ms: Add GprsMs class to hold per-MS information

Currently only TBF objects are used to handle the data flow between
the MS and the SGSN. MS specific data (e.g. pending LLC frames, TLLI)
is copied between successive TBFs. If all TBFs (uplink and downlink)
are idle for some time, all information about the MS is discarded in
the PCU. This makes the implementation of some features more
difficult, e.g. proper TLLI and timing advance handling,
connection based CS selection, and proper management of multiple TBF.

This commit adds the GprsMs class that is intended to hold
information directly related to the MS and to keep references to the
active TBFs.

The class is not yet integrated with the other PCU code. A GprsMs
object container and MS specific fields (TA, CS) will be added in
later commits.

Note that calling detach_tbf() can possibly delete the MS object
depending on the callback implementation.

Ticket: #1674
Sponsored-by: On-Waves ehf
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 683a64c..7b2d32d 100644
--- a/tests/Makefile.am
+++ b/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 tbf/TbfTest types/TypesTest
+check_PROGRAMS = rlcmac/RLCMACTest alloc/AllocTest tbf/TbfTest types/TypesTest ms/MsTest
 noinst_PROGRAMS = emu/pcu_emu
 
 rlcmac_RLCMACTest_SOURCES = rlcmac/RLCMACTest.cpp
@@ -43,6 +43,16 @@
 	$(LIBOSMOCORE_LIBS) \
 	$(COMMON_LA)
 
+ms_MsTest_SOURCES = ms/MsTest.cpp
+ms_MsTest_LDADD = \
+	$(top_builddir)/src/libgprs.la \
+	$(LIBOSMOGB_LIBS) \
+	$(LIBOSMOGSM_LIBS) \
+	$(LIBOSMOCORE_LIBS) \
+	$(COMMON_LA)
+
+ms_MsTest_LDFLAGS = \
+	-Wl,-u,bssgp_prim_cb
 
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
 $(srcdir)/package.m4: $(top_srcdir)/configure.ac
@@ -67,7 +77,8 @@
 	rlcmac/RLCMACTest.ok rlcmac/RLCMACTest.err \
 	alloc/AllocTest.ok alloc/AllocTest.err \
 	tbf/TbfTest.ok tbf/TbfTest.err \
-	types/TypesTest.ok types/TypesTest.err
+	types/TypesTest.ok types/TypesTest.err \
+	ms/MsTest.ok ms/MsTest.err
 
