fix dyn TS init: properly identify BTS on OML OPSTART ACK

Commit "dyn ts, bts_ipaccess_nanobts.c: init PDCH on Chan OPSTART ACK"
bf7099262adf0f27e71a08387747c5cb0d459360 Icf6e25ff068e8a2600562d52726ead65e864ec02
introduced signal S_NM_OPSTART_ACK and passed the FOM header to identify the BTS
by. But the FOM header's BTS number is zero on each Abis/IP link, and the BTS
and TRX are actually identified by msgb->dst == e1inp_sign_link, member trx. So
the initial implementation associated *all* Channel OPSTART ACKs with BTS 0.

Pass the entire msgb as S_NM_OPSTART_ACK signal argument, implement a
abis_nm_get_ts() to retrieve the proper timeslot and use that during timeslot
init.

Related: OS#3351 OS#3205
Change-Id: I45ce5c24cb62d00f350df1af1be6c11104d74193

4 files changed, 37 insertions, 27 deletions

diff --git a/include/osmocom/bsc/abis_nm.h b/include/osmocom/bsc/abis_nm.h
index 9586deddd..ef9e4f5fc 100644
--- a/include/osmocom/bsc/abis_nm.h
+++ b/include/osmocom/bsc/abis_nm.h
@@ -171,4 +171,6 @@ int abis_nm_select_newest_sw(const struct abis_nm_sw_desc *sw, const size_t len)
 /* Helper functions for updating attributes */
 int abis_nm_update_max_power_red(struct gsm_bts_trx *trx);
 
+struct gsm_bts_trx_ts *abis_nm_get_ts(const struct msgb *oml_msg);
+
 #endif /* _NM_H */
diff --git a/include/osmocom/bsc/signal.h b/include/osmocom/bsc/signal.h
index 1dde26772..1b351aa4a 100644
--- a/include/osmocom/bsc/signal.h
+++ b/include/osmocom/bsc/signal.h
@@ -71,7 +71,7 @@ enum signal_nm {
 	S_NM_STATECHG_OPER,	/* Operational State changed*/
 	S_NM_STATECHG_ADM,	/* Administrative State changed */
 	S_NM_OM2K_CONF_RES,	/* OM2K Configuration Result */
-	S_NM_OPSTART_ACK,	/* Received OPSTART ACK, arg is struct abis_om_fom_hdr* */
+	S_NM_OPSTART_ACK,	/* Received OPSTART ACK, arg is struct msgb *oml_msg */
 };
 
 /* SS_LCHAN signals */
diff --git a/src/osmo-bsc/abis_nm.c b/src/osmo-bsc/abis_nm.c
index 9dc1f62cb..cb1cc56ea 100644
--- a/src/osmo-bsc/abis_nm.c
+++ b/src/osmo-bsc/abis_nm.c
@@ -671,11 +671,36 @@ static int abis_nm_rx_lmt_event(struct msgb *mb)
 	return 0;
 }
 
+/* From a received OML message, determine the matching struct gsm_bts_trx_ts instance.
+ * Note that the BTS-TRX-TS numbers received in the FOM header do not correspond to the local bts->nr and
+ * bts->trx->nr. Rather, the trx is identified by the e1inp_sign_link* found in msg->dst, and the TS is
+ * then obtained by the FOM header's TS number. */
+struct gsm_bts_trx_ts *abis_nm_get_ts(const struct msgb *oml_msg)
+{
+	struct abis_om_fom_hdr *foh = msgb_l3(oml_msg);
+	struct e1inp_sign_link *sign_link = oml_msg->dst;
+	struct gsm_bts_trx *trx = sign_link->trx;
+	uint8_t ts_nr = foh->obj_inst.ts_nr;
+	if (!trx) {
+		LOGP(DNM, LOGL_ERROR, "%s Channel OPSTART ACK for sign_link without trx\n",
+		     abis_nm_dump_foh(foh));
+		return NULL;
+	}
+	if (ts_nr >= ARRAY_SIZE(trx->ts)) {
+		LOGP(DNM, LOGL_ERROR, "bts%u-trx%u %s Channel OPSTART ACK for non-existent TS\n",
+		     trx->bts->nr, trx->nr, abis_nm_dump_foh(foh));
+		return NULL;
+	}
+	return &trx->ts[ts_nr];
+}
+
 static int abis_nm_rx_opstart_ack(struct msgb *mb)
 {
 	struct abis_om_fom_hdr *foh = msgb_l3(mb);
-	DEBUGPFOH(DNM, foh, "Opstart ACK\n");
-	osmo_signal_dispatch(SS_NM, S_NM_OPSTART_ACK, foh);
+	struct e1inp_sign_link *sign_link = mb->dst;
+	struct gsm_bts_trx *trx = sign_link->trx;
+	DEBUGPFOH(DNM, foh, "bts=%u trx=%u Opstart ACK\n", trx->bts->nr, trx->nr);
+	osmo_signal_dispatch(SS_NM, S_NM_OPSTART_ACK, mb);
 	return 0;
 }
 
diff --git a/src/osmo-bsc/bts_ipaccess_nanobts.c b/src/osmo-bsc/bts_ipaccess_nanobts.c
index 843f264ae..0e23955c8 100644
--- a/src/osmo-bsc/bts_ipaccess_nanobts.c
+++ b/src/osmo-bsc/bts_ipaccess_nanobts.c
@@ -298,40 +298,23 @@ static int sw_activ_rep(struct msgb *mb)
 	return 0;
 }
 
-static struct gsm_bts_trx_ts *gsm_bts_trx_ts(struct gsm_network *net,
-					     int bts_nr, int trx_nr, int ts_nr)
-{
-	struct gsm_bts *bts;
-	struct gsm_bts_trx *trx;
-	bts = gsm_bts_num(net, bts_nr);
-	if (!bts)
-		return NULL;
-	trx = gsm_bts_trx_by_nr(bts, trx_nr);
-	if (!trx)
-		return NULL;
-	if (ts_nr < 0 || ts_nr > ARRAY_SIZE(trx->ts))
-		return NULL;
-	return &trx->ts[ts_nr];
-}
-
-static void nm_rx_opstart_ack_chan(struct abis_om_fom_hdr *foh)
+static void nm_rx_opstart_ack_chan(struct msgb *oml_msg)
 {
 	struct gsm_bts_trx_ts *ts;
-	ts = gsm_bts_trx_ts(bsc_gsmnet, foh->obj_inst.bts_nr, foh->obj_inst.trx_nr, foh->obj_inst.ts_nr);
-	if (!ts) {
-		LOGP(DNM, LOGL_ERROR, "%s Channel OPSTART ACK for non-existent TS\n",
-		     abis_nm_dump_foh(foh));
+	ts = abis_nm_get_ts(oml_msg);
+	if (!ts)
+		/* error already logged in abis_nm_get_ts() */
 		return;
-	}
 
 	gsm_ts_check_init(ts);
 }
 
-static void nm_rx_opstart_ack(struct abis_om_fom_hdr *foh)
+static void nm_rx_opstart_ack(struct msgb *oml_msg)
 {
+	struct abis_om_fom_hdr *foh = msgb_l3(oml_msg);
 	switch (foh->obj_class) {
 	case NM_OC_CHANNEL:
-		nm_rx_opstart_ack_chan(foh);
+		nm_rx_opstart_ack_chan(oml_msg);
 		break;
 	default:
 		break;