Fix: tun issue with virtio_net_hdr (#254)

core/device/tun/tun_wireguard_linux.go

@@ -0,0 +1,24 @@
+//go:build linux && !(amd64 || arm64)
+
+package tun
+
+import (
+	"unsafe"
+)
+
+const (
+	virtioNetHdrLen = int(unsafe.Sizeof(virtioNetHdr{}))
+	offset          = virtioNetHdrLen + 0 /* NO_PI */
+	defaultMTU      = 1500
+)
+
+// virtioNetHdr is defined in the kernel in include/uapi/linux/virtio_net.h. The
+// kernel symbol is virtio_net_hdr.
+type virtioNetHdr struct {
+	flags      uint8
+	gsoType    uint8
+	hdrLen     uint16
+	gsoSize    uint16
+	csumStart  uint16
+	csumOffset uint16
+}

core/device/tun/tun_wireguard_unix.go

@@ -1,8 +1,7 @@
-//go:build unix
+//go:build unix && !linux
 
 package tun
 
-//nolint:all
 const (
 	offset     = 4 /* 4 bytes TUN_PI */
 	defaultMTU = 1500