A subscriber may have a few active transactions at the same time.
For example, one can receive SMS messages during a call, or during
an active SS/USSD session.
We already have connection ref-counting and transactions for CC
and SMS, so let's also use both for SS/USSD.
Change-Id: I21c6777cb88f1f4f80f75dcd39734e952bd4e8b0
Refactor:
1. Glue the gsm_subscriber_connection alloc to the subscr_conn_fsm.
2. Add separate AUTH_CIPH state to the FSM.
3. Use conn->use_count to trigger conn release.
4. Add separate RELEASING state to the FSM.
5. Add rate counters for each of the three Complete Layer 3 types.
Details:
1. Glue the gsm_subscriber_connection alloc to the subscr_conn_fsm.
Historically, a gsm_subscriber_connection was allocated in libbsc land, and
only upon Complete Layer 3 did libmsc add the fsm instance. After splitting
openbsc.git into a separate osmo-msc, this is no longer necessary, hence:
Closely tie gsm_subscriber_connection allocation to the subscr_conn_fsm
instance: talloc the conn as a child of the FSM instance, and discard the conn
as soon as the FSM terminates.
2. Add separate AUTH_CIPH state to the FSM.
Decoding the Complete Layer 3 message is distinctly separate from waiting for
the VLR FSMs to conclude. Use the NEW state as "we don't know if this is a
valid message yet", and the AUTH_CIPH state as "evaluating, don't release".
A profound effect of this: should we for any odd reason fail to leave the FSM's
NEW state, the conn will be released right at the end of msc_compl_l3(),
without needing to trigger release in each code path.
3. Use conn->use_count to trigger conn release.
Before, the FSM itself would hold a use count on the conn, and hence we would
need to ask it whether it is ready to release the conn yet by dispatching
events, to achieve a use_count decrement.
Instead, unite the FSM instance and conn, and do not hold a use count by the
FSM. Hence, trigger an FSM "UNUSED" event only when the use_count reaches zero.
As long as use counts are done correctly, the FSM will terminate correctly.
These exceptions:
- The new AUTH_CIPH state explicitly ignores UNUSED events, since we expect the
use count to reach zero while evaluating Authentication and Ciphering. (I
experimented with holding a use count by AUTH_CIPH onenter() and releasing by
onleave(), but the use count and thus the conn are released before the next
state can initiate transactions that would increment the use count again.
Same thing for the VLR FSMs holding a use count, they should be done before
we advance to the next state. The easiest is to simply expect zero use count
during the AUTH_CIPH state.)
- A CM Service Request means that even though the MSC would be through with all
it wants to do, we shall still wait for a request to follow from the MS.
Hence the FSM holds a use count on itself while a CM Service is pending.
- While waiting for a Release/Clear Complete, the FSM holds a use count on
itself.
4. Add separate RELEASING state to the FSM.
If we decide to release for other reasons than a use count reaching zero, we
still need to be able to wait for the msc_dtap() use count on the conn to
release.
(An upcoming patch will further use the RELEASING state to properly wait for
Clear Complete / Release Complete messages.)
5. Add rate counters for each of the three Complete Layer 3 types.
Besides LU, also count CM Service Request and Paging Response
acceptance/rejections. Without these counters, only very few of the auth+ciph
outcomes actually show in the counters.
Related: OS#3122
Change-Id: I55feb379e176a96a831e105b86202b17a0ffe889
So far we hit a running T308 during CC release when caused by a BSSMAP Clear
Request, and we loudly log that as error.
However, now I understand that T308 is a direct cause of the dispatch of a REL
IND towards MNCC, which is used to indicate teardown to MNCC. So during
_gsm48_cc_trans_free(), we first clear all timers, then invoke
mncc_release_ind() which starts another timer (useful for graceful CC Release,
but in this code path the intention is immediate release). Simply immediately
cancel the timer again and release the conn.
A separate question is whether a BSSMAP Clear Request should be less aggressive
in releasing the connections; i.e. instead of calling trans_free() all around,
to rather ask each transaction to "please stop soon", somehow.
Related: OS#3062
Change-Id: I231fdb574a086a206321148474cbdc7ca9cf39f0
I assumed that trans_free() would always be called before freeing the FSM. But
the actual conn free dance that tries to make sure a release is triggered from
all directions actually may run into a situation where conn->fi is NULL.
The situation is described in OS#3125.
For now simply drop the assert.
The subscr conn and FSM dealloc will soon be glued firmly together; but I want
to add a test against OS#3062 before that, and that would also hit above assertion.
Related: OS#3125 OS#3062
Change-Id: I5c30e0f9545fb76615776ff6cc16b56aeb5b043a
Match osmo-bsc's naming of the subscriber connection's FSM instance; 'conn->fi'
makes more sense anyway than 'conn->conn_fsm'.
BTW, an upcoming commit will do away with the legacy from libbsc/libmsc duality
and firmly glue the conn allocation to the fi.
