mncc: Implement CRCX->MDCX for handover for direct rtp mode
Implement sending MDCX on the newly allocated channel and send
the data to the same destination as the currently connected one.
This way the receiver can implement RTP RFC Appendix A.1 and
deal with the new source.
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index 776a11d..4cfba1c 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -1460,6 +1460,15 @@
{
struct rtp_socket *old_rs, *new_rs, *other_rs;
+ /* Ask the new socket to send to the already known port. */
+ if (new_lchan->conn->mncc_rtp_bridge) {
+ LOGP(DHO, LOGL_DEBUG, "Forwarding RTP\n");
+ rsl_ipacc_mdcx(new_lchan,
+ old_lchan->abis_ip.connect_ip,
+ old_lchan->abis_ip.connect_port, 0);
+ return 0;
+ }
+
if (ipacc_rtp_direct) {
LOGP(DHO, LOGL_ERROR, "unable to handover in direct RTP mode\n");
return 0;
@@ -1504,11 +1513,19 @@
return 0;
}
+static void maybe_switch_for_handover(struct gsm_lchan *lchan)
+{
+ struct gsm_lchan *old_lchan;
+ old_lchan = bsc_handover_pending(lchan);
+ if (old_lchan)
+ switch_for_handover(old_lchan, lchan);
+}
+
/* some other part of the code sends us a signal */
static int handle_abisip_signal(unsigned int subsys, unsigned int signal,
void *handler_data, void *signal_data)
{
- struct gsm_lchan *lchan = signal_data, *old_lchan;
+ struct gsm_lchan *lchan = signal_data;
int rc;
struct gsm_network *net;
struct gsm_trans *trans;
@@ -1561,9 +1578,7 @@
* Do we have a handover pending for this new lchan? In that
* case re-route the audio from the old channel to the new one.
*/
- old_lchan = bsc_handover_pending(lchan);
- if (old_lchan)
- switch_for_handover(old_lchan, lchan);
+ maybe_switch_for_handover(lchan);
break;
case S_ABISIP_DLCX_IND:
/* the BTS tells us a RTP stream has been disconnected */
@@ -3065,6 +3080,7 @@
* complains about both rtp and rtp payload2 being present in the
* same package!
*/
+ trans->conn->mncc_rtp_connect_pending = 1;
return rsl_ipacc_mdcx(lchan, rtp->ip, rtp->port, 0);
}
@@ -3077,7 +3093,7 @@
llist_for_each_entry(tmp, &net->trans_list, entry) {
if (!tmp->conn)
continue;
- if (tmp->conn->lchan != lchan)
+ if (tmp->conn->lchan != lchan && tmp->conn->ho_lchan != lchan)
continue;
trans = tmp;
break;
@@ -3097,9 +3113,15 @@
gsm_lchan_name(lchan));
mncc_recv_rtp_sock(net, trans, MNCC_RTP_CREATE);
}
+ /*
+ * TODO: this appears to be too early? Why not until after
+ * the handover detect or the handover complete?
+ */
+ maybe_switch_for_handover(lchan);
break;
case S_ABISIP_MDCX_ACK:
- if (lchan->conn->mncc_rtp_bridge) {
+ if (lchan->conn->mncc_rtp_connect_pending) {
+ lchan->conn->mncc_rtp_connect_pending = 0;
LOGP(DMNCC, LOGL_NOTICE, "%s sending pending RTP connect ind.\n",
gsm_lchan_name(lchan));
mncc_recv_rtp_sock(net, trans, MNCC_RTP_CONNECT);