Commit Graph

95 Commits

Author SHA1 Message Date
Neels Hofmeyr e60254118c dissolve bsc_grace_paging_request()
RF-locking: simply ask bsc_grace_allow_new_connection() at the start of
page_subscriber(). Before this patch, we would log an INFO of "Paging request
failed" when RF-locked, for each BTS. Instead log "RF-locked". (An upcoming
patch will introduce a LOG_PAGING() macro that will trivially add more log
context there, so not bothering now.)

Drop LAC condition: since Stefan introduced page_subscriber() starting 2018
Ic3c62ff0fccea586794ea4b3c275a0685cc9326e, matching a requested LAC to a
specific BTS is done *before* calling page_subscriber().

BTW: the msc->core_lac (config 'core-location-area-code') has not had an effect
on Paging maybe ever. I opened OS#4751.

Change-Id: Ic8696414a1db8f4b1be502d6434599f684746ed6
2020-09-16 21:54:52 +00:00
Harald Welte 210aa95d49 Implement support for receiving BSSMAP CommonID from MSC
The MSC may at any time send a BSSMAP CommonID message via a
SCCP connection to inform us of the IMSI of the subscriber.  Let's
make use of that information by associating a related bsc_subscr
and updating the identity of the bsc_subscr_conn_fsm for improved
logging / filtering.

Closes: OS#2969
Change-Id: I52c43fb940f0db796adf4c0adb2260321c721c39
2020-08-17 13:04:03 +02:00
Pau Espin 388ed58482 Move struct gsm_bts: gsm_data.* => bts.*
Place all code related to the object into the related file.

Having all the data model in one file made sense in early stage of
development to make progress quickly, but nowadays it hurts more than
helps, due to constantly growing size and more and more bits being
added to the model, gaining in complexity.

Currently, having lots of different objects mixed up in gsm_data.h is a hole
of despair, where nobody can make any sense were to properly put new stuff
in, ending up with functions related to same object in different files
or with wrong prefixes, declarations of non-existing functions, etc.
because people cannot make up their mind on strict relation to objects
in the data model.
Splitting them in files really helps finding code operating on a
specific object and helping with logically splitting in the future.

Change-Id: I00c15f5285b5c1a0109279b7ab192d5467a04ece
2020-07-18 21:45:32 +00:00
Neels Hofmeyr b523f54de4 RR Channel Release: pass Cause code from BSSMAP Clear to the BTS
In lchan.release, add 'cause_rr', and set RR Channel Release message's cause
value to lchan.release.cause_rr.

In lchan_release(), do not set lchan.release.rsl_error_cause to the RR cause
value, these are unrelated. Store in new lchan.release.cause_rr instead. The
rsl_error_cause is apparently only used for logging, except for one place in
lchan_fsm_wait_activ_ack() that compares it to RSL_ERR_RCH_ALR_ACTV_ALLOC, so
there should not be a functional difference by this fix.

Propagate the BSSMAP Clear Command cause to the RR Channel Release:

Add struct gscon_clear_cmd_data as event data for GSCON_EV_A_CLEAR_CMD -- so
far it sent the is_csfb flag, add the gsm0808_cause; invoking the event happens
in bssmap_handle_clear_cmd().

Adjust event handling in gscon_fsm_allstate(); there, pass the cause to
gscon_release_lchans(). In gscon_release_lchans(), pass the cause to
gscon_release_lchan(), and then lchan_release(), which sets the new
lchan.release.cause_rr to the passed cause value.

As soon as the lchan FSM enters the proper state, it calls
gsm48_send_rr_release(). There, set the cause value in the encoded message to
lchan.release.cause_rr.

Interworking with osmo-msc: so far, osmo-msc fails to set the Clear Command
cause code for normal release, it just passes 0 which amounts to
GSM0808_CAUSE_RADIO_INTERFACE_MESSAGE_FAILURE. Before this patch, osmo-bsc
always sent GSM48_RR_CAUSE_NORMAL in the RR Channel Release, and after this
patch it will receive 0 == GSM0808_CAUSE_RADIO_INTERFACE_MESSAGE_FAILURE from
osmo-msc and more accurately translate that to GSM48_RR_CAUSE_PROT_ERROR_UNSPC.
This means in practice that we will now see an error cause in RR Channel
Release instead of GSM48_RR_CAUSE_NORMAL when working with osmo-msc. For
changing osmo-msc to send GSM0808_CAUSE_CALL_CONTROL instead (which translates
to GSM48_RR_CAUSE_NORMAL), see OS#4664 and change-id
I1347ed72ae7d7ea73a557b866e764819c5ef8c42 (osmo-msc).

