Return-path: Received: from nick.hrz.tu-chemnitz.de ([134.109.228.11]:48608 "EHLO nick.hrz.tu-chemnitz.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755928Ab3FGRFv (ORCPT ); Fri, 7 Jun 2013 13:05:51 -0400 From: Simon Wunderlich To: linux-wireless@vger.kernel.org Cc: Johannes Berg , Mathias Kretschmer , Simon Wunderlich Subject: [PATCH 4/5] mac80211: add channel switch command and beacon callbacks Date: Fri, 7 Jun 2013 19:05:44 +0200 Message-Id: <1370624745-2267-5-git-send-email-siwu@hrz.tu-chemnitz.de> (sfid-20130607_190600_804211_2D52B78C) In-Reply-To: <1370624745-2267-1-git-send-email-siwu@hrz.tu-chemnitz.de> References: <1370624745-2267-1-git-send-email-siwu@hrz.tu-chemnitz.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: The count field in CSA must be decremented with each beacon transmitted. This patch implements the functionality for drivers using ieee80211_beacon_get(). Other drivers must call back manually after reaching count == 0. This patch also contains the handling and finish worker for the channel switch command. Signed-off-by: Simon Wunderlich Signed-off-by: Mathias Kretschmer --- Changes to RFCv1: * use beacons as supplied from nl80211 without generating/parsing them * update beacons using offsets * report back by calling the channel switch event in cfg80211 --- include/net/mac80211.h | 21 +++++++++ net/mac80211/cfg.c | 106 +++++++++++++++++++++++++++++++++++++++++++- net/mac80211/driver-ops.h | 11 +++++ net/mac80211/ieee80211_i.h | 11 +++++ net/mac80211/iface.c | 2 + net/mac80211/trace.h | 20 +++++++++ net/mac80211/tx.c | 45 +++++++++++++++++++ 7 files changed, 214 insertions(+), 2 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index a405a7a..efaacd1 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1078,6 +1078,7 @@ enum ieee80211_vif_flags { * @addr: address of this interface * @p2p: indicates whether this AP or STA interface is a p2p * interface, i.e. a GO or p2p-sta respectively + * @csa_active: marks whether a channel switch is going on * @driver_flags: flags/capabilities the driver has for this interface, * these need to be set (or cleared) when the interface is added * or, if supported by the driver, the interface type is changed @@ -1100,6 +1101,7 @@ struct ieee80211_vif { struct ieee80211_bss_conf bss_conf; u8 addr[ETH_ALEN]; bool p2p; + bool csa_active; u8 cab_queue; u8 hw_queue[IEEE80211_NUM_ACS]; @@ -2631,6 +2633,14 @@ enum ieee80211_roc_type { * @ipv6_addr_change: IPv6 address assignment on the given interface changed. * Currently, this is only called for managed or P2P client interfaces. * This callback is optional; it must not sleep. + * + * @channel_switch_beacon: Starts a channel switch for the 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 + * ieee80211_finish_csa(). Drivers which use ieee80211_get_beacon() + * already get this done by mac80211. + * */ struct ieee80211_ops { void (*tx)(struct ieee80211_hw *hw, @@ -2818,6 +2828,7 @@ struct ieee80211_ops { struct ieee80211_vif *vif, struct inet6_dev *idev); #endif + void (*channel_switch_beacon)(struct ieee80211_vif *vif); }; /** @@ -3313,6 +3324,16 @@ static inline struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw, } /** + * ieee80211_finish_csa - notify mac80211 about channel switch + * @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 + * notify mac80211 that the channel can be changed. + */ +void ieee80211_finish_csa(struct ieee80211_vif *vif); + +/** * ieee80211_proberesp_get - retrieve a Probe Response template * @hw: pointer obtained from ieee80211_alloc_hw(). * @vif: &struct ieee80211_vif pointer from the add_interface callback. diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 1f8e5cf..24b39c7 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -854,8 +854,8 @@ static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata, return 0; } -static int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata, - struct cfg80211_beacon_data *params) +int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata, + struct cfg80211_beacon_data *params) { struct beacon_data *new, *old; int new_head_len, new_tail_len; @@ -2851,6 +2851,107 @@ error: return NULL; } +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); + struct ieee80211_local *local = sdata->local; + int err; + + if (!ieee80211_sdata_running(sdata)) + return; + + if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP)) + return; + + netif_carrier_off(sdata->dev); + err = ieee80211_vif_use_channel(sdata, &local->csa_chandef, + IEEE80211_CHANCTX_SHARED); + netif_carrier_on(sdata->dev); + if (WARN_ON(err < 0)) + return; + netif_carrier_on(sdata->dev); + + err = ieee80211_assign_beacon(sdata, sdata->u.ap.next_beacon); + cfg80211_beacon_free(sdata->u.ap.next_beacon); + sdata->u.ap.next_beacon = NULL; + + ieee80211_wake_queues_by_reason(&sdata->local->hw, + IEEE80211_MAX_QUEUE_MAP, + IEEE80211_QUEUE_STOP_REASON_CSA); + + ieee80211_bss_info_change_notify(sdata, err); + + cfg80211_ch_switch_notify(sdata->dev, &local->csa_chandef); +} + +static int ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev, + struct cfg80211_csa_settings *params) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct ieee80211_local *local = sdata->local; + struct ieee80211_chanctx_conf *chanctx_conf; + struct ieee80211_chanctx *chanctx; + int err; + + if (!list_empty(&local->roc_list) || local->scanning) + return -EBUSY; + + /* don't handle if chanctx is used */ + if (local->use_chanctx) + return -EBUSY; + + rcu_read_lock(); + mutex_lock(&local->chanctx_mtx); + chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); + if (!chanctx_conf) { + mutex_unlock(&local->chanctx_mtx); + rcu_read_unlock(); + return -EBUSY; + } + + /* don't handle for multi-VIF cases */ + chanctx = container_of(chanctx_conf, struct ieee80211_chanctx, conf); + if (chanctx->refcount > 1) { + mutex_unlock(&local->chanctx_mtx); + rcu_read_unlock(); + return -EBUSY; + } + mutex_unlock(&local->chanctx_mtx); + rcu_read_unlock(); + + /* only handle AP for now. */ + switch (sdata->vif.type) { + case NL80211_IFTYPE_AP: + break; + default: + return -EOPNOTSUPP; + } + + 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; + + if (params->block_tx) + ieee80211_stop_queues_by_reason(&local->hw, + IEEE80211_MAX_QUEUE_MAP, + IEEE80211_QUEUE_STOP_REASON_CSA); + + err = ieee80211_assign_beacon(sdata, ¶ms->beacon_csa); + if (err < 0) + return err; + + local->csa_chandef = params->chandef; + + ieee80211_bss_info_change_notify(sdata, err); + drv_channel_switch_beacon(sdata); + + return 0; +} + static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev, struct ieee80211_channel *chan, bool offchan, unsigned int wait, const u8 *buf, size_t len, @@ -3567,4 +3668,5 @@ struct cfg80211_ops mac80211_config_ops = { .get_et_strings = ieee80211_get_et_strings, .get_channel = ieee80211_cfg_get_channel, .start_radar_detection = ieee80211_start_radar_detection, + .channel_switch = ieee80211_channel_switch, }; diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index b931c96..47a97ef 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -1072,4 +1072,15 @@ static inline void drv_ipv6_addr_change(struct ieee80211_local *local, } #endif +static inline void +drv_channel_switch_beacon(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_local *local = sdata->local; + if (local->ops->channel_switch_beacon) { + trace_drv_channel_switch_beacon(sdata); + local->ops->channel_switch_beacon(&sdata->vif); + } +} + + #endif /* __MAC80211_DRIVER_OPS */ diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 7a6f1a0..d34d816 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -258,6 +258,8 @@ struct ieee80211_if_ap { struct beacon_data __rcu *beacon; struct probe_resp __rcu *probe_resp; + /* to be used after channel switch. */ + struct cfg80211_beacon_data *next_beacon; struct list_head vlans; struct ps_data ps; @@ -713,6 +715,10 @@ struct ieee80211_sub_if_data { struct ieee80211_tx_queue_params