mac80211: Copy tx'ed beacons to monitor mode

When debugging wireless powersave issues on the AP side it's quite helpful
to see our own beacons that are transmitted by the hardware/driver. However,
this is not that easy since beacons don't pass through the regular TX queues.

Preferably drivers would call ieee80211_tx_status also for tx'ed beacons
but that's not always possible. Hence, just send a copy of each beacon
generated by ieee80211_beacon_get_tim to monitor devices when they are
getting fetched by the driver.

Also add a HW flag IEEE80211_HW_BEACON_TX_STATUS that can be used by
drivers to indicate that they report TX status for beacons.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
(with a fix from Christian Lamparted rolled in)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 3424ac6efb2a1dd248a02e292cc01160925e8e54..301fceb2fd1001ed35da89124c3d5637986718e2 100644 (file)
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1898,6 +1898,9 @@ struct ieee80211_txq {
  * @IEEE80211_HW_SUPPORTS_AMSDU_IN_AMPDU: The driver supports receiving A-MSDUs
  *     within A-MPDU.
  *
+ * @IEEE80211_HW_BEACON_TX_STATUS: The device/driver provides TX status
+ *     for sent beacons.
+ *
  * @NUM_IEEE80211_HW_FLAGS: number of hardware flags, used for sizing arrays
  */
 enum ieee80211_hw_flags {
@@ -1932,6 +1935,7 @@ enum ieee80211_hw_flags {
        IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS,
        IEEE80211_HW_TDLS_WIDER_BW,
        IEEE80211_HW_SUPPORTS_AMSDU_IN_AMPDU,
+       IEEE80211_HW_BEACON_TX_STATUS,
 
        /* keep last, obviously */
        NUM_IEEE80211_HW_FLAGS

diff --git a/net/mac80211/debugfs.c b/net/mac80211/debugfs.c
index 41726fd4bb789a2b1ae574845e2fe05e05425860..3636b45440ab40ecc3c618a916b1305bacfe1bc7 100644 (file)
--- a/net/mac80211/debugfs.c
+++ b/net/mac80211/debugfs.c
@@ -124,6 +124,7 @@ static const char *hw_flag_names[NUM_IEEE80211_HW_FLAGS + 1] = {
        FLAG(SINGLE_SCAN_ON_ALL_BANDS),
        FLAG(TDLS_WIDER_BW),
        FLAG(SUPPORTS_AMSDU_IN_AMPDU),
+       FLAG(BEACON_TX_STATUS),
 
        /* keep last for the build bug below */
        (void *)0x1

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 84e0e8c7fb236952dfc1cfcb23204623e80d7867..73540723be37a29cf6f5282fab14ac46bb8c8706 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3512,6 +3512,12 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
 {
        struct ieee80211_mutable_offsets offs = {};
        struct sk_buff *bcn = __ieee80211_beacon_get(hw, vif, &offs, false);
+       struct sk_buff *copy;
+       struct ieee80211_supported_band *sband;
+       int shift;
+
+       if (!bcn)
+               return bcn;
 
        if (tim_offset)
                *tim_offset = offs.tim_offset;
@@ -3519,6 +3525,19 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
        if (tim_length)
                *tim_length = offs.tim_length;
 
+       if (ieee80211_hw_check(hw, BEACON_TX_STATUS) ||
+           !hw_to_local(hw)->monitors)
+               return bcn;
+
+       /* send a copy to monitor interfaces */
+       copy = skb_copy(bcn, GFP_ATOMIC);
+       if (!copy)
+               return bcn;
+
+       shift = ieee80211_vif_get_shift(vif);
+       sband = hw->wiphy->bands[ieee80211_get_sdata_band(vif_to_sdata(vif))];
+       ieee80211_tx_monitor(hw_to_local(hw), copy, sband, 1, shift, false);
+
        return bcn;
 }
 EXPORT_SYMBOL(ieee80211_beacon_get_tim);