| 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 | * Copyright 2013-2015 Intel Mobile Communications GmbH |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License version 2 as |
| 13 | * published by the Free Software Foundation. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/if_arp.h> |
| 17 | #include <linux/etherdevice.h> |
| 18 | #include <linux/rtnetlink.h> |
| 19 | #include <net/sch_generic.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/export.h> |
| 22 | #include <net/mac80211.h> |
| 23 | |
| 24 | #include "ieee80211_i.h" |
| 25 | #include "driver-ops.h" |
| 26 | #include "mesh.h" |
| 27 | |
| 28 | #define IEEE80211_PROBE_DELAY (HZ / 33) |
| 29 | #define IEEE80211_CHANNEL_TIME (HZ / 33) |
| 30 | #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9) |
| 31 | |
| 32 | void ieee80211_rx_bss_put(struct ieee80211_local *local, |
| 33 | struct ieee80211_bss *bss) |
| 34 | { |
| 35 | if (!bss) |
| 36 | return; |
| 37 | cfg80211_put_bss(local->hw.wiphy, |
| 38 | container_of((void *)bss, struct cfg80211_bss, priv)); |
| 39 | } |
| 40 | |
| 41 | static bool is_uapsd_supported(struct ieee802_11_elems *elems) |
| 42 | { |
| 43 | u8 qos_info; |
| 44 | |
| 45 | if (elems->wmm_info && elems->wmm_info_len == 7 |
| 46 | && elems->wmm_info[5] == 1) |
| 47 | qos_info = elems->wmm_info[6]; |
| 48 | else if (elems->wmm_param && elems->wmm_param_len == 24 |
| 49 | && elems->wmm_param[5] == 1) |
| 50 | qos_info = elems->wmm_param[6]; |
| 51 | else |
| 52 | /* no valid wmm information or parameter element found */ |
| 53 | return false; |
| 54 | |
| 55 | return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; |
| 56 | } |
| 57 | |
| 58 | struct ieee80211_bss * |
| 59 | ieee80211_bss_info_update(struct ieee80211_local *local, |
| 60 | struct ieee80211_rx_status *rx_status, |
| 61 | struct ieee80211_mgmt *mgmt, size_t len, |
| 62 | struct ieee802_11_elems *elems, |
| 63 | struct ieee80211_channel *channel) |
| 64 | { |
| 65 | bool beacon = ieee80211_is_beacon(mgmt->frame_control); |
| 66 | struct cfg80211_bss *cbss; |
| 67 | struct ieee80211_bss *bss; |
| 68 | int clen, srlen; |
| 69 | struct cfg80211_inform_bss bss_meta = {}; |
| 70 | bool signal_valid; |
| 71 | |
| 72 | if (ieee80211_hw_check(&local->hw, SIGNAL_DBM)) |
| 73 | bss_meta.signal = rx_status->signal * 100; |
| 74 | else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC)) |
| 75 | bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal; |
| 76 | |
| 77 | bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20; |
| 78 | if (rx_status->flag & RX_FLAG_5MHZ) |
| 79 | bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5; |
| 80 | if (rx_status->flag & RX_FLAG_10MHZ) |
| 81 | bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10; |
| 82 | |
| 83 | bss_meta.chan = channel; |
| 84 | cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, |
| 85 | mgmt, len, GFP_ATOMIC); |
| 86 | if (!cbss) |
| 87 | return NULL; |
| 88 | /* In case the signal is invalid update the status */ |
| 89 | signal_valid = abs(channel->center_freq - cbss->channel->center_freq) |
| 90 | <= local->hw.wiphy->max_adj_channel_rssi_comp; |
| 91 | if (!signal_valid) |
| 92 | rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL; |
| 93 | |
| 94 | bss = (void *)cbss->priv; |
| 95 | |
| 96 | if (beacon) |
| 97 | bss->device_ts_beacon = rx_status->device_timestamp; |
| 98 | else |
| 99 | bss->device_ts_presp = rx_status->device_timestamp; |
| 100 | |
| 101 | if (elems->parse_error) { |
| 102 | if (beacon) |
| 103 | bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; |
| 104 | else |
| 105 | bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; |
| 106 | } else { |
| 107 | if (beacon) |
| 108 | bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; |
| 109 | else |
| 110 | bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; |
| 111 | } |
| 112 | |
| 113 | /* save the ERP value so that it is available at association time */ |
| 114 | if (elems->erp_info && (!elems->parse_error || |
| 115 | !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { |
| 116 | bss->erp_value = elems->erp_info[0]; |
| 117 | bss->has_erp_value = true; |
| 118 | if (!elems->parse_error) |
| 119 | bss->valid_data |= IEEE80211_BSS_VALID_ERP; |
| 120 | } |
| 121 | |
| 122 | /* replace old supported rates if we get new values */ |
| 123 | if (!elems->parse_error || |
| 124 | !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { |
| 125 | srlen = 0; |
| 126 | if (elems->supp_rates) { |
| 127 | clen = IEEE80211_MAX_SUPP_RATES; |
| 128 | if (clen > elems->supp_rates_len) |
| 129 | clen = elems->supp_rates_len; |
| 130 | memcpy(bss->supp_rates, elems->supp_rates, clen); |
| 131 | srlen += clen; |
| 132 | } |
| 133 | if (elems->ext_supp_rates) { |
| 134 | clen = IEEE80211_MAX_SUPP_RATES - srlen; |
| 135 | if (clen > elems->ext_supp_rates_len) |
| 136 | clen = elems->ext_supp_rates_len; |
| 137 | memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, |
| 138 | clen); |
| 139 | srlen += clen; |
| 140 | } |
| 141 | if (srlen) { |
| 142 | bss->supp_rates_len = srlen; |
| 143 | if (!elems->parse_error) |
| 144 | bss->valid_data |= IEEE80211_BSS_VALID_RATES; |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | if (!elems->parse_error || |
| 149 | !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { |
| 150 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
