9 files changed, 82 insertions, 30 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index eca36abca8f5..d1e05aeb0c09 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1134,6 +1134,9 @@ struct cfg80211_ops {
  *      by default -- this flag will be set depending on the kernel's default
  *      on wiphy_new(), but can be changed by the driver if it has a good
  *      reason to override the default
+ * @WIPHY_FLAG_4ADDR_AP: supports 4addr mode even on AP (with a single station
+ *      on a VLAN interface)
+ * @WIPHY_FLAG_4ADDR_STATION: supports 4addr mode even as a station
  */
 enum wiphy_flags {
         WIPHY_FLAG_CUSTOM_REGULATORY    = BIT(0),
@@ -1141,6 +1144,8 @@ enum wiphy_flags {
         WIPHY_FLAG_DISABLE_BEACON_HINTS = BIT(2),
         WIPHY_FLAG_NETNS_OK             = BIT(3),
         WIPHY_FLAG_PS_ON_BY_DEFAULT     = BIT(4),
+        WIPHY_FLAG_4ADDR_AP             = BIT(5),
+        WIPHY_FLAG_4ADDR_STATION        = BIT(6),
 };
 
 /**
@@ -1366,6 +1371,10 @@ struct cfg80211_cached_keys;
  * @ssid_len: (private) Used by the internal configuration code
  * @wext: (private) Used by the internal wireless extensions compat code
  * @wext_bssid: (private) Used by the internal wireless extensions compat code
+ * @use_4addr: indicates 4addr mode is used on this interface, must be
+ *      set by driver (if supported) on add_interface BEFORE registering the
+ *      netdev and may otherwise be used by driver read-only, will be update
+ *      by cfg80211 on change_interface
  */
 struct wireless_dev {
         struct wiphy *wiphy;
@@ -1379,6 +1388,8 @@ struct wireless_dev {
 
         struct work_struct cleanup_work;
 
+        bool use_4addr;
+
         /* currently used for IBSS and SME - might be rearranged later */
         u8 ssid[IEEE80211_MAX_SSID_LEN];
         u8 ssid_len;
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 7d591816ed10..c484a882140e 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -42,15 +42,6 @@ static bool nl80211_params_check(enum nl80211_iftype type,
         if (!nl80211_type_check(type))
                 return false;
 
-        if (params->use_4addr > 0) {
-                switch(type) {
-                case NL80211_IFTYPE_AP_VLAN:
-                case NL80211_IFTYPE_STATION:
-                        break;
-                default:
-                        return false;
-                }
-        }
         return true;
 }
 
@@ -107,12 +98,16 @@ static int ieee80211_change_iface(struct wiphy *wiphy,
                                             params->mesh_id_len,
                                             params->mesh_id);
 
-        if (params->use_4addr >= 0)
-                sdata->use_4addr = !!params->use_4addr;
-
         if (sdata->vif.type != NL80211_IFTYPE_MONITOR || !flags)
                 return 0;
 
+        if (type == NL80211_IFTYPE_AP_VLAN &&
+            params && params->use_4addr == 0)
+                rcu_assign_pointer(sdata->u.vlan.sta, NULL);
+        else if (type == NL80211_IFTYPE_STATION &&
+                 params && params->use_4addr >= 0)
+                sdata->u.mgd.use_4addr = params->use_4addr;
+
         sdata->u.mntr_flags = *flags;
         return 0;
 }
@@ -827,7 +822,7 @@ static int ieee80211_change_station(struct wiphy *wiphy,
                         return -EINVAL;
                 }
 
-                if (vlansdata->use_4addr) {
+                if (params->vlan->ieee80211_ptr->use_4addr) {
                         if (vlansdata->u.vlan.sta)
                                 return -EBUSY;
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 87d27f450a05..f13d76c9b575 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -312,6 +312,8 @@ struct ieee80211_if_managed {
         } mfp; /* management frame protection */
 
         int wmm_last_param_set;
+
+        u8 use_4addr;
 };
 
 enum ieee80211_ibss_request {
@@ -459,8 +461,6 @@ struct ieee80211_sub_if_data {
         int force_unicast_rateidx; /* forced TX rateidx for unicast frames */
         int max_ratectrl_rateidx; /* max TX rateidx for rate control */
 
-        bool use_4addr; /* use 4-address frames */
-
         union {
                 struct ieee80211_if_ap ap;
                 struct ieee80211_if_wds wds;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1f02b0610e82..1bf12a26b45e 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -752,7 +752,8 @@ int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
                 ieee80211_mandatory_rates(sdata->local,
                         sdata->local->hw.conf.channel->band);
         sdata->drop_unencrypted = 0;
-        sdata->use_4addr = 0;
+        if (type == NL80211_IFTYPE_STATION)
+                sdata->u.mgd.use_4addr = false;
 
         return 0;
 }
@@ -810,6 +811,12 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
         /* setup type-dependent data */
         ieee80211_setup_sdata(sdata, type);
 
+        if (params) {
+                ndev->ieee80211_ptr->use_4addr = params->use_4addr;
+                if (type == NL80211_IFTYPE_STATION)
+                        sdata->u.mgd.use_4addr = params->use_4addr;
+        }
+
         ret = register_netdevice(ndev);
         if (ret)
                 goto fail;
@@ -820,9 +827,6 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
                                             params->mesh_id_len,
                                             params->mesh_id);
 
