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Commit | Line | Data |
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0a51b27e | 1 | /* |
5484e237 JB |
2 | * Scanning implementation |
3 | * | |
0a51b27e JB |
4 | * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> |
5 | * Copyright 2004, Instant802 Networks, Inc. | |
6 | * Copyright 2005, Devicescape Software, Inc. | |
7 | * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> | |
8 | * Copyright 2007, Michael Wu <flamingice@sourmilk.net> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/wireless.h> | |
16 | #include <linux/if_arp.h> | |
078e1e60 | 17 | #include <linux/rtnetlink.h> |
0a51b27e | 18 | #include <net/mac80211.h> |
0a51b27e JB |
19 | |
20 | #include "ieee80211_i.h" | |
24487981 | 21 | #include "driver-ops.h" |
5484e237 | 22 | #include "mesh.h" |
0a51b27e JB |
23 | |
24 | #define IEEE80211_PROBE_DELAY (HZ / 33) | |
25 | #define IEEE80211_CHANNEL_TIME (HZ / 33) | |
96f7e739 | 26 | #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8) |
0a51b27e | 27 | |
c2b13452 | 28 | struct ieee80211_bss * |
5484e237 JB |
29 | ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, |
30 | u8 *ssid, u8 ssid_len) | |
31 | { | |
0c1ad2ca JB |
32 | struct cfg80211_bss *cbss; |
33 | ||
34 | cbss = cfg80211_get_bss(local->hw.wiphy, | |
35 | ieee80211_get_channel(local->hw.wiphy, freq), | |
36 | bssid, ssid, ssid_len, 0, 0); | |
37 | if (!cbss) | |
38 | return NULL; | |
39 | return (void *)cbss->priv; | |
5484e237 JB |
40 | } |
41 | ||
00d3f14c | 42 | static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) |
5484e237 | 43 | { |
0c1ad2ca | 44 | struct ieee80211_bss *bss = (void *)cbss->priv; |
5484e237 | 45 | |
5484e237 JB |
46 | kfree(bss_mesh_id(bss)); |
47 | kfree(bss_mesh_cfg(bss)); | |
5484e237 JB |
48 | } |
49 | ||
50 | void ieee80211_rx_bss_put(struct ieee80211_local *local, | |
c2b13452 | 51 | struct ieee80211_bss *bss) |
5484e237 | 52 | { |
0c1ad2ca JB |
53 | if (!bss) |
54 | return; | |
55 | cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); | |
5484e237 JB |
56 | } |
57 | ||
c2b13452 | 58 | struct ieee80211_bss * |
5484e237 JB |
59 | ieee80211_bss_info_update(struct ieee80211_local *local, |
60 | struct ieee80211_rx_status *rx_status, | |
61 | struct ieee80211_mgmt *mgmt, | |
62 | size_t len, | |
63 | struct ieee802_11_elems *elems, | |
2a519311 JB |
64 | struct ieee80211_channel *channel, |
65 | bool beacon) | |
5484e237 | 66 | { |
0c1ad2ca | 67 | struct cfg80211_bss *cbss; |
c2b13452 | 68 | struct ieee80211_bss *bss; |
00d3f14c | 69 | int clen; |
2a519311 JB |
70 | s32 signal = 0; |
71 | ||
77965c97 | 72 | if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) |
2a519311 | 73 | signal = rx_status->signal * 100; |
77965c97 | 74 | else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) |
2a519311 | 75 | signal = (rx_status->signal * 100) / local->hw.max_signal; |
2a519311 | 76 | |
0c1ad2ca JB |
77 | cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, |
78 | mgmt, len, signal, GFP_ATOMIC); | |
5484e237 | 79 | |
0c1ad2ca | 80 | if (!cbss) |
00d3f14c JB |
81 | return NULL; |
82 | ||
0c1ad2ca JB |
83 | cbss->free_priv = ieee80211_rx_bss_free; |
84 | bss = (void *)cbss->priv; | |
5484e237 JB |
85 | |
86 | /* save the ERP value so that it is available at association time */ | |
87 | if (elems->erp_info && elems->erp_info_len >= 1) { | |
88 | bss->erp_value = elems->erp_info[0]; | |
89 | bss->has_erp_value = 1; | |
90 | } | |
91 | ||
5484e237 JB |
92 | if (elems->tim) { |
93 | struct ieee80211_tim_ie *tim_ie = | |
94 | (struct ieee80211_tim_ie *)elems->tim; | |
95 | bss->dtim_period = tim_ie->dtim_period; | |
96 | } | |
97 | ||
6a211bf1 JB |
98 | /* set default value for buggy AP/no TIM element */ |
99 | if (bss->dtim_period == 0) | |
5484e237 JB |
100 | bss->dtim_period = 1; |
101 | ||
102 | bss->supp_rates_len = 0; | |