| 151 | bss->uapsd_supported = is_uapsd_supported(elems); |
| 152 | if (!elems->parse_error) |
| 153 | bss->valid_data |= IEEE80211_BSS_VALID_WMM; |
| 154 | } |
| 155 | |
| 156 | if (beacon) { |
| 157 | struct ieee80211_supported_band *sband = |
| 158 | local->hw.wiphy->bands[rx_status->band]; |
| 159 | if (!(rx_status->flag & RX_FLAG_HT) && |
| 160 | !(rx_status->flag & RX_FLAG_VHT)) |
| 161 | bss->beacon_rate = |
| 162 | &sband->bitrates[rx_status->rate_idx]; |
| 163 | } |
| 164 | |
| 165 | return bss; |
| 166 | } |
| 167 | |
| 168 | void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) |
| 169 | { |
| 170 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
| 171 | struct ieee80211_sub_if_data *sdata1, *sdata2; |
| 172 | struct ieee80211_mgmt *mgmt = (void *)skb->data; |
| 173 | struct ieee80211_bss *bss; |
| 174 | u8 *elements; |
| 175 | struct ieee80211_channel *channel; |
| 176 | size_t baselen; |
| 177 | struct ieee802_11_elems elems; |
| 178 | |
| 179 | if (skb->len < 24 || |
| 180 | (!ieee80211_is_probe_resp(mgmt->frame_control) && |
| 181 | !ieee80211_is_beacon(mgmt->frame_control))) |
| 182 | return; |
| 183 | |
| 184 | sdata1 = rcu_dereference(local->scan_sdata); |
| 185 | sdata2 = rcu_dereference(local->sched_scan_sdata); |
| 186 | |
| 187 | if (likely(!sdata1 && !sdata2)) |
| 188 | return; |
| 189 | |
| 190 | if (ieee80211_is_probe_resp(mgmt->frame_control)) { |
| 191 | struct cfg80211_scan_request *scan_req; |
| 192 | struct cfg80211_sched_scan_request *sched_scan_req; |
| 193 | |
| 194 | scan_req = rcu_dereference(local->scan_req); |
| 195 | sched_scan_req = rcu_dereference(local->sched_scan_req); |
| 196 | |
| 197 | /* ignore ProbeResp to foreign address unless scanning |
| 198 | * with randomised address |
| 199 | */ |
| 200 | if (!(sdata1 && |
| 201 | (ether_addr_equal(mgmt->da, sdata1->vif.addr) || |
| 202 | scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) && |
| 203 | !(sdata2 && |
| 204 | (ether_addr_equal(mgmt->da, sdata2->vif.addr) || |
| 205 | sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR))) |
| 206 | return; |
| 207 | |
| 208 | elements = mgmt->u.probe_resp.variable; |
| 209 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); |
| 210 | } else { |
| 211 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); |
| 212 | elements = mgmt->u.beacon.variable; |
| 213 | } |
| 214 | |
| 215 | if (baselen > skb->len) |
| 216 | return; |
| 217 | |
| 218 | ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems); |
| 219 | |
| 220 | channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq); |
| 221 | |
| 222 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) |
| 223 | return; |
| 224 | |
| 225 | bss = ieee80211_bss_info_update(local, rx_status, |
| 226 | mgmt, skb->len, &elems, |
| 227 | channel); |
| 228 | if (bss) |
| 229 | ieee80211_rx_bss_put(local, bss); |
| 230 | } |
| 231 | |
| 232 | static void |
| 233 | ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef, |
| 234 | enum nl80211_bss_scan_width scan_width) |
| 235 | { |
| 236 | memset(chandef, 0, sizeof(*chandef)); |
| 237 | switch (scan_width) { |
| 238 | case NL80211_BSS_CHAN_WIDTH_5: |
| 239 | chandef->width = NL80211_CHAN_WIDTH_5; |
| 240 | break; |
| 241 | case NL80211_BSS_CHAN_WIDTH_10: |
| 242 | chandef->width = NL80211_CHAN_WIDTH_10; |
| 243 | break; |
| 244 | default: |
| 245 | chandef->width = NL80211_CHAN_WIDTH_20_NOHT; |
| 246 | break; |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | /* return false if no more work */ |
| 251 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) |
| 252 | { |
| 253 | struct cfg80211_scan_request *req; |
| 254 | struct cfg80211_chan_def chandef; |
| 255 | u8 bands_used = 0; |
| 256 | int i, ielen, n_chans; |
| 257 | |
| 258 | req = rcu_dereference_protected(local->scan_req, |
| 259 | lockdep_is_held(&local->mtx)); |
| 260 | |
| 261 | if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) |
| 262 | return false; |
| 263 | |
| 264 | if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) { |
| 265 | for (i = 0; i < req->n_channels; i++) { |
| 266 | local->hw_scan_req->req.channels[i] = req->channels[i]; |
| 267 | bands_used |= BIT(req->channels[i]->band); |
| 268 | } |
| 269 | |
| 270 | n_chans = req->n_channels; |
| 271 | } else { |
| 272 | do { |
| 273 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) |
| 274 | return false; |
| 275 | |
| 276 | n_chans = 0; |
| 277 | |
| 278 | for (i = 0; i < req->n_channels; i++) { |
| 279 | if (req->channels[i]->band != |
| 280 | local->hw_scan_band) |
| 281 | continue; |
| 282 | local->hw_scan_req->req.channels[n_chans] = |
| 283 | req->channels[i]; |
| 284 | n_chans++; |
| 285 | bands_used |= BIT(req->channels[i]->band); |
| 286 | } |
| 287 | |
| 288 | local->hw_scan_band++; |
| 289 | } while (!n_chans); |
| 290 | } |
| 291 | |
| 292 | local->hw_scan_req->req.n_channels = n_chans; |
| 293 | ieee80211_prepare_scan_chandef(&chandef, req->scan_width); |
| 294 | |
| 295 | ielen = ieee80211_build_preq_ies(local, |
| 296 | (u8 *)local->hw_scan_req->req.ie, |
| 297 | local->hw_scan_ies_bufsize, |
| 298 | &local->hw_scan_req->ies, |
| 299 | req->ie, req->ie_len, |
| 300 | bands_used, req->rates, &chandef); |
| 301 | local->hw_scan_req->req.ie_len = ielen; |
| 302 | local->hw_scan_req->req.no_cck = req->no_cck; |
| 303 | ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr); |
| 304 | ether_addr_copy(local->hw_scan_req->req.mac_addr_mask, |
