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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> | |
5a0e3ad6 | 19 | #include <linux/slab.h> |
0a51b27e | 20 | #include <net/mac80211.h> |
0a51b27e JB |
21 | |
22 | #include "ieee80211_i.h" | |
24487981 | 23 | #include "driver-ops.h" |
5484e237 | 24 | #include "mesh.h" |
0a51b27e JB |
25 | |
26 | #define IEEE80211_PROBE_DELAY (HZ / 33) | |
27 | #define IEEE80211_CHANNEL_TIME (HZ / 33) | |
96f7e739 | 28 | #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8) |
0a51b27e | 29 | |
c2b13452 | 30 | struct ieee80211_bss * |
5484e237 JB |
31 | ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, |
32 | u8 *ssid, u8 ssid_len) | |
33 | { | |
0c1ad2ca JB |
34 | struct cfg80211_bss *cbss; |
35 | ||
36 | cbss = cfg80211_get_bss(local->hw.wiphy, | |
37 | ieee80211_get_channel(local->hw.wiphy, freq), | |
38 | bssid, ssid, ssid_len, 0, 0); | |
39 | if (!cbss) | |
40 | return NULL; | |
41 | return (void *)cbss->priv; | |
5484e237 JB |
42 | } |
43 | ||
00d3f14c | 44 | static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) |
5484e237 | 45 | { |
0c1ad2ca | 46 | struct ieee80211_bss *bss = (void *)cbss->priv; |
5484e237 | 47 | |
5484e237 JB |
48 | kfree(bss_mesh_id(bss)); |
49 | kfree(bss_mesh_cfg(bss)); | |
5484e237 JB |
50 | } |
51 | ||
52 | void ieee80211_rx_bss_put(struct ieee80211_local *local, | |
c2b13452 | 53 | struct ieee80211_bss *bss) |
5484e237 | 54 | { |
0c1ad2ca JB |
55 | if (!bss) |
56 | return; | |
57 | cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); | |
5484e237 JB |
58 | } |
59 | ||
ab13315a KV |
60 | static bool is_uapsd_supported(struct ieee802_11_elems *elems) |
61 | { | |
62 | u8 qos_info; | |
63 | ||
64 | if (elems->wmm_info && elems->wmm_info_len == 7 | |
65 | && elems->wmm_info[5] == 1) | |
66 | qos_info = elems->wmm_info[6]; | |
67 | else if (elems->wmm_param && elems->wmm_param_len == 24 | |
68 | && elems->wmm_param[5] == 1) | |
69 | qos_info = elems->wmm_param[6]; | |
70 | else | |
71 | /* no valid wmm information or parameter element found */ | |
72 | return false; | |
73 | ||
74 | return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; | |
75 | } | |
76 | ||
c2b13452 | 77 | struct ieee80211_bss * |
5484e237 JB |
78 | ieee80211_bss_info_update(struct ieee80211_local *local, |
79 | struct ieee80211_rx_status *rx_status, | |
80 | struct ieee80211_mgmt *mgmt, | |
81 | size_t len, | |
82 | struct ieee802_11_elems *elems, | |
2a519311 JB |
83 | struct ieee80211_channel *channel, |
84 | bool beacon) | |
5484e237 | 85 | { |
0c1ad2ca | 86 | struct cfg80211_bss *cbss; |
c2b13452 | 87 | struct ieee80211_bss *bss; |
f0b058b6 | 88 | int clen, srlen; |
2a519311 JB |
89 | s32 signal = 0; |
90 | ||
77965c97 | 91 | if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) |
2a519311 | 92 | signal = rx_status->signal * 100; |
77965c97 | 93 | else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) |
2a519311 | 94 | signal = (rx_status->signal * 100) / local->hw.max_signal; |
2a519311 | 95 | |
0c1ad2ca JB |
96 | cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, |
97 | mgmt, len, signal, GFP_ATOMIC); | |
5484e237 | 98 | |
0c1ad2ca | 99 | if (!cbss) |
00d3f14c JB |
100 | return NULL; |
101 | ||
0c1ad2ca JB |
102 | cbss->free_priv = ieee80211_rx_bss_free; |
103 | bss = (void *)cbss->priv; | |
5484e237 JB |
104 | |
105 | /* save the ERP value so that it is available at association time */ | |
106 | if (elems->erp_info && elems->erp_info_len >= 1) { | |
107 | bss->erp_value = elems->erp_info[0]; | |
108 | bss->has_erp_value = 1; | |
109 | } | |
110 | ||
5484e237 JB |
111 | if (elems->tim) { |
