/* OsmoHLR VTY implementation */

/* (C) 2016 sysmocom s.f.m.c. GmbH <info@sysmocom.de>
 * Author: Neels Hofmeyr <nhofmeyr@sysmocom.de>
 * (C) 2018 Harald Welte <laforge@gnumonks.org>
 *
 * All Rights Reserved
 *
 * (C) 2018 Harald Welte <laforge@gnumonks.org>
 *
 * All Rights Reserved
 *
 * 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/>.
 *
 */

#include <errno.h>

#include <osmocom/core/talloc.h>
#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
#include <osmocom/vty/vty.h>
#include <osmocom/vty/stats.h>
#include <osmocom/vty/command.h>
#include <osmocom/vty/logging.h>
#include <osmocom/vty/misc.h>
#include <osmocom/abis/ipa.h>

#include <osmocom/hlr/db.h>
#include <osmocom/hlr/hlr.h>
#include <osmocom/hlr/hlr_vty.h>
#include <osmocom/hlr/hlr_vty_subscr.h>
#include <osmocom/hlr/hlr_ussd.h>
#include <osmocom/hlr/gsup_server.h>

static const struct value_string gsm48_gmm_cause_vty_names[] = {
	{ GMM_CAUSE_IMSI_UNKNOWN,	"imsi-unknown" },
	{ GMM_CAUSE_ILLEGAL_MS,		"illegal-ms" },
	{ GMM_CAUSE_PLMN_NOTALLOWED,	"plmn-not-allowed" },
	{ GMM_CAUSE_LA_NOTALLOWED,	"la-not-allowed" },
	{ GMM_CAUSE_ROAMING_NOTALLOWED,	"roaming-not-allowed" },
	{ GMM_CAUSE_NO_SUIT_CELL_IN_LA,	"no-suitable-cell-in-la" },
	{ GMM_CAUSE_NET_FAIL,		"net-fail" },
	{ GMM_CAUSE_CONGESTION,		"congestion" },
	{ GMM_CAUSE_GSM_AUTH_UNACCEPT,	"auth-unacceptable" },
	{ GMM_CAUSE_PROTO_ERR_UNSPEC,	"proto-error-unspec" },
	{ 0, NULL },
};

/* TS 24.008 4.4.4.7 */
static const struct value_string gsm48_gmm_cause_vty_descs[] = {
	{ GMM_CAUSE_IMSI_UNKNOWN,	" #02: (IMSI unknown in HLR)" },
	{ GMM_CAUSE_ILLEGAL_MS,		" #03  (Illegal MS)" },
	{ GMM_CAUSE_PLMN_NOTALLOWED,	" #11: (PLMN not allowed)" },
	{ GMM_CAUSE_LA_NOTALLOWED,	" #12: (Location Area not allowed)" },
	{ GMM_CAUSE_ROAMING_NOTALLOWED,	" #13: (Roaming not allowed in this location area)" },
	{ GMM_CAUSE_NO_SUIT_CELL_IN_LA,	" #15: (No Suitable Cells In Location Area [continue search in PLMN])." },
	{ GMM_CAUSE_NET_FAIL,		" #17: (Network Failure)" },
	{ GMM_CAUSE_CONGESTION,		" #22: (Congestion)" },
	{ GMM_CAUSE_GSM_AUTH_UNACCEPT,	" #23: (GSM authentication unacceptable [UMTS])" },
	{ GMM_CAUSE_PROTO_ERR_UNSPEC,	"#111: (Protocol error, unspecified)" },
	{ 0, NULL },
};


struct cmd_node hlr_node = {
	HLR_NODE,
	"%s(config-hlr)# ",
	1,
};

DEFUN(cfg_hlr,
      cfg_hlr_cmd,
      "hlr",
      "Configure the HLR")
{
	vty->node = HLR_NODE;
	return CMD_SUCCESS;
}

struct cmd_node gsup_node = {
	GSUP_NODE,
	"%s(config-hlr-gsup)# ",
	1,
};

