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/* MSC Handover API */
/*
* (C) 2019 by sysmocom - s.m.f.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* SPDX-License-Identifier: AGPL-3.0+
*
* Author: Neels Hofmeyr
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/core/sockaddr_str.h>
#include <osmocom/mgcp_client/mgcp_client.h>
#include <osmocom/msc/neighbor_ident.h>
#include <osmocom/msc/ran_msg.h>
#include <osmocom/msc/mncc_call.h>
struct gsm0808_handover_required;
struct msc_a;
struct ran_dec_handover_required;
#define LOG_HO(msc_a, level, fmt, args...) \
LOGPFSML((msc_a)? ((msc_a)->ho.fi ? : (msc_a)->c.fi) : NULL, \
level, "%s" fmt, (msc_a->ho.fi ? "" : "HO: "), ##args)
enum msc_ho_fsm_state {
MSC_HO_ST_REQUIRED,
MSC_HO_ST_WAIT_REQUEST_ACK,
MSC_HO_ST_WAIT_COMPLETE,
};
enum msc_ho_fsm_event {
MSC_HO_EV_RX_REQUEST_ACK,
MSC_HO_EV_RX_DETECT,
MSC_HO_EV_RX_COMPLETE,
MSC_HO_EV_RX_FAILURE,
MSC_HO_EV_MNCC_FORWARDING_COMPLETE,
MSC_HO_EV_MNCC_FORWARDING_FAILED,
};
struct msc_ho_state {
struct osmo_fsm_inst *fi;
struct ran_handover_required info;
unsigned int next_cil_idx;
bool subsequent_ho;
bool ready_to_switch_rtp;
bool rtp_switched_to_new_cell;
struct {
enum osmo_rat_type ran_type;
struct gsm0808_cell_id cid;
struct osmo_cell_global_id cgi;
enum msc_neighbor_type type;
union {
struct ran_peer *ran_peer;
const char *msc_ipa_name;
};
/* The RTP address from Handover Request Acknowledge.
* Might be from AoIP Transport Layer Address from a BSC RAN peer,
* or from MNCC forwarding for inter-MSC handover. */
struct osmo_sockaddr_str ran_remote_rtp;
/* The codec from Handover Request Acknowledge. */
bool codec_present;
enum mgcp_codecs codec;
/* Inter-MSC voice forwarding via MNCC, to the remote MSC. The Prepare Handover Response sent us the
* Handover Number the remote MSC assigned. This is a call to that Handover Number, via PBX.
* (NULL if not an inter-MSC Handover) */
struct mncc_call *mncc_forwarding_to_remote_ran;
} new_cell;
struct {
/* Saved RTP IP:port and codec in case we need to roll back */
struct osmo_sockaddr_str ran_remote_rtp;
enum mgcp_codecs codec;
} old_cell;
};
void msc_ho_start(struct msc_a *msc_a, const struct ran_handover_required *ho_req);
enum msc_neighbor_type msc_ho_find_target_cell(struct msc_a *msc_a, const struct gsm0808_cell_id *cid,
const struct neighbor_ident_entry **remote_msc,
struct ran_peer **ran_peer_from_neighbor_ident,
struct ran_peer **ran_peer_from_seen_cells);
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