mac80211: support remain-on-channel command
Johannes Berg [Wed, 23 Dec 2009 12:15:42 +0000 (13:15 +0100)]
This implements the new remain-on-channel cfg80211
command in mac80211, extending the work interface.

Also change the work purge code to be able to clean
up events properly (pretending they timed out.)

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/cfg.c
net/mac80211/ieee80211_i.h
net/mac80211/main.c
net/mac80211/mlme.c
net/mac80211/offchannel.c
net/mac80211/work.c

index ea862df..2e5e841 100644 (file)
@@ -1441,6 +1441,28 @@ static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
        return -EINVAL;
 }
 
+static int ieee80211_remain_on_channel(struct wiphy *wiphy,
+                                      struct net_device *dev,
+                                      struct ieee80211_channel *chan,
+                                      enum nl80211_channel_type channel_type,
+                                      unsigned int duration,
+                                      u64 *cookie)
+{
+       struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+       return ieee80211_wk_remain_on_channel(sdata, chan, channel_type,
+                                             duration, cookie);
+}
+
+static int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
+                                             struct net_device *dev,
+                                             u64 cookie)
+{
+       struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
+       return ieee80211_wk_cancel_remain_on_channel(sdata, cookie);
+}
+
 struct cfg80211_ops mac80211_config_ops = {
        .add_virtual_intf = ieee80211_add_iface,
        .del_virtual_intf = ieee80211_del_iface,
@@ -1487,4 +1509,6 @@ struct cfg80211_ops mac80211_config_ops = {
        CFG80211_TESTMODE_CMD(ieee80211_testmode_cmd)
        .set_power_mgmt = ieee80211_set_power_mgmt,
        .set_bitrate_mask = ieee80211_set_bitrate_mask,
+       .remain_on_channel = ieee80211_remain_on_channel,
+       .cancel_remain_on_channel = ieee80211_cancel_remain_on_channel,
 };
index fd912eb..23547eb 100644 (file)
@@ -225,9 +225,11 @@ struct mesh_preq_queue {
 };
 
 enum ieee80211_work_type {
+       IEEE80211_WORK_ABORT,
        IEEE80211_WORK_DIRECT_PROBE,
        IEEE80211_WORK_AUTH,
        IEEE80211_WORK_ASSOC,
+       IEEE80211_WORK_REMAIN_ON_CHANNEL,
 };
 
 /**
@@ -283,6 +285,9 @@ struct ieee80211_work {
                        u8 supp_rates_len;
                        bool wmm_used, use_11n;
                } assoc;
+               struct {
+                       unsigned long timeout;
+               } remain;
        };
 
        int ie_len;
@@ -729,6 +734,10 @@ struct ieee80211_local {
        enum nl80211_channel_type oper_channel_type;
        struct ieee80211_channel *oper_channel, *csa_channel;
 
+       /* Temporary remain-on-channel for off-channel operations */
+       struct ieee80211_channel *tmp_channel;
+       enum nl80211_channel_type tmp_channel_type;
+
        /* SNMP counters */
        /* dot11CountersTable */
        u32 dot11TransmittedFragmentCount;
@@ -1162,6 +1171,12 @@ void free_work(struct ieee80211_work *wk);
 void ieee80211_work_purge(struct ieee80211_sub_if_data *sdata);
 ieee80211_rx_result ieee80211_work_rx_mgmt(struct ieee80211_sub_if_data *sdata,
                                           struct sk_buff *skb);
+int ieee80211_wk_remain_on_channel(struct ieee80211_sub_if_data *sdata,
+                                  struct ieee80211_channel *chan,
+                                  enum nl80211_channel_type channel_type,
+                                  unsigned int duration, u64 *cookie);
+int ieee80211_wk_cancel_remain_on_channel(
+       struct ieee80211_sub_if_data *sdata, u64 cookie);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
index 5fcd354..d0a14d9 100644 (file)
@@ -107,6 +107,9 @@ int ieee80211_hw_config(struct ieee80211_local *local, u32 changed)
        if (scan_chan) {
                chan = scan_chan;
                channel_type = NL80211_CHAN_NO_HT;
+       } else if (local->tmp_channel) {
+               chan = scan_chan = local->tmp_channel;
+               channel_type = local->tmp_channel_type;
        } else {
                chan = local->oper_channel;
                channel_type = local->oper_channel_type;
index e44f1ed..32d6e66 100644 (file)
@@ -857,6 +857,9 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
        if (sdata->local->scanning)
                return;
 
