Refactor out connection related functions to a separate file

cmd/syncthing/connections.go

@@ -0,0 +1,262 @@
+// Copyright (C) 2015 The Syncthing Authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the Free
+// Software Foundation, either version 3 of the License, or (at your option)
+// any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+// more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"crypto/tls"
+	"fmt"
+	"io"
+	"net"
+	"strings"
+	"time"
+
+	"github.com/syncthing/protocol"
+	"github.com/syncthing/syncthing/internal/events"
+	"github.com/syncthing/syncthing/internal/model"
+)
+
+func listenConnect(myID protocol.DeviceID, m *model.Model, tlsCfg *tls.Config) {
+	var conns = make(chan *tls.Conn)
+
+	// Listen
+	for _, addr := range cfg.Options().ListenAddress {
+		go listenTLS(conns, addr, tlsCfg)
+	}
+
+	// Connect
+	go dialTLS(m, conns, tlsCfg)
+
+next:
+	for conn := range conns {
+		certs := conn.ConnectionState().PeerCertificates
+		if cl := len(certs); cl != 1 {
+			l.Infof("Got peer certificate list of length %d != 1 from %s; protocol error", cl, conn.RemoteAddr())
+			conn.Close()
+			continue
+		}
+		remoteCert := certs[0]
+		remoteID := protocol.NewDeviceID(remoteCert.Raw)
+
+		if remoteID == myID {
+			l.Infof("Connected to myself (%s) - should not happen", remoteID)
+			conn.Close()
+			continue
+		}
+
+		if m.ConnectedTo(remoteID) {
+			l.Infof("Connected to already connected device (%s)", remoteID)
+			conn.Close()
+			continue
+		}
+
+		for deviceID, deviceCfg := range cfg.Devices() {
+			if deviceID == remoteID {
+				// Verify the name on the certificate. By default we set it to
+				// "syncthing" when generating, but the user may have replaced
+				// the certificate and used another name.
+				certName := deviceCfg.CertName
+				if certName == "" {
+					certName = tlsDefaultCommonName
+				}
+				err := remoteCert.VerifyHostname(certName)
+				if err != nil {
+					// Incorrect certificate name is something the user most
+					// likely wants to know about, since it's an advanced
+					// config. Warn instead of Info.
+					l.Warnf("Bad certificate from %s (%v): %v", remoteID, conn.RemoteAddr(), err)
+					conn.Close()
+					continue next
+				}
+
+				// If rate limiting is set, we wrap the connection in a
+				// limiter.
+				wr := io.Writer(conn)
+				if writeRateLimit != nil {
+					wr = &limitedWriter{conn, writeRateLimit}
+				}
+
+				rd := io.Reader(conn)
+				if readRateLimit != nil {
+					rd = &limitedReader{conn, readRateLimit}
+				}
+
+				name := fmt.Sprintf("%s-%s", conn.LocalAddr(), conn.RemoteAddr())
+				protoConn := protocol.NewConnection(remoteID, rd, wr, m, name, deviceCfg.Compression)
+
+				l.Infof("Established secure connection to %s at %s", remoteID, name)
+				if debugNet {
+					l.Debugf("cipher suite %04X", conn.ConnectionState().CipherSuite)
+				}
+				events.Default.Log(events.DeviceConnected, map[string]string{
+					"id":   remoteID.String(),
+					"addr": conn.RemoteAddr().String(),
+				})
+
+				m.AddConnection(conn, protoConn)
+				continue next
+			}
+		}
+
