A rule carrying sender, destination, or eavesdrop was refused whole,
and a peer whose AddMatch fails gets no signals at all. That is a
poor trade for keys clients attach as a matter of course: better a
filter wider than asked for than a subscription that never happened.
They are accepted and ignored rather than honoured. Widening costs
nothing here since Finit is the only sender on this bus, and what it
emits through the match table is state any peer that got this far may
already read.
argN and argNpath still take the whole rule down. Honouring them
means parsing message bodies, and nothing asks for them yet.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Finit had no way to answer the question every service manager gets
asked: what is running, and change it. D-Bus is how the rest of
userspace asks, but linking libdbus, sd-bus or GIO into PID 1 buys a
dependency, an allocator and a main loop we do not control.
So libink: the wire format, an object tree, and a bus of Finit's own
at /run/finit/bus, gated like INIT_SOCKET. It speaks the standard
org.freedesktop.DBus, .Peer, .Introspectable interfaces, and Finit's
own Manager1, Service1 and Cond1 on top. Methods that change
something are marked privileged and answered only for a caller the
kernel vouched for, via SO_PEERCRED.
Server and client both, since initctl is the first thing that needs
to talk to it, and its Start/Stop/Restart/Reload now go over the bus
rather than the legacy socket.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Joachim Wiberg