112 | struct ieee80211_tim_ie *tim_ie = | |
113 | (struct ieee80211_tim_ie *)elems->tim; | |
114 | bss->dtim_period = tim_ie->dtim_period; | |
115 | } | |
116 | ||
f0b058b6 SG |
117 | /* replace old supported rates if we get new values */ |
118 | srlen = 0; | |
5484e237 | 119 | if (elems->supp_rates) { |
f0b058b6 | 120 | clen = IEEE80211_MAX_SUPP_RATES; |
5484e237 JB |
121 | if (clen > elems->supp_rates_len) |
122 | clen = elems->supp_rates_len; | |
f0b058b6 SG |
123 | memcpy(bss->supp_rates, elems->supp_rates, clen); |
124 | srlen += clen; | |
5484e237 JB |
125 | } |
126 | if (elems->ext_supp_rates) { | |
f0b058b6 | 127 | clen = IEEE80211_MAX_SUPP_RATES - srlen; |
5484e237 JB |
128 | if (clen > elems->ext_supp_rates_len) |
129 | clen = elems->ext_supp_rates_len; | |
f0b058b6 SG |
130 | memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen); |
131 | srlen += clen; | |
5484e237 | 132 | } |
f0b058b6 SG |
133 | if (srlen) |
134 | bss->supp_rates_len = srlen; | |
5484e237 | 135 | |
5484e237 | 136 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
ab13315a | 137 | bss->uapsd_supported = is_uapsd_supported(elems); |
5484e237 JB |
138 | |
139 | if (!beacon) | |
140 | bss->last_probe_resp = jiffies; | |
141 | ||
5484e237 JB |
142 | return bss; |
143 | } | |
0a51b27e | 144 | |
98c8fccf | 145 | ieee80211_rx_result |
f1d58c25 | 146 | ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) |
98c8fccf | 147 | { |
f1d58c25 | 148 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
98c8fccf | 149 | struct ieee80211_mgmt *mgmt; |
c2b13452 | 150 | struct ieee80211_bss *bss; |
98c8fccf JB |
151 | u8 *elements; |
152 | struct ieee80211_channel *channel; | |
153 | size_t baselen; | |
154 | int freq; | |
155 | __le16 fc; | |
156 | bool presp, beacon = false; | |
157 | struct ieee802_11_elems elems; | |
158 | ||
159 | if (skb->len < 2) | |
160 | return RX_DROP_UNUSABLE; | |
161 | ||
162 | mgmt = (struct ieee80211_mgmt *) skb->data; | |
163 | fc = mgmt->frame_control; | |
164 | ||
165 | if (ieee80211_is_ctl(fc)) | |
166 | return RX_CONTINUE; | |
167 | ||
168 | if (skb->len < 24) | |
169 | return RX_DROP_MONITOR; | |
170 | ||
171 | presp = ieee80211_is_probe_resp(fc); | |
172 | if (presp) { | |
173 | /* ignore ProbeResp to foreign address */ | |
47846c9b | 174 | if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) |
98c8fccf JB |
175 | return RX_DROP_MONITOR; |
176 | ||
177 | presp = true; | |
178 | elements = mgmt->u.probe_resp.variable; | |
179 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); | |
180 | } else { | |
181 | beacon = ieee80211_is_beacon(fc); | |
182 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); | |
183 | elements = mgmt->u.beacon.variable; | |
184 | } | |
185 | ||
186 | if (!presp && !beacon) | |
187 | return RX_CONTINUE; | |
188 | ||
189 | if (baselen > skb->len) | |
190 | return RX_DROP_MONITOR; | |
191 | ||
192 | ieee802_11_parse_elems(elements, skb->len - baselen, &elems); | |
193 | ||
194 | if (elems.ds_params && elems.ds_params_len == 1) | |
195 | freq = ieee80211_channel_to_frequency(elems.ds_params[0]); | |
196 | else | |
197 | freq = rx_status->freq; | |
198 | ||
199 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); | |
200 | ||
201 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) | |
202 | return RX_DROP_MONITOR; | |
203 | ||
204 | bss = ieee80211_bss_info_update(sdata->local, rx_status, | |
205 | mgmt, skb->len, &elems, | |
2a519311 | 206 | channel, beacon); |
d048e503 JM |
207 | if (bss) |
208 | ieee80211_rx_bss_put(sdata->local, bss); | |
98c8fccf JB |
209 | |
210 | dev_kfree_skb(skb); | |
211 | return RX_QUEUED; | |
