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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 | ||
0a51b27e | 15 | #include <linux/if_arp.h> |
078e1e60 | 16 | #include <linux/rtnetlink.h> |
df13cce5 HS |
17 | #include <linux/pm_qos_params.h> |
18 | #include <net/sch_generic.h> | |
0a51b27e | 19 | #include <net/mac80211.h> |
0a51b27e JB |
20 | |
21 | #include "ieee80211_i.h" | |
24487981 | 22 | #include "driver-ops.h" |
5484e237 | 23 | #include "mesh.h" |
0a51b27e JB |
24 | |
25 | #define IEEE80211_PROBE_DELAY (HZ / 33) | |
26 | #define IEEE80211_CHANNEL_TIME (HZ / 33) | |
96f7e739 | 27 | #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8) |
0a51b27e | 28 | |
c2b13452 | 29 | struct ieee80211_bss * |
5484e237 JB |
30 | ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, |
31 | u8 *ssid, u8 ssid_len) | |
32 | { | |
0c1ad2ca JB |
33 | struct cfg80211_bss *cbss; |
34 | ||
35 | cbss = cfg80211_get_bss(local->hw.wiphy, | |
36 | ieee80211_get_channel(local->hw.wiphy, freq), | |
37 | bssid, ssid, ssid_len, 0, 0); | |
38 | if (!cbss) | |
39 | return NULL; | |
40 | return (void *)cbss->priv; | |
5484e237 JB |
41 | } |
42 | ||
00d3f14c | 43 | static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) |
5484e237 | 44 | { |
0c1ad2ca | 45 | struct ieee80211_bss *bss = (void *)cbss->priv; |
5484e237 | 46 | |
5484e237 JB |
47 | kfree(bss_mesh_id(bss)); |
48 | kfree(bss_mesh_cfg(bss)); | |
5484e237 JB |
49 | } |
50 | ||
51 | void ieee80211_rx_bss_put(struct ieee80211_local *local, | |
c2b13452 | 52 | struct ieee80211_bss *bss) |
5484e237 | 53 | { |
0c1ad2ca JB |
54 | if (!bss) |
55 | return; | |
56 | cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); | |
5484e237 JB |
57 | } |
58 | ||
ab13315a KV |
59 | static bool is_uapsd_supported(struct ieee802_11_elems *elems) |
60 | { | |
61 | u8 qos_info; | |
62 | ||
63 | if (elems->wmm_info && elems->wmm_info_len == 7 | |
64 | && elems->wmm_info[5] == 1) | |
65 | qos_info = elems->wmm_info[6]; | |
66 | else if (elems->wmm_param && elems->wmm_param_len == 24 | |
67 | && elems->wmm_param[5] == 1) | |
68 | qos_info = elems->wmm_param[6]; | |
69 | else | |
70 | /* no valid wmm information or parameter element found */ | |
71 | return false; | |
72 | ||
73 | return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; | |
74 | } | |
75 | ||
c2b13452 | 76 | struct ieee80211_bss * |
5484e237 JB |
77 | ieee80211_bss_info_update(struct ieee80211_local *local, |
78 | struct ieee80211_rx_status *rx_status, | |
79 | struct ieee80211_mgmt *mgmt, | |
80 | size_t len, | |
81 | struct ieee802_11_elems *elems, | |
2a519311 JB |
82 | struct ieee80211_channel *channel, |
83 | bool beacon) | |
5484e237 | 84 | { |
0c1ad2ca | 85 | struct cfg80211_bss *cbss; |
c2b13452 | 86 | struct ieee80211_bss *bss; |
00d3f14c | 87 | int clen; |
2a519311 JB |
88 | s32 signal = 0; |
89 | ||
77965c97 | 90 | if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) |
2a519311 | 91 | signal = rx_status->signal * 100; |
77965c97 | 92 | else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) |
2a519311 | 93 | signal = (rx_status->signal * 100) / local->hw.max_signal; |
2a519311 | 94 | |
0c1ad2ca JB |
95 | cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, |
96 | mgmt, len, signal, GFP_ATOMIC); | |
5484e237 | 97 | |
0c1ad2ca | 98 | if (!cbss) |
00d3f14c JB |
99 | return NULL; |
100 | ||
0c1ad2ca JB |
101 | cbss->free_priv = ieee80211_rx_bss_free; |
102 | bss = (void *)cbss->priv; | |
5484e237 JB |
103 | |
