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osmo-bsc/src/osmo-bsc/lchan_fsm.c

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/* osmo-bsc API to allocate an lchan, complete with dyn TS switchover.
*
* (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Neels Hofmeyr <neels@hofmeyr.de>
*
* 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/gsm/rsl.h>
#include <osmocom/core/byteswap.h>
#include <osmocom/gsm/protocol/gsm_08_08.h>
#include <osmocom/mgcp_client/mgcp_client_endpoint_fsm.h>
#include <osmocom/bsc/debug.h>
#include <osmocom/bsc/lchan_fsm.h>
#include <osmocom/bsc/lchan_rtp_fsm.h>
#include <osmocom/bsc/timeslot_fsm.h>
#include <osmocom/bsc/bsc_subscr_conn_fsm.h>
#include <osmocom/bsc/handover.h>
#include <osmocom/bsc/abis_rsl.h>
#include <osmocom/bsc/bsc_rll.h>
#include <osmocom/bsc/gsm_04_08_rr.h>
#include <osmocom/bsc/assignment_fsm.h>
#include <osmocom/bsc/handover_fsm.h>
#include <osmocom/bsc/bsc_msc_data.h>
#include <osmocom/bsc/codec_pref.h>
#include <osmocom/bsc/bts.h>
static struct osmo_fsm lchan_fsm;
struct gsm_lchan *lchan_fi_lchan(struct osmo_fsm_inst *fi)
{
OSMO_ASSERT(fi);
OSMO_ASSERT(fi->fsm == &lchan_fsm);
OSMO_ASSERT(fi->priv);
return fi->priv;
}
bool lchan_may_receive_data(struct gsm_lchan *lchan)
{
if (!lchan || !lchan->fi)
return false;
switch (lchan->fi->state) {
case LCHAN_ST_WAIT_RLL_RTP_ESTABLISH:
case LCHAN_ST_ESTABLISHED:
case LCHAN_ST_WAIT_RR_CHAN_MODE_MODIFY_ACK:
return true;
default:
return false;
}
}
void lchan_set_last_error(struct gsm_lchan *lchan, const char *fmt, ...)
{
va_list ap;
/* This dance allows using an existing error reason in above fmt */
char *last_error_was = lchan->last_error;
lchan->last_error = NULL;
if (fmt) {
va_start(ap, fmt);
lchan->last_error = talloc_vasprintf(lchan->ts->trx, fmt, ap);
va_end(ap);
LOG_LCHAN(lchan, LOGL_ERROR, "%s\n", lchan->last_error);
}
if (last_error_was)
talloc_free(last_error_was);
}
/* The idea here is that we must not require to change any lchan state in order to deny a request. */
#define lchan_on_activation_failure(lchan, for_conn, activ_for) \
_lchan_on_activation_failure(lchan, for_conn, activ_for, \
__FILE__, __LINE__)
static void _lchan_on_activation_failure(struct gsm_lchan *lchan, enum lchan_activate_mode activ_for,
struct gsm_subscriber_connection *for_conn,
const char *file, int line)
{
if (lchan->activate.concluded)
return;
lchan->activate.concluded = true;
switch (activ_for) {
case FOR_MS_CHANNEL_REQUEST:
if (!lchan->activate.immediate_assignment_sent) {
/* Failure before Immediate Assignment message, send a reject. */
LOG_LCHAN(lchan, LOGL_NOTICE, "Tx Immediate Assignment Reject (%s)\n",
lchan->last_error ? : "unknown error");
rsl_tx_imm_ass_rej(lchan->ts->trx->bts, lchan->rqd_ref);
}
/* Otherwise, likely the MS never showed up after the Assignment, and the failure cause
* (Timeout?) was already logged elsewhere. Just continue to tear down the lchan after
* lchan_on_activation_failure(), no additional action or logging needed. */
break;
case FOR_ASSIGNMENT:
LOG_LCHAN(lchan, LOGL_NOTICE, "Signalling Assignment FSM of error (%s)\n",
lchan->last_error ? : "unknown error");
_osmo_fsm_inst_dispatch(for_conn->assignment.fi, ASSIGNMENT_EV_LCHAN_ERROR, lchan,
file, line);
return;
case FOR_HANDOVER:
LOG_LCHAN(lchan, LOGL_NOTICE, "Signalling Handover FSM of error (%s)\n",
lchan->last_error ? : "unknown error");
if (!for_conn) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for Handover failed, but activation request has"
" no conn\n");
break;
}
if (!for_conn->ho.fi) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for Handover failed, but conn has no ongoing"
" handover procedure\n");
break;
}
_osmo_fsm_inst_dispatch(for_conn->ho.fi, HO_EV_LCHAN_ERROR, lchan, file, line);
break;
case FOR_VTY:
LOG_LCHAN(lchan, LOGL_ERROR, "VTY user invoked lchan activation failed (%s)\n",
lchan->last_error ? : "unknown error");
break;
default:
LOG_LCHAN(lchan, LOGL_ERROR, "lchan activation failed (%s)\n",
lchan->last_error ? : "unknown error");
break;
}
}
static void lchan_on_fully_established(struct gsm_lchan *lchan)
{
if (lchan->activate.concluded)
return;
lchan->activate.concluded = true;
switch (lchan->activate.info.activ_for) {
case FOR_MS_CHANNEL_REQUEST:
/* No signalling to do here, MS is free to use the channel, and should go on to connect
* to the MSC and establish a subscriber connection. */
break;
case FOR_ASSIGNMENT:
if (!lchan->conn) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for assignment succeeded, but lchan has no conn:"
" cannot trigger appropriate actions. Release.\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
if (!lchan->conn->assignment.fi) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for assignment succeeded, but lchan has no"
" assignment ongoing: cannot trigger appropriate actions. Release.\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
osmo_fsm_inst_dispatch(lchan->conn->assignment.fi, ASSIGNMENT_EV_LCHAN_ESTABLISHED,
lchan);
/* The lchan->fi_rtp will be notified of LCHAN_RTP_EV_ESTABLISHED in
* gscon_change_primary_lchan() upon assignment_success(). On failure before then, we
* will try to roll back a modified RTP connection. */
break;
case FOR_HANDOVER:
if (!lchan->conn) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for handover succeeded, but lchan has no conn\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
if (!lchan->conn->ho.fi) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for handover succeeded, but lchan has no"
" handover ongoing\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
osmo_fsm_inst_dispatch(lchan->conn->ho.fi, HO_EV_LCHAN_ESTABLISHED, lchan);
/* The lchan->fi_rtp will be notified of LCHAN_RTP_EV_ESTABLISHED in
* gscon_change_primary_lchan() upon handover_end(HO_RESULT_OK). On failure before then,
* we will try to roll back a modified RTP connection. */
break;
default:
LOG_LCHAN(lchan, LOGL_NOTICE, "lchan %s fully established\n",
lchan_activate_mode_name(lchan->activate.info.activ_for));
break;
}
}
struct osmo_tdef_state_timeout lchan_fsm_timeouts[32] = {
[LCHAN_ST_WAIT_TS_READY] = { .T=-5 },
[LCHAN_ST_WAIT_ACTIV_ACK] = { .T=-6 },
[LCHAN_ST_WAIT_RLL_RTP_ESTABLISH] = { .T=3101 },
[LCHAN_ST_WAIT_RLL_RTP_RELEASED] = { .T=3109 },
[LCHAN_ST_WAIT_BEFORE_RF_RELEASE] = { .T=3111 },
[LCHAN_ST_WAIT_RF_RELEASE_ACK] = { .T=3111 },
[LCHAN_ST_WAIT_AFTER_ERROR] = { .T=-3111 },
};
/* Transition to a state, using the T timer defined in lchan_fsm_timeouts.
* The actual timeout value is in turn obtained from network->T_defs.