Related: OS#3122
Change-Id: If442f2ba78d9722b1065ec30c9a13f372b6a8caa
In trans_free(), call subscr_conn_release_when_unused(), so that we are sure to
clean up after the last transaction is done.
This fixes an error where a conn lingered after a CC failure, because that code
path forgot to trigger cleanup.
Rationale: so far we were triggering the release check after each DTAP dispatch
(compl_l3 and "normal" DTAP), which is sufficient for properly closed
transactions. We also need a check for when a timeout clears an erratic trans.
Adjust test expectation of test_call_mo_to_unknown_timeout to show that the
error is now fixed.
msc_vlr_test_reject_concurrency now sees an additional release checking event
when the SMS transaction is done, which is expected and does not affect the
test otherwise.
Related: OS#2779
Change-Id: I46ff2e9b09b67e4e0d79cccf8c04936f17281fcb
Make sure to deactivate trans.cc.timer when freeing a CC transaction.
Log an error if should be necessary.
This prevents a segfault when we receive a BSSMAP Clear Request from BSC during
an ongoing CC operation. The BSSMAP Clear Request currently triggers immediate
freeing of the conn, while we should still do a graceful release first. While
this patch does not fix the underlying error, it does prevent the MSC from
crashing due to a stale timer, whatever the cause might be.
Related: OS#3062
Change-Id: I86b666f23402a6d94af2d903e514770d1fd5157f
When hunting a conn use count bug, it was very hard to figure out who's (not)
using the conn. To ease tracking down this bug and future bugs, explicitly name
what a conn is being reserved for, and track in a bit mask.
Show in the DREF logs what uses and un-uses a conn. See the test expectation
updates, which nicely show how that clarifies the state of the conn in the
logs.
On errors, log them, but don't fail hard: if one conn use/un-use fails, we
don't want to crash the entire MSC before we have to.
Change-Id: I259aa0eec41efebb4c8221275219433eafaa549b
A valid subscriber is indespensible when allocating a new
transaction. Return NULL if no subscriber is supplied. This
will cause unidentified subscribers to be rejected.
Note: Under normal conditions, the problem does not occour,
but it is still possible that a misbehaving MS might trigger
the problem by sending a SETUP command before authenticating
the subscriber. (unencrypted networks)
Change-Id: Ia8739b6e329ab02c0064270d02ad1d6ee245520d
osmo-nitb becomes osmo-msc
add DIUCS debug log constant
add iucs.[hc]
add msc vty, remove nitb vty
add libiudummy, to avoid linking Iu deps in tests
Use new msc_tx_dtap() instead of gsm0808_submit_dtap()
libmgcp: add mgcpgw client API
bridge calls via mgcpgw
Enable MSC specific CTRL commands, bsc_base_ctrl_cmds_install() still needs to
be split up.
Change-Id: I5b5b6a9678b458affa86800afb1ec726e66eed88
Original libvlr code is by Harald Welte <laforge@gnumonks.org>,
polished and tweaked by Neels Hofmeyr <nhofmeyr@sysmocom.de>.
This is a long series of trial-and-error development collapsed in one patch.
This may be split in smaller commits if reviewers prefer that. If we can keep
it as one, we have saved ourselves the additional separation work.
SMS:
The SQL based lookup of SMS for attached subscribers no longer works since the
SQL database no longer has the subscriber data. Replace with a round-robin on
the SMS recipient MSISDNs paired with a VLR subscriber RAM lookup whether the
subscriber is currently attached.
If there are many SMS for not-attached subscribers in the SMS database, this
will become inefficient: a DB hit returns a pending SMS, the RAM lookup will
reveal that the subscriber is not attached, after which the DB is hit for the
next SMS. It would become more efficient e.g. by having an MSISDN based hash
list for the VLR subscribers and by marking non-attached SMS recipients in the
SMS database so that they can be excluded with the SQL query already.
There is a sanity limit to do at most 100 db hits per attempt to find a pending
SMS. So if there are more than 100 stored SMS waiting for their recipients to
actually attach to the MSC, it may take more than one SMS queue trigger to
deliver SMS for subscribers that are actually attached.
This is not very beautiful, but is merely intended to carry us over to a time
when we have a proper separate SMSC entity.
Introduce gsm_subscriber_connection ref-counting in libmsc.
Remove/Disable VTY and CTRL commands to create subscribers, which is now a task
of the OsmoHLR. Adjust the python tests accordingly.
Remove VTY cmd subscriber-keep-in-ram.
Use OSMO_GSUP_PORT = 4222 instead of 2222. See
I4222e21686c823985be8ff1f16b1182be8ad6175.
So far use the LAC from conn->bts, will be replaced by conn->lac in
Id3705236350d5f69e447046b0a764bbabc3d493c.
Related: OS#1592 OS#1974
Change-Id: I639544a6cdda77a3aafc4e3446a55393f60e4050
This is the first step in creating this repository from the legacy openbsc.git.
Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.
Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7
Vadim Yanitskiy
Harald Welte
Neels Hofmeyr