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ms: Support new and old TLLIs 

According to the specification (GSM 04.08/24.008, 4.7.1.5) after a
new P-TMSI has been assigned, the old P-TMSI must be kept basically
until it has been used by both sides. Since the TLLI will be derived
from the P-TMSI, the old TLLI must also be kept until the new TLLI
has been used by both MS and SGSN.

This commit modifies the TLLI handling of GprsMs accordingly.
set_tlli() is only used with TLLIs derived from MS messages,
confirm_tlli() is used with TLLIs derived from messages received from
the SGSN. tlli() returns the value set by the MS. check_tlli()
matches each of the TLLI used by either MS or SGSN as well as the old
TLLI until it has been confirmed.

Sponsored-by: On-Waves ehf
This commit is contained in:
Jacob Erlbeck 2015-05-15 15:50:43 +02:00
parent e43460b50f
commit 9399046729
12 changed files with 235 additions and 46 deletions
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16
src/gprs_bssgp_pcu.cpp
View File

@ -118,6 +118,7 @@ static int gprs_bssgp_pcu_rx_dl_ud(struct msgb *msg, struct tlv_parsed *tp)
struct bssgp_ud_hdr *budh;
uint32_t tlli;
uint32_t tlli_old = 0;
uint8_t *data;
uint16_t len;
char imsi[16] = "000";
@ -163,9 +164,22 @@ static int gprs_bssgp_pcu_rx_dl_ud(struct msgb *msg, struct tlv_parsed *tp)
LOGP(DBSSGP, LOGL_NOTICE, "BSSGP missing mandatory "
"PDU_LIFETIME IE\n");
/* get optional TLLI old */
if (TLVP_PRESENT(tp, BSSGP_IE_TLLI))
{
uint8_t tlli_len = TLVP_LEN(tp, BSSGP_IE_PDU_LIFETIME);
uint16_t *e_tlli_old = (uint16_t *) TLVP_VAL(tp, BSSGP_IE_TLLI);
if (tlli_len == 2)
tlli_old = ntohs(*e_tlli_old);
else
LOGP(DBSSGP, LOGL_NOTICE, "BSSGP invalid length of "
"TLLI (old) IE\n");
}
LOGP(DBSSGP, LOGL_INFO, "LLC [SGSN -> PCU] = TLLI: 0x%08x IMSI: %s len: %d\n", tlli, imsi, len);
return gprs_rlcmac_dl_tbf::handle(the_pcu.bts, tlli, imsi, ms_class, delay_csec, data, len);
return gprs_rlcmac_dl_tbf::handle(the_pcu.bts, tlli, tlli_old, imsi,
ms_class, delay_csec, data, len);
}
int gprs_bssgp_pcu_rx_paging_ps(struct msgb *msg, struct tlv_parsed *tp)

46
src/gprs_ms.cpp
View File

@ -58,6 +58,8 @@ GprsMs::GprsMs(uint32_t tlli) :
m_ul_tbf(NULL),
m_dl_tbf(NULL),
m_tlli(tlli),
m_new_ul_tlli(0),
m_new_dl_tlli(0),
m_is_idle(true),
m_ref(0),
m_list(this)
@ -185,12 +187,52 @@ void GprsMs::update_status()
void GprsMs::set_tlli(uint32_t tlli)
{
if (tlli == m_tlli)
if (tlli == m_tlli || tlli == m_new_ul_tlli)
return;
if (tlli != m_new_dl_tlli) {
LOGP(DRLCMAC, LOGL_INFO,
"Modifying MS object, UL TLLI: 0x%08x -> 0x%08x, "
"not yet confirmed\n",
this->tlli(), tlli);
m_new_ul_tlli = tlli;
return;
}
LOGP(DRLCMAC, LOGL_INFO,
"Modifying MS object, TLLI: 0x%08x -> 0x%08x\n",
"Modifying MS object, TLLI: 0x%08x -> 0x%08x, "
"already confirmed partly\n",
m_tlli, tlli);
m_tlli = tlli;
m_new_dl_tlli = 0;
m_new_ul_tlli = 0;
}
bool GprsMs::confirm_tlli(uint32_t tlli)
{
if (tlli == m_tlli || tlli == m_new_dl_tlli)
return false;
if (tlli != m_new_ul_tlli) {
/* The MS has not sent a message with the new TLLI, which may
* happen according to the spec [TODO: add reference]. */
LOGP(DRLCMAC, LOGL_INFO,
"The MS object cannot fully confirm an unexpected TLLI: 0x%08x, "
"partly confirmed\n", tlli);
/* Use the network's idea of TLLI as candidate, this does not
* change the result value of tlli() */
m_new_dl_tlli = tlli;
return false;
}
LOGP(DRLCMAC, LOGL_INFO,
"Modifying MS object, TLLI: 0x%08x confirmed\n", tlli);
m_tlli = tlli;
m_new_dl_tlli = 0;
m_new_ul_tlli = 0;
return true;
}

