TBF: add N3101 counter

Properly reset the counter when receiving valid RLCMAC block and update
it when no data is received as per 3GPP TS 44.060 §8.1.1.1

Change-Id: I2f79c6153dc4073c9d293b2824979e6381576682
Fixes: OS#2407

3 files changed, 30 insertions, 0 deletions

diff --git a/src/bts.cpp b/src/bts.cpp
index 9e8a6c83..867658ee 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -996,6 +996,10 @@ void gprs_rlcmac_pdch::rcv_control_ack(Packet_Control_Acknowledgement_t *packet,
 			     ms->dl_tbf() ? ms->dl_tbf()->state_name() : "None");
 		return;
 	}
+
+	/* Reset N3101 counter: */
+	tbf->m_n3101 = 0;
+
 	tbf->update_ms(tlli, GPRS_RLCMAC_UL_TBF);
 
 	LOGPTBF(tbf, LOGL_DEBUG, "RX: [PCU <- BTS] Packet Control Ack\n");
@@ -1185,6 +1189,9 @@ void gprs_rlcmac_pdch::rcv_control_dl_ack_nack(Packet_Downlink_Ack_Nack_t *ack_n
 		return;
 	}
 
+	/* Reset N3101 counter: */
+	tbf->m_n3101 = 0;
+
 	if (tbf->handle_ack_nack())
 		LOGPTBF(tbf, LOGL_NOTICE, "Recovered downlink ack\n");
 
@@ -1249,6 +1256,9 @@ void gprs_rlcmac_pdch::rcv_control_egprs_dl_ack_nack(EGPRS_PD_AckNack_t *ack_nac
 		return;
 	}
 
+	/* Reset N3101 counter: */
+	tbf->m_n3101 = 0;
+
 	if (tbf->handle_ack_nack())
 		LOGPTBF(tbf, LOGL_NOTICE, "Recovered EGPRS downlink ack\n");
 
@@ -1417,6 +1427,9 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 		}
 		LOGPTBFDL(dl_tbf, LOGL_ERROR,
 			"RX: [PCU <- BTS] FIXME: Packet resource request\n");
+
+		/* Reset N3101 counter: */
+		dl_tbf->m_n3101 = 0;
 	} else {
 		struct gprs_rlcmac_ul_tbf *ul_tbf;
 		int8_t tfi = request->ID.u.Global_TFI.u.UPLINK_TFI;
@@ -1427,6 +1440,9 @@ void gprs_rlcmac_pdch::rcv_resource_request(Packet_Resource_Request_t *request,
 		}
 		LOGPTBFUL(ul_tbf, LOGL_ERROR,
 			"RX: [PCU <- BTS] %s FIXME: Packet resource request\n");
+
+		/* Reset N3101 counter: */
+		ul_tbf->m_n3101 = 0;
 	}
 }
 
@@ -1579,6 +1595,9 @@ int gprs_rlcmac_pdch::rcv_data_block(uint8_t *data, uint8_t data_len, uint32_t f
 		return 0;
 	}
 
+	/* Reset N3101 counter: */
+	tbf->m_n3101 = 0;
+
 	return tbf->rcv_data_block_acknowledged(&rlc_dec, data, meas);
 }
 
diff --git a/src/tbf.cpp b/src/tbf.cpp
index a5eedd93..dc0777f6 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -177,6 +177,7 @@ gprs_rlcmac_tbf::gprs_rlcmac_tbf(BTS *bts_, gprs_rlcmac_tbf_direction dir) :
 	was_releasing(0),
 	upgrade_to_multislot(0),
 	bts(bts_),
+	m_n3101(0),
 	m_tfi(0),
 	m_created_ts(0),
 	m_ctrs(NULL),
@@ -740,6 +741,14 @@ void gprs_rlcmac_tbf::poll_timeout()
 
 	poll_state = GPRS_RLCMAC_POLL_NONE;
 
+	m_n3101++;
+	if (m_n3101 == bts->bts_data()->n3101) {
+		LOGP(DRLCMAC, LOGL_NOTICE, " N3101 exceeded MAX (%u)\n", bts->bts_data()->n3101);
+		set_state(GPRS_RLCMAC_RELEASING);
+		t_start(T3169, bts->bts_data()->t3169, 0, "MAX N3101 reached", false);
+		return;
+	}
+
 	if (ul_tbf && ul_tbf->handle_ctrl_ack()) {
 		if (!ul_tbf->ctrl_ack_to_toggle()) {
 			LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET CONTROL ACK for PACKET UPLINK ACK\n");
diff --git a/src/tbf.h b/src/tbf.h
index 06c9f60c..4489695e 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -296,6 +296,8 @@ struct gprs_rlcmac_tbf {
 	/* store the BTS this TBF belongs to */
 	BTS *bts;
 
+	uint8_t m_n3101; /* N3101 counter */
+
 	/*
 	 * private fields. We can't make it private as it is breaking the
 	 * llist macros.