add iu_common.h using C structs to describe PER encoded Iu headers
diff --git a/src/iu_common.h b/src/iu_common.h
new file mode 100644
index 0000000..11c2a79
--- /dev/null
+++ b/src/iu_common.h
@@ -0,0 +1,23 @@
+#pragma once
+
+/* A humble attempt of reading the Iu messages (RUA/RANAP/HNBAP) without an asn.1 parser.
+ * Not actually used anywhere (yet?) */
+
+struct iu_common_hdr {
+ uint8_t msg_type;
+ uint8_t procedure_code;
+ uint8_t criticality;
+ uint8_t len; /* first byte of length field */
+ uint8_t payload[0]; /* possible further length field + payload */
+ /* extension? */
+ /* ? */
+ /* number of ProtocolIEs */
+} __attribute__ ((packed));
+
+struct iu_common_ie {
+ uint16_t iei;
+ uint8_t criticality;
+ uint8_t len; /* first byte of length field */
+ uint8_t payload[0]; /* possible further length field + payload */
+} __attribute__ ((packed));
+