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 !(local->hw.flags & IEEE80211_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, 1); 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, 0); 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, 0); 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 bool offchannel_ps_enable) 107 { 108 struct ieee80211_sub_if_data *sdata; 109 110 if (WARN_ON(local->use_chanctx)) 111 return; 112 113 /* 114 * notify the AP about us leaving the channel and stop all 115 * STA interfaces. 116 */ 117 mutex_lock(&local->iflist_mtx); 118 list_for_each_entry(sdata, &local->interfaces, list) { 119 if (!ieee80211_sdata_running(sdata)) 120 continue; 121 122 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 123 continue; 124 125 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 126 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 127 128 /* Check to see if we should disable beaconing. */ 129 if (sdata->vif.type == NL80211_IFTYPE_AP || 130 sdata->vif.type == NL80211_IFTYPE_ADHOC || 131 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 132 ieee80211_bss_info_change_notify( 133 sdata, BSS_CHANGED_BEACON_ENABLED); 134 135 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 136 netif_tx_stop_all_queues(sdata->dev); 137 if (offchannel_ps_enable && 138 (sdata->vif.type == NL80211_IFTYPE_STATION) && 139 sdata->u.mgd.associated) 140 ieee80211_offchannel_ps_enable(sdata); 141 } 142 } 143 mutex_unlock(&local->iflist_mtx); 144 } 145 146 void ieee80211_offchannel_return(struct ieee80211_local *local, 147 bool offchannel_ps_disable) 148 { 149 struct ieee80211_sub_if_data *sdata; 150 151 if (WARN_ON(local->use_chanctx)) 152 return; 153 154 mutex_lock(&local->iflist_mtx); 155 list_for_each_entry(sdata, &local->interfaces, list) { 156 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 157 continue; 158 159 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 160 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 161 162 if (!ieee80211_sdata_running(sdata)) 163 continue; 164 165 /* Tell AP we're back */ 166 if (offchannel_ps_disable && 167 sdata->vif.type == NL80211_IFTYPE_STATION) { 168 if (sdata->u.mgd.associated) 169 ieee80211_offchannel_ps_disable(sdata); 170 } 171 172 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 173 /* 174 * This may wake up queues even though the driver 175 * currently has them stopped. This is not very 176 * likely, since the driver won't have gotten any 177 * (or hardly any) new packets while we weren't 178 * on the right channel, and even if it happens 179 * it will at most lead to queueing up one more 180 * packet per queue in mac80211 rather than on 181 * the interface qdisc. 182 */ 183 netif_tx_wake_all_queues(sdata->dev); 184 } 185 186 if (sdata->vif.type == NL80211_IFTYPE_AP || 187 sdata->vif.type == NL80211_IFTYPE_ADHOC || 188 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 189 ieee80211_bss_info_change_notify( 190 sdata, BSS_CHANGED_BEACON_ENABLED); 191 } 192 mutex_unlock(&local->iflist_mtx); 193 } 194 195 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc) 196 { 197 if (roc->notified) 198 return; 199 200 if (roc->mgmt_tx_cookie) { 201 if (!WARN_ON(!roc->frame)) { 202 ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7, 203 roc->chan->band); 204 roc->frame = NULL; 205 } 206 } else { 207 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie, 208 roc->chan, roc->req_duration, 209 GFP_KERNEL); 210 } 211 212 roc->notified = true; 213 } 214 215 static void ieee80211_hw_roc_start(struct work_struct *work) 216 { 217 struct ieee80211_local *local = 218 container_of(work, struct ieee80211_local, hw_roc_start); 219 struct ieee80211_roc_work *roc, *dep, *tmp; 220 221 mutex_lock(&local->mtx); 222 223 if (list_empty(&local->roc_list)) 224 goto out_unlock; 225 226 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 227 list); 228 229 if (!roc->started) 230 goto out_unlock; 231 232 roc->hw_begun = true; 233 roc->hw_start_time = local->hw_roc_start_time; 234 235 ieee80211_handle_roc_started(roc); 236 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) { 237 ieee80211_handle_roc_started(dep); 238 239 if (dep->duration > roc->duration) { 240 u32 dur = dep->duration; 241 dep->duration = dur - roc->duration; 242 roc->duration = dur; 243 list_move(&dep->list, &roc->list); 244 } 245 } 246 out_unlock: 247 mutex_unlock(&local->mtx); 248 } 249 250 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 251 { 252 struct ieee80211_local *local = hw_to_local(hw); 253 254 local->hw_roc_start_time = jiffies; 255 256 trace_api_ready_on_channel(local); 257 258 ieee80211_queue_work(hw, &local->hw_roc_start); 259 } 260 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 261 262 void ieee80211_start_next_roc(struct ieee80211_local *local) 263 { 264 struct ieee80211_roc_work *roc; 265 266 lockdep_assert_held(&local->mtx); 267 268 if (list_empty(&local->roc_list)) { 269 ieee80211_run_deferred_scan(local); 270 return; 271 } 272 273 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 274 list); 275 276 if (WARN_ON_ONCE(roc->started)) 277 return; 