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_MONITOR) 120 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 121 122 /* Check to see if we should disable beaconing. */ 123 if (sdata->vif.type == NL80211_IFTYPE_AP || 124 sdata->vif.type == NL80211_IFTYPE_ADHOC || 125 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 126 ieee80211_bss_info_change_notify( 127 sdata, BSS_CHANGED_BEACON_ENABLED); 128 129 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 130 netif_tx_stop_all_queues(sdata->dev); 131 if (offchannel_ps_enable && 132 (sdata->vif.type == NL80211_IFTYPE_STATION) && 133 sdata->u.mgd.associated) 134 ieee80211_offchannel_ps_enable(sdata); 135 } 136 } 137 mutex_unlock(&local->iflist_mtx); 138 } 139 140 void ieee80211_offchannel_return(struct ieee80211_local *local, 141 bool offchannel_ps_disable) 142 { 143 struct ieee80211_sub_if_data *sdata; 144 145 mutex_lock(&local->iflist_mtx); 146 list_for_each_entry(sdata, &local->interfaces, list) { 147 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 148 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 149 150 if (!ieee80211_sdata_running(sdata)) 151 continue; 152 153 /* Tell AP we're back */ 154 if (offchannel_ps_disable && 155 sdata->vif.type == NL80211_IFTYPE_STATION) { 156 if (sdata->u.mgd.associated) 157 ieee80211_offchannel_ps_disable(sdata); 158 } 159 160 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 161 /* 162 * This may wake up queues even though the driver 163 * currently has them stopped. This is not very 164 * likely, since the driver won't have gotten any 165 * (or hardly any) new packets while we weren't 166 * on the right channel, and even if it happens 167 * it will at most lead to queueing up one more 168 * packet per queue in mac80211 rather than on 169 * the interface qdisc. 170 */ 171 netif_tx_wake_all_queues(sdata->dev); 172 } 173 174 if (sdata->vif.type == NL80211_IFTYPE_AP || 175 sdata->vif.type == NL80211_IFTYPE_ADHOC || 176 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 177 ieee80211_bss_info_change_notify( 178 sdata, BSS_CHANGED_BEACON_ENABLED); 179 } 180 mutex_unlock(&local->iflist_mtx); 181 } 182 183 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc) 184 { 185 if (roc->notified) 186 return; 187 188 if (roc->mgmt_tx_cookie) { 189 if (!WARN_ON(!roc->frame)) { 190 ieee80211_tx_skb(roc->sdata, roc->frame); 191 roc->frame = NULL; 192 } 193 } else { 194 cfg80211_ready_on_channel(&roc->sdata->wdev, (unsigned long)roc, 195 roc->chan, roc->chan_type, 196 roc->req_duration, GFP_KERNEL); 197 } 198 199 roc->notified = true; 200 } 201 202 static void ieee80211_hw_roc_start(struct work_struct *work) 203 { 204 struct ieee80211_local *local = 205 container_of(work, struct ieee80211_local, hw_roc_start); 206 struct ieee80211_roc_work *roc, *dep, *tmp; 207 208 mutex_lock(&local->mtx); 209 210 if (list_empty(&local->roc_list)) 211 goto out_unlock; 212 213 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 214 list); 215 216 if (!roc->started) 217 goto out_unlock; 218 219 roc->hw_begun = true; 220 roc->hw_start_time = local->hw_roc_start_time; 221 222 ieee80211_handle_roc_started(roc); 223 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) { 224 ieee80211_handle_roc_started(dep); 225 226 if (dep->duration > roc->duration) { 227 u32 dur = dep->duration; 228 dep->duration = dur - roc->duration; 229 roc->duration = dur; 230 list_del(&dep->list); 231 list_add(&dep->list, &roc->list); 232 } 233 } 234 out_unlock: 235 mutex_unlock(&local->mtx); 236 } 237 238 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 239 { 240 struct ieee80211_local *local = hw_to_local(hw); 241 242 local->hw_roc_start_time = jiffies; 243 244 trace_api_ready_on_channel(local); 245 246 ieee80211_queue_work(hw, &local->hw_roc_start); 247 } 248 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 249 250 void ieee80211_start_next_roc(struct ieee80211_local *local) 251 { 252 struct ieee80211_roc_work *roc; 253 254 lockdep_assert_held(&local->mtx); 255 256 if (list_empty(&local->roc_list)) { 257 ieee80211_run_deferred_scan(local); 258 return; 259 } 260 261 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 262 list); 263 264 if (WARN_ON_ONCE(roc->started)) 265 return; 266 267 if (local->ops->remain_on_channel) { 268 int ret, duration = roc->duration; 269 270 /* XXX: duplicated, see ieee80211_start_roc_work() */ 271 if (!duration) 272 duration = 10; 273 274 ret = drv_remain_on_channel(local, roc->chan, 275 roc->chan_type, 276 duration); 277 278 roc->started = true; 279 280 if (ret) { 281 wiphy_warn(local->hw.wiphy, 282 "failed to start next HW ROC (%d)\n", ret); 283 /* 284 * queue the work struct again to avoid recursion 285 * when multiple failures occur 286 */ 