103 | if (elems->supp_rates) { | |
104 | clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len; | |
105 | if (clen > elems->supp_rates_len) | |
106 | clen = elems->supp_rates_len; | |
107 | memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates, | |
108 | clen); | |
109 | bss->supp_rates_len += clen; | |
110 | } | |
111 | if (elems->ext_supp_rates) { | |
112 | clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len; | |
113 | if (clen > elems->ext_supp_rates_len) | |
114 | clen = elems->ext_supp_rates_len; | |
115 | memcpy(&bss->supp_rates[bss->supp_rates_len], | |
116 | elems->ext_supp_rates, clen); | |
117 | bss->supp_rates_len += clen; | |
118 | } | |
119 | ||
5484e237 JB |
120 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
121 | ||
122 | if (!beacon) | |
123 | bss->last_probe_resp = jiffies; | |
124 | ||
5484e237 JB |
125 | return bss; |
126 | } | |
0a51b27e | 127 | |
98c8fccf | 128 | ieee80211_rx_result |
f1d58c25 | 129 | ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) |
98c8fccf | 130 | { |
f1d58c25 | 131 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
98c8fccf | 132 | struct ieee80211_mgmt *mgmt; |
c2b13452 | 133 | struct ieee80211_bss *bss; |
98c8fccf JB |
134 | u8 *elements; |
135 | struct ieee80211_channel *channel; | |
136 | size_t baselen; | |
137 | int freq; | |
138 | __le16 fc; | |
139 | bool presp, beacon = false; | |
140 | struct ieee802_11_elems elems; | |
141 | ||
142 | if (skb->len < 2) | |
143 | return RX_DROP_UNUSABLE; | |
144 | ||
145 | mgmt = (struct ieee80211_mgmt *) skb->data; | |
146 | fc = mgmt->frame_control; | |
147 | ||
148 | if (ieee80211_is_ctl(fc)) | |
149 | return RX_CONTINUE; | |
150 | ||
151 | if (skb->len < 24) | |
152 | return RX_DROP_MONITOR; | |
153 | ||
154 | presp = ieee80211_is_probe_resp(fc); | |
155 | if (presp) { | |
156 | /* ignore ProbeResp to foreign address */ | |
47846c9b | 157 | if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) |
98c8fccf JB |
158 | return RX_DROP_MONITOR; |
159 | ||
160 | presp = true; | |
161 | elements = mgmt->u.probe_resp.variable; | |
162 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); | |
163 | } else { | |
164 | beacon = ieee80211_is_beacon(fc); | |
165 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); | |
166 | elements = mgmt->u.beacon.variable; | |
167 | } | |
168 | ||
169 | if (!presp && !beacon) | |
170 | return RX_CONTINUE; | |
171 | ||
172 | if (baselen > skb->len) | |
173 | return RX_DROP_MONITOR; | |
174 | ||
175 | ieee802_11_parse_elems(elements, skb->len - baselen, &elems); | |
176 | ||
177 | if (elems.ds_params && elems.ds_params_len == 1) | |
178 | freq = ieee80211_channel_to_frequency(elems.ds_params[0]); | |
179 | else | |
180 | freq = rx_status->freq; | |
181 | ||
182 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); | |
183 | ||
184 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) | |
185 | return RX_DROP_MONITOR; | |
186 | ||
187 | bss = ieee80211_bss_info_update(sdata->local, rx_status, | |
188 | mgmt, skb->len, &elems, | |
2a519311 | 189 | channel, beacon); |
d048e503 JM |
190 | if (bss) |
191 | ieee80211_rx_bss_put(sdata->local, bss); | |
98c8fccf JB |
192 | |
193 | dev_kfree_skb(skb); | |
194 | return RX_QUEUED; | |
195 | } | |
196 | ||
4d36ec58 JB |
197 | /* return false if no more work */ |
198 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) | |
199 | { | |
200 | struct cfg80211_scan_request *req = local->scan_req; | |
201 | enum ieee80211_band band; | |
202 | int i, ielen, n_chans; | |
203 | ||
204 | do { | |
205 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) | |
206 | return false; | |
207 | ||
208 | band = local->hw_scan_band; | |
209 | n_chans = 0; | |
210 | for (i = 0; i < req->n_channels; i++) { | |
211 | if (req->channels[i]->band == band) { | |
212 | local->hw_scan_req->channels[n_chans] = | |
