Commit Graph

8 Commits

Author SHA1 Message Date
Philipp Maier b15af63ae9 codec_pref: also check physical channels
At the moment codec_pref only checks the codec configuration, but it
does not check if there is actually a matching physical channel
available. This should be checked too we must make sure that the codec
we select fits the physical channels available on the BTS.

Change-Id: I2d29dfed450e5ef93c26ed5ec9fdc0730eb3d7dd
Related: OS#3503
2018-10-10 11:58:02 +02:00
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 67e47c6076 codec_pref: Add Codec List to COMPLETE LAYER 3 INFORMATION
The COMPLETE LAYER 3 INFORMATION message lacks the Codec List (BSS Supported)
information element. This information element is mandatory for networks
that use an IP based user plane (AoIP).

- Add function to generate the speech codec list from the current codec
  settings (Available codecs)
- Generate and embed information element in L3 Compl. message

Depends: libosmocore I4e656731b16621736c7a2f4e64d9ce63b1064e98

Change-Id: Id6f2af3fdab45bf05f06aec03e222734d7a4cf70
Related: OS#3548
2018-09-24 11:35:52 +02:00
Philipp Maier f96c04a198 codec_pref: add AMR configuration bits to make_scl_config() in unit-test
The the function make_scl_config() is used to generate realistically
looking speech codec lists to perform the unit tests for codec_pref.c.
This function does not yet populate the S0-S15 bits for AMR codecs. Lets
make sure that at least the default configuration is populated here.

Change-Id: I534239416c038ea856c128659f314aa521f85c15
2018-09-14 20:05:02 +02:00
Neels Hofmeyr b5ce49f872 cosmetic: reduce bsc_api.h
Remove as much as possible from bsc_api.h. Use '#pragma once'. Tweak head
comment.

BSC_API_CONN_POL_{ACCEPT,REJECT}: only user is static complete_layer3(), just
use a bool return value instead.

msc_connected(): only used in osmo_bsc_api.c, make static there.

Instead of including gsm_data.h, declare structs opaquely, include stdint.h.
codec_pref_test.c used this as indirect gsm_data.h include via osmo_bsc.h,
include gsm_data.h there directly.

osmo_bsc.h: instead of including bsc_api.h, declare opaque structs.

gsm_04_08_rr.h: declare opaque structs to replace indirect include of
gsm_data.h.

Change-Id: Ia9c0f9828317236048e40ec9ecf9990592e2190a
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
Philipp Maier 5bc43cd107 codec_pref: check bts codec support
The vty option bts->codec-support allows the user to set the supported
codecs per BTS level. However, those values are currently only used to
make the handover decision but the logic that handles the BSSMAP
ASSIGNMENT REQUEST does not check those flags.

- Do not ignore bts->codec-support flags on BSSMAP ASSIGNMENT REQUEST

Change-Id: I285234e9c81de74d9fb9907fca2c443b08537435
Closes: OS#3361
2018-07-22 06:16:11 +00:00
Philipp Maier 844876f8d5 codec_pref: move match_codec_pref() to separate c-file and add unit-test
At the moment there are three sources that may advertise a list of
supported audio codec/rate settings. There is the MS that advertises
advertises a speech codec list and the MSC that sends a channel type
information element over A and there are also settings in the bsc
configuration file that may restrict the codec/rate types that are
allowed to use.

The function match_codec_pref() looks at all of the three buckets and
selects a codec that satisfies all three. This is already a somewhat
complicated process, overit is very isolated, so lets give it its own
c-file.

Due to the lack of unit-tests it is very hard to make changes here so
lets add also unit-test to make sure that regressions are catched early.

- Put match_codec_pref() and all its helper functions into a separate
  c-file.
- Add a unit test.

Change-Id: Iabedfdcec8b99a319f2d57cbea45c5e36c7b6e29
Related: OS#3361
2018-07-22 06:16:11 +00:00