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 /* 111 * notify the AP about us leaving the channel and stop all 112 * STA interfaces. 113 */ 114 mutex_lock(&local->iflist_mtx); 115 list_for_each_entry(sdata, &local->interfaces, list) { 116 if (!ieee80211_sdata_running(sdata)) 117 continue; 118 119 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 120 continue; 121 122 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 123 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 124 125 /* Check to see if we should disable beaconing. */ 126 if (sdata->vif.type == NL80211_IFTYPE_AP || 127 sdata->vif.type == NL80211_IFTYPE_ADHOC || 128 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 129 ieee80211_bss_info_change_notify( 130 sdata, BSS_CHANGED_BEACON_ENABLED); 131 132 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 133 netif_tx_stop_all_queues(sdata->dev); 134 if (offchannel_ps_enable && 135 (sdata->vif.type == NL80211_IFTYPE_STATION) && 136 sdata->u.mgd.associated) 137 ieee80211_offchannel_ps_enable(sdata); 138 } 139 } 140 mutex_unlock(&local->iflist_mtx); 141 } 142 143 void ieee80211_offchannel_return(struct ieee80211_local *local, 144 bool offchannel_ps_disable) 145 { 146 struct ieee80211_sub_if_data *sdata; 147 148 mutex_lock(&local->iflist_mtx); 149 list_for_each_entry(sdata, &local->interfaces, list) { 150 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) 151 continue; 152 153 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 154 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 155 156 if (!ieee80211_sdata_running(sdata)) 157 continue; 158 159 /* Tell AP we're back */ 160 if (offchannel_ps_disable && 161 sdata->vif.type == NL80211_IFTYPE_STATION) { 162 if (sdata->u.mgd.associated) 163 ieee80211_offchannel_ps_disable(sdata); 164 } 165 166 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 167 /* 168 * This may wake up queues even though the driver 169 * currently has them stopped. This is not very 170 * likely, since the driver won't have gotten any 171 * (or hardly any) new packets while we weren't 172 * on the right channel, and even if it happens 173 * it will at most lead to queueing up one more 174 * packet per queue in mac80211 rather than on 175 * the interface qdisc. 176 */ 177 netif_tx_wake_all_queues(sdata->dev); 178 } 179 180 if (sdata->vif.type == NL80211_IFTYPE_AP || 181 sdata->vif.type == NL80211_IFTYPE_ADHOC || 182 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 183 ieee80211_bss_info_change_notify( 184 sdata, BSS_CHANGED_BEACON_ENABLED); 185 } 186 mutex_unlock(&local->iflist_mtx); 187 } 188 189 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc) 190 { 191 if (roc->notified) 192 return; 193 194 if (roc->mgmt_tx_cookie) { 195 if (!WARN_ON(!roc->frame)) { 196 ieee80211_tx_skb(roc->sdata, roc->frame); 197 roc->frame = NULL; 198 } 199 } else { 200 cfg80211_ready_on_channel(&roc->sdata->wdev, (unsigned long)roc, 201 roc->chan, roc->chan_type, 202 roc->req_duration, GFP_KERNEL); 203 } 204 205 roc->notified = true; 206 } 207 208 static void ieee80211_hw_roc_start(struct work_struct *work) 209 { 210 struct ieee80211_local *local = 211 container_of(work, struct ieee80211_local, hw_roc_start); 212 struct ieee80211_roc_work *roc, *dep, *tmp; 213 214 mutex_lock(&local->mtx); 215 216 if (list_empty(&local->roc_list)) 217 goto out_unlock; 218 219 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 220 list); 221 222 if (!roc->started) 223 goto out_unlock; 224 225 roc->hw_begun = true; 226 roc->hw_start_time = local->hw_roc_start_time; 227 228 ieee80211_handle_roc_started(roc); 229 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) { 230 ieee80211_handle_roc_started(dep); 231 232 if (dep->duration > roc->duration) { 233 u32 dur = dep->duration; 234 dep->duration = dur - roc->duration; 235 roc->duration = dur; 236 list_move(&dep->list, &roc->list); 237 } 238 } 239 out_unlock: 240 mutex_unlock(&local->mtx); 241 } 242 243 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 244 { 245 struct ieee80211_local *local = hw_to_local(hw); 246 247 local->hw_roc_start_time = jiffies; 248 249 trace_api_ready_on_channel(local); 250 251 ieee80211_queue_work(hw, &local->hw_roc_start); 252 } 253 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 254 255 void ieee80211_start_next_roc(struct ieee80211_local *local) 256 { 257 struct ieee80211_roc_work *roc; 258 259 lockdep_assert_held(&local->mtx); 260 261 if (list_empty(&local->roc_list)) { 262 ieee80211_run_deferred_scan(local); 263 