vlr_sgs: Balance use_count incremented in vlr_sgs_loc_update

During a recent pcap trace, it was spotted that subscriber coming from
SGs had a use count with 16 "SGs" items, and later it incremented to 17.
Further investigation shows that the related use_count item was never
decreased, meaning every time an SGs-LU was sent by the MME, the item
was incremented further and never decremented.

Let's rename the item to be referenced while in LU, and then decremented
when LU is done. At that time, either the LU was accepted and the
subscriber object has a use_count item "attached", or it was rejected
and we already sent the reject messages, so we are fine deleting it if
needed.

Related: SYS#5337
Change-Id: I22c386f02ffa57428f700b003cc2cf23133598d0
This commit is contained in:
Pau Espin 2021-08-24 14:56:03 +02:00
parent 25b3ffb5f4
commit 017ba1fa30
2 changed files with 7 additions and 2 deletions

View File

@ -26,7 +26,7 @@ enum vlr_lu_type;
struct vlr_subscr;
struct vlr_instance;
#define VSUB_USE_SGS "SGs"
#define VSUB_USE_SGS_LU "SGs-lu"
#define VSUB_USE_SGS_PAGING_REQ "SGs-paging-req"
/* See also 3GPP TS 29.118, chapter 4.2.2 States at the VLR */

View File

@ -83,7 +83,7 @@ int vlr_sgs_loc_update(struct vlr_instance *vlr, struct vlr_sgs_cfg *cfg,
OSMO_ASSERT(cfg);
OSMO_ASSERT(imsi);
vsub = vlr_subscr_find_or_create_by_imsi(vlr, imsi, VSUB_USE_SGS, NULL);
vsub = vlr_subscr_find_or_create_by_imsi(vlr, imsi, VSUB_USE_SGS_LU, NULL);
if (!vsub) {
LOGP(DSGS, LOGL_ERROR, "VLR subscriber allocation failed\n");
return -EINVAL;
@ -119,6 +119,9 @@ void vlr_sgs_loc_update_acc_sent(struct vlr_subscr *vsub)
{
osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_TX_LU_ACCEPT, NULL);
/* Balance vlr_subscr_find_or_create_by_imsi() in vlr_sgs_loc_update() */
vlr_subscr_put(vsub, VSUB_USE_SGS_LU);
/* FIXME: At this point we need to check the status of Ts5 and if
* it is still running this means the LU has interrupted the paging,
* and we need to start paging again. 3GPP TS 29.118,
@ -130,6 +133,8 @@ void vlr_sgs_loc_update_acc_sent(struct vlr_subscr *vsub)
void vlr_sgs_loc_update_rej_sent(struct vlr_subscr *vsub)
{
osmo_fsm_inst_dispatch(vsub->sgs_fsm, SGS_UE_E_TX_LU_REJECT, NULL);
/* Balance vlr_subscr_find_or_create_by_imsi() in vlr_sgs_loc_update() */
vlr_subscr_put(vsub, VSUB_USE_SGS_LU);
}
/*! Perform an SGs IMSI detach.