/
pair.go
91 lines (75 loc) · 1.84 KB
/
pair.go
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package netx
import (
"errors"
"net"
"os"
"syscall"
)
// ConnPair returns a pair of connections, each of them being the end of a
// bidirectional communcation channel. network should be one of "tcp", "tcp4",
// "tcp6", or "unix".
func ConnPair(network string) (net.Conn, net.Conn, error) {
switch network {
case "unix":
return UnixConnPair()
case "tcp", "tcp4", "tcp6":
return TCPConnPair(network)
default:
return nil, nil, errors.New("unsupported network pair: " + network)
}
}
// TCPConnPair returns a pair of TCP connections, each of them being the end of a
// bidirectional communication channel.
func TCPConnPair(network string) (nc1 *net.TCPConn, nc2 *net.TCPConn, err error) {
var lstn *net.TCPListener
var ch1 = make(chan error, 1)
var ch2 = make(chan *net.TCPConn, 1)
if lstn, err = net.ListenTCP(network, nil); err != nil {
return
}
defer lstn.Close()
go func() {
var conn *net.TCPConn
var err error
if conn, err = net.DialTCP(network, nil, lstn.Addr().(*net.TCPAddr)); err != nil {
ch1 <- err
} else {
ch2 <- conn
}
}()
if nc1, err = lstn.AcceptTCP(); err != nil {
return
}
select {
case nc2 = <-ch2:
case err = <-ch1:
nc1.Close()
nc1 = nil
}
return
}
// UnixConnPair returns a pair of unix connections, each of them being the end of a
// bidirection communication channel.
func UnixConnPair() (uc1 *net.UnixConn, uc2 *net.UnixConn, err error) {
var fd1 int
var fd2 int
if fd1, fd2, err = socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM, 0); err != nil {
return
}
f1 := os.NewFile(uintptr(fd1), "")
f2 := os.NewFile(uintptr(fd2), "")
defer f1.Close()
defer f2.Close()
var c1 net.Conn
var c2 net.Conn
if c1, err = net.FileConn(f1); err != nil {
return
}
if c2, err = net.FileConn(f2); err != nil {
c1.Close()
return
}
uc1 = c1.(*net.UnixConn)
uc2 = c2.(*net.UnixConn)
return
}