213 | req->channels[i]; | |
214 | n_chans++; | |
215 | } | |
216 | } | |
217 | ||
218 | local->hw_scan_band++; | |
219 | } while (!n_chans); | |
220 | ||
221 | local->hw_scan_req->n_channels = n_chans; | |
222 | ||
223 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, | |
224 | req->ie, req->ie_len, band); | |
225 | local->hw_scan_req->ie_len = ielen; | |
226 | ||
227 | return true; | |
228 | } | |
229 | ||
9050bdd8 KV |
230 | /* |
231 | * inform AP that we will go to sleep so that it will buffer the frames | |
232 | * while we scan | |
233 | */ | |
234 | static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata) | |
235 | { | |
236 | struct ieee80211_local *local = sdata->local; | |
7c3f4bbe VN |
237 | |
238 | local->scan_ps_enabled = false; | |
9050bdd8 KV |
239 | |
240 | /* FIXME: what to do when local->pspolling is true? */ | |
241 | ||
242 | del_timer_sync(&local->dynamic_ps_timer); | |
243 | cancel_work_sync(&local->dynamic_ps_enable_work); | |
244 | ||
245 | if (local->hw.conf.flags & IEEE80211_CONF_PS) { | |
7c3f4bbe | 246 | local->scan_ps_enabled = true; |
9050bdd8 KV |
247 | local->hw.conf.flags &= ~IEEE80211_CONF_PS; |
248 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); | |
249 | } | |
250 | ||
7c3f4bbe VN |
251 | if (!(local->scan_ps_enabled) || |
252 | !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) | |
9050bdd8 KV |
253 | /* |
254 | * If power save was enabled, no need to send a nullfunc | |
255 | * frame because AP knows that we are sleeping. But if the | |
256 | * hardware is creating the nullfunc frame for power save | |
257 | * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not | |
258 | * enabled) and power save was enabled, the firmware just | |
259 | * sent a null frame with power save disabled. So we need | |
260 | * to send a new nullfunc frame to inform the AP that we | |
261 | * are again sleeping. | |
262 | */ | |
263 | ieee80211_send_nullfunc(local, sdata, 1); | |
264 | } | |
265 | ||
266 | /* inform AP that we are awake again, unless power save is enabled */ | |
267 | static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata) | |
268 | { | |
269 | struct ieee80211_local *local = sdata->local; | |
270 | ||
965bedad | 271 | if (!local->ps_sdata) |
9050bdd8 | 272 | ieee80211_send_nullfunc(local, sdata, 0); |
7c3f4bbe | 273 | else if (local->scan_ps_enabled) { |
9050bdd8 KV |
274 | /* |
275 | * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware | |
276 | * will send a nullfunc frame with the powersave bit set | |
277 | * even though the AP already knows that we are sleeping. | |
278 | * This could be avoided by sending a null frame with power | |
279 | * save bit disabled before enabling the power save, but | |
280 | * this doesn't gain anything. | |
281 | * | |
282 | * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need | |
283 | * to send a nullfunc frame because AP already knows that | |
284 | * we are sleeping, let's just enable power save mode in | |
285 | * hardware. | |
286 | */ | |
287 | local->hw.conf.flags |= IEEE80211_CONF_PS; | |
288 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); | |
7c3f4bbe VN |
289 | } else if (local->hw.conf.dynamic_ps_timeout > 0) { |
290 | /* | |
291 | * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer | |
292 | * had been running before leaving the operating channel, | |
293 | * restart the timer now and send a nullfunc frame to inform | |
294 | * the AP that we are awake. | |
295 | */ | |
296 | ieee80211_send_nullfunc(local, sdata, 0); | |
297 | mod_timer(&local->dynamic_ps_timer, jiffies + | |
298 | msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); | |
9050bdd8 KV |
299 | } |
300 | } | |
301 | ||
2a519311 | 302 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
0a51b27e JB |
303 | { |
304 | struct ieee80211_local *local = hw_to_local(hw); | |
