[codecs filter] MT call: apply remote call leg codecs

Collect either the SDP or the Bearer Capabilites in the incoming
MNCC in the new codecs filter.

So far just collect the info and do not change the behavior, using the
filter result will follow in a subsequent patch.

Related: SYS#5066
Change-Id: I84d9bbca3e4061da622b1b2fc0bde8868e7e3521

2 files changed, 25 insertions, 0 deletions

diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 5c7ff1fbd..c9a46f849 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -683,7 +683,28 @@ static int gsm48_cc_tx_setup(struct gsm_trans *trans, void *arg)
 	codec_filter_init(&trans->cc.codecs);
 	codec_filter_set_ran(&trans->cc.codecs, trans->msc_a->c.ran->type);
 	codec_filter_set_bss(&trans->cc.codecs, &trans->msc_a->cc.compl_l3_codec_list_bss_supported);
+	/* sdp.remote: if SDP is included in the MNCC, take that as definitive list of remote audio codecs. */
+	if (setup->sdp[0]) {
+		rc = sdp_msg_from_sdp_str(&trans->cc.codecs.remote, setup->sdp);
+		if (rc)
+			LOG_TRANS(trans, LOGL_ERROR, "Failed to parse remote call leg SDP: %d\n", rc);
+	}
+	/* sdp.remote: if there is no SDP information or we failed to parse it, try using the Bearer Capability from
+	 * MNCC, if any. */
+	if (!trans->cc.codecs.remote.audio_codecs.count && (setup->fields & MNCC_F_BEARER_CAP)) {
+		trans->cc.codecs.remote = (struct sdp_msg){};
+		sdp_audio_codecs_from_bearer_cap(&trans->cc.codecs.remote.audio_codecs,
+						 &setup->bearer_cap);
+	}
+	if (!trans->cc.codecs.remote.audio_codecs.count)
+		LOG_TRANS(trans, LOGL_INFO,
+			  "Got no information of remote audio codecs: neither SDP nor Bearer Capability. Trying anyway.\n");
 
+	codec_filter_run(&trans->cc.codecs);
+	LOG_TRANS(trans, LOGL_DEBUG, "codecs: %s\n", codec_filter_to_str(&trans->cc.codecs));
+
+	/* NEAR FUTURE: upcoming patch will use the codecs filter to determine the Bearer Cap to send to the MS.
+	 * So far just gathering information in the new codecs filter. */
 	/* bearer capability */
 	if (setup->fields & MNCC_F_BEARER_CAP) {
 		/* Create a copy of the bearer capability in the transaction struct, so we
diff --git a/tests/msc_vlr/msc_vlr_test_call.err b/tests/msc_vlr/msc_vlr_test_call.err
index ccf2144de..fdbbb5099 100644
--- a/tests/msc_vlr/msc_vlr_test_call.err
+++ b/tests/msc_vlr/msc_vlr_test_call.err
@@ -761,6 +761,8 @@ DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RES
 DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
 DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
 DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T303 with 30 seconds
+DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) Got no information of remote audio codecs: neither SDP nor Bearer Capability. Trying anyway.
+DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) codecs: :0{AMR:octet-align=1#112,AMR-WB/16000:octet-align=1#113} (from: RAN={AMR:octet-align=1#112,AMR-WB/16000:octet-align=1#113})
 DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state NULL -> CALL_PRESENT
 DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_SETUP
 DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu
@@ -1231,6 +1233,8 @@ DREF msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RES
 DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: Received Event MSC_A_EV_TRANSACTION_ACCEPTED
 DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_AUTHENTICATED}: state_chg to MSC_A_ST_COMMUNICATING
 DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) starting timer T303 with 30 seconds
+DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) Got no information of remote audio codecs: neither SDP nor Bearer Capability. Trying anyway.
+DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) codecs: :0{AMR:octet-align=1#112,AMR-WB/16000:octet-align=1#113} (from: RAN={AMR:octet-align=1#112,AMR-WB/16000:octet-align=1#113})
 DCC trans(CC:NULL IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP callref-0x423 tid-0) new state NULL -> CALL_PRESENT
 DIUCS msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: Sending DTAP: CC GSM48_MT_CC_SETUP
 DMSC msc_a(IMSI-901700000010650:MSISDN-42342:TMSI-0x03020100:UTRAN-Iu:PAGING_RESP){MSC_A_ST_COMMUNICATING}: RAN encode: DTAP on UTRAN-Iu