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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) | |
306fe938 | 173 | return RX_CONTINUE; |
98c8fccf JB |
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) | |
59eb21a6 BR |
199 | freq = ieee80211_channel_to_frequency(elems.ds_params[0], |
200 | rx_status->band); | |
98c8fccf JB |
201 | else |
202 | freq = rx_status->freq; | |
203 | ||
204 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); | |
205 | ||
206 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) | |
207 | return RX_DROP_MONITOR; | |
208 | ||
209 | bss = ieee80211_bss_info_update(sdata->local, rx_status, | |
210 | mgmt, skb->len, &elems, | |
2a519311 | 211 | channel, beacon); |
d048e503 JM |
212 | if (bss) |
213 | ieee80211_rx_bss_put(sdata->local, bss); | |
98c8fccf | 214 | |
b23b025f BG |
215 | /* If we are on-operating-channel, and this packet is for the |
216 | * current channel, pass the pkt on up the stack so that | |
217 | * the rest of the stack can make use of it. | |
218 | */ | |
219 | if (ieee80211_cfg_on_oper_channel(sdata->local) | |
220 | && (channel == sdata->local->oper_channel)) | |
221 | return RX_CONTINUE; | |
222 | ||
98c8fccf JB |
223 | dev_kfree_skb(skb); |
224 | return RX_QUEUED; | |
225 | } | |
226 | ||
4d36ec58 JB |
227 | /* return false if no more work */ |
228 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) | |
229 | { | |
230 | struct cfg80211_scan_request *req = local->scan_req; | |
231 | enum ieee80211_band band; | |
232 | int i, ielen, n_chans; | |
233 | ||
234 | do { | |
235 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) | |
236 | return false; | |
237 | ||
238 | band = local->hw_scan_band; | |
239 | n_chans = 0; | |
240 | for (i = 0; i < req->n_channels; i++) { | |
241 | if (req->channels[i]->band == band) { | |
242 | local->hw_scan_req->channels[n_chans] = | |
243 | req->channels[i]; | |
244 | n_chans++; | |
245 | } | |
246 | } | |
247 | ||
248 | local->hw_scan_band++; | |
249 | } while (!n_chans); | |
250 | ||
251 | local->hw_scan_req->n_channels = n_chans; | |
252 | ||
253 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, | |
651b5225 JM |
254 | req->ie, req->ie_len, band, (u32) -1, |
255 | 0); | |
4d36ec58 JB |
256 | local->hw_scan_req->ie_len = ielen; |
257 | ||
258 | return true; | |
259 | } | |
260 | ||
d07bfd8b | 261 | static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, |
e229f844 | 262 | bool was_hw_scan) |
0a51b27e JB |
263 | { |
264 | struct ieee80211_local *local = hw_to_local(hw); | |
d07bfd8b JB |
265 | bool on_oper_chan; |
266 | bool enable_beacons = false; | |
0a51b27e | 267 | |
e229f844 | 268 | lockdep_assert_held(&local->mtx); |
5bc75728 | 269 | |
6d3560d4 JB |
270 | /* |
271 | * It's ok to abort a not-yet-running scan (that | |
272 | * we have one at all will be verified by checking | |
273 | * local->scan_req next), but not to complete it | |
274 | * successfully. | |
275 | */ | |
276 | if (WARN_ON(!local->scanning && !aborted)) | |
277 | aborted = true; | |
5bc75728 | 278 | |
e229f844 | 279 | if (WARN_ON(!local->scan_req)) |
d07bfd8b | 280 | return; |
de95a54b | 281 | |
4d36ec58 | 282 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { |
6eb11a9a SG |
283 | int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); |
284 | if (rc == 0) | |
d07bfd8b | 285 | return; |
4d36ec58 JB |
286 | } |
287 | ||
288 | kfree(local->hw_scan_req); | |
289 | local->hw_scan_req = NULL; | |
f3b85252 | 290 | |
5ba63533 | 291 | if (local->scan_req != local->int_scan_req) |
2a519311 JB |
292 | cfg80211_scan_done(local->scan_req, aborted); |
293 | local->scan_req = NULL; | |
