Request Osmux CID and forward it in Assign Req and Assign Compl

Related: OS#2551
Depends: osmo-mgw.git I73b4c62baf39050da81d65553cbea07bc51163de
Change-Id: I5b14e34481e890669c9ee02dba81eba84293cebb

7 files changed, 111 insertions, 8 deletions

diff --git a/include/osmocom/msc/call_leg.h b/include/osmocom/msc/call_leg.h
index d8380f52b..f35816c47 100644
--- a/include/osmocom/msc/call_leg.h
+++ b/include/osmocom/msc/call_leg.h
@@ -44,6 +44,8 @@ struct call_leg {
 
 	/* Prevent events from deallocating for certain release code paths, to prevent use-after-free problems. */
 	bool deallocating;
+
+	bool ran_peer_supports_osmux;
 };
 
 enum call_leg_event {
diff --git a/include/osmocom/msc/ran_msg.h b/include/osmocom/msc/ran_msg.h
index 4d0485d43..af0822b70 100644
--- a/include/osmocom/msc/ran_msg.h
+++ b/include/osmocom/msc/ran_msg.h
@@ -84,6 +84,8 @@ struct ran_assignment_command {
 	const struct osmo_sockaddr_str *cn_rtp;
 	const struct gsm0808_channel_type *channel_type;
 	enum nsap_addr_enc rab_assign_addr_enc;
+	bool osmux_present;
+	uint8_t osmux_cid;
 };
 
 struct ran_cipher_mode_command {
@@ -223,6 +225,8 @@ struct ran_msg {
 			struct osmo_sockaddr_str remote_rtp;
 			bool codec_present;
 			enum mgcp_codecs codec;
+			bool osmux_present;
+			uint8_t osmux_cid;
 		} assignment_complete;
 		struct {
 			enum gsm0808_cause bssap_cause;
diff --git a/include/osmocom/msc/rtp_stream.h b/include/osmocom/msc/rtp_stream.h
index 794e8066f..c53c4f179 100644
--- a/include/osmocom/msc/rtp_stream.h
+++ b/include/osmocom/msc/rtp_stream.h
@@ -44,6 +44,15 @@ struct rtp_stream {
 	struct osmo_mgcpc_ep_ci *ci;
 
 	enum mgcp_connection_mode crcx_conn_mode;
+
+	/* configured to use Osmux */
+	bool use_osmux;
+	/* Allocated by our MGW, negative means invalid, not yet known */
+	int local_osmux_cid;
+	/* Allocated by BSC MGW, negative means invalid, not yet known */
+	int remote_osmux_cid;
+	 /* Whether remote_osmux_cid has been communicated to MGW */
+	bool remote_osmux_cid_sent_to_mgw;
 };
 
 #define RTP_STREAM_FMT "local=" RTP_IP_PORT_FMT ",remote=" RTP_IP_PORT_FMT
@@ -57,6 +66,7 @@ int rtp_stream_do_mdcx(struct rtp_stream *rtps);
 
 void rtp_stream_set_codec(struct rtp_stream *rtps, enum mgcp_codecs codec);
 void rtp_stream_set_remote_addr(struct rtp_stream *rtps, const struct osmo_sockaddr_str *r);
+void rtp_stream_set_remote_osmux_cid(struct rtp_stream *rtps, uint8_t osmux_cid);
 int rtp_stream_commit(struct rtp_stream *rtps);
 
