SMSCB: Send ETWS Primary Notifiation via RSL to BTS

In addition to transmission of the ETWS Primary Notification via all
dedicated channels, we also need to send it to the BTS for transmission
via PCH (P1 Rest Octets) and for forwarding to PCU for PACCH
transmission.

Change-Id: I7e45b0373458a4348b12b92dd92861062532548b

4 files changed, 44 insertions, 6 deletions

diff --git a/include/osmocom/bsc/abis_rsl.h b/include/osmocom/bsc/abis_rsl.h
index ec630909c..4ccfd148e 100644
--- a/include/osmocom/bsc/abis_rsl.h
+++ b/include/osmocom/bsc/abis_rsl.h
@@ -91,6 +91,7 @@ int rsl_chan_ms_power_ctrl(struct gsm_lchan *lchan, unsigned int fpc, int dbm);
 int rsl_sms_cb_command(struct gsm_bts *bts, uint8_t chan_number,
 		       struct rsl_ie_cb_cmd_type cb_command,
 		       bool use_extended_cbch, const uint8_t *data, int len);
+int rsl_etws_pn_command(struct gsm_bts *bts, uint8_t chan_nr, const uint8_t *data, int len);
 
 /* some Nokia specific stuff */
 int rsl_nokia_si_begin(struct gsm_bts_trx *trx);
diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h
index 8dfbc6425..f6d6d5e92 100644
--- a/include/osmocom/bsc/gsm_data.h
+++ b/include/osmocom/bsc/gsm_data.h
@@ -1266,6 +1266,7 @@ struct gsm_bts {
 	struct osmo_timer_list cbch_timer;
 	struct bts_smscb_chan_state cbch_basic;
 	struct bts_smscb_chan_state cbch_extended;
+	struct osmo_timer_list etws_timer;	/* when to stop ETWS PN */
 };
 
 /* One rejected BTS */
diff --git a/src/osmo-bsc/abis_rsl.c b/src/osmo-bsc/abis_rsl.c
index 06d19a5d5..4a7d104e8 100644
--- a/src/osmo-bsc/abis_rsl.c
+++ b/src/osmo-bsc/abis_rsl.c
@@ -2203,6 +2203,25 @@ int abis_rsl_rcvmsg(struct msgb *msg)
 	return rc;
 }
 
+/* Send an Osmocom-specific Abis RSL message for ETWS Primary Notification */
+int rsl_etws_pn_command(struct gsm_bts *bts, uint8_t chan_nr, const uint8_t *data, int len)
+{
+	struct abis_rsl_dchan_hdr *dh;
+	struct msgb *msg = rsl_msgb_alloc();
+	if (!msg)
+		return -1;
+	dh = (struct abis_rsl_dchan_hdr *) msgb_put(msg, sizeof(*dh));
+	init_dchan_hdr(dh, RSL_MT_OSMO_ETWS_CMD);
+	dh->c.msg_discr = ABIS_RSL_MDISC_COM_CHAN;
+	dh->chan_nr = chan_nr;
+
+	msgb_tlv_put(msg, RSL_IE_SMSCB_MSG, len, data);
+
+	msg->dst = bts->c0->rsl_link;
+
+	return abis_rsl_sendmsg(msg);
+}
+
 int rsl_sms_cb_command(struct gsm_bts *bts, uint8_t chan_number,
 		       struct rsl_ie_cb_cmd_type cb_command,
 		       bool use_extended_cbch, const uint8_t *data, int len)
diff --git a/src/osmo-bsc/smscb.c b/src/osmo-bsc/smscb.c
index 319ef21a7..8d48af9fe 100644
--- a/src/osmo-bsc/smscb.c
+++ b/src/osmo-bsc/smscb.c
@@ -40,6 +40,7 @@
 #include <osmocom/bsc/vty.h>
 #include <osmocom/bsc/gsm_04_08_rr.h>
 #include <osmocom/bsc/lchan_fsm.h>
+#include <osmocom/bsc/abis_rsl.h>
 
 /*********************************************************************************
  * Helper Functions
@@ -461,8 +462,15 @@ static int tx_cbsp_keepalive_compl(struct bsc_cbc_link *cbc)
  * Per-BTS Processing of CBSP from CBC, called via cbsp_per_bts()
  *********************************************************************************/
 
-static void etws_primary_to_dedicated(struct gsm_bts *bts,
-				      const struct osmo_cbsp_write_replace *wrepl)
+/* timer call-back once ETWS warning period has expired */
+static void etws_pn_cb(void *data)
+{
+	struct gsm_bts *bts = (struct gsm_bts *)data;
+	LOG_BTS(bts, DCBS, LOGL_NOTICE, "ETWS PN Timeout; disabling broadcast via PCH\n");
+	rsl_etws_pn_command(bts, RSL_CHAN_PCH_AGCH, NULL, 0);
+}
+
+static void etws_primary_to_bts(struct gsm_bts *bts, const struct osmo_cbsp_write_replace *wrepl)
 {
 	uint8_t etws_primary[ETWS_PRIM_NOTIF_SIZE];
 	struct gsm_bts_trx *trx;
@@ -491,7 +499,18 @@ static void etws_primary_to_dedicated(struct gsm_bts *bts,
 	LOG_BTS(bts, DCBS, LOGL_NOTICE, "Sent ETWS Primary Notification via %u dedicated channels\n",
 		count);
 
-	/* FIXME: Notify BTS of primary ETWS notification via vendor-specific Abis message */
+	/* Notify BTS of primary ETWS notification via vendor-specific Abis message */
+	if (osmo_bts_has_feature(&bts->features, BTS_FEAT_ETWS_PN)) {
+		rsl_etws_pn_command(bts, RSL_CHAN_PCH_AGCH, etws_primary, sizeof(etws_primary));
+		LOG_BTS(bts, DCBS, LOGL_NOTICE, "Sent ETWS Primary Notification via common channel\n");
+		if (wrepl->u.emergency.warning_period != 0xffffffff) {
+			osmo_timer_setup(&bts->etws_timer, etws_pn_cb, bts);
+			osmo_timer_schedule(&bts->etws_timer, wrepl->u.emergency.warning_period, 0);
+		} else
+			LOG_BTS(bts, DCBS, LOGL_NOTICE, "Unlimited ETWS PN broadcast, this breaks "
+				"normal network operation due to PCH blockage\n");
+	} else
+		LOG_BTS(bts, DCBS, LOGL_ERROR, "BTS doesn't support RSL command for ETWS PN\n");
 }
 
 /*! Try to execute a write-replace operation; roll-back if it fails.
@@ -563,9 +582,7 @@ static int bts_rx_write_replace(struct gsm_bts *bts, const struct osmo_cbsp_deco
 	int rc;
 
 	if (!wrepl->is_cbs) {
-		/* send through any active dedicated channels of this BTS */
-		etws_primary_to_dedicated(bts, wrepl);
-		/* TODO: send via RSL to BTS for transmission on PCH */
+		etws_primary_to_bts(bts, wrepl);
 		return 0;
 	}