gbproxy: Forward MS_REGISTR_ENQ/_RESP correctly

We need to save the BSS NSE <-> IMSI mapping to correctly route the
answer.

Related: OS#4472
Change-Id: I1908bbe8db11271dbd3f45b0d9f1bc0bfe48f239
This commit is contained in:
Daniel Willmann 2021-07-06 14:02:41 +02:00
parent 361d0b566a
commit f024eeb9e7
2 changed files with 40 additions and 0 deletions

View File

@ -194,6 +194,7 @@ struct gbproxy_sgsn {
enum cache_usage_type {
CACHE_USAGE_PAGING,
CACHE_USAGE_MS_REG_ENQ,
};
/* TLLI cache */

View File

@ -1114,6 +1114,26 @@ static int gbprox_rx_sig_from_bss(struct gbproxy_nse *nse, struct msgb *msg, uin
rc = gbprox_relay2nse(msg, nse, 0);
break;
}
case BSSGP_PDUT_MS_REGISTR_ENQ:
{
struct gbproxy_sgsn *sgsn;
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp[0], BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp[0], BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
sgsn = gbproxy_select_sgsn(nse->cfg, NULL);
if (!sgsn) {
LOGP(DGPRS, LOGL_ERROR, "Could not find any SGSN, dropping message!\n");
rc = -EINVAL;
break;
}
gbproxy_imsi_cache_update(nse, mi.imsi, CACHE_USAGE_MS_REG_ENQ);
rc = gbprox_relay2nse(msg, sgsn->nse, 0);
break;
}
default:
LOGPNSE(nse, LOGL_ERROR, "Rx %s: Implementation missing\n", pdut_name);
break;
@ -1444,6 +1464,25 @@ static int gbprox_rx_sig_from_sgsn(struct gbproxy_nse *nse, struct msgb *msg, ui
case BSSGP_PDUT_RAN_INFO_APP_ERROR:
rc = gbprox_rx_rim_from_sgsn(tp, nse, msg, log_pfx, pdut_name);
break;
case BSSGP_PDUT_MS_REGISTR_ENQ_RESP:
{
struct gbproxy_nse *nse_peer;
struct osmo_mobile_identity mi;
const uint8_t *mi_data = TLVP_VAL(&tp[0], BSSGP_IE_IMSI);
uint8_t mi_len = TLVP_LEN(&tp[0], BSSGP_IE_IMSI);
osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
nse_peer = gbproxy_nse_by_imsi(cfg, mi.imsi, CACHE_USAGE_MS_REG_ENQ);
if (!nse_peer) {
LOGPNSE(nse, LOGL_ERROR, "Rx %s: Cannot find NSE\n", pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_INV_MAND_INF, NULL, msg);
} else if (nse_peer->sgsn_facing) {
LOGPNSE(nse, LOGL_ERROR, "Forwarding %s failed: IMSI cache contains SGSN NSE", pdut_name);
return tx_status(nse, ns_bvci, BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
}
gbproxy_imsi_cache_remove(cfg, mi.imsi, CACHE_USAGE_MS_REG_ENQ);
gbprox_relay2nse(msg, nse_peer, ns_bvci);
break;
}
default:
LOGPNSE(nse, LOGL_NOTICE, "Rx %s: Not supported\n", pdut_name);
rate_ctr_inc(rate_ctr_group_get_ctr(cfg->ctrg, GBPROX_GLOB_CTR_PROTO_ERR_SGSN));