lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 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 | |
| 15 | #include <linux/if_arp.h> |
| 16 | #include <linux/etherdevice.h> |
| 17 | #include <linux/rtnetlink.h> |
| 18 | #include <linux/pm_qos.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 / 8) |
| 31 | |
| 32 | struct ieee80211_bss * |
| 33 | ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq, |
| 34 | u8 *ssid, u8 ssid_len) |
| 35 | { |
| 36 | struct cfg80211_bss *cbss; |
| 37 | |
| 38 | cbss = cfg80211_get_bss(local->hw.wiphy, |
| 39 | ieee80211_get_channel(local->hw.wiphy, freq), |
| 40 | bssid, ssid, ssid_len, 0, 0); |
| 41 | if (!cbss) |
| 42 | return NULL; |
| 43 | return (void *)cbss->priv; |
| 44 | } |
| 45 | |
| 46 | static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss) |
| 47 | { |
| 48 | struct ieee80211_bss *bss = (void *)cbss->priv; |
| 49 | |
| 50 | kfree(bss_mesh_id(bss)); |
| 51 | kfree(bss_mesh_cfg(bss)); |
| 52 | } |
| 53 | |
| 54 | void ieee80211_rx_bss_put(struct ieee80211_local *local, |
| 55 | struct ieee80211_bss *bss) |
| 56 | { |
| 57 | if (!bss) |
| 58 | return; |
| 59 | cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv)); |
| 60 | } |
| 61 | |
| 62 | static bool is_uapsd_supported(struct ieee802_11_elems *elems) |
| 63 | { |
| 64 | u8 qos_info; |
| 65 | |
| 66 | if (elems->wmm_info && elems->wmm_info_len == 7 |
| 67 | && elems->wmm_info[5] == 1) |
| 68 | qos_info = elems->wmm_info[6]; |
| 69 | else if (elems->wmm_param && elems->wmm_param_len == 24 |
| 70 | && elems->wmm_param[5] == 1) |
| 71 | qos_info = elems->wmm_param[6]; |
| 72 | else |
| 73 | /* no valid wmm information or parameter element found */ |
| 74 | return false; |
| 75 | |
| 76 | return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD; |
| 77 | } |
| 78 | |
| 79 | struct ieee80211_bss * |
| 80 | ieee80211_bss_info_update(struct ieee80211_local *local, |
| 81 | struct ieee80211_rx_status *rx_status, |
| 82 | struct ieee80211_mgmt *mgmt, |
| 83 | size_t len, |
| 84 | struct ieee802_11_elems *elems, |
| 85 | struct ieee80211_channel *channel, |
| 86 | bool beacon) |
| 87 | { |
| 88 | struct cfg80211_bss *cbss; |
| 89 | struct ieee80211_bss *bss; |
| 90 | int clen, srlen; |
| 91 | s32 signal = 0; |
| 92 | |
| 93 | if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) |
| 94 | signal = rx_status->signal * 100; |
| 95 | else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC) |
| 96 | signal = (rx_status->signal * 100) / local->hw.max_signal; |
| 97 | |
| 98 | cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel, |
| 99 | mgmt, len, signal, GFP_ATOMIC); |
| 100 | |
| 101 | if (!cbss) |
| 102 | return NULL; |
| 103 | |
| 104 | cbss->free_priv = ieee80211_rx_bss_free; |
| 105 | bss = (void *)cbss->priv; |
| 106 | |
| 107 | if (elems->parse_error) { |
| 108 | if (beacon) |
| 109 | bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON; |
| 110 | else |
| 111 | bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP; |
| 112 | } else { |
| 113 | if (beacon) |
| 114 | bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON; |
| 115 | else |
| 116 | bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP; |
| 117 | } |
| 118 | |
| 119 | /* save the ERP value so that it is available at association time */ |
| 120 | if (elems->erp_info && elems->erp_info_len >= 1 && |
| 121 | (!elems->parse_error || |
| 122 | !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) { |
| 123 | bss->erp_value = elems->erp_info[0]; |
| 124 | bss->has_erp_value = true; |
| 125 | if (!elems->parse_error) |
| 126 | bss->valid_data |= IEEE80211_BSS_VALID_ERP; |
| 127 | } |
| 128 | |
| 129 | if (elems->tim && (!elems->parse_error || |
| 130 | !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) { |
| 131 | struct ieee80211_tim_ie *tim_ie = |
| 132 | (struct ieee80211_tim_ie *)elems->tim; |
| 133 | bss->dtim_period = tim_ie->dtim_period; |
| 134 | if (!elems->parse_error) |
| 135 | bss->valid_data |= IEEE80211_BSS_VALID_DTIM; |
| 136 | } |
| 137 | |
| 138 | /* If the beacon had no TIM IE, or it was invalid, use 1 */ |
| 139 | if (beacon && !bss->dtim_period) |
