func listen(netw, addr string) (fd int, err error) {
var (
family int
socktype int
protocol int
sockaddr syscall.Sockaddr
)
netAddr, err := ResolveAddr(netw, addr)
if err != nil {
return -1, err
}
switch netAddr.(type) {
case *net.TCPAddr, *net.UDPAddr:
default:
return -1, ErrUnsupportedProtocol
}
family = sockaddrnet.NetAddrAF(netAddr)
protocol = sockaddrnet.NetAddrIPPROTO(netAddr)
sockaddr = sockaddrnet.NetAddrToSockaddr(netAddr)
socktype = sockaddrnet.NetAddrSOCK(netAddr)
if fd, err = socket(family, socktype, protocol); err != nil {
return -1, err
}
if err = syscall.Bind(fd, sockaddr); err != nil {
syscall.Close(fd)
return -1, err
}
if protocol == syscall.IPPROTO_TCP {
// by default golang/net sets TCP no delay to true.
if err = setNoDelay(fd, true); err != nil {
syscall.Close(fd)
return -1, err
}
}
if err = syscall.SetNonblock(fd, true); err != nil {
syscall.Close(fd)
return -1, err
}
return fd, nil
}
func dial(dialer net.Dialer, netw, addr string) (c net.Conn, err error) {
var (
fd int
lfamily int
rfamily int
socktype int
lprotocol int
rprotocol int
file *os.File
deadline time.Time
remoteSockaddr syscall.Sockaddr
localSockaddr syscall.Sockaddr
)
netAddr, err := ResolveAddr(netw, addr)
if err != nil {
return nil, err
}
switch netAddr.(type) {
case *net.TCPAddr, *net.UDPAddr:
default:
return nil, ErrUnsupportedProtocol
}
switch {
case !dialer.Deadline.IsZero():
deadline = dialer.Deadline
case dialer.Timeout != 0:
deadline = time.Now().Add(dialer.Timeout)
}
localSockaddr = sockaddrnet.NetAddrToSockaddr(dialer.LocalAddr)
remoteSockaddr = sockaddrnet.NetAddrToSockaddr(netAddr)
rfamily = sockaddrnet.NetAddrAF(netAddr)
rprotocol = sockaddrnet.NetAddrIPPROTO(netAddr)
socktype = sockaddrnet.NetAddrSOCK(netAddr)
if dialer.LocalAddr != nil {
switch dialer.LocalAddr.(type) {
case *net.TCPAddr, *net.UDPAddr:
default:
return nil, ErrUnsupportedProtocol
}
// check family and protocols match.
lfamily = sockaddrnet.NetAddrAF(dialer.LocalAddr)
lprotocol = sockaddrnet.NetAddrIPPROTO(dialer.LocalAddr)
if lfamily != rfamily || lprotocol != rprotocol {
return nil, &net.AddrError{Err: "unexpected address type", Addr: netAddr.String()}
}
}
// look at dialTCP in http://golang.org/src/net/tcpsock_posix.go .... !
// here we just try again 3 times.
for i := 0; i < 3; i++ {
if !deadline.IsZero() && deadline.Before(time.Now()) {
err = errTimeout
break
}
if fd, err = socket(rfamily, socktype, rprotocol); err != nil {
return nil, err
}
if localSockaddr != nil {
if err = syscall.Bind(fd, localSockaddr); err != nil {
syscall.Close(fd)
return nil, err
}
}
if err = syscall.SetNonblock(fd, true); err != nil {
syscall.Close(fd)
return nil, err
}
if err = connect(fd, remoteSockaddr, deadline); err != nil {
syscall.Close(fd)
continue // try again.
}
break
}
if err != nil {
return nil, err
}
if rprotocol == syscall.IPPROTO_TCP {
// by default golang/net sets TCP no delay to true.
if err = setNoDelay(fd, true); err != nil {
syscall.Close(fd)
return nil, err
}
}
// File Name get be nil
file = os.NewFile(uintptr(fd), filePrefix+strconv.Itoa(os.Getpid()))
if c, err = net.FileConn(file); err != nil {
syscall.Close(fd)
return nil, err
}
if err = file.Close(); err != nil {
syscall.Close(fd)
c.Close()
return nil, err
}
// c = wrapConnWithRemoteAddr(c, netAddr)
return c, err
}