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
73
74
75
76
77
78
79
80
81
|
package main
import (
"io"
"log"
"net"
"sync"
"github.com/ishidawataru/sctp"
)
// SCTPProxy is a proxy for SCTP connections. It implements the Proxy interface to
// handle SCTP traffic forwarding between the frontend and backend addresses.
type SCTPProxy struct {
listener *sctp.SCTPListener
frontendAddr *sctp.SCTPAddr
backendAddr *sctp.SCTPAddr
}
// NewSCTPProxy creates a new SCTPProxy.
func NewSCTPProxy(listener *sctp.SCTPListener, backendAddr *sctp.SCTPAddr) (*SCTPProxy, error) {
return &SCTPProxy{
listener: listener,
frontendAddr: listener.Addr().(*sctp.SCTPAddr),
backendAddr: backendAddr,
}, nil
}
func (proxy *SCTPProxy) clientLoop(client *sctp.SCTPConn, quit chan bool) {
backend, err := sctp.DialSCTP("sctp", nil, proxy.backendAddr)
if err != nil {
log.Printf("Can't forward traffic to backend sctp/%v: %s\n", proxy.backendAddr, err)
client.Close()
return
}
clientC := sctp.NewSCTPSndRcvInfoWrappedConn(client)
backendC := sctp.NewSCTPSndRcvInfoWrappedConn(backend)
var wg sync.WaitGroup
broker := func(to, from net.Conn) {
io.Copy(to, from)
from.Close()
to.Close()
wg.Done()
}
wg.Add(2)
go broker(clientC, backendC)
go broker(backendC, clientC)
finish := make(chan struct{})
go func() {
wg.Wait()
close(finish)
}()
select {
case <-quit:
case <-finish:
}
clientC.Close()
backendC.Close()
<-finish
}
// Run starts forwarding the traffic using SCTP.
func (proxy *SCTPProxy) Run() {
quit := make(chan bool)
defer close(quit)
for {
client, err := proxy.listener.Accept()
if err != nil {
log.Printf("Stopping proxy on sctp/%v for sctp/%v (%s)", proxy.frontendAddr, proxy.backendAddr, err)
return
}
go proxy.clientLoop(client.(*sctp.SCTPConn), quit)
}
}
// Close stops forwarding the traffic.
func (proxy *SCTPProxy) Close() { proxy.listener.Close() }
|