305 | struct ieee80211_sub_if_data *sdata; | |
f3b85252 | 306 | bool was_hw_scan; |
0a51b27e | 307 | |
f3b85252 | 308 | mutex_lock(&local->scan_mtx); |
5bc75728 | 309 | |
6d3560d4 JB |
310 | /* |
311 | * It's ok to abort a not-yet-running scan (that | |
312 | * we have one at all will be verified by checking | |
313 | * local->scan_req next), but not to complete it | |
314 | * successfully. | |
315 | */ | |
316 | if (WARN_ON(!local->scanning && !aborted)) | |
317 | aborted = true; | |
5bc75728 | 318 | |
f3b85252 JB |
319 | if (WARN_ON(!local->scan_req)) { |
320 | mutex_unlock(&local->scan_mtx); | |
321 | return; | |
de95a54b JB |
322 | } |
323 | ||
4d36ec58 JB |
324 | was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
325 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { | |
326 | ieee80211_queue_delayed_work(&local->hw, | |
327 | &local->scan_work, 0); | |
328 | mutex_unlock(&local->scan_mtx); | |
329 | return; | |
330 | } | |
331 | ||
332 | kfree(local->hw_scan_req); | |
333 | local->hw_scan_req = NULL; | |
f3b85252 | 334 | |
5ba63533 | 335 | if (local->scan_req != local->int_scan_req) |
2a519311 JB |
336 | cfg80211_scan_done(local->scan_req, aborted); |
337 | local->scan_req = NULL; | |
15db0b7f | 338 | local->scan_sdata = NULL; |
2a519311 | 339 | |
fbe9c429 | 340 | local->scanning = 0; |
58905ca5 | 341 | local->scan_channel = NULL; |
f3b85252 JB |
342 | |
343 | /* we only have to protect scan_req and hw/sw scan */ | |
344 | mutex_unlock(&local->scan_mtx); | |
345 | ||
e8975581 | 346 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
5cff20e6 JB |
347 | if (was_hw_scan) |
348 | goto done; | |
0a51b27e | 349 | |
3ac64bee | 350 | ieee80211_configure_filter(local); |
0a51b27e | 351 | |
24487981 | 352 | drv_sw_scan_complete(local); |
80e775bf | 353 | |
078e1e60 JB |
354 | mutex_lock(&local->iflist_mtx); |
355 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 356 | if (!ieee80211_sdata_running(sdata)) |
fb9ddbf0 JB |
357 | continue; |
358 | ||
0a51b27e | 359 | /* Tell AP we're back */ |
05c914fe | 360 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { |
77fdaa12 | 361 | if (sdata->u.mgd.associated) { |
9050bdd8 | 362 | ieee80211_scan_ps_disable(sdata); |
53623f1a | 363 | netif_wake_queue(sdata->dev); |
0a51b27e JB |
364 | } |
365 | } else | |
53623f1a | 366 | netif_wake_queue(sdata->dev); |
078e1e60 | 367 | |
14b80724 JB |
368 | /* re-enable beaconing */ |
369 | if (sdata->vif.type == NL80211_IFTYPE_AP || | |
370 | sdata->vif.type == NL80211_IFTYPE_ADHOC || | |
371 | sdata->vif.type == NL80211_IFTYPE_MESH_POINT) | |
2d0ddec5 JB |
372 | ieee80211_bss_info_change_notify( |
373 | sdata, BSS_CHANGED_BEACON_ENABLED); | |
0a51b27e | 374 | } |
078e1e60 | 375 | mutex_unlock(&local->iflist_mtx); |
0a51b27e JB |
376 | |
377 | done: | |
5cff20e6 | 378 | ieee80211_recalc_idle(local); |
0a51b27e | 379 | ieee80211_mlme_notify_scan_completed(local); |
46900298 | 380 | ieee80211_ibss_notify_scan_completed(local); |
472dbc45 | 381 | ieee80211_mesh_notify_scan_completed(local); |
0a51b27e JB |
382 | } |
383 | EXPORT_SYMBOL(ieee80211_scan_completed); | |
384 | ||
f3b85252 JB |
385 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
386 | { | |
387 | struct ieee80211_sub_if_data *sdata; | |
388 | ||
389 | /* | |
390 | * Hardware/driver doesn't support hw_scan, so use software | |
391 | * scanning instead. First send a nullfunc frame with power save | |
392 | * bit on so that AP will buffer the frames for us while we are not | |
393 | * listening, then send probe requests to each channel and wait for | |
394 | * the responses. After all channels are scanned, tune back to the | |
395 | * original channel and send a nullfunc frame with power save bit | |
396 | * off to trigger the AP to send us all the buffered frames. | |
397 | * | |
398 | * Note that while local->sw_scanning is true everything else but | |
