Commit Graph

118 Commits

Author SHA1 Message Date
Neels Hofmeyr a6078fe1d8 use libosmocore osmo_tdef
Move the T_defs API to libosmocore as osmo_tdefs: remove the local T_defs API
and use libosmocore's osmo_tdef* API instead.

The root reason is moving the mgw_endpoint_fsm to libosmo-mgcp-client to be
able to use it in osmo-msc for inter-MSC handover.

When adding osmo_tdef, the new concept of timer groups was added to the API. It
would make sense to apply group names here as well, but do not modify the VTY
configuration for timers. The future might bring separate groups (or not).

Depends: Ibd6b1ed7f1bd6e1f2e0fde53352055a4468f23e5 (libosmocore)
Change-Id: I66674a5d8403d820038762888c846bae10ceac58
2019-04-23 21:57:44 +02:00
Daniel Willmann 1d5eda4b4c gsm_data.h: Remove unused variable from OpenBSC times
This variable does not seem to be used anywere in OsmoBSC, seems to be a
remnant from OpenBSC times.

Change-Id: I5e4aa352fa5f16f6ff64738f25afd1a844fa4fcb
2019-04-17 16:01:11 +00:00
Neels Hofmeyr c15f6cd640 Handover Request: also parse Chosen Algorithm IE, pass to lchan activation
During inter-BSC-incoming, the MSC sends the chosen encryption algorithm in the
Handover Request message. Actually parse this Chosen Encryption Algorithm IE.

Place the chosen algorithm and the CK into lchan_activate_info->encr so that
the new lchan will use the same ciphering on this new BSS as it did on the old
BSS.

Change-Id: I5b269f50bd2092516bfdf87746196983d3ac49d1
2019-04-08 16:26:28 +02:00
Neels Hofmeyr 58cf1b1f66 lchan activation: add explicit encryption info to activation
For intra-BSC handover, the previous encryption is copied from the old lchan,
which of course is not available during inter-BSC handover.  Hence the lchan
activation info needs to include an explicit encryption information, and we
must not rely on the presence of the previous lchan to copy encryption
information from.

Add struct lchan_activate_info.encr to allow passing encryption info through
lchan_activate() without requiring a previous struct gsm_lchan to be present.

Instead of copying from the old lchan, always copy encryption info to
lchan_activate_info, and during activation, just before sending the Channel
Activation, copy the lchan_activate_info.encr to the new lchan.

This prepares for upcoming I5b269f50bd2092516bfdf87746196983d3ac49d1 which
obtains the encryption information from an intra-BSC-incoming Handover Request
message.

Related: OS#3842
Related: I5b269f50bd2092516bfdf87746196983d3ac49d1
Change-Id: Ib3d259a5711add65ab7298bfa3977855a17a1642
2019-04-08 16:26:28 +02:00
Neels Hofmeyr 0848ff84b7 Revert "assignment_fsm: Properly support assigning signalling mode TCH/x"
This commit breaks voice channel assignment. It results in the
Assignment Complete sent to the MSC for a voice lchan lacking
AoIP Transport Layer Address, Speech Version and Speech Codec.
Hence the MSC cannot complete the Assignment for a voice call.
Let's revisit this patch, test thoroughly and re-merge later.

This reverts commit 4d3a21269b.

Reason for revert: <INSERT REASONING HERE>

Change-Id: I72aaa03539919e7e85b5b75b133326cec5e68bc9
2019-03-14 22:47:31 +00:00
Pau Espin a115052e4f Move msc related code from gsm_data to bsc_msc
This way ipaccess utils can be built without requiring libosmo-sigtran.

Change-Id: I508188896be58ddc3bd4e9c3c661c258c06866f4
2019-03-14 17:07:45 +01:00
Sylvain Munaut 4d3a21269b assignment_fsm: Properly support assigning signalling mode TCH/x
To support the 3 possible preferences, the changes needed were:
 - Replace 'full_rate' bool with a 3 option enum to represent
   the channels types for signalling
 - Switch from _pref/_alt to using an array sorted in preference
   order

Change-Id: I4c7499c8c866ea3ff7b1327edb3615d003d927d3
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
2019-03-14 08:31:58 +00:00
Neels Hofmeyr 90db2a1888 cosmetic: drop unused struct mgcp_ctx shadow
Change-Id: If9c705e9fe6dba9225f7dec045e790af7a875ee8
2019-03-04 22:53:58 +01:00
Philipp Maier bb66d1095b assignment_fsm: fix channel allocator preferences
When the MSC allocates a channel through the ASSIGNMENT REQUEST, it may
ask for a TCH/H and a TCH/F at the same time and tell which of the two
types it prefers.

