Commit Graph

25 Commits

Author SHA1 Message Date
Max 7d41d870de Remove redundancy in LAC processing
Always use LAC which is part of Cell Global ID otherwise we might end up
in a situation where separately stored LAC differs.

Both are described in 3GPP TS 23.008 $2.4 as temporary subscriber data
to be stored in VLR. Both are defined in 3GPP TS 23.003. The LAC is part
of LAI which is part of CGI so there should be no case when those values
differ for a given subscriber.

Change-Id: I993ebc3e14f25e83124b6d3f8461a4b18f971f8e
2018-12-19 11:48:33 +01:00
Neels Hofmeyr d50f8988f7 vlr_lu_fsm: drop unused out_state INIT -> WAIT_IMEI
There is no state transition from INIT to WAIT_IMEI, only to WAIT_SUB_PRES.

If there were code to skip WAIT_SUB_PRES, the allowed state transitions would
have to be the same as for WAIT_SUB_PRES, i.e. also WAIT_IMEI_TMSI and
WAIT_TMSI_CNF. For now just opt for the status quo.

Change-Id: I18ef9e8c96b52401d98f49dc410f13681231b533
2018-12-17 14:39:16 +00:00
Neels Hofmeyr 5f1ac6dce6 tweak comment to indicate sub_pres_vlr fsm as dead code
sub_pres_vlr_fsm_start() only ever has an effect if ms_not_reachable_flag ==
true. But there simply is no code that sets this flag. So
sub_pres_vlr_fsm_start() is currently dead code.

Also, examining the FSM, if it should ever be set to true, this would halt the
LU/CM Service/Paging response, since the FSM would merely change its state
without dispatching asynchronous messages. No chance of finishing.

Short of dropping the code entirely, first just mark it. The point being that
this models some FSM definition from 3GPP specs, and we have a couple other
"if (0)" branches in the VLR...

Change-Id: I198d442e9ed288f37c7d4e5ec87b82dc53114e99
2018-12-17 14:39:16 +00:00
Neels Hofmeyr aa14bac370 LU: do not always invoke sub_pres_vlr_fsm_start()
sub_pres_vlr_fsm_start() starts the FSM, invokes the START event, and then this
FSM invariably always directly terminates when vsub->ms_not_reachable_flag ==
false.

So if it is false, there is not much use in instantiating a whole FSM instance
that just terminates again, we might as well directly issue the
parent-term-event and save some logging space.

The same condition is already in place in the vlr_proc_acc_fsm.c in
_proc_arq_vlr_node2_post_vlr() for CM Service Request and Paging Response. Now
also skip this for LU.

Change-Id: Id2303a795dfd381f76e94ff8ff2f495926ca8ba0
2018-12-11 11:37:27 +00:00
Philipp Maier 6038ad4cf9 vlr: drop unused is_ps parameter in vlr_subscr_req_lu()
the function vlr_subscr_req_lu() has a parameter is_ps, which is set
to vsub->vlr->cfg.is_ps by the only caller in vlr_lu_fsm.c. Inside the
function one can see that vsub->vlr->cfg.is_ps is used directly to
decide between PS or CS LU, we could also use is_ps there. Presumably
the parameter is_ps had been abandonned in an early development stage
and was not removed, so lets drop the parameter.

Change-Id: Id239721773b90099d122b232dae1ba457be9d255
2018-11-16 18:11:50 +00:00
Neels Hofmeyr dd2aeba02c lu_fsm: result cb: use proper cause type (warning/coverity)
enum gsm48_gmm_cause is the wrong enum to pass to lu_fsm_failure(). Use enum
gsm48_reject_value instead.

Change-Id: If661f72056decb28c0ee82ad2449630a24d4f31c
2018-10-30 19:51:15 +01:00
Stefan Sperling defc3c8caf implement periodic Location Update expiry in the VLR
Remove subscribers which fail to send periodic Location Updates from the
list of subscribers known to the VLR. This complements the IMSI detach
procedure: periodic LU expiry triggers an implicit IMSI detach.

Expired subscribers are purged from a periodic timer which iterates
over all subscribers once per minute.

Subscribers with an active connection do not expire. This is controlled
by the subscriber conn FSM which sets a subscriber's the LU expiry timeout
value to GSM_SUBSCRIBER_NO_EXPIRATION while a connection is active.

Add support for fake time with osmo_clock_gettime() to msc_vlr tests.

This functionality existed in OpenBSC but was lost during the nitb split.
This code took some inspiration from the OpenBSC implementation.

Related: OS#1976
Change-Id: Iebdee8b12d22acfcfb265ee41e71cfc8d9eb3ba9
2018-05-23 14:55:00 +02:00
Neels Hofmeyr 158095960b refactor VLR FSM result handling
Instead of keeping separate enums for FSM results and translating between those
and the actual 04.08 reject causes that will ultimately reach the MS, just pass
enum gsm48_reject_value cause codes around everywhere.

