With this we can stabilize how naming works for network interfaces. A
user can request through a kernel cmdline option or an env var which
scheme to follow. The idea is that installers use this to set into stone
(a very soft stone though) the scheme used during installation so that
interface naming doesn't change afterwards anymore.
Why use env vars and kernel cmdline options, and not a config file of
its own?
Well, first of all there's no obvious existing one to use. But more
importantly: I have the feeling that this logic is kind of an incomplete
hack, and I simply don't want to do advertise this as a perfectly
working solution. So far we used env vars for the non-so-official
options and proper config files for the official stuff. Given how
incomplete this logic is (i.e. the big variable for naming remains the
kernel, which might expose sysfs attributes in newer versions that we
check for and didn't exist in older versions — and other problems like
this), I am simply not confident in giving this first-class exposure in
a primary configuration file.
Fixes: #10448
Before:
Assertion 'mknod(devname, mode, devnum) == 0' failed at ../src/test/test-udev.c:116, function run(). Aborting.
Assertion 'unlink(devname) == 0' failed at ../src/test/test-udev.c:118, function run(). Aborting.
After:
mknod() failed for '/dev/sda': Operation not permitted
unlink('/dev/sda') failed: No such file or directory
cg_ns_supported() caches, so the condition was really checked just once, but
it looks weird to assign the return value to arg_use_cgns (if the variable is not present),
because then the other checks are effectively equivalent to
if (cg_ns_supported() && cg_ns_supported()) { ...
and later
if (!cg_ns_supported() || !cg_ns_supported()) { ...
This is convenient when working with device units in systemd. Instead of
converting the systemd unit name to a path to feed to udevadm, udevadm
info|trigger can be called directly on the unit name.
The man page is reworked a bit to describe the modern syntax with positional
arguments first. It's just simpler to use than the positional options.
udevadm would dump help() output, instead of printing a message about what is
wrong. That's just bad UX. Let's use a different message if the argument is
missing, and a different one if it is invalid.
Also, rework the code to separate the business logic from argument parsing.
Let's not use "default:" in switch statements. This way, the compiler will warn
us if we miss one of the cases.
An earlier commit 0e408b82b (dhcp6-client: handle IAID with value zero)
introduced a flag to sd_dhcp6_client to distinguish between an unset
IAID and a value set to zero.
However, that was not sufficient and broke leaving the setting
uninitialized in networkd configuration. The configuration parsing
also must distinguish between the default, unset value and an
explict zero configuration.
Fixes: 0e408b82b8
We'd only set the description after the device appeared in sysfs, so
we'd always print
"A start job is running for dev-disk-by\x2duuid-aaaa ... aaaa.device (42s / 1min 30s)"
Let's make this
"A start job is running for /dev/disk/by-duuid/aaaa ... aaaa (42s / 1min 30s)"
https://bugzilla.redhat.com/show_bug.cgi?id=1655860
That's what the function is for after all, and only if it's done there
we can verify the effect of .nspawn files correctly too: after all we
should not just validate that everything configured on the command line
makes sense, but the stuff configured in the .nspawn files, too.
This then let's us to ensure it's called after we parsed the cmdline,
and after we loaded the settings file, so that it these env var settings
override everything loaded from there.
PATH_MAX is supposed to include the terminating NUL byte. But we already
check that there is no NUL byte in the specified path. Hence the maximum
length we can expect is PATH_MAX - 1.
This doesn't change much, but makes this use of PATH_MAX consistent with the
rest of the codebase.
https://tools.ietf.org/html/rfc1035#section-2.3.1 says (approximately)
that only letters, numbers, and non-leading non-trailing dashes are allowed
(for entries with A/AAAA records). We set no restrictions.
hosts(5) says:
> Host names may contain only alphanumeric characters, minus signs ("-"), and
> periods ("."). They must begin with an alphabetic character and end with an
> alphanumeric character.
nss-files follows those rules, and will ignore names in /etc/hosts that do not
follow this rule.
Let's follow the documented rules for /etc/hosts. In particular, this makes us
consitent with nss-files, reducing surprises for the user.
I'm pretty sure we should apply stricter filtering to names received over DNS
and LLMNR and MDNS, but it's a bigger project, because the rules differ
depepending on which level the label appears (rules for top-level names are
stricter), and this patch takes the minimalistic approach and only changes
behaviour for /etc/hosts.
Escape syntax is also disallowed in /etc/hosts, even if the resulting character
would be allowed. Other tools that parse /etc/hosts do not support this, and
there is no need to use it because no allowed characters benefit from escaping.
Do not treat various errors (missing hostname, invalid address) as fatal,
just warn and continue. /etc/hosts is written by humans and we should not
reject the whole file just because a singly entry is not to our liking.
Handle comments as described in hosts(5):
everything from the comment character until the end of the line should be
ignored.
Fixes#10779.
Add tests.
This has the side effect to upgrade the log level at which the log is emitted
from debug to warning.
This might be better since after all we didn't apply a tmpfiles.d/ rule and
that actually might end up being problematic eventually.
We're always interested into finding unsafe transitions so let's make the
helper return true when it finds such transitions so we don't need to negate
its results.
No functional changes.
and let's emit a more comprehensive warning when an unsafe transition is
encountered.
Before this patch:
Unsafe symlinks encountered in /run/nrpe, refusing.
After:
Detected unsafe path transition / → /run during canonicalization of /run/nrpe.
We previously returned -EPERM but it can be returned for various other reasons
too.
Let's use -ENOLINK instead as this value shouldn't be used currently. This
allows users of CHASE_SAFE to detect without any ambiguities when unsafe
transitions are encountered by chase_symlinks().
All current users of CHASE_SAFE that explicitly reacted on -EPERM have been
converted to react on -ENOLINK.
When using networkd we currently have no way of ensuring that static
neighbor entries are set when our link comes up. This change adds a new
section to the network definition that allows multiple static neighbors
to be set on a link.
This allows us to convey that we are performing multiple link
configuration changes in parallel. This is needed to support configuring
neighbors while simultaneously configuring addresses and routes.
This will be useful to assert that our static route configuration always
happens after address configuration once our individual configure state
goes away.