 void rtp_stream_release(struct rtp_stream *rtps);
diff --git a/src/libmsc/call_leg.c b/src/libmsc/call_leg.c
index 46405bcaa..794eda286 100644
--- a/src/libmsc/call_leg.c
+++ b/src/libmsc/call_leg.c
@@ -321,6 +321,10 @@ int call_leg_ensure_ci(struct call_leg *cl, enum rtp_direction dir, uint32_t cal
 	if (call_leg_ensure_rtp_alloc(cl, dir, call_id, for_trans))
 		return -EIO;
 	cl->rtp[dir]->crcx_conn_mode = cl->crcx_conn_mode[dir];
+	if (dir == RTP_TO_RAN && cl->ran_peer_supports_osmux) {
+		cl->rtp[dir]->use_osmux = true;
+		cl->rtp[dir]->remote_osmux_cid = -1; /* wildcard */
+	}
 	if (codec_if_known)
 		rtp_stream_set_codec(cl->rtp[dir], *codec_if_known);
 	if (remote_addr_if_known && osmo_sockaddr_str_is_set(remote_addr_if_known))
diff --git a/src/libmsc/msc_a.c b/src/libmsc/msc_a.c
index cfba545be..b311df349 100644
--- a/src/libmsc/msc_a.c
+++ b/src/libmsc/msc_a.c
@@ -527,6 +527,8 @@ static void msc_a_call_leg_ran_local_addr_available(struct msc_a *msc_a)
 		.assignment_command = {
 			.cn_rtp = &msc_a->cc.call_leg->rtp[RTP_TO_RAN]->local,
 			.channel_type = &channel_type,
+			.osmux_present = msc_a->cc.call_leg->rtp[RTP_TO_RAN]->use_osmux,
+			.osmux_cid = msc_a->cc.call_leg->rtp[RTP_TO_RAN]->local_osmux_cid,
 		},
 	};
 	if (msc_a_ran_down(msc_a, MSC_ROLE_I, &msg)) {
@@ -620,8 +622,9 @@ static void msc_a_fsm_communicating(struct osmo_fsm_inst *fi, uint32_t event, vo
 			return;
 		}
 		LOG_MSC_A(msc_a, LOGL_DEBUG,
-			  "MGW endpoint's RTP address available for the CI %s: " OSMO_SOCKADDR_STR_FMT "\n",
-			  rtp_direction_name(rtps->dir), OSMO_SOCKADDR_STR_FMT_ARGS(&rtps->local));
+			  "MGW endpoint's RTP address available for the CI %s: " OSMO_SOCKADDR_STR_FMT " (osmux=%s:%d)\n",
+			  rtp_direction_name(rtps->dir), OSMO_SOCKADDR_STR_FMT_ARGS(&rtps->local),
+			  rtps->use_osmux ? "yes" : "no", rtps->local_osmux_cid);
 		switch (rtps->dir) {
 		case RTP_TO_RAN:
 			msc_a_call_leg_ran_local_addr_available(msc_a);
@@ -1257,9 +1260,20 @@ static void msc_a_up_call_assignment_complete(struct msc_a *msc_a, const struct
 		return;
 	}
 
+	if (rtps_to_ran->use_osmux != ac->assignment_complete.osmux_present) {
+		LOG_MSC_A_CAT(msc_a, DCC, LOGL_ERROR, "Osmux usage ass request and complete don't match: %d vs %d\n",
+			 rtps_to_ran->use_osmux, ac->assignment_complete.osmux_present);
+		call_leg_release(msc_a->cc.call_leg);
+		return;
+	}
+
 	/* Update RAN-side endpoint CI: */
 	rtp_stream_set_codec(rtps_to_ran, ac->assignment_complete.codec);
 	rtp_stream_set_remote_addr(rtps_to_ran, &ac->assignment_complete.remote_rtp);
+	if (rtps_to_ran->use_osmux)
+		rtp_stream_set_remote_osmux_cid(rtps_to_ran,
+						ac->assignment_complete.osmux_cid);
+
 	rtp_stream_commit(rtps_to_ran);
 
 	/* Setup CN side endpoint CI:
@@ -1592,6 +1606,8 @@ int msc_tx_common_id(struct msc_a *msc_a, enum msc_role to_role)
 static int msc_a_start_assignment(struct msc_a *msc_a, struct gsm_trans *cc_trans)
 {
 	struct call_leg *cl = msc_a->cc.call_leg;
+	struct msc_i *msc_i = msc_a_msc_i(msc_a);
+	struct gsm_network *net = msc_a_net(msc_a);
 
 	OSMO_ASSERT(!msc_a->cc.active_trans);
 	msc_a->cc.active_trans = cc_trans;
@@ -1612,6 +1628,16 @@ static int msc_a_start_assignment(struct msc_a *msc_a, struct gsm_trans *cc_tran
 			cl->crcx_conn_mode[RTP_TO_RAN] = MGCP_CONN_LOOPBACK;
 	}
 