212 | } | |
213 | ||
4d36ec58 JB |
214 | /* return false if no more work */ |
215 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) | |
216 | { | |
217 | struct cfg80211_scan_request *req = local->scan_req; | |
218 | enum ieee80211_band band; | |
219 | int i, ielen, n_chans; | |
220 | ||
221 | do { | |
222 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) | |
223 | return false; | |
224 | ||
225 | band = local->hw_scan_band; | |
226 | n_chans = 0; | |
227 | for (i = 0; i < req->n_channels; i++) { | |
228 | if (req->channels[i]->band == band) { | |
229 | local->hw_scan_req->channels[n_chans] = | |
230 | req->channels[i]; | |
231 | n_chans++; | |
232 | } | |
233 | } | |
234 | ||
235 | local->hw_scan_band++; | |
236 | } while (!n_chans); | |
237 | ||
238 | local->hw_scan_req->n_channels = n_chans; | |
239 | ||
240 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, | |
241 | req->ie, req->ie_len, band); | |
242 | local->hw_scan_req->ie_len = ielen; | |
243 | ||
244 | return true; | |
245 | } | |
246 | ||
2a519311 | 247 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
0a51b27e JB |
248 | { |
249 | struct ieee80211_local *local = hw_to_local(hw); | |
f3b85252 | 250 | bool was_hw_scan; |
0a51b27e | 251 | |
b5878a2d JB |
252 | trace_api_scan_completed(local, aborted); |
253 | ||
f3b85252 | 254 | mutex_lock(&local->scan_mtx); |
5bc75728 | 255 | |
6d3560d4 JB |
256 | /* |
257 | * It's ok to abort a not-yet-running scan (that | |
258 | * we have one at all will be verified by checking | |
259 | * local->scan_req next), but not to complete it | |
260 | * successfully. | |
261 | */ | |
262 | if (WARN_ON(!local->scanning && !aborted)) | |
263 | aborted = true; | |
5bc75728 | 264 | |
f3b85252 JB |
265 | if (WARN_ON(!local->scan_req)) { |
266 | mutex_unlock(&local->scan_mtx); | |
267 | return; | |
de95a54b JB |
268 | } |
269 | ||
4d36ec58 JB |
270 | was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
271 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { | |
272 | ieee80211_queue_delayed_work(&local->hw, | |
273 | &local->scan_work, 0); | |
274 | mutex_unlock(&local->scan_mtx); | |
275 | return; | |
276 | } | |
277 | ||
278 | kfree(local->hw_scan_req); | |
279 | local->hw_scan_req = NULL; | |
f3b85252 | 280 | |
5ba63533 | 281 | if (local->scan_req != local->int_scan_req) |
2a519311 JB |
282 | cfg80211_scan_done(local->scan_req, aborted); |
283 | local->scan_req = NULL; | |
15db0b7f | 284 | local->scan_sdata = NULL; |
2a519311 | 285 | |
fbe9c429 | 286 | local->scanning = 0; |
58905ca5 | 287 | local->scan_channel = NULL; |
f3b85252 | 288 | |
543708be JB |
289 | drv_sw_scan_complete(local); |
290 | ||
f3b85252 JB |
291 | /* we only have to protect scan_req and hw/sw scan */ |
292 | mutex_unlock(&local->scan_mtx); | |
293 | ||
e8975581 | 294 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
5cff20e6 JB |
295 | if (was_hw_scan) |
296 | goto done; | |
0a51b27e | 297 | |
3ac64bee | 298 | ieee80211_configure_filter(local); |
0a51b27e | 299 | |
b203ffc3 | 300 | ieee80211_offchannel_return(local, true); |
0a51b27e JB |
301 | |
302 | done: | |
5cff20e6 | 303 | ieee80211_recalc_idle(local); |
0a51b27e | 304 | ieee80211_mlme_notify_scan_completed(local); |
46900298 | 305 | ieee80211_ibss_notify_scan_completed(local); |
472dbc45 | 306 | ieee80211_mesh_notify_scan_completed(local); |
81ac3462 | 307 | ieee80211_queue_work(&local->hw, &local->work_work); |
0a51b27e JB |
308 | } |
309 | EXPORT_SYMBOL(ieee80211_scan_completed); | |
310 | ||
f3b85252 JB |
311 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
312 | { | |
f3b85252 JB |
313 | /* |
