Commit | Line | Data |
---|---|---|
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; |
f0b058b6 | 87 | int clen, srlen; |
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 | ||
f0b058b6 SG |
116 | /* replace old supported rates if we get new values */ |
117 | srlen = 0; | |
5484e237 | 118 | if (elems->supp_rates) { |
f0b058b6 | 119 | clen = IEEE80211_MAX_SUPP_RATES; |
5484e237 JB |
120 | if (clen > elems->supp_rates_len) |
121 | clen = elems->supp_rates_len; | |
f0b058b6 SG |
122 | memcpy(bss->supp_rates, elems->supp_rates, clen); |
123 | srlen += clen; | |
5484e237 JB |
124 | } |
125 | if (elems->ext_supp_rates) { | |
f0b058b6 | 126 | clen = IEEE80211_MAX_SUPP_RATES - srlen; |
5484e237 JB |
127 | if (clen > elems->ext_supp_rates_len) |
128 | clen = elems->ext_supp_rates_len; | |
f0b058b6 SG |
129 | memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen); |
130 | srlen += clen; | |
5484e237 | 131 | } |
f0b058b6 SG |
132 | if (srlen) |
133 | bss->supp_rates_len = srlen; | |
5484e237 | 134 | |
5484e237 | 135 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
ab13315a | 136 | bss->uapsd_supported = is_uapsd_supported(elems); |
5484e237 JB |
137 | |
138 | if (!beacon) | |
139 | bss->last_probe_resp = jiffies; | |
140 | ||
5484e237 JB |
141 | return bss; |
142 | } | |
0a51b27e | 143 | |
98c8fccf | 144 | ieee80211_rx_result |
f1d58c25 | 145 | ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) |
98c8fccf | 146 | { |
f1d58c25 | 147 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
98c8fccf | 148 | struct ieee80211_mgmt *mgmt; |
c2b13452 | 149 | struct ieee80211_bss *bss; |
98c8fccf JB |
150 | u8 *elements; |
151 | struct ieee80211_channel *channel; | |
152 | size_t baselen; | |
153 | int freq; | |
154 | __le16 fc; | |
155 | bool presp, beacon = false; | |
156 | struct ieee802_11_elems elems; | |
157 | ||
158 | if (skb->len < 2) | |
159 | return RX_DROP_UNUSABLE; | |
160 | ||
161 | mgmt = (struct ieee80211_mgmt *) skb->data; | |
162 | fc = mgmt->frame_control; | |
163 | ||
164 | if (ieee80211_is_ctl(fc)) | |
165 | return RX_CONTINUE; | |
166 | ||
167 | if (skb->len < 24) | |
168 | return RX_DROP_MONITOR; | |
169 | ||
170 | presp = ieee80211_is_probe_resp(fc); | |
171 | if (presp) { | |
172 | /* ignore ProbeResp to foreign address */ | |
47846c9b | 173 | if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) |
98c8fccf JB |
174 | return RX_DROP_MONITOR; |
175 | ||
176 | presp = true; | |
177 | elements = mgmt->u.probe_resp.variable; | |
178 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); | |
179 | } else { | |
180 | beacon = ieee80211_is_beacon(fc); | |
181 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); | |
182 | elements = mgmt->u.beacon.variable; | |
183 | } | |
184 | ||
185 | if (!presp && !beacon) | |
186 | return RX_CONTINUE; | |
187 | ||
188 | if (baselen > skb->len) | |
189 | return RX_DROP_MONITOR; | |
190 | ||
191 | ieee802_11_parse_elems(elements, skb->len - baselen, &elems); | |
192 | ||
193 | if (elems.ds_params && elems.ds_params_len == 1) | |
194 | freq = ieee80211_channel_to_frequency(elems.ds_params[0]); | |
195 | else | |
196 | freq = rx_status->freq; | |
197 | ||
198 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); | |
199 | ||
200 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) | |
201 | return RX_DROP_MONITOR; | |
202 | ||
203 | bss = ieee80211_bss_info_update(sdata->local, rx_status, | |
204 | mgmt, skb->len, &elems, | |