+       if (sdata->local->tmp_channel)
+               return;
+
        mutex_lock(&ifmgd->mtx);
 
        if (!ifmgd->associated)
index 2cd880e..a7bbfc4 100644 (file)
@@ -106,9 +106,13 @@ void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
                /*
                 * only handle non-STA interfaces here, STA interfaces
                 * are handled in ieee80211_offchannel_stop_station(),
-                * e.g., from the background scan state machine
+                * e.g., from the background scan state machine.
+                *
+                * In addition, do not stop monitor interface to allow it to be
+                * used from user space controlled off-channel operations.
                 */
-               if (sdata->vif.type != NL80211_IFTYPE_STATION)
+               if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+                   sdata->vif.type != NL80211_IFTYPE_MONITOR)
                        netif_stop_queue(sdata->dev);
        }
        mutex_unlock(&local->iflist_mtx);
index 0b8c31c..0acea7c 100644 (file)
@@ -538,6 +538,44 @@ ieee80211_associate(struct ieee80211_work *wk)
        return WORK_ACT_NONE;
 }
 
+static enum work_action __must_check
+ieee80211_remain_on_channel_timeout(struct ieee80211_work *wk)
+{
+       struct ieee80211_sub_if_data *sdata = wk->sdata;
+       struct ieee80211_local *local = sdata->local;
+
+       /*
+        * First time we run, do nothing -- the generic code will
+        * have switched to the right channel etc.
+        */
+       if (wk->timeout != wk->remain.timeout) {
+               wk->timeout = wk->remain.timeout;
+               return WORK_ACT_NONE;
+       }
+
+       /*
+        * We are done serving the remain-on-channel command; kill the work
+        * item to allow idle state to be entered again. In addition, clear the
+        * temporary channel information to allow operational channel to be
+        * used.
+        */
+       list_del(&wk->list);
+       free_work(wk);
+
+       if (local->tmp_channel) {
+               cfg80211_remain_on_channel_expired(sdata->dev, (u64)wk,
+                                                  local->tmp_channel,
+                                                  local->tmp_channel_type,
+                                                  GFP_KERNEL);
+
+               local->tmp_channel = NULL;
+               ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+               ieee80211_offchannel_return(local, true);
+       }
+
+       return WORK_ACT_NONE;
+}
+
 static void ieee80211_auth_challenge(struct ieee80211_work *wk,
                                     struct ieee80211_mgmt *mgmt,
                                     size_t len)
@@ -825,6 +863,8 @@ static void ieee80211_work_work(struct work_struct *work)
                        /* nothing */
                        rma = WORK_ACT_NONE;
                        break;
+               case IEEE80211_WORK_ABORT:
+                       rma = WORK_ACT_TIMEOUT;
                case IEEE80211_WORK_DIRECT_PROBE:
                        rma = ieee80211_direct_probe(wk);
                        break;
@@ -834,6 +874,9 @@ static void ieee80211_work_work(struct work_struct *work)
                case IEEE80211_WORK_ASSOC:
                        rma = ieee80211_associate(wk);
                        break;
+               case IEEE80211_WORK_REMAIN_ON_CHANNEL:
+                       rma = ieee80211_remain_on_channel_timeout(wk);
+                       break;
                }
 
