cfg80211: Support multiple CSA counters

Change the type of NL80211_ATTR_CSA_C_OFF_BEACON and
NL80211_ATTR_CSA_C_OFF_PRESP to be NLA_BINARY which allows
userspace to use beacons and probe responses with
multiple CSA counters.
This isn't breaking the API since userspace can
continue to use nla_put_u16 for this attributes, which
is equivalent to a single element u16 array.
In addition advertise max number of supported CSA counters.
This is needed when using CSA and eCSA IEs together.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 22 insertions, 7 deletions

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index f46e1e15746d..447cb58f0d77 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -694,8 +694,10 @@ struct cfg80211_ap_settings {
  *
  * @chandef: defines the channel to use after the switch
  * @beacon_csa: beacon data while performing the switch
- * @counter_offset_beacon: offset for the counter within the beacon (tail)
- * @counter_offset_presp: offset for the counter within the probe response
+ * @counter_offsets_beacon: offsets of the counters within the beacon (tail)
+ * @counter_offsets_presp: offsets of the counters within the probe response
+ * @n_counter_offsets_beacon: number of csa counters the beacon (tail)
+ * @n_counter_offsets_presp: number of csa counters in the probe response
  * @beacon_after: beacon data to be used on the new channel
  * @radar_required: whether radar detection is required on the new channel
  * @block_tx: whether transmissions should be blocked while changing
@@ -704,7 +706,10 @@ struct cfg80211_ap_settings {
 struct cfg80211_csa_settings {
 	struct cfg80211_chan_def chandef;
 	struct cfg80211_beacon_data beacon_csa;
-	u16 counter_offset_beacon, counter_offset_presp;
+	const u16 *counter_offsets_beacon;
+	const u16 *counter_offsets_presp;
+	unsigned int n_counter_offsets_beacon;
+	unsigned int n_counter_offsets_presp;
 	struct cfg80211_beacon_data beacon_after;
 	bool radar_required;
 	bool block_tx;
@@ -3048,6 +3053,13 @@ struct wiphy {
 
 	u16 max_ap_assoc_sta;
 
+	/*
+	 * Number of supported csa_counters in beacons and probe responses.
+	 * This value should be set if the driver wishes to limit the number of
+	 * csa counters. Default (0) means infinite.
+	 */
+	u8 max_num_csa_counters;
+
 	char priv[0] __aligned(NETDEV_ALIGN);
 };
 
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index ec90fc9d2358..0cfa827123ff 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1528,10 +1528,10 @@ enum nl80211_commands {
  *	operation).
  * @NL80211_ATTR_CSA_IES: Nested set of attributes containing the IE information
  *	for the time while performing a channel switch.
- * @NL80211_ATTR_CSA_C_OFF_BEACON: Offset of the channel switch counter
- *	field in the beacons tail (%NL80211_ATTR_BEACON_TAIL).
- * @NL80211_ATTR_CSA_C_OFF_PRESP: Offset of the channel switch counter
- *	field in the probe response (%NL80211_ATTR_PROBE_RESP).
+ * @NL80211_ATTR_CSA_C_OFF_BEACON: An array of offsets (u16) to the channel
+ *	switch counters in the beacons tail (%NL80211_ATTR_BEACON_TAIL).
+ * @NL80211_ATTR_CSA_C_OFF_PRESP: An array of offsets (u16) to the channel
+ *	switch counters in the probe response (%NL80211_ATTR_PROBE_RESP).
  *
  * @NL80211_ATTR_RXMGMT_FLAGS: flags for nl80211_send_mgmt(), u32.
  *	As specified in the &enum nl80211_rxmgmt_flags.
@@ -1581,6 +1581,8 @@ enum nl80211_commands {
  *
  * @NL80211_ATTR_CSA_C_OFFSETS_TX: An array of csa counter offsets (u16) which
  *	should be updated when the frame is transmitted.
+ * @NL80211_ATTR_MAX_CSA_COUNTERS: U8 attribute used to advertise the maximum
+ *	supported number of csa counters.
  *
  * @NL80211_ATTR_TDLS_PEER_CAPABILITY: flags for TDLS peer capabilities, u32.
  *	As specified in the &enum nl80211_tdls_peer_capability.
@@ -1927,6 +1929,7 @@ enum nl80211_attrs {
 	NL80211_ATTR_IFACE_SOCKET_OWNER,
 
 	NL80211_ATTR_CSA_C_OFFSETS_TX,
+	NL80211_ATTR_MAX_CSA_COUNTERS,
 
 	/* add attributes here, update the policy in nl80211.c */