+	if (net->use_osmux != OSMUX_USAGE_OFF) {
+		msc_i = msc_a_msc_i(msc_a);
+		if (msc_i->c.remote_to) {
+			/* TODO: investigate what to do in this case */
+			LOG_MSC_A(msc_a, LOGL_ERROR, "Osmux not yet supported for inter-MSC");
+		} else {
+			cl->ran_peer_supports_osmux = msc_i->ran_conn->ran_peer->remote_supports_osmux;
+		}
+	}
+
 	/* This will lead to either MSC_EV_CALL_LEG_LOCAL_ADDR_AVAILABLE or MSC_EV_CALL_LEG_TERM.
 	 * If the local address is already known, then immediately trigger. */
 	if (call_leg_local_ip(cl, RTP_TO_RAN))
diff --git a/src/libmsc/ran_msg_a.c b/src/libmsc/ran_msg_a.c
index 64590a1fe..fd8afdccd 100644
--- a/src/libmsc/ran_msg_a.c
+++ b/src/libmsc/ran_msg_a.c
@@ -269,6 +269,7 @@ static int ran_a_decode_assignment_complete(struct ran_dec *ran_dec, struct msgb
 {
 	struct tlv_p_entry *ie_aoip_transp_addr = TLVP_GET(tp, GSM0808_IE_AOIP_TRASP_ADDR);
 	struct tlv_p_entry *ie_speech_codec = TLVP_GET(tp, GSM0808_IE_SPEECH_CODEC);
+	struct tlv_p_entry *ie_osmux_cid = TLVP_GET(tp, GSM0808_IE_OSMO_OSMUX_CID);
 	struct sockaddr_storage rtp_addr;
 	struct sockaddr_in *rtp_addr_in;
 	struct gsm0808_speech_codec sc;
@@ -300,6 +301,15 @@ static int ran_a_decode_assignment_complete(struct ran_dec *ran_dec, struct msgb
 		}
 	}
 
+	if (ie_osmux_cid) {
+		rc = gsm0808_dec_osmux_cid(&ran_dec_msg.assignment_complete.osmux_cid, ie_osmux_cid->val, ie_osmux_cid->len);
+		if (rc < 0) {
+			LOG_RAN_A_DEC_MSG(LOGL_ERROR, "Unable to decode Osmux CID\n");
+			return -EINVAL;
+		}
+		ran_dec_msg.assignment_complete.osmux_present = true;
+	}
+
 	if (ie_speech_codec) {
 		/* Decode Speech Codec (Chosen) element */
 		rc = gsm0808_dec_speech_codec(&sc, ie_speech_codec->val, ie_speech_codec->len);
@@ -902,6 +912,13 @@ static int ran_a_channel_type_to_speech_codec_list(struct gsm0808_speech_codec_l
 	return 0;
 }
 
+static void _gsm0808_assignment_extend_osmux(struct msgb *msg, uint8_t cid)
+{
+	OSMO_ASSERT(msg->l3h[1] == msgb_l3len(msg) - 2); /*TL not in len */
+	msgb_tv_put(msg, GSM0808_IE_OSMO_OSMUX_CID, cid);
+	msg->l3h[1] = msgb_l3len(msg) - 2;
+}
+
 /* Compose a BSSAP Assignment Command.
  * Passing an RTP address is optional.
  * The msub is passed merely for error logging. */
@@ -912,6 +929,7 @@ static struct msgb *ran_a_make_assignment_command(struct osmo_fsm_inst *log_fi,
 	struct gsm0808_speech_codec_list *use_scl = NULL;
 	struct sockaddr_storage rtp_addr;
 	struct sockaddr_storage *use_rtp_addr = NULL;
+	struct msgb *msg;
 	int rc;
 
 	if (!ac->channel_type) {
@@ -952,7 +970,10 @@ static struct msgb *ran_a_make_assignment_command(struct osmo_fsm_inst *log_fi,
 		}
 	}
 
-	return gsm0808_create_ass(ac->channel_type, NULL, use_rtp_addr, use_scl, NULL);
+	msg = gsm0808_create_ass(ac->channel_type, NULL, use_rtp_addr, use_scl, NULL);
+	if (ac->osmux_present)
+		_gsm0808_assignment_extend_osmux(msg, ac->osmux_cid);
+	return msg;
 }
 
