ASCI: Add function to reactivate channel

Reactivation will modify parameters on an already activated channel. On
a VGCS/VBS channel it can be used to prepare channel for assignment of
the mobile station to it.

During assignment the channel is reactivated. The timing advance of the
mobile station is given. The uplink is activated and is waiting for the
mobile station to establish, to complete the assignment.

For reference see patent EP 1 858 275 A1.

Change-Id: I77f413cf70c2f5f8e8f525686eee40548521c71b
Related: OS#4851

1 files changed, 36 insertions, 13 deletions

diff --git a/src/common/rsl.c b/src/common/rsl.c
index 9bdc7303..e0720223 100644
--- a/src/common/rsl.c
+++ b/src/common/rsl.c
@@ -1795,14 +1795,36 @@ static int rsl_rx_chan_activ(struct msgb *msg)
 	struct tlv_parsed tp;
 	const struct tlv_p_entry *ie;
 	uint8_t type, cause;
+	bool reactivation = false;
 	int rc;
 
-	if (lchan->state != LCHAN_S_NONE) {
+	if (rsl_tlv_parse(&tp, msgb_l3(msg), msgb_l3len(msg)) < 0) {
+		LOGPLCHAN(lchan, DRSL, LOGL_ERROR, "%s(): rsl_tlv_parse() failed\n", __func__);
+		return rsl_tx_chan_act_nack(lchan, RSL_ERR_PROTO);
+	}
+
+	/* 9.3.3 Activation Type */
+	if (!TLVP_PRESENT(&tp, RSL_IE_ACT_TYPE)) {
+		LOGPLCHAN(lchan, DRSL, LOGL_NOTICE, "missing Activation Type\n");
+		return rsl_tx_chan_act_nack(lchan, RSL_ERR_MAND_IE_ERROR);
+	}
+	type = *TLVP_VAL(&tp, RSL_IE_ACT_TYPE);
+	if ((type & RSL_ACT_TYPE_REACT)) {
+		type -= RSL_ACT_TYPE_REACT;
+		reactivation = true;
+	}
+
+	if (!reactivation && lchan->state != LCHAN_S_NONE) {
 		LOGPLCHAN(lchan, DRSL, LOGL_ERROR, "error: lchan is not available, but in state: %s.\n",
 			  gsm_lchans_name(lchan->state));
 		return rsl_tx_chan_act_nack(lchan, RSL_ERR_EQUIPMENT_FAIL);
 	}
 
+	if (reactivation && lchan->state == LCHAN_S_NONE) {
+		LOGPLCHAN(lchan, DRSL, LOGL_ERROR, "error: reactivation on inactive lchan.\n");
+		return rsl_tx_chan_act_nack(lchan, RSL_ERR_EQUIPMENT_FAIL);
+	}
+
 	/* We need to pick the real TS here to check NM state: */
 	primary_ts = ts->vamos.is_shadow ? ts->vamos.peer : ts;
 	if (primary_ts->mo.nm_state.operational != NM_OPSTATE_ENABLED ||
@@ -1845,18 +1867,6 @@ static int rsl_rx_chan_activ(struct msgb *msg)
 		.current = 0,
 	};
 
-	if (rsl_tlv_parse(&tp, msgb_l3(msg), msgb_l3len(msg)) < 0) {
-		LOGPLCHAN(lchan, DRSL, LOGL_ERROR, "%s(): rsl_tlv_parse() failed\n", __func__);
-		return rsl_tx_chan_act_nack(lchan, RSL_ERR_PROTO);
-	}
-
-	/* 9.3.3 Activation Type */
-	if (!TLVP_PRESENT(&tp, RSL_IE_ACT_TYPE)) {
-		LOGPLCHAN(lchan, DRSL, LOGL_NOTICE, "missing Activation Type\n");
-		return rsl_tx_chan_act_nack(lchan, RSL_ERR_MAND_IE_ERROR);
-	}
-	type = *TLVP_VAL(&tp, RSL_IE_ACT_TYPE);
-
 	/* 9.3.6 Channel Mode */
 	if (type != RSL_ACT_OSMO_PDCH) {
 		if (rsl_handle_chan_mod_ie(lchan, &tp, &cause) != 0)
@@ -2103,6 +2113,19 @@ static int rsl_rx_chan_activ(struct msgb *msg)
 	else
 		lchan->top_acch_active = false;
 
+	/* set ASCI channel into right state */
+	if (reactivation && rsl_chan_rt_is_asci(lchan->rsl_chan_rt))
+		vgcs_lchan_react(lchan);
+
+	/* on reactivation, the channel is already activated */
+	if (reactivation) {
+		rc = rsl_tx_chan_act_ack(lchan);
+		if (rc < 0)
+			LOGP(DRSL, LOGL_ERROR, "%s Cannot send act ack: %d\n",
+			     gsm_ts_and_pchan_name(ts), rc);
+		return 0;
+	}
+
 	/* actually activate the channel in the BTS */
 	rc = l1sap_chan_act(lchan->ts->trx, dch->chan_nr);
 	if (rc < 0)