399 | * nullfunc frames and probe requests will be dropped in | |
400 | * ieee80211_tx_h_check_assoc(). | |
401 | */ | |
24487981 | 402 | drv_sw_scan_start(local); |
f3b85252 JB |
403 | |
404 | mutex_lock(&local->iflist_mtx); | |
405 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 406 | if (!ieee80211_sdata_running(sdata)) |
f3b85252 JB |
407 | continue; |
408 | ||
409 | /* disable beaconing */ | |
410 | if (sdata->vif.type == NL80211_IFTYPE_AP || | |
411 | sdata->vif.type == NL80211_IFTYPE_ADHOC || | |
412 | sdata->vif.type == NL80211_IFTYPE_MESH_POINT) | |
2d0ddec5 JB |
413 | ieee80211_bss_info_change_notify( |
414 | sdata, BSS_CHANGED_BEACON_ENABLED); | |
f3b85252 | 415 | |
142b9f50 HS |
416 | /* |
417 | * only handle non-STA interfaces here, STA interfaces | |
418 | * are handled in the scan state machine | |
419 | */ | |
420 | if (sdata->vif.type != NL80211_IFTYPE_STATION) | |
53623f1a | 421 | netif_stop_queue(sdata->dev); |
f3b85252 JB |
422 | } |
423 | mutex_unlock(&local->iflist_mtx); | |
424 | ||
977923b0 | 425 | local->next_scan_state = SCAN_DECISION; |
f3b85252 JB |
426 | local->scan_channel_idx = 0; |
427 | ||
a80f7c0b JB |
428 | drv_flush(local, false); |
429 | ||
3ac64bee | 430 | ieee80211_configure_filter(local); |
f3b85252 | 431 | |
42935eca LR |
432 | ieee80211_queue_delayed_work(&local->hw, |
433 | &local->scan_work, | |
434 | IEEE80211_CHANNEL_TIME); | |
f3b85252 JB |
435 | |
436 | return 0; | |
437 | } | |
438 | ||
439 | ||
440 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, | |
441 | struct cfg80211_scan_request *req) | |
442 | { | |
443 | struct ieee80211_local *local = sdata->local; | |
f3b85252 JB |
444 | int rc; |
445 | ||
446 | if (local->scan_req) | |
447 | return -EBUSY; | |
448 | ||
449 | if (local->ops->hw_scan) { | |
450 | u8 *ies; | |
f3b85252 | 451 | |
4d36ec58 JB |
452 | local->hw_scan_req = kmalloc( |
453 | sizeof(*local->hw_scan_req) + | |
454 | req->n_channels * sizeof(req->channels[0]) + | |
455 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + | |
456 | req->ie_len, GFP_KERNEL); | |
457 | if (!local->hw_scan_req) | |
f3b85252 JB |
458 | return -ENOMEM; |
459 | ||
4d36ec58 JB |
460 | local->hw_scan_req->ssids = req->ssids; |
461 | local->hw_scan_req->n_ssids = req->n_ssids; | |
462 | ies = (u8 *)local->hw_scan_req + | |
463 | sizeof(*local->hw_scan_req) + | |
464 | req->n_channels * sizeof(req->channels[0]); | |
465 | local->hw_scan_req->ie = ies; | |
466 | ||
467 | local->hw_scan_band = 0; | |
f3b85252 JB |
468 | } |
469 | ||
470 | local->scan_req = req; | |
471 | local->scan_sdata = sdata; | |
472 | ||
af6b6374 JB |
473 | if (!list_empty(&local->work_list)) { |
474 | /* wait for the work to finish/time out */ | |
f3b85252 JB |
475 | return 0; |
476 | } | |
477 | ||
478 | if (local->ops->hw_scan) | |
fbe9c429 | 479 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
f3b85252 | 480 | else |
fbe9c429 | 481 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
f3b85252 JB |
482 | /* |
483 | * Kicking off the scan need not be protected, | |
484 | * only the scan variable stuff, since now | |
485 | * local->scan_req is assigned and other callers | |
486 | * will abort their scan attempts. | |
487 | * | |
488 | * This avoids getting a scan_mtx -> iflist_mtx | |
489 | * dependency, so that the scan completed calls | |
490 | * have more locking freedom. | |
491 | */ | |
5cff20e6 JB |
492 | |
493 | ieee80211_recalc_idle(local); | |
f3b85252 JB |
494 | mutex_unlock(&local->scan_mtx); |
495 | ||
4d36ec58 JB |
496 | if (local->ops->hw_scan) { |
497 | WARN_ON(!ieee80211_prep_hw_scan(local)); | |
498 | rc = drv_hw_scan(local, local->hw_scan_req); | |
499 | } else | |
f3b85252 JB |
500 | rc = ieee80211_start_sw_scan(local); |
501 | ||
502 | mutex_lock(&local->scan_mtx); | |
503 | ||
504 | if (rc) { | |
4d36ec58 JB |
505 | kfree(local->hw_scan_req); |
