iwlwifi: tracing: decouple from mac80211

In order to be able to properly record SKBs that didn't come through
mac80211, don't rely on the IEEE80211_TX_CTRL_PORT_CTRL_PROTO flag
but instead check for ETH_P_PAE directly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-devtrace.h b/drivers/net/wireless/intel/iwlwifi/iwl-devtrace.h
index f4d3cd0..545d14b 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/iwl-devtrace.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-devtrace.h
@@ -1,6 +1,7 @@
 /******************************************************************************
  *
  * Copyright(c) 2009 - 2014 Intel Corporation. All rights reserved.
+ * Copyright(C) 2016 Intel Deutschland GmbH
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of version 2 of the GNU General Public License as
@@ -33,11 +34,29 @@
 static inline bool iwl_trace_data(struct sk_buff *skb)
 {
        struct ieee80211_hdr *hdr = (void *)skb->data;
-       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+       __le16 fc = hdr->frame_control;
+       int offs = 24; /* start with normal header length */
 
-       if (!ieee80211_is_data(hdr->frame_control))
+       if (!ieee80211_is_data(fc))
                return false;
-       return !(info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO);
+
+       /* Try to determine if the frame is EAPOL. This might have false
+        * positives (if there's no RFC 1042 header and we compare to some
+        * payload instead) but since we're only doing tracing that's not
+        * a problem.
+        */
+
+       if (ieee80211_has_a4(fc))
+               offs += 6;
+       if (ieee80211_is_data_qos(fc))
+               offs += 2;
+       /* don't account for crypto - these are unencrypted */
+
+       /* also account for the RFC 1042 header, of course */
+       offs += 6;
+
+       return skb->len > offs + 2 &&
+              *(__be16 *)(skb->data + offs) == cpu_to_be16(ETH_P_PAE);
 }
 
 static inline size_t iwl_rx_trace_len(const struct iwl_trans *trans,