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Merge branch 'upstream-fixes' into upstream
[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         /* Change the state to associating */
51         spin_lock_irqsave(&mac->lock, flags);
52         mac->associnfo.associating = 1;
53         mac->associated = 0; /* just to make sure */
54
55         /* Set a timer for timeout */
56         /* FIXME: make timeout configurable */
57         if (likely(mac->running))
58                 schedule_delayed_work(&mac->associnfo.timeout, 5 * HZ);
59         spin_unlock_irqrestore(&mac->lock, flags);
60 }
61
62 void
63 ieee80211softmac_assoc_timeout(void *d)
64 {
65         struct ieee80211softmac_device *mac = (struct ieee80211softmac_device *)d;
66         unsigned long flags;
67
68         spin_lock_irqsave(&mac->lock, flags);
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                 spin_unlock_irqrestore(&mac->lock, flags);
73                 return;
74         }
75         mac->associnfo.associating = 0;
76         mac->associnfo.bssvalid = 0;
77         mac->associated = 0;
78         spin_unlock_irqrestore(&mac->lock, flags);
79
80         dprintk(KERN_INFO PFX "assoc request timed out!\n");
81         /* FIXME: we need to know the network here. that requires a bit of restructuring */
82         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_TIMEOUT, NULL);
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->associated = 0;
97         mac->associnfo.bssvalid = 0;
98         mac->associnfo.associating = 0;
99         ieee80211softmac_init_txrates(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->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(struct net_device *dev, void *context)
168 {
169         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
170         ieee80211softmac_assoc_work((void*)mac);
171 }
172
173 /* This function is called to handle userspace requests (asynchronously) */
174 void
175 ieee80211softmac_assoc_work(void *d)
176 {
177         struct ieee80211softmac_device *mac = (struct ieee80211softmac_device *)d;
178         struct ieee80211softmac_network *found = NULL;
179         struct ieee80211_network *net = NULL, *best = NULL;
180         int bssvalid;
181         unsigned long flags;
182
183         /* ieee80211_disassoc might clear this */
184         bssvalid = mac->associnfo.bssvalid;
185
186         /* meh */
187         if (mac->associated)
188                 ieee80211softmac_send_disassoc_req(mac, WLAN_REASON_DISASSOC_STA_HAS_LEFT);
189
190         /* try to find the requested network in our list, if we found one already */
191         if (bssvalid || mac->associnfo.bssfixed)
192                 found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);       
193         
194         /* Search the ieee80211 networks for this network if we didn't find it by bssid,
195          * but only if we've scanned at least once (to get a better list of networks to
196          * select from). If we have not scanned before, the !found logic below will be
197          * invoked and will scan. */
198         if (!found && (mac->associnfo.scan_retry < IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT))
199         {
200                 s8 rssi = -128; /* if I don't initialise, gcc emits an invalid warning
201                                    because it cannot follow the best pointer logic. */
202                 spin_lock_irqsave(&mac->ieee->lock, flags);
203                 list_for_each_entry(net, &mac->ieee->network_list, list) {
204                         /* we're supposed to find the network with
205                          * the best signal here, as we're asked to join
206                          * any network with a specific ESSID, and many
207                          * different ones could have that.
208                          *
209                          * I'll for now just go with the reported rssi.
210                          *
211                          * We also should take into account the rateset
212                          * here to find the best BSSID to try.