| 140 | bss->dtim_period = 1; |
| 141 | |
| 142 | /* replace old supported rates if we get new values */ |
| 143 | if (!elems->parse_error || |
| 144 | !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) { |
| 145 | srlen = 0; |
| 146 | if (elems->supp_rates) { |
| 147 | clen = IEEE80211_MAX_SUPP_RATES; |
| 148 | if (clen > elems->supp_rates_len) |
| 149 | clen = elems->supp_rates_len; |
| 150 | memcpy(bss->supp_rates, elems->supp_rates, clen); |
| 151 | srlen += clen; |
| 152 | } |
| 153 | if (elems->ext_supp_rates) { |
| 154 | clen = IEEE80211_MAX_SUPP_RATES - srlen; |
| 155 | if (clen > elems->ext_supp_rates_len) |
| 156 | clen = elems->ext_supp_rates_len; |
| 157 | memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, |
| 158 | clen); |
| 159 | srlen += clen; |
| 160 | } |
| 161 | if (srlen) { |
| 162 | bss->supp_rates_len = srlen; |
| 163 | if (!elems->parse_error) |
| 164 | bss->valid_data |= IEEE80211_BSS_VALID_RATES; |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | if (!elems->parse_error || |
| 169 | !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) { |
| 170 | bss->wmm_used = elems->wmm_param || elems->wmm_info; |
| 171 | bss->uapsd_supported = is_uapsd_supported(elems); |
| 172 | if (!elems->parse_error) |
| 173 | bss->valid_data |= IEEE80211_BSS_VALID_WMM; |
| 174 | } |
| 175 | |
| 176 | if (!beacon) |
| 177 | bss->last_probe_resp = jiffies; |
| 178 | |
| 179 | return bss; |
| 180 | } |
| 181 | |
| 182 | ieee80211_rx_result |
| 183 | ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) |
| 184 | { |
| 185 | struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb); |
| 186 | struct ieee80211_mgmt *mgmt; |
| 187 | struct ieee80211_bss *bss; |
| 188 | u8 *elements; |
| 189 | struct ieee80211_channel *channel; |
| 190 | size_t baselen; |
| 191 | int freq; |
| 192 | __le16 fc; |
| 193 | bool presp, beacon = false; |
| 194 | struct ieee802_11_elems elems; |
| 195 | |
| 196 | if (skb->len < 2) |
| 197 | return RX_DROP_UNUSABLE; |
| 198 | |
| 199 | mgmt = (struct ieee80211_mgmt *) skb->data; |
| 200 | fc = mgmt->frame_control; |
| 201 | |
| 202 | if (ieee80211_is_ctl(fc)) |
| 203 | return RX_CONTINUE; |
| 204 | |
| 205 | if (skb->len < 24) |
| 206 | return RX_CONTINUE; |
| 207 | |
| 208 | presp = ieee80211_is_probe_resp(fc); |
| 209 | if (presp) { |
| 210 | /* ignore ProbeResp to foreign address */ |
| 211 | if (compare_ether_addr(mgmt->da, sdata->vif.addr)) |
| 212 | return RX_DROP_MONITOR; |
| 213 | |
| 214 | presp = true; |
| 215 | elements = mgmt->u.probe_resp.variable; |
| 216 | baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable); |
| 217 | } else { |
| 218 | beacon = ieee80211_is_beacon(fc); |
| 219 | baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable); |
| 220 | elements = mgmt->u.beacon.variable; |
| 221 | } |
| 222 | |
| 223 | if (!presp && !beacon) |
| 224 | return RX_CONTINUE; |
| 225 | |
| 226 | if (baselen > skb->len) |
| 227 | return RX_DROP_MONITOR; |
| 228 | |
| 229 | ieee802_11_parse_elems(elements, skb->len - baselen, &elems); |
| 230 | |
| 231 | if (elems.ds_params && elems.ds_params_len == 1) |
| 232 | freq = ieee80211_channel_to_frequency(elems.ds_params[0], |
| 233 | rx_status->band); |
| 234 | else |
| 235 | freq = rx_status->freq; |
| 236 | |
| 237 | channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq); |
| 238 | |
| 239 | if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) |
| 240 | return RX_DROP_MONITOR; |
| 241 | |
| 242 | bss = ieee80211_bss_info_update(sdata->local, rx_status, |
| 243 | mgmt, skb->len, &elems, |
| 244 | channel, beacon); |
| 245 | if (bss) |
| 246 | ieee80211_rx_bss_put(sdata->local, bss); |
| 247 | |
| 248 | if (channel == sdata->local->oper_channel) |
| 249 | return RX_CONTINUE; |
| 250 | |
| 251 | dev_kfree_skb(skb); |
| 252 | return RX_QUEUED; |
| 253 | } |
| 254 | |
| 255 | /* return false if no more work */ |
| 256 | static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) |
| 257 | { |
| 258 | struct cfg80211_scan_request *req = local->scan_req; |
| 259 | enum ieee80211_band band; |
| 260 | int i, ielen, n_chans; |
| 261 | |
| 262 | if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) |