return; 264 } 265 266 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 267 list); 268 269 if (WARN_ON_ONCE(roc->started)) 270 return; 271 272 if (local->ops->remain_on_channel) { 273 int ret, duration = roc->duration; 274 275 /* XXX: duplicated, see ieee80211_start_roc_work() */ 276 if (!duration) 277 duration = 10; 278 279 ret = drv_remain_on_channel(local, roc->chan, 280 roc->chan_type, 281 duration); 282 283 roc->started = true; 284 285 if (ret) { 286 wiphy_warn(local->hw.wiphy, 287 "failed to start next HW ROC (%d)\n", ret); 288 /* 289 * queue the work struct again to avoid recursion 290 * when multiple failures occur 291 */ 292 ieee80211_remain_on_channel_expired(&local->hw); 293 } 294 } else { 295 /* delay it a bit */ 296 ieee80211_queue_delayed_work(&local->hw, &roc->work, 297 round_jiffies_relative(HZ/2)); 298 } 299 } 300 301 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc) 302 { 303 struct ieee80211_roc_work *dep, *tmp; 304 305 /* was never transmitted */ 306 if (roc->frame) { 307 cfg80211_mgmt_tx_status(&roc->sdata->wdev, 308 (unsigned long)roc->frame, 309 roc->frame->data, roc->frame->len, 310 false, GFP_KERNEL); 311 kfree_skb(roc->frame); 312 } 313 314 if (!roc->mgmt_tx_cookie) 315 cfg80211_remain_on_channel_expired(&roc->sdata->wdev, 316 (unsigned long)roc, 317 roc->chan, roc->chan_type, 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 local->tmp_channel_type = roc->chan_type; 357 ieee80211_hw_config(local, 0); 358 359 /* tell userspace or send frame */ 360 ieee80211_handle_roc_started(roc); 361 list_for_each_entry(dep, &roc->dependents, list) 362 ieee80211_handle_roc_started(dep); 363 364 /* if it was pure TX, just finish right away */ 365 if (!roc->duration) 366 goto finish; 367 368 roc->started = true; 369 ieee80211_queue_delayed_work(&local->hw, &roc->work, 370 msecs_to_jiffies(roc->duration)); 371 } else { 372 /* finish this ROC */ 373 finish: 374 list_del(&roc->list); 375 started = roc->started; 376 ieee80211_roc_notify_destroy(roc); 377 378 if (started) { 379 drv_flush(local, false); 380 381 local->tmp_channel = NULL; 382 ieee80211_hw_config(local, 0); 383 384 ieee80211_offchannel_return(local, true); 385 } 386 387 ieee80211_recalc_idle(local); 388 389 if (started) 390 ieee80211_start_next_roc(local); 391 } 392 393 out_unlock: 394 mutex_unlock(&local->mtx); 395 } 396 397 static void ieee80211_hw_roc_done(struct work_struct *work) 398 { 399 struct ieee80211_local *local = 400 container_of(work, struct ieee80211_local, hw_roc_done); 401 struct ieee80211_roc_work *roc; 402 403 mutex_lock(&local->mtx); 404 405 if (list_empty(&local->roc_list)) 406 goto out_unlock; 407 408 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 409 list); 410 411 if (!roc->started) 412 goto out_unlock; 413 414 list_del(&roc->list); 415 416 ieee80211_roc_notify_destroy(roc); 417 418 /* if there's another roc, start it now */ 419 ieee80211_start_next_roc(local); 420 421 out_unlock: 422 mutex_unlock(&local->mtx); 423 } 424 425 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 426 { 427 struct ieee80211_local *local = hw_to_local(hw); 428 429 trace_api_remain_on_channel_expired(local); 430 431 ieee80211_queue_work(hw, &local->hw_roc_done); 432 } 433 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 434 435 void ieee80211_roc_setup(struct ieee80211_local *local) 436 { 437 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 438 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 439 INIT_LIST_HEAD(&local->roc_list); 440 } 441 442 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata) 443 { 444 struct ieee80211_local *local = sdata->local; 445 struct ieee80211_roc_work *roc, *tmp; 446 LIST_HEAD(tmp_list); 447 448 mutex_lock(&local->mtx); 449 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { 450 if (roc->sdata != sdata) 451 continue; 452 453 if (roc->started && local->ops->remain_on_channel) { 454 /* can race, so ignore return value */ 455 drv_cancel_remain_on_channel(local); 456 } 457 458 list_move_tail(&roc->list, &tmp_list); 459 roc->abort = true; 460 } 461 462 ieee80211_start_next_roc(local); 463 mutex_unlock(&local->mtx); 464 465 list_for_each_entry_safe(roc, tmp, &tmp_list, list) { 466 if (local->ops->remain_on_channel) { 467 list_del(&roc->list); 468 ieee80211_roc_notify_destroy(roc); 469 } else { 470 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0); 471 472 /* work will clean up etc */ 473 flush_delayed_work(&roc->work); 474 } 475 } 476 477 WARN_ON_ONCE(!list_empty(&tmp_list)); 478 } 479