15db0b7f | 294 | local->scan_sdata = NULL; |
2a519311 | 295 | |
fbe9c429 | 296 | local->scanning = 0; |
58905ca5 | 297 | local->scan_channel = NULL; |
f3b85252 | 298 | |
b23b025f BG |
299 | on_oper_chan = ieee80211_cfg_on_oper_channel(local); |
300 | ||
d07bfd8b | 301 | if (was_hw_scan || !on_oper_chan) |
b23b025f | 302 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
d07bfd8b | 303 | else |
59bdf3b0 BG |
304 | /* Set power back to normal operating levels. */ |
305 | ieee80211_hw_config(local, 0); | |
a0daa0e7 | 306 | |
e229f844 | 307 | if (!was_hw_scan) { |
b23b025f | 308 | bool on_oper_chan2; |
e229f844 SG |
309 | ieee80211_configure_filter(local); |
310 | drv_sw_scan_complete(local); | |
b23b025f BG |
311 | on_oper_chan2 = ieee80211_cfg_on_oper_channel(local); |
312 | /* We should always be on-channel at this point. */ | |
313 | WARN_ON(!on_oper_chan2); | |
314 | if (on_oper_chan2 && (on_oper_chan != on_oper_chan2)) | |
315 | enable_beacons = true; | |
316 | ||
317 | ieee80211_offchannel_return(local, enable_beacons, true); | |
e229f844 | 318 | } |
0a51b27e | 319 | |
5cff20e6 | 320 | ieee80211_recalc_idle(local); |
e229f844 | 321 | |
0a51b27e | 322 | ieee80211_mlme_notify_scan_completed(local); |
46900298 | 323 | ieee80211_ibss_notify_scan_completed(local); |
472dbc45 | 324 | ieee80211_mesh_notify_scan_completed(local); |
81ac3462 | 325 | ieee80211_queue_work(&local->hw, &local->work_work); |
0a51b27e | 326 | } |
8789d459 JB |
327 | |
328 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) | |
329 | { | |
330 | struct ieee80211_local *local = hw_to_local(hw); | |
331 | ||
332 | trace_api_scan_completed(local, aborted); | |
333 | ||
334 | set_bit(SCAN_COMPLETED, &local->scanning); | |
335 | if (aborted) | |
336 | set_bit(SCAN_ABORTED, &local->scanning); | |
337 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); | |
338 | } | |
0a51b27e JB |
339 | EXPORT_SYMBOL(ieee80211_scan_completed); |
340 | ||
f3b85252 JB |
341 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
342 | { | |
f3b85252 JB |
343 | /* |
344 | * Hardware/driver doesn't support hw_scan, so use software | |
345 | * scanning instead. First send a nullfunc frame with power save | |
346 | * bit on so that AP will buffer the frames for us while we are not | |
347 | * listening, then send probe requests to each channel and wait for | |
348 | * the responses. After all channels are scanned, tune back to the | |
349 | * original channel and send a nullfunc frame with power save bit | |
350 | * off to trigger the AP to send us all the buffered frames. | |
351 | * | |
352 | * Note that while local->sw_scanning is true everything else but | |
353 | * nullfunc frames and probe requests will be dropped in | |
354 | * ieee80211_tx_h_check_assoc(). | |
355 | */ | |
24487981 | 356 | drv_sw_scan_start(local); |
f3b85252 | 357 | |
df13cce5 | 358 | local->leave_oper_channel_time = 0; |
977923b0 | 359 | local->next_scan_state = SCAN_DECISION; |
f3b85252 JB |
360 | local->scan_channel_idx = 0; |
361 | ||
b23b025f BG |
362 | /* We always want to use off-channel PS, even if we |
363 | * are not really leaving oper-channel. Don't | |
364 | * tell the AP though, as long as we are on-channel. | |
365 | */ | |
366 | ieee80211_offchannel_enable_all_ps(local, false); | |
a80f7c0b | 367 | |
3ac64bee | 368 | ieee80211_configure_filter(local); |
f3b85252 | 369 | |
59bdf3b0 BG |
370 | /* We need to set power level at maximum rate for scanning. */ |
371 | ieee80211_hw_config(local, 0); | |
372 | ||
42935eca LR |
373 | ieee80211_queue_delayed_work(&local->hw, |
374 | &local->scan_work, | |
375 | IEEE80211_CHANNEL_TIME); | |
f3b85252 JB |
376 | |
