code markers to indicate RAN connection setupneels/vgcs

Change-Id: I964c6e1fc63ba70e89fc775eb34d23db686cbb35

8 files changed, 138 insertions, 7 deletions

diff --git a/doc/examples/osmo-msc/osmo-msc.cfg b/doc/examples/osmo-msc/osmo-msc.cfg
index b08623787..776a3f376 100644
--- a/doc/examples/osmo-msc/osmo-msc.cfg
+++ b/doc/examples/osmo-msc/osmo-msc.cfg
@@ -20,3 +20,7 @@ msc
  assign-tmsi
  auth-tuple-max-reuse-count 3
  auth-tuple-reuse-on-error 1
+
+ # 123: LAC der BSS
+ # 1.23.3: SCCP point-code der BSS
+ neighbor a lac 123 ran-pc 1.23.3
diff --git a/include/osmocom/msc/msc_a.h b/include/osmocom/msc/msc_a.h
index 3b1115500..4460b5194 100644
--- a/include/osmocom/msc/msc_a.h
+++ b/include/osmocom/msc/msc_a.h
@@ -138,6 +138,10 @@ struct msc_a {
 	struct osmo_use_count use_count;
 	struct osmo_use_count_entry use_count_buf[8];
 	int32_t max_total_use_count;
+
+	struct {
+		struct ran_conn *ran_conn;
+	} vgcs;
 };
 
 osmo_static_assert(offsetof(struct msc_a, c) == 0, msc_role_common_first_member_of_msc_a);
diff --git a/include/osmocom/msc/ran_conn.h b/include/osmocom/msc/ran_conn.h
index 7aa50df07..77de0e1e9 100644
--- a/include/osmocom/msc/ran_conn.h
+++ b/include/osmocom/msc/ran_conn.h
@@ -18,9 +18,16 @@ struct ran_conn {
 	uint32_t sccp_conn_id;
 
 	/* MSC role that this RAN connection belongs to. This will be either an msc_i (currently active
-	 * connection) or an msc_t (transitory new connection during Handover). */
+	 * connection) or an msc_t (transitory new connection during Handover).
+	 * Used for usual L3 ran_conn to a subscriber. */
 	struct osmo_fsm_inst *msc_role;
 
+	/* For BCC, we have N connections to BSS. When receiving messages for a group call peer, dispatch to the VGCS
+	 * management. */
+	struct {
+		struct msc_a *calling_subscriber;
+	} vgcs;
+
 	bool closing;
 };
 
diff --git a/include/osmocom/msc/ran_msg.h b/include/osmocom/msc/ran_msg.h
index 3e0ac6071..0df504b85 100644
--- a/include/osmocom/msc/ran_msg.h
+++ b/include/osmocom/msc/ran_msg.h
@@ -69,6 +69,9 @@ enum ran_msg_type {
 	RAN_MSG_HANDOVER_SUCCEEDED,
 	RAN_MSG_HANDOVER_COMPLETE,
 	RAN_MSG_HANDOVER_FAILURE,
+	RAN_MSG_VGCS_SETUP,
+	RAN_MSG_VGCS_SETUP_ACK,
+	...
 };
 
 extern const struct value_string ran_msg_type_names[];
diff --git a/src/libmsc/msc_a.c b/src/libmsc/msc_a.c
index e8dc58b8a..961fcf8bb 100644
--- a/src/libmsc/msc_a.c
+++ b/src/libmsc/msc_a.c
@@ -1373,6 +1373,9 @@ int msc_a_up_l3(struct msc_a *msc_a, struct msgb *msg)
 	case GSM48_PDISC_TEST:
 		rc = gsm0414_rcv_test(msc_a, msg);
 		break;
+	case GSM48_PDISC_BCC:
+		rc = rcv_bcc(msc_a, msg);
+		break;
 	default:
 		LOG_MSC_A_CAT(msc_a, DRLL, LOGL_NOTICE, "Unknown "
 			"GSM 04.08 discriminator 0x%02x\n", pdisc);
@@ -1682,6 +1685,35 @@ int msc_a_ran_dec_from_msc_i(struct msc_a *msc_a, struct msc_a_ran_dec_data *d)
 	return rc;
 }
 
