mac80211: handle extended channel switch announcement

Handle the (public) extended channel switch announcement
action frames. Parts of the data in these frames isn't
really in IEs, but put it into the elems struct anyway
to simplify the handling.

Signed-off-by: Johannes Berg <[e-mail]>

include/linux/ieee80211.h

···
 				} __packed chan_switch;
 				struct{
 					u8 action_code;
+					struct ieee80211_ext_chansw_ie data;
+					u8 variable[0];
+				} __packed ext_chan_switch;
+				struct{
+					u8 action_code;
 					u8 dialog_token;
 					u8 element_id;
 					u8 length;
···
 
 /* Public action codes */
 enum ieee80211_pub_actioncode {
+	WLAN_PUB_ACTION_EXT_CHANSW_ANN = 4,
 	WLAN_PUB_ACTION_TDLS_DISCOVER_RES = 14,
 };
 

net/mac80211/mlme.c

···
 	enum rx_mgmt_action rma = RX_MGMT_NONE;
 	u8 deauth_buf[IEEE80211_DEAUTH_FRAME_LEN];
 	u16 fc;
+	struct ieee802_11_elems elems;
+	int ies_len;
 
 	rx_status = (struct ieee80211_rx_status *) skb->cb;
 	mgmt = (struct ieee80211_mgmt *) skb->data;
···
 		break;
 	case IEEE80211_STYPE_ACTION:
 		if (mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT) {
-			struct ieee802_11_elems elems;
-			int ies_len = skb->len -
-				      offsetof(struct ieee80211_mgmt,
-					       u.action.u.chan_switch.variable);
+			ies_len = skb->len -
+				  offsetof(struct ieee80211_mgmt,
+					   u.action.u.chan_switch.variable);
 
 			if (ies_len < 0)
 				break;
···
 
 			if (elems.parse_error)
 				break;
+
+			ieee80211_sta_process_chanswitch(sdata,
+							 rx_status->mactime,
+							 &elems);
+		} else if (mgmt->u.action.category == WLAN_CATEGORY_PUBLIC) {
+			ies_len = skb->len -
+				  offsetof(struct ieee80211_mgmt,
+					   u.action.u.ext_chan_switch.variable);
+
+			if (ies_len < 0)
+				break;
+
+			ieee802_11_parse_elems(
+				mgmt->u.action.u.ext_chan_switch.variable,
+				ies_len, &elems);
+
+			if (elems.parse_error)
+				break;
+
+			/* for the handling code pretend this was also an IE */
+			elems.ext_chansw_ie =
+				&mgmt->u.action.u.ext_chan_switch.data;
 
 			ieee80211_sta_process_chanswitch(sdata,
 							 rx_status->mactime,

net/mac80211/rx.c

···
 		}
 
 		break;
+	case WLAN_CATEGORY_PUBLIC:
+		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
+			goto invalid;
+		if (sdata->vif.type != NL80211_IFTYPE_STATION)
+			break;
+		if (!rx->sta)
+			break;
+		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
+			break;
+		if (mgmt->u.action.u.ext_chan_switch.action_code !=
+				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
+			break;
+		if (len < offsetof(struct ieee80211_mgmt,
+				   u.action.u.ext_chan_switch.variable))
+			goto invalid;
+		goto queue;
 	case WLAN_CATEGORY_VHT:
 		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
 		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&