Previously the client had heuristics to calculate which DNS search domains
to set, based on the peers' names. Unfortunately that prevented us from
doing some things we wanted to do server-side related to node sharing.
So, bump MapRequest.Version to 9 to signal that the client only uses the
explicitly configured DNS search domains and doesn't augment it with its own
list.
Updates tailscale/corp#1026
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If no interfaces are up, calm down and stop spamming so much. It was
noticed as especially bad on Windows, but probably was bad
everywhere. I just have the best network conditions testing on a
Windows VM.
Updates #604
When the network link changes, existing UDP sockets fail immediately
and permanently on macOS.
The forwarder set up a single UDP conn and never changed it.
As a result, any time there was a network link change,
all forwarded DNS queries failed.
To fix this, create a new connection when send requests
fail because of network unreachability.
This change is darwin-only, although extended it to other platforms
should be straightforward.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
While we're here, parseQuery into a plain function.
This is helpful for fuzzing. (Which I did a bit of. Didn't find anything.)
And clean up a few minor things.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
It turns out that otherwise we don't know what exactly was set.
Also remove the now unused RootDomain config option.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
Previously, a type AAAA query would be answered with an A record
if only an IPv4 address was available. This is irrelevant for us
while we only use IPv4, but it will be a bug one day,
so it's worth being precise about semantics.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
The previous approach modifies name in-place in the request slice to avoid an allocation.
This is incorrect: the question section of a DNS request
must be copied verbatim, without any such modification.
Software may rely on it (we rely on other resolvers doing it it in tsdns/forwarder).
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
This change adds to tsdns the ability to delegate lookups to upstream nameservers.
This is crucial for setting Magic DNS as the system resolver.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
