nl/cfg80211: add the NL80211_CMD_SET_MCAST_RATE command

This command triggers a new callback: set_mcast_rate(). It enables
the user to change the rate used to send multicast frames for vif
configured as IBSS or MESH_POINT
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -1545,6 +1545,9 @@ struct cfg80211_gtk_rekey_data {
  *	to a merge.
  * @leave_ibss: Leave the IBSS.
  *
+ * @set_mcast_rate: Set the specified multicast rate (only if vif is in ADHOC or
+ *	MESH mode)
+ *
  * @set_wiphy_params: Notify that wiphy parameters have changed;
  *	@changed bitfield (see &enum wiphy_params_flags) describes which values
  *	have changed. The actual parameter values are available in
@@ -1749,6 +1752,9 @@ struct cfg80211_ops {
 			     struct cfg80211_ibss_params *params);
 	int	(*leave_ibss)(struct wiphy *wiphy, struct net_device *dev);
 
+	int	(*set_mcast_rate)(struct wiphy *wiphy, struct net_device *dev,
+				  int rate[IEEE80211_NUM_BANDS]);
+
 	int	(*set_wiphy_params)(struct wiphy *wiphy, u32 changed);
 
 	int	(*set_tx_power)(struct wiphy *wiphy, struct wireless_dev *wdev,

include/uapi/linux/nl80211.h

@@ -578,6 +578,9 @@
  *	station, due to particular reason. %NL80211_ATTR_CONN_FAILED_REASON
  *	is used for this.
  *
+ * @NL80211_CMD_SET_MCAST_RATE: Change the rate used to send multicast frames
+ *	for IBSS or MESH vif.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -726,6 +729,8 @@ enum nl80211_commands {
 
 	NL80211_CMD_CONN_FAILED,
 
+	NL80211_CMD_SET_MCAST_RATE,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */

net/wireless/nl80211.c

@@ -1110,6 +1110,7 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 portid, u32 seq, int flag
 			goto nla_put_failure;
 	}
 	CMD(start_p2p_device, START_P2P_DEVICE);
+	CMD(set_mcast_rate, SET_MCAST_RATE);
 
 #ifdef CONFIG_NL80211_TESTMODE
 	CMD(testmode_cmd, TESTMODE);
@@ -5448,6 +5449,36 @@ static int nl80211_leave_ibss(struct sk_buff *skb, struct genl_info *info)
 	return cfg80211_leave_ibss(rdev, dev, false);
 }
 
+static int nl80211_set_mcast_rate(struct sk_buff *skb, struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	int mcast_rate[IEEE80211_NUM_BANDS];
+	u32 nla_rate;
+	int err;
+
+	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_ADHOC &&
+	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
+		return -EOPNOTSUPP;
+
+	if (!rdev->ops->set_mcast_rate)
+		return -EOPNOTSUPP;
+
+	memset(mcast_rate, 0, sizeof(mcast_rate));
+
+	if (!info->attrs[NL80211_ATTR_MCAST_RATE])
+		return -EINVAL;
+
+	nla_rate = nla_get_u32(info->attrs[NL80211_ATTR_MCAST_RATE]);
+	if (!nl80211_parse_mcast_rate(rdev, mcast_rate, nla_rate))
+		return -EINVAL;
+
+	err = rdev->ops->set_mcast_rate(&rdev->wiphy, dev, mcast_rate);
+
+	return err;
+}
+
+
 #ifdef CONFIG_NL80211_TESTMODE
 static struct genl_multicast_group nl80211_testmode_mcgrp = {
 	.name = "testmode",
@@ -7629,6 +7660,14 @@ static struct genl_ops nl80211_ops[] = {
 		.internal_flags = NL80211_FLAG_NEED_WDEV_UP |
 				  NL80211_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL80211_CMD_SET_MCAST_RATE,
+		.doit = nl80211_set_mcast_rate,
+		.policy = nl80211_policy,
+		.flags = GENL_ADMIN_PERM,
+		.internal_flags = NL80211_FLAG_NEED_NETDEV |
+				  NL80211_FLAG_NEED_RTNL,
+	},
 };
 
 static struct genl_multicast_group nl80211_mlme_mcgrp = {