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!
This adds test-bus-proxy which should be used to test correct behavior of
systemd-bus-proxyd. The first test that was added is to verify we actually
receive NameAcquired signals for ourselves on bus-connect.
If the caller does not specify arg1 for NameOwnerChanged matches, we
really must take the ID from arg2 or arg3, if provided. They are
guaranteed to be identical to arg1 if either is supplied, but there is no
strict requiredment that arg1 is supplied. Hence, make sure to always
take the more restrictive match. Otherwise, we install rather wide
matches without anyone requiring them.
Make sure we don't install NameOwnerChanged matches if the caller passed
a destination='' match (except if it is the broadcast address). Per spec,
all NameOwnerChanged signals are broadcasts.
Only the NameLost/NameAcquired signals are unicasts, but those are never
received through sd-bus. Instead, the bus-proxy synthesizes them and it
already installs proper matches for them.
In gvariant, all fixed-size objects need to be sized a multiple of their
alignment. If a structure has only fixed-size members, it is required to
be fixed size itself. If you imagine a structure like (ty), you have an
8-byte member followed by an 1-byte member. Hence, the overall inner-size
is 9. The alignment of the object is 8, though. Therefore, the specs
mandates final padding after fixed-size structures, to make sure it's
sized a multiple of its alignment (=> 16).
On the gvariant decoder side, we already account for this in
bus_gvariant_get_size(), as we apply overall padding to the size of the
structure. Therefore, our decoder correctly skips such final padding when
parsing fixed-size structure.
On the gvariant encoder side, however, we don't account for this final
padding. This patch fixes the structure and dict-entry encoders to
properly place such padding at the end of non-uniform fixed-size
structures.
The problem can be easily seen by running:
$ busctl --user monitor
and
$ busctl call --user org.freedesktop.systemd1 / org.foobar foobar "(ty)" 777 8
The monitor will fail to parse the message and print an error. With this
patch applied, everything works fine again.
This patch also adds a bunch of test-cases to force non-uniform
structures with non-pre-aligned positions.
Thanks to Jan Alexander Steffens <jan.steffens@gmail.com> for spotting
this and narrowing it down to non-uniform gvariant structures. Fixes#597.
So right now our object-tree is limited to 2 levels at most
('/' and '/foo/...../bar'). We never link any intermediate levels, even
though that was clearly the plan. Fix the bus_node_allocate() helper to
actually link all intermediate nodes, too, not just the root node.
This fixes a simple inverse ptr-diff bug.
The downside of this fix is that we clearly never tested (nor used) the
object tree in any way. The only reason that the introspection works is
that our enumerators shortcut the object tree.
Lets see whether that code actually works..
Thanks to: Nathaniel McCallum <nathaniel@themccallums.org>
..for reporting this. See #524 for an actual example code.
It is highly confusing if a getter function returns 0, but the value is
set to NULL. This, right now, triggers assertions as code relies on the
returned values to be non-NULL.
Like with sd-bus-creds and friends, return 0 only if a value is actually
available.
Discussed with Tom, and actually fixes real bugs as in #512.
We were ignoring failures from unhexchar, which meant that invalid
hex characters were being turned into garbage rather than the string
rejected.
Fix this by making unhexmem return an error code, also change the API
slightly, to return the size of the returned memory, reflecting the
fact that the memory is a binary blob,and not a string.
For convenience, still append a trailing NULL byte to the returned
memory (not included in the returned size), allowing callers to
treat it as a string without doing a second copy.
Given a container "foo", that maps user id $UID to container user, using
user namespaces, this NSS module extenstion will now map the $UID to a
name "vu-foo-$TUID" for the translated UID $UID.
Similar, userns groups are mapped to "vg-foo-$TGID" for translated GIDs
of $GID.
This simple change should make userns users more discoverable. Also,
given that many tools like "adduser" check NSS before allocating a UID,
should lower the chance of UID range conflicts between tools.
