mac80211: allow drivers to access key sequence counter

In order to implement GTK rekeying, the device needs
to be able to encrypt frames with the right PN/IV and
check the PN/IV in RX frames. To be able to tell it
about all those counters, we need to be able to get
them from mac80211, this adds the required API.

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

1 files changed, 60 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0aae7bc1eeae..84770cedae2d 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2592,6 +2592,66 @@ void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
                             struct sk_buff *skb, u8 *p2k);
 
 /**
+ * struct ieee80211_key_seq - key sequence counter
+ *
+ * @tkip: TKIP data, containing IV32 and IV16 in host byte order
+ * @ccmp: PN data, most significant byte first (big endian,
+ *      reverse order than in packet)
+ * @aes_cmac: PN data, most significant byte first (big endian,
+ *      reverse order than in packet)
+ */
+struct ieee80211_key_seq {
+        union {
+                struct {
+                        u32 iv32;
+                        u16 iv16;
+                } tkip;
+                struct {
+                        u8 pn[6];
+                } ccmp;
+                struct {
+                        u8 pn[6];
+                } aes_cmac;
+        };
+};
+
+/**
+ * ieee80211_get_key_tx_seq - get key TX sequence counter
+ *
+ * @keyconf: the parameter passed with the set key
+ * @seq: buffer to receive the sequence data
+ *
+ * This function allows a driver to retrieve the current TX IV/PN
+ * for the given key. It must not be called if IV generation is
+ * offloaded to the device.
+ *
+ * Note that this function may only be called when no TX processing
+ * can be done concurrently, for example when queues are stopped
+ * and the stop has been synchronized.
+ */
+void ieee80211_get_key_tx_seq(struct ieee80211_key_conf *keyconf,
+                              struct ieee80211_key_seq *seq);
+
+/**
+ * ieee80211_get_key_rx_seq - get key RX sequence counter
+ *
+ * @keyconf: the parameter passed with the set key
+ * @tid: The TID, or -1 for the management frame value (CCMP only);
+ *      the value on TID 0 is also used for non-QoS frames. For
+ *      CMAC, only TID 0 is valid.
+ * @seq: buffer to receive the sequence data
+ *
+ * This function allows a driver to retrieve the current RX IV/PNs
+ * for the given key. It must not be called if IV checking is done
+ * by the device and not by mac80211.
+ *
+ * Note that this function may only be called when no RX processing
+ * can be done concurrently.
+ */
+void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
+                              int tid, struct ieee80211_key_seq *seq);
+
+/**
  * ieee80211_gtk_rekey_notify - notify userspace supplicant of rekeying
  * @vif: virtual interface the rekeying was done on
  * @bssid: The BSSID of the AP, for checking association