Add ban management routines to Lua API

Those functions are:
 * minetest.get_ban_list()
 * minetest.get_ban_description(ip_or_name)
 * minetest.ban_player(name)
 * minetest.unban_player_or_ip(ip_or_name)

doc/lua_api.txt

@@ -932,6 +932,12 @@ Server:
 minetest.request_shutdown() -> request for server shutdown
 minetest.get_server_status() -> server status string
 
+Bans:
+minetest.get_ban_list() -> ban list (same as minetest.get_ban_description(""))
+minetest.get_ban_description(ip_or_name) -> ban description (string)
+minetest.ban_player(name) -> ban a player
+minetest.unban_player_or_ip(name) -> unban player or IP address
+
 Random:
 minetest.get_connected_players() -> list of ObjectRefs
 minetest.hash_node_position({x=,y=,z=}) -> 48-bit integer

src/scriptapi.cpp

@@ -4584,6 +4584,56 @@ static int l_get_player_privs(lua_State *L)
 	return 1;
 }
 
+// get_ban_list()
+static int l_get_ban_list(lua_State *L)
+{
+	lua_pushstring(L, get_server(L)->getBanDescription("").c_str());
+	return 1;
+}
+
+// get_ban_description()
+static int l_get_ban_description(lua_State *L)
+{
+	const char * ip_or_name = luaL_checkstring(L, 1);
+	lua_pushstring(L, get_server(L)->getBanDescription(std::string(ip_or_name)).c_str());
+	return 1;
+}
+
+// ban_player()
+static int l_ban_player(lua_State *L)
+{
+	const char * name = luaL_checkstring(L, 1);
+	Player *player = get_env(L)->getPlayer(name);
+	if(player == NULL)
+	{
+		lua_pushboolean(L, false); // no such player
+		return 1;
+	}
+	try
+	{
+		Address addr = get_server(L)->getPeerAddress(get_env(L)->getPlayer(name)->peer_id);
+		std::string ip_str = addr.serializeString();
+		get_server(L)->setIpBanned(ip_str, name);
+	}
+	catch(con::PeerNotFoundException) // unlikely
+	{
+		dstream << __FUNCTION_NAME << ": peer was not found" << std::endl;
+		lua_pushboolean(L, false); // error
+		return 1;
+	}
+	lua_pushboolean(L, true);
+	return 1;
+}
+
+// unban_player_or_ip()
+static int l_unban_player_of_ip(lua_State *L)
+{
+	const char * ip_or_name = luaL_checkstring(L, 1);
+	get_server(L)->unsetIpBanned(ip_or_name);
+	lua_pushboolean(L, true);
+	return 1;
+}
+
 // get_inventory(location)
 static int l_get_inventory(lua_State *L)
 {
@@ -4946,6 +4996,10 @@ static const struct luaL_Reg minetest_f [] = {
 	{"chat_send_all", l_chat_send_all},
 	{"chat_send_player", l_chat_send_player},
 	{"get_player_privs", l_get_player_privs},
+	{"get_ban_list", l_get_ban_list},
+	{"get_ban_description", l_get_ban_description},
+	{"ban_player", l_ban_player},
+	{"unban_player_or_ip", l_unban_player_of_ip},
 	{"get_inventory", l_get_inventory},
 	{"create_detached_inventory_raw", l_create_detached_inventory_raw},
 	{"get_dig_params", l_get_dig_params},