377 | return 0; | |
378 | } | |
379 | ||
380 | ||
381 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, | |
382 | struct cfg80211_scan_request *req) | |
383 | { | |
384 | struct ieee80211_local *local = sdata->local; | |
f3b85252 JB |
385 | int rc; |
386 | ||
e229f844 SG |
387 | lockdep_assert_held(&local->mtx); |
388 | ||
f3b85252 JB |
389 | if (local->scan_req) |
390 | return -EBUSY; | |
391 | ||
6e7e6213 JL |
392 | if (!list_empty(&local->work_list)) { |
393 | /* wait for the work to finish/time out */ | |
c0ce77b8 JB |
394 | local->scan_req = req; |
395 | local->scan_sdata = sdata; | |
396 | return 0; | |
397 | } | |
398 | ||
f3b85252 JB |
399 | if (local->ops->hw_scan) { |
400 | u8 *ies; | |
f3b85252 | 401 | |
4d36ec58 JB |
402 | local->hw_scan_req = kmalloc( |
403 | sizeof(*local->hw_scan_req) + | |
404 | req->n_channels * sizeof(req->channels[0]) + | |
405 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + | |
406 | req->ie_len, GFP_KERNEL); | |
407 | if (!local->hw_scan_req) | |
f3b85252 JB |
408 | return -ENOMEM; |
409 | ||
4d36ec58 JB |
410 | local->hw_scan_req->ssids = req->ssids; |
411 | local->hw_scan_req->n_ssids = req->n_ssids; | |
412 | ies = (u8 *)local->hw_scan_req + | |
413 | sizeof(*local->hw_scan_req) + | |
414 | req->n_channels * sizeof(req->channels[0]); | |
415 | local->hw_scan_req->ie = ies; | |
416 | ||
417 | local->hw_scan_band = 0; | |
6e7e6213 JL |
418 | |
419 | /* | |
420 | * After allocating local->hw_scan_req, we must | |
421 | * go through until ieee80211_prep_hw_scan(), so | |
422 | * anything that might be changed here and leave | |
423 | * this function early must not go after this | |
424 | * allocation. | |
425 | */ | |
f3b85252 JB |
426 | } |
427 | ||
428 | local->scan_req = req; | |
429 | local->scan_sdata = sdata; | |
430 | ||
f3b85252 | 431 | if (local->ops->hw_scan) |
fbe9c429 | 432 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
f3b85252 | 433 | else |
fbe9c429 | 434 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
6e7e6213 | 435 | |
5cff20e6 | 436 | ieee80211_recalc_idle(local); |
f3b85252 | 437 | |
4d36ec58 JB |
438 | if (local->ops->hw_scan) { |
439 | WARN_ON(!ieee80211_prep_hw_scan(local)); | |
a060bbfe | 440 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
4d36ec58 | 441 | } else |
f3b85252 JB |
442 | rc = ieee80211_start_sw_scan(local); |
443 | ||
f3b85252 | 444 | if (rc) { |
4d36ec58 JB |
445 | kfree(local->hw_scan_req); |
446 | local->hw_scan_req = NULL; | |
fbe9c429 | 447 | local->scanning = 0; |
f3b85252 | 448 | |
5cff20e6 JB |
449 | ieee80211_recalc_idle(local); |
450 | ||
f3b85252 JB |
451 | local->scan_req = NULL; |
452 | local->scan_sdata = NULL; | |
453 | } | |
454 | ||
455 | return rc; | |
456 | } | |
457 | ||
df13cce5 HS |
458 | static unsigned long |
459 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) | |
460 | { | |
461 | /* | |
462 | * TODO: channel switching also consumes quite some time, | |
463 | * add that delay as well to get a better estimation | |
464 | */ | |
465 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) | |
466 | return IEEE80211_PASSIVE_CHANNEL_TIME; | |
467 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; | |
468 | } | |
469 | ||
e229f844 SG |
470 | static void ieee80211_scan_state_decision(struct ieee80211_local *local, |
471 | unsigned long *next_delay) | |
7d3be3cc | 472 | { |
142b9f50 | 473 | bool associated = false; |
df13cce5 HS |
474 | bool tx_empty = true; |
475 | bool bad_latency; | |
476 | bool listen_int_exceeded; | |
477 | unsigned long min_beacon_int = 0; | |
142b9f50 | 478 | struct ieee80211_sub_if_data *sdata; |
df13cce5 | 479 | struct ieee80211_channel *next_chan; |