104 | /* save the ERP value so that it is available at association time */ | |
105 | if (elems->erp_info && elems->erp_info_len >= 1) { | |
106 | bss->erp_value = elems->erp_info[0]; | |
107 | bss->has_erp_value = 1; | |
108 | } | |
109 | ||
5484e237 JB |
110 | if (elems->tim) { |
111 | struct ieee80211_tim_ie *tim_ie = | |
112 | (struct ieee80211_tim_ie *)elems->tim; | |
113 | bss->dtim_period = tim_ie->dtim_period; | |
114 | } | |
115 | ||
5484e237 JB |
116 | bss->supp_rates_len = 0; |
117 | if (elems->supp_rates) { | |
118 | clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len; | |
119 | if (clen > elems->supp_rates_len) | |
120 | clen = elems->supp_rates_len; | |
121 | memcpy(&bss->supp_rates[bss->supp_rates_len], elems->supp_rates, | |
122 | clen); | |
123 | bss->supp_rates_len += clen; | |
124 | } | |
125 | if (elems->ext_supp_rates) { | |
126 | clen = IEEE80211_MAX_SUPP_RATES - bss->supp_rates_len; | |
127 | if (clen > elems->ext_supp_rates_len) | |
128 | clen = elems->ext_supp_rates_len; | |
129 | memcpy(&bss->supp_rates[bss->supp_rates_len], | |
130 | elems->ext_supp_rates, clen); | |
131 | bss->supp_rates_len += clen; | |
132 | } | |
133 | ||
5484e237 | 134 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
ab13315a | 135 | bss->uapsd_supported = is_uapsd_supported(elems); |
5484e237 JB |
136 | |
137 | if (!beacon) | |
138 | bss->last_probe_resp = jiffies; | |
139 | ||
5484e237 JB |
140 | return bss; |
141 | } | |
0a51b27e | 142 | |
98c8fccf | 143 | ieee80211_rx_result |
f1d58c25 | 144 | ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) |
98c8fccf | 145 | { |
f1d58c25 | 146 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
98c8fccf | 147 | struct ieee80211_mgmt *mgmt; |
c2b13452 | 148 | struct ieee80211_bss *bss; |
98c8fccf JB |
149 | u8 *elements; |
150 | struct ieee80211_channel *channel; | |
151 | size_t baselen; | |
152 | int freq; | |
153 | __le16 fc; | |
154 | bool presp, beacon = false; | |
155 | struct ieee802_11_elems elems; | |
156 | ||
157 | if (skb->len < 2) | |
158 | return RX_DROP_UNUSABLE; | |
159 | ||
160 | mgmt = (struct ieee80211_mgmt *) skb->data; | |
161 | fc = mgmt->frame_control; | |
162 | ||
163 | if (ieee80211_is_ctl(fc)) | |
164 | return RX_CONTINUE; | |
165 | ||
166 | if (skb->len < 24) | |
167 | return RX_DROP_MONITOR; | |
168 | ||
169 | presp = ieee80211_is_probe_resp(fc); | |
170 | if (presp) { | |
171 | /* ignore ProbeResp to foreign address */ | |
47846c9b | 172 | if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) |
98c8fccf JB |
173 | return RX_DROP_MONITOR; |
174 | ||
175 | presp = true; | |
176 | elements = mgmt->u.probe_resp.variable; | |
177 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); | |
178 | } else { | |
179 | beacon = ieee80211_is_beacon(fc); | |
180 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); | |
181 | elements = mgmt->u.beacon.variable; | |
182 | } | |
183 | ||
184 | if (!presp && !beacon) | |
185 | return RX_CONTINUE; | |
186 | ||
187 | if (baselen > skb->len) | |
188 | return RX_DROP_MONITOR; | |
189 | ||
190 | ieee802_11_parse_elems(elements, skb->len - baselen, &elems); | |
191 | ||
192 | if (elems.ds_params && elems.ds_params_len == 1) | |
193 | freq = ieee80211_channel_to_frequency(elems.ds_params[0]); | |
194 | else | |
195 | freq = rx_status->freq; | |
196 | ||
197 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); | |
198 | ||
199 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) | |
200 | return RX_DROP_MONITOR; | |
201 | ||
202 | bss = ieee80211_bss_info_update(sdata->local, rx_status, | |
