Merge branch 'master' into upstream
[linux-2.6.git] / 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 /* Sends out a disassociation request to the desired AP */
86 void
87 ieee80211softmac_disassoc(struct ieee80211softmac_device *mac, u16 reason)
88 {
89         unsigned long flags;
90         struct ieee80211softmac_network *found;
91
92         if (mac->associnfo.bssvalid && mac->associated) {
93                 found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);
94                 if (found)
95                         ieee80211softmac_send_mgt_frame(mac, found, IEEE80211_STYPE_DISASSOC, reason);
96         } else if (mac->associnfo.associating) {
97                 cancel_delayed_work(&mac->associnfo.timeout);
98         }
99
100         /* Change our state */
101         spin_lock_irqsave(&mac->lock, flags);
102         /* Do NOT clear bssvalid as that will break ieee80211softmac_assoc_work! */
103         mac->associated = 0;
104         mac->associnfo.associating = 0;
105         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_DISASSOCIATED, NULL);
106         spin_unlock_irqrestore(&mac->lock, flags);
107 }
108
109 static inline int
110 we_support_all_basic_rates(struct ieee80211softmac_device *mac, u8 *from, u8 from_len)
111 {
112         int idx, search, found;
113         u8 rate, search_rate;
114
115         for (idx = 0; idx < (from_len); idx++) {
116                 rate = (from)[idx];
117                 if (!(rate & IEEE80211_BASIC_RATE_MASK))
118                         continue;
119                 found = 0;
120                 rate &= ~IEEE80211_BASIC_RATE_MASK;
121                 for (search = 0; search < mac->ratesinfo.count; search++) {
122                         search_rate = mac->ratesinfo.rates[search];
123                         search_rate &= ~IEEE80211_BASIC_RATE_MASK;
124                         if (rate == search_rate) {
125                                 found = 1;
126                                 break;
127                         }
128                 }
129                 if (!found)
130                         return 0;
131         }
132         return 1;
133 }
134
135 static int
136 network_matches_request(struct ieee80211softmac_device *mac, struct ieee80211_network *net)
137 {
138         /* we cannot associate to networks whose name we don't know */
139         if (ieee80211_is_empty_essid(net->ssid, net->ssid_len))
140                 return 0;
141         /* do not associate to a network whose BSSBasicRateSet we cannot support */
142         if (!we_support_all_basic_rates(mac, net->rates, net->rates_len))
143                 return 0;
144         /* do we really need to check the ex rates? */
145         if (!we_support_all_basic_rates(mac, net->rates_ex, net->rates_ex_len))
146                 return 0;
147
148         /* assume that users know what they're doing ...
149          * (note we don't let them select a net we're incompatible with) */
150         if (mac->associnfo.bssfixed) {
151                 return !memcmp(mac->associnfo.bssid, net->bssid, ETH_ALEN);
152         }
153
154         /* if 'ANY' network requested, take any that doesn't have privacy enabled */
155         if (mac->associnfo.req_essid.len == 0 
156             && !(net->capability & WLAN_CAPABILITY_PRIVACY))
157                 return 1;
158         if (net->ssid_len != mac->associnfo.req_essid.len)
159                 return 0;
160         if (!memcmp(net->ssid, mac->associnfo.req_essid.data, mac->associnfo.req_essid.len))
161                 return 1;
162         return 0;
163 }
164
165 static void
166 ieee80211softmac_assoc_notify(struct net_device *dev, void *context)
167 {
168         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
169         ieee80211softmac_assoc_work((void*)mac);
170 }
171
172 /* This function is called to handle userspace requests (asynchronously) */
173 void
174 ieee80211softmac_assoc_work(void *d)
175 {
176         struct ieee80211softmac_device *mac = (struct ieee80211softmac_device *)d;
177         struct ieee80211softmac_network *found = NULL;
178         struct ieee80211_network *net = NULL, *best = NULL;
179         unsigned long flags;
180         
181         /* meh */
182         if (mac->associated)
183                 ieee80211softmac_disassoc(mac, WLAN_REASON_DISASSOC_STA_HAS_LEFT);
184
185         /* try to find the requested network in our list, if we found one already */
186         if (mac->associnfo.bssvalid || mac->associnfo.bssfixed)
187                 found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);       
188         
189         /* Search the ieee80211 networks for this network if we didn't find it by bssid,
190          * but only if we've scanned at least once (to get a better list of networks to
191          * select from). If we have not scanned before, the !found logic below will be
192          * invoked and will scan. */
193         if (!found && (mac->associnfo.scan_retry < IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT))
194         {
195                 s8 rssi = -128; /* if I don't initialise, gcc emits an invalid warning
196                                    because it cannot follow the best pointer logic. */
197                 spin_lock_irqsave(&mac->ieee->lock, flags);
198                 list_for_each_entry(net, &mac->ieee->network_list, list) {
199                         /* we're supposed to find the network with
200                          * the best signal here, as we're asked to join
201                          * any network with a specific ESSID, and many
202                          * different ones could have that.
