scan.c 20 KB

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