list_del(&aq->list);
 291         spin_unlock_irqrestore(&mac->lock, flags);
 292
 293         /* Free it */
 294         kfree(aq);
 295         return 0;
 296 }
 297
 298 /*
 299  * Handle deauthorization
 300  */
 301 static void
 302 ieee80211softmac_deauth_from_net(struct ieee80211softmac_device *mac,
 303         struct ieee80211softmac_network *net)
 304 {
 305         struct ieee80211softmac_auth_queue_item *aq = NULL;
 306         struct list_head *list_ptr;
 307         unsigned long flags;
 308
 309         /* deauthentication implies disassociation */
 310         ieee80211softmac_disassoc(mac);
 311
 312         /* Lock and reset status flags */
 313         spin_lock_irqsave(&mac->lock, flags);
 314         net->authenticating = 0;
 315         net->authenticated = 0;
 316
 317         /* Find correct auth queue item, if it exists */
 318         list_for_each(list_ptr, &mac->auth_queue) {
 319                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 320                 if (!memcmp(net->bssid, aq->net->bssid, ETH_ALEN))
 321                         break;
 322                 else
 323                         aq = NULL;
 324         }
 325
 326         /* Cancel pending work */
 327         if(aq != NULL)
 328                 /* Not entirely safe?  What about running work? */
 329                 cancel_delayed_work(&aq->work);
 330
 331         /* Free our network ref */
 332         ieee80211softmac_del_network_locked(mac, net);
 333         if(net->challenge != NULL)
 334                 kfree(net->challenge);
 335         kfree(net);
 336
 337         /* can't transmit data right now... */
 338         netif_carrier_off(mac->dev);
 339         spin_unlock_irqrestore(&mac->lock, flags);
 340 }
 341
 342 /*
 343  * Sends a deauth request to the desired AP
 344  */
 345 int
 346 ieee80211softmac_deauth_req(struct ieee80211softmac_device *mac,
 347         struct ieee80211softmac_network *net, int reason)
 348 {
 349         int ret;
 350
 351         /* Make sure the network is authenticated */
 352         if (!net->authenticated)
 353         {
 354                 dprintkl(KERN_DEBUG PFX "Can't send deauthentication packet, network is not authenticated.\n");
 355                 /* Error okay? */
 356                 return -EPERM;
 357         }
 358
 359         /* Send the de-auth packet */
 360         if((ret = ieee80211softmac_send_mgt_frame(mac, net, IEEE80211_STYPE_DEAUTH, reason)))
 361                 return ret;
 362
 363         ieee80211softmac_deauth_from_net(mac, net);
 364         return 0;
 365 }
 366
 367 /*
 368  * This should be registered with ieee80211 as handle_deauth
 369  */
 370 int
 371 ieee80211softmac_deauth_resp(struct net_device *dev, struct ieee80211_deauth *deauth)
 372 {
 373
 374         struct ieee80211softmac_network *net = NULL;
 375         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 376
 377         if (unlikely(!mac->running))
 378                 return -ENODEV;
 379
 380         if (!deauth) {
 381                 dprintk("deauth without deauth packet. eek!\n");
 382                 return 0;
 383         }
 384
 385         net = ieee80211softmac_get_network_by_bssid(mac, deauth->header.addr2);
 386
 387         if (net == NULL) {
 388                 dprintkl(KERN_DEBUG PFX "Received deauthentication packet from "MAC_FMT", but that network is unknown.\n",
 389                         MAC_ARG(deauth->header.addr2));
 390                 return 0;
 391         }
 392
 393         /* Make sure the network is authenticated */
 394         if(!net->authenticated)
 395         {
 396                 dprintkl(KERN_DEBUG PFX "Can't perform deauthentication, network is not authenticated.\n");
 397                 /* Error okay? */
 398                 return -EPERM;
 399         }
 400
 401         ieee80211softmac_deauth_from_net(mac, net);
 402
 403         /* let's try to re-associate */
 404         schedule_delayed_work(&mac->associnfo.work, 0);
 405         return 0;
 406 }