17
src/gprs_ms.h
View File

@ -51,8 +51,10 @@ public:
gprs_rlcmac_ul_tbf *ul_tbf() const {return m_ul_tbf;}
gprs_rlcmac_dl_tbf *dl_tbf() const {return m_dl_tbf;}
uint32_t tlli() const {return m_tlli;}
uint32_t tlli() const;
void set_tlli(uint32_t tlli);
bool confirm_tlli(uint32_t tlli);
bool check_tlli(uint32_t tlli);
void attach_tbf(gprs_rlcmac_tbf *tbf);
void attach_ul_tbf(gprs_rlcmac_ul_tbf *tbf);
@ -78,7 +80,20 @@ private:
gprs_rlcmac_ul_tbf *m_ul_tbf;
gprs_rlcmac_dl_tbf *m_dl_tbf;
uint32_t m_tlli;
uint32_t m_new_ul_tlli;
uint32_t m_new_dl_tlli;
bool m_is_idle;
int m_ref;
LListHead<GprsMs> m_list;
};
inline uint32_t GprsMs::tlli() const
{
return m_new_ul_tlli ? m_new_ul_tlli : m_tlli;
}
inline bool GprsMs::check_tlli(uint32_t tlli)
{
return tlli != 0 &&
(tlli == m_tlli || tlli == m_new_ul_tlli || tlli == m_new_dl_tlli);
}

4
src/gprs_ms_storage.cpp
View File

@ -58,9 +58,9 @@ GprsMs *GprsMsStorage::get_ms(uint32_t tlli, uint32_t old_tlli, const char *imsi
llist_for_each(pos, &m_list) {
ms = pos->entry();
if (tlli && ms->tlli() == tlli)
if (ms->check_tlli(tlli))
break;
if (old_tlli && ms->tlli() == old_tlli)
if (ms->check_tlli(old_tlli))
break;
/* TODO: Check for IMSI */

25
src/tbf.cpp
View File

@ -95,8 +95,10 @@ void gprs_rlcmac_tbf::update_ms(uint32_t tlli)
{
if (!ms())
set_ms(bts->ms_store().get_or_create_ms(tlli));
else
else if (direction == GPRS_RLCMAC_UL_TBF)
ms()->set_tlli(tlli);
else
ms()->confirm_tlli(tlli);
}
gprs_rlcmac_ul_tbf *tbf_alloc_ul(struct gprs_rlcmac_bts *bts,
@ -814,27 +816,6 @@ void gprs_rlcmac_tbf::update_tlli(uint32_t 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->ul_tbf_by_tlli(m_tlli);
if (ul_tbf) {
ul_tbf->m_tlli = tlli;
changedUl = true;
}
}
/* update the timing advance for the new tlli */
bts->timing_advance()->update(m_tlli, tlli, ta);