* Assumes local variable fi exists. */
#define lchan_fsm_state_chg(state) \
osmo_tdef_fsm_inst_state_chg(fi, state, \
lchan_fsm_timeouts, \
((struct gsm_lchan*)(fi->priv))->ts->trx->bts->network->T_defs, \
5)
/* Set a failure message, trigger the common actions to take on failure, transition to a state to
* continue with (using state timeouts from lchan_fsm_timeouts[]). Assumes local variable fi exists. */
#define lchan_fail_to(STATE_CHG, fmt, args...) do { \
struct gsm_lchan *_lchan = fi->priv; \
struct osmo_fsm *fsm = fi->fsm; \
uint32_t state_was = fi->state; \
/* Snapshot the target state, in case the macro argument evaluates differently later */ \
const uint32_t state_chg = STATE_CHG; \
LOG_LCHAN(_lchan, LOGL_DEBUG, "Handling failure, will then transition to state %s\n", \
osmo_fsm_state_name(fsm, state_chg)); \
lchan_set_last_error(_lchan, "lchan %s in state %s: " fmt, \
_lchan->activate.concluded ? "failure" : "allocation failed", \
osmo_fsm_state_name(fsm, state_was), ## args); \
lchan_on_activation_failure(_lchan, _lchan->activate.info.activ_for, _lchan->conn); \
if (fi->state != state_chg) \
lchan_fsm_state_chg(state_chg); \
else \
LOG_LCHAN(_lchan, LOGL_DEBUG, "After failure handling, already in state %s\n", \
osmo_fsm_state_name(fsm, state_chg)); \
} while(0)
/* Which state to transition to when lchan_fail() is called in a given state. */
uint32_t lchan_fsm_on_error[34] = {
[LCHAN_ST_UNUSED] = LCHAN_ST_UNUSED,
[LCHAN_ST_WAIT_TS_READY] = LCHAN_ST_UNUSED,
[LCHAN_ST_WAIT_ACTIV_ACK] = LCHAN_ST_BORKEN,
[LCHAN_ST_WAIT_RLL_RTP_ESTABLISH] = LCHAN_ST_WAIT_RF_RELEASE_ACK,
[LCHAN_ST_ESTABLISHED] = LCHAN_ST_WAIT_RLL_RTP_RELEASED,
[LCHAN_ST_WAIT_RLL_RTP_RELEASED] = LCHAN_ST_WAIT_RF_RELEASE_ACK,
[LCHAN_ST_WAIT_BEFORE_RF_RELEASE] = LCHAN_ST_WAIT_RF_RELEASE_ACK,
[LCHAN_ST_WAIT_RF_RELEASE_ACK] = LCHAN_ST_BORKEN,
[LCHAN_ST_WAIT_AFTER_ERROR] = LCHAN_ST_UNUSED,
[LCHAN_ST_BORKEN] = LCHAN_ST_BORKEN,
[LCHAN_ST_WAIT_RR_CHAN_MODE_MODIFY_ACK] = LCHAN_ST_BORKEN,
[LCHAN_ST_WAIT_RSL_CHAN_MODE_MODIFY_ACK] = LCHAN_ST_BORKEN,
};
#define lchan_fail(fmt, args...) lchan_fail_to(lchan_fsm_on_error[fi->state], fmt, ## args)
void lchan_activate(struct gsm_lchan *lchan, struct lchan_activate_info *info)
{
int rc;
OSMO_ASSERT(lchan && info);
if (!lchan_state_is(lchan, LCHAN_ST_UNUSED))
goto abort;
/* ensure some basic sanity up first, before we enter the machine. */
OSMO_ASSERT(lchan->ts && lchan->ts->fi && lchan->fi);
switch (info->activ_for) {
case FOR_ASSIGNMENT:
if (!info->for_conn
|| !info->for_conn->fi) {
LOG_LCHAN(lchan, LOGL_ERROR, "Activation requested, but no conn\n");
goto abort;
}
if (info->for_conn->assignment.new_lchan != lchan) {
LOG_LCHAN(lchan, LOGL_ERROR,
"Activation for Assignment requested, but conn's state does"
" not reflect this lchan to be activated (instead: %s)\n",
info->for_conn->assignment.new_lchan?
gsm_lchan_name(info->for_conn->assignment.new_lchan)
: "NULL");
goto abort;
}
break;
case FOR_HANDOVER:
if (!info->for_conn
|| !info->for_conn->fi) {
LOG_LCHAN(lchan, LOGL_ERROR, "Activation requested, but no conn\n");
goto abort;
}
if (!info->for_conn->ho.fi) {
LOG_LCHAN(lchan, LOGL_ERROR,
"Activation for Handover requested, but conn has no HO pending.\n");
goto abort;
}
if (info->for_conn->ho.new_lchan != lchan) {
LOG_LCHAN(lchan, LOGL_ERROR,
"Activation for Handover requested, but conn's HO state does"
" not reflect this lchan to be activated (instead: %s)\n",
info->for_conn->ho.new_lchan?
gsm_lchan_name(info->for_conn->ho.new_lchan)
: "NULL");
goto abort;
}
break;
default:
break;
}
/* To make sure that the lchan is actually allowed to initiate an activation, feed through an FSM
* event. */
rc = osmo_fsm_inst_dispatch(lchan->fi, LCHAN_EV_ACTIVATE, info);
if (rc) {
LOG_LCHAN(lchan, LOGL_ERROR,
"Activation requested, but cannot dispatch LCHAN_EV_ACTIVATE event\n");
goto abort;
}
return;
abort:
lchan_on_activation_failure(lchan, info->activ_for, info->for_conn);
/* Remain in state UNUSED */
}
static void lchan_fsm_update_id(struct gsm_lchan *lchan)
{
osmo_fsm_inst_update_id_f(lchan->fi, "%u-%u-%u-%s-%u",
lchan->ts->trx->bts->nr, lchan->ts->trx->nr, lchan->ts->nr,
gsm_pchan_id(lchan->ts->pchan_on_init), lchan->nr);
if (lchan->fi_rtp)
osmo_fsm_inst_update_id_f(lchan->fi_rtp, lchan->fi->id);
}
extern void lchan_rtp_fsm_init();
void lchan_fsm_init()
{
OSMO_ASSERT(osmo_fsm_register(&lchan_fsm) == 0);
lchan_rtp_fsm_init();
}
void lchan_fsm_alloc(struct gsm_lchan *lchan)
{
OSMO_ASSERT(lchan->ts);
OSMO_ASSERT(lchan->ts->fi);
OSMO_ASSERT(!lchan->fi);
lchan->fi = osmo_fsm_inst_alloc_child(&lchan_fsm, lchan->ts->fi, TS_EV_LCHAN_UNUSED);
OSMO_ASSERT(lchan->fi);
lchan->fi->priv = lchan;
lchan_fsm_update_id(lchan);
LOGPFSML(lchan->fi, LOGL_DEBUG, "new lchan\n");
}
/* Clear volatile state of the lchan. Clear all except
* - the ts backpointer,
* - the nr,
* - name,
* - the FSM instance including its current state,
* - last_error string.