203                          *
204                          * I'll for now just go with the reported rssi.
205                          *
206                          * We also should take into account the rateset
207                          * here to find the best BSSID to try.
208                          */
209                         if (network_matches_request(mac, net)) {
210                                 if (!best) {
211                                         best = net;
212                                         rssi = best->stats.rssi;
213                                         continue;
214                                 }
215                                 /* we already had a matching network, so
216                                  * compare their properties to get the
217                                  * better of the two ... (see above)
218                                  */
219                                 if (rssi < net->stats.rssi) {
220                                         best = net;
221                                         rssi = best->stats.rssi;
222                                 }
223                         }
224                 }
225                 /* if we unlock here, we might get interrupted and the `best'
226                  * pointer could go stale */
227                 if (best) {
228                         found = ieee80211softmac_create_network(mac, best);
229                         /* if found is still NULL, then we got -ENOMEM somewhere */
230                         if (found)
231                                 ieee80211softmac_add_network(mac, found);
232                 }
233                 spin_unlock_irqrestore(&mac->ieee->lock, flags);
234         }
235
236         if (!found) {
237                 if (mac->associnfo.scan_retry > 0) {
238                         spin_lock_irqsave(&mac->lock, flags);
239                         mac->associnfo.scan_retry--;
240                         spin_unlock_irqrestore(&mac->lock, flags);
241                 
242                         /* We know of no such network. Let's scan. 
243                          * NB: this also happens if we had no memory to copy the network info...
244                          * Maybe we can hope to have more memory after scanning finishes ;)
245                          */
246                         dprintk(KERN_INFO PFX "Associate: Scanning for networks first.\n");
247                         ieee80211softmac_notify(mac->dev, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, ieee80211softmac_assoc_notify, NULL);
248                         if (ieee80211softmac_start_scan(mac))
249                                 dprintk(KERN_INFO PFX "Associate: failed to initiate scan. Is device up?\n");
250                         return;
251                 } else {
252                         spin_lock_irqsave(&mac->lock, flags);
253                         mac->associnfo.associating = 0;
254                         mac->associated = 0;
255                         spin_unlock_irqrestore(&mac->lock, flags);
256
257                         dprintk(KERN_INFO PFX "Unable to find matching network after scan!\n");
258                         /* reset the retry counter for the next user request since we
259                          * break out and don't reschedule ourselves after this point. */
260                         mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
261                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_NET_NOT_FOUND, NULL);
262                         return;
263                 }
264         }
265
266         /* reset the retry counter for the next user request since we
267          * now found a net and will try to associate to it, but not
268          * schedule this function again. */
269         mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
270         mac->associnfo.bssvalid = 1;
271         memcpy(mac->associnfo.bssid, found->bssid, ETH_ALEN);
272         /* copy the ESSID for displaying it */
273         mac->associnfo.associate_essid.len = found->essid.len;
274         memcpy(mac->associnfo.associate_essid.data, found->essid.data, IW_ESSID_MAX_SIZE + 1);
275         
276         /* we found a network! authenticate (if necessary) and associate to it. */
277         if (!found->authenticated) {
278                 /* This relies on the fact that _auth_req only queues the work,
279                  * otherwise adding the notification would be racy. */
280                 if (!ieee80211softmac_auth_req(mac, found)) {
281                         dprintk(KERN_INFO PFX "cannot associate without being authenticated, requested authentication\n");
282                         ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify, NULL, GFP_KERNEL);
283                 } else {
284                         printkl(KERN_WARNING PFX "Not authenticated, but requesting authentication failed. Giving up to associate\n");
285                         ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, found);
286                 }
287                 return;
288         }
289         /* finally! now we can start associating */
290         ieee80211softmac_assoc(mac, found);
291 }
292
293 /* call this to do whatever is necessary when we're associated */
294 static void
295 ieee80211softmac_associated(struct ieee80211softmac_device *mac,
296         struct ieee80211_assoc_response * resp,
297         struct ieee80211softmac_network *net)
298 {
299         mac->associnfo.associating = 0;
