[PATCH] osmo-pcu[master]: Handle packet access reject during EPDAN/PDAN with channel d...

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arvind.sirsikar gerrit-no-reply at lists.osmocom.org
Fri Nov 11 11:50:27 UTC 2016


Hello Max, Jenkins Builder,

I'd like you to reexamine a change.  Please visit

    https://gerrit.osmocom.org/1209

to look at the new patch set (#4).

Handle packet access reject during EPDAN/PDAN with channel description

When PDAN/EPDAN with channel description is received, PCU will generate the
packet access reject if no resources are present. The encoding is done
based on section 7.1.3.2.1 and 8.1.2.5 of 44.060 version 7.27.0 Release 7.
This patch also includes the test case to validate the generated
packet access reject message.

This patch is integration tested on Osmo-trx setup with Ettus B210 board
and LG F70 MS with some simulation code changes in Osmo-pcu.

Change-Id: I096a3bb44a65533b9e9b091925dd5f70a8696d6
---
M src/bts.cpp
M src/encoding.cpp
M src/encoding.h
M src/gprs_rlcmac_sched.cpp
M src/tbf.cpp
M src/tbf.h
M tests/tbf/TbfTest.cpp
M tests/tbf/TbfTest.err
M tests/tbf/TbfTest.ok
9 files changed, 135 insertions(+), 12 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/osmo-pcu refs/changes/09/1209/4

diff --git a/src/bts.cpp b/src/bts.cpp
index 4e6b5e9..0668c2d 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -1077,16 +1077,23 @@
 	}
 	/* check for channel request */
 	if (ack_nack->Exist_Channel_Request_Description) {
-		LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
-			"message, so we provide one:\n");
 
 		/* This call will register the new TBF with the MS on success */
-		tbf_alloc_ul(bts_data(), tbf->trx->trx_no,
+		gprs_rlcmac_ul_tbf *ul_tbf = tbf_alloc_ul(bts_data(),
+			tbf->trx->trx_no,
 			tbf->ms_class(), tbf->ms()->egprs_ms_class(),
 			tbf->tlli(), tbf->ta(), tbf->ms());
 
-		/* schedule uplink assignment */
-		tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
+		/* schedule uplink assignment or reject*/
+		if (ul_tbf) {
+			LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
+				"message, so we provide one:\n");
+			tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
+		} else {
+			LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
+				"message, so we pacekt access reject:\n");
+			tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ;
+		}
 	}
 	/* get measurements */
 	if (tbf->ms()) {
@@ -1179,16 +1186,23 @@
 
 	/* check for channel request */
 	if (ack_nack->Exist_ChannelRequestDescription) {
-		LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
-			"message, so we provide one:\n");
 
 		/* This call will register the new TBF with the MS on success */
-		tbf_alloc_ul(bts_data(), tbf->trx->trx_no,
+		gprs_rlcmac_ul_tbf *ul_tbf = tbf_alloc_ul(bts_data(),
+			tbf->trx->trx_no,
 			tbf->ms_class(), tbf->ms()->egprs_ms_class(),
 			tbf->tlli(), tbf->ta(), tbf->ms());
 
-		/* schedule uplink assignment */
-		tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
+		/* schedule uplink assignment or reject*/
+		if (ul_tbf) {
+			LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
+				"message, so we provide one:\n");
+			tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
+		} else {
+			LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack "
+				"message, so we send packet access reject:\n");
+			tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ;
+		}
 	}
 
 	/* get measurements */
diff --git a/src/encoding.cpp b/src/encoding.cpp
index ca72b0f..e5a8605 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -1391,3 +1391,28 @@
 
 	return AR_NEED_MORE_BLOCKS;
 }
+
+/*
+ * Refer 44.060 version 7.27.0 Release 7
+ * section 7.1.3.2.1 On receipt of a PACKET RESOURCE REQUEST message
+ * 8.1.2.5 Establishment of uplink TBF
+ */
+void Encoding::write_packet_access_reject(
+	bitvec * dest, uint32_t tlli)
+{
+	unsigned wp = 0;
+
+	bitvec_write_field(dest, wp, 0x1, 2);  // Payload Type
+	bitvec_write_field(dest, wp, 0x0, 2);  // Uplink block with TDMA FN
+	bitvec_write_field(dest, wp, 0, 1);  // No Polling Bit
+	bitvec_write_field(dest, wp, 0x0, 3);  // Uplink state flag
+	bitvec_write_field(dest, wp,
+				MT_PACKET_ACCESS_REJECT, 6);  // MESSAGE TYPE
+	bitvec_write_field(dest, wp, 0, 2); // fixed 00
+	bitvec_write_field(dest, wp, 0x0, 1);  //  TLLI / G-RNTI : bit (32)
+	bitvec_write_field(dest, wp, tlli, 32); // CONTENTION_RESOLUTION_TLLI
+	bitvec_write_field(dest, wp, 1, 1);  //  WAIT_INDICATION size in seconds
+	/* TODO: make it configurable */
+	bitvec_write_field(dest, wp, 5, 8);  //  WAIT_INDICATION value
+	bitvec_write_field(dest, wp, 0, 1);  //  WAIT_INDICATION size in seconds
+}
diff --git a/src/encoding.h b/src/encoding.h
index 79dc32d..6164b89 100644
--- a/src/encoding.h
+++ b/src/encoding.h
@@ -74,6 +74,9 @@
 
