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