*/
static void lchan_reset(struct gsm_lchan *lchan)
{
LOG_LCHAN(lchan, LOGL_DEBUG, "Clearing lchan state\n");
if (lchan->conn)
gscon_forget_lchan(lchan->conn, lchan);
if (lchan->rqd_ref) {
talloc_free(lchan->rqd_ref);
lchan->rqd_ref = NULL;
}
if (lchan->fi_rtp)
osmo_fsm_inst_term(lchan->fi_rtp, OSMO_FSM_TERM_REQUEST, 0);
if (lchan->mgw_endpoint_ci_bts) {
osmo_mgcpc_ep_ci_dlcx(lchan->mgw_endpoint_ci_bts);
lchan->mgw_endpoint_ci_bts = NULL;
}
/* NUL all volatile state */
*lchan = (struct gsm_lchan){
.ts = lchan->ts,
.nr = lchan->nr,
.fi = lchan->fi,
.name = lchan->name,
.meas_rep_last_seen_nr = 255,
.last_error = lchan->last_error,
.release.rr_cause = GSM48_RR_CAUSE_NORMAL,
};
}
static void lchan_fsm_unused_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
struct gsm_bts *bts = lchan->ts->trx->bts;
lchan_reset(lchan);
osmo_fsm_inst_dispatch(lchan->ts->fi, TS_EV_LCHAN_UNUSED, lchan);
/* Poll the channel request queue, so that waiting calls can make use of the lchan that just
* has become unused now. */
abis_rsl_chan_rqd_queue_poll(bts);
}
static void lchan_fsm_wait_after_error_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
struct gsm_bts *bts = lchan->ts->trx->bts;
/* We also need to poll the channel request queue when the FSM enters the WAIT_AFTER_ERROR
* state. In case of an emergency call the channel request queue will skip the waiting
* period. */
abis_rsl_chan_rqd_queue_poll(bts);
}
/* Configure the multirate setting on this channel. */
static int lchan_mr_config(struct gsm_lchan *lchan, uint16_t s15_s0)
{
struct gsm48_multi_rate_conf mr_conf;
bool full_rate = (lchan->type == GSM_LCHAN_TCH_F);
struct gsm_bts *bts = lchan->ts->trx->bts;
struct amr_multirate_conf *mr;
int rc;
int rc_rate;
struct gsm48_multi_rate_conf mr_conf_filtered;
const struct gsm48_multi_rate_conf *mr_conf_bts;
/* Generate mr conf struct from S15-S0 bits */
if (gsm48_mr_cfg_from_gsm0808_sc_cfg(&mr_conf, s15_s0) < 0) {
LOG_LCHAN(lchan, LOGL_ERROR,
"can not determine multirate configuration, S15-S0 (%04x) are ambiguous!\n", s15_s0);
return -EINVAL;
}
/* Do not include 12.2 kbps rate when S1 is set. */
if (lchan->type == GSM_LCHAN_TCH_H && (s15_s0 & GSM0808_SC_CFG_AMR_4_75_5_90_7_40_12_20)) {
/* See also 3GPP TS 28.062, chapter 7.11.3.1.3: "In case this Configuration
* "Config-NB-Code = 1" is signalled in the TFO Negotiation for the HR_AMR
* Codec Type,then it shall be assumed that AMR mode 12.2 kbps is (of course)
* not included. */
mr_conf.m12_2 = 0;
}
/* There are two different active sets, depending on the channel rate,
* make sure the appropate one is selected. */
if (full_rate)
mr = &bts->mr_full;
else
mr = &bts->mr_half;
mr_conf_bts = (struct gsm48_multi_rate_conf *)mr->gsm48_ie;
if (lchan->activate.info.activ_for == FOR_VTY)
/* If the channel is activated manually from VTY, then there is no
* conn attached to the lchan, also no MSC is involved. Since this
* option is for debugging and the codec choice is an intentional
* decision by the VTY user, we do not filter the mr_conf. */
memcpy(&mr_conf_filtered, &mr_conf, sizeof(mr_conf_filtered));
else {
/* The VTY allows to forbid certain codec rates. Unfortunately we can
* not articulate all of the prohibitions on through S0-S15 on the A
* interface. To ensure that the VTY settings are observed we create
* a manipulated copy of the mr_conf that ensures forbidden codec rates
* are not used in the multirate configuration IE. */
rc_rate = calc_amr_rate_intersection(&mr_conf_filtered, &lchan->conn->sccp.msc->amr_conf, &mr_conf);
if (rc_rate < 0) {
LOG_LCHAN(lchan, LOGL_ERROR,
"can not encode multirate configuration (invalid amr rate setting, MSC)\n");
return -EINVAL;
}
}
/* The two last codec rates which are defined for AMR do only work with
* full rate channels. We will pinch off those rates für half-rate
* channels to ensure they are not included accidently. */
if (!full_rate) {
if (mr_conf_filtered.m10_2 || mr_conf_filtered.m12_2)
LOG_LCHAN(lchan, LOGL_ERROR, "ignoring unsupported amr codec rates\n");
mr_conf_filtered.m10_2 = 0;
mr_conf_filtered.m12_2 = 0;
}
/* Ensure that the resulting filtered conf is coherent with the
* configuration that is set for the BTS and the specified rate.
* if the channel activation was triggerd by the VTY, do not
* filter anything (see also comment above) */
if (lchan->activate.info.activ_for != FOR_VTY) {
rc_rate = calc_amr_rate_intersection(&mr_conf_filtered, mr_conf_bts, &mr_conf_filtered);
if (rc_rate < 0) {
LOG_LCHAN(lchan, LOGL_ERROR,
"can not encode multirate configuration (invalid amr rate setting, BTS)\n");
return -EINVAL;
}
}
/* Set the ICMI according to the BTS. Above gsm48_mr_cfg_from_gsm0808_sc_cfg() always sets ICMI = 1, which
* carried through all of the above rate intersections. */
mr_conf_filtered.icmi = mr_conf_bts->icmi;
mr_conf_filtered.smod = mr_conf_bts->smod;
/* Proceed with the generation of the multirate configuration IE
* (MS and BTS) */
rc = gsm48_multirate_config(lchan->mr_ms_lv, &mr_conf_filtered, mr->ms_mode, mr->num_modes);
if (rc != 0) {
LOG_LCHAN(lchan, LOGL_ERROR, "can not encode multirate configuration (MS)\n");
return -EINVAL;
}
rc = gsm48_multirate_config(lchan->mr_bts_lv, &mr_conf_filtered, mr->bts_mode, mr->num_modes);
if (rc != 0) {
LOG_LCHAN(lchan, LOGL_ERROR, "can not encode multirate configuration (BTS)\n");
return -EINVAL;
}
lchan->s15_s0 = s15_s0;
return 0;
}
static void lchan_fsm_unused(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct lchan_activate_info *info = data;
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_ACTIVATE:
OSMO_ASSERT(info);
OSMO_ASSERT(!lchan->conn);
OSMO_ASSERT(!lchan->mgw_endpoint_ci_bts);
lchan_set_last_error(lchan, NULL);
lchan->release.requested = false;
lchan->activate.info = *info;
lchan->activate.concluded = false;
lchan_fsm_state_chg(LCHAN_ST_WAIT_TS_READY);
break;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_wait_ts_ready_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
struct gsm_bts *bts = lchan->ts->trx->bts;
struct osmo_mgcpc_ep_ci *use_mgwep_ci;
struct gsm_lchan *old_lchan = lchan->activate.info.re_use_mgw_endpoint_from_lchan;
struct lchan_activate_info *info = &lchan->activate.info;
int ms_power_dbm;
if (lchan->release.requested) {
lchan_fail("Release requested while activating");
return;
}
lchan->conn = info->for_conn;
/* If there is a previous lchan, and the new lchan is on the same cell as previous one,
* take over power and TA values. Otherwise, use max power and zero TA. */
if (old_lchan && old_lchan->ts->trx->bts == bts) {
ms_power_dbm = ms_pwr_dbm(bts->band, old_lchan->ms_power);
lchan_update_ms_power_ctrl_level(lchan, ms_power_dbm >= 0 ? ms_power_dbm : bts->ms_max_power);
lchan->bs_power = old_lchan->bs_power;
} else {
lchan_update_ms_power_ctrl_level(lchan, bts->ms_max_power);
/* Upon last entering the UNUSED state, from lchan_reset():
* - bs_power is still zero, 0dB reduction, output power = Pn.
