oml: Delay Tx of OPSTART(BBTRANSC) after rx of RSL CONNECT ACK

nanoBTS waits until receiving OPSTART in order to establish the RSL
connection socket against BSC, hence we cannot wait until the socket is
established at the BSC in order to send the OPSTART.
Still this way we make sure the RSL CONNECT is acked before attempting
an OPSTART at the BSC.

Change-Id: Ief46bad5075b656c13d1f09a0724e33283148236

4 files changed, 91 insertions, 7 deletions

diff --git a/src/osmo-bsc/abis_nm.c b/src/osmo-bsc/abis_nm.c
index b151f36e6..938f45d13 100644
--- a/src/osmo-bsc/abis_nm.c
+++ b/src/osmo-bsc/abis_nm.c
@@ -2966,6 +2966,7 @@ static int abis_nm_rx_ipacc(struct msgb *msg)
 		signal.foh = foh;
 		osmo_signal_dispatch(SS_NM, S_NM_IPACC_NACK, &signal);
 		break;
+	case NM_MT_IPACC_RSL_CONNECT_ACK:
 	case NM_MT_IPACC_SET_NVATTR_ACK:
 	case NM_MT_IPACC_SET_ATTR_ACK:
 		signal.bts = bts;
diff --git a/src/osmo-bsc/bts_ipaccess_nanobts.c b/src/osmo-bsc/bts_ipaccess_nanobts.c
index 0af5a2874..316594465 100644
--- a/src/osmo-bsc/bts_ipaccess_nanobts.c
+++ b/src/osmo-bsc/bts_ipaccess_nanobts.c
@@ -443,12 +443,56 @@ static void nm_rx_ipacc_set_attr_ack(struct ipacc_ack_signal_data *sig_data)
 	}
 }
 
+static void nm_rx_ipacc_rsl_connect_ack(struct ipacc_ack_signal_data *sig_data)
+{
+	struct gsm_bts *bts = sig_data->bts;
+	struct abis_om_fom_hdr *foh = sig_data->foh;
+	struct gsm_bts_trx *trx;
+
+	if (foh->obj_class != NM_OC_BASEB_TRANSC) {
+		LOGPFOH(DNM, LOGL_ERROR, foh, "IPACC RSL Connect ACK received on incorrect object class %d!\n", foh->obj_class);
+		return;
+	}
+
+	trx = gsm_bts_trx_num(bts, foh->obj_inst.trx_nr);
+	osmo_fsm_inst_dispatch(trx->bb_transc.mo.fi, NM_EV_RSL_CONNECT_ACK, NULL);
+}
+
 static void nm_rx_ipacc_ack(struct ipacc_ack_signal_data *sig_data)
 {
 	switch (sig_data->foh->msg_type) {
 	case NM_MT_IPACC_SET_ATTR_ACK:
 		nm_rx_ipacc_set_attr_ack(sig_data);
 		break;
+	case NM_MT_IPACC_RSL_CONNECT_ACK:
+		nm_rx_ipacc_rsl_connect_ack(sig_data);
+		break;
+	default:
+		break;
+	}
+}
+
+static void nm_rx_ipacc_rsl_connect_nack(struct ipacc_ack_signal_data *sig_data)
+{
+	struct gsm_bts *bts = sig_data->bts;
+	struct abis_om_fom_hdr *foh = sig_data->foh;
+	struct gsm_bts_trx *trx;
+
+	if (foh->obj_class != NM_OC_BASEB_TRANSC) {
+		LOGPFOH(DNM, LOGL_ERROR, foh, "IPACC RSL Connect NACK received on incorrect object class %d!\n", foh->obj_class);
+		return;
+	}
+
+	trx = gsm_bts_trx_num(bts, foh->obj_inst.trx_nr);
+	osmo_fsm_inst_dispatch(trx->bb_transc.mo.fi, NM_EV_RSL_CONNECT_NACK, NULL);
+}
+
+static void nm_rx_ipacc_nack(struct ipacc_ack_signal_data *sig_data)
+{
+	switch (sig_data->foh->msg_type) {
+	case NM_MT_IPACC_RSL_CONNECT_ACK:
+		nm_rx_ipacc_rsl_connect_nack(sig_data);
+		break;
 	default:
 		break;
 	}
@@ -487,6 +531,9 @@ static int bts_ipa_nm_sig_cb(unsigned int subsys, unsigned int signal,
 	case S_NM_IPACC_ACK:
 		nm_rx_ipacc_ack(signal_data);
 		return 0;
+	case S_NM_IPACC_NACK:
+		nm_rx_ipacc_nack(signal_data);
+		return 0;
 	default:
 		break;
 	}
diff --git a/src/osmo-bsc/nm_bb_transc_fsm.c b/src/osmo-bsc/nm_bb_transc_fsm.c
index bf2469145..3a8786bfe 100644
--- a/src/osmo-bsc/nm_bb_transc_fsm.c
+++ b/src/osmo-bsc/nm_bb_transc_fsm.c
@@ -32,6 +32,7 @@
 #include <osmocom/bsc/signal.h>
 #include <osmocom/bsc/abis_nm.h>
 #include <osmocom/bsc/bts_ipaccess_nanobts_omlattr.h>
+#include <osmocom/bsc/ipaccess.h>
 #include <osmocom/bsc/nm_common_fsm.h>
 #include <osmocom/bsc/debug.h>
 