213                          */
214                         if (network_matches_request(mac, net)) {
215                                 if (!best) {
216                                         best = net;
217                                         rssi = best->stats.rssi;
218                                         continue;
219                                 }
220                                 /* we already had a matching network, so
221                                  * compare their properties to get the
222                                  * better of the two ... (see above)
223                                  */
224                                 if (rssi < net->stats.rssi) {
225                                         best = net;
226                                         rssi = best->stats.rssi;
227                                 }
228                         }
229                 }
230                 /* if we unlock here, we might get interrupted and the `best'
231                  * pointer could go stale */
232                 if (best) {
233                         found = ieee80211softmac_create_network(mac, best);
234                         /* if found is still NULL, then we got -ENOMEM somewhere */
235                         if (found)
236                                 ieee80211softmac_add_network(mac, found);
237                 }
238                 spin_unlock_irqrestore(&mac->ieee->lock, flags);
239         }
240
241         if (!found) {
242                 if (mac->associnfo.scan_retry > 0) {
243                         spin_lock_irqsave(&mac->lock, flags);
244                         mac->associnfo.scan_retry--;
245                         spin_unlock_irqrestore(&mac->lock, flags);
246                 
247                         /* We know of no such network. Let's scan. 
248                          * NB: this also happens if we had no memory to copy the network info...
249                          * Maybe we can hope to have more memory after scanning finishes ;)
250                          */
251                         dprintk(KERN_INFO PFX "Associate: Scanning for networks first.\n");
252                         ieee80211softmac_notify(mac->dev, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, ieee80211softmac_assoc_notify, NULL);
253                         if (ieee80211softmac_start_scan(mac))
254                                 dprintk(KERN_INFO PFX "Associate: failed to initiate scan. Is device up?\n");
255                         return;
256                 } else {
257                         spin_lock_irqsave(&mac->lock, flags);
258                         mac->associnfo.associating = 0;
259                         mac->associated = 0;
260                         spin_unlock_irqrestore(&mac->lock, flags);
261
262                         dprintk(KERN_INFO PFX "Unable to find matching network after scan!\n");
263                         /* reset the retry counter for the next user request since we
264                          * break out and don't reschedule ourselves after this point. */
265                         mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
266                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_NET_NOT_FOUND, NULL);
267                         return;
268                 }
269         }
270
271         /* reset the retry counter for the next user request since we
272          * now found a net and will try to associate to it, but not
273          * schedule this function again. */
274         mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
275         mac->associnfo.bssvalid = 1;
276         memcpy(mac->associnfo.bssid, found->bssid, ETH_ALEN);
277         /* copy the ESSID for displaying it */
278         mac->associnfo.associate_essid.len = found->essid.len;
279         memcpy(mac->associnfo.associate_essid.data, found->essid.data, IW_ESSID_MAX_SIZE + 1);
280         
281         /* we found a network! authenticate (if necessary) and associate to it. */
282         if (!found->authenticated) {
283                 /* This relies on the fact that _auth_req only queues the work,
284                  * otherwise adding the notification would be racy. */
285                 if (!ieee80211softmac_auth_req(mac, found)) {
286                         dprintk(KERN_INFO PFX "cannot associate without being authenticated, requested authentication\n");
287                         ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify, NULL, GFP_KERNEL);
288                 } else {
289                         printkl(KERN_WARNING PFX "Not authenticated, but requesting authentication failed. Giving up to associate\n");
290                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, found);
291                 }
292                 return;
293         }
294         /* finally! now we can start associating */
295         ieee80211softmac_assoc(mac, found);
296 }
297
298 /* call this to do whatever is necessary when we're associated */
299 static void
300 ieee80211softmac_associated(struct ieee80211softmac_device *mac,
301         struct ieee80211_assoc_response * resp,
302         struct ieee80211softmac_network *net)
303 {
304         mac->associnfo.associating = 0;
305         mac->associnfo.supported_rates = net->supported_rates;
