x.net: new net module (#6130)

vlib/x/net/util.v

@@ -0,0 +1,24 @@
+module net
+
+const (
+	socket_max_port = u16(0xFFFF)
+)
+
+// validate_port checks whether a port is valid
+// and returns the port or an error
+pub fn validate_port(port int) ?u16 {
+	if port <= socket_max_port {
+		return u16(port)
+	} else {
+		return err_port_out_of_range
+	}
+}
+
+// split address splits an address into its host name and its port
+pub fn split_address(addr string) ?(string, u16) {
+	port := addr.all_after_last(':').int()
+	address := addr.all_before_last(':')
+
+	p := validate_port(port)?
+	return address, p
+}