osmo-v5/src/v5x_internal.h

#pragma once

/* (C) 2021 by Harald Welte <laforge@gnumonks.org>
 * (C) 2022 by Andreas Eversberg <jolly@eversberg.eu>
 *
 * 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.
 *
 */


#include <stdint.h>

#include <osmocom/core/utils.h>
#include <osmocom/core/fsm.h>
#include <osmocom/core/select.h>
#include <osmocom/gsm/lapd_core.h>

#include "ph_socket.h"

/* Table 35/G.964 */
enum v5x_mph_prim {
	MPH_UBR,	/* Unblock (req) */
	MPH_UBI,	/* Unblock (ind) */
	MPH_BR,		/* Block (req) */
	MPH_BI,		/* Block (ind) */
	MPH_AR,		/* Activate (req) */
	MPH_AI,		/* Activate (ind) */
	MPH_AWI,	/* Access activation by user (ind) */
	MPH_DSAI,	/* DS Activated (ind) */
	MPH_DR,		/* Deactivate (req) */
	MPH_DI,		/* Deactivate (ind) */
	MPH_GI,		/* Grading Information */
	MPH_DB,		/* Block D-Channel from user port */
	MPH_DU,		/* Unblock D-Channel from user port */
};

/* Table 3/G.964 */
enum v5x_fe_prim {
	FE_establish_req	= 0x00,
	FE_establish_ack_ind	= 0x03,
	FE_establish_ind	= 0x01,
	FE_establish_ack_req	= 0x02,
	FE_line_signal_req	= 0x10,
	FE_line_signal_ind	= 0x11,
	FE_protocol_param_req	= 0x20,
	FE_disconnect_req	= 0x30,
	FE_disconnect_compl_req	= 0x32,
	FE_disconnect_compl_ind	= 0x33,
};

/* Table 3/G.964 */
enum v5x_mgmt_prim {
	MDU_CTRL_port_blocked,
	MDU_CTRL_port_unblocked,
	MDU_CTRL_port_restart_req,
	MDU_CTRL_port_restart_ack,
	MDU_CTRL_port_restart_compl,
	MDU_error_ind,
};

struct osmo_fsm_inst;

enum v5x_dialect {
	V5X_DIALECT_V51		= 1,
	V5X_DIALECT_V52		= 2,
};

enum v5x_user_type {
	V5X_USER_TYPE_ISDN	= 1,
	V5X_USER_TYPE_PSTN	= 2,
};

/* forward-declarations */
struct v5x_interface;
struct v5x_instance;
struct v5x_user_port;
struct v5x_link;

/* A C-channel is a 64k timeslot used for signalling */
struct v5x_c_channel {
	struct v5x_link *link;			/* back-pointer */
	struct v5x_timeslot *ts;		/* E1 link timeslot. NULL = C-channel doesn't exist */
	bool active;				/* false == standby */
};

/* one physical E1 timeslot used on an E1 interface part of a V5.2 interface */
struct v5x_timeslot {
	uint8_t nr;
	struct v5x_link *link;			/* back-pointer */
	struct v5x_user_port *v5up;		/* user port that this TS is assigned to */
	uint16_t l3_address;
};

/* one physical E1 interface used within a V5.2 interface */
struct v5x_link {
	uint8_t id;
	struct v5x_interface *interface;	/* back-pointer */
	struct v5x_timeslot ts[32];		/* 32 E1 slots; 0 not available */
	struct v5x_c_channel c_channel[3];	/* 64k signaling possible on TS16, TS15 and TS31 */
	struct osmo_fsm_inst *l1_link_fi;	/* Layer 1 Link FSM instance */
};

