platform: Add link flags

experimental/libbox/link_flags_linux.go

@@ -0,0 +1,30 @@
+package libbox
+
+import (
+	"net"
+	"syscall"
+)
+
+// copied from net.linkFlags
+func linkFlags(rawFlags uint32) net.Flags {
+	var f net.Flags
+	if rawFlags&syscall.IFF_UP != 0 {
+		f |= net.FlagUp
+	}
+	if rawFlags&syscall.IFF_RUNNING != 0 {
+		f |= net.FlagRunning
+	}
+	if rawFlags&syscall.IFF_BROADCAST != 0 {
+		f |= net.FlagBroadcast
+	}
+	if rawFlags&syscall.IFF_LOOPBACK != 0 {
+		f |= net.FlagLoopback
+	}
+	if rawFlags&syscall.IFF_POINTOPOINT != 0 {
+		f |= net.FlagPointToPoint
+	}
+	if rawFlags&syscall.IFF_MULTICAST != 0 {
+		f |= net.FlagMulticast
+	}
+	return f
+}