203 | mgmt, skb->len, &elems, | |
2a519311 | 204 | channel, beacon); |
d048e503 JM |
205 | if (bss) |
206 | ieee80211_rx_bss_put(sdata->local, bss); | |
98c8fccf JB |
207 | |
208 | dev_kfree_skb(skb); | |
209 | return RX_QUEUED; | |
210 | } | |
211 | ||
4d36ec58 JB |
212 | /* return false if no more work */ |
213 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) | |
214 | { | |
215 | struct cfg80211_scan_request *req = local->scan_req; | |
216 | enum ieee80211_band band; | |
217 | int i, ielen, n_chans; | |
218 | ||
219 | do { | |
220 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) | |
221 | return false; | |
222 | ||
223 | band = local->hw_scan_band; | |
224 | n_chans = 0; | |
225 | for (i = 0; i < req->n_channels; i++) { | |
226 | if (req->channels[i]->band == band) { | |
227 | local->hw_scan_req->channels[n_chans] = | |
228 | req->channels[i]; | |
229 | n_chans++; | |
230 | } | |
231 | } | |
232 | ||
233 | local->hw_scan_band++; | |
234 | } while (!n_chans); | |
235 | ||
236 | local->hw_scan_req->n_channels = n_chans; | |
237 | ||
238 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, | |
239 | req->ie, req->ie_len, band); | |
240 | local->hw_scan_req->ie_len = ielen; | |
241 | ||
242 | return true; | |
243 | } | |
244 | ||
2a519311 | 245 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
0a51b27e JB |
246 | { |
247 | struct ieee80211_local *local = hw_to_local(hw); | |
f3b85252 | 248 | bool was_hw_scan; |
0a51b27e | 249 | |
b5878a2d JB |
250 | trace_api_scan_completed(local, aborted); |
251 | ||
f3b85252 | 252 | mutex_lock(&local->scan_mtx); |
5bc75728 | 253 | |
6d3560d4 JB |
254 | /* |
255 | * It's ok to abort a not-yet-running scan (that | |
256 | * we have one at all will be verified by checking | |
257 | * local->scan_req next), but not to complete it | |
258 | * successfully. | |
259 | */ | |
260 | if (WARN_ON(!local->scanning && !aborted)) | |
261 | aborted = true; | |
5bc75728 | 262 | |
f3b85252 JB |
263 | if (WARN_ON(!local->scan_req)) { |
264 | mutex_unlock(&local->scan_mtx); | |
265 | return; | |
de95a54b JB |
266 | } |
267 | ||
4d36ec58 JB |
268 | was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
269 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { | |
270 | ieee80211_queue_delayed_work(&local->hw, | |
271 | &local->scan_work, 0); | |
272 | mutex_unlock(&local->scan_mtx); | |
273 | return; | |
274 | } | |
275 | ||
276 | kfree(local->hw_scan_req); | |
277 | local->hw_scan_req = NULL; | |
f3b85252 | 278 | |
5ba63533 | 279 | if (local->scan_req != local->int_scan_req) |
2a519311 JB |
280 | cfg80211_scan_done(local->scan_req, aborted); |
281 | local->scan_req = NULL; | |
15db0b7f | 282 | local->scan_sdata = NULL; |
2a519311 | 283 | |
fbe9c429 | 284 | local->scanning = 0; |
58905ca5 | 285 | local->scan_channel = NULL; |
f3b85252 JB |
286 | |
287 | /* we only have to protect scan_req and hw/sw scan */ | |
288 | mutex_unlock(&local->scan_mtx); | |
289 | ||
e8975581 | 290 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
5cff20e6 JB |
291 | if (was_hw_scan) |
292 | goto done; | |
0a51b27e | 293 | |
3ac64bee | 294 | ieee80211_configure_filter(local); |
0a51b27e | 295 | |
24487981 | 296 | drv_sw_scan_complete(local); |
80e775bf | 297 | |
b203ffc3 | 298 | ieee80211_offchannel_return(local, true); |
0a51b27e JB |
299 | |
300 | done: | |
5cff20e6 | 301 | ieee80211_recalc_idle(local); |
0a51b27e | 302 | ieee80211_mlme_notify_scan_completed(local); |
46900298 | 303 | ieee80211_ibss_notify_scan_completed(local); |
