Osmocom's Base Station Controller for 2G mobile networks https://osmocom.org/projects/osmobsc
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
osmo-bsc/src/osmo-bsc/assignment_fsm.c

1010 lines
35 KiB

/* osmo-bsc BSSMAP Assignment procedure implementation.
*
* (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/core/tdef.h>
#include <osmocom/gsm/gsm0808.h>
#include <osmocom/mgcp_client/mgcp_client_endpoint_fsm.h>
#include <osmocom/bsc/debug.h>
#include <osmocom/bsc/gsm_data.h>
#include <osmocom/bsc/lchan_fsm.h>
#include <osmocom/bsc/bsc_subscr_conn_fsm.h>
#include <osmocom/bsc/osmo_bsc_lcls.h>
#include <osmocom/bsc/bsc_msc_data.h>
#include <osmocom/bsc/gsm_08_08.h>
#include <osmocom/bsc/gsm_04_08_rr.h>
#include <osmocom/bsc/lchan_select.h>
#include <osmocom/bsc/abis_rsl.h>
#include <osmocom/bsc/bts.h>
#include <osmocom/bsc/bsc_stats.h>
#include <osmocom/bsc/assignment_fsm.h>
static struct osmo_fsm assignment_fsm;
struct gsm_subscriber_connection *assignment_fi_conn(struct osmo_fsm_inst *fi)
{
OSMO_ASSERT(fi);
OSMO_ASSERT(fi->fsm == &assignment_fsm);
OSMO_ASSERT(fi->priv);
return fi->priv;
}
static const struct osmo_tdef_state_timeout assignment_fsm_timeouts[32] = {
[ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE] = { .T=10 },
[ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE] = { .keep_timer=true },
[ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED] = { .keep_timer=true },
[ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC] = { .T=23042 },
};
/* Transition to a state, using the T timer defined in assignment_fsm_timeouts.
* The actual timeout value is in turn obtained from network->T_defs.
* Assumes local variable fi exists. */
#define assignment_fsm_state_chg(state) \
osmo_tdef_fsm_inst_state_chg(fi, state, \
assignment_fsm_timeouts, \
((struct gsm_subscriber_connection*)(fi->priv))->network->T_defs, \
5)
/* Log failure and transition to ASSIGNMENT_ST_FAILURE, which triggers the appropriate actions. */
#define assignment_fail(cause, fmt, args...) do { \
struct gsm_subscriber_connection *_conn = fi->priv; \
_conn->assignment.failure_cause = cause; \
LOG_ASSIGNMENT(_conn, LOGL_ERROR, "Assignment failed in state %s, cause %s: " fmt "\n", \
osmo_fsm_inst_state_name(fi), gsm0808_cause_name(cause), ## args); \
assignment_count_result(CTR_ASSIGNMENT_ERROR); \
on_assignment_failure(_conn); \
} while (0)
/* Assume presence of local var 'conn' as struct gsm_subscriber_connection */
#define assignment_count(counter) do { \
struct gsm_bts *bts = conn_get_bts(conn); \
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "incrementing rate counter: %s %s\n", \
bsc_ctr_description[BSC_##counter].name, \
bsc_ctr_description[BSC_##counter].description); \
rate_ctr_inc(rate_ctr_group_get_ctr(conn->network->bsc_ctrs, BSC_##counter)); \
if (bts) { \
rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_##counter)); \
switch (gsm48_chan_mode_to_non_vamos(conn->assignment.req.ch_mode_rate_list[0].chan_mode)) { \
case GSM48_CMODE_SIGN: \
rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_##counter##_SIGN)); \
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "incrementing rate counter: bts%u %s %s\n", \
bts->nr, \
bts_ctr_description[BTS_##counter##_SIGN].name, \
bts_ctr_description[BTS_##counter##_SIGN].description); \
break; \
case GSM48_CMODE_SPEECH_V1: \
case GSM48_CMODE_SPEECH_EFR: \
case GSM48_CMODE_SPEECH_AMR: \
rate_ctr_inc(rate_ctr_group_get_ctr(bts->bts_ctrs, BTS_##counter##_SPEECH)); \
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "incrementing rate counter: bts%u %s %s\n", \
bts->nr, \
bts_ctr_description[BTS_##counter##_SPEECH].name, \
bts_ctr_description[BTS_##counter##_SPEECH].description); \
break; \
default: \
break; \
} \
} \
} while (0)
#define assignment_count_result(counter) do { \
if (!conn->assignment.result_rate_ctr_done) { \
assignment_count(counter); \
conn->assignment.result_rate_ctr_done = true; \
} else \
LOG_ASSIGNMENT(conn, LOGL_DEBUG, \
"result rate counter already recorded, NOT counting as: %s %s\n", \
