nl80211: Add CONTROL_PORT_OVER_NL80211 attribute

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -647,6 +647,8 @@ struct survey_info {
  *	allowed through even on unauthorized ports
  * @control_port_no_encrypt: TRUE to prevent encryption of control port
  *	protocol frames.
+ * @control_port_over_nl80211: TRUE if userspace expects to exchange control
+ *	port frames over NL80211 instead of the network interface.
  * @wep_keys: static WEP keys, if not NULL points to an array of
  *	CFG80211_MAX_WEP_KEYS WEP keys
  * @wep_tx_key: key index (0..3) of the default TX static WEP key
@@ -662,6 +664,7 @@ struct cfg80211_crypto_settings {
 	bool control_port;
 	__be16 control_port_ethertype;
 	bool control_port_no_encrypt;
+	bool control_port_over_nl80211;
 	struct key_params *wep_keys;
 	int wep_tx_key;
 	const u8 *psk;

include/uapi/linux/nl80211.h

@@ -542,7 +542,8 @@
  *	IEs in %NL80211_ATTR_IE, %NL80211_ATTR_AUTH_TYPE, %NL80211_ATTR_USE_MFP,
  *	%NL80211_ATTR_MAC, %NL80211_ATTR_WIPHY_FREQ, %NL80211_ATTR_CONTROL_PORT,
  *	%NL80211_ATTR_CONTROL_PORT_ETHERTYPE,
- *	%NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT, %NL80211_ATTR_MAC_HINT, and
+ *	%NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT,
+ *	%NL80211_ATTR_CONTROL_PORT_OVER_NL80211, %NL80211_ATTR_MAC_HINT, and
  *	%NL80211_ATTR_WIPHY_FREQ_HINT.
  *	If included, %NL80211_ATTR_MAC and %NL80211_ATTR_WIPHY_FREQ are
  *	restrictions on BSS selection, i.e., they effectively prevent roaming
@@ -1488,6 +1489,15 @@ enum nl80211_commands {
  * @NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT: When included along with
  *	%NL80211_ATTR_CONTROL_PORT_ETHERTYPE, indicates that the custom
  *	ethertype frames used for key negotiation must not be encrypted.
+ * @NL80211_ATTR_CONTROL_PORT_OVER_NL80211: A flag indicating whether control
+ *	port frames (e.g. of type given in %NL80211_ATTR_CONTROL_PORT_ETHERTYPE)
+ *	will be sent directly to the network interface or sent via the NL80211
+ *	socket.  If this attribute is missing, then legacy behavior of sending
+ *	control port frames directly to the network interface is used.  If the
+ *	flag is included, then control port frames are sent over NL80211 instead
+ *	using %CMD_CONTROL_PORT_FRAME.  If control port routing over NL80211 is
+ *	to be used then userspace must also use the %NL80211_ATTR_SOCKET_OWNER
+ *	flag.
  *
  * @NL80211_ATTR_TESTDATA: Testmode data blob, passed through to the driver.
  *	We recommend using nested, driver-specific attributes within this.
@@ -2647,6 +2657,8 @@ enum nl80211_attrs {
 	NL80211_ATTR_NSS,
 	NL80211_ATTR_ACK_SIGNAL,
 
+	NL80211_ATTR_CONTROL_PORT_OVER_NL80211,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,

net/wireless/nl80211.c

@@ -287,6 +287,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_CONTROL_PORT] = { .type = NLA_FLAG },
 	[NL80211_ATTR_CONTROL_PORT_ETHERTYPE] = { .type = NLA_U16 },
 	[NL80211_ATTR_CONTROL_PORT_NO_ENCRYPT] = { .type = NLA_FLAG },
+	[NL80211_ATTR_CONTROL_PORT_OVER_NL80211] = { .type = NLA_FLAG },
 	[NL80211_ATTR_PRIVACY] = { .type = NLA_FLAG },
 	[NL80211_ATTR_CIPHER_SUITE_GROUP] = { .type = NLA_U32 },
 	[NL80211_ATTR_WPA_VERSIONS] = { .type = NLA_U32 },
@@ -8211,6 +8212,22 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+static int validate_pae_over_nl80211(struct cfg80211_registered_device *rdev,
+				     struct genl_info *info)
+{
+	if (!info->attrs[NL80211_ATTR_SOCKET_OWNER]) {
+		GENL_SET_ERR_MSG(info, "SOCKET_OWNER not set");
+		return -EINVAL;
+	}
+
+	if (!rdev->ops->tx_control_port ||
+	    !wiphy_ext_feature_isset(&rdev->wiphy,
+				     NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211))
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
 static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
 				   struct genl_info *info,
 				   struct cfg80211_crypto_settings *settings,
@@ -8234,6 +8251,15 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
 	} else
 		settings->control_port_ethertype = cpu_to_be16(ETH_P_PAE);
 
+	if (info->attrs[NL80211_ATTR_CONTROL_PORT_OVER_NL80211]) {
+		int r = validate_pae_over_nl80211(rdev, info);
+
+		if (r < 0)
+			return r;
+
+		settings->control_port_over_nl80211 = true;
+	}
+
 	if (info->attrs[NL80211_ATTR_CIPHER_SUITES_PAIRWISE]) {
 		void *data;
 		int len, i;