Implement AoIP, port to M3UA SIGTRAN (large addition and refactoring)

This was originally a long series of commits converging to the final result
seen in this patch. It does not make much sense to review the smaller steps'
trial and error, we need to review this entire change as a whole.

Implement AoIP in osmo-msc and osmo-bsc.

Change over to the new libosmo-sigtran API with support for proper
SCCP/M3UA/SCTP stacking, as mandated by 3GPP specifications for the IuCS and
IuPS interfaces.

From here on, a separate osmo-stp process is required for SCCP routing between
OsmoBSC / OsmoHNBGW <-> OsmoMSC / OsmoSGSN

Patch-by: pmaier, nhofmeyr, laforge
Change-Id: I5ae4e05ee7c57cad341ea5e86af37c1f6b0ffa77

1 files changed, 12 insertions, 11 deletions

diff --git a/src/libmsc/osmo_msc.c b/src/libmsc/osmo_msc.c
index ddc383612..866cfbd07 100644
--- a/src/libmsc/osmo_msc.c
+++ b/src/libmsc/osmo_msc.c
@@ -29,11 +29,12 @@
 #include <openbsc/vlr.h>
 #include <openbsc/osmo_msc.h>
 #include <openbsc/iu.h>
+#include <openbsc/a_iface.h>
 
 #include <openbsc/gsm_04_11.h>
 
 /* Receive a SAPI-N-REJECT from BSC */
-static void msc_sapi_n_reject(struct gsm_subscriber_connection *conn, int dlci)
+void msc_sapi_n_reject(struct gsm_subscriber_connection *conn, int dlci)
 {
 	int sapi = dlci & 0x7;
 
@@ -106,24 +107,24 @@ void msc_dtap(struct gsm_subscriber_connection *conn, uint8_t link_id, struct ms
 }
 
 /* Receive an ASSIGNMENT COMPLETE from BSC */
-static void msc_assign_compl(struct gsm_subscriber_connection *conn,
-			     uint8_t rr_cause, uint8_t chosen_channel,
-			     uint8_t encr_alg_id, uint8_t speec)
+void msc_assign_compl(struct gsm_subscriber_connection *conn,
+		      uint8_t rr_cause, uint8_t chosen_channel,
+		      uint8_t encr_alg_id, uint8_t speec)
 {
 	LOGP(DRR, LOGL_DEBUG, "MSC assign complete (do nothing).\n");
 }
 
 /* Receive an ASSIGNMENT FAILURE from BSC */
-static void msc_assign_fail(struct gsm_subscriber_connection *conn,
-			    uint8_t cause, uint8_t *rr_cause)
+void msc_assign_fail(struct gsm_subscriber_connection *conn,
+		     uint8_t cause, uint8_t *rr_cause)
 {
 	LOGP(DRR, LOGL_DEBUG, "MSC assign failure (do nothing).\n");
 }
 
 /* Receive a CLASSMARK CHANGE from BSC */
-static void msc_classmark_chg(struct gsm_subscriber_connection *conn,
-			      const uint8_t *cm2, uint8_t cm2_len,
-			      const uint8_t *cm3, uint8_t cm3_len)
+void msc_classmark_chg(struct gsm_subscriber_connection *conn,
+		       const uint8_t *cm2, uint8_t cm2_len,
+		       const uint8_t *cm3, uint8_t cm3_len)
 {
 	if (cm2 && cm2_len) {
 		if (cm2_len > sizeof(conn->classmark.classmark2)) {
@@ -250,7 +251,7 @@ void msc_subscr_con_free(struct gsm_subscriber_connection *conn)
 }
 
 /* Receive a CLEAR REQUEST from BSC */
-static int msc_clear_request(struct gsm_subscriber_connection *conn, uint32_t cause)
+int msc_clear_request(struct gsm_subscriber_connection *conn, uint32_t cause)
 {
 	msc_subscr_conn_close(conn, cause);
 	return 1;
@@ -290,7 +291,7 @@ static void msc_subscr_conn_release_all(struct gsm_subscriber_connection *conn,
 		 * says "unknown UE" for each release outcome. */
 		break;
 	case RAN_GERAN_A:
-		/* future: a_iface_tx_clear_cmd(conn); */
+		a_iface_tx_clear_cmd(conn);
 		break;
 	default:
 		LOGP(DMM, LOGL_ERROR, "%s: Unknown RAN type, cannot tx release/clear\n",