 	static void encode_rbb(const char *show_rbb, uint8_t *rbb);
 
+	static void write_packet_access_reject(
+		bitvec * dest, uint32_t tlli);
+
 	static void write_packet_uplink_ack(
 			struct gprs_rlcmac_bts *bts, bitvec * dest,
 			struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
diff --git a/src/gprs_rlcmac_sched.cpp b/src/gprs_rlcmac_sched.cpp
index f486075..a3723df 100644
--- a/src/gprs_rlcmac_sched.cpp
+++ b/src/gprs_rlcmac_sched.cpp
@@ -72,7 +72,8 @@
 			*poll_tbf = dl_tbf;
 		if (dl_tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_SEND_ASS)
 			*dl_ass_tbf = dl_tbf;
-		if (dl_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS)
+		if (dl_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS
+		 || dl_tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ)
 			*ul_ass_tbf = dl_tbf;
 	}
 
@@ -137,7 +138,11 @@
 		 */
 
 		if (tbf == ul_ass_tbf && tbf->direction == GPRS_RLCMAC_DL_TBF)
-			msg = ul_ass_tbf->create_ul_ass(fn, ts);
+			if (tbf->ul_ass_state ==
+					GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ)
+				msg = ul_ass_tbf->create_packet_access_reject();
+			else
+				msg = ul_ass_tbf->create_ul_ass(fn, ts);
 		else if (tbf == dl_ass_tbf && tbf->direction == GPRS_RLCMAC_UL_TBF)
 			msg = dl_ass_tbf->create_dl_ass(fn, ts);
 		else if (tbf == ul_ack_tbf)
diff --git a/src/tbf.cpp b/src/tbf.cpp
index 0ac8ace..2d82727 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -1013,6 +1013,29 @@
 	return msg;
 }
 
+struct msgb *gprs_rlcmac_tbf::create_packet_access_reject()
+{
+	struct msgb *msg;
+
+	msg = msgb_alloc(23, "rlcmac_ul_ass_rej");
+
+	bitvec *packet_access_rej = bitvec_alloc(23);
+
+	bitvec_unhex(packet_access_rej,
+		"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+
+	Encoding::write_packet_access_reject(
+		packet_access_rej, tlli());
+
+	bitvec_pack(packet_access_rej, msgb_put(msg, 23));
+
+	bitvec_free(packet_access_rej);
+	ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
+
+	return msg;
+
+}
+
 struct msgb *gprs_rlcmac_tbf::create_ul_ass(uint32_t fn, uint8_t ts)
 {
 	struct msgb *msg;
diff --git a/src/tbf.h b/src/tbf.h
index 3205f6e..e044053 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -64,6 +64,7 @@
 enum gprs_rlcmac_tbf_ul_ass_state {
 	GPRS_RLCMAC_UL_ASS_NONE = 0,
 	GPRS_RLCMAC_UL_ASS_SEND_ASS, /* send uplink assignment on next RTS */
+	GPRS_RLCMAC_UL_ASS_SEND_ASS_REJ, /* send assignment reject next RTS */
 	GPRS_RLCMAC_UL_ASS_WAIT_ACK, /* wait for PACKET CONTROL ACK */
 };
 
@@ -103,6 +104,7 @@
 
 	struct msgb *create_dl_ass(uint32_t fn, uint8_t ts);
 	struct msgb *create_ul_ass(uint32_t fn, uint8_t ts);
+	struct msgb *create_packet_access_reject();
 
 	GprsMs *ms() const;
 	void set_ms(GprsMs *ms);
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index 339390b..213bd12 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -2831,6 +2831,29 @@
 	ARRAY_SIZE(default_categories),
 };
 
