mac80211_hwsim: Group radios

Currently all radios receive all traffic on the simulated air
if they are tuned to the same channel. This patch introduces
the concept of grouping, which allows to assign a radio to
certain group. Only radios in the same group can 'see' each other.

Each bit in /debug/ieee80211/phy*/hwsim/group
represents one group. By default all radios belong to the same group "1",
e.g. bit 1 is set. Additionally a radio can belong to several groups.
Signed-off-by: Daniel Wagner <wagi@monom.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -291,6 +291,14 @@ struct mac80211_hwsim_data {
 	bool ps_poll_pending;
 	struct dentry *debugfs;
 	struct dentry *debugfs_ps;
+
+	/*
+	 * Only radios in the same group can communicate together (the
+	 * channel has to match too). Each bit represents a group. A
+	 * radio can be in more then one group.
+	 */
+	u64 group;
+	struct dentry *debugfs_group;
 };
 
 
@@ -412,7 +420,8 @@ static bool mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
 
 		if (!data2->started || !data2->radio_enabled ||
 		    !hwsim_ps_rx_ok(data2, skb) ||
-		    data->channel->center_freq != data2->channel->center_freq)
+		    data->channel->center_freq != data2->channel->center_freq ||
+		    !(data->group & data2->group))
 			continue;
 
 		nskb = skb_copy(skb, GFP_ATOMIC);
@@ -720,6 +729,7 @@ static void mac80211_hwsim_free(void)
 	spin_unlock_bh(&hwsim_radio_lock);
 
 	list_for_each_entry(data, &tmplist, list) {
+		debugfs_remove(data->debugfs_group);
 		debugfs_remove(data->debugfs_ps);
 		debugfs_remove(data->debugfs);
 		ieee80211_unregister_hw(data->hw);
@@ -872,6 +882,24 @@ DEFINE_SIMPLE_ATTRIBUTE(hwsim_fops_ps, hwsim_fops_ps_read, hwsim_fops_ps_write,
 			"%llu\n");
 
 
+static int hwsim_fops_group_read(void *dat, u64 *val)
+{
+	struct mac80211_hwsim_data *data = dat;
+	*val = data->group;
+	return 0;
+}
+
+static int hwsim_fops_group_write(void *dat, u64 val)
+{
+	struct mac80211_hwsim_data *data = dat;
+	data->group = val;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(hwsim_fops_group,
+			hwsim_fops_group_read, hwsim_fops_group_write,
+			"%llx\n");
+
 static int __init init_mac80211_hwsim(void)
 {
 	int i, err = 0;
@@ -976,6 +1004,8 @@ static int __init init_mac80211_hwsim(void)
 
 			hw->wiphy->bands[band] = sband;
 		}
+		/* By default all radios are belonging to the first group */
+		data->group = 1;
 
 		/* Work to be done prior to ieee80211_register_hw() */
 		switch (regtest) {
@@ -1100,6 +1130,9 @@ static int __init init_mac80211_hwsim(void)
 		data->debugfs_ps = debugfs_create_file("ps", 0666,
 						       data->debugfs, data,
 						       &hwsim_fops_ps);
+		data->debugfs_group = debugfs_create_file("group", 0666,
+							data->debugfs, data,
+							&hwsim_fops_group);
 
 		setup_timer(&data->beacon_timer, mac80211_hwsim_beacon,
 			    (unsigned long) hw);