The usual Data Coding Scheme value in the mobile-originated USSD
request (processUnstructuredSS-Request) is 0x0f, which means:
0000 .... = Coding Group: Coding Group 0 (Language using the GSM 7 bit default alphabet)
.... 1111 = Language: unspecified
However some modems are known to use a different default value, if
not specified explicitly (AT+CUSD has optional DCS parameter):
0000 .... = Coding Group: Coding Group 0 (Language using the GSM 7 bit default alphabet)
.... 0000 = Language: German (0)
In function rx_proc_ss_req(), we should not be using req.ussd_text,
because this field has been deprecated and may contain unexpected
data. For example, in the abovementioned case it would contain the
7 bit encoded ussd-String 'aa510c061b01'O and osmo-hlr would indeed
fail to find a matching route for a non-ASCII string.
Instead of relaying on gsm0480_parse_facility_ie(), let's check the
Data Coding Scheme value and decode the request string ourselves.
Expect the Coding Group 0, but be more tolerant to the indicated
language: print a warning and treat it as '1111'B (unspecified).
Change-Id: Ib7bac660b1a7942adcfbe7b14f162c95061a25db
Related: OS#6075
An internal handler may want to continue session, e.g. to request
more information from the MS. Let's make the handlers responsible
for session state management, and check that state before calling
ss_session_free(), so a session can remain alive.
Before this patch ss->state was not set/used at all...
Change-Id: I49262e7fe26f29dedbf126087cfb8f3bb3c548dc
To be prepared for the future in public API, wrap the new osmo_ipa_name struct
in an enum-type and union called osmo_cni_peer.
During code review it was requested to insert an ability to handle different
kinds of peer id, in order to be able to add a Global Title in the future.
Use the generic osmo_cni_peer only in the publicly visible API. For osmo-hlr
internal code, I intend to postpone implementing this into the future, when a
different peer identification actually gets introduced.
This way we don't need to implement it now in all osmo-hlr code paths (save
time now), but still make all external API users aware that this type may be
extended in the future.
Change-Id: Ide9dcdca283ab989240cfc6e53e9211862a199c5
These are seemingly orthogonal changes in one patch, because they are in fact
sufficiently intertwined that we are not willing to spend the time to separate
them. They are also refactoring changes, unlikely to make sense on their own.
** lu_fsm:
Attempting to make luop.c keep state about incoming GSUP requests made me find
shortcomings in several places:
- since it predates osmo_fsm, it is a state machine that does not strictly
enforce the order of state transitions or the right sequence of incoming
events.
- several places OSMO_ASSERT() on data received from the network.
- modifies the subscriber state before a LU is accepted.
- dead code about canceling a subscriber in a previous VLR. That would be a
good thing to actually do, which should also be trivial now that we record
vlr_name and sgsn_name, but I decided to remove the dead code for now.
To both step up the LU game *and* make it easier for me to integrate
osmo_gsup_req handling, I decided to create a lu_fsm, drawing from my, by now,
ample experience of writing osmo_fsms.
** osmo_gsup_req:
Prepare for D-GSM, where osmo-hlr will do proxy routing for remote HLRs /
communicate with remote MSCs via a proxy:
a) It is important that a response that osmo-hlr generates and that is sent
back to a requesting MSC contains all IEs that are needed to route it back to
the requester. Particularly source_name must become destination_name in the
response to be able to even reach the requesting MSC. Other fields are also
necessary to match, which were so far taken care of in individual numerous code
paths.
b) For some operations, the response to a GSUP request is generated
asynchronously (like Update Location Request -> Response, or taking the
response from an EUSE, or the upcoming proxying to a remote HLR). To be able to
feed a request message's information back into the response, we must thus keep
the request data around. Since struct osmo_gsup_message references a lot of
external data, usually with pointers directly into the received msgb, it is not
so trivial to pass GSUP message data around asynchronously, on its own.
osmo_gsup_req is the combined solution for both a and b: it keeps all data for
a GSUP message by taking ownership of the incoming msgb, and it provides an
explicit API "forcing" callers to respond with osmo_gsup_req_respond(), so that
all code paths trivially are definitely responding with the correct IEs set to
match the request's routing (by using osmo_gsup_make_response() recently added
to libosmocore).