287 ieee80211_remain_on_channel_expired(&local->hw); 288 } 289 } else { 290 /* delay it a bit */ 291 ieee80211_queue_delayed_work(&local->hw, &roc->work, 292 round_jiffies_relative(HZ/2)); 293 } 294 } 295 296 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc) 297 { 298 struct ieee80211_roc_work *dep, *tmp; 299 300 /* was never transmitted */ 301 if (roc->frame) { 302 cfg80211_mgmt_tx_status(&roc->sdata->wdev, 303 (unsigned long)roc->frame, 304 roc->frame->data, roc->frame->len, 305 false, GFP_KERNEL); 306 kfree_skb(roc->frame); 307 } 308 309 if (!roc->mgmt_tx_cookie) 310 cfg80211_remain_on_channel_expired(&roc->sdata->wdev, 311 (unsigned long)roc, 312 roc->chan, roc->chan_type, 313 GFP_KERNEL); 314 315 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) 316 ieee80211_roc_notify_destroy(dep); 317 318 kfree(roc); 319 } 320 321 void ieee80211_sw_roc_work(struct work_struct *work) 322 { 323 struct ieee80211_roc_work *roc = 324 container_of(work, struct ieee80211_roc_work, work.work); 325 struct ieee80211_sub_if_data *sdata = roc->sdata; 326 struct ieee80211_local *local = sdata->local; 327 bool started; 328 329 mutex_lock(&local->mtx); 330 331 if (roc->abort) 332 goto finish; 333 334 if (WARN_ON(list_empty(&local->roc_list))) 335 goto out_unlock; 336 337 if (WARN_ON(roc != list_first_entry(&local->roc_list, 338 struct ieee80211_roc_work, 339 list))) 340 goto out_unlock; 341 342 if (!roc->started) { 343 struct ieee80211_roc_work *dep; 344 345 /* start this ROC */ 346 347 /* switch channel etc */ 348 ieee80211_recalc_idle(local); 349 350 local->tmp_channel = roc->chan; 351 local->tmp_channel_type = roc->chan_type; 352 ieee80211_hw_config(local, 0); 353 354 /* tell userspace or send frame */ 355 ieee80211_handle_roc_started(roc); 356 list_for_each_entry(dep, &roc->dependents, list) 357 ieee80211_handle_roc_started(dep); 358 359 /* if it was pure TX, just finish right away */ 360 if (!roc->duration) 361 goto finish; 362 363 roc->started = true; 364 ieee80211_queue_delayed_work(&local->hw, &roc->work, 365 msecs_to_jiffies(roc->duration)); 366 } else { 367 /* finish this ROC */ 368 finish: 369 list_del(&roc->list); 370 started = roc->started; 371 ieee80211_roc_notify_destroy(roc); 372 373 if (started) { 374 drv_flush(local, false); 375 376 local->tmp_channel = NULL; 377 ieee80211_hw_config(local, 0); 378 379 ieee80211_offchannel_return(local, true); 380 } 381 382 ieee80211_recalc_idle(local); 383 384 if (started) 385 ieee80211_start_next_roc(local); 386 } 387 388 out_unlock: 389 mutex_unlock(&local->mtx); 390 } 391 392 static void ieee80211_hw_roc_done(struct work_struct *work) 393 { 394 struct ieee80211_local *local = 395 container_of(work, struct ieee80211_local, hw_roc_done); 396 struct ieee80211_roc_work *roc; 397 398 mutex_lock(&local->mtx); 399 400 if (list_empty(&local->roc_list)) 401 goto out_unlock; 402 403 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, 404 list); 405 406 if (!roc->started) 407 goto out_unlock; 408 409 list_del(&roc->list); 410 411 ieee80211_roc_notify_destroy(roc); 412 413 /* if there's another roc, start it now */ 414 ieee80211_start_next_roc(local); 415 416 out_unlock: 417 mutex_unlock(&local->mtx); 418 } 419 420 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 421 { 422 struct ieee80211_local *local = hw_to_local(hw); 423 424 trace_api_remain_on_channel_expired(local); 425 426 ieee80211_queue_work(hw, &local->hw_roc_done); 427 } 428 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 429 430 void ieee80211_roc_setup(struct ieee80211_local *local) 431 { 432 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 433 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 434 INIT_LIST_HEAD(&local->roc_list); 435 } 436 437 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata) 438 { 439 struct ieee80211_local *local = sdata->local; 440 struct ieee80211_roc_work *roc, *tmp; 441 LIST_HEAD(tmp_list); 442 443 mutex_lock(&local->mtx); 444 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { 445 if (roc->sdata != sdata) 446 continue; 447 448 if (roc->started && local->ops->remain_on_channel) { 449 /* can race, so ignore return value */ 450 drv_cancel_remain_on_channel(local); 451 } 452 453 list_move_tail(&roc->list, &tmp_list); 454 roc->abort = true; 455 } 456 457 ieee80211_start_next_roc(local); 458 mutex_unlock(&local->mtx); 459 460 list_for_each_entry_safe(roc, tmp, &tmp_list, list) { 461 if (local->ops->remain_on_channel) { 462 list_del(&roc->list); 463 ieee80211_roc_notify_destroy(roc); 464 } else { 465 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0); 466 467 /* work will clean up etc */ 468 flush_delayed_work(&roc->work); 469 } 470 } 471 472 WARN_ON_ONCE(!list_empty(&tmp_list)); 473 } 474