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         DECLARE_MAC_BUF(mac2);
  39
  40         if (net->authenticating || net->authenticated)
  41                 return 0;
  42         net->authenticating = 1;
  43
  44         /* Add the network if it's not already added */
  45         ieee80211softmac_add_network(mac, net);
  46
  47         dprintk(KERN_NOTICE PFX "Queueing Authentication Request to %s\n", print_mac(mac2, net->bssid));
  48         /* Queue the auth request */
  49         auth = (struct ieee80211softmac_auth_queue_item *)
  50                 kmalloc(sizeof(struct ieee80211softmac_auth_queue_item), GFP_KERNEL);
  51         if(auth == NULL)
  52                 return -ENOMEM;
  53
  54         auth->net = net;
  55         auth->mac = mac;
  56         auth->retry = IEEE80211SOFTMAC_AUTH_RETRY_LIMIT;
  57         auth->state = IEEE80211SOFTMAC_AUTH_OPEN_REQUEST;
  58         INIT_DELAYED_WORK(&auth->work, ieee80211softmac_auth_queue);
  59
  60         /* Lock (for list) */
  61         spin_lock_irqsave(&mac->lock, flags);
  62
  63         /* add to list */
  64         list_add_tail(&auth->list, &mac->auth_queue);
  65         queue_delayed_work(mac->wq, &auth->work, 0);
  66         spin_unlock_irqrestore(&mac->lock, flags);
  67
  68         return 0;
  69 }
  70
  71
  72 /* Sends an auth request to the desired AP and handles timeouts */
  73 static void
  74 ieee80211softmac_auth_queue(struct work_struct *work)
  75 {
  76         struct ieee80211softmac_device *mac;
  77         struct ieee80211softmac_auth_queue_item *auth;
  78         struct ieee80211softmac_network *net;
  79         unsigned long flags;
  80         DECLARE_MAC_BUF(mac2);
  81
  82         auth = container_of(work, struct ieee80211softmac_auth_queue_item,
  83                             work.work);
  84         net = auth->net;
  85         mac = auth->mac;
  86
  87         if(auth->retry > 0) {
  88                 /* Switch to correct channel for this network */
  89                 mac->set_channel(mac->dev, net->channel);
  90
  91                 /* Lock and set flags */
  92                 spin_lock_irqsave(&mac->lock, flags);
  93                 if (unlikely(!mac->running)) {
  94                         /* Prevent reschedule on workqueue flush */
  95                         spin_unlock_irqrestore(&mac->lock, flags);
  96                         return;
  97                 }
  98                 net->authenticated = 0;
  99                 /* add a timeout call so we eventually give up waiting for an auth reply */
 100                 queue_delayed_work(mac->wq, &auth->work, IEEE80211SOFTMAC_AUTH_TIMEOUT);
 101                 auth->retry--;
 102                 spin_unlock_irqrestore(&mac->lock, flags);
 103                 if (ieee80211softmac_send_mgt_frame(mac, auth->net, IEEE80211_STYPE_AUTH, auth->state))
 104                         dprintk(KERN_NOTICE PFX "Sending Authentication Request to %s failed (this shouldn't happen, wait for the timeout).\n",
 105                                 print_mac(mac2, net->bssid));
 106                 else
 107                         dprintk(KERN_NOTICE PFX "Sent Authentication Request to %s.\n", print_mac(mac2, net->bssid));
 108                 return;
 109         }
 110
 111         printkl(KERN_WARNING PFX "Authentication timed out with %s\n", print_mac(mac2, net->bssid));
 112         /* Remove this item from the queue */
 113         spin_lock_irqsave(&mac->lock, flags);
 114         net->authenticating = 0;
 115         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_AUTH_TIMEOUT, net);
 116         cancel_delayed_work(&auth->work); /* just to make sure... */
 117         list_del(&auth->list);
 118         spin_unlock_irqrestore(&mac->lock, flags);
 119         /* Free it */
 120         kfree(auth);
 121 }
 122
 123 /* Sends a response to an auth challenge (for shared key auth). */
 124 static void
 125 ieee80211softmac_auth_challenge_response(struct work_struct *work)
 126 {
 127         struct ieee80211softmac_auth_queue_item *aq =
 128                 container_of(work, struct ieee80211softmac_auth_queue_item,
 129                              work.work);
 130