| 263 | return false; |
| 264 | |
| 265 | do { |
| 266 | if (local->hw_scan_band == IEEE80211_NUM_BANDS) |
| 267 | return false; |
| 268 | |
| 269 | band = local->hw_scan_band; |
| 270 | n_chans = 0; |
| 271 | for (i = 0; i < req->n_channels; i++) { |
| 272 | if (req->channels[i]->band == band) { |
| 273 | local->hw_scan_req->channels[n_chans] = |
| 274 | req->channels[i]; |
| 275 | n_chans++; |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | local->hw_scan_band++; |
| 280 | } while (!n_chans); |
| 281 | |
| 282 | local->hw_scan_req->n_channels = n_chans; |
| 283 | |
| 284 | ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie, |
| 285 | req->ie, req->ie_len, band, |
| 286 | req->rates[band], 0); |
| 287 | local->hw_scan_req->ie_len = ielen; |
| 288 | local->hw_scan_req->no_cck = req->no_cck; |
| 289 | |
| 290 | return true; |
| 291 | } |
| 292 | |
| 293 | static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted, |
| 294 | bool was_hw_scan) |
| 295 | { |
| 296 | struct ieee80211_local *local = hw_to_local(hw); |
| 297 | |
| 298 | lockdep_assert_held(&local->mtx); |
| 299 | |
| 300 | /* |
| 301 | * It's ok to abort a not-yet-running scan (that |
| 302 | * we have one at all will be verified by checking |
| 303 | * local->scan_req next), but not to complete it |
| 304 | * successfully. |
| 305 | */ |
| 306 | if (WARN_ON(!local->scanning && !aborted)) |
| 307 | aborted = true; |
| 308 | |
| 309 | if (WARN_ON(!local->scan_req)) |
| 310 | return; |
| 311 | |
| 312 | if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) { |
| 313 | int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req); |
| 314 | if (rc == 0) |
| 315 | return; |
| 316 | } |
| 317 | |
| 318 | kfree(local->hw_scan_req); |
| 319 | local->hw_scan_req = NULL; |
| 320 | |
| 321 | if (local->scan_req != local->int_scan_req) |
| 322 | cfg80211_scan_done(local->scan_req, aborted); |
| 323 | local->scan_req = NULL; |
| 324 | local->scan_sdata = NULL; |
| 325 | |
| 326 | local->scanning = 0; |
| 327 | local->scan_channel = NULL; |
| 328 | |
| 329 | /* Set power back to normal operating levels. */ |
| 330 | ieee80211_hw_config(local, 0); |
| 331 | |
| 332 | if (!was_hw_scan) { |
| 333 | ieee80211_configure_filter(local); |
| 334 | drv_sw_scan_complete(local); |
| 335 | ieee80211_offchannel_return(local); |
| 336 | } |
| 337 | |
| 338 | ieee80211_recalc_idle(local); |
| 339 | |
| 340 | ieee80211_mlme_notify_scan_completed(local); |
| 341 | ieee80211_ibss_notify_scan_completed(local); |
| 342 | ieee80211_mesh_notify_scan_completed(local); |
| 343 | ieee80211_queue_work(&local->hw, &local->work_work); |
| 344 | } |
| 345 | |
| 346 | void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) |
| 347 | { |
| 348 | struct ieee80211_local *local = hw_to_local(hw); |
| 349 | |
| 350 | trace_api_scan_completed(local, aborted); |
| 351 | |
| 352 | set_bit(SCAN_COMPLETED, &local->scanning); |
| 353 | if (aborted) |
| 354 | set_bit(SCAN_ABORTED, &local->scanning); |
| 355 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0); |
| 356 | } |
| 357 | EXPORT_SYMBOL(ieee80211_scan_completed); |
| 358 | |
| 359 | static int ieee80211_start_sw_scan(struct ieee80211_local *local) |
| 360 | { |
| 361 | /* |
| 362 | * Hardware/driver doesn't support hw_scan, so use software |
| 363 | * scanning instead. First send a nullfunc frame with power save |
| 364 | * bit on so that AP will buffer the frames for us while we are not |
| 365 | * listening, then send probe requests to each channel and wait for |
| 366 | * the responses. After all channels are scanned, tune back to the |
| 367 | * original channel and send a nullfunc frame with power save bit |
| 368 | * off to trigger the AP to send us all the buffered frames. |
| 369 | * |
| 370 | * Note that while local->sw_scanning is true everything else but |
| 371 | * nullfunc frames and probe requests will be dropped in |
| 372 | * ieee80211_tx_h_check_assoc(). |
| 373 | */ |
| 374 | drv_sw_scan_start(local); |
| 375 | |
| 376 | local->leave_oper_channel_time = jiffies; |
| 377 | local->next_scan_state = SCAN_DECISION; |
| 378 | local->scan_channel_idx = 0; |
| 379 | |
