Commit Graph

40 Commits

Author SHA1 Message Date
Jacob Erlbeck 8ff3fb04f2 sgsn: Do authentication based on SRES values
Currently the SRES value in the Auth & Ciph Response is ignored.

This patch checks the SRES value in response against the value stored
in mm->auth_triplet.sres. If they don't match, an Auth & Ciph Reject
message is sent to the MS. If they match, the mm->is_authenticated
flag is set.

Note that the procedure will not be started yet.

Sponsored-by: On-Waves ehf
2014-12-08 10:51:38 +01:00
Jacob Erlbeck bd0cf1190a sgsn: Change Auth&Ciph timer handling
Currently mmctx_timer_start is called from within
gsm48_tx_gmm_auth_ciph_req which differs from the way e.g. the
identification procedure is implemented. It also makes it more
difficult to restart the procedure after timeout, which is not
implemented yet. In addition, the timer is not properly stopped when
an AUTH & CIPH response is received.

This patch removes this timer start from gsm48_tx_gmm_auth_ciph_req,
adds the retransmission of Auth & Ciph requests to the timer callback
function, and properly stops the timer in
gsm48_rx_gmm_auth_ciph_resp.

Sponsored-by: On-Waves ehf
2014-12-08 10:50:52 +01:00
Jacob Erlbeck 02ab91e6a7 sgsn: Cross-link gsm_subscriber and sgsn_mm_ctx
To implement subscriber based authorization a data structure is
needed that keeps the subscriber data. The MSC already uses a similar
struct named gsm_subscriber whose implementation is split into a
generic part (allocation, retrieval, reference counting, list
maintenance) and MSC related parts. For GPRS, only the generic part
will be used and specific fields may be added when needed.

This patch adds a field mm to struct gsm_subscriber that will be used
by the SGSN to store a reference to the current MM context (or NULL
if there is none). This also adds a field subscr to struct
sgsn_mm_ctx that reversely points to a gsm_subscriber (or NULL if
there is none).  Either both fields are NULL or both fields are
non-NULL. Note that subscr is being reference counted.

Sponsored-by: On-Waves ehf
2014-11-14 10:26:49 +01:00
Jacob Erlbeck a0b6efb368 sgsn: Remove explicit sgsn_instance parameters
Currently the function in sgsn_auth.c either have an sgsn_config or
an sgsn_instance parameter. Since then global sgsn variable is
already being used in that file and since other parts of the SGSN
related code also rely on a global sgsn singleton, these parameters
pretend to provide a flexibility that is not really supported.

Therefore this patch removes these parameters except for the ACL
related functions, which do not call code that uses the sgsn
variable.

Sponsored-by: On-Waves ehf
2014-11-14 10:26:06 +01:00
Jacob Erlbeck f951a01bb2 sgsn: Refactor sgsn_auth to separate request and authorization
Currently the authorization is done in sgsn_auth_request for ACL
based authorization. This doesn't match the way remote authorization
would work, so that there is a second call to sgsn_auth_state already
present in sgsn_auth_update.

This patch removes the autorization check completely from
sgsn_auth_request which in turn calls sgsn_auth_update directly now.

Sponsored-by: On-Waves ehf
2014-11-14 10:23:54 +01:00
Jacob Erlbeck 423f8bfa02 sgsn: Make authorization asynchronous
Currently the authorization of an IMSI is done by checking ACLs
synchronously which is not feasible when the subscriber data has to
be retrieved from an external source.

This patch changes this by using a callback when the information is
available. This is also done when only ACL are checked, in this case
the callback is invoked from within sgsn_auth_request(). The callback
function sgsn_update_subscriber_data calls sgsn_auth_update which
in turn calls either gsm0408_gprs_access_granted or
gsm0408_gprs_access_denied. gsm48_gmm_authorize is extended by a call
to sgsn_auth_request when IMSI and IMEI are available but the
auth_state is unknown.

The change has been successfully tested with single phones (E71 and
IPhone 5c).

Sponsored-by: On-Waves ehf
2014-11-14 09:58:28 +01:00
Jacob Erlbeck 0c06f98ced sgsn: Move IMSI authorization to gsm48_gmm_authorize
Currently the IMSI is only checked immediately when an Attach Request
is received that contains an IMSI IE. If it contains a P-TMSI
instead, access is always granted.

This commit moves the IMSI check to gsm48_gmm_authorize where it is
applied when IMSI and IMEI have been acquired. This fixes the
authorization when the Attach Accept doesn't contain an IMSI.

