tbf: Learn and propagate the TLLI changes due a new P-TMSI

During a routing area update a new P-TMSI was assigned. During
the PACKET CONTROL ACK on the DL we notice the change of TLLI
but didn't propagate this. This means that a Routing Area Update
Complete was only sent after a new RACH request.

Addresses:
<0007> gprs_rlcmac_meas.cpp:103 UL RSSI of TLLI=0x88661bc6: -67 dBm
<0002> bts.cpp:945 Got ACK, but UL TBF is gone TLLI=0xe512eba3
<0007> gprs_rlcmac_meas.cpp:158 DL packet loss of IMSI=274080000004765 / TLLI=0xe512eba3: 0%
<0002> tbf.cpp:668 TBF TFI=0 TLLI=0x88661bc6 T3169 timeout during transsmission
<0002> tbf.cpp:690 - Assignment was on PACCH
<0002> tbf.cpp:694 - No uplink data received yet

.gitignore

@@ -34,6 +34,7 @@ tests/atconfig
 tests/package.m4
 tests/alloc/AllocTest
 tests/rlcmac/RLCMACTest
+tests/tbf/TbfTest
 tests/emu/pcu_emu
 tests/testsuite
 tests/testsuite.log

src/tbf.cpp

@@ -1618,9 +1618,32 @@ void gprs_rlcmac_tbf::update_tlli(uint32_t tlli)
 	if (tlli == m_tlli)
 		return;
 
-#warning "TODO.. find the DL/UL opposite and update the TLLI too"
-	LOGP(DRLCMAC, LOGL_NOTICE, "%s changing tlli to TLLI=0x%08x\n",
-		tbf_name(this), tlli);
+	bool changedUl = false;
+
+	/*
+	 * During a Routing Area Update (due the assignment of a new
+	 * P-TMSI) the tlli can change. We notice this when receiving
+	 * a PACKET CONTROL ACK.
+	 * When we get a TLLI change on the DL we will look if there
+	 * is a UL TBF and change the tlli there as well.
+	 *
+	 * TODO: There could be multiple DL and UL TBFs and we should
+	 * have a proper way to link all the related TBFs so we can do
+	 * a group update.
+	 */
+	if (m_tlli_valid && direction == GPRS_RLCMAC_DL_TBF) {
+		gprs_rlcmac_tbf *ul_tbf;
+		ul_tbf = bts->tbf_by_tlli(m_tlli, GPRS_RLCMAC_UL_TBF);
+
+		if (ul_tbf) {
+			ul_tbf->m_tlli = tlli;
+			changedUl = true;
+		}
+	}
+
+	LOGP(DRLCMAC, LOGL_NOTICE,
+		"%s changing tlli from TLLI=0x%08x TLLI=0x%08x ul_changed=%d\n",
+		tbf_name(this), m_tlli, tlli, changedUl);
 	m_tlli = tlli;
 }
 

tests/Makefile.am

@@ -1,6 +1,6 @@
 AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGB_CFLAGS) $(LIBOSMOGSM_CFLAGS) -I$(top_srcdir)/src/
 
-check_PROGRAMS = rlcmac/RLCMACTest alloc/AllocTest
+check_PROGRAMS = rlcmac/RLCMACTest alloc/AllocTest tbf/TbfTest
 noinst_PROGRAMS = emu/pcu_emu
 
 rlcmac_RLCMACTest_SOURCES = rlcmac/RLCMACTest.cpp
@@ -17,6 +17,14 @@ alloc_AllocTest_LDADD = \
 	$(LIBOSMOCORE_LIBS) \
 	$(COMMON_LA)
 
+tbf_TbfTest_SOURCES = tbf/TbfTest.cpp
+tbf_TbfTest_LDADD = \
+	$(LIBOSMOGB_LIBS) \
+	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMOCORE_LIBS) \
+	$(COMMON_LA) \
+	$(top_builddir)/src/libgprs.la
+
 emu_pcu_emu_SOURCES = emu/pcu_emu.cpp emu/test_replay_gprs_attach.cpp \
 	emu/openbsc_clone.c emu/openbsc_clone.h emu/gprs_tests.h \
 	emu/test_pdp_activation.cpp
@@ -49,7 +57,8 @@ $(srcdir)/package.m4: $(top_srcdir)/configure.ac
 EXTRA_DIST = \
 	testsuite.at $(srcdir)/package.m4 $(TESTSUITE)	\
 	rlcmac/RLCMACTest.ok rlcmac/RLCMACTest.err \
-	alloc/AllocTest.ok alloc/AllocTest.err
+	alloc/AllocTest.ok alloc/AllocTest.err \
+	tbf/TbfTest.ok tbf/TbfTest.err
 