Collapse some VLR *_timeout() and *_cancel() api to just *_cancel() with a
gsm48 cause arg.

(Hopefully) improve a few reject causes, but otherwise just aim for more
transparent decisions on which cause value is used, for future fixes of
returned causes.

Depends: I6661f139e68a498fb1bef10c266c2f064b72774a (libosmocore)
Change-Id: I27bf8d68737ff1f8dc6d11fb1eac3d391aab0cb1
2018-04-12 19:40:00 +00:00
Stefan Sperling 3a74128ccc restore sending of optional MM info messages
Since commit 2483f1b050 the function
gsm48_tx_mm_info() was not called anymore. No MM info messages were
transmitted to phones even if MM info messages were enabled via VTY.

With this commit, we call gsm48_tx_mm_info() after successfully
processing an IMSI ATTACH location update.

Change-Id: Ice5963d84253eb8c803cd2dfa8b25a4db5382827
Related: OS#2850
2018-03-13 21:13:27 +01:00
Neels Hofmeyr fa10eda6d7 vlr_ciph_result: fix use after free of imeisv
Define the struct vlr_ciph_result member .imeisv not as a char* but a char[] of
appropriate length, to avoid the need to point to external memory.

Thus fix a use-after-free in msc_cipher_mode_compl(), which defined the
imeisv[] buffer in a sub-scope within that function, so that the .imeisv
pointer was already invalid when fed to vlr_subscr_rx_ciph_res().

Did you notice that the commit summary rhymes?

Closes: OS#3053
Change-Id: I90cfb952a7dec6d104200872164ebadb25d0260d
2018-03-13 01:29:04 +01:00
Neels Hofmeyr 7795a19ced vlr: fix GSM AKA in a UMTS AKA capable environment
Switch by vsub->sec_ctx to use the proper Kc for ciphering.

Even on an R99 capable MS with a UMTS AKA capable USIM, the MS may still choose
to only perform GSM AKA, as long as the bearer is GERAN. The VLR already stores
whether the MS replied with a GSM AKA SRES or a UMTS AKA RES in vsub->sec_ctx.
So far, though, we were always using the UMTS AKA Kc just because the USIM and
core net are capable of it, ignoring the choice the MS might have made in the
Authentication Response.

In msc_vlr_test_gsm_ciph, fix the test expectations to the correct GSM AKA Kc
keys, showing that all of LU, CM Service Request and Paging Response now
support MS choosing GSM AKA in a UMTS capable environment.

Related: OS#2793
Change-Id: I42ce51ae979f42d173a45ae69273071c426bf97c
2018-03-10 20:58:24 +00:00
Neels Hofmeyr c5e0ace751 vlr_lu_fsm: guard against using the wrong fi
Various functions in vlr_lu_fsm.c belong to one of the four FSMs defined in
that file. After the recent error was uncovered where the lu_fsm called
lu_compl_fsm()'s termination function, I want to make sure it's correct.

Introduce distinct inline functions to dereference the respective fi->priv
pointers, each asserting that the fi indeed belongs to the proper FSM. Use
those *everywhere* to dereference fi->priv.

From this patch on, we are sure beyond doubt that we are not inadvertently
passing an fi pointer to the wrong FSM's handling functions, though we will
only catch this at runtime -- but then will immediately know the reason.

vlr_lu_fsm.c is the only file defining more than one FSM, so the other FSM
definitions are already reasonably safe.

Change-Id: I7419a780ff2d8b02efc4195bb1702818e4df181c
2018-03-02 03:21:14 +01:00
Neels Hofmeyr d2278ec899 vlr: fix post-auth LU failure handling
From the vlr_loc_update() FSM, don't call the vlr_lu_compl_fsm_failure()
function. These are two distinct FSMs with distinct priv pointers, but they are
defined in the same .c file.

In vlr_loc_upd_post_auth(), change two erratic calls of
vlr_lu_compl_fsm_failure() to lu_fsm_failure(), so that the proper fi and priv
struct are used.

Fixes: OS#2947
Change-Id: I7fd2c6fa23254fffd0d526e53541f4068153929f
2018-03-02 03:20:21 +01:00
Neels Hofmeyr 379d5799f0 implement support for 3-digit MNC with leading zeros
Add 3-digit flags and use the new RAI and LAI API from libosmocore throughout
the code base to be able to handle an MNC < 100 that has three digits (leading
zeros).

Depends: Id2240f7f518494c9df6c8bda52c0d5092f90f221 (libosmocore),
         Ib7176b1d65a03b76f41f94bc9d3293a8a07d24c6 (libosmocore)
Change-Id: I82f0016d9512ee8722a3489a3cb4b6c704a271fc
2018-02-28 19:30:14 +01:00
Max 770fbd2024 GSUP: check osmo_gsup_encode() result
Check and handle gracefully any error which might appear in
osmo_gsup_encode() - mark corresponding functions with
warn_unused_result attribute to make sure this failure is always checked
against.

