handover: Fix the handover signalling for IP based BTSes
This was reported by Kevin when he was testing handover. The problem
is the order of the signal handlers for S_ABISIP_CRCX_ACK. Right now
the handover signal handler is called before the one inside the libmsc
gsm_04_08.c. This means S_HANDOVER_ACK is signalled _before_ there is a
rtp socket created for the channel. The result is that the MDCX will
never be sent and the called will not be properly switched _after_ the
handover detection.
I do not want to play with the order of signal handlers, remove the
CRCX ack handling from the handover_logic.c and force the NITB (and
later the BSC) to check if the lchan is involved with a handover and
do the switching in there. This means right now we do what two signal
handlers did in one.
Reproduced and tested with the FakeBTS Handover test.
Log message:
<0004> abis_rsl.c:1954 (bts=1,trx=0,ts=3,ss=0) IPAC_CRCX_ACK ...
<000c> gsm_04_08.c:1400 no RTP socket for new_lchan
<001a> rtp_proxy.c:533 rtp_socket_create(): success
<001a> rtp_proxy.c:615 rtp_socket_bind(rs=0x48703c8, IP=0.0.0.0): ...
diff --git a/openbsc/src/libbsc/handover_logic.c b/openbsc/src/libbsc/handover_logic.c
index d2cd5ef..9cf26af 100644
--- a/openbsc/src/libbsc/handover_logic.c
+++ b/openbsc/src/libbsc/handover_logic.c
@@ -329,23 +329,6 @@
return 0;
}
-static int ho_ipac_crcx_ack(struct gsm_lchan *new_lchan)
-{
- struct bsc_handover *ho;
- struct ho_signal_data sig_ho;
-
- ho = bsc_ho_by_new_lchan(new_lchan);
- if (!ho) {
- /* it is perfectly normal, we have CRCX even in non-HO cases */
- return 0;
- }
-
- sig_ho.old_lchan = ho->old_lchan;
- sig_ho.new_lchan = new_lchan;
- osmo_signal_dispatch(SS_HO, S_HANDOVER_ACK, &sig_ho);
- return 0;
-}
-
static int ho_logic_sig_cb(unsigned int subsys, unsigned int signal,
void *handler_data, void *signal_data)
{
@@ -369,14 +352,6 @@
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;
}
@@ -384,8 +359,16 @@
return 0;
}
+struct gsm_lchan *bsc_handover_pending(struct gsm_lchan *new_lchan)
+{
+ struct bsc_handover *ho;
+ ho = bsc_ho_by_new_lchan(new_lchan);
+ if (!ho)
+ return NULL;
+ return ho->old_lchan;
+}
+
static __attribute__((constructor)) void on_dso_load_ho_logic(void)
{
osmo_signal_register_handler(SS_LCHAN, ho_logic_sig_cb, NULL);
- osmo_signal_register_handler(SS_ABISIP, ho_logic_sig_cb, NULL);
}