| /* (C) 2017 by sysmocom s.f.m.c. GmbH |
| * All Rights Reserved |
| * |
| * Author: Philipp Maier |
| * |
| * 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 <osmocom/core/logging.h> |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/timer.h> |
| #include <osmocom/core/fsm.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <osmocom/msc/debug.h> |
| #include <osmocom/msc/a_reset.h> |
| #include <osmocom/msc/msc_common.h> |
| |
| #define RESET_RESEND_INTERVAL 2 /* sec */ |
| #define RESET_RESEND_TIMER_NO 16 /* See also 3GPP TS 48.008 Chapter 3.1.4.1.3.2 */ |
| |
| enum reset_fsm_states { |
| ST_DISC, /* Disconnected from remote end */ |
| ST_CONN, /* We have a confirmed connection */ |
| }; |
| |
| enum reset_fsm_evt { |
| EV_CONN_ACK, /* Received either BSSMAP RESET or BSSMAP RESET |
| * ACK from the remote end */ |
| }; |
| |
| /* Reset context data (callbacks, state machine etc...) */ |
| struct reset_ctx { |
| /* Callback function to be called when a connection |
| * failure is detected and a rest must occur */ |
| void (*cb)(void *priv); |
| |
| /* Privated data for the callback function */ |
| void *priv; |
| }; |
| |
| static const struct value_string fsm_event_names[] = { |
| OSMO_VALUE_STRING(EV_CONN_ACK), |
| {0, NULL} |
| }; |
| |
| /* Disconnected state */ |
| static void fsm_disc_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| osmo_fsm_inst_state_chg(fi, ST_CONN, 0, 0); |
| } |
| |
| /* Timer callback to retransmit the reset signal */ |
| static int fsm_reset_ack_timeout_cb(struct osmo_fsm_inst *fi) |
| { |
| struct reset_ctx *reset_ctx = (struct reset_ctx *)fi->priv; |
| LOGPFSML(fi, LOGL_NOTICE, "(re)sending BSSMAP RESET message...\n"); |
| reset_ctx->cb(reset_ctx->priv); |
| osmo_fsm_inst_state_chg(fi, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO); |
| return 0; |
| } |
| |
| static struct osmo_fsm_state reset_fsm_states[] = { |
| [ST_DISC] = { |
| .in_event_mask = (1 << EV_CONN_ACK), |
| .out_state_mask = (1 << ST_CONN) | (1 << ST_DISC), |
| .name = "DISC", |
| .action = fsm_disc_cb, |
| }, |
| [ST_CONN] = { |
| .in_event_mask = (1 << EV_CONN_ACK), |
| .name = "CONN", |
| }, |
| }; |
| |
| /* State machine definition */ |
| static struct osmo_fsm fsm = { |
| .name = "A-RESET", |
| .states = reset_fsm_states, |
| .num_states = ARRAY_SIZE(reset_fsm_states), |
| .log_subsys = DMSC, |
| .timer_cb = fsm_reset_ack_timeout_cb, |
| .event_names = fsm_event_names, |
| }; |
| |
| /* Create and start state machine which handles the reset/reset-ack procedure */ |
| struct osmo_fsm_inst *a_reset_alloc(void *ctx, const char *name, void *cb, |
| void *priv, bool already_connected) |
| { |
| OSMO_ASSERT(name); |
| |
| struct reset_ctx *reset_ctx; |
| struct osmo_fsm_inst *reset_fsm; |
| |
| /* Register the fsm description (if not already done) */ |
| if (osmo_fsm_find_by_name(fsm.name) != &fsm) |
| osmo_fsm_register(&fsm); |
| |
| /* Allocate and configure a new fsm instance */ |
| reset_ctx = talloc_zero(ctx, struct reset_ctx); |
| OSMO_ASSERT(reset_ctx); |
| reset_ctx->priv = priv; |
| reset_ctx->cb = cb; |
| reset_fsm = osmo_fsm_inst_alloc(&fsm, ctx, reset_ctx, LOGL_DEBUG, name); |
| OSMO_ASSERT(reset_fsm); |
| |
| if (already_connected) |
| osmo_fsm_inst_state_chg(reset_fsm, ST_CONN, 0, 0); |
| else { |
| /* kick off reset-ack sending mechanism */ |
| osmo_fsm_inst_state_chg(reset_fsm, ST_DISC, RESET_RESEND_INTERVAL, |
| RESET_RESEND_TIMER_NO); |
| } |
| |
| return reset_fsm; |
| } |
| |
| /* Confirm that we sucessfully received a reset acknowlege message */ |
| void a_reset_ack_confirm(struct osmo_fsm_inst *reset_fsm) |
| { |
| OSMO_ASSERT(reset_fsm); |
| osmo_fsm_inst_dispatch(reset_fsm, EV_CONN_ACK, NULL); |
| } |
| |
| /* Check if we have a connection to a specified msc */ |
| bool a_reset_conn_ready(struct osmo_fsm_inst *reset_fsm) |
| { |
| /* If no reset context is supplied, we assume that |
| * the connection can't be ready! */ |
| if (!reset_fsm) |
| return false; |
| |
| if (reset_fsm->state == ST_CONN) |
| return true; |
| |
| return false; |
| } |