The current LAPD control field for indication/disconnect/etc
is wrong and currently we are only interested in the actual
A-Bis data spoken between the BTS and BSC and not on the indication
of the physical line (connection, disconnect, release..)
When using ISDN as network type and using a fake LAPD encapsulation
wireshark should be able to recognize some bits if dump.
Append a dummy LAPD header. It is not clear to me if the Control field
of the LAPD frame is part of the msg or if we need to add it as well.
TODO:
- Do the same for the B Channel
- Write out time
- Check if more of the LAPD frame needs to be prepended. The
information from the mISDNhead comes into mind. Maybe it makes
sense to start a custom wireshark mISDN dissector.
gsm_subscriber is now refcounted, the db backend is leaking
a lot less, db_get_subscriber will allocate the subscr record
now, subscr_* will look up a subscriber in the list of currently
active subscribers and add an ref to this one.
The db test cases pass, more testing will be when next to the bts
Call use_lchan early in allocate_loc_updating_req, do not directly call
rsl_chan_release but go through channel alloc to take the use_count into
account.
As reported by the operator the rejecting didn't work after the
first fix (wrong logic/missing negation). The hypothesis is that
that the lchan was released before the reject timeout was fired.
Fix it by getting a reference on the lchan when allocating a
logical operation and release the reference when the operation
is finished or timed out.
We are going to have logical operations like Phone Call, SMS,
Paging, Updating Request on a logical channel and for each of
these operations we might need to store state. For now pointers
in gsm_lchan look like the best way of doing this and we start
by introducing an operation for the location updating request.
The new flow of things are:
- We get the location updating request and update/create
the subscriber and maybe send the identity requests to
the mobile station
- We start the updating timer, if it times out we will
reject the mobile station.
- Once we get the Identity Responses we have asked for
and the reject timer did not fire yet we might accept
the user.
When a channel is allocated, start a timeout, when a lchan_use
is used the timer will be restarted, when the timeout fires
we will try to recycle or restart the timer.
I removed gsm48_sendmsg(msg) when removing the send_sms from the
_acc method. This is obviously wrong. Fix the regression, spotted
while testing with LaF0rge. This regression was introduced in r120.
gsm_data.h add new callbacks, add some parameters, update bsc_hack and
other call sites.
Remember that we need to ACCEPT/REJECT the LOCATION UPDATE REQUEST and
then send the ACCEPT or schedule the sending of the reject. Currently
it is possible that for a new subscriber that we do not have a !subscbr
yet, we will trigger an IDENTITY REQUEST and schedule the reject timer.
This may lead to rejecting AND accepting (a new subscriber). This issue
is triggered when allowing everyone to connect to the network.
On channel allocation the bsc_hack added a cookie to the lchan on
ack and nack we will take a look and then assume it is the channel
we have allocated. This can be easily exploited by a MS sending fake
responses to paging commands. After the channel has been acked we would
have to ask for the tmsi or find the information on the channel
allocation. For now we will guess.
Currently it is not possible to know for which tmsi the channel
is going to be allocated. The bsc_hack will guess.. in the future
it might be forced to ask for the tmsi after the channel has been
opened...
Add a callback to the gsm_network. When updating the location and
assigning a new tmsi callback into the bsc_hack.c and have a queue
of mobile stations to page, allocate a channel for and ultimately
dial.
Holger Freyther
Harald Welte