                switch (rma) {
@@ -900,14 +943,25 @@ void ieee80211_work_init(struct ieee80211_local *local)
 void ieee80211_work_purge(struct ieee80211_sub_if_data *sdata)
 {
        struct ieee80211_local *local = sdata->local;
-       struct ieee80211_work *wk, *tmp;
+       struct ieee80211_work *wk;
 
        mutex_lock(&local->work_mtx);
-       list_for_each_entry_safe(wk, tmp, &local->work_list, list) {
+       list_for_each_entry(wk, &local->work_list, list) {
                if (wk->sdata != sdata)
                        continue;
-               list_del(&wk->list);
-               free_work(wk);
+               wk->type = IEEE80211_WORK_ABORT;
+       }
+       mutex_unlock(&local->work_mtx);
+
+       /* run cleanups etc. */
+       ieee80211_work_work(&local->work_work);
+
+       mutex_lock(&local->work_mtx);
+       list_for_each_entry(wk, &local->work_list, list) {
+               if (wk->sdata != sdata)
+                       continue;
+               WARN_ON(1);
+               break;
        }
        mutex_unlock(&local->work_mtx);
 }
@@ -949,3 +1003,75 @@ ieee80211_rx_result ieee80211_work_rx_mgmt(struct ieee80211_sub_if_data *sdata,
 
        return RX_CONTINUE;
 }
+
+int ieee80211_wk_remain_on_channel(struct ieee80211_sub_if_data *sdata,
+                                  struct ieee80211_channel *chan,
+                                  enum nl80211_channel_type channel_type,
+                                  unsigned int duration, u64 *cookie)
+{
+       struct ieee80211_local *local = sdata->local;
+       struct ieee80211_work *wk;
+
+       wk = kzalloc(sizeof(*wk), GFP_KERNEL);
+       if (!wk)
+               return -ENOMEM;
+
+       wk->type = IEEE80211_WORK_REMAIN_ON_CHANNEL;
+       wk->chan = chan;
+       wk->sdata = sdata;
+
+       wk->remain.timeout = jiffies + msecs_to_jiffies(duration);
+
+       *cookie = (u64)wk;
+
+       ieee80211_add_work(wk);
+
+       /*
+        * TODO: could optimize this by leaving the station vifs in awake mode
+        * if they happen to be on the same channel as the requested channel
+        */
+       ieee80211_offchannel_stop_beaconing(local);
+       ieee80211_offchannel_stop_station(local);
+
+       sdata->local->tmp_channel = chan;
+       sdata->local->tmp_channel_type = channel_type;
+       ieee80211_hw_config(sdata->local, IEEE80211_CONF_CHANGE_CHANNEL);
+
+       cfg80211_ready_on_channel(sdata->dev, (u64)wk, chan, channel_type,
+                                 duration, GFP_KERNEL);
+
+       return 0;
+}
+
+int ieee80211_wk_cancel_remain_on_channel(struct ieee80211_sub_if_data *sdata,
+                                         u64 cookie)
+{
+       struct ieee80211_local *local = sdata->local;
+       struct ieee80211_work *wk, *tmp;
+       bool found = false;
+
+       mutex_lock(&local->work_mtx);
+       list_for_each_entry_safe(wk, tmp, &local->work_list, list) {
+               if ((u64)wk == cookie) {
+                       found = true;
+                       list_del(&wk->list);
+                       free_work(wk);
+                       break;
+               }
+       }
+       mutex_unlock(&local->work_mtx);
+
+       if (!found)
+               return -ENOENT;
+
+       if (sdata->local->tmp_channel) {
+               sdata->local->tmp_channel = NULL;
+               ieee80211_hw_config(sdata->local,
+                                   IEEE80211_CONF_CHANGE_CHANNEL);
+               ieee80211_offchannel_return(sdata->local, true);
+       }
+
+       ieee80211_recalc_idle(local);
+
+       return 0;
+}