| 305 | req->mac_addr_mask); |
| 306 | |
| 307 | return true; |
| 308 | } |
| 309 | |
| 310 | static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
| 311 | { |
| 312 | struct ieee80211_local *local = hw_to_local(hw); |
| 313 | bool hw_scan = local->ops->hw_scan; |
| 314 | bool was_scanning = local->scanning; |
| 315 | struct cfg80211_scan_request *scan_req; |
| 316 | struct ieee80211_sub_if_data *scan_sdata; |
| 317 | struct ieee80211_sub_if_data *sdata; |
| 318 | |
| 319 | lockdep_assert_held(&local->mtx); |
| 320 | |
| 321 | /* |
| 322 | * It's ok to abort a not-yet-running scan (that |
| 323 | * we have one at all will be verified by checking |
| 324 | * local->scan_req next), but not to complete it |
| 325 | * successfully. |
| 326 | */ |
| 327 | if (WARN_ON(!local->scanning && !aborted)) |
| 328 | aborted = true; |
| 329 | |
| 330 | if (WARN_ON(!local->scan_req)) |
| 331 | return; |
| 332 | |
| 333 | if (hw_scan && !aborted && |
| 334 | !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) && |
| 335 | ieee80211_prep_hw_scan(local)) { |
| 336 | int rc; |
| 337 | |
| 338 | rc = drv_hw_scan(local, |
| 339 | rcu_dereference_protected(local->scan_sdata, |
| 340 | lockdep_is_held(&local->mtx)), |
| 341 | local->hw_scan_req); |
| 342 | |
| 343 | if (rc == 0) |
| 344 | return; |
| 345 | } |
| 346 | |
| 347 | kfree(local->hw_scan_req); |
| 348 | local->hw_scan_req = NULL; |
| 349 | |
| 350 | scan_req = rcu_dereference_protected(local->scan_req, |
| 351 | lockdep_is_held(&local->mtx)); |
| 352 | |
| 353 | if (scan_req != local->int_scan_req) |
| 354 | cfg80211_scan_done(scan_req, aborted); |
| 355 | RCU_INIT_POINTER(local->scan_req, NULL); |
| 356 | |
| 357 | scan_sdata = rcu_dereference_protected(local->scan_sdata, |
| 358 | lockdep_is_held(&local->mtx)); |
| 359 | RCU_INIT_POINTER(local->scan_sdata, NULL); |
| 360 | |
| 361 | local->scanning = 0; |
| 362 | local->scan_chandef.chan = NULL; |
| 363 | |
| 364 | /* Set power back to normal operating levels. */ |
| 365 | ieee80211_hw_config(local, 0); |
| 366 | |
| 367 | if (!hw_scan) { |
| 368 | ieee80211_configure_filter(local); |
| 369 | drv_sw_scan_complete(local, scan_sdata); |
| 370 | ieee80211_offchannel_return(local); |
| 371 | } |
| 372 | |
| 373 | ieee80211_recalc_idle(local); |
| 374 | |
| 375 | ieee80211_mlme_notify_scan_completed(local); |
| 376 | ieee80211_ibss_notify_scan_completed(local); |
| 377 | |
| 378 | /* Requeue all the work that might have been ignored while |
| 379 | * the scan was in progress; if there was none this will |
| 380 | * just be a no-op for the particular interface. |
| 381 | */ |
| 382 | list_for_each_entry_rcu(sdata, &local->interfaces, list) { |
| 383 | if (ieee80211_sdata_running(sdata)) |
| 384 | ieee80211_queue_work(&sdata->local->hw, &sdata->work); |
| 385 | } |
| 386 | |
| 387 | if (was_scanning) |
| 388 | ieee80211_start_next_roc(local); |
| 389 | } |
| 390 | |
| 391 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
| 392 | { |
| 393 | struct ieee80211_local *local = hw_to_local(hw); |
| 394 | |
| 395 | trace_api_scan_completed(local, aborted); |
| 396 | |
| 397 | set_bit(SCAN_COMPLETED, &local->scanning); |
| 398 | if (aborted) |
| 399 | set_bit(SCAN_ABORTED, &local->scanning); |
| 400 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); |
| 401 | } |
| 402 | EXPORT_SYMBOL(ieee80211_scan_completed); |
| 403 | |
| 404 | static int ieee80211_start_sw_scan(struct ieee80211_local *local, |
| 405 | struct ieee80211_sub_if_data *sdata) |
| 406 | { |
| 407 | /* Software scan is not supported in multi-channel cases */ |
| 408 | if (local->use_chanctx) |
| 409 | return -EOPNOTSUPP; |
| 410 | |
| 411 | /* |
| 412 | * Hardware/driver doesn't support hw_scan, so use software |
| 413 | * scanning instead. First send a nullfunc frame with power save |
| 414 | * bit on so that AP will buffer the frames for us while we are not |
| 415 | * listening, then send probe requests to each channel and wait for |
| 416 | * the responses. After all channels are scanned, tune back to the |
| 417 | * original channel and send a nullfunc frame with power save bit |
| 418 | * off to trigger the AP to send us all the buffered frames. |
| 419 | * |
| 420 | * Note that while local->sw_scanning is true everything else but |
| 421 | * nullfunc frames and probe requests will be dropped in |
| 422 | * ieee80211_tx_h_check_assoc(). |
| 423 | */ |
| 424 | drv_sw_scan_start(local, sdata, local->scan_addr); |
| 425 | |
| 426 | local->leave_oper_channel_time = jiffies; |
| 427 | local->next_scan_state = SCAN_DECISION; |
| 428 | local->scan_channel_idx = 0; |
| 429 | |
| 430 | ieee80211_offchannel_stop_vifs(local); |
| 431 | |
| 432 | /* ensure nullfunc is transmitted before leaving operating channel */ |
| 433 | ieee80211_flush_queues(local, NULL, false); |
| 434 | |
| 435 | ieee80211_configure_filter(local); |
| 436 | |
| 437 | /* We need to set power level at maximum rate for scanning. */ |
| 438 | ieee80211_hw_config(local, 0); |
| 439 | |
| 440 | ieee80211_queue_delayed_work(&local->hw, |
| 441 | &local->scan_work, 0); |
| 442 | |
| 443 | return 0; |
| 444 | } |
| 445 | |
| 446 | static bool ieee80211_can_scan(struct ieee80211_local *local, |
| 447 | struct ieee80211_sub_if_data *sdata) |
| 448 | { |
| 449 | if (ieee80211_is_radar_required(local)) |
| 450 | return false; |
| 451 | |
| 452 | if (!list_empty(&local->roc_list)) |
