Introduce OSMO_SS7_PC_INVALID to mark an unset point code.
Add static osmo_ss7_pc_is_valid() (name matches schema of
osmo_ss7_pc_is_local()).
In osmo_ss7_pointcode_print(), return "(no PC)" if !osmo_ss7_pc_is_valid(), for
convenient printing of any PC state.
Subsequent patches will use this for
osmo_ss7_instance (I7f0f0c89b7335d9da24161bfac8234be214ca00c)
as well as osmo_sccp_user (I8684c9b559712072c772012890bbf7efa7c8eb35).
Rationale:
Currently, in osmo_ss7_vty.c we had "if (inst->cfg.primary_pc)" suggesting 0 is
invalid, but in struct osmo_sccp_user we have flag pc_valid suggesting 0 is
indeed valid. All known point code formats are <= 24bit, so we can easily use
0xffffffff as indicator for an unset PC, which removes the need to remember to
set a second field for validity and keeps the structs nice and lean.
Change-Id: Ib5715bf03a4de7713a7a809dfd821c700255ba8c
Neels Hofmeyr
b711e14504