3
src/tbf.h
View File

@ -328,7 +328,8 @@ struct gprs_rlcmac_dl_tbf : public gprs_rlcmac_tbf {
/* dispatch Unitdata.DL messages */
static int handle(struct gprs_rlcmac_bts *bts,
const uint32_t tlli, const char *imsi, const uint8_t ms_class,
const uint32_t tlli, const uint32_t old_tlli,
const char *imsi, const uint8_t ms_class,
const uint16_t delay_csec, const uint8_t *data, const uint16_t len);
int append_data(const uint8_t ms_class,

19
src/tbf_dl.cpp
View File

@ -135,9 +135,10 @@ int gprs_rlcmac_dl_tbf::append_data(const uint8_t ms_class,
}
static struct gprs_rlcmac_dl_tbf *tbf_lookup_dl(BTS *bts,
const uint32_t tlli, const char *imsi)
const uint32_t tlli, const uint32_t tlli_old,
const char *imsi)
{
GprsMs *ms = bts->ms_store().get_ms(tlli, 0, imsi);
GprsMs *ms = bts->ms_store().get_ms(tlli, tlli_old, imsi);
if (!ms)
return NULL;
@ -146,7 +147,8 @@ static struct gprs_rlcmac_dl_tbf *tbf_lookup_dl(BTS *bts,
static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
const char *imsi,
const uint32_t tlli, const uint8_t ms_class,
const uint32_t tlli, const uint32_t tlli_old,
const uint8_t ms_class,
const uint8_t *data, const uint16_t len)
{
uint8_t trx, ta, ss;
@ -160,7 +162,7 @@ static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
/* check for uplink data, so we copy our informations */
#warning "Do the same look up for IMSI, TLLI and OLD_TLLI"
#warning "Refactor the below lines... into a new method"
ms = bts->bts->ms_store().get_ms(tlli, 0, imsi);
ms = bts->bts->ms_store().get_ms(tlli, tlli_old, imsi);
if (ms)
ul_tbf = ms->ul_tbf();
@ -229,22 +231,25 @@ static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
* TODO: split into unit test-able parts...
*/
int gprs_rlcmac_dl_tbf::handle(struct gprs_rlcmac_bts *bts,
const uint32_t tlli, const char *imsi,
const uint32_t tlli, const uint32_t tlli_old, const char *imsi,
const uint8_t ms_class, const uint16_t delay_csec,
const uint8_t *data, const uint16_t len)
{
struct gprs_rlcmac_dl_tbf *dl_tbf;
/* check for existing TBF */
dl_tbf = tbf_lookup_dl(bts->bts, tlli, imsi);
dl_tbf = tbf_lookup_dl(bts->bts, tlli, tlli_old, imsi);
if (dl_tbf) {
int rc = dl_tbf->append_data(ms_class, delay_csec, data, len);
if (rc >= 0)
dl_tbf->assign_imsi(imsi);
if (dl_tbf->ms())
dl_tbf->ms()->confirm_tlli(tlli);
return rc;
}
return tbf_new_dl_assignment(bts, imsi, tlli, ms_class, data, len);
return tbf_new_dl_assignment(bts, imsi, tlli, tlli_old, ms_class, data, len);
}
struct msgb *gprs_rlcmac_dl_tbf::llc_dequeue(bssgp_bvc_ctx *bctx)

