osmo_counter will be soon deprecated. Use the newer and more flexible
osmo_stat_item instead.
Depends on: Id2462c4866bd22bc2338c9c8f69b775f88ae7511 (libosmocore)
Change-Id: I6a20123b263f4f808153794ee8a735092deb399e
If we 100% sure that trans == NULL, it makes more sense to use
generic LOGP(DSS, LOGL_*, ...) call, so the logs can reflect
more information than such dummy prefix:
trans(NULL NULL callref-0x0 tid-0) ...
Change-Id: I6b68a0f0b32eb126e0f7e914a314130254d28467
In gsm0911_gsup_rx() we do call vlr_subscr_find_by_imsi(), which
increases subscriber's reference count by one using the function
name as the token. However, we never release this token, so the
reference count grows on every received GSUP PROC-SS message.
Change-Id: I5540556b1c75f6873883e46b78656f31fc1ef186
This message can be used by the HLR/EUSE to indicate that something
went wrong, e.g. the connection with EUSE is lost, EUSE or the MS
did not respond in time, etc. OsmoMSC needs to release the SS/USSD
transaction, and send GSM 04.80 RELEASE COMPLETE message to the MS
if there is an active RAN connection.
Change-Id: I076d12ef24d7320eda1df1ee4588da7375ef3d9e
Related: (TTCN-3) I5586a88136c936441a842f49248824680603672e
Related: OS#2931
This check was copy-pasted from the CC handling code during the
initial development of "SS/USSD over GSUP" feature. It probably
makes sense for MT calls, but definitely not for SS/USSD.
Change-Id: I2899a23ee49fd7917443943629603700a5025cf4
This check was copy-pasted either from CC, or from SMS handling
code during the initial development of "SS/USSD over GSUP". Now
this is the only one survived after the recent refactoring.
I doubt this is exactly the right way to check whether subscriber
is attached or not. Moreover, this check should rather be done in
a single place, rather then in each CC/SS/SMS handler separately.
Change-Id: I7bd48860e923cb1f1a5bccc4b0f497ec1a7bcf84
In case of network-originated SS/USSD session establishment, we
need to verify the received GSUP PROC_SS_REQ message and make
sure that all mandatory IEs are present.
There is no sensible need to allocate a new transaction before
doing all the checks, other than the ability to use LOG_TRANS().
This complicates the code, so let's avoid the early allocation.
Change-Id: I4e027b19e8065a39324a1647957cef4066b82ce7
It is expected that establish_nc_ss_trans() returns an allocated
transaction in successful case, or NULL in case of error. The
function assumes two scenarios:
- the subscriber already has an active RAN connection,
- RAN connection needs to be established (Paging).
In the first case, a pointer to the transaction is returned as
expected, but in case of Paging, NULL has always been returned,
even if there were no errors. Let's fix this.
Change-Id: I9dcee64dd0b435ef29630c223132b81724701f93
3GPP TS 49.008 '4.3 Roles of MSC-A, MSC-I and MSC-T' defines distinct roles:
- MSC-A is responsible for managing subscribers,
- MSC-I is the gateway to the RAN.
- MSC-T is a second transitory gateway to another RAN during Handover.
After inter-MSC Handover, the MSC-I is handled by a remote MSC instance, while
the original MSC-A retains the responsibility of subscriber management.
MSC-T exists in this patch but is not yet used, since Handover is only prepared
for, not yet implemented.
Facilitate Inter-MSC and inter-BSC Handover by the same internal split of MSC
roles.
Compared to inter-MSC Handover, mere inter-BSC has the obvious simplifications:
- all of MSC-A, MSC-I and MSC-T roles will be served by the same osmo-msc
instance,
- messages between MSC-A and MSC-{I,T} don't need to be routed via E-interface
(GSUP),
- no call routing between MSC-A and -I via MNCC necessary.