472dbc45 | 304 | ieee80211_mesh_notify_scan_completed(local); |
81ac3462 | 305 | ieee80211_queue_work(&local->hw, &local->work_work); |
0a51b27e JB |
306 | } |
307 | EXPORT_SYMBOL(ieee80211_scan_completed); | |
308 | ||
f3b85252 JB |
309 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
310 | { | |
f3b85252 JB |
311 | /* |
312 | * Hardware/driver doesn't support hw_scan, so use software | |
313 | * scanning instead. First send a nullfunc frame with power save | |
314 | * bit on so that AP will buffer the frames for us while we are not | |
315 | * listening, then send probe requests to each channel and wait for | |
316 | * the responses. After all channels are scanned, tune back to the | |
317 | * original channel and send a nullfunc frame with power save bit | |
318 | * off to trigger the AP to send us all the buffered frames. | |
319 | * | |
320 | * Note that while local->sw_scanning is true everything else but | |
321 | * nullfunc frames and probe requests will be dropped in | |
322 | * ieee80211_tx_h_check_assoc(). | |
323 | */ | |
24487981 | 324 | drv_sw_scan_start(local); |
f3b85252 | 325 | |
b203ffc3 | 326 | ieee80211_offchannel_stop_beaconing(local); |
f3b85252 | 327 | |
df13cce5 | 328 | local->leave_oper_channel_time = 0; |
977923b0 | 329 | local->next_scan_state = SCAN_DECISION; |
f3b85252 JB |
330 | local->scan_channel_idx = 0; |
331 | ||
a80f7c0b JB |
332 | drv_flush(local, false); |
333 | ||
3ac64bee | 334 | ieee80211_configure_filter(local); |
f3b85252 | 335 | |
42935eca LR |
336 | ieee80211_queue_delayed_work(&local->hw, |
337 | &local->scan_work, | |
338 | IEEE80211_CHANNEL_TIME); | |
f3b85252 JB |
339 | |
340 | return 0; | |
341 | } | |
342 | ||
343 | ||
344 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, | |
345 | struct cfg80211_scan_request *req) | |
346 | { | |
347 | struct ieee80211_local *local = sdata->local; | |
f3b85252 JB |
348 | int rc; |
349 | ||
350 | if (local->scan_req) | |
351 | return -EBUSY; | |
352 | ||
6e7e6213 JL |
353 | if (!list_empty(&local->work_list)) { |
354 | /* wait for the work to finish/time out */ | |
c0ce77b8 JB |
355 | local->scan_req = req; |
356 | local->scan_sdata = sdata; | |
357 | return 0; | |
358 | } | |
359 | ||
f3b85252 JB |
360 | if (local->ops->hw_scan) { |
361 | u8 *ies; | |
f3b85252 | 362 | |
4d36ec58 JB |
363 | local->hw_scan_req = kmalloc( |
364 | sizeof(*local->hw_scan_req) + | |
365 | req->n_channels * sizeof(req->channels[0]) + | |
366 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + | |
367 | req->ie_len, GFP_KERNEL); | |
368 | if (!local->hw_scan_req) | |
f3b85252 JB |
369 | return -ENOMEM; |
370 | ||
4d36ec58 JB |
371 | local->hw_scan_req->ssids = req->ssids; |
372 | local->hw_scan_req->n_ssids = req->n_ssids; | |
373 | ies = (u8 *)local->hw_scan_req + | |
374 | sizeof(*local->hw_scan_req) + | |
375 | req->n_channels * sizeof(req->channels[0]); | |
376 | local->hw_scan_req->ie = ies; | |
377 | ||
378 | local->hw_scan_band = 0; | |
6e7e6213 JL |
379 | |
380 | /* | |
381 | * After allocating local->hw_scan_req, we must | |
382 | * go through until ieee80211_prep_hw_scan(), so | |
383 | * anything that might be changed here and leave | |
384 | * this function early must not go after this | |
385 | * allocation. | |
386 | */ | |
f3b85252 JB |
387 | } |
388 | ||
389 | local->scan_req = req; | |
390 | local->scan_sdata = sdata; | |
391 | ||
f3b85252 | 392 | if (local->ops->hw_scan) |
fbe9c429 | 393 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
f3b85252 | 394 | else |