* - TA is still zero, to be determined by RACH. */
/* Default BS Power reduction value (in 2 dB steps) */
if (bts->bs_power_ctrl.mode == GSM_PWR_CTRL_MODE_DYN_BTS)
lchan->bs_power = bts->bs_power_ctrl.bs_power_max_db / 2;
else
lchan->bs_power = bts->bs_power_ctrl.bs_power_val_db / 2;
}
if (info->chan_mode == GSM48_CMODE_SPEECH_AMR) {
if (lchan_mr_config(lchan, info->s15_s0) < 0) {
lchan_fail("Can not generate multirate configuration IE\n");
return;
}
}
switch (info->chan_mode) {
case GSM48_CMODE_SIGN:
lchan->rsl_cmode = RSL_CMOD_SPD_SIGN;
lchan->tch_mode = GSM48_CMODE_SIGN;
break;
case GSM48_CMODE_SPEECH_V1:
case GSM48_CMODE_SPEECH_EFR:
case GSM48_CMODE_SPEECH_AMR:
lchan->rsl_cmode = RSL_CMOD_SPD_SPEECH;
lchan->tch_mode = info->chan_mode;
break;
default:
lchan_fail("Not implemented: cannot activate for chan mode %s",
gsm48_chan_mode_name(info->chan_mode));
return;
}
use_mgwep_ci = lchan_use_mgw_endpoint_ci_bts(lchan);
LOG_LCHAN(lchan, LOGL_INFO,
"Activation requested: %s voice=%s MGW-ci=%s type=%s tch-mode=%s encr-alg=A5/%u ck=%s\n",
lchan_activate_mode_name(lchan->activate.info.activ_for),
lchan->activate.info.requires_voice_stream ? "yes" : "no",
lchan->activate.info.requires_voice_stream ?
(use_mgwep_ci ? osmo_mgcpc_ep_ci_name(use_mgwep_ci) : "new")
: "none",
gsm_lchant_name(lchan->type),
gsm48_chan_mode_name(lchan->tch_mode),
(lchan->activate.info.encr.alg_id ? : 1)-1,
lchan->activate.info.encr.key_len ? osmo_hexdump_nospc(lchan->activate.info.encr.key,
lchan->activate.info.encr.key_len) : "none");
/* Ask for the timeslot to make ready for this lchan->type.
* We'll receive LCHAN_EV_TS_READY or LCHAN_EV_TS_ERROR in response. */
osmo_fsm_inst_dispatch(lchan->ts->fi, TS_EV_LCHAN_REQUESTED, lchan);
/* Prepare an MGW endpoint CI if appropriate. */
if (lchan->activate.info.requires_voice_stream)
lchan_rtp_fsm_start(lchan);
}
static void lchan_fsm_wait_ts_ready(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_TS_READY:
/* timeslot agrees that we may Chan Activ now. Sending it in onenter. */
lchan_fsm_state_chg(LCHAN_ST_WAIT_ACTIV_ACK);
break;
case LCHAN_EV_RTP_RELEASED:
case LCHAN_EV_RTP_ERROR:
if (lchan->release.in_release_handler) {
/* Already in release, the RTP is not the initial cause of failure.
* Just ignore. */
return;
}
lchan_fail("Failed to setup RTP stream: %s in state %s\n",
osmo_fsm_event_name(fi->fsm, event),
osmo_fsm_inst_state_name(fi));
return;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_wait_activ_ack_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
int rc;
uint8_t act_type;
uint8_t ho_ref = 0;
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
if (lchan->release.requested) {
lchan_fail_to(LCHAN_ST_UNUSED, "Release requested while activating");
return;
}
switch (lchan->activate.info.activ_for) {
case FOR_MS_CHANNEL_REQUEST:
act_type = RSL_ACT_INTRA_IMM_ASS;
break;
case FOR_HANDOVER:
act_type = lchan->conn->ho.async ? RSL_ACT_INTER_ASYNC : RSL_ACT_INTER_SYNC;
ho_ref = lchan->conn->ho.ho_ref;
break;
default:
case FOR_ASSIGNMENT:
act_type = RSL_ACT_INTRA_NORM_ASS;
break;
}
lchan->encr = lchan->activate.info.encr;
rc = rsl_tx_chan_activ(lchan, act_type, ho_ref);
if (rc) {
lchan_fail_to(LCHAN_ST_UNUSED, "Tx Chan Activ failed: %s (%d)", strerror(-rc), rc);
return;
}
if (lchan->activate.info.ta_known)
lchan->last_ta = lchan->activate.info.ta;
}
static void lchan_fsm_post_activ_ack(struct osmo_fsm_inst *fi);
static void lchan_fsm_wait_activ_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_RSL_CHAN_ACTIV_ACK:
lchan->activate.activ_ack = true;
lchan_fsm_post_activ_ack(fi);
break;
case LCHAN_EV_RSL_CHAN_ACTIV_NACK:
lchan->release.in_release_handler = true;
if (data) {
uint32_t next_state;
lchan->release.rsl_error_cause = *(uint8_t*)data;
lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
lchan->release.in_error = true;
if (lchan->release.rsl_error_cause != RSL_ERR_RCH_ALR_ACTV_ALLOC)
next_state = LCHAN_ST_BORKEN;
else
/* Taking this over from legacy code: send an RF Chan Release even though
* the Activ was NACKed. Is this really correct? */
next_state = LCHAN_ST_WAIT_RF_RELEASE_ACK;
lchan_fail_to(next_state, "Chan Activ NACK: %s (0x%x)",
rsl_err_name(lchan->release.rsl_error_cause), lchan->release.rsl_error_cause);
} else {
lchan->release.rsl_error_cause = RSL_ERR_IE_NONEXIST;
lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
lchan->release.in_error = true;
lchan_fail_to(LCHAN_ST_BORKEN, "Chan Activ NACK without cause IE");
}
lchan->release.in_release_handler = false;
break;
case LCHAN_EV_RTP_RELEASED:
case LCHAN_EV_RTP_ERROR:
if (lchan->release.in_release_handler) {
/* Already in release, the RTP is not the initial cause of failure.
* Just ignore. */
return;
}
lchan_fail_to(LCHAN_ST_WAIT_RF_RELEASE_ACK,
"Failed to setup RTP stream: %s in state %s\n",
osmo_fsm_event_name(fi->fsm, event),
osmo_fsm_inst_state_name(fi));
return;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_post_activ_ack(struct osmo_fsm_inst *fi)
{
int rc;
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
if (lchan->release.requested) {
lchan_fail_to(LCHAN_ST_WAIT_RF_RELEASE_ACK, "Release requested while activating");
return;
}
switch (lchan->activate.info.activ_for) {
case FOR_MS_CHANNEL_REQUEST:
rc = rsl_tx_imm_assignment(lchan);
if (rc) {
lchan_fail("Failed to Tx RR Immediate Assignment message (rc=%d %s)\n",
rc, strerror(-rc));
return;
}
LOG_LCHAN(lchan, LOGL_DEBUG, "Tx RR Immediate Assignment\n");
lchan->activate.immediate_assignment_sent = true;
break;
case FOR_ASSIGNMENT:
if (!lchan->conn) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for assignment succeeded, but lchan has no conn:"
" cannot trigger appropriate actions. Release.\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
if (!lchan->conn->assignment.fi) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for assignment succeeded, but lchan has no"
" assignment ongoing: cannot trigger appropriate actions. Release.\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
/* After the Chan Activ Ack, the MS expects to receive an RR Assignment Command.
* Let the assignment_fsm handle that. */
osmo_fsm_inst_dispatch(lchan->conn->assignment.fi, ASSIGNMENT_EV_LCHAN_ACTIVE, lchan);
break;
case FOR_HANDOVER:
if (!lchan->conn) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for handover succeeded, but lchan has no conn:"
" cannot trigger appropriate actions. Release.\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
if (!lchan->conn->ho.fi) {
LOG_LCHAN(lchan, LOGL_ERROR,
"lchan activation for handover succeeded, but lchan has no"
" handover ongoing: cannot trigger appropriate actions. Release.\n");
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL);
break;
}
/* After the Chan Activ Ack of the new lchan, send the MS an RR Handover Command on the
* old channel. The handover_fsm handles that. */
osmo_fsm_inst_dispatch(lchan->conn->ho.fi, HO_EV_LCHAN_ACTIVE, lchan);
break;
default:
LOG_LCHAN(lchan, LOGL_NOTICE, "lchan %s is now active\n",
lchan_activate_mode_name(lchan->activate.info.activ_for));
break;
}
lchan_fsm_state_chg(LCHAN_ST_WAIT_RLL_RTP_ESTABLISH);
}
static void lchan_fsm_wait_rll_rtp_establish_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
if (lchan->fi_rtp)
osmo_fsm_inst_dispatch(lchan->fi_rtp, LCHAN_RTP_EV_LCHAN_READY, 0);
/* Prepare an MGW endpoint CI if appropriate (late). */
else if (lchan->activate.info.requires_voice_stream)
lchan_rtp_fsm_start(lchan);
/* When activating a channel for VTY, skip waiting for activity from
* lchan_rtp_fsm, but only if no voice stream is required. */
if (lchan->activate.info.activ_for == FOR_VTY &&
!lchan->activate.info.requires_voice_stream) {
lchan_fsm_state_chg(LCHAN_ST_ESTABLISHED);
}
}
static void lchan_fsm_wait_rll_rtp_establish(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_RLL_ESTABLISH_IND:
if (!lchan->activate.info.requires_voice_stream
|| lchan_rtp_established(lchan)) {
LOG_LCHAN(lchan, LOGL_DEBUG,
"%s\n",
(lchan->activate.info.requires_voice_stream ?
