CBSP (Cell Broadcast Service Protocol; 3GPP TS 48.049) support

This introduces definitions as well as a parser+encoder for the
Cell Broadcast Service Protocol (CBSP) as specified in 3GPP TS 48.049.

CBSP is used on the interface between CBC and BSC.

Related: OS#3537
Change-Id: I5b7ae08f67e415967b60ac4b824db9e22ca00935

2 files changed, 420 insertions, 0 deletions

diff --git a/include/osmocom/gsm/cbsp.h b/include/osmocom/gsm/cbsp.h
new file mode 100644
index 00000000..d47b37bb
--- /dev/null
+++ b/include/osmocom/gsm/cbsp.h
@@ -0,0 +1,292 @@
+#pragma once
+
+#include <stdint.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/gsm/protocol/gsm_48_049.h>
+#include <osmocom/gsm/gsm0808_utils.h>
+
+/* Definitions for parsed / abstract representation of messages in the
+ * CBSP (Cell Broadcast Service Protocol).  Data here is *not* formatted
+ * like the * on-the-wire format.  Any similarities are coincidetial ;) */
+
+/* Copyright (C) 2019  Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* Decoded 8.2.3 Message Content */
+struct osmo_cbsp_content {
+	struct llist_head list;
+	uint8_t user_len;
+	uint8_t data[82];
+};
+
+/* Decoded Entry in a 8.2.6 Cell List */
+struct osmo_cbsp_cell_ent {
+	struct llist_head list;		/* entry in osmo_cbsp_cell_list.list */
+	union gsm0808_cell_id_u cell_id;
+};
+struct osmo_cbsp_cell_list {
+	enum CELL_IDENT id_discr;
+	struct llist_head list;		/* list of osmo_cbsp_cell_ent */
+};
+
+/* Decoded Entry in a 8.2.10 Completed List */
+struct osmo_cbsp_num_compl_ent {
+	struct llist_head list;		/* entry in osmo_cbsp_num_compl_list.list */
+	union gsm0808_cell_id_u cell_id;
+	uint16_t num_compl;
+	uint8_t num_bcast_info;
+};
+struct osmo_cbsp_num_compl_list {
+	enum CELL_IDENT id_discr;
+	struct llist_head list;		/* list of osmo_cbsp_num_compl_ent */
+};
+
+/* Decoded Entry in a 8.2.12 Radio Resource Loading List */
+struct osmo_cbsp_loading_ent {
+	struct llist_head list;		/* entry in osmo_cbsp_loading_list */
+	union gsm0808_cell_id_u cell_id;
+	uint8_t load[2];
+};
+struct osmo_cbsp_loading_list {
+	enum CELL_IDENT id_discr;
+	struct llist_head list;		/* list of osmo_cbsp_loading_ent */
+};
+
+/* Decoded Entry in a 8.2.11 Failure List */
+struct osmo_cbsp_fail_ent {
+	struct llist_head list;		/* entry in a fail_list below */
+	enum CELL_IDENT id_discr;
+	union gsm0808_cell_id_u cell_id;
+	uint8_t cause;
+};
+
+
+/* 8.1.3.1 */
+struct osmo_cbsp_write_replace {
+	uint16_t msg_id;		/* 8.2.16 M */
+	uint16_t new_serial_nr;		/* 8.2.5 M */
+	uint16_t *old_serial_nr;	/* 8.2.4 */
+	struct osmo_cbsp_cell_list cell_list;
+
+	bool is_cbs;
+	union {
+		struct {
+			enum cbsp_channel_ind channel_ind;
+			enum cbsp_category category;
+			uint16_t rep_period;
+			uint16_t num_bcast_req;
+			/* num_of_pages implicit as llist_count(msg_content) */
+			uint8_t dcs;
+			struct llist_head msg_content;
+		} cbs;
+		struct {
+			uint8_t indicator;
+			uint16_t warning_type;
+			uint8_t warning_sec_info[50];
+			uint32_t warning_period;	/* in seconds; 0xffffffff = unlimited */
