syncthing/lib/connections/structs.go
Jakob Borg e52be3d83e lib/connections, lib/model: Refactor connection close handling (fixes #3466)
So there were some issues here. The main problem was that
model.Close(deviceID) was overloaded to mean "the connection was closed
by the protocol layer" and "i want to close this connection". That meant
it could get called twice - once *to* close the connection and then once
more when the connection *was* closed.

After this refactor there is instead a Closed(conn) method that is the
callback. I didn't need to change the parameter in the end, but I think
it's clearer what it means when it takes the connection that was closed
instead of a device ID. To close a connection, the new close(deviceID)
method is used instead, which only closes the underlying connection and
leaves the cleanup to the Closed() callback.

I also changed how we do connection switching. Instead of the connection
service calling close and then adding the connection, it just adds the
new connection. The model knows that it already has a connection and
makes sure to close and clean out that one before adding the new
connection.

To make sure to sequence this properly I added a new map of channels
that get created on connection add and closed by Closed(), so that
AddConnection() can do the close and wait for the cleanup to happen
before proceeding.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3490
2016-08-10 09:37:32 +00:00

101 lines
2.7 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"
"fmt"
"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
}
func (c Connection) String() string {
return fmt.Sprintf("%s-%s/%s", c.LocalAddr(), c.RemoteAddr(), c.Type)
}
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) 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)
}
}