Right now, we never install destination matches on kdbus as the kernel did
not support MATCH rules on those. With the introduction of
KDBUS_ITEM_DST_ID we can now match on destination IDs, so add explicit
support for those.
This requires a recent kdbus module to work. However, there seems to be no
user-space that uses "Destination=''" matches, yet, so old kdbus modules
still work fine (we couldn't find any real user).
This is needed to match on unicast signals in bus-proxy. A followup will
add support for this.
After some reconsideration, we decided to move the binary protocol
back to 64-bit wide UIDs and GIDs. After all, it should be possible
to redefine [gu]id_t to uint64_t and things should continue to
work. As we want to avoid such data types in kdbus.h, let's move
back to 64-bit values and be safe.
In sd-bus, we have to do a translation between uint64_t and gid_t
now for supplementary gids.
Some inline comments have also been updated in kdbus upstream.
Follow two small changes in the kdbus API:
* Flags are now returned in cmd->return_flags by KDBUS_CMD_NAME_ACQUIRE
* struct kdbus_item_list has been dropped. The information stored in
this struct was redundant since awhile already, as all commands
report their returned slice size anyway.
Catch up with latest changes in kdbus.ko:
* Signals can be sent as unicast now, hence they need to be marked as
such with the KDBUS_MSG_SIGNAL in the message flags.
* Follow ioctl number change for KDBUS_CMD_FREE
Sync kdbus.h with upstream changes:
* Two optional cancellation points where added for synchronously
blocking KDBUS_CMD_SEND commands: A sigmask to change the mask
of accepted signals before the task is put to sleep, and a
generic file descriptor that can be written to, in order to cancel
the command. Both methods are currently unused.
* The KDBUS_CMD_CANCEL ioctl was removed. sd-bus was never using
that command, so there's no change needed.
* Some kerneldoc fixes
Sync up with recent kdbus changed:
* several ioctls gained .size and .items members (but still unused)
* CMD_SEND gained its own ioctl structure
* several members of kdbus_msg were dropped as they were only used during
SEND, not during RECV etc.
* CMD_RECV and CMD_SEND now share a kdbus_reply member which contains the
offset and size of the returned message.
kdbus-git gained two new features:
* memfd offsets: This allows to specify a 'start' offset in kdbus_memfd
so you can send partial memfd hunks instead of always
the full memfd
* KDBUS_HELLO_UNPRIVILEGED: If passed during HELLO, the client will be
treated as unprivileged.
Also:
- adds support for euid, suid, fsuid, egid, sgid, fsgid fields.
- makes augmentation of creds with data from /proc explicitly
controllable to give apps better control over this, given that this is
racy.
- enables augmentation for kdbus connections (previously we only did it
for dbus1). This is useful since with recent kdbus versions it is
possible for clients to control the metadata they want to send.
- changes sd_bus_query_sender_privilege() to take the euid of the client
into consideration, if known
- when we don't have permissions to read augmentation data from /proc,
don't fail, just don't add the data in
kdbus has seen a larger update than expected lately, most notably with
kdbusfs, a file system to expose the kdbus control files:
* Each time a file system of this type is mounted, a new kdbus
domain is created.
* The layout inside each mount point is the same as before, except
that domains are not hierarchically nested anymore.
* Domains are therefore also unnamed now.
* Unmounting a kdbusfs will automatically also detroy the
associated domain.
* Hence, the action of creating a kdbus domain is now as
privileged as mounting a filesystem.
* This way, we can get around creating dev nodes for everything,
which is last but not least something that is not limited by
20-bit minor numbers.
The kdbus specific bits in nspawn have all been dropped now, as nspawn
can rely on the container OS to set up its own kdbus domain, simply by
mounting a new instance.
A new set of mounts has been added to mount things *after* the kernel
modules have been loaded. For now, only kdbus is in this set, which is
invoked with mount_setup_late().
The metadata logic in kdbus has seen a rework, and the only mandatory
change we have to follow for now is that attach_flags in kdbus_cmd_hello
is now split into two parts, attach_flags_send and attach_flags_recv.
Catch up with some changes in kdbus.h:
* KDBUS_{ITEM,ATTACH}_CONN_NAME were renamed to
KDBUS_{ITEM,ATTACH}_CONN_DESCRIPTION, so the term 'name' is not
overloaded as much.
* The item types were re-ordered a little so they are lined up to the
order of the corresponding KDBUS_ATTACH flags
* A new item type KDBUS_ITEM_OWNED_NAME was introduced, designated to
store a struct kdbus_name in item->name. KDBUS_ITEM_NAME soley
stores data in item->str now
* Some kerneldoc fixes
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.
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.
Sync kdbus.h once again. Two thing have changed:
a) KDBUS_CMD_EP_* was renamed to KDBUS_CMD_ENDPOINT_*
b) struct kdbus_cmd_hello and struct kdbus_cmd_make gained a
'features' bitfield (which is currently unused)
The KDBUS_CMD_FREE ioctl now uses a struct rather than a direct pointer
to the offset to free.
The KDBUS_CMD_MSG_CANCEL ioctl has also changes, but there's no user of
it yet in systemd.
The kdbus logic name registry logic was changed to transport the actual
name to acquire, release or report in a kdbus item.
This brings the name API a little more in line with other calls, and allows
for later augmentation.
Follow that change on the systemd side.
Bring kdbus.h in sync with recent policy related changes. Most notably,
KDBUS_MAKE_POLICY_OPEN is now gone. The rest doesn't matter for systemd
at this point, as the policy functionality was not yet used.
David Herrmann