Allow configuring SI13 CCN_ACTIVE bit from VTY, enable by default on osmo-bts

This is required in order to tell MS that osmo-pcu now supports
Network Assisted Cell Change (NACC).

Other BTS are not enabled by default since NACC support is not known to
work nor tested there.

Depends: libosmocore.git Change-Id I61991266b95d0c13d51b47906cc07846e9cf1390
Related: SYS#4909
Change-Id: If91d85331d402c3ab9c32b70c2c66cd7ba6ceb28

4 files changed, 33 insertions, 0 deletions

diff --git a/include/osmocom/bsc/bts.h b/include/osmocom/bsc/bts.h
index b81f45fb2..6797d1c70 100644
--- a/include/osmocom/bsc/bts.h
+++ b/include/osmocom/bsc/bts.h
@@ -387,6 +387,10 @@ struct gsm_bts {
 		uint8_t net_ctrl_ord;
 		bool ctrl_ack_type_use_block;
 		bool egprs_pkt_chan_request;
+		struct {
+			bool active; /* CCN_ACTIVE */
+			bool forced_vty; /* set by VTY ? */
+		} ccn; /* TS 44.060 sec 8.8.2 */
 	} gprs;
 
 	/* threshold (in percent) when BTS shall send CCCH LOAD IND */
diff --git a/src/osmo-bsc/bsc_vty.c b/src/osmo-bsc/bsc_vty.c
index 478121723..03b87b44a 100644
--- a/src/osmo-bsc/bsc_vty.c
+++ b/src/osmo-bsc/bsc_vty.c
@@ -758,6 +758,9 @@ static void config_write_bts_gprs(struct vty *vty, struct gsm_bts *bts)
 		bts->gprs.net_ctrl_ord, VTY_NEWLINE);
 	if (!bts->gprs.ctrl_ack_type_use_block)
 		vty_out(vty, "  gprs control-ack-type-rach%s", VTY_NEWLINE);
+	if (bts->gprs.ccn.forced_vty)
+		vty_out(vty, "  gprs ccn-active %d%s",
+			bts->gprs.ccn.active ? 1 : 0, VTY_NEWLINE);
 	vty_out(vty, "  gprs cell bvci %u%s", bts->gprs.cell.bvci,
 		VTY_NEWLINE);
 	for (i = 0; i < ARRAY_SIZE(bts->gprs.cell.timer); i++)
@@ -3486,6 +3489,24 @@ DEFUN_USRATTR(cfg_bts_gprs_ctrl_ack,
 	return CMD_SUCCESS;
 }
 
+DEFUN_USRATTR(cfg_bts_gprs_ccn_active,
+	      cfg_bts_gprs_ccn_active_cmd,
+	      X(BSC_VTY_ATTR_RESTART_ABIS_RSL_LINK),
+	      "gprs ccn-active (0|1|default)",
+	      GPRS_TEXT
+	      "Set CCN_ACTIVE in the GPRS Cell Options IE on the BCCH (SI13)\n"
+	      "Disable\n" "Enable\n" "Default based on BTS type support\n")
+{
+	struct gsm_bts *bts = vty->index;
+
+	bts->gprs.ccn.forced_vty = strcmp(argv[0], "default") != 0;
+
+	if (bts->gprs.ccn.forced_vty)
+		bts->gprs.ccn.active = argv[0][0] == '1';
+
+	return CMD_SUCCESS;
+}
+
 DEFUN_USRATTR(cfg_no_bts_gprs_ctrl_ack,
 	      cfg_no_bts_gprs_ctrl_ack_cmd,
 	      X(BSC_VTY_ATTR_RESTART_ABIS_RSL_LINK),
@@ -7637,6 +7658,7 @@ int bsc_vty_init(struct gsm_network *network)
 	install_element(BTS_NODE, &cfg_bts_gprs_rac_cmd);
 	install_element(BTS_NODE, &cfg_bts_gprs_net_ctrl_ord_cmd);
 	install_element(BTS_NODE, &cfg_bts_gprs_ctrl_ack_cmd);
+	install_element(BTS_NODE, &cfg_bts_gprs_ccn_active_cmd);
 	install_element(BTS_NODE, &cfg_no_bts_gprs_ctrl_ack_cmd);
 	install_element(BTS_NODE, &cfg_bts_gprs_bvci_cmd);
 	install_element(BTS_NODE, &cfg_bts_gprs_cell_timer_cmd);
diff --git a/src/osmo-bsc/bts_sysmobts.c b/src/osmo-bsc/bts_sysmobts.c
index e319f2cbc..f24c615bf 100644
--- a/src/osmo-bsc/bts_sysmobts.c
+++ b/src/osmo-bsc/bts_sysmobts.c
@@ -61,6 +61,7 @@ int bts_model_sysmobts_init(void)
 	osmo_bts_set_feature(&model_sysmobts.features, BTS_FEAT_EGPRS);
 	osmo_bts_set_feature(&model_sysmobts.features, BTS_FEAT_PAGING_COORDINATION);
 	osmo_bts_set_feature(&model_sysmobts.features, BTS_FEAT_IPV6_NSVC);
+	osmo_bts_set_feature(&model_sysmobts.features, BTS_FEAT_CCN);
 
 	model_sysmobts.nm_att_tlvdef.def[NM_ATT_OSMO_NS_LINK_CFG].type = TLV_TYPE_TL16V;
 
diff --git a/src/osmo-bsc/system_information.c b/src/osmo-bsc/system_information.c
index 10b0e4df8..d018ec37c 100644
--- a/src/osmo-bsc/system_information.c
+++ b/src/osmo-bsc/system_information.c
@@ -1206,6 +1206,7 @@ static struct osmo_gsm48_si13_info si13_default = {
 			.pfc_supported = 0,
 			.dtm_supported = 0,
 			.bss_paging_coordination = 0,
+			.ccn_active = false,
 		},
 	},
 	.pwr_ctrl_pars = {
@@ -1255,6 +1256,11 @@ static int generate_si13(enum osmo_sysinfo_type t, struct gsm_bts *bts)
 	else
 		si13_default.cell_opts.ext_info.bss_paging_coordination = 0;
 
+	si13_default.cell_opts.ext_info.ccn_active = bts->gprs.ccn.forced_vty ?
+						     bts->gprs.ccn.active :
+						     osmo_bts_has_feature(&bts->model->features,
+									  BTS_FEAT_CCN);
+
 	ret = osmo_gsm48_rest_octets_si13_encode(si13->rest_octets, &si13_default);
 	if (ret < 0)
 		return ret;