DEFUN(cfg_gsup,
      cfg_gsup_cmd,
      "gsup",
      "Configure GSUP options")
{
	vty->node = GSUP_NODE;
	return CMD_SUCCESS;
}

static int config_write_hlr(struct vty *vty)
{
	vty_out(vty, "hlr%s", VTY_NEWLINE);

	if (g_hlr->reject_cause != GMM_CAUSE_IMSI_UNKNOWN)
		vty_out(vty, " reject-cause not-found %s%s",
			get_value_string_or_null(gsm48_gmm_cause_vty_names,
						 (uint32_t) g_hlr->reject_cause), VTY_NEWLINE);
	if (g_hlr->no_proxy_reject_cause != GMM_CAUSE_IMSI_UNKNOWN)
		vty_out(vty, " reject-cause no-proxy %s%s",
			get_value_string_or_null(gsm48_gmm_cause_vty_names,
						 (uint32_t) g_hlr->no_proxy_reject_cause), VTY_NEWLINE);
	if (g_hlr->store_imei)
		vty_out(vty, " store-imei%s", VTY_NEWLINE);
	if (g_hlr->db_file_path && strcmp(g_hlr->db_file_path, HLR_DEFAULT_DB_FILE_PATH))
		vty_out(vty, " database %s%s", g_hlr->db_file_path, VTY_NEWLINE);
	if (g_hlr->subscr_create_on_demand) {
		const char *flags_str = "none";
		uint8_t flags = g_hlr->subscr_create_on_demand_flags;
		unsigned int rand_msisdn_len = g_hlr->subscr_create_on_demand_rand_msisdn_len;

		if ((flags & DB_SUBSCR_FLAG_NAM_CS) && (flags & DB_SUBSCR_FLAG_NAM_PS))
			flags_str = "cs+ps";
		else if (flags & DB_SUBSCR_FLAG_NAM_CS)
			flags_str = "cs";
		else if (flags & DB_SUBSCR_FLAG_NAM_PS)
			flags_str = "ps";

		if (rand_msisdn_len)
			vty_out(vty, " subscriber-create-on-demand %i %s%s", rand_msisdn_len, flags_str, VTY_NEWLINE);
		else
			vty_out(vty, " subscriber-create-on-demand no-msisdn %s%s", flags_str, VTY_NEWLINE);
	}
	return CMD_SUCCESS;
}

static int config_write_hlr_gsup(struct vty *vty)
{
	vty_out(vty, " gsup%s", VTY_NEWLINE);
	if (g_hlr->gsup_bind_addr)
		vty_out(vty, "  bind ip %s%s", g_hlr->gsup_bind_addr, VTY_NEWLINE);
	if (g_hlr->gsup_unit_name.serno)
		vty_out(vty, "  ipa-name %s%s", g_hlr->gsup_unit_name.serno, VTY_NEWLINE);
	return CMD_SUCCESS;
}

static void show_one_conn(struct vty *vty, const struct osmo_gsup_conn *conn)
{
	const struct ipa_server_conn *isc = conn->conn;
	char *name;
	int rc;

	rc = osmo_gsup_conn_ccm_get(conn, (uint8_t **) &name, IPAC_IDTAG_SERNR);
	OSMO_ASSERT(rc);

	vty_out(vty, " '%s' from %s:%5u, CS=%u, PS=%u%s",
		name, isc->addr, isc->port, conn->supports_cs, conn->supports_ps,
		VTY_NEWLINE);
}

DEFUN(show_gsup_conn, show_gsup_conn_cmd,
	"show gsup-connections",
	SHOW_STR "GSUP Connections from VLRs, SGSNs, EUSEs\n")
{
	struct osmo_gsup_server *gs = g_hlr->gs;
	struct osmo_gsup_conn *conn;

	llist_for_each_entry(conn, &gs->clients, list)
		show_one_conn(vty, conn);

	return CMD_SUCCESS;
}

DEFUN(cfg_hlr_gsup_bind_ip,
      cfg_hlr_gsup_bind_ip_cmd,
      "bind ip A.B.C.D",
      "Listen/Bind related socket option\n"
      IP_STR
      "IPv4 Address to bind the GSUP interface to\n")
{
	if(g_hlr->gsup_bind_addr)
		talloc_free(g_hlr->gsup_bind_addr);
	g_hlr->gsup_bind_addr = talloc_strdup(g_hlr, argv[0]);

	return CMD_SUCCESS;
}

DEFUN(cfg_hlr_gsup_ipa_name,
      cfg_hlr_gsup_ipa_name_cmd,
      "ipa-name NAME",
      "Set the IPA name of this HLR, for proxying to remote HLRs\n"
      "A globally unique name for this HLR. For example: PLMN + redundancy server number: HLR-901-70-0. "
      "This name is used for GSUP routing and must be set if multiple HLRs interconnect (e.g. mslookup "
      "for Distributed GSM).\n")
{
	if (vty->type != VTY_FILE) {
		vty_out(vty, "gsup/ipa-name: The GSUP IPA name cannot be changed at run-time; "
			"It can only be set in the configuration file.%s", VTY_NEWLINE);
		return CMD_WARNING;
	}

	g_hlr->gsup_unit_name.serno = talloc_strdup(g_hlr, argv[0]);
	return CMD_SUCCESS;
}