bsc_ctr_description[BSC_##counter].name, \
bsc_ctr_description[BSC_##counter].description); \
} while (0)
void assignment_reset(struct gsm_subscriber_connection *conn)
{
if (conn->assignment.new_lchan) {
struct gsm_lchan *lchan = conn->assignment.new_lchan;
conn->assignment.new_lchan = NULL;
lchan_release(lchan, false, true, RSL_ERR_EQUIPMENT_FAIL, NULL);
}
if (conn->assignment.created_ci_for_msc) {
/* Store ci pointer locally, because gscon_forget_mgw_endpoint_ci() NULLs
* conn->assignment.created_ci_for_msc. */
struct osmo_mgcpc_ep_ci *ci = conn->assignment.created_ci_for_msc;
gscon_forget_mgw_endpoint_ci(conn, ci);
/* If this is the last endpoint released, the mgw_endpoint_fsm will terminate and tell
* the gscon about it. */
osmo_mgcpc_ep_ci_dlcx(ci);
}
conn->assignment = (struct assignment_fsm_data){
.fi = conn->assignment.fi, /* The FSM shall clear itself when it's done. */
};
}
static void on_assignment_failure(struct gsm_subscriber_connection *conn)
{
/* Send Assignment Failure to MSC only when the assignment was requested via BSSAP. Do not send anything to the
* MSC if re-assignment was requested for congestion resolution, for VAMOS multiplexing, or by VTY. */
if (conn->assignment.req.assign_for == ASSIGN_FOR_BSSMAP_REQ) {
struct msgb *resp = gsm0808_create_assignment_failure(conn->assignment.failure_cause, NULL);
if (!resp) {
LOG_ASSIGNMENT(conn, LOGL_ERROR, "Unable to compose BSSMAP Assignment Failure message\n");
} else {
rate_ctr_inc(rate_ctr_group_get_ctr(conn->sccp.msc->msc_ctrs, MSC_CTR_BSSMAP_TX_DT1_ASSIGMENT_FAILURE));
gscon_sigtran_send(conn, resp);
}
}
/* If assignment failed as early as in assignment_fsm_start(), there may not be an fi yet. */
if (conn->assignment.fi) {
LOG_ASSIGNMENT(conn, LOGL_ERROR, "Assignment failed\n");
osmo_fsm_inst_term(conn->assignment.fi, OSMO_FSM_TERM_ERROR, 0);
}
}
static void _gsm0808_ass_compl_extend_osmux(struct msgb *msg, uint8_t cid)
{
OSMO_ASSERT(msg->l3h[1] == msgb_l3len(msg) - 2); /*TL not in len */
msgb_tv_put(msg, GSM0808_IE_OSMO_OSMUX_CID, cid);
msg->l3h[1] = msgb_l3len(msg) - 2;
}
static void send_assignment_complete(struct gsm_subscriber_connection *conn)
{
int rc;
struct gsm0808_speech_codec sc;
struct gsm0808_speech_codec *sc_ptr = NULL;
struct sockaddr_storage addr_local;
struct sockaddr_storage *addr_local_p = NULL;
uint8_t osmux_cid = 0;
int perm_spch = 0;
uint8_t chosen_channel;
struct msgb *resp;
struct gsm_lchan *lchan = conn->lchan;
struct osmo_fsm_inst *fi = conn->fi;
chosen_channel = gsm0808_chosen_channel(lchan->type, lchan->current_ch_mode_rate.chan_mode);
if (!chosen_channel) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to compose Chosen Channel for mode=%s type=%s",
get_value_string(gsm48_chan_mode_names, lchan->current_ch_mode_rate.chan_mode),
gsm_lchant_name(lchan->type));
return;
}
/* Generate voice related fields */
if (conn->assignment.requires_voice_stream) {
perm_spch = gsm0808_permitted_speech(lchan->type, lchan->current_ch_mode_rate.chan_mode);
if (gscon_is_aoip(conn)) {
if (!osmo_mgcpc_ep_ci_get_crcx_info_to_sockaddr(conn->user_plane.mgw_endpoint_ci_msc,
&addr_local)) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to compose RTP address of MGW -> MSC");
return;
}
addr_local_p = &addr_local;
}
if (gscon_is_aoip(conn) && conn->assignment.req.use_osmux) {
if (!osmo_mgcpc_ep_ci_get_crcx_info_to_osmux_cid(conn->user_plane.mgw_endpoint_ci_msc,
&osmux_cid)) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to compose Osmux CID of MGW -> MSC");
return;
}
}
/* Only AoIP networks include a speech codec (choosen) in the
* assignment complete message. */
if (gscon_is_aoip(conn)) {
/* Extrapolate speech codec from speech mode */
gsm0808_speech_codec_from_chan_type(&sc, perm_spch);
sc.cfg = conn->lchan->activate.ch_mode_rate.s15_s0;
sc_ptr = &sc;
}
}
resp = gsm0808_create_ass_compl2(lchan->abis_ip.ass_compl.rr_cause,
chosen_channel,
ALG_A5_NR_TO_BSSAP(lchan->encr.alg_a5_n), perm_spch,
addr_local_p, sc_ptr, NULL, lcls_get_status(conn));
if (!resp) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to compose Assignment Complete message");
