On certain distributions such as NixOS the mtime of `/etc/hosts` is
locked to a fixed value. In such cases, only checking the last mtime of
`/etc/hosts` is not enough - we also need to check if the st_ino/st_dev
match up. Thus, let's make sure make sure that systemd-resolved also
rereads `/etc/hosts` if the inode or the device containing `/etc/hosts` changes.
Test script:
```bash
hosts="/etc/hosts"
echo "127.0.0.1 testpr" > "hosts_new"
mv "hosts_new" "$hosts"
resolvectl query testpr || exit 1
mtime="$(stat -c %y "$hosts")"
echo "127.0.0.1 newhost" > "hosts_tmp"
touch -d "$mtime" "hosts_tmp"
install -p "hosts_tmp" "$hosts"
sleep 10
resolvectl query newhost || exit 1
rm -f "hosts_tmp"
```
Closes#14456.
Widely accepted certificates for IP addresses are expensive and only
affordable for larger organizations. Therefore if the user provides
the hostname in the DNS= option, we should use it instead of the IP
address.
Section 6.2 of RFC4034 requires that "all uppercase US-ASCII letters in
the DNS names contained within the RDATA are replaced by the corresponding
lowercase US-ASCII letters" for a long list of RR types.
Fixes#14891
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.
We don't need a seperate output parameter that is of type int. glibc() says
that the type is "unsigned", but the kernel thinks it's "int". And the
"alternative names" interface also uses ints. So let's standarize on ints,
since it's clearly not realisitic to have interface numbers in the upper half
of unsigned int range.
If a daemon is not started as root, most likely it also can't create its
directory and let's not try to resolve the user in that case either.
Create /run/systemd/netif/lldp with tmpfiles.d like other netif directories.
This is also very helpful for preparing a RootImage for the daemons as NSS crud
is not needed.
This cleans up and unifies the outut of --help texts a bit:
1. Highlight the human friendly description string, not the command
line via ANSI sequences. Previously both this description string and
the brief command line summary was marked with the same ANSI
highlight sequence, but given we auto-page to less and less does not
honour multi-line highlights only the command line summary was
affectively highlighted. Rationale: for highlighting the description
instead of the command line: the command line summary is relatively
boring, and mostly the same for out tools, the description on the
other hand is pregnant, important and captions the whole thing and
hence deserves highlighting.
2. Always suffix "Options" with ":" in the help text
3. Rename "Flags" → "Options" in one case
4. Move commands to the top in a few cases
5. add coloring to many more help pages
6. Unify on COMMAND instead of {COMMAND} in the command line summary.
Some tools did it one way, others the other way. I am not sure what
precisely {} is supposed to mean, that uppercasing doesn't, hence
let's simplify and stick to the {}-less syntax
And minor other tweaks.
Validate the IP address in the certificate for DNS-over-TLS in strict mode when GnuTLS is used. As this is not yet the case in contrast to the documentation.
Increase the required version to ensure TLS 1.3 is always supported when using GnuTLS for DNS-over-TLS and allow further changes to use recent API additions.
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.
The DnsStreamType was added to track different types of DNS TCP streams,
instead of refcounting all of them together. However, the stream type was
not actually set into the stream->type field, so while the reference count
was correctly incremented per-stream-type, the reference count was always
decremented in the cleanup function for stream type 0, leading to
underflow for the type 0 stream (unsigned) refcount, and preventing new
type 0 streams from being created.
Since type 0 is DNS_STREAM_LOOKUP, which is used to communicate with
upstream nameservers, once the refcount underflows the stub resolver
no longer is able to successfully fall back to TCP upstream lookups
for any truncated UDP packets.
This was found because lookups of A records with a large number of
addresses, too much to fit into a single 512 byte DNS UDP reply,
were causing getaddrinfo() to fall back to TCP and trigger this bug,
which then caused the TCP fallback for later large record lookups
to fail with 'connection timed out; no servers could be reached'.
The stream type was introduced in commit:
652ba568c6
Prefer TLS 1.3 before TLS 1.2 for DNS-over-TLS support, otherwise
servers compliant with RFC 8446 might end up agreeing TLS 1.2 plus a
downgrade signal which is not expected by GnuTLS clients. This manifests
in the following error:
Failed to invoke gnutls_handshake: An illegal parameter has been received.
Fixes: #13528
Fixes: v242-962-g9c0624dcdb ("resolved: support TLS 1.3 when using GnuTLS for DNS-over-TLS")
For executables which take a verb, we should list the verbs first, and
then options which modify those verbs second. The general layout of
the man page is from general description to specific details, usually
Overview, Commands, Options, Return Value, Examples, References.
"reset" is more understandable. The verb is "revert", but it might actually be
better to have a description which uses different words instead of duplicating
the name of the command.
379158684a (commitcomment-34992552)
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.
This doesn't matter much, but let's just do the loop once and allocate
the populate the result set on the fly. If we find an error, it'll get
cleaned up automatically.
Change the resolved.conf Cache option to a tri-state "no, no-negative, yes" values.
If a lookup returns SERVFAIL systemd-resolved will cache the result for 30s (See 201d995),
however, there are several use cases on which this condition is not acceptable (See systemd#5552 comments)
and the only workaround would be to disable cache entirely or flush it , which isn't optimal.
This change adds the 'no-negative' option when set it avoids putting in cache
negative answers but still works the same heuristics for positive answers.
Signed-off-by: Jorge Niedbalski <jnr@metaklass.org>