| 453 | return false; |
| 454 | |
| 455 | if (sdata->vif.type == NL80211_IFTYPE_STATION && |
| 456 | sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL) |
| 457 | return false; |
| 458 | |
| 459 | return true; |
| 460 | } |
| 461 | |
| 462 | void ieee80211_run_deferred_scan(struct ieee80211_local *local) |
| 463 | { |
| 464 | lockdep_assert_held(&local->mtx); |
| 465 | |
| 466 | if (!local->scan_req || local->scanning) |
| 467 | return; |
| 468 | |
| 469 | if (!ieee80211_can_scan(local, |
| 470 | rcu_dereference_protected( |
| 471 | local->scan_sdata, |
| 472 | lockdep_is_held(&local->mtx)))) |
| 473 | return; |
| 474 | |
| 475 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, |
| 476 | round_jiffies_relative(0)); |
| 477 | } |
| 478 | |
| 479 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, |
| 480 | unsigned long *next_delay) |
| 481 | { |
| 482 | int i; |
| 483 | struct ieee80211_sub_if_data *sdata; |
| 484 | struct cfg80211_scan_request *scan_req; |
| 485 | enum ieee80211_band band = local->hw.conf.chandef.chan->band; |
| 486 | u32 tx_flags; |
| 487 | |
| 488 | scan_req = rcu_dereference_protected(local->scan_req, |
| 489 | lockdep_is_held(&local->mtx)); |
| 490 | |
| 491 | tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK; |
| 492 | if (scan_req->no_cck) |
| 493 | tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE; |
| 494 | |
| 495 | sdata = rcu_dereference_protected(local->scan_sdata, |
| 496 | lockdep_is_held(&local->mtx)); |
| 497 | |
| 498 | for (i = 0; i < scan_req->n_ssids; i++) |
| 499 | ieee80211_send_probe_req( |
| 500 | sdata, local->scan_addr, NULL, |
| 501 | scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len, |
| 502 | scan_req->ie, scan_req->ie_len, |
| 503 | scan_req->rates[band], false, |
| 504 | tx_flags, local->hw.conf.chandef.chan, true); |
| 505 | |
| 506 | /* |
| 507 | * After sending probe requests, wait for probe responses |
| 508 | * on the channel. |
| 509 | */ |
| 510 | *next_delay = IEEE80211_CHANNEL_TIME; |
| 511 | local->next_scan_state = SCAN_DECISION; |
| 512 | } |
| 513 | |
| 514 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, |
| 515 | struct cfg80211_scan_request *req) |
| 516 | { |
| 517 | struct ieee80211_local *local = sdata->local; |
| 518 | int rc; |
| 519 | |
| 520 | lockdep_assert_held(&local->mtx); |
| 521 | |
| 522 | if (local->scan_req || ieee80211_is_radar_required(local)) |
| 523 | return -EBUSY; |
| 524 | |
| 525 | if (!ieee80211_can_scan(local, sdata)) { |
| 526 | /* wait for the work to finish/time out */ |
| 527 | rcu_assign_pointer(local->scan_req, req); |
| 528 | rcu_assign_pointer(local->scan_sdata, sdata); |
| 529 | return 0; |
| 530 | } |
| 531 | |
| 532 | if (local->ops->hw_scan) { |
| 533 | u8 *ies; |
| 534 | |
| 535 | local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len; |
| 536 | |
| 537 | if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) { |
| 538 | int i, n_bands = 0; |
| 539 | u8 bands_counted = 0; |
| 540 | |
| 541 | for (i = 0; i < req->n_channels; i++) { |
| 542 | if (bands_counted & BIT(req->channels[i]->band)) |
| 543 | continue; |
| 544 | bands_counted |= BIT(req->channels[i]->band); |
| 545 | n_bands++; |
| 546 | } |
| 547 | |
| 548 | local->hw_scan_ies_bufsize *= n_bands; |
| 549 | } |
| 550 | |
| 551 | local->hw_scan_req = kmalloc( |
| 552 | sizeof(*local->hw_scan_req) + |
| 553 | req->n_channels * sizeof(req->channels[0]) + |
| 554 | local->hw_scan_ies_bufsize, GFP_KERNEL); |
| 555 | if (!local->hw_scan_req) |
| 556 | return -ENOMEM; |
| 557 | |
| 558 | local->hw_scan_req->req.ssids = req->ssids; |
| 559 | local->hw_scan_req->req.n_ssids = req->n_ssids; |
| 560 | ies = (u8 *)local->hw_scan_req + |
| 561 | sizeof(*local->hw_scan_req) + |
| 562 | req->n_channels * sizeof(req->channels[0]); |
| 563 | local->hw_scan_req->req.ie = ies; |
| 564 | local->hw_scan_req->req.flags = req->flags; |
| 565 | |
| 566 | local->hw_scan_band = 0; |
| 567 | |
| 568 | /* |
| 569 | * After allocating local->hw_scan_req, we must |
| 570 | * go through until ieee80211_prep_hw_scan(), so |
| 571 | * anything that might be changed here and leave |
| 572 | * this function early must not go after this |
| 573 | * allocation. |
| 574 | */ |
| 575 | } |
| 576 | |
| 577 | rcu_assign_pointer(local->scan_req, req); |
| 578 | rcu_assign_pointer(local->scan_sdata, sdata); |
| 579 | |
| 580 | if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR) |
| 581 | get_random_mask_addr(local->scan_addr, |
| 582 | req->mac_addr, |
| 583 | req->mac_addr_mask); |
| 584 | else |
| 585 | memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN); |
| 586 | |
| 587 | if (local->ops->hw_scan) { |
| 588 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
| 589 | } else if ((req->n_channels == 1) && |
| 590 | (req->channels[0] == local->_oper_chandef.chan)) { |
| 591 | /* |
| 592 | * If we are scanning only on the operating channel |
| 593 | * then we do not need to stop normal activities |
| 594 | */ |
| 595 | unsigned long next_delay; |
| 596 | |
| 597 | __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning); |
| 598 | |
| 599 | ieee80211_recalc_idle(local); |
| 600 | |
| 601 | /* Notify driver scan is starting, keep order of operations |
| 602 | * same as normal software scan, in case that matters. */ |
| 603 | drv_sw_scan_start(local, sdata, local->scan_addr); |
| 604 | |
