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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 | ||
e5b900d2 JB |
117 | /* If the beacon had no TIM IE, or it was invalid, use 1 */ |
118 | if (beacon && !bss->dtim_period) | |
119 | bss->dtim_period = 1; | |
120 | ||
f0b058b6 SG |
121 | /* replace old supported rates if we get new values */ |
122 | srlen = 0; | |
5484e237 | 123 | if (elems->supp_rates) { |
f0b058b6 | 124 | clen = IEEE80211_MAX_SUPP_RATES; |
5484e237 JB |
125 | if (clen > elems->supp_rates_len) |
126 | clen = elems->supp_rates_len; | |
f0b058b6 SG |
127 | memcpy(bss->supp_rates, elems->supp_rates, clen); |
128 | srlen += clen; | |
5484e237 JB |
129 | } |
130 | if (elems->ext_supp_rates) { | |
f0b058b6 | 131 | clen = IEEE80211_MAX_SUPP_RATES - srlen; |
5484e237 JB |
132 | if (clen > elems->ext_supp_rates_len) |
133 | clen = elems->ext_supp_rates_len; | |
f0b058b6 SG |
134 | memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen); |
135 | srlen += clen; | |
5484e237 | 136 | } |
f0b058b6 SG |
137 | if (srlen) |
138 | bss->supp_rates_len = srlen; | |
5484e237 | 139 | |
5484e237 | 140 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
ab13315a | 141 | bss->uapsd_supported = is_uapsd_supported(elems); |
5484e237 JB |
142 | |
143 | if (!beacon) | |
144 | bss->last_probe_resp = jiffies; | |
145 | ||
5484e237 JB |
146 | return bss; |
147 | } | |
0a51b27e | 148 | |
98c8fccf | 149 | ieee80211_rx_result |
f1d58c25 | 150 | ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) |
98c8fccf | 151 | { |
f1d58c25 | 152 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
98c8fccf | 153 | struct ieee80211_mgmt *mgmt; |
c2b13452 | 154 | struct ieee80211_bss *bss; |
98c8fccf JB |
155 | u8 *elements; |
156 | struct ieee80211_channel *channel; | |
157 | size_t baselen; | |
158 | int freq; | |
159 | __le16 fc; | |
160 | bool presp, beacon = false; | |
161 | struct ieee802_11_elems elems; | |
162 | ||
163 | if (skb->len < 2) | |
164 | return RX_DROP_UNUSABLE; | |
165 | ||
166 | mgmt = (struct ieee80211_mgmt *) skb->data; | |
167 | fc = mgmt->frame_control; | |
168 | ||
169 | if (ieee80211_is_ctl(fc)) | |
170 | return RX_CONTINUE; | |
171 | ||
172 | if (skb->len < 24) | |
173 | return RX_DROP_MONITOR; | |
174 | ||
175 | presp = ieee80211_is_probe_resp(fc); | |
176 | if (presp) { | |
177 | /* ignore ProbeResp to foreign address */ | |
47846c9b | 178 | if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) |
98c8fccf JB |
179 | return RX_DROP_MONITOR; |
180 | ||
181 | presp = true; | |
182 | elements = mgmt->u.probe_resp.variable; | |
183 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); | |
184 | } else { | |
185 | beacon = ieee80211_is_beacon(fc); | |
186 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); | |
187 | elements = mgmt->u.beacon.variable; | |
188 | } | |
189 | ||
190 | if (!presp && !beacon) | |
191 | return RX_CONTINUE; | |
192 | ||
193 | if (baselen > skb->len) | |
194 | return RX_DROP_MONITOR; | |
195 | ||
196 | ieee802_11_parse_elems(elements, skb->len - baselen, &elems); | |
197 | ||
198 | if (elems.ds_params && elems.ds_params_len == 1) | |
199 | freq = ieee80211_channel_to_frequency(elems.ds_params[0]); | |
200 | else | |
201 | freq = rx_status->freq; | |
202 | ||
203 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); | |
204 | ||
