osmo-nitb supports the modification of an lchan if the lchan is
compatible but in the wrong mode. This feature was dropped in the
transition to AoIP/bsc-split. However, osmo-bsc still has code to
generate and parse the messeages, but the FSMs do not support a mode
modify yetm
Lets add handling for mode-modify to the lchan_fsm and assignment_fsm in
order to support mode modify again
Change-Id: I2c5a283b1ee33745cc1fcfcc09a0f9382224e2eb
Related: OS#4549
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
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
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
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
In case a given channel combination contains a CBCH, it replaces sub-slot 2
with a CBCH, i.e. we must not attempt to allocate the same for SDCCH.
On timeslot initialization, immediately place such an lchan FSM into new state
LCHAN_ST_CBCH, so that it never appears unused and never is picked during
lchan_select(). Also set lchan->type = GSM_LCHAN_CBCH.
Verified by configuring CBCH timeslots and watching 'show lchan summary'.
Immediately after RSL and OML are up, these pchan types show lchan 2 in state
CBCH:
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
With a 'phys_chan_config ccch+sdcch4+cbch' and three phones simultaneously
requesting USSD, I see:
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 0, Type SDCCH, State ESTABLISHED - L1 MS Power: 14 dBm RXL-FULL-dl: -53 dBm RXL-FULL-ul: -47 dBm
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 1, Type SDCCH, State ESTABLISHED - L1 MS Power: 30 dBm RXL-FULL-dl: -47 dBm RXL-FULL-ul: -47 dBm
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 3, Type SDCCH, State ESTABLISHED - L1 MS Power: 16 dBm RXL-FULL-dl: -47 dBm RXL-FULL-ul: -47 dBm
With 'phys_chan_config SDCCH8+CBCH' and three phones simultaneously attaching,
I see:
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 0, Type SDCCH, State WAIT_RLL_RTP_ESTABLISH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 1, Type SDCCH, State WAIT_RLL_RTP_ESTABLISH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 3, Type SDCCH, State WAIT_RLL_RTP_ESTABLISH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
i.e. in all cases the CBCH lchan remains occupied and is not allocated as
SDCCH.
Detaching and re-attaching the BTS reliably brings back the CBCH state. Also
verified that changing the osmo-bsc config from telnet vty and dropping oml
followed by the BTS re-attaching brings back the CBCH state.
Change-Id: I2bafc5f696e818e38f8907ad0c8f38494df0623d
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
Philipp Maier
Neels Hofmeyr