@@ -63,6 +64,8 @@ static void st_op_disabled_notinstalled_on_enter(struct osmo_fsm_inst *fi, uint3
 	bb_transc->mo.get_attr_sent = false;
 	bb_transc->mo.get_attr_rep_received = false;
 	bb_transc->mo.adm_unlock_sent = false;
+	bb_transc->mo.rsl_connect_sent = false;
+	bb_transc->mo.rsl_connect_ack_received = false;
 	bb_transc->mo.opstart_sent = false;
 }
 
@@ -125,14 +128,22 @@ static void configure_loop(struct gsm_bts_bb_trx *bb_transc, const struct gsm_nm
 				      NM_STATE_UNLOCKED);
 	}
 
+	/* Provision BTS with RSL IP addr & port to connect to: */
 	if (allow_opstart && state->administrative == NM_STATE_UNLOCKED &&
-	    !bb_transc->mo.opstart_sent) {
-		bb_transc->mo.opstart_sent = true;
-		abis_nm_opstart(trx->bts, NM_OC_BASEB_TRANSC, trx->bts->bts_nr, trx->nr, 0xff);
-		/* TRX software is active, tell it to initiate RSL Link */
+	    !bb_transc->mo.rsl_connect_sent && !bb_transc->mo.rsl_connect_ack_received) {
+		bb_transc->mo.rsl_connect_sent = true;
 		abis_nm_ipaccess_rsl_connect(trx, trx->bts->ip_access.rsl_ip,
 					     3003, trx->rsl_tei_primary);
 	}
+
+	/* OPSTART after receiving RSL CONNECT ACK. We cannot delay until the
+	 * RSL/IPA socket is connected to us because nanoBTS only attempts
+	 * connection after receiving an OPSTART: */
+	if (allow_opstart && state->administrative == NM_STATE_UNLOCKED &&
+	    bb_transc->mo.rsl_connect_ack_received && !bb_transc->mo.opstart_sent) {
+		bb_transc->mo.opstart_sent = true;
+		abis_nm_opstart(trx->bts, NM_OC_BASEB_TRANSC, trx->bts->bts_nr, trx->nr, 0xff);
+	}
 }
 
 static void st_op_disabled_dependency_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
@@ -150,6 +161,7 @@ static void st_op_disabled_dependency_on_enter(struct osmo_fsm_inst *fi, uint32_
 static void st_op_disabled_dependency(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 {
 	struct gsm_bts_bb_trx *bb_transc = (struct gsm_bts_bb_trx *)fi->priv;
+	struct gsm_bts_trx *trx = gsm_bts_bb_trx_get_trx(bb_transc);
 	struct nm_statechg_signal_data *nsd;
 	const struct gsm_nm_state *new_state;
 