| 380 | ieee80211_offchannel_stop_vifs(local); |
| 381 | |
| 382 | ieee80211_configure_filter(local); |
| 383 | |
| 384 | /* We need to set power level at maximum rate for scanning. */ |
| 385 | ieee80211_hw_config(local, 0); |
| 386 | |
| 387 | ieee80211_queue_delayed_work(&local->hw, |
| 388 | &local->scan_work, 0); |
| 389 | |
| 390 | return 0; |
| 391 | } |
| 392 | |
| 393 | |
| 394 | static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, |
| 395 | struct cfg80211_scan_request *req) |
| 396 | { |
| 397 | struct ieee80211_local *local = sdata->local; |
| 398 | int rc; |
| 399 | |
| 400 | lockdep_assert_held(&local->mtx); |
| 401 | |
| 402 | if (local->scan_req) |
| 403 | return -EBUSY; |
| 404 | |
| 405 | if (!list_empty(&local->work_list)) { |
| 406 | /* wait for the work to finish/time out */ |
| 407 | local->scan_req = req; |
| 408 | local->scan_sdata = sdata; |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | if (local->ops->hw_scan) { |
| 413 | u8 *ies; |
| 414 | |
| 415 | local->hw_scan_req = kmalloc( |
| 416 | sizeof(*local->hw_scan_req) + |
| 417 | req->n_channels * sizeof(req->channels[0]) + |
| 418 | 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len + |
| 419 | req->ie_len, GFP_KERNEL); |
| 420 | if (!local->hw_scan_req) |
| 421 | return -ENOMEM; |
| 422 | |
| 423 | local->hw_scan_req->ssids = req->ssids; |
| 424 | local->hw_scan_req->n_ssids = req->n_ssids; |
| 425 | ies = (u8 *)local->hw_scan_req + |
| 426 | sizeof(*local->hw_scan_req) + |
| 427 | req->n_channels * sizeof(req->channels[0]); |
| 428 | local->hw_scan_req->ie = ies; |
| 429 | |
| 430 | local->hw_scan_band = 0; |
| 431 | |
| 432 | /* |
| 433 | * After allocating local->hw_scan_req, we must |
| 434 | * go through until ieee80211_prep_hw_scan(), so |
| 435 | * anything that might be changed here and leave |
| 436 | * this function early must not go after this |
| 437 | * allocation. |
| 438 | */ |
| 439 | } |
| 440 | |
| 441 | local->scan_req = req; |
| 442 | local->scan_sdata = sdata; |
| 443 | |
| 444 | if (local->ops->hw_scan) |
| 445 | __set_bit(SCAN_HW_SCANNING, &local->scanning); |
| 446 | else |
| 447 | __set_bit(SCAN_SW_SCANNING, &local->scanning); |
| 448 | |
| 449 | ieee80211_recalc_idle(local); |
| 450 | |
| 451 | if (local->ops->hw_scan) { |
| 452 | WARN_ON(!ieee80211_prep_hw_scan(local)); |
| 453 | rc = drv_hw_scan(local, sdata, local->hw_scan_req); |
| 454 | } else |
| 455 | rc = ieee80211_start_sw_scan(local); |
| 456 | |
| 457 | if (rc) { |
| 458 | kfree(local->hw_scan_req); |
| 459 | local->hw_scan_req = NULL; |
| 460 | local->scanning = 0; |
| 461 | |
| 462 | ieee80211_recalc_idle(local); |
| 463 | |
| 464 | local->scan_req = NULL; |
| 465 | local->scan_sdata = NULL; |
| 466 | } |
| 467 | |
| 468 | return rc; |
| 469 | } |
| 470 | |
| 471 | static unsigned long |
| 472 | ieee80211_scan_get_channel_time(struct ieee80211_channel *chan) |
| 473 | { |
| 474 | /* |
| 475 | * TODO: channel switching also consumes quite some time, |
| 476 | * add that delay as well to get a better estimation |
| 477 | */ |
| 478 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN) |
| 479 | return IEEE80211_PASSIVE_CHANNEL_TIME; |
| 480 | return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME; |
| 481 | } |
| 482 | |
| 483 | static void ieee80211_scan_state_decision(struct ieee80211_local *local, |
| 484 | unsigned long *next_delay) |
| 485 | { |
| 486 | bool associated = false; |
| 487 | bool tx_empty = true; |
| 488 | bool bad_latency; |
| 489 | bool listen_int_exceeded; |
| 490 | unsigned long min_beacon_int = 0; |
| 491 | struct ieee80211_sub_if_data *sdata; |
| 492 | struct ieee80211_channel *next_chan; |
| 493 | |
| 494 | /* |
| 495 | * check if at least one STA interface is associated, |
| 496 | * check if at least one STA interface has pending tx frames |
| 497 | * and grab the lowest used beacon interval |
| 498 | */ |
| 499 | mutex_lock(&local->iflist_mtx); |
| 500 | list_for_each_entry(sdata, &local->interfaces, list) { |
| 501 | if (!ieee80211_sdata_running(sdata)) |
| 502 | continue; |
| 503 | |
| 504 | if (sdata->vif.type == NL80211_IFTYPE_STATION) { |
| 505 | if (sdata->u.mgd.associated) { |