A test for this is in Ie6c99f28b610a67f2d59ec00b3541940e882251b
(osmo-ttcn3-hacks).

Related: SYS#4872
Change-Id: I734cc55c501d61bbdadee81a223b26f9df57f959
2020-07-16 12:03:19 +00:00
Vadim Yanitskiy 6281d4f869 fix crashes due to OSMO_ASSERT(conn->lchan)
Starting from ttcn3-bsc-test-sccplite build #777, it was noticed
that osmo-bsc crashes with the following message:

  Assert failed conn->lchan include/osmocom/bsc/gsm_data.h:1376

The cause of this is a recently merged patch that calls conn_get_bts() during
assignment_fsm rate counter dispatch:
"Count assignment rates per BTS as well"
commit b5ccf09fc4
Change-Id I0009e51d4caf68e762138d98e2e23d49acc3cc1a

The root cause being that the assignment_fsm attempts to count an Assignment
event for a BTS after the lchan has already been released and disassociated
from the conn.

The assertion is found in conn_get_bts(), which is used in various places. In
fact, each caller is a potential DoS risk -- though most are in code paths that
are guaranteed to have an lchan and bts present, having an OSMO_ASSERT() on the
relatively volatile presence of an lchan is not a good idea for osmo-bsc's
stability and error resilience.

- Change conn_get_bts() to return NULL in the lack of an lchan.
- Adjust all callers of conn_get_bts() to gracefully handle a NULL return val.
- Same for cgi_for_msc() and callers, closely related.

Here is a backtrace:

  Program received signal SIGABRT
  pwndbg> bt
    0x0000555555be6e52 in conn_get_bts (conn=0x622000057160) at include/osmocom/bsc/gsm_data.h:1376
    0x0000555555c1edc8 in assignment_fsm_timer_cb (fi=0x612000060220) at assignment_fsm.c:758
    0x00007ffff72b1104 in fsm_tmr_cb (data=0x612000060220) at libosmocore/src/fsm.c:325
    0x00007ffff72ab062 in osmo_timers_update () at libosmocore/src/timer.c:257
    0x00007ffff72ab5d2 in _osmo_select_main (polling=0) at libosmocore/src/select.c:260
    0x00007ffff72abd2f in osmo_select_main_ctx (polling=<optimized out>) at libosmocore/src/select.c:291
    0x0000555555e1b81b in main (argc=3, argv=0x7fffffffe1b8) at osmo_bsc_main.c:953
    0x00007ffff6752002 in __libc_start_main () from /usr/lib/libc.so.6
    0x0000555555b61bbe in _start ()

In the case of the assignment_fsm counter, we now miss a chance to increase a
BTS counter for a failed Assignment, but this is a separate problem. The main
point of this patch is that osmo-bsc must not crash.

Related: OS#4620, OS#4619
Patch-by: fixeria
Tweaked-by: neels
Fixes: I0009e51d4caf68e762138d98e2e23d49acc3cc1a
Change-Id: Id681dfb0ad654bdb4b71805d1ad4f39a8bf6bbd1
2020-06-23 12:53:50 +00:00
Neels Hofmeyr a87646cd84 use osmo_mobile_identity API everywhere
Depends: If4f7be606e54cfa1c59084cf169785b1cbda5cf5 (libosmocore)
Change-Id: I71c3b4c65dbfdfa51409e09d4868aea83225338a
2020-06-16 14:56:57 +02:00
Neels Hofmeyr 06a14d289b flatten: move network->bsc_data->* to network->*
The separate struct osmo_bsc_data is like another separate struct gsm_network
for no reason. It is labeled "per-BSC data". These days, all of this is a
single BSC and there will not be different sets of osmo_bsc_data.

Drop struct osmo_bsc_data, move its members directly into gsm_network.

Some places tested 'if (net->bsc_data)', which is always true. Modify those
cases to rather do checks like 'if (net->rf_ctrl)', which are also always true
AFAICT, to keep as much unmodified logic as possible in this patch.

Change-Id: Ic7ae65e3b36e6e4b279eb01ad594f1226b5929e0
2020-05-29 20:16:40 +00:00
Neels Hofmeyr 6a8955b741 drop all BSC originated USSD notification features
The BSC is the wrong network component to originate USSD messaging, as can be
seen in the hacks in the USSD code: for example, the BSC would send a CM
Service Accept message as if an MSC had accepted the connection, dispatch a
USSD and directly send some RR release message (without proper tear down
messaging like the lchan_fsm does these days). This made sense in the osmo-nitb
world, but by now we are aiming for solid 3GPP compliance. The BSC shall not
originate USSD messages.

