diff --git a/include/net/mac80211.h b/include/net/mac80211.h index f4ab2fb4d50c..df1004be7ba5 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -2750,11 +2750,13 @@ enum ieee80211_roc_type { * @channel_switch_beacon: Starts a channel switch to a new channel. * Beacons are modified to include CSA or ECSA IEs before calling this * function. The corresponding count fields in these IEs must be - * decremented, and when they reach zero the driver must call + * decremented, and when they reach 1 the driver must call * ieee80211_csa_finish(). Drivers which use ieee80211_beacon_get() * get the csa counter decremented by mac80211, but must check if it is - * zero using ieee80211_csa_is_complete() after the beacon has been + * 1 using ieee80211_csa_is_complete() after the beacon has been * transmitted and then call ieee80211_csa_finish(). + * If the CSA count starts as zero or 1, this function will not be called, + * since there won't be any time to beacon before the switch anyway. * * @join_ibss: Join an IBSS (on an IBSS interface); this is called after all * information in bss_conf is set up and the beacon can be retrieved. A @@ -3452,13 +3454,13 @@ static inline struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw, * @vif: &struct ieee80211_vif pointer from the add_interface callback. * * After a channel switch announcement was scheduled and the counter in this - * announcement hit zero, this function must be called by the driver to + * announcement hits 1, this function must be called by the driver to * notify mac80211 that the channel can be changed. */ void ieee80211_csa_finish(struct ieee80211_vif *vif); /** - * ieee80211_csa_is_complete - find out if counters reached zero + * ieee80211_csa_is_complete - find out if counters reached 1 * @vif: &struct ieee80211_vif pointer from the add_interface callback. * * This function returns whether the channel switch counters reached zero. diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index f111f8df4e65..032081c4cc65 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -2988,28 +2988,26 @@ cfg80211_beacon_dup(struct cfg80211_beacon_data *beacon) return new_beacon; } -void ieee80211_csa_finalize_work(struct work_struct *work) +void ieee80211_csa_finish(struct ieee80211_vif *vif) +{ + struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); + + ieee80211_queue_work(&sdata->local->hw, + &sdata->csa_finalize_work); +} +EXPORT_SYMBOL(ieee80211_csa_finish); + +static void ieee80211_csa_finalize(struct ieee80211_sub_if_data *sdata) { - struct ieee80211_sub_if_data *sdata = - container_of(work, struct ieee80211_sub_if_data, - csa_finalize_work); struct ieee80211_local *local = sdata->local; int err, changed = 0; - sdata_lock(sdata); - /* AP might have been stopped while waiting for the lock. */ - if (!sdata->vif.csa_active) - goto unlock; - - if (!ieee80211_sdata_running(sdata)) - goto unlock; - sdata->radar_required = sdata->csa_radar_required; mutex_lock(&local->mtx); err = ieee80211_vif_change_channel(sdata, &changed); mutex_unlock(&local->mtx); if (WARN_ON(err < 0)) - goto unlock; + return; if (!local->use_chanctx) { local->_oper_chandef = sdata->csa_chandef; @@ -3023,7 +3021,7 @@ void ieee80211_csa_finalize_work(struct work_struct *work) case NL80211_IFTYPE_AP: err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon); if (err < 0) - goto unlock; + return; changed |= err; kfree(sdata->u.ap.next_beacon); @@ -3038,12 +3036,12 @@ void ieee80211_csa_finalize_work(struct work_struct *work) case NL80211_IFTYPE_MESH_POINT: err = ieee80211_mesh_finish_csa(sdata); if (err < 0) - goto unlock; + return; break; #endif default: WARN_ON(1); - goto unlock; + return; } ieee80211_wake_queues_by_reason(&sdata->local->hw, @@ -3051,6 +3049,23 @@ void ieee80211_csa_finalize_work(struct work_struct *work) IEEE80211_QUEUE_STOP_REASON_CSA); cfg80211_ch_switch_notify(sdata->dev, &sdata->csa_chandef); +} + +void ieee80211_csa_finalize_work(struct work_struct *work) +{ + struct ieee80211_sub_if_data *sdata = + container_of(work, struct ieee80211_sub_if_data, + csa_finalize_work); + + sdata_lock(sdata); + /* AP might have been stopped while waiting for the lock. */ + if (!sdata->vif.csa_active) + goto unlock; + + if (!ieee80211_sdata_running(sdata)) + goto unlock; + + ieee80211_csa_finalize(sdata); unlock: sdata_unlock(sdata); @@ -3064,7 +3079,7 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev, struct ieee80211_chanctx_conf *chanctx_conf; struct ieee80211_chanctx *chanctx; struct ieee80211_if_mesh __maybe_unused *ifmsh; - int err, num_chanctx; + int err, num_chanctx, changed = 0; lockdep_assert_held(&sdata->wdev.mtx); @@ -3105,19 +3120,40 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev, switch (sdata->vif.type) { case NL80211_IFTYPE_AP: - sdata->csa_counter_offset_beacon = - params->counter_offset_beacon; - sdata->csa_counter_offset_presp = params->counter_offset_presp; sdata->u.ap.next_beacon = cfg80211_beacon_dup(¶ms->beacon_after); if (!sdata->u.ap.next_beacon) return -ENOMEM; + /* + * With a count of 0, we don't have to wait for any + * TBTT before switching, so complete the CSA + * immediately. In theory, with a count == 1 we + * should delay the switch until just before the next + * TBTT, but that would complicate things so we switch + * immediately too. If we would delay the switch + * until the next TBTT, we would have to set the probe + * response here. + * + * TODO: A channel switch with count <= 1 without + * sending a CSA action frame is kind of useless, + * because the clients won't know we're changing + * channels. The action frame must be implemented + * either here or in the userspace. + */ + if (params->count <= 1) + break; + + sdata->csa_counter_offset_beacon = + params->counter_offset_beacon; + sdata->csa_counter_offset_presp = params->counter_offset_presp; err = ieee80211_assign_beacon(sdata, ¶ms->beacon_csa); if (err < 0) { kfree(sdata->u.ap.next_beacon); return err; } + changed |= err; + break; case NL80211_IFTYPE_ADHOC: if (!sdata->vif.bss_conf.ibss_joined) @@ -3145,9 +3181,16 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev, params->chandef.chan->band) return -EINVAL; - err = ieee80211_ibss_csa_beacon(sdata, params); - if (err < 0) - return err; + /* see comments in the NL80211_IFTYPE_AP block */ + if (params->count > 1) { + err = ieee80211_ibss_csa_beacon(sdata, params); + if (err < 0) + return err; + changed |= err; + } + + ieee80211_send_action_csa(sdata, params); + break; #ifdef CONFIG_MAC80211_MESH case NL80211_IFTYPE_MESH_POINT: @@ -3172,12 +3215,19 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev, if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_NONE) ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_INIT; - err = ieee80211_mesh_csa_beacon(sdata, params, - (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT)); - if (err < 0) { - ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE; - return err; + /* see comments in the NL80211_IFTYPE_AP block */ + if (params->count > 1) { + err = ieee80211_mesh_csa_beacon(sdata, params); + if (err < 0) { + ifmsh->csa_role = IEEE80211_MESH_CSA_ROLE_NONE; + return err; + } + changed |= err; } + + if (ifmsh->csa_role == IEEE80211_MESH_CSA_ROLE_INIT) + ieee80211_send_action_csa(sdata, params); + break; #endif default: @@ -3194,8 +3244,13 @@ int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev, sdata->csa_chandef = params->chandef; sdata->vif.csa_active = true; - ieee80211_bss_info_change_notify(sdata, err); - drv_channel_switch_beacon(sdata, ¶ms->chandef); + if (changed) { + ieee80211_bss_info_change_notify(sdata, changed); + drv_channel_switch_beacon(sdata, ¶ms->chandef); + } else { + /* if the beacon didn't change, we can finalize immediately */ + ieee80211_csa_finalize(sdata); + } return 0; } diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c index 771080ec7212..ed7eec3f6ee0 100644 --- a/net/mac80211/ibss.c +++ b/net/mac80211/ibss.c @@ -521,12 +521,6 @@ int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata, if (old_presp) kfree_rcu(old_presp, rcu_head); - /* it might not send the beacon for a while. send an action frame - * immediately to announce the channel switch. - */ - if (csa_settings) - ieee80211_send_action_csa(sdata, csa_settings); - return BSS_CHANGED_BEACON; out: return ret; diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 428f5bd874e3..96eb272297e1 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1412,8 +1412,7 @@ void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata); void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb); int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata, - struct cfg80211_csa_settings *csa_settings, - bool csa_action); + struct cfg80211_csa_settings *csa_settings); int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata); /* scan/BSS handling */ diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index b4219937e75e..b02ac3378b13 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -1066,7 +1066,8 @@ int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata) /* Remove the CSA and MCSP elements from the beacon */ tmp_csa_settings = rcu_dereference(ifmsh->csa); rcu_assign_pointer(ifmsh->csa, NULL); - kfree_rcu(tmp_csa_settings, rcu_head); + if (tmp_csa_settings) + kfree_rcu(tmp_csa_settings, rcu_head); ret = ieee80211_mesh_rebuild_beacon(sdata); if (ret) return -EINVAL; @@ -1079,8 +1080,7 @@ int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata) } int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata, - struct cfg80211_csa_settings *csa_settings, - bool csa_action) + struct cfg80211_csa_settings *csa_settings) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; struct mesh_csa_settings *tmp_csa_settings; @@ -1104,9 +1104,6 @@ int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata, return ret; } - if (csa_action) - ieee80211_send_action_csa(sdata, csa_settings); - return BSS_CHANGED_BEACON; } diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 27c990bf2320..bb990ecfa655 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2402,15 +2402,6 @@ static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata, return 0; } -void ieee80211_csa_finish(struct ieee80211_vif *vif) -{ - struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); - - ieee80211_queue_work(&sdata->local->hw, - &sdata->csa_finalize_work); -} -EXPORT_SYMBOL(ieee80211_csa_finish); - static void ieee80211_update_csa(struct ieee80211_sub_if_data *sdata, struct beacon_data *beacon) { @@ -2439,8 +2430,12 @@ static void ieee80211_update_csa(struct ieee80211_sub_if_data *sdata, if (WARN_ON(counter_offset_beacon >= beacon_data_len)) return; - /* warn if the driver did not check for/react to csa completeness */ - if (WARN_ON(beacon_data[counter_offset_beacon] == 0)) + /* Warn if the driver did not check for/react to csa + * completeness. A beacon with CSA counter set to 0 should + * never occur, because a counter of 1 means switch just + * before the next beacon. + */ + if (WARN_ON(beacon_data[counter_offset_beacon] == 1)) return; beacon_data[counter_offset_beacon]--; @@ -2506,7 +2501,7 @@ bool ieee80211_csa_is_complete(struct ieee80211_vif *vif) if (WARN_ON(counter_beacon > beacon_data_len)) goto out; - if (beacon_data[counter_beacon] == 0) + if (beacon_data[counter_beacon] == 1) ret = true; out: rcu_read_unlock();