-        if (params && params->use_4addr >= 0)
-                sdata->use_4addr = !!params->use_4addr;
-
         mutex_lock(&local->iflist_mtx);
         list_add_tail_rcu(&sdata->list, &local->interfaces);
         mutex_unlock(&local->iflist_mtx);
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 8084b622e97e..dd8ec8d5e8b2 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -328,7 +328,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
         if (!wiphy)
                 return NULL;
 
-        wiphy->flags |= WIPHY_FLAG_NETNS_OK;
+        wiphy->flags |= WIPHY_FLAG_NETNS_OK |
+                        WIPHY_FLAG_4ADDR_AP |
+                        WIPHY_FLAG_4ADDR_STATION;
         wiphy->privid = mac80211_wiphy_privid;
 
         /* Yes, putting cfg80211_bss into ieee80211_bss is a hack */
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) {
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index b3c1faeb5927..5af2f40ea4db 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1051,7 +1051,7 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
 
         hdr = (struct ieee80211_hdr *) skb->data;
 
-        if ((sdata->vif.type == NL80211_IFTYPE_AP_VLAN) && sdata->use_4addr)
+        if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
                 tx->sta = rcu_dereference(sdata->u.vlan.sta);
         if (!tx->sta)
                 tx->sta = sta_info_get(local, hdr->addr1);
@@ -1632,8 +1632,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
         switch (sdata->vif.type) {
         case NL80211_IFTYPE_AP_VLAN:
                 rcu_read_lock();
-                if (sdata->use_4addr)
-                        sta = rcu_dereference(sdata->u.vlan.sta);
+                sta = rcu_dereference(sdata->u.vlan.sta);
                 if (sta) {
                         fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
                         /* RA TA DA SA */
@@ -1727,7 +1726,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
 #endif
         case NL80211_IFTYPE_STATION:
                 memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
-                if (sdata->use_4addr && ethertype != ETH_P_PAE) {
+                if (sdata->u.mgd.use_4addr && ethertype != ETH_P_PAE) {
                         fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
                         /* RA TA DA SA */
                         memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 6634188f9453..b7b0f67b0c61 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -968,6 +968,28 @@ static int parse_monitor_flags(struct nlattr *nla, u32 *mntrflags)
         return 0;
 }
 
+static int nl80211_valid_4addr(struct cfg80211_registered_device *rdev,
+                               u8 use_4addr, enum nl80211_iftype iftype)
+{
+        if (!use_4addr)
+                return 0;
+
+        switch (iftype) {
+        case NL80211_IFTYPE_AP_VLAN:
+                if (rdev->wiphy.flags & WIPHY_FLAG_4ADDR_AP)
+                        return 0;
+                break;
+        case NL80211_IFTYPE_STATION:
+                if (rdev->wiphy.flags & WIPHY_FLAG_4ADDR_STATION)
+                        return 0;
+                break;
+        default:
+                break;
+        }
+
+        return -EOPNOTSUPP;
+}
+
 static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
 {
         struct cfg80211_registered_device *rdev;
@@ -1011,6 +1033,9 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
         if (info->attrs[NL80211_ATTR_4ADDR]) {
                 params.use_4addr = !!nla_get_u8(info->attrs[NL80211_ATTR_4ADDR]);
                 change = true;
+                err = nl80211_valid_4addr(rdev, params.use_4addr, ntype);
+                if (err)
+                        goto unlock;
         } else {
                 params.use_4addr = -1;
         }
@@ -1034,6 +1059,9 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
         else
                 err = 0;
 
+        if (!err && params.use_4addr != -1)
+                dev->ieee80211_ptr->use_4addr = params.use_4addr;
+
  unlock:
         dev_put(dev);
         cfg80211_unlock_rdev(rdev);
@@ -1081,8 +1109,12 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
                 params.mesh_id_len = nla_len(info->attrs[NL80211_ATTR_MESH_ID]);
         }
 
-        if (info->attrs[NL80211_ATTR_4ADDR])
+        if (info->attrs[NL80211_ATTR_4ADDR]) {
                 params.use_4addr = !!nla_get_u8(info->attrs[NL80211_ATTR_4ADDR]);
+                err = nl80211_valid_4addr(rdev, params.use_4addr, type);
+                if (err)
+                        goto unlock;
+        }
 
         err = parse_monitor_flags(type == NL80211_IFTYPE_MONITOR ?
                                   info->attrs[NL80211_ATTR_MNTR_FLAGS] : NULL,
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 5aa39f7cf9b9..17a7a4cfc617 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -659,6 +659,8 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
                 return -EOPNOTSUPP;
 
         if (ntype != otype) {
+                dev->ieee80211_ptr->use_4addr = false;
+
                 switch (otype) {
                 case NL80211_IFTYPE_ADHOC:
                         cfg80211_leave_ibss(rdev, dev, false);
@@ -682,5 +684,8 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 
         WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
 
+        if (!err && params && params->use_4addr != -1)
+                dev->ieee80211_ptr->use_4addr = params->use_4addr;
+
         return err;
 }