Commit Graph

12 Commits

Author SHA1 Message Date
Neels Hofmeyr 46c06e28c1 add LOG_RAN_CONN() to use the conn->fi->id for context
For each conn, set a default logging category, to distinguish categories for
BSSMAP and RANAP based conns.

LOG_RAN_CONN(): log with the conn's default category,

LOG_RAN_CONN_CAT(): log with a manually set category (mostly for keeping
previous DMM logging on the same category).

In some places, replace LOGP() using manual context with LOG_RAN_CONN(), and
remove the manual context info, now provided by the conn->fi->id.

This is loosely related to inter-BSC and inter-MSC handover: to speed up
refactoring, I want to avoid the need for manual logging context and just use
this LOG_RAN_CONN().

Change-Id: I0a7809840428b1e028df6eb683bc5ffcc8df474a
2019-01-12 09:51:22 +00:00
Neels Hofmeyr c036b79918 rename gsm_subscriber_connection to ran_conn
In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.

* Name choice:

In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.

The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.

* Rationale:

A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.

Also:

- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*

Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
2018-11-30 22:45:42 +01:00
Neels Hofmeyr 3117b701c8 A5/n Ciph: request Classmark Update if missing
When the VLR requests a Ciphering Mode with vlr_ops.set_ciph_mode(), and if we
need a ciph algo flag from a Classmark information that is not yet known
(usually CM 2 during LU), send a BSSMAP Classmark Request to get it.

To manage the intermission of the Classmark Request, add
- msc_classmark_request_then_cipher_mode_cmd(),
- state SUBSCR_CONN_S_WAIT_CLASSMARK_UPDATE,
- event SUBSCR_CONN_E_CLASSMARK_UPDATE.

From state AUTH_CIPH, switch to state WAIT_CLASSMARK_UPDATE. Once the BSSMAP
Classmark Response, is received, switch back to SUBSCR_CONN_S_AUTH_CIPH and
re-initiate Ciphering Mode.

To be able to re-enter the Ciphering Mode algo decision, factor it out into
msc_geran_set_cipher_mode().

Rationale:

In the following commit, essentially we stopped supporting A5/3 ciphering:

commit 71330720b6
"MSC: Intersect configured A5 algorithms with MS-supported ones"
Change-Id: Id124923ee52a357cb7d3e04d33f585214774f3a3

A5/3 was no longer supported because from that commit on, we strictly checked
the MS-supported ciphers, but we did not have Classmark 2 available during
Location Updating.

This patch changes that: when Classmark 2 is missing, actively request it by a
BSSMAP Classmark Request; continue Ciphering only after the Response. Always
request missing Classmark, even if a lesser cipher were configured available.

If the Classmark Update response fails to come in, cause an attach failure.
Instead, we could attempt to use a lesser cipher that is also enabled. That is
left as a future feature, should that become relevant. I think it's unlikely.

Technically, we could now end up requesting a Classmark Updating both during LU
(vlr_lu_fsm) and CM Service/Paging Response (proc_arq_fsm), but in practice the
only time we lack a Classmark is: during Location Updating with A5/3 enabled.
A5/1 support is indicated in CM1 which is always available, and A5/3 support is
indicated in CM2, which is always available during CM Service Request as well
as Paging Response. So this patch has practical relevance only for Location
Updating. For networks that permit only A5/3, this patch fixes Location
Updating. For networks that support A5/3 and A5/1, so far we always used A5/1
during LU, and after this patch we request CM2 and likely use A5/3 instead.

In msc_vlr_test_gsm_ciph, verify that requesting Classmark 2 for A5/3 works
during LU. Also verify that the lack of a Classmark Response results in attach
failure.

In msc_vlr_test_gsm_ciph, a hacky unit test fakes a situation where a CM2 is
missing during proc_arq_fsm and proves that that code path works, even though
the practical relevance is currently zero. It would only become interesting if
ciphering algorithms A5/4 and higher became relevant, because support of those
would be indicated in Classmark 3, which would always require a Classmark
Request.

Related: OS#3043
Depends: I4a2e1d3923e33912579c4180aa1ff8e8f5abb7e7 (libosmocore)
Change-Id: I73c7cb6a86624695bd9c0f59abb72e2fdc655131
2018-09-17 02:08:07 +02:00
Philipp Maier f913e5f575 a_reset: cleanup + remove dead code
a_reset.c/h was originally developed to be used in both, bsc and
msc without changes. Unfortunately no suitable library has been
found for a_reset.c/h so the file ended up as duplicated code in
both split brances. Eventually we decided to specialize the
generalized code again, which means some of the functions needed
only by osmo-bsc are removed.

- Remove dead code
- Fix timer identification number (T16)
- use fi->priv to hold context info
- Minor cosmetic fixes

Change-Id: I8e489eb494d358d130e51cb2167929edeaa12e92
Depends: libosmocore I36d221c973d3890721ef1d376fb9be82c4311378
Related: OS#3103
2018-05-17 20:14:01 +00:00
Harald Welte 1f477442dd Introduce new BSSAP logging category/subsystem
Having all BSSAP related logs in the "DMSC" category is overly
generic, and dosn't provide useful granularity.

Change-Id: Id1e52dad03840dfd026fb23f3845a8771c8cc308
2018-02-09 02:22:22 +01:00
Harald Welte 6de46595f2 a_iface_bssap.c: Use LOGPCONN() whenever possible
Change-Id: Ic1c9d14b892154d51165598338d23a924a772265
2018-02-09 02:22:22 +01:00
Harald Welte 54a10efea0 Don't answer to BSC-originated RESET with another RESET
If the BSC is contacting us for the first time and sending a BSSMAP
RESET, then we should simply ACK that and transition into the
"connected" state, where connection-oriented and connectionless
procedures are permitted.

This patch is a bit large for such a seemingly simple behavioural
change, but the existing data model didn't permit a more
straight-forward implementation.

Change-Id: Ie67e7ed20a6c42afe99bafef96d85a4e083dd057
Closes: OS#2914
2018-02-09 02:20:51 +01:00
Neels Hofmeyr 703638e79a cosmetic: move translation of vlr_ciph into msc_vlr_set_ciph_mode()
a_iface_tx_cipher_mode() is a bit too far away from the VLR to be handling its
ciphering enums. Instead, construct the gsm0808_encrypt_info in the
msc_vlr_set_ciph_mode() callback.

Greatly simplify the sanity checking code: a_iface_tx_cipher_mode() no longer
needs to re-verify the presence of the gsm0808_encrypt_info contents.

Change-Id: Id46f9a513b555d0a481f7124c9984c2b5b196b3e
2017-12-18 05:18:11 +01:00
Neels Hofmeyr fb21d9dde6 compiler warning: drop double 'const' in a_iface_tx_cipher_mode()
Change-Id: I3b8baa9a259704e719ce7f12776f2d2125ebdef0
2017-12-14 03:51:34 +01:00
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
Philipp Maier 4502f5ff58 a_iface: fix memory leaks
Fix multiple memory leaske in A/BSSMAP code

Change-Id: I90703c96e6a266a1cfa60b184139375aeb9ae32d
2017-09-11 10:14:00 +02:00
Neels Hofmeyr 9084396467 rename include/openbsc to include/osmocom/msc
Change-Id: I1f96a1285bbd1b4607614856bca935d5c26e2da9
2017-09-06 16:41:25 +02:00