fbe9c429 | 395 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
6e7e6213 | 396 | |
f3b85252 JB |
397 | /* |
398 | * Kicking off the scan need not be protected, | |
399 | * only the scan variable stuff, since now | |
400 | * local->scan_req is assigned and other callers | |
401 | * will abort their scan attempts. | |
402 | * | |
6e7e6213 JL |
403 | * This avoids too many locking dependencies |
404 | * so that the scan completed calls have more | |
405 | * locking freedom. | |
f3b85252 | 406 | */ |
5cff20e6 JB |
407 | |
408 | ieee80211_recalc_idle(local); | |
f3b85252 JB |
409 | mutex_unlock(&local->scan_mtx); |
410 | ||
4d36ec58 JB |
411 | if (local->ops->hw_scan) { |
412 | WARN_ON(!ieee80211_prep_hw_scan(local)); | |
a060bbfe | 413 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 | 414 | } else |
f3b85252 JB |
415 | rc = ieee80211_start_sw_scan(local); |
416 | ||
417 | mutex_lock(&local->scan_mtx); | |
418 | ||
419 | if (rc) { | |
4d36ec58 JB |
420 | kfree(local->hw_scan_req); |
421 | local->hw_scan_req = NULL; | |
fbe9c429 | 422 | local->scanning = 0; |
f3b85252 | 423 | |
5cff20e6 JB |
424 | ieee80211_recalc_idle(local); |
425 | ||
f3b85252 JB |
426 | local->scan_req = NULL; |
427 | local->scan_sdata = NULL; | |
428 | } | |
429 | ||
430 | return rc; | |
431 | } | |
432 | ||
df13cce5 HS |
433 | static unsigned long |
434 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) | |
435 | { | |
436 | /* | |
437 | * TODO: channel switching also consumes quite some time, | |
438 | * add that delay as well to get a better estimation | |
439 | */ | |
440 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) | |
441 | return IEEE80211_PASSIVE_CHANNEL_TIME; | |
442 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; | |
443 | } | |
444 | ||
2fb3f028 HS |
445 | static int ieee80211_scan_state_decision(struct ieee80211_local *local, |
446 | unsigned long *next_delay) | |
7d3be3cc | 447 | { |
142b9f50 | 448 | bool associated = false; |
df13cce5 HS |
449 | bool tx_empty = true; |
450 | bool bad_latency; | |
451 | bool listen_int_exceeded; | |
452 | unsigned long min_beacon_int = 0; | |
142b9f50 | 453 | struct ieee80211_sub_if_data *sdata; |
df13cce5 | 454 | struct ieee80211_channel *next_chan; |
142b9f50 HS |
455 | |
456 | /* if no more bands/channels left, complete scan and advance to the idle state */ | |
7d3be3cc HS |
457 | if (local->scan_channel_idx >= local->scan_req->n_channels) { |
458 | ieee80211_scan_completed(&local->hw, false); | |
459 | return 1; | |
460 | } | |
2fb3f028 | 461 | |
df13cce5 HS |
462 | /* |
463 | * check if at least one STA interface is associated, | |
464 | * check if at least one STA interface has pending tx frames | |
465 | * and grab the lowest used beacon interval | |
466 | */ | |
142b9f50 HS |
467 | mutex_lock(&local->iflist_mtx); |
468 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 469 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
470 | continue; |
471 | ||
472 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
473 | if (sdata->u.mgd.associated) { | |
474 | associated = true; | |
df13cce5 HS |
475 | |
476 | if (sdata->vif.bss_conf.beacon_int < | |
477 | min_beacon_int || min_beacon_int == 0) | |
478 | min_beacon_int = | |
479 | sdata->vif.bss_conf.beacon_int; | |
480 | ||
481 | if (!qdisc_all_tx_empty(sdata->dev)) { | |
482 | tx_empty = false; | |
483 | break; | |
484 | } | |
142b9f50 HS |
485 | } |
486 | } | |
487 | } | |
488 | mutex_unlock(&local->iflist_mtx); | |
489 | ||
490 | if (local->scan_channel) { | |
