Add mslookup client to find remote home HLRs of unknown IMSIs, and
proxy/forward GSUP for those to the right remote HLR instances.
Add remote_hlr.c to manage one GSUP client per remote HLR GSUP address.
Add proxy.c to keep state about remotely handled IMSIs (remote GSUP address,
MSISDN, and probably more in future patches). The mslookup_server that
determines whether a given MSISDN is attached locally now also needs to look in
the proxy record: it is always the osmo-hlr immediately peering for the MSC
that should respond to mslookup service address queries like SIP and SMPP.
(Only gsup.hlr service is always answered by the home HLR.)
Add dgsm.c to set up an mdns mslookup client, ask for IMSI homes, and to decide
which GSUP is handled locally and which needs to go to a remote HLR.
Add full VTY config and VTY tests.
For a detailed overview of the D-GSM and mslookup related files, please see the
elaborate comment at the top of mslookup.c (already added in an earlier patch).
Change-Id: I2fe453553c90e6ee527ed13a13089900efd488aa
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
mslookup is a key concept in Distributed GSM, which allows querying the current
location of a subscriber in a number of cooperating but independent core
network sites, by arbitrary service names and by MSISDN/IMSI.
Add the abstract mslookup client library. An actual lookup method (besides
mslookup_client_fake.c) is added in a subsequent patch.
For a detailed overview of this and upcoming patches, please see the elaborate
comment at the top of mslookup.c.
Add as separate library, libosmo-mslookup, to allow adding D-GSM capability to
arbitrary client programs.
osmo-hlr will be the only mslookup server implementation, added in a subsequent
patch.
osmo-hlr itself will also use this library and act as an mslookup client, when
requesting the home HLR for locally unknown IMSIs.
Related: OS#4237
Patch-by: osmith, nhofmeyr
Change-Id: I83487ab8aad1611eb02e997dafbcb8344da13df1
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
Tweak unit test binaries to still used DEBUG loglevels, so that their expected
outputs remain unchanged (and nicely verbose).
Adjust test_nodes.vty, now expecting the 'notice' log levels upon
'show running-config'.
Change-Id: Ic061e61c9625b49cef8bc2a2c0b936e262c22268
DLGSUP must no longer be added to applications' logging category arrays after
change-id Id974c7be158e4d60421a98110f5c807aefd31119 in libosmocore.
Todo: once above change is merged to libosmocore, bump the required libosmocore
version in configure.ac.
Change-Id: I74ab1a031d1ed144468b016294d2965eba5e7d1d
Neels Hofmeyr
Oliver Smith
Harald Welte
Neels Hofmeyr