syncthing/lib/connections/structs.go

233 lines
5.6 KiB
Go

// Copyright (C) 2016 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 https://mozilla.org/MPL/2.0/.
package connections
import (
"crypto/tls"
"fmt"
"io"
"net"
"net/url"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/nat"
"github.com/syncthing/syncthing/lib/protocol"
)
// Connection is what we expose to the outside. It is a protocol.Connection
// that can be closed and has some metadata.
type Connection interface {
protocol.Connection
Type() string
Transport() string
RemoteAddr() net.Addr
Priority() int
String() string
Crypto() string
}
// completeConn is the aggregation of an internalConn and the
// protocol.Connection running on top of it. It implements the Connection
// interface.
type completeConn struct {
internalConn
protocol.Connection
}
func (c completeConn) Close(err error) {
c.Connection.Close(err)
c.internalConn.Close()
}
type tlsConn interface {
io.ReadWriteCloser
ConnectionState() tls.ConnectionState
RemoteAddr() net.Addr
SetDeadline(time.Time) error
SetWriteDeadline(time.Time) error
LocalAddr() net.Addr
}
// internalConn is the raw TLS connection plus some metadata on where it
// came from (type, priority).
type internalConn struct {
tlsConn
connType connType
priority int
}
type connType int
const (
connTypeRelayClient connType = iota
connTypeRelayServer
connTypeTCPClient
connTypeTCPServer
connTypeQUICClient
connTypeQUICServer
)
func (t connType) String() string {
switch t {
case connTypeRelayClient:
return "relay-client"
case connTypeRelayServer:
return "relay-server"
case connTypeTCPClient:
return "tcp-client"
case connTypeTCPServer:
return "tcp-server"
case connTypeQUICClient:
return "quic-client"
case connTypeQUICServer:
return "quic-server"
default:
return "unknown-type"
}
}
func (t connType) Transport() string {
switch t {
case connTypeRelayClient, connTypeRelayServer:
return "relay"
case connTypeTCPClient, connTypeTCPServer:
return "tcp"
case connTypeQUICClient, connTypeQUICServer:
return "quic"
default:
return "unknown"
}
}
func (c internalConn) Close() {
// *tls.Conn.Close() does more than it says on the tin. Specifically, it
// sends a TLS alert message, which might block forever if the
// connection is dead and we don't have a deadline set.
_ = c.SetWriteDeadline(time.Now().Add(250 * time.Millisecond))
_ = c.tlsConn.Close()
}
func (c internalConn) Type() string {
return c.connType.String()
}
func (c internalConn) Priority() int {
return c.priority
}
func (c internalConn) Crypto() string {
cs := c.ConnectionState()
return fmt.Sprintf("%s-%s", tlsVersionNames[cs.Version], tlsCipherSuiteNames[cs.CipherSuite])
}
func (c internalConn) Transport() string {
transport := c.connType.Transport()
host, _, err := net.SplitHostPort(c.LocalAddr().String())
if err != nil {
return transport
}
ip := net.ParseIP(host)
if ip == nil {
return transport
}
if ip.To4() != nil {
return transport + "4"
}
return transport + "6"
}
func (c internalConn) String() string {
return fmt.Sprintf("%s-%s/%s/%s", c.LocalAddr(), c.RemoteAddr(), c.Type(), c.Crypto())
}
type dialerFactory interface {
New(config.Wrapper, *tls.Config) genericDialer
Priority() int
AlwaysWAN() bool
Valid(config.Configuration) error
String() string
}
type genericDialer interface {
Dial(protocol.DeviceID, *url.URL) (internalConn, error)
RedialFrequency() time.Duration
}
type listenerFactory interface {
New(*url.URL, config.Wrapper, *tls.Config, chan internalConn, *nat.Service) genericListener
Valid(config.Configuration) error
}
type genericListener interface {
Serve()
Stop()
URI() *url.URL
// A given address can potentially be mutated by the listener.
// For example we bind to tcp://0.0.0.0, but that for example might return
// tcp://gateway1.ip and tcp://gateway2.ip as WAN addresses due to there
// being multiple gateways, and us managing to get a UPnP mapping on both
// and tcp://192.168.0.1 and tcp://10.0.0.1 due to there being multiple
// network interfaces. (The later case for LAN addresses is made up just
// to provide an example)
WANAddresses() []*url.URL
LANAddresses() []*url.URL
Error() error
OnAddressesChanged(func(genericListener))
String() string
Factory() listenerFactory
NATType() string
}
type Model interface {
protocol.Model
AddConnection(conn Connection, hello protocol.HelloResult)
Connection(remoteID protocol.DeviceID) (Connection, bool)
OnHello(protocol.DeviceID, net.Addr, protocol.HelloResult) error
GetHello(protocol.DeviceID) protocol.HelloIntf
}
// serviceFunc wraps a function to create a suture.Service without stop
// functionality.
type serviceFunc func()
func (f serviceFunc) Serve() { f() }
func (f serviceFunc) Stop() {}
type onAddressesChangedNotifier struct {
callbacks []func(genericListener)
}
func (o *onAddressesChangedNotifier) OnAddressesChanged(callback func(genericListener)) {
o.callbacks = append(o.callbacks, callback)
}
func (o *onAddressesChangedNotifier) notifyAddressesChanged(l genericListener) {
for _, callback := range o.callbacks {
callback(l)
}
}
type dialTarget struct {
addr string
dialer genericDialer
priority int
uri *url.URL
deviceID protocol.DeviceID
}
func (t dialTarget) Dial() (internalConn, error) {
l.Debugln("dialing", t.deviceID, t.uri, "prio", t.priority)
conn, err := t.dialer.Dial(t.deviceID, t.uri)
if err != nil {
l.Debugln("dialing", t.deviceID, t.uri, "error:", err)
} else {
l.Debugln("dialing", t.deviceID, t.uri, "success:", conn)
}
return conn, err
}