 131         /* Send our response */
 132         ieee80211softmac_send_mgt_frame(aq->mac, aq->net, IEEE80211_STYPE_AUTH, aq->state);
 133 }
 134
 135 /* Handle the auth response from the AP
 136  * This should be registered with ieee80211 as handle_auth
 137  */
 138 int
 139 ieee80211softmac_auth_resp(struct net_device *dev, struct ieee80211_auth *auth)
 140 {
 141
 142         struct list_head *list_ptr;
 143         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 144         struct ieee80211softmac_auth_queue_item *aq = NULL;
 145         struct ieee80211softmac_network *net = NULL;
 146         unsigned long flags;
 147         u8 * data;
 148         DECLARE_MAC_BUF(mac2);
 149
 150         if (unlikely(!mac->running))
 151                 return -ENODEV;
 152
 153         /* Find correct auth queue item */
 154         spin_lock_irqsave(&mac->lock, flags);
 155         list_for_each(list_ptr, &mac->auth_queue) {
 156                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 157                 net = aq->net;
 158                 if (!memcmp(net->bssid, auth->header.addr2, ETH_ALEN))
 159                         break;
 160                 else
 161                         aq = NULL;
 162         }
 163         spin_unlock_irqrestore(&mac->lock, flags);
 164
 165         /* Make sure that we've got an auth queue item for this request */
 166         if(aq == NULL)
 167         {
 168                 dprintkl(KERN_DEBUG PFX "Authentication response received from %s but no queue item exists.\n", print_mac(mac2, auth->header.addr2));
 169                 /* Error #? */
 170                 return -1;
 171         }
 172
 173         /* Check for out of order authentication */
 174         if(!net->authenticating)
 175         {
 176                 dprintkl(KERN_DEBUG PFX "Authentication response received from %s but did not request authentication.\n",print_mac(mac2, auth->header.addr2));
 177                 return -1;
 178         }
 179
 180         /* Parse the auth packet */
 181         switch(le16_to_cpu(auth->algorithm)) {
 182         case WLAN_AUTH_OPEN:
 183                 /* Check the status code of the response */
 184
 185                 switch(le16_to_cpu(auth->status)) {
 186                 case WLAN_STATUS_SUCCESS:
 187                         /* Update the status to Authenticated */
 188                         spin_lock_irqsave(&mac->lock, flags);
 189                         net->authenticating = 0;
 190                         net->authenticated = 1;
 191                         spin_unlock_irqrestore(&mac->lock, flags);
 192
 193                         /* Send event */
 194                         printkl(KERN_NOTICE PFX "Open Authentication completed with %s\n", print_mac(mac2, net->bssid));
 195                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 196                         break;
 197                 default:
 198                         /* Lock and reset flags */
 199                         spin_lock_irqsave(&mac->lock, flags);
 200                         net->authenticated = 0;
 201                         net->authenticating = 0;
 202                         spin_unlock_irqrestore(&mac->lock, flags);
 203
 204                         printkl(KERN_NOTICE PFX "Open Authentication with %s failed, error code: %i\n",
 205                                 print_mac(mac2, net->bssid), le16_to_cpup(&auth->status));
 206                         /* Count the error? */
 207                         break;
 208                 }
 209                 goto free_aq;
 210                 break;
 211         case WLAN_AUTH_SHARED_KEY:
 212                 /* Figure out where we are in the process */
 213                 switch(le16_to_cpu(auth->transaction)) {
 214                 case IEEE80211SOFTMAC_AUTH_SHARED_CHALLENGE:
 215                         /* Check to make sure we have a challenge IE */
 216                         data = (u8 *)auth->info_element;
 217                         if (*data++ != MFIE_TYPE_CHALLENGE) {
 218                                 printkl(KERN_NOTICE PFX "Shared Key Authentication failed due to a missing challenge.\n");
 219                                 break;