@@ -159,6 +171,14 @@ static void st_op_disabled_dependency(struct osmo_fsm_inst *fi, uint32_t event,
 		bb_transc->mo.get_attr_sent = false;
 		configure_loop(bb_transc, &bb_transc->mo.nm_state, false);
 		return;
+	case NM_EV_RSL_CONNECT_ACK:
+		bb_transc->mo.rsl_connect_ack_received = true;
+		bb_transc->mo.rsl_connect_sent = false;
+		configure_loop(bb_transc, &bb_transc->mo.nm_state, false);
+		break;
+	case NM_EV_RSL_CONNECT_NACK:
+		ipaccess_drop_oml_deferred(trx->bts);
+		break;
 	case NM_EV_STATE_CHG_REP:
 		nsd = (struct nm_statechg_signal_data *)data;
 		new_state = &nsd->new_state;
@@ -207,6 +227,14 @@ static void st_op_disabled_offline(struct osmo_fsm_inst *fi, uint32_t event, voi
 		bb_transc->mo.get_attr_sent = false;
 		configure_loop(bb_transc, &bb_transc->mo.nm_state, true);
 		return;
+	case NM_EV_RSL_CONNECT_ACK:
+		bb_transc->mo.rsl_connect_ack_received = true;
+		bb_transc->mo.rsl_connect_sent = false;
+		configure_loop(bb_transc, &bb_transc->mo.nm_state, true);
+		break;
+	case NM_EV_RSL_CONNECT_NACK:
+		ipaccess_drop_oml_deferred(trx->bts);
+		break;
 	case NM_EV_STATE_CHG_REP:
 		nsd = (struct nm_statechg_signal_data *)data;
 		new_state = &nsd->new_state;
@@ -251,8 +279,10 @@ static void st_op_enabled_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state
 	  reused as soon as we move back to Disabled */
 	bb_transc->mo.get_attr_sent = false;
 	bb_transc->mo.get_attr_rep_received = false;
-	bb_transc->mo.opstart_sent = false;
 	bb_transc->mo.adm_unlock_sent = false;
+	bb_transc->mo.rsl_connect_ack_received = false;
+	bb_transc->mo.rsl_connect_sent = false;
+	bb_transc->mo.opstart_sent = false;
 
 	nm_bb_transc_fsm_becomes_enabled(bb_transc);
 }
@@ -330,7 +360,9 @@ static struct osmo_fsm_state nm_bb_transc_fsm_states[] = {
 	[NM_BB_TRANSC_ST_OP_DISABLED_DEPENDENCY] = {
 		.in_event_mask =
 			X(NM_EV_STATE_CHG_REP) |
-			X(NM_EV_GET_ATTR_REP),
+			X(NM_EV_GET_ATTR_REP) |
+			X(NM_EV_RSL_CONNECT_ACK) |
+			X(NM_EV_RSL_CONNECT_NACK),
 		.out_state_mask =
 			X(NM_BB_TRANSC_ST_OP_DISABLED_NOTINSTALLED) |
 			X(NM_BB_TRANSC_ST_OP_DISABLED_OFFLINE) |
@@ -342,7 +374,9 @@ static struct osmo_fsm_state nm_bb_transc_fsm_states[] = {
 	[NM_BB_TRANSC_ST_OP_DISABLED_OFFLINE] = {
 		.in_event_mask =
 			X(NM_EV_STATE_CHG_REP) |
-			X(NM_EV_GET_ATTR_REP),
+			X(NM_EV_GET_ATTR_REP) |
+			X(NM_EV_RSL_CONNECT_ACK) |
+			X(NM_EV_RSL_CONNECT_NACK),
 		.out_state_mask =
 			X(NM_BB_TRANSC_ST_OP_DISABLED_NOTINSTALLED) |
 			X(NM_BB_TRANSC_ST_OP_DISABLED_DEPENDENCY) |
diff --git a/src/osmo-bsc/nm_common_fsm.c b/src/osmo-bsc/nm_common_fsm.c
index b0902b171..2bf38ac31 100644
--- a/src/osmo-bsc/nm_common_fsm.c
+++ b/src/osmo-bsc/nm_common_fsm.c
@@ -33,6 +33,8 @@ const struct value_string nm_fsm_event_names[] = {
 	{ NM_EV_OML_DOWN, "OML_DOWN" },
 	{ NM_EV_FORCE_LOCK, "FORCE_LOCK_CHG" },
 	{ NM_EV_FEATURE_NEGOTIATED, "FEATURE_NEGOTIATED" },
+	{ NM_EV_RSL_CONNECT_ACK, "RSL_CONNECT_ACK" },
+	{ NM_EV_RSL_CONNECT_NACK, "RSL_CONNECT_NACK" },
 	{ 0, NULL }
 };