Introduce Neighbor Resolution Service

This new CTRL interface allows users of this BSC (such as attached PCU)
to gather neighbor information.

This interface is needed for PCU to translate ARFCN+BSIC keys provided
by MS in the Um side into CGI + RAC keys used to identify target cells
in RIM procedures against SGSNs on the Gb interface.

This patch extends the already existing neighbor information storage in
the VTY by allowing storage of CGI + RAC (RAC couldn't be stored
beforehand).

Related: SYS#4909
Depends: libosmocore.git Change-Id If48f412c32e8e5a3e604a78d12b74787a4786374
Change-Id: Ib07c9d23026332a207d4b7a0f7b4e76c0094e379

1 files changed, 103 insertions, 0 deletions

diff --git a/src/osmo-bsc/neighbor_ident.c b/src/osmo-bsc/neighbor_ident.c
index 4a0cd47ad..185cd0b07 100644
--- a/src/osmo-bsc/neighbor_ident.c
+++ b/src/osmo-bsc/neighbor_ident.c
@@ -33,6 +33,13 @@
 
 #include <osmocom/bsc/neighbor_ident.h>
 
+#include <osmocom/ctrl/control_cmd.h>
+#include <osmocom/ctrl/control_if.h>
+
+#include <osmocom/bsc/gsm_data.h>
+#include <osmocom/bsc/bts.h>
+#include <osmocom/bsc/debug.h>
+
 struct neighbor_ident_list {
 	struct llist_head list;
 };
@@ -253,3 +260,99 @@ void neighbor_ident_iter(const struct neighbor_ident_list *nil,
 			return;
 	}
 }
+
+/* Neighbor Resolution CTRL iface */
+
+CTRL_CMD_DEFINE_RO(neighbor_resolve_cgi_ps_from_lac_ci, "neighbor_resolve_cgi_ps_from_lac_ci");
+
+static int get_neighbor_resolve_cgi_ps_from_lac_ci(struct ctrl_cmd *cmd, void *data)
+{
+	struct gsm_network *net = (struct gsm_network *)data;
+	struct gsm_bts *bts_tmp, *bts_found = NULL;
+	const struct gsm0808_cell_id_list2 *tgt_cell_li = NULL;
+	char *tmp = NULL, *tok, *saveptr;
+	struct neighbor_ident_key ni;
+	unsigned lac, cell_id;
+	const struct osmo_cell_global_id_ps *cgi_ps;
+
+	if (!cmd->variable)
+		goto fmt_err;
+
+	tmp = talloc_strdup(cmd, cmd->variable);
+	if (!tmp) {
+		cmd->reply = "OOM";
+		return CTRL_CMD_ERROR;
+	}
+
+	if (!(tok = strtok_r(tmp, ".", &saveptr)))
+		goto fmt_err;
+	OSMO_ASSERT(strcmp(tok, "neighbor_resolve_cgi_ps_from_lac_ci") == 0);
+
+	if (!(tok = strtok_r(NULL, ".", &saveptr)))
+		goto fmt_err;
+	lac = atoi(tok);
+
+	if (!(tok = strtok_r(NULL, ".", &saveptr)))
+		goto fmt_err;
+	cell_id = atoi(tok);
+
+	if (!(tok = strtok_r(NULL, ".", &saveptr)))
+		goto fmt_err;
+	ni.arfcn = atoi(tok);
+
+	if (!(tok = strtok_r(NULL, "\0", &saveptr)))
+		goto fmt_err;
+	ni.bsic = atoi(tok);
+
+	ni.from_bts = NEIGHBOR_IDENT_KEY_ANY_BTS;
+
+	llist_for_each_entry(bts_tmp, &net->bts_list, list) {
+		if (bts_tmp->location_area_code != lac)
+			continue;
+		if (bts_tmp->cell_identity != cell_id)
+			continue;
+		bts_found = bts_tmp;
+		ni.from_bts = bts_tmp->nr;
+		break;
+	}
+
+	if (!bts_found)
+		goto notfound_err;
+
+	LOG_BTS(bts_found, DLINP, LOGL_DEBUG, "Resolving neigbhor arfcn=%u bsic=%u\n", ni.arfcn, ni.bsic);
+
+	if (!neighbor_ident_key_valid(&ni))
+		goto fmt_err;
+
+	tgt_cell_li = neighbor_ident_get(net->neighbor_bss_cells, &ni);
+	if (!tgt_cell_li || tgt_cell_li->id_discr != CELL_IDENT_WHOLE_GLOBAL_PS || tgt_cell_li->id_list_len < 1)
+		goto notfound_err;
+	cgi_ps = &tgt_cell_li->id_list[0].global_ps;
+
+	ctrl_cmd_reply_printf(cmd, "%s", osmo_cgi_ps_name(cgi_ps));
+	talloc_free(tmp);
+	return CTRL_CMD_REPLY;
+
+notfound_err:
+	talloc_free(tmp);
+	cmd->reply = talloc_strdup(cmd, "No target CGI PS found");
+	return CTRL_CMD_ERROR;
+fmt_err:
+	talloc_free(tmp);
+	cmd->reply = talloc_strdup(cmd, "The format is <src_lac>,<src_cell_id>,<dst_arfcn>,<dst_bsic>");
+	return CTRL_CMD_ERROR;
+}
+
+int neighbor_ctrl_cmds_install(struct gsm_network *net)
+{
+	int rc;
+
+	rc = ctrl_cmd_install(CTRL_NODE_ROOT, &cmd_neighbor_resolve_cgi_ps_from_lac_ci);
+	return rc;
+}
+
+struct ctrl_handle *neighbor_controlif_setup(struct gsm_network *net)
+{
+	return ctrl_interface_setup_dynip2(net, net->neigh_ctrl.addr, net->neigh_ctrl.port,
+					   NULL, _LAST_CTRL_NODE_NEIGHBOR);
+}