commit 57b5ce072e7361218a8e2ea1d62960cbb71d9cff
author Luis R. Rodriguez <mcgrof@qca.qualcomm.com> Thu Jul 12 11:49:18 2012 -0700
committer Johannes Berg <johannes.berg@intel.com> Tue Jul 17 12:16:39 2012 +0200
tree c00265b8f2123f860978d293fa122427ea2139f8
parent b594bab9021f5225a24bcb69d7f7b7272419adb2

cfg80211: add cellular base station regulatory hint support

Cellular base stations can provide hints to cfg80211 about
where they think we are. This can be done for example on
a cell phone. To enable these hints we simply allow them
through as user regulatory hints but we allow userspace
to clasify the hint as either coming directly from the
user or coming from a cellular base station. This option
is only available when you enable
CONFIG_CFG80211_CERTIFICATION_ONUS.

The base station hints themselves will not be processed
by the core unless at least one device on the system
supports this feature.

Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/reg.c

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index ad6f9029..83583a9 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -97,9 +97,16 @@
  *     - cfg80211_world_regdom
  *     - cfg80211_regdom
  *     - last_request
+ *     - reg_num_devs_support_basehint
  */
 static DEFINE_MUTEX(reg_mutex);
 
+/*
+ * Number of devices that registered to the core
+ * that support cellular base station regulatory hints
+ */
+static int reg_num_devs_support_basehint;
+
 static inline void assert_reg_lock(void)
 {
 	lockdep_assert_held(&reg_mutex);
@@ -911,6 +918,59 @@
 		handle_channel(wiphy, initiator, band, i);
 }
 
+static bool reg_request_cell_base(struct regulatory_request *request)
+{
+	if (request->initiator != NL80211_REGDOM_SET_BY_USER)
+		return false;
+	if (request->user_reg_hint_type != NL80211_USER_REG_HINT_CELL_BASE)
+		return false;
+	return true;
+}
+
+bool reg_last_request_cell_base(void)
+{
+	assert_cfg80211_lock();
+
+	mutex_lock(&reg_mutex);
+	return reg_request_cell_base(last_request);
+	mutex_unlock(&reg_mutex);
+}
+
+#ifdef CONFIG_CFG80211_CERTIFICATION_ONUS
+
+/* Core specific check */
+static int reg_ignore_cell_hint(struct regulatory_request *pending_request)
+{
+	if (!reg_num_devs_support_basehint)
+		return -EOPNOTSUPP;
+
+	if (reg_request_cell_base(last_request)) {
+		if (!regdom_changes(pending_request->alpha2))
+			return -EALREADY;
+		return 0;
+	}
+	return 0;
+}
+
+/* Device specific check */
+static bool reg_dev_ignore_cell_hint(struct wiphy *wiphy)
+{
+	if (!(wiphy->features & NL80211_FEATURE_CELL_BASE_REG_HINTS))
+		return true;
+	return false;
+}
+#else
+static int reg_ignore_cell_hint(struct regulatory_request *pending_request)
+{
+	return -EOPNOTSUPP;
+}
+static int reg_dev_ignore_cell_hint(struct wiphy *wiphy)
+{
+	return true;
+}
+#endif
+
+
 static bool ignore_reg_update(struct wiphy *wiphy,
 			      enum nl80211_reg_initiator initiator)
 {
@@ -944,6 +1004,9 @@
 		return true;
 	}
 
+	if (reg_request_cell_base(last_request))
+		return reg_dev_ignore_cell_hint(wiphy);
+
 	return false;
 }
 
@@ -1307,6 +1370,13 @@
 		return 0;
 	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
 
+		if (reg_request_cell_base(last_request)) {
+			/* Trust a Cell base station over the AP's country IE */
+			if (regdom_changes(pending_request->alpha2))
+				return -EOPNOTSUPP;
+			return -EALREADY;
+		}
+
 		last_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
 
 		if (unlikely(!is_an_alpha2(pending_request->alpha2)))
@@ -1351,6 +1421,12 @@
 
 		return REG_INTERSECT;
 	case NL80211_REGDOM_SET_BY_USER:
+		if (reg_request_cell_base(pending_request))
+			return reg_ignore_cell_hint(pending_request);
+
+		if (reg_request_cell_base(last_request))
+			return -EOPNOTSUPP;
+
 		if (last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)
 			return REG_INTERSECT;
 		/*
@@ -1640,7 +1716,8 @@
 }
 
 /* User hints */
-int regulatory_hint_user(const char *alpha2)
+int regulatory_hint_user(const char *alpha2,
+			 enum nl80211_user_reg_hint_type user_reg_hint_type)
 {
 	struct regulatory_request *request;
 
@@ -1654,6 +1731,7 @@
 	request->alpha2[0] = alpha2[0];
 	request->alpha2[1] = alpha2[1];
 	request->initiator = NL80211_REGDOM_SET_BY_USER;
+	request->user_reg_hint_type = user_reg_hint_type;
 
 	queue_regulatory_request(request);
 
@@ -1906,7 +1984,7 @@
 	 * settings, user regulatory settings takes precedence.
 	 */
 	if (is_an_alpha2(alpha2))
-		regulatory_hint_user(user_alpha2);
+		regulatory_hint_user(user_alpha2, NL80211_USER_REG_HINT_USER);
 
 	if (list_empty(&tmp_reg_req_list))
 		return;
@@ -2081,9 +2159,16 @@
 	else {
 		if (is_unknown_alpha2(rd->alpha2))
 			pr_info("Regulatory domain changed to driver built-in settings (unknown country)\n");
-		else
-			pr_info("Regulatory domain changed to country: %c%c\n",
-				rd->alpha2[0], rd->alpha2[1]);
+		else {
+			if (reg_request_cell_base(last_request))
+				pr_info("Regulatory domain changed "
+					"to country: %c%c by Cell Station\n",
+					rd->alpha2[0], rd->alpha2[1]);
+			else
+				pr_info("Regulatory domain changed "
+					"to country: %c%c\n",
+					rd->alpha2[0], rd->alpha2[1]);
+		}
 	}
 	print_dfs_region(rd->dfs_region);
 	print_rd_rules(rd);
@@ -2293,6 +2378,18 @@
 }
 #endif /* CONFIG_HOTPLUG */
 
+void wiphy_regulatory_register(struct wiphy *wiphy)
+{
+	assert_cfg80211_lock();
+
+	mutex_lock(&reg_mutex);
+
+	if (!reg_dev_ignore_cell_hint(wiphy))
+		reg_num_devs_support_basehint++;
+
+	mutex_unlock(&reg_mutex);
+}
+
 /* Caller must hold cfg80211_mutex */
 void reg_device_remove(struct wiphy *wiphy)
 {
@@ -2302,6 +2399,9 @@
 
 	mutex_lock(&reg_mutex);
 
+	if (!reg_dev_ignore_cell_hint(wiphy))
+		reg_num_devs_support_basehint--;
+
 	kfree(wiphy->regd);
 
 	if (last_request)
@@ -2367,7 +2467,8 @@
 	 * as a user hint.
 	 */
 	if (!is_world_regdom(ieee80211_regdom))
-		regulatory_hint_user(ieee80211_regdom);
+		regulatory_hint_user(ieee80211_regdom,
+				     NL80211_USER_REG_HINT_USER);
 
 	return 0;
 }