Using the code of this commit, it was possible to provision GPRS
services and access a website from a G1 phone (Qualcomm MSM7k baseband chipset)
using a nanoBTS, Osmo-SGSN and OpenGGSN.
There is still no fragment re-assembly in the uplink path yet,
despite the (untested) code present in the gprs_sndcp.c file
This only works for packets that are small enough to not need
fragmentation at the SNDCP layer (dns queries, ntp and the like).
It requires libgtp built from OpenGGSN dc3744fda045f9fca83de6881176987335a309a8
or later. Plain 0.90 will NOT work.
Using this version, I could see bi-directional traffic from various
phones going all the way through BTS, OsmoSGSN, OpenGGSN and being routed
to and from the real internet. Time to celebrate...
* 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.
When we send a downlink unit-data request via BSSGP, there is a lot
of information that needs to be copied from the mm context, such as
the IMSI, DRX parametes, MS radio access parameters, ...
This is a quite strange layering violation, since we now need to pass
a pointer to the MM ctx from GMM through LLC into BSSGP :(
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.
When we issue a RF Channel Release in case of a failure we receive
RLL release indications after the channel was tearn down and we
issue another RF Channel Release as a result. The channel allocator
might have already allocated this channel and we release the channel
again with another MS on it.
Make rsl_rf_chan_release take an error argument and make it set
a new state in case of an error and change the RF Channel Release
ack to not set the state back to none in case of an error but wait
for a timeout that is a bit higher than T3111.
I tested this with removing the battery during a phonecall and
waiting for the channel failure. With this test we only send the
release once.
Change gprs_nsvc_reset to return void instead of a int
as the gb_proxy.c currently ignores the reutnr value anyway.
Change the caller inside gprs_ns to return the newly allocated
nsvc instead of the return of gprs_nsvc_reset.
Almost all parameters about the SGSNs NS-VC can be specified in the NS
protocol node. All that needs to remain in the gbproxy config node
is "nsip sgsn nsei XXX".
* 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
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.
We want the VTY and telnet code to be independent from the BSC
application(s). As a side note, we also like to eliminate static
global variables for 'struct gsm_network' all over the code.
As such, telnet_init() is now passed along a "private" pointer,
which getst stored in telnet_connection.priv. This telnet_connection
is then stored in vty->priv, which in turn gets dereferenced if
anyone needs a reference to 'struct gsm_network' from the BSC vty
code.
Also:
* vty_init() now calls cmd_init()
* the ugliness that telnet_init() calls back into the application by means of
bsc_vty_init() function has been removed.
* telnet_init() now returns any errors, so the main program can exit
e.g. if the port is already in use.
This enables us to make the VTY completely independent of any
compile-time program-specific information, i.e. one step closer
to using VTY as a shared library from multiple programs.
So far, we only started the ALIVE procedure on RESET-ACK if the
remote end was the SGSN. This resulted in the BSS->Proxy connections
only being tested for alive-status from the BSS side, but not from
our side.
Also: export nsvc_by_nsvci() function as a public API function.
This is a generic MI extraction for the MI if it is followed
after a classmark. For the Phase1 Phones the classmark2 is not
four bytes but it might be different. This code can be used
by the CM Service Request handling as well.
We go from no size checks to some content checking. We should
refactor the whole classmark2 + mi parsing that is used throughout
the code into one place with proper size checking. This is the
start and requires a new libosmocore as well.
Using "end" you can always return to the "enable" level, and from
there the "show" commands are available. So no more need for
exit/exit/exit/exit/disable.
Some BSS that connect to the proxy do not continue to perform the
RESET procedure after a timeout. In order to resurrect them, we
simply start a RESET procedure.
Harald Welte
Holger Hans Peter Freyther