wifi: mac80211: expand __ieee80211_data_to_8023() status

Make __ieee80211_data_to_8023() return more individual drop
reasons instead of just doing RX_DROP_U_INVALID_8023.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/drop.h

@@ -62,6 +62,10 @@ typedef unsigned int __bitwise ieee80211_rx_result;
 	R(RX_DROP_U_SHORT_CMAC)			\
 	R(RX_DROP_U_SHORT_CMAC256)		\
 	R(RX_DROP_U_SHORT_GMAC)			\
+	R(RX_DROP_U_UNEXPECTED_VLAN_4ADDR)	\
+	R(RX_DROP_U_UNEXPECTED_STA_4ADDR)	\
+	R(RX_DROP_U_UNEXPECTED_VLAN_MCAST)	\
+	R(RX_DROP_U_NOT_PORT_CONTROL)		\
 /* this line for the trailing \ - add before this */
 
 /* having two enums allows for checking ieee80211_rx_result use with sparse */

net/mac80211/rx.c

@@ -2476,7 +2476,7 @@ static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
 	return 0;
 }
 
-static int
+static ieee80211_rx_result
 __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
 {
 	struct ieee80211_sub_if_data *sdata = rx->sdata;
@@ -2488,32 +2488,31 @@ __ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
 	*port_control = false;
 	if (ieee80211_has_a4(hdr->frame_control) &&
 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
-		return -1;
+		return RX_DROP_U_UNEXPECTED_VLAN_4ADDR;
 
 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
-
 		if (!sdata->u.mgd.use_4addr)
-			return -1;
+			return RX_DROP_U_UNEXPECTED_STA_4ADDR;
 		else if (!ether_addr_equal(hdr->addr1, sdata->vif.addr))
 			check_port_control = true;
 	}
 
 	if (is_multicast_ether_addr(hdr->addr1) &&
 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
-		return -1;
+		return RX_DROP_U_UNEXPECTED_VLAN_MCAST;
 
 	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
 	if (ret < 0)
-		return ret;
+		return RX_DROP_U_INVALID_8023;
 
 	ehdr = (struct ethhdr *) rx->skb->data;
 	if (ehdr->h_proto == rx->sdata->control_port_protocol)
 		*port_control = true;
 	else if (check_port_control)
-		return -1;
+		return RX_DROP_U_NOT_PORT_CONTROL;
 
-	return 0;
+	return RX_CONTINUE;
 }
 
 bool ieee80211_is_our_addr(struct ieee80211_sub_if_data *sdata,
@@ -3124,7 +3123,6 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
 	__le16 fc = hdr->frame_control;
 	ieee80211_rx_result res;
 	bool port_control;
-	int err;
 
 	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
 		return RX_CONTINUE;
@@ -3145,9 +3143,9 @@ ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
 		return RX_DROP_MONITOR;
 	}
 
-	err = __ieee80211_data_to_8023(rx, &port_control);
-	if (unlikely(err))
-		return RX_DROP_U_INVALID_8023;
+	res = __ieee80211_data_to_8023(rx, &port_control);
+	if (unlikely(res != RX_CONTINUE))
+		return res;
 
 	res = ieee80211_rx_mesh_data(rx->sdata, rx->sta, rx->skb);
 	if (res != RX_CONTINUE)