create ASP+AS only once per cs7 instance
Refactor osmo_bsc_sigtran_init(): invoke osmo_sccp_simple_client_on_ss7_id()
exactly once per cs7 instance.
When introducing MSC pooling to the ttcn3-bsc-tests, it became apparent that
osmo-bsc rapidly huts down and re-creates the SCTP link for each configured
MSC. This manifested in an osmo-stp crash (fixed in libosmo-sccp
I9b3ae6dfcf6efeabb7fb6c33503d1d7924fec2fa). I first tried to fix it by only
restarting an ASP when it wasn't found in the AS yet, but that created obscure
problems described in OS#4635 which in turn completely broke ttcn3-msc-tests.
This solution keeps osmo_sccp_simple_client_on_ss7_id() unchanged and instead
invokes it exactly once per cs7 instance.
Keep the same auto-config logic, but change and improve the mechanisms to
achieve it:
Replace the fail_on_next_invalid_cfg flag with a more accurate check against
remote PC collisions between configured MSCs. Before this patch, the code made
sure that at most one MSC lacks an explicit remote address (and cs7 instance),
so that no two MSCs get the same default remote PC. This patch more accurately
checks that no two MSCs use the same remote PC on the same cs7 instance,
period, whether implicitly or explicitly configured.
Before this patch, the logic amounted to creating cs7 instance 0 implicitly,
but it was not very obvious: If an 'msc' has an msc-addr configured, it is
associated with the cs7 instance that has this addr in its address book. If it
has no msc-addr configured, then msc->a.cs7_instance_valid == false. In that
case, msc->a.cs7_instance is still 0 (from talloc_zero) and hence
osmo_sccp_simple_client_on_ss7_id(ss7_id = 0) created cs7 instance 0. In this
patch, that logic remains unchanged, but is written out more explicitly: if any
msc has no cs7 instance associated, make sure to create cs7 instance 0
beforehand.
Then iterate all osmo_ss7_instances. If at least one MSC uses it, set up the
SCCP client on it and connect all MSCs as appropriate.
Related: OS#4625 OS#4635
Change-Id: I16f4f7f447f69525a2f57c4649ab295112904d6a
1 file changed