Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq
[linux-2.6] / net / ieee80211 / softmac / ieee80211softmac_assoc.c
1 /*
2  * This file contains the softmac's association 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 /*
30  * Overview
31  *
32  * Before you can associate, you have to authenticate.
33  *
34  */
35
36 /* Sends out an association request to the desired AP */
37 static void
38 ieee80211softmac_assoc(struct ieee80211softmac_device *mac, struct ieee80211softmac_network *net)
39 {
40         unsigned long flags;
41
42         /* Switch to correct channel for this network */
43         mac->set_channel(mac->dev, net->channel);
44
45         /* Send association request */
46         ieee80211softmac_send_mgt_frame(mac, net, IEEE80211_STYPE_ASSOC_REQ, 0);
47
48         dprintk(KERN_INFO PFX "sent association request!\n");
49
50         spin_lock_irqsave(&mac->lock, flags);
51         mac->associnfo.associated = 0; /* just to make sure */
52
53         /* Set a timer for timeout */
54         /* FIXME: make timeout configurable */
55         if (likely(mac->running))
56                 schedule_delayed_work(&mac->associnfo.timeout, 5 * HZ);
57         spin_unlock_irqrestore(&mac->lock, flags);
58 }
59
60 void
61 ieee80211softmac_assoc_timeout(struct work_struct *work)
62 {
63         struct ieee80211softmac_device *mac =
64                 container_of(work, struct ieee80211softmac_device,
65                              associnfo.timeout.work);
66         struct ieee80211softmac_network *n;
67
68         mutex_lock(&mac->associnfo.mutex);
69         /* we might race against ieee80211softmac_handle_assoc_response,
70          * so make sure only one of us does something */
71         if (!mac->associnfo.associating)
72                 goto out;
73         mac->associnfo.associating = 0;
74         mac->associnfo.bssvalid = 0;
75         mac->associnfo.associated = 0;
76
77         n = ieee80211softmac_get_network_by_bssid_locked(mac, mac->associnfo.bssid);
78
79         dprintk(KERN_INFO PFX "assoc request timed out!\n");
80         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_TIMEOUT, n);
81 out:
82         mutex_unlock(&mac->associnfo.mutex);
83 }
84
85 void
86 ieee80211softmac_disassoc(struct ieee80211softmac_device *mac)
87 {
88         unsigned long flags;
89
90         spin_lock_irqsave(&mac->lock, flags);
91         if (mac->associnfo.associating)
92                 cancel_delayed_work(&mac->associnfo.timeout);
93
94         netif_carrier_off(mac->dev);
95
96         mac->associnfo.associated = 0;
97         mac->associnfo.bssvalid = 0;
98         mac->associnfo.associating = 0;
99         ieee80211softmac_init_bss(mac);
100         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_DISASSOCIATED, NULL);
101         spin_unlock_irqrestore(&mac->lock, flags);
102 }
103
104 /* Sends out a disassociation request to the desired AP */
105 void
106 ieee80211softmac_send_disassoc_req(struct ieee80211softmac_device *mac, u16 reason)
107 {
108         struct ieee80211softmac_network *found;
109
110         if (mac->associnfo.bssvalid && mac->associnfo.associated) {
111                 found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);
112                 if (found)
113                         ieee80211softmac_send_mgt_frame(mac, found, IEEE80211_STYPE_DISASSOC, reason);
114         }
115
116         ieee80211softmac_disassoc(mac);
117 }
118
119 static inline int
120 we_support_all_basic_rates(struct ieee80211softmac_device *mac, u8 *from, u8 from_len)
121 {
122         int idx;
123         u8 rate;
124
125         for (idx = 0; idx < (from_len); idx++) {
126                 rate = (from)[idx];
127                 if (!(rate & IEEE80211_BASIC_RATE_MASK))
128                         continue;
129                 rate &= ~IEEE80211_BASIC_RATE_MASK;
130                 if (!ieee80211softmac_ratesinfo_rate_supported(&mac->ratesinfo, rate))
131                         return 0;
132         }
133         return 1;
134 }
135
136 static int
137 network_matches_request(struct ieee80211softmac_device *mac, struct ieee80211_network *net)
138 {
139         /* we cannot associate to networks whose name we don't know */
140         if (ieee80211_is_empty_essid(net->ssid, net->ssid_len))
141                 return 0;
142         /* do not associate to a network whose BSSBasicRateSet we cannot support */
143         if (!we_support_all_basic_rates(mac, net->rates, net->rates_len))
144                 return 0;
145         /* do we really need to check the ex rates? */
146         if (!we_support_all_basic_rates(mac, net->rates_ex, net->rates_ex_len))
147                 return 0;
148
149         /* assume that users know what they're doing ...
