Commit Graph

14 Commits

Author SHA1 Message Date
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
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
Max 923a23900e VLR: constify GSUP-related function parameters
Change-Id: If3852e096210713cb5297f6b42ed66dbb98c4a50
2018-01-24 13:55:03 +01:00
Max dcc193d3a6 Add control command to expire subscriber
It's equivalent of existing vty command: common part is extracted into
shared helper function.

Change-Id: I267886b7c79ed6d9c2f34a2e60d2972b7f4f4036
2018-01-05 10:10:35 +00:00
Max a263bb215b VLR: log subscriber update
* move log helpers to generic header
* log subscriber update

It's handy for troubleshooting issues with subscriber update via GSUP
from HLR.

Change-Id: I1958aeeb3ea99831c7e2c5ee9a6b59834baf4520
2017-12-31 11:01:46 +00:00
Max 7772c7de55 VLR: remove unused parameter
The expire_lu is never used but is printed for every subscriber. Let's
remove it to avoid confusion.

Change-Id: I6f7ad1670836384d1e6a58f47a13464fdbbf8509
2017-12-29 18:12:37 +01:00
Neels Hofmeyr 2ff5bcdc38 fix paging: add timeout to discard unsuccessful paging
Currently, if there is no reply from the BSS / RNC, a subscriber will remain as
"already paged" forever, and is never going to be paged again. Even on IMSI
Detach, the pending request will keep a ref count on the vlr_subscr.

Add a paging timeout, as gsm_network->paging_timeout and in the VTY on the
'msc' node as 'paging timeout (default|<1-65535>'. (There is a 'network' /
'T3113' in OsmoBSC, but to not confuse the two, give this a different name.)

Add test_ms_timeout_paging() test to verify the timeout works.

I hit this while testing Paging across multiple hNodeB, when a UE lost
connection to the hNodeB. I noticed that no matter how long I wait, no Paging
is sent out anymore, and found this embarrassing issue. Good grief...

The choice of 10 seconds is taken from https://osmocom.org/issues/2756

Change-Id: I2db6f1e2ad341cf9c2cc7a21ec2fca0bae5b2db5
2017-12-20 23:07:10 +01:00
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 e3d72d7827 cosmetic prep: publish vlr_use_umts_aka() decision
During Set Ciphering Mode on GERAN, it is required to know whether UMTS AKA is
used to decide which Kc to pick. Change static function is_umts_auth() into
public vlr_use_umts_aka(), so future patches can re-use it.

Prepares: If04e405426c55a81341747a9b450a69188525d5c
Change-Id: I85d784c62ecbabdb6186a3dae4dcd554e7921041
2017-12-18 05:18:11 +01:00
Neels Hofmeyr cf30913c8e fix BSSMAP Cipher Mode Cmd: properly set permitted algorithms
The bit shifting is performed in gsm0808_enc_encrypt_info(), and must not be
done when populating the gsm0808_encrypt_info struct.

Provide vlr_ciph_to_gsm0808_alg_id() to translate the enum vlr_ciph to the
GSM0808_* constants we need to put in the gsm0808_encrypt_info struct instead.

Related: OS#2745
Change-Id: If75f95e8a5cc8b9979610ce6d746c1f0073ee39a
2017-12-18 03:48:24 +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 33f534136c cosmetic: vlr: rename auth_tuple_max_use_count to _reuse_
The name auth_tuple_max_use_count suggests that if I want to use each auth
tuple exactly once, I need to set it to 1. Curiously, so far you need to set
to intended uses - 1.

Reflect this in its name by renaming to auth_tuple_max_reuse_count.

I first considered to not rename but change the if-conditions so that == 1
means each tuple is used once, and upon struct vlr allocation, set the default
to 1. That would also logically entail that setting to 0 means to re-use
vectors infinitely often, like now a value < 0 does. That means, when
allocating a vlr struct zeroed out, we would by default have the most
dangerous/unsafe configuration. It's no problem to set a default to 1 upon
allocation, but by renaming the variable instead, we get safer alloc-zero
behavior and don't need to change any conditionals in the code (even though the
patch ends up considerably larger from all the renaming).

Change-Id: I0b036cae1536d5d6fb2304f837ed1a6c3713be55
2017-10-31 02:02:43 +01:00
Neels Hofmeyr 9084396467 rename include/openbsc to include/osmocom/msc
Change-Id: I1f96a1285bbd1b4607614856bca935d5c26e2da9
2017-09-06 16:41:25 +02:00