/***********************************************************************
 * USSD Entity
 ***********************************************************************/

#include <osmocom/hlr/hlr_ussd.h>

#define USSD_STR "USSD Configuration\n"
#define UROUTE_STR "Routing Configuration\n"
#define PREFIX_STR "Prefix-Matching Route\n" "USSD Prefix\n"

#define INT_CHOICE "(own-msisdn|own-imsi|test-idle)"
#define INT_STR "Internal USSD Handler\n" \
		"Respond with subscribers' own MSISDN\n" \
		"Respond with subscribers' own IMSI\n" \
		"Keep the session idle (useful for testing)\n"

#define EXT_STR "External USSD Handler\n" \
		"Name of External USSD Handler (IPA CCM ID)\n"

DEFUN(cfg_ussd_route_pfx_int, cfg_ussd_route_pfx_int_cmd,
	"ussd route prefix PREFIX internal " INT_CHOICE,
	USSD_STR UROUTE_STR PREFIX_STR INT_STR)
{
	const struct hlr_iuse *iuse = iuse_find(argv[1]);
	struct hlr_ussd_route *rt = ussd_route_find_prefix(g_hlr, argv[0]);
	if (rt) {
		vty_out(vty, "%% Cannot add [another?] route for prefix %s%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}
	ussd_route_prefix_alloc_int(g_hlr, argv[0], iuse);

	return CMD_SUCCESS;
}

DEFUN(cfg_ussd_route_pfx_ext, cfg_ussd_route_pfx_ext_cmd,
	"ussd route prefix PREFIX external EUSE",
	USSD_STR UROUTE_STR PREFIX_STR EXT_STR)
{
	struct hlr_euse *euse = euse_find(g_hlr, argv[1]);
	struct hlr_ussd_route *rt = ussd_route_find_prefix(g_hlr, argv[0]);
	if (rt) {
		vty_out(vty, "%% Cannot add [another?] route for prefix %s%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}
	if (!euse) {
		vty_out(vty, "%% Cannot find euse '%s'%s", argv[1], VTY_NEWLINE);
		return CMD_WARNING;
	}
	ussd_route_prefix_alloc_ext(g_hlr, argv[0], euse);

	return CMD_SUCCESS;
}

DEFUN(cfg_ussd_no_route_pfx, cfg_ussd_no_route_pfx_cmd,
	"no ussd route prefix PREFIX",
	NO_STR USSD_STR UROUTE_STR PREFIX_STR)
{
	struct hlr_ussd_route *rt = ussd_route_find_prefix(g_hlr, argv[0]);
	if (!rt) {
		vty_out(vty, "%% Cannot find route for prefix %s%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}
	ussd_route_del(rt);

	return CMD_SUCCESS;
}

DEFUN(cfg_ussd_defaultroute, cfg_ussd_defaultroute_cmd,
	"ussd default-route external EUSE",
	USSD_STR "Configure default-route for all USSD to unknown destinations\n"
	EXT_STR)
{
	struct hlr_euse *euse;

	euse = euse_find(g_hlr, argv[0]);
	if (!euse) {
		vty_out(vty, "%% Cannot find EUSE %s%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}

	if (g_hlr->euse_default != euse) {
		vty_out(vty, "Switching default route from %s to %s%s",
			g_hlr->euse_default ? g_hlr->euse_default->name : "<none>",
			euse->name, VTY_NEWLINE);
		g_hlr->euse_default = euse;
	}

	return CMD_SUCCESS;
}

DEFUN(cfg_ussd_no_defaultroute, cfg_ussd_no_defaultroute_cmd,
	"no ussd default-route",
	NO_STR USSD_STR "Remove the default-route for all USSD to unknown destinations\n")
{
	g_hlr->euse_default = NULL;

	return CMD_SUCCESS;
}

DEFUN(cfg_database, cfg_database_cmd,
	"database PATH",
	"Set the path to the HLR database file\n"
	"Relative or absolute file system path to the database file (default is '" HLR_DEFAULT_DB_FILE_PATH "')\n")
{
	osmo_talloc_replace_string(g_hlr, &g_hlr->db_file_path, argv[0]);
	return CMD_SUCCESS;
}

struct cmd_node euse_node = {
	EUSE_NODE,
	"%s(config-hlr-euse)# ",
	1,
};