+		if !cfg.IgnoredDevice(remoteID) {
+			events.Default.Log(events.DeviceRejected, map[string]string{
+				"device":  remoteID.String(),
+				"address": conn.RemoteAddr().String(),
+			})
+			l.Infof("Connection from %s with unknown device ID %s", conn.RemoteAddr(), remoteID)
+		} else {
+			l.Infof("Connection from %s with ignored device ID %s", conn.RemoteAddr(), remoteID)
+		}
+
+		conn.Close()
+	}
+}
+
+func listenTLS(conns chan *tls.Conn, addr string, tlsCfg *tls.Config) {
+	if debugNet {
+		l.Debugln("listening on", addr)
+	}
+
+	tcaddr, err := net.ResolveTCPAddr("tcp", addr)
+	if err != nil {
+		l.Fatalln("listen (BEP):", err)
+	}
+	listener, err := net.ListenTCP("tcp", tcaddr)
+	if err != nil {
+		l.Fatalln("listen (BEP):", err)
+	}
+
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			l.Warnln("Accepting connection:", err)
+			continue
+		}
+
+		if debugNet {
+			l.Debugln("connect from", conn.RemoteAddr())
+		}
+
+		tcpConn := conn.(*net.TCPConn)
+		setTCPOptions(tcpConn)
+
+		tc := tls.Server(conn, tlsCfg)
+		err = tc.Handshake()
+		if err != nil {
+			l.Infoln("TLS handshake:", err)
+			tc.Close()
+			continue
+		}
+
+		conns <- tc
+	}
+
+}
+
+func dialTLS(m *model.Model, conns chan *tls.Conn, tlsCfg *tls.Config) {
+	delay := time.Second
+	for {
+	nextDevice:
+		for deviceID, deviceCfg := range cfg.Devices() {
+			if deviceID == myID {
+				continue
+			}
+
+			if m.ConnectedTo(deviceID) {
+				continue
+			}
+
+			var addrs []string
+			for _, addr := range deviceCfg.Addresses {
+				if addr == "dynamic" {
+					if discoverer != nil {
+						t := discoverer.Lookup(deviceID)
+						if len(t) == 0 {
+							continue
+						}
+						addrs = append(addrs, t...)
+					}
+				} else {
+					addrs = append(addrs, addr)
+				}
+			}
+
+			for _, addr := range addrs {
+				host, port, err := net.SplitHostPort(addr)
+				if err != nil && strings.HasPrefix(err.Error(), "missing port") {
+					// addr is on the form "1.2.3.4"
+					addr = net.JoinHostPort(addr, "22000")
+				} else if err == nil && port == "" {
+					// addr is on the form "1.2.3.4:"
+					addr = net.JoinHostPort(host, "22000")
+				}
+				if debugNet {
+					l.Debugln("dial", deviceCfg.DeviceID, addr)
+				}
+
+				raddr, err := net.ResolveTCPAddr("tcp", addr)
+				if err != nil {
+					if debugNet {
+						l.Debugln(err)
+					}
+					continue
+				}
+
+				conn, err := net.DialTCP("tcp", nil, raddr)
+				if err != nil {
+					if debugNet {
+						l.Debugln(err)
+					}
+					continue
+				}
+
+				setTCPOptions(conn)
+
+				tc := tls.Client(conn, tlsCfg)
+				err = tc.Handshake()
+				if err != nil {
+					l.Infoln("TLS handshake:", err)
+					tc.Close()
+					continue
+				}
+
+				conns <- tc
+				continue nextDevice
+			}
+		}
+
+		time.Sleep(delay)
+		delay *= 2
+		if maxD := time.Duration(cfg.Options().ReconnectIntervalS) * time.Second; delay > maxD {
+			delay = maxD
+		}
+	}
+}
+
+func setTCPOptions(conn *net.TCPConn) {
+	var err error
+	if err = conn.SetLinger(0); err != nil {
+		l.Infoln(err)
+	}
+	if err = conn.SetNoDelay(false); err != nil {
+		l.Infoln(err)
+	}