return;
}
if (gscon_is_aoip(conn) && conn->assignment.requires_voice_stream &&
conn->assignment.req.use_osmux)
_gsm0808_ass_compl_extend_osmux(resp, osmux_cid);
rate_ctr_inc(rate_ctr_group_get_ctr(conn->sccp.msc->msc_ctrs, MSC_CTR_BSSMAP_TX_DT1_ASSIGMENT_COMPLETE));
rc = gscon_sigtran_send(conn, resp);
if (rc) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable send Assignment Complete message: rc=%d %s",
rc, strerror(-rc));
return;
}
}
static void assignment_success(struct gsm_subscriber_connection *conn)
{
struct gsm_bts *bts;
bool lchan_changed = (conn->assignment.new_lchan != NULL);
/* Take on the new lchan. If there only was a Channel Mode Modify, then there is no new lchan to take on. */
if (lchan_changed) {
gscon_change_primary_lchan(conn, conn->assignment.new_lchan);
OSMO_ASSERT((bts = conn_get_bts(conn)) != NULL);
if (is_siemens_bts(bts) && ts_is_tch(conn->lchan->ts)) {
/* HACK: store the actual Classmark 2 LV from the subscriber and use it here! */
uint8_t cm2_lv[] = { 0x02, 0x00, 0x00 };
send_siemens_mrpci(conn->lchan, cm2_lv);
}
/* apply LCLS configuration (if any) */
lcls_apply_config(conn);
}
conn->assignment.new_lchan = NULL;
if (conn->assignment.req.assign_for == ASSIGN_FOR_BSSMAP_REQ) {
send_assignment_complete(conn);
/* If something went wrong during send_assignment_complete(), the fi will be gone from
* error handling in there. Almost a success, but then again the whole thing failed. */
if (!conn->assignment.fi) {
/* The lchan was ready, and we failed to tell the MSC about it. By releasing this lchan,
* the conn will notice that its primary lchan is gone and should clean itself up. */
lchan_release(conn->lchan, true, true, RSL_ERR_EQUIPMENT_FAIL,
gscon_last_eutran_plmn(conn));
return;
}
}
/* Rembered this only for error handling: should assignment fail, assignment_reset() will release
* the MGW endpoint right away. If successful, the conn continues to use the endpoint. */
conn->assignment.created_ci_for_msc = NULL;
/* New RTP information is now accepted. If there is no RTP stream, this information is zero / empty. Either way
* store the result of this assignment. */
conn->user_plane.msc_assigned_cic = conn->assignment.req.msc_assigned_cic;
osmo_strlcpy(conn->user_plane.msc_assigned_rtp_addr, conn->assignment.req.msc_rtp_addr,
sizeof(conn->user_plane.msc_assigned_rtp_addr));
conn->user_plane.msc_assigned_rtp_port = conn->assignment.req.msc_rtp_port;
assignment_count_result(CTR_ASSIGNMENT_COMPLETED);
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "Assignment successful\n");
osmo_fsm_inst_term(conn->assignment.fi, OSMO_FSM_TERM_REGULAR, 0);
}
static void assignment_fsm_update_id(struct gsm_subscriber_connection *conn)
{
/* Assignment can do a new channel activation, in which case new_lchan points at the new lchan.
* Or assignment can Channel Mode Modify the already used lchan, in which case new_lchan == NULL. */
struct gsm_lchan *new_lchan = (conn->assignment.new_lchan ? : conn->lchan);
if (!new_lchan) {
osmo_fsm_inst_update_id(conn->assignment.fi, conn->fi->id);
return;
}
osmo_fsm_inst_update_id_f(conn->assignment.fi, "%s_%u-%u-%u-%s%s%s-%s%u",
conn->fi->id,
new_lchan->ts->trx->bts->nr, new_lchan->ts->trx->nr, new_lchan->ts->nr,
gsm_pchan_id(new_lchan->ts->pchan_on_init),
(new_lchan->ts->pchan_on_init == new_lchan->ts->pchan_is)? "" : "as",
(new_lchan->ts->pchan_on_init == new_lchan->ts->pchan_is)? ""
: gsm_pchan_id(new_lchan->ts->pchan_is),
new_lchan->vamos.is_secondary ? "shadow" : "",
new_lchan->nr - (new_lchan->vamos.is_secondary ? new_lchan->ts->max_primary_lchans : 0));
}
static bool lchan_type_compat_with_mode(enum gsm_chan_t type, const struct channel_mode_and_rate *ch_mode_rate)
{
enum gsm48_chan_mode chan_mode = ch_mode_rate->chan_mode;
enum channel_rate chan_rate = ch_mode_rate->chan_rate;
switch (gsm48_chan_mode_to_non_vamos(chan_mode)) {
case GSM48_CMODE_SIGN:
switch (type) {
case GSM_LCHAN_TCH_F: return chan_rate == CH_RATE_FULL;
case GSM_LCHAN_TCH_H: return chan_rate == CH_RATE_HALF;
