From 681d119047761cc59a15c0bb86891f3a878997cf Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Thu, 3 Feb 2011 18:35:19 +0200 Subject: mac80211: Add testing functionality for TKIP TKIP countermeasures depend on devices being able to detect Michael MIC failures on received frames and for stations to report errors to the AP. In order to test that behavior, it is useful to be able to send out TKIP frames with incorrect Michael MIC. This testing behavior has minimal effect on the TX path, so it can be added to mac80211 for convenient use. The interface for using this functionality is a file in mac80211 netdev debugfs (tkip_mic_test). Writing a MAC address to the file makes mac80211 generate a dummy data frame that will be sent out using invalid Michael MIC value. In AP mode, the address needs to be for one of the associated stations or ff:ff:ff:ff:ff:ff to use a broadcast frame. In station mode, the address can be anything, e.g., the current BSSID. It should be noted that this functionality works correctly only when associated and using TKIP. Signed-off-by: Jouni Malinen Acked-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/wpa.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'net/mac80211/wpa.c') diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index cd5e730873a8..f1765de2f4bf 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -46,6 +46,11 @@ ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) data = skb->data + hdrlen; data_len = skb->len - hdrlen; + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) { + /* Need to use software crypto for the test */ + info->control.hw_key = NULL; + } + if (info->control.hw_key && !(tx->flags & IEEE80211_TX_FRAGMENTED) && !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { @@ -64,6 +69,8 @@ ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY]; mic = skb_put(skb, MICHAEL_MIC_LEN); michael_mic(key, hdr, data, data_len, mic); + if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) + mic[0]++; return TX_CONTINUE; } -- cgit v1.2.3