mac80211: add debug file for mic failure

The mic failure count provides the number of mic failures that
have happened on a given key (without a countermeasure being
started, since that would remove the key).

Signed-off-by: Saravana <saravanad@posedge.com>
[fix NULL pointer issues]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/net/mac80211/debugfs_key.c b/net/mac80211/debugfs_key.c
index 2d4235497f1b..c3a3082b72e5 100644
--- a/net/mac80211/debugfs_key.c
+++ b/net/mac80211/debugfs_key.c
@@ -199,6 +199,22 @@ static ssize_t key_icverrors_read(struct file *file, char __user *userbuf,
 }
 KEY_OPS(icverrors);
 
+static ssize_t key_mic_failures_read(struct file *file, char __user *userbuf,
+                                     size_t count, loff_t *ppos)
+{
+        struct ieee80211_key *key = file->private_data;
+        char buf[20];
+        int len;
+
+        if (key->conf.cipher != WLAN_CIPHER_SUITE_TKIP)
+                return -EINVAL;
+
+        len = scnprintf(buf, sizeof(buf), "%u\n", key->u.tkip.mic_failures);
+
+        return simple_read_from_buffer(userbuf, count, ppos, buf, len);
+}
+KEY_OPS(mic_failures);
+
 static ssize_t key_key_read(struct file *file, char __user *userbuf,
                             size_t count, loff_t *ppos)
 {
@@ -260,6 +276,7 @@ void ieee80211_debugfs_key_add(struct ieee80211_key *key)
         DEBUGFS_ADD(rx_spec);
         DEBUGFS_ADD(replays);
         DEBUGFS_ADD(icverrors);
+        DEBUGFS_ADD(mic_failures);
         DEBUGFS_ADD(key);
         DEBUGFS_ADD(ifindex);
 };