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 { 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 mutex_lock(&local->iflist_mtx); 117 list_for_each_entry(sdata, &local->interfaces, list) { 118 if (!ieee80211_sdata_running(sdata)) 119 continue; 120 121 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 122 continue; 123 124 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 125 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 126 127 /* Check to see if we should disable beaconing. */ 128 if (sdata->vif.type == NL80211_IFTYPE_AP || 129 sdata->vif.type == NL80211_IFTYPE_ADHOC || 130 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 131 ieee80211_bss_info_change_notify( 132 sdata, BSS_CHANGED_BEACON_ENABLED); 133 134 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 135 netif_tx_stop_all_queues(sdata->dev); 136 if (sdata->vif.type == NL80211_IFTYPE_STATION && 137 sdata->u.mgd.associated) 138 ieee80211_offchannel_ps_enable(sdata); 139 } 140 } 141 mutex_unlock(&local->iflist_mtx); 142 } 143 144 void ieee80211_offchannel_return(struct ieee80211_local *local) 145 { 146 struct ieee80211_sub_if_data *sdata; 147 148 if (WARN_ON(local->use_chanctx)) 149 return; 150 151 mutex_lock(&local->iflist_mtx); 152 list_for_each_entry(sdata, &local->interfaces, list) { 153 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 154 continue; 155 156 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 157 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 158 159 if (!ieee80211_sdata_running(sdata)) 160 continue; 161 162 /* Tell AP we're back */ 163 if (sdata->vif.type == NL80211_IFTYPE_STATION && 164 sdata->u.mgd.associated) 165 ieee80211_offchannel_ps_disable(sdata); 166 167 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 168 /* 169 * This may wake up queues even though the driver 170 * currently has them stopped. This is not very 171 * likely, since the driver won't have gotten any 172 * (or hardly any) new packets while we weren't 173 * on the right channel, and even if it happens 174 * it will at most lead to queueing up one more 175 * packet per queue in mac80211 rather than on 176 * the interface qdisc. 177 */ 178 netif_tx_wake_all_queues(sdata->dev); 179 } 180 181 if (sdata->vif.type == NL80211_IFTYPE_AP || 182 sdata->vif.type == NL80211_IFTYPE_ADHOC || 183 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 184 ieee80211_bss_info_change_notify( 185 sdata, BSS_CHANGED_BEACON_ENABLED); 186 } 187 mutex_unlock(&local->iflist_mtx); 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); 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) 303 { 304 struct ieee80211_roc_work *dep, *tmp; 305 306 /* was never transmitted */ 307 if (roc->frame) { 308 cfg80211_mgmt_tx_status(&roc->sdata->wdev, 309 (unsigned long)roc->frame, 310 roc->frame->data, roc->frame->len, 311 false, GFP_KERNEL); 312 kfree_skb(roc->frame); 313 } 314 315 if (!roc->mgmt_tx_cookie) 316 cfg80211_remain_on_channel_expired(&roc->sdata->wdev, 317 roc->cookie, roc->chan, 318 GFP_KERNEL); 319 320 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) 321 ieee80211_roc_notify_destroy(dep); 322 323 kfree(roc); 324 } 325 326 void ieee80211_sw_roc_work(struct work_struct *work) 327 { 328 struct ieee80211_roc_work *roc = 329 container_of(work, struct ieee80211_roc_work, work.work); 330 struct ieee80211_sub_if_data *sdata = roc->sdata; 331 struct ieee80211_local *local = sdata->local; 332 bool started; 333 334 mutex_lock(&local->mtx); 335 336 if (roc->abort) 337 goto finish; 338 339 if (WARN_ON(list_empty(&local->roc_list))) 340 goto out_unlock; 341 342 if (WARN_ON(roc != list_first_entry(&local->roc_list, 343 struct ieee80211_roc_work, 344 list))) 345 goto out_unlock; 346 347 if (!roc->started) { 348 struct ieee80211_roc_work *dep; 349 350 /* start this ROC */ 351 352 /* switch channel etc */ 353 ieee80211_recalc_idle(local); 354 355 local->tmp_channel = roc->chan; 356 ieee80211_hw_config(local, 0); 357 358 /* tell userspace or send frame */ 359 ieee80211_handle_roc_started(roc); 360 list_for_each_entry(dep, &roc->dependents, list) 361 ieee80211_handle_roc_started(dep); 362 363 /* if it was pure TX, just finish right away */ 364 if (!roc->duration) 365 goto finish; 366 367 roc->started = true; 368 ieee80211_queue_delayed_work(&local->hw, &roc->work, 369 msecs_to_jiffies(roc->duration)); 370 } else { 371 /* finish this ROC */ 372 finish: 373 list_del(&roc->list); 374 started = roc->started; 375 ieee80211_roc_notify_destroy(roc); 376 377 if (started) { 378 drv_flush(local, false); 379 380 local->tmp_channel = NULL; 381 ieee80211_hw_config(local, 0); 382 383 ieee80211_offchannel_return(local); 384 } 385 386 ieee80211_recalc_idle(local); 387 388 if (started) 389 ieee80211_start_next_roc(local); 390 } 391 392 out_unlock: 393 mutex_unlock(&local->mtx); 394 } 395 396 static void ieee80211_hw_roc_done(struct work_struct *work) 397 { 398 struct ieee80211_local *local = 399 container_of(work, struct ieee80211_local, hw_roc_done); 400 struct ieee80211_roc_work *roc; 401 402 mutex_lock(&local->mtx); 403 404 if (list_empty(&local->roc_list)) 405 goto out_unlock; 406 407 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 408 list); 409 410 if (!roc->started) 411 goto out_unlock; 412 413 list_del(&roc->list); 414 415 ieee80211_roc_notify_destroy(roc); 416 417 /* if there's another roc, start it now */ 418 ieee80211_start_next_roc(local); 419 420 out_unlock: 421 mutex_unlock(&local->mtx); 422 } 423 424 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 425 { 426 struct ieee80211_local *local = hw_to_local(hw); 427 428 trace_api_remain_on_channel_expired(local); 429 430 ieee80211_queue_work(hw, &local->hw_roc_done); 431 } 432 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 433 434 void ieee80211_roc_setup(struct ieee80211_local *local) 435 { 436 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 437 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 438 INIT_LIST_HEAD(&local->roc_list); 439 } 440 441 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata) 442 { 443 struct ieee80211_local *local = sdata->local; 444 struct ieee80211_roc_work *roc, *tmp; 445 LIST_HEAD(tmp_list); 446 447 mutex_lock(&local->mtx); 448 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { 449 if (roc->sdata != sdata) 450 continue; 451 452 if (roc->started && local->ops->remain_on_channel) { 453 /* can race, so ignore return value */ 454 drv_cancel_remain_on_channel(local); 455 } 456 457 list_move_tail(&roc->list, &tmp_list); 458 roc->abort = true; 459 } 460 mutex_unlock(&local->mtx); 461 462 list_for_each_entry_safe(roc, tmp, &tmp_list, list) { 463 if (local->ops->remain_on_channel) { 464 list_del(&roc->list); 465 ieee80211_roc_notify_destroy(roc); 466 } else { 467 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0); 468 469 /* work will clean up etc */ 470 flush_delayed_work(&roc->work); 471 } 472 } 473 474 WARN_ON_ONCE(!list_empty(&tmp_list)); 475 } 476