1 files changed, 42 insertions, 0 deletions
diff --git a/protm.h b/protm.h
new file mode 100644
index 0000000..4939df2
--- /dev/null
+++ b/protm.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <stdlib.h>
+#include <stdint.h>
+
+
+#define PROTM_MAX_SIZE 65536
+
+#define PROTM_TYPE_ESTAB 1
+#define PROTM_TYPE_TERM 2
+#define PROTM_TYPE_DATA 3
+#define PROTM_TYPE_RR 4
+#define PROTM_TYPE_RR_POLL 5
+
+struct __attribute__((packed)) protm {
+	uint8_t type;
+	union {
+		struct {
+			uint8_t ack;
+		} estab;
+		struct {
+			uint8_t ack;
+		} term;
+		struct {
+			uint8_t seqnum, rr;
+			uint32_t size;
+			// An IPv4 packet is at most 65536 bytes, so the data portion
+			// left after allowing for the IPv4 and ICMP headers as well
+			// as those for this protocol, is surely at most 65536 bytes.
+			uint8_t data[65536];
+		} data;
+		struct {
+			uint8_t rr, nrej;
+			uint8_t rej[256];
+		} rr;
+		struct {
+			// empty
+		} rr_poll;
+	};
+};
+
+size_t protm_size(const struct protm *pm);