314 | * Hardware/driver doesn't support hw_scan, so use software | |
315 | * scanning instead. First send a nullfunc frame with power save | |
316 | * bit on so that AP will buffer the frames for us while we are not | |
317 | * listening, then send probe requests to each channel and wait for | |
318 | * the responses. After all channels are scanned, tune back to the | |
319 | * original channel and send a nullfunc frame with power save bit | |
320 | * off to trigger the AP to send us all the buffered frames. | |
321 | * | |
322 | * Note that while local->sw_scanning is true everything else but | |
323 | * nullfunc frames and probe requests will be dropped in | |
324 | * ieee80211_tx_h_check_assoc(). | |
325 | */ | |
24487981 | 326 | drv_sw_scan_start(local); |
f3b85252 | 327 | |
b203ffc3 | 328 | ieee80211_offchannel_stop_beaconing(local); |
f3b85252 | 329 | |
df13cce5 | 330 | local->leave_oper_channel_time = 0; |
977923b0 | 331 | local->next_scan_state = SCAN_DECISION; |
f3b85252 JB |
332 | local->scan_channel_idx = 0; |
333 | ||
a80f7c0b JB |
334 | drv_flush(local, false); |
335 | ||
3ac64bee | 336 | ieee80211_configure_filter(local); |
f3b85252 | 337 | |
42935eca LR |
338 | ieee80211_queue_delayed_work(&local->hw, |
339 | &local->scan_work, | |
340 | IEEE80211_CHANNEL_TIME); | |
f3b85252 JB |
341 | |
342 | return 0; | |
343 | } | |
344 | ||
345 | ||
346 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, | |
347 | struct cfg80211_scan_request *req) | |
348 | { | |
349 | struct ieee80211_local *local = sdata->local; | |
f3b85252 JB |
350 | int rc; |
351 | ||
352 | if (local->scan_req) | |
353 | return -EBUSY; | |
354 | ||
6e7e6213 JL |
355 | if (!list_empty(&local->work_list)) { |
356 | /* wait for the work to finish/time out */ | |
c0ce77b8 JB |
357 | local->scan_req = req; |
358 | local->scan_sdata = sdata; | |
359 | return 0; | |
360 | } | |
361 | ||
f3b85252 JB |
362 | if (local->ops->hw_scan) { |
363 | u8 *ies; | |
f3b85252 | 364 | |
4d36ec58 JB |
365 | local->hw_scan_req = kmalloc( |
366 | sizeof(*local->hw_scan_req) + | |
367 | req->n_channels * sizeof(req->channels[0]) + | |
368 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + | |
369 | req->ie_len, GFP_KERNEL); | |
370 | if (!local->hw_scan_req) | |
f3b85252 JB |
371 | return -ENOMEM; |
372 | ||
4d36ec58 JB |
373 | local->hw_scan_req->ssids = req->ssids; |
374 | local->hw_scan_req->n_ssids = req->n_ssids; | |
375 | ies = (u8 *)local->hw_scan_req + | |
376 | sizeof(*local->hw_scan_req) + | |
377 | req->n_channels * sizeof(req->channels[0]); | |
378 | local->hw_scan_req->ie = ies; | |
379 | ||
380 | local->hw_scan_band = 0; | |
6e7e6213 JL |
381 | |
382 | /* | |
383 | * After allocating local->hw_scan_req, we must | |
384 | * go through until ieee80211_prep_hw_scan(), so | |
385 | * anything that might be changed here and leave | |
386 | * this function early must not go after this | |
387 | * allocation. | |
388 | */ | |
f3b85252 JB |
389 | } |
390 | ||
391 | local->scan_req = req; | |
392 | local->scan_sdata = sdata; | |
393 | ||
f3b85252 | 394 | if (local->ops->hw_scan) |
fbe9c429 | 395 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
f3b85252 | 396 | else |
fbe9c429 | 397 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
6e7e6213 | 398 | |
f3b85252 JB |
399 | /* |
400 | * Kicking off the scan need not be protected, | |
401 | * only the scan variable stuff, since now | |
402 | * local->scan_req is assigned and other callers | |
403 | * will abort their scan attempts. | |
404 | * | |
6e7e6213 JL |
405 | * This avoids too many locking dependencies |
406 | * so that the scan completed calls have more | |