 /* For an A5/N number a5_n set dst to the matching GSM0808_ALG_ID_A5_<n>. */
diff --git a/src/libmsc/rtp_stream.c b/src/libmsc/rtp_stream.c
index afe24ad51..c3880bf7b 100644
--- a/src/libmsc/rtp_stream.c
+++ b/src/libmsc/rtp_stream.c
@@ -82,11 +82,19 @@ void rtp_stream_update_id(struct rtp_stream *rtps)
 			OSMO_STRBUF_PRINTF(sb, ":no-codec");
 		else if (!rtps->codec_sent_to_mgw)
 			OSMO_STRBUF_PRINTF(sb, ":codec-not-sent");
+		if (rtps->use_osmux) {
+			if (rtps->remote_osmux_cid < 0)
+				OSMO_STRBUF_PRINTF(sb, ":no-remote-osmux-cid");
+			else if (!rtps->remote_osmux_cid_sent_to_mgw)
+				OSMO_STRBUF_PRINTF(sb, ":remote-osmux-cid-not-sent");
+		}
 	}
 	if (osmo_sockaddr_str_is_set(&rtps->local))
 		OSMO_STRBUF_PRINTF(sb, ":local-%s-%u", rtps->local.ip, rtps->local.port);
 	if (osmo_sockaddr_str_is_set(&rtps->remote))
 		OSMO_STRBUF_PRINTF(sb, ":remote-%s-%u", rtps->remote.ip, rtps->remote.port);
+	if (rtps->use_osmux)
+		OSMO_STRBUF_PRINTF(sb, ":osmux-%d-%d", rtps->local_osmux_cid, rtps->remote_osmux_cid);
 
 	/* Replace any dots in the IP address, dots not allowed as FSM instance name */
 	for (p = buf; *p; p++)
@@ -117,6 +125,8 @@ struct rtp_stream *rtp_stream_alloc(struct call_leg *parent_call_leg, enum rtp_d
 		.call_id = call_id,
 		.for_trans = for_trans,
 		.dir = dir,
+		.local_osmux_cid = -2,
+		.remote_osmux_cid = -2,
 	};
 
 	rtp_stream_update_id(rtps);
@@ -130,6 +140,7 @@ static void check_established(struct rtp_stream *rtps)
 	    && osmo_sockaddr_str_is_set(&rtps->local)
 	    && osmo_sockaddr_str_is_set(&rtps->remote)
 	    && rtps->remote_sent_to_mgw
+	    && (!rtps->use_osmux || rtps->remote_osmux_cid_sent_to_mgw)
 	    && rtps->codec_known)
 		rtp_stream_state_chg(rtps, RTP_STREAM_ST_ESTABLISHED);
 }
@@ -148,17 +159,27 @@ static void rtp_stream_fsm_establishing_established(struct osmo_fsm_inst *fi, ui
 		}
 
 		osmo_sockaddr_str_from_str(&rtps->local, crcx_info->addr, crcx_info->port);
+		if (rtps->use_osmux != crcx_info->x_osmo_osmux_use) {
+			LOG_RTPS(rtps, LOGL_ERROR, "Osmux usage request and response don't match: %d vs %d",
+				 rtps->use_osmux, crcx_info->x_osmo_osmux_use);
+			/* TODO: proper failure path */
+			OSMO_ASSERT(rtps->use_osmux != crcx_info->x_osmo_osmux_use);
+		}
+		if (crcx_info->x_osmo_osmux_use)
+			rtps->local_osmux_cid = crcx_info->x_osmo_osmux_cid;
 		rtp_stream_update_id(rtps);
 		osmo_fsm_inst_dispatch(fi->proc.parent, CALL_LEG_EV_RTP_STREAM_ADDR_AVAILABLE, rtps);
 		check_established(rtps);
 