142b9f50 | 480 | |
df13cce5 HS |
481 | /* |
482 | * check if at least one STA interface is associated, | |
483 | * check if at least one STA interface has pending tx frames | |
484 | * and grab the lowest used beacon interval | |
485 | */ | |
142b9f50 HS |
486 | mutex_lock(&local->iflist_mtx); |
487 | list_for_each_entry(sdata, &local->interfaces, list) { | |
9607e6b6 | 488 | if (!ieee80211_sdata_running(sdata)) |
142b9f50 HS |
489 | continue; |
490 | ||
491 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { | |
492 | if (sdata->u.mgd.associated) { | |
493 | associated = true; | |
df13cce5 HS |
494 | |
495 | if (sdata->vif.bss_conf.beacon_int < | |
496 | min_beacon_int || min_beacon_int == 0) | |
497 | min_beacon_int = | |
498 | sdata->vif.bss_conf.beacon_int; | |
499 | ||
500 | if (!qdisc_all_tx_empty(sdata->dev)) { | |
501 | tx_empty = false; | |
502 | break; | |
503 | } | |
142b9f50 HS |
504 | } |
505 | } | |
506 | } | |
507 | mutex_unlock(&local->iflist_mtx); | |
508 | ||
b23b025f BG |
509 | next_chan = local->scan_req->channels[local->scan_channel_idx]; |
510 | ||
511 | if (ieee80211_cfg_on_oper_channel(local)) { | |
512 | /* We're currently on operating channel. */ | |
4f2e9d91 | 513 | if (next_chan == local->oper_channel) |
b23b025f BG |
514 | /* We don't need to move off of operating channel. */ |
515 | local->next_scan_state = SCAN_SET_CHANNEL; | |
516 | else | |
517 | /* | |
518 | * We do need to leave operating channel, as next | |
519 | * scan is somewhere else. | |
520 | */ | |
521 | local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL; | |
522 | } else { | |
142b9f50 HS |
523 | /* |
524 | * we're currently scanning a different channel, let's | |
df13cce5 HS |
525 | * see if we can scan another channel without interfering |
526 | * with the current traffic situation. | |
527 | * | |
528 | * Since we don't know if the AP has pending frames for us | |
529 | * we can only check for our tx queues and use the current | |
530 | * pm_qos requirements for rx. Hence, if no tx traffic occurs | |
531 | * at all we will scan as many channels in a row as the pm_qos | |
532 | * latency allows us to. Additionally we also check for the | |
533 | * currently negotiated listen interval to prevent losing | |
534 | * frames unnecessarily. | |
535 | * | |
536 | * Otherwise switch back to the operating channel. | |
142b9f50 | 537 | */ |
df13cce5 HS |
538 | |
539 | bad_latency = time_after(jiffies + | |
540 | ieee80211_scan_get_channel_time(next_chan), | |
541 | local->leave_oper_channel_time + | |
f8965467 | 542 | usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); |
df13cce5 HS |
543 | |
544 | listen_int_exceeded = time_after(jiffies + | |
545 | ieee80211_scan_get_channel_time(next_chan), | |
546 | local->leave_oper_channel_time + | |
547 | usecs_to_jiffies(min_beacon_int * 1024) * | |
548 | local->hw.conf.listen_interval); | |
549 | ||
550 | if (associated && ( !tx_empty || bad_latency || | |
551 | listen_int_exceeded)) | |
977923b0 | 552 | local->next_scan_state = SCAN_ENTER_OPER_CHANNEL; |
142b9f50 | 553 | else |
977923b0 | 554 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
555 | } |
556 | ||
2fb3f028 | 557 | *next_delay = 0; |
2fb3f028 HS |
558 | } |
559 | ||
142b9f50 HS |
560 | static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local, |
561 | unsigned long *next_delay) | |
562 | { | |
b23b025f BG |
563 | /* PS will already be in off-channel mode, |
564 | * we do that once at the beginning of scanning. | |
565 | */ | |
566 | ieee80211_offchannel_stop_vifs(local, false); | |
142b9f50 | 567 | |
a80f7c0b JB |
568 | /* |