Deprecate all VTY and CTRL commands related to USSD:
VTY
 [no] bsc-welcome-text
 [no] bsc-msc-lost-text
 [no] bsc-grace-text
 [no] missing-msc-text
 (the commands with 'no' are ignored, without 'no' lead to an error)
CTRL
 ussd-notify-v1

Drop (already unused) ussd.h.
Drop gsm_04_80.h, gsm_04_80_utils.c, and all calling code.

Drop "RF grace" notification, where osmo-bsc was able to notify active
subscribers that the RF was being turned off.

Change-Id: Iaef6f2e01b4dbf2bff0a0bb50d6851f50ae79f6a
2020-05-29 20:16:40 +00:00
Alexander Chemeris 3a656da1c6 bssap: Handle BSSMAP CONFUSION message.
We decode the mesage and print it to the log files at ERROR log level.
We also count it in the BSSMAP message counters. There is not much
else we could do about it.

Depends: If8afd2d096fb66c6c2f255a08fc1129de3d09cec (libosmocore)
Change-Id: Ib4cd94f185f751b2384842222678ff671ac413c4
2020-05-19 20:00:32 +00:00
Alexander Chemeris 7b9c8ea175 log: Fix "Paging request failed" logging level
"Paging request failed" message can be logged e.g. when we're already
paging this subscriber which means we get hundreds of these messages
in a perfectly normal situation. Let's demote this to INFO and adjust
the wording.

Change-Id: I97214796906ac599338e87b2b4b5465ab6b2447a
2020-05-16 17:54:16 +03:00
Alexander Chemeris aac5423415 stats: Rename BSSMAP Rx message counters to match Tx ones.
Change-Id: I29e42687ac084a60007f0b1ec6ec0a102fb4007f
2020-05-11 12:03:21 +03:00
Alexander Chemeris 98824b8f06 stats: Add counters for Tx BSSMAP messages.
We already have counters for Rx side, now we also count Tx side.
See comments in the msc_ctr_description array implementation for
the details.

Change-Id: I89a173f6bdd9a3c21233fe01d07ab2ff0442bb10
2020-05-11 12:03:21 +03:00
Alexander Chemeris 169c229d27 stats: Only dereference a connection pointer after checking for NULL.
Addresses CID 210261.

Change-Id: Ic7e7c92c5b9ff696fa7f4cd0d69451cd22333f71
2020-05-11 00:33:05 +03:00
Alexander Chemeris e26b153bd8 stats: Add counters for received BSSMAP messages.
Change-Id: I3f08d71b58b4e8d6f61376d85c2051e194aa8e43
2020-05-09 12:26:06 +03:00
Alexander Chemeris 13e5aa24ce Fix indent whitespace and log message.
Change-Id: I985bf8ac4ce6136812692c06b6dc78edc6bde652
2020-05-09 00:07:58 +00:00
Pau Espin 8ada920779 bssap: Avoid logging error if no optional Global Call Ref IE received
Also take the chance to simplify related code and print erroneous IE
data.

Change-Id: I27ee9c6112f96d6839b8b6141888ac8fe377db65
2020-02-12 16:38:12 +01:00
Martin Hauke a29affda98 Fix some typos
Fix typos and common misspellings in code comments and in the manual.

Change-Id: I46fc9d424620c77ae9ccf78b58081bd303386d7c
2019-11-13 22:10:41 +01:00
Pau Espin 83c0f76d21 bssap: Parse Osmux CID on BSSAP Assign Req recv and use it in MGCP
The Osmux CID obtained from the MSC is passed to the co-located BSC MGW
to configure the MSC-side MGW conn of a call leg.

Depends on: osmo-mgw.git I73b4c62baf39050da81d65553cbea07bc51163de
Change-Id: I86e7e13fc7921e3209fb764c0e7797e7ec09b79e
2019-05-19 22:36:18 +00:00
Pau Espin a94907ec06 bssap: Detect MSC Osmux support on RESET (ACK) recv
Related: OS#2551
Depends on: libosmocore I28f83e2e32b9533c99e65ccc1562900ac2aec74e
Change-Id: I830e38cc1ffb8b6ebbe299567507160f19beb528
2019-05-19 07:26:28 +00:00
Neels Hofmeyr 67f9fd5526 fix inter-BSC-HO-incoming for AoIP (2/2)
For AoIP, the AoIP Transport Layer Address IE must be included in the Handover
Request Acknowledge message, so the MSC can send RTP to the right place. Add
this IE for AoIP.