491 | /* | |
492 | * we're currently scanning a different channel, let's | |
df13cce5 HS |
493 | * see if we can scan another channel without interfering |
494 | * with the current traffic situation. | |
495 | * | |
496 | * Since we don't know if the AP has pending frames for us | |
497 | * we can only check for our tx queues and use the current | |
498 | * pm_qos requirements for rx. Hence, if no tx traffic occurs | |
499 | * at all we will scan as many channels in a row as the pm_qos | |
500 | * latency allows us to. Additionally we also check for the | |
501 | * currently negotiated listen interval to prevent losing | |
502 | * frames unnecessarily. | |
503 | * | |
504 | * Otherwise switch back to the operating channel. | |
142b9f50 | 505 | */ |
df13cce5 HS |
506 | next_chan = local->scan_req->channels[local->scan_channel_idx]; |
507 | ||
508 | bad_latency = time_after(jiffies + | |
509 | ieee80211_scan_get_channel_time(next_chan), | |
510 | local->leave_oper_channel_time + | |
511 | usecs_to_jiffies(pm_qos_requirement(PM_QOS_NETWORK_LATENCY))); | |
512 | ||
513 | listen_int_exceeded = time_after(jiffies + | |
514 | ieee80211_scan_get_channel_time(next_chan), | |
515 | local->leave_oper_channel_time + | |
516 | usecs_to_jiffies(min_beacon_int * 1024) * | |
517 | local->hw.conf.listen_interval); | |
518 | ||
519 | if (associated && ( !tx_empty || bad_latency || | |
520 | listen_int_exceeded)) | |
977923b0 | 521 | local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; |
142b9f50 | 522 | else |
977923b0 | 523 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
524 | } else { |
525 | /* | |
526 | * we're on the operating channel currently, let's | |
527 | * leave that channel now to scan another one | |
528 | */ | |
977923b0 | 529 | local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; |
142b9f50 HS |
530 | } |
531 | ||
2fb3f028 | 532 | *next_delay = 0; |
2fb3f028 HS |
533 | return 0; |
534 | } | |
535 | ||
142b9f50 HS |
536 | static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, |
537 | unsigned long *next_delay) | |
538 | { | |
b203ffc3 | 539 | ieee80211_offchannel_stop_station(local); |
142b9f50 HS |
540 | |
541 | __set_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
542 | ||
a80f7c0b JB |
543 | /* |
544 | * What if the nullfunc frames didn't arrive? | |
545 | */ | |
546 | drv_flush(local, false); | |
547 | if (local->ops->flush) | |
548 | *next_delay = 0; | |
549 | else | |
550 | *next_delay = HZ / 10; | |
551 | ||
df13cce5 HS |
552 | /* remember when we left the operating channel */ |
553 | local->leave_oper_channel_time = jiffies; | |
554 | ||
142b9f50 | 555 | /* advance to the next channel to be scanned */ |
977923b0 | 556 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
557 | } |
558 | ||
559 | static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, | |
560 | unsigned long *next_delay) | |
561 | { | |
142b9f50 HS |
562 | /* switch back to the operating channel */ |
563 | local->scan_channel = NULL; | |
564 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); | |
565 | ||
566 | /* | |
b203ffc3 JM |
567 | * Only re-enable station mode interface now; beaconing will be |
568 | * re-enabled once the full scan has been completed. | |
142b9f50 | 569 | */ |
b203ffc3 | 570 | ieee80211_offchannel_return(local, false); |
142b9f50 HS |
571 | |
572 | __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
573 | ||
574 | *next_delay = HZ / 5; | |
977923b0 | 575 | local->next_scan_state = SCAN_DECISION; |
142b9f50 HS |
576 | } |
