syncthing/lib/dialer/public.go
2017-02-09 08:04:16 +01:00

100 lines
2.9 KiB
Go

// Copyright (C) 2015 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 dialer
import (
"fmt"
"net"
"time"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
)
// Dial tries dialing via proxy if a proxy is configured, and falls back to
// a direct connection if no proxy is defined, or connecting via proxy fails.
func Dial(network, addr string) (net.Conn, error) {
if usingProxy {
return dialWithFallback(proxyDialer.Dial, net.Dial, network, addr)
}
return net.Dial(network, addr)
}
// DialTimeout tries dialing via proxy with a timeout if a proxy is configured,
// and falls back to a direct connection if no proxy is defined, or connecting
// via proxy fails. The timeout can potentially be applied twice, once trying
// to connect via the proxy connection, and second time trying to connect
// directly.
func DialTimeout(network, addr string, timeout time.Duration) (net.Conn, error) {
if usingProxy {
// Because the proxy package is poorly structured, we have to
// construct a struct that matches proxy.Dialer but has a timeout
// and reconstrcut the proxy dialer using that, in order to be able to
// set a timeout.
dd := &timeoutDirectDialer{
timeout: timeout,
}
// Check if the dialer we are getting is not timeoutDirectDialer we just
// created. It could happen that usingProxy is true, but getDialer
// returns timeoutDirectDialer due to env vars changing.
if timeoutProxyDialer := getDialer(dd); timeoutProxyDialer != dd {
directDialFunc := func(inetwork, iaddr string) (net.Conn, error) {
return net.DialTimeout(inetwork, iaddr, timeout)
}
return dialWithFallback(timeoutProxyDialer.Dial, directDialFunc, network, addr)
}
}
return net.DialTimeout(network, addr, timeout)
}
// SetTCPOptions sets our default TCP options on a TCP connection, possibly
// digging through dialerConn to extract the *net.TCPConn
func SetTCPOptions(conn net.Conn) error {
switch conn := conn.(type) {
case *net.TCPConn:
var err error
if err = conn.SetLinger(0); err != nil {
return err
}
if err = conn.SetNoDelay(false); err != nil {
return err
}
if err = conn.SetKeepAlivePeriod(60 * time.Second); err != nil {
return err
}
if err = conn.SetKeepAlive(true); err != nil {
return err
}
return nil
case dialerConn:
return SetTCPOptions(conn.Conn)
default:
return fmt.Errorf("unknown connection type %T", conn)
}
}
func SetTrafficClass(conn net.Conn, class int) error {
switch conn := conn.(type) {
case *net.TCPConn:
e1 := ipv4.NewConn(conn).SetTOS(class)
e2 := ipv6.NewConn(conn).SetTrafficClass(class)
if e1 != nil {
return e1
}
return e2
case dialerConn:
return SetTrafficClass(conn.Conn, class)
default:
return fmt.Errorf("unknown connection type %T", conn)
}
}