2a519311 | 205 | channel, beacon); |
d048e503 JM |
206 | if (bss) |
207 | ieee80211_rx_bss_put(sdata->local, bss); | |
98c8fccf JB |
208 | |
209 | dev_kfree_skb(skb); | |
210 | return RX_QUEUED; | |
211 | } | |
212 | ||
4d36ec58 JB |
213 | /* return false if no more work */ |
214 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) | |
215 | { | |
216 | struct cfg80211_scan_request *req = local->scan_req; | |
217 | enum ieee80211_band band; | |
218 | int i, ielen, n_chans; | |
219 | ||
220 | do { | |
221 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) | |
222 | return false; | |
223 | ||
224 | band = local->hw_scan_band; | |
225 | n_chans = 0; | |
226 | for (i = 0; i < req->n_channels; i++) { | |
227 | if (req->channels[i]->band == band) { | |
228 | local->hw_scan_req->channels[n_chans] = | |
229 | req->channels[i]; | |
230 | n_chans++; | |
231 | } | |
232 | } | |
233 | ||
234 | local->hw_scan_band++; | |
235 | } while (!n_chans); | |
236 | ||
237 | local->hw_scan_req->n_channels = n_chans; | |
238 | ||
239 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, | |
240 | req->ie, req->ie_len, band); | |
241 | local->hw_scan_req->ie_len = ielen; | |
242 | ||
243 | return true; | |
244 | } | |
245 | ||
2a519311 | 246 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
0a51b27e JB |
247 | { |
248 | struct ieee80211_local *local = hw_to_local(hw); | |
f3b85252 | 249 | bool was_hw_scan; |
0a51b27e | 250 | |
b5878a2d JB |
251 | trace_api_scan_completed(local, aborted); |
252 | ||
f3b85252 | 253 | mutex_lock(&local->scan_mtx); |
5bc75728 | 254 | |
6d3560d4 JB |
255 | /* |
256 | * It's ok to abort a not-yet-running scan (that | |
257 | * we have one at all will be verified by checking | |
258 | * local->scan_req next), but not to complete it | |
259 | * successfully. | |
260 | */ | |
261 | if (WARN_ON(!local->scanning && !aborted)) | |
262 | aborted = true; | |
5bc75728 | 263 | |
f3b85252 JB |
264 | if (WARN_ON(!local->scan_req)) { |
265 | mutex_unlock(&local->scan_mtx); | |
266 | return; | |
de95a54b JB |
267 | } |
268 | ||
4d36ec58 JB |
269 | was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
270 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { | |
271 | ieee80211_queue_delayed_work(&local->hw, | |
272 | &local->scan_work, 0); | |
273 | mutex_unlock(&local->scan_mtx); | |
274 | return; | |
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 JB |
287 | |
288 | /* we only have to protect scan_req and hw/sw scan */ | |
289 | mutex_unlock(&local->scan_mtx); | |
290 | ||
e8975581 | 291 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
5cff20e6 JB |
292 | if (was_hw_scan) |
293 | goto done; | |
0a51b27e | 294 | |
3ac64bee | 295 | ieee80211_configure_filter(local); |
0a51b27e | 296 | |
24487981 | 297 | drv_sw_scan_complete(local); |
80e775bf | 298 | |
b203ffc3 | 299 | ieee80211_offchannel_return(local, true); |
0a51b27e JB |
300 | |
301 | done: | |
5cff20e6 | 302 | ieee80211_recalc_idle(local); |
0a51b27e | 303 | ieee80211_mlme_notify_scan_completed(local); |
46900298 | 304 | ieee80211_ibss_notify_scan_completed(local); |
472dbc45 | 305 | ieee80211_mesh_notify_scan_completed(local); |
81ac3462 | 306 | ieee80211_queue_work(&local->hw, &local->work_work); |
0a51b27e JB |
307 | } |
308 | EXPORT_SYMBOL(ieee80211_scan_completed); | |
309 | ||
f3b85252 JB |
310 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
311 | { | |
f3b85252 JB |
312 | /* |