This is the largest code bomb I have submitted, ever. Out of principle, I
apologize to everyone trying to read this as a whole. Unfortunately, I see no
sense in trying to split this patch into smaller bits. It would be a huge
amount of work to introduce these changes in separate chunks, especially if
each should in turn be useful and pass all test suites. So, unfortunately, we
are stuck with this code bomb.
The following are some details and rationale for this rather huge refactoring:
* separate MSC subscriber management from ran_conn
struct ran_conn is reduced from the pivotal subscriber management entity it has
been so far to a mere storage for an SCCP connection ID and an MSC subscriber
reference.
The new pivotal subscriber management entity is struct msc_a -- struct msub
lists the msc_a, msc_i, msc_t roles, the vast majority of code paths however
use msc_a, since MSC-A is where all the interesting stuff happens.
Before handover, msc_i is an FSM implementation that encodes to the local
ran_conn. After inter-MSC Handover, msc_i is a compatible but different FSM
implementation that instead forwards via/from GSUP. Same goes for the msc_a
struct: if osmo-msc is the MSC-I "RAN proxy" for a remote MSC-A role, the
msc_a->fi is an FSM implementation that merely forwards via/from GSUP.
* New SCCP implementation for RAN access
To be able to forward BSSAP and RANAP messages via the GSUP interface, the
individual message layers need to be cleanly separated. The IuCS implementation
used until now (iu_client from libosmo-ranap) did not provide this level of
separation, and needed a complete rewrite. It was trivial to implement this in
such a way that both BSSAP and RANAP can be handled by the same SCCP code,
hence the new SCCP-RAN layer also replaces BSSAP handling.
sccp_ran.h: struct sccp_ran_inst provides an abstract handler for incoming RAN
connections. A set of callback functions provides implementation specific
details.
* RAN Abstraction (BSSAP vs. RANAP)
The common SCCP implementation did set the theme for the remaining refactoring:
make all other MSC code paths entirely RAN-implementation-agnostic.
ran_infra.c provides data structures that list RAN implementation specifics,
from logging to RAN de-/encoding to SCCP callbacks and timers. A ran_infra
pointer hence allows complete abstraction of RAN implementations:
- managing connected RAN peers (BSC, RNC) in ran_peer.c,
- classifying and de-/encoding RAN PDUs,
- recording connected LACs and cell IDs and sending out Paging requests to
matching RAN peers.
* RAN RESET now also for RANAP
ran_peer.c absorbs the reset_fsm from a_reset.c; in consequence, RANAP also
supports proper RESET semantics now. Hence osmo-hnbgw now also needs to provide
proper RESET handling, which it so far duly ignores. (TODO)
* RAN de-/encoding abstraction
The RAN abstraction mentioned above serves not only to separate RANAP and BSSAP
implementations transparently, but also to be able to optionally handle RAN on
distinct levels. Before Handover, all RAN messages are handled by the MSC-A
role. However, after an inter-MSC Handover, a standalone MSC-I will need to
decode RAN PDUs, at least in order to manage Assignment of RTP streams between
BSS/RNC and MNCC call forwarding.
ran_msg.h provides a common API with abstraction for:
- receiving events from RAN, i.e. passing RAN decode from the BSC/RNC and
MS/UE: struct ran_dec_msg represents RAN messages decoded from either BSSMAP
or RANAP;
- sending RAN events: ran_enc_msg is the counterpart to compose RAN messages
that should be encoded to either BSSMAP or RANAP and passed down to the
BSC/RNC and MS/UE.
The RAN-specific implementations are completely contained by ran_msg_a.c and
ran_msg_iu.c.
In particular, Assignment and Ciphering have so far been distinct code paths
for BSSAP and RANAP, with switch(via_ran){...} statements all over the place.
Using RAN_DEC_* and RAN_ENC_* abstractions, these are now completely unified.
Note that SGs does not qualify for RAN abstraction: the SGs interface always
remains with the MSC-A role, and SGs messages follow quite distinct semantics
from the fairly similar GERAN and UTRAN.
