We now have a function that generates BSSGP PS and CS paging request.
It is called from the libgtp code when we receive a GTP packet from
the GGSN for a MM context that is in SUSPEND state. We then issue
a PS paging request to the Cell with the BVCI where the last RA update
was being performed.
TODO: We still don't enqueue the GTP packet (and transmit it on paging
complete), and we don't rate-limit the paging requests, i.e. every GTP packet
will trigger another paging request.
We probably also need some kind of logic that marks the phone as UNREGISTERED
if it doesn't respond to paging requests for some time.
Some phones (notably a Ericsson Mobile Platform based E-TEN M800)
insist on sending PDP CTX DEACT messages for contexts that have already
been deactivated. The spec doesn't really say what we should do in
this case. But since there is no "reject", we simply acknowledge it.
Right now the memcpy with the data will copy data to itself as
the new_msg->data and msg->data are the same due the previous
copying of the header which included copying the list entry..
We allocate a message as big as the current one, then we have to
set all pointers by looking of how far they are away from the
msg->_data and add that to the new pointers.
Also copy the OpenBSC/GPRS specific CB data, also do the same
for calculating the offset to the data... At the end we should
end up with a copy...
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...
We have to copy the sin_addr.s_addr, rather than the entire sin_addr. The
latter results in the destination interpreting it as an IPv6 address, as
the only differentiator between IPv4 and IPv6 is the size of the payload
of this IE.
* 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.
This is of course not the correct way of dealing with it, but for
now it should make the Ericsson Mobile Plafrom based phones happy
(they insist to do a suspend/resume cycle before pdp ctx act)
GRE has the strange notion of keepalive messages being encapsulated IPv4
packets adressed back to the sender. Since we actually really only care
about frame relay, this is a bit strange. However, we'll do some sanity
checks and send it back through our GRE socket...
0 Reserved for ANSI Annex D and CCITT Annex A link management
1 - 15 Reserved
16 - 1007 Any PVC
1008 - 1018 Reserved
1019 - 1022 Reserved for LMI multicast
1023 Reserved for LMI link management
According to the spec, after an incoming RESET or RESET_ACK, we shall start the
TEST procedure, not the ALIVE procedure.
Also, when we start the TEST procedure, we have to always send a NS_ALIVE
packet at the same time (we didn't in the case of incoming RESET).
Furthermore, we now only start TIMER_TNS_ALIVE from within the
TIMER_TNS_RESET callback code, where we also make sure that the
alive_retries counter is reset to zero.
Harald Welte
Holger Hans Peter Freyther