| 605 | ieee80211_configure_filter(local); /* accept probe-responses */ |
| 606 | |
| 607 | /* We need to ensure power level is at max for scanning. */ |
| 608 | ieee80211_hw_config(local, 0); |
| 609 | |
| 610 | if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR | |
| 611 | IEEE80211_CHAN_RADAR)) || |
| 612 | !req->n_ssids) { |
| 613 | next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; |
| 614 | } else { |
| 615 | ieee80211_scan_state_send_probe(local, &next_delay); |
| 616 | next_delay = IEEE80211_CHANNEL_TIME; |
| 617 | } |
| 618 | |
| 619 | /* Now, just wait a bit and we are all done! */ |
| 620 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, |
| 621 | next_delay); |
| 622 | return 0; |
| 623 | } else { |
| 624 | /* Do normal software scan */ |
| 625 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
| 626 | } |
| 627 | |
| 628 | ieee80211_recalc_idle(local); |
| 629 | |
| 630 | if (local->ops->hw_scan) { |
| 631 | WARN_ON(!ieee80211_prep_hw_scan(local)); |
| 632 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
| 633 | } else { |
| 634 | rc = ieee80211_start_sw_scan(local, sdata); |
| 635 | } |
| 636 | |
| 637 | if (rc) { |
| 638 | kfree(local->hw_scan_req); |
| 639 | local->hw_scan_req = NULL; |
| 640 | local->scanning = 0; |
| 641 | |
| 642 | ieee80211_recalc_idle(local); |
| 643 | |
| 644 | local->scan_req = NULL; |
| 645 | RCU_INIT_POINTER(local->scan_sdata, NULL); |
| 646 | } |
| 647 | |
| 648 | return rc; |
| 649 | } |
| 650 | |
| 651 | static unsigned long |
| 652 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) |
| 653 | { |
| 654 | /* |
| 655 | * TODO: channel switching also consumes quite some time, |
| 656 | * add that delay as well to get a better estimation |
| 657 | */ |
| 658 | if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) |
| 659 | return IEEE80211_PASSIVE_CHANNEL_TIME; |
| 660 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; |
| 661 | } |
| 662 | |
| 663 | static void ieee80211_scan_state_decision(struct ieee80211_local *local, |
| 664 | unsigned long *next_delay) |
| 665 | { |
| 666 | bool associated = false; |
| 667 | bool tx_empty = true; |
| 668 | bool bad_latency; |
| 669 | struct ieee80211_sub_if_data *sdata; |
| 670 | struct ieee80211_channel *next_chan; |
| 671 | enum mac80211_scan_state next_scan_state; |
| 672 | struct cfg80211_scan_request *scan_req; |
| 673 | |
| 674 | /* |
| 675 | * check if at least one STA interface is associated, |
| 676 | * check if at least one STA interface has pending tx frames |
| 677 | * and grab the lowest used beacon interval |
| 678 | */ |
| 679 | mutex_lock(&local->iflist_mtx); |
| 680 | list_for_each_entry(sdata, &local->interfaces, list) { |
| 681 | if (!ieee80211_sdata_running(sdata)) |
| 682 | continue; |
| 683 | |
| 684 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { |
| 685 | if (sdata->u.mgd.associated) { |
| 686 | associated = true; |
| 687 | |
| 688 | if (!qdisc_all_tx_empty(sdata->dev)) { |
| 689 | tx_empty = false; |
| 690 | break; |
| 691 | } |
| 692 | } |
| 693 | } |
| 694 | } |
| 695 | mutex_unlock(&local->iflist_mtx); |
| 696 | |
| 697 | scan_req = rcu_dereference_protected(local->scan_req, |
| 698 | lockdep_is_held(&local->mtx)); |
| 699 | |
| 700 | next_chan = scan_req->channels[local->scan_channel_idx]; |
| 701 | |
| 702 | /* |
| 703 | * we're currently scanning a different channel, let's |
| 704 | * see if we can scan another channel without interfering |
| 705 | * with the current traffic situation. |
| 706 | * |
| 707 | * Keep good latency, do not stay off-channel more than 125 ms. |
| 708 | */ |
| 709 | |
| 710 | bad_latency = time_after(jiffies + |
| 711 | ieee80211_scan_get_channel_time(next_chan), |
| 712 | local->leave_oper_channel_time + HZ / 8); |
| 713 | |
| 714 | if (associated && !tx_empty) { |
| 715 | if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY) |
| 716 | next_scan_state = SCAN_ABORT; |
| 717 | else |
| 718 | next_scan_state = SCAN_SUSPEND; |
| 719 | } else if (associated && bad_latency) { |
| 720 | next_scan_state = SCAN_SUSPEND; |
| 721 | } else { |
| 722 | next_scan_state = SCAN_SET_CHANNEL; |
| 723 | } |
| 724 | |
| 725 | local->next_scan_state = next_scan_state; |
| 726 | |
| 727 | *next_delay = 0; |
| 728 | } |
| 729 | |
| 730 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
| 731 | unsigned long *next_delay) |
| 732 | { |
| 733 | int skip; |
| 734 | struct ieee80211_channel *chan; |
| 735 | enum nl80211_bss_scan_width oper_scan_width; |
| 736 | struct cfg80211_scan_request *scan_req; |
| 737 | |
| 738 | scan_req = rcu_dereference_protected(local->scan_req, |
| 739 | lockdep_is_held(&local->mtx)); |
| 740 | |
| 741 | skip = 0; |
| 742 | chan = scan_req->channels[local->scan_channel_idx]; |
| 743 | |
| 744 | local->scan_chandef.chan = chan; |
| 745 | local->scan_chandef.center_freq1 = chan->center_freq; |
| 746 | local->scan_chandef.center_freq2 = 0; |
| 747 | switch (scan_req->scan_width) { |
| 748 | case NL80211_BSS_CHAN_WIDTH_5: |
| 749 | local->scan_chandef.width = NL80211_CHAN_WIDTH_5; |
| 750 | break; |
| 751 | case NL80211_BSS_CHAN_WIDTH_10: |
| 752 | local->scan_chandef.width = NL80211_CHAN_WIDTH_10; |
| 753 | break; |
| 754 | case NL80211_BSS_CHAN_WIDTH_20: |
| 755 | /* If scanning on oper channel, use whatever channel-type |
| 756 | * is currently in use. |
| 757 | */ |
| 758 | oper_scan_width = cfg80211_chandef_to_scan_width( |
| 759 | &local->_oper_chandef); |
