diff --git a/src/libvlr/vlr_sgs.c b/src/libvlr/vlr_sgs.c index 861489227..538c9f28f 100644 --- a/src/libvlr/vlr_sgs.c +++ b/src/libvlr/vlr_sgs.c @@ -131,10 +131,17 @@ void vlr_sgs_imsi_detach(struct vlr_instance *vlr, const char *imsi, enum sgsap_ { struct vlr_subscr *vsub; enum sgs_ue_fsm_event evt; + vsub = vlr_subscr_find_by_imsi(vlr, imsi); if (!vsub) return; + /* See also: 3GPP TS 29.118, 5.6.3 Procedures in the VLR: In case of + * an implicit detach, we are supposed to check if the state of the + * SGs-association, and only when it is not SGs-NULL, we may proceed. */ + if (vsub->sgs_fsm->state == SGS_UE_ST_NULL && type == SGSAP_ID_NONEPS_T_IMPLICIT_UE_EPS_NONEPS) + return; + switch (type) { case SGSAP_ID_NONEPS_T_EXPLICIT_UE_NONEPS: evt = SGS_UE_E_RX_DETACH_IND_FROM_UE; @@ -153,6 +160,11 @@ void vlr_sgs_imsi_detach(struct vlr_instance *vlr, const char *imsi, enum sgsap_ osmo_fsm_inst_dispatch(vsub->sgs_fsm, evt, NULL); vlr_subscr_put(vsub); + + /* Detaching from non EPS services essentially means that the + * subscriber is detached from 2G. In any case the VLR will + * get rid of the subscriber. */ + vlr_subscr_expire(vsub); } /*! Perform an SGs EPS detach.