The process of channel allocation currently selects, based on the BTS,
MSC and MS capabilites exactly one apropriate codec/rate (e.g. TCH/H)
and then tries to allocate it. If that allocation fails, there is no way
to try the second choice and the assignment fails.

For example: The MSC asks for TCH/F and TCH/H, prefering TCH/F, then the
channel allocator will try TCH/F and if it fails (all TCH/F are
currently in use), then TCH/H is never tried.

Since the BSC currently only trys the first best codec/rate that is
supported it also ignores the preference.

Lets fix those problems by including the preference information and both
possible codec/rate settings into the channel allocation decision.

Change-Id: I5239e05c1cfbcb8af28f43373a58fa6c2d216c51
Related: OS#3503
2019-02-21 10:17:37 +01:00
Neels Hofmeyr 7cfdbe7272 comments: clarify usage of conn.assignment and .handover scopes
Change-Id: I7ef602c3ce086aecbc3ae3ae6d3fd33ad2b9f85c
2019-02-06 14:10:20 +01:00
Neels Hofmeyr 4daa21076f handover_fsm: do not access conn->assignment.req, it may be outdated
handover_fsm.c accesses conn->assignment.req.s15_s0 to find out the current
lchan's AMR configuration. However, conn->assignment.* values are only valid
during an ongoing assignment.  Those values may be overwritten by any failed
Assignment attempt, at any time, and hence do not reflect the currently
assigned conn->lchan. Those realms must be kept separate.

The assignment.req.s15_s0 get passed to lchan_activate(), so it makes most
sense to store these values in struct gsm_lchan once the lchan activation
succeeded.

Add gsm_lchan.s15_s0, store the s15_s0 received in lchan_activate_info during
lchan_activate().

In handover_fsm.c, use conn->lchan->s15_s0 instead of conn->assignment.*.

Change-Id: Id8018fd9d56421f2ab7be91703018f6d6f21c929
2019-02-06 01:30:44 +01:00
Harald Welte 963763dfec Implement CSFB "Fast Return" Handling at RR RELEASE
When the MSC sends a BSSMAP CLEAR CMD containing a CSFB Indication IE,
it lets us know that the to-be-released connection related to a CSFB
call.

We as the BSC then subsequently should include the "Cell Selection
Indicator after release of all TCH and SDCCH" IE in the RR RELEASE
message sent to the MS/UE.  This IE contains the LTE neighbor cells
that we're configured to broadcast in si2quater.

That in turn will make sure the MS/UE can return very quickly to
the LTE cell.

Closes: OS#3777
Change-Id: Ibfbb87e2e16b05032ad1cb91c11fad1b2f76d755
Requires: libosmocore Id4bd7f7543f5b0f4f6f876e283bd065039c37646
Requires: libosmocore I0e101af316438b56d63d43fc2cb16d7caf563d07
Requires: libosmocore I8980a6b6d1973b67a2d9ad411c878d956fb428d1
2019-02-05 16:04:35 +01:00
Harald Welte 57658ecdc7 gsm_data: Add gsm_bts_name() just like we have gsm_{trx,ts,lchan}_name()
Change-Id: Icd7fd6273396026c5fe2da600f35631b1bac1614
2019-02-05 09:23:20 +00:00
Neels Hofmeyr 38134eac8b comments: describe some lchan details
(requested by pespin)

Change-Id: I04ec4ce1fd2b7b110bb496186aae39ecfbbc3628
2018-12-21 03:02:27 +01:00
Neels Hofmeyr 700e518a6b make sure early lchan act failure resets the lchan
Fix crash after AMR configuration fails.

The crash is due to an assertion that finds a non-NULL conn in the lchan, when
re-using an lchan that has failed in AMR configuration earlier on. That is
because the AMR config still happens in state UNUSED.

  DCHAN ERROR lchan(0-0-2-TCH_F_TCH_H_PDCH-0)[0x6120000066a0]{UNUSED}: (type=TCH_F) lchan allocation failed in state UNUSED: Can not generate multirate configuration IE
  ...
  DCHAN DEBUG lchan(0-0-2-TCH_F_TCH_H_PDCH-0)[0x6120000066a0]{UNUSED}: (type=TCH_F) After failure handling, already in state UNUSED
  ...
  ...
  DCHAN DEBUG lchan(0-0-2-TCH_F_TCH_H_PDCH-0)[0x6120000066a0]{UNUSED}: Received Event LCHAN_EV_ACTIVATE (lchan_fsm.c:324)
  Assert failed !lchan->conn ../../../../src/osmo-bsc/src/osmo-bsc/lchan_fsm.c:491

The FSM design idea is that when returning to the UNUSED state, all lchan state
is cleared. However, when calling lchan_activate(), a failure may happen still
in state UNUSED, so that we don't transition *back* to UNUSED properly.