| 506 | associated = true; |
| 507 | |
| 508 | if (sdata->vif.bss_conf.beacon_int < |
| 509 | min_beacon_int || min_beacon_int == 0) |
| 510 | min_beacon_int = |
| 511 | sdata->vif.bss_conf.beacon_int; |
| 512 | |
| 513 | if (!qdisc_all_tx_empty(sdata->dev)) { |
| 514 | tx_empty = false; |
| 515 | break; |
| 516 | } |
| 517 | } |
| 518 | } |
| 519 | } |
| 520 | mutex_unlock(&local->iflist_mtx); |
| 521 | |
| 522 | next_chan = local->scan_req->channels[local->scan_channel_idx]; |
| 523 | |
| 524 | /* |
| 525 | * we're currently scanning a different channel, let's |
| 526 | * see if we can scan another channel without interfering |
| 527 | * with the current traffic situation. |
| 528 | * |
| 529 | * Since we don't know if the AP has pending frames for us |
| 530 | * we can only check for our tx queues and use the current |
| 531 | * pm_qos requirements for rx. Hence, if no tx traffic occurs |
| 532 | * at all we will scan as many channels in a row as the pm_qos |
| 533 | * latency allows us to. Additionally we also check for the |
| 534 | * currently negotiated listen interval to prevent losing |
| 535 | * frames unnecessarily. |
| 536 | * |
| 537 | * Otherwise switch back to the operating channel. |
| 538 | */ |
| 539 | |
| 540 | bad_latency = time_after(jiffies + |
| 541 | ieee80211_scan_get_channel_time(next_chan), |
| 542 | local->leave_oper_channel_time + |
| 543 | usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY))); |
| 544 | |
| 545 | listen_int_exceeded = time_after(jiffies + |
| 546 | ieee80211_scan_get_channel_time(next_chan), |
| 547 | local->leave_oper_channel_time + |
| 548 | usecs_to_jiffies(min_beacon_int * 1024) * |
| 549 | local->hw.conf.listen_interval); |
| 550 | |
| 551 | if (associated && (!tx_empty || bad_latency || listen_int_exceeded)) |
| 552 | local->next_scan_state = SCAN_SUSPEND; |
| 553 | else |
| 554 | local->next_scan_state = SCAN_SET_CHANNEL; |
| 555 | |
| 556 | *next_delay = 0; |
| 557 | } |
| 558 | |
| 559 | static void ieee80211_scan_state_set_channel(struct ieee80211_local *local, |
| 560 | unsigned long *next_delay) |
| 561 | { |
| 562 | int skip; |
| 563 | struct ieee80211_channel *chan; |
| 564 | |
| 565 | skip = 0; |
| 566 | chan = local->scan_req->channels[local->scan_channel_idx]; |
| 567 | |
| 568 | local->scan_channel = chan; |
| 569 | |
| 570 | if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL)) |
| 571 | skip = 1; |
| 572 | |
| 573 | /* advance state machine to next channel/band */ |
| 574 | local->scan_channel_idx++; |
| 575 | |
| 576 | if (skip) { |
| 577 | /* if we skip this channel return to the decision state */ |
| 578 | local->next_scan_state = SCAN_DECISION; |
| 579 | return; |
| 580 | } |
| 581 | |
| 582 | /* |
| 583 | * Probe delay is used to update the NAV, cf. 11.1.3.2.2 |
| 584 | * (which unfortunately doesn't say _why_ step a) is done, |
| 585 | * but it waits for the probe delay or until a frame is |
| 586 | * received - and the received frame would update the NAV). |
| 587 | * For now, we do not support waiting until a frame is |
| 588 | * received. |
| 589 | * |
| 590 | * In any case, it is not necessary for a passive scan. |
| 591 | */ |
| 592 | if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN || |
| 593 | !local->scan_req->n_ssids) { |
| 594 | *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; |
| 595 | local->next_scan_state = SCAN_DECISION; |
| 596 | return; |
| 597 | } |
| 598 | |
| 599 | /* active scan, send probes */ |
| 600 | *next_delay = IEEE80211_PROBE_DELAY; |
| 601 | local->next_scan_state = SCAN_SEND_PROBE; |
| 602 | } |
| 603 | |
| 604 | static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, |
| 605 | unsigned long *next_delay) |
| 606 | { |
| 607 | int i; |
| 608 | struct ieee80211_sub_if_data *sdata = local->scan_sdata; |
| 609 | enum ieee80211_band band = local->hw.conf.channel->band; |
| 610 | |
| 611 | for (i = 0; i < local->scan_req->n_ssids; i++) |
| 612 | ieee80211_send_probe_req( |
| 613 | sdata, NULL, |
| 614 | local->scan_req->ssids[i].ssid, |
| 615 | local->scan_req->ssids[i].ssid_len, |
| 616 | local->scan_req->ie, local->scan_req->ie_len, |
