[BSC] Allow manual override of neighbor cell list

So far, OpenBSC simply assumed that all BTS's configured in openbsc.cfg are
neighbors of each other.  While this is true for small site installations,
it is definitely not true in most real world cases.  We now have the
following new commands at the 'configure bts' level:

'neighbor-list mode (auto|manual)' for selecting the mode

'neighbor-list (add|del) arfcn <0-1024>'
	for adding/deleting ARFCN in manual mode

openbsc/include/openbsc/gsm_data.h

@@ -531,6 +531,7 @@ struct gsm_bts {
 		struct gsm_nm_state nm_state;
 	} site_mgr;
 
+	int neigh_list_manual_mode;
 	/* parameters from which we build SYSTEM INFORMATION */
 	struct {
 		struct gsm48_rach_control rach_control;

openbsc/src/bsc_vty.c

@@ -488,6 +488,16 @@ static void config_write_bts_single(struct vty *vty, struct gsm_bts *bts)
 	if (bts->paging.free_chans_need >= 0)
 		vty_out(vty, "  paging free %d%s", bts->paging.free_chans_need, VTY_NEWLINE);
 
+	vty_out(vty, "  neighbor-list mode %s%s",
+		bts->neigh_list_manual_mode ? "manual" : "automatic", VTY_NEWLINE);
+	if (bts->neigh_list_manual_mode) {
+		for (i = 0; i < 1024; i++) {
+			if (bitvec_get_bit_pos(&bts->si_common.neigh_list, i))
+				vty_out(vty, "  neighbor-list add arfcn %u%s",
+					i, VTY_NEWLINE);
+		}
+	}
+
 	config_write_bts_gprs(vty, bts);
 
 	llist_for_each_entry(trx, &bts->trx_list, list)
@@ -2116,6 +2126,50 @@ DEFUN(cfg_bts_si_static, cfg_bts_si_static_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_bts_neigh_mode, cfg_bts_neigh_mode_cmd,
+	"neighbor-list mode (automatic|manual)",
+	"Neighbor List\n" "Mode of Neighbor List generation\n"
+	"Automatically from all BTS in this OpenBSC\n" "Manual\n")
+{
+	struct gsm_bts *bts = vty->index;
+
+	if (!strcmp(argv[0], "manual")) {
+		/* make sure we clear the current list when switching to
+		 * manual mode */
+		if (bts->neigh_list_manual_mode == 0)
+			memset(&bts->si_common.data.neigh_list, 0,
+				sizeof(bts->si_common.data.neigh_list));
+		bts->neigh_list_manual_mode = 1;
+	} else
+		bts->neigh_list_manual_mode = 0;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_bts_neigh, cfg_bts_neigh_cmd,
+	"neighbor-list (add|del) arfcn <0-1024>",
+	"Neighbor List\n" "Add to manual neighbor list\n"
+	"Delete from manual neighbor list\n" "ARFCN of neighbor\n"
+	"ARFCN of neighbor\n")
+{
+	struct gsm_bts *bts = vty->index;
+	struct bitvec *bv = &bts->si_common.neigh_list;
+	uint16_t arfcn = atoi(argv[1]);
+
+	if (!bts->neigh_list_manual_mode) {
+		vty_out(vty, "%% Cannot configure neighbor list in "
+			"automatic mode%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if (!strcmp(argv[0], "add"))
+		bitvec_set_bit_pos(bv, arfcn, 1);
+	else
+		bitvec_set_bit_pos(bv, arfcn, 0);
+
+	return CMD_SUCCESS;
+}
+
 
 #define TRX_TEXT "Radio Transceiver\n"
 
@@ -2614,6 +2668,8 @@ int bsc_vty_init(void)
 	install_element(BTS_NODE, &cfg_bts_pag_free_cmd);
 	install_element(BTS_NODE, &cfg_bts_si_mode_cmd);
 	install_element(BTS_NODE, &cfg_bts_si_static_cmd);
+	install_element(BTS_NODE, &cfg_bts_neigh_mode_cmd);
+	install_element(BTS_NODE, &cfg_bts_neigh_cmd);
 
 	install_element(BTS_NODE, &cfg_trx_cmd);
 	install_node(&trx_node, dummy_config_write);

openbsc/src/gsm_data.c

@@ -207,6 +207,8 @@ struct gsm_bts *gsm_bts_alloc(struct gsm_network *net, enum gsm_bts_type type,
 	bts->num_trx = 0;
 	INIT_LLIST_HEAD(&bts->trx_list);
 	bts->ms_max_power = 15;	/* dBm */
+
+	bts->neigh_list_manual_mode = 0;
 	bts->si_common.cell_sel_par.cell_resel_hyst = 2; /* 4 dB */
 	bts->si_common.cell_sel_par.rxlev_acc_min = 0;
 	bts->si_common.neigh_list.data = bts->si_common.data.neigh_list;

openbsc/src/system_information.c

@@ -207,11 +207,14 @@ static int generate_bcch_chan_list(u_int8_t *chan_list, struct gsm_bts *bts)
 	/* Zero-initialize the bit-vector */
 	memset(bv->data, 0, bv->data_len);
 
-	/* first we generate a bitvec of the BCCH ARFCN's in our BSC */
-	llist_for_each_entry(cur_bts, &bts->network->bts_list, list) {
-		if (cur_bts == bts)
-			continue;
-		bitvec_set_bit_pos(bv, cur_bts->c0->arfcn, 1);
+	/* Generate list of neighbor cells if we are in automatic mode */
+	if (bts->neigh_list_manual_mode == 0) {
+		/* first we generate a bitvec of the BCCH ARFCN's in our BSC */
+		llist_for_each_entry(cur_bts, &bts->network->bts_list, list) {
+			if (cur_bts == bts)
+				continue;
+			bitvec_set_bit_pos(bv, cur_bts->c0->arfcn, 1);
+		}
 	}
 
 	/* then we generate a GSM 04.08 frequency list from the bitvec */