506 | local->hw_scan_req = NULL; | |
fbe9c429 | 507 | local->scanning = 0; |
f3b85252 | 508 | |
5cff20e6 JB |
509 | ieee80211_recalc_idle(local); |
510 | ||
f3b85252 JB |
511 | local->scan_req = NULL; |
512 | local->scan_sdata = NULL; | |
513 | } | |
514 | ||
515 | return rc; | |
516 | } | |
517 | ||
2fb3f028 HS |
518 | static int ieee80211_scan_state_decision(struct ieee80211_local *local, |
519 | unsigned long *next_delay) | |
7d3be3cc | 520 | { |
142b9f50 HS |
521 | bool associated = false; |
522 | struct ieee80211_sub_if_data *sdata; | |
523 | ||
524 | /* if no more bands/channels left, complete scan and advance to the idle state */ | |
7d3be3cc HS |
525 | if (local->scan_channel_idx >= local->scan_req->n_channels) { |
526 | ieee80211_scan_completed(&local->hw, false); | |
527 | return 1; | |
528 | } | |
2fb3f028 | 529 | |
142b9f50 HS |
530 | /* check if at least one STA interface is associated */ |
531 | mutex_lock(&local->iflist_mtx); | |
532 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 533 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
534 | continue; |
535 | ||
536 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
537 | if (sdata->u.mgd.associated) { | |
538 | associated = true; | |
539 | break; | |
540 | } | |
541 | } | |
542 | } | |
543 | mutex_unlock(&local->iflist_mtx); | |
544 | ||
545 | if (local->scan_channel) { | |
546 | /* | |
547 | * we're currently scanning a different channel, let's | |
548 | * switch back to the operating channel now if at least | |
549 | * one interface is associated. Otherwise just scan the | |
550 | * next channel | |
551 | */ | |
552 | if (associated) | |
977923b0 | 553 | local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; |
142b9f50 | 554 | else |
977923b0 | 555 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
556 | } else { |
557 | /* | |
558 | * we're on the operating channel currently, let's | |
559 | * leave that channel now to scan another one | |
560 | */ | |
977923b0 | 561 | local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; |
142b9f50 HS |
562 | } |
563 | ||
2fb3f028 | 564 | *next_delay = 0; |
2fb3f028 HS |
565 | return 0; |
566 | } | |
567 | ||
142b9f50 HS |
568 | static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, |
569 | unsigned long *next_delay) | |
570 | { | |
571 | struct ieee80211_sub_if_data *sdata; | |
572 | ||
573 | /* | |
574 | * notify the AP about us leaving the channel and stop all STA interfaces | |
575 | */ | |
576 | mutex_lock(&local->iflist_mtx); | |
577 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 578 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
579 | continue; |
580 | ||
581 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
53623f1a | 582 | netif_stop_queue(sdata->dev); |
142b9f50 HS |
583 | if (sdata->u.mgd.associated) |
584 | ieee80211_scan_ps_enable(sdata); | |
585 | } | |
586 | } | |
587 | mutex_unlock(&local->iflist_mtx); | |
588 | ||
589 | __set_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
590 | ||
a80f7c0b JB |
591 | /* |
592 | * What if the nullfunc frames didn't arrive? | |
593 | */ | |
594 | drv_flush(local, false); | |
595 | if (local->ops->flush) | |
596 | *next_delay = 0; | |
597 | else | |
598 | *next_delay = HZ / 10; | |
599 | ||
142b9f50 | 600 | /* advance to the next channel to be scanned */ |
977923b0 | 601 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
602 | } |
603 | ||
604 | static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, | |
605 | unsigned long *next_delay) | |
606 | { | |
607 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
608 | ||
609 | /* switch back to the operating channel */ | |
610 | local->scan_channel = NULL; | |
611 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); | |
612 | ||
613 | /* | |
614 | * notify the AP about us being back and restart all STA interfaces | |