Adjust all osmo-hlr code paths to use *only* osmo_gsup_req to respond to
incoming requests received on the GSUP server (above LU code being one of
them).
In fact, the same should be done on the client side. Hence osmo_gsup_req is
implemented in a server/client agnostic way, and is placed in
libosmo-gsupclient. As soon as we see routing errors in complex GSUP setups,
using osmo_gsup_req in the related GSUP client is likely to resolve those
problems without much thinking required beyond making all code paths use it.
libosmo-gsupclient is hence added to osmo-hlr binary's own library
dependencies. It would have been added by the D-GSM proxy routing anyway, we
are just doing it a little sooner.
** cni_peer_id.c / osmo_ipa_name:
We so far handle an IPA unit name as pointer + size, or as just pointer with
implicit talloc size. To ease working with GSUP peer identification data, I
require:
- a non-allocated storage of an IPA Name. It brings the drawback of being
size limited, but our current implementation is anyway only able to handle
MSC and SGSN names of 31 characters (see struct hlr_subscriber).
- a single-argument handle for IPA Name,
- easy to use utility functions like osmo_ipa_name_to_str(), osmo_ipa_name_cmp(), and copying
by simple assignment, a = b.
Hence this patch adds a osmo_ipa_name in cni_peer_id.h and cni_peer_id.c. Heavily
used in LU and osmo_gsup_req.
Depends: libosmocore Id9692880079ea0f219f52d81b1923a76fc640566
Change-Id: I3a8dff3d4a1cbe10d6ab08257a0138d6b2a082d9
Throughout osmo-hlr's code, the GSUP msgb allocation is duplicated as:
msgb_alloc_headroom(1024+16, 16, "foo");
Instead, use one common function to keep the magic numbers in one place.
Change-Id: I40e99b5bc4fd8f750da7643c03b2119ac3bfd95e
Apply the same headers structure that we keep in most Osmocom source trees:
Keep noinst_HEADERS in include/osmocom/hlr and include them using
#include <osmocom/hlr/*.h>
The only header kept in src/ is db_bootstrap.h, because it is generated during
build time. If it was built in include/osmocom/hlr, we would need db.o to
depend on db_bootstrap.h in a different subdir, which automake can't do well.
Change-Id: Ic912fe27f545b85443c5fb713d8c3c8aac23c9ad
The SS payload is mandatory for GSUP PROC_SS_{REQ,RSP} messages
with session state BEGIN or CONTINUE, and optional for the END.
Make sure that it's present for both BEGIN and CONTINUE, consider
received message as incorrect otherwise. In case of the END, call
handle_ussd() / handle_ss() only if SS payload is present.
Change-Id: Ia71cabbf396bd1388e764a1749e953ac1782e307
Fixes: CID#188841
We have nothing to do with GSM 04.80 at the HLR - it's only used to
encapsulate the SS payload between MS and MSC. This is not that
critical, but may be misleading.
Also, gsm0480_msgb_alloc_name() allocates a smaller buffer:
return msgb_alloc_headroom(1024, 128, name);
than osmo_gsup_client_msgb_alloc() does:
return msgb_alloc_headroom(4000, 64, __func__);
Change-Id: Icdab40c6a933888eb9f51bee9c5264c8919dbf7b
Save the source IPA name in ss_session, so we can send "invalid IMSI"
messages to the originating MSC.
Remove the fixed size from ss->vlr_number (we don't know the size of the
IPA name when it does not come from the database). Add
ss->vlr_number_len to give osmo_gsup_addr_send() the format it expects,
and to have one less place in the code where the IPA names are not
stored as blob.
