Implement IuCS (large refactoring and addition)

osmo-nitb becomes osmo-msc
add DIUCS debug log constant
add iucs.[hc]
add msc vty, remove nitb vty
add libiudummy, to avoid linking Iu deps in tests
Use new msc_tx_dtap() instead of gsm0808_submit_dtap()
libmgcp: add mgcpgw client API
bridge calls via mgcpgw

mgcp: hack RAB success from nano3G: patch first RTP payload
The ip.access nano3G needs the first RTP payload's first two bytes to read hex
'e400', or it will reject the RAB assignment. Add flag
patched_first_rtp_payload to mgcp_rtp_state to detect the first RTP payload on
a stream, and overwrite its first bytes with e400. This should probably be
configurable, but seems to not harm other femto cells (as long as we patch only
the first RTP payload in each stream). Only do this when sending to the BTS
side.

Change-Id: I5b5b6a9678b458affa86800afb1ec726e66eed88

1 files changed, 18 insertions, 6 deletions

diff --git a/src/libmsc/transaction.c b/src/libmsc/transaction.c
index 41fb5a914..73c509c2c 100644
--- a/src/libmsc/transaction.c
+++ b/src/libmsc/transaction.c
@@ -180,23 +180,35 @@ int trans_assign_trans_id(struct gsm_network *net, struct vlr_subscr *vsub,
  * \param[in] conn Connection to check
  * \returns 1 in case there is a transaction, 0 otherwise
  */
-int trans_has_conn(const struct gsm_subscriber_connection *conn)
+struct gsm_trans *trans_has_conn(const struct gsm_subscriber_connection *conn)
 {
 	struct gsm_trans *trans;
 
 	llist_for_each_entry(trans, &conn->network->trans_list, entry)
 		if (trans->conn == conn)
-			return 1;
+			return trans;
 
-	return 0;
+	return NULL;
 }
 
+/*
+ * Free all transactions that are associated with the released
+ * connection. The transaction code will inform the CC or SMS
+ * facilities that will send the release indications.
+ */
 void trans_conn_closed(struct gsm_subscriber_connection *conn)
 {
-	struct gsm_trans *trans, *t2;
+	struct gsm_trans *trans;
 
-	llist_for_each_entry_safe(trans, t2, &conn->network->trans_list, entry) {
-		if (trans->conn == conn)
+	/* As part of the CC REL_IND the remote leg might be released and this
+	 * will trigger the call to trans_free. This is something the llist
+	 * macro can not handle and we will need to re-iterate the list.
+	 */
+restart:
+	llist_for_each_entry(trans, &conn->network->trans_list, entry) {
+		if (trans->conn == conn) {
 			trans_free(trans);
+			goto restart;
+		}
 	}
 }