+	if err = conn.SetKeepAlivePeriod(60 * time.Second); err != nil {
+		l.Infoln(err)
+	}
+	if err = conn.SetKeepAlive(true); err != nil {
+		l.Infoln(err)
+	}
+}

cmd/syncthing/main.go

@@ -19,7 +19,6 @@ import (
 	"crypto/tls"
 	"flag"
 	"fmt"
-	"io"
 	"log"
 	"net"
 	"net/http"
@@ -900,239 +899,6 @@ func shutdown() {
 	stop <- exitSuccess
 }
 
-func listenConnect(myID protocol.DeviceID, m *model.Model, tlsCfg *tls.Config) {
-	var conns = make(chan *tls.Conn)
-
-	// Listen
-	for _, addr := range cfg.Options().ListenAddress {
-		go listenTLS(conns, addr, tlsCfg)
-	}
-
-	// Connect
-	go dialTLS(m, conns, tlsCfg)
-
-next:
-	for conn := range conns {
-		certs := conn.ConnectionState().PeerCertificates
-		if cl := len(certs); cl != 1 {
-			l.Infof("Got peer certificate list of length %d != 1 from %s; protocol error", cl, conn.RemoteAddr())
-			conn.Close()
-			continue
-		}
-		remoteCert := certs[0]
-		remoteID := protocol.NewDeviceID(remoteCert.Raw)
-
-		if remoteID == myID {
-			l.Infof("Connected to myself (%s) - should not happen", remoteID)
-			conn.Close()
-			continue
-		}
-
-		if m.ConnectedTo(remoteID) {
-			l.Infof("Connected to already connected device (%s)", remoteID)
-			conn.Close()
-			continue
-		}
-
-		for deviceID, deviceCfg := range cfg.Devices() {
-			if deviceID == remoteID {
-				// Verify the name on the certificate. By default we set it to
-				// "syncthing" when generating, but the user may have replaced
-				// the certificate and used another name.
-				certName := deviceCfg.CertName
-				if certName == "" {
-					certName = tlsDefaultCommonName
-				}
-				err := remoteCert.VerifyHostname(certName)
-				if err != nil {
-					// Incorrect certificate name is something the user most
-					// likely wants to know about, since it's an advanced
-					// config. Warn instead of Info.
-					l.Warnf("Bad certificate from %s (%v): %v", remoteID, conn.RemoteAddr(), err)
-					conn.Close()
-					continue next
-				}
-
-				// If rate limiting is set, we wrap the connection in a
-				// limiter.
-				wr := io.Writer(conn)
-				if writeRateLimit != nil {
-					wr = &limitedWriter{conn, writeRateLimit}
-				}
-
-				rd := io.Reader(conn)
-				if readRateLimit != nil {
-					rd = &limitedReader{conn, readRateLimit}
-				}
-
-				name := fmt.Sprintf("%s-%s", conn.LocalAddr(), conn.RemoteAddr())
-				protoConn := protocol.NewConnection(remoteID, rd, wr, m, name, deviceCfg.Compression)
-
-				l.Infof("Established secure connection to %s at %s", remoteID, name)
-				if debugNet {
-					l.Debugf("cipher suite %04X", conn.ConnectionState().CipherSuite)
-				}
-				events.Default.Log(events.DeviceConnected, map[string]string{
-					"id":   remoteID.String(),
-					"addr": conn.RemoteAddr().String(),
-				})
-
-				m.AddConnection(conn, protoConn)
-				continue next
-			}
-		}
-
-		if !cfg.IgnoredDevice(remoteID) {
-			events.Default.Log(events.DeviceRejected, map[string]string{
-				"device":  remoteID.String(),
-				"address": conn.RemoteAddr().String(),
-			})
-			l.Infof("Connection from %s with unknown device ID %s", conn.RemoteAddr(), remoteID)
-		} else {