| 617 | local->scan_req->rates[band], false, |
| 618 | local->scan_req->no_cck); |
| 619 | |
| 620 | /* |
| 621 | * After sending probe requests, wait for probe responses |
| 622 | * on the channel. |
| 623 | */ |
| 624 | *next_delay = IEEE80211_CHANNEL_TIME; |
| 625 | local->next_scan_state = SCAN_DECISION; |
| 626 | } |
| 627 | |
| 628 | static void ieee80211_scan_state_suspend(struct ieee80211_local *local, |
| 629 | unsigned long *next_delay) |
| 630 | { |
| 631 | /* switch back to the operating channel */ |
| 632 | local->scan_channel = NULL; |
| 633 | ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); |
| 634 | |
| 635 | /* disable PS */ |
| 636 | ieee80211_offchannel_return(local); |
| 637 | |
| 638 | *next_delay = HZ / 5; |
| 639 | /* afterwards, resume scan & go to next channel */ |
| 640 | local->next_scan_state = SCAN_RESUME; |
| 641 | } |
| 642 | |
| 643 | static void ieee80211_scan_state_resume(struct ieee80211_local *local, |
| 644 | unsigned long *next_delay) |
| 645 | { |
| 646 | ieee80211_offchannel_stop_vifs(local); |
| 647 | |
| 648 | if (local->ops->flush) { |
| 649 | drv_flush(local, false); |
| 650 | *next_delay = 0; |
| 651 | } else |
| 652 | *next_delay = HZ / 10; |
| 653 | |
| 654 | /* remember when we left the operating channel */ |
| 655 | local->leave_oper_channel_time = jiffies; |
| 656 | |
| 657 | /* advance to the next channel to be scanned */ |
| 658 | local->next_scan_state = SCAN_SET_CHANNEL; |
| 659 | } |
| 660 | |
| 661 | void ieee80211_scan_work(struct work_struct *work) |
| 662 | { |
| 663 | struct ieee80211_local *local = |
| 664 | container_of(work, struct ieee80211_local, scan_work.work); |
| 665 | struct ieee80211_sub_if_data *sdata; |
| 666 | unsigned long next_delay = 0; |
| 667 | bool aborted, hw_scan; |
| 668 | |
| 669 | mutex_lock(&local->mtx); |
| 670 | |
| 671 | sdata = local->scan_sdata; |
| 672 | |
| 673 | if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) { |
| 674 | aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning); |
| 675 | goto out_complete; |
| 676 | } |
| 677 | |
| 678 | if (!sdata || !local->scan_req) |
| 679 | goto out; |
| 680 | |
| 681 | if (local->scan_req && !local->scanning) { |
| 682 | struct cfg80211_scan_request *req = local->scan_req; |
| 683 | int rc; |
| 684 | |
| 685 | local->scan_req = NULL; |
| 686 | local->scan_sdata = NULL; |
| 687 | |
| 688 | rc = __ieee80211_start_scan(sdata, req); |
| 689 | if (rc) { |
| 690 | /* need to complete scan in cfg80211 */ |
| 691 | local->scan_req = req; |
| 692 | aborted = true; |
| 693 | goto out_complete; |
| 694 | } else |
| 695 | goto out; |
| 696 | } |
| 697 | |
| 698 | /* |
| 699 | * Avoid re-scheduling when the sdata is going away. |
| 700 | */ |
| 701 | if (!ieee80211_sdata_running(sdata)) { |
| 702 | aborted = true; |
| 703 | goto out_complete; |
| 704 | } |
| 705 | |
| 706 | /* |
| 707 | * as long as no delay is required advance immediately |
| 708 | * without scheduling a new work |
| 709 | */ |
| 710 | do { |
| 711 | if (!ieee80211_sdata_running(sdata)) { |
| 712 | aborted = true; |
| 713 | goto out_complete; |
| 714 | } |
| 715 | |
| 716 | switch (local->next_scan_state) { |
| 717 | case SCAN_DECISION: |
| 718 | /* if no more bands/channels left, complete scan */ |
| 719 | if (local->scan_channel_idx >= local->scan_req->n_channels) { |
| 720 | aborted = false; |
| 721 | goto out_complete; |
| 722 | } |
| 723 | ieee80211_scan_state_decision(local, &next_delay); |
| 724 | break; |
| 725 | case SCAN_SET_CHANNEL: |
| 726 | ieee80211_scan_state_set_channel(local, &next_delay); |
| 727 | break; |
| 728 | case SCAN_SEND_PROBE: |
| 729 | ieee80211_scan_state_send_probe(local, &next_delay); |
| 730 | break; |
| 731 | case SCAN_SUSPEND: |
| 732 | ieee80211_scan_state_suspend(local, &next_delay); |
| 733 | break; |
| 734 | case SCAN_RESUME: |
| 735 | ieee80211_scan_state_resume(local, &next_delay); |
| 736 | break; |
| 737 | } |
| 738 | } while (next_delay == 0); |
| 739 | |
| 740 | ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay); |
| 741 | goto out; |
| 742 | |
| 743 | out_complete: |
| 744 | hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); |
