sgs_iface: detect and react to VLR/HLR failure

The HLR (which is connected via the GSUP interface) may fail and
disconnect. On the next location update the VLR will try to talk to the
HLR and fail. This failure event is not communicated towards the SGs
related code and the SGs-association will remain in the LA-PRESENT state
forever. Lets add code to report the problem to the SGs code and trigger
a RESET an the SGs interface.

- Add a flag to report an HLR problem back to the SGs code
- Fix the FSM that controls the reset
- Make sure the all SGs associations are reset when the failure occurs.

Change-Id: Icc7df92879728bc98c85fc1d5d8b4c6246501b12
Related: OS#3859
changes/59/13559/4
Philipp Maier 4 years ago committed by Harald Welte
parent b683dcfe6b
commit 483cea889c
  1. 1
      include/osmocom/msc/vlr_sgs.h
  2. 16
      src/libmsc/sgs_iface.c
  3. 4
      src/libvlr/vlr.c
  4. 49
      src/libvlr/vlr_sgs_fsm.c

@ -75,6 +75,7 @@ static inline const char *vlr_sgs_state_counter_name(enum vlr_sgs_state_ctr Ns)
/* This callback function is called when an SGs location update is complete */
struct sgs_lu_response {
bool accepted;
bool error;
struct vlr_subscr *vsub;
};
typedef void (*vlr_sgs_lu_response_cb_t) (struct sgs_lu_response *response);

@ -376,15 +376,26 @@ static void sgs_tx_loc_upd_resp_cb(struct sgs_lu_response *response)
unsigned int new_id_len = 0;
uint8_t resp_msg_type;
/* Determine message type that is sent next (needed for logging) */
if (response->accepted)
resp_msg_type = SGSAP_MSGT_LOC_UPD_ACK;
else if (response->error)
resp_msg_type = SGSAP_MSGT_RESET_IND;
else
resp_msg_type = SGSAP_MSGT_LOC_UPD_REJ;
/* Determine MME */
mme = sgs_mme_ctx_by_vsub(vsub, resp_msg_type);
if (!mme)
return;
/* Handle error (HLR failure) */
if (response->error) {
osmo_fsm_inst_dispatch(mme->fi, SGS_VLRR_E_START_RESET, NULL);
return;
}
/* Handle LU accept/reject */
if (response->accepted) {
if (vsub->tmsi_new != GSM_RESERVED_TMSI) {
new_id_len = gsm48_generate_mid_from_tmsi(new_id, vsub->tmsi_new);
@ -1120,6 +1131,10 @@ static void sgs_vlr_reset_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event,
reset_params.vlr_name_present = true;
reset_ind = gsm29118_create_reset_ind(&reset_params);
sgs_tx(sgc, reset_ind);
/* Perform a reset of the SGS FSM of all subscribers that are present in the VLR */
vlr_sgs_reset(gsm_network->vlr);
osmo_fsm_inst_state_chg(fi, SGS_VLRR_ST_WAIT_ACK, sgs->cfg.timer[SGS_STATE_TS11], 11);
break;
default:
@ -1187,6 +1202,7 @@ static const struct osmo_fsm_state sgs_vlr_reset_fsm_states[] = {
static struct osmo_fsm sgs_vlr_reset_fsm = {
.name = "SGs-VLR-RESET",
.states = sgs_vlr_reset_fsm_states,
.num_states = ARRAY_SIZE(sgs_vlr_reset_fsm_states),
.allstate_event_mask = S(SGS_VLRR_E_START_RESET),
.allstate_action = sgs_vlr_reset_fsm_allstate,
.timer_cb = sgs_vlr_reset_fsm_timer_cb,

@ -854,7 +854,7 @@ static int vlr_subscr_handle_isd_req(struct vlr_subscr *vsub,
static int vlr_subscr_handle_lu_res(struct vlr_subscr *vsub,
const struct osmo_gsup_message *gsup)
{
struct sgs_lu_response sgs_lu_response;
struct sgs_lu_response sgs_lu_response = {0};
bool sgs_lu_in_progress = false;
if (vsub->sgs_fsm->state == SGS_UE_ST_LA_UPD_PRES)
@ -885,7 +885,7 @@ static int vlr_subscr_handle_lu_res(struct vlr_subscr *vsub,
static int vlr_subscr_handle_lu_err(struct vlr_subscr *vsub,
const struct osmo_gsup_message *gsup)
{
struct sgs_lu_response sgs_lu_response;
struct sgs_lu_response sgs_lu_response = {0};
bool sgs_lu_in_progress = false;
if (vsub->sgs_fsm->state == SGS_UE_ST_LA_UPD_PRES)

@ -48,24 +48,6 @@ static const struct value_string sgs_ue_fsm_event_names[] = {
{0, NULL}
};
/* Initiate location update and change to SGS_UE_ST_LA_UPD_PRES state */
static void perform_lu(struct osmo_fsm_inst *fi)
{
struct vlr_subscr *vsub = fi->priv;
int rc;
osmo_fsm_inst_state_chg(fi, SGS_UE_ST_LA_UPD_PRES, 0, 0);
vsub->ms_not_reachable_flag = false;
/* Note: At the moment we allocate a new TMSI on each LU. */
rc = vlr_subscr_alloc_tmsi(vsub);
if (rc != 0)
LOGPFSML(fi, LOGL_ERROR, "(sub %s) VLR LU tmsi allocation failed\n", vlr_subscr_name(vsub));
rc = vlr_subscr_req_lu(vsub);
if (rc != 0)
LOGPFSML(fi, LOGL_ERROR, "(sub %s) HLR LU request failed\n", vlr_subscr_name(vsub));
}
/* Send the SGs Association to NULL state immediately */
static void to_null(struct osmo_fsm_inst *fi)
{
@ -86,6 +68,37 @@ static void to_null(struct osmo_fsm_inst *fi)
osmo_timer_del(&vsub->sgs.Ts5);
}
/* Initiate location update and change to SGS_UE_ST_LA_UPD_PRES state */
static void perform_lu(struct osmo_fsm_inst *fi)
{
struct vlr_subscr *vsub = fi->priv;
struct sgs_lu_response sgs_lu_response = {0};
int rc;
/* Note: At the moment we allocate a new TMSI on each LU. */
rc = vlr_subscr_alloc_tmsi(vsub);
if (rc != 0) {
LOGPFSML(fi, LOGL_ERROR, "(sub %s) VLR LU tmsi allocation failed\n", vlr_subscr_name(vsub));
goto error;
}
rc = vlr_subscr_req_lu(vsub);
if (rc != 0) {
LOGPFSML(fi, LOGL_ERROR, "(sub %s) HLR LU request failed\n", vlr_subscr_name(vsub));
goto error;
}
osmo_fsm_inst_state_chg(fi, SGS_UE_ST_LA_UPD_PRES, 0, 0);
vsub->ms_not_reachable_flag = false;
return;
error:
to_null(fi);
sgs_lu_response.error = true;
sgs_lu_response.vsub = vsub;
vsub->sgs.response_cb(&sgs_lu_response);
}
/* Respawn a pending paging (Timer is reset and a new paging request is sent) */
static void respawn_paging(struct vlr_subscr *vsub)
{

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