150          * (note we don't let them select a net we're incompatible with) */
151         if (mac->associnfo.bssfixed) {
152                 return !memcmp(mac->associnfo.bssid, net->bssid, ETH_ALEN);
153         }
154
155         /* if 'ANY' network requested, take any that doesn't have privacy enabled */
156         if (mac->associnfo.req_essid.len == 0
157             && !(net->capability & WLAN_CAPABILITY_PRIVACY))
158                 return 1;
159         if (net->ssid_len != mac->associnfo.req_essid.len)
160                 return 0;
161         if (!memcmp(net->ssid, mac->associnfo.req_essid.data, mac->associnfo.req_essid.len))
162                 return 1;
163         return 0;
164 }
165
166 static void
167 ieee80211softmac_assoc_notify_scan(struct net_device *dev, int event_type, void *context)
168 {
169         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
170         ieee80211softmac_assoc_work(&mac->associnfo.work.work);
171 }
172
173 static void
174 ieee80211softmac_assoc_notify_auth(struct net_device *dev, int event_type, void *context)
175 {
176         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
177
178         switch (event_type) {
179         case IEEE80211SOFTMAC_EVENT_AUTHENTICATED:
180                 ieee80211softmac_assoc_work(&mac->associnfo.work.work);
181                 break;
182         case IEEE80211SOFTMAC_EVENT_AUTH_FAILED:
183         case IEEE80211SOFTMAC_EVENT_AUTH_TIMEOUT:
184                 ieee80211softmac_disassoc(mac);
185                 break;
186         }
187 }
188
189 /* This function is called to handle userspace requests (asynchronously) */
190 void
191 ieee80211softmac_assoc_work(struct work_struct *work)
192 {
193         struct ieee80211softmac_device *mac =
194                 container_of(work, struct ieee80211softmac_device,
195                              associnfo.work.work);
196         struct ieee80211softmac_network *found = NULL;
197         struct ieee80211_network *net = NULL, *best = NULL;
198         int bssvalid;
199         unsigned long flags;
200
201         mutex_lock(&mac->associnfo.mutex);
202
203         if (!mac->associnfo.associating)
204                 goto out;
205
206         /* ieee80211_disassoc might clear this */
207         bssvalid = mac->associnfo.bssvalid;
208
209         /* meh */
210         if (mac->associnfo.associated)
211                 ieee80211softmac_send_disassoc_req(mac, WLAN_REASON_DISASSOC_STA_HAS_LEFT);
212
213         /* try to find the requested network in our list, if we found one already */
214         if (bssvalid || mac->associnfo.bssfixed)
215                 found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);
216
217         /* Search the ieee80211 networks for this network if we didn't find it by bssid,
218          * but only if we've scanned at least once (to get a better list of networks to
219          * select from). If we have not scanned before, the !found logic below will be
220          * invoked and will scan. */
221         if (!found && (mac->associnfo.scan_retry < IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT))
222         {
223                 s8 rssi = -128; /* if I don't initialise, gcc emits an invalid warning
224                                    because it cannot follow the best pointer logic. */
225                 spin_lock_irqsave(&mac->ieee->lock, flags);
226                 list_for_each_entry(net, &mac->ieee->network_list, list) {
227                         /* we're supposed to find the network with
228                          * the best signal here, as we're asked to join
229                          * any network with a specific ESSID, and many
230                          * different ones could have that.
231                          *
232                          * I'll for now just go with the reported rssi.
233                          *
234                          * We also should take into account the rateset
235                          * here to find the best BSSID to try.
236                          */
237                         if (network_matches_request(mac, net)) {
238                                 if (!best) {
239                                         best = net;
240                                         rssi = best->stats.rssi;
241                                         continue;
242                                 }
243                                 /* we already had a matching network, so
244                                  * compare their properties to get the
245                                  * better of the two ... (see above)
246                                  */
247                                 if (rssi < net->stats.rssi) {
248                                         best = net;
249                                         rssi = best->stats.rssi;
250                                 }
251                         }
252                 }
253                 /* if we unlock here, we might get interrupted and the `best'
254                  * pointer could go stale */
255                 if (best) {
256                         found = ieee80211softmac_create_network(mac, best);
257                         /* if found is still NULL, then we got -ENOMEM somewhere */
258                         if (found)
259                                 ieee80211softmac_add_network(mac, found);
260                 }
261                 spin_unlock_irqrestore(&mac->ieee->lock, flags);
262         }
263
264         if (!found) {
265                 if (mac->associnfo.scan_retry > 0) {
266                         mac->associnfo.scan_retry--;
267
268                         /* We know of no such network. Let's scan.
