In subsequent commits, calls to if_nametoindex() will be replaced by a wrapper
that falls back to alternative name resolution over netlink. netlink support
requires libsystemd (for sd-netlink), and we don't want to add any functions
that require netlink in basic/. So stuff that calls if_nametoindex() for user
supplied interface names, and everything that depends on that, needs to be
moved.
Notifications are only sent for the top object, and not for individual
links. This should be enough for the most obvious cases where somebody
just cares about the effective set of servers.
Fixes#13721.
This matches what is done in networkd very closely. In fact even the
policy descriptions are all identical (with s/network/resolve), except
for the last one:
resolved has org.freedesktop.resolve1.revert while
networkd has org.freedesktop.network1.revert-ntp and
org.freedesktop.network1.revert-dns so the description is a bit different.
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.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
The changes both networkd and resolved to make use of the watch_bind
feature of sd-bus to connect to the system bus. This way, both daemons
can be started during early boot, and automatically and instantly
connect to the system bus as it becomes available.
This replaces prior code that used a time-based retry logic to connect
to the bus.
Let's remove a number of synchronization points from our service
startups: let's drop synchronous match installation, and let's opt for
asynchronous instead.
Also, let's use sd_bus_match_signal() instead of sd_bus_add_match()
where we can.
This adds "systemd-resolve --reset-server-features" for explicitly
forgetting what we learnt. This might be useful for debugging
purposes, and to force systemd-resolved to restart its learning logic
for all DNS servers.
https://tools.ietf.org/html/rfc5891#section-4.2.3.1 says that
> The Unicode string MUST NOT contain "--" (two consecutive hyphens) in the third
> and fourth character positions and MUST NOT start or end with a "-" (hyphen).
This means that libidn2 refuses to encode such names.
Let's just resolve them without trying to use IDN.
When we return the full RR wire data, let's make sure the TTL included in it is
adjusted by the time the RR sat in the cache.
As an optimization we do this only for ResolveRecord() and not for
ResolveHostname() and friends, since adjusting the TTL means copying the RR
object, and we don#t want to do that if there's no reason to.
(ResolveHostname() and friends don't return the TTL hence there's no reason to
in that case)
When we get a literal IP address as string that includes a zone suffix, process
this properly and return the parsed ifindex back to the client, and include it
in the canonical name in case of a link-local IP address.
Previously, we checked only for the various SetLinkXYZ() calls on the Manager
object exposed on the bus if the specified interface is managed/unmanaged by
networkd (as we don't permit overriding DNS configuration via bus calls if
networkd owns the device), but the equivalent SetXYZ() calls on the Link object
did not have such a check. Fix that by moving the appropriate check into the
latter, as the former just calls that anyway.
Make sure we can parse DNS server addresses that use the "zone id" syntax for
local link addresses, i.e. "fe80::c256:27ff:febb:12f%wlp3s0", when reading
/etc/resolv.conf.
Also make sure we spit this out correctly again when writing /etc/resolv.conf
and via the bus.
Fixes: #3359
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
