// Copyright (C) 2015 The Syncthing Authors. // // This Source Code Form is subject to the terms of the Mozilla Public // License, v. 2.0. If a copy of the MPL was not distributed with this file, // You can obtain one at http://mozilla.org/MPL/2.0/. package connections import ( "crypto/tls" "net" "net/url" "strings" "github.com/syncthing/syncthing/lib/dialer" "github.com/syncthing/syncthing/lib/model" "github.com/syncthing/syncthing/lib/osutil" ) func init() { dialers["tcp"] = tcpDialer listeners["tcp"] = tcpListener } func tcpDialer(uri *url.URL, tlsCfg *tls.Config) (*tls.Conn, error) { // Check that there is a port number in uri.Host, otherwise add one. host, port, err := net.SplitHostPort(uri.Host) if err != nil && strings.HasPrefix(err.Error(), "missing port") { // addr is on the form "1.2.3.4" uri.Host = net.JoinHostPort(uri.Host, "22000") } else if err == nil && port == "" { // addr is on the form "1.2.3.4:" uri.Host = net.JoinHostPort(host, "22000") } // Don't try to resolve the address before dialing. The dialer may be a // proxy, and we should let the proxy do the resolving in that case. conn, err := dialer.Dial("tcp", uri.Host) if err != nil { l.Debugln(err) return nil, err } tc := tls.Client(conn, tlsCfg) err = tc.Handshake() if err != nil { tc.Close() return nil, err } return tc, nil } func tcpListener(uri *url.URL, tlsCfg *tls.Config, conns chan<- model.IntermediateConnection) { tcaddr, err := net.ResolveTCPAddr("tcp", uri.Host) if err != nil { l.Fatalln("listen (BEP/tcp):", err) return } listener, err := net.ListenTCP("tcp", tcaddr) if err != nil { l.Fatalln("listen (BEP/tcp):", err) return } for { conn, err := listener.Accept() if err != nil { l.Warnln("Accepting connection (BEP/tcp):", err) continue } l.Debugln("connect from", conn.RemoteAddr()) err = osutil.SetTCPOptions(conn.(*net.TCPConn)) if err != nil { l.Infoln(err) } tc := tls.Server(conn, tlsCfg) err = tc.Handshake() if err != nil { l.Infoln("TLS handshake (BEP/tcp):", err) tc.Close() continue } conns <- model.IntermediateConnection{ tc, model.ConnectionTypeDirectAccept, } } }