DEFUN(cfg_euse, cfg_euse_cmd,
	"euse NAME",
	"Configure a particular External USSD Entity\n"
	"Alphanumeric name of the External USSD Entity\n")
{
	struct hlr_euse *euse;
	const char *id = argv[0];

	euse = euse_find(g_hlr, id);
	if (!euse) {
		euse = euse_alloc(g_hlr, id);
		if (!euse)
			return CMD_WARNING;
	}
	vty->index = euse;
	vty->index_sub = &euse->description;
	vty->node = EUSE_NODE;

	return CMD_SUCCESS;
}

DEFUN(cfg_no_euse, cfg_no_euse_cmd,
	"no euse NAME",
	NO_STR "Remove a particular External USSD Entity\n"
	"Alphanumeric name of the External USSD Entity\n")
{
	struct hlr_euse *euse = euse_find(g_hlr, argv[0]);
	if (!euse) {
		vty_out(vty, "%% Cannot remove non-existent EUSE %s%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}
	if (g_hlr->euse_default == euse) {
		vty_out(vty, "%% Cannot remove EUSE %s, it is the default route%s", argv[0], VTY_NEWLINE);
		return CMD_WARNING;
	}
	euse_del(euse);
	return CMD_SUCCESS;
}

static void dump_one_euse(struct vty *vty, struct hlr_euse *euse)
{
	vty_out(vty, " euse %s%s", euse->name, VTY_NEWLINE);
}

static int config_write_euse(struct vty *vty)
{
	struct hlr_euse *euse;
	struct hlr_ussd_route *rt;

	llist_for_each_entry(euse, &g_hlr->euse_list, list)
		dump_one_euse(vty, euse);

	llist_for_each_entry(rt, &g_hlr->ussd_routes, list) {
		vty_out(vty, " ussd route prefix %s %s %s%s", rt->prefix,
			rt->is_external ? "external" : "internal",
			rt->is_external ? rt->u.euse->name : rt->u.iuse->name,
			VTY_NEWLINE);
	}

	if (g_hlr->euse_default)
		vty_out(vty, " ussd default-route external %s%s", g_hlr->euse_default->name, VTY_NEWLINE);

	if (g_hlr->ncss_guard_timeout != NCSS_GUARD_TIMEOUT_DEFAULT)
		vty_out(vty, " ncss-guard-timeout %i%s",
			g_hlr->ncss_guard_timeout, VTY_NEWLINE);

	return 0;
}

DEFUN(cfg_ncss_guard_timeout, cfg_ncss_guard_timeout_cmd,
	"ncss-guard-timeout <0-255>",
	"Set guard timer for NCSS (call independent SS) session activity\n"
	"Guard timer value (sec.), or 0 to disable")
{
	g_hlr->ncss_guard_timeout = atoi(argv[0]);
	return CMD_SUCCESS;
}


DEFUN(cfg_reject_cause, cfg_reject_cause_cmd,
      "reject-cause TYPE CAUSE", "") /* Dynamically Generated */
{
	int cause_code = get_string_value(gsm48_gmm_cause_vty_names, argv[1]);
	OSMO_ASSERT(cause_code >= 0);

	if (strcmp(argv[0], "not-found") == 0)
		g_hlr->reject_cause = (enum gsm48_gmm_cause) cause_code;
	if (strcmp(argv[0], "no-proxy") == 0)
		g_hlr->no_proxy_reject_cause = (enum gsm48_gmm_cause) cause_code;

	return CMD_SUCCESS;
}

DEFUN(cfg_store_imei, cfg_store_imei_cmd,
	"store-imei",
	"Save the IMEI in the database when receiving Check IMEI requests. Note that an MSC does not necessarily send"
	" Check IMEI requests (for OsmoMSC, you may want to set 'check-imei-rqd 1').")
{
	g_hlr->store_imei = true;
	return CMD_SUCCESS;
}

DEFUN(cfg_no_store_imei, cfg_no_store_imei_cmd,
	"no store-imei",
	"Do not save the IMEI in the database, when receiving Check IMEI requests.")
{
	g_hlr->store_imei = false;
	return CMD_SUCCESS;
}

