1 /* 2 * Off-channel operation helpers 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 2009 Johannes Berg <johannes@sipsolutions.net> 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 #include <linux/export.h> 16 #include <net/mac80211.h> 17 #include "ieee80211_i.h" 18 #include "driver-ops.h" 19 20 /* 21 * Tell our hardware to disable PS. 22 * Optionally inform AP that we will go to sleep so that it will buffer 23 * the frames while we are doing off-channel work. This is optional 24 * because we *may* be doing work on-operating channel, and want our 25 * hardware unconditionally awake, but still let the AP send us normal frames. 26 */ 27 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) 28 { 29 struct ieee80211_local *local = sdata->local; 30 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 31 32 local->offchannel_ps_enabled = false; 33 34 /* FIXME: what to do when local->pspolling is true? */ 35 36 del_timer_sync(&local->dynamic_ps_timer); 37 del_timer_sync(&ifmgd->bcn_mon_timer); 38 del_timer_sync(&ifmgd->conn_mon_timer); 39 40 cancel_work_sync(&local->dynamic_ps_enable_work); 41 42 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 43 local->offchannel_ps_enabled = true; 44 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 45 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 46 } 47 48 if (!local->offchannel_ps_enabled || 49 !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK)) 50 /* 51 * If power save was enabled, no need to send a nullfunc 52 * frame because AP knows that we are sleeping. But if the 53 * hardware is creating the nullfunc frame for power save 54 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 55 * enabled) and power save was enabled, the firmware just 56 * sent a null frame with power save disabled. So we need 57 * to send a new nullfunc frame to inform the AP that we 58 * are again sleeping. 59 */ 60 ieee80211_send_nullfunc(local, sdata, true); 61 } 62 63 /* inform AP that we are awake again, unless power save is enabled */ 64 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) 65 { 66 struct ieee80211_local *local = sdata->local; 67 68 if (!local->ps_sdata) 69 ieee80211_send_nullfunc(local, sdata, false); 70 else if (local->offchannel_ps_enabled) { 71 /* 72 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 73 * will send a nullfunc frame with the powersave bit set 74 * even though the AP already knows that we are sleeping. 75 * This could be avoided by sending a null frame with power 76 * save bit disabled before enabling the power save, but 77 * this doesn't gain anything. 78 * 79 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 80 * to send a nullfunc frame because AP already knows that 81 * we are sleeping, let's just enable power save mode in 82 * hardware. 83 */ 84 /* TODO: Only set hardware if CONF_PS changed? 85 * TODO: Should we set offchannel_ps_enabled to false? 86 */ 87 local->hw.conf.flags |= IEEE80211_CONF_PS; 88 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 89 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 90 /* 91 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 92 * had been running before leaving the operating channel, 93 * restart the timer now and send a nullfunc frame to inform 94 * the AP that we are awake. 95 */ 96 ieee80211_send_nullfunc(local, sdata, false); 97 mod_timer(&local->dynamic_ps_timer, jiffies + 98 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 99 } 100 101 ieee80211_sta_reset_beacon_monitor(sdata); 102 ieee80211_sta_reset_conn_monitor(sdata); 103 } 104 105 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) 106 { 107 struct ieee80211_sub_if_data *sdata; 108 109 if (WARN_ON(local->use_chanctx)) 110 return; 111 112 /* 113 * notify the AP about us leaving the channel and stop all 114 * STA interfaces. 115 */ 116 117 /* 118 * Stop queues and transmit all frames queued by the driver 119 * before sending nullfunc to enable powersave at the AP. 120 */ 121 ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP, 122 IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, 123 false); 124 ieee80211_flush_queues(local, NULL, false); 125 126 mutex_lock(&local->iflist_mtx); 127 list_for_each_entry(sdata, &local->interfaces, list) { 128 if (!ieee80211_sdata_running(sdata)) 129 continue; 130 131 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 132 continue; 133 134 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 135 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 136 137 /* Check to see if we should disable beaconing. */ 138 if (sdata->vif.bss_conf.enable_beacon) { 139 set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, 140 &sdata->state); 141 sdata->vif.bss_conf.enable_beacon = false; 142 