+		} emergency;
+	} u;
+};
+
+/* 8.1.3.2 */
+struct osmo_cbsp_write_replace_complete {
+	uint16_t msg_id;
+	uint16_t new_serial_nr;
+	uint16_t *old_serial_nr;
+	struct osmo_cbsp_num_compl_list num_compl_list;
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind *channel_ind;
+};
+
+/* 8.1.3.3 */
+struct osmo_cbsp_write_replace_failure {
+	uint16_t msg_id;
+	uint16_t new_serial_nr;
+	uint16_t *old_serial_nr;
+	struct llist_head fail_list;		/* list of osmo_cbsp_fail_ent */
+	struct osmo_cbsp_num_compl_list num_compl_list;
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind *channel_ind;
+};
+
+/* 8.1.3.4 */
+struct osmo_cbsp_kill {
+	uint16_t msg_id;
+	uint16_t old_serial_nr;
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind *channel_ind;
+};
+
+/* 8.1.3.5 */
+struct osmo_cbsp_kill_complete {
+	uint16_t msg_id;
+	uint16_t old_serial_nr;
+	struct osmo_cbsp_num_compl_list num_compl_list;
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind *channel_ind;
+};
+
+/* 8.1.3.6 */
+struct osmo_cbsp_kill_failure {
+	uint16_t msg_id;
+	uint16_t old_serial_nr;
+	struct llist_head fail_list;		/* list of osmo_cbsp_fail_ent */
+	struct osmo_cbsp_num_compl_list num_compl_list;
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind *channel_ind;
+};
+
+/* 8.1.3.7 */
+struct osmo_cbsp_load_query {
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind channel_ind;
+};
+
+/* 8.1.3.8 */
+struct osmo_cbsp_load_query_complete {
+	struct osmo_cbsp_loading_list loading_list;
+	enum cbsp_channel_ind channel_ind;
+};
+
+/* 8.1.3.9 */
+struct osmo_cbsp_load_query_failure {
+	struct llist_head fail_list;		/* list of osmo_cbsp_fail_ent */
+	enum cbsp_channel_ind channel_ind;
+	struct osmo_cbsp_loading_list loading_list;
+};
+
+/* 8.1.3.10 */
+struct osmo_cbsp_msg_status_query {
+	uint16_t msg_id;
+	uint16_t old_serial_nr;
+	struct osmo_cbsp_cell_list cell_list;
+	enum cbsp_channel_ind channel_ind;
+};
+
+/* 8.1.3.11 */
+struct osmo_cbsp_msg_status_query_complete {
+	uint16_t msg_id;
+	uint16_t old_serial_nr;
+	struct osmo_cbsp_num_compl_list num_compl_list;
+	enum cbsp_channel_ind channel_ind;
+};
+
+/* 8.1.3.12 */
+struct osmo_cbsp_msg_status_query_failure {
+	uint16_t msg_id;
+	uint16_t old_serial_nr;
+	struct llist_head fail_list;		/* list of osmo_cbsp_fail_ent */
+	enum cbsp_channel_ind channel_ind;
+	struct osmo_cbsp_num_compl_list num_compl_list;
+};
+
+/* 8.1.3.16 */
+struct osmo_cbsp_reset {
+	struct osmo_cbsp_cell_list cell_list;
+};
+
+/* 8.1.3.17 */
+struct osmo_cbsp_reset_complete {
+	struct osmo_cbsp_cell_list cell_list;
+};
+
+/* 8.1.3.18 */
+struct osmo_cbsp_reset_failure {
+	struct llist_head fail_list;		/* list of osmo_cbsp_fail_ent */
+	struct osmo_cbsp_cell_list cell_list;
+};
+
+/* 8.1.3.18a */
+struct osmo_cbsp_keep_alive {
+	uint8_t repetition_period;
+};
+
+/* 8.1.3.18b */
+struct osmo_cbsp_keep_alive_complete {
+};
+
+/* 8.1.3.19 */
+struct osmo_cbsp_restart {
+	struct osmo_cbsp_cell_list cell_list;
+	uint8_t bcast_msg_type;
+	uint8_t recovery_ind;