313 | * Hardware/driver doesn't support hw_scan, so use software | |
314 | * scanning instead. First send a nullfunc frame with power save | |
315 | * bit on so that AP will buffer the frames for us while we are not | |
316 | * listening, then send probe requests to each channel and wait for | |
317 | * the responses. After all channels are scanned, tune back to the | |
318 | * original channel and send a nullfunc frame with power save bit | |
319 | * off to trigger the AP to send us all the buffered frames. | |
320 | * | |
321 | * Note that while local->sw_scanning is true everything else but | |
322 | * nullfunc frames and probe requests will be dropped in | |
323 | * ieee80211_tx_h_check_assoc(). | |
324 | */ | |
24487981 | 325 | drv_sw_scan_start(local); |
f3b85252 | 326 | |
b203ffc3 | 327 | ieee80211_offchannel_stop_beaconing(local); |
f3b85252 | 328 | |
df13cce5 | 329 | local->leave_oper_channel_time = 0; |
977923b0 | 330 | local->next_scan_state = SCAN_DECISION; |
f3b85252 JB |
331 | local->scan_channel_idx = 0; |
332 | ||
a80f7c0b JB |
333 | drv_flush(local, false); |
334 | ||
3ac64bee | 335 | ieee80211_configure_filter(local); |
f3b85252 | 336 | |
42935eca LR |
337 | ieee80211_queue_delayed_work(&local->hw, |
338 | &local->scan_work, | |
339 | IEEE80211_CHANNEL_TIME); | |
f3b85252 JB |
340 | |
341 | return 0; | |
342 | } | |
343 | ||
344 | ||
345 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, | |
346 | struct cfg80211_scan_request *req) | |
347 | { | |
348 | struct ieee80211_local *local = sdata->local; | |
f3b85252 JB |
349 | int rc; |
350 | ||
351 | if (local->scan_req) | |
352 | return -EBUSY; | |
353 | ||
6e7e6213 JL |
354 | if (!list_empty(&local->work_list)) { |
355 | /* wait for the work to finish/time out */ | |
c0ce77b8 JB |
356 | local->scan_req = req; |
357 | local->scan_sdata = sdata; | |
358 | return 0; | |
359 | } | |
360 | ||
f3b85252 JB |
361 | if (local->ops->hw_scan) { |
362 | u8 *ies; | |
f3b85252 | 363 | |
4d36ec58 JB |
364 | local->hw_scan_req = kmalloc( |
365 | sizeof(*local->hw_scan_req) + | |
366 | req->n_channels * sizeof(req->channels[0]) + | |
367 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + | |
368 | req->ie_len, GFP_KERNEL); | |
369 | if (!local->hw_scan_req) | |
f3b85252 JB |
370 | return -ENOMEM; |
371 | ||
4d36ec58 JB |
372 | local->hw_scan_req->ssids = req->ssids; |
373 | local->hw_scan_req->n_ssids = req->n_ssids; | |
374 | ies = (u8 *)local->hw_scan_req + | |
375 | sizeof(*local->hw_scan_req) + | |
376 | req->n_channels * sizeof(req->channels[0]); | |
377 | local->hw_scan_req->ie = ies; | |
378 | ||
379 | local->hw_scan_band = 0; | |
6e7e6213 JL |
380 | |
381 | /* | |
382 | * After allocating local->hw_scan_req, we must | |
383 | * go through until ieee80211_prep_hw_scan(), so | |
384 | * anything that might be changed here and leave | |
385 | * this function early must not go after this | |
386 | * allocation. | |
387 | */ | |
f3b85252 JB |
388 | } |
389 | ||
390 | local->scan_req = req; | |
391 | local->scan_sdata = sdata; | |
392 | ||
f3b85252 | 393 | if (local->ops->hw_scan) |
fbe9c429 | 394 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
f3b85252 | 395 | else |
fbe9c429 | 396 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
6e7e6213 | 397 | |
f3b85252 JB |
398 | /* |
399 | * Kicking off the scan need not be protected, | |
400 | * only the scan variable stuff, since now | |
401 | * local->scan_req is assigned and other callers | |
