[handover] implement TCH RTP stream handover
This patch takes care of handling the RTP streams / sockets during
an in-call handover from one BTS to another BTS.
It only works in combination with rtp_proxy mode.
diff --git a/openbsc/src/handover_logic.c b/openbsc/src/handover_logic.c
index 2c75497..3007d25 100644
--- a/openbsc/src/handover_logic.c
+++ b/openbsc/src/handover_logic.c
@@ -40,6 +40,7 @@
#include <openbsc/signal.h>
#include <openbsc/talloc.h>
#include <openbsc/transaction.h>
+#include <openbsc/rtp_proxy.h>
struct bsc_handover {
struct llist_head list;
@@ -173,6 +174,10 @@
ho->T3103.data = ho;
bsc_schedule_timer(&ho->T3103, 10, 0);
+ /* create a RTP connection */
+ if (is_ipaccess_bts(new_lchan->ts->trx->bts))
+ rsl_ipacc_crcx(new_lchan);
+
return 0;
}
@@ -213,7 +218,6 @@
trans_lchan_change(ho->old_lchan, new_lchan);
/* do something to re-route the actual speech frames ! */
- //tch_remap(ho->old_lchan, ho->new_lchan);
talloc_free(ho);
@@ -255,6 +259,61 @@
return 0;
}
+static int ho_ipac_crcx_ack(struct gsm_lchan *new_lchan)
+{
+ struct bsc_handover *ho;
+ struct rtp_socket *old_rs, *new_rs, *other_rs;
+
+ ho = bsc_ho_by_new_lchan(new_lchan);
+ if (!ho) {
+ LOGP(DHO, LOGL_ERROR, "unable to find HO record\n");
+ return -ENODEV;
+ }
+
+ if (ipacc_rtp_direct) {
+ LOGP(DHO, LOGL_ERROR, "unable to handover in direct RTP mode\n");
+ return 0;
+ }
+
+ /* RTP Proxy mode */
+ new_rs = new_lchan->abis_ip.rtp_socket;
+ old_rs = ho->old_lchan->abis_ip.rtp_socket;
+
+ if (!new_rs) {
+ LOGP(DHO, LOGL_ERROR, "no RTP socket for new_lchan\n");
+ return -EIO;
+ }
+
+ rsl_ipacc_mdcx_to_rtpsock(new_lchan);
+
+ if (!old_rs) {
+ LOGP(DHO, LOGL_ERROR, "no RTP socekt for old_lchan\n");
+ return -EIO;
+ }
+
+ /* copy rx_action and reference to other sock */
+ new_rs->rx_action = old_rs->rx_action;
+ new_rs->tx_action = old_rs->tx_action;
+ new_rs->transmit = old_rs->transmit;
+
+ switch (ho->old_lchan->abis_ip.rtp_socket->rx_action) {
+ case RTP_PROXY:
+ other_rs = old_rs->proxy.other_sock;
+ rtp_socket_proxy(new_rs, other_rs);
+ /* delete reference to other end socket to prevent
+ * rtp_socket_free() from removing the inverse reference */
+ old_rs->proxy.other_sock = NULL;
+ break;
+ case RTP_RECV_UPSTREAM:
+ new_rs->receive = old_rs->receive;
+ break;
+ case RTP_NONE:
+ break;
+ }
+
+ return 0;
+}
+
static int ho_logic_sig_cb(unsigned int subsys, unsigned int signal,
void *handler_data, void *signal_data)
{
@@ -276,6 +335,14 @@
return ho_gsm48_ho_fail(lchan);
}
break;
+ case SS_ABISIP:
+ lchan = signal_data;
+ switch (signal) {
+ case S_ABISIP_CRCX_ACK:
+ return ho_ipac_crcx_ack(lchan);
+ break;
+ }
+ break;
default:
break;
}
@@ -286,4 +353,5 @@
static __attribute__((constructor)) void on_dso_load_ho_logic(void)
{
register_signal_handler(SS_LCHAN, ho_logic_sig_cb, NULL);
+ register_signal_handler(SS_ABISIP, ho_logic_sig_cb, NULL);
}