205 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) | |
206 | return RX_DROP_MONITOR; | |
207 | ||
208 | bss = ieee80211_bss_info_update(sdata->local, rx_status, | |
209 | mgmt, skb->len, &elems, | |
2a519311 | 210 | channel, beacon); |
d048e503 JM |
211 | if (bss) |
212 | ieee80211_rx_bss_put(sdata->local, bss); | |
98c8fccf JB |
213 | |
214 | dev_kfree_skb(skb); | |
215 | return RX_QUEUED; | |
216 | } | |
217 | ||
4d36ec58 JB |
218 | /* return false if no more work */ |
219 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) | |
220 | { | |
221 | struct cfg80211_scan_request *req = local->scan_req; | |
222 | enum ieee80211_band band; | |
223 | int i, ielen, n_chans; | |
224 | ||
225 | do { | |
226 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) | |
227 | return false; | |
228 | ||
229 | band = local->hw_scan_band; | |
230 | n_chans = 0; | |
231 | for (i = 0; i < req->n_channels; i++) { | |
232 | if (req->channels[i]->band == band) { | |
233 | local->hw_scan_req->channels[n_chans] = | |
234 | req->channels[i]; | |
235 | n_chans++; | |
236 | } | |
237 | } | |
238 | ||
239 | local->hw_scan_band++; | |
240 | } while (!n_chans); | |
241 | ||
242 | local->hw_scan_req->n_channels = n_chans; | |
243 | ||
244 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, | |
651b5225 JM |
245 | req->ie, req->ie_len, band, (u32) -1, |
246 | 0); | |
4d36ec58 JB |
247 | local->hw_scan_req->ie_len = ielen; |
248 | ||
249 | return true; | |
250 | } | |
251 | ||
e229f844 SG |
252 | static bool __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, |
253 | bool was_hw_scan) | |
0a51b27e JB |
254 | { |
255 | struct ieee80211_local *local = hw_to_local(hw); | |
0a51b27e | 256 | |
e229f844 | 257 | lockdep_assert_held(&local->mtx); |
5bc75728 | 258 | |
6d3560d4 JB |
259 | /* |
260 | * It's ok to abort a not-yet-running scan (that | |
261 | * we have one at all will be verified by checking | |
262 | * local->scan_req next), but not to complete it | |
263 | * successfully. | |
264 | */ | |
265 | if (WARN_ON(!local->scanning && !aborted)) | |
266 | aborted = true; | |
5bc75728 | 267 | |
e229f844 SG |
268 | if (WARN_ON(!local->scan_req)) |
269 | return false; | |
de95a54b | 270 | |
4d36ec58 | 271 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { |
6eb11a9a SG |
272 | int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); |
273 | if (rc == 0) | |
274 | return false; | |
4d36ec58 JB |
275 | } |
276 | ||
277 | kfree(local->hw_scan_req); | |
278 | local->hw_scan_req = NULL; | |
f3b85252 | 279 | |
5ba63533 | 280 | if (local->scan_req != local->int_scan_req) |
2a519311 JB |
281 | cfg80211_scan_done(local->scan_req, aborted); |
282 | local->scan_req = NULL; | |
15db0b7f | 283 | local->scan_sdata = NULL; |
2a519311 | 284 | |
fbe9c429 | 285 | local->scanning = 0; |
58905ca5 | 286 | local->scan_channel = NULL; |
f3b85252 | 287 | |
e229f844 SG |
288 | return true; |
289 | } | |
0a51b27e | 290 | |
e229f844 SG |
291 | static void __ieee80211_scan_completed_finish(struct ieee80211_hw *hw, |
292 | bool was_hw_scan) | |
293 | { | |
294 | struct ieee80211_local *local = hw_to_local(hw); | |
a0daa0e7 | 295 | |
e229f844 SG |
296 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
297 | if (!was_hw_scan) { | |
298 | ieee80211_configure_filter(local); | |
299 | drv_sw_scan_complete(local); | |
300 | ieee80211_offchannel_return(local, true); | |