569 | * What if the nullfunc frames didn't arrive? | |
570 | */ | |
571 | drv_flush(local, false); | |
572 | if (local->ops->flush) | |
573 | *next_delay = 0; | |
574 | else | |
575 | *next_delay = HZ / 10; | |
576 | ||
df13cce5 HS |
577 | /* remember when we left the operating channel */ |
578 | local->leave_oper_channel_time = jiffies; | |
579 | ||
142b9f50 | 580 | /* advance to the next channel to be scanned */ |
977923b0 | 581 | local->next_scan_state = SCAN_SET_CHANNEL; |
142b9f50 HS |
582 | } |
583 | ||
584 | static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local, | |
585 | unsigned long *next_delay) | |
586 | { | |
142b9f50 HS |
587 | /* switch back to the operating channel */ |
588 | local->scan_channel = NULL; | |
b23b025f BG |
589 | if (!ieee80211_cfg_on_oper_channel(local)) |
590 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); | |
142b9f50 HS |
591 | |
592 | /* | |
b23b025f BG |
593 | * Re-enable vifs and beaconing. Leave PS |
594 | * in off-channel state..will put that back | |
595 | * on-channel at the end of scanning. | |
142b9f50 | 596 | */ |
b23b025f | 597 | ieee80211_offchannel_return(local, true, false); |
142b9f50 HS |
598 | |
599 | *next_delay = HZ / 5; | |
977923b0 | 600 | local->next_scan_state = SCAN_DECISION; |
142b9f50 HS |
601 | } |
602 | ||
2fb3f028 HS |
603 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
604 | unsigned long *next_delay) | |
605 | { | |
606 | int skip; | |
607 | struct ieee80211_channel *chan; | |
2fb3f028 | 608 | |
7d3be3cc HS |
609 | skip = 0; |
610 | chan = local->scan_req->channels[local->scan_channel_idx]; | |
611 | ||
584991dc | 612 | local->scan_channel = chan; |
b23b025f BG |
613 | |
614 | /* Only call hw-config if we really need to change channels. */ | |
4f2e9d91 | 615 | if (chan != local->hw.conf.channel) |
b23b025f BG |
616 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) |
617 | skip = 1; | |
7d3be3cc | 618 | |
7d3be3cc HS |
619 | /* advance state machine to next channel/band */ |
620 | local->scan_channel_idx++; | |
621 | ||
0ee9c13c HS |
622 | if (skip) { |
623 | /* if we skip this channel return to the decision state */ | |
624 | local->next_scan_state = SCAN_DECISION; | |
2fb3f028 | 625 | return; |
0ee9c13c | 626 | } |
7d3be3cc HS |
627 | |
628 | /* | |
629 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 | |
630 | * (which unfortunately doesn't say _why_ step a) is done, | |
631 | * but it waits for the probe delay or until a frame is | |
632 | * received - and the received frame would update the NAV). | |
633 | * For now, we do not support waiting until a frame is | |
634 | * received. | |
635 | * | |
636 | * In any case, it is not necessary for a passive scan. | |
637 | */ | |
638 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || | |
639 | !local->scan_req->n_ssids) { | |
640 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; | |
977923b0 | 641 | local->next_scan_state = SCAN_DECISION; |
2fb3f028 | 642 | return; |
7d3be3cc HS |
643 | } |
644 | ||
2fb3f028 | 645 | /* active scan, send probes */ |
7d3be3cc | 646 | *next_delay = IEEE80211_PROBE_DELAY; |
977923b0 | 647 | local->next_scan_state = SCAN_SEND_PROBE; |
7d3be3cc HS |
648 | } |
649 | ||
650 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, | |
651 | unsigned long *next_delay) | |
652 | { | |
653 | int i; | |
654 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; | |
655 | ||
656 | for (i = 0; i < local->scan_req->n_ssids; i++) | |
657 | ieee80211_send_probe_req( | |
658 | sdata, NULL, | |
659 | local->scan_req->ssids[i].ssid, | |
660 | local->scan_req->ssids[i].ssid_len, | |
661 | local->scan_req->ie, local->scan_req->ie_len); | |