Looking up the IPA name from struct osmo_gsup_conn could either be done
like in osmo_gsup_server_ccm_cb() by reading the IPA IEs (which has a
FIXME comment), or by finding the route associated with conn. I went
with the latter approach, because it seems cleaner to me.
Related: OS#3710
Change-Id: If5a65f471672949192061c5fe396603611123bc1
hlr_ussd.c so far hardcoded osmo-msc's default IPA-name and hence was
only able to negotiate USSD sessions to
- a single osmo-msc
- that has no custom IPA-name set.
Fix: correctly route USSD to any number of MSC with any custom IPA
names.
Resolve the right MSC's IPA name from the USSD session's IMSI, using
hlr_subscriber->vlr_number to determine the right GSUP peer. Cache it in
ss_session->vlr_number to have at most one db hit for routing per
session.
Related: OS#3710
Change-Id: I18067bfadd33a6bc59a9ee336b6937313826fce3
It may happen that either the MS or an ESME would become
unresponsive, e.g. due to a bug, or a dropped message. This
is why we have SS session timeout, that prevents keeping
'stalled' sessions forever.
For some reason, it wasn't properly resceduled in case of
subsequent SS/USSD activity, so the lifetime of a session
was limited. Let's properly (re)schedule it.
Change-Id: I11aeacf012b06d3d0b5cc6e64baecf857b645fda
Related: OS#3717
It may happen that either the MS or an ESME would become
unresponsive, e.g. due to a bug, or a dropped message.
This is why we have SS session timeout, that prevents
keeping 'stalled' sessions forever.
Let's introduce a VTY option, which can be used to configure
this timer (by default it's set to 30 seconds):
hlr
...
! Use 0 to disable this timer
ncss-guard-timeout 30
Change-Id: I971fc2cee6fd46d4d5d6dac6c634e0b22fff183d
Related: OS#3717
At the moment, all available IUSE handlers do assume a single
request-response operation, e.g. MS requests its MSISDN - IUSE
responds. No further nor intermediate communications is required.
Let's immediately terminate such SS sessions in order to avoid
waiting for the session inactivity watchdog (i.e. timeout).
Change-Id: Iaefe37512da79e10fbe92378236bfff0eae0f8b9
As we don't store any SS related information (e.g. call forwarding
preferences) in the database, we don't handle 'structured' SS
requests at all. Let's reject them by sending error message
with FACILITY_NOT_SUPPORTED code.
Change-Id: Ia1317c5d372a42473cce65c0c985103e43be77fd
Related: OS#3651
Before this patch, the default route logic was not implemented. The
user could specify a default-route, but it wouldn't be used by the
actual routing logic. Let's fix that.
Change-Id: I0b04a75dc297f088f13da413d08c52e0747e46e6
According to GSM TS 03.38, section 6.1.2.1, CR symbol at the end
is optional, and moreover libosmogsm encoding API will carry
about the bit padding itself.
Change-Id: I09e8a67758698f3b7a578eab956311e269d091ee
We need to distinguish between both EUSE and IUSE, and properly
print their names. Otherwise, garbage is printed in case of IUSE.
Change-Id: I497e7c1fe41279afdb1256ee69e166066a6462bb
There are some requests that are best served inside the HLR, as it
has access to subscriber information such as MSISDN and IMSI.
This unfortunately required quite some restructuring of the USSD
related structures including the VTY syntax for adding routes.
The default config file has been updated to replicate the *#100#
built-in behavior of old OsmoNITB.
Closes: OS#2566
Change-Id: I1d09fab810a6bb9ab02904de72dbc9e8a414f9f9
We don't want any SS session to run for more than 30s. The timeout
is currently not refreshed.
If we need more comprehensive timeout handling, using osmo_fsm for SS
sessions might make sense.
Change-Id: I5c9fb6b619402d2a23fea9db99590143d85ac11a
Vadim Yanitskiy
Neels Hofmeyr
Oliver Smith
Harald Welte