301 | } | |
0a51b27e | 302 | |
7da7cc1d | 303 | mutex_lock(&local->mtx); |
5cff20e6 | 304 | ieee80211_recalc_idle(local); |
7da7cc1d | 305 | mutex_unlock(&local->mtx); |
e229f844 | 306 | |
0a51b27e | 307 | ieee80211_mlme_notify_scan_completed(local); |
46900298 | 308 | ieee80211_ibss_notify_scan_completed(local); |
472dbc45 | 309 | ieee80211_mesh_notify_scan_completed(local); |
81ac3462 | 310 | ieee80211_queue_work(&local->hw, &local->work_work); |
0a51b27e | 311 | } |
8789d459 JB |
312 | |
313 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) | |
314 | { | |
315 | struct ieee80211_local *local = hw_to_local(hw); | |
316 | ||
317 | trace_api_scan_completed(local, aborted); | |
318 | ||
319 | set_bit(SCAN_COMPLETED, &local->scanning); | |
320 | if (aborted) | |
321 | set_bit(SCAN_ABORTED, &local->scanning); | |
322 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); | |
323 | } | |
0a51b27e JB |
324 | EXPORT_SYMBOL(ieee80211_scan_completed); |
325 | ||
f3b85252 JB |
326 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
327 | { | |
f3b85252 JB |
328 | /* |
329 | * Hardware/driver doesn't support hw_scan, so use software | |
330 | * scanning instead. First send a nullfunc frame with power save | |
331 | * bit on so that AP will buffer the frames for us while we are not | |
332 | * listening, then send probe requests to each channel and wait for | |
333 | * the responses. After all channels are scanned, tune back to the | |
334 | * original channel and send a nullfunc frame with power save bit | |
335 | * off to trigger the AP to send us all the buffered frames. | |
336 | * | |
337 | * Note that while local->sw_scanning is true everything else but | |
338 | * nullfunc frames and probe requests will be dropped in | |
339 | * ieee80211_tx_h_check_assoc(). | |
340 | */ | |
24487981 | 341 | drv_sw_scan_start(local); |
f3b85252 | 342 | |
b203ffc3 | 343 | ieee80211_offchannel_stop_beaconing(local); |
f3b85252 | 344 | |
df13cce5 | 345 | local->leave_oper_channel_time = 0; |
977923b0 | 346 | local->next_scan_state = SCAN_DECISION; |
f3b85252 JB |
347 | local->scan_channel_idx = 0; |
348 | ||
a80f7c0b JB |
349 | drv_flush(local, false); |
350 | ||
3ac64bee | 351 | ieee80211_configure_filter(local); |
f3b85252 | 352 | |
42935eca LR |
353 | ieee80211_queue_delayed_work(&local->hw, |
354 | &local->scan_work, | |
355 | IEEE80211_CHANNEL_TIME); | |
f3b85252 JB |
356 | |
357 | return 0; | |
358 | } | |
359 | ||
360 | ||
361 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, | |
362 | struct cfg80211_scan_request *req) | |
363 | { | |
364 | struct ieee80211_local *local = sdata->local; | |
f3b85252 JB |
365 | int rc; |
366 | ||
e229f844 SG |
367 | lockdep_assert_held(&local->mtx); |
368 | ||
f3b85252 JB |
369 | if (local->scan_req) |
370 | return -EBUSY; | |
371 | ||
6e7e6213 JL |
372 | if (!list_empty(&local->work_list)) { |
373 | /* wait for the work to finish/time out */ | |
c0ce77b8 JB |
374 | local->scan_req = req; |
375 | local->scan_sdata = sdata; | |
376 | return 0; | |
377 | } | |
378 | ||
f3b85252 JB |
379 | if (local->ops->hw_scan) { |
380 | u8 *ies; | |
f3b85252 | 381 | |
4d36ec58 JB |
382 | local->hw_scan_req = kmalloc( |
383 | sizeof(*local->hw_scan_req) + | |
384 | req->n_channels * sizeof(req->channels[0]) + | |
385 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + | |
386 | req->ie_len, GFP_KERNEL); | |
387 | if (!local->hw_scan_req) | |
f3b85252 JB |
388 | return -ENOMEM; |
389 | ||
4d36ec58 JB |
390 | local->hw_scan_req->ssids = req->ssids; |
391 | local->hw_scan_req->n_ssids = req->n_ssids; | |
392 | ies = (u8 *)local->hw_scan_req + | |
393 | sizeof(*local->hw_scan_req) + | |
394 | req->n_channels * sizeof(req->channels[0]); | |
395 | local->hw_scan_req->ie = ies; | |
396 | ||
397 | local->hw_scan_band = 0; | |
6e7e6213 JL |
398 | |
399 | /* | |
400 | * After allocating local->hw_scan_req, we must | |
401 | * go through until ieee80211_prep_hw_scan(), so | |
402 | * anything that might be changed here and leave | |
403 | * this function early must not go after this | |
404 | * allocation. | |
405 | */ | |
f3b85252 JB |
406 | } |
407 | ||
408 | local->scan_req = req; | |
409 | local->scan_sdata = sdata; | |
410 | ||
f3b85252 | 411 | if (local->ops->hw_scan) |
fbe9c429 | 412 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
f3b85252 | 413 | else |
fbe9c429 | 414 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
6e7e6213 | 415 | |
5cff20e6 | 416 | ieee80211_recalc_idle(local); |
f3b85252 | 417 | |
4d36ec58 JB |
418 | if (local->ops->hw_scan) { |
419 | WARN_ON(!ieee80211_prep_hw_scan(local)); | |
a060bbfe | 420 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 | 421 | } else |
f3b85252 JB |
422 | rc = ieee80211_start_sw_scan(local); |
423 | ||
f3b85252 | 424 | if (rc) { |
4d36ec58 JB |
425 | kfree(local->hw_scan_req); |
426 | local->hw_scan_req = NULL; | |
fbe9c429 | 427 | local->scanning = 0; |
f3b85252 | 428 | |
5cff20e6 JB |
429 | ieee80211_recalc_idle(local); |
430 | ||
f3b85252 JB |
431 | local->scan_req = NULL; |
432 | local->scan_sdata = NULL; | |
433 | } | |
434 | ||
435 | return rc; | |
436 | } | |
437 | ||
df13cce5 HS |
438 | static unsigned long |
439 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) | |
440 | { | |
441 | /* | |
442 | * TODO: channel switching also consumes quite some time, | |
443 | * add that delay as well to get a better estimation | |
444 | */ | |
445 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) | |
446 | return IEEE80211_PASSIVE_CHANNEL_TIME; | |
447 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; | |
448 | } | |
449 | ||
e229f844 SG |
450 | static void ieee80211_scan_state_decision(struct ieee80211_local *local, |
451 | unsigned long *next_delay) | |
7d3be3cc | 452 | { |
142b9f50 | 453 | bool associated = false; |
df13cce5 HS |
454 | bool tx_empty = true; |
455 | bool bad_latency; | |
456 | bool listen_int_exceeded; | |
457 | unsigned long min_beacon_int = 0; | |
142b9f50 | 458 | struct ieee80211_sub_if_data *sdata; |
df13cce5 | 459 | struct ieee80211_channel *next_chan; |
142b9f50 | 460 | |
df13cce5 HS |
461 | /* |
462 | * check if at least one STA interface is associated, | |
463 | * check if at least one STA interface has pending tx frames | |
464 | * and grab the lowest used beacon interval | |
465 | */ | |
142b9f50 HS |
466 | mutex_lock(&local->iflist_mtx); |
467 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 468 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
469 | continue; |
470 | ||
471 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
472 | if (sdata->u.mgd.associated) { | |
473 | associated = true; | |
df13cce5 HS |
474 | |