"RTP already established earlier" : "no voice stream required"));
lchan_fsm_state_chg(LCHAN_ST_ESTABLISHED);
}
return;
case LCHAN_EV_RTP_READY:
if (lchan->sapis[0] != LCHAN_SAPI_UNUSED)
lchan_fsm_state_chg(LCHAN_ST_ESTABLISHED);
return;
case LCHAN_EV_RTP_RELEASED:
case LCHAN_EV_RTP_ERROR:
if (lchan->release.in_release_handler) {
/* Already in release, the RTP is not the initial cause of failure.
* Just ignore. */
return;
}
lchan_fail("Failed to setup RTP stream: %s in state %s\n",
osmo_fsm_event_name(fi->fsm, event),
osmo_fsm_inst_state_name(fi));
return;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_wait_rr_chan_mode_modify_ack_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
gsm48_lchan_modify(lchan, lchan->activate.info.chan_mode);
}
static void lchan_fsm_wait_rr_chan_mode_modify_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
switch (event) {
case LCHAN_EV_RR_CHAN_MODE_MODIFY_ACK:
lchan_fsm_state_chg(LCHAN_ST_WAIT_RSL_CHAN_MODE_MODIFY_ACK);
return;
case LCHAN_EV_RR_CHAN_MODE_MODIFY_ERROR:
lchan_fail("Failed to change channel mode on the MS side: %s in state %s\n",
osmo_fsm_event_name(fi->fsm, event),
osmo_fsm_inst_state_name(fi));
return;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_wait_rsl_chan_mode_modify_ack_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
int rc;
rc = rsl_chan_mode_modify_req(lchan);
if (rc < 0) {
lchan_fail("Failed to send rsl message to change the channel mode on the BTS side: state %s\n",
osmo_fsm_inst_state_name(fi));
}
}
static void lchan_fsm_wait_rsl_chan_mode_modify_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_RSL_CHAN_MODE_MODIFY_ACK:
if (lchan->activate.info.requires_voice_stream)
lchan_fsm_state_chg(LCHAN_ST_WAIT_RLL_RTP_ESTABLISH);
else
lchan_fsm_state_chg(LCHAN_ST_ESTABLISHED);
return;
case LCHAN_EV_RSL_CHAN_MODE_MODIFY_NACK:
lchan_fail("Failed to change channel mode on the BTS side: %s in state %s\n",
osmo_fsm_event_name(fi->fsm, event),
osmo_fsm_inst_state_name(fi));
return;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
if (lchan->release.requested) {
lchan_fail("Release requested while activating");
return;
}
lchan_on_fully_established(lchan);
}
#define for_each_sapi(sapi, start, lchan) \
for (sapi = start; sapi < ARRAY_SIZE(lchan->sapis); sapi++)
static int next_active_sapi(struct gsm_lchan *lchan, int from_sapi)
{
int sapi;
for_each_sapi(sapi, from_sapi, lchan) {
if (lchan->sapis[sapi] == LCHAN_SAPI_UNUSED)
continue;
return sapi;
}
return sapi;
}
#define for_each_active_sapi(sapi, start, lchan) \
for (sapi = next_active_sapi(lchan, start); \
sapi < ARRAY_SIZE(lchan->sapis); sapi=next_active_sapi(lchan, sapi+1))
static int lchan_active_sapis(struct gsm_lchan *lchan, int start)
{
int sapis = 0;
int sapi;
for_each_active_sapi(sapi, start, lchan) {
LOG_LCHAN(lchan, LOGL_DEBUG,
"Still active: SAPI[%d] (%d)\n", sapi, lchan->sapis[sapi]);
sapis ++;
}
LOG_LCHAN(lchan, LOGL_DEBUG, "Still active SAPIs: %d\n", sapis);
return sapis;
}
static void handle_rll_rel_ind_or_conf(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
uint8_t link_id;
uint8_t sapi;
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
OSMO_ASSERT(data);
link_id = *(uint8_t*)data;
sapi = link_id & 7;
LOG_LCHAN(lchan, LOGL_DEBUG, "Rx RLL Release %s: SAPI=%u link_id=0x%x\n",
event == LCHAN_EV_RLL_REL_CONF ? "CONF" : "IND", sapi, link_id);
/* TODO this reflects the code state before the lchan FSM. However, it would make more sense to
* me that a Release IND is indeed a cue for us to send a Release Request, and not count it as an
* equal to Release CONF. */
lchan->sapis[sapi] = LCHAN_SAPI_UNUSED;
rll_indication(lchan, link_id, BSC_RLLR_IND_REL_IND);
/* Releasing SAPI 0 means the conn becomes invalid; but not if the link_id contains a TCH flag.
* (TODO: is this the correct interpretation?) */
if (lchan->conn && sapi == 0 && !(link_id & 0xc0)) {
LOG_LCHAN(lchan, LOGL_DEBUG, "lchan is releasing\n");
gscon_lchan_releasing(lchan->conn, lchan);
}
/* The caller shall check whether all SAPIs are released and cause a state chg */
}
static void lchan_fsm_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
struct lchan_activate_info *info;
struct osmo_mgcpc_ep_ci *use_mgwep_ci;
switch (event) {
case LCHAN_EV_RLL_ESTABLISH_IND:
/* abis_rsl.c has noticed that a SAPI was established, no need to take action here. */
return;
case LCHAN_EV_RLL_REL_IND:
case LCHAN_EV_RLL_REL_CONF:
handle_rll_rel_ind_or_conf(fi, event, data);
if (!lchan_active_sapis(lchan, 0))
lchan_fsm_state_chg(LCHAN_ST_WAIT_RLL_RTP_RELEASED);
return;
case LCHAN_EV_RTP_RELEASED:
case LCHAN_EV_RTP_ERROR:
if (lchan->release.in_release_handler) {
/* Already in release, the RTP is not the initial cause of failure.
* Just ignore. */
return;
}
lchan_fail("RTP stream closed unexpectedly: %s in state %s\n",
osmo_fsm_event_name(fi->fsm, event),
osmo_fsm_inst_state_name(fi));
return;
case LCHAN_EV_REQUEST_MODE_MODIFY:
/* FIXME: Add missing implementation to handle an already existing RTP voice stream on MODE MODIFY.
* there may be transitions from VOICE to SIGNALLING and also from VOICE to VOICE with a different
* codec. */
if (lchan->fi_rtp) {
lchan_fail("MODE MODIFY not implemented when RTP voice stream is already active (VOICE => SIGNALLING, VOICE/CODEC_A => VOICE/CODEC_B)\n");
return;
}
info = data;
lchan->activate.info = *info;
use_mgwep_ci = lchan_use_mgw_endpoint_ci_bts(lchan);
if (info->chan_mode == GSM48_CMODE_SPEECH_AMR) {
if (lchan_mr_config(lchan, info->s15_s0) < 0) {
lchan_fail("Can not generate multirate configuration IE\n");
return;
}
}
LOG_LCHAN(lchan, LOGL_INFO,
"Modification requested: %s voice=%s MGW-ci=%s type=%s tch-mode=%s encr-alg=A5/%u ck=%s\n",
lchan_activate_mode_name(lchan->activate.info.activ_for),
lchan->activate.info.requires_voice_stream ? "yes" : "no",
lchan->activate.info.requires_voice_stream ?
