syncthing/lib/connections/structs.go

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// 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 (
"context"
"crypto/tls"
"fmt"
"io"
"net"
"net/url"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/connections/registry"
"github.com/syncthing/syncthing/lib/nat"
"github.com/syncthing/syncthing/lib/osutil"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syncthing/syncthing/lib/stats"
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"github.com/thejerf/suture/v4"
)
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
isLocal bool
priority int
establishedAt time.Time
}
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 newInternalConn(tc tlsConn, connType connType, isLocal bool, priority int) internalConn {
return internalConn{
tlsConn: tc,
connType: connType,
isLocal: isLocal,
priority: priority,
establishedAt: time.Now().Truncate(time.Second),
}
}
func (c internalConn) Close() error {
// *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))
return c.tlsConn.Close()
}
func (c internalConn) Type() string {
return c.connType.String()
}
func (c internalConn) IsLocal() bool {
return c.isLocal
}
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()
ip, err := osutil.IPFromAddr(c.LocalAddr())
if err != nil {
return transport
}
if ip.To4() != nil {
return transport + "4"
}
return transport + "6"
}
func (c internalConn) EstablishedAt() time.Time {
return c.establishedAt
}
func (c internalConn) String() string {
t := "WAN"
if c.isLocal {
t = "LAN"
}
return fmt.Sprintf("%s-%s/%s/%s/%s-P%d", c.LocalAddr(), c.RemoteAddr(), c.Type(), c.Crypto(), t, c.Priority())
}
type dialerFactory interface {
New(config.OptionsConfiguration, *tls.Config, *registry.Registry, *lanChecker) genericDialer
AlwaysWAN() bool
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Valid(config.Configuration) error
String() string
}
type commonDialer struct {
trafficClass int
reconnectInterval time.Duration
tlsCfg *tls.Config
lanChecker *lanChecker
lanPriority int
wanPriority int
}
func (d *commonDialer) RedialFrequency() time.Duration {
return d.reconnectInterval
}
func (d *commonDialer) Priority(host string) int {
if d.lanChecker.isLANHost(host) {
return d.lanPriority
}
return d.wanPriority
}
type genericDialer interface {
Dial(context.Context, protocol.DeviceID, *url.URL) (internalConn, error)
RedialFrequency() time.Duration
Priority(host string) int
}
type listenerFactory interface {
New(*url.URL, config.Wrapper, *tls.Config, chan internalConn, *nat.Service, *registry.Registry, *lanChecker) genericListener
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Valid(config.Configuration) error
}
type ListenerAddresses struct {
URI *url.URL
WANAddresses []*url.URL
LANAddresses []*url.URL
}
type genericListener interface {
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suture.Service
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(ListenerAddresses))
String() string
Factory() listenerFactory
NATType() string
}
type Model interface {
protocol.Model
AddConnection(conn protocol.Connection, hello protocol.Hello)
NumConnections() int
Connection(remoteID protocol.DeviceID) (protocol.Connection, bool)
OnHello(protocol.DeviceID, net.Addr, protocol.Hello) error
GetHello(protocol.DeviceID) protocol.HelloIntf
DeviceStatistics() (map[protocol.DeviceID]stats.DeviceStatistics, error)
}
type onAddressesChangedNotifier struct {
callbacks []func(ListenerAddresses)
}
func (o *onAddressesChangedNotifier) OnAddressesChanged(callback func(ListenerAddresses)) {
o.callbacks = append(o.callbacks, callback)
}
func (o *onAddressesChangedNotifier) notifyAddressesChanged(l genericListener) {
o.notifyAddresses(ListenerAddresses{
URI: l.URI(),
WANAddresses: l.WANAddresses(),
LANAddresses: l.LANAddresses(),
})
}
func (o *onAddressesChangedNotifier) clearAddresses(l genericListener) {
o.notifyAddresses(ListenerAddresses{
URI: l.URI(),
})
}
func (o *onAddressesChangedNotifier) notifyAddresses(l ListenerAddresses) {
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(ctx context.Context) (internalConn, error) {
l.Debugln("dialing", t.deviceID, t.uri, "prio", t.priority)
return t.dialer.Dial(ctx, t.deviceID, t.uri)
}