475 | if (sdata->vif.bss_conf.beacon_int < | |
476 | min_beacon_int || min_beacon_int == 0) | |
477 | min_beacon_int = | |
478 | sdata->vif.bss_conf.beacon_int; | |
479 | ||
480 | if (!qdisc_all_tx_empty(sdata->dev)) { | |
481 | tx_empty = false; | |
482 | break; | |
483 | } | |
142b9f50 HS |
484 | } |
485 | } | |
486 | } | |
487 | mutex_unlock(&local->iflist_mtx); | |
488 | ||
489 | if (local->scan_channel) { | |
490 | /* | |
491 | * we're currently scanning a different channel, let's | |
df13cce5 HS |
492 | * see if we can scan another channel without interfering |
493 | * with the current traffic situation. | |
494 | * | |
495 | * Since we don't know if the AP has pending frames for us | |
496 | * we can only check for our tx queues and use the current | |
497 | * pm_qos requirements for rx. Hence, if no tx traffic occurs | |
498 | * at all we will scan as many channels in a row as the pm_qos | |
499 | * latency allows us to. Additionally we also check for the | |
500 | * currently negotiated listen interval to prevent losing | |
501 | * frames unnecessarily. | |
502 | * | |
503 | * Otherwise switch back to the operating channel. | |
142b9f50 | 504 | */ |
df13cce5 HS |
505 | next_chan = local->scan_req->channels[local->scan_channel_idx]; |
506 | ||
507 | bad_latency = time_after(jiffies + | |
508 | ieee80211_scan_get_channel_time(next_chan), | |
509 | local->leave_oper_channel_time + | |
f8965467 | 510 | usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); |
df13cce5 HS |
511 | |
512 | listen_int_exceeded = time_after(jiffies + | |
513 | ieee80211_scan_get_channel_time(next_chan), | |
514 | local->leave_oper_channel_time + | |
515 | usecs_to_jiffies(min_beacon_int * 1024) * | |
516 | local->hw.conf.listen_interval); | |
517 | ||
518 | if (associated && ( !tx_empty || bad_latency || | |
519 | listen_int_exceeded)) | |
977923b0 | 520 | local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; |
142b9f50 | 521 | else |
977923b0 | 522 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
523 | } else { |
524 | /* | |
525 | * we're on the operating channel currently, let's | |
526 | * leave that channel now to scan another one | |
527 | */ | |
977923b0 | 528 | local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; |
142b9f50 HS |
529 | } |
530 | ||
2fb3f028 | 531 | *next_delay = 0; |
2fb3f028 HS |
532 | } |
533 | ||
142b9f50 HS |
534 | static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, |
535 | unsigned long *next_delay) | |
536 | { | |
b203ffc3 | 537 | ieee80211_offchannel_stop_station(local); |
142b9f50 HS |
538 | |
539 | __set_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
540 | ||
a80f7c0b JB |
541 | /* |
542 | * What if the nullfunc frames didn't arrive? | |
543 | */ | |
544 | drv_flush(local, false); | |
545 | if (local->ops->flush) | |
546 | *next_delay = 0; | |
547 | else | |
548 | *next_delay = HZ / 10; | |
549 | ||
df13cce5 HS |
550 | /* remember when we left the operating channel */ |
551 | local->leave_oper_channel_time = jiffies; | |
552 | ||
142b9f50 | 553 | /* advance to the next channel to be scanned */ |
977923b0 | 554 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
555 | } |
556 | ||
557 | static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, | |
558 | unsigned long *next_delay) | |
559 | { | |
142b9f50 HS |
560 | /* switch back to the operating channel */ |