577 | ||
2fb3f028 HS |
578 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
579 | unsigned long *next_delay) | |
580 | { | |
581 | int skip; | |
582 | struct ieee80211_channel *chan; | |
2fb3f028 | 583 | |
7d3be3cc HS |
584 | skip = 0; |
585 | chan = local->scan_req->channels[local->scan_channel_idx]; | |
586 | ||
584991dc JB |
587 | local->scan_channel = chan; |
588 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) | |
7d3be3cc HS |
589 | skip = 1; |
590 | ||
7d3be3cc HS |
591 | /* advance state machine to next channel/band */ |
592 | local->scan_channel_idx++; | |
593 | ||
0ee9c13c HS |
594 | if (skip) { |
595 | /* if we skip this channel return to the decision state */ | |
596 | local->next_scan_state = SCAN_DECISION; | |
2fb3f028 | 597 | return; |
0ee9c13c | 598 | } |
7d3be3cc HS |
599 | |
600 | /* | |
601 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 | |
602 | * (which unfortunately doesn't say _why_ step a) is done, | |
603 | * but it waits for the probe delay or until a frame is | |
604 | * received - and the received frame would update the NAV). | |
605 | * For now, we do not support waiting until a frame is | |
606 | * received. | |
607 | * | |
608 | * In any case, it is not necessary for a passive scan. | |
609 | */ | |
610 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || | |
611 | !local->scan_req->n_ssids) { | |
612 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; | |
977923b0 | 613 | local->next_scan_state = SCAN_DECISION; |
2fb3f028 | 614 | return; |
7d3be3cc HS |
615 | } |
616 | ||
2fb3f028 | 617 | /* active scan, send probes */ |
7d3be3cc | 618 | *next_delay = IEEE80211_PROBE_DELAY; |
977923b0 | 619 | local->next_scan_state = SCAN_SEND_PROBE; |
7d3be3cc HS |
620 | } |
621 | ||
622 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, | |
623 | unsigned long *next_delay) | |
624 | { | |
625 | int i; | |
626 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
627 | ||
628 | for (i = 0; i < local->scan_req->n_ssids; i++) | |
629 | ieee80211_send_probe_req( | |
630 | sdata, NULL, | |
631 | local->scan_req->ssids[i].ssid, | |
632 | local->scan_req->ssids[i].ssid_len, | |
633 | local->scan_req->ie, local->scan_req->ie_len); | |
634 | ||
635 | /* | |
636 | * After sending probe requests, wait for probe responses | |
637 | * on the channel. | |
638 | */ | |
639 | *next_delay = IEEE80211_CHANNEL_TIME; | |
977923b0 | 640 | local->next_scan_state = SCAN_DECISION; |
7d3be3cc HS |
641 | } |
642 | ||
c2b13452 | 643 | void ieee80211_scan_work(struct work_struct *work) |
0a51b27e JB |
644 | { |
645 | struct ieee80211_local *local = | |
646 | container_of(work, struct ieee80211_local, scan_work.work); | |
647 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
0a51b27e JB |
648 | unsigned long next_delay = 0; |
649 | ||
f3b85252 JB |
650 | mutex_lock(&local->scan_mtx); |
651 | if (!sdata || !local->scan_req) { | |
652 | mutex_unlock(&local->scan_mtx); | |
653 | return; | |
654 | } | |
655 | ||
4d36ec58 | 656 | if (local->hw_scan_req) { |
a060bbfe | 657 | int rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 JB |
658 | mutex_unlock(&local->scan_mtx); |
659 | if (rc) | |
660 | ieee80211_scan_completed(&local->hw, true); | |
661 | return; | |
662 | } | |
663 | ||
fbe9c429 | 664 | if (local->scan_req && !local->scanning) { |
f3b85252 JB |
665 | struct cfg80211_scan_request *req = local->scan_req; |
666 | int rc; | |
667 | ||
668 | local->scan_req = NULL; | |
15db0b7f | 669 | local->scan_sdata = NULL; |
f3b85252 JB |
670 | |
