cfg80211: restructure AP/GO mode API

The AP/GO mode API isn't very clearly defined, it
has "set beacon" and "new beacon" etc.

Modify the API to the following:
 * start AP -- all settings
 * change beacon -- new beacon data
 * stop AP -- stop AP mode operation

This also reflects in the nl80211 API, rename
the commands there correspondingly (but keep
the old names for compatibility.)

Overall, this makes it much clearer what's going
on in the API.

Kalle developed the ath6kl changes, I created
the rest of the patch.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 68 insertions, 93 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index c3de921..f7eb25a 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -489,27 +489,13 @@ static int ieee80211_get_station(struct wiphy *wiphy, struct net_device *dev,
 	return ret;
 }
 
-static void ieee80211_config_ap_ssid(struct ieee80211_sub_if_data *sdata,
-				     struct beacon_parameters *params)
-{
-	struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
-
-	bss_conf->ssid_len = params->ssid_len;
-
-	if (params->ssid_len)
-		memcpy(bss_conf->ssid, params->ssid, params->ssid_len);
-
-	bss_conf->hidden_ssid =
-		(params->hidden_ssid != NL80211_HIDDEN_SSID_NOT_IN_USE);
-}
-
 static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
-				    u8 *resp, size_t resp_len)
+				    const u8 *resp, size_t resp_len)
 {
 	struct sk_buff *new, *old;
 
 	if (!resp || !resp_len)
-		return -EINVAL;
+		return 1;
 
 	old = rtnl_dereference(sdata->u.ap.probe_resp);
 
@@ -520,50 +506,28 @@ static int ieee80211_set_probe_resp(struct ieee80211_sub_if_data *sdata,
 	memcpy(skb_put(new, resp_len), resp, resp_len);
 
 	rcu_assign_pointer(sdata->u.ap.probe_resp, new);
-	synchronize_rcu();
-
-	if (old)
+	if (old) {
+		/* TODO: use call_rcu() */
+		synchronize_rcu();
 		dev_kfree_skb(old);
+	}
 
 	return 0;
 }
 
-/*
- * This handles both adding a beacon and setting new beacon info
- */
-static int ieee80211_config_beacon(struct ieee80211_sub_if_data *sdata,
-				   struct beacon_parameters *params)
+static 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;
-	int size;
-	int err = -EINVAL;
-	u32 changed = 0;
+	int size, err;
+	u32 changed = BSS_CHANGED_BEACON;
 
 	old = rtnl_dereference(sdata->u.ap.beacon);
 
-	/* head must not be zero-length */
-	if (params->head && !params->head_len)
-		return -EINVAL;
-
-	/*
-	 * This is a kludge. beacon interval should really be part
-	 * of the beacon information.
-	 */
-	if (params->interval &&
-	    (sdata->vif.bss_conf.beacon_int != params->interval)) {
-		sdata->vif.bss_conf.beacon_int = params->interval;
-		ieee80211_bss_info_change_notify(sdata,
-						 BSS_CHANGED_BEACON_INT);
-	}
-
 	/* Need to have a beacon head if we don't have one yet */
 	if (!params->head && !old)
-		return err;
-
-	/* sorry, no way to start beaconing without dtim period */
-	if (!params->dtim_period && !old)
-		return err;
+		return -EINVAL;
 
 	/* new or old head? */
 	if (params->head)
@@ -586,12 +550,6 @@ static int ieee80211_config_beacon(struct ieee80211_sub_if_data *sdata,
 
 	/* start filling the new info now */
 
-	/* new or old dtim period? */
-	if (params->dtim_period)
-		new->dtim_period = params->dtim_period;
-	else
-		new->dtim_period = old->dtim_period;
-
 	/*
 	 * pointers go into the block we allocated,
 	 * memory is | beacon_data | head | tail |
@@ -614,46 +572,37 @@ static int ieee80211_config_beacon(struct ieee80211_sub_if_data *sdata,
 		if (old)
 			memcpy(new->tail, old->tail, new_tail_len);
 
-	sdata->vif.bss_conf.dtim_period = new->dtim_period;
-
-	rcu_assign_pointer(sdata->u.ap.beacon, new);
-
-	synchronize_rcu();
-
-	kfree(old);
-
 	err = ieee80211_set_probe_resp(sdata, params->probe_resp,
 				       params->probe_resp_len);
-	if (!err)
+	if (err < 0)
+		return err;
+	if (err == 0)
 		changed |= BSS_CHANGED_AP_PROBE_RESP;
 
-	ieee80211_config_ap_ssid(sdata, params);
-	changed |= BSS_CHANGED_BEACON_ENABLED |
-		   BSS_CHANGED_BEACON |
-		   BSS_CHANGED_SSID;
+	rcu_assign_pointer(sdata->u.ap.beacon, new);
+
+	if (old)
+		kfree_rcu(old, rcu_head);
 
-	ieee80211_bss_info_change_notify(sdata, changed);
-	return 0;
+	return changed;
 }
 
-static int ieee80211_add_beacon(struct wiphy *wiphy, struct net_device *dev,
-				struct beacon_parameters *params)
+static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
+			      struct cfg80211_ap_settings *params)
 {
-	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct beacon_data *old;
 	struct ieee80211_sub_if_data *vlan;
-	int ret;
-
-	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	u32 changed = BSS_CHANGED_BEACON_INT |
+		      BSS_CHANGED_BEACON_ENABLED |
+		      BSS_CHANGED_BEACON |
+		      BSS_CHANGED_SSID;
+	int err;
 
 	old = rtnl_dereference(sdata->u.ap.beacon);
 	if (old)
 		return -EALREADY;
 