| 760 | if (chan == local->_oper_chandef.chan && |
| 761 | oper_scan_width == scan_req->scan_width) |
| 762 | local->scan_chandef = local->_oper_chandef; |
| 763 | else |
| 764 | local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT; |
| 765 | break; |
| 766 | } |
| 767 | |
| 768 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) |
| 769 | skip = 1; |
| 770 | |
| 771 | /* advance state machine to next channel/band */ |
| 772 | local->scan_channel_idx++; |
| 773 | |
| 774 | if (skip) { |
| 775 | /* if we skip this channel return to the decision state */ |
| 776 | local->next_scan_state = SCAN_DECISION; |
| 777 | return; |
| 778 | } |
| 779 | |
| 780 | /* |
| 781 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 |
| 782 | * (which unfortunately doesn't say _why_ step a) is done, |
| 783 | * but it waits for the probe delay or until a frame is |
| 784 | * received - and the received frame would update the NAV). |
| 785 | * For now, we do not support waiting until a frame is |
| 786 | * received. |
| 787 | * |
| 788 | * In any case, it is not necessary for a passive scan. |
| 789 | */ |
| 790 | if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) || |
| 791 | !scan_req->n_ssids) { |
| 792 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; |
| 793 | local->next_scan_state = SCAN_DECISION; |
| 794 | return; |
| 795 | } |
| 796 | |
| 797 | /* active scan, send probes */ |
| 798 | *next_delay = IEEE80211_PROBE_DELAY; |
| 799 | local->next_scan_state = SCAN_SEND_PROBE; |
| 800 | } |
| 801 | |
| 802 | static void ieee80211_scan_state_suspend(struct ieee80211_local *local, |
| 803 | unsigned long *next_delay) |
| 804 | { |
| 805 | /* switch back to the operating channel */ |
| 806 | local->scan_chandef.chan = NULL; |
| 807 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
| 808 | |
| 809 | /* disable PS */ |
| 810 | ieee80211_offchannel_return(local); |
| 811 | |
| 812 | *next_delay = HZ / 5; |
| 813 | /* afterwards, resume scan & go to next channel */ |
| 814 | local->next_scan_state = SCAN_RESUME; |
| 815 | } |
| 816 | |
| 817 | static void ieee80211_scan_state_resume(struct ieee80211_local *local, |
| 818 | unsigned long *next_delay) |
| 819 | { |
| 820 | ieee80211_offchannel_stop_vifs(local); |
| 821 | |
| 822 | if (local->ops->flush) { |
| 823 | ieee80211_flush_queues(local, NULL, false); |
| 824 | *next_delay = 0; |
| 825 | } else |
| 826 | *next_delay = HZ / 10; |
| 827 | |
| 828 | /* remember when we left the operating channel */ |
| 829 | local->leave_oper_channel_time = jiffies; |
| 830 | |
| 831 | /* advance to the next channel to be scanned */ |
| 832 | local->next_scan_state = SCAN_SET_CHANNEL; |
| 833 | } |
| 834 | |
| 835 | void ieee80211_scan_work(struct work_struct *work) |
| 836 | { |
| 837 | struct ieee80211_local *local = |
| 838 | container_of(work, struct ieee80211_local, scan_work.work); |
| 839 | struct ieee80211_sub_if_data *sdata; |
| 840 | struct cfg80211_scan_request *scan_req; |
| 841 | unsigned long next_delay = 0; |
| 842 | bool aborted; |
| 843 | |
| 844 | mutex_lock(&local->mtx); |
| 845 | |
| 846 | if (!ieee80211_can_run_worker(local)) { |
| 847 | aborted = true; |
| 848 | goto out_complete; |
| 849 | } |
| 850 | |
| 851 | sdata = rcu_dereference_protected(local->scan_sdata, |
| 852 | lockdep_is_held(&local->mtx)); |
| 853 | scan_req = rcu_dereference_protected(local->scan_req, |
| 854 | lockdep_is_held(&local->mtx)); |
| 855 | |
| 856 | /* When scanning on-channel, the first-callback means completed. */ |
| 857 | if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) { |
| 858 | aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); |
| 859 | goto out_complete; |
| 860 | } |
| 861 | |
| 862 | if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { |
| 863 | aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); |
| 864 | goto out_complete; |
| 865 | } |
| 866 | |
| 867 | if (!sdata || !scan_req) |
| 868 | goto out; |
| 869 | |
| 870 | if (!local->scanning) { |
| 871 | int rc; |
| 872 | |
| 873 | RCU_INIT_POINTER(local->scan_req, NULL); |
| 874 | RCU_INIT_POINTER(local->scan_sdata, NULL); |
| 875 | |
| 876 | rc = __ieee80211_start_scan(sdata, scan_req); |
| 877 | if (rc) { |
| 878 | /* need to complete scan in cfg80211 */ |
| 879 | rcu_assign_pointer(local->scan_req, scan_req); |
| 880 | aborted = true; |
| 881 | goto out_complete; |
| 882 | } else |
| 883 | goto out; |
| 884 | } |
| 885 | |
| 886 | /* |
| 887 | * as long as no delay is required advance immediately |
| 888 | * without scheduling a new work |
| 889 | */ |
| 890 | do { |
| 891 | if (!ieee80211_sdata_running(sdata)) { |
| 892 | aborted = true; |
| 893 | goto out_complete; |
| 894 | } |
| 895 | |
| 896 | switch (local->next_scan_state) { |
| 897 | case SCAN_DECISION: |
| 898 | /* if no more bands/channels left, complete scan */ |
| 899 | if (local->scan_channel_idx >= scan_req->n_channels) { |
| 900 | aborted = false; |
| 901 | goto out_complete; |
| 902 | } |
| 903 | ieee80211_scan_state_decision(local, &next_delay); |
| 904 | break; |
| 905 | case SCAN_SET_CHANNEL: |
| 906 | ieee80211_scan_state_set_channel(local, &next_delay); |
| 907 | break; |
| 908 | case SCAN_SEND_PROBE: |
| 909 | ieee80211_scan_state_send_probe(local, &next_delay); |
| 910 | break; |
| 911 | case SCAN_SUSPEND: |
| 912 | ieee80211_scan_state_suspend(local, &next_delay); |
| 913 | break; |
| 914 | case SCAN_RESUME: |