Change-Id: I4551212011fb0bd898c020a183756ed7a9afb9e5
Related: OS#2864
2018-02-08 09:29:50 +00:00
Harald Welte 71c51df07d Shift ciphering algorithm selection from VLR to MSC
The VLR code seems to have the assumption that there is one particular
algorithm to be used, as opposed to one of a set of algorithms.

What's missing is basically to decide when/where to pick the best
algorithm within the capabilities of the phone (classmark) and the
network configuration (net->a5_encryption_mask).  So far, libvlr has no
notion of classmark.  Rather, libmsc has.

Why does the VLR care about the particular algorithm at all?  The VLR
should probably simply decide if it should use encryption or not, and if
so, the MSC will figure which algorithm to use.

Change-Id: I5ed80ca2086560a5975a758ec568a034a9a8ab89
2018-01-28 00:09:41 +00:00
Neels Hofmeyr 2ef2da54ab cosmetic prep: tell vlr_ops.set_ciph_mode() whether UMTS AKA is used
In case of UMTS AKA, the Kc for ciphering must be derived from the 3G auth
tokens. tuple->vec.kc was calculated from the GSM algorithm and is not
necessarily a match for the UMTS AKA tokens.

To decide (in an upcoming patch) whether to use UMTS AKA derived Kc or the Kc
from the auth vector, the set_ciph_mode() from vlr_ops needs to know whether
UMTS AKA is being used. This could possibly derived from the msc_conn_ref, but
all flags are already available in the vlr_lu_fsm and vlr_access_req_fsm. Hence
add a umts_aka flag to the set_ciph_mode() callback invocation. The VLR FSMs
thus decide whether UMTS AKA or GSM AKA is to be used during Ciphering Mode
Command, which makes more sense than re-implementing the same decision process
in the MSC.

I considered placing the Kc derivation in vlr_set_ciph_mode() and only tell the
MSC's set_ciph_mode() implementation the precise keys it should use, but the
RAN particulars, and whether a Kc is used at all, rather belong with the MSC.

Related: OS#2745
Prepares: If04e405426c55a81341747a9b450a69188525d5c
Change-Id: I983c48347faf4ee1b405d8174b4e006c904157cf
2017-12-18 05:18:11 +01:00
Neels Hofmeyr 1a5bcd5c3b sub_pres_vlr_fsm_start: fix heap use after free
When sub_pres_vlr_fsm_start() is called, it dispatches an event which may in
some cases already cause tear down and free of the parent FSM instance, after
which storing the returned instance pointer in that parent's metadata will use
freed memory. Instead, pass the target pointer to remember the instance at to
sub_pres_vlr_fsm_start() and assign the pointer *before* firing the event.

Explain so in a new comment.

I haven't checked whether that pointer is actually used at all -- this is the
easiest way to fix the use-after-free without getting sucked into semantic
questions.

Change-Id: Ibdc0b64cd12ba3e2b9737e3517d8484e67abcf04
2017-11-20 13:49:32 +00:00
Neels Hofmeyr bffa684e1a cosmetic: vlr: declare a struct in .h; drop unused header
In vlr_core.h, "pre-declare" a struct used in function declaration.

In vlr_lu_fsm.c, gsup.h is not used, drop the #include.

Change-Id: I61d793c3001abbe6d381be1ae0bb350b07403e88
2017-10-04 11:14:39 +00:00
Max 43b01b0514 Remove rest_octets.h
The MSC should not fiddle with low-level SI details like rest octets
anyway. Unfortunately simply removing the header is impossible as it
causes massive fallout due to missing includes. Fixed it as well.

The only other parameter which required removal is cell_ro_sel_par which
is not referenced anywhere in the code anyway.

Change-Id: Ibff77330de056fad4288cd4c48d016aad8105354
2017-09-15 11:31:03 +02:00
Neels Hofmeyr 9084396467 rename include/openbsc to include/osmocom/msc
Change-Id: I1f96a1285bbd1b4607614856bca935d5c26e2da9
2017-09-06 16:41:25 +02:00
Neels Hofmeyr 84da6b1edb Implement IuCS (large refactoring and addition)
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
2017-08-08 19:17:53 +02:00
Neels Hofmeyr 54a706cf92 vlr: LU FSM: enable Retrieve_IMEISV_If_Required
Change-Id: I121b95ad6d5ecb7603815eece2b43008de487a8a
2017-08-07 16:52:25 +02:00
Neels Hofmeyr ef9126c4dc vlr: place comments on if (0) cases
Change-Id: I56c1e61dedeac01a4e24452feee6616782783d8f
2017-08-07 16:52:23 +02:00
Harald Welte b8b85a1b2e Add libvlr implementation
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.

Related: OS#1592
Change-Id: Ie303c98f8c18e40c87c1b68474b35de332033622
2017-07-21 18:32:03 +02:00