402 | * will abort their scan attempts. | |
403 | * | |
6e7e6213 JL |
404 | * This avoids too many locking dependencies |
405 | * so that the scan completed calls have more | |
406 | * locking freedom. | |
f3b85252 | 407 | */ |
5cff20e6 JB |
408 | |
409 | ieee80211_recalc_idle(local); | |
f3b85252 JB |
410 | mutex_unlock(&local->scan_mtx); |
411 | ||
4d36ec58 JB |
412 | if (local->ops->hw_scan) { |
413 | WARN_ON(!ieee80211_prep_hw_scan(local)); | |
a060bbfe | 414 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 | 415 | } else |
f3b85252 JB |
416 | rc = ieee80211_start_sw_scan(local); |
417 | ||
418 | mutex_lock(&local->scan_mtx); | |
419 | ||
420 | if (rc) { | |
4d36ec58 JB |
421 | kfree(local->hw_scan_req); |
422 | local->hw_scan_req = NULL; | |
fbe9c429 | 423 | local->scanning = 0; |
f3b85252 | 424 | |
5cff20e6 JB |
425 | ieee80211_recalc_idle(local); |
426 | ||
f3b85252 JB |
427 | local->scan_req = NULL; |
428 | local->scan_sdata = NULL; | |
429 | } | |
430 | ||
431 | return rc; | |
432 | } | |
433 | ||
df13cce5 HS |
434 | static unsigned long |
435 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) | |
436 | { | |
437 | /* | |
438 | * TODO: channel switching also consumes quite some time, | |
439 | * add that delay as well to get a better estimation | |
440 | */ | |
441 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) | |
442 | return IEEE80211_PASSIVE_CHANNEL_TIME; | |
443 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; | |
444 | } | |
445 | ||
2fb3f028 HS |
446 | static int ieee80211_scan_state_decision(struct ieee80211_local *local, |
447 | unsigned long *next_delay) | |
7d3be3cc | 448 | { |
142b9f50 | 449 | bool associated = false; |
df13cce5 HS |
450 | bool tx_empty = true; |
451 | bool bad_latency; | |
452 | bool listen_int_exceeded; | |
453 | unsigned long min_beacon_int = 0; | |
142b9f50 | 454 | struct ieee80211_sub_if_data *sdata; |
df13cce5 | 455 | struct ieee80211_channel *next_chan; |
142b9f50 HS |
456 | |
457 | /* if no more bands/channels left, complete scan and advance to the idle state */ | |
7d3be3cc HS |
458 | if (local->scan_channel_idx >= local->scan_req->n_channels) { |
459 | ieee80211_scan_completed(&local->hw, false); | |
460 | return 1; | |
461 | } | |
2fb3f028 | 462 | |
df13cce5 HS |
463 | /* |
464 | * check if at least one STA interface is associated, | |
465 | * check if at least one STA interface has pending tx frames | |
466 | * and grab the lowest used beacon interval | |
467 | */ | |
142b9f50 HS |
468 | mutex_lock(&local->iflist_mtx); |
469 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 470 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
471 | continue; |
472 | ||
473 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
474 | if (sdata->u.mgd.associated) { | |
475 | associated = true; | |
df13cce5 HS |
476 | |
477 | if (sdata->vif.bss_conf.beacon_int < | |
478 | min_beacon_int || min_beacon_int == 0) | |
479 | min_beacon_int = | |
480 | sdata->vif.bss_conf.beacon_int; | |
481 | ||
482 | if (!qdisc_all_tx_empty(sdata->dev)) { | |
483 | tx_empty = false; | |
484 | break; | |
485 | } | |
142b9f50 HS |
486 | } |
487 | } | |
488 | } | |
489 | mutex_unlock(&local->iflist_mtx); | |
490 | ||
491 | if (local->scan_channel) { | |
492 | /* | |
493 | * we're currently scanning a different channel, let's | |
df13cce5 HS |
494 | * see if we can scan another channel without interfering |
495 | * with the current traffic situation. | |
496 | * | |