(use_mgwep_ci ? osmo_mgcpc_ep_ci_name(use_mgwep_ci) : "new")
: "none",
gsm_lchant_name(lchan->type),
gsm48_chan_mode_name(lchan->tch_mode),
(lchan->activate.info.encr.alg_id ? : 1) - 1,
lchan->activate.info.encr.key_len ? osmo_hexdump_nospc(lchan->activate.info.encr.key,
lchan->activate.info.encr.key_len) : "none");
/* While the mode is changed the lchan is virtually "not activated", at least
* from the FSM implementations perspective */
lchan->activate.concluded = false;
/* Initiate mode modification, start with the MS side (RR) */
lchan_fsm_state_chg(LCHAN_ST_WAIT_RR_CHAN_MODE_MODIFY_ACK);
return;
default:
OSMO_ASSERT(false);
}
}
static bool should_sacch_deact(struct gsm_lchan *lchan)
{
switch (lchan->ts->pchan_is) {
case GSM_PCHAN_TCH_F:
case GSM_PCHAN_TCH_H:
case GSM_PCHAN_CCCH_SDCCH4:
case GSM_PCHAN_CCCH_SDCCH4_CBCH:
case GSM_PCHAN_SDCCH8_SACCH8C:
case GSM_PCHAN_SDCCH8_SACCH8C_CBCH:
return true;
default:
return false;
}
}
static void lchan_do_release(struct gsm_lchan *lchan)
{
if (lchan->release.do_rr_release && lchan->sapis[0] != LCHAN_SAPI_UNUSED)
gsm48_send_rr_release(lchan);
if (lchan->fi_rtp)
osmo_fsm_inst_dispatch(lchan->fi_rtp, LCHAN_RTP_EV_RELEASE, 0);
if (should_sacch_deact(lchan))
rsl_deact_sacch(lchan);
}
static void lchan_fsm_wait_rll_rtp_released_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
int sapis;
int sapi;
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
for (sapi=0; sapi < ARRAY_SIZE(lchan->sapis); sapi++)
if (lchan->sapis[sapi])
LOG_LCHAN(lchan, LOGL_DEBUG, "SAPI[%d] = %d\n", sapi, lchan->sapis[sapi]);
/* It could be that we receive LCHAN_EV_RTP_RELEASED synchronously and
as a result we may end up in state WAIT_BEFORE_RF_RELEASE after
lchan_do_release has returned */
lchan_do_release(lchan);
sapis = 0;
for_each_active_sapi(sapi, 1, lchan) {
uint8_t link_id = sapi;
if (lchan->type == GSM_LCHAN_TCH_F || lchan->type == GSM_LCHAN_TCH_H)
link_id |= 0x40;
LOG_LCHAN(lchan, LOGL_DEBUG, "Tx: Release SAPI %u link_id 0x%x\n", sapi, link_id);
rsl_release_request(lchan, link_id, RSL_REL_LOCAL_END);
sapis ++;
}
/* Do not wait for Nokia BTS to send the confirm. */
if (is_nokia_bts(lchan->ts->trx->bts)
&& lchan->ts->trx->bts->nokia.no_loc_rel_cnf) {
LOG_LCHAN(lchan, LOGL_DEBUG, "Nokia InSite BTS: not waiting for RELease CONFirm\n");
for_each_active_sapi(sapi, 1, lchan)
lchan->sapis[sapi] = LCHAN_SAPI_UNUSED;
sapis = 0;
}
if (!sapis && !lchan->fi_rtp && fi->state == LCHAN_ST_WAIT_RLL_RTP_RELEASED)
lchan_fsm_state_chg(LCHAN_ST_WAIT_BEFORE_RF_RELEASE);
}
static void lchan_fsm_wait_rll_rtp_released(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_RLL_REL_IND:
case LCHAN_EV_RLL_REL_CONF:
/* When we're telling the MS to release, we're fine to carry on with RF Channel Release
* when SAPI 0 release is not confirmed yet.
* TODO: that's how the code was before lchan FSM, is this correct/useful? */
handle_rll_rel_ind_or_conf(fi, event, data);
break;
case LCHAN_EV_RTP_RELEASED:
case LCHAN_EV_RTP_ERROR:
break;
default:
OSMO_ASSERT(false);
}
if (!lchan_active_sapis(lchan, 1) && !lchan->fi_rtp)
lchan_fsm_state_chg(LCHAN_ST_WAIT_BEFORE_RF_RELEASE);
}
static void lchan_fsm_wait_rf_release_ack_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
int rc;
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
/* For planned releases, a conn has already forgotten about the lchan. And later on, in
* lchan_reset(), we make sure it does. But in case of releases from error handling, the
* conn might as well notice now already that its lchan is becoming unusable. */
if (lchan->conn) {
gscon_forget_lchan(lchan->conn, lchan);
lchan_forget_conn(lchan);
}
rc = rsl_tx_rf_chan_release(lchan);
if (rc)
LOG_LCHAN(lchan, LOGL_ERROR, "Failed to Tx RSL RF Channel Release: rc=%d %s\n",
rc, strerror(-rc));
}
static void lchan_fsm_wait_rf_release_ack(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (event) {
case LCHAN_EV_RSL_RF_CHAN_REL_ACK:
if (lchan->release.in_error)
lchan_fsm_state_chg(LCHAN_ST_WAIT_AFTER_ERROR);
else
lchan_fsm_state_chg(LCHAN_ST_UNUSED);
break;
case LCHAN_EV_RTP_RELEASED:
/* ignore late lchan_rtp_fsm release events */
return;
default:
OSMO_ASSERT(false);
}
}
static void lchan_fsm_borken_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
struct gsm_bts *bts = lchan->ts->trx->bts;
enum bts_counter_id ctr;
switch (prev_state) {
case LCHAN_ST_UNUSED:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_UNUSED;
break;
case LCHAN_ST_WAIT_ACTIV_ACK:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_WAIT_ACTIV_ACK;
break;
case LCHAN_ST_WAIT_RF_RELEASE_ACK:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_WAIT_RF_RELEASE_ACK;
break;
case LCHAN_ST_BORKEN:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_BORKEN;
break;
case LCHAN_ST_WAIT_RR_CHAN_MODE_MODIFY_ACK:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_WAIT_RR_CHAN_MODE_MODIFY_ACK;
break;
case LCHAN_ST_WAIT_RSL_CHAN_MODE_MODIFY_ACK:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_WAIT_RSL_CHAN_MODE_MODIFY_ACK;
break;
default:
ctr = BTS_CTR_LCHAN_BORKEN_FROM_UNKNOWN;
}
rate_ctr_inc(&bts->bts_ctrs->ctr[ctr]);
if (prev_state != LCHAN_ST_BORKEN)
osmo_stat_item_inc(bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
/* The actual action besides all the beancounting above */
lchan_reset(lchan);
}
static void lchan_fsm_borken(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
struct gsm_bts *bts = lchan->ts->trx->bts;
switch (event) {
case LCHAN_EV_RSL_CHAN_ACTIV_ACK:
/* A late Chan Activ ACK? Release. */
rate_ctr_inc(&bts->bts_ctrs->ctr[BTS_CTR_LCHAN_BORKEN_EV_CHAN_ACTIV_ACK]);
osmo_stat_item_dec(bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
lchan->release.in_error = true;
