kdbus learned a new ioctl to tell userspace about a bus creator's
credentials, which is what we need to implement sd_bus_get_owner_creds() for
kdbus.
Move the function from sd-bus.c to bus-control.c to be able to reuse
the bus_populate_creds_from_items() helper.
Clean up the function namespace by renaming the following:
sd_bus_get_owner_uid() → sd_bus_get_name_creds_uid()
sd_bus_get_owner_machine_id() → sd_bus_get_name_machine_id()
sd_bus_get_peer_creds() → sd_bus_get_owner_creds()
kdbus learned a new command to query a bus creator's credentials. Sync
kdbus.h first, which also renames some struct to more generic terms.
That is, however, not an ABI break this time.
We can simplify our code quite a bit if we explicitly check for the
ifindex being 1 on Linux as a loopback check. Apparently, this is
hardcoded on Linux on the kernel, and effectively exported to userspace
via rtnl and such, hence we should be able to rely on it.
kdbus_msg.timeout_ns now takes an absolute value, based on CLOCK_MONOTONIC,
in order to eventually support automatically restarted syscalls.
Signed-off-by: Daniel Mack <daniel@zonque.org>
In kdbus.h, the following details changed:
* All commands gained a 'kernel_flags' field to report the flags supported
by the driver. Before, this was done in the 'flags' field in a
bidirectional way, which turned out to be a problem for the code in
sd-bus, as many parts of it reuse the same ioctl struct more than once
and consider them to be owned by userspace.
* Name listings are now returned by a new struct instead of reusing struct
kdbus_cmd_name for that matter. This way, we don't add more unneeded
fields to it and make the API cleaner.
* 'conn_flags' was renamed to 'flags' in struct kdbus_cmd_hello to make
the API a bit more unified.
kdbus.h now has KDBUS_ATTACH_COMM split into KDBUS_ATTACH_TID_COMM and
KDBUS_ATTACH_PID_COMM. The items were split already, so the change in
systemd is easy.
In kdbus.h, the 'features' field has been dropped again. Instead of
negotiating features that way, we decided to make the kernel return the
set of supported flags in each ioctl struct's .flags field, in both the
success and error cases.
Without the socket open we are going to crash and burn. If for
whatever reason we fail during deserialization we will fail when
trying to open the socket. In this case it is better to unlink the old
socket and maybe lose some messages, than to continue without the
notification socket.
Of course this situation should not happen, but we should handle
it as gracefully as possible anyway.
https://bugzilla.redhat.com/show_bug.cgi?id=1099299
Commit 864e17068 ("nspawn: actually allow access to /dev/net/tun in the
container") added "/dev/net/tun" to the list of allowed devices but forgot
to tweak the array length, which caused "/dev/kdbus/*" to be missed.
If we don't have privileges to setup the namespaces then we are most likely
running inside some sort of unprivileged container, hence not being able to
create namespace is not a problem because spawned service can't access host
system anyway.
Before returning from function we should reset ret to NULL, thus cleanup
function is nop.
Also context_str() returns pointer to a string containing context but not a
copy, hence we must make copy it explicitly.
'GetConnectionUnixProcessID', 'GetConnectionUnixUser' and
'GetConnectionSELinuxSecurityContext' methods should return
'NameHasNoOwner' error (if chosen name is not available on bus)
with more detailed description - like dbus-1:
Could not get PID of name 'org.freedesktop.test': no such name.
Could not get UID of name 'org.freedesktop.test': no such name.
Could not get security context of name 'org.freedesktop.test': no such name.
Otherwise we have only laconic message without proper dbus error:
Error System.Error.ENXIO: No such device or address
Under an SELinux system, we want the file that is created to
have a proper context, different from the default for files in /run.
This is so that the policy can give access to almost everyone to
this file.
After all, we set AllowIsolate exclusively for target units so far, and
this is more or less the only thing tht makes sense, hence also use
".target" as completion suffix by default.