| 915 | ieee80211_scan_state_resume(local, &next_delay); |
| 916 | break; |
| 917 | case SCAN_ABORT: |
| 918 | aborted = true; |
| 919 | goto out_complete; |
| 920 | } |
| 921 | } while (next_delay == 0); |
| 922 | |
| 923 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
| 924 | goto out; |
| 925 | |
| 926 | out_complete: |
| 927 | __ieee80211_scan_completed(&local->hw, aborted); |
| 928 | out: |
| 929 | mutex_unlock(&local->mtx); |
| 930 | } |
| 931 | |
| 932 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
| 933 | struct cfg80211_scan_request *req) |
| 934 | { |
| 935 | int res; |
| 936 | |
| 937 | mutex_lock(&sdata->local->mtx); |
| 938 | res = __ieee80211_start_scan(sdata, req); |
| 939 | mutex_unlock(&sdata->local->mtx); |
| 940 | |
| 941 | return res; |
| 942 | } |
| 943 | |
| 944 | int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, |
| 945 | const u8 *ssid, u8 ssid_len, |
| 946 | struct ieee80211_channel **channels, |
| 947 | unsigned int n_channels, |
| 948 | enum nl80211_bss_scan_width scan_width) |
| 949 | { |
| 950 | struct ieee80211_local *local = sdata->local; |
| 951 | int ret = -EBUSY, i, n_ch = 0; |
| 952 | enum ieee80211_band band; |
| 953 | |
| 954 | mutex_lock(&local->mtx); |
| 955 | |
| 956 | /* busy scanning */ |
| 957 | if (local->scan_req) |
| 958 | goto unlock; |
| 959 | |
| 960 | /* fill internal scan request */ |
| 961 | if (!channels) { |
| 962 | int max_n; |
| 963 | |
| 964 | for (band = 0; band < IEEE80211_NUM_BANDS; band++) { |
| 965 | if (!local->hw.wiphy->bands[band]) |
| 966 | continue; |
| 967 | |
| 968 | max_n = local->hw.wiphy->bands[band]->n_channels; |
| 969 | for (i = 0; i < max_n; i++) { |
| 970 | struct ieee80211_channel *tmp_ch = |
| 971 | &local->hw.wiphy->bands[band]->channels[i]; |
| 972 | |
| 973 | if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR | |
| 974 | IEEE80211_CHAN_DISABLED)) |
| 975 | continue; |
| 976 | |
| 977 | local->int_scan_req->channels[n_ch] = tmp_ch; |
| 978 | n_ch++; |
| 979 | } |
| 980 | } |
| 981 | |
| 982 | if (WARN_ON_ONCE(n_ch == 0)) |
| 983 | goto unlock; |
| 984 | |
| 985 | local->int_scan_req->n_channels = n_ch; |
| 986 | } else { |
| 987 | for (i = 0; i < n_channels; i++) { |
| 988 | if (channels[i]->flags & (IEEE80211_CHAN_NO_IR | |
| 989 | IEEE80211_CHAN_DISABLED)) |
| 990 | continue; |
| 991 | |
| 992 | local->int_scan_req->channels[n_ch] = channels[i]; |
| 993 | n_ch++; |
| 994 | } |
| 995 | |
| 996 | if (WARN_ON_ONCE(n_ch == 0)) |
| 997 | goto unlock; |
| 998 | |
| 999 | local->int_scan_req->n_channels = n_ch; |
| 1000 | } |
| 1001 | |
| 1002 | local->int_scan_req->ssids = &local->scan_ssid; |
| 1003 | local->int_scan_req->n_ssids = 1; |
| 1004 | local->int_scan_req->scan_width = scan_width; |
| 1005 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
| 1006 | local->int_scan_req->ssids[0].ssid_len = ssid_len; |
| 1007 | |
| 1008 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
| 1009 | unlock: |
| 1010 | mutex_unlock(&local->mtx); |
| 1011 | return ret; |
| 1012 | } |
| 1013 | |
| 1014 | /* |
| 1015 | * Only call this function when a scan can't be queued -- under RTNL. |
| 1016 | */ |
| 1017 | void ieee80211_scan_cancel(struct ieee80211_local *local) |
| 1018 | { |
| 1019 | /* |
| 1020 | * We are canceling software scan, or deferred scan that was not |
| 1021 | * yet really started (see __ieee80211_start_scan ). |
| 1022 | * |
| 1023 | * Regarding hardware scan: |
| 1024 | * - we can not call __ieee80211_scan_completed() as when |
| 1025 | * SCAN_HW_SCANNING bit is set this function change |
| 1026 | * local->hw_scan_req to operate on 5G band, what race with |
| 1027 | * driver which can use local->hw_scan_req |
| 1028 | * |
| 1029 | * - we can not cancel scan_work since driver can schedule it |
| 1030 | * by ieee80211_scan_completed(..., true) to finish scan |
| 1031 | * |
| 1032 | * Hence we only call the cancel_hw_scan() callback, but the low-level |
| 1033 | * driver is still responsible for calling ieee80211_scan_completed() |
| 1034 | * after the scan was completed/aborted. |
| 1035 | */ |
| 1036 | |
| 1037 | mutex_lock(&local->mtx); |
| 1038 | if (!local->scan_req) |
| 1039 | goto out; |
| 1040 | |
| 1041 | /* |
| 1042 | * We have a scan running and the driver already reported completion, |
| 1043 | * but the worker hasn't run yet or is stuck on the mutex - mark it as |
| 1044 | * cancelled. |
| 1045 | */ |
| 1046 | if (test_bit(SCAN_HW_SCANNING, &local->scanning) && |
| 1047 | test_bit(SCAN_COMPLETED, &local->scanning)) { |
| 1048 | set_bit(SCAN_HW_CANCELLED, &local->scanning); |
| 1049 | goto out; |
| 1050 | } |
| 1051 | |
| 1052 | if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { |
| 1053 | /* |
| 1054 | * Make sure that __ieee80211_scan_completed doesn't trigger a |
| 1055 | * scan on another band. |
| 1056 | */ |
| 1057 | set_bit(SCAN_HW_CANCELLED, &local->scanning); |
| 1058 | if (local->ops->cancel_hw_scan) |
| 1059 | drv_cancel_hw_scan(local, |
| 1060 | rcu_dereference_protected(local->scan_sdata, |
| 1061 | lockdep_is_held(&local->mtx))); |
| 1062 | goto out; |
| 1063 | } |
| 1064 | |
| 1065 | /* |
| 1066 | * If the work is currently running, it must be blocked on |
| 1067 | * the mutex, but we'll set scan_sdata = NULL and it'll |
| 1068 | * simply exit once it acquires the mutex. |
| 1069 | */ |
| 1070 | cancel_delayed_work(&local->scan_work); |