497 | * Since we don't know if the AP has pending frames for us | |
498 | * we can only check for our tx queues and use the current | |
499 | * pm_qos requirements for rx. Hence, if no tx traffic occurs | |
500 | * at all we will scan as many channels in a row as the pm_qos | |
501 | * latency allows us to. Additionally we also check for the | |
502 | * currently negotiated listen interval to prevent losing | |
503 | * frames unnecessarily. | |
504 | * | |
505 | * Otherwise switch back to the operating channel. | |
142b9f50 | 506 | */ |
df13cce5 HS |
507 | next_chan = local->scan_req->channels[local->scan_channel_idx]; |
508 | ||
509 | bad_latency = time_after(jiffies + | |
510 | ieee80211_scan_get_channel_time(next_chan), | |
511 | local->leave_oper_channel_time + | |
512 | usecs_to_jiffies(pm_qos_requirement(PM_QOS_NETWORK_LATENCY))); | |
513 | ||
514 | listen_int_exceeded = time_after(jiffies + | |
515 | ieee80211_scan_get_channel_time(next_chan), | |
516 | local->leave_oper_channel_time + | |
517 | usecs_to_jiffies(min_beacon_int * 1024) * | |
518 | local->hw.conf.listen_interval); | |
519 | ||
520 | if (associated && ( !tx_empty || bad_latency || | |
521 | listen_int_exceeded)) | |
977923b0 | 522 | local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; |
142b9f50 | 523 | else |
977923b0 | 524 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
525 | } else { |
526 | /* | |
527 | * we're on the operating channel currently, let's | |
528 | * leave that channel now to scan another one | |
529 | */ | |
977923b0 | 530 | local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; |
142b9f50 HS |
531 | } |
532 | ||
2fb3f028 | 533 | *next_delay = 0; |
2fb3f028 HS |
534 | return 0; |
535 | } | |
536 | ||
142b9f50 HS |
537 | static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, |
538 | unsigned long *next_delay) | |
539 | { | |
b203ffc3 | 540 | ieee80211_offchannel_stop_station(local); |
142b9f50 HS |
541 | |
542 | __set_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
543 | ||
a80f7c0b JB |
544 | /* |
545 | * What if the nullfunc frames didn't arrive? | |
546 | */ | |
547 | drv_flush(local, false); | |
548 | if (local->ops->flush) | |
549 | *next_delay = 0; | |
550 | else | |
551 | *next_delay = HZ / 10; | |
552 | ||
df13cce5 HS |
553 | /* remember when we left the operating channel */ |
554 | local->leave_oper_channel_time = jiffies; | |
555 | ||
142b9f50 | 556 | /* advance to the next channel to be scanned */ |
977923b0 | 557 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
558 | } |
559 | ||
560 | static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, | |
561 | unsigned long *next_delay) | |
562 | { | |
142b9f50 HS |
563 | /* switch back to the operating channel */ |
564 | local->scan_channel = NULL; | |
565 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); | |
566 | ||
567 | /* | |
b203ffc3 JM |
568 | * Only re-enable station mode interface now; beaconing will be |
569 | * re-enabled once the full scan has been completed. | |
142b9f50 | 570 | */ |
b203ffc3 | 571 | ieee80211_offchannel_return(local, false); |
142b9f50 HS |
572 | |
573 | __clear_bit(SCAN_OFF_CHANNEL, &local->scanning); | |
574 | ||
575 | *next_delay = HZ / 5; | |
977923b0 | 576 | local->next_scan_state = SCAN_DECISION; |
142b9f50 HS |
577 | } |
578 | ||
2fb3f028 HS |
579 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
580 | unsigned long *next_delay) | |
581 | { | |
582 | int skip; | |