lchan->release.rsl_error_cause = RSL_ERR_INTERWORKING;
lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
lchan_fsm_state_chg(LCHAN_ST_WAIT_RF_RELEASE_ACK);
return;
case LCHAN_EV_RSL_CHAN_ACTIV_NACK:
/* A late Chan Activ NACK? Ok then, unused. */
rate_ctr_inc(&bts->bts_ctrs->ctr[BTS_CTR_LCHAN_BORKEN_EV_CHAN_ACTIV_NACK]);
osmo_stat_item_dec(bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
lchan_fsm_state_chg(LCHAN_ST_UNUSED);
return;
case LCHAN_EV_RSL_RF_CHAN_REL_ACK:
/* A late Release ACK? */
rate_ctr_inc(&bts->bts_ctrs->ctr[BTS_CTR_LCHAN_BORKEN_EV_RF_CHAN_REL_ACK]);
osmo_stat_item_dec(bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
lchan->release.in_error = true;
lchan->release.rsl_error_cause = RSL_ERR_INTERWORKING;
lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
lchan_fsm_state_chg(LCHAN_ST_WAIT_AFTER_ERROR);
/* TODO: we used to do this only for sysmobts:
int do_free = is_osmobts(ts->trx->bts);
LOGP(DRSL, LOGL_NOTICE,
"%s CHAN REL ACK for broken channel. %s.\n",
gsm_lchan_name(lchan),
do_free ? "Releasing it" : "Keeping it broken");
if (do_free)
do_lchan_free(lchan);
* Clarify the reason. If a BTS sends a RF Chan Rel ACK, we can consider it released,
* independently from the BTS model, right?? */
return;
case LCHAN_EV_RTP_RELEASED:
case LCHAN_EV_RTP_ERROR:
return;
default:
OSMO_ASSERT(false);
}
}
#define S(x) (1 << (x))
static const struct osmo_fsm_state lchan_fsm_states[] = {
[LCHAN_ST_UNUSED] = {
.name = "UNUSED",
.onenter = lchan_fsm_unused_onenter,
.action = lchan_fsm_unused,
.in_event_mask = 0
| S(LCHAN_EV_ACTIVATE)
,
.out_state_mask = 0
| S(LCHAN_ST_WAIT_TS_READY)
| S(LCHAN_ST_CBCH)
| S(LCHAN_ST_BORKEN)
,
},
[LCHAN_ST_CBCH] = {
.name = "CBCH",
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
,
},
[LCHAN_ST_WAIT_TS_READY] = {
.name = "WAIT_TS_READY",
.onenter = lchan_fsm_wait_ts_ready_onenter,
.action = lchan_fsm_wait_ts_ready,
.in_event_mask = 0
| S(LCHAN_EV_TS_READY)
| S(LCHAN_EV_RTP_ERROR)
| S(LCHAN_EV_RTP_RELEASED)
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_ACTIV_ACK)
| S(LCHAN_ST_WAIT_RLL_RTP_RELEASED)
,
},
[LCHAN_ST_WAIT_ACTIV_ACK] = {
.name = "WAIT_ACTIV_ACK",
.onenter = lchan_fsm_wait_activ_ack_onenter,
.action = lchan_fsm_wait_activ_ack,
.in_event_mask = 0
| S(LCHAN_EV_RSL_CHAN_ACTIV_ACK)
| S(LCHAN_EV_RSL_CHAN_ACTIV_NACK)
| S(LCHAN_EV_RTP_ERROR)
| S(LCHAN_EV_RTP_RELEASED)
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_RLL_RTP_ESTABLISH)
| S(LCHAN_ST_BORKEN)
| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)
,
},
[LCHAN_ST_WAIT_RLL_RTP_ESTABLISH] = {
.name = "WAIT_RLL_RTP_ESTABLISH",
.onenter = lchan_fsm_wait_rll_rtp_establish_onenter,
.action = lchan_fsm_wait_rll_rtp_establish,
.in_event_mask = 0
| S(LCHAN_EV_RLL_ESTABLISH_IND)
| S(LCHAN_EV_RTP_READY)
| S(LCHAN_EV_RTP_ERROR)
| S(LCHAN_EV_RTP_RELEASED)
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_ESTABLISHED)
| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)
| S(LCHAN_ST_WAIT_RLL_RTP_RELEASED)
,
},
[LCHAN_ST_WAIT_RR_CHAN_MODE_MODIFY_ACK] = {
.name = "WAIT_CHAN_RR_MODE_MODIFY_ACK",
.onenter = lchan_fsm_wait_rr_chan_mode_modify_ack_onenter,
.action = lchan_fsm_wait_rr_chan_mode_modify_ack,
.in_event_mask = 0
| S(LCHAN_EV_RR_CHAN_MODE_MODIFY_ACK)
| S(LCHAN_EV_RR_CHAN_MODE_MODIFY_ERROR)
,
.out_state_mask = 0
| S(LCHAN_ST_BORKEN)
| S(LCHAN_ST_WAIT_RSL_CHAN_MODE_MODIFY_ACK)
,
},
[LCHAN_ST_WAIT_RSL_CHAN_MODE_MODIFY_ACK] = {
.name = "WAIT_RSL_CHAN_MODE_MODIFY_ACK",
.onenter = lchan_fsm_wait_rsl_chan_mode_modify_ack_onenter,
.action = lchan_fsm_wait_rsl_chan_mode_modify_ack,
.in_event_mask = 0
| S(LCHAN_EV_RSL_CHAN_MODE_MODIFY_ACK)
| S(LCHAN_EV_RSL_CHAN_MODE_MODIFY_NACK)
,
.out_state_mask = 0
| S(LCHAN_ST_BORKEN)
| S(LCHAN_ST_WAIT_RLL_RTP_ESTABLISH)
,
},
[LCHAN_ST_ESTABLISHED] = {
.name = "ESTABLISHED",
.onenter = lchan_fsm_established_onenter,
.action = lchan_fsm_established,
.in_event_mask = 0
| S(LCHAN_EV_RLL_REL_IND)
| S(LCHAN_EV_RLL_REL_CONF)
| S(LCHAN_EV_RLL_ESTABLISH_IND) /* ignored */
| S(LCHAN_EV_RTP_ERROR)
| S(LCHAN_EV_RTP_RELEASED)
| S(LCHAN_EV_REQUEST_MODE_MODIFY)
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_RLL_RTP_RELEASED)
| S(LCHAN_ST_WAIT_BEFORE_RF_RELEASE)
| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)
| S(LCHAN_ST_WAIT_RR_CHAN_MODE_MODIFY_ACK)
,
},
[LCHAN_ST_WAIT_RLL_RTP_RELEASED] = {
.name = "WAIT_RLL_RTP_RELEASED",
.onenter = lchan_fsm_wait_rll_rtp_released_onenter,
.action = lchan_fsm_wait_rll_rtp_released,
.in_event_mask = 0
| S(LCHAN_EV_RLL_REL_IND)
| S(LCHAN_EV_RLL_REL_CONF)
| S(LCHAN_EV_RTP_ERROR)
| S(LCHAN_EV_RTP_RELEASED)
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_BEFORE_RF_RELEASE)
| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)
,
},
[LCHAN_ST_WAIT_BEFORE_RF_RELEASE] = {
.name = "WAIT_BEFORE_RF_RELEASE",
.in_event_mask = 0
| S(LCHAN_EV_RLL_REL_IND) /* allow late REL_IND of SAPI[0] */
| S(LCHAN_EV_RTP_RELEASED) /* ignore late lchan_rtp_fsm release events */
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)
,
},
[LCHAN_ST_WAIT_RF_RELEASE_ACK] = {
.name = "WAIT_RF_RELEASE_ACK",
.onenter = lchan_fsm_wait_rf_release_ack_onenter,
.action = lchan_fsm_wait_rf_release_ack,
.in_event_mask = 0
| S(LCHAN_EV_RSL_RF_CHAN_REL_ACK)
| S(LCHAN_EV_RTP_RELEASED) /* ignore late lchan_rtp_fsm release events */
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_AFTER_ERROR)
| S(LCHAN_ST_BORKEN)
,
},
[LCHAN_ST_WAIT_AFTER_ERROR] = {
.name = "WAIT_AFTER_ERROR",
.onenter = lchan_fsm_wait_after_error_onenter,
.in_event_mask = 0
| S(LCHAN_EV_RTP_RELEASED) /* ignore late lchan_rtp_fsm release events */
,
.out_state_mask = 0
| S(LCHAN_ST_UNUSED)
,
},
[LCHAN_ST_BORKEN] = {
.name = "BORKEN",
.onenter = lchan_fsm_borken_onenter,