269                          * NB: this also happens if we had no memory to copy the network info...
270                          * Maybe we can hope to have more memory after scanning finishes ;)
271                          */
272                         dprintk(KERN_INFO PFX "Associate: Scanning for networks first.\n");
273                         ieee80211softmac_notify(mac->dev, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, ieee80211softmac_assoc_notify_scan, NULL);
274                         if (ieee80211softmac_start_scan(mac))
275                                 dprintk(KERN_INFO PFX "Associate: failed to initiate scan. Is device up?\n");
276                         goto out;
277                 } else {
278                         mac->associnfo.associating = 0;
279                         mac->associnfo.associated = 0;
280
281                         dprintk(KERN_INFO PFX "Unable to find matching network after scan!\n");
282                         /* reset the retry counter for the next user request since we
283                          * break out and don't reschedule ourselves after this point. */
284                         mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
285                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_NET_NOT_FOUND, NULL);
286                         goto out;
287                 }
288         }
289
290         /* reset the retry counter for the next user request since we
291          * now found a net and will try to associate to it, but not
292          * schedule this function again. */
293         mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
294         mac->associnfo.bssvalid = 1;
295         memcpy(mac->associnfo.bssid, found->bssid, ETH_ALEN);
296         /* copy the ESSID for displaying it */
297         mac->associnfo.associate_essid.len = found->essid.len;
298         memcpy(mac->associnfo.associate_essid.data, found->essid.data, IW_ESSID_MAX_SIZE + 1);
299
300         /* we found a network! authenticate (if necessary) and associate to it. */
301         if (found->authenticating) {
302                 dprintk(KERN_INFO PFX "Already requested authentication, waiting...\n");
303                 if(!mac->associnfo.assoc_wait) {
304                         mac->associnfo.assoc_wait = 1;
305                         ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify_auth, NULL, GFP_KERNEL);
306                 }
307                 goto out;
308         }
309         if (!found->authenticated && !found->authenticating) {
310                 /* This relies on the fact that _auth_req only queues the work,
311                  * otherwise adding the notification would be racy. */
312                 if (!ieee80211softmac_auth_req(mac, found)) {
313                         if(!mac->associnfo.assoc_wait) {
314                                 dprintk(KERN_INFO PFX "Cannot associate without being authenticated, requested authentication\n");
315                                 mac->associnfo.assoc_wait = 1;
316                                 ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify_auth, NULL, GFP_KERNEL);
317                         }
318                 } else {
319                         printkl(KERN_WARNING PFX "Not authenticated, but requesting authentication failed. Giving up to associate\n");
320                         mac->associnfo.assoc_wait = 0;
321                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, found);
322                 }
323                 goto out;
324         }
325         /* finally! now we can start associating */
326         mac->associnfo.assoc_wait = 0;
327         ieee80211softmac_assoc(mac, found);
328
329 out:
330         mutex_unlock(&mac->associnfo.mutex);
331 }
332
333 /* call this to do whatever is necessary when we're associated */
334 static void
335 ieee80211softmac_associated(struct ieee80211softmac_device *mac,
336         struct ieee80211_assoc_response * resp,
337         struct ieee80211softmac_network *net)
338 {
339         u16 cap = le16_to_cpu(resp->capability);
340         u8 erp_value = net->erp_value;
341
342         mac->associnfo.associating = 0;
343         mac->bssinfo.supported_rates = net->supported_rates;
344         ieee80211softmac_recalc_txrates(mac);
345
346         mac->associnfo.associated = 1;
347
348         mac->associnfo.short_preamble_available =
349                 (cap & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0;
350         ieee80211softmac_process_erp(mac, erp_value);
351
352         if (mac->set_bssid_filter)
353                 mac->set_bssid_filter(mac->dev, net->bssid);
354         memcpy(mac->ieee->bssid, net->bssid, ETH_ALEN);
355         netif_carrier_on(mac->dev);
356
357         mac->association_id = le16_to_cpup(&resp->aid);
358 }
359
360 /* received frame handling functions */
361 int
362 ieee80211softmac_handle_assoc_response(struct net_device * dev,
363                                        struct ieee80211_assoc_response * resp,
364                                        struct ieee80211_network * _ieee80211_network)
365 {
366         /* NOTE: the network parameter has to be mostly ignored by
