1 files changed, 69 insertions, 0 deletions

diff --git a/src/common/l1sap.c b/src/common/l1sap.c
index f4f32466..dfc81a47 100644
--- a/src/common/l1sap.c
+++ b/src/common/l1sap.c
@@ -119,6 +119,72 @@ static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx,
 	return 1;
 }
 
+static int check_acc_delay(struct ph_rach_ind_param *rach_ind,
+	struct gsm_bts_role_bts *btsb, uint8_t *acc_delay)
+{
+	*acc_delay = rach_ind->acc_delay;
+	return *acc_delay <= btsb->max_ta;
+}
+
+/* special case where handover RACH is detected */
+static int l1sap_handover_rach(struct gsm_bts_trx *trx,
+	struct osmo_phsap_prim *l1sap, struct ph_rach_ind_param *rach_ind)
+{
+	struct gsm_lchan *lchan;
+	uint8_t chan_nr;
+	uint8_t tn, ss;
+
+	chan_nr = rach_ind->chan_nr;
+	tn = L1SAP_CHAN2TS(chan_nr);
+	ss = l1sap_chan2ss(chan_nr);
+	lchan = &trx->ts[tn].lchan[ss];
+
+	handover_rach(lchan, rach_ind->ra, rach_ind->acc_delay);
+
+	/* must return 0, so in case of msg at l1sap, it will be freed */
+	return 0;
+}
+
+/* RACH received from bts model */
+static int l1sap_ph_rach_ind(struct gsm_bts_trx *trx,
+	 struct osmo_phsap_prim *l1sap, struct ph_rach_ind_param *rach_ind)
+{
+	struct gsm_bts *bts = trx->bts;
+	struct gsm_bts_role_bts *btsb = bts->role;
+	struct lapdm_channel *lc;
+	uint8_t acc_delay;
+
+	DEBUGP(DL1P, "Rx PH-RA.ind");
+
+	lc = &trx->ts[0].lchan[4].lapdm_ch;
+
+	/* check for under/overflow / sign */
+	if (!check_acc_delay(rach_ind, btsb, &acc_delay)) {
+		LOGP(DL1C, LOGL_INFO, "ignoring RACH request %u > max_ta(%u)\n",
+		     acc_delay, btsb->max_ta);
+		return 0;
+	}
+
+	/* check for handover rach */
+	if (trx != bts->c0 && rach_ind->chan_nr != 0x88)
+		return l1sap_handover_rach(trx, l1sap, rach_ind);
+
+	/* check for packet access */
+	if (trx == bts->c0
+	 && L1SAP_IS_PACKET_RACH(rach_ind->ra)) {
+		LOGP(DL1P, LOGL_INFO, "RACH for packet access\n");
+		pcu_tx_rach_ind(bts, rach_ind->acc_delay << 2,
+			rach_ind->ra, rach_ind->fn);
+		return 0;
+	}
+
+	LOGP(DL1P, LOGL_INFO, "RACH for RR access (toa=%d, ra=%d)\n",
+		rach_ind->acc_delay, rach_ind->ra);
+	lapdm_phsap_up(&l1sap->oph, &lc->lapdm_dcch);
+
+	return 0;
+}
+
 /* any L1 prim received from bts model */
 int l1sap_up(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap)
 {
@@ -129,6 +195,9 @@ int l1sap_up(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap)
 	case OSMO_PRIM(PRIM_PH_RTS, PRIM_OP_INDICATION):
 		rc = l1sap_ph_rts_ind(trx, l1sap, &l1sap->u.data);
 		break;
+	case OSMO_PRIM(PRIM_PH_RACH, PRIM_OP_INDICATION):
+		rc = l1sap_ph_rach_ind(trx, l1sap, &l1sap->u.rach_ind);
+		break;
 	default:
 		LOGP(DL1P, LOGL_NOTICE, "unknown prim %d op %d\n",
 			l1sap->oph.primitive, l1sap->oph.operation);