-	ret = ieee80211_config_beacon(sdata, params);
-	if (ret)
-		return ret;
-
 	/*
 	 * Apply control port protocol, this allows us to
 	 * not encrypt dynamic WEP control frames.
@@ -667,14 +616,32 @@ static int ieee80211_add_beacon(struct wiphy *wiphy, struct net_device *dev,
 			params->crypto.control_port_no_encrypt;
 	}
 
+	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
+	sdata->vif.bss_conf.dtim_period = params->dtim_period;
+
+	sdata->vif.bss_conf.ssid_len = params->ssid_len;
+	if (params->ssid_len)
+		memcpy(sdata->vif.bss_conf.ssid, params->ssid,
+		       params->ssid_len);
+	sdata->vif.bss_conf.hidden_ssid =
+		(params->hidden_ssid != NL80211_HIDDEN_SSID_NOT_IN_USE);
+
+	err = ieee80211_assign_beacon(sdata, &params->beacon);
+	if (err < 0)
+		return err;
+	changed |= err;
+
+	ieee80211_bss_info_change_notify(sdata, changed);
+
 	return 0;
 }
 
-static int ieee80211_set_beacon(struct wiphy *wiphy, struct net_device *dev,
-				struct beacon_parameters *params)
+static int ieee80211_change_beacon(struct wiphy *wiphy, struct net_device *dev,
+				   struct cfg80211_beacon_data *params)
 {
 	struct ieee80211_sub_if_data *sdata;
 	struct beacon_data *old;
+	int err;
 
 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
@@ -682,10 +649,14 @@ static int ieee80211_set_beacon(struct wiphy *wiphy, struct net_device *dev,
 	if (!old)
 		return -ENOENT;
 
-	return ieee80211_config_beacon(sdata, params);
+	err = ieee80211_assign_beacon(sdata, params);
+	if (err < 0)
+		return err;
+	ieee80211_bss_info_change_notify(sdata, err);
+	return 0;
 }
 
-static int ieee80211_del_beacon(struct wiphy *wiphy, struct net_device *dev)
+static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
 {
 	struct ieee80211_sub_if_data *sdata;
 	struct beacon_data *old;
@@ -697,10 +668,11 @@ static int ieee80211_del_beacon(struct wiphy *wiphy, struct net_device *dev)
 		return -ENOENT;
 
 	RCU_INIT_POINTER(sdata->u.ap.beacon, NULL);
-	synchronize_rcu();
-	kfree(old);
+
+	kfree_rcu(old, rcu_head);
 
 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
+
 	return 0;
 }
 
@@ -2699,9 +2671,9 @@ struct cfg80211_ops mac80211_config_ops = {
 	.get_key = ieee80211_get_key,
 	.set_default_key = ieee80211_config_default_key,
 	.set_default_mgmt_key = ieee80211_config_default_mgmt_key,
-	.add_beacon = ieee80211_add_beacon,
-	.set_beacon = ieee80211_set_beacon,
-	.del_beacon = ieee80211_del_beacon,
+	.start_ap = ieee80211_start_ap,
+	.change_beacon = ieee80211_change_beacon,
+	.stop_ap = ieee80211_stop_ap,
 	.add_station = ieee80211_add_station,
 	.del_station = ieee80211_del_station,
 	.change_station = ieee80211_change_station,
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 74594f0..67aed1e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -228,7 +228,7 @@ struct ieee80211_rx_data {
 struct beacon_data {
 	u8 *head, *tail;
 	int head_len, tail_len;
-	int dtim_period;
+	struct rcu_head rcu_head;
 };
 
 struct ieee80211_if_ap {
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1be0ca2..c6eadac 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2206,7 +2206,8 @@ void ieee80211_tx_pending(unsigned long data)
 
 /* functions for drivers to get certain frames */
 
-static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
+static void ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
+				     struct ieee80211_if_ap *bss,
 				     struct sk_buff *skb,
 				     struct beacon_data *beacon)
 {
@@ -2223,7 +2224,7 @@ static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
 					  IEEE80211_MAX_AID+1);
 
 	if (bss->dtim_count == 0)
-		bss->dtim_count = beacon->dtim_period - 1;
+		bss->dtim_count = sdata->vif.bss_conf.dtim_period - 1;
 	else
 		bss->dtim_count--;
 
@@ -2231,7 +2232,7 @@ static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
 	*pos++ = WLAN_EID_TIM;
 	*pos++ = 4;
 	*pos++ = bss->dtim_count;
-	*pos++ = beacon->dtim_period;
+	*pos++ = sdata->vif.bss_conf.dtim_period;
 
 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
 		aid0 = 1;
@@ -2324,12 +2325,14 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 			 * of the tim bitmap in mac80211 and the driver.
 			 */
 			if (local->tim_in_locked_section) {
-				ieee80211_beacon_add_tim(ap, skb, beacon);
+				ieee80211_beacon_add_tim(sdata, ap, skb,
+							 beacon);
 			} else {
 				unsigned long flags;
 
 				spin_lock_irqsave(&local->tim_lock, flags);
-				ieee80211_beacon_add_tim(ap, skb, beacon);
+				ieee80211_beacon_add_tim(sdata, ap, skb,
+							 beacon);
 				spin_unlock_irqrestore(&local->tim_lock, flags);
 			}