mac80211: Add support for hardware ARP query filtering

Some hardware allow extended filtering of ARP frames not intended for
the host. To perform such filtering, the hardware needs to know the current
IP address(es) of the host, bound to its interface.

Add support for ARP filtering to mac80211 by adding a new op to the driver
interface, allowing to configure the current IP addresses. This op is called
upon association with the currently configured address(es), and when
associated whenever the IP address(es) change.

This patch adds configuration of IPv4 addresses only, as IPv6 addresses don't
need ARP filtering.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index f26440a46df..74b9b49ddfa 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -19,6 +19,7 @@
 #include <linux/wireless.h>
 #include <linux/device.h>
 #include <linux/ieee80211.h>
+#include <linux/inetdevice.h>
 #include <net/cfg80211.h>
 
 /**
@@ -1532,6 +1533,16 @@ enum ieee80211_ampdu_mlme_action {
  *      of the bss parameters has changed when a call is made. The callback
  *      can sleep.
  *
+ * @configure_arp_filter: Configuration function for hardware ARP query filter.
+ *      This function is called with all the IP addresses configured to the
+ *      interface as argument - all ARP queries targeted to any of these
+ *      addresses must pass through. If the hardware filter does not support
+ *      enought addresses, hardware filtering must be disabled. The ifa_list
+ *      argument may be NULL, indicating that filtering must be disabled.
+ *      This function is called upon association complete with current
+ *      address(es), and while associated whenever the IP address(es) change.
+ *      The callback can sleep.
+ *
  * @prepare_multicast: Prepare for multicast filter configuration.
  *      This callback is optional, and its return value is passed
  *      to configure_filter(). This callback must be atomic.
@@ -1671,6 +1682,9 @@ struct ieee80211_ops {
                                  struct ieee80211_vif *vif,
                                  struct ieee80211_bss_conf *info,
                                  u32 changed);
+        int (*configure_arp_filter)(struct ieee80211_hw *hw,
+                                    struct ieee80211_vif *vif,
+                                    struct in_ifaddr *ifa_list);
         u64 (*prepare_multicast)(struct ieee80211_hw *hw,
                                  struct netdev_hw_addr_list *mc_list);
         void (*configure_filter)(struct ieee80211_hw *hw,