407 | * locking freedom. | |
f3b85252 | 408 | */ |
5cff20e6 JB |
409 | |
410 | ieee80211_recalc_idle(local); | |
f3b85252 JB |
411 | mutex_unlock(&local->scan_mtx); |
412 | ||
4d36ec58 JB |
413 | if (local->ops->hw_scan) { |
414 | WARN_ON(!ieee80211_prep_hw_scan(local)); | |
a060bbfe | 415 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 | 416 | } else |
f3b85252 JB |
417 | rc = ieee80211_start_sw_scan(local); |
418 | ||
419 | mutex_lock(&local->scan_mtx); | |
420 | ||
421 | if (rc) { | |
4d36ec58 JB |
422 | kfree(local->hw_scan_req); |
423 | local->hw_scan_req = NULL; | |
fbe9c429 | 424 | local->scanning = 0; |
f3b85252 | 425 | |
5cff20e6 JB |
426 | ieee80211_recalc_idle(local); |
427 | ||
f3b85252 JB |
428 | local->scan_req = NULL; |
429 | local->scan_sdata = NULL; | |
430 | } | |
431 | ||
432 | return rc; | |
433 | } | |
434 | ||
df13cce5 HS |
435 | static unsigned long |
436 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) | |
437 | { | |
438 | /* | |
439 | * TODO: channel switching also consumes quite some time, | |
440 | * add that delay as well to get a better estimation | |
441 | */ | |
442 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) | |
443 | return IEEE80211_PASSIVE_CHANNEL_TIME; | |
444 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; | |
445 | } | |
446 | ||
2fb3f028 HS |
447 | static int ieee80211_scan_state_decision(struct ieee80211_local *local, |
448 | unsigned long *next_delay) | |
7d3be3cc | 449 | { |
142b9f50 | 450 | bool associated = false; |
df13cce5 HS |
451 | bool tx_empty = true; |
452 | bool bad_latency; | |
453 | bool listen_int_exceeded; | |
454 | unsigned long min_beacon_int = 0; | |
142b9f50 | 455 | struct ieee80211_sub_if_data *sdata; |
df13cce5 | 456 | struct ieee80211_channel *next_chan; |
142b9f50 HS |
457 | |
458 | /* if no more bands/channels left, complete scan and advance to the idle state */ | |
7d3be3cc HS |
459 | if (local->scan_channel_idx >= local->scan_req->n_channels) { |
460 | ieee80211_scan_completed(&local->hw, false); | |
461 | return 1; | |
462 | } | |
2fb3f028 | 463 | |
df13cce5 HS |
464 | /* |
465 | * check if at least one STA interface is associated, | |
466 | * check if at least one STA interface has pending tx frames | |
467 | * and grab the lowest used beacon interval | |
468 | */ | |
142b9f50 HS |
469 | mutex_lock(&local->iflist_mtx); |
470 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 471 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
472 | continue; |
473 | ||
474 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
475 | if (sdata->u.mgd.associated) { | |
476 | associated = true; | |
df13cce5 HS |
477 | |
478 | if (sdata->vif.bss_conf.beacon_int < | |
479 | min_beacon_int || min_beacon_int == 0) | |
480 | min_beacon_int = | |
481 | sdata->vif.bss_conf.beacon_int; | |
482 | ||
483 | if (!qdisc_all_tx_empty(sdata->dev)) { | |
484 | tx_empty = false; | |
485 | break; | |
486 | } | |
142b9f50 HS |
487 | } |
488 | } | |
489 | } | |
490 | mutex_unlock(&local->iflist_mtx); | |
491 | ||
492 | if (local->scan_channel) { | |
493 | /* | |
494 | * we're currently scanning a different channel, let's | |
df13cce5 HS |
495 | * see if we can scan another channel without interfering |
496 | * with the current traffic situation. | |
497 | * | |
498 | * Since we don't know if the AP has pending frames for us | |
499 | * we can only check for our tx queues and use the current | |
500 | * pm_qos requirements for rx. Hence, if no tx traffic occurs | |
501 | * at all we will scan as many channels in a row as the pm_qos | |
502 | * latency allows us to. Additionally we also check for the | |
503 | * currently negotiated listen interval to prevent losing | |
504 | * frames unnecessarily. | |
505 | * | |
506 | * Otherwise switch back to the operating channel. | |
142b9f50 | 507 | */ |
df13cce5 HS |
508 | next_chan = local->scan_req->channels[local->scan_channel_idx]; |
509 | ||
510 | bad_latency = time_after(jiffies + | |
511 | ieee80211_scan_get_channel_time(next_chan), | |
512 | local->leave_oper_channel_time + | |
f8965467 | 513 | usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); |
df13cce5 HS |
514 | |
515 | listen_int_exceeded = time_after(jiffies + | |
516 | ieee80211_scan_get_channel_time(next_chan), | |
517 | local->leave_oper_channel_time + | |
518 | usecs_to_jiffies(min_beacon_int * 1024) * | |
519 | local->hw.conf.listen_interval); | |
520 | ||
521 | if (associated && ( !tx_empty || bad_latency || | |
522 | listen_int_exceeded)) | |
977923b0 | 523 | local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; |
142b9f50 | 524 | else |
977923b0 | 525 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
526 | } else { |
527 | /* | |
528 | * we're on the operating channel currently, let's | |
529 | * leave that channel now to scan another one | |
530 | */ | |
977923b0 | 531 | local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; |
142b9f50 HS |
532 | } |
533 | ||
2fb3f028 | 534 | *next_delay = 0; |
2fb3f028 HS |
535 | return 0; |
536 | } | |
537 | ||
142b9f50 HS |
538 | static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, |
539 | unsigned long *next_delay) | |
540 | { | |
b203ffc3 | 541 | ieee80211_offchannel_stop_station(local); |
142b9f50 HS |
542 | |
543 | __set_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
544 | ||
a80f7c0b JB |
545 | /* |
546 | * What if the nullfunc frames didn't arrive? | |
547 | */ | |
548 | drv_flush(local, false); | |
549 | if (local->ops->flush) | |
550 | *next_delay = 0; | |
551 | else | |
552 | *next_delay = HZ / 10; | |
553 | ||
df13cce5 HS |
554 | /* remember when we left the operating channel */ |
555 | local->leave_oper_channel_time = jiffies; | |
556 | ||
142b9f50 | 557 | /* advance to the next channel to be scanned */ |
977923b0 | 558 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
559 | } |
560 | ||
561 | static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, | |
562 | unsigned long *next_delay) | |
563 | { | |
142b9f50 HS |
564 | /* switch back to the operating channel */ |
565 | local->scan_channel = NULL; | |
566 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); | |
567 | ||
568 | /* | |
b203ffc3 JM |
569 | * Only re-enable station mode interface now; beaconing will be |
570 | * re-enabled once the full scan has been completed. | |
142b9f50 | 571 | */ |
b203ffc3 | 572 | ieee80211_offchannel_return(local, false); |
142b9f50 HS |
573 | |
574 | __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
575 | ||
576 | *next_delay = HZ / 5; | |
977923b0 | 577 | local->next_scan_state = SCAN_DECISION; |
142b9f50 HS |
578 | } |
579 | ||
2fb3f028 HS |
580 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
581 | unsigned long *next_delay) | |
582 | { | |
583 | int skip; | |
584 | struct ieee80211_channel *chan; | |
2fb3f028 | 585 | |
7d3be3cc HS |
586 | skip = 0; |
587 | chan = local->scan_req->channels[local->scan_channel_idx]; | |
588 | ||
584991dc JB |
589 | local->scan_channel = chan; |
590 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) | |
7d3be3cc HS |
591 | skip = 1; |
592 | ||
7d3be3cc HS |
593 | /* advance state machine to next channel/band */ |
594 | local->scan_channel_idx++; | |
595 | ||
0ee9c13c HS |
596 | if (skip) { |
597 | /* if we skip this channel return to the decision state */ | |
