First we have the Complete Layer3 Information, then we have
the IE for the Layer3 information, then the GSM48 hdr, then
the actual content with data. Right now we are parsing the
LU but we are not filtering anything yet.
The MSC does not respond to a SCCP CR with Paging Response as GSM
payload, when the response comes in 'too late'. Prevent the MUX having
stale connections and start removing old connections every 20 minutes.
The adding of the innocent looking code was actually overwrote
the fd and then stupid things happened. Rename variables to avoid
that. rc,ret should be scratch variables...
We do want to send PING/PONG in both ways to have a heartbeat
on the TCP connection. When switching over to SCTP we can rely
on the builtin heartbeat functionality.
We will send a ping every 20 seconds and if we have no pong
within 5 seconds we will close down the BSC connection and
wait for a reconnect. We will start this after having
authenticated the BSC and we stop the timer when destructing
the BSC connection.
The code needs to be refactored but this is fixing the leak for
now. We used to forward everything to the BSC but now we handle
the DLCX locally and this means we need to clear the patched
message. We should refactor it to not generate the patched msg
until a lot later.
In case we can not find the SCCP connection we still want to
free any pending transaction ids and reset the BSC inside the
endpoint. In most cases this should be already done when the
SCCP connection or the whole BSC is gone.
Remember that we have seen a CC and have a valid destination
local reference now and only send a fake RLC to the MSC when
we had connections in this state.
For now close the connection when having a short read. This might
be due a network issue (loss of segment) or similiar. As we are not
handling these issues well, let us close the connection.
When setting a new MSC timeslot to a SCCP connection check if
any of the existing connections have this timeslot, if so we will
send a DLCX down the stream to make sure it is closed there, when
we will CRCX this new timeslot we will happily reallocate it.
When the SCCP connection goes away, or we get a DLCX from the
network, or the BSC is gone we will send a DLCX message down the
stream as well.
When we receive a CRCX from the network we will forward the CRCX
as usual and send a dummy MDCX after it.
For the DLCX and the dummy MDCX we send a custom MGCP message
that will not provoke an answer. Even if the downstream MGCP GW
will answer we will ignore it due the dummy transaction id that
is not used anywhere else.
This change should make sure that we close the dowstream endpoint
all the time, even when the DLCX arrives after the SCCP connection
is torndown.
When sending a MSG to the MSC try to find the to be used "src" reference
by comparing the reference on the BSC and the BSC connection. Only this
tuple needs to be unique.
Actually only when looking at the SRC REF we need to compare the BSC as the
dest reference should be unique but we are just making the check a bit stronger
to make it look symmetric.
If we find the connection of a different BSC at least log the
BSCs that had duplicated references. We should also dump the
src ref and such but i am not doing this right now.
Holger Hans Peter Freyther