278 279 if (local->ops->remain_on_channel) { 280 int ret, duration = roc->duration; 281 282 /* XXX: duplicated, see ieee80211_start_roc_work() */ 283 if (!duration) 284 duration = 10; 285 286 ret = drv_remain_on_channel(local, roc->sdata, roc->chan, 287 duration); 288 289 roc->started = true; 290 291 if (ret) { 292 wiphy_warn(local->hw.wiphy, 293 "failed to start next HW ROC (%d)\n", ret); 294 /* 295 * queue the work struct again to avoid recursion 296 * when multiple failures occur 297 */ 298 ieee80211_remain_on_channel_expired(&local->hw); 299 } 300 } else { 301 /* delay it a bit */ 302 ieee80211_queue_delayed_work(&local->hw, &roc->work, 303 round_jiffies_relative(HZ/2)); 304 } 305 } 306 307 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc) 308 { 309 struct ieee80211_roc_work *dep, *tmp; 310 311 /* was never transmitted */ 312 if (roc->frame) { 313 cfg80211_mgmt_tx_status(&roc->sdata->wdev, 314 (unsigned long)roc->frame, 315 roc->frame->data, roc->frame->len, 316 false, GFP_KERNEL); 317 kfree_skb(roc->frame); 318 } 319 320 if (!roc->mgmt_tx_cookie) 321 cfg80211_remain_on_channel_expired(&roc->sdata->wdev, 322 roc->cookie, roc->chan, 323 GFP_KERNEL); 324 325 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) 326 ieee80211_roc_notify_destroy(dep); 327 328 kfree(roc); 329 } 330 331 void ieee80211_sw_roc_work(struct work_struct *work) 332 { 333 struct ieee80211_roc_work *roc = 334 container_of(work, struct ieee80211_roc_work, work.work); 335 struct ieee80211_sub_if_data *sdata = roc->sdata; 336 struct ieee80211_local *local = sdata->local; 337 bool started; 338 339 mutex_lock(&local->mtx); 340 341 if (roc->abort) 342 goto finish; 343 344 if (WARN_ON(list_empty(&local->roc_list))) 345 goto out_unlock; 346 347 if (WARN_ON(roc != list_first_entry(&local->roc_list, 348 struct ieee80211_roc_work, 349 list))) 350 goto out_unlock; 351 352 if (!roc->started) { 353 struct ieee80211_roc_work *dep; 354 355 /* start this ROC */ 356 357 /* switch channel etc */ 358 ieee80211_recalc_idle(local); 359 360 local->tmp_channel = roc->chan; 361 ieee80211_hw_config(local, 0); 362 363 /* tell userspace or send frame */ 364 ieee80211_handle_roc_started(roc); 365 list_for_each_entry(dep, &roc->dependents, list) 366 ieee80211_handle_roc_started(dep); 367 368 /* if it was pure TX, just finish right away */ 369 if (!roc->duration) 370 goto finish; 371 372 roc->started = true; 373 ieee80211_queue_delayed_work(&local->hw, &roc->work, 374 msecs_to_jiffies(roc->duration)); 375 } else { 376 /* finish this ROC */ 377 finish: 378 list_del(&roc->list); 379 started = roc->started; 380 ieee80211_roc_notify_destroy(roc); 381 382 if (started) { 383 drv_flush(local, false); 384 385 local->tmp_channel = NULL; 386 ieee80211_hw_config(local, 0); 387 388 ieee80211_offchannel_return(local, true); 389 } 390 391 ieee80211_recalc_idle(local); 392 393 if (started) 394 ieee80211_start_next_roc(local); 395 } 396 397 out_unlock: 398 mutex_unlock(&local->mtx); 399 } 400 401 static void ieee80211_hw_roc_done(struct work_struct *work) 402 { 403 struct ieee80211_local *local = 404 container_of(work, struct ieee80211_local, hw_roc_done); 405 struct ieee80211_roc_work *roc; 406 407 mutex_lock(&local->mtx); 408 409 if (list_empty(&local->roc_list)) 410 goto out_unlock; 411 412 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 413 list); 414 415 if (!roc->started) 416 goto out_unlock; 417 418 list_del(&roc->list); 419 420 ieee80211_roc_notify_destroy(roc); 421 422 /* if there's another roc, start it now */ 423 ieee80211_start_next_roc(local); 424 425 out_unlock: 426 mutex_unlock(&local->mtx); 427 } 428 429 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 430 { 431 struct ieee80211_local *local = hw_to_local(hw); 432 433 trace_api_remain_on_channel_expired(local); 434 435 ieee80211_queue_work(hw, &local->hw_roc_done); 436 } 437 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 438 439 void ieee80211_roc_setup(struct ieee80211_local *local) 440 { 441 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 442 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 443 INIT_LIST_HEAD(&local->roc_list); 444 } 445 446 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata) 447 { 448 struct ieee80211_local *local = sdata->local; 449 struct ieee80211_roc_work *roc, *tmp; 450 LIST_HEAD(tmp_list); 451 452 mutex_lock(&local->mtx); 453 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { 454 if (roc->sdata != sdata) 455 continue; 456 457 if (roc->started && local->ops->remain_on_channel) { 458 /* can race, so ignore return value */ 459 drv_cancel_remain_on_channel(local); 460 } 461 462 list_move_tail(&roc->list, &tmp_list); 463 roc->abort = true; 464 } 465 mutex_unlock(&local->mtx); 466 467 list_for_each_entry_safe(roc, tmp, &tmp_list, list) { 468 if (local->ops->remain_on_channel) { 469 list_del(&roc->list); 470 ieee80211_roc_notify_destroy(roc); 471 } else { 472 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0); 473 474 /* work will clean up etc */ 475 flush_delayed_work(&roc->work); 476 } 477 } 478 479 WARN_ON_ONCE(!list_empty(&tmp_list)); 480 } 481