94
tests/ms/MsTest.cpp
View File

@ -232,6 +232,99 @@ static void test_ms_replace_tbf()
printf("=== end %s ===\n", __func__);
}
static void test_ms_change_tlli()
{
uint32_t start_tlli = 0xaa000000;
uint32_t new_ms_tlli = 0xff001111;
uint32_t other_sgsn_tlli = 0xff00eeee;
GprsMs *ms;
printf("=== start %s ===\n", __func__);
ms = new GprsMs(start_tlli);
OSMO_ASSERT(ms->is_idle());
/* MS announces TLLI, SGSN uses it immediately */
ms->set_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(start_tlli));
ms->confirm_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(!ms->check_tlli(start_tlli));
/* MS announces TLLI, SGSN uses it later */
ms->set_tlli(start_tlli);
ms->confirm_tlli(start_tlli);
ms->set_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(start_tlli));
ms->confirm_tlli(start_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(start_tlli));
ms->set_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(start_tlli));
ms->confirm_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(!ms->check_tlli(start_tlli));
/* MS announces TLLI, SGSN uses it later after another new TLLI */
ms->set_tlli(start_tlli);
ms->confirm_tlli(start_tlli);
ms->set_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(start_tlli));
ms->confirm_tlli(other_sgsn_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(other_sgsn_tlli));
ms->set_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(other_sgsn_tlli));
ms->confirm_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(!ms->check_tlli(start_tlli));
OSMO_ASSERT(!ms->check_tlli(other_sgsn_tlli));
/* SGSN uses the new TLLI before it is announced by the MS (shouldn't
* happen in normal use) */
ms->set_tlli(start_tlli);
ms->confirm_tlli(start_tlli);
ms->confirm_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == start_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(ms->check_tlli(start_tlli));
ms->set_tlli(new_ms_tlli);
OSMO_ASSERT(ms->tlli() == new_ms_tlli);
OSMO_ASSERT(ms->check_tlli(new_ms_tlli));
OSMO_ASSERT(!ms->check_tlli(start_tlli));
delete ms;
printf("=== end %s ===\n", __func__);
}
static void test_ms_storage()
{
uint32_t tlli = 0xffeeddbb;
@ -320,6 +413,7 @@ int main(int argc, char **argv)
test_ms_state();
test_ms_callback();
test_ms_replace_tbf();
test_ms_change_tlli();
test_ms_storage();
if (getenv("TALLOC_REPORT_FULL"))

17
tests/ms/MsTest.err
View File

@ -18,6 +18,23 @@ Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 D
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 = 0xaa000000
Modifying MS object, UL TLLI: 0xaa000000 -> 0xff001111, not yet confirmed
Modifying MS object, TLLI: 0xff001111 confirmed
Modifying MS object, UL TLLI: 0xff001111 -> 0xaa000000, not yet confirmed
Modifying MS object, TLLI: 0xaa000000 confirmed
Modifying MS object, UL TLLI: 0xaa000000 -> 0xff001111, not yet confirmed
Modifying MS object, TLLI: 0xff001111 confirmed
Modifying MS object, UL TLLI: 0xff001111 -> 0xaa000000, not yet confirmed
Modifying MS object, TLLI: 0xaa000000 confirmed
Modifying MS object, UL TLLI: 0xaa000000 -> 0xff001111, not yet confirmed
The MS object cannot fully confirm an unexpected TLLI: 0xff00eeee, partly confirmed
Modifying MS object, TLLI: 0xff001111 confirmed
Modifying MS object, UL TLLI: 0xff001111 -> 0xaa000000, not yet confirmed
Modifying MS object, TLLI: 0xaa000000 confirmed
The MS object cannot fully confirm an unexpected TLLI: 0xff001111, partly confirmed
Modifying MS object, TLLI: 0xaa000000 -> 0xff001111, already confirmed partly
Destroying MS object, TLLI = 0xff001111
Creating MS object, TLLI = 0xffeeddbb
Creating MS object, TLLI = 0xffeeddbc
Attaching TBF to MS object, TLLI = 0xffeeddbb, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)

2
tests/ms/MsTest.ok
View File

@ -8,5 +8,7 @@
ms_active() was called
ms_idle() was called
=== end test_ms_replace_tbf ===
=== start test_ms_change_tlli ===
=== end test_ms_change_tlli ===
=== start test_ms_storage ===
=== end test_ms_storage ===

