type safety for 'bool downstream'

funky naming 'stream.down', because downstream.downstream is just too long...

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Id234654fa8960e7430fc33119f36fd94b858d242
diff --git a/bpf_progs/bpf_net_helpers.h b/bpf_progs/bpf_net_helpers.h
index 9522f87..f3c7de5 100644
--- a/bpf_progs/bpf_net_helpers.h
+++ b/bpf_progs/bpf_net_helpers.h
@@ -91,9 +91,9 @@
 #define INGRESS ((struct egress_bool){ .egress = false })
 #define EGRESS ((struct egress_bool){ .egress = true })
 
-// constants for passing in to 'bool downstream'
-static const bool UPSTREAM = false;
-static const bool DOWNSTREAM = true;
+struct stream_bool { bool down; };
+#define UPSTREAM ((struct stream_bool){ .down = false })
+#define DOWNSTREAM ((struct stream_bool){ .down = true })
 
 struct rawip_bool { bool rawip; };
 #define ETHER ((struct rawip_bool){ .rawip = false })