Sponsored-by: On-Waves ehf
2014-11-14 09:27:23 +01:00
Jacob Erlbeck 93eae8ec78 sgsn: Reorganize and fix gsm48_gmm_authorize
Currently the order of the 'if' clauses in gsm48_gmm_authorize
doesn't match the order in which the conditional parts are entered.
This makes it difficult to maintain. In addition the t3350_mode is
not stored in every path, so that this information is lost when the
identification procedure is started. Since the default value
coincidentally is GMM_T3350_MODE_ATT, this doesn't hurt for Attach
Requests which are the only messages that initially trigger the
authentication yet.

This patch changes the order of the 'if' clause to match the
processing order, it removes the t3350_mode parameter entirely and
introduces a mm->pending_req field. The latter must be set when the
request that causes the authorization before calling
gsm48_gmm_authorize. The gprs_t3350_mode enum is extended by
GMM_T3350_MODE_NONE (value 0, which is the default) to make it
possible to detect related initialisation errors or race conditions.

Sponsored-by: On-Waves ehf
2014-11-14 08:57:50 +01:00
Jacob Erlbeck 5a38f6470e sgsn: Handle Detach Requests even when there is no mmctx
Currently, when a Detach Request is received with an unknown TLLI,
it is answered by another Detach Request (!), even when a power_off
Type is used.

This patch uses gsm48_rx_gmm_det_req to handle the message instead.
So this function is changed to cope with a NULL mmctx. In that case
it doesn't unassign the llme, so this must be done manually
afterwards.

Sponsored-by: On-Waves ehf
2014-10-27 15:34:14 +01:00
Jacob Erlbeck 3b5d407203 sgsn: Moved IMSI ACL management to sgsn_auth.c
Currently the ACL code is located in sgsn_vty.c.

This commit moves this to a new file sgsn_auth.c as a first step to
make authorization more flexible in order to implement remote
acquisition on subsciber data.

Sponsored-by: On-Waves ehf
2014-10-27 13:06:55 +01:00
Jacob Erlbeck 78ecaf0561 sgsn: Send detach(re-attach) instead of gmm status if TLLI unknown
The osmo-sgsn sends Status messages (or nothing in case of non
GMM/GSM) when the TLLI is unknown. This prevents the MS from
reconnecting.

This patch adds the initiation of an MT detach procedure to force a
re-attach to set up a valid LLE context if an LLE or an MM context
cannot be found. Since this can also be triggered by non-GMM SAPI
messages, a GPRS application callback sgsn_force_reattach_oldmsg is
added which in turn calls the GMM layer to generate the GSM 04.08
specific messages.

Note that the MS can be left in REGISTERED state after initially
wanting to detach itself, since it will receive a Detach Req
(re-attach) when sending a DEACT PDP CTX REQ after the SGSN or
gbproxy (P-TMSI patching enabled) has been restarted. This same
behaviour has been observed with another SGSN.

Sponsored-by: On-Waves ehf
2014-10-27 10:50:36 +01:00
Jacob Erlbeck 99985b5ea8 sgsn: Delete PDP contexts properly
Currently the PDP contexts are hard freed (via sgsn_pdp_ctx_free)
at some places in gprs_gmm.c on the reception of a Detach Req and on
re-use of an IMSI that is already associated with an MM context. This
can lead to segfaults when there is a pending request or a data
indication at libgtp.

This patch add a new function sgsn_pdp_ctx_terminate that de-associates
the PTP context from the MM context, deactivates SNDCP, sets pdp->mm
to NULL and then calls sgsn_delete_pdp_ctx. sgsn_libgtp is updated to
check for pdp->mm being non-NULL before dereferencing it. The
sgsn_pdp_ctx_terminate function will be called for each PDP context of
an MM context before this context is going to be deleted via
sgsn_mm_ctx_free. To ensure, that the ctx->llme (which is accessed
during the deactivation of SNDCP) remains valid, the call to
gprs_llgmm_assign is moved after the call to sgsn_mm_ctx_free. The
handling of re-used IMSIs is changed to mimic the processing of a
Detach Req.

Addresses:
<0002> gprs_gmm.c:654 MM(/f6b31ab0) Deleting old MM Context for same
    IMSI p_tmsi_old=0xc6f19134
<000f> gprs_sgsn.c:259 PDP freeing PDP context that still has a
    libgtp handle attached to it, this shouldn't happen!
[...]
SEGFAULT