-			l.Infof("Connection from %s with ignored device ID %s", conn.RemoteAddr(), remoteID)
-		}
-
-		conn.Close()
-	}
-}
-
-func listenTLS(conns chan *tls.Conn, addr string, tlsCfg *tls.Config) {
-	if debugNet {
-		l.Debugln("listening on", addr)
-	}
-
-	tcaddr, err := net.ResolveTCPAddr("tcp", addr)
-	if err != nil {
-		l.Fatalln("listen (BEP):", err)
-	}
-	listener, err := net.ListenTCP("tcp", tcaddr)
-	if err != nil {
-		l.Fatalln("listen (BEP):", err)
-	}
-
-	for {
-		conn, err := listener.Accept()
-		if err != nil {
-			l.Warnln("Accepting connection:", err)
-			continue
-		}
-
-		if debugNet {
-			l.Debugln("connect from", conn.RemoteAddr())
-		}
-
-		tcpConn := conn.(*net.TCPConn)
-		setTCPOptions(tcpConn)
-
-		tc := tls.Server(conn, tlsCfg)
-		err = tc.Handshake()
-		if err != nil {
-			l.Infoln("TLS handshake:", err)
-			tc.Close()
-			continue
-		}
-
-		conns <- tc
-	}
-
-}
-
-func dialTLS(m *model.Model, conns chan *tls.Conn, tlsCfg *tls.Config) {
-	delay := time.Second
-	for {
-	nextDevice:
-		for deviceID, deviceCfg := range cfg.Devices() {
-			if deviceID == myID {
-				continue
-			}
-
-			if m.ConnectedTo(deviceID) {
-				continue
-			}
-
-			var addrs []string
-			for _, addr := range deviceCfg.Addresses {
-				if addr == "dynamic" {
-					if discoverer != nil {
-						t := discoverer.Lookup(deviceID)
-						if len(t) == 0 {
-							continue
-						}
-						addrs = append(addrs, t...)
-					}
-				} else {
-					addrs = append(addrs, addr)
-				}
-			}
-
-			for _, addr := range addrs {
-				host, port, err := net.SplitHostPort(addr)
-				if err != nil && strings.HasPrefix(err.Error(), "missing port") {
-					// addr is on the form "1.2.3.4"
-					addr = net.JoinHostPort(addr, "22000")
-				} else if err == nil && port == "" {
-					// addr is on the form "1.2.3.4:"
-					addr = net.JoinHostPort(host, "22000")
-				}
-				if debugNet {
-					l.Debugln("dial", deviceCfg.DeviceID, addr)
-				}
-
-				raddr, err := net.ResolveTCPAddr("tcp", addr)
-				if err != nil {
-					if debugNet {
-						l.Debugln(err)
-					}
-					continue
-				}
-
-				conn, err := net.DialTCP("tcp", nil, raddr)
-				if err != nil {
-					if debugNet {
-						l.Debugln(err)
-					}
-					continue
-				}
-
-				setTCPOptions(conn)
-
-				tc := tls.Client(conn, tlsCfg)
-				err = tc.Handshake()
-				if err != nil {
-					l.Infoln("TLS handshake:", err)
-					tc.Close()
-					continue
-				}
-
-				conns <- tc
-				continue nextDevice
-			}
-		}
-
-		time.Sleep(delay)
-		delay *= 2
-		if maxD := time.Duration(cfg.Options().ReconnectIntervalS) * time.Second; delay > maxD {
-			delay = maxD
-		}
-	}
-}
-
-func setTCPOptions(conn *net.TCPConn) {
-	var err error
-	if err = conn.SetLinger(0); err != nil {
-		l.Infoln(err)
-	}
-	if err = conn.SetNoDelay(false); err != nil {
-		l.Infoln(err)
-	}
-	if err = conn.SetKeepAlivePeriod(60 * time.Second); err != nil {
-		l.Infoln(err)
-	}
-	if err = conn.SetKeepAlive(true); err != nil {
-		l.Infoln(err)
-	}
-}
-
 func discovery(extPort int) *discover.Discoverer {
 	opts := cfg.Options()
 	disc := discover.NewDiscoverer(myID, opts.ListenAddress)