case GSM_LCHAN_SDCCH: return chan_rate == CH_RATE_SDCCH;
default: return false;
}
case GSM48_CMODE_SPEECH_V1:
case GSM48_CMODE_SPEECH_AMR:
case GSM48_CMODE_DATA_3k6:
case GSM48_CMODE_DATA_6k0:
/* these services can all run on TCH/H, but we may have
* an explicit override by the 'chan_rate' argument */
switch (type) {
case GSM_LCHAN_TCH_F:
return chan_rate == CH_RATE_FULL;
case GSM_LCHAN_TCH_H:
return chan_rate == CH_RATE_HALF;
default:
return false;
}
case GSM48_CMODE_DATA_12k0:
case GSM48_CMODE_DATA_14k5:
case GSM48_CMODE_SPEECH_EFR:
/* these services all explicitly require a TCH/F */
return type == GSM_LCHAN_TCH_F;
default:
return false;
}
}
void assignment_fsm_init()
{
OSMO_ASSERT(osmo_fsm_register(&assignment_fsm) == 0);
}
static int check_requires_voice(bool *requires_voice, enum gsm48_chan_mode chan_mode)
{
*requires_voice = false;
switch (gsm48_chan_mode_to_non_vamos(chan_mode)) {
case GSM48_CMODE_SPEECH_V1:
case GSM48_CMODE_SPEECH_EFR:
case GSM48_CMODE_SPEECH_AMR:
*requires_voice = true;
break;
case GSM48_CMODE_SIGN:
*requires_voice = false;
break;
default:
return -EINVAL;
}
return 0;
}
/* Check if the incoming assignment requests requires a voice stream or not,
* we will look at the preferred and the alternate channel mode and also make
* sure that both are consistent. */
static int check_requires_voice_stream(struct gsm_subscriber_connection *conn)
{
bool requires_voice_pref = false, requires_voice_alt;
struct assignment_request *req = &conn->assignment.req;
struct osmo_fsm_inst *fi = conn->fi;
int i, rc;
/* When the assignment request indicates that there is an alternate
* rate available (e.g. "Full or Half rate channel, Half rate
* preferred..."), then both must be either voice or either signalling,
* a mismatch is not permitted */
for (i = 0; i < req->n_ch_mode_rate; i++) {
rc = check_requires_voice(&requires_voice_alt, req->ch_mode_rate_list[i].chan_mode);
if (rc < 0) {
assignment_fail(GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_NOT_SUPP,
"Channel mode not supported (prev level %d): %s", i,
gsm48_chan_mode_name(req->ch_mode_rate_list[i].chan_mode));
return -EINVAL;
}
if (i==0)
requires_voice_pref = requires_voice_alt;
else if (requires_voice_alt != requires_voice_pref) {
assignment_fail(GSM0808_CAUSE_REQ_CODEC_TYPE_OR_CONFIG_NOT_SUPP,
"Requested a mix of Signalling and non-Signalling channel modes: %s != %s",
gsm48_chan_mode_name(req->ch_mode_rate_list[0].chan_mode),
gsm48_chan_mode_name(req->ch_mode_rate_list[i].chan_mode));
return -EINVAL;
}
}
conn->assignment.requires_voice_stream = requires_voice_pref;
return 0;
}
/* Decide if we should re-use an existing lchan. For this we check if the
* current lchan is compatible with one of the requested modes. */
static bool reuse_existing_lchan(struct gsm_subscriber_connection *conn)
{
struct assignment_request *req = &conn->assignment.req;
int i;
if (!conn->lchan)
return false;
/* Check if the currently existing lchan is compatible with the
* preferred rate/codec. */
for (i = 0; i < req->n_ch_mode_rate; i++) {
if (!lchan_type_compat_with_mode(conn->lchan->type, &req->ch_mode_rate_list[i]))
continue;
conn->assignment.selected_ch_mode_rate = req->ch_mode_rate_list[i];
return true;
}
return false;
}
static int _reassignment_request(enum assign_for assign_for, struct gsm_lchan *lchan, struct gsm_lchan *to_lchan,
enum gsm_chan_t new_lchan_type, int tsc_set, int tsc)
{
struct gsm_subscriber_connection *conn = lchan->conn;
struct assignment_request req = {
.assign_for = assign_for,
.aoip = gscon_is_aoip(conn),
.msc_assigned_cic = conn->user_plane.msc_assigned_cic,
.msc_rtp_port = conn->user_plane.msc_assigned_rtp_port,
.n_ch_mode_rate = 1,
.ch_mode_rate_list = { lchan->current_ch_mode_rate },
.target_lchan = to_lchan,
.tsc_set = {
.present = (tsc_set >= 0),
.val = tsc_set,
},
.tsc = {
.present = (tsc >= 0),
.val = tsc,
},
};
if (to_lchan)
new_lchan_type = to_lchan->type;
req.ch_mode_rate_list[0].chan_rate = chan_t_to_chan_rate(new_lchan_type);
/* lchan activation will automatically convert chan_mode to a VAMOS equivalent if required.
