cfg80211/mac80211: move interface counting for combination check to mac80211

Move the counting part of the interface combination check from
cfg80211 to mac80211.

This is needed to simplify locking when the driver has to perform a
combination check by itself (eg. with channel-switch).

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

11 files changed, 110 insertions, 80 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 92a65c331cf4..fb8afcee62b4 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -662,7 +662,6 @@ struct cfg80211_acl_data {
  * @p2p_opp_ps: P2P opportunistic PS
  * @acl: ACL configuration used by the drivers which has support for
  *	MAC address based access control
- * @radar_required: set if radar detection is required
  */
 struct cfg80211_ap_settings {
 	struct cfg80211_chan_def chandef;
@@ -680,7 +679,6 @@ struct cfg80211_ap_settings {
 	u8 p2p_ctwindow;
 	bool p2p_opp_ps;
 	const struct cfg80211_acl_data *acl;
-	bool radar_required;
 };
 
 /**
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 906bc3b05aae..8bf94eaa0456 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -972,7 +972,6 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	sdata->needed_rx_chains = sdata->local->rx_chains;
 
 	mutex_lock(&local->mtx);
-	sdata->radar_required = params->radar_required;
 	err = ieee80211_vif_use_channel(sdata, &params->chandef,
 					IEEE80211_CHANCTX_SHARED);
 	mutex_unlock(&local->mtx);
@@ -2930,7 +2929,6 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 	/* whatever, but channel contexts should not complain about that one */
 	sdata->smps_mode = IEEE80211_SMPS_OFF;
 	sdata->needed_rx_chains = local->rx_chains;
-	sdata->radar_required = true;
 
 	err = ieee80211_vif_use_channel(sdata, chandef,
 					IEEE80211_CHANCTX_SHARED);
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index b297bd3043a8..623b336f3efd 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -519,6 +519,7 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_chanctx *ctx;
+	u8 radar_detect_width = 0;
 	int ret;
 
 	lockdep_assert_held(&local->mtx);
@@ -526,6 +527,22 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
 	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
 
 	mutex_lock(&local->chanctx_mtx);
+
+	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
+					    chandef,
+					    sdata->wdev.iftype);
+	if (ret < 0)
+		goto out;
+	if (ret > 0)
+		radar_detect_width = BIT(chandef->width);
+
+	sdata->radar_required = ret;
+
+	ret = ieee80211_check_combinations(sdata, chandef, mode,
+					   radar_detect_width);
+	if (ret < 0)
+		goto out;
+
 	__ieee80211_vif_release_channel(sdata);
 
 	ctx = ieee80211_find_chanctx(local, chandef, mode);
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 222c28b75315..09213fd87f8d 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1805,6 +1805,10 @@ int ieee80211_cs_headroom(struct ieee80211_local *local,
 			  enum nl80211_iftype iftype);
 void ieee80211_recalc_dtim(struct ieee80211_local *local,
 			   struct ieee80211_sub_if_data *sdata);
+int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
+				 const struct cfg80211_chan_def *chandef,
+				 enum ieee80211_chanctx_mode chanmode,
+				 u8 radar_detect);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 73af7398850b..436f98870066 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2797,3 +2797,75 @@ void ieee80211_recalc_dtim(struct ieee80211_local *local,
 
