do CN CRCX first
In order to send the MSC's RTP endpoint IP address+port in the inital
SDP, move the MGCP CRCX up to an earlier point in the sequence of
establishing a voice call.
Update the voice call sequence chart to show the effects.
Related: SYS#5066
Change-Id: Ie433db1ba0c46d4b97538a969233c155cefac21c
diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 8eb76b3..4bd6bfa 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -515,10 +515,6 @@
unsigned int payload_len = msgb_l3len(msg) - sizeof(*gh);
struct tlv_parsed tp;
struct gsm_mncc setup;
- struct osmo_sockaddr_str *rtp_cn_local;
- struct sdp_msg *sdp;
- struct msc_a *msc_a = trans->msc_a;
- int rc;
gsm48_start_guard_timer(trans);
@@ -543,6 +539,8 @@
msgb_free(gcr_msg);
}
+ OSMO_ASSERT(trans->msc_a);
+
tlv_parse(&tp, &gsm48_att_tlvdef, gh->data, payload_len, 0, 0);
/* emergency setup is identified by msg_type */
if (msg_type == GSM48_MT_CC_EMERG_SETUP) {
@@ -612,8 +610,6 @@
TLVP_VAL(&tp, GSM48_IE_CC_CAP)-1);
}
- new_cc_state(trans, GSM_CSTATE_INITIATED);
-
/* MO call leg starting, gather all codec information so far known: */
codec_filter_init(&trans->cc.codecs);
codec_filter_set_ran(&trans->cc.codecs, trans->msc_a->c.ran->type);
@@ -628,15 +624,53 @@
rate_ctr_inc(rate_ctr_group_get_ctr(trans->net->msc_ctrs, MSC_CTR_CALL_MO_SETUP));
+ new_cc_state(trans, GSM_CSTATE_INITIATED);
+
+ /* To complete the MNCC_SETUP_IND, we need to provide an RTP address and port. First instruct the MGW to create
+ * a CN-side RTP conn, and continue with MNCC_SETUP_IND once that is done. Leave trans.cc in GSM_CSTATE_NULL and
+ * note down the msg_type to indicate that we indeed composed an MNCC_SETUP_IND for later. */
+ setup.msg_type = MNCC_SETUP_IND;
+ trans->cc.msg = setup;
+ return msc_a_try_call_assignment(trans);
+ /* continue in gsm48_cc_rx_setup_cn_local_rtp_port_known() */
+}
+
+/* Callback for MNCC_SETUP_IND waiting for the core network RTP port to be established by the MGW (via msc_a) */
+void gsm48_cc_rx_setup_cn_local_rtp_port_known(struct gsm_trans *trans)
+{
+ struct msc_a *msc_a = trans->msc_a;
+ struct gsm_mncc setup = trans->cc.msg;
+ struct osmo_sockaddr_str *rtp_cn_local;
+ struct sdp_msg *sdp;
+ int rc;
+
+ if (trans->cc.state != GSM_CSTATE_INITIATED
+ || setup.msg_type != MNCC_SETUP_IND) {
+ LOG_TRANS(trans, LOGL_ERROR,
+ "Unexpected CC state. Expected GSM_CSTATE_NULL and a buffered MNCC_SETUP_IND message,"
+ " found CC state %d and msg_type %s\n",
+ trans->cc.state, get_mncc_name(setup.msg_type));
+ trans->callref = 0;
+ trans_free(trans);
+ return;
+ }
+
+ if (!msc_a) {
+ LOG_TRANS(trans, LOGL_ERROR, "No connection for CC trans\n");
+ trans->callref = 0;
+ trans_free(trans);
+ return;
+ }
+
+ /* 'setup' above has taken the value of trans->cc.msg, we can now clear that. */
+ trans->cc.msg = (struct gsm_mncc){};
+
/* Insert the CN side RTP port now available into SDP and compose SDP string */
rtp_cn_local = call_leg_local_ip(msc_a->cc.call_leg, RTP_TO_CN);
if (!osmo_sockaddr_str_is_nonzero(rtp_cn_local)) {
LOG_TRANS(trans, LOGL_ERROR, "Cannot compose SDP for MNCC_SETUP_IND: no RTP set up for the CN side\n");
- /* FIXME: re-add below two lines as soon as CN CRCX is done first
- * (see Change-Id Ie433db1ba0c46d4b97538a969233c155cefac21c).
- * keeping it non-fatal for the moment, for tests to continue succeeding. */
- //trans_free(trans);
- //return -EINVAL;
+ trans_free(trans);
+ return;
}
codec_filter_set_local_rtp(&trans->cc.codecs, rtp_cn_local);
@@ -646,16 +680,11 @@
if (rc >= sizeof(setup.sdp)) {
LOG_TRANS(trans, LOGL_ERROR, "MNCC_SETUP_IND: SDP too long (%d > %zu bytes)\n", rc, sizeof(setup.sdp));
trans_free(trans);
- return -EINVAL;
+ return;
}
/* indicate setup to MNCC */
mncc_recvmsg(trans->net, trans, MNCC_SETUP_IND, &setup);
-
- /* MNCC code will modify the channel asynchronously, we should
- * ipaccess-bind only after the modification has been made to the
- * lchan->tch_mode */
- return 0;
}
static int gsm48_cc_tx_setup(struct gsm_trans *trans, void *arg)
@@ -698,8 +727,6 @@
gh->msg_type = GSM48_MT_CC_SETUP;
- gsm48_start_cc_timer(trans, 0x303, GSM48_T303);
-
/* MT call leg is starting. Gather all codecs information so far known.
* (Usually) paging has succeeded, and now we're processing the MNCC Setup from the remote MO call leg.
* Initialize the codecs filter with this side's BSS' codec list, received at Complete Layer 3.