615 | */ | |
616 | mutex_lock(&local->iflist_mtx); | |
617 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 618 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
619 | continue; |
620 | ||
621 | /* Tell AP we're back */ | |
622 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
623 | if (sdata->u.mgd.associated) | |
624 | ieee80211_scan_ps_disable(sdata); | |
53623f1a | 625 | netif_wake_queue(sdata->dev); |
142b9f50 HS |
626 | } |
627 | } | |
628 | mutex_unlock(&local->iflist_mtx); | |
629 | ||
630 | __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
631 | ||
632 | *next_delay = HZ / 5; | |
977923b0 | 633 | local->next_scan_state = SCAN_DECISION; |
142b9f50 HS |
634 | } |
635 | ||
2fb3f028 HS |
636 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
637 | unsigned long *next_delay) | |
638 | { | |
639 | int skip; | |
640 | struct ieee80211_channel *chan; | |
2fb3f028 | 641 | |
7d3be3cc HS |
642 | skip = 0; |
643 | chan = local->scan_req->channels[local->scan_channel_idx]; | |
644 | ||
584991dc JB |
645 | local->scan_channel = chan; |
646 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) | |
7d3be3cc HS |
647 | skip = 1; |
648 | ||
7d3be3cc HS |
649 | /* advance state machine to next channel/band */ |
650 | local->scan_channel_idx++; | |
651 | ||
0ee9c13c HS |
652 | if (skip) { |
653 | /* if we skip this channel return to the decision state */ | |
654 | local->next_scan_state = SCAN_DECISION; | |
2fb3f028 | 655 | return; |
0ee9c13c | 656 | } |
7d3be3cc HS |
657 | |
658 | /* | |
659 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 | |
660 | * (which unfortunately doesn't say _why_ step a) is done, | |
661 | * but it waits for the probe delay or until a frame is | |
662 | * received - and the received frame would update the NAV). | |
663 | * For now, we do not support waiting until a frame is | |
664 | * received. | |
665 | * | |
666 | * In any case, it is not necessary for a passive scan. | |
667 | */ | |
668 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || | |
669 | !local->scan_req->n_ssids) { | |
670 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; | |
977923b0 | 671 | local->next_scan_state = SCAN_DECISION; |
2fb3f028 | 672 | return; |
7d3be3cc HS |
673 | } |
674 | ||
2fb3f028 | 675 | /* active scan, send probes */ |
7d3be3cc | 676 | *next_delay = IEEE80211_PROBE_DELAY; |
977923b0 | 677 | local->next_scan_state = SCAN_SEND_PROBE; |
7d3be3cc HS |
678 | } |
679 | ||
680 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, | |
681 | unsigned long *next_delay) | |
682 | { | |
683 | int i; | |
684 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
685 | ||
686 | for (i = 0; i < local->scan_req->n_ssids; i++) | |
687 | ieee80211_send_probe_req( | |
688 | sdata, NULL, | |
689 | local->scan_req->ssids[i].ssid, | |
690 | local->scan_req->ssids[i].ssid_len, | |
691 | local->scan_req->ie, local->scan_req->ie_len); | |
692 | ||
693 | /* | |
694 | * After sending probe requests, wait for probe responses | |
695 | * on the channel. | |
696 | */ | |
697 | *next_delay = IEEE80211_CHANNEL_TIME; | |
977923b0 | 698 | local->next_scan_state = SCAN_DECISION; |
7d3be3cc HS |
699 | } |
700 | ||
c2b13452 | 701 | void ieee80211_scan_work(struct work_struct *work) |
0a51b27e JB |
702 | { |
703 | struct ieee80211_local *local = | |
704 | container_of(work, struct ieee80211_local, scan_work.work); | |
705 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
0a51b27e JB |
706 | unsigned long next_delay = 0; |
707 | ||
f3b85252 JB |
708 | mutex_lock(&local->scan_mtx); |
709 | if (!sdata || !local->scan_req) { | |
710 | mutex_unlock(&local->scan_mtx); | |
711 | return; | |
712 | } | |
713 | ||
4d36ec58 JB |
714 | if (local->hw_scan_req) { |
715 | int rc = drv_hw_scan(local, local->hw_scan_req); | |
716 | mutex_unlock(&local->scan_mtx); | |
717 | if (rc) | |
