The park machinery was welded to broker uid resolution; a handler
that cannot answer yet, like a device-settle call waiting for the
event queue to drain, had no way to defer. link_call_park() holds
the request, link_call_resume() re-runs the handler with
link_call_resumed() reading true, and the expire sweep remains the
backstop for a resume that never comes.
Resume also no longer drops a local caller's kernel group set in the
privileged re-check: group source now keys on broker-ness.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Device seqnums are 64-bit; the writer and reader stopped at u32.
Adds t/x/d to the skip path so a{sv} consumers tolerate them.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
On the local bus SO_PEERCRED says who is calling and the kernel is the
one saying it. Behind a broker one connection carries every caller,
so that credential describes dbus-daemon and nothing else, and every
privileged method was refused there, root included.
Ask the bus driver instead. libink parks the call and hands us the
sender; we ask GetConnectionUnixUser and answer when the reply lands,
through the same event loop as everything else. Nothing blocks:
blocking in PID 1 is why libuEv exists. That needs calls libink can
make on a connection it already has, so it gained those too.
Answers are cached, since a bus never reuses a unique name while it
runs. Not across a restart though: a new dbus-daemon numbers from
scratch and :1.7 becomes somebody else, so the cache goes when the
broker does. A sender name too long to key on is refused rather than
truncated, two callers sharing a truncated key would share an
identity.
Privilege is no longer uid 0 alone. The socket is already owned by
the --with-group group, so refusing its members every method that
changes anything left a wheel user able to open the bus and unable to
reboot. Both gates now say the same thing.
Group membership needs NSS, which the C library loads with dlopen(),
so the lookup is compiled out where Finit is built to link statically.
That leaves such a build root-only, which is worth saying out loud
rather than leaving to be discovered.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The summary table, the per-service detail, JSON and the quiet and
ident forms all read state Finit already publishes, so they read it
from the bus like everything else rather than through a second path
that has to be kept in step.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Runlevel and version are state, not actions, so they belong behind
org.freedesktop.DBus.Properties rather than another method each.
Finit also claims org.finit on the system bus when it finds one, so
ordinary D-Bus clients can reach it without knowing about
/run/finit/bus. Opportunistic on purpose: no dbus-daemon is a normal
state for the systems Finit runs on, not an error to report.
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