So, first transition out of UNUSED before failures can happen. (Other ways to
solve this would be to invoke lchan clearing even if already in UNUSED, but
semantically, transitioning first makes more sense.)

Upon LCHAN_EV_ACTIVATE, just remember the lchan_activate_info and transition to
WAIT_TS_READY, so that on lchan_fail(), we can normally transition back to
UNUSED and clear the lchan.

Move the initial lchan activation code to lchan_fsm_wait_ts_ready_onenter().

Also, there is a bit of duplication of members of the lchan->activate (lchan
state) and the lchan_activate_info (passed to lchan_activate()) structs. The
fix for this also removes the dup:

Add struct lchan_activate_info as child struct at lchan->activate.info, drop
the other lchan->activate members that would dup .info.*. Move struct
lchan_activate_info declaration to gsm_data.h.

Apply the new '.info' member struct throughout the code.

Related: OS#3737
Change-Id: Ide665b10fa3f4583059c55346db8da833959e3cc
2018-12-21 03:02:27 +01:00
Max fe65ece24c LCLS: update parameter representation
* use osmo_lcls struct from libosmocore
* use enum values instead of magic numbers

Change-Id: I5e962d4fbb24bf1fb2398dc13e142a4a3304d858
Related: OS#3659
2018-12-18 17:48:46 +00:00
Pau Espin 1cf21de48f Add VTY option to avoid sending empty Full BCCH Info for disabled SI
According to 3GPP TS 08.58 §8.5.1 BCCH INFORMATION:
"If the Full BCCH information element is not included this indicates that
transmission of the indicated SYSTEM INFORMATION message shall be stopped."

However, some ipaccess nanoBTS firmware versions are known to not support
some SI elements and also to dislike receiving BCCH Information for those SI,
even if received with empty BCCH Information meaning they should not be used.

Upon receival of this kind of message, nanoBTS sends a Failure Report
with following text:
Type=processing failure, Severity=critical failure, Probable cause=Manufacturer specific values: Fatal software error, Additional Text=l2_bch.c:1149
****
** l2_bch.c#1149:BCHbcchSItypeValid( prim_p->infoType )
** IPA_SW_FATAL_ERROR
** In task "TRX Proc:L2_BCH" @ (325).
****

This kind of issue only appears with some fw versions, since it's known
to work fine in other ones, so let's not disable this kind of mesage by
default on all BTs of type "nanobts".

Instead, add a VTY command that allows disabling this kind of message in
order to be able to operate those nanoBTS units.

Fixes: OS#3707
Change-Id: Idec1daabc21de4eea5c55edd1dbb0e0775720fc7
2018-12-14 20:06:37 +00:00
Pau Espin 1b96334b26 paging: Add VTY options to calculate T3113 timeout dynamically
The idea is to have a base static value which is set like before "timer
t3113 [seconds]", but now have a part of this timeout calculated
dynamically based on BTS channel configuration and channel load.

This patch only implements initial support to calculate based on channel
configuration, but doesn't include code to calculate based on channel
load. To implement the later part, we probably need to keep track of BTS
paging queues per paging group, which we don't do nowadays.

Dynamic calculation is enabled by default, and default static base value
is decreased accordingly. This way, in a typical setup were the default
10 seconds were used, now the calculated final value is 11 seconds.
That's intended because it was observed experimentally in osmo-gsm-tester with
a similar channel setup that sometimes paging response can arrive slightly
later than 10 seconds.

Related: OS#3680
Change-Id: I4fb2969b690151415038631fb6ad059aa6835c7f
2018-12-05 19:40:23 +00:00
Pau Espin 0ba20df9ee bsc: Add define for ts_as_pchan_for_each_lchan with ts->pchan_on_init
It will be used further in follow-up patches. It also provides a place
to document its (intricate) logic around it and its possible uses.

