This repository has been archived by the owner on May 26, 2022. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 8
/
reuseport.go
72 lines (61 loc) · 1.83 KB
/
reuseport.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
package tcpreuse
import (
"context"
"net"
"syscall"
reuseport "github.com/libp2p/go-reuseport"
)
var fallbackDialer net.Dialer
// reuseErrShouldRetry diagnoses whether to retry after a reuse error.
// if we failed to bind, we should retry. if bind worked and this is a
// real dial error (remote end didnt answer) then we should not retry.
func reuseErrShouldRetry(err error) bool {
if err == nil {
return false // hey, it worked! no need to retry.
}
// if it's a network timeout error, it's a legitimate failure.
if nerr, ok := err.(net.Error); ok && nerr.Timeout() {
return false
}
errno, ok := err.(syscall.Errno)
if !ok { // not an errno? who knows what this is. retry.
return true
}
switch errno {
case syscall.EADDRINUSE, syscall.EADDRNOTAVAIL:
return true // failure to bind. retry.
case syscall.ECONNREFUSED:
return false // real dial error
default:
return true // optimistically default to retry.
}
}
// Dials using reuseport and then redials normally if that fails.
// TODO(anacrolix): This shouldn't fail anymore: Remove fallback.
func reuseDial(ctx context.Context, laddr *net.TCPAddr, network, raddr string) (con net.Conn, err error) {
if laddr == nil {
return fallbackDialer.DialContext(ctx, network, raddr)
}
d := net.Dialer{
LocalAddr: laddr,
Control: reuseport.Control,
}
defer func() {
if err != nil {
return
}
// This is transplanted from go-reuseport, which once set no linger on
// dialing and may be a requirement for desired behaviour in this
// package.
con.(*net.TCPConn).SetLinger(0)
}()
con, err = d.DialContext(ctx, network, raddr)
if err == nil {
return con, nil
}
if reuseErrShouldRetry(err) && ctx.Err() == nil {
log.Debugf("failed to reuse port, dialing with a random port: %s", err)
con, err = fallbackDialer.DialContext(ctx, network, raddr)
}
return con, err
}