583 | struct ieee80211_channel *chan; | |
2fb3f028 | 584 | |
7d3be3cc HS |
585 | skip = 0; |
586 | chan = local->scan_req->channels[local->scan_channel_idx]; | |
587 | ||
584991dc JB |
588 | local->scan_channel = chan; |
589 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) | |
7d3be3cc HS |
590 | skip = 1; |
591 | ||
7d3be3cc HS |
592 | /* advance state machine to next channel/band */ |
593 | local->scan_channel_idx++; | |
594 | ||
0ee9c13c HS |
595 | if (skip) { |
596 | /* if we skip this channel return to the decision state */ | |
597 | local->next_scan_state = SCAN_DECISION; | |
2fb3f028 | 598 | return; |
0ee9c13c | 599 | } |
7d3be3cc HS |
600 | |
601 | /* | |
602 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 | |
603 | * (which unfortunately doesn't say _why_ step a) is done, | |
604 | * but it waits for the probe delay or until a frame is | |
605 | * received - and the received frame would update the NAV). | |
606 | * For now, we do not support waiting until a frame is | |
607 | * received. | |
608 | * | |
609 | * In any case, it is not necessary for a passive scan. | |
610 | */ | |
611 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || | |
612 | !local->scan_req->n_ssids) { | |
613 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; | |
977923b0 | 614 | local->next_scan_state = SCAN_DECISION; |
2fb3f028 | 615 | return; |
7d3be3cc HS |
616 | } |
617 | ||
2fb3f028 | 618 | /* active scan, send probes */ |
7d3be3cc | 619 | *next_delay = IEEE80211_PROBE_DELAY; |
977923b0 | 620 | local->next_scan_state = SCAN_SEND_PROBE; |
7d3be3cc HS |
621 | } |
622 | ||
623 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, | |
624 | unsigned long *next_delay) | |
625 | { | |
626 | int i; | |
627 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
628 | ||
629 | for (i = 0; i < local->scan_req->n_ssids; i++) | |
630 | ieee80211_send_probe_req( | |
631 | sdata, NULL, | |
632 | local->scan_req->ssids[i].ssid, | |
633 | local->scan_req->ssids[i].ssid_len, | |
634 | local->scan_req->ie, local->scan_req->ie_len); | |
635 | ||
636 | /* | |
637 | * After sending probe requests, wait for probe responses | |
638 | * on the channel. | |
639 | */ | |
640 | *next_delay = IEEE80211_CHANNEL_TIME; | |
977923b0 | 641 | local->next_scan_state = SCAN_DECISION; |
7d3be3cc HS |
642 | } |
643 | ||
c2b13452 | 644 | void ieee80211_scan_work(struct work_struct *work) |
0a51b27e JB |
645 | { |
646 | struct ieee80211_local *local = | |
647 | container_of(work, struct ieee80211_local, scan_work.work); | |
648 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
0a51b27e JB |
649 | unsigned long next_delay = 0; |
650 | ||
f3b85252 JB |
651 | mutex_lock(&local->scan_mtx); |
652 | if (!sdata || !local->scan_req) { | |
653 | mutex_unlock(&local->scan_mtx); | |
654 | return; | |
655 | } | |
656 | ||
4d36ec58 | 657 | if (local->hw_scan_req) { |
a060bbfe | 658 | int rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 JB |
659 | mutex_unlock(&local->scan_mtx); |
660 | if (rc) | |
661 | ieee80211_scan_completed(&local->hw, true); | |
662 | return; | |
663 | } | |
664 | ||
fbe9c429 | 665 | if (local->scan_req && !local->scanning) { |
f3b85252 JB |
666 | struct cfg80211_scan_request *req = local->scan_req; |
667 | int rc; | |
668 | ||
669 | local->scan_req = NULL; | |
15db0b7f | 670 | local->scan_sdata = NULL; |
f3b85252 JB |
671 | |
672 | rc = __ieee80211_start_scan(sdata, req); | |
673 | mutex_unlock(&local->scan_mtx); | |