 DISTCLEANFILES = atconfig
 
diff --git a/tests/ms/MsTest.cpp b/tests/ms/MsTest.cpp
new file mode 100644
index 0000000..59c92b3
--- /dev/null
+++ b/tests/ms/MsTest.cpp
@@ -0,0 +1,283 @@
+/*
+ * MsTest.cpp
+ *
+ * Copyright (C) 2015 by Sysmocom s.f.m.c. GmbH
+ *
+ * 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 "tbf.h"
+#include "gprs_debug.h"
+#include "gprs_ms.h"
+
+extern "C" {
+#include "pcu_vty.h"
+
+#include <osmocom/core/application.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/vty/vty.h>
+}
+
+#include <errno.h>
+
+void *tall_pcu_ctx;
+int16_t spoof_mnc = 0, spoof_mcc = 0;
+
+static void test_ms_state()
+{
+	uint32_t tlli = 0xffeeddbb;
+	gprs_rlcmac_dl_tbf *dl_tbf;
+	gprs_rlcmac_ul_tbf *ul_tbf;
+	GprsMs *ms;
+
+	printf("=== start %s ===\n", __func__);
+
+	ms = new GprsMs(tlli);
+	OSMO_ASSERT(ms->is_idle());
+
+	dl_tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_dl_tbf);
+	dl_tbf->direction = GPRS_RLCMAC_DL_TBF;
+	ul_tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_ul_tbf);
+	ul_tbf->direction = GPRS_RLCMAC_UL_TBF;
+
+	ms->attach_tbf(ul_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == ul_tbf);
+	OSMO_ASSERT(ms->dl_tbf() == NULL);
+
+	ms->attach_tbf(dl_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == ul_tbf);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
+
+	ms->detach_tbf(ul_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
+
+	ms->detach_tbf(dl_tbf);
+	/* The ms object is freed now */
+	ms = NULL;
+
+	talloc_free(dl_tbf);
+	talloc_free(ul_tbf);
+
+	printf("=== end %s ===\n", __func__);
+}
+
+static void test_ms_callback()
+{
+	uint32_t tlli = 0xffeeddbb;
+	gprs_rlcmac_dl_tbf *dl_tbf;
+	gprs_rlcmac_ul_tbf *ul_tbf;
+	GprsMs *ms;
+	static enum {UNKNOWN, IS_IDLE, IS_ACTIVE} last_cb = UNKNOWN;
+
+	struct MyCallback: public GprsMs::Callback {
+		virtual void ms_idle(class GprsMs *ms) {
+			OSMO_ASSERT(ms->is_idle());
+			printf("  ms_idle() was called\n");
+			last_cb = IS_IDLE;
+		}
+		virtual void ms_active(class GprsMs *ms) {
+			OSMO_ASSERT(!ms->is_idle());
+			printf("  ms_active() was called\n");
+			last_cb = IS_ACTIVE;
+		}
+	} cb;
+
+	printf("=== start %s ===\n", __func__);
+
+	ms = new GprsMs(tlli);
+	ms->set_callback(&cb);
+
+	OSMO_ASSERT(ms->is_idle());
+
+	dl_tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_dl_tbf);
+	dl_tbf->direction = GPRS_RLCMAC_DL_TBF;
+	ul_tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_ul_tbf);
+	ul_tbf->direction = GPRS_RLCMAC_UL_TBF;
+
+	OSMO_ASSERT(last_cb == UNKNOWN);
+
+	ms->attach_tbf(ul_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == ul_tbf);
+	OSMO_ASSERT(ms->dl_tbf() == NULL);
+	OSMO_ASSERT(last_cb == IS_ACTIVE);
+
+	last_cb = UNKNOWN;
+
+	ms->attach_tbf(dl_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == ul_tbf);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
+	OSMO_ASSERT(last_cb == UNKNOWN);
+
+	ms->detach_tbf(ul_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
+	OSMO_ASSERT(last_cb == UNKNOWN);
+
+	ms->detach_tbf(dl_tbf);
+	OSMO_ASSERT(ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == NULL);
+	OSMO_ASSERT(last_cb == IS_IDLE);
+
+	last_cb = UNKNOWN;
+	delete ms;
+
+	talloc_free(dl_tbf);
+	talloc_free(ul_tbf);
+
+	printf("=== end %s ===\n", __func__);
+}
+
+static void test_ms_replace_tbf()
+{
+	uint32_t tlli = 0xffeeddbb;
+	gprs_rlcmac_dl_tbf *dl_tbf[2];
+	gprs_rlcmac_ul_tbf *ul_tbf;
+	GprsMs *ms;
+	static bool was_idle;
+
+	struct MyCallback: public GprsMs::Callback {
+		virtual void ms_idle(class GprsMs *ms) {
+			OSMO_ASSERT(ms->is_idle());
+			printf("  ms_idle() was called\n");
+			was_idle = true;
+		}
+		virtual void ms_active(class GprsMs *ms) {
+			OSMO_ASSERT(!ms->is_idle());
+			printf("  ms_active() was called\n");
+		}
+	} cb;
+
+	printf("=== start %s ===\n", __func__);
+
+	ms = new GprsMs(tlli);
+	ms->set_callback(&cb);
+
+	OSMO_ASSERT(ms->is_idle());
+	was_idle = false;
+
+	dl_tbf[0] = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_dl_tbf);
