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