 DISTCLEANFILES = atconfig
 

tests/tbf/TbfTest.cpp

@@ -0,0 +1,102 @@
+/*
+ * TbfTest.cpp
+ *
+ * Copyright (C) 2013 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "bts.h"
+#include "tbf.h"
+#include "gprs_debug.h"
+
+extern "C" {
+#include <osmocom/core/application.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+}
+
+void *tall_pcu_ctx;
+int16_t spoof_mnc = 0, spoof_mcc = 0;
+
+static void test_tbf_tlli_update()
+{
+	BTS the_bts;
+	the_bts.bts_data()->alloc_algorithm = alloc_algorithm_a;
+	the_bts.bts_data()->trx[0].pdch[2].enable();
+	the_bts.bts_data()->trx[0].pdch[3].enable();
+
+	/*
+	 * Make a uplink and downlink allocation
+	 */
+	gprs_rlcmac_tbf *dl_tbf = tbf_alloc(the_bts.bts_data(),
+						NULL, GPRS_RLCMAC_DL_TBF, 0,
+						0, 0, 0);
+	dl_tbf->update_tlli(0x2342);
+	dl_tbf->tlli_mark_valid();
+	dl_tbf->ta = 4;
+	the_bts.timing_advance()->remember(0x2342, dl_tbf->ta);
+
+	gprs_rlcmac_tbf *ul_tbf = tbf_alloc(the_bts.bts_data(),
+						ul_tbf, GPRS_RLCMAC_UL_TBF, 0,
+						0, 0, 0);
+	ul_tbf->update_tlli(0x2342);
+	ul_tbf->tlli_mark_valid();
+	
+
+	OSMO_ASSERT(the_bts.tbf_by_tlli(0x2342, GPRS_RLCMAC_DL_TBF) == dl_tbf);
+	OSMO_ASSERT(the_bts.tbf_by_tlli(0x2342, GPRS_RLCMAC_UL_TBF) == ul_tbf);
+
+
+	/*
+	 * Now check.. that DL changes and that the timing advance
+	 * has changed.
+	 */
+	dl_tbf->update_tlli(0x4232);
+	OSMO_ASSERT(!the_bts.tbf_by_tlli(0x2342, GPRS_RLCMAC_DL_TBF));
+	OSMO_ASSERT(!the_bts.tbf_by_tlli(0x2342, GPRS_RLCMAC_UL_TBF));
+
+	
+	OSMO_ASSERT(the_bts.tbf_by_tlli(0x4232, GPRS_RLCMAC_DL_TBF) == dl_tbf);
+	OSMO_ASSERT(the_bts.tbf_by_tlli(0x4232, GPRS_RLCMAC_UL_TBF) == ul_tbf);
+}
+
+int main(int argc, char **argv)
+{
+	tall_pcu_ctx = talloc_named_const(NULL, 1, "moiji-mobile TbfTest context");
+	if (!tall_pcu_ctx)
+		abort();
+
+	msgb_set_talloc_ctx(tall_pcu_ctx);
+	osmo_init_logging(&gprs_log_info);
+	log_set_use_color(osmo_stderr_target, 0);
+	log_set_print_filename(osmo_stderr_target, 0);
+
+	test_tbf_tlli_update();
+	return EXIT_SUCCESS;
+}
+
+/*
+ * stubs that should not be reached
+ */
+extern "C" {
+void l1if_pdch_req() { abort(); }
+void l1if_connect_pdch() { abort(); }
+void l1if_close_pdch() { abort(); }
+void l1if_open_pdch() { abort(); }
+}

tests/tbf/TbfTest.err

@@ -0,0 +1,3 @@
+TBF(TFI=0 TLLI=0x00000000 DIR=DL) changing tlli from TLLI=0x00000000 TLLI=0x00002342 ul_changed=0
+TBF(TFI=0 TLLI=0x00000000 DIR=UL) changing tlli from TLLI=0x00000000 TLLI=0x00002342 ul_changed=0
+TBF(TFI=0 TLLI=0x00002342 DIR=DL) changing tlli from TLLI=0x00002342 TLLI=0x00004232 ul_changed=1

tests/testsuite.at

@@ -15,3 +15,10 @@ cat $abs_srcdir/alloc/AllocTest.ok > expout
 cat $abs_srcdir/alloc/AllocTest.err > experr
 AT_CHECK([$abs_top_builddir/tests/alloc/AllocTest], [0], [expout], [experr])
 AT_CLEANUP
+
+AT_SETUP([tbf])
+AT_KEYWORDS([tbf])
+cat $abs_srcdir/tbf/TbfTest.ok > expout
+cat $abs_srcdir/tbf/TbfTest.err > experr
+AT_CHECK([$abs_top_builddir/tests/tbf/TbfTest], [0], [expout], [experr])
+AT_CLEANUP