ieee80211_bss_info_change_notify( 143 sdata, BSS_CHANGED_BEACON_ENABLED); 144 } 145 146 if (sdata->vif.type == NL80211_IFTYPE_STATION && 147 sdata->u.mgd.associated) 148 ieee80211_offchannel_ps_enable(sdata); 149 } 150 mutex_unlock(&local->iflist_mtx); 151 } 152 153 void ieee80211_offchannel_return(struct ieee80211_local *local) 154 { 155 struct ieee80211_sub_if_data *sdata; 156 157 if (WARN_ON(local->use_chanctx)) 158 return; 159 160 mutex_lock(&local->iflist_mtx); 161 list_for_each_entry(sdata, &local->interfaces, list) { 162 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 163 continue; 164 165 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 166 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 167 168 if (!ieee80211_sdata_running(sdata)) 169 continue; 170 171 /* Tell AP we're back */ 172 if (sdata->vif.type == NL80211_IFTYPE_STATION && 173 sdata->u.mgd.associated) 174 ieee80211_offchannel_ps_disable(sdata); 175 176 if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, 177 &sdata->state)) { 178 sdata->vif.bss_conf.enable_beacon = true; 179 ieee80211_bss_info_change_notify( 180 sdata, BSS_CHANGED_BEACON_ENABLED); 181 } 182 } 183 mutex_unlock(&local->iflist_mtx); 184 185 ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP, 186 IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL, 187 false); 188 } 189 190 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc) 191 { 192 if (roc->notified) 193 return; 194 195 if (roc->mgmt_tx_cookie) { 196 if (!WARN_ON(!roc->frame)) { 197 ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7, 198 roc->chan->band); 199 roc->frame = NULL; 200 } 201 } else { 202 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie, 203 roc->chan, roc->req_duration, 204 GFP_KERNEL); 205 } 206 207 roc->notified = true; 208 } 209 210 static void ieee80211_hw_roc_start(struct work_struct *work) 211 { 212 struct ieee80211_local *local = 213 container_of(work, struct ieee80211_local, hw_roc_start); 214 struct ieee80211_roc_work *roc, *dep, *tmp; 215 216 mutex_lock(&local->mtx); 217 218 if (list_empty(&local->roc_list)) 219 goto out_unlock; 220 221 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 222 list); 223 224 if (!roc->started) 225 goto out_unlock; 226 227 roc->hw_begun = true; 228 roc->hw_start_time = local->hw_roc_start_time; 229 230 ieee80211_handle_roc_started(roc); 231 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) { 232 ieee80211_handle_roc_started(dep); 233 234 if (dep->duration > roc->duration) { 235 u32 dur = dep->duration; 236 dep->duration = dur - roc->duration; 237 roc->duration = dur; 238 list_move(&dep->list, &roc->list); 239 } 240 } 241 out_unlock: 242 mutex_unlock(&local->mtx); 243 } 244 245 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 246 { 247 struct ieee80211_local *local = hw_to_local(hw); 248 249 local->hw_roc_start_time = jiffies; 250 251 trace_api_ready_on_channel(local); 252 253 ieee80211_queue_work(hw, &local->hw_roc_start); 254 } 255 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 256 257 void ieee80211_start_next_roc(struct ieee80211_local *local) 258 { 259 struct ieee80211_roc_work *roc; 260 261 lockdep_assert_held(&local->mtx); 262 263 if (list_empty(&local->roc_list)) { 264 ieee80211_run_deferred_scan(local); 265 return; 266 } 267 268 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 269 list); 270 271 if (WARN_ON_ONCE(roc->started)) 272 return; 273 274 if (local->ops->remain_on_channel) { 275 int ret, duration = roc->duration; 276 277 /* XXX: duplicated, see ieee80211_start_roc_work() */ 278 if (!duration) 279 duration = 10; 280 281 ret = drv_remain_on_channel(local, roc->sdata, roc->chan, 282 duration, roc->type); 283 284 roc->started = true; 285 286 if (ret) { 287 wiphy_warn(local->hw.wiphy, 288 "failed to start next HW ROC (%d)\n", ret); 289 /* 290 * queue the work struct again to avoid recursion 291 * when multiple failures occur 292 */ 293 ieee80211_remain_on_channel_expired(&local->hw); 294 } 295 } else { 296 /* delay it a bit */ 297 ieee80211_queue_delayed_work(&local->hw, &roc->work, 298 round_jiffies_relative(HZ/2)); 299 } 300 } 301 302 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free) 303 { 304 struct ieee80211_roc_work *dep, *tmp; 305 306 if (WARN_ON(roc->to_be_freed)) 307 return; 308 309 /* was never transmitted */ 310 if (roc->frame) { 311 cfg80211_mgmt_tx_status(&roc->sdata->wdev, 312 (unsigned long)roc->frame, 313 roc->frame->data, roc->frame->len, 314 false, GFP_KERNEL); 315 kfree_skb(roc->frame); 316 } 317 318 if (!roc->mgmt_tx_cookie) 319 cfg80211_remain_on_channel_expired(&roc->sdata->wdev, 320 roc->cookie, roc->chan, 321 GFP_KERNEL); 322 323 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) 324 