306         ieee80211softmac_recalc_txrates(mac);
307
308         mac->associated = 1;
309         if (mac->set_bssid_filter)
310                 mac->set_bssid_filter(mac->dev, net->bssid);
311         memcpy(mac->ieee->bssid, net->bssid, ETH_ALEN);
312         netif_carrier_on(mac->dev);
313         
314         mac->association_id = le16_to_cpup(&resp->aid);
315 }
316
317 /* received frame handling functions */
318 int
319 ieee80211softmac_handle_assoc_response(struct net_device * dev,
320                                        struct ieee80211_assoc_response * resp,
321                                        struct ieee80211_network * _ieee80211_network_do_not_use)
322 {
323         /* NOTE: the network parameter has to be ignored by
324          *       this code because it is the ieee80211's pointer
325          *       to the struct, not ours (we made a copy)
326          */
327         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
328         u16 status = le16_to_cpup(&resp->status);
329         struct ieee80211softmac_network *network = NULL;
330         unsigned long flags;
331
332         if (unlikely(!mac->running))
333                 return -ENODEV;
334         
335         spin_lock_irqsave(&mac->lock, flags);
336
337         if (!mac->associnfo.associating) {
338                 /* we race against the timeout function, so make sure
339                  * only one of us can do work */
340                 spin_unlock_irqrestore(&mac->lock, flags);
341                 return 0;
342         }
343         network = ieee80211softmac_get_network_by_bssid_locked(mac, resp->header.addr3);
344
345         /* someone sending us things without us knowing him? Ignore. */
346         if (!network) {
347                 dprintk(KERN_INFO PFX "Received unrequested assocation response from " MAC_FMT "\n", MAC_ARG(resp->header.addr3));
348                 spin_unlock_irqrestore(&mac->lock, flags);
349                 return 0;
350         }
351
352         /* now that we know it was for us, we can cancel the timeout */
353         cancel_delayed_work(&mac->associnfo.timeout);
354
355         switch (status) {
356                 case 0:
357                         dprintk(KERN_INFO PFX "associated!\n");
358                         ieee80211softmac_associated(mac, resp, network);
359                         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATED, network);
360                         break;
361                 case WLAN_REASON_STA_REQ_ASSOC_WITHOUT_AUTH:
362                         if (!network->auth_desynced_once) {
363                                 /* there seem to be a few rare cases where our view of
364                                  * the world is obscured, or buggy APs that don't DEAUTH
365                                  * us properly. So we handle that, but allow it only once.
366                                  */
367                                 printkl(KERN_INFO PFX "We were not authenticated during association, retrying...\n");
368                                 network->authenticated = 0;
369                                 /* we don't want to do this more than once ... */
370                                 network->auth_desynced_once = 1;
371                                 schedule_work(&mac->associnfo.work);
372                                 break;
373                         }
374                 default:
375                         dprintk(KERN_INFO PFX "associating failed (reason: 0x%x)!\n", status);
376                         mac->associnfo.associating = 0;
377                         mac->associnfo.bssvalid = 0;
378                         mac->associated = 0;
379                         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, network);
380         }
381         
382         spin_unlock_irqrestore(&mac->lock, flags);
383         return 0;
384 }
385
386 int
387 ieee80211softmac_handle_disassoc(struct net_device * dev,
388                                  struct ieee80211_disassoc *disassoc)
389 {
390         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
391
392         if (unlikely(!mac->running))
393                 return -ENODEV;
394
395         if (memcmp(disassoc->header.addr2, mac->associnfo.bssid, ETH_ALEN))
396                 return 0;
397
398         if (memcmp(disassoc->header.addr1, mac->dev->dev_addr, ETH_ALEN))
399                 return 0;
400
401         dprintk(KERN_INFO PFX "got disassoc frame\n");
402         ieee80211softmac_disassoc(mac);
403
404         /* try to reassociate */
405         schedule_work(&mac->associnfo.work);
406
407         return 0;
408 }
409
410 int
411 ieee80211softmac_handle_reassoc_req(struct net_device * dev,
412                                     struct ieee80211_reassoc_request * resp)
413 {
414         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
415         struct ieee80211softmac_network *network;
416
417         if (unlikely(!mac->running))
418                 return -ENODEV;
419
420         network = ieee80211softmac_get_network_by_bssid(mac, resp->header.addr3);
421         if (!network) {
422                 dprintkl(KERN_INFO PFX "reassoc request from unknown network\n");
423                 return 0;
424         }
425         schedule_work(&mac->associnfo.work);
426
427         return 0;
428 }