 220                         }
 221                         /* Save the challenge */
 222                         spin_lock_irqsave(&mac->lock, flags);
 223                         net->challenge_len = *data++;
 224                         if (net->challenge_len > WLAN_AUTH_CHALLENGE_LEN)
 225                                 net->challenge_len = WLAN_AUTH_CHALLENGE_LEN;
 226                         kfree(net->challenge);
 227                         net->challenge = kmemdup(data, net->challenge_len,
 228                                                  GFP_ATOMIC);
 229                         if (net->challenge == NULL) {
 230                                 printkl(KERN_NOTICE PFX "Shared Key "
 231                                         "Authentication failed due to "
 232                                         "memory shortage.\n");
 233                                 spin_unlock_irqrestore(&mac->lock, flags);
 234                                 break;
 235                         }
 236                         aq->state = IEEE80211SOFTMAC_AUTH_SHARED_RESPONSE;
 237
 238                         /* We reuse the work struct from the auth request here.
 239                          * It is safe to do so as each one is per-request, and
 240                          * at this point (dealing with authentication response)
 241                          * we have obviously already sent the initial auth
 242                          * request. */
 243                         cancel_delayed_work(&aq->work);
 244                         INIT_DELAYED_WORK(&aq->work, &ieee80211softmac_auth_challenge_response);
 245                         queue_delayed_work(mac->wq, &aq->work, 0);
 246                         spin_unlock_irqrestore(&mac->lock, flags);
 247                         return 0;
 248                 case IEEE80211SOFTMAC_AUTH_SHARED_PASS:
 249                         kfree(net->challenge);
 250                         net->challenge = NULL;
 251                         net->challenge_len = 0;
 252                         /* Check the status code of the response */
 253                         switch(auth->status) {
 254                         case WLAN_STATUS_SUCCESS:
 255                                 /* Update the status to Authenticated */
 256                                 spin_lock_irqsave(&mac->lock, flags);
 257                                 net->authenticating = 0;
 258                                 net->authenticated = 1;
 259                                 spin_unlock_irqrestore(&mac->lock, flags);
 260                                 printkl(KERN_NOTICE PFX "Shared Key Authentication completed with %s\n",
 261                                         print_mac(mac2, net->bssid));
 262                                 ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 263                                 break;
 264                         default:
 265                                 printkl(KERN_NOTICE PFX "Shared Key Authentication with %s failed, error code: %i\n",
 266                                         print_mac(mac2, net->bssid), le16_to_cpup(&auth->status));
 267                                 /* Lock and reset flags */
 268                                 spin_lock_irqsave(&mac->lock, flags);
 269                                 net->authenticating = 0;
 270                                 net->authenticated = 0;
 271                                 spin_unlock_irqrestore(&mac->lock, flags);
 272                                 /* Count the error? */
 273                                 break;
 274                         }
 275                         goto free_aq;
 276                         break;
 277                 default:
 278                         printkl(KERN_WARNING PFX "Unhandled Authentication Step: %i\n", auth->transaction);
 279                         break;
 280                 }
 281                 goto free_aq;
 282                 break;
 283         default:
 284                 /* ERROR */
 285                 goto free_aq;
 286                 break;
 287         }
 288         return 0;
 289 free_aq:
 290         /* Cancel the timeout */
 291         spin_lock_irqsave(&mac->lock, flags);