* MGW and RTP stream management
So far, managing MGW endpoints via MGCP was tightly glued in-between
GSM-04.08-CC on the one and MNCC on the other side. Prepare for switching RTP
streams between different RAN peers by moving to object-oriented
implementations: implement struct call_leg and struct rtp_stream with distinct
FSMs each. For MGW communication, use the osmo_mgcpc_ep API that has originated
from osmo-bsc and recently moved to libosmo-mgcp-client for this purpose.
Instead of implementing a sequence of events with code duplication for the RAN
and CN sides, the idea is to manage each RTP stream separately by firing and
receiving events as soon as codecs and RTP ports are negotiated, and letting
the individual FSMs take care of the MGW management "asynchronously". The
caller provides event IDs and an FSM instance that should be notified of RTP
stream setup progress. Hence it becomes possible to reconnect RTP streams from
one GSM-04.08-CC to another (inter-BSC Handover) or between CC and MNCC RTP
peers (inter-MSC Handover) without duplicating the MGCP code for each
transition.
The number of FSM implementations used for MGCP handling may seem a bit of an
overkill. But in fact, the number of perspectives on RTP forwarding are far
from trivial:
- an MGW endpoint is an entity with N connections, and MGCP "sessions" for
configuring them by talking to the MGW;
- an RTP stream is a remote peer connected to one of the endpoint's
connections, which is asynchronously notified of codec and RTP port choices;
- a call leg is the higher level view on either an MT or MO side of a voice
call, a combination of two RTP streams to forward between two remote peers.
BSC MGW PBX
CI CI
[MGW-endpoint]
[--rtp_stream--] [--rtp_stream--]
[----------------call_leg----------------]
* Use counts
Introduce using the new osmo_use_count API added to libosmocore for this
purpose. Each use token has a distinct name in the logging, which can be a
globally constant name or ad-hoc, like the local __func__ string constant. Use
in the new struct msc_a, as well as change vlr_subscr to the new osmo_use_count
API.
* FSM Timeouts
Introduce using the new osmo_tdef API, which provides a common VTY
implementation for all timer numbers, and FSM state transitions with the
correct timeout. Originated in osmo-bsc, recently moved to libosmocore.
Depends: Ife31e6798b4e728a23913179e346552a7dd338c0 (libosmocore)
Ib9af67b100c4583342a2103669732dab2e577b04 (libosmocore)
Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore)
Ie9e2add7bbfae651c04e230d62e37cebeb91b0f5 (libosmo-sccp)
I26be5c4b06a680f25f19797407ab56a5a4880ddc (osmo-mgw)
Ida0e59f9a1f2dd18efea0a51680a67b69f141efa (osmo-mgw)
I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw)
Change-Id: I27e4988e0371808b512c757d2b52ada1615067bd
It may happen that either the MS or an EUSE would become
unresponsive during a call independent SS session, e.g.
due to a bug, or a dropped message. In such cases, the
corresponding transaction would remain unfreed forever.
This change introduces a guard timer, that prevents keeping
'stalled' NCSS sessions forever. As soon as it expires, both
sides (i.e. MS and EUSE) are getting notified, and the
transaction is being released.
By default, the timer expires after 30 seconds. As soon as
either the MS, or an EUSE initiates any activity,
the watchdog timer is rescheduled.
The timeout value can be configured from the VTY:
msc
...
! Use 0 to disable this timer
ncss guard-timeout 30
Please note that changing the timeout value at run-time
doesn't affect the existing NCSS sessions, excepting the
case when the timer is disabled at run-time.
This change makes TC_lu_and_ss_session_timeout pass.
Change-Id: Icf4d87c45e90324764073e8230e0fb9cb96dd9cb
Related Change-Id: (TTCN) I3e1791773d56617172ae27a46889a1ae4d400e2f
Related: OS#3655
According to GSM 04.07, the TI flag takes one bit and can be
either of the following:
'0'B - transaction is allocated by sender of a message,
'1'B - transaction is allocated by receiver of a message.
