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>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index eca36abca8f52b96d605f053e244487fc8e59fc6..d1e05aeb0c09f3cd7a954ea21a002d679caf42cc 100644 (file)
--- 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 7d591816ed104bb25d72ede8da3a89601c59cbde..c484a882140ed7db639312acdce49a2431347ed8 100644 (file)
--- 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 87d27f450a057aeaff5da167ec98c1dcb04932b1..f13d76c9b575706423f1dd3d79366078afd9df18 100644 (file)
--- 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 1f02b0610e822954d5cdcbe768a0f3ac2824fea0..1bf12a26b45e5eceac427bd9696b520aa215da42 100644 (file)
--- 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 8084b622e97eb0e0ca4f297b494f76e9297f87c7..dd8ec8d5e8b21bc927561bbd697653d46a3c0b94 100644 (file)
--- 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 775365f856c92b6b5b395879d4504a2aefb0b3ad..96f13ad05d3caf29edb5c1aa9d25b2eaeb16c0fd 100644 (file)
--- 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 b3c1faeb5927be4a1db2573e6320f9b30fa3d0ff..5af2f40ea4db78a431cab962de24c4751801ea4a 100644 (file)
--- 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 6634188f94538027c603a9aec528457d1f283301..b7b0f67b0c611940fe1ae20bd5a8e56c95c98339 100644 (file)
--- 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 5aa39f7cf9b94b4e8d4488b2361a640478f7f138..17a7a4cfc617a5ff013c7f61d8cfe9d69710646b 100644 (file)
--- 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;
 }