/* one V5.x interface between AN (Access Network) and LE (Local Exchange) */
struct v5x_interface {
	struct llist_head list;			/* instance.interfaces */
	struct v5x_instance *instance;		/* back-pointer */
	enum v5x_dialect dialect;
	uint32_t id;				/* interface id */
	uint8_t variant;			/* provitioning variant */
	struct v5x_link *primary_link;		/* one of the links below */
	struct v5x_link *secondary_link;	/* one of the links below */
	/* 1..16 links in one interface */
	struct v5x_link links[16];

	struct {
		struct v5x_ctrl_proto *ctrl;	/* common control protocol instance */
		struct lapv5_instance *li;	/* Control data link */
		bool established;		/* track if link is up or down */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} control;
	struct {
		struct lapv5_instance *li;	/* Link control data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
		struct osmo_fsm_inst *fi;	/* Link Control FSM instance */
	} lcp;
	struct {
		struct lapv5_instance *li;	/* PSTN data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} pstn;
	struct {
		struct lapv5_instance *li;	/* BCC data link */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} bcc;
	struct {
		struct lapv5_instance *li;	/* Protection data link 1 + 2 */
		struct v5x_c_channel *c_chan;	/* pointer to active C-channel */
	} protection[2];

	struct llist_head user_ports;		/* list of v5x_user_port */
};

struct v5x_ctrl_proto {
	struct v5x_user_port *v5up;		/* back pointer, if port control is used */
	struct v5x_interface *v5if;		/* back pointer, if common control is used */
	struct osmo_fsm_inst *fi;		/* control FSM */
	struct llist_head tx_queue;		/* list of message to be transmitted */
	struct msgb *tx_msg;			/* copy of unacked message, for second try */
};

struct v5x_pstn_proto {
	struct v5x_user_port *v5up;		/* back pointer, if port control is used */
	struct osmo_fsm_inst *fi;		/* control FSM */
	uint8_t S_s, S_a, S_r;			/* sequence numbers */
	struct msgb *tx_msg;			/* copy of unacked message, for repitition */
	int timeout_event;			/* event when timer times out */
	int timeout_count;			/* how many times the timer was started/timed out */
	struct osmo_timer_list timer_Tr;	/* extra timer for receive sequence ack */
	struct osmo_timer_list timer_Tt;	/* extra timer for transmit sequence ack */
};

/* one user-facing port (subscriber line) */
struct v5x_user_port {
	struct llist_head list; 		/* part of v5x_instance.ports */
	struct v5x_interface *inst; 		/* back-pointer to instance we're part of */

	uint16_t nr; 				/* port-number in decoded form (0..32767) */
	char ifname[64];			/* name of interface, also used for PH-socket */
	enum v5x_user_type type;		/* type of port (ISDN/PSTN) */

	struct v5x_ctrl_proto *ctrl;		/* port control protocol instance */
	struct osmo_fsm_inst *port_fi;		/* port FSM */
	uint8_t ts_nr[2];			/* time slots used (one for PSTN, two for ISDN) */
	uint8_t link_nr[2];			/* link used */
	uint8_t ts_activated[2];		/* set if data stream is active */
	struct {
	} isdn;
	struct {
		struct v5x_pstn_proto *proto;
	} pstn;
	ph_socket_t ph_socket;			/* unix socket to connect port to */
	bool le_unblocked;			/* if port is not blocked by LE */
	bool an_unblocked;			/* if port is not blocked by AN */
};

struct v5x_instance {
	struct llist_head list;			/* part of global list of instances */
	struct llist_head interfaces;		/* v5x_interface.list */
};

struct v5x_instance *v5x_instance_alloc(void *ctx);
struct v5x_interface *v5x_interface_alloc(struct v5x_instance *v5i, enum v5x_dialect dialect,
	int (*ph_data_req_cb)(struct msgb *msg, void *cbdata));
struct v5x_user_port *v5x_user_port_create(struct v5x_interface *v5if, uint16_t nr, enum v5x_user_type,
	uint8_t ts1, uint8_t ts2);
void v5x_interface_free(struct v5x_interface *v5if);
struct v5x_user_port *v5x_user_port_find(struct v5x_interface *v5if, uint16_t nr, bool is_isdn);
void v5x_user_port_destroy(struct v5x_user_port *v5up);
//FIXME: move this
void ph_socket_rx_cb(ph_socket_t *s, int channel, uint8_t prim, uint8_t *data, int length);