cfg80211: introduce capability for 4addr mode

It's very likely that not many devices will support
four-address mode in station or AP mode so introduce
capability bits for both modes, set them in mac80211
and check them when userspace tries to use the mode.
Also, keep track of 4addr in cfg80211 (wireless_dev)
and not in mac80211 any more. mac80211 can also be
improved for the VLAN case by not looking at the
4addr flag but maintaining the station pointer for
it correctly. However, keep track of use_4addr for
station mode in mac80211 to avoid all the derefs.

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

1 files changed, 9 insertions, 5 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 775365f856c9..96f13ad05d3c 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1192,10 +1192,13 @@ __ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
         struct net_device *dev = sdata->dev;
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
 
-        if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->use_4addr &&
-            ieee80211_has_a4(hdr->frame_control))
+        if (ieee80211_has_a4(hdr->frame_control) &&
+            sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
                 return -1;
-        if (sdata->use_4addr && is_multicast_ether_addr(hdr->addr1))
+
+        if (is_multicast_ether_addr(hdr->addr1) &&
+            ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta) ||
+             (sdata->vif.type == NL80211_IFTYPE_STATION && sdata->u.mgd.use_4addr)))
                 return -1;
 
         return ieee80211_data_to_8023(rx->skb, dev->dev_addr, sdata->vif.type);
@@ -1245,7 +1248,8 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
         if ((sdata->vif.type == NL80211_IFTYPE_AP ||
              sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
             !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
-            (rx->flags & IEEE80211_RX_RA_MATCH) && !rx->sdata->use_4addr) {
+            (rx->flags & IEEE80211_RX_RA_MATCH) &&
+            (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
                 if (is_multicast_ether_addr(ehdr->h_dest)) {
                         /*
                          * send multicast frames both to higher layers in
@@ -2007,7 +2011,7 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
 
         switch (sdata->vif.type) {
         case NL80211_IFTYPE_STATION:
-                if (!bssid && !sdata->use_4addr)
+                if (!bssid && !sdata->u.mgd.use_4addr)
                         return 0;
                 if (!multicast &&
                     compare_ether_addr(sdata->dev->dev_addr, hdr->addr1) != 0) {