nl80211/cfg80211: add radar detection command/event

Add new NL80211_CMD_RADAR_DETECT, which starts the Channel
Availability Check (CAC). This command will also notify the
usermode about events (CAC finished, CAC aborted, radar
detected, NOP finished).
Once radar detection has started it should continuously
monitor for radars as long as the channel is active.

This patch enables DFS for AP mode in nl80211/cfg80211.

Based on original patch by Victor Goldenshtein <victorg@ti.com>

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
[remove WIPHY_FLAG_HAS_RADAR_DETECT again -- my mistake]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 61 insertions, 0 deletions

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 5309b34930e..90b7af86f39 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -603,6 +603,14 @@
  *	command is used in AP/P2P GO mode. Driver has to make sure to clear its
  *	ACL list during %NL80211_CMD_STOP_AP.
  *
+ * @NL80211_CMD_RADAR_DETECT: Start a Channel availability check (CAC). Once
+ *	a radar is detected or the channel availability scan (CAC) has finished
+ *	or was aborted, or a radar was detected, usermode will be notified with
+ *	this event. This command is also used to notify userspace about radars
+ *	while operating on this channel.
+ *	%NL80211_ATTR_RADAR_EVENT is used to inform about the type of the
+ *	event.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -755,6 +763,8 @@ enum nl80211_commands {
 
 	NL80211_CMD_SET_MAC_ACL,
 
+	NL80211_CMD_RADAR_DETECT,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */
@@ -1342,6 +1352,9 @@ enum nl80211_commands {
  *	number of MAC addresses that a device can support for MAC
  *	ACL.
  *
+ * @NL80211_ATTR_RADAR_EVENT: Type of radar event for notification to userspace,
+ *	contains a value of enum nl80211_radar_event (u32).
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -1620,6 +1633,8 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_MAC_ACL_MAX,
 
+	NL80211_ATTR_RADAR_EVENT,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -2022,6 +2037,10 @@ enum nl80211_band_attr {
  *	on this channel in current regulatory domain.
  * @NL80211_FREQUENCY_ATTR_MAX_TX_POWER: Maximum transmission power in mBm
  *	(100 * dBm).
+ * @NL80211_FREQUENCY_ATTR_DFS_STATE: current state for DFS
+ *	(enum nl80211_dfs_state)
+ * @NL80211_FREQUENCY_ATTR_DFS_TIME: time in miliseconds for how long
+ *	this channel is in this DFS state.
  * @NL80211_FREQUENCY_ATTR_MAX: highest frequency attribute number
  *	currently defined
  * @__NL80211_FREQUENCY_ATTR_AFTER_LAST: internal use
@@ -2034,6 +2053,8 @@ enum nl80211_frequency_attr {
 	NL80211_FREQUENCY_ATTR_NO_IBSS,
 	NL80211_FREQUENCY_ATTR_RADAR,
 	NL80211_FREQUENCY_ATTR_MAX_TX_POWER,
+	NL80211_FREQUENCY_ATTR_DFS_STATE,
+	NL80211_FREQUENCY_ATTR_DFS_TIME,
 
 	/* keep last */
 	__NL80211_FREQUENCY_ATTR_AFTER_LAST,
@@ -3489,4 +3510,44 @@ enum nl80211_acl_policy {
 	NL80211_ACL_POLICY_DENY_UNLESS_LISTED,
 };
 
+/**
+ * enum nl80211_radar_event - type of radar event for DFS operation
+ *
+ * Type of event to be used with NL80211_ATTR_RADAR_EVENT to inform userspace
+ * about detected radars or success of the channel available check (CAC)
+ *
+ * @NL80211_RADAR_DETECTED: A radar pattern has been detected. The channel is
+ *	now unusable.
+ * @NL80211_RADAR_CAC_FINISHED: Channel Availability Check has been finished,
+ *	the channel is now available.
+ * @NL80211_RADAR_CAC_ABORTED: Channel Availability Check has been aborted, no
+ *	change to the channel status.
+ * @NL80211_RADAR_NOP_FINISHED: The Non-Occupancy Period for this channel is
+ *	over, channel becomes usable.
+ */
+enum nl80211_radar_event {
+	NL80211_RADAR_DETECTED,
+	NL80211_RADAR_CAC_FINISHED,
+	NL80211_RADAR_CAC_ABORTED,
+	NL80211_RADAR_NOP_FINISHED,
+};
+
+/**
+ * enum nl80211_dfs_state - DFS states for channels
+ *
+ * Channel states used by the DFS code.
+ *
+ * @IEEE80211_DFS_USABLE: The channel can be used, but channel availability
+ *	check (CAC) must be performed before using it for AP or IBSS.
+ * @IEEE80211_DFS_UNAVAILABLE: A radar has been detected on this channel, it
+ *	is therefore marked as not available.
+ * @IEEE80211_DFS_AVAILABLE: The channel has been CAC checked and is available.
+ */
+
+enum nl80211_dfs_state {
+	NL80211_DFS_USABLE,
+	NL80211_DFS_UNAVAILABLE,
+	NL80211_DFS_AVAILABLE,
+};
+
 #endif /* __LINUX_NL80211_H */