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 <siwu@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxxxx>
---
Changes to PATCHv1:
* don't switch when CAC is active
* add hw to parameters for driver
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 | 33 ++++++++++++++
net/mac80211/cfg.c | 109 +++++++++++++++++++++++++++++++++++++++++++-
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 | 68 +++++++++++++++++++++++++++
7 files changed, 252 insertions(+), 2 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index a405a7a..f0592cd 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 +2633,16 @@ 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_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() and then call
+ * ieee80211_csa_finish().
+ *
*/
struct ieee80211_ops {
void (*tx)(struct ieee80211_hw *hw,
@@ -2818,6 +2830,8 @@ struct ieee80211_ops {
struct ieee80211_vif *vif,
struct inet6_dev *idev);
#endif
+ void (*channel_switch_beacon)(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif);
};
/**
@@ -3313,6 +3327,25 @@ static inline struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
}
/**
+ * ieee80211_csa_finish - 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_csa_finish(struct ieee80211_vif *vif);
+
+/**
+ * ieee80211_csa_is_complete - find out if counters reached zero
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ *
+ * This function checks the registered beacon if the counters reached zero.
+ */
+int ieee80211_csa_is_complete(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 5ffc7d9..e468465 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;
@@ -2854,6 +2854,110 @@ 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;
+
+ if (sdata->wdev.cac_started)
+ 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,
@@ -3581,4 +3685,5 @@ 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..a8952f6 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(&local->hw, &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..97751e4 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2320,6 +2320,71 @@ 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 = NULL;
+ sdata = vif_to_sdata(vif);
+
+ vif->csa_active = 0;
+ 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)
+{
+ 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;
+
+ if (WARN_ON(((u8 *)beacon->tail)[counter_beacon] == 0))
+ return;
+
+ ((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;
+ if (WARN_ON(counter_presp > resp->len))
+ return;
+
+ ((u8 *)resp->data)[counter_presp]--;
+ }
+}
+
+int ieee80211_csa_is_complete(struct ieee80211_vif *vif)
+{
+ struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
+ struct beacon_data *beacon = NULL;
+ int counter_beacon = sdata->csa_counter_offset_beacon;
+
+ if (!sdata || !ieee80211_sdata_running(sdata))
+ return 0;
+
+ if (vif->type == NL80211_IFTYPE_AP) {
+ struct ieee80211_if_ap *ap = &sdata->u.ap;
+ beacon = rcu_dereference(ap->beacon);
+
+ } else {
+ WARN_ON(1);
+ return 0;
+ }
+
+ if (WARN_ON(counter_beacon > beacon->tail_len))
+ return 0;
+
+ if (((u8 *)beacon->tail)[counter_beacon] == 0)
+ return 1;
+
+ return 0;
+}
+EXPORT_SYMBOL(ieee80211_csa_is_complete);
+
struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
u16 *tim_offset, u16 *tim_length)
@@ -2350,6 +2415,9 @@ 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)
+ ieee80211_update_csa(sdata, beacon);
+
/*
* headroom, head length,
* tail length and maximum TIM length
--
1.7.10.4
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