tbf: Do not reuse old TBF after RACH requests

Currently existing TBF can be reused after an MS has sent a RACH
request. Since the MS can be or most probably is in packet idle mode
in that case, the TBF are no longer usable even if they share the
PDCHs and the control TS with the new one.

There are occasional freezes where the MS does no longer react to
messages sent on the PACCH.

This change aborts all pending TBFs if a new TBF is or has been
established via RACH.

Sponsored-by: On-Waves ehf

2 files changed, 21 insertions, 13 deletions

diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index c868ca2d..d2b4cfc9 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -963,9 +963,8 @@ static void test_tbf_dl_flow_and_rach_single_phase()
 	OSMO_ASSERT(ms2 == ms);
 	OSMO_ASSERT(ms1 != ms);
 
-	/* DL TBF should be the same */
-	OSMO_ASSERT(ms->dl_tbf());
-	OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
+	/* DL TBF should be removed */
+	OSMO_ASSERT(!ms->dl_tbf());
 
 	/* No queued packets should be lost */
 	OSMO_ASSERT(ms->llc_queue()->size() == 2);
diff --git a/tests/tbf/TbfTest.err b/tests/tbf/TbfTest.err
index 8f920ca0..350966ea 100644
--- a/tests/tbf/TbfTest.err
+++ b/tests/tbf/TbfTest.err
@@ -1902,8 +1902,12 @@ Got RLC block, coding scheme: CS-1, length: 23 (23))
 +++++++++++++++++++++++++ RX : Uplink Control Block +++++++++++++++++++++++++
 ------------------------- RX : Uplink Control Block -------------------------
 Got RACH from TLLI=0xf1223344 while TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) still exists. Release pending DL TBF
-TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) changes state from ASSIGN to WAIT RELEASE
-TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=WAIT RELEASE) restarting timer 3193 while old timer 0 pending 
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) changes state from ASSIGN to RELEASING
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING) free
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING) stopping timer 0.
+PDCH(TS 7, TRX 0): Detaching TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING), 0 TBFs, USFs = 00, TFIs = 00000000.
+Detaching TBF from MS object, TLLI = 0xf1223344, TBF = TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING)
+********** TBF ends here **********
 MS requests UL TBF in packet resource request of single block, so we provide one:
 ********** TBF starts here **********
 Allocating UL TBF: MS_CLASS=1/0
@@ -1945,15 +1949,15 @@ Slot Allocation (Algorithm A) for class 1
 - Skipping TS 4, because not enabled
 - Skipping TS 5, because not enabled
 - Skipping TS 6, because not enabled
-- Assign downlink TS=7 TFI=1
-PDCH(TS 7, TRX 0): Attaching TBF(TFI=1 TLLI=0x00000000 DIR=DL STATE=NULL), 2 TBFs, USFs = 01, TFIs = 00000003.
+- Assign downlink TS=7 TFI=0
+PDCH(TS 7, TRX 0): Attaching TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL), 1 TBFs, USFs = 01, TFIs = 00000001.
 - Setting Control TS 7
-Attaching TBF to MS object, TLLI = 0xf1223344, TBF = TBF(TFI=1 TLLI=0xf1223344 DIR=DL STATE=NULL)
-Allocated TBF(TFI=1 TLLI=0xf1223344 DIR=DL STATE=NULL): trx = 0, ul_slots = 80, dl_slots = 80
+Attaching TBF to MS object, TLLI = 0xf1223344, TBF = TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=NULL)
+Allocated TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=NULL): trx = 0, ul_slots = 80, dl_slots = 80
 TBF(TFI=0 TLLI=0xf1223344 DIR=UL STATE=FLOW) Trigger downlink assignment on PACCH
 Send dowlink assignment on PACCH, because TBF(TFI=0 TLLI=0xf1223344 DIR=UL STATE=FLOW) exists
-TBF(TFI=1 TLLI=0xf1223344 DIR=DL STATE=NULL) changes state from NULL to ASSIGN
-TBF(TFI=1 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) starting timer 0.
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=NULL) changes state from NULL to ASSIGN
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) starting timer 0.
 Got RLC block, coding scheme: CS-1, length: 23 (23))
   UL data: 3c 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
 Got CS-1 RLC block: R=0, SI=0, TFI=0, CPS=0, RSB=0, rc=184
@@ -2096,8 +2100,13 @@ TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=FLOW): Got CS-1 RLC data block: CV=0, BSN
 - BSN 0 storing in window (0..63)
 TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=FLOW): data_length=20, data=f1 22 33 44 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
 Decoded premier TLLI=0x00000000 of UL DATA TFI=0.
-Detaching TBF from MS object, TLLI = 0xf1223344, TBF = TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN)
-Attaching TBF to MS object, TLLI = 0x00000000, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=ASSIGN)
+Got RACH from TLLI=0x00000000 while TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) still exists. Killing pending DL TBF
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=ASSIGN) changes state from ASSIGN to RELEASING
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING) free
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING) stopping timer 0.
+PDCH(TS 7, TRX 0): Detaching TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING), 0 TBFs, USFs = 01, TFIs = 00000000.
+Detaching TBF from MS object, TLLI = 0xf1223344, TBF = TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=RELEASING)
+********** TBF ends here **********
 Modifying MS object, TLLI = 0x00000000, IMSI '' -> '0011223344'
 Modifying MS object, TLLI = 0x00000000, MS class 0 -> 1
 Clearing MS object, TLLI: 0xf1223344, IMSI: '0011223344'