Currently the LLME is not deleted when a GMM Status message is
received for which a mmctx cannot be found. This can fill the LLME
list with unneeded entries.
This patch adds code to unassign the LLME in that case.
Ticket: OW#1324
Sponsored-by: On-Waves ehf
The following functions are not being used:
- gsm48_tx_gmm_status_oldmsg
- gsm48_tx_sm_status_oldmsg
This patch removes the function definitions.
Sponsored-by: On-Waves ehf
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
Currently, every time the SGSN received a Detach Request from the MS
via an established logical link, it is answered by a Detach Accept.
This violates the specification (GSM 04.08, 4.7.4.1.2 and .3), which
states, that it should only be sent, if "the detach type IE value
indicates that the detach request has not been sent due to switching
off".
This patch adds a conditional to limit the sending of Detach Accept
accordingly.
Sponsored-by: On-Waves ehf
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
Currently each received Ident Resp triggers an Attach Accept/Reject
if IMSI and IMEI are known. This has led to duplicated Attach Accept
messages when used with the gbproxy (IMSI acquisition active) and
with certain mobile equipment (iOS).
This patch modifies gsm48_rx_gmm_id_resp to discard Ident Resp messages
if all required information (IMEI and IMSI) has been gathered.
Ticket: OW#1322
Sponsored-by: On-Waves ehf
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
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
On a Detach/Re-attach cycle the Address Sanitizer detected a
use-after-free kind of problem. That is because we tried to
destroy the LLME twice. The first time it is destroyed as part
of the Detach handling ans the second time it is destroyed as
part of destroying the old MM context.
In case the GPRS GMM detach message is lost the SGSN needs
to reply besides not having a MM entry.
The alternative would have been to add NULL checks for all
usages of ctx->llme which would not have helped with the
readability.
Sponsored-by: On-Waves ehf
The wrong field has been use for the field length computation. This
hadn't any impact so far, since
sizeof(ctx->imei) == sizeof(ctx->imsi)
This patch fixes the computation to use the right field.
Sponsored-by: On-Waves ehf
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)
This adds a minimalistic ACL by which certain, individual roaming IMSIs
can be authorized to use the SGSN. So you can selectively bypass the
'MCC+MNC == first 5 digits of IMSI' checking for a couple of IMSIs
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.
In case a MS (of which we have no MM context) sends us anything but a
GMM ATTACH REQUEST, we need to send it a LLC XID RESET (by means of
issuing LLGMM-RESET.req). Otherwise the phone will expect us to send a
specific unacknowledged sequence number that we don't know.
Thanks to Holger for pointing this bug out to me.
It seems to commonly occur when a MS is doing network re-selection and
(erroneously) sends a RA UPD REQ instead of an ATTACH REQ. The RA UPD
REJ that we sent was never seen by the GMM entity in the MS, as the LLC
entity discarded it due to sequence number mis-match.
gprs_gmm.c:240:2: warning: passing argument 4 of ‘gprs_llc_tx_ui’ discards qualifiers from pointer target type
../../include/openbsc/gprs_llc.h:151:5: note: expected ‘void *’ but argument is of type ‘const struct sgsn_mm_ctx *’
gprs_gmm.c:349:11: warning: unused variable ‘ptsig’
gprs_gmm.c:601:5: warning: too many arguments for format
gprs_gmm.c:987:25: warning: initialization discards qualifiers from pointer target type
gprs_gmm.c:1010:6: warning: ‘rc’ may be used uninitialized in this function
The byte ordering is a bit odd: The least significant byte is ahead of
the most significant byte, different from everything else in GSM that
seems to be big-endian.
Thanks to Seungju Kim <admin@manateeshome.com> for repoerting the bug.
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.
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>
In case we get a RA UPD REQ on a new cell (both served by the same
SGSN), the LLC stack should not allocate a ne LLE/LLME, as the latter
would reset the V(u)sent / V(u)recv to zero and make the MS discard
our responses.
Instead, whenever the LLC stack sees a foreign TLLI, it should always
convert it to the local TLLI before doing any lookup for a LLE/LLME.
The reason for this is quite simple: We want to make sure anyone
running a customized version of OpenBSC to operate a network will
have to release all custom modifiations to the source code.
As we do not yet use the HLR from the SGSN, we allow all MS to
attach to our GPRS network. However, if this is running in a public
environment, it could cause service interruption to users of commercial
GPRS networks.
Thus, we now check if the first 5 digits of the IMSI match the MCC/MNC
of the cell that they want to register to. Thus, any subscribers with
SIM cards from real operators will no longer be accepted.
If a MS changes RA, the RA will arrive in the new cell using the old
TLLI (masked as foreign TLLI). So we need to look-up the TLLI
in a special way, using the old RA as indicated in the 04.08 GMM
message.
There is still another bug remaining: As we somehow create a new LLC,
the sequence numbers of our responses start from 0 again, which is not
what the MS expects. This needs to be fixed in a follow-up patch.
Once The TLLI (or P-TMSI of which it is derived) change has been
confirmed by the MS, we need to unassign the old TLLI but keep
the new TLLI _without_ re-setting the LLC entity structure such
as VUsend /VUrecv counters.
Jacob Erlbeck
Daniel Willmann
Harald Welte