Change-Id: Ia1d4bdbfca6b9719f54ee609b6bfadf7f3a4bb43
2018-12-05 16:06:47 +00:00
Pau Espin 7ae0f9c271 bsc: ts_for_each_lchan: Improve documentation
Change-Id: Id7c050087c14aae3f01c6d41d21cf861ff53621c
2018-11-29 15:39:02 +00:00
Pau Espin d3e8e0cf4c bsc: ts_as_pchan_for_each_lchan: reorder and improve documentation
It is moved prior to its user in the header file.

Change-Id: I59f52401ba37b351ba3848e8e9ffb3b24c259496
2018-11-29 15:39:02 +00:00
Neels Hofmeyr 369fba25de send Immediate Assignment Reject only before Immediate Assignment
Set flag lchan->activate.immediate_assignment_sent to true when sending, and
omit a reject after that.

lchan->activate gets completely zeroed in lchan_reset(), which sets that flag
back to false whenever an lchan becomes inactive.

Related: OS#3709
Change-Id: I9ad094d272254d7aee9b0a676201d4ed8cd727ca
2018-11-27 01:35:15 +01:00
Pau Espin 167cb82866 bsc: Enable force-combined-si on nanoBTS by default
Some nanoBTS firmwares (if not all) are known to not work properly with
SI2ter. If BSC enables SI2ter through RSL, SI3 bit announcing SI2ter
available will be forwarded by nanoBTS to MS, but will still only send
SI2 message instead of expected SI2ter during TC=5 (see GSM 05.02 sec 6.3.4 "Mapping
of BCCH data"). As a result, some MS won't allow registering to the
network.

To avoid this kind of scenario, enable force-combined-si by default on
nanoBTS while still allowing to overwrite the feature through VTY. Other
BTS models are kept with force-combined-si disabled by default as
usually, since they seems to be working fine when SI2ter is enabled.

Related: OS#3063
Change-Id: Ide6e8967de0eedc9e2bcaf4414aaa537b009d72d
2018-11-20 16:43:55 +00:00
Neels Hofmeyr eee24eb964 cosmetic: lchan: introduce sub-struct lchan->release.*
Put all lchan release related flags and settings in a sub-struct named
'release' to better indicate what those fields are for. There is no functional
change.

Change-Id: Icfddc6010e5d7c309f1a7ed3526b5b635ffeaf11
2018-11-14 17:33:00 +01:00
Neels Hofmeyr 5b1a7d1e9b lchan release: always Deact SACCH
If an lchan is being released and had a SACCH active, there is no reason to
omit the Deact SACCH message ever. All of the callers that passed
do_deact_sacch = false did so for no good reason.

Drop the do_deact_sacch flag everywhere and, when the lchan type matches and
SAPI[0] is still active, simply always send a Deact SACCH message.

The do_deact_sacch flag was carried over from legacy code, by me, mainly
because I never really understood why it was there. I do hope I'm correct now,
asserting that having this flag makes no sense.

Change-Id: Id3301df059582da2377ef82feae554e94fa42035
2018-11-14 16:16:30 +00:00
Neels Hofmeyr 478e991a78 fix: send RR Release (e.g. after BSSMAP Clear Cmd)
After commit [1], the code makes sure to disassociate lchan and conn before
invoking the lchan release. However, we only send RR Release if a conn is
present, which clearly is nonsense after [1].

[1] commit 8b818a01b0
    "subscr conn: properly forget lchan before release"
    Change-Id: I4fd582b41ba4599af704d670af83651d2450b1db

Manage sending of RR Release via a flag, set during invoking lchan release.

Add do_rr_release arg to lchan_release(), gscon_release_lchans(). In
lchan_fsm.c, send RR Release only if do_rr_release was passed true; do not care
whether a conn is still associated (because it won't ever be since [1]).

That way we can intelligently decide what release process makes sense (whether
the lchan terminates the subscriber connection or whether the connection goes
on at another lchan), and still disassociate lchan and conn early.

BTW, this problem wasn't caught by the stock OsmoBSC TTCN3 tests, because the
f_expect_chan_rel() don't care whether an RR Release happens or not. This is
being fixed by Ibc64058f1e214bea585f4e8dcb66f3df8ead3845.

So far this patch should fix BSC_Tests_LCLS.TC_lcls_connect_clear.

Related: OS#3413
Change-Id: I666b3b4f45706d898d664d380bd0fd2b018be358
2018-11-14 16:16:30 +00:00
Philipp Maier 89d72d8055 gsm_data: make cgi_for_msc available for other modules
The function cgi_for_msc() provides an easy way to get a cell global id
for an msc/bts combination. This function is currently statically
defined in gsm_08_08.c. Lets move it to gsm_data.c and make it publicly
available.