561 | local->scan_channel = NULL; | |
562 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); | |
563 | ||
564 | /* | |
b203ffc3 JM |
565 | * Only re-enable station mode interface now; beaconing will be |
566 | * re-enabled once the full scan has been completed. | |
142b9f50 | 567 | */ |
b203ffc3 | 568 | ieee80211_offchannel_return(local, false); |
142b9f50 HS |
569 | |
570 | __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
571 | ||
572 | *next_delay = HZ / 5; | |
977923b0 | 573 | local->next_scan_state = SCAN_DECISION; |
142b9f50 HS |
574 | } |
575 | ||
2fb3f028 HS |
576 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
577 | unsigned long *next_delay) | |
578 | { | |
579 | int skip; | |
580 | struct ieee80211_channel *chan; | |
2fb3f028 | 581 | |
7d3be3cc HS |
582 | skip = 0; |
583 | chan = local->scan_req->channels[local->scan_channel_idx]; | |
584 | ||
584991dc JB |
585 | local->scan_channel = chan; |
586 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) | |
7d3be3cc HS |
587 | skip = 1; |
588 | ||
7d3be3cc HS |
589 | /* advance state machine to next channel/band */ |
590 | local->scan_channel_idx++; | |
591 | ||
0ee9c13c HS |
592 | if (skip) { |
593 | /* if we skip this channel return to the decision state */ | |
594 | local->next_scan_state = SCAN_DECISION; | |
2fb3f028 | 595 | return; |
0ee9c13c | 596 | } |
7d3be3cc HS |
597 | |
598 | /* | |
599 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 | |
600 | * (which unfortunately doesn't say _why_ step a) is done, | |
601 | * but it waits for the probe delay or until a frame is | |
602 | * received - and the received frame would update the NAV). | |
603 | * For now, we do not support waiting until a frame is | |
604 | * received. | |
605 | * | |
606 | * In any case, it is not necessary for a passive scan. | |
607 | */ | |
608 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || | |
609 | !local->scan_req->n_ssids) { | |
610 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; | |
977923b0 | 611 | local->next_scan_state = SCAN_DECISION; |
2fb3f028 | 612 | return; |
7d3be3cc HS |
613 | } |
614 | ||
2fb3f028 | 615 | /* active scan, send probes */ |
7d3be3cc | 616 | *next_delay = IEEE80211_PROBE_DELAY; |
977923b0 | 617 | local->next_scan_state = SCAN_SEND_PROBE; |
7d3be3cc HS |
618 | } |
619 | ||
620 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, | |
621 | unsigned long *next_delay) | |
622 | { | |
623 | int i; | |
624 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
625 | ||
626 | for (i = 0; i < local->scan_req->n_ssids; i++) | |
627 | ieee80211_send_probe_req( | |
628 | sdata, NULL, | |
629 | local->scan_req->ssids[i].ssid, | |
630 | local->scan_req->ssids[i].ssid_len, | |
631 | local->scan_req->ie, local->scan_req->ie_len); | |
632 | ||
633 | /* | |
634 | * After sending probe requests, wait for probe responses | |
635 | * on the channel. | |
636 | */ | |
637 | *next_delay = IEEE80211_CHANNEL_TIME; | |
977923b0 | 638 | local->next_scan_state = SCAN_DECISION; |
7d3be3cc HS |
639 | } |
640 | ||
c2b13452 | 641 | void ieee80211_scan_work(struct work_struct *work) |
0a51b27e JB |
642 | { |
643 | struct ieee80211_local *local = | |
644 | container_of(work, struct ieee80211_local, scan_work.work); | |
645 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
0a51b27e | 646 | unsigned long next_delay = 0; |