 	ps->dtim_count = dtim_count;
 }
+
+int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
+				 const struct cfg80211_chan_def *chandef,
+				 enum ieee80211_chanctx_mode chanmode,
+				 u8 radar_detect)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct ieee80211_sub_if_data *sdata_iter;
+	enum nl80211_iftype iftype = sdata->wdev.iftype;
+	int num[NUM_NL80211_IFTYPES];
+	struct ieee80211_chanctx *ctx;
+	int num_different_channels = 1;
+	int total = 1;
+
+	lockdep_assert_held(&local->chanctx_mtx);
+
+	if (WARN_ON(hweight32(radar_detect) > 1))
+		return -EINVAL;
+
+	if (WARN_ON(chanmode == IEEE80211_CHANCTX_SHARED && !chandef->chan))
+		return -EINVAL;
+
+	if (WARN_ON(iftype >= NUM_NL80211_IFTYPES))
+		return -EINVAL;
+
+	/* Always allow software iftypes */
+	if (local->hw.wiphy->software_iftypes & BIT(iftype)) {
+		if (radar_detect)
+			return -EINVAL;
+		return 0;
+	}
+
+	memset(num, 0, sizeof(num));
+
+	if (iftype != NL80211_IFTYPE_UNSPECIFIED)
+		num[iftype] = 1;
+
+	list_for_each_entry(ctx, &local->chanctx_list, list) {
+		if (ctx->conf.radar_enabled)
+			radar_detect |= BIT(ctx->conf.def.width);
+		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) {
+			num_different_channels++;
+			continue;
+		}
+		if ((chanmode == IEEE80211_CHANCTX_SHARED) &&
+		    cfg80211_chandef_compatible(chandef,
+						&ctx->conf.def))
+			continue;
+		num_different_channels++;
+	}
+
+	list_for_each_entry_rcu(sdata_iter, &local->interfaces, list) {
+		struct wireless_dev *wdev_iter;
+
+		wdev_iter = &sdata_iter->wdev;
+
+		if (sdata_iter == sdata ||
+		    rcu_access_pointer(sdata_iter->vif.chanctx_conf) == NULL ||
+		    local->hw.wiphy->software_iftypes & BIT(wdev_iter->iftype))
+			continue;
+
+		num[wdev_iter->iftype]++;
+		total++;
+	}
+
+	if (total == 1 && !radar_detect)
+		return 0;
+
+	return cfg80211_check_combinations(local->hw.wiphy,
+					   num_different_channels,
+					   radar_detect, num);
+}
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 6f6f75609852..6684c5d965d8 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -417,6 +417,9 @@ cfg80211_can_change_interface(struct cfg80211_registered_device *rdev,
 			      struct wireless_dev *wdev,
 			      enum nl80211_iftype iftype)
 {
+	/* TODO: For this function, we'll probably need to keep some
+	 * kind of interface combination check in cfg80211...
+	 */
 	return cfg80211_can_use_iftype_chan(rdev, wdev, iftype, NULL,
 					    CHAN_MODE_UNDEFINED, 0);
 }
@@ -431,16 +434,6 @@ cfg80211_can_add_interface(struct cfg80211_registered_device *rdev,
 	return cfg80211_can_change_interface(rdev, NULL, iftype);
 }
 
-static inline int
-cfg80211_can_use_chan(struct cfg80211_registered_device *rdev,
-		      struct wireless_dev *wdev,
-		      struct ieee80211_channel *chan,
-		      enum cfg80211_chan_mode chanmode)
-{
-	return cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					    chan, chanmode, 0);
-}
-
 static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
 {
 	unsigned long end = jiffies;
diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index a6b5bdad039c..faf4961d47d8 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -135,6 +135,10 @@ static int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
 		radar_detect_width = BIT(params->chandef.width);
 	}
 
+	/* TODO: We need to check the combinations at this point, we
+	 * probably must move this call down to join_ibss() in
+	 * mac80211.
+	 */
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
 					   check_chan,
 					   (params->channel_fixed &&
diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index 6ebe883653a4..3ddfb7cd335e 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -99,7 +99,6 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 			 const struct mesh_config *conf)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
-	u8 radar_detect_width = 0;
 	int err;
 
 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
@@ -179,22 +178,6 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 				     NL80211_IFTYPE_MESH_POINT))
 		return -EINVAL;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy,
-					    &setup->chandef,
-					    NL80211_IFTYPE_MESH_POINT);
-	if (err < 0)
-		return err;
-
-	if (err > 0)
-		radar_detect_width = BIT(setup->chandef.width);
-
-	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					   setup->chandef.chan,
-					   CHAN_MODE_SHARED,
-					   radar_detect_width);
-	if (err)
-		return err;
-
 	err = rdev_join_mesh(rdev, dev, conf, setup);
 	if (!err) {
 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
@@ -240,17 +223,6 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 		if (!netif_running(wdev->netdev))
 			return -ENETDOWN;
 