Change-Id: I301fac6e83a429ae59b5c586aa283ad7ba54053d
Related: OS#3645
2018-11-09 11:01:19 +00:00
Oliver Smith 8d8d710a28 vty: add 'show rejected-bts'
Print IDs and IPs of recently rejected BTS devices. Example output:

OsmoBSC> show rejected-bts
Date                Site ID BTS ID IP
------------------- ------- ------ ---------------
2018-10-25 09:36:28    1234      0    192.168.1.37

Related: OS#2841
Change-Id: Iba3bfe8fc9432b7ae8f819df8bd71b35b3ec507e
2018-10-30 16:25:29 +01:00
Philipp Maier c9a4f697d3 codec_pref: handle S0-S15 in ASSIGNMENT REQUEST
Opposed to all other codecs that are common in GSM, AMR requires a codec
configuration that is expressed by a bitmask (S0 to S15) in the speech
codec list in the ASSIGNMENT REQUEST. Also the BSC acknowledges those
configuration in the ASSIGNMENT COMPLETE message.

At the moment osmo-bsc ignores all incoming configuration bits. The bits
in the ASSIGNMENT COMPLETE speech codec (choosen) field are hardcoded.

- Store the configuration bits while parsing the ASSIGNMENT COMPLETE
- Create an intersection with the configuration that is actually
  supported by the BSS
- Return the resulting (chosen) configuration bits with the assignment
  complete message.
- Use the (highest of the) agreed codec rates in RSL channel activation.

Change-Id: I2d8ded51b3eb4c003fe2da6f2d6f48d001b73737
Related: OS#3529
2018-10-05 07:58:22 +00:00
Philipp Maier ef121b2408 gsm_data: remove unused struct member chan_mode
Remove unused gsm_subscriber_connection.user_plane.chan_mode.
There is only one VTY command that displays it along other
parameters, but it is used no where else. Lets remove it.

It was forgotten to be removed in:

commit 31f525e756
Date   Mon May 14 18:14:15 2018 +0200
"large refactoring: use FSMs for lchans; add inter-BSC HO"
change-id I82e3f918295daa83274a4cf803f046979f284366

Change-Id: I10049c14ea206a4daafbdad01634d57c72a79d7c
2018-09-17 14:55:13 +02:00
Philipp Maier 7f52bdadbd gsm_data: remove unused struct member full_rate.
Remove unused member gsm_subscriber_connection.user_plane.full_rate.

It was forgotten to be removed in:

commit 31f525e756
Date   Mon May 14 18:14:15 2018 +0200
"large refactoring: use FSMs for lchans; add inter-BSC HO"
change-id I82e3f918295daa83274a4cf803f046979f284366

Change-Id: I3a14efe0039ff4690e27e3b083eb23c1b2a616c3
2018-09-17 14:54:40 +02:00
Harald Welte 24286f37b7 Introduce gsm48_lchan2chan_desc_as_configured()
gsm48_lchan2chan_desc_as_configured() is similar to gsm48_lchan2chan_desc(),
but uses the *configured* channel combination, rather than the currently
active one.

Change-Id: Id4043218fb770e8420f19a4ef9428680ecdfd286
Related: OS#3532
2018-09-09 17:23:56 +02:00
Harald Welte 251bec1e5d gsm48_lchan2chan_desc() belongs to gsm_data.h
The function is defined in gsm_data.c, so it should be declared
in gsm_data.h and not in gsm_04_08_rr.h

Change-Id: I5200063fb43c857a984ea8e41a8485d796e49cde
2018-09-09 17:23:56 +02:00
Neels Hofmeyr 193c1e3ab0 lchan_fsm: safer 'concluded' flag
The flag lchan->activate.concluded prevents entering the
lchan_on_fully_established()/lchan_on_activation_failure() more than once. So
far it was checked by callers, instead place in the functions themselves.

There is a potential functional change here, since during lchan_fail(), the
concluded flag was set only after entering lchan_on_activation_failure(). Now
it is already set at the start and prevents multiple re-entry beyond doubt.

This patch is not a result of an actual observed faulty behavior, just from
reading the code and seeing the slight loophole.

Change-Id: I0c906438b05442d66255203eb816453b7193a6d8
2018-08-29 02:02:10 +02:00
Pau Espin 9862bcb5cd Fix heap-use-after-free due to OML link destruction
ipaccess_drop_oml was being called inside an osmo_fd cb context, were
-EBADF must be returned if the structure holding the osmo_fd is freed.
In the middle of the path (see OS#3495 for path tree) it goes through a
signal dispatch, so it's impossible to make sure we return some value to
the osmo_fd cb. As a result, it is required to defer dropping the OML
Link from current code path and do it through a timer.