31
tests/tbf/TbfTest.cpp
View File

@ -51,6 +51,8 @@ static void check_tbf(gprs_rlcmac_tbf *tbf)
static void test_tbf_tlli_update()
{
BTS the_bts;
GprsMs *ms, *ms_new;
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();
@ -63,6 +65,7 @@ static void test_tbf_tlli_update()
0, 0, 0);
dl_tbf->update_tlli(0x2342);
dl_tbf->tlli_mark_valid();
dl_tbf->update_ms(0x2342);
dl_tbf->ta = 4;
the_bts.timing_advance()->remember(0x2342, dl_tbf->ta);
@ -71,23 +74,33 @@ static void test_tbf_tlli_update()
0, 0, 0);
ul_tbf->update_tlli(0x2342);
ul_tbf->tlli_mark_valid();
OSMO_ASSERT(the_bts.dl_tbf_by_tlli(0x2342) == dl_tbf);
OSMO_ASSERT(the_bts.ul_tbf_by_tlli(0x2342) == ul_tbf);
ms = the_bts.ms_by_tlli(0x2342);
OSMO_ASSERT(ms != NULL);
OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
OSMO_ASSERT(ms->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.dl_tbf_by_tlli(0x2342));
OSMO_ASSERT(!the_bts.ul_tbf_by_tlli(0x2342));
ms->confirm_tlli(0x4232);
OSMO_ASSERT(the_bts.dl_tbf_by_tlli(0x4232) == dl_tbf);
OSMO_ASSERT(the_bts.ul_tbf_by_tlli(0x4232) == ul_tbf);
/* It is still there, since the new TLLI has not been used for UL yet */
ms_new = the_bts.ms_by_tlli(0x2342);
OSMO_ASSERT(ms == ms_new);
ms_new = the_bts.ms_by_tlli(0x4232);
OSMO_ASSERT(ms == ms_new);
OSMO_ASSERT(ms->dl_tbf() == dl_tbf);
OSMO_ASSERT(ms->ul_tbf() == ul_tbf);
/* Now use the new TLLI for UL */
ms->set_tlli(0x4232);
ms_new = the_bts.ms_by_tlli(0x2342);
OSMO_ASSERT(ms_new == NULL);
OSMO_ASSERT(the_bts.timing_advance()->recall(0x4232) == 4);
}
@ -318,7 +331,7 @@ static void test_tbf_exhaustion()
snprintf(imsi, sizeof(imsi)-1, "001001%9d", i);
rc = gprs_rlcmac_dl_tbf::handle(bts, tlli, imsi, ms_class,
rc = gprs_rlcmac_dl_tbf::handle(bts, tlli, 0, imsi, ms_class,
delay_csec, buf, sizeof(buf));
if (rc < 0)

7
tests/tbf/TbfTest.err
View File

@ -6,6 +6,8 @@ Slot Allocation (Algorithm A) for class 0
- Assign downlink TS=2
- Setting Control TS 2
TBF(TFI=0 TLLI=0x00000000 DIR=DL STATE=NULL) changing tlli from TLLI=0x00000000 TLLI=0x00002342 ul_changed=0
Creating MS object, TLLI = 0x00002342
Attaching TBF to MS object, TLLI = 0x00002342, TBF = TBF(TFI=0 TLLI=0x00002342 DIR=DL STATE=NULL)
********** TBF starts here **********
Allocating UL TBF: TFI=0 TRX=0 MS_CLASS=0
Slot Allocation (Algorithm A) for class 0
@ -13,8 +15,11 @@ Slot Allocation (Algorithm A) for class 0
- Skipping TS 1, because not enabled
- Assign uplink TS=2 USF=0
- Setting Control TS 2
Attaching TBF to MS object, TLLI = 0x00002342, TBF = TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL)
TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=NULL) changing tlli from TLLI=0x00000000 TLLI=0x00002342 ul_changed=0
TBF(TFI=0 TLLI=0x00002342 DIR=DL STATE=NULL) changing tlli from TLLI=0x00002342 TLLI=0x00004232 ul_changed=1
TBF(TFI=0 TLLI=0x00002342 DIR=DL STATE=NULL) changing tlli from TLLI=0x00002342 TLLI=0x00004232 ul_changed=0
The MS object cannot fully confirm an unexpected TLLI: 0x00004232, partly confirmed
Modifying MS object, TLLI: 0x00002342 -> 0x00004232, already confirmed partly
Searching for first unallocated TFI: TRX=0 first TS=4
Found TFI=0.
********** TBF starts here **********