300         mac->associated = 1;
301         if (mac->set_bssid_filter)
302                 mac->set_bssid_filter(mac->dev, net->bssid);
303         memcpy(mac->ieee->bssid, net->bssid, ETH_ALEN);
304         netif_carrier_on(mac->dev);
305         
306         mac->association_id = le16_to_cpup(&resp->aid);
307 }
308
309 /* received frame handling functions */
310 int
311 ieee80211softmac_handle_assoc_response(struct net_device * dev,
312                                        struct ieee80211_assoc_response * resp,
313                                        struct ieee80211_network * _ieee80211_network_do_not_use)
314 {
315         /* NOTE: the network parameter has to be ignored by
316          *       this code because it is the ieee80211's pointer
317          *       to the struct, not ours (we made a copy)
318          */
319         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
320         u16 status = le16_to_cpup(&resp->status);
321         struct ieee80211softmac_network *network = NULL;
322         unsigned long flags;
323
324         if (unlikely(!mac->running))
325                 return -ENODEV;
326         
327         spin_lock_irqsave(&mac->lock, flags);
328
329         if (!mac->associnfo.associating) {
330                 /* we race against the timeout function, so make sure
331                  * only one of us can do work */
332                 spin_unlock_irqrestore(&mac->lock, flags);
333                 return 0;
334         }
335         network = ieee80211softmac_get_network_by_bssid_locked(mac, resp->header.addr3);
336
337         /* someone sending us things without us knowing him? Ignore. */
338         if (!network) {
339                 dprintk(KERN_INFO PFX "Received unrequested assocation response from " MAC_FMT "\n", MAC_ARG(resp->header.addr3));
340                 spin_unlock_irqrestore(&mac->lock, flags);
341                 return 0;
342         }
343
344         /* now that we know it was for us, we can cancel the timeout */
345         cancel_delayed_work(&mac->associnfo.timeout);
346
347         switch (status) {
348                 case 0:
349                         dprintk(KERN_INFO PFX "associated!\n");
350                         ieee80211softmac_associated(mac, resp, network);
351                         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATED, network);
352                         break;
353                 case WLAN_REASON_STA_REQ_ASSOC_WITHOUT_AUTH:
354                         if (!network->auth_desynced_once) {
355                                 /* there seem to be a few rare cases where our view of
356                                  * the world is obscured, or buggy APs that don't DEAUTH
357                                  * us properly. So we handle that, but allow it only once.
358                                  */
359                                 printkl(KERN_INFO PFX "We were not authenticated during association, retrying...\n");
360                                 network->authenticated = 0;
361                                 /* we don't want to do this more than once ... */
362                                 network->auth_desynced_once = 1;
363                                 schedule_work(&mac->associnfo.work);
364                                 break;
365                         }
366                 default:
367                         dprintk(KERN_INFO PFX "associating failed (reason: 0x%x)!\n", status);
368                         mac->associnfo.associating = 0;
369                         mac->associnfo.bssvalid = 0;
370                         mac->associated = 0;
371                         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, network);
372         }
373         
374         spin_unlock_irqrestore(&mac->lock, flags);
375         return 0;
376 }
377
378 int
379 ieee80211softmac_handle_disassoc(struct net_device * dev,
380                                  struct ieee80211_disassoc *disassoc)
381 {
382         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
383         unsigned long flags;
384
385         if (unlikely(!mac->running))
386                 return -ENODEV;
387
388         if (memcmp(disassoc->header.addr2, mac->associnfo.bssid, ETH_ALEN))
389                 return 0;
390
391         if (memcmp(disassoc->header.addr1, mac->dev->dev_addr, ETH_ALEN))
392                 return 0;
393
394         dprintk(KERN_INFO PFX "got disassoc frame\n");
395         netif_carrier_off(dev);
396         spin_lock_irqsave(&mac->lock, flags);
397         mac->associnfo.bssvalid = 0;
398         mac->associated = 0;
399         ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_DISASSOCIATED, NULL);
400         schedule_work(&mac->associnfo.work);
401         spin_unlock_irqrestore(&mac->lock, flags);
402         
403         return 0;
404 }
405
406 int
407 ieee80211softmac_handle_reassoc_req(struct net_device * dev,
408                                     struct ieee80211_reassoc_request * resp)
409 {
410         struct ieee80211softmac_device *mac = ieee80211_priv(dev);
411         struct ieee80211softmac_network *network;
412
413         if (unlikely(!mac->running))
414                 return -ENODEV;
415
416         network = ieee80211softmac_get_network_by_bssid(mac, resp->header.addr3);
417         if (!network) {
418                 dprintkl(KERN_INFO PFX "reassoc request from unknown network\n");
419                 return 0;
420         }
421         schedule_work(&mac->associnfo.work);
422
423         return 0;
424 }