.action = lchan_fsm_borken,
.in_event_mask = 0
| S(LCHAN_EV_RSL_CHAN_ACTIV_ACK)
| S(LCHAN_EV_RSL_CHAN_ACTIV_NACK)
| S(LCHAN_EV_RSL_RF_CHAN_REL_ACK)
| S(LCHAN_EV_RTP_ERROR)
| S(LCHAN_EV_RTP_RELEASED)
,
.out_state_mask = 0
| S(LCHAN_ST_WAIT_RF_RELEASE_ACK)
| S(LCHAN_ST_UNUSED)
| S(LCHAN_ST_WAIT_AFTER_ERROR)
,
},
};
static const struct value_string lchan_fsm_event_names[] = {
OSMO_VALUE_STRING(LCHAN_EV_ACTIVATE),
OSMO_VALUE_STRING(LCHAN_EV_TS_READY),
OSMO_VALUE_STRING(LCHAN_EV_TS_ERROR),
OSMO_VALUE_STRING(LCHAN_EV_RSL_CHAN_ACTIV_ACK),
OSMO_VALUE_STRING(LCHAN_EV_RSL_CHAN_ACTIV_NACK),
OSMO_VALUE_STRING(LCHAN_EV_RLL_ESTABLISH_IND),
OSMO_VALUE_STRING(LCHAN_EV_RTP_READY),
OSMO_VALUE_STRING(LCHAN_EV_RTP_ERROR),
OSMO_VALUE_STRING(LCHAN_EV_RTP_RELEASED),
OSMO_VALUE_STRING(LCHAN_EV_RLL_REL_IND),
OSMO_VALUE_STRING(LCHAN_EV_RLL_REL_CONF),
OSMO_VALUE_STRING(LCHAN_EV_RSL_RF_CHAN_REL_ACK),
OSMO_VALUE_STRING(LCHAN_EV_RLL_ERR_IND),
OSMO_VALUE_STRING(LCHAN_EV_RR_CHAN_MODE_MODIFY_ACK),
OSMO_VALUE_STRING(LCHAN_EV_RR_CHAN_MODE_MODIFY_ERROR),
OSMO_VALUE_STRING(LCHAN_EV_RSL_CHAN_MODE_MODIFY_ACK),
OSMO_VALUE_STRING(LCHAN_EV_RSL_CHAN_MODE_MODIFY_NACK),
{}
};
static void lchan_fsm_allstate_action(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
switch (event) {
case LCHAN_EV_TS_ERROR:
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
if (fi->state == LCHAN_ST_BORKEN) {
rate_ctr_inc(&lchan->ts->trx->bts->bts_ctrs->ctr[BTS_CTR_LCHAN_BORKEN_EV_TS_ERROR]);
osmo_stat_item_dec(lchan->ts->trx->bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
}
lchan_fail_to(LCHAN_ST_UNUSED, "LCHAN_EV_TS_ERROR");
return;
}
case LCHAN_EV_RLL_ERR_IND:
/* let's just ignore this. We are already logging the
* fact that this message was received inside
* abis_rsl.c. There can be any number of reasons why the
* radio link layer failed */
return;
default:
return;
}
}
void lchan_fsm_skip_error(struct gsm_lchan *lchan)
{
struct osmo_fsm_inst *fi = lchan->fi;
if (fi->state == LCHAN_ST_WAIT_AFTER_ERROR)
lchan_fsm_state_chg(LCHAN_ST_UNUSED);
}
static int lchan_fsm_timer_cb(struct osmo_fsm_inst *fi)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
switch (fi->state) {
case LCHAN_ST_WAIT_BEFORE_RF_RELEASE:
lchan_fsm_state_chg(LCHAN_ST_WAIT_RF_RELEASE_ACK);
return 0;
case LCHAN_ST_WAIT_AFTER_ERROR:
lchan_fsm_state_chg(LCHAN_ST_UNUSED);
return 0;
default:
lchan->release.in_error = true;
lchan->release.rsl_error_cause = RSL_ERR_INTERWORKING;
lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
lchan_fail("Timeout");
return 0;
}
}
void lchan_release(struct gsm_lchan *lchan, bool do_rr_release,
bool err, enum gsm48_rr_cause cause_rr)
{
if (!lchan || !lchan->fi)
return;
if (lchan->release.in_release_handler)
return;
lchan->release.in_release_handler = true;
struct osmo_fsm_inst *fi = lchan->fi;
lchan->release.in_error = err;
lchan->release.do_rr_release = do_rr_release;
lchan->release.rr_cause = cause_rr;
/* States waiting for events will notice the desire to release when done waiting, so it is enough
* to mark for release. */
lchan->release.requested = true;
/* If we took the RTP over from another lchan, put it back. */
if (lchan->fi_rtp && lchan->release.in_error)
osmo_fsm_inst_dispatch(lchan->fi_rtp, LCHAN_RTP_EV_ROLLBACK, 0);
/* But when in error, don't wait for the next state to pick up release_requested. */
if (lchan->release.in_error) {
switch (lchan->fi->state) {
default:
/* Normally we signal release in lchan_fsm_wait_rll_rtp_released_onenter(). When
* skipping that, do it now. */
lchan_do_release(lchan);
/* fall thru */
case LCHAN_ST_WAIT_RLL_RTP_RELEASED:
lchan_fsm_state_chg(LCHAN_ST_WAIT_RF_RELEASE_ACK);
goto exit_release_handler;
case LCHAN_ST_WAIT_TS_READY:
lchan_fsm_state_chg(LCHAN_ST_WAIT_RLL_RTP_RELEASED);
goto exit_release_handler;
case LCHAN_ST_WAIT_RF_RELEASE_ACK:
case LCHAN_ST_BORKEN:
goto exit_release_handler;
}
}
/* The only non-broken state that would stay stuck without noticing the release_requested flag
* is: */
if (fi->state == LCHAN_ST_ESTABLISHED)
lchan_fsm_state_chg(LCHAN_ST_WAIT_RLL_RTP_RELEASED);
exit_release_handler:
lchan->release.in_release_handler = false;
}
static void lchan_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
{
struct gsm_lchan *lchan = lchan_fi_lchan(fi);
if (lchan->fi->state == LCHAN_ST_BORKEN) {
rate_ctr_inc(&lchan->ts->trx->bts->bts_ctrs->ctr[BTS_CTR_LCHAN_BORKEN_EV_TEARDOWN]);
osmo_stat_item_dec(lchan->ts->trx->bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
}
lchan_reset(lchan);
if (lchan->last_error) {
talloc_free(lchan->last_error);
lchan->last_error = NULL;
}
lchan->fi = NULL;
}
/* The conn is deallocating, just forget all about it */
void lchan_forget_conn(struct gsm_lchan *lchan)
{
struct gsm_subscriber_connection *conn;
if (!lchan)
return;
lchan->activate.info.for_conn = NULL;
conn = lchan->conn;
if (conn) {
/* Log for both lchan FSM and conn FSM to ease reading the log in case of problems */
if (lchan->fi)
LOGPFSML(lchan->fi, LOGL_DEBUG, "lchan detaches from conn %s\n",
conn->fi? osmo_fsm_inst_name(conn->fi) : "(conn without FSM)");
if (conn->fi)
LOGPFSML(conn->fi, LOGL_DEBUG, "lchan %s detaches from conn\n",
lchan->fi? osmo_fsm_inst_name(lchan->fi) : gsm_lchan_name(lchan));
}
lchan_forget_mgw_endpoint(lchan);
lchan->conn = NULL;
}
static struct osmo_fsm lchan_fsm = {
.name = "lchan",
.states = lchan_fsm_states,
.num_states = ARRAY_SIZE(lchan_fsm_states),
.log_subsys = DCHAN,
.event_names = lchan_fsm_event_names,
.allstate_action = lchan_fsm_allstate_action,
.allstate_event_mask = 0
| S(LCHAN_EV_TS_ERROR)
| S(LCHAN_EV_RLL_ERR_IND)
,
.timer_cb = lchan_fsm_timer_cb,
.cleanup = lchan_fsm_cleanup,
};
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