+void test_packet_access_rej_epdan()
+{
+	BTS the_bts;
+	uint32_t tlli = 0xffeeddcc;
+
+	printf("=== start %s ===\n", __func__);
+	setup_bts(&the_bts, 4);
+	static gprs_rlcmac_dl_tbf *dl_tbf = tbf_init(&the_bts, 1);
+
+	dl_tbf->update_ms(tlli, GPRS_RLCMAC_DL_TBF);
+
+	struct msgb *msg = dl_tbf->create_packet_access_reject();
+
+	printf("packet reject: %s\n",
+			osmo_hexdump(msg->data, 23));
+
+	OSMO_ASSERT(!strcmp(osmo_hexdump(msg->data, 23),
+			    "40 84 7f f7 6e e6 41 4b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b "));
+	printf("=== end %s ===\n", __func__);
+
+}
+
+
 int main(int argc, char **argv)
 {
 	struct vty_app_info pcu_vty_info = {0};
@@ -2874,6 +2897,7 @@
 	test_tbf_li_decoding();
 	test_tbf_epdan_out_of_rx_window();
 	test_immediate_assign_rej();
+	test_packet_access_rej_epdan();
 
 	if (getenv("TALLOC_REPORT_FULL"))
 		talloc_report_full(tall_pcu_ctx, stderr);
diff --git a/tests/tbf/TbfTest.err b/tests/tbf/TbfTest.err
index 627cdc3..a680812 100644
--- a/tests/tbf/TbfTest.err
+++ b/tests/tbf/TbfTest.err
@@ -6846,3 +6846,27 @@
 No PDCH available.
 No PDCH resource for single block allocation.sending Immediate Assignment Uplink (AGCH) reject
 Sending data request: trx=0 ts=0 sapi=2 arfcn=0 fn=0 block=0 data=4d 06 3a 10 70 8b 29 14 70 8b 29 14 70 8b 29 14 70 8b 29 14 0b 2b 2b 
+Searching for first unallocated TFI: TRX=0
+ Found TFI=0.
+********** TBF starts here **********
+Allocating DL TBF: MS_CLASS=11/11
+Creating MS object, TLLI = 0x00000000
+Modifying MS object, TLLI = 0x00000000, MS class 0 -> 11
+Modifying MS object, TLLI = 0x00000000, EGPRS MS class 0 -> 11
+Slot Allocation (Algorithm A) for class 11
+- Skipping TS 0, because not enabled
+- Skipping TS 1, because not enabled
+- Skipping TS 2, because not enabled
+- Skipping TS 3, because not enabled
+- Skipping TS 5, because not enabled
+- Skipping TS 6, because not enabled
+- Skipping TS 7, because not enabled
+- Assign downlink TS=4 TFI=0
+PDCH(TS 4, TRX 0): Attaching TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL), 1 TBFs, USFs = 00, TFIs = 00000001.
+- Setting Control TS 4
+Attaching TBF to MS object, TLLI = 0x00000000, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Allocated TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL): trx = 0, ul_slots = 10, dl_slots = 10
+Modifying MS object, TLLI = 0x00000000, TA 220 -> 0
+TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL) changes state from NULL to FLOW
+The MS object cannot fully confirm an unexpected TLLI: 0xffeeddcc, partly confirmed
+TBF(TFI=0 TLLI=0xffeeddcc DIR=DL STATE=FLOW) append
diff --git a/tests/tbf/TbfTest.ok b/tests/tbf/TbfTest.ok
index f921dfc..dc07fc7 100644
--- a/tests/tbf/TbfTest.ok
+++ b/tests/tbf/TbfTest.ok
@@ -72,3 +72,6 @@
 === end test_immediate_assign_rej_multi_block ===
 === start test_immediate_assign_rej_single_block ===
 === end test_immediate_assign_rej_single_block ===
+=== start test_packet_access_rej_epdan ===
+packet reject: 40 84 7f f7 6e e6 41 4b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 
+=== end test_packet_access_rej_epdan ===

-- 
To view, visit https://gerrit.osmocom.org/1209
To unsubscribe, visit https://gerrit.osmocom.org/settings

Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I096a3bb44a65533b9e9b091925dd5f70a8696d6
Gerrit-PatchSet: 4
Gerrit-Project: osmo-pcu
Gerrit-Branch: master
Gerrit-Owner: arvind.sirsikar <arvind.sirsikar at radisys.com>
Gerrit-Reviewer: Harald Welte <laforge at gnumonks.org>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: Max <msuraev at sysmocom.de>
Gerrit-Reviewer: arvind.sirsikar <arvind.sirsikar at radisys.com>



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