@@ -788,6 +815,8 @@
rate_ctr_inc(rate_ctr_group_get_ctr(trans->net->msc_ctrs, MSC_CTR_CALL_MT_SETUP));
+ gsm48_start_cc_timer(trans, 0x303, GSM48_T303);
+
return trans_tx_gsm48(trans, msg);
}
@@ -846,8 +875,6 @@
/* IMSI of called subscriber */
OSMO_STRLCPY_ARRAY(call_conf.imsi, trans->vsub->imsi);
- new_cc_state(trans, GSM_CSTATE_MO_TERM_CALL_CONF);
-
/* Assign call (if not done yet) */
rc = msc_a_try_call_assignment(trans);
@@ -856,8 +883,45 @@
if (rc)
return rc;
- return mncc_recvmsg(trans->net, trans, MNCC_CALL_CONF_IND,
- &call_conf);
+ /* Directly ack with MNCC_CALL_CONF_IND, not yet containing SDP or RTP IP:port information. */
+ new_cc_state(trans, GSM_CSTATE_MO_TERM_CALL_CONF);
+ return mncc_recvmsg(trans->net, trans, MNCC_CALL_CONF_IND, &call_conf);
+}
+
+static int mncc_recv_rtp(struct gsm_network *net, struct gsm_trans *trans, uint32_t callref,
+ int cmd, struct osmo_sockaddr_str *rtp_addr, uint32_t payload_type,
+ uint32_t payload_msg_type, const struct sdp_msg *sdp);
+
+int gsm48_cc_mt_rtp_port_and_codec_known(struct gsm_trans *trans)
+{
+ struct msc_a *msc_a = trans->msc_a;
+ struct osmo_sockaddr_str *rtp_cn_local;
+ struct gsm_mncc_rtp;
+
+ if (!msc_a) {
+ LOG_TRANS(trans, LOGL_ERROR, "No connection for CC trans\n");
+ trans->callref = 0;
+ trans_free(trans);
+ return -EINVAL;
+ }
+
+ /* Insert the CN side RTP port now available into SDP */
+ rtp_cn_local = call_leg_local_ip(msc_a->cc.call_leg, RTP_TO_CN);
+ if (!rtp_cn_local) {
+ LOG_TRANS(trans, LOGL_ERROR, "Cannot compose SDP for MNCC_RTP_CREATE: no RTP set up for the CN side\n");
+ trans_free(trans);
+ return -EINVAL;
+ }
+ codec_filter_set_local_rtp(&trans->cc.codecs, rtp_cn_local);
+
+ codec_filter_run(&trans->cc.codecs);
+ LOG_TRANS(trans, LOGL_DEBUG, "codecs: %s\n", codec_filter_to_str(&trans->cc.codecs));
+
+ if (!sdp_audio_codec_is_set(&trans->cc.codecs.assignment))
+ return 0;
+
+ return mncc_recv_rtp(msc_a_net(msc_a), trans, trans->callref, MNCC_RTP_CREATE, rtp_cn_local, 0, 0,
+ &trans->cc.codecs.result);
}
static int gsm48_cc_tx_call_proc_and_assign(struct gsm_trans *trans, void *arg)
@@ -1839,6 +1903,61 @@
return msc_a_try_call_assignment(trans);
}
+int cc_cn_local_rtp_port_known(struct gsm_trans *cc_trans)
+{
+ switch(cc_trans->cc.state) {
+ case GSM_CSTATE_INITIATED:
+ if (cc_trans->cc.msg.msg_type != MNCC_SETUP_IND) {
+ LOG_TRANS(cc_trans, LOGL_ERROR, "Assuming MO call, expected MNCC_SETUP_IND to be prepared\n");
+ return -EINVAL;
+ }
+ /* This is the MO call leg, waiting for a CN RTP be able to send initial MNCC_SETUP_IND. */
+ gsm48_cc_rx_setup_cn_local_rtp_port_known(cc_trans);
+ return 0;
+
+ case GSM_CSTATE_MO_TERM_CALL_CONF:
+ /* This is the MT call leg, waiting for a CN RTP to be able to send MNCC_CALL_CONF_IND. */
+ return gsm48_cc_mt_rtp_port_and_codec_known(cc_trans);
+
+ default:
+ LOG_TRANS(cc_trans, LOGL_ERROR, "CN RTP address available, but in unexpected state %d\n",
+ cc_trans->cc.state);
+ return -EINVAL;
+ }
+}
+
+int cc_assignment_done(struct gsm_trans *trans)
+{
+ struct msc_a *msc_a = trans->msc_a;
+
+ switch (trans->cc.state) {
+ case GSM_CSTATE_INITIATED:
+ case GSM_CSTATE_MO_CALL_PROC:
+ /* MO call */
+ break;
+
+ case GSM_CSTATE_CALL_RECEIVED:
+ case GSM_CSTATE_MO_TERM_CALL_CONF:
+ /* MT call */
+ break;
+
+ case GSM_CSTATE_ACTIVE:
+ /* already active. MNCC finished before Abis completed the Assignment. */
+ break;
+
+ default:
+ LOG_TRANS(trans, LOGL_ERROR, "Assignment done in unexpected CC state: %d\n", trans->cc.state);
+ return -EINVAL;
+ }
+
+ if (!call_leg_local_ip(msc_a->cc.call_leg, RTP_TO_CN)) {
+ LOG_TRANS(trans, LOGL_DEBUG,
+ "Assignment complete, but still waiting for the CRCX OK on the CN side RTP\n");
+ return 0;
+ }
+ return gsm48_tch_rtp_create(trans);
+}
+
/* Trigger TCH_RTP_CREATE acknowledgement */
int gsm48_tch_rtp_create(struct gsm_trans *trans)
{