add ran_infra.force_mgw_codecs_to_ran

Indicate in the ran_infra data structure whether a RAN needs specific
codecs to be set up on the RAN facing MGW endpoint.

This allows setting forced RAN codecs as first-class citizen in the
ran_infra data structure, instead of special cases in the code (for IuUP
on IuCS).

Will be used in subsequent commit
I37f65c36af2679ecba1040a11a9aa0eb9481d817, submitted separately for
easier readability.

Change-Id: I37f65c36af2679ecba1040a11a9aa0eb9481d817
diff --git a/include/osmocom/msc/ran_infra.h b/include/osmocom/msc/ran_infra.h
index 38c424f..262a9c8 100644
--- a/include/osmocom/msc/ran_infra.h
+++ b/include/osmocom/msc/ran_infra.h
@@ -4,6 +4,7 @@
 #include <osmocom/gsm/gsup.h>
 #include <osmocom/msc/sccp_ran.h>
 #include <osmocom/msc/ran_msg.h>
+#include <osmocom/msc/sdp_msg.h>
 
 struct osmo_tdef;
 
@@ -25,6 +26,10 @@
 	const ran_dec_l2_t ran_dec_l2;
 	const ran_encode_t ran_encode;
 	struct sccp_ran_inst *sri;
+	/* To always set up the MGW endpoint facing the RAN side with specific codecs, list those here. Otherwise leave
+	 * empty (to use the result of codecs filtering). This exists for IuCS, to always set the MGW endpoint facing
+	 * RAN to IUFP, to decapsulate the IuUP headers. */
+	struct sdp_audio_codecs force_mgw_codecs_to_ran;
 };
 
 extern struct ran_infra msc_ran_infra[];