* So rather always pass the plain non-VAMOS mode. */
req.ch_mode_rate_list[0].chan_mode = gsm48_chan_mode_to_non_vamos(lchan->current_ch_mode_rate.chan_mode);
OSMO_STRLCPY_ARRAY(req.msc_rtp_addr, conn->user_plane.msc_assigned_rtp_addr);
if (conn->user_plane.mgw_endpoint_ci_msc) {
req.use_osmux = osmo_mgcpc_ep_ci_get_crcx_info_to_osmux_cid(conn->user_plane.mgw_endpoint_ci_msc,
&req.osmux_cid);
}
return osmo_fsm_inst_dispatch(conn->fi, GSCON_EV_ASSIGNMENT_START, &req);
}
int reassignment_request_to_lchan(enum assign_for assign_for, struct gsm_lchan *lchan, struct gsm_lchan *to_lchan,
int tsc_set, int tsc)
{
return _reassignment_request(assign_for, lchan, to_lchan, 0, tsc_set, tsc);
}
int reassignment_request_to_chan_type(enum assign_for assign_for, struct gsm_lchan *lchan,
enum gsm_chan_t new_lchan_type)
{
return _reassignment_request(assign_for, lchan, NULL, new_lchan_type, -1, -1);
}
void assignment_fsm_start(struct gsm_subscriber_connection *conn, struct gsm_bts *bts,
struct assignment_request *req)
{
static const char *rate_names[] = {
[CH_RATE_SDCCH] = "SDCCH",
[CH_RATE_HALF] = "HR",
[CH_RATE_FULL] = "FR",
};
struct osmo_fsm_inst *fi;
int i;
OSMO_ASSERT(conn);
OSMO_ASSERT(conn->fi);
OSMO_ASSERT(!conn->assignment.fi);
OSMO_ASSERT(!conn->assignment.new_lchan);
fi = osmo_fsm_inst_alloc_child(&assignment_fsm, conn->fi, GSCON_EV_ASSIGNMENT_END);
OSMO_ASSERT(fi);
conn->assignment.fi = fi;
fi->priv = conn;
/* Create a copy of the request data and use that copy from now on. */
conn->assignment.req = *req;
req = &conn->assignment.req;
assignment_count(CTR_ASSIGNMENT_ATTEMPTED);
/* Check if we need a voice stream. If yes, set the appropriate struct
* members in conn */
if (check_requires_voice_stream(conn) < 0)
return;
if (!req->target_lchan && reuse_existing_lchan(conn)) {
/* The already existing lchan is suitable for this mode */
conn->assignment.new_lchan = NULL;
/* If the requested mode and the current TCH mode matches up, just send the
* assignment complete directly and be done with the assignment procedure. */
if (conn->lchan->current_ch_mode_rate.chan_mode == conn->assignment.selected_ch_mode_rate.chan_mode) {
LOG_ASSIGNMENT(conn, LOGL_DEBUG,
"Current lchan mode is compatible with requested chan_mode,"
" sending BSSMAP Assignment Complete directly."
" requested chan_mode=%s; current lchan is %s\n",
gsm48_chan_mode_name(conn->assignment.selected_ch_mode_rate.chan_mode),
gsm_lchan_name(conn->lchan));
if (req->assign_for == ASSIGN_FOR_BSSMAP_REQ)
send_assignment_complete(conn);
/* If something went wrong during send_assignment_complete(),
* the fi will be gone from error handling in there. */
if (conn->assignment.fi) {
assignment_count_result(CTR_ASSIGNMENT_COMPLETED);
osmo_fsm_inst_term(conn->assignment.fi, OSMO_FSM_TERM_REGULAR, 0);
}
return;
}
/* The requested mode does not match the current TCH mode but the lchan is
* compatible. We will initiate a mode modify procedure. */
LOG_ASSIGNMENT(conn, LOGL_DEBUG,
"Current lchan mode is not compatible with requested chan_mode,"
" so we will modify it. requested chan_mode=%s; current lchan is %s\n",
gsm48_chan_mode_name(conn->assignment.selected_ch_mode_rate.chan_mode),
gsm_lchan_name(conn->lchan));
assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_LCHAN_MODIFIED);
return;
}
if (req->target_lchan) {
bool matching_mode;
/* The caller already picked a target lchan to assign to. No need to try re-using the current lchan or
* picking a new one. */
if (!lchan_state_is(req->target_lchan, LCHAN_ST_UNUSED)) {
assignment_fail(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE,
"Assignment to lchan %s requested, but lchan is already in use (state=%s)\n",
gsm_lchan_name(req->target_lchan),
osmo_fsm_inst_state_name(req->target_lchan->fi));
return;
}
conn->assignment.new_lchan = req->target_lchan;
matching_mode = false;
for (i = 0; i < req->n_ch_mode_rate; i++) {
if (!lchan_type_compat_with_mode(conn->assignment.new_lchan->type, &req->ch_mode_rate_list[i]))
continue;
conn->assignment.selected_ch_mode_rate = req->ch_mode_rate_list[i];
matching_mode = true;
}
if (!matching_mode) {
OSMO_ASSERT(conn->lchan);
assignment_fail(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE,
