syncthing/lib/connections/structs.go
Jakob Borg d507126101 lib/protocol: Understand older/newer Hello messages (fixes #3287)
This is in preparation for future changes, but also improves the
handling when talking to pre-v0.13 clients. It breaks out the Hello
message and magic from the rest of the protocol implementation, with the
intention that this small part of the protocol will survive future
changes.

To enable this, and future testing, the new ExchangeHello function takes
an interface that can be implemented by future Hello versions and
returns a version indendent result type. It correctly detects pre-v0.13
protocols and returns a "too old" error message which gets logged to the
user at warning level:

   [I6KAH] 09:21:36 WARNING: Connecting to [...]:
     the remote device speaks an older version of the protocol (v0.12) not
     compatible with this version

Conversely, something entirely unknown will generate:

   [I6KAH] 09:40:27 WARNING: Connecting to [...]:
     the remote device speaks an unknown (newer?) version of the protocol

The intention is that in future iterations the Hello exchange will
succeed on at least one side and ExchangeHello will return the actual
data from the Hello together with ErrTooOld and an even more precise
message can be generated.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3289
2016-06-09 10:50:14 +00:00

96 lines
2.6 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 http://mozilla.org/MPL/2.0/.
package connections
import (
"crypto/tls"
"net"
"net/url"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/nat"
"github.com/syncthing/syncthing/lib/protocol"
)
type IntermediateConnection struct {
*tls.Conn
Type string
Priority int
}
type Connection struct {
IntermediateConnection
protocol.Connection
}
type dialerFactory interface {
New(*config.Wrapper, *tls.Config) genericDialer
Priority() int
Enabled(config.Configuration) bool
String() string
}
type genericDialer interface {
Dial(protocol.DeviceID, *url.URL) (IntermediateConnection, error)
RedialFrequency() time.Duration
}
type listenerFactory interface {
New(*url.URL, *config.Wrapper, *tls.Config, chan IntermediateConnection, *nat.Service) genericListener
Enabled(config.Configuration) bool
}
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
}
type Model interface {
protocol.Model
AddConnection(conn Connection, hello protocol.HelloResult)
ConnectedTo(remoteID protocol.DeviceID) bool
IsPaused(remoteID protocol.DeviceID) bool
OnHello(protocol.DeviceID, net.Addr, protocol.HelloResult)
GetHello(protocol.DeviceID) protocol.Version13HelloMessage
}
// 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)
}
}