Fixes following ASan report:
20180822124927913  <0004> abis_nm.c:787 OC=RADIO-CARRIER(02) INST=(00,00,ff): CHANGE ADMINISTRATIVE STATE NACK CAUSE=Message cannot be performed
20180822124927913  <0004> osmo_bsc_main.c:186 Got CHANGE ADMINISTRATIVE STATE NACK going to drop the OML links.
20180822124927913  <0015> bts_ipaccess_nanobts.c:406 (bts=0) Dropping OML link.
...
=================================================================
==17607==ERROR: AddressSanitizer: heap-use-after-free on address 0x62e000060a68 at pc 0x7f5ea8e27086 bp 0x7ffde92b6d80 sp 0x7ffde92b6d78
READ of size 8 at 0x62e000060a68 thread T0
    #0 0x7f5ea8e27085 in handle_ts1_write input/ipaccess.c:371
    #1 0x7f5ea8e27085 in ipaccess_fd_cb input/ipaccess.c:391
    #2 0x7f5ea9147ca8 in osmo_fd_disp_fds libosmocore/src/select.c:217
    #3 0x7f5ea9147ca8 in osmo_select_main libosmocore/src/select.c:257
    #4 0x555813ab79d6 in main osmo-bsc/osmo_bsc_main.c:922
    #5 0x7f5ea76d02e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #6 0x555813ab84e9 in _start (/bin/osmo-bsc+0x34d4e9)

Fixes: OS#3495
Change-Id: I7c794c763481c28e8c35dc9b11d27969e16feb3c
2018-08-23 16:47:30 +02:00
Neels Hofmeyr 6d568ed7ff cosmetic: constify gsm_bts_num() net arg
Change-Id: I9a078ffb781ee55c0ca114fa0d752c1b53067419
2018-07-28 12:18:23 +02:00
Neels Hofmeyr d5df9a1d0d lchan_fsm: add in_release_handler flag
If a release event is being handled, ignore other ricocheting release events
until that release handling has concluded.

For example, if an lchan is regularly released, it signals the lchan RTP FSM to
release, which then calls back to say "RTP is released" on termination -- this
should not trigger other state changes than the initial release intends.

Change-Id: Iec41e006b6ab9d0f618d36925341f9536353e5d8
2018-07-28 12:18:23 +02:00
Neels Hofmeyr ac85b34476 lchan_fsm: split off lchan_rtp_fsm, establish RTP a bit earlier
Change-Id: Id7a4407d9b63be05ce63f5f2768b7d7e3d5c86fb
2018-07-28 12:18:23 +02:00
Neels Hofmeyr dbb38d532b fix BSC_CTR_ASSIGNMENT doc strings
Change-Id: I9de0c16a14edd8bf4f02b7781ccfd211e0a79463
2018-07-28 12:18:23 +02:00
Neels Hofmeyr bcdbfb7406 fix nanobts: timeslot FSM: use flags to remember OML,RSL status
Before this patch, the timeslot FSM receives OML and RSL ready events.
Afterwards, it relies on examining the RSL and OML status to match the received
events. This doesn't work for the ip.access nanobts, which fails to change the
CHANNEL OM's operational status even though it has sent an Opstart ACK.  We
receive OML CHANNEL Opstart ACK, but the mo's state left at OP_STATE=Disabled.
We apparently cannot rely on the gsm_abis_mo state as assumed before this
patch, since changing the state depends on each BTS vendor's OML
implementation.

Also, implementation wise, it is better to not include assumptions on RSL and
OML implementations in the timeslot FSM. Simply receive the OML and RSL ready
events and remember that they arrived in dedicated flags.

Remove the no longer needed oml_is_ts_ready() callback from struct
gsm_bts_model added in:

  commit 91aa68f762
  "dyn TS: init only when both RSL and the Channel OM are established"
  I99f29d2ba079f6f4b77f0af12d9784588d2f56b3

This keeps osmo-bts operational while fixing ip.access nanobts, where the
CHANNEL OM's state prevented the timeslot FSM from entering operation.

Change-Id: I4843d03b3237cdcca0ad2041ef6895ff253d8419
2018-07-28 12:18:23 +02:00
Neels Hofmeyr 31f525e756 large refactoring: use FSMs for lchans; add inter-BSC HO
Add FSMs:

- timeslot_fsm: handle dynamic timeslots and OML+RSL availability.
- lchan_fsm: handle an individual lchan activation, RTP stream and release,
  signal the appropriate calling FSMs on success, failure, release.
- mgw_endpoint_fsm: handle one entire endpoint with several CI.
- assignment_fsm: BSSMAP Assignment Request.
- handover_fsm: all of intra, inter-MO and inter-MT handover.

Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing
the maximum amount events (32), and it is more logical to treat assignment,
handover and MGW procedures in separate FSMs.

- Add logging macros for each FSM type:
  - LOG_TS()
  - LOG_LCHAN()
  - LOG_MGWEP(), LOG_CI()
  - LOG_ASSIGNMENT()
  - LOG_HO()
  These log with the osmo_fsm_inst where present.
  New style decision: logging without a final newline char is awkward,
  especially for gsmtap logging and when other logs interleave LOGPC() calls;
  we have various cases where the final \n goes missing, and also this invokes
  the log category checking N times instead of once.
  So I decided to make these macros *always* append a newline, but only if
  there is no final newline yet. I hope that the compiler optimizes the
  strlen() of the constant format strings away. Thus I can log with or without
  typing "\n" and always get an \n termination anyway.

General:

- replace osmo_timers, state enums and program-wide osmo_signal_dispatch()
  with dedicated FSM timeouts, states and events.

- introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def.
  These can be used (with some macro magic) to define a state's timeout once,
  and not make mistakes for each osmo_fsm_inst_state_chg().

Details:

bsc_subscr_conn_fsm.c:

- move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and
  mgw_endpoint_fsm.

- There is exactly one state for an ongoing Assignment, with all details
  handled in conn->assignment.fi. The state relies on the assignment_fsm's
  timeout.

- There is one state for an ongoing Handover; except for an incoming Handover
  from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn
  are both established.

- move bssmap_add_lcls_status() to osmo_bsc_lcls.c

abis_rsl.c:

- move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in
  abis_rsl.c

- reduce some rsl functions to merely send a message, rename to "_tx_".
  - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the
    lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function.

- move all timers and error/release handling away into various FSMs.

- tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an
  lchan passed, but just mode,type that they require. Rename to
  ipacc_speech_mode*() and ipacc_payload_type().

- add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR
  message received during BSSMAP Handover Command.

- move various logging to LOG_LCHAN() in order to log with the lchan FSM instance.
  One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging
  from DRR to DRSL. It might actually make sense to combine those categories.

- lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance.

- handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's
  correct).

- gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during
  inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS.

assignment_fsm.c:

- the Chan Mode Modify in case of re-using the same lchan is not implemented
  yet, because this was also missing in the previous implementation (OS#3357).

osmo_bsc_api.c:

- simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to
  lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv
  twice, once by member assignment and then again with a memcpy.)

- During handover, we used to copy the MR config from the old lchan. Since we
  may handover between FR and HR, rather set the MR Config anew every time, so
  that FR rates are always available on FR lchans, and never on HR lchans.

Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore),
         I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore)
Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-07-28 12:18:23 +02:00
Neels Hofmeyr 596c402835 add gsm_timers, for Tnnn definitions usable by FSMs
Change-Id: If212fcd042051b6fa53484254223614c5b93a9c6
2018-07-28 12:18:23 +02:00
Neels Hofmeyr 149160f9f1 fix / clarify rsl dtap cache
In certain situations like handover or assignment, DTAP must not go out via RSL
directly but is cached to be submitted later. Make sure that all RSL DTAP
sending adheres to this:

gscon_submit_rsl_dtap() is the new "public" API to request an RSL DTAP to be
sent. Depending on the gscon's state, this ends up in the cache or is sent
directly. When caching, there is no way to tell whether sending will succeed or
not, so semantically it does not make sense to even return a result code. Just
return void. Change all "public" callers to gscon_submit_rsl_dtap().

Merge gsm0808_submit_dtap() and submit_dtap() guts to gsm0808_send_rsl_dtap(),
static in bsc_subscr_conn_fsm.c: directly send DTAP, assume a conn->lchan to be
present, or otherwise trigger a BSSMAP Clear Request.

The static submit_dtap() becomes a thin convenience wrapper.

Move ho_dtap_cache* functions to bsc_subscr_conn_fsm.c and rename to
gscon_dtap_cache_* -- they are not only for handover, also for assignment.