671 | rc = __ieee80211_start_scan(sdata, req); | |
672 | mutex_unlock(&local->scan_mtx); | |
673 | ||
674 | if (rc) | |
675 | ieee80211_scan_completed(&local->hw, true); | |
676 | return; | |
677 | } | |
678 | ||
679 | mutex_unlock(&local->scan_mtx); | |
680 | ||
5bc75728 JB |
681 | /* |
682 | * Avoid re-scheduling when the sdata is going away. | |
683 | */ | |
9607e6b6 | 684 | if (!ieee80211_sdata_running(sdata)) { |
f3b85252 | 685 | ieee80211_scan_completed(&local->hw, true); |
0a51b27e | 686 | return; |
f3b85252 | 687 | } |
0a51b27e | 688 | |
f502d09b HS |
689 | /* |
690 | * as long as no delay is required advance immediately | |
691 | * without scheduling a new work | |
692 | */ | |
693 | do { | |
977923b0 | 694 | switch (local->next_scan_state) { |
2fb3f028 HS |
695 | case SCAN_DECISION: |
696 | if (ieee80211_scan_state_decision(local, &next_delay)) | |
f502d09b HS |
697 | return; |
698 | break; | |
2fb3f028 HS |
699 | case SCAN_SET_CHANNEL: |
700 | ieee80211_scan_state_set_channel(local, &next_delay); | |
701 | break; | |
f502d09b HS |
702 | case SCAN_SEND_PROBE: |
703 | ieee80211_scan_state_send_probe(local, &next_delay); | |
704 | break; | |
142b9f50 HS |
705 | case SCAN_LEAVE_OPER_CHANNEL: |
706 | ieee80211_scan_state_leave_oper_channel(local, &next_delay); | |
707 | break; | |
708 | case SCAN_ENTER_OPER_CHANNEL: | |
709 | ieee80211_scan_state_enter_oper_channel(local, &next_delay); | |
710 | break; | |
f502d09b HS |
711 | } |
712 | } while (next_delay == 0); | |
0a51b27e | 713 | |
42935eca | 714 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
0a51b27e JB |
715 | } |
716 | ||
f3b85252 JB |
717 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
718 | struct cfg80211_scan_request *req) | |
0a51b27e | 719 | { |
f3b85252 | 720 | int res; |
de95a54b | 721 | |
f3b85252 JB |
722 | mutex_lock(&sdata->local->scan_mtx); |
723 | res = __ieee80211_start_scan(sdata, req); | |
724 | mutex_unlock(&sdata->local->scan_mtx); | |
0a51b27e | 725 | |
f3b85252 | 726 | return res; |
0a51b27e JB |
727 | } |
728 | ||
f3b85252 JB |
729 | int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, |
730 | const u8 *ssid, u8 ssid_len) | |
0a51b27e | 731 | { |
0a51b27e | 732 | struct ieee80211_local *local = sdata->local; |
f3b85252 | 733 | int ret = -EBUSY; |
2a519311 | 734 | |
f3b85252 | 735 | mutex_lock(&local->scan_mtx); |
0a51b27e | 736 | |
f3b85252 JB |
737 | /* busy scanning */ |
738 | if (local->scan_req) | |
739 | goto unlock; | |
9116dd01 | 740 | |
5ba63533 JB |
741 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
742 | local->int_scan_req->ssids[0].ssid_len = ssid_len; | |
9116dd01 | 743 | |
5ba63533 | 744 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
f3b85252 JB |
745 | unlock: |
746 | mutex_unlock(&local->scan_mtx); | |
747 | return ret; | |
0a51b27e | 748 | } |
5bb644a0 JB |
749 | |
750 | void ieee80211_scan_cancel(struct ieee80211_local *local) | |
751 | { | |
15db0b7f | 752 | bool abortscan; |
5bb644a0 JB |
753 | |
754 | cancel_delayed_work_sync(&local->scan_work); | |
755 | ||
756 | /* | |
757 | * Only call this function when a scan can't be | |
758 | * queued -- mostly at suspend under RTNL. | |
759 | */ | |
760 | mutex_lock(&local->scan_mtx); | |
15db0b7f JB |
761 | abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || |
762 | (!local->scanning && local->scan_req); | |
5bb644a0 JB |
763 | mutex_unlock(&local->scan_mtx); |
764 | ||
15db0b7f | 765 | if (abortscan) |
5bb644a0 JB |
766 | ieee80211_scan_completed(&local->hw, true); |
767 | } |