Added paging PS support by Ivan Kluchnikov

Original code: c7e7f6868b
(The code was committed earlier, but got lost somehow.)

I added IMSI, so the paging request is sent in correct paging group.
Also I excluded rest octets from pseudo length.

It is tested and it work.

src/gprs_bssgp_pcu.cpp

@@ -247,6 +247,28 @@ int gprs_bssgp_pcu_rx_dl_ud(struct msgb *msg, struct tlv_parsed *tp)
 	return 0;
 }
 
+int gprs_bssgp_pcu_rx_paging_ps(struct msgb *msg, struct tlv_parsed *tp)
+{
+	char imsi[16];
+	uint8_t *ptmsi = (uint8_t *) TLVP_VAL(tp, BSSGP_IE_TMSI);
+	uint16_t ptmsi_len = TLVP_LEN(tp, BSSGP_IE_TMSI);
+
+	LOGP(DBSSGP, LOGL_NOTICE, " P-TMSI = ");
+	for (int i = 0; i < ptmsi_len; i++)
+	{
+		LOGPC(DBSSGP, LOGL_NOTICE, "%02x", ptmsi[i]);
+	}
+	LOGPC(DBSSGP, LOGL_NOTICE, "\n");
+
+	if (parse_imsi(tp, imsi))
+	{
+		LOGP(DBSSGP, LOGL_ERROR, "No IMSI\n");
+		return -EINVAL;
+	}
+
+	return gprs_rlcmac_paging_request(ptmsi, ptmsi_len, imsi);
+}
+
 /* Receive a BSSGP PDU from a BSS on a PTP BVCI */
 int gprs_bssgp_pcu_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx)
 {
@@ -321,7 +343,8 @@ int gprs_bssgp_pcu_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp
 			bvc_timeout(NULL);
 			break;
 		case BSSGP_PDUT_PAGING_PS:
-			LOGP(DBSSGP, LOGL_DEBUG, "rx BSSGP_PDUT_PAGING_PS\n");
+			LOGP(DBSSGP, LOGL_NOTICE, "RX: [SGSN->PCU] BSSGP_PDUT_PAGING_PS\n");
+			gprs_bssgp_pcu_rx_paging_ps(msg, tp);
 			break;
 		case BSSGP_PDUT_PAGING_CS:
 			LOGP(DBSSGP, LOGL_DEBUG, "rx BSSGP_PDUT_PAGING_CS\n");
@@ -390,7 +413,8 @@ int gprs_bssgp_pcu_rcvmsg(struct msgb *msg)
 
 	if (!bctx
 	 && pdu_type != BSSGP_PDUT_BVC_RESET_ACK
-	 && pdu_type != BSSGP_PDUT_BVC_UNBLOCK_ACK)
+	 && pdu_type != BSSGP_PDUT_BVC_UNBLOCK_ACK
+	 && pdu_type != BSSGP_PDUT_PAGING_PS)
 	{
 		LOGP(DBSSGP, LOGL_NOTICE, "NSEI=%u/BVCI=%u Rejecting PDU "
 			"type %u for unknown BVCI\n", msgb_nsei(msg), ns_bvci,

src/gprs_rlcmac.cpp

@@ -1573,6 +1573,43 @@ void write_packet_downlink_assignment(RlcMacDownlink_t * block, uint8_t old_tfi,
 	block->u.Packet_Downlink_Assignment.Exist_AdditionsR99        = 0x0; // AdditionsR99 = off
 }
 
+/* generate paging request */
+int write_paging_request(bitvec * dest, uint8_t *ptmsi, uint16_t ptmsi_len)
+{
+	unsigned wp = 0;
+	int plen;
+
+	bitvec_write_field(dest, wp,0x0,4);  // Skip Indicator
+	bitvec_write_field(dest, wp,0x6,4);  // Protocol Discriminator
+	bitvec_write_field(dest, wp,0x21,8); // Paging Request Message Type
+
+	bitvec_write_field(dest, wp,0x0,4);  // Page Mode
+	bitvec_write_field(dest, wp,0x0,4);  // Channel Needed
+
+	// Mobile Identity
+	bitvec_write_field(dest, wp,ptmsi_len+1,8);  // Mobile Identity length
+	bitvec_write_field(dest, wp,0xf,4);          // unused
+	bitvec_write_field(dest, wp,0x4,4);          // PTMSI type
+	for (int i = 0; i < ptmsi_len; i++)
+	{
+		bitvec_write_field(dest, wp,ptmsi[i],8); // PTMSI
+	}
+	if ((wp % 8)) {
+		LOGP(DRLCMACUL, LOGL_ERROR, "Length of PAG.REQ without rest "
+			"octets is not multiple of 8 bits, PLEASE FIX!\n");
+		exit (0);
+	}
+	plen = wp / 8;
+	bitvec_write_field(dest, wp,0x0,1); // "L" NLN(PCH) = off
+	bitvec_write_field(dest, wp,0x0,1); // "L" Priority1 = off
+	bitvec_write_field(dest, wp,0x1,1); // "L" Priority2 = off
+	bitvec_write_field(dest, wp,0x0,1); // "L" Group Call information = off
+	bitvec_write_field(dest, wp,0x0,1); // "H" Packet Page Indication 1 = packet paging procedure
+	bitvec_write_field(dest, wp,0x1,1); // "H" Packet Page Indication 2 = packet paging procedure
+
+	return plen;
+}
+
 /* generate uplink ack */
 void write_packet_uplink_ack(RlcMacDownlink_t * block, struct gprs_rlcmac_tbf *tbf,
 	uint8_t final)
@@ -1700,3 +1737,16 @@ int gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf)
 
 	return 0;
 }
+
+int gprs_rlcmac_paging_request(uint8_t *ptmsi, uint16_t ptmsi_len,
+	const char *imsi)
+{
+	LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] Paging Request (CCCH)\n");
+	bitvec *paging_request = bitvec_alloc(23);
+	bitvec_unhex(paging_request, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	int plen = write_paging_request(paging_request, ptmsi, ptmsi_len);
+	pcu_l1if_tx_pch(paging_request, plen, (char *)imsi);
+	bitvec_free(paging_request);
+
+	return 0;
+}

src/gprs_rlcmac.h

@@ -363,6 +363,9 @@ void gprs_rlcmac_trigger_downlink_assignment(struct gprs_rlcmac_tbf *tbf,
 int gprs_rlcmac_downlink_ack(struct gprs_rlcmac_tbf *tbf, uint8_t final,
         uint8_t ssn, uint8_t *rbb);
 
+int gprs_rlcmac_paging_request(uint8_t *ptmsi, uint16_t ptmsi_len,
+	const char *imsi);
+
 unsigned write_packet_paging_request(bitvec * dest);
 
 unsigned write_repeated_page_info(bitvec * dest, unsigned& wp, uint8_t len,

src/pcu_l1_if.cpp

@@ -203,7 +203,9 @@ static int pcu_rx_data_cnf(struct gsm_pcu_if_data *data_cnf)
 
 	switch (data_cnf->sapi) {
 	case PCU_IF_SAPI_PCH:
-		rc = gprs_rlcmac_imm_ass_cnf(data_cnf->data, data_cnf->fn);
+		if (data_cnf->data[2] == 0x3f)
+			rc = gprs_rlcmac_imm_ass_cnf(data_cnf->data,
+				data_cnf->fn);
 		break;
 	default:
 		LOGP(DL1IF, LOGL_ERROR, "Received PCU data confirm with "