Depends: Ia71542ea37d4fd2c9fb9b40357db7aeb111ec576 (libosmocore)
Depends: Id617265337f09dfb6ddfe111ef5e578cd3dc9f63 (libosmocore)
Change-Id: Ia05e37da125eb6e7b7be9b974b73261bd72de1f4
2019-05-05 13:27:25 +02:00
Sylvain Munaut aa82492ad6 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

Originally merged as Change-Id I4c7499c8c866ea3ff7b1327edb3615d003d927d3,
reverted because the change broke voice calls. Re-submitting with the fix:
don't forget to set conn->assignment.requires_voice_stream.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Change-Id: I7513d2cbe8b695ba6f031ad11560c63a6535cf2d
2019-05-03 16:10:33 +02:00
Neels Hofmeyr f14aaa4ba1 move mgw endpoint FSM to osmo-mgw.git
osmo-mgw.git also includes fixes of the MGW endpoint FSM, for example
I92a9944acc96398acd6649f9c3c5badec5dd6dcc.

Depends: I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw)
Change-Id: I03e6b48d9b0a5370310d5f56809259ff7909cf9d
2019-04-30 02:24:18 +02:00
Philipp Maier 023fc49ed6 osmo_bsc_bssap: check bssmap length field
At the moment the length field of the bssmap header is not parsed.
Instead the length is computed out of the known header length and the
number of bytes received. This is prone to error, lets make sure that
extranous data at the end of a message is ignored by parsing the bssmap
length correctly.

Change-Id: Idef2e783d2377a2ad1f697ea4d26491a32b3e549
Related: OS#3806
2019-03-27 08:01:38 +00:00
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
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
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
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
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
Pau Espin 1aea16f54f bsc: bssap: Set subscr log context during paging
Change-Id: I3998a35ff6ea29440882514bbb30cafed66f03fa
2018-12-12 00:58:40 +01:00
Pau Espin d5c7582f72 bsc: dtap: Set subscr log context
Change-Id: I362a7d10f5ca9a95b594f7caafd7ed5b10fd059a
2018-12-11 17:25:22 +01:00
Vadim Yanitskiy 0620b37189 osmo_bsc_bssap.c: fix incorrect link_id assignment
Every DTAP message coming from the MSC has a header (see struct
dtap_header) that contains message type, length, and link ID.
The link ID indicates SAPI and channel type of a given message.

In dtap_rcvmsg() we allocate a new message buffer and copy the
received message into it. The old message buffer is freed by
the caller then.

The link ID value parsed from DTAP header is usually being stored
in the control buffer of a message buffer (i.e. msgb->cb). Due to
a mistake, it was stored in the old (to be freed) message, while
the new (to be forwarded) message always had link_id = 0x00!

This change resolves the problem with sending SMS during a voice
call, when MT signalling goes through FACCH, while MO signalling
goes through SACCH.

Change-Id: I7675e1ce4436fad836778261ac9d446fa8f81483
Related: OS#3716
2018-12-01 22:06:40 +07:00
Max 42bd128ffc LCLS: tighten GCR check
Use stricter checks for received Global Call Reference.

Change-Id: I9690e1b2d14e41471413bb35eb22fa6c4c4d67fd
Related: OS#2487
2018-11-18 20:19:44 +00:00
Oliver Smith 75f038ddd3 cipher mode reject: send proper cause codes
bssmap_handle_cipher_mode() had code paths doing "goto reject" without
setting a meaningful cause value.

Related: OS#3186
Change-Id: Ia608fa34a6a2d3035a66d05fbc38553ac5186804
2018-10-25 10:15:33 +02:00
Oliver Smith dadd4055c3 cosmetic: fix spec ref for gsm0808_cipher_mode()
Change-Id: I359caf1dd30f033c0b606040ccf27aa4c5a9d2c6
2018-10-25 10:15:23 +02:00
Harald Welte 3c4661b5c8 bssmap_handle_cipher_mode(): Don't sent reject if !conn
We can only send a reject response if we have a valid conn.

Change-Id: I0ea535f494173ad4996c70dc82d7f69455e4e15e
Fixes: Coverity CID#188824
2018-10-21 12:19:45 +00:00
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
Neels Hofmeyr e2209c20c5 Implement RR Classmark Enquiry
If the MSC sends a BSSMAP Classmark Request, send an RR Classmark Enquiry to
the MS.

