Commit Graph

5 Commits

Author SHA1 Message Date
Neels Hofmeyr 3c7656a481 Iu: add UEA encryption
Add vty 'encryption uea 0 1 2', defaults to 'encryption uea 0' to yield
previous behavior.

If any UEA above 0 is enabled, include the UEA key in the Iu Security
Mode Command.

I noticed that only the code bit in st_iu_security_cmd_on_enter()
affects the test. The same code in gsm48_gmm_authorize() seems to be
dead code? But applying the patch there as well just to be safe.

We cannot yet verify the chosen UEA to match a configured UEA level,
because the iu_client.c does not send us message details with the
RANAP_IU_EVENT_SECURITY_MODE_COMPLETE.
Also we cannot yet send the set of configured UEA to the hNodeB, since,
again, iu_client.c does not provide the proper API for it.
The proper solution here is to completely dissolve iu_client.c and do
all Iu handling in osmo-sgsn itself -- see OS#5487.

Related: SYS#5516
Related: I1a7c3b156830058c43f15f55883ea301d2d01d5f (osmo-ttcn3-hacks)
Change-Id: I27e8e0078c45426bf227bb44aac82a4875d18d0f
2022-03-10 19:07:38 +01:00
Eric Wild 2f898265d0 add support for multiple encryption algorithms and a5/4
Change-Id: Ie6700c4e9d2df1eb5fde1b971e287b62668cc2de
Related: SYS#5324
2021-06-16 16:43:23 +02:00
Pau Espin e5c8998f9c Support forwarding RIM messages over GTPCv1 EUTRAN<->GERAN
MMEs connect over Gn interface using GTPCv1 towards the SGSN in order to
exchange RIM PDUs by using "RAN Information Relay" GTPCv1 message type.
For more info, see 3GPP TS 29.060 sec 7.5.14.1 "RAN Information Relay"

In order to support it, this commit does the following:

* Uses new libgtp APIs to rx and tx RAN Information Relay messages. The
  same "gsn" object is reused, ie. the local GTPCv1 socket address used
  for exchanging messages against GGSN is reused.
* Adds a new "sgsn_mme_ctx" struct holding information about MMEs
  allowed by the SGSN, each one containing information about the GTP
  address it uses, the in/out routing based on TAI requests, etc. The
  set of MMEs and their config can be set up using new VTY node introduced
  in this commit.
* The RIM related code in SGSN is refactored to allow forwarding from
  and to several types of addresses/interfaces.

Depends: osmo-ggsn.git Change-Id Iea3eb032ccd4aed5187baca7f7719349d76039d4
Depends: libosmocore.git Change-Id I534db7d8bc5ceb19a2a6866f07d5f5c70e456c5c
Related: SYS#5314
Change-Id: I396450b8d8b66595dab8ff7bf41cbf964bb40d93
2021-05-19 11:45:05 +02:00
Pau Espin 3caa7f6d97 Iu: Drop timer X3314
This Iu timer is Osmocom specific, but is made to resemble T3314
timer from GERAN (also named READY timer).

The idea of this activity timer was to arm it whenever PMM state
transitions to CONNECTED, and then rearm it every time there's some
sort of activity, until there's none for some time, then we send a
Release Command to close the conn with the HNGBW/RNC. That's the
same principle as per spec-defined READY timer T3314.

However, there's still a fundamental problem with it: GTP-U in
GERAN passes through the SGSN, but in UTRAN, the GTP-U stream
goes directly from the HnodeB to the GGSN. Hence, there's no proper
way to re-arm this timer upon activity in UTRAN, basically because
the SGSN will never see (userplane data) activity. That explains why
the E_MM_PDU_RECEPTION event exists for mm_state_gb_fsm, but doesn't
exist for mm_state_iu_fsm.
As a result, the timer is currently never rearmed, which means it
will transition to IDLE always after 44 seconds (default value) once
it went into CONNECTED state.

In UTRAN, there is a SCCP connection for each subscriber between
RNC/hNB and SGSN. If the subscriber is no longer in the respective
state, the RNC/hNB should release that IuPS SCCP connection, whcih
in turn means the SGSN cleans up its state.
Furthermore, SCCP has a built-in IT (inactivity timer). So should
the RNC/hNB die, that timer would time out, and the SGSN-side local
SCCP stack (provider) wold send a RELEASE.ind for that connection
to the user (SGSN).

TLDR; this timer is not really needed and cannot be implemented
properly in UTRAN, so let's remove it.

Related: OS#5116
Change-Id: Ibc71829e417bf2dd0c27deb842369dd4f17010d6
2021-04-14 12:14:52 +02:00
Daniel Willmann ef3c9af0f9 gbproxy: Add SGSN NRI configuration
In order to support SGSN pooling we need to configure the various NRI
parameters such as the bitlen, NULL NRI, and which NRIs are assigned to
which SGSN.

Related: OS#4890, OS#4472
Change-Id: Id67592aa7712e5e04e7264b2fb8f26d57eb7e69e
2020-12-29 16:38:49 +01:00