syncthing/lib/connections/tcp_dial.go
Jakob Borg c6334e61aa
all: Support multiple device connections (fixes #141) (#8918)
This adds the ability to have multiple concurrent connections to a single device. This is primarily useful when the network has multiple physical links for aggregated bandwidth. A single connection will never see a higher rate than a single link can give, but multiple connections are load-balanced over multiple links.

It is also incidentally useful for older multi-core CPUs, where bandwidth could be limited by the TLS performance of a single CPU core -- using multiple connections achieves concurrency in the required crypto calculations...

Co-authored-by: Simon Frei <freisim93@gmail.com>
Co-authored-by: tomasz1986 <twilczynski@naver.com>
Co-authored-by: bt90 <btom1990@googlemail.com>
2023-09-06 12:52:01 +02:00

98 lines
2.4 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 (
"context"
"crypto/tls"
"net/url"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/connections/registry"
"github.com/syncthing/syncthing/lib/dialer"
"github.com/syncthing/syncthing/lib/protocol"
)
func init() {
factory := &tcpDialerFactory{}
for _, scheme := range []string{"tcp", "tcp4", "tcp6"} {
dialers[scheme] = factory
}
}
type tcpDialer struct {
commonDialer
registry *registry.Registry
}
func (d *tcpDialer) Dial(ctx context.Context, _ protocol.DeviceID, uri *url.URL) (internalConn, error) {
uri = fixupPort(uri, config.DefaultTCPPort)
timeoutCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
defer cancel()
conn, err := dialer.DialContextReusePortFunc(d.registry)(timeoutCtx, uri.Scheme, uri.Host)
if err != nil {
return internalConn{}, err
}
err = dialer.SetTCPOptions(conn)
if err != nil {
l.Debugln("Dial (BEP/tcp): setting tcp options:", err)
}
err = dialer.SetTrafficClass(conn, d.trafficClass)
if err != nil {
l.Debugln("Dial (BEP/tcp): setting traffic class:", err)
}
tc := tls.Client(conn, d.tlsCfg)
err = tlsTimedHandshake(tc)
if err != nil {
tc.Close()
return internalConn{}, err
}
priority := d.wanPriority
isLocal := d.lanChecker.isLAN(conn.RemoteAddr())
if isLocal {
priority = d.lanPriority
}
return newInternalConn(tc, connTypeTCPClient, isLocal, priority), nil
}
type tcpDialerFactory struct{}
func (tcpDialerFactory) New(opts config.OptionsConfiguration, tlsCfg *tls.Config, registry *registry.Registry, lanChecker *lanChecker) genericDialer {
return &tcpDialer{
commonDialer: commonDialer{
trafficClass: opts.TrafficClass,
reconnectInterval: time.Duration(opts.ReconnectIntervalS) * time.Second,
tlsCfg: tlsCfg,
lanChecker: lanChecker,
lanPriority: opts.ConnectionPriorityTCPLAN,
wanPriority: opts.ConnectionPriorityTCPWAN,
allowsMultiConns: true,
},
registry: registry,
}
}
func (tcpDialerFactory) AlwaysWAN() bool {
return false
}
func (tcpDialerFactory) Valid(_ config.Configuration) error {
// Always valid
return nil
}
func (tcpDialerFactory) String() string {
return "TCP Dialer"
}