tx_conf[IEEE80211_NUM_ACS]; + struct work_struct csa_finalize_work; + int csa_counter_offset_beacon; + int csa_counter_offset_presp; + /* used to reconfigure hardware SM PS */ struct work_struct recalc_smps; @@ -1340,6 +1346,8 @@ void ieee80211_roc_purge(struct ieee80211_local *local, void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free); void ieee80211_sw_roc_work(struct work_struct *work); void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc); +/* channel switch handling */ +void ieee80211_csa_finalize_work(struct work_struct *work); /* interface handling */ int ieee80211_iface_init(void); @@ -1362,6 +1370,9 @@ void ieee80211_del_virtual_monitor(struct ieee80211_local *local); bool __ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata); void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata); +int ieee80211_assign_beacon(struct ieee80211_sub_if_data *sdata, + struct cfg80211_beacon_data *params); + static inline bool ieee80211_sdata_running(struct ieee80211_sub_if_data *sdata) { diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 7cabaf2..d17692d 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -800,6 +800,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, cancel_work_sync(&local->dynamic_ps_enable_work); cancel_work_sync(&sdata->recalc_smps); + cancel_work_sync(&sdata->csa_finalize_work); cancel_delayed_work_sync(&sdata->dfs_cac_timer_work); @@ -1263,6 +1264,7 @@ static void ieee80211_setup_sdata(struct ieee80211_sub_if_data *sdata, skb_queue_head_init(&sdata->skb_queue); INIT_WORK(&sdata->work, ieee80211_iface_work); INIT_WORK(&sdata->recalc_smps, ieee80211_recalc_smps_work); + INIT_WORK(&sdata->csa_finalize_work, ieee80211_csa_finalize_work); switch (type) { case NL80211_IFTYPE_P2P_GO: diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h index c215fafd7..6b2af54 100644 --- a/net/mac80211/trace.h +++ b/net/mac80211/trace.h @@ -1906,6 +1906,26 @@ TRACE_EVENT(api_radar_detected, ) ); +TRACE_EVENT(drv_channel_switch_beacon, + TP_PROTO(struct ieee80211_sub_if_data *sdata), + + TP_ARGS(sdata), + + TP_STRUCT__entry( + VIF_ENTRY + ), + + TP_fast_assign( + VIF_ASSIGN; + ), + + TP_printk( + VIF_PR_FMT " channel switch", + VIF_PR_ARG + ) +); + + #ifdef CONFIG_MAC80211_MESSAGE_TRACING #undef TRACE_SYSTEM #define TRACE_SYSTEM mac80211_msg diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 4105d0c..0f1916f 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2320,6 +2320,47 @@ static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata, return 0; } +void ieee80211_finish_csa(struct ieee80211_vif *vif) +{ + struct ieee80211_sub_if_data *sdata = NULL; + sdata = vif_to_sdata(vif); + + vif->csa_active = 0; + ieee80211_queue_work(&sdata->local->hw, + &sdata->csa_finalize_work); +} +EXPORT_SYMBOL(ieee80211_finish_csa); + +static int ieee80211_update_csa(struct ieee80211_sub_if_data *sdata, + struct beacon_data *beacon) +{ + struct probe_resp *resp; + int counter_beacon = sdata->csa_counter_offset_beacon; + int counter_presp = sdata->csa_counter_offset_presp; + + if (WARN_ON(counter_beacon > beacon->tail_len)) + return 1; + + ((u8 *)beacon->tail)[counter_beacon]--; + + if (counter_presp && sdata->vif.type == NL80211_IFTYPE_AP) { + resp = rcu_dereference(sdata->u.ap.probe_resp); + if (WARN_ON(!resp)) + return 1; + if (WARN_ON(counter_presp > resp->len)) + return 1; + + ((u8 *)resp->data)[counter_presp]--; + } + + if (((u8 *)beacon->tail)[counter_beacon] == 0) { + sdata->vif.csa_active = 0; + ieee80211_finish_csa(&sdata->vif); + return 1; + } + return 0; +} + struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw, struct ieee80211_vif *vif, u16 *tim_offset, u16 *tim_length) @@ -2350,6 +2391,10 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw, struct beacon_data *beacon = rcu_dereference(ap->beacon); if (beacon) { + if (sdata->vif.csa_active) + if (ieee80211_update_csa(sdata, beacon)) + goto out; + /* * headroom, head length, * tail length and maximum TIM length -- 1.7.10.4