wintun: Migrate from unsafe buffer handling to encoding/binary

Signed-off-by: Simon Rozman <simon@rozman.si>

diff --git a/tun/tun_windows.go b/tun/tun_windows.go
index 838fdd1f2136f17ebde37dfc8b4ccd5d6cb103ee..5640a5d065a68bc58abebcdcee48fc4a4bf164c1 100644 (file)
--- a/tun/tun_windows.go
+++ b/tun/tun_windows.go
@@ -6,10 +6,10 @@
 package tun
 
 import (
+       "encoding/binary"
        "errors"
        "os"
        "sync"
-       "unsafe"
 
        "golang.org/x/sys/windows"
        "golang.zx2c4.com/wireguard/tun/wintun"
@@ -230,16 +230,18 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
        for {
                if tun.rdBuff.offset+packetExchangeAlignment <= tun.rdBuff.avail {
                        // Get packet from the exchange buffer.
-                       size := *(*uint32)(unsafe.Pointer(&tun.rdBuff.data[tun.rdBuff.offset]))
+                       packet := tun.rdBuff.data[tun.rdBuff.offset:]
+                       size := binary.LittleEndian.Uint32(packet[:4])
                        pSize := packetAlign(packetExchangeAlignment + size)
                        if packetSizeMax < size || tun.rdBuff.avail < tun.rdBuff.offset+pSize {
                                // Invalid packet size.
                                tun.rdBuff.avail = 0
                                continue
                        }
+                       packet = packet[:pSize]
 
                        // Copy data.
-                       copy(buff[offset:], tun.rdBuff.data[tun.rdBuff.offset+packetExchangeAlignment:][:size])
+                       copy(buff[offset:], packet[packetExchangeAlignment:][:size])
                        tun.rdBuff.offset += pSize
                        return int(size), nil
                }
@@ -330,8 +332,9 @@ func (tun *nativeTun) putTunPacket(buff []byte) error {
        }
 
        // Write packet to the exchange buffer.
-       *(*uint32)(unsafe.Pointer(&tun.wrBuff.data[tun.wrBuff.offset])) = size
-       copy(tun.wrBuff.data[tun.wrBuff.offset+packetExchangeAlignment:][:size], buff)
+       packet := tun.wrBuff.data[tun.wrBuff.offset:][:pSize]
+       binary.LittleEndian.PutUint32(packet[:4], size)
+       copy(packet[packetExchangeAlignment:][:size], buff)
 
        tun.wrBuff.packetNum++
        tun.wrBuff.offset += pSize