662 | ||
663 | /* | |
664 | * After sending probe requests, wait for probe responses | |
665 | * on the channel. | |
666 | */ | |
667 | *next_delay = IEEE80211_CHANNEL_TIME; | |
977923b0 | 668 | local->next_scan_state = SCAN_DECISION; |
7d3be3cc HS |
669 | } |
670 | ||
c2b13452 | 671 | void ieee80211_scan_work(struct work_struct *work) |
0a51b27e JB |
672 | { |
673 | struct ieee80211_local *local = | |
674 | container_of(work, struct ieee80211_local, scan_work.work); | |
d07bfd8b | 675 | struct ieee80211_sub_if_data *sdata; |
0a51b27e | 676 | unsigned long next_delay = 0; |
d07bfd8b | 677 | bool aborted, hw_scan; |
0a51b27e | 678 | |
259b62e3 | 679 | mutex_lock(&local->mtx); |
8789d459 | 680 | |
d07bfd8b JB |
681 | sdata = local->scan_sdata; |
682 | ||
259b62e3 | 683 | if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { |
8789d459 | 684 | aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); |
259b62e3 | 685 | goto out_complete; |
8789d459 JB |
686 | } |
687 | ||
259b62e3 SG |
688 | if (!sdata || !local->scan_req) |
689 | goto out; | |
f3b85252 | 690 | |
fbe9c429 | 691 | if (local->scan_req && !local->scanning) { |
f3b85252 JB |
692 | struct cfg80211_scan_request *req = local->scan_req; |
693 | int rc; | |
694 | ||
695 | local->scan_req = NULL; | |
15db0b7f | 696 | local->scan_sdata = NULL; |
f3b85252 JB |
697 | |
698 | rc = __ieee80211_start_scan(sdata, req); | |
259b62e3 | 699 | if (rc) { |
3aed49ef SG |
700 | /* need to complete scan in cfg80211 */ |
701 | local->scan_req = req; | |
259b62e3 SG |
702 | aborted = true; |
703 | goto out_complete; | |
704 | } else | |
705 | goto out; | |
f3b85252 JB |
706 | } |
707 | ||
5bc75728 JB |
708 | /* |
709 | * Avoid re-scheduling when the sdata is going away. | |
710 | */ | |
9607e6b6 | 711 | if (!ieee80211_sdata_running(sdata)) { |
259b62e3 SG |
712 | aborted = true; |
713 | goto out_complete; | |
f3b85252 | 714 | } |
0a51b27e | 715 | |
f502d09b HS |
716 | /* |
717 | * as long as no delay is required advance immediately | |
718 | * without scheduling a new work | |
719 | */ | |
720 | do { | |
977923b0 | 721 | switch (local->next_scan_state) { |
2fb3f028 | 722 | case SCAN_DECISION: |
e229f844 SG |
723 | /* if no more bands/channels left, complete scan */ |
724 | if (local->scan_channel_idx >= local->scan_req->n_channels) { | |
725 | aborted = false; | |
726 | goto out_complete; | |
727 | } | |
728 | ieee80211_scan_state_decision(local, &next_delay); | |
f502d09b | 729 | break; |
2fb3f028 HS |
730 | case SCAN_SET_CHANNEL: |
731 | ieee80211_scan_state_set_channel(local, &next_delay); | |
732 | break; | |
f502d09b HS |
733 | case SCAN_SEND_PROBE: |
734 | ieee80211_scan_state_send_probe(local, &next_delay); | |
735 | break; | |
142b9f50 HS |
736 | case SCAN_LEAVE_OPER_CHANNEL: |
737 | ieee80211_scan_state_leave_oper_channel(local, &next_delay); | |
738 | break; | |
739 | case SCAN_ENTER_OPER_CHANNEL: | |
740 | ieee80211_scan_state_enter_oper_channel(local, &next_delay); | |
741 | break; | |
f502d09b HS |
742 | } |
743 | } while (next_delay == 0); | |
0a51b27e | 744 | |
42935eca | 745 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
d07bfd8b | 746 | goto out; |
259b62e3 SG |
747 | |
748 | out_complete: | |
e229f844 | 749 | hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
d07bfd8b | 750 | __ieee80211_scan_completed(&local->hw, aborted, hw_scan); |
259b62e3 SG |
751 | out: |
752 | mutex_unlock(&local->mtx); | |
0a51b27e JB |
753 | } |
754 | ||
f3b85252 JB |
755 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
756 | struct cfg80211_scan_request *req) | |
0a51b27e | 757 | { |
f3b85252 | 758 | int res; |
de95a54b | 759 | |