+int msc_a_rx_vgcs_decoded(struct osmo_fsm_inst *caller_fi, void *caller_data, const struct ran_msg *msg)
+{
+	struct msc_a *msc_a = caller_fi;
+	struct ran_conn *from_ran_conn = caller_data;
+
+	switch (msg->msg_type) {
+	case RAN_MSG_VGCS_SETUP_ACK:
+		handle setup ack from peer from_ran_conn->ran_peer
+	}
+}
+
+int msc_a_rx_vgcs(struct msc_a *msc_a, struct ran_conn *from_conn, struct msgb *msg)
+{
+	/* Feed through the decoding mechanism ran_msg. The decoded message arrives in msc_a_rx_vgcs_decoded() */
+	ran_dec = (struct ran_dec) {
+		.caller_fi = fi,
+		.caller_data = from_conn,
+		.decode_cb = msc_a_rx_vgcs_decoded,
+	};
+	struct ran_peer *ran_peer = from_conn->ran_peer;
+	struct ran_inra *ran = ran_peer->sri->ran;
+	if (!ran->ran_dec_l2) {
+		LOGPFSML(fi, LOGL_ERROR, "No ran_dec_l2() defined for RAN type %s\n",
+			 osmo_rat_type_name(ran->type));
+		return -ENOTSUP;
+	}
+	return ran->ran_dec_l2(&ran_dec, msg);
+}
+
 static int msc_a_ran_dec_from_msc_t(struct msc_a *msc_a, struct msc_a_ran_dec_data *d)
 {
 	struct msc_t *msc_t = msc_a_msc_t(msc_a);
diff --git a/src/libmsc/msc_bcc.c b/src/libmsc/msc_bcc.c
new file mode 100644
index 000000000..ded6e0744
--- /dev/null
+++ b/src/libmsc/msc_bcc.c
@@ -0,0 +1,43 @@
+
+int rcv_bcc(msc_a, msg)
+{
+	trans_alloc wie in gsm0408_rcv_cc()
+
+
+	struct gsm0808_cell_id cid = {
+		.lac = my_lac,
+	};
+
+	struct ran_peer *rp_from_neighbor_ident = NULL;
+	struct ran_peer *rp_from_cell_id = NULL;
+	struct ran_peer *rp;
+
+	switch (msc_ho_find_target_cell(msc_a, cid, &e, &rp_from_neighbor_ident, &rp_from_cell_id)) {
+	case MSC_NEIGHBOR_TYPE_REMOTE_MSC:
+		ERROR
+
+	case MSC_NEIGHBOR_TYPE_LOCAL_RAN_PEER:
+		rp = rp_from_neighbor_ident ? : rp_from_cell_id;
+		OSMO_ASSERT(rp);
+		msc_a->ho.new_cell.type = MSC_NEIGHBOR_TYPE_LOCAL_RAN_PEER;
+		msc_a->ho.new_cell.ran_peer = rp;
+		return true;
+
+	default:
+		break;
+	}
+
+	/* Now rp points at the ran_peer for my_lac */
+
+	/* new conn */
+	msc_a->vgcs.conn = ran_conn_create_outgoing(rp);
+	msc_a->vgcs.conn->vgcs.calling_subscriber = msc_a;
+
+	/* send first message */
+	ran_conn_down_l2_co(msc_a->vgcs.conn, l3_msg, true);
+
+	/* later */
+	ran_conn_down_l2_co(msc_a->vgcs.conn, l3_msg, false);
+
+	...
+}
diff --git a/src/libmsc/ran_msg_a.c b/src/libmsc/ran_msg_a.c
index 19402bc11..0241a349e 100644
--- a/src/libmsc/ran_msg_a.c
+++ b/src/libmsc/ran_msg_a.c
@@ -742,6 +742,33 @@ static int ran_a_decode_handover_failure(struct ran_dec *ran_dec, const struct m
 	return ran_decoded(ran_dec, &ran_dec_msg);
 }
 