598 | local->next_scan_state = SCAN_DECISION; | |
2fb3f028 | 599 | return; |
0ee9c13c | 600 | } |
7d3be3cc HS |
601 | |
602 | /* | |
603 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 | |
604 | * (which unfortunately doesn't say _why_ step a) is done, | |
605 | * but it waits for the probe delay or until a frame is | |
606 | * received - and the received frame would update the NAV). | |
607 | * For now, we do not support waiting until a frame is | |
608 | * received. | |
609 | * | |
610 | * In any case, it is not necessary for a passive scan. | |
611 | */ | |
612 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || | |
613 | !local->scan_req->n_ssids) { | |
614 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; | |
977923b0 | 615 | local->next_scan_state = SCAN_DECISION; |
2fb3f028 | 616 | return; |
7d3be3cc HS |
617 | } |
618 | ||
2fb3f028 | 619 | /* active scan, send probes */ |
7d3be3cc | 620 | *next_delay = IEEE80211_PROBE_DELAY; |
977923b0 | 621 | local->next_scan_state = SCAN_SEND_PROBE; |
7d3be3cc HS |
622 | } |
623 | ||
624 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, | |
625 | unsigned long *next_delay) | |
626 | { | |
627 | int i; | |
628 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
629 | ||
630 | for (i = 0; i < local->scan_req->n_ssids; i++) | |
631 | ieee80211_send_probe_req( | |
632 | sdata, NULL, | |
633 | local->scan_req->ssids[i].ssid, | |
634 | local->scan_req->ssids[i].ssid_len, | |
635 | local->scan_req->ie, local->scan_req->ie_len); | |
636 | ||
637 | /* | |
638 | * After sending probe requests, wait for probe responses | |
639 | * on the channel. | |
640 | */ | |
641 | *next_delay = IEEE80211_CHANNEL_TIME; | |
977923b0 | 642 | local->next_scan_state = SCAN_DECISION; |
7d3be3cc HS |
643 | } |
644 | ||
c2b13452 | 645 | void ieee80211_scan_work(struct work_struct *work) |
0a51b27e JB |
646 | { |
647 | struct ieee80211_local *local = | |
648 | container_of(work, struct ieee80211_local, scan_work.work); | |
649 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
0a51b27e JB |
650 | unsigned long next_delay = 0; |
651 | ||
f3b85252 JB |
652 | mutex_lock(&local->scan_mtx); |
653 | if (!sdata || !local->scan_req) { | |
654 | mutex_unlock(&local->scan_mtx); | |
655 | return; | |
656 | } | |
657 | ||
4d36ec58 | 658 | if (local->hw_scan_req) { |
a060bbfe | 659 | int rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 JB |
660 | mutex_unlock(&local->scan_mtx); |
661 | if (rc) | |
662 | ieee80211_scan_completed(&local->hw, true); | |
663 | return; | |
664 | } | |
665 | ||
fbe9c429 | 666 | if (local->scan_req && !local->scanning) { |
f3b85252 JB |
667 | struct cfg80211_scan_request *req = local->scan_req; |
668 | int rc; | |
669 | ||
670 | local->scan_req = NULL; | |
15db0b7f | 671 | local->scan_sdata = NULL; |
f3b85252 JB |
672 | |
673 | rc = __ieee80211_start_scan(sdata, req); | |
674 | mutex_unlock(&local->scan_mtx); | |
675 | ||
676 | if (rc) | |
677 | ieee80211_scan_completed(&local->hw, true); | |
678 | return; | |
679 | } | |
680 | ||
681 | mutex_unlock(&local->scan_mtx); | |
682 | ||
5bc75728 JB |
683 | /* |
684 | * Avoid re-scheduling when the sdata is going away. | |
685 | */ | |
9607e6b6 | 686 | if (!ieee80211_sdata_running(sdata)) { |
f3b85252 | 687 | ieee80211_scan_completed(&local->hw, true); |
0a51b27e | 688 | return; |
f3b85252 | 689 | } |
0a51b27e | 690 | |
f502d09b HS |
691 | /* |
692 | * as long as no delay is required advance immediately | |
693 | * without scheduling a new work | |
694 | */ | |
695 | do { | |
977923b0 | 696 | switch (local->next_scan_state) { |