If GetManagedObjects is called on /foo/bar, then it should also include
the object /foo/bar, if it exists. Right now, we only include objects
underneath /foo/bar/.
This follows the behavior of existing dbus implementations.
Obsoletes #527 and fixes#525. Reported by: Nathaniel McCallum
All other *_get_description() functions use 'const char**', so make sure
sd_bus_slot_get_description() does the same.
This changes API, but ABI stays stable. I think this is fine, but I
wouldn't mind bumping SONAME.
Reported in #528.
Right now, if you're already in a session and call CreateSession, we
return information about the current session of yours. This is highy
confusing and a nasty hack. Avoid that, and instead return a commonly
known error, so the caller can detect that.
This has the side-effect, that we no longer override XDG_VTNR and XDG_SEAT
in pam_systemd, if you're already in a session. But this sounds like the
right thing to do, anyway.
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.
Running `busctl monitor` currently buffers data for several seconds /
kilobytes before writing stdout. This is highly confusing if you dump in a
file, ^C busctl and then end up with a file with data of the last few
_seconds_ missing.
Fix this by explicitly flushing after each signal.
sd_bus_flush_close_unref() is a call that simply combines sd_bus_flush()
(which writes all unwritten messages out) + sd_bus_close() (which
terminates the connection, releasing all unread messages) +
sd_bus_unref() (which frees the connection).
The combination of this call is used pretty frequently in systemd tools
right before exiting, and should also be relevant for most external
clients, and is hence useful to cover in a call of its own.
Previously the combination of the three calls was already done in the
_cleanup_bus_close_unref_ macro, but this was only available internally.
Also see #327
When we get notifications from the kernel, we always turn them into
synthetic dbus1 messages. This means, we do *not* consume the kdbus
message, and as such have to free the offset.
Right now, the translation-helpers told the caller that they consumed the
message, which is wrong. Fix this by explicitly releasing all kernel
messages that are translated.
Though currently unused by us, netlink attribute types support embedding flags to indicate
if the type is encoded in network byte-order and if it is a nested attribute. Read out
these flags when parsing the message.
We will now swap the byteorder in case it is non-native when reading out integers (though
this is not needed by any of the types we currently support). We do not enforce the NESTED
flag, as the kernel gets this wrong in many cases.
Instead of representing containers as several arrays, make a new
netlink_container struct and keep one array of these structs. We
also introduce netlink_attribute structs that in the future will
hold meta-information about each atribute.
The kernel bonding layer allows passing an array of ARP IP targets as
bond-configuration. Due to the weird implementation of arrays in netlink
(which we haven't figure out a generic way to support, yet), we usually
hard-code the supported array-sizes. However, this should not be exported
from sd-netlink.
Instead, make sure the caller just uses it's current hack of enumerating
the types, and the sd-netlink core will have it's own list of supported
array-sizes (to be removed in future extensions, btw!). If either does not
match, we will just return a normal error.
Note that we provide 2 constants for ARP_IP_TARGETS_MAX now. However, both
have very different reasons:
- the constant in netdev-bond.c is used to warn the user that the given
number of targets might not be supported by the kernel (even though the
kernel might increase that number at _any_ time)
- the constant in sd-netlink is solely used due to us missing a proper
array implementation. Once that's supported in the type-system, it can
be removed without notice
Last but not least, this patch turns the log_error() into a log_warning().
Given that the previous condition was off-by-one, anyway, it never hit at
the right time. Thus, it was probably of no real use.
Explicitly export the root type-system to the type-system callers. This
avoids treating NULL as root, which for one really looks backwards (NULL
is usually a leaf, not root), and secondly prevents us from properly
debugging calling into non-nested types.
Also rename the root to "type_system_root". Once we support more than
rtnl, well will have to revisit that, anyway.
Empty type-systems are just fine. Avoid the nasty hack in
union-type-systems that treat empty type-systems as invalid. Instead check
for the actual types-array and make sure it's non-NULL (which is even true
for empty type-systems, due to "empty_types" array).
In sd-netlink-message, we always guarantee that the currently selected
type-system is non-NULL. Otherwise, we would be unable to parse any types
in the current container level. Hence, this assertion must be true:
message->container_type_system[m->n_containers] != NULL
During message_new() we currently do not verify that this assertion is
true. Instead, we blindly access nl_type->type_system and use it (which
might be NULL for basic types and unions). Fix this, by explicitly
checking that the root-level type is nested.
Note that this is *not* a strict requirement of netlink, but it's a strict
requirement for all message types we currently support. Furthermore, all
the callers of message_new() already verify that only supported types are
passed, therefore, this is a pure cosmetic check. However, it might be
needed on the future, so make sure we don't trap into this once we change
the type-system.
The NETLINK_TYPE_META pseudo-type is actually equivalent to an empty
nested type. Drop it and define an empty type-system instead.
This also has the nice side-effect that m->container_type_system[0] is
never NULL (which has really nasty side-effects if you try to read
attributes).
Right now we store the maximum type-ID of a type-system. This prevents us
from creating empty type-systems. Store the "count" instead, which should
be treated as max+1.
Note that type_system_union_protocol_get_type_system() currently has a
nasty hack to treat empty type-systems as invalid. This might need some
modification later on as well.
size_t is usually 64bit and int 32bit on a 64bit machine. This probably
does not matter for netlink message sizes, but nevertheless, avoid
hard-coding it anywhere.
Same as NLType, move NLTypeSystem into netlink-types.c and hide it from
the outside. Provide an accessor function for the 'max' field that is used
to allocate suitable array sizes.
Note that this will probably be removed later on, anyway. Once we support
bigger type-systems, it just seems impractical to allocate such big arrays
for each container entry. An RBTree would probably do just fine.
If we extend NLType to support arrays and further extended types, we
really want to avoid hard-coding the type-layout outside of
netlink-types.c. We already avoid accessing nl_type->type_system outside
of netlink-types.c, extend this to also avoid accessing any other fields.
Provide accessor functions for nl_type->type and nl_type->size and then
move NLType away from the type-system header.
With this in place, follow-up patches can safely turn "type_system" and
"type_system_union" into a real "union { }", and then add another type for
arrays.
Make sure we never access type->type_system or type->type_system_union
directly. This is an implementation detail of the type-system and we
should always use the accessors. Right now, they only exist for 2-level
accesses (type-system to type-system). This patch introduces the 1-level
accessors (type to type-system) and makes use of it.
This patch makes sure the proper assertions are in place, so we never
accidentally access sub-type-systems for non-nested/union types.
Note that this places hard-asserts on the accessors. This should be fine,
as we expect callers to only access sub type-systems if they *know*
they're dealing with nested types.
The NLA_ names are used to name real datatypes we extract out of netlink
messages. The kernel has an internal enum with the same names
(NLA_foobar), which is *NOT* binary compatible to our types. Furthermore,
we support a different set of types than the kernel (as we try to treat
some kernel peculiarities as our own types to simplify the API).
Rename NLA_ to NETLINK_TYPE_ to make clear that this is our own set of
types.
In kdbus we still have to support org.freedesktop.DBus matches even though
there is no real bus driver. The reason is that bus-control.c turns
NameOwnerChanged matches into proper kdbus matches. If we drop DRIVER
matches early, we will never match on name-changes for kdbus.
Two ways to fix this:
1) Install DRIVER matches on kdbus (which is the simple way our and which
is what this patch does).
2) Properly fix the scope-detection to let NameOwnerChanged matches
through (or better: block anything with Member!=NameOwnerChanged).
./configure --enable/disable-kdbus can be used to set the default
behavior regarding kdbus.
If no kdbus kernel support is available, dbus-dameon will be used.
With --enable-kdbus, the kernel command line option "kdbus=0" can
be used to disable kdbus.
With --disable-kdbus, the kernel command line option "kdbus=1" is
required to enable kdbus support.
XDG refers to X Desktop Group, a former name for freedesktop.org.
This group is responsible for specifications like basedirs,
.desktop files and icon naming, but as far as I know, it has never
tried to redefine basename().
I think these references were meant to say XPG (X/Open Portability
Guide), a precursor of POSIX. POSIX is better-known and less easily
confused with XDG, and is how the basename(3) man page describes
the libgen.h version of basename().
The other version of basename() is glibc-specific and is described
in basename(3) as "the GNU version"; specifically mention that
version, to disambiguate.
Matches that can only match against messages from the
org.freedesktop.DBus.Local service (or the local interfaces or path)
should never be installed server side, suppress them hence.
Similar, on kdbus matches that can only match driver messages shouldn't
be passed to the kernel.
If we call EPOLL_CTL_DEL, we *REALLY* expect the file-descriptor to be
present in that given epoll-set. We actually track such state via our
s->io.registered flag, so it better be true.
Make sure if that's not true, we treat it similar to assert_return() (ie.,
print a loud warning).
This ports a lot of manual code over to sigprocmask_many() and friends.
Also, we now consistly check for sigprocmask() failures with
assert_se(), since the call cannot realistically fail unless there's a
programming error.
Also encloses a few sd_event_add_signal() calls with (void) when we
ignore the return values for it knowingly.
Currently, the HASHMAP iterators stop at the first NULL entry in a
hashmap. This is non-obvious and breaks users like sd-device, which
legitimately store NULL values in a hashmap.
Fix all the iterators by taking a pointer to the value storage, instead of
returning it. The iterators now return a boolean that tells whether the
end of the list was reached.
Current users of HASHMAP_FOREACH() are *NOT* changed to explicitly check
for NULL. If it turns out, there were users that inserted NULL into
hashmaps, but didn't properly check for it during iteration, then we
really want to find those and fix them.
DBus-spec defines two different pattern matchings:
1) Path and namespace prefix matching. In this case, A matches B either
if both are equal, or if B is fully included in the namespace of A.
In other words, A has to be a prefix of B, but end with a separator
character (or the following character in B must be one).
This is used for path_namespace= and arg0namespace=
2) The other pattern matching is used for arg0path= which does a two-way
matching. That is, A must be a prefix of B, or B a prefix of A.
Furthermore, the prefix must end with a separator.
Fix the sd-bus helpers to reflect that. The 'simple_' and 'complex_'
prefixes don't make any sense now, but.. eh..
Make sure we actually verify our match-rules are executed properly. Right
now all we test is the bloom-matches, which are non-reliable as they leave
through false-positives.
DBus spec clearly defines arg0path= to be a two-way matching. That is,
either the matcher or the matchee can be a prefix of the other to match.
This is not possible to implement with bloom-filters. Instead, we'd have
to add a separate filter for each prefix. This is non-trivial, though.
Hence, just skip the match for now and match locally.
Lets look at an example where we add arg0="/foo/bar/waldo" to a
bloom-filter. The following strings are added:
"arg0:/foo/bar/waldo"
"arg0-slash-prefix:/foo/bar"
"arg0-slash-prefix:/foo"
Two problems arise:
1) If we match on "arg0path=/foo/bar/waldo", the dbus-spec explicitly
states that equal strings are also considered prefixes. However, in the
bloom-match, we can only provide a single match-filter. Therefore, we have
to add "arg0-slash-prefix:/foo/bar/waldo" there, but this never occured in
the bloom-mask of the message.
Hence, this patch makes sure bloom_add_prefixes() adds the full path as
prefix, too.
2) If we match on "arg0path=/foo/", the dbus-spec states that arg0path
does prefix-matching with the trailing slash _included_, unlike
path_namespace= matches, which does *not* include them. This is
inconsistent, but we have to support the specs. Therefore, we must add
prefixes with _and_ without trailing separators.
Hence, this patch makes sure bloom_add_prefixes() adds all prefixes with
the trailing slash included.
The final set of strings added therefore is:
"arg0:/foo/bar/waldo"
"arg0-slash-prefix:/foo/bar/waldo"
"arg0-slash-prefix:/foo/bar/"
"arg0-slash-prefix:/foo/bar"
"arg0-slash-prefix:/foo/"
"arg0-slash-prefix:/foo"
"arg0-slash-prefix:/"
This appears to be the right time to do it for SOCK_STREAM
unix sockets.
Also: condition bus_get_owner_creds_dbus1 was reversed. Split
it out to a separate variable for clarity and fix.
https://bugzilla.redhat.com/show_bug.cgi?id=1224211
SELinux information cannot be retrieved this way, since we are
using stream unix sockets and SCM_SECURITY does not work for
them.
SCM_CREDENTIALS use dropped to be consistent. We also should
get this information at connection time.
https://bugzilla.redhat.com/show_bug.cgi?id=1224211
"SCM_SECURITY was only added for datagram sockets."
Also, when the child is potentially long-running make sure to set a
death signal.
Also, ignore the result of the reset operations explicitly by casting
them to (void).
Right now we always pass KDBUS_ITEM_ATTACH_FLAGS_RECV to
KDBUS_CMD_BUS_MAKE, effectively forcing every bus connection to do the
same during KDBUS_CMD_HELLO. This used to be a workaround to make sure all
metadata is always present. However, we refrained from that approach and
intend to make all metadata collection solely rely on /proc access
restrictions. Therefore, there is no need to force the send-flags mask on
newly created buses.
We protect most of the API from use accross forks, but we still allow both
sd_event and sd_event_source objects to be unref'ed. This would cause
problems as it would unregister sources from the underlying eventfd, hence
also affecting the original instance in the parent process.
This fixes the issue by not touching the fds on unref when done accross a fork,
but still free the memory.
This fixes a regression introduced by
"udevd: move main-loop to sd-event": 693d371d30
where the worker processes were disabling the inotify event source in the
main daemon.
In device_update_properties_bufs(), the strv is built from pointers into the
single nul-terminated buf_nulstr string, to avoid allocating the key=value
strings twice. However, we must not do that while building and
GREEDY_REALLOC0()'ing buf_nulstr, as each time when this actually reallocates
memory the pointers we wrote into buf_strv so far become invalid.
So change the logic to first completely build the new buf_nulstr, and then
iterate over it to pick out the pointers to the individual key=value strings
for properties_strv.
This fixes invalid environment for udev callouts.
A NULL pointer was inserted as the first element of the strv.
This had the effect of always passing the empty environment to processes
spawned by udev.
Reported by Michał Bartoszkiewicz.
With the v221 release these APIs should be public, stable APIs, hence
let's install their headers by default now, and add their symbols to the
.sym file.
Building with address sanitizer enabled on GCC 5.1.x a memory leak
is reported because we never close the bus, fix it by using
cleanup variable attribute.
Whenever systemd is re-executed, it tries to create a system bus via
kdbus. If the system did not have kdbus loaded during bootup, but the
module is loaded later on manually, this will cause two system buses
running (kdbus and dbus-daemon in parallel).
This patch makes sure we never try to create kdbus buses if it wasn't
explicitly requested on the command-line.
This patch add support to create vti6 tunnel
test:
vt6.network
[Match]
Name=wlan0
[Network]
Tunnel=ip6vti
vti6.netdev
[NetDev]
Name=ip6vti
Kind=vti6
[Tunnel]
Local=2a00:ffde:4567:edde::4987
Remote=2001:473:fece:cafe::5179
ip link
11: ip6_vti0@NONE: <NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT
group default
link/tunnel6 :: brd ::
12: ip6vti@wlan0: <POINTOPOINT,NOARP> mtu 1500 qdisc noop state DOWN
mode DEFAULT group default
link/tunnel6 2a00:ffde:4567:edde::4987 peer 2001:473:fece:cafe::5179
A number of fields do not apply to all processes, including: there a
processes without a controlling tty, without parent process, without
service, user services or session. To distuingish these cases from the
case where we simply don't have the data, always return ENXIO for them,
while returning ENODATA for the case where we really lack the
information.
Also update the credentials dumping code to show this properly. Fields
that are known but do not apply are now shown as "n/a".
Note that this also changes some of the calls in process-util.c and
cgroup-util.c to return ENXIO for these cases.
If NULL is specified for the bus it is now automatically derived from
the passed in message.
This commit also changes a number of invocations of sd_bus_send() to
make use of this.
This should simplify the prototype a bit. The bus parameter is redundant
in most cases, and in the few where it matters it can be derived from
the message via sd_bus_message_get_bus().
We introduce two news types of benchmarks in chart-mode:
- 'legacy' connects using the session bus
- 'direct' connects using a peer-to-peer socket
We should probably also introduce a mode for testing the dbus1-kdbus proxy.
Otherwise it might happen that by the time PID 1 adds our process to the
scope unit the process might already have died, if the process is
short-running (such as an invocation to /bin/true).
https://bugs.freedesktop.org/show_bug.cgi?id=86520
This reverts b67f944. Lazy loading of device properties does not work for devices
that are received over netlink, as these are sealed. Reinstate the unconditional
loading of the device db.
Reported by: Mantas Mikulėnas <grawity@gmail.com>.
So far we authenticate direct connections primarily at connection time,
but let's also do this for each method individually, by attaching the
creds we need for that right away.
Boolean arithmetic is great, use it!
if (a && !b)
return 1;
if (!a && b)
return -1,
is equivalent to
if (a != b)
return a - b;
Furthermore:
r = false;
if (condition)
r = true;
is equivalent to:
r = condition;
sd_device_new_from_* now returns -ENODEV when the device does not exist, and the enumerator
silently drops these errors as missing devices is exepected.
It is still possible to include uninitialized ones, but now that is opt-in. In most
cases people only want initialized devices. Exception is if you want to work without
udev running.
Suggested by David Herrmann.
We are talking about one member of a group of things (resource limits, signals,
timeouts), without specifying which one. An indenfinite article is in order.
When we are talking about the control process, it's a specific one, so the
definite article is used.
Whenever we provide a bus API that allows clients to create and manage
server-side objects, we need to provide a unique name for these objects.
There are two ways to provide them:
1) Let the server choose a name and return it as method reply.
2) Let the client pass its name of choice in the method arguments.
The first method is the easiest one to implement. However, it suffers from
a race condition: If a client creates an object asynchronously, it cannot
destroy that object until it received the method reply. It cannot know the
name of the new object, thus, it cannot destroy it. Furthermore, this
method enforces a round-trip. If the client _depends_ on the method call
to succeed (eg., it would close() the connection if it failed), the client
usually has no reason to wait for the method reply. Instead, the client
can immediately schedule further method calls on the newly created object
(in case the API guarantees in-order method-call handling).
The second method fixes both problems: The client passes an object name
with the method-call. The server uses it to create the object. Therefore,
the client can schedule object destruction even if the object-creation
hasn't finished, yet (again, requiring in-order method-call handling).
Furthermore, the client can schedule further method calls on the newly
created object, before the constructor returned.
There're two problems to solve, though:
1) Object names are usually defined via dbus object paths, which are
usually globally namespaced. Therefore, multiple clients must be able
to choose unique object names without interference.
2) If multiple libraries share the same bus connection, they must be
able to choose unique object names without interference.
The first problem is solved easily by prefixing a name with the
unique-bus-name of a connection. The server side must enforce this and
reject any other name.
The second problem is solved by providing unique suffixes from within
sd-bus. As long as sd-bus always returns a fresh new ID, if requested,
multiple libraries will never interfere. This implementation re-uses
bus->cookie as ID generator, which already provides unique IDs for each
bus connection.
This patch introduces two new helpers:
bus_path_encode_unique(sd_bus *bus,
const char *prefix,
const char *sender_id,
const char *external_id,
char **ret_path);
This creates a new object-path via the template
'/prefix/sender_id/external_id'. That is, it appends two new labels to
the given prefix. If 'sender_id' is NULL, it will use
bus->unique_name, if 'external_id' is NULL, it will allocate a fresh,
unique cookie from bus->cookie.
bus_path_decode_unique(const char *path,
const char *prefix,
char **ret_sender,
char **ret_external);
This reverses what bus_path_encode_unique() did. It parses 'path' from
the template '/prefix/sender/external' and returns both suffix-labels
in 'ret_sender' and 'ret_external'. In case the template does not
match, 0 is returned and both output arguments are set to NULL.
Otherwise, 1 is returned and the output arguments contain the decoded
labels.
Note: Client-side allocated IDs are inspired by the Wayland protocol
(which itself was inspired by X11). Wayland uses those IDs heavily
to avoid round-trips. Clients can create server-side objects and
send method calls without any round-trip and waiting for any object
IDs to be returned. But unlike Wayland, DBus uses gobally namespaced
object names. Therefore, we have to add the extra step by adding the
unique-name of the bus connection.
Users might have hard time figuring out why exactly their systemctl request
failed. If dbus job fails try to figure out more details about failure by
examining Result property of the service.
https://bugzilla.redhat.com/show_bug.cgi?id=1016680
Avoid unbound for(;;) loop and use the established coding-style:
while ((r = sd_bus_message_read*(...)) > 0) {
}
if (r < 0)
return r;
This is much easier to read and used all over the code base.
If necessary the passed string is enclosed in "", and all special
characters escapes.
This also ports over usage in bus-util.c and job.c to use this, instead
of a incorrect local implementation that forgets to properly escape.
Interactive authorization should only happen asynchronously, hence
disallow it in synchronous bus_verify_polkit(), and rename it to
bus_test_polkit(). This way even if the bus message header asks for
interactive authorization, we'll ask for non-interactive authorization
which is actually the desired behaviour if CanSuspend, CanHibernate and
friends, which call this function.
Change cunescape() to return a normal error code, so that we can
distuingish OOM errors from parse errors.
This also adds a flags parameter to control whether "relaxed" or normal
parsing shall be done. If set no parse failures are generated, and the
only reason why cunescape() can fail is OOM.
I shall not use alloca() within loops
I shall not use alloca() within loops
I shall not use alloca() within loops
I shall not use alloca() within loops
...
This provides equivalent functionality to libudev-device, but in the
systemd style. The public API only caters to creating sd_device objects
from for devices that already exist in /sys, there is no support for
listening for monitoring events or creating devices received over
the udev netlink protocol.
The private API contains the necessary functionality to make sd-device
a drop-in replacement for libudev-device, but which we would not
otherwise want to export.
like:
src/shared/install.c: In function ‘unit_file_lookup_state’:
src/shared/install.c:1861:16: warning: ‘r’ may be used uninitialized in
this function [-Wmaybe-uninitialized]
return r < 0 ? r : state;
^
src/shared/install.c:1796:13: note: ‘r’ was declared here
int r;
^
We strips out NLMSG_DONE piece from a multi-part message adding into the
receive queue only the messages containing actual data.
If we send a request to the kernel for getting the forwarding database table (just an example),
the response will be a multi-part message like below:
1. FDB entry 1;
2. FDB entry 2;
3. NLMSG_DONE;
We strip out "3. NLMSG_DONE;" part and places into the receive queue a pointer to
"1. FDB entry 1; 2. FDB entry 2".
But if the FDB table is empty, the respose from the kernel will look like below:
1. NLMSG_DONE;
We strip out "1. NLMSG_DONE;" part and since there is no actual data got, it continues
waiting until reaching timeout.
Therefore, a call to "sd_rtnl_call" to send and wait for a response from kernel will exit
with timeout which is interpreted as error in communication.
This patch puts the NLMSG_DONE message on the receive queue if it ends an empty multi-part
message. This situation is detected in sd_rtnl_call() and in the callback code and NULL is
returned to the caller instead.
[tomegun:
- added/reworded commit message
- extend the same support to sd_rtnl_call_async()
- drop debug logging from library, we only do this if something is really wrong, but an
empty multi-part message is perfectly normal
- modernize the code we touch whilst we are at it]
Coverity was complaining that CMSG_NXTHDR is used without
checking the return value. In this case it cannot fail, but
it is a good excuse to simplify the function a bit.
CID #1261726.
Do not rely on nl_pid == 0, but check the groups instead. We currently avoid using
nl_pid == 0 for unicast anyway, so this should be redundant, but let's try to be
correct.
The error code is called EDEADLK, stop using legacy names like EDEADLOCK.
Note that _some_ weird architectures define them differently (namely, mips
and sparc), but on all sane architectures they're exactly the same. So
stay with the widely used code, which is EDEADLK.
"Notifications are of informal nature and no reply is expected, therefore the
sequence number is typically set to 0."[1]
If networkd is started soon after recent netlink activity, then there
will be messages with sequence number 0 in the buffer.
The first thing networkd does is to request a dump of all the links. If
it uses sequence number 0 for this, then it may confuse the dump request's
response with that of a notification.
This will result in it failing to properly enumerate all the links,
but more importantly, when it comes to enumerate all the addresses, it
will still have the link dump in progress, so the address enumeration
will fail with -EBUSY.
[1]: http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_types
[tomegun: sequence -> serial]
If we receive an sd_bus_message from the kernel, m->kdbus will contain
additional items that cannot be used when sending a message. Therefore,
always remarshal the message if it is used again.
Usually when using loop_read(), we want to read the full buffer.
Add a helper that mirrors loop_write(), and returns 0 when full buffer
was read, and an error otherwise.
Use -ENODATA for the short read, to distinguish it from a read error.
Currently the code will silently blank out events if there are more
then 512 epoll events, causing them never to be handled at all. This
patch removes the cap on the number of events for epoll_wait, thereby
avoiding this issue.
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.
Introduce BindCarrier= to indicate the set of links that determine if
the current link should be brought UP or DOWN.
[tomegun: add a bit to commit message]
The kernel part of kdbus does not allow userspace to make any assumption on
which unique address the first user on the bus will get.
Instead, use sd_bus_get_unique_name() to get the server's address.
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.
This change exposed a bug in kernel headers:
/usr/include/linux/if_bridge.h:184:20: error: field 'ip6' has incomplete type
struct in6_addr ip6;
^
/usr/include/linux/if_tunnel.h:76:19: error: field 'prefix' has incomplete type
struct in6_addr prefix;
^
Include <sys/socket.h> from util.h and bus-message.h in order to
build errors like the ones below on kdbus enabled systems.
./src/shared/util.h:976:32: warning: its scope is only this definition or declaration, which is probably not what you want
In file included from src/libsystemd/sd-bus/bus-kernel.c:37:0:
./src/shared/util.h:1081:28: warning: 'struct msghdr' declared inside parameter list
void cmsg_close_all(struct msghdr *mh);
^
CC src/libsystemd/sd-bus/libsystemd_la-bus-creds.lo
In file included from src/libsystemd/sd-bus/bus-creds.c:25:0:
./src/shared/util.h:976:32: warning: 'struct ucred' declared inside parameter list
int getpeercred(int fd, struct ucred *ucred);
^
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
Also, allow clients to alter their own objects without any further
priviliges. i.e. this allows clients to kill and lock their own sessions
without involving PK.
Most of our client tools want to set this bit for all their method
calls, even though it defaults to off in sd-bus, and rightfully so.
Hence, to simplify thing, introduce a per sd_bus-object flag that sets
the default value for all messages created on the connection.