ieee80211_roc_notify_destroy(dep, true); 325 326 if (free) 327 kfree(roc); 328 else 329 roc->to_be_freed = true; 330 } 331 332 void ieee80211_sw_roc_work(struct work_struct *work) 333 { 334 struct ieee80211_roc_work *roc = 335 container_of(work, struct ieee80211_roc_work, work.work); 336 struct ieee80211_sub_if_data *sdata = roc->sdata; 337 struct ieee80211_local *local = sdata->local; 338 bool started, on_channel; 339 340 mutex_lock(&local->mtx); 341 342 if (roc->to_be_freed) 343 goto out_unlock; 344 345 if (roc->abort) 346 goto finish; 347 348 if (WARN_ON(list_empty(&local->roc_list))) 349 goto out_unlock; 350 351 if (WARN_ON(roc != list_first_entry(&local->roc_list, 352 struct ieee80211_roc_work, 353 list))) 354 goto out_unlock; 355 356 if (!roc->started) { 357 struct ieee80211_roc_work *dep; 358 359 WARN_ON(local->use_chanctx); 360 361 /* If actually operating on the desired channel (with at least 362 * 20 MHz channel width) don't stop all the operations but still 363 * treat it as though the ROC operation started properly, so 364 * other ROC operations won't interfere with this one. 365 */ 366 roc->on_channel = roc->chan == local->_oper_chandef.chan && 367 local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 && 368 local->_oper_chandef.width != NL80211_CHAN_WIDTH_10; 369 370 /* start this ROC */ 371 ieee80211_recalc_idle(local); 372 373 if (!roc->on_channel) { 374 ieee80211_offchannel_stop_vifs(local); 375 376 local->tmp_channel = roc->chan; 377 ieee80211_hw_config(local, 0); 378 } 379 380 /* tell userspace or send frame */ 381 ieee80211_handle_roc_started(roc); 382 list_for_each_entry(dep, &roc->dependents, list) 383 ieee80211_handle_roc_started(dep); 384 385 /* if it was pure TX, just finish right away */ 386 if (!roc->duration) 387 goto finish; 388 389 roc->started = true; 390 ieee80211_queue_delayed_work(&local->hw, &roc->work, 391 msecs_to_jiffies(roc->duration)); 392 } else { 393 /* finish this ROC */ 394 finish: 395 list_del(&roc->list); 396 started = roc->started; 397 on_channel = roc->on_channel; 398 ieee80211_roc_notify_destroy(roc, !roc->abort); 399 400 if (started && !on_channel) { 401 ieee80211_flush_queues(local, NULL, false); 402 403 local->tmp_channel = NULL; 404 ieee80211_hw_config(local, 0); 405 406 ieee80211_offchannel_return(local); 407 } 408 409 ieee80211_recalc_idle(local); 410 411 if (started) 412 ieee80211_start_next_roc(local); 413 else if (list_empty(&local->roc_list)) 414 ieee80211_run_deferred_scan(local); 415 } 416 417 out_unlock: 418 mutex_unlock(&local->mtx); 419 } 420 421 static void ieee80211_hw_roc_done(struct work_struct *work) 422 { 423 struct ieee80211_local *local = 424 container_of(work, struct ieee80211_local, hw_roc_done); 425 struct ieee80211_roc_work *roc; 426 427 mutex_lock(&local->mtx); 428 429 if (list_empty(&local->roc_list)) 430 goto out_unlock; 431 432 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 433 list); 434 435 if (!roc->started) 436 goto out_unlock; 437 438 list_del(&roc->list); 439 440 ieee80211_roc_notify_destroy(roc, true); 441 442 /* if there's another roc, start it now */ 443 ieee80211_start_next_roc(local); 444 445 out_unlock: 446 mutex_unlock(&local->mtx); 447 } 448 449 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 450 { 451 struct ieee80211_local *local = hw_to_local(hw); 452 453 trace_api_remain_on_channel_expired(local); 454 455 ieee80211_queue_work(hw, &local->hw_roc_done); 456 } 457 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 458 459 void ieee80211_roc_setup(struct ieee80211_local *local) 460 { 461 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 462 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 463 INIT_LIST_HEAD(&local->roc_list); 464 } 465 466 void ieee80211_roc_purge(struct ieee80211_local *local, 467 struct ieee80211_sub_if_data *sdata) 468 { 469 struct ieee80211_roc_work *roc, *tmp; 470 LIST_HEAD(tmp_list); 471 472 mutex_lock(&local->mtx); 473 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { 474 if (sdata && roc->sdata != sdata) 475 continue; 476 477 if (roc->started && local->ops->remain_on_channel) { 478 /* can race, so ignore return value */ 479 drv_cancel_remain_on_channel(local); 480 } 481 482 list_move_tail(&roc->list, &tmp_list); 483 roc->abort = true; 484 } 485 mutex_unlock(&local->mtx); 486 487 list_for_each_entry_safe(roc, tmp, &tmp_list, list) { 488 if (local->ops->remain_on_channel) { 489 list_del(&roc->list); 490 ieee80211_roc_notify_destroy(roc, true); 491 } else { 492 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0); 493 494 /* work will clean up etc */ 495 flush_delayed_work(&roc->work); 496 WARN_ON(!roc->to_be_freed); 497 kfree(roc); 498 } 499 } 500 501 WARN_ON_ONCE(!list_empty(&tmp_list)); 502 } 503