xudt: Implement address and data extraction

The cellmgr-ng unfortunately looks at the data being sent and can't
handle the presence of XUDT at all. Add the structure definition
and refactor extraction code to work on offsets. Add a unit test.

Change-Id: I45a7447cc1be432fff34849e0e35abc0410cf153

1 files changed, 54 insertions, 0 deletions

diff --git a/include/osmocom/sccp/sccp_types.h b/include/osmocom/sccp/sccp_types.h
index ab7f74f..18b54f4 100644
--- a/include/osmocom/sccp/sccp_types.h
+++ b/include/osmocom/sccp/sccp_types.h
@@ -422,6 +422,60 @@ struct sccp_data_unitdata_service {
 	uint8_t			data[0];
 } __attribute__((packed));
 
+/* Extended unitdata (XUDT) */
+struct sccp_data_ext_unitdata {
+	/* mandatory */
+	uint8_t			type;
+	uint8_t			proto_class;
+	uint8_t			hop_counter;
+
+	/* variable */
+	uint8_t			variable_called;
+	uint8_t			variable_calling;
+	uint8_t			variable_data;
+
+#if VARIABLE
+	called party address
+	calling party address
+	data
+#endif
+
+#if OPTIONAL
+	segmentation
+	importance
+#endif
+
+	uint8_t			data[0];
+
+} __attribute__((packed));
+
+
+/* Extended unitdata service (XUDTS) */
+struct  sccp_data_ext_unitdata_service {
+	/* mandantory */
+	uint8_t			type;
+	uint8_t			return_cause;
+	uint8_t			hop_counter;
+
+
+	/* variable */
+	uint8_t			variable_called;
+	uint8_t			variable_calling;
+	uint8_t			variable_data;
+
+#if VARIABLE
+	called party address
+	calling party address
+	data
+#endif
+
+#if OPTIONAL
+	segmentation
+	importancd
+#endif
+
+	uint8_t			data[0];
+} __attribute__((packed));
 
 struct sccp_data_it {
 	/* mandatory */