e229f844 | 647 | bool aborted, hw_scan, finish; |
0a51b27e | 648 | |
259b62e3 | 649 | mutex_lock(&local->mtx); |
8789d459 | 650 | |
259b62e3 | 651 | if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { |
8789d459 | 652 | aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); |
259b62e3 | 653 | goto out_complete; |
8789d459 JB |
654 | } |
655 | ||
259b62e3 SG |
656 | if (!sdata || !local->scan_req) |
657 | goto out; | |
f3b85252 | 658 | |
fbe9c429 | 659 | if (local->scan_req && !local->scanning) { |
f3b85252 JB |
660 | struct cfg80211_scan_request *req = local->scan_req; |
661 | int rc; | |
662 | ||
663 | local->scan_req = NULL; | |
15db0b7f | 664 | local->scan_sdata = NULL; |
f3b85252 JB |
665 | |
666 | rc = __ieee80211_start_scan(sdata, req); | |
259b62e3 SG |
667 | if (rc) { |
668 | aborted = true; | |
669 | goto out_complete; | |
670 | } else | |
671 | goto out; | |
f3b85252 JB |
672 | } |
673 | ||
5bc75728 JB |
674 | /* |
675 | * Avoid re-scheduling when the sdata is going away. | |
676 | */ | |
9607e6b6 | 677 | if (!ieee80211_sdata_running(sdata)) { |
259b62e3 SG |
678 | aborted = true; |
679 | goto out_complete; | |
f3b85252 | 680 | } |
0a51b27e | 681 | |
259b62e3 SG |
682 | mutex_unlock(&local->mtx); |
683 | ||
f502d09b HS |
684 | /* |
685 | * as long as no delay is required advance immediately | |
686 | * without scheduling a new work | |
687 | */ | |
688 | do { | |
977923b0 | 689 | switch (local->next_scan_state) { |
2fb3f028 | 690 | case SCAN_DECISION: |
e229f844 SG |
691 | /* if no more bands/channels left, complete scan */ |
692 | if (local->scan_channel_idx >= local->scan_req->n_channels) { | |
693 | aborted = false; | |
694 | goto out_complete; | |
695 | } | |
696 | ieee80211_scan_state_decision(local, &next_delay); | |
f502d09b | 697 | break; |
2fb3f028 HS |
698 | case SCAN_SET_CHANNEL: |
699 | ieee80211_scan_state_set_channel(local, &next_delay); | |
700 | break; | |
f502d09b HS |
701 | case SCAN_SEND_PROBE: |
702 | ieee80211_scan_state_send_probe(local, &next_delay); | |
703 | break; | |
142b9f50 HS |
704 | case SCAN_LEAVE_OPER_CHANNEL: |
705 | ieee80211_scan_state_leave_oper_channel(local, &next_delay); | |
706 | break; | |
707 | case SCAN_ENTER_OPER_CHANNEL: | |
708 | ieee80211_scan_state_enter_oper_channel(local, &next_delay); | |
709 | break; | |
f502d09b HS |
710 | } |
711 | } while (next_delay == 0); | |
0a51b27e | 712 | |
42935eca | 713 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
259b62e3 SG |
714 | return; |
715 | ||
716 | out_complete: | |
e229f844 SG |
717 | hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
718 | finish = __ieee80211_scan_completed(&local->hw, aborted, hw_scan); | |
259b62e3 | 719 | mutex_unlock(&local->mtx); |
e229f844 SG |
720 | if (finish) |
721 | __ieee80211_scan_completed_finish(&local->hw, hw_scan); | |
259b62e3 SG |
722 | return; |
723 | ||
724 | out: | |
725 | mutex_unlock(&local->mtx); | |
0a51b27e JB |
726 | } |
727 | ||
f3b85252 JB |
728 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
729 | struct cfg80211_scan_request *req) | |
0a51b27e | 730 | { |
f3b85252 | 731 | int res; |
de95a54b | 732 | |
a1699b75 | 733 | mutex_lock(&sdata->local->mtx); |
f3b85252 | 734 | res = __ieee80211_start_scan(sdata, req); |
a1699b75 | 735 | mutex_unlock(&sdata->local->mtx); |
0a51b27e | 736 | |