+/* es braucht decode nur für die empfangenen msgs; encode nur für die gesendeten msgs. */
+static int ran_a_decode_vgcs_setup_ack(struct ran_dec *ran_dec, const struct msgb *msg, const struct tlv_parsed *tp)
+{
+	// lese die TLV von tp und fülle die struct, wie z.b. in ran_a_decode_handover_request()
+
+	struct ran_msg ran_dec_msg = {
+		.msg_type = RAN_MSG_VGCS_SETUP_ACK,
+		.msg_name = "BSSMAP VGCS SETUP ACK",
+
+		.vgcs_setup = {
+			.members = from TLV in tp
+		},
+	};
+
+	// return decoded struct to caller
+	return ran_decoded(ran_dec, &ran_dec_msg);
+}
+
+struct msgb *ran_a_make_vgcs_setup(struct osmo_fsm_inst *log_fi, const struct ran_msg *msg)
+{
+	// lies das dekodierte struct 'msg' und schreibe es encoded in einen neuen msgb
+
+	// implement gsm0808_create_vgcs_setup in libosmocore/src/gsm/gsm0808.c
+	struct msgb *new_msg = gsm0808_create_vgcs_setup(msg->vgcs_setup.foo, msg->vgcs_setup.bar);
+	return new_msg;
+}
+
 static int ran_a_decode_bssmap(struct ran_dec *ran_dec, struct msgb *bssmap)
 {
 	struct tlv_parsed tp[2];
@@ -836,6 +863,9 @@ static int ran_a_decode_bssmap(struct ran_dec *ran_dec, struct msgb *bssmap)
 	case BSS_MAP_MSG_HANDOVER_FAILURE:
 		return ran_a_decode_handover_failure(ran_dec, bssmap, tp);
 
+	case BSS_MAP_MSG_VGCS_SETUP_ACK: <-- add in osmocom/gsm/protocol/gsm_08_08.h
+		return ran_a_decode_vgcs_setup_ack(...); <-- to be implemented here
+
 	default:
 		LOG_RAN_A_DEC(ran_dec, LOGL_ERROR, "Unimplemented msg type: %s\n", gsm0808_bssmap_name(msg_type));
 		return -EINVAL;
@@ -1281,6 +1311,9 @@ static struct msgb *_ran_a_encode(struct osmo_fsm_inst *caller_fi, const struct
 	case RAN_MSG_HANDOVER_FAILURE:
 		return ran_a_make_handover_failure(caller_fi, ran_enc_msg);
 
+	case RAN_MSG_VGCS_SETUP:
+		return ran_a_make_vgcs_setup(caller_fi, ran_enc_msg); <-- to be implemented
+
 	default:
 		LOG_RAN_A_ENC(caller_fi, LOGL_ERROR, "Unimplemented RAN-encode message type: %s\n",
 			       ran_msg_type_name(ran_enc_msg->msg_type));
diff --git a/src/libmsc/ran_peer.c b/src/libmsc/ran_peer.c
index fcb5f5ad2..ab19c200d 100644
--- a/src/libmsc/ran_peer.c
+++ b/src/libmsc/ran_peer.c
@@ -399,12 +399,17 @@ void ran_peer_st_ready(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 			return;
 		}
 
-		an_apdu = (struct an_apdu){
-			.an_proto = rp->sri->ran->an_proto,
-			.msg = ctx->msg,
-		};
-
-		osmo_fsm_inst_dispatch(ctx->conn->msc_role, MSC_EV_FROM_RAN_UP_L2, &an_apdu);
+		if (ctx->conn->msc_role) {
+			/* "normal" A connection, dispatch to MSC-I or MSC-T */
+			an_apdu = (struct an_apdu){
+				.an_proto = rp->sri->ran->an_proto,
+					.msg = ctx->msg,
+			};
+			osmo_fsm_inst_dispatch(ctx->conn->msc_role, MSC_EV_FROM_RAN_UP_L2, &an_apdu);
+		} else if (ctx->conn->vgcs->calling_subscriber) {
+			/* VGCS related */
+			msc_a_rx_vgcs(ctx->conn->vgcs->calling_subscriber, ctx->conn, ctx->msg);
+		}
 		return;
 
 	case RAN_PEER_EV_MSG_DOWN_CO_INITIAL: