To be able to use `systemd-run` or `machinectl login` on a container
that is in a private user namespace, the sub-process must have entered
the user namespace before connecting to the container's D-Bus, otherwise
the UID and GID in the peer credentials are garbage.
So we extend namespace_open and namespace_enter to support UID namespaces,
and we enter the UID namespace in bus_container_connect_{socket,kernel}.
namespace_open will degrade to a no-op if user namespaces are not enabled
in the kernel.
Special handling is required for the setns call in namespace_enter with
a user namespace, since transitioning to your own namespace is forbidden,
as it would result in re-entering your user namespace as root.
Arguably it may be valid to check this at the call site, rather than
inside namespace_enter, but it is less code to do it inside, and if the
intention of calling namespace_enter is to *be* in the target namespace,
rather than to transition to the target namespace, it is a reasonable
approach.
The check for whether the user namespace is the same must happen before
entering namespaces, as we may not be able to access /proc during the
intermediate transition stage.
We can't instead attempt to enter the user namespace and then ignore
the failure from it being the same namespace, since the error code is
not distinct, and we can't compare namespaces while mid-transition.
The following functions return immediately if a null pointer was passed.
* calendar_spec_free
* link_address_free
* manager_free
* sd_bus_unref
* sd_journal_close
* udev_monitor_unref
* udev_unref
It is therefore not needed that a function caller repeats a corresponding check.
This issue was fixed by using the software Coccinelle 1.0.1.
Whenever one of our calls is invoked with a non-NULL, writable
sd_bus_error parameter, let's fill in some valid error on failure. We
previously only filled in remote errors, but never local errors, which is
hard to handle by users. Hence, let's clean this up to always fill in
the error.
This introduces a new bus_assert_return() macro that works like
assert_return() but optionally also initializes a bus_error struct.
Fixes#224.
Based on a patch by Umut Tezduyar.
We should not fall back to dbus-1 and connect to the proxy when kdbus
returns an error that indicates that kdbus is running but just does not
accept new connections because of quota limits or something similar.
Using is_kdbus_available() in libsystemd/ requires it to move from
shared/ to libsystemd/.
Based on a patch from David Herrmann:
https://github.com/systemd/systemd/pull/886
Previously, if the event loop never ran before sd_event_now() would
fail. With this change it will instead fall back to invoking now(). This
way, the function cannot fail anymore, except for programming error when
invoking it with wrong parameters.
This takes into account the fact that many callers did not handle the
error condition correctly, and if the callers did, then they kept simply
invoking now() as fall back on their own. Hence let's shorten the code
using this call, and make things more robust, and let's just fall back
to now() internally.
Whether now() is used or the cache timestamp may still be detected via
the return value of sd_event_now(). If > 0 is returned, then the fall
back to now() was used, if == 0 is returned, then the cached value was
returned.
This patch also simplifies many of the invocations of sd_event_now():
the manual fall back to now() can be removed. Also, in cases where the
call is invoked withing void functions we can now protect the invocation
via assert_se(), acknowledging the fact that the call cannot fail
anymore except for programming errors with the parameters.
This change is inspired by #841.
Using --size option triggers an assert failure below because
parse_size() requires the second argument, base, being either 1000 or
1024. As it's for a packet size, it'd be better using IEC binary
suffix (base 1024) IMHO.
$ busctl --size 2048
Assertion 'base == 1000 || base == 1024' failed at src/basic/util.c:2222,
function parse_size(). Aborting.
Aborted (core dumped)
In member_compare_func(), it compares interface, type and name of
members. But as it can contain NULL pointer, it needs to check them
before calling strcmp(). So make it as a separate strcmp_ptr
function (named after streq_ptr) so that it can be used by others.
Also let streq_ptr() to use it in order to make the code simpler.
We *must not* assume that an entry returned by KDBUS_CMD_LIST only
carries a single KDBUS_ITEM_OWNED_NAME. Similarly, we already parse
multiple such items for message-metadata, so make sure we support the
same on KDBUS_CMD_LIST.
By relying on the kernel to return all names separately, we limit the
kernel API significantly. Stop this and let the kernel decide how to
return its data.
Some places invoked fflush() directly with their own manual error
checking, let's unify all that by using fflush_and_check().
This also unifies the general error paths of fflush()+rename() file
writers.
The gvariant root container contains a 'variant' at the end, which embeds
the whole message body. This variant *must* contain a structure so we are
compatible to dbus1. Otherwise, it could encode at most 1 type, instead
of a full signature.
Our gvariant message parser already parses the variant-content as a
structure, so we're mostly good. However, it does *not* include the
opening and closing parantheses, nor does it parse them.
This patch fixes the decoder to verify a message contains the
parantheses, and also make the encoder add those parantheses into the
marshaled message.
If c->item_size is 0, the next item to parse in a structure is empty.
However, this also implies that the signature must be empty. The latter
case is already handled just fine by enter_struct_or_dict_entry() so
there is no reason to handle the same case in the caller.
Right now sd_bus_message_skip() will abort execution if passed a
signature of the unary type "()". Regardless whether this should be
supported or not, we really must not abort. Drop the incorrect assertion
and add a test-case for this.
Each signal of the ObjectManager interface carries the path of the object
in question as an argument. Therefore, a caller will deduce the object
this signal is generated for, by parsing the _argument_. A caller will
*not* use the object-path of the message itself (i.e., message->path).
This is done on purpose, so the caller can rely on message->path to be
the path of the actual object-manager that generated this signal, instead
of the path of the object that triggered this signal.
This commit fixes all InterfacesAdded/Removed signals to use the path of
the closest object-manager as message->path. 'closest' in this case means
closest parent with at least one object-manager registered.
This fix raises the question what happens if we stack object-managers in
a hierarchy. Two implementations are possible: First, we report each
object only on the nearest object-manager. Second, we report it on each
parent object-manager. This patch chooses the former. This is compatible
with other existing ObjectManager implementations, which are required to
call GetManagedObjects() recursively on each object they find, which
implements the ObjectManager interface.
In bus_kernel_translate_message(), we print a DEBUG message on unknown
items. But right now, we also print this message for KDBUS_ITEM_TIMESTAMP
despite parsing it properly. Fix this!
Lennart Poettering