f3b85252 | 737 | return res; |
0a51b27e JB |
738 | } |
739 | ||
f3b85252 | 740 | int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, |
be4a4b6a JB |
741 | const u8 *ssid, u8 ssid_len, |
742 | struct ieee80211_channel *chan) | |
0a51b27e | 743 | { |
0a51b27e | 744 | struct ieee80211_local *local = sdata->local; |
f3b85252 | 745 | int ret = -EBUSY; |
fb63bc41 | 746 | enum ieee80211_band band; |
2a519311 | 747 | |
a1699b75 | 748 | mutex_lock(&local->mtx); |
0a51b27e | 749 | |
f3b85252 JB |
750 | /* busy scanning */ |
751 | if (local->scan_req) | |
752 | goto unlock; | |
9116dd01 | 753 | |
be4a4b6a JB |
754 | /* fill internal scan request */ |
755 | if (!chan) { | |
756 | int i, nchan = 0; | |
757 | ||
758 | for (band = 0; band < IEEE80211_NUM_BANDS; band++) { | |
759 | if (!local->hw.wiphy->bands[band]) | |
760 | continue; | |
761 | for (i = 0; | |
762 | i < local->hw.wiphy->bands[band]->n_channels; | |
763 | i++) { | |
764 | local->int_scan_req->channels[nchan] = | |
765 | &local->hw.wiphy->bands[band]->channels[i]; | |
766 | nchan++; | |
767 | } | |
768 | } | |
769 | ||
770 | local->int_scan_req->n_channels = nchan; | |
771 | } else { | |
772 | local->int_scan_req->channels[0] = chan; | |
773 | local->int_scan_req->n_channels = 1; | |
774 | } | |
775 | ||
776 | local->int_scan_req->ssids = &local->scan_ssid; | |
777 | local->int_scan_req->n_ssids = 1; | |
5ba63533 JB |
778 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
779 | local->int_scan_req->ssids[0].ssid_len = ssid_len; | |
9116dd01 | 780 | |
5ba63533 | 781 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
f3b85252 | 782 | unlock: |
a1699b75 | 783 | mutex_unlock(&local->mtx); |
f3b85252 | 784 | return ret; |
0a51b27e | 785 | } |
5bb644a0 | 786 | |
4136c422 SG |
787 | /* |
788 | * Only call this function when a scan can't be queued -- under RTNL. | |
789 | */ | |
5bb644a0 JB |
790 | void ieee80211_scan_cancel(struct ieee80211_local *local) |
791 | { | |
4136c422 | 792 | bool abortscan, finish; |
5bb644a0 JB |
793 | |
794 | /* | |
4136c422 SG |
795 | * We are only canceling software scan, or deferred scan that was not |
796 | * yet really started (see __ieee80211_start_scan ). | |
797 | * | |
798 | * Regarding hardware scan: | |
799 | * - we can not call __ieee80211_scan_completed() as when | |
800 | * SCAN_HW_SCANNING bit is set this function change | |
801 | * local->hw_scan_req to operate on 5G band, what race with | |
802 | * driver which can use local->hw_scan_req | |
803 | * | |
804 | * - we can not cancel scan_work since driver can schedule it | |
805 | * by ieee80211_scan_completed(..., true) to finish scan | |
806 | * | |
807 | * Hence low lever driver is responsible for canceling HW scan. | |
5bb644a0 | 808 | */ |
4136c422 | 809 | |
a1699b75 | 810 | mutex_lock(&local->mtx); |
4136c422 | 811 | abortscan = local->scan_req && !test_bit(SCAN_HW_SCANNING, &local->scanning); |
e229f844 SG |
812 | if (abortscan) |
813 | finish = __ieee80211_scan_completed(&local->hw, true, false); | |
a1699b75 | 814 | mutex_unlock(&local->mtx); |
5bb644a0 | 815 | |
4136c422 SG |
816 | if (abortscan) { |
817 | /* The scan is canceled, but stop work from being pending */ | |
818 | cancel_delayed_work_sync(&local->scan_work); | |
819 | if (finish) | |
820 | __ieee80211_scan_completed_finish(&local->hw, false); | |
821 | } | |
5bb644a0 | 822 | } |