Also, document this functionality more prominently, including with a
reference from sd_event_exit().
This is mostly to make things complete, as previously we supported NULL
callbacks only in _add_time() and _add_signal(). However, I think this
makes snese for IO event sources too (think: when some fd such as a pipe
end sees SIGHUP or so, exit), as well as defer or post event sources (i.e. exit
once we got nothing else to do). This also adds support for inotify
event sources, simply to complete things (I can't see the immediate use,
but maybe someone else comes up with it).
The only event source type that doesn't allow callback=NULL now are exit
callbacks, but for them they make little sense, as the event loop is
exiting then anyway.
Currently, if an event source callback returns an error, we'll disable
the event source and continue. This adds a per-event source flag that if
turned on goes further: the event loop is also exited, propagating the
error code.
This is inspired by some patterns repeatedly seen in #15206.
The idea is that event sources that server the "primary" function of a
program are marked like this, so that if they fail the failure is
instantly propagated and terminates the program.
By settings AI_ADDRCONFIG in hints we cannot for example resolve "localhost"
when the local machine only has a loopback interface. This seems like an
unnecessary restriction, drop it.
Inspired by https://bugzilla.redhat.com/show_bug.cgi?id=1839007.
Like it's customary in our codebase bus_error_message() internally takes
abs() of the passed error anyway, hence no need to explicitly negate it.
We mostly got this right, but in too many cases we didn't. Fix that.
We generally don't support prefix being != /usr, and this is hardcoded
all over the place. In the systemd.pc file it wasn't so far. Let's
adjust this to match the rest of the codebase.
This really doesn't matter given that AF_xyz and PF_xyz are equivalent
in all ways, but we almost always use AF_xyz, hence stick to it
universally and convert the remaining PF_ to AF_
sd_seat_get_sessions() would return 0 in the 'n_uids' (now 'ret_n_uids') output
parameter when 'uid' (now 'ret_uids') was passed as NULL.
While at it, drop FOREACH_WORD() use.
Also use any whitespace as separator. In practice this shouldn't matter, since
logind always uses spaces, but it seems nicer to not specify this explicitly,
and the default is more flexible.
This tries to address the "bind"/"unbind" uevent kernel API breakage, by
changing the semantics of device tags.
Previously, tags would be applied on uevents (and the database entries
they result in) only depending on the immediate context. This means that
if one uevent causes the tag to be set and the next to be unset, this
would immediately effect what apps would see and the database entries
would contain each time. This is problematic however, as tags are a
filtering concept, and if tags vanish then clients won't hence notice
when a device stops being relevant to them since not only the tags
disappear but immediately also the uevents for it are filtered including
the one necessary for the app to notice that the device lost its tag and
hence relevance.
With this change tags become "sticky". If a tag is applied is once
applied to a device it will stay in place forever, until the device is
removed. Tags can never be removed again. This means that an app
watching a specific set of devices by filtering for a tag is guaranteed
to not only see the events where the tag is set but also all follow-up
events where the tags might be removed again.
This change of behaviour is unfortunate, but is required due to the
kernel introducing new "bind" and "unbind" uevents that generally have
the effect that tags and properties disappear and apps hence don't
notice when a device looses relevance to it. "bind"/"unbind" events were
introduced in kernel 4.12, and are now used in more and more subsystems.
The introduction broke userspace widely, and this commit is an attempt
to provide a way for apps to deal with it.
While tags are now "sticky" a new automatic device property
CURRENT_TAGS is introduced (matching the existing TAGS property) that
always reflects the precise set of tags applied on the most recent
events. Thus, when subscribing to devices through tags, all devices that
ever had the tag put on them will be be seen, and by CURRENT_TAGS it may
be checked whether the device right at the moment matches the tag
requirements.
See: #7587#7018#8221
For discussion around this see: https://pagure.io/fedora-workstation/issue/82
Recovery keys for homed are very similar to regular passwords, except
that they are exclusively generated by the computer, and not chosen by
the user. The idea is that they are printed or otherwise stored
externally and not what users type in every day.
Taking inspiration from Windows and MacOS this uses 256bit keys. We
format them in 64 yubikey modhex characters, in groups of 8 chars
separated by dashes.
Why yubikey modhex? modhex only uses characters that are are located at
the same place in western keyboard designs. This should reduce the
chance for incorrect inputs for a major chunk of our users, though
certainly not all. This is particular relevant during early boot and
recovery situations, where there's a good chance the keyboard mapping is
not correctly set up.
let's make sure we collect the right error code from errno, otherwise
we'll see EPERM (i.e. error 1) for all errors readv() returns (since it
returns -1 on error), including EAGAIN.
This is definitely backport material.
A fix-up for 3691bcf3c5.
Fixes: #16699
We frequently want to set a timer relative to the current time. Let's
add an explicit API for this. This not only saves us a few lines of code
everywhere and simplifies things, but also allows us to do correct
overflow checking.
SD_JOURNAL_FOREACH_DATA() and SD_JOURNAL_FOREACH_UNIQUE() would immediately
terminate when a field couldn't be accessed. This can happen for example when a
field is compressed with an unavailable compression format. But it's likely
that this is the wrong thing to do: the caller for example might want to
iterate over the fields but isn't interested in all of them. coredumpctl is
like this: it uses SD_JOURNAL_FOREACH_DATA() but only uses a subset of the
fields.
Add two new functions sd_journal_enumerate_good_data() and
sd_journal_enumerate_good_unique() that retry sd_journal_enumerate_data() and
sd_journal_enumerate_unique() if the return value is something that applies to
a single field: ENOBUS, E2BIG, EOPNOTSUPP.
Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1856037.
An alternative would be to make the macros themselves smarter instead of adding
new symbols, and do the looping internally in the macro. I don't like that
approach for two reasons. First, it would embed the logic in the macro, so
recompilation would be required if we decide to update the logic. With the
current version of the patch, recompilation is required to use the new symbols,
but after that, library upgrades are enough. So the current approach is safer
in case further updates are needed. Second, our headers use primitive C, and it
is hard to do the macros without using newer features.
When sd_netlink_call_async() timed out, then we reply the synthetic
error message, but it was not sealed. So, reading the message causes
the following assertion:
```
Assertion 'm->sealed' failed at src/libsystemd/sd-netlink/netlink-message.c:652, function netlink_message_read_internal(). Ignoring.
```
When renaming a network interface, the new name may be used as an
alternative name. In that case, let's swap the current name and the
alternative name. That is, first drop the new name from the list of
alternative names, then rename the interface, finally set the old name
as an alternative name.
Lennart Poettering