mac80211: add pre_channel_switch driver operation

Some drivers may need to prepare for a channel switch also when it is
initiated from the remote side (eg. station, P2P client).  To make
this possible, add a generic callback that can be called for all
interface types.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index ec0a5b07055b3fe680b42c0ac1bdf092c993df0b..19e4159ce3a32497931dfc6f796a58572782c263 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2832,6 +2832,10 @@ enum ieee80211_roc_type {
  *     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.
+ * @pre_channel_switch: This is an optional callback that is called
+ *     before a channel switch procedure is started (ie. when a STA
+ *     gets a CSA or an userspace initiated channel-switch), allowing
+ *     the driver to prepare for the channel switch.
  *
  * @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
@@ -3038,6 +3042,9 @@ struct ieee80211_ops {
        void (*channel_switch_beacon)(struct ieee80211_hw *hw,
                                      struct ieee80211_vif *vif,
                                      struct cfg80211_chan_def *chandef);
+       int (*pre_channel_switch)(struct ieee80211_hw *hw,
+                                 struct ieee80211_vif *vif,
+                                 struct ieee80211_channel_switch *ch_switch);
 
        int (*join_ibss)(struct ieee80211_hw *hw, struct ieee80211_vif *vif);
        void (*leave_ibss)(struct ieee80211_hw *hw, struct ieee80211_vif *vif);

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 3a04f2edd3c3b93192b7a011b1f549a7a054d916..647a2f6eb7dc4688e6e217593126df46594e2560 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3104,6 +3104,7 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
 {
        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
        struct ieee80211_local *local = sdata->local;
+       struct ieee80211_channel_switch ch_switch;
        struct ieee80211_chanctx_conf *conf;
        struct ieee80211_chanctx *chanctx;
        int err, changed = 0;
@@ -3139,6 +3140,10 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
                goto out;
        }
 
+       err = drv_pre_channel_switch(sdata, &ch_switch);
+       if (err)
+               goto out;
+
        err = ieee80211_vif_reserve_chanctx(sdata, &params->chandef,
                                            chanctx->mode,
                                            params->radar_required);
@@ -3152,6 +3157,12 @@ __ieee80211_channel_switch(struct wiphy *wiphy, struct net_device *dev,
                goto out;
        }
 
+       ch_switch.timestamp = 0;
+       ch_switch.device_timestamp = 0;
+       ch_switch.block_tx = params->block_tx;
+       ch_switch.chandef = params->chandef;
+       ch_switch.count = params->count;
+
        err = ieee80211_set_csa_beacon(sdata, params, &changed);
        if (err) {
                ieee80211_vif_unreserve_chanctx(sdata);

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 196d48c68134a08b644fc97f8f1a1fc740ec7bdf..5522672129cee745f29b91568a0c135d06283def 100644 (file)
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -1196,6 +1196,24 @@ drv_channel_switch_beacon(struct ieee80211_sub_if_data *sdata,
        }
 }
 
+static inline int
+drv_pre_channel_switch(struct ieee80211_sub_if_data *sdata,
+                      struct ieee80211_channel_switch *ch_switch)
+{
+       struct ieee80211_local *local = sdata->local;
+       int ret = 0;
+
+       if (!check_sdata_in_driver(sdata))
+               return -EIO;
+
+       trace_drv_pre_channel_switch(local, sdata, ch_switch);
+       if (local->ops->pre_channel_switch)
+               ret = local->ops->pre_channel_switch(&local->hw, &sdata->vif,
+                                                    ch_switch);
+       trace_drv_return_int(local, ret);
+       return ret;
+}
+
 static inline int drv_join_ibss(struct ieee80211_local *local,
                                struct ieee80211_sub_if_data *sdata)
 {

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index f2e048fa250c556b9070d36e8cd693c16ada6d66..d23d6d97e453036d8fb4a4df2c719c56f02cbaac 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1057,6 +1057,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
        struct ieee80211_chanctx *chanctx;
        enum ieee80211_band current_band;
        struct ieee80211_csa_ie csa_ie;
+       struct ieee80211_channel_switch ch_switch;
        int res;
 
        sdata_assert_lock(sdata);
@@ -1128,6 +1129,22 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                }
        }
 
+       ch_switch.timestamp = timestamp;
+       ch_switch.device_timestamp = device_timestamp;
+       ch_switch.block_tx = csa_ie.mode;
+       ch_switch.chandef = csa_ie.chandef;
+       ch_switch.count = csa_ie.count;
+
+       if (drv_pre_channel_switch(sdata, &ch_switch)) {
+               sdata_info(sdata,
+                          "preparing for channel switch failed, disconnecting\n");
+               ieee80211_queue_work(&local->hw,
+                                    &ifmgd->csa_connection_drop_work);
+               mutex_unlock(&local->chanctx_mtx);
+               mutex_unlock(&local->mtx);
+               return;
+       }
+
        res = ieee80211_vif_reserve_chanctx(sdata, &csa_ie.chandef,
                                            chanctx->mode, false);
        if (res) {
@@ -1153,14 +1170,6 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 
        if (local->ops->channel_switch) {
                /* use driver's channel switch callback */
-               struct ieee80211_channel_switch ch_switch = {
-                       .timestamp = timestamp,
-                       .device_timestamp = device_timestamp,
-                       .block_tx = csa_ie.mode,
-                       .chandef = csa_ie.chandef,
-                       .count = csa_ie.count,
-               };
-
                drv_channel_switch(local, &ch_switch);
                return;
        }

diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 853c440218d4bb0083ab76b1ee868eaedefbb99f..30476d2c7302fdc07b73c9738e45c82b54f214c2 100644 (file)
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -2108,6 +2108,39 @@ TRACE_EVENT(drv_channel_switch_beacon,
        )
 );
 
+TRACE_EVENT(drv_pre_channel_switch,
+       TP_PROTO(struct ieee80211_local *local,
+                struct ieee80211_sub_if_data *sdata,
+                struct ieee80211_channel_switch *ch_switch),
+
+       TP_ARGS(local, sdata, ch_switch),
+
+       TP_STRUCT__entry(
+               LOCAL_ENTRY
+               VIF_ENTRY
+               CHANDEF_ENTRY
+               __field(u64, timestamp)
+               __field(bool, block_tx)
+               __field(u8, count)
+       ),
+
+       TP_fast_assign(
+               LOCAL_ASSIGN;
+               VIF_ASSIGN;
+               CHANDEF_ASSIGN(&ch_switch->chandef)
+               __entry->timestamp = ch_switch->timestamp;
+               __entry->block_tx = ch_switch->block_tx;
+               __entry->count = ch_switch->count;
+       ),
+
+       TP_printk(
+               LOCAL_PR_FMT VIF_PR_FMT " prepare channel switch to "
+               CHANDEF_PR_FMT  " count:%d block_tx:%d timestamp:%llu",
+               LOCAL_PR_ARG, VIF_PR_ARG, CHANDEF_PR_ARG, __entry->count,
+               __entry->block_tx, __entry->timestamp
+       )
+);
+
 
 #ifdef CONFIG_MAC80211_MESSAGE_TRACING
 #undef TRACE_SYSTEM