718 | ieee80211_scan_completed(&local->hw, true); | |
719 | return; | |
720 | } | |
721 | ||
fbe9c429 | 722 | if (local->scan_req && !local->scanning) { |
f3b85252 JB |
723 | struct cfg80211_scan_request *req = local->scan_req; |
724 | int rc; | |
725 | ||
726 | local->scan_req = NULL; | |
15db0b7f | 727 | local->scan_sdata = NULL; |
f3b85252 JB |
728 | |
729 | rc = __ieee80211_start_scan(sdata, req); | |
730 | mutex_unlock(&local->scan_mtx); | |
731 | ||
732 | if (rc) | |
733 | ieee80211_scan_completed(&local->hw, true); | |
734 | return; | |
735 | } | |
736 | ||
737 | mutex_unlock(&local->scan_mtx); | |
738 | ||
5bc75728 JB |
739 | /* |
740 | * Avoid re-scheduling when the sdata is going away. | |
741 | */ | |
9607e6b6 | 742 | if (!ieee80211_sdata_running(sdata)) { |
f3b85252 | 743 | ieee80211_scan_completed(&local->hw, true); |
0a51b27e | 744 | return; |
f3b85252 | 745 | } |
0a51b27e | 746 | |
f502d09b HS |
747 | /* |
748 | * as long as no delay is required advance immediately | |
749 | * without scheduling a new work | |
750 | */ | |
751 | do { | |
977923b0 | 752 | switch (local->next_scan_state) { |
2fb3f028 HS |
753 | case SCAN_DECISION: |
754 | if (ieee80211_scan_state_decision(local, &next_delay)) | |
f502d09b HS |
755 | return; |
756 | break; | |
2fb3f028 HS |
757 | case SCAN_SET_CHANNEL: |
758 | ieee80211_scan_state_set_channel(local, &next_delay); | |
759 | break; | |
f502d09b HS |
760 | case SCAN_SEND_PROBE: |
761 | ieee80211_scan_state_send_probe(local, &next_delay); | |
762 | break; | |
142b9f50 HS |
763 | case SCAN_LEAVE_OPER_CHANNEL: |
764 | ieee80211_scan_state_leave_oper_channel(local, &next_delay); | |
765 | break; | |
766 | case SCAN_ENTER_OPER_CHANNEL: | |
767 | ieee80211_scan_state_enter_oper_channel(local, &next_delay); | |
768 | break; | |
f502d09b HS |
769 | } |
770 | } while (next_delay == 0); | |
0a51b27e | 771 | |
42935eca | 772 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
0a51b27e JB |
773 | } |
774 | ||
f3b85252 JB |
775 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
776 | struct cfg80211_scan_request *req) | |
0a51b27e | 777 | { |
f3b85252 | 778 | int res; |
de95a54b | 779 | |
f3b85252 JB |
780 | mutex_lock(&sdata->local->scan_mtx); |
781 | res = __ieee80211_start_scan(sdata, req); | |
782 | mutex_unlock(&sdata->local->scan_mtx); | |
0a51b27e | 783 | |
f3b85252 | 784 | return res; |
0a51b27e JB |
785 | } |
786 | ||
f3b85252 JB |
787 | int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, |
788 | const u8 *ssid, u8 ssid_len) | |
0a51b27e | 789 | { |
0a51b27e | 790 | struct ieee80211_local *local = sdata->local; |
f3b85252 | 791 | int ret = -EBUSY; |
2a519311 | 792 | |
f3b85252 | 793 | mutex_lock(&local->scan_mtx); |
0a51b27e | 794 | |
f3b85252 JB |
795 | /* busy scanning */ |
796 | if (local->scan_req) | |
797 | goto unlock; | |
9116dd01 | 798 | |
5ba63533 JB |
799 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
800 | local->int_scan_req->ssids[0].ssid_len = ssid_len; | |
9116dd01 | 801 | |
5ba63533 | 802 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
f3b85252 JB |
803 | unlock: |
804 | mutex_unlock(&local->scan_mtx); | |
805 | return ret; | |
0a51b27e | 806 | } |
5bb644a0 JB |
807 | |
808 | void ieee80211_scan_cancel(struct ieee80211_local *local) | |
809 | { | |
15db0b7f | 810 | bool abortscan; |
5bb644a0 JB |
811 | |
812 | cancel_delayed_work_sync(&local->scan_work); | |
813 | ||
814 | /* | |
815 | * Only call this function when a scan can't be | |
816 | * queued -- mostly at suspend under RTNL. | |
817 | */ | |
818 | mutex_lock(&local->scan_mtx); | |
15db0b7f JB |
819 | abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || |
820 | (!local->scanning && local->scan_req); | |
5bb644a0 JB |
821 | mutex_unlock(&local->scan_mtx); |
822 | ||
15db0b7f | 823 | if (abortscan) |
5bb644a0 JB |
824 | ieee80211_scan_completed(&local->hw, true); |
825 | } |