/* * Off-channel operation helpers * * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> * Copyright 2004, Instant802 Networks, Inc. * Copyright 2005, Devicescape Software, Inc. * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> * Copyright 2007, Michael Wu <flamingice@sourmilk.net> * Copyright 2009 Johannes Berg <johannes@sipsolutions.net> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/export.h> #include <net/mac80211.h> #include "ieee80211_i.h" #include "driver-ops.h" /* * Tell our hardware to disable PS. * Optionally inform AP that we will go to sleep so that it will buffer * the frames while we are doing off-channel work. This is optional * because we *may* be doing work on-operating channel, and want our * hardware unconditionally awake, but still let the AP send us normal frames. */ static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; local->offchannel_ps_enabled = false; /* FIXME: what to do when local->pspolling is true? */ del_timer_sync(&local->dynamic_ps_timer); del_timer_sync(&ifmgd->bcn_mon_timer); del_timer_sync(&ifmgd->conn_mon_timer); cancel_work_sync(&local->dynamic_ps_enable_work); if (local->hw.conf.flags & IEEE80211_CONF_PS) { local->offchannel_ps_enabled = true; local->hw.conf.flags &= ~IEEE80211_CONF_PS; ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); } if (!local->offchannel_ps_enabled || !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) /* * If power save was enabled, no need to send a nullfunc * frame because AP knows that we are sleeping. But if the * hardware is creating the nullfunc frame for power save * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not * enabled) and power save was enabled, the firmware just * sent a null frame with power save disabled. So we need * to send a new nullfunc frame to inform the AP that we * are again sleeping. */ ieee80211_send_nullfunc(local, sdata, 1); } /* inform AP that we are awake again, unless power save is enabled */ static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; if (!local->ps_sdata) ieee80211_send_nullfunc(local, sdata, 0); else if (local->offchannel_ps_enabled) { /* * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware * will send a nullfunc frame with the powersave bit set * even though the AP already knows that we are sleeping. * This could be avoided by sending a null frame with power * save bit disabled before enabling the power save, but * this doesn't gain anything. * * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need * to send a nullfunc frame because AP already knows that * we are sleeping, let's just enable power save mode in * hardware. */ /* TODO: Only set hardware if CONF_PS changed? * TODO: Should we set offchannel_ps_enabled to false? */ local->hw.conf.flags |= IEEE80211_CONF_PS; ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); } else if (local->hw.conf.dynamic_ps_timeout > 0) { /* * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer * had been running before leaving the operating channel, * restart the timer now and send a nullfunc frame to inform * the AP that we are awake. */ ieee80211_send_nullfunc(local, sdata, 0); mod_timer(&local->dynamic_ps_timer, jiffies + msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); } ieee80211_sta_reset_beacon_monitor(sdata); ieee80211_sta_reset_conn_monitor(sdata); } void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; if (WARN_ON(local->use_chanctx)) return; /* * notify the AP about us leaving the channel and stop all * STA interfaces. */ /* * Stop queues and transmit all frames queued by the driver * before sending nullfunc to enable powersave at the AP. */ ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL); drv_flush(local, false); mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (!ieee80211_sdata_running(sdata)) continue; if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) continue; if (sdata->vif.type != NL80211_IFTYPE_MONITOR) set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); /* Check to see if we should disable beaconing. */ if (sdata->vif.bss_conf.enable_beacon) { set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); sdata->vif.bss_conf.enable_beacon = false; ieee80211_bss_info_change_notify( sdata, BSS_CHANGED_BEACON_ENABLED); } if (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.associated) ieee80211_offchannel_ps_enable(sdata); } mutex_unlock(&local->iflist_mtx); } void ieee80211_offchannel_return(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; if (WARN_ON(local->use_chanctx)) return; mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) continue; if (sdata->vif.type != NL80211_IFTYPE_MONITOR) clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); if (!ieee80211_sdata_running(sdata)) continue; /* Tell AP we're back */ if (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.associated) ieee80211_offchannel_ps_disable(sdata); if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state)) { sdata->vif.bss_conf.enable_beacon = true; ieee80211_bss_info_change_notify( sdata, BSS_CHANGED_BEACON_ENABLED); } } mutex_unlock(&local->iflist_mtx); ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL); } void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc) { if (roc->notified) return; if (roc->mgmt_tx_cookie) { if (!WARN_ON(!roc->frame)) { ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7, roc->chan->band); roc->frame = NULL; } } else { cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie, roc->chan, roc->req_duration, GFP_KERNEL); } roc->notified = true; } static void ieee80211_hw_roc_start(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, hw_roc_start); struct ieee80211_roc_work *roc, *dep, *tmp; mutex_lock(&local->mtx); if (list_empty(&local->roc_list)) goto out_unlock; roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, list); if (!roc->started) goto out_unlock; roc->hw_begun = true; roc->hw_start_time = local->hw_roc_start_time; ieee80211_handle_roc_started(roc); list_for_each_entry_safe(dep, tmp, &roc->dependents, list) { ieee80211_handle_roc_started(dep); if (dep->duration > roc->duration) { u32 dur = dep->duration; dep->duration = dur - roc->duration; roc->duration = dur; list_move(&dep->list, &roc->list); } } out_unlock: mutex_unlock(&local->mtx); } void ieee80211_ready_on_channel(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); local->hw_roc_start_time = jiffies; trace_api_ready_on_channel(local); ieee80211_queue_work(hw, &local->hw_roc_start); } EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); void ieee80211_start_next_roc(struct ieee80211_local *local) { struct ieee80211_roc_work *roc; lockdep_assert_held(&local->mtx); if (list_empty(&local->roc_list)) { ieee80211_run_deferred_scan(local); return; } roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, list); if (WARN_ON_ONCE(roc->started)) return; if (local->ops->remain_on_channel) { int ret, duration = roc->duration; /* XXX: duplicated, see ieee80211_start_roc_work() */ if (!duration) duration = 10; ret = drv_remain_on_channel(local, roc->sdata, roc->chan, duration); roc->started = true; if (ret) { wiphy_warn(local->hw.wiphy, "failed to start next HW ROC (%d)\n", ret); /* * queue the work struct again to avoid recursion * when multiple failures occur */ ieee80211_remain_on_channel_expired(&local->hw); } } else { /* delay it a bit */ ieee80211_queue_delayed_work(&local->hw, &roc->work, round_jiffies_relative(HZ/2)); } } void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc) { struct ieee80211_roc_work *dep, *tmp; /* was never transmitted */ if (roc->frame) { cfg80211_mgmt_tx_status(&roc->sdata->wdev, (unsigned long)roc->frame, roc->frame->data, roc->frame->len, false, GFP_KERNEL); kfree_skb(roc->frame); } if (!roc->mgmt_tx_cookie) cfg80211_remain_on_channel_expired(&roc->sdata->wdev, roc->cookie, roc->chan, GFP_KERNEL); list_for_each_entry_safe(dep, tmp, &roc->dependents, list) ieee80211_roc_notify_destroy(dep); kfree(roc); } void ieee80211_sw_roc_work(struct work_struct *work) { struct ieee80211_roc_work *roc = container_of(work, struct ieee80211_roc_work, work.work); struct ieee80211_sub_if_data *sdata = roc->sdata; struct ieee80211_local *local = sdata->local; bool started; mutex_lock(&local->mtx); if (roc->abort) goto finish; if (WARN_ON(list_empty(&local->roc_list))) goto out_unlock; if (WARN_ON(roc != list_first_entry(&local->roc_list, struct ieee80211_roc_work, list))) goto out_unlock; if (!roc->started) { struct ieee80211_roc_work *dep; /* start this ROC */ /* switch channel etc */ ieee80211_recalc_idle(local); local->tmp_channel = roc->chan; ieee80211_hw_config(local, 0); /* tell userspace or send frame */ ieee80211_handle_roc_started(roc); list_for_each_entry(dep, &roc->dependents, list) ieee80211_handle_roc_started(dep); /* if it was pure TX, just finish right away */ if (!roc->duration) goto finish; roc->started = true; ieee80211_queue_delayed_work(&local->hw, &roc->work, msecs_to_jiffies(roc->duration)); } else { /* finish this ROC */ finish: list_del(&roc->list); started = roc->started; ieee80211_roc_notify_destroy(roc); if (started) { drv_flush(local, false); local->tmp_channel = NULL; ieee80211_hw_config(local, 0); ieee80211_offchannel_return(local); } ieee80211_recalc_idle(local); if (started) ieee80211_start_next_roc(local); } out_unlock: mutex_unlock(&local->mtx); } static void ieee80211_hw_roc_done(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, hw_roc_done); struct ieee80211_roc_work *roc; mutex_lock(&local->mtx); if (list_empty(&local->roc_list)) goto out_unlock; roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work, list); if (!roc->started) goto out_unlock; list_del(&roc->list); ieee80211_roc_notify_destroy(roc); /* if there's another roc, start it now */ ieee80211_start_next_roc(local); out_unlock: mutex_unlock(&local->mtx); } void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); trace_api_remain_on_channel_expired(local); ieee80211_queue_work(hw, &local->hw_roc_done); } EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); void ieee80211_roc_setup(struct ieee80211_local *local) { INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); INIT_LIST_HEAD(&local->roc_list); } void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; struct ieee80211_roc_work *roc, *tmp; LIST_HEAD(tmp_list); mutex_lock(&local->mtx); list_for_each_entry_safe(roc, tmp, &local->roc_list, list) { if (roc->sdata != sdata) continue; if (roc->started && local->ops->remain_on_channel) { /* can race, so ignore return value */ drv_cancel_remain_on_channel(local); } list_move_tail(&roc->list, &tmp_list); roc->abort = true; } mutex_unlock(&local->mtx); list_for_each_entry_safe(roc, tmp, &tmp_list, list) { if (local->ops->remain_on_channel) { list_del(&roc->list); ieee80211_roc_notify_destroy(roc); } else { ieee80211_queue_delayed_work(&local->hw, &roc->work, 0); /* work will clean up etc */ flush_delayed_work(&roc->work); } } WARN_ON_ONCE(!list_empty(&tmp_list)); }