DEFUN(cfg_subscr_create_on_demand, cfg_subscr_create_on_demand_cmd,
	"subscriber-create-on-demand (no-msisdn|<3-15>) (none|cs|ps|cs+ps)",
	"Make a new record when a subscriber is first seen.\n"
	"Do not automatically assign MSISDN.\n"
	"Length of an automatically assigned MSISDN.\n"
	"Do not allow any NAM (Network Access Mode) by default.\n"
	"Allow access to circuit switched NAM by default.\n"
	"Allow access to packet switched NAM by default.\n"
	"Allow access to circuit and packet switched NAM by default.\n")
{
	unsigned int rand_msisdn_len = 0;
	uint8_t flags = 0x00;

	if (strcmp(argv[0], "no-msisdn") != 0)
		rand_msisdn_len = atoi(argv[0]);

	if (strstr(argv[1], "cs"))
		flags |= DB_SUBSCR_FLAG_NAM_CS;
	if (strstr(argv[1], "ps"))
		flags |= DB_SUBSCR_FLAG_NAM_PS;

	g_hlr->subscr_create_on_demand = true;
	g_hlr->subscr_create_on_demand_rand_msisdn_len = rand_msisdn_len;
	g_hlr->subscr_create_on_demand_flags = flags;

	return CMD_SUCCESS;
}

DEFUN(cfg_no_subscr_create_on_demand, cfg_no_subscr_create_on_demand_cmd,
	"no subscriber-create-on-demand",
	"Do not make a new record when a subscriber is first seen.\n")
{
	g_hlr->subscr_create_on_demand = false;
	return CMD_SUCCESS;
}

/***********************************************************************
 * Common Code
 ***********************************************************************/

int hlr_vty_go_parent(struct vty *vty)
{
	switch (vty->node) {
	case GSUP_NODE:
	case EUSE_NODE:
		vty->node = HLR_NODE;
		vty->index = NULL;
		vty->index_sub = NULL;
		break;
	default:
	case HLR_NODE:
		vty->node = CONFIG_NODE;
		vty->index = NULL;
		break;
	case CONFIG_NODE:
		vty->node = ENABLE_NODE;
		vty->index = NULL;
		break;
	}

	return vty->node;
}

int hlr_vty_is_config_node(struct vty *vty, int node)
{
	switch (node) {
	/* add items that are not config */
	case CONFIG_NODE:
		return 0;

	default:
		return 1;
	}
}

void hlr_vty_init(void *hlr_ctx)
{
	cfg_reject_cause_cmd.string =
		vty_cmd_string_from_valstr(hlr_ctx,
					   gsm48_gmm_cause_vty_names,
					   "reject-cause (not-found|no-proxy) (", "|", ")",
					   VTY_DO_LOWER);

	cfg_reject_cause_cmd.doc =
		vty_cmd_string_from_valstr(hlr_ctx,
					   gsm48_gmm_cause_vty_descs,
					   "GSUP/GMM cause to be sent\n"
					   "in the case the IMSI could not be found in the database\n"
					   "in the case no remote HLR reponded to mslookup GSUP request\n",
					   "\n", "", 0);

	logging_vty_add_cmds();
	osmo_talloc_vty_add_cmds();
	osmo_stats_vty_add_cmds();

	install_element_ve(&show_gsup_conn_cmd);

	install_element(CONFIG_NODE, &cfg_hlr_cmd);
	install_node(&hlr_node, config_write_hlr);

	install_element(HLR_NODE, &cfg_gsup_cmd);
	install_node(&gsup_node, config_write_hlr_gsup);

	install_element(GSUP_NODE, &cfg_hlr_gsup_bind_ip_cmd);
	install_element(GSUP_NODE, &cfg_hlr_gsup_ipa_name_cmd);

	install_element(HLR_NODE, &cfg_database_cmd);

	install_element(HLR_NODE, &cfg_euse_cmd);
	install_element(HLR_NODE, &cfg_no_euse_cmd);
	install_node(&euse_node, config_write_euse);
	install_element(HLR_NODE, &cfg_ussd_route_pfx_int_cmd);
	install_element(HLR_NODE, &cfg_ussd_route_pfx_ext_cmd);
	install_element(HLR_NODE, &cfg_ussd_no_route_pfx_cmd);
	install_element(HLR_NODE, &cfg_ussd_defaultroute_cmd);
	install_element(HLR_NODE, &cfg_ussd_no_defaultroute_cmd);
	install_element(HLR_NODE, &cfg_ncss_guard_timeout_cmd);
	install_element(HLR_NODE, &cfg_reject_cause_cmd);
	install_element(HLR_NODE, &cfg_store_imei_cmd);
	install_element(HLR_NODE, &cfg_no_store_imei_cmd);
	install_element(HLR_NODE, &cfg_subscr_create_on_demand_cmd);
	install_element(HLR_NODE, &cfg_no_subscr_create_on_demand_cmd);

	hlr_vty_subscriber_init();
}