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                 printkl(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                 printkl(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                         if (net->challenge != NULL)
 223                                 kfree(net->challenge);
 224                         net->challenge = kmalloc(net->challenge_len, GFP_ATOMIC);
 225                         memcpy(net->challenge, data, net->challenge_len);
 226                         aq->state = IEEE80211SOFTMAC_AUTH_SHARED_RESPONSE;
 227
 228                         /* We reuse the work struct from the auth request here.
 229                          * It is safe to do so as each one is per-request, and
 230                          * at this point (dealing with authentication response)
 231                          * we have obviously already sent the initial auth
 232                          * request. */
 233                         cancel_delayed_work(&aq->work);
 234                         INIT_DELAYED_WORK(&aq->work, &ieee80211softmac_auth_challenge_response);
 235                         schedule_delayed_work(&aq->work, 0);
 236                         spin_unlock_irqrestore(&mac->lock, flags);
 237                         return 0;
 238                 case IEEE80211SOFTMAC_AUTH_SHARED_PASS:
 239                         kfree(net->challenge);
 240                         net->challenge = NULL;
 241                         net->challenge_len = 0;
 242                         /* Check the status code of the response */
 243                         switch(auth->status) {
 244                         case WLAN_STATUS_SUCCESS:
 245                                 /* Update the status to Authenticated */
 246                                 spin_lock_irqsave(&mac->lock, flags);
 247                                 net->authenticating = 0;
 248                                 net->authenticated = 1;
 249                                 spin_unlock_irqrestore(&mac->lock, flags);
 250                                 printkl(KERN_NOTICE PFX "Shared Key Authentication completed with "MAC_FMT"\n",
 251                                         MAC_ARG(net->bssid));
 252                                 ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_AUTHENTICATED, net);
 253                                 break;
 254                         default:
 255                                 printkl(KERN_NOTICE PFX "Shared Key Authentication with "MAC_FMT" failed, error code: %i\n",
 256                                         MAC_ARG(net->bssid), le16_to_cpup(&auth->status));
 257                                 /* Lock and reset flags */
 258                                 spin_lock_irqsave(&mac->lock, flags);
 259                                 net->authenticating = 0;
 260                                 net->authenticated = 0;
 261                                 spin_unlock_irqrestore(&mac->lock, flags);
 262                                 /* Count the error? */
 263                                 break;
 264                         }
 265                         goto free_aq;
 266                         break;
 267                 default:
 268                         printkl(KERN_WARNING PFX "Unhandled Authentication Step: %i\n", auth->transaction);
 269                         break;
 270                 }
 271                 goto free_aq;
 272                 break;
 273         default:
 274                 /* ERROR */
 275                 goto free_aq;
 276                 break;
 277         }
 278         return 0;
 279 free_aq:
 280         /* Cancel the timeout */
 281         spin_lock_irqsave(&mac->lock, flags);
 282         cancel_delayed_work(&aq->work);
 283         /* Remove this item from the queue */
 284         list_del(&aq->list);
 285         spin_unlock_irqrestore(&mac->lock, flags);
 286
 287         /* Free it */
 288         kfree(aq);
 289         return 0;
 290 }
 291
 292 /*
 293  * Handle deauthorization
 294  */
 295 static void
 296 ieee80211softmac_deauth_from_net(struct ieee80211softmac_device *mac,
 297         struct ieee80211softmac_network *net)
 298 {
 299         struct ieee80211softmac_auth_queue_item *aq = NULL;
 300         struct list_head *list_ptr;
 301         unsigned long flags;
 302
 303         /* deauthentication implies disassociation */
 304         ieee80211softmac_disassoc(mac);
 305
 306         /* Lock and reset status flags */
 307         spin_lock_irqsave(&mac->lock, flags);
 308         net->authenticating = 0;
 309         net->authenticated = 0;
 310
 311         /* Find correct auth queue item, if it exists */
 312         list_for_each(list_ptr, &mac->auth_queue) {
 313                 aq = list_entry(list_ptr, struct ieee80211softmac_auth_queue_item, list);
 314                 if (!memcmp(net->bssid, aq->net->bssid, ETH_ALEN))
 315                         break;
 316                 else
 317                         aq = NULL;
 318         }
 319
 320         /* Cancel pending work */
 321         if(aq != NULL)
 322                 /* Not entirely safe?  What about running work? */
 323                 cancel_delayed_work(&aq->work);
 324
 325         /* Free our network ref */
 326         ieee80211softmac_del_network_locked(mac, net);
 327         if(net->challenge != NULL)
 328                 kfree(net->challenge);
 329         kfree(net);
 330
 331         /* can't transmit data right now... */
 332         netif_carrier_off(mac->dev);
 333         spin_unlock_irqrestore(&mac->lock, flags);
 334 }
 335
 336 /*
 337  * Sends a deauth request to the desired AP
 338  */
 339 int
 340 ieee80211softmac_deauth_req(struct ieee80211softmac_device *mac,
 341         struct ieee80211softmac_network *net, int reason)
 342 {
 343         int ret;
 344
 345         /* Make sure the network is authenticated */
 346         if (!net->authenticated)
 347         {
 348                 printkl(KERN_DEBUG PFX "Can't send deauthentication packet, network is not authenticated.\n");
 349                 /* Error okay? */
 350                 return -EPERM;
 351         }
 352
 353         /* Send the de-auth packet */
 354         if((ret = ieee80211softmac_send_mgt_frame(mac, net, IEEE80211_STYPE_DEAUTH, reason)))
 355                 return ret;
 356
 357         ieee80211softmac_deauth_from_net(mac, net);
 358         return 0;
 359 }
 360
 361 /*
 362  * This should be registered with ieee80211 as handle_deauth
 363  */
 364 int
 365 ieee80211softmac_deauth_resp(struct net_device *dev, struct ieee80211_deauth *deauth)
 366 {
 367
 368         struct ieee80211softmac_network *net = NULL;
 369         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
 370
 371         if (unlikely(!mac->running))
 372                 return -ENODEV;
 373
 374         if (!deauth) {
 375                 dprintk("deauth without deauth packet. eek!\n");
 376                 return 0;
 377         }
 378
 379         net = ieee80211softmac_get_network_by_bssid(mac, deauth->header.addr2);
 380
 381         if (net == NULL) {
 382                 printkl(KERN_DEBUG PFX "Received deauthentication packet from "MAC_FMT", but that network is unknown.\n",
 383                         MAC_ARG(deauth->header.addr2));
 384                 return 0;
 385         }
 386
 387         /* Make sure the network is authenticated */
 388         if(!net->authenticated)
 389         {
 390                 printkl(KERN_DEBUG PFX "Can't perform deauthentication, network is not authenticated.\n");
 391                 /* Error okay? */
 392                 return -EPERM;
 393         }
 394
 395         ieee80211softmac_deauth_from_net(mac, net);
 396
 397         /* let's try to re-associate */
 398         schedule_delayed_work(&mac->associnfo.work, 0);
 399         return 0;
 400 }