| 745 | __ieee80211_scan_completed(&local->hw, aborted, hw_scan); |
| 746 | out: |
| 747 | mutex_unlock(&local->mtx); |
| 748 | } |
| 749 | |
| 750 | int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata, |
| 751 | struct cfg80211_scan_request *req) |
| 752 | { |
| 753 | int res; |
| 754 | |
| 755 | mutex_lock(&sdata->local->mtx); |
| 756 | res = __ieee80211_start_scan(sdata, req); |
| 757 | mutex_unlock(&sdata->local->mtx); |
| 758 | |
| 759 | return res; |
| 760 | } |
| 761 | |
| 762 | int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata, |
| 763 | const u8 *ssid, u8 ssid_len, |
| 764 | struct ieee80211_channel *chan) |
| 765 | { |
| 766 | struct ieee80211_local *local = sdata->local; |
| 767 | int ret = -EBUSY; |
| 768 | enum ieee80211_band band; |
| 769 | |
| 770 | mutex_lock(&local->mtx); |
| 771 | |
| 772 | /* busy scanning */ |
| 773 | if (local->scan_req) |
| 774 | goto unlock; |
| 775 | |
| 776 | /* fill internal scan request */ |
| 777 | if (!chan) { |
| 778 | int i, max_n; |
| 779 | int n_ch = 0; |
| 780 | |
| 781 | for (band = 0; band < IEEE80211_NUM_BANDS; band++) { |
| 782 | if (!local->hw.wiphy->bands[band]) |
| 783 | continue; |
| 784 | |
| 785 | max_n = local->hw.wiphy->bands[band]->n_channels; |
| 786 | for (i = 0; i < max_n; i++) { |
| 787 | struct ieee80211_channel *tmp_ch = |
| 788 | &local->hw.wiphy->bands[band]->channels[i]; |
| 789 | |
| 790 | if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS | |
| 791 | IEEE80211_CHAN_DISABLED)) |
| 792 | continue; |
| 793 | |
| 794 | local->int_scan_req->channels[n_ch] = tmp_ch; |
| 795 | n_ch++; |
| 796 | } |
| 797 | } |
| 798 | |
| 799 | if (WARN_ON_ONCE(n_ch == 0)) |
| 800 | goto unlock; |
| 801 | |
| 802 | local->int_scan_req->n_channels = n_ch; |
| 803 | } else { |
| 804 | if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS | |
| 805 | IEEE80211_CHAN_DISABLED))) |
| 806 | goto unlock; |
| 807 | |
| 808 | local->int_scan_req->channels[0] = chan; |
| 809 | local->int_scan_req->n_channels = 1; |
| 810 | } |
| 811 | |
| 812 | local->int_scan_req->ssids = &local->scan_ssid; |
| 813 | local->int_scan_req->n_ssids = 1; |
| 814 | memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN); |
| 815 | local->int_scan_req->ssids[0].ssid_len = ssid_len; |
| 816 | |
| 817 | ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req); |
| 818 | unlock: |
| 819 | mutex_unlock(&local->mtx); |
| 820 | return ret; |
| 821 | } |
| 822 | |
| 823 | /* |
| 824 | * Only call this function when a scan can't be queued -- under RTNL. |
| 825 | */ |
| 826 | void ieee80211_scan_cancel(struct ieee80211_local *local) |
| 827 | { |
| 828 | /* |
| 829 | * We are canceling software scan, or deferred scan that was not |
| 830 | * yet really started (see __ieee80211_start_scan ). |
| 831 | * |
| 832 | * Regarding hardware scan: |
| 833 | * - we can not call __ieee80211_scan_completed() as when |
| 834 | * SCAN_HW_SCANNING bit is set this function change |
| 835 | * local->hw_scan_req to operate on 5G band, what race with |
| 836 | * driver which can use local->hw_scan_req |
| 837 | * |
| 838 | * - we can not cancel scan_work since driver can schedule it |
| 839 | * by ieee80211_scan_completed(..., true) to finish scan |
| 840 | * |
| 841 | * Hence we only call the cancel_hw_scan() callback, but the low-level |
| 842 | * driver is still responsible for calling ieee80211_scan_completed() |
| 843 | * after the scan was completed/aborted. |
| 844 | */ |
| 845 | |
| 846 | mutex_lock(&local->mtx); |
| 847 | if (!local->scan_req) |
| 848 | goto out; |
| 849 | |
| 850 | /* |
| 851 | * We have a scan running and the driver already reported completion, |
| 852 | * but the worker hasn't run yet or is stuck on the mutex - mark it as |
| 853 | * cancelled. |
| 854 | */ |
| 855 | if (test_bit(SCAN_HW_SCANNING, &local->scanning) && |
| 856 | test_bit(SCAN_COMPLETED, &local->scanning)) { |
| 857 | set_bit(SCAN_HW_CANCELLED, &local->scanning); |
| 858 | goto out; |
| 859 | } |
| 860 | |
| 861 | if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { |
| 862 | /* |
| 863 | * Make sure that __ieee80211_scan_completed doesn't trigger a |
| 864 | * scan on another band. |
