cfg80211: support reloading regulatory database

If the regulatory database is loaded, and then updated, it may
be necessary to reload it. Add an nl80211 command to do this.

Note that this just reloads the database, it doesn't re-apply
the rules from it immediately.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 60 insertions, 20 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index e9aeb05aaf3e..180addda52af 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -781,6 +781,8 @@ static int query_regdb(const char *alpha2)
 	const struct fwdb_header *hdr = regdb;
 	const struct fwdb_country *country;
 
+	ASSERT_RTNL();
+
 	if (IS_ERR(regdb))
 		return PTR_ERR(regdb);
 
@@ -796,41 +798,47 @@ static int query_regdb(const char *alpha2)
 
 static void regdb_fw_cb(const struct firmware *fw, void *context)
 {
+	int set_error = 0;
+	bool restore = true;
 	void *db;
 
 	if (!fw) {
 		pr_info("failed to load regulatory.db\n");
-		regdb = ERR_PTR(-ENODATA);
-		goto restore;
-	}
-
-	if (!valid_regdb(fw->data, fw->size)) {
+		set_error = -ENODATA;
+	} else if (!valid_regdb(fw->data, fw->size)) {
 		pr_info("loaded regulatory.db is malformed\n");
-		release_firmware(fw);
-		regdb = ERR_PTR(-EINVAL);
-		goto restore;
+		set_error = -EINVAL;
 	}
 
-	db = kmemdup(fw->data, fw->size, GFP_KERNEL);
-	release_firmware(fw);
+	rtnl_lock();
+	if (WARN_ON(regdb && !IS_ERR(regdb))) {
+		/* just restore and free new db */
+	} else if (set_error) {
+		regdb = ERR_PTR(set_error);
+	} else if (fw) {
+		db = kmemdup(fw->data, fw->size, GFP_KERNEL);
+		if (db) {
+			regdb = db;
+			restore = context && query_regdb(context);
+		} else {
+			restore = true;
+		}
+	}
 
-	if (!db)
-		goto restore;
-	regdb = db;
+	if (restore)
+		restore_regulatory_settings(true);
 
-	if (query_regdb(context))
-		goto restore;
-	goto free;
- restore:
-	rtnl_lock();
-	restore_regulatory_settings(true);
 	rtnl_unlock();
- free:
+
 	kfree(context);
+
+	release_firmware(fw);
 }
 
 static int query_regdb_file(const char *alpha2)
 {
+	ASSERT_RTNL();
+
 	if (regdb)
 		return query_regdb(alpha2);
 
@@ -843,6 +851,38 @@ static int query_regdb_file(const char *alpha2)
 				       (void *)alpha2, regdb_fw_cb);
 }
 
+int reg_reload_regdb(void)
+{
+	const struct firmware *fw;
+	void *db;
+	int err;
+
+	err = request_firmware(&fw, "regulatory.db", &reg_pdev->dev);
+	if (err)
+		return err;
+
+	if (!valid_regdb(fw->data, fw->size)) {
+		err = -ENODATA;
+		goto out;
+	}
+
+	db = kmemdup(fw->data, fw->size, GFP_KERNEL);
+	if (!db) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	rtnl_lock();
+	if (!IS_ERR_OR_NULL(regdb))
+		kfree(regdb);
+	regdb = db;
+	rtnl_unlock();
+
+ out:
+	release_firmware(fw);
+	return err;
+}
+
 static bool reg_query_database(struct regulatory_request *request)
 {
 	/* query internal regulatory database (if it exists) */