device: create beginnings of conn_windows

device/conn_default.go

@@ -1,4 +1,5 @@
 // +build !linux android
+// +build !windows
 
 /* SPDX-License-Identifier: MIT
  *

device/conn_windows.go

@@ -0,0 +1,185 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+import (
+	"net"
+	"os"
+	"syscall"
+)
+
+type nativeBind struct {
+	ipv4 *net.UDPConn
+	ipv4Raw syscall.RawConn
+	ipv6 *net.UDPConn
+	ipv6Raw syscall.RawConn
+}
+
+type NativeEndpoint net.UDPAddr
+
+var _ Bind = (*nativeBind)(nil)
+var _ Endpoint = (*NativeEndpoint)(nil)
+
+func CreateEndpoint(s string) (Endpoint, error) {
+	addr, err := parseEndpoint(s)
+	return (*NativeEndpoint)(addr), err
+}
+
+func (_ *NativeEndpoint) ClearSrc() {}
+
+func (e *NativeEndpoint) DstIP() net.IP {
+	return (*net.UDPAddr)(e).IP
+}
+
+func (e *NativeEndpoint) SrcIP() net.IP {
+	return nil // not supported
+}
+
+func (e *NativeEndpoint) DstToBytes() []byte {
+	addr := (*net.UDPAddr)(e)
+	out := addr.IP.To4()
+	if out == nil {
+		out = addr.IP
+	}
+	out = append(out, byte(addr.Port&0xff))
+	out = append(out, byte((addr.Port>>8)&0xff))
+	return out
+}
+
+func (e *NativeEndpoint) DstToString() string {
+	return (*net.UDPAddr)(e).String()
+}
+
+func (e *NativeEndpoint) SrcToString() string {
+	return ""
+}
+
+func listenNet(network string, port int) (*net.UDPConn, int, error) {
+
+	// listen
+
+	conn, err := net.ListenUDP(network, &net.UDPAddr{Port: port})
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// retrieve port
+
+	laddr := conn.LocalAddr()
+	uaddr, err := net.ResolveUDPAddr(
+		laddr.Network(),
+		laddr.String(),
+	)
+	if err != nil {
+		return nil, 0, err
+	}
+	return conn, uaddr.Port, nil
+}
+
+func extractErrno(err error) error {
+	opErr, ok := err.(*net.OpError)
+	if !ok {
+		return nil
+	}
+	syscallErr, ok := opErr.Err.(*os.SyscallError)
+	if !ok {
+		return nil
+	}
+	return syscallErr.Err
+}
+
+func CreateBind(uport uint16, device *Device) (Bind, uint16, error) {
+	var err error
+	var bind nativeBind
+
+	port := int(uport)
+
+	bind.ipv4, port, err = listenNet("udp4", port)
+	if err != nil && extractErrno(err) != syscall.EAFNOSUPPORT {
+		return nil, 0, err
+	}
+
+	bind.ipv6, port, err = listenNet("udp6", port)
+	if err != nil && extractErrno(err) != syscall.EAFNOSUPPORT {
+		bind.ipv4.Close()
+		bind.ipv4 = nil
+		return nil, 0, err
+	}
+
+	bind.ipv4Raw, err = bind.ipv4.SyscallConn()
+	if err != nil {
+		bind.ipv4.Close()
+		bind.ipv4 = nil
+		return nil, 0, err
+		bind.ipv6.Close()
+		bind.ipv6 = nil
+		return nil, 0, err
+	}
+	bind.ipv6Raw, err = bind.ipv6.SyscallConn()
+	if err != nil {
+		bind.ipv4.Close()
+		bind.ipv4 = nil
+		return nil, 0, err
+		bind.ipv6.Close()
+		bind.ipv6 = nil
+		return nil, 0, err
+	}
+	return &bind, uint16(port), nil
+}
+
+func (bind *nativeBind) Close() error {
+	var err1, err2 error
+	if bind.ipv4 != nil {
+		err1 = bind.ipv4.Close()
+	}
+	if bind.ipv6 != nil {
+		err2 = bind.ipv6.Close()
+	}
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func (bind *nativeBind) ReceiveIPv4(buff []byte) (int, Endpoint, error) {
+	if bind.ipv4 == nil {
+		return 0, nil, syscall.EAFNOSUPPORT
+	}
+	n, endpoint, err := bind.ipv4.ReadFromUDP(buff)
+	if endpoint != nil {
+		endpoint.IP = endpoint.IP.To4()
+	}
+	return n, (*NativeEndpoint)(endpoint), err
+}
+
+func (bind *nativeBind) ReceiveIPv6(buff []byte) (int, Endpoint, error) {
+	if bind.ipv6 == nil {
+		return 0, nil, syscall.EAFNOSUPPORT
+	}
+	n, endpoint, err := bind.ipv6.ReadFromUDP(buff)
+	return n, (*NativeEndpoint)(endpoint), err
+}
+
+func (bind *nativeBind) Send(buff []byte, endpoint Endpoint, now bool) error {
+	var err error
+	nend := endpoint.(*NativeEndpoint)
+	if nend.IP.To4() != nil {
+		if bind.ipv4 == nil {
+			return syscall.EAFNOSUPPORT
+		}
+		_, err = bind.ipv4.WriteToUDP(buff, (*net.UDPAddr)(nend))
+	} else {
+		if bind.ipv6 == nil {
+			return syscall.EAFNOSUPPORT
+		}
+		_, err = bind.ipv6.WriteToUDP(buff, (*net.UDPAddr)(nend))
+	}
+	return err
+}
+
+func (bind *nativeBind) Flush() error {
+	return nil
+}