Ticket: OW#1311
Sponsored-by: On-Waves ehf
2014-10-27 10:25:13 +01:00
Daniel Willmann b15ceec33f gprs_sgsn.h: Add two macros to log details of MM/PDP contexts 2014-09-22 10:47:11 +02:00
Holger Hans Peter Freyther 90e9a445c8 gprs: Fix compiler warnings in sgsn_main.c
sgsn_main.c: In function ‘main’:
sgsn_main.c:345:2: warning: implicit declaration of function ‘gprs_sndcp_vty_init’ [-Wimplicit-function-declaration]
  gprs_sndcp_vty_init();
  ^
sgsn_main.c:354:2: warning: implicit declaration of function ‘sgsn_gtp_init’ [-Wimplicit-function-declaration]
  rc = sgsn_gtp_init(&sgsn_inst);
  ^
2014-04-04 12:51:28 +02:00
Holger Hans Peter Freyther 1768a5765d gprs: Reduce the number of compiler warnings in gprs_gmm.c
CC       gprs_gmm.o
gprs_gmm.c: In function ‘gsm48_tx_gmm_att_ack’:
gprs_gmm.c:350:11: warning: unused variable ‘ptsig’ [-Wunused-variable]
  uint8_t *ptsig, *mid;
           ^
gprs_gmm.c: In function ‘gsm48_rx_gmm_auth_ciph_resp’:
gprs_gmm.c:524:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
  int rc;
      ^
gprs_gmm.c: In function ‘gsm48_rx_gmm_att_req’:
gprs_gmm.c:703:9: warning: implicit declaration of function ‘sgsn_acl_lookup’ [-Wimplicit-function-declaration]
         !sgsn_acl_lookup(mi_string))) {
         ^
gprs_gmm.c:632:40: warning: variable ‘old_ra_info’ set but not used [-Wunused-but-set-variable]
  uint8_t *cur = gh->data, *msnc, *mi, *old_ra_info, *ms_ra_acc_cap;
                                        ^
gprs_gmm.c: In function ‘gsm48_rx_gmm_ra_upd_req’:
gprs_gmm.c:915:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
  int rc;
      ^
gprs_gmm.c:910:11: warning: variable ‘ms_ra_acc_cap’ set but not used [-Wunused-but-set-variable]
  uint8_t *ms_ra_acc_cap;
           ^
gprs_gmm.c: At top level:
gprs_gmm.c:458:12: warning: ‘gsm48_tx_gmm_auth_ciph_req’ defined but not used [-Wunused-function]
 static int gsm48_tx_gmm_auth_ciph_req(struct sgsn_mm_ctx *mm, uint8_t *rand,
            ^
gprs_gmm.c:501:12: warning: ‘gsm48_tx_gmm_auth_ciph_rej’ defined but not used [-Wunused-function]
 static int gsm48_tx_gmm_auth_ciph_rej(struct sgsn_mm_ctx *mm)
            ^
gprs_gmm.c:1169:13: warning: ‘msgb_put_pdp_addr_ipv4’ defined but not used [-Wunused-function]
 static void msgb_put_pdp_addr_ipv4(struct msgb *msg, uint32_t ipaddr)
             ^
gprs_gmm.c:1180:13: warning: ‘msgb_put_pdp_addr_ppp’ defined but not used [-Wunused-function]
 static void msgb_put_pdp_addr_ppp(struct msgb *msg)
2014-04-04 12:41:03 +02:00
Holger Hans Peter Freyther a27303094a sgsn/ctrl: Add ctrl interface, implement listing subscribers
Add the control interface with no hierachy right now and implement
the first command to list IMSI + Context Address of active sessions.
sgsn_cmd_handle could share more code with bsc variant.

Fixes: SYS#264, SYS#265
2014-03-23 18:34:58 +01:00
Alexander Chemeris 84402c0c82 sgsn: Fix lengths of MS Network Capability and MS Radio Access Capability elements.
Original code was inconsistent about lengths and could lead to out
of bounds write. Lengths were also inconsistent with the TS 24.008.

Fixes: Coverity CID 1040714.
2013-07-04 18:34:49 +02:00
Holger Hans Peter Freyther 26d0fe3c89 gprs_sgsn.h: Include timer.h for the timer struct 2012-01-06 18:52:05 +01:00
Harald Welte 4b2ed35b8f GPRS: Fix buffer overflow in case of very long MS RA CAP IE
The MS Radio Access Capability IE can be _very_ long in some recent
high-end mobile phones, way beyond the old 14-byte limit.  We increase
our array to 52 bytes, and make sure not to overflow that buffer.
2011-07-27 23:35:38 +02:00
Pablo Neira Ayuso bf540cb7c3 src: use namespace prefix osmo_timer* for timer functions
Summary of changes:

s/struct timer_list/struct osmo_timer_list/g
s/bsc_add_timer/osmo_timer_add/g
s/bsc_schedule_timer/osmo_timer_schedule/g
s/bsc_del_timer/osmo_timer_del/g
s/bsc_timer_pending/osmo_timer_pending/g
s/bsc_nearest_timer/osmo_timers_nearest/g
s/bsc_prepare_timers/osmo_timers_prepare/g
s/bsc_update_timers/osmo_timers_update/g
s/bsc_timer_check/osmo_timers_check/g
2011-05-06 12:11:06 +02:00
Pablo Neira Ayuso 136f453dd2 src: use new library libosmogsm and new path to headers in libosmocore
libosmogsm is a new library that is distributed in the libosmocore.
Now, openbsc depends on it. This patch gets openbsc with this
change.