+};
+
+/* 8.1.3.20 */
+struct osmo_cbsp_failure {
+	struct llist_head fail_list;		/* list of osmo_cbsp_fail_ent */
+	uint8_t bcast_msg_type;
+};
+
+/* 8.1.3.21 */
+struct osmo_cbsp_error_ind {
+	enum cbsp_cell_id_cause cause;
+	uint16_t *msg_id;
+	uint16_t *new_serial_nr;
+	uint16_t *old_serial_nr;
+	enum cbsp_channel_ind *channel_ind;
+};
+
+
+/* decoded CBSP message */
+struct osmo_cbsp_decoded {
+	enum cbsp_msg_type msg_type;
+	union {
+		struct osmo_cbsp_write_replace write_replace;
+		struct osmo_cbsp_write_replace_complete write_replace_compl;
+		struct osmo_cbsp_write_replace_failure write_replace_fail;
+
+		struct osmo_cbsp_kill kill;
+		struct osmo_cbsp_kill_complete kill_compl;
+		struct osmo_cbsp_kill_failure kill_fail;
+
+		struct osmo_cbsp_load_query load_query;
+		struct osmo_cbsp_load_query_complete load_query_compl;
+		struct osmo_cbsp_load_query_failure load_query_fail;
+
+		struct osmo_cbsp_msg_status_query msg_status_query;
+		struct osmo_cbsp_msg_status_query_complete msg_status_query_compl;
+		struct osmo_cbsp_msg_status_query_failure msg_status_query_fail;
+
+		/* TODO: set DRX */
+
+		struct osmo_cbsp_reset reset;
+		struct osmo_cbsp_reset_complete reset_compl;
+		struct osmo_cbsp_reset_failure reset_fail;
+
+		struct osmo_cbsp_restart restart;
+
+		struct osmo_cbsp_failure failure;
+
+		struct osmo_cbsp_error_ind error_ind;
+
+		struct osmo_cbsp_keep_alive keep_alive;
+		struct osmo_cbsp_keep_alive_complete keep_alive_compl;
+	} u;
+};
+
+struct msgb *osmo_cbsp_msgb_alloc(void *ctx, const char *name);
+struct msgb *osmo_cbsp_encode(void *ctx, const struct osmo_cbsp_decoded *in);
+struct osmo_cbsp_decoded *osmo_cbsp_decode(void *ctx, struct msgb *in);
+void osmo_cbsp_init_struct(struct osmo_cbsp_decoded *cbsp, enum cbsp_msg_type msg_type);
+struct osmo_cbsp_decoded *osmo_cbsp_decoded_alloc(void *ctx,  enum cbsp_msg_type msg_type);
+
+int osmo_cbsp_recv_buffered(void *ctx, int fd, struct msgb **rmsg, struct msgb **tmp_msg);
diff --git a/include/osmocom/gsm/protocol/gsm_48_049.h b/include/osmocom/gsm/protocol/gsm_48_049.h
new file mode 100644
index 00000000..27fc9d0c
--- /dev/null
+++ b/include/osmocom/gsm/protocol/gsm_48_049.h
@@ -0,0 +1,128 @@
+#pragma once
+#include <stdint.h>
+#include <osmocom/core/utils.h>
+
+/* CBSP is an ETSI/3GPP standard protocol used between CBC (Cell
+ * Brodadcast Centre) and BSC (Base Station Controller) in 2G/GSM/GERAN
+ * networks.  It is specified in 3GPP TS 48.049.
+ *
+ * (C) 2019 by Harald Welte <laforge@gnumonks.org>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * Released under the terms of the GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ */
+
+/* 5.2 TCP/IP */
+#define CBSP_TCP_PORT 48049
+
+/* 8.2.1 Information Element Identifiers */
+enum cbsp_iei {
+	CBSP_IEI_MSG_CONTENT		= 0x01,
+	CBSP_IEI_OLD_SERIAL_NR		= 0x02,
+	CBSP_IEI_NEW_SERIAL_NR		= 0x03,
+	CBSP_IEI_CELL_LIST		= 0x04,
+	CBSP_IEI_CATEGORY		= 0x05,
+	CBSP_IEI_REP_PERIOD		= 0x06,
+	CBSP_IEI_NUM_BCAST_REQ		= 0x07,
+	CBSP_IEI_NUM_BCAST_COMPL_LIST	= 0x08,