 292         cancel_delayed_work(&aq->work);
 293         /* Remove this item from the queue */
 294         list_del(&aq->list);
 295         spin_unlock_irqrestore(&mac->lock, flags);
 296
 297         /* Free it */
 298         kfree(aq);
 299         return 0;
 300 }
 301
 302 /*
 303  * Handle deauthorization
 304  */
 305 static void
 306 ieee80211softmac_deauth_from_net(struct ieee80211softmac_device *mac,
 307         struct ieee80211softmac_network *net)
 308 {
 309         struct ieee80211softmac_auth_queue_item *aq = NULL;
 310         struct list_head *list_ptr;
 311         unsigned long flags;
 312
 313         /* deauthentication implies disassociation */
 314         ieee80211softmac_disassoc(mac);
 315
 316         /* Lock and reset status flags */
 317         spin_lock_irqsave(&mac->lock, flags);
 318         net->authenticating = 0;
 319         net->authenticated = 0;
 320
 321         /* Find correct auth queue item, if it exists */
 322         list_for_each(list_ptr, &mac->auth_queue) {
 323                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 324                 if (!memcmp(net->bssid, aq->net->bssid, ETH_ALEN))
 325                         break;
 326                 else
 327                         aq = NULL;
 328         }
 329
 330         /* Cancel pending work */
 331         if(aq != NULL)
 332                 /* Not entirely safe?  What about running work? */
 333                 cancel_delayed_work(&aq->work);
 334
 335         /* Free our network ref */
 336         ieee80211softmac_del_network_locked(mac, net);
 337         if(net->challenge != NULL)
 338                 kfree(net->challenge);
 339         kfree(net);
 340
 341         /* can't transmit data right now... */
 342         netif_carrier_off(mac->dev);
 343         spin_unlock_irqrestore(&mac->lock, flags);
 344
 345         ieee80211softmac_try_reassoc(mac);
 346 }
 347
 348 /*
 349  * Sends a deauth request to the desired AP
 350  */
 351 int
 352 ieee80211softmac_deauth_req(struct ieee80211softmac_device *mac,
 353         struct ieee80211softmac_network *net, int reason)
 354 {
 355         int ret;
 356
 357         /* Make sure the network is authenticated */
 358         if (!net->authenticated)
 359         {
 360                 dprintkl(KERN_DEBUG PFX "Can't send deauthentication packet, network is not authenticated.\n");
 361                 /* Error okay? */
 362                 return -EPERM;
 363         }
 364
 365         /* Send the de-auth packet */
 366         if((ret = ieee80211softmac_send_mgt_frame(mac, net, IEEE80211_STYPE_DEAUTH, reason)))
 367                 return ret;
 368
 369         ieee80211softmac_deauth_from_net(mac, net);
 370         return 0;
 371 }
 372
 373 /*
 374  * This should be registered with ieee80211 as handle_deauth
 375  */
 376 int
 377 ieee80211softmac_deauth_resp(struct net_device *dev, struct ieee80211_deauth *deauth)
 378 {
 379
 380         struct ieee80211softmac_network *net = NULL;
 381         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 382         DECLARE_MAC_BUF(mac2);
 383
 384         if (unlikely(!mac->running))
 385                 return -ENODEV;
 386
 387         if (!deauth) {
 388                 dprintk("deauth without deauth packet. eek!\n");
 389                 return 0;
 390         }
 391
 392         net = ieee80211softmac_get_network_by_bssid(mac, deauth->header.addr2);
 393
 394         if (net == NULL) {
 395                 dprintkl(KERN_DEBUG PFX "Received deauthentication packet from %s, but that network is unknown.\n",
 396                         print_mac(mac2, deauth->header.addr2));
 397                 return 0;
 398         }
 399
 400         /* Make sure the network is authenticated */
 401         if(!net->authenticated)
 402         {
 403                 dprintkl(KERN_DEBUG PFX "Can't perform deauthentication, network is not authenticated.\n");
 404                 /* Error okay? */
 405                 return -EPERM;
 406         }
 407
 408         ieee80211softmac_deauth_from_net(mac, net);
 409
 410         /* let's try to re-associate */
 411         queue_delayed_work(mac->wq, &mac->associnfo.work, 0);
 412         return 0;
 413 }