support unix domain sockets

irc/server.go

@@ -267,19 +267,15 @@ func (server *Server) Run() {
 
 func (server *Server) acceptClient(conn clientConn) {
 	// check IP address
-	ipaddr := net.ParseIP(utils.IPString(conn.Conn.RemoteAddr()))
-	if ipaddr == nil {
-		conn.Conn.Write([]byte(couldNotParseIPMsg))
-		conn.Conn.Close()
-		return
-	}
-
-	isBanned, banMsg := server.checkBans(ipaddr)
-	if isBanned {
-		// this might not show up properly on some clients, but our objective here is just to close the connection out before it has a load impact on us
-		conn.Conn.Write([]byte(fmt.Sprintf(errorMsg, banMsg)))
-		conn.Conn.Close()
-		return
+	ipaddr := utils.AddrToIP(conn.Conn.RemoteAddr())
+	if ipaddr != nil {
+		isBanned, banMsg := server.checkBans(ipaddr)
+		if isBanned {
+			// this might not show up properly on some clients, but our objective here is just to close the connection out before it has a load impact on us
+			conn.Conn.Write([]byte(fmt.Sprintf(errorMsg, banMsg)))
+			conn.Conn.Close()
+			return
+		}
 	}
 
 	server.logger.Debug("localconnect-ip", fmt.Sprintf("Client connecting from %v", ipaddr))
@@ -336,7 +332,23 @@ func (server *Server) checkBans(ipaddr net.IP) (banned bool, message string) {
 // createListener starts the given listeners.
 func (server *Server) createListener(addr string, tlsConfig *tls.Config) *ListenerWrapper {
 	// make listener
-	listener, err := net.Listen("tcp", addr)
+	var listener net.Listener
+	var err error
+	optional_unix_prefix := "unix:"
+	optional_prefix_len := len(optional_unix_prefix)
+	if len(addr) >= optional_prefix_len && strings.ToLower(addr[0:optional_prefix_len]) == optional_unix_prefix {
+		addr = addr[optional_prefix_len:]
+		if len(addr) == 0 || addr[0] != '/' {
+			log.Fatal("Bad unix socket address", addr)
+		}
+	}
+	if len(addr) > 0 && addr[0] == '/' {
+		// https://stackoverflow.com/a/34881585
+		os.Remove(addr)
+		listener, err = net.Listen("unix", addr)
+	} else {
+		listener, err = net.Listen("tcp", addr)
+	}
 	if err != nil {
 		log.Fatal(server, "listen error: ", err)
 	}