mac80211: allow low-level drivers to set netdev feature bits

Low level drivers can now set certain netdev feature bits in
netdev_features member of the ieee80211_hw struct. These will be
propagated to every netdev created from this HW.

The white-listed features currently include only ones related to HW
checksumming.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 14 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 1937c7d98304..0286c0476e44 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1297,6 +1297,10 @@ enum ieee80211_hw_flags {
  *      reports, by default it is set to _MCS, _GI and _BW but doesn't
  *      include _FMT. Use %IEEE80211_RADIOTAP_MCS_HAVE_* values, only
  *      adding _BW is supported today.
+ *
+ * @netdev_features: netdev features to be set in each netdev created
+ *      from this HW. Note only HW checksum features are currently
+ *      compatible with mac80211. Other feature bits will be rejected.
  */
 struct ieee80211_hw {
         struct ieee80211_conf conf;
@@ -1319,6 +1323,7 @@ struct ieee80211_hw {
         u8 max_tx_aggregation_subframes;
         u8 offchannel_tx_hw_queue;
         u8 radiotap_mcs_details;
+        netdev_features_t netdev_features;
 };
 
 /**
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index d4c19a7773db..f970e0b3c4b9 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1352,6 +1352,8 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
                         sdata->u.mgd.use_4addr = params->use_4addr;
         }
 
+        ndev->features |= local->hw.netdev_features;
+
         ret = register_netdevice(ndev);
         if (ret)
                 goto fail;
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index f5548e953259..779ac613ee57 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -682,6 +682,7 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
         enum ieee80211_band band;
         int channels, max_bitrates;
         bool supp_ht;
+        netdev_features_t feature_whitelist;
         static const u32 cipher_suites[] = {
                 /* keep WEP first, it may be removed below */
                 WLAN_CIPHER_SUITE_WEP40,
@@ -708,6 +709,12 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
         if ((hw->flags & IEEE80211_HW_SCAN_WHILE_IDLE) && !local->ops->hw_scan)
                 return -EINVAL;
 
+        /* Only HW csum features are currently compatible with mac80211 */
+        feature_whitelist = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+                            NETIF_F_HW_CSUM;
+        if (WARN_ON(hw->netdev_features & ~feature_whitelist))
+                return -EINVAL;
+
         if (hw->max_report_rates == 0)
                 hw->max_report_rates = hw->max_rates;