ath9k: Set BSSID mask based on configured interfaces

Instead of using a hardcoded BSSID mask (mask for own addresses),
iterate through all active interfaces and determine the minimal mask
that covers all local addresses.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/virtual.c b/drivers/net/wireless/ath9k/virtual.c
new file mode 100644
index 0000000..52d5021
--- /dev/null
+++ b/drivers/net/wireless/ath9k/virtual.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2008-2009 Atheros Communications Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ath9k.h"
+
+struct ath9k_vif_iter_data {
+	int count;
+	u8 *addr;
+};
+
+static void ath9k_vif_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
+{
+	struct ath9k_vif_iter_data *iter_data = data;
+	u8 *nbuf;
+
+	nbuf = krealloc(iter_data->addr, (iter_data->count + 1) * ETH_ALEN,
+			GFP_ATOMIC);
+	if (nbuf == NULL)
+		return;
+
+	memcpy(nbuf + iter_data->count * ETH_ALEN, mac, ETH_ALEN);
+	iter_data->addr = nbuf;
+	iter_data->count++;
+}
+
+void ath9k_set_bssid_mask(struct ieee80211_hw *hw)
+{
+	struct ath_softc *sc = hw->priv;
+	struct ath9k_vif_iter_data iter_data;
+	int i, j;
+	u8 mask[ETH_ALEN];
+
+	/*
+	 * Add primary MAC address even if it is not in active use since it
+	 * will be configured to the hardware as the starting point and the
+	 * BSSID mask will need to be changed if another address is active.
+	 */
+	iter_data.addr = kmalloc(ETH_ALEN, GFP_ATOMIC);
+	if (iter_data.addr) {
+		memcpy(iter_data.addr, sc->sc_ah->macaddr, ETH_ALEN);
+		iter_data.count = 1;
+	} else
+		iter_data.count = 0;
+
+	/* Get list of all active MAC addresses */
+	ieee80211_iterate_active_interfaces_atomic(hw, ath9k_vif_iter,
+						   &iter_data);
+
+	/* Generate an address mask to cover all active addresses */
+	memset(mask, 0, ETH_ALEN);
+	for (i = 0; i < iter_data.count; i++) {
+		u8 *a1 = iter_data.addr + i * ETH_ALEN;
+		for (j = i + 1; j < iter_data.count; j++) {
+			u8 *a2 = iter_data.addr + j * ETH_ALEN;
+			mask[0] |= a1[0] ^ a2[0];
+			mask[1] |= a1[1] ^ a2[1];
+			mask[2] |= a1[2] ^ a2[2];
+			mask[3] |= a1[3] ^ a2[3];
+			mask[4] |= a1[4] ^ a2[4];
+			mask[5] |= a1[5] ^ a2[5];
+		}
+	}
+
+	kfree(iter_data.addr);
+
+	/* Invert the mask and configure hardware */
+	sc->bssidmask[0] = ~mask[0];
+	sc->bssidmask[1] = ~mask[1];
+	sc->bssidmask[2] = ~mask[2];
+	sc->bssidmask[3] = ~mask[3];
+	sc->bssidmask[4] = ~mask[4];
+	sc->bssidmask[5] = ~mask[5];
+
+	ath9k_hw_setbssidmask(sc);
+}