Search Linux Wireless

[PATCH v3] mac80211: don't drop null frames during software scan

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



ieee80211_tx_h_check_assoc() was dropping everything else than probe
requests during software scan. So the null frame with the power save
bit was dropped and AP never received it. This meant that AP never
buffered any frames for the station during software scan.

Fix this by allowing to transmit both probe request and null frames
during software scan. Tested with stlc45xx.

Signed-off-by: Kalle Valo <kalle.valo@xxxxxxxxx>
---

 net/mac80211/scan.c |   13 +++++++++++++
 net/mac80211/tx.c   |    9 ++++++++-
 2 files changed, 21 insertions(+), 1 deletions(-)

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 5030a3c..46f35dc 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -409,6 +409,19 @@ int ieee80211_start_scan(struct ieee80211_sub_if_data *scan_sdata,
 		return 0;
 	}
 
+	/*
+	 * Hardware/driver doesn't support hw_scan, so use software
+	 * scanning instead. First send a nullfunc frame with power save
+	 * bit on so that AP will buffer the frames for us while we are not
+	 * listening, then send probe requests to each channel and wait for
+	 * the responses. After all channels are scanned, tune back to the
+	 * original channel and send a nullfunc frame with power save bit
+	 * off to trigger the AP to send us all the buffered frames.
+	 *
+	 * Note that while local->sw_scanning is true everything else but
+	 * nullfunc frames and probe requests will be dropped in
+	 * ieee80211_tx_h_check_assoc().
+	 */
 	local->sw_scanning = true;
 	if (local->ops->sw_scan_start)
 		local->ops->sw_scan_start(local_to_hw(local));
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 457238a..525d261 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -193,7 +193,14 @@ ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
 		return TX_CONTINUE;
 
 	if (unlikely(tx->local->sw_scanning) &&
-	    !ieee80211_is_probe_req(hdr->frame_control))
+	    !ieee80211_is_probe_req(hdr->frame_control) &&
+	    !ieee80211_is_nullfunc(hdr->frame_control))
+		/*
+		 * When software scanning only nullfunc frames (to notify
+		 * the sleep state to the AP) and probe requests (for the
+		 * active scan) are allowed, everything else should be
+		 * dropped. See ieee80211_start_scan() for more.
+		 */
 		return TX_DROP;
 
 	if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)

--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Host AP]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Linux Kernel]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Device Mapper]
  Powered by Linux