"Assignment of lchan %s to %s type %s requested, but lchan is not compatible",
gsm_lchan_name(conn->lchan),
gsm_lchan_name(req->target_lchan),
gsm_lchant_name(conn->assignment.new_lchan->type));
return;
}
} else {
/* Try to allocate a new lchan in order of preference */
for (i = 0; i < req->n_ch_mode_rate; i++) {
conn->assignment.new_lchan = lchan_select_by_chan_mode(bts,
req->ch_mode_rate_list[i].chan_mode,
req->ch_mode_rate_list[i].chan_rate,
SELECT_FOR_ASSIGNMENT, conn->lchan);
if (!conn->assignment.new_lchan)
continue;
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "selected new lchan %s for mode[%d] = %s channel_rate=%d\n",
gsm_lchan_name(conn->assignment.new_lchan),
i, gsm48_chan_mode_name(req->ch_mode_rate_list[i].chan_mode),
req->ch_mode_rate_list[i].chan_rate);
conn->assignment.selected_ch_mode_rate = req->ch_mode_rate_list[i];
break;
}
}
/* Check whether the lchan allocation was successful or not and tear
* down the assignment in case of failure. */
if (!conn->assignment.new_lchan) {
assignment_count_result(CTR_ASSIGNMENT_NO_CHANNEL);
assignment_fail(GSM0808_CAUSE_NO_RADIO_RESOURCE_AVAILABLE,
"BSSMAP Assignment Command:"
" No lchan available for: pref=%s:%s / alt1=%s:%s / alt2=%s:%s",
gsm48_chan_mode_name(req->ch_mode_rate_list[0].chan_mode),
rate_names[req->ch_mode_rate_list[0].chan_rate],
req->n_ch_mode_rate > 1 ? gsm48_chan_mode_name(req->ch_mode_rate_list[1].chan_mode) : "",
req->n_ch_mode_rate > 1 ? rate_names[req->ch_mode_rate_list[1].chan_rate] : "",
req->n_ch_mode_rate > 2 ? gsm48_chan_mode_name(req->ch_mode_rate_list[2].chan_mode) : "",
req->n_ch_mode_rate > 2 ? rate_names[req->ch_mode_rate_list[2].chan_rate] : ""
);
return;
}
assignment_fsm_update_id(conn);
LOG_ASSIGNMENT(conn, LOGL_INFO, "Starting Assignment: chan_mode=%s, chan_type=%s,"
" aoip=%s MSC-rtp=%s:%u (osmux=%s)\n",
gsm48_chan_mode_name(conn->assignment.selected_ch_mode_rate.chan_mode),
rate_names[conn->assignment.selected_ch_mode_rate.chan_rate],
req->aoip ? "yes" : "no", req->msc_rtp_addr, req->msc_rtp_port,
req->use_osmux ? "yes" : "no");
assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE);
}
static void assignment_fsm_wait_lchan_active_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
struct assignment_request *req = &conn->assignment.req;
struct lchan_activate_info activ_info = {
.activ_for = ACTIVATE_FOR_ASSIGNMENT,
.for_conn = conn,
.ch_mode_rate = conn->assignment.selected_ch_mode_rate,
.encr = conn->lchan->encr,
.requires_voice_stream = conn->assignment.requires_voice_stream,
.msc_assigned_cic = req->msc_assigned_cic,
.re_use_mgw_endpoint_from_lchan = conn->lchan,
.ta = conn->lchan->last_ta,
.ta_known = true,
.tsc_set = req->tsc_set,
.tsc = req->tsc,
.vamos = conn->assignment.new_lchan->vamos.is_secondary,
};
lchan_activate(conn->assignment.new_lchan, &activ_info);
}
static void assignment_fsm_wait_lchan_active(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
switch (event) {
case ASSIGNMENT_EV_LCHAN_ACTIVE:
if (data != conn->assignment.new_lchan) {
LOG_ASSIGNMENT(conn, LOGL_ERROR, "Some unrelated lchan was activated, ignoring: %s\n",
gsm_lchan_name(data));
return;
}
/* The TS may have changed its pchan_is */
assignment_fsm_update_id(conn);
assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE);
return;
default:
OSMO_ASSERT(false);
}
}
static void assignment_fsm_wait_rr_ass_complete_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
int rc;
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
/* There may be situations where the SDCCH gets released while the TCH is still being activated. We will then
* receive ChanActivAck message from the BTS when the TCH is ready. Since the SDCCH is already released by
* then conn->lchan will be NULL in this case. */
if (!conn->lchan) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to send RR Assignment Command: conn without lchan");
return;
}
rc = gsm48_send_rr_ass_cmd(conn->lchan, conn->assignment.new_lchan,
conn->lchan->ms_power);
if (rc)
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE, "Unable to send RR Assignment Command");
}
static uint8_t get_cause(void *data)
{
if (data)
return *(uint8_t*)data;
return GSM0808_CAUSE_EQUIPMENT_FAILURE;
}