+	CBSP_IEI_FAILURE_LIST		= 0x09,
+	CBSP_IEI_RR_LOADING_LIST	= 0x0a,
+	CBSP_IEI_CAUSE			= 0x0b,
+	CBSP_IEI_DCS			= 0x0c,
+	CBSP_IEI_RECOVERY_IND		= 0x0d,
+	CBSP_IEI_MSG_ID			= 0x0e,
+	CBSP_IEI_EMERG_IND		= 0x0f,
+	CBSP_IEI_WARN_TYPE		= 0x10,
+	CBSP_IEI_WARN_SEC_INFO		= 0x11,
+	CBSP_IEI_CHANNEL_IND		= 0x12,
+	CBSP_IEI_NUM_OF_PAGES		= 0x13,
+	CBSP_IEI_SCHEDULE_PERIOD	= 0x14,
+	CBSP_IEI_NUM_OF_RES_SLOTS	= 0x15,
+	CBSP_IEI_BCAST_MSG_TYPE		= 0x16,
+	CBSP_IEI_WARNING_PERIOD		= 0x17,
+	CBSP_IEI_KEEP_ALIVE_REP_PERIOD	= 0x18,
+};
+
+/* 8.2.2 Message Type */
+enum cbsp_msg_type {
+	CBSP_MSGT_WRITE_REPLACE		= 0x01,
+	CBSP_MSGT_WRITE_REPLACE_COMPL	= 0x02,
+	CBSP_MSGT_WRITE_REPLACE_FAIL	= 0x03,
+	CBSP_MSGT_KILL			= 0x04,
+	CBSP_MSGT_KILL_COMPL		= 0x05,
+	CBSP_MSGT_KILL_FAIL		= 0x06,
+	CBSP_MSGT_LOAD_QUERY		= 0x07,
+	CBSP_MSGT_LOAD_QUERY_COMPL	= 0x08,
+	CBSP_MSGT_LOAD_QUERY_FAIL	= 0x09,
+	CBSP_MSGT_MSG_STATUS_QUERY	= 0x0a,
+	CBSP_MSGT_MSG_STATUS_QUERY_COMPL= 0x0b,
+	CBSP_MSGT_MSG_STATUS_QUERY_FAIL	= 0x0c,
+	CBSP_MSGT_SET_DRX		= 0x0d,
+	CBSP_MSGT_SET_DRX_COMPL		= 0x0e,
+	CBSP_MSGT_SET_DRX_FAIL		= 0x0f,
+	CBSP_MSGT_RESET			= 0x10,
+	CBSP_MSGT_RESET_COMPL		= 0x11,
+	CBSP_MSGT_RESET_FAIL		= 0x12,
+	CBSP_MSGT_RESTART		= 0x13,
+	CBSP_MSGT_FAILURE		= 0x14,
+	CBSP_MSGT_ERROR_IND		= 0x15,
+	CBSP_MSGT_KEEP_ALIVE		= 0x16,
+	CBSP_MSGT_KEEP_ALIVE_COMPL	= 0x17,
+};
+
+/* 8.2.7 Category */
+enum cbsp_category {
+	CBSP_CATEG_HIGH_PRIO		= 0x00,
+	CBSP_CATEG_BACKGROUND		= 0x01,
+	CBSP_CATEG_NORMAL		= 0x02,
+};
+
+/* Cell ID Discriminator (8.2.11, ...) */
+enum cbsp_cell_id_disc {
+	CBSP_CIDD_WHOLE_CGI		= 0x0,
+	CBSP_CIDD_LAC_CI		= 0x1,
+	CBSP_CIDD_CI			= 0x2,
+	CBSP_CIDD_LAI			= 0x4,
+	CBSP_CIDD_LAC			= 0x5,
+	CBSP_CIDD_ALL_IN_BSC		= 0x6,
+};
+
+/* 8.2.13 Cause */
+enum cbsp_cell_id_cause {
+	CBSP_CAUSE_PARAM_NOT_RECOGNISED			= 0x00,
+	CBSP_CAUSE_PARAM_VAL_INVALID			= 0x01,
+	CBSP_CAUSE_MSG_REF_NOT_IDENTIFIED		= 0x02,
+	CBSP_CAUSE_CELL_ID_NOT_VALID			= 0x03,
+	CBSP_CAUSE_UNRECOGNISED_MSG			= 0x04,
+	CBSP_CAUSE_MISSING_MAND_IE			= 0x05,
+	CBSP_CAUSE_BSC_CAPACITY_EXCEEDED		= 0x06,
+	CBSP_CAUSE_CELL_MEMORY_EXCEEDED			= 0x07,
+	CBSP_CAUSE_BSC_MEMORY_EXCEEDED			= 0x08,
+	CBSP_CAUSE_CB_NOT_SUPPORTED			= 0x09,
+	CBSP_CAUSE_CB_NOT_OPERATIONAL			= 0x0a,
+	CBSP_CAUSE_INCOMPATIBLE_DRX_PARAM		= 0x0b,
+	CBSP_CAUSE_EXT_CHAN_NOT_SUPPORTED		= 0x0c,
+	CBSP_CAUSE_MSG_REF_ALREADY_USED			= 0x0d,
+	CBSP_CAUSE_UNSPECIFIED_ERROR			= 0x0e,
+	CBSP_CAUSE_LAI_OR_LAC_NPT_VALID			= 0x0f,
+};
+
+/* 8.2.20 Chanel Indicator */
+enum cbsp_channel_ind {
+	CBSP_CHAN_IND_BASIC	= 0,
+	CBSP_CHAN_IND_EXTENDED	= 1,
+};
+
+/* not explicitly specified, but every message starts with those mandatory elements */
+struct cbsp_header {
+	uint8_t msg_type;
+	uint8_t len[3]; /* excluding the header */
+} __attribute__((packed));
+
+extern const struct value_string cbsp_msg_type_names[];
+extern const struct value_string cbsp_iei_names[];
+extern const struct value_string cbsp_category_names[];
+extern const struct tlv_definition cbsp_att_tlvdef;