Commit Graph

9 Commits

Author SHA1 Message Date
Jacob Erlbeck befc760f86 tbf: Store MS class in GprsMs objects
The ms_class value is a property of the MS and thus belongs to the
GprsMs class. Nevertheless the MS object is created after the TLLI
gets known, so the value still has to be stored in the TBF initially.

This commit add the ms_class value to the GprsMs class and introduces
TBF accessor functions which either access that object or, if that is
not available, the value stored locally.

Ticket: #1674
Sponsored-by: On-Waves ehf
2015-06-08 09:38:49 +02:00
Jacob Erlbeck 489a2b35d8 tbf: Move the LLC queue to GprsMs
Currently the enqueued DL LLC messages which have not yet passed to
RLC/MAC encoding are eventually copied from one TBF to the next one
(see gprs_rlcmac_dl_tbf::reuse_tbf). Since the enqueued LLC messages
are related to a specific MS, they should be stored at that layer.

This commit moves the gprs_llc_queue object to GprsMs and changes the
TBF's accessor methods accordingly. The LLC copying code is removed
from gprs_rlcmac_dl_tbf::reuse_tbf().

Sponsored-by: On-Waves ehf
2015-06-08 09:38:44 +02:00
Jacob Erlbeck d9e102472a ms: Add timer
Currently the MS object is immediately idle when all TBFs are
detached and if no guard is being used. Since the plan is to use the
MS objects to pass information from one TBF to the next one even
across the gap of some seconds of inactivity, a mechanism is needed
to keep the MS objects around for some time.

This commit extends the GprsMs class by a timer that keeps the MS
objects in non-idle state for some time after all TBFs have been
detached. The set_timeout method must be used with a non-zero value
to activate this feature.

Sponsored-by: On-Waves ehf
2015-05-28 16:38:16 +02:00
Jacob Erlbeck 9200ce6019 tbf: Store the timing advance (TA) value in the GprsMs object
The TA value rather relates to an MS and not to a single TBF. So all
TBFs share the same TA value. Currently the TA value is stored per
TBF and eventually copied from an old TBF to a new one. It is in
general only passed with an RACH request when the TLLI and thus the
MS is not yet known.

This commit adds a TA member to the GprsMs class and uses that one
when the TBF is associated to an MS object. Since the TBF is not
always associated with an MS object (after RACH or when it has been
replaced by another TBF), the TA value is still stored in each TBF
and that value is used as long as no MS object is being associated.

Sponsored-by: On-Waves ehf
2015-05-28 13:58:23 +02:00
Jacob Erlbeck b0e5eaf59a tbf: Move IMSI to MS object
Currently the IMSI is stored in the TBFs. Since it directly refers to
an MS, it should rather be stored in an MS object.

This patch move the m_imsi field from gprs_rlcmac_tbf to GprsMs,
changes gprs_rlcmac_tbf::imsi() to get the IMSI from the associated
MS object, and adds getter and setter to GprsMs. Before changing the
IMSI of the associated MS object, assign_imsi() checks if there is
already another MS object with the same IMSI and eventually resets
the IMSI of that one. So using update_ms() and assign_imsi() ensures
that there are not two MS object entries is the storage with the
same TLLI or the same IMSI.

Ticket: #1674
Sponsored-by: On-Waves ehf
2015-05-28 12:28:40 +02:00
Jacob Erlbeck 9399046729 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
2015-05-21 17:10:42 +02:00
Jacob Erlbeck 5367086175 ms: Add MS storage class
Currently the MS objects are contained in the TBF objects only. To
allow for an extended life time after the TBF objects have been freed
and to find them based on TLLI, a container for the MS objects is
needed.

This commit adds the container class and also adds the corresponding
m_list member to GprsMs. Further integration into the PCU code is not
yet done.

Ticket: #1674
Sponsored-by: On-Waves ehf
2015-05-20 11:36:12 +02:00
Jacob Erlbeck fecece0e59 tbf: Add MS object management to TBF code
This commit adds MS object creation and cleanup to the TBF related
code. MS objects are created when a TBF that has been "anonymous" so
far gets associated with a TLLI. When a TBF is replaced by another,
the old TBF is detached and the new one is attached to the MS. When
all TBFs have been detached, the MS object gets deleted.

The TBF related code should not call attach_tbf/detach_tbf directly
but use set_ms instead to make sure, that the references are updated
properly. GprsMs::detach_tbf also calls set_ms(NULL) on the detached
TBF object.

The MS object is not really used yet, the focus is still on object
creation, TBF association, and cleanup.

Ticket: #1674
Sponsored-by: On-Waves ehf
2015-05-20 11:31:07 +02:00
Jacob Erlbeck e04e0b0a20 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
2015-05-20 11:30:41 +02:00