Since we store transaction ID in gsm_trans structure, we also store
TI flag (as a part of transaction ID), which in this context means:
'0'B - transaction is allocated by us (OsmoMSC),
'1'B - transaction is allocated by some MS.
In 100% cases, trans_assign_trans_id() is used to assign transaction IDs
to transactions allocated by us (i.e. OsmoMSC) for MT connections. And
there is no need to use it for MO transactions, because they basically
already do contain a valid transaction ID assigned by the MS.
Change-Id: Ie11999900b1789652ee078d34636dcda1e137eb0
Add an SGs interface (3GPP TS 29.118) to osmo-msc in order to support
SMS tunneling and Circuit Switched Fallback (CSFB)
Change-Id: I73359925fc1ca72b33a1466e6ac41307f2f0b11d
Related: OS#3615
Log transaction allocation errors as such. While at it, use proper
subsystem to log missing VLR subscriber.
Change-Id: I617be8793b9416ccd49022c72f7d93df7f4fb4d9
In gsm0911_rcv_nc_ss() we sometimes use pdisc parsed from msgb and
sometimes constant. This function is only called when protocol
discriminator is GSM48_PDISC_NC_SS so there's no point in parsing it
again from msgb.
Let's make it consistent and always use constant.
Change-Id: Iae40bf9906fe676ff817c709120015fca4c9e042
Always use LAC which is part of Cell Global ID otherwise we might end up
in a situation where separately stored LAC differs.
Both are described in 3GPP TS 23.008 $2.4 as temporary subscriber data
to be stored in VLR. Both are defined in 3GPP TS 23.003. The LAC is part
of LAI which is part of CGI so there should be no case when those values
differ for a given subscriber.
Change-Id: I993ebc3e14f25e83124b6d3f8461a4b18f971f8e
For hysterical raisins, there are some header files that contain few
declarations, and where the name doesn't reflect the content. Combine them to
new msc_common.h:
- common.h
- common_cs.h
- osmo_msc.h
Change-Id: I9e3a587342f8d398fb27354a2f2475f8797cdb28
Following previous rename of gsm_subscriber_connection:
Some functions and #defines are still called like "msc_conn" or just "msc_",
while they are clearly about a RAN conn.
To avoid confusion with the future separate concepts of MSC roles and a RAN
connection, rename all those to match the common "ran_conn" prefix.
Change-Id: Ia17a0a35f11911e00e19cafb5d7828d729a69640
In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.
* Name choice:
In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.
The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.
* Rationale:
A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.
Also:
- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*
Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
osmo-hlr has recently (as of Change-Id
Iad227bb477d64da30dd6bfbbe1bd0c0a55be9474) a working shared library
implementation of libosmo-gsup-client.
We can remove the local implementation in osmo-msc and use the
system-installed shared library instead.
Change-Id: I6f542945403cf2e3ddac419186b09ec0e2d43b69
Since we don't process SS/USSD requests in OsmoMSC anymore, there
are some useless GSM 04.80 functions remained from the past.
In particular, this change does the following:
- removes both gsm0480_send_{ussd_response|return_error}
functions because they are not used anymore;
- changes symbol prefix from 'gsm0480_' to 'msc_', in order to
avoid possible conflicts with the libosmogsm's GSM 04.80 API;
- cleans up useless includes;
Change-Id: I2990d8627bce0ce6afb1dcf6b11bb194292380d3
This change introduces some new rate counters for call-independent
SS/USSD connections. As OsmoMSC doesn't handle the messages itself,
and only responsible for dispatching messages between both
A and GSUP interfaces, the following is taken into account:
- MS-initiated and network-initiated requests to establish
a NC SS/USSD session (transaction) - "nc_ss:m{o|t}_requests";
- successfully established MS-initiated and network-initiated
SS/USSD sessions (transactions) - "nc_ss:m{o|t}_established".
