propagate RSL error cause codes to RR Channel Release cause

In various places that receive an error cause from RSL and place it in
lchan.release.rsl_error_cause, translate it to an RR cause and place that in
the recently added lchan.release.rr_cause. Hence the RR Channel Release message
now reflects more specific error causes when the reason for the error was
received in an RSL message's cause value.

Change-Id: I46eb12c91a8c08162b43dd22c7ba825ef3bbc6ac

4 files changed, 34 insertions, 0 deletions

diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h
index 43d7040fc..c35798192 100644
--- a/include/osmocom/bsc/gsm_data.h
+++ b/include/osmocom/bsc/gsm_data.h
@@ -1898,5 +1898,6 @@ int bts_count_free_ts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan);
 bool trx_has_valid_pchan_config(const struct gsm_bts_trx *trx);
 
 enum gsm48_rr_cause bsc_gsm48_rr_cause_from_gsm0808_cause(enum gsm0808_cause c);
+enum gsm48_rr_cause bsc_gsm48_rr_cause_from_rsl_cause(uint8_t c);
 
 #endif /* _GSM_DATA_H */
diff --git a/src/osmo-bsc/bsc_subscr_conn_fsm.c b/src/osmo-bsc/bsc_subscr_conn_fsm.c
index 0ed6715be..72f24749f 100644
--- a/src/osmo-bsc/bsc_subscr_conn_fsm.c
+++ b/src/osmo-bsc/bsc_subscr_conn_fsm.c
@@ -783,6 +783,8 @@ static void gscon_fsm_allstate(struct osmo_fsm_inst *fi, uint32_t event, void *d
 		if (conn->lchan) {
 			conn->lchan->release.in_error = true;
 			conn->lchan->release.rsl_error_cause = data ? *(uint8_t*)data : RSL_ERR_IE_ERROR;
+			conn->lchan->release.rr_cause =
+				bsc_gsm48_rr_cause_from_rsl_cause(conn->lchan->release.rsl_error_cause);
 		}
 		gscon_bssmap_clear(conn, GSM0808_CAUSE_RADIO_INTERFACE_FAILURE);
 		break;
diff --git a/src/osmo-bsc/gsm_data.c b/src/osmo-bsc/gsm_data.c
index 860e236fe..a4f6b7f36 100644
--- a/src/osmo-bsc/gsm_data.c
+++ b/src/osmo-bsc/gsm_data.c
@@ -1867,3 +1867,29 @@ enum gsm48_rr_cause bsc_gsm48_rr_cause_from_gsm0808_cause(enum gsm0808_cause c)
 		return GSM48_RR_CAUSE_ABNORMAL_UNSPEC;
 	}
 }
+
+/* Map RSL_ERR_* cause codes to gsm48_rr_cause codes.
+ * The mappings were chosen by naive guessing without a proper specification available. */
+enum gsm48_rr_cause bsc_gsm48_rr_cause_from_rsl_cause(uint8_t c)
+{
+	switch (c) {
+	case RSL_ERR_NORMAL_UNSPEC:
+		return GSM48_RR_CAUSE_NORMAL;
+	case RSL_ERR_MAND_IE_ERROR:
+		return GSM48_RR_CAUSE_INVALID_MAND_INF;
+	case RSL_ERR_OPT_IE_ERROR:
+		return GSM48_RR_CAUSE_COND_IE_ERROR;
+	case RSL_ERR_INVALID_MESSAGE:
+	case RSL_ERR_MSG_DISCR:
+	case RSL_ERR_MSG_TYPE:
+	case RSL_ERR_MSG_SEQ:
+	case RSL_ERR_IE_ERROR:
+	case RSL_ERR_IE_NONEXIST:
+	case RSL_ERR_IE_LENGTH:
+	case RSL_ERR_IE_CONTENT:
+	case RSL_ERR_PROTO:
+		return GSM48_RR_CAUSE_PROT_ERROR_UNSPC;
+	default:
+		return GSM48_RR_CAUSE_ABNORMAL_UNSPEC;
+	}
+}
diff --git a/src/osmo-bsc/lchan_fsm.c b/src/osmo-bsc/lchan_fsm.c
index dfb8a053d..bcf7c4b06 100644
--- a/src/osmo-bsc/lchan_fsm.c
+++ b/src/osmo-bsc/lchan_fsm.c
@@ -681,6 +681,7 @@ static void lchan_fsm_wait_activ_ack(struct osmo_fsm_inst *fi, uint32_t event, v
 		if (data) {
 			uint32_t next_state;
 			lchan->release.rsl_error_cause = *(uint8_t*)data;
+			lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
 			lchan->release.in_error = true;
 			if (lchan->release.rsl_error_cause != RSL_ERR_RCH_ALR_ACTV_ALLOC)
 				next_state = LCHAN_ST_BORKEN;
@@ -693,6 +694,7 @@ static void lchan_fsm_wait_activ_ack(struct osmo_fsm_inst *fi, uint32_t event, v
 				      rsl_err_name(lchan->release.rsl_error_cause), lchan->release.rsl_error_cause);
 		} else {
 			lchan->release.rsl_error_cause = RSL_ERR_IE_NONEXIST;
+			lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
 			lchan->release.in_error = true;
 			lchan_fail_to(LCHAN_ST_BORKEN, "Chan Activ NACK without cause IE");
 		}
@@ -1109,6 +1111,7 @@ static void lchan_fsm_borken(struct osmo_fsm_inst *fi, uint32_t event, void *dat
 		osmo_stat_item_dec(lchan->ts->trx->bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
 		lchan->release.in_error = true;
 		lchan->release.rsl_error_cause = RSL_ERR_INTERWORKING;
+		lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
 		lchan_fsm_state_chg(LCHAN_ST_WAIT_RF_RELEASE_ACK);
 		return;
 
@@ -1125,6 +1128,7 @@ static void lchan_fsm_borken(struct osmo_fsm_inst *fi, uint32_t event, void *dat
 		osmo_stat_item_dec(lchan->ts->trx->bts->bts_statg->items[BTS_STAT_LCHAN_BORKEN], 1);
 		lchan->release.in_error = true;
 		lchan->release.rsl_error_cause = RSL_ERR_INTERWORKING;
+		lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
 		lchan_fsm_state_chg(LCHAN_ST_WAIT_AFTER_ERROR);
 		/* TODO: we used to do this only for sysmobts:
 			int do_free = is_sysmobts_v2(ts->trx->bts);
@@ -1353,6 +1357,7 @@ int lchan_fsm_timer_cb(struct osmo_fsm_inst *fi)
 	default:
 		lchan->release.in_error = true;
 		lchan->release.rsl_error_cause = RSL_ERR_INTERWORKING;
+		lchan->release.rr_cause = bsc_gsm48_rr_cause_from_rsl_cause(lchan->release.rsl_error_cause);
 		lchan_fail("Timeout");
 		return 0;
 	}