| 865 | */ |
| 866 | set_bit(SCAN_HW_CANCELLED, &local->scanning); |
| 867 | if (local->ops->cancel_hw_scan) |
| 868 | drv_cancel_hw_scan(local, local->scan_sdata); |
| 869 | goto out; |
| 870 | } |
| 871 | |
| 872 | /* |
| 873 | * If the work is currently running, it must be blocked on |
| 874 | * the mutex, but we'll set scan_sdata = NULL and it'll |
| 875 | * simply exit once it acquires the mutex. |
| 876 | */ |
| 877 | cancel_delayed_work(&local->scan_work); |
| 878 | /* and clean up */ |
| 879 | __ieee80211_scan_completed(&local->hw, true, false); |
| 880 | out: |
| 881 | mutex_unlock(&local->mtx); |
| 882 | } |
| 883 | |
| 884 | int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata, |
| 885 | struct cfg80211_sched_scan_request *req) |
| 886 | { |
| 887 | struct ieee80211_local *local = sdata->local; |
| 888 | int ret, i; |
| 889 | |
| 890 | mutex_lock(&sdata->local->mtx); |
| 891 | |
| 892 | if (local->sched_scanning) { |
| 893 | ret = -EBUSY; |
| 894 | goto out; |
| 895 | } |
| 896 | |
| 897 | if (!local->ops->sched_scan_start) { |
| 898 | ret = -ENOTSUPP; |
| 899 | goto out; |
| 900 | } |
| 901 | |
| 902 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { |
| 903 | local->sched_scan_ies.ie[i] = kzalloc(2 + |
| 904 | IEEE80211_MAX_SSID_LEN + |
| 905 | local->scan_ies_len + |
| 906 | req->ie_len, |
| 907 | GFP_KERNEL); |
| 908 | if (!local->sched_scan_ies.ie[i]) { |
| 909 | ret = -ENOMEM; |
| 910 | goto out_free; |
| 911 | } |
| 912 | |
| 913 | local->sched_scan_ies.len[i] = |
| 914 | ieee80211_build_preq_ies(local, |
| 915 | local->sched_scan_ies.ie[i], |
| 916 | req->ie, req->ie_len, i, |
| 917 | (u32) -1, 0); |
| 918 | } |
| 919 | |
| 920 | ret = drv_sched_scan_start(local, sdata, req, |
| 921 | &local->sched_scan_ies); |
| 922 | if (ret == 0) { |
| 923 | local->sched_scanning = true; |
| 924 | goto out; |
| 925 | } |
| 926 | |
| 927 | out_free: |
| 928 | while (i > 0) |
| 929 | kfree(local->sched_scan_ies.ie[--i]); |
| 930 | out: |
| 931 | mutex_unlock(&sdata->local->mtx); |
| 932 | return ret; |
| 933 | } |
| 934 | |
| 935 | int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata) |
| 936 | { |
| 937 | struct ieee80211_local *local = sdata->local; |
| 938 | int ret = 0, i; |
| 939 | |
| 940 | mutex_lock(&sdata->local->mtx); |
| 941 | |
| 942 | if (!local->ops->sched_scan_stop) { |
| 943 | ret = -ENOTSUPP; |
| 944 | goto out; |
| 945 | } |
| 946 | |
| 947 | if (local->sched_scanning) { |
| 948 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) |
| 949 | kfree(local->sched_scan_ies.ie[i]); |
| 950 | |
| 951 | drv_sched_scan_stop(local, sdata); |
| 952 | local->sched_scanning = false; |
| 953 | } |
| 954 | out: |
| 955 | mutex_unlock(&sdata->local->mtx); |
| 956 | |
| 957 | return ret; |
| 958 | } |
| 959 | |
| 960 | void ieee80211_sched_scan_results(struct ieee80211_hw *hw) |
| 961 | { |
| 962 | struct ieee80211_local *local = hw_to_local(hw); |
| 963 | |
| 964 | trace_api_sched_scan_results(local); |
| 965 | |
| 966 | cfg80211_sched_scan_results(hw->wiphy); |
| 967 | } |
| 968 | EXPORT_SYMBOL(ieee80211_sched_scan_results); |
| 969 | |
| 970 | void ieee80211_sched_scan_stopped_work(struct work_struct *work) |
| 971 | { |
| 972 | struct ieee80211_local *local = |
| 973 | container_of(work, struct ieee80211_local, |
| 974 | sched_scan_stopped_work); |
| 975 | int i; |
| 976 | |
| 977 | mutex_lock(&local->mtx); |
| 978 | |
| 979 | if (!local->sched_scanning) { |
| 980 | mutex_unlock(&local->mtx); |
| 981 | return; |
| 982 | } |
| 983 | |
| 984 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) |
| 985 | kfree(local->sched_scan_ies.ie[i]); |
| 986 | |
| 987 | local->sched_scanning = false; |
| 988 | |
| 989 | mutex_unlock(&local->mtx); |
| 990 | |
| 991 | cfg80211_sched_scan_stopped(local->hw.wiphy); |
| 992 | } |
| 993 | |
| 994 | void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw) |
| 995 | { |
| 996 | struct ieee80211_local *local = hw_to_local(hw); |
| 997 | |
| 998 | trace_api_sched_scan_stopped(local); |
| 999 | |
| 1000 | ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work); |
| 1001 | } |
| 1002 | EXPORT_SYMBOL(ieee80211_sched_scan_stopped); |