(The reverse direction, i.e. sending a BSSMAP Classmark Update back to the MSC,
is already implemented.)

Related: OS#3043 (A5/3 encryption)
Related: osmo-ttcn3-hacks Idaab4d568cf986b4897ba008f6262c839d1592fb
Change-Id: If5db638fd6e8d9c2ef9e139e99f0fabe1ef16ddf
2018-09-18 14:34:32 +02:00
Neels Hofmeyr a15dd1f9bd inter-BSC HO incoming: send BSSMAP HO Complete directly
Before Handover is fully completed, the gscon remains in an INIT state. To send
back the BSSMAP Handover Complete message, use osmo_bsc_sigtran_send() directly
to not thwart the message due to the gscon state.

(The gscon state will change to ACTIVE right after that, once the handover FSM
is done.)

Change-Id: Ic48ae2bb23565015d5e2ccb56308fad09347b51a
2018-09-07 16:24:32 +02:00
Neels Hofmeyr 128600c561 inter-BSC HO: send failure msg directly
If inter-BSC HO failed, the conn is by definition not in an active state, and
hence it makes no sense to verify the gscon FSM state before sending. Directly
call osmo_bsc_sigtran_send().

Change-Id: Ic49c94462041800674fa961c4d19c0c045bfe0c0
2018-08-29 02:02:10 +02:00
Neels Hofmeyr 721c762e3b log: 'sending BSSMAP HO Request ACK'
Change-Id: Ie472c32861d9c9ca9ebec0221837030ffd83c73a
2018-08-29 02:02:10 +02:00
Philipp Maier 628a05e738 GSCON: call api of a_reset.c with msc object directly
The API of a_reset.c is currently called with a pointer to struct
reset_ctx. This puts the responsibility of checking the presence of
msc->a.reset_fsm to the caller. It would be much more effective if the
caller would check if msc->a.reset_fsm before dereferencing it.

This also fixes at least one segfault that ocurrs when gscon_timer_cb()
is called but no sccp connection is present yet. Therefore the pointer
to bsc_msc_data would not be populated. This is now detected by
a_reset.c itsself.

- minor code cleanups
- call a_reset.c functions with msc (struct bsc_msc_data)

Change-Id: I0802aaadf0af4e58e41c98999e8c6823838adb61
Related: OS#3447
2018-08-07 15:11:41 +00:00
Neels Hofmeyr 8757f42c8e cosmetic: dissolve bsc_api.c
gsm0808_page() is just a thin wrapper for rsl_paging_cmd(), the only caller is
page_ms() from paging.c. Directly call rsl_paging_cmd() instead.

Move gsm0808_cipher_mode() to the only caller in osmo_bsc_bssap.c, make static.

Change-Id: Ib7ce026b52d4ba3e53a8b2824e74ea92432c48c5
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 6242742d20 rename gsm_04_08_utils.[hc] to gsm_04_08_rr
"utils" suggests thin helpers to aid using a proper API, while this .c file
actually *is* the proper RR API. Rename from "utils" to "rr".

Change-Id: I0ffff63d57f03cb324df8e40e41caea5b55a2c85
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
Harald Welte b5f81b9fbd Reject ASSIGNMENT REQ with CIC but no AoIP transp addr in AoIP case
If we receive a BSSMAP ASSIGNMENT REQ for a speech channel
containing only a CIC but no AoIP transport layer address, then that's
illegal and must be rejected.

In Change-Id If362a0084de452727cd063063dfb645eca2f9beb we re-introduced
accepting CIC-only ASSIGNMENT REQ, but we failed to verify that this
actually only happens over a SCCPlite A interface.

This fixes the BSC_Tests.TC_assignment_cic_only testcase.

Change-Id: Ia6e3897edca48b9f838ea69939d9b8be7185abf8
2018-06-05 21:57:54 +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
Harald Welte f6029bac5e bsc: Don't reject ASSIGNMENT for Audio in IPA/SCCPlite case
Change-Id: If362a0084de452727cd063063dfb645eca2f9beb
2018-05-25 18:58:16 +00:00
Harald Welte 584ab8e11f bsc: Add mgcp_port_to_cic() to determine CIC from RTP Port
Also: Move mgcp_timeslot_to_port() next to it, as they are
more or less the inverse transformation of each other.

Change-Id: Ica908e2bb8fc4e59e0d146b428c93a9efc385688
2018-05-25 18:58:16 +00:00