367          *       this code because it is the ieee80211's pointer
368          *       to the struct, not ours (we made a copy)
369          */
370         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
371         u16 status = le16_to_cpup(&resp->status);
372         struct ieee80211softmac_network *network = NULL;
373         unsigned long flags;
374
375         if (unlikely(!mac->running))
376                 return -ENODEV;
377
378         spin_lock_irqsave(&mac->lock, flags);
379
380         if (!mac->associnfo.associating) {
381                 /* we race against the timeout function, so make sure
382                  * only one of us can do work */
383                 spin_unlock_irqrestore(&mac->lock, flags);
384                 return 0;
385         }
386         network = ieee80211softmac_get_network_by_bssid_locked(mac, resp->header.addr3);
387
388         /* someone sending us things without us knowing him? Ignore. */
389         if (!network) {
390                 dprintk(KERN_INFO PFX "Received unrequested assocation response from " MAC_FMT "\n", MAC_ARG(resp->header.addr3));
391                 spin_unlock_irqrestore(&mac->lock, flags);
392                 return 0;
393         }
394
395         /* now that we know it was for us, we can cancel the timeout */
396         cancel_delayed_work(&mac->associnfo.timeout);
397
398         /* if the association response included an ERP IE, update our saved
399          * copy */
400         if (_ieee80211_network->flags & NETWORK_HAS_ERP_VALUE)
401                 network->erp_value = _ieee80211_network->erp_value;
402
403         switch (status) {
404                 case 0:
405                         dprintk(KERN_INFO PFX "associated!\n");
406                         ieee80211softmac_associated(mac, resp, network);
407                         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATED, network);
408                         break;
409                 case WLAN_REASON_STA_REQ_ASSOC_WITHOUT_AUTH:
410                         if (!network->auth_desynced_once) {
411                                 /* there seem to be a few rare cases where our view of
412                                  * the world is obscured, or buggy APs that don't DEAUTH
413                                  * us properly. So we handle that, but allow it only once.
414                                  */
415                                 printkl(KERN_INFO PFX "We were not authenticated during association, retrying...\n");
416                                 network->authenticated = 0;
417                                 /* we don't want to do this more than once ... */
418                                 network->auth_desynced_once = 1;
419                                 schedule_delayed_work(&mac->associnfo.work, 0);
420                                 break;
421                         }
422                 default:
423                         dprintk(KERN_INFO PFX "associating failed (reason: 0x%x)!\n", status);
424                         mac->associnfo.associating = 0;
425                         mac->associnfo.bssvalid = 0;
426                         mac->associnfo.associated = 0;
427                         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, network);
428         }
429
430         spin_unlock_irqrestore(&mac->lock, flags);
431         return 0;
432 }
433
434 void
435 ieee80211softmac_try_reassoc(struct ieee80211softmac_device *mac)
436 {
437         unsigned long flags;
438
439         spin_lock_irqsave(&mac->lock, flags);
440         mac->associnfo.associating = 1;
441         schedule_delayed_work(&mac->associnfo.work, 0);
442         spin_unlock_irqrestore(&mac->lock, flags);
443 }
444
445 int
446 ieee80211softmac_handle_disassoc(struct net_device * dev,
447                                  struct ieee80211_disassoc *disassoc)
448 {
449         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
450
451         if (unlikely(!mac->running))
452                 return -ENODEV;
453
454         if (memcmp(disassoc->header.addr2, mac->associnfo.bssid, ETH_ALEN))
455                 return 0;
456
457         if (memcmp(disassoc->header.addr1, mac->dev->dev_addr, ETH_ALEN))
458                 return 0;
459
460         dprintk(KERN_INFO PFX "got disassoc frame\n");
461         ieee80211softmac_disassoc(mac);
462
463         ieee80211softmac_try_reassoc(mac);
464
465         return 0;
466 }
467
468 int
469 ieee80211softmac_handle_reassoc_req(struct net_device * dev,
470                                     struct ieee80211_reassoc_request * resp)
471 {
472         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
473         struct ieee80211softmac_network *network;
474
475         if (unlikely(!mac->running))
476                 return -ENODEV;
477
478         network = ieee80211softmac_get_network_by_bssid(mac, resp->header.addr3);
479         if (!network) {
480                 dprintkl(KERN_INFO PFX "reassoc request from unknown network\n");
481                 return 0;
482         }
483         schedule_delayed_work(&mac->associnfo.work, 0);
484
485         return 0;
486 }