cfg80211: allow wiphy specific regdomain management

Add a new regulatory flag that allows a driver to manage regdomain
changes/updates for its own wiphy.
A self-managed wiphys only employs regulatory information obtained from
the FW and driver and does not use other cfg80211 sources like
beacon-hints, country-code IEs and hints from other devices on the same
system. Conversely, a self-managed wiphy does not share its regulatory
hints with other devices in the system. If a system contains several
devices, one or more of which are self-managed, there might be
contradictory regulatory settings between them. Usage of flag is
generally discouraged. Only use it if the FW/driver is incompatible
with non-locally originated hints.

A new API lets the driver send a complete regdomain, to be applied on
its wiphy only.

After a wiphy-specific regdomain change takes place, usermode will get
a new type of change notification. The regulatory core also takes care
enforce regulatory restrictions, in case some interfaces are on
forbidden channels.

Signed-off-by: Jonathan Doron <jonathanx.doron@intel.com>
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 88 insertions, 0 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 2d9760084b74..c040f8a0f1ed 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1307,6 +1307,9 @@ static bool ignore_reg_update(struct wiphy *wiphy,
 {
 	struct regulatory_request *lr = get_last_request();
 
+	if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
+		return true;
+
 	if (!lr) {
 		REG_DBG_PRINT("Ignoring regulatory request set by %s "
 			      "since last_request is not set\n",
@@ -2147,11 +2150,52 @@ static void reg_process_pending_beacon_hints(void)
 	spin_unlock_bh(&reg_pending_beacons_lock);
 }
 
+static void reg_process_self_managed_hints(void)
+{
+	struct cfg80211_registered_device *rdev;
+	struct wiphy *wiphy;
+	const struct ieee80211_regdomain *tmp;
+	const struct ieee80211_regdomain *regd;
+	enum ieee80211_band band;
+	struct regulatory_request request = {};
+
+	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+		wiphy = &rdev->wiphy;
+
+		spin_lock(&reg_requests_lock);
+		regd = rdev->requested_regd;
+		rdev->requested_regd = NULL;
+		spin_unlock(&reg_requests_lock);
+
+		if (regd == NULL)
+			continue;
+
+		tmp = get_wiphy_regdom(wiphy);
+		rcu_assign_pointer(wiphy->regd, regd);
+		rcu_free_regdom(tmp);
+
+		for (band = 0; band < IEEE80211_NUM_BANDS; band++)
+			handle_band_custom(wiphy, wiphy->bands[band], regd);
+
+		reg_process_ht_flags(wiphy);
+
+		request.wiphy_idx = get_wiphy_idx(wiphy);
+		request.alpha2[0] = regd->alpha2[0];
+		request.alpha2[1] = regd->alpha2[1];
+		request.initiator = NL80211_REGDOM_SET_BY_DRIVER;
+
+		nl80211_send_wiphy_reg_change_event(&request);
+	}
+
+	reg_check_channels();
+}
+
 static void reg_todo(struct work_struct *work)
 {
 	rtnl_lock();
 	reg_process_pending_hints();
 	reg_process_pending_beacon_hints();
+	reg_process_self_managed_hints();
 	rtnl_unlock();
 }
 
@@ -2432,6 +2476,8 @@ static void restore_regulatory_settings(bool reset_user)
 	world_alpha2[1] = cfg80211_world_regdom->alpha2[1];
 
 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+		if (rdev->wiphy.regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
+			continue;
 		if (rdev->wiphy.regulatory_flags & REGULATORY_CUSTOM_REG)
 			restore_custom_reg_settings(&rdev->wiphy);
 	}
@@ -2835,10 +2881,52 @@ int set_regdom(const struct ieee80211_regdomain *rd)
 	return 0;
 }
 
+int regulatory_set_wiphy_regd(struct wiphy *wiphy,
+			      struct ieee80211_regdomain *rd)
+{
+	const struct ieee80211_regdomain *regd;
+	const struct ieee80211_regdomain *prev_regd;
+	struct cfg80211_registered_device *rdev;
+
+	if (WARN_ON(!wiphy || !rd))
+		return -EINVAL;
+
+	if (WARN(!(wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED),
+		 "wiphy should have REGULATORY_WIPHY_SELF_MANAGED\n"))
+		return -EPERM;
+
+	if (WARN(!is_valid_rd(rd), "Invalid regulatory domain detected\n")) {
+		print_regdomain_info(rd);
+		return -EINVAL;
+	}
+
+	regd = reg_copy_regd(rd);
+	if (IS_ERR(regd))
+		return PTR_ERR(regd);
+
+	rdev = wiphy_to_rdev(wiphy);
+
+	spin_lock(&reg_requests_lock);
+	prev_regd = rdev->requested_regd;
+	rdev->requested_regd = regd;
+	spin_unlock(&reg_requests_lock);
+
+	kfree(prev_regd);
+
+	schedule_work(&reg_work);
+	return 0;
+}
+EXPORT_SYMBOL(regulatory_set_wiphy_regd);
+
 void wiphy_regulatory_register(struct wiphy *wiphy)
 {
 	struct regulatory_request *lr;
 
+	/* self-managed devices ignore external hints */
+	if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
+		wiphy->regulatory_flags |= REGULATORY_DISABLE_BEACON_HINTS |
+					   REGULATORY_COUNTRY_IE_IGNORE;
+
 	if (!reg_dev_ignore_cell_hint(wiphy))
 		reg_num_devs_support_basehint++;