iwlwifi : Set monitor mode for 4965

The patch leverages mac80211 configure_filter to enable iwl4965
monitor mode.

Signed-off-by: Abhijeet Kolekar <abhijeet.kolekar@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index f56b9a9..866a93e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -2617,7 +2617,9 @@
 		rx_start->byte_count = amsdu->byte_count;
 		rx_end = (__le32 *) (((u8 *) hdr) + len);
 	}
-	if (len > priv->hw_params.max_pkt_size || len < 16) {
+	/* In monitor mode allow 802.11 ACk frames (10 bytes) */
+	if (len > priv->hw_params.max_pkt_size ||
+	    len < ((priv->iw_mode == IEEE80211_IF_TYPE_MNTR) ? 10 : 16)) {
 		IWL_WARNING("byte count out of range [16,4K] : %d\n", len);
 		return;
 	}
@@ -2989,6 +2991,13 @@
 			      rx_status.ssi, rx_status.noise, rx_status.signal,
 			      (unsigned long long)rx_status.mactime);
 
+
+	if (priv->iw_mode == IEEE80211_IF_TYPE_MNTR) {
+		iwl4965_handle_data_packet(priv, 1, include_phy,
+						 rxb, &rx_status);
+		return;
+	}
+
 	network_packet = iwl4965_is_network_packet(priv, header);
 	if (network_packet) {
 		priv->last_rx_rssi = rx_status.ssi;