a1699b75 | 760 | mutex_lock(&sdata->local->mtx); |
f3b85252 | 761 | res = __ieee80211_start_scan(sdata, req); |
a1699b75 | 762 | mutex_unlock(&sdata->local->mtx); |
0a51b27e | 763 | |
f3b85252 | 764 | return res; |
0a51b27e JB |
765 | } |
766 | ||
f3b85252 | 767 | int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, |
be4a4b6a JB |
768 | const u8 *ssid, u8 ssid_len, |
769 | struct ieee80211_channel *chan) | |
0a51b27e | 770 | { |
0a51b27e | 771 | struct ieee80211_local *local = sdata->local; |
f3b85252 | 772 | int ret = -EBUSY; |
fb63bc41 | 773 | enum ieee80211_band band; |
2a519311 | 774 | |
a1699b75 | 775 | mutex_lock(&local->mtx); |
0a51b27e | 776 | |
f3b85252 JB |
777 | /* busy scanning */ |
778 | if (local->scan_req) | |
779 | goto unlock; | |
9116dd01 | 780 | |
be4a4b6a JB |
781 | /* fill internal scan request */ |
782 | if (!chan) { | |
783 | int i, nchan = 0; | |
784 | ||
785 | for (band = 0; band < IEEE80211_NUM_BANDS; band++) { | |
786 | if (!local->hw.wiphy->bands[band]) | |
787 | continue; | |
788 | for (i = 0; | |
789 | i < local->hw.wiphy->bands[band]->n_channels; | |
790 | i++) { | |
791 | local->int_scan_req->channels[nchan] = | |
792 | &local->hw.wiphy->bands[band]->channels[i]; | |
793 | nchan++; | |
794 | } | |
795 | } | |
796 | ||
797 | local->int_scan_req->n_channels = nchan; | |
798 | } else { | |
799 | local->int_scan_req->channels[0] = chan; | |
800 | local->int_scan_req->n_channels = 1; | |
801 | } | |
802 | ||
803 | local->int_scan_req->ssids = &local->scan_ssid; | |
804 | local->int_scan_req->n_ssids = 1; | |
5ba63533 JB |
805 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
806 | local->int_scan_req->ssids[0].ssid_len = ssid_len; | |
9116dd01 | 807 | |
5ba63533 | 808 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
f3b85252 | 809 | unlock: |
a1699b75 | 810 | mutex_unlock(&local->mtx); |
f3b85252 | 811 | return ret; |
0a51b27e | 812 | } |
5bb644a0 | 813 | |
4136c422 SG |
814 | /* |
815 | * Only call this function when a scan can't be queued -- under RTNL. | |
816 | */ | |
5bb644a0 JB |
817 | void ieee80211_scan_cancel(struct ieee80211_local *local) |
818 | { | |
494486f8 | 819 | bool abortscan; |
5bb644a0 JB |
820 | |
821 | /* | |
4136c422 SG |
822 | * We are only canceling software scan, or deferred scan that was not |
823 | * yet really started (see __ieee80211_start_scan ). | |
824 | * | |
825 | * Regarding hardware scan: | |
826 | * - we can not call __ieee80211_scan_completed() as when | |
827 | * SCAN_HW_SCANNING bit is set this function change | |
828 | * local->hw_scan_req to operate on 5G band, what race with | |
829 | * driver which can use local->hw_scan_req | |
830 | * | |
831 | * - we can not cancel scan_work since driver can schedule it | |
832 | * by ieee80211_scan_completed(..., true) to finish scan | |
833 | * | |
834 | * Hence low lever driver is responsible for canceling HW scan. | |
5bb644a0 | 835 | */ |
4136c422 | 836 | |
a1699b75 | 837 | mutex_lock(&local->mtx); |
4136c422 | 838 | abortscan = local->scan_req && !test_bit(SCAN_HW_SCANNING, &local->scanning); |
4136c422 | 839 | if (abortscan) { |
d07bfd8b JB |
840 | /* |
841 | * The scan is canceled, but stop work from being pending. | |
842 | * | |
843 | * If the work is currently running, it must be blocked on | |
844 | * the mutex, but we'll set scan_sdata = NULL and it'll | |
845 | * simply exit once it acquires the mutex. | |
846 | */ | |
847 | cancel_delayed_work(&local->scan_work); | |
848 | /* and clean up */ | |
849 | __ieee80211_scan_completed(&local->hw, true, false); | |
4136c422 | 850 | } |
d07bfd8b | 851 | mutex_unlock(&local->mtx); |
5bb644a0 | 852 | } |