This turns resolve-tool into a multi-call binary. When invoked as
"resolvconf" it provides minimal compatibility with the resolvconf(8)
tool of various distributions (and FreeBSD as it appears).
This new interface understands to varying degrees features of the two
major implementations of resolvconf(8): Debian's original one and
"openresolv". Specifically:
Fully supported:
-a -d (supported by all implementations)
-f (introduced by openresolv)
Somewhat supported:
-x (introduced by openresolv, mapped to a '~.' domain entry)
Unsupported and ignored:
-m -p (introduced by openresolv, not really necessary for us)
Unsupported and resulting in failure:
-u (supported by all other implementations)
-I -i -l -R -r -v -V
(all introduced by openresolv)
--enable-updates --disable-updates --updates-are-enabled
(specific to Debian's implementation)
Of course, resolvconf(8) is a tool with multiple backends, in our
implementation systemd-resolved is the only backend.
Fixes: #7202
DNS queries have a timeout of DNS_TRANSACTION_ATTEMPTS_MAX *
DNS_TIMEOUT_MAX_USEC = 120 s. Calls to the ResolveHostname method of
the org.freedesktop.resolve1.Manager interface have various call
timeouts that are smaller than 120 s. So it seems correct to adjust
the call timeout to the maximum query timeout and to unify the call
timeout among all callers.
A timeout of 120 s might seem large, in particular since BIND does seem
to have a query timeout of 10 s. However, it seems match the timeout
value of 120 s of Unbound. Moreover, the query and timeout handling of
resolve have problems and might be improved in the future, so this
change is at best an interim solution.
This is useful to debug things, but also to hook up external post-up
scripts with resolved.
Eventually this code might be useful to implement a
resolvconf(8)-compatible interface for compatibility purposes. Since the
semantics don't map entirely cleanly as first step we add a native
interface for pushing DNS configuration into resolved, that exposes the
correct semantics, before adding any compatibility interface.
See: #7202
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.
When we a reply message gets longer than the client supports we need to
truncate the response and set the TC bit, and we already do that.
However, we are not supposed to send incomplete RRs in that case, but
instead truncate right at a record boundary. Do that.
This fixes the "Message parser reports malformed message packet."
warning the venerable "host" tool outputs when a very large response is
requested.
See: #6520
Let's increase a number of timeouts as they apparently are too short for
some real-world lookups.
See:
https://github.com/systemd/systemd/issues/4003#issuecomment-279842616
In particular we change the following timeouts:
1) The first UDP retry we increase 500ms → 750ms. This is a good idea,
since some servers need relatively long responses for trivial lookups,
and giving up our first attempt also has the effect of trying a
different server for the next attempt which has the side effect that
we'll run two down-grade iterations in parallel, on both servers.
Hence, let's give servers a bit more time in the first iteration.
2) Permit 24 retries instead of just 16 per transactions. If we end up
downgrading all the way down to UDP for a lookup we already need 5
iterations for that. If we want permit a couple of lost packages for
each (let's say 4), then we already need 20 iterations.
3) Increase the overall query timeout on the service side to 60s (from
45s), simply because very long and slow DNSSEC + CNAME chains (such as
us.ynuf.alipay.com) hit this boundary too easily. The client side
timeout for the bus method call is increased to 90s, in order to have
room for the dbus reply to go through
And then show it, to make things a bit friendlier to the user if we fail
acquiring some props.
In fact, this fixes a number of actual bugs, where we used an error
structure for output that we actually never got an error in.
The new command shows the per-link and global DNS configuration currently in
effect. This is useful to quickly see the DNS settings resolved acquired from
networkd and that was pushed into it via the bus APIs.
- Move gcrypt.h include inside grcrypt-util.h.
- Allow gcrypt-util.[ch] to be compiled even without gcrypt.
This allows the logic in files using gcrypt to be simplified.
- Fix compilation of systemd-resolve without gcrypt.
systemd-resolved already supported that.
Fixes#2711.
The output didn't specify if the default for --cname/--search/--legend and
other options was yes or no. Change the description to be explicit about that.
Also make the --help output and man page closer.
The tool resolves way more than just hosts, hence give it a more generic name. This should be safe, as the tool is
currently undocumented. Before we add documentation for it, let's get the name right.
This also moves the C source into src/resolve/ (from src/resolve-host/), since the old name is a misnomer now. Also,
since it links directly to many of the C files of resolved it really belongs into resolved's directory anyway.
2016-01-25 16:00:28 +01:00
Renamed from src/resolve-host/resolve-host.c (Browse further)