static void assignment_fsm_wait_rr_ass_complete(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
switch (event) {
case ASSIGNMENT_EV_RR_ASSIGNMENT_COMPLETE:
assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED);
return;
case ASSIGNMENT_EV_LCHAN_ESTABLISHED:
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "lchan established, still waiting for RR Assignment Complete\n");
/* The lchan is already done with all of its RTP setup. We will notice the lchan state
* being LCHAN_ST_ESTABLISHED in assignment_fsm_wait_lchan_established_onenter(). */
return;
case ASSIGNMENT_EV_RR_ASSIGNMENT_FAIL:
assignment_count_result(CTR_ASSIGNMENT_FAILED);
assignment_fail(get_cause(data), "Rx RR Assignment Failure");
return;
default:
OSMO_ASSERT(false);
}
}
static void assignment_fsm_post_lchan_established(struct osmo_fsm_inst *fi);
static void assignment_fsm_wait_lchan_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
/* Do we still need to wait for the RTP stream at all? */
if (lchan_state_is(conn->assignment.new_lchan, LCHAN_ST_ESTABLISHED)) {
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "lchan fully established, no need to wait\n");
assignment_fsm_post_lchan_established(fi);
}
}
static void assignment_fsm_wait_lchan_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
switch (event) {
case ASSIGNMENT_EV_LCHAN_ESTABLISHED:
assignment_fsm_post_lchan_established(fi);
return;
default:
OSMO_ASSERT(false);
}
}
static void assignment_fsm_post_lchan_established(struct osmo_fsm_inst *fi)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
if (conn->assignment.requires_voice_stream)
assignment_fsm_state_chg(ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC);
else
assignment_success(conn);
}
static void assignment_fsm_wait_mgw_endpoint_to_msc_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
OSMO_ASSERT(conn->assignment.requires_voice_stream);
LOG_ASSIGNMENT(conn, LOGL_DEBUG,
"Connecting MGW endpoint to the MSC's RTP port: %s:%u\n",
conn->assignment.req.msc_rtp_addr,
conn->assignment.req.msc_rtp_port);
/* Assignment can do a new channel activation, in which case new_lchan points at the new lchan.
* Or assignment can Channel Mode Modify the already used lchan, in which case new_lchan == NULL. */
if (!gscon_connect_mgw_to_msc(conn,
conn->assignment.new_lchan ? : conn->lchan,
conn->assignment.req.msc_rtp_addr,
conn->assignment.req.msc_rtp_port,
fi,
ASSIGNMENT_EV_MSC_MGW_OK,
ASSIGNMENT_EV_MSC_MGW_FAIL,
NULL,
&conn->assignment.created_ci_for_msc)) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to connect MGW endpoint to the MSC side");
return;
}
}
static void assignment_fsm_wait_mgw_endpoint_to_msc(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
switch (event) {
case ASSIGNMENT_EV_MSC_MGW_OK:
/* For AoIP, we created the MGW endpoint. Ensure it is really there, and log it. */
if (gscon_is_aoip(conn)) {
const struct mgcp_conn_peer *mgw_info;
mgw_info = osmo_mgcpc_ep_ci_get_rtp_info(conn->user_plane.mgw_endpoint_ci_msc);
if (!mgw_info) {
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to retrieve RTP port info allocated by MGW for"
" the MSC side.");
return;
}
LOG_ASSIGNMENT(conn, LOGL_DEBUG, "MGW's MSC side CI: %s:%u\n",
mgw_info->addr, mgw_info->port);
}
assignment_success(conn);
return;
case ASSIGNMENT_EV_MSC_MGW_FAIL:
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE,
"Unable to connect MGW endpoint to the MSC side");
return;
default:
OSMO_ASSERT(false);
}
}
static void assignment_fsm_wait_lchan_modified_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
struct gsm_lchan *lchan = conn->lchan;
struct assignment_request *req = &conn->assignment.req;
struct lchan_modify_info modif_info = {
.modify_for = MODIFY_FOR_ASSIGNMENT,
.ch_mode_rate = conn->assignment.selected_ch_mode_rate,
.requires_voice_stream = conn->assignment.requires_voice_stream,
.msc_assigned_cic = req->msc_assigned_cic,
/* keep previous training sequence code. TSC is always present, TSC Set may or may not be an explicit
* value. */
.tsc_set = {
.present = (lchan->tsc_set >= 0),
.val = lchan->tsc_set,
},
.tsc = {
.present = true,
.val = lchan->tsc,
},
};
lchan_mode_modify(lchan, &modif_info);
}
static void assignment_fsm_wait_lchan_modified(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
