diff options
Diffstat (limited to 'openbsc/src/libcommon-cs/a_reset.c')
| -rw-r--r-- | openbsc/src/libcommon-cs/a_reset.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/openbsc/src/libcommon-cs/a_reset.c b/openbsc/src/libcommon-cs/a_reset.c new file mode 100644 index 000000000..94d215562 --- /dev/null +++ b/openbsc/src/libcommon-cs/a_reset.c @@ -0,0 +1,186 @@ +/* (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 <openbsc/debug.h> +#include <openbsc/bsc_msc_data.h> +#include <openbsc/osmo_bsc_sigtran.h> + +#define RESET_RESEND_INTERVAL 2 /* sec */ +#define RESET_RESEND_TIMER_NO 1234 /* FIXME: dig out the real timer number */ +#define BAD_CONNECTION_THRESOLD 3 /* connection failures */ + +enum fsm_states { + ST_DISC, /* Disconnected from remote end */ + ST_CONN, /* We have a confirmed connection */ +}; + +static const struct value_string fsm_state_names[] = { + {ST_DISC, "ST_DISC (disconnected)"}, + {ST_CONN, "ST_CONN (connected)"}, + {0, NULL}, +}; + +enum fsm_evt { + EV_RESET_ACK, /* got reset acknowlegement from remote end */ + EV_N_DISCONNECT, /* lost a connection */ + EV_N_CONNECT, /* made a successful connection */ +}; + +static const struct value_string fsm_evt_names[] = { + {EV_RESET_ACK, "EV_RESET_ACK"}, + {EV_N_DISCONNECT, "EV_N_DISCONNECT"}, + {EV_N_CONNECT, "EV_N_CONNECT"}, + {0, NULL}, +}; + +/* Disconnected state */ +static void fsm_disc_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct a_reset_ctx *reset = (struct a_reset_ctx *)data; + OSMO_ASSERT(reset); + + LOGP(DMSC, LOGL_NOTICE, "(%s) fsm-state (msc-reset): %s, fsm-event: %s\n", reset->name, + get_value_string(fsm_state_names, ST_CONN), get_value_string(fsm_evt_names, event)); + + reset->conn_loss_counter = 0; + osmo_fsm_inst_state_chg(fi, ST_CONN, 0, 0); +} + +/* Connected state */ +static void fsm_conn_cb(struct osmo_fsm_inst *fi, uint32_t event, void *data) +{ + struct a_reset_ctx *reset = (struct a_reset_ctx *)data; + OSMO_ASSERT(reset); + + LOGP(DMSC, LOGL_NOTICE, "(%s) fsm-state (msc-reset): %s, fsm-event: %s\n", reset->name, + get_value_string(fsm_state_names, ST_CONN), get_value_string(fsm_evt_names, event)); + + switch (event) { + case EV_N_DISCONNECT: + if (reset->conn_loss_counter >= BAD_CONNECTION_THRESOLD) { + LOGP(DMSC, LOGL_NOTICE, "(%s) SIGTRAN connection down, reconnecting...\n", reset->name); + osmo_fsm_inst_state_chg(fi, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO); + } else + reset->conn_loss_counter++; + break; + case EV_N_CONNECT: + reset->conn_loss_counter = 0; + break; + } +} + +/* Timer callback to retransmit the reset signal */ +static int fsm_reset_ack_timeout_cb(struct osmo_fsm_inst *fi) +{ + struct a_reset_ctx *reset = (struct a_reset_ctx *)fi->priv; + + LOGP(DMSC, LOGL_NOTICE, "(%s) reset-ack timeout (T%i) in state %s, resending...\n", reset->name, fi->T, + get_value_string(fsm_state_names, fi->state)); + + reset->cb(reset->priv); + + osmo_fsm_inst_state_chg(fi, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO); + return 0; +} + +static struct osmo_fsm_state fsm_states[] = { + [ST_DISC] = { + .in_event_mask = (1 << EV_RESET_ACK), + .out_state_mask = (1 << ST_DISC) | (1 << ST_CONN), + .name = "DISC", + .action = fsm_disc_cb, + }, + [ST_CONN] = { + .in_event_mask = (1 << EV_N_DISCONNECT) | (1 << EV_N_CONNECT), + .out_state_mask = (1 << ST_DISC) | (1 << ST_CONN), + .name = "CONN", + .action = fsm_conn_cb, + }, +}; + +/* State machine definition */ +static struct osmo_fsm fsm = { + .name = "FSM RESET", + .states = fsm_states, + .num_states = ARRAY_SIZE(fsm_states), + .log_subsys = DMSC, + .timer_cb = fsm_reset_ack_timeout_cb, +}; + +/* Create and start state machine which handles the reset/reset-ack procedure */ +void a_reset_start(struct a_reset_ctx *reset) +{ + OSMO_ASSERT(reset); + + osmo_fsm_register(&fsm); + reset->fsm = osmo_fsm_inst_alloc(&fsm, NULL, NULL, LOGL_DEBUG, "FSM RESET INST"); + OSMO_ASSERT(reset->fsm); + + reset->fsm->priv = reset; + + /* kick off reset-ack sending mechanism */ + osmo_fsm_inst_state_chg(reset->fsm, ST_DISC, RESET_RESEND_INTERVAL, RESET_RESEND_TIMER_NO); +} + +/* Confirm that we sucessfully received a reset acknowlege message */ +void a_reset_ack_confirm(struct a_reset_ctx *reset) +{ + OSMO_ASSERT(reset); + OSMO_ASSERT(reset->fsm); + + osmo_fsm_inst_dispatch(reset->fsm, EV_RESET_ACK, reset); +} + +/* Report a failed connection */ +void a_reset_conn_fail(struct a_reset_ctx *reset) +{ + OSMO_ASSERT(reset); + OSMO_ASSERT(reset->fsm); + + osmo_fsm_inst_dispatch(reset->fsm, EV_N_DISCONNECT, reset); +} + +/* Report a successful connection */ +void a_reset_conn_success(struct a_reset_ctx *reset) +{ + OSMO_ASSERT(reset); + OSMO_ASSERT(reset->fsm); + + osmo_fsm_inst_dispatch(reset->fsm, EV_N_CONNECT, reset); +} + +/* Check if we have a connection to a specified msc */ +bool a_reset_conn_ready(struct a_reset_ctx *reset) +{ + OSMO_ASSERT(reset); + OSMO_ASSERT(reset->fsm); + + if (reset->fsm->state == ST_CONN) + return true; + + return false; +} |