There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
Let's use strjoina() rather than strjoin() for construct dbus match
strings.
Also, while we are at it, fix parameter ordering, so that our functions
always put the object first, like it is customary for OO-like
programming.
The following details are passed:
- unit: the primary name of the unit upon which the action was
invoked (i.e. after resolving any aliases);
- verb: one of 'start', 'stop', 'reload', 'restart', 'try-restart',
'reload-or-restart', 'reload-or-try-restart', 'kill',
'reset-failed', or 'set-property', corresponding to the
systemctl verb used to invoke the action.
Typical use of these details in a polkit policy rule might be:
// Allow alice to manage example.service;
// fall back to implicit authorization otherwise.
polkit.addRule(function(action, subject) {
if (action.id == "org.freedesktop.systemd1.manage-units" &&
action.lookup("unit") == "example.service" &&
subject.user == "alice") {
return polkit.Result.YES;
}
});
We also supply a custom polkit message that includes the unit's name and
the requested operation.
Extra details for an action can be supplied when calling polkit's
CheckAuthorization method. Details are a list of key/value string pairs.
Custom policy can use these details when making authorization decisions.
Let's add a way to get the type-specific D-Bus interface of a unit from
either its type or name to src/basic/unit-name.[ch]. That way we can
share it with the client side, where it is useful in tools like cgls or
machinectl.
Also ports over machinectl to make use of this.
Currently, PID1 installs an unfiltered NameOwnerChanged signal match, and
dispatches the signals itself. This does not scale, as right now, PID1
wakes up every time a bus client connects.
To fix this, install individual matches once they are requested by
unit_watch_bus_name(), and remove the watches again through their slot in
unit_unwatch_bus_name().
If the bus is not available during unit_watch_bus_name(), just store
name in the 'watch_bus' hashmap, and let bus_setup_api() do the installing
later.
On dbus1, we receive systemd1.Agent signals via the private socket, hence
it's trusted. However, on kdbus we receive it on the system bus. We must
make sure it's sent by UID=0, otherwise unprivileged users can fake it.
Furthermore, never forward broadcasts we sent ourself. This might happen
on kdbus, as we forward the message on the same bus we received it on,
thus ending up in an endless loop.
It's primarily just a property of the Manager object after all, and we
try to refer to PID 1 as "manager" instead of "systemd", hence let's to
stick to this here too.
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().
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.
On kdbus, we get cgroups-agent messages via the system bus, not the
private systemd socket. Therefore, we must install the match properly or
we will never receive cgroup notifications.
Forwarding messages that are not rewinded will drop data. Fix this for
cgroups-agent messages that we might remarshal before forwarding to the
system bus.
On large system we hit the limit on 512 simultaneous dbus
connections, resulting in tons of annoying messages:
Too many concurrent connections, refusing
This patch raises the limit to 4096.
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.
- Always issue selinux access check as early as possible, and PK check
as late as possible.
- Introduce a new policykit action for altering environment
- Open most remaining bus calls to unprivileged clients via PK
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.
If the format string contains %m, clearly errno must have a meaningful
value, so we might as well use log_*_errno to have ERRNO= logged.
Using:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/'
Plus some whitespace, linewrap, and indent adjustments.
As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
strv_extend returns 0 in the case of success which means that
else if (bus_track_deserialize_item(&m->deserialized_subscribed, l) == 0)
log_warning("Unknown serialization item '%s'", l);
will be printed when value is added correctly.
It is redundant to store 'hash' and 'compare' function pointers in
struct Hashmap separately. The functions always comprise a pair.
Store a single pointer to struct hash_ops instead.
systemd keeps hundreds of hashmaps, so this saves a little bit of
memory.
DBus methods that retrieve information can be called by anyone.
DBus methods that modify state of units are verified via polkit
action: org.freedesktop.systemd1.manage-units
DBus methods that modify state of unit files are verified via polkit
action: org.freedesktop.systemd1.manage-unit-files
DBus methods that reload the entire daemon state are verified via polkit
action: org.freedesktop.systemd1.reload-daemon
DBus methods that modify job state are callable from the clients
that started the job.
root (ie: CAP_SYS_ADMIN) can continue to perform all calls, property
access etc. There are several DBus methods that can only be
called by root.
Open up the dbus1 policy for the above methods.
(Heavily modified by Lennart, making use of the new
bus_verify_polkit_async() version that doesn't force us to always
pass the original callback around. Also, interactive auhentication must
be opt-in, not unconditional, hence I turned this off.)
This reflects how this field will be used, to not only track where
to send signals, but also which callers (other than root) are allowed
to call DBus methods on the Job.
This makes callback behaviour more like sd-event or sd-resolve, and
creates proper object for unregistering callbacks.
Taking the refernce to the slot is optional. If not taken life time of
the slot will be bound to the underlying bus object (or in the case of
an async call until the reply has been recieved).
safe_close() automatically becomes a NOP when a negative fd is passed,
and returns -1 unconditionally. This makes it easy to write lines like
this:
fd = safe_close(fd);
Which will close an fd if it is open, and reset the fd variable
correctly.
By making use of this new scheme we can drop a > 200 lines of code that
was required to test for non-negative fds or to reset the closed fd
variable afterwards.
GCC optimizes strlen("string constant") to a constant, even with -O0.
Thus, replace patterns like sizeof("string constant")-1 with
strlen("string constant") where possible, for clarity. In particular,
for expressions intended to add up the lengths of components going into
a string, this often makes it clearer that the expression counts the
trailing '\0' exactly once, by putting the +1 for the '\0' at the end of
the expression, rather than hidden in a sizeof in the middle of the
expression.
This is primarily useful for services that need to track clients which
reference certain objects they maintain, or which explicitly want to
subscribe to certain events. Something like this is done in a large
number of services, and not trivial to do. Hence, let's unify this at
one place.
This also ports over PID 1 to use this to ensure that subscriptions to
job and manager events are correctly tracked. As a side-effect this
makes sure we properly serialize and restore the track list across
daemon reexec/reload, which didn't work correctly before.
This also simplifies how we distribute messages to broadcast to the
direct busses: we only track subscriptions for the API bus and
implicitly assume that all direct busses are subscribed. This should be
a pretty OK simplification since clients connected via direct bus
connections are shortlived anyway.
Previously the returned object of constructor functions where sometimes
returned as last, sometimes as first and sometimes as second parameter.
Let's clean this up a bit. Here are the new rules:
1. The object the new object is derived from is put first, if there is any
2. The object we are creating will be returned in the next arguments
3. This is followed by any additional arguments
Rationale:
For functions that operate on an object we always put that object first.
Constructors should probably not be too different in this regard. Also,
if the additional parameters might want to use varargs which suggests to
put them last.
Note that this new scheme only applies to constructor functions, not to
all other functions. We do give a lot of freedom for those.
Note that this commit only changes the order of the new functions we
added, for old ones we accept the wrong order and leave it like that.