674 | ||
675 | if (rc) | |
676 | ieee80211_scan_completed(&local->hw, true); | |
677 | return; | |
678 | } | |
679 | ||
680 | mutex_unlock(&local->scan_mtx); | |
681 | ||
5bc75728 JB |
682 | /* |
683 | * Avoid re-scheduling when the sdata is going away. | |
684 | */ | |
9607e6b6 | 685 | if (!ieee80211_sdata_running(sdata)) { |
f3b85252 | 686 | ieee80211_scan_completed(&local->hw, true); |
0a51b27e | 687 | return; |
f3b85252 | 688 | } |
0a51b27e | 689 | |
f502d09b HS |
690 | /* |
691 | * as long as no delay is required advance immediately | |
692 | * without scheduling a new work | |
693 | */ | |
694 | do { | |
977923b0 | 695 | switch (local->next_scan_state) { |
2fb3f028 HS |
696 | case SCAN_DECISION: |
697 | if (ieee80211_scan_state_decision(local, &next_delay)) | |
f502d09b HS |
698 | return; |
699 | break; | |
2fb3f028 HS |
700 | case SCAN_SET_CHANNEL: |
701 | ieee80211_scan_state_set_channel(local, &next_delay); | |
702 | break; | |
f502d09b HS |
703 | case SCAN_SEND_PROBE: |
704 | ieee80211_scan_state_send_probe(local, &next_delay); | |
705 | break; | |
142b9f50 HS |
706 | case SCAN_LEAVE_OPER_CHANNEL: |
707 | ieee80211_scan_state_leave_oper_channel(local, &next_delay); | |
708 | break; | |
709 | case SCAN_ENTER_OPER_CHANNEL: | |
710 | ieee80211_scan_state_enter_oper_channel(local, &next_delay); | |
711 | break; | |
f502d09b HS |
712 | } |
713 | } while (next_delay == 0); | |
0a51b27e | 714 | |
42935eca | 715 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
0a51b27e JB |
716 | } |
717 | ||
f3b85252 JB |
718 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
719 | struct cfg80211_scan_request *req) | |
0a51b27e | 720 | { |
f3b85252 | 721 | int res; |
de95a54b | 722 | |
f3b85252 JB |
723 | mutex_lock(&sdata->local->scan_mtx); |
724 | res = __ieee80211_start_scan(sdata, req); | |
725 | mutex_unlock(&sdata->local->scan_mtx); | |
0a51b27e | 726 | |
f3b85252 | 727 | return res; |
0a51b27e JB |
728 | } |
729 | ||
f3b85252 JB |
730 | int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, |
731 | const u8 *ssid, u8 ssid_len) | |
0a51b27e | 732 | { |
0a51b27e | 733 | struct ieee80211_local *local = sdata->local; |
f3b85252 | 734 | int ret = -EBUSY; |
2a519311 | 735 | |
f3b85252 | 736 | mutex_lock(&local->scan_mtx); |
0a51b27e | 737 | |
f3b85252 JB |
738 | /* busy scanning */ |
739 | if (local->scan_req) | |
740 | goto unlock; | |
9116dd01 | 741 | |
5ba63533 JB |
742 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
743 | local->int_scan_req->ssids[0].ssid_len = ssid_len; | |
9116dd01 | 744 | |
5ba63533 | 745 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
f3b85252 JB |
746 | unlock: |
747 | mutex_unlock(&local->scan_mtx); | |
748 | return ret; | |
0a51b27e | 749 | } |
5bb644a0 JB |
750 | |
751 | void ieee80211_scan_cancel(struct ieee80211_local *local) | |
752 | { | |
15db0b7f | 753 | bool abortscan; |
5bb644a0 JB |
754 | |
755 | cancel_delayed_work_sync(&local->scan_work); | |
756 | ||
757 | /* | |
758 | * Only call this function when a scan can't be | |
759 | * queued -- mostly at suspend under RTNL. | |
760 | */ | |
761 | mutex_lock(&local->scan_mtx); | |
15db0b7f JB |
762 | abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || |
763 | (!local->scanning && local->scan_req); | |
5bb644a0 JB |
764 | mutex_unlock(&local->scan_mtx); |
765 | ||
15db0b7f | 766 | if (abortscan) |
5bb644a0 JB |
767 | ieee80211_scan_completed(&local->hw, true); |
768 | } |