Change-Id: I23c9475abc9951d82f3342fdc5aaa367836f7741
According to GSM TS 02.90, section 4.3, release of the connection
used for SS/USSD is normally the responsibility of the network.
But the user may also initiate connection release, e.g. by
pressing the 'red button'.
TTCN-3 test case: I7936ed5072ed2ae02f039dc90a1fece1e7f70a70
Change-Id: I76fc277bf9db614a97824b1541cd5bb75aa3e29d
This change introduces a possibility to establish network-initiated
SS/USSD transactions with a subscriber in either IDLE, or DEDICATED
state. In the first case, a new transaction is established using
Paging procedure. If a subscriber already has an active connection,
a separate new transaction is established.
TTCN-3 test case: I073893c6e11be27e9e36f98f11c1491d0c173985
Change-Id: Ief14f8914ef013bd6efd7be842f81fbf053f02e2
In order to be able to support external SS/USSD gateway, we should
not terminate the GSM 04.80 messages at OsmoMSC. Instead, we need
to follow the GSM TS 09.11 specification, and forward all messages
unhandled by OsmoMSC to OsmoHLR over GSUP protocol.
This change implements forwarding of MO SS/USSD messages. The
forwarding assumes transcoding between GSM 04.80 messages and
GSUP messages. The payload of Facility IE is carried 'as is'.
As a side-effect, this will disable the osmo-msc internal handler
implementing the "*#100#" for obtaining the subscribers own phone
number. In order to re-gain this functionality, you will need a
modern osmo-hlr (Change-Id I1d09fab810a6bb9ab02904de72dbc9e8a414f9f9)
and the following line in your osmo-hlr.cfg:
hlr
ussd route prefix *#100# internal own-msisdn
TTCN-3 test case: I01de73aced6057328a121577a5a83bc2615fb2d4
Change-Id: Ide5f7e350b537db80cd8326fc59c8bf2e01cb68c
There is no need to pass a pointer to a ss_request struct when
calling the gsm0480_send_ussd_* functions, because they only
use both transaction ID and InvokeID from there, which may
be passed directly.
This change allows one to use this API without parsing the
whole GSM 04.80 message, or when parsing is failed. Moreover,
if InvokeID is not available, one can pass any incorrect,
(e.g. negative) value, so the universal NULL tag will be used.
Finally, setting a TI flag is also up to the caller.
Change-Id: I13d5abbfdcf8238ebaf0566c420f09cd9255b648
Previously it was intended that we are always parsing the
whole GSM 04.80 message, including the Invoke ID. But
there is no need to do that, since we are going to
forward the Facility IE payload to HLR in near future.
Moreover, there was a mistake (my bad) - transaction is
being established before parsing of the message, so the
req structure remains uninitialized until that.
Let's just send RELEASE COMPLETE message without any Cause or
Facility IEs. We could indicate a problem using the first one,
but according to GSM TS 04.80, the Cause IE only makes sense
when "its functional handling is specified in the service
description or GSM TS 09.11".
Change-Id: Iecba2dccada9bbcdeb3a9dfd868719aeedc07022
During a long time, we had both file and symbol names, actually
related to Supplementary Services, with the 'ussd' abbreviation.
This is not absolutely wrong, but isn't correct at the same time.
USSD is a kind of Supplementary Services, this is only a part
of them. There are also 'structured' Supplementary Services,
which can be call related or call independent.
The "Signalling interworking for supplementary services" is
defined by GSM TS 09.11, and this is exactly what MSC should
implement. Let's use the specification number for naming, as
we do e.g. in the GSM 04.11 (SMS) implementation.
Change-Id: Ic1eaceddb58132318e4e941be542da34b8ebefe1
Martin Hauke
Alexander Couzens
Harald Welte