2fb3f028 HS |
697 | case SCAN_DECISION: |
698 | if (ieee80211_scan_state_decision(local, &next_delay)) | |
f502d09b HS |
699 | return; |
700 | break; | |
2fb3f028 HS |
701 | case SCAN_SET_CHANNEL: |
702 | ieee80211_scan_state_set_channel(local, &next_delay); | |
703 | break; | |
f502d09b HS |
704 | case SCAN_SEND_PROBE: |
705 | ieee80211_scan_state_send_probe(local, &next_delay); | |
706 | break; | |
142b9f50 HS |
707 | case SCAN_LEAVE_OPER_CHANNEL: |
708 | ieee80211_scan_state_leave_oper_channel(local, &next_delay); | |
709 | break; | |
710 | case SCAN_ENTER_OPER_CHANNEL: | |
711 | ieee80211_scan_state_enter_oper_channel(local, &next_delay); | |
712 | break; | |
f502d09b HS |
713 | } |
714 | } while (next_delay == 0); | |
0a51b27e | 715 | |
42935eca | 716 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
0a51b27e JB |
717 | } |
718 | ||
f3b85252 JB |
719 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
720 | struct cfg80211_scan_request *req) | |
0a51b27e | 721 | { |
f3b85252 | 722 | int res; |
de95a54b | 723 | |
f3b85252 JB |
724 | mutex_lock(&sdata->local->scan_mtx); |
725 | res = __ieee80211_start_scan(sdata, req); | |
726 | mutex_unlock(&sdata->local->scan_mtx); | |
0a51b27e | 727 | |
f3b85252 | 728 | return res; |
0a51b27e JB |
729 | } |
730 | ||
f3b85252 | 731 | int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, |
be4a4b6a JB |
732 | const u8 *ssid, u8 ssid_len, |
733 | struct ieee80211_channel *chan) | |
0a51b27e | 734 | { |
0a51b27e | 735 | struct ieee80211_local *local = sdata->local; |
f3b85252 | 736 | int ret = -EBUSY; |
be4a4b6a | 737 | enum nl80211_band band; |
2a519311 | 738 | |
f3b85252 | 739 | mutex_lock(&local->scan_mtx); |
0a51b27e | 740 | |
f3b85252 JB |
741 | /* busy scanning */ |
742 | if (local->scan_req) | |
743 | goto unlock; | |
9116dd01 | 744 | |
be4a4b6a JB |
745 | /* fill internal scan request */ |
746 | if (!chan) { | |
747 | int i, nchan = 0; | |
748 | ||
749 | for (band = 0; band < IEEE80211_NUM_BANDS; band++) { | |
750 | if (!local->hw.wiphy->bands[band]) | |
751 | continue; | |
752 | for (i = 0; | |
753 | i < local->hw.wiphy->bands[band]->n_channels; | |
754 | i++) { | |
755 | local->int_scan_req->channels[nchan] = | |
756 | &local->hw.wiphy->bands[band]->channels[i]; | |
757 | nchan++; | |
758 | } | |
759 | } | |
760 | ||
761 | local->int_scan_req->n_channels = nchan; | |
762 | } else { | |
763 | local->int_scan_req->channels[0] = chan; | |
764 | local->int_scan_req->n_channels = 1; | |
765 | } | |
766 | ||
767 | local->int_scan_req->ssids = &local->scan_ssid; | |
768 | local->int_scan_req->n_ssids = 1; | |
5ba63533 JB |
769 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
770 | local->int_scan_req->ssids[0].ssid_len = ssid_len; | |
9116dd01 | 771 | |
5ba63533 | 772 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
f3b85252 JB |
773 | unlock: |
774 | mutex_unlock(&local->scan_mtx); | |
775 | return ret; | |
0a51b27e | 776 | } |
5bb644a0 JB |
777 | |
778 | void ieee80211_scan_cancel(struct ieee80211_local *local) | |
779 | { | |
15db0b7f | 780 | bool abortscan; |
5bb644a0 JB |
781 | |
782 | cancel_delayed_work_sync(&local->scan_work); | |
783 | ||
784 | /* | |
785 | * Only call this function when a scan can't be | |
786 | * queued -- mostly at suspend under RTNL. | |
787 | */ | |
788 | mutex_lock(&local->scan_mtx); | |
15db0b7f JB |
789 | abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || |
790 | (!local->scanning && local->scan_req); | |
5bb644a0 JB |
791 | mutex_unlock(&local->scan_mtx); |
792 | ||
15db0b7f | 793 | if (abortscan) |
5bb644a0 JB |
794 | ieee80211_scan_completed(&local->hw, true); |
795 | } |