inter-BSC HO: add neighbor_ident API to manage neighbor-BSS-cells

Depends: Ia71ba742108b5ff020997bfb612ad5eb30d04fcd (libosmocore)
Change-Id: I0153d7069817fba9146ddc11214de2757d7d37bf

4 files changed, 92 insertions, 0 deletions

diff --git a/include/osmocom/bsc/Makefile.am b/include/osmocom/bsc/Makefile.am
index dfab5929c..0b576cddd 100644
--- a/include/osmocom/bsc/Makefile.am
+++ b/include/osmocom/bsc/Makefile.am
@@ -28,6 +28,7 @@ noinst_HEADERS = \
 	meas_feed.h \
 	meas_rep.h \
 	misdn.h \
+	neighbor_ident.h \
 	network_listen.h \
 	openbscdefines.h \
 	osmo_bsc.h \
diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h
index 579461732..a16a4b743 100644
--- a/include/osmocom/bsc/gsm_data.h
+++ b/include/osmocom/bsc/gsm_data.h
@@ -35,6 +35,7 @@
 struct mgcp_client_conf;
 struct mgcp_client;
 struct mgcp_ctx;
+struct gsm0808_cell_id;
 
 /** annotations for msgb ownership */
 #define __uses
@@ -750,6 +751,12 @@ struct load_counter {
 	unsigned int used;
 };
 
+/* Useful to track N-N relations between BTS, for example neighbors. */
+struct gsm_bts_ref {
+	struct llist_head entry;
+	struct gsm_bts *bts;
+};
+
 /* One BTS */
 struct gsm_bts {
 	/* list header in net->bts_list */
@@ -984,6 +991,11 @@ struct gsm_bts {
 
 	struct handover_cfg *ho;
 
+	/* A list of struct gsm_bts_ref, indicating neighbors of this BTS.
+	 * When the si_common neigh_list is in automatic mode, it is populated from this list as well as
+	 * gsm_network->neighbor_bss_cells. */
+	struct llist_head local_neighbors;
+
 	/* BTS-specific overrides for timer values from struct gsm_network. */
 	uint8_t T3122;	/* ASSIGMENT REJECT wait indication */
 
@@ -998,6 +1010,13 @@ struct gsm_network *gsm_network_init(void *ctx);
 
 struct gsm_bts *gsm_bts_alloc(struct gsm_network *net, uint8_t bts_num);
 struct gsm_bts *gsm_bts_num(struct gsm_network *net, int num);
+bool gsm_bts_matches_lai(const struct gsm_bts *bts, const struct osmo_location_area_id *lai);
+bool gsm_bts_matches_cell_id(const struct gsm_bts *bts, const struct gsm0808_cell_id *cell_id);
+struct gsm_bts *gsm_bts_by_cell_id(const struct gsm_network *net,
+				   const struct gsm0808_cell_id *cell_id,
+				   int match_idx);
+int gsm_bts_local_neighbor_add(struct gsm_bts *bts, struct gsm_bts *neighbor);
+int gsm_bts_local_neighbor_del(struct gsm_bts *bts, const struct gsm_bts *neighbor);
 
 struct gsm_bts_trx *gsm_bts_trx_alloc(struct gsm_bts *bts);
 struct gsm_bts_trx *gsm_bts_trx_num(const struct gsm_bts *bts, int num);
@@ -1281,6 +1300,9 @@ struct gsm_network {
 		struct mgcp_client_conf *conf;
 		struct mgcp_client *client;
 	} mgw;
+
+	/* Remote BSS Cell Identifier Lists */
+	struct neighbor_ident_list *neighbor_bss_cells;
 };
 
 static inline const struct osmo_location_area_id *bts_lai(struct gsm_bts *bts)
diff --git a/include/osmocom/bsc/handover.h b/include/osmocom/bsc/handover.h
index 772ab98e2..aa117cc24 100644
--- a/include/osmocom/bsc/handover.h
+++ b/include/osmocom/bsc/handover.h
@@ -6,6 +6,8 @@
 #include <osmocom/core/timer.h>
 #include <osmocom/gsm/gsm_utils.h>
 