 		if ((!rtps->remote_sent_to_mgw || !rtps->codec_sent_to_mgw)
 		    && osmo_sockaddr_str_is_set(&rtps->remote)
+		    && (!rtps->use_osmux || rtps->remote_osmux_cid_sent_to_mgw)
 		    && rtps->codec_known) {
 			LOG_RTPS(rtps, LOGL_DEBUG,
-				 "local ip:port set;%s%s triggering MDCX to send the new settings\n",
+				 "local ip:port set;%s%s%s triggering MDCX to send the new settings\n",
 				 (!rtps->remote_sent_to_mgw)? " remote ip:port not yet sent," : "",
-				 (!rtps->codec_sent_to_mgw)? " codec not yet sent," : "");
+				 (!rtps->codec_sent_to_mgw)? " codec not yet sent," : "",
+				 (rtps->use_osmux && !rtps->remote_osmux_cid_sent_to_mgw) ? "Osmux CID not yet sent,": "");
 			rtp_stream_do_mdcx(rtps);
 		}
 		return;
@@ -172,6 +193,7 @@ static void rtp_stream_fsm_establishing_established(struct osmo_fsm_inst *fi, ui
 	case RTP_STREAM_EV_MDCX_FAIL:
 		rtps->remote_sent_to_mgw = false;
 		rtps->codec_sent_to_mgw = false;
+		rtps->remote_osmux_cid_sent_to_mgw = false;
 		rtp_stream_update_id(rtps);
 		rtp_stream_state_chg(rtps, RTP_STREAM_ST_DISCARDING);
 		return;
@@ -280,6 +302,8 @@ static int rtp_stream_do_mgcp_verb(struct rtp_stream *rtps, enum mgcp_verb verb,
 	verb_info = (struct mgcp_conn_peer){
 		.call_id = rtps->call_id,
 		.ptime = 20,
+		.x_osmo_osmux_use = rtps->use_osmux,
+		.x_osmo_osmux_cid = rtps->remote_osmux_cid,
 	};
 
 	if (verb == MGCP_VERB_CRCX)
@@ -353,9 +377,10 @@ int rtp_stream_commit(struct rtp_stream *rtps)
 		return 0;
 	}
 
-	LOG_RTPS(rtps, LOGL_DEBUG, "Committing: Tx MDCX to update the MGW: updating%s%s\n",
+	LOG_RTPS(rtps, LOGL_DEBUG, "Committing: Tx MDCX to update the MGW: updating%s%s%s\n",
 		 rtps->remote_sent_to_mgw ? "" : " remote-RTP-IP-port",
-		 rtps->codec_sent_to_mgw ? "" : " codec");
+		 rtps->codec_sent_to_mgw ? "" : " codec",
+		 (!rtps->use_osmux || rtps->remote_osmux_cid_sent_to_mgw) ? "" : " remote-Osmux-CID");
 	return rtp_stream_do_mdcx(rtps);
 }
 
@@ -380,6 +405,16 @@ void rtp_stream_set_remote_addr(struct rtp_stream *rtps, const struct osmo_socka
 	rtp_stream_update_id(rtps);
 }
 
+void rtp_stream_set_remote_osmux_cid(struct rtp_stream *rtps, uint8_t osmux_cid)
+{
+	if (rtps->fi->state == RTP_STREAM_ST_ESTABLISHED)
+		rtp_stream_state_chg(rtps, RTP_STREAM_ST_ESTABLISHING);
+	LOG_RTPS(rtps, LOGL_DEBUG, "setting remote Osmux CID to %u\n", osmux_cid);
+	rtps->remote_osmux_cid = osmux_cid;
+	rtps->remote_osmux_cid_sent_to_mgw = false;
+	rtp_stream_update_id(rtps);
+}
+
 bool rtp_stream_is_established(struct rtp_stream *rtps)
 {
 	if (!rtps)
@@ -389,7 +424,8 @@ bool rtp_stream_is_established(struct rtp_stream *rtps)
 	if (rtps->fi->state != RTP_STREAM_ST_ESTABLISHED)
 		return false;
 	if (!rtps->remote_sent_to_mgw
-	    || !rtps->codec_sent_to_mgw)
+	    || !rtps->codec_sent_to_mgw
+	    || (rtps->use_osmux && !rtps->remote_osmux_cid_sent_to_mgw))
 		return false;
 	return true;
 }