Function gsm0808_submit_dtap() m
Introduce function gscon_submit_rsl_dtap()

Change-Id: I6ffd7aa641c8905292c769400048c96aa0949585
2018-07-28 12:18:23 +02:00
Neels Hofmeyr 19bed23065 inter-BSC HO: add neighbor_ident API to manage neighbor-BSS-cells
Depends: Ia71ba742108b5ff020997bfb612ad5eb30d04fcd (libosmocore)
Change-Id: I0153d7069817fba9146ddc11214de2757d7d37bf
2018-07-28 12:18:23 +02:00
Neels Hofmeyr 0c1ac9f010 make T10 configurable like the rest of them
Change-Id: I112c0db17d355d57eb08bc67121ccf49fbf53943
2018-06-08 16:16:42 +00:00
Neels Hofmeyr fc622c7241 drop dead code: conn->T10, handled by gscon instead
Change-Id: Ief20cb0f46dd93f46dd765dca307724dc2b3487c
2018-06-08 16:16:42 +00:00
Neels Hofmeyr 0abe84e679 HO: introduce T7, T8, T101 timers
Will be used in upcoming inter-BSC handover.

Change-Id: If9ecccc793426d214019f299b19d6ffa5a186546
2018-06-08 16:16:42 +00:00
Neels Hofmeyr c19581f268 remove struct bsc_api
struct bsc_api was used to provide an abstract API for both osmo-bsc and
osmo-msc, between BSC and MSC. That's no longer needed, so get rid of it, to
prevent code turbulences it creates for no reason.

Change-Id: I3fd5888c63a0b4f95520a498320aa105a6d60579
2018-06-07 19:09:06 +02:00
Neels Hofmeyr 958f259f95 dissolve libbsc: move all to src/osmo-bsc, link .o files
Move all of libbsc/ into osmo-bsc/, and separate/move some implementations to
allow linking from utils/* and ipaccess/* without pulling in unccessary
dependencies.

Some utilities use gsm_network and gsm_bts structs, which already include data
structures for fairly advanced uses. Move initialization that only osmo-bsc
needs into new bsc_network_init() and bsc_bts_alloc_register() functions, so
that the leaner tools can use the old gsm_* versions without the need to link
everything (e.g. handover and lchan alloc code).

In some instances, there need to be stubs if to cut off linking "just before
the RSL level" and prevent dependencies from creeping in.
- abis_rsl_rcvmsg(): the only program currently interpreting RSL messages is
  osmo-bsc, the utils are merely concerned with OML, if at all.
- paging_flush_bts(): ip.access nanobts models call this when the RSL link is
  dropped. Only osmo-bsc actually needs to do anything there.
- on_gsm_ts_init(): the mechanism to trigger timeslot initialization is related
  to OML, while this action to take on init would pull in RSL dependencies.
utils/ and ipaccess/ each have a stubs.c file to implement these stubs. Tests
implement stubs inline where required.

From src/utils/, src/ipaccess/ and tests/*/, link in .o files from osmo-bsc/.
In order for this to work, the osmo-bsc subdir must be built before the other
source trees. (An alternative would be to include the .c files as sources, but
that would re-compile them in every source tree. Not a large burden really, but
unless linking .o files gives problems, let's have the quicker build.)

Minor obvious cleanups creep in with this patch, I will not bother to name them
individually now unless code review asks me to.

Rationale:

1) libbsc has been separate to use it for osmo-nitb and osmo-bsc in the old
openbsc.git. This is no longer required, and spreading over libbsc and osmo-bsc
is distracting.

2) Recently, ridiculous linking requirements have made adding new functions
cumbersome, because libbsc has started depending on osmo-bsc/*.c
implementations: on gscon FSM and bssap functions. For example, neither
bs11_config nor ipaccess-config nor bts_test need handover_cfg or BSSMAP
message composition. It makes no sense to link the entire osmo-bsc to it, nor
do we want to keep adding stubs to each linking realm.

Change-Id: I36a586726f5818121abe54d25654819fc451d3bf
2018-06-07 19:09:06 +02:00
Harald Welte c997ceb750 Add initial 3GPP LCLS support to OsmoBSC
This code contains the following code:
* receive/parse/interpret LCLS specific BSSMAP IEs and PDUs
* osmo_fsm handling the various states and their transitions
* call leg correlation (finding the other subscr_conn with same GCR)
* communication between the two call-leg LCLS FSMs
* detection of supported / unsupported LCLS configurations
* display of GCR / LCLS information in "show conns"
* switch the media streams locally using MDCX to the MGW

Closes: OS#1602
Change-Id: I614fade62834def5cafc94c4d2578cd747a3f9f7
2018-06-02 20:56:17 +02:00