+#include <osmocom/bsc/neighbor_ident.h>
+
 struct gsm_lchan;
 struct gsm_bts;
 struct gsm_subscriber_connection;
@@ -94,3 +96,7 @@ struct handover_decision_callbacks {
 
 void handover_decision_callbacks_register(struct handover_decision_callbacks *hdc);
 struct handover_decision_callbacks *handover_decision_callbacks_get(int hodec_id);
+
+struct gsm_bts *bts_by_neighbor_ident(const struct gsm_network *net,
+				      const struct neighbor_ident_key *search_for);
+struct neighbor_ident_key *bts_ident_key(const struct gsm_bts *bts);
diff --git a/include/osmocom/bsc/neighbor_ident.h b/include/osmocom/bsc/neighbor_ident.h
new file mode 100644
index 000000000..bba18c3e3
--- /dev/null
+++ b/include/osmocom/bsc/neighbor_ident.h
@@ -0,0 +1,63 @@
+/* Manage identity of neighboring BSS cells for inter-BSC handover */
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <osmocom/core/linuxlist.h>
+
+struct vty;
+struct gsm_network;
+struct gsm_bts;
+struct neighbor_ident_list;
+struct gsm0808_cell_id_list2;
+
+enum bsic_kind {
+	BSIC_NONE,
+	BSIC_6BIT,
+	BSIC_9BIT,
+};
+
+#define NEIGHBOR_IDENT_KEY_ANY_BTS -1
+
+struct neighbor_ident_key {
+	int from_bts; /*< BTS nr 0..255 or NEIGHBOR_IDENT_KEY_ANY_BTS */
+	uint16_t arfcn;
+	enum bsic_kind bsic_kind;
+	uint16_t bsic;
+};
+
+const char *neighbor_ident_key_name(const struct neighbor_ident_key *ni_key);
+
+struct neighbor_ident_list *neighbor_ident_init(void *talloc_ctx);
+void neighbor_ident_free(struct neighbor_ident_list *nil);
+
+bool neighbor_ident_key_match(const struct neighbor_ident_key *entry,
+			      const struct neighbor_ident_key *search_for,
+			      bool exact_match);
+
+int neighbor_ident_add(struct neighbor_ident_list *nil, const struct neighbor_ident_key *key,
+		       const struct gsm0808_cell_id_list2 *val);
+const struct gsm0808_cell_id_list2 *neighbor_ident_get(const struct neighbor_ident_list *nil,
+						       const struct neighbor_ident_key *key);
+bool neighbor_ident_del(struct neighbor_ident_list *nil, const struct neighbor_ident_key *key);
+void neighbor_ident_clear(struct neighbor_ident_list *nil);
+
+void neighbor_ident_iter(const struct neighbor_ident_list *nil,
+			 bool (* iter_cb )(const struct neighbor_ident_key *key,
+					   const struct gsm0808_cell_id_list2 *val,
+					   void *cb_data),
+			 void *cb_data);
+
+void neighbor_ident_vty_init(struct gsm_network *net, struct neighbor_ident_list *nil);
+void neighbor_ident_vty_write(struct vty *vty, const char *indent, struct gsm_bts *bts);
+
+#define NEIGHBOR_IDENT_VTY_KEY_PARAMS "arfcn <0-1023> (bsic|bsic9) (<0-511>|any)"
+#define NEIGHBOR_IDENT_VTY_KEY_DOC \
+	"ARFCN of neighbor cell\n" "ARFCN value\n" \
+	"BSIC of neighbor cell\n" "9-bit BSIC of neighbor cell\n" "BSIC value\n" \
+	"for all BSICs / use any BSIC in this ARFCN\n"
+bool neighbor_ident_vty_parse_key_params(struct vty *vty, const char **argv,
+					 struct neighbor_ident_key *key);
+bool neighbor_ident_bts_parse_key_params(struct vty *vty, struct gsm_bts *bts, const char **argv,
+					 struct neighbor_ident_key *key);