| 1071 | /* and clean up */ |
| 1072 | __ieee80211_scan_completed(&local->hw, true); |
| 1073 | out: |
| 1074 | mutex_unlock(&local->mtx); |
| 1075 | } |
| 1076 | |
| 1077 | int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, |
| 1078 | struct cfg80211_sched_scan_request *req) |
| 1079 | { |
| 1080 | struct ieee80211_local *local = sdata->local; |
| 1081 | struct ieee80211_scan_ies sched_scan_ies = {}; |
| 1082 | struct cfg80211_chan_def chandef; |
| 1083 | int ret, i, iebufsz, num_bands = 0; |
| 1084 | u32 rate_masks[IEEE80211_NUM_BANDS] = {}; |
| 1085 | u8 bands_used = 0; |
| 1086 | u8 *ie; |
| 1087 | size_t len; |
| 1088 | |
| 1089 | iebufsz = local->scan_ies_len + req->ie_len; |
| 1090 | |
| 1091 | lockdep_assert_held(&local->mtx); |
| 1092 | |
| 1093 | if (!local->ops->sched_scan_start) |
| 1094 | return -ENOTSUPP; |
| 1095 | |
| 1096 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { |
| 1097 | if (local->hw.wiphy->bands[i]) { |
| 1098 | bands_used |= BIT(i); |
| 1099 | rate_masks[i] = (u32) -1; |
| 1100 | num_bands++; |
| 1101 | } |
| 1102 | } |
| 1103 | |
| 1104 | ie = kzalloc(num_bands * iebufsz, GFP_KERNEL); |
| 1105 | if (!ie) { |
| 1106 | ret = -ENOMEM; |
| 1107 | goto out; |
| 1108 | } |
| 1109 | |
| 1110 | ieee80211_prepare_scan_chandef(&chandef, req->scan_width); |
| 1111 | |
| 1112 | len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz, |
| 1113 | &sched_scan_ies, req->ie, |
| 1114 | req->ie_len, bands_used, |
| 1115 | rate_masks, &chandef); |
| 1116 | |
| 1117 | ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies); |
| 1118 | if (ret == 0) { |
| 1119 | rcu_assign_pointer(local->sched_scan_sdata, sdata); |
| 1120 | rcu_assign_pointer(local->sched_scan_req, req); |
| 1121 | } |
| 1122 | |
| 1123 | kfree(ie); |
| 1124 | |
| 1125 | out: |
| 1126 | if (ret) { |
| 1127 | /* Clean in case of failure after HW restart or upon resume. */ |
| 1128 | RCU_INIT_POINTER(local->sched_scan_sdata, NULL); |
| 1129 | RCU_INIT_POINTER(local->sched_scan_req, NULL); |
| 1130 | } |
| 1131 | |
| 1132 | return ret; |
| 1133 | } |
| 1134 | |
| 1135 | int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, |
| 1136 | struct cfg80211_sched_scan_request *req) |
| 1137 | { |
| 1138 | struct ieee80211_local *local = sdata->local; |
| 1139 | int ret; |
| 1140 | |
| 1141 | mutex_lock(&local->mtx); |
| 1142 | |
| 1143 | if (rcu_access_pointer(local->sched_scan_sdata)) { |
| 1144 | mutex_unlock(&local->mtx); |
| 1145 | return -EBUSY; |
| 1146 | } |
| 1147 | |
| 1148 | ret = __ieee80211_request_sched_scan_start(sdata, req); |
| 1149 | |
| 1150 | mutex_unlock(&local->mtx); |
| 1151 | return ret; |
| 1152 | } |
| 1153 | |
| 1154 | int ieee80211_request_sched_scan_stop(struct ieee80211_local *local) |
| 1155 | { |
| 1156 | struct ieee80211_sub_if_data *sched_scan_sdata; |
| 1157 | int ret = -ENOENT; |
| 1158 | |
| 1159 | mutex_lock(&local->mtx); |
| 1160 | |
| 1161 | if (!local->ops->sched_scan_stop) { |
| 1162 | ret = -ENOTSUPP; |
| 1163 | goto out; |
| 1164 | } |
| 1165 | |
| 1166 | /* We don't want to restart sched scan anymore. */ |
| 1167 | RCU_INIT_POINTER(local->sched_scan_req, NULL); |
| 1168 | |
| 1169 | sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata, |
| 1170 | lockdep_is_held(&local->mtx)); |
| 1171 | if (sched_scan_sdata) { |
| 1172 | ret = drv_sched_scan_stop(local, sched_scan_sdata); |
| 1173 | if (!ret) |
| 1174 | RCU_INIT_POINTER(local->sched_scan_sdata, NULL); |
| 1175 | } |
| 1176 | out: |
| 1177 | mutex_unlock(&local->mtx); |
| 1178 | |
| 1179 | return ret; |
| 1180 | } |
| 1181 | |
| 1182 | void ieee80211_sched_scan_results(struct ieee80211_hw *hw) |
| 1183 | { |
| 1184 | struct ieee80211_local *local = hw_to_local(hw); |
| 1185 | |
| 1186 | trace_api_sched_scan_results(local); |
| 1187 | |
| 1188 | cfg80211_sched_scan_results(hw->wiphy); |
| 1189 | } |
| 1190 | EXPORT_SYMBOL(ieee80211_sched_scan_results); |
| 1191 | |
| 1192 | void ieee80211_sched_scan_end(struct ieee80211_local *local) |
| 1193 | { |
| 1194 | mutex_lock(&local->mtx); |
| 1195 | |
| 1196 | if (!rcu_access_pointer(local->sched_scan_sdata)) { |
| 1197 | mutex_unlock(&local->mtx); |
| 1198 | return; |
| 1199 | } |
| 1200 | |
| 1201 | RCU_INIT_POINTER(local->sched_scan_sdata, NULL); |
| 1202 | |
| 1203 | /* If sched scan was aborted by the driver. */ |
| 1204 | RCU_INIT_POINTER(local->sched_scan_req, NULL); |
| 1205 | |
| 1206 | mutex_unlock(&local->mtx); |
| 1207 | |
| 1208 | cfg80211_sched_scan_stopped(local->hw.wiphy); |
| 1209 | } |
| 1210 | |
| 1211 | void ieee80211_sched_scan_stopped_work(struct work_struct *work) |
| 1212 | { |
| 1213 | struct ieee80211_local *local = |
| 1214 | container_of(work, struct ieee80211_local, |
| 1215 | sched_scan_stopped_work); |
| 1216 | |
| 1217 | ieee80211_sched_scan_end(local); |
| 1218 | } |
| 1219 | |
| 1220 | void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) |
| 1221 | { |
| 1222 | struct ieee80211_local *local = hw_to_local(hw); |
| 1223 | |
| 1224 | trace_api_sched_scan_stopped(local); |
| 1225 | |
| 1226 | /* |
| 1227 | * this shouldn't really happen, so for simplicity |
| 1228 | * simply ignore it, and let mac80211 reconfigure |
| 1229 | * the sched scan later on. |
| 1230 | */ |
| 1231 | if (local->in_reconfig) |
| 1232 | return; |
| 1233 | |
| 1234 | schedule_work(&local->sched_scan_stopped_work); |
| 1235 | } |
| 1236 | EXPORT_SYMBOL(ieee80211_sched_scan_stopped); |