mac80211: move TKIP TX IVs to public part of key struct

Some drivers/devices might want to set the IVs by
themselves (and still let mac80211 generate MMIC).

Specifically, this is needed when the device does
offloading at certain times, and the driver has
to make sure that the IVs of new tx frames (from
the host) are synchronized with IVs that were
potentially used during the offloading.

Similarly to CCMP, move the TX IVs of TKIP keys to the
public part of the key struct, and export a function
to add the IV right into the crypto header.

The public tx_pn field is defined as atomic64, so define
TKIP_PN_TO_IV16/32 helper macros to convert it to iv16/32
when needed.

Since the iv32 used for the p1k cache is taken
directly from the frame, we can safely remove
iv16/32 from being protected by tkip.txlock.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 20 insertions, 3 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 57147749ae42..15879b49baad 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1521,9 +1521,8 @@ enum ieee80211_key_flags {
  *	wants to be given when a frame is transmitted and needs to be
  *	encrypted in hardware.
  * @cipher: The key's cipher suite selector.
- * @tx_pn: PN used for TX on non-TKIP keys, may be used by the driver
- *	as well if it needs to do software PN assignment by itself
- *	(e.g. due to TSO)
+ * @tx_pn: PN used for TX keys, may be used by the driver as well if it
+ *	needs to do software PN assignment by itself (e.g. due to TSO)
  * @flags: key flags, see &enum ieee80211_key_flags.
  * @keyidx: the key index (0-3)
  * @keylen: key material length
@@ -1549,6 +1548,9 @@ struct ieee80211_key_conf {
 
 #define IEEE80211_MAX_PN_LEN	16
 
+#define TKIP_PN_TO_IV16(pn) ((u16)(pn & 0xffff))
+#define TKIP_PN_TO_IV32(pn) ((u32)((pn >> 16) & 0xffffffff))
+
 /**
  * struct ieee80211_key_seq - key sequence counter
  *
@@ -4447,6 +4449,21 @@ void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
 			    struct sk_buff *skb, u8 *p2k);
 
 /**
+ * ieee80211_tkip_add_iv - write TKIP IV and Ext. IV to pos
+ *
+ * @pos: start of crypto header
+ * @keyconf: the parameter passed with the set key
+ * @pn: PN to add
+ *
+ * Returns: pointer to the octet following IVs (i.e. beginning of
+ * the packet payload)
+ *
+ * This function writes the tkip IV value to pos (which should
+ * point to the crypto header)
+ */
+u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key_conf *keyconf, u64 pn);
+
+/**
  * ieee80211_get_key_tx_seq - get key TX sequence counter
  *
  * @keyconf: the parameter passed with the set key