This patch also rewrites all include path to the new
osmocom/[gsm|core]

Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
2011-03-23 18:17:56 +01:00
Harald Welte c728eeaf9b SGSN: Avoid duplicate MM contexts in case MS and SGSN disagree on P-TMSI 2010-12-26 19:20:07 +01:00
Harald Welte a9b473a3c2 SGSN: Implement network-initiated PDP CTX DEACT when GGSN restarts
If the GGSN restarts, its restart counter will increase.  We can
detect that and accordingly release/delete all PDP contexts for
that GGSN.
2010-12-26 19:20:03 +01:00
Harald Welte 496aee463f [SGSN] Call libosmocore helper to load cipher plugins 2010-07-02 22:54:55 +02:00
Harald Welte efbdee9a5c [GPSR] SGSN: Keep traffic counters for each PDP context 2010-06-10 15:12:38 +02:00
Harald Welte 96df60637a [GPRS] add comments to SGSN header file 2010-06-03 06:38:09 +02:00
Harald Welte 807a5d8264 [GPRS] Major LLC / TLLI handling fixes
* separate the LLME and LLE state in the LLC layer
* introduce gprs_llgmm_assign() function for LLGMM-ASSIGN.req primitive
* change QoS profile to match 'real' SGSN
* Update the new TLLI when assigning a P-TMSI

The result now is that the LLC layer is notified of TLLI changes, which in turn
means it doesn't allocate a new LLE structure every TLLI change, which again
in turn means that the UI frame sequence number does not reset to zero.

As a result, MS should no longer ignore frames based on wrong UI sequence number.
2010-06-01 11:57:13 +02:00
Harald Welte c2e8cc4a10 [GPRS] Implement TMSI reallocation and timers 3350 + 3370
Our state transitions and timers now reflect 04.08 for GMM much
better than before.  Also, we allocate a new P-TMSI on every ATTACH
and RA UPDATE, as some phones seem to get confused if they don't
get a P-TMSI.
2010-05-31 20:23:38 +02:00
Harald Welte cd4dd4d7ff [GPRS] fix numerous compiler warnings 2010-05-18 17:20:49 +02:00
Harald Welte 6463c0799c [GPRS] SGSN: TMSI allocation 2010-05-18 17:04:55 +02:00
Harald Welte 77289c202f [GPRS] SGSN: properly delete a PDP context after receiving PDP CTX DEACT REQ 2010-05-18 14:32:29 +02:00
Harald Welte 8acd88f369 [GPRS] SGSN: Include rate counters in MM Context 2010-05-18 10:57:45 +02:00
Harald Welte 6abf94e420 [GPRS] Properly connect GPRS SM with LIBGTP for PDP context activation
* store LLC SAPI as part of PDP ctx
* store NSEI + BVCI as part of MM ctx
* export gsm48_tx_gsm_act_pdp_acc() and call it from sgsn_libgtp.c
* create and use gsm48_tx_gsm_act_pdp_rej for error cases
* print SAPI as part of VTY show pdp
2010-05-18 10:35:06 +02:00
Harald Welte d193cb327a [GPRS] More work on a real SGSN 2010-05-17 22:58:03 +02:00
Harald Welte 8fc1a46f28 [SGSN] remove the mmctx->sgsn pointer
We never want to support multiple sgsn's within one process, so
there is no point in passing them around all the time.
2010-05-17 00:53:10 +02:00
Harald Welte 2720e7310d [GPRS] Initial untested support for libgtp
libgtp of the OpenGGSN project will allow us to speak the GTPv0/v1
protocol of the interface between SGSN and GGSN.

This commit includes code for the main libgtp integration (file
descriptor, select loop, timer) as well as code to encode/send
a CREATE PDP CONTEXT request.
2010-05-17 00:44:57 +02:00
Harald Welte ba850c529e [gprs] cosmetic updates in header file 2010-05-04 07:20:44 +02:00
Harald Welte eaa614cb9e [gprs] Use stdint.h types (uintXX_t instead of u_intXX_t)
libosmocore already uses them, it's time (at least for new code)
in openbsc to do the same.
2010-05-04 07:20:43 +02:00
Harald Welte f533e13c14 [gprs] add some Iu specific SGSN MM state fields 2010-05-04 07:20:42 +02:00
Harald Welte 9b455bf801 Create new 'gprs-sgsn' branch on top of 'gprs-conf'
This branch contains the partial SGSN/GGSN implementation that
was originally developed as part of the gprs branch.
2010-05-04 07:20:41 +02:00