-		/* cfg80211_can_use_chan() calls
-		 * cfg80211_can_use_iftype_chan() with no radar
-		 * detection, so if we're trying to use a radar
-		 * channel here, something is wrong.
-		 */
-		WARN_ON_ONCE(chandef->chan->flags & IEEE80211_CHAN_RADAR);
-		err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
-					    CHAN_MODE_SHARED);
-		if (err)
-			return err;
-
 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 						     chandef->chan);
 		if (!err)
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index c52ff59a3e96..4b4ba707fab9 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -233,14 +233,8 @@ int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
 	if (!req.bss)
 		return -ENOENT;
 
-	err = cfg80211_can_use_chan(rdev, wdev, req.bss->channel,
-				    CHAN_MODE_SHARED);
-	if (err)
-		goto out;
-
 	err = rdev_auth(rdev, dev, &req);
 
-out:
 	cfg80211_put_bss(&rdev->wiphy, req.bss);
 	return err;
 }
@@ -306,16 +300,10 @@ int cfg80211_mlme_assoc(struct cfg80211_registered_device *rdev,
 	if (!req->bss)
 		return -ENOENT;
 
-	err = cfg80211_can_use_chan(rdev, wdev, chan, CHAN_MODE_SHARED);
-	if (err)
-		goto out;
-
 	err = rdev_assoc(rdev, dev, req);
 	if (!err)
 		cfg80211_hold_bss(bss_from_pub(req->bss));
-
-out:
-	if (err)
+	else
 		cfg80211_put_bss(&rdev->wiphy, req->bss);
 
 	return err;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 4f82b9b71db1..2b99aad33ae0 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3155,7 +3155,6 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_ap_settings params;
 	int err;
-	u8 radar_detect_width = 0;
 
 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_AP &&
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
@@ -3275,24 +3274,6 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 				     wdev->iftype))
 		return -EINVAL;
 
-	err = cfg80211_chandef_dfs_required(wdev->wiphy,
-					    &params.chandef,
-					    NL80211_IFTYPE_AP);
-	if (err < 0)
-		return err;
-
-	if (err > 0) {
-		params.radar_required = true;
-		radar_detect_width = BIT(params.chandef.width);
-	}
-
-	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					   params.chandef.chan,
-					   CHAN_MODE_SHARED,
-					   radar_detect_width);
-	if (err)
-		return err;
-
 	if (info->attrs[NL80211_ATTR_ACL_POLICY]) {
 		params.acl = parse_acl_data(&rdev->wiphy, info);
 		if (IS_ERR(params.acl))
@@ -5823,12 +5804,6 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 	if (!rdev->ops->start_radar_detection)
 		return -EOPNOTSUPP;
 
-	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
-					   chandef.chan, CHAN_MODE_SHARED,
-					   BIT(chandef.width));
-	if (err)
-		return err;
-
 	cac_time_ms = cfg80211_chandef_dfs_cac_time(&rdev->wiphy, &chandef);
 	if (WARN_ON(!cac_time_ms))
 		cac_time_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
@@ -5957,6 +5932,10 @@ skip_beacons:
 		params.radar_required = true;
 	}
 
+	/* TODO: I left this here for now.  With channel switch, the
+	 * verification is a bit more complicated, because we only do
+	 * it later when the channel switch really happens.
+	 */
 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
 					   params.chandef.chan,
 					   CHAN_MODE_SHARED,
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 46f404df35e3..9bfc4c621509 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1375,6 +1375,11 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
 
 	num[iftype] = 1;
 
+	/* TODO: We'll probably not need this anymore, since this
+	 * should only be called with CHAN_MODE_UNDEFINED. There are
+	 * still a couple of pending calls where other chanmodes are
+	 * used, but we should get rid of them.
+	 */
 	switch (chanmode) {
 	case CHAN_MODE_UNDEFINED:
 		break;