+	dl_tbf[0]->direction = GPRS_RLCMAC_DL_TBF;
+	dl_tbf[1] = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_dl_tbf);
+	dl_tbf[1]->direction = GPRS_RLCMAC_DL_TBF;
+	ul_tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_ul_tbf);
+	ul_tbf->direction = GPRS_RLCMAC_UL_TBF;
+
+	ms->attach_tbf(dl_tbf[0]);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf[0]);
+	OSMO_ASSERT(!was_idle);
+
+	ms->attach_tbf(dl_tbf[1]);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf[1]);
+	OSMO_ASSERT(!was_idle);
+
+	ms->attach_tbf(ul_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == ul_tbf);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf[1]);
+	OSMO_ASSERT(!was_idle);
+
+	ms->detach_tbf(ul_tbf);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf[1]);
+	OSMO_ASSERT(!was_idle);
+
+	ms->detach_tbf(dl_tbf[0]);
+	OSMO_ASSERT(!ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == dl_tbf[1]);
+	OSMO_ASSERT(!was_idle);
+
+	ms->detach_tbf(dl_tbf[1]);
+	OSMO_ASSERT(ms->is_idle());
+	OSMO_ASSERT(ms->ul_tbf() == NULL);
+	OSMO_ASSERT(ms->dl_tbf() == NULL);
+	OSMO_ASSERT(was_idle);
+
+	delete ms;
+
+	talloc_free(dl_tbf[0]);
+	talloc_free(dl_tbf[1]);
+	talloc_free(ul_tbf);
+
+	printf("=== end %s ===\n", __func__);
+}
+
+
+static const struct log_info_cat default_categories[] = {
+	{"DPCU", "", "GPRS Packet Control Unit (PCU)", LOGL_INFO, 1},
+};
+
+static int filter_fn(const struct log_context *ctx,
+	struct log_target *tar)
+{
+	return 1;
+}
+
+const struct log_info debug_log_info = {
+	filter_fn,
+	(struct log_info_cat*)default_categories,
+	ARRAY_SIZE(default_categories),
+};
+
+int main(int argc, char **argv)
+{
+	struct vty_app_info pcu_vty_info = {0};
+
+	tall_pcu_ctx = talloc_named_const(NULL, 1, "MsTest context");
+	if (!tall_pcu_ctx)
+		abort();
+
+	msgb_set_talloc_ctx(tall_pcu_ctx);
+	osmo_init_logging(&debug_log_info);
+	log_set_use_color(osmo_stderr_target, 0);
+	log_set_print_filename(osmo_stderr_target, 0);
+	log_set_log_level(osmo_stderr_target, LOGL_INFO);
+
+	vty_init(&pcu_vty_info);
+	pcu_vty_init(&debug_log_info);
+
+	test_ms_state();
+	test_ms_callback();
+	test_ms_replace_tbf();
+
+	if (getenv("TALLOC_REPORT_FULL"))
+		talloc_report_full(tall_pcu_ctx, stderr);
+
+	return EXIT_SUCCESS;
+}
+
+extern "C" {
+void l1if_pdch_req() { abort(); }
+void l1if_connect_pdch() { abort(); }
+void l1if_close_pdch() { abort(); }
+void l1if_open_pdch() { abort(); }
+}
diff --git a/tests/ms/MsTest.err b/tests/ms/MsTest.err
new file mode 100644
index 0000000..d2e20c4
--- /dev/null
+++ b/tests/ms/MsTest.err
@@ -0,0 +1,20 @@
+Creating MS object, TLLI = 0xffeeddbb
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Destroying MS object, TLLI = 0xffeeddbb
+Creating MS object, TLLI = 0xffeeddbb
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Destroying MS object, TLLI = 0xffeeddbb
+Creating MS object, TLLI = 0xffeeddbb
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
+Detaching TBF from MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL)
+Destroying MS object, TLLI = 0xffeeddbb
diff --git a/tests/ms/MsTest.ok b/tests/ms/MsTest.ok
new file mode 100644
index 0000000..a0d4e9e
--- /dev/null
+++ b/tests/ms/MsTest.ok
@@ -0,0 +1,10 @@
+=== start test_ms_state ===
+=== end test_ms_state ===
+=== start test_ms_callback ===
+  ms_active() was called
+  ms_idle() was called
+=== end test_ms_callback ===
+=== start test_ms_replace_tbf ===
+  ms_active() was called
+  ms_idle() was called
+=== end test_ms_replace_tbf ===
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 2a21a93..f1f4032 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -29,3 +29,10 @@
 cat $abs_srcdir/types/TypesTest.err > experr
 AT_CHECK([$OSMO_QEMU $abs_top_builddir/tests/types/TypesTest], [0], [expout], [experr])
 AT_CLEANUP
+
+AT_SETUP([ms])
+AT_KEYWORDS([ms])
+cat $abs_srcdir/ms/MsTest.ok > expout
+cat $abs_srcdir/ms/MsTest.err > experr
+AT_CHECK([$OSMO_QEMU $abs_top_builddir/tests/ms/MsTest], [0], [expout], [experr])
+AT_CLEANUP