switch (event) {
case ASSIGNMENT_EV_LCHAN_MODIFIED:
assignment_fsm_post_lchan_established(fi);
return;
default:
OSMO_ASSERT(false);
}
}
#define S(x) (1 << (x))
static const struct osmo_fsm_state assignment_fsm_states[] = {
[ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE] = {
.name = "WAIT_LCHAN_ACTIVE",
.onenter = assignment_fsm_wait_lchan_active_onenter,
.action = assignment_fsm_wait_lchan_active,
.in_event_mask = 0
| S(ASSIGNMENT_EV_LCHAN_ACTIVE)
,
.out_state_mask = 0
| S(ASSIGNMENT_ST_WAIT_LCHAN_ACTIVE)
| S(ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE)
| S(ASSIGNMENT_ST_WAIT_LCHAN_MODIFIED)
,
},
[ASSIGNMENT_ST_WAIT_RR_ASS_COMPLETE] = {
.name = "WAIT_RR_ASS_COMPLETE",
.onenter = assignment_fsm_wait_rr_ass_complete_onenter,
.action = assignment_fsm_wait_rr_ass_complete,
.in_event_mask = 0
| S(ASSIGNMENT_EV_RR_ASSIGNMENT_COMPLETE)
| S(ASSIGNMENT_EV_RR_ASSIGNMENT_FAIL)
| S(ASSIGNMENT_EV_LCHAN_ESTABLISHED)
,
.out_state_mask = 0
| S(ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED)
,
},
[ASSIGNMENT_ST_WAIT_LCHAN_ESTABLISHED] = {
.name = "WAIT_LCHAN_ESTABLISHED",
.onenter = assignment_fsm_wait_lchan_established_onenter,
.action = assignment_fsm_wait_lchan_established,
.in_event_mask = 0
| S(ASSIGNMENT_EV_LCHAN_ESTABLISHED)
,
.out_state_mask = 0
| S(ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC)
,
},
[ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC] = {
.name = "WAIT_MGW_ENDPOINT_TO_MSC",
.onenter = assignment_fsm_wait_mgw_endpoint_to_msc_onenter,
.action = assignment_fsm_wait_mgw_endpoint_to_msc,
.in_event_mask = 0
| S(ASSIGNMENT_EV_MSC_MGW_OK)
| S(ASSIGNMENT_EV_MSC_MGW_FAIL)
,
},
[ASSIGNMENT_ST_WAIT_LCHAN_MODIFIED] = {
.name = "WAIT_LCHAN_MODIFIED",
.onenter = assignment_fsm_wait_lchan_modified_onenter,
.action = assignment_fsm_wait_lchan_modified,
.in_event_mask = 0
| S(ASSIGNMENT_EV_LCHAN_MODIFIED)
,
.out_state_mask = 0
| S(ASSIGNMENT_ST_WAIT_MGW_ENDPOINT_TO_MSC)
,
},
};
static const struct value_string assignment_fsm_event_names[] = {
OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_ACTIVE),
OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_ESTABLISHED),
OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_MODIFIED),
OSMO_VALUE_STRING(ASSIGNMENT_EV_LCHAN_ERROR),
OSMO_VALUE_STRING(ASSIGNMENT_EV_MSC_MGW_OK),
OSMO_VALUE_STRING(ASSIGNMENT_EV_MSC_MGW_FAIL),
OSMO_VALUE_STRING(ASSIGNMENT_EV_RR_ASSIGNMENT_COMPLETE),
OSMO_VALUE_STRING(ASSIGNMENT_EV_RR_ASSIGNMENT_FAIL),
OSMO_VALUE_STRING(ASSIGNMENT_EV_CONN_RELEASING),
{}
};
static void assignment_fsm_allstate_action(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
/* Assignment can do a new channel activation, in which case new_lchan points at the new lchan.
* Or assignment can Channel Mode Modify the already used lchan, in which case new_lchan == NULL. */
struct gsm_lchan *new_lchan = conn->assignment.new_lchan ? : conn->lchan;
switch (event) {
case ASSIGNMENT_EV_CONN_RELEASING:
assignment_count_result(CTR_ASSIGNMENT_STOPPED);
osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REQUEST, 0);
return;
case ASSIGNMENT_EV_LCHAN_ERROR:
if (data != new_lchan)
return;
assignment_fail(new_lchan->activate.gsm0808_error_cause,
"Failed to %s lchan %s",
conn->assignment.new_lchan ? "activate" : "modify",
gsm_lchan_name(new_lchan));
return;
default:
return;
}
}
static int assignment_fsm_timer_cb(struct osmo_fsm_inst *fi)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
assignment_count_result(CTR_ASSIGNMENT_TIMEOUT);
assignment_fail(GSM0808_CAUSE_EQUIPMENT_FAILURE, "Timeout");
return 0;
}
void assignment_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
{
struct gsm_subscriber_connection *conn = assignment_fi_conn(fi);
assignment_reset(conn);
conn->assignment.fi = NULL;
}
static struct osmo_fsm assignment_fsm = {
.name = "assignment",
.states = assignment_fsm_states,
.num_states = ARRAY_SIZE(assignment_fsm_states),
.log_subsys = DAS,
.event_names = assignment_fsm_event_names,
.allstate_action = assignment_fsm_allstate_action,
.allstate_event_mask = 0
| S(ASSIGNMENT_EV_CONN_RELEASING)
| S(ASSIGNMENT_EV_LCHAN_ERROR)
,
.timer_cb = assignment_fsm_timer_cb,
.cleanup = assignment_fsm_cleanup,
};