* net/dns, net/dns/resolver, wgengine: refactor DNS request path
Previously, method calls into the DNS manager/resolver types handled DNS
requests rather than DNS packets. This is fine for UDP as one packet
corresponds to one request or response, however will not suit an
implementation that supports DNS over TCP.
To support PRs implementing this in the future, wgengine delegates
all handling/construction of packets to the magic DNS endpoint, to
the DNS types themselves. Handling IP packets at this level enables
future support for both UDP and TCP.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Combine the code between `LocalBackend.CheckIPForwarding` and
`controlclient.ipForwardingBroken`.
Fixes#4300
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Currently if the passed in host is an IP, Lookup still attempts to
resolve it with a dns server. This makes it just return the IP directly.
Updates tailscale/corp#4475
Signed-off-by: Maisem Ali <maisem@tailscale.com>
When the context is canceled, dc.dialOne returns an error from line 345.
This causes the defer on line 312 to try to resolve the host again, which
triggers a dns lookup of "127.0.0.1" from derp.
Updates tailscale/corp#4475
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Plumb the outbound injection path to allow passing netstack
PacketBuffers down to the tun Read, where they are decref'd to enable
buffer re-use. This removes one packet alloc & copy, and reduces GC
pressure by pooling outbound injected packets.
Fixes#2741
Signed-off-by: James Tucker <james@tailscale.com>
The best flag to use on Win7 and Win8.0 is deprecated in Win8.1, so we resolve
the flag depending on OS version info.
Fixes https://github.com/tailscale/tailscale/issues/4201
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Incidentally, simplify the go generate CI workflow, by
marking the dnsfallback update non-hermetic (so CI will
skip it) rather than manually filter it out of `go list`.
Updates #4194
Signed-off-by: David Anderson <danderson@tailscale.com>
As of Go 1.18, the register ABI list includes arm64, amd64,
ppc64, and ppc64le. This is a large enough percentage of the
architectures that it's not worth explaining.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Customer reported an issue where the connections were not closing, and
would instead just stay open. This commit makes it so that we close out
the connection regardless of what error we see. I've verified locally
that it fixes the issue, we should add a test for this.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
If it's in a non-standard table, as it is on Unifi UDM Pro, apparently.
Updates #4038 (probably fixes, but don't have hardware to verify)
Change-Id: I2cb9a098d8bb07d1a97a6045b686aca31763a937
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I introduced a bug in 8fe503057d when unifying oneConnListener
implementations.
The NewOneConnListenerFrom API was easy to misuse (its Close method
closes the underlying Listener), and we did (via http.Serve, which
closes the listener after use, which meant we were close the peerapi's
listener, even though we only wanted its Addr)
Instead, combine those two constructors into one and pass in the Addr
explicitly, without delegating through to any Listener.
Change-Id: I061d7e5f842e0cada416e7b2dd62100d4f987125
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If we've already connected to a certain name's IP in the past, don't
assume the problem was DNS related. That just puts unnecessarily load
on our bootstrap DNS servers during regular restarts of Tailscale
infrastructure components.
Also, if we do do a bootstrap DNS lookup and it gives the same IP(s)
that we already tried, don't try them again.
Change-Id: I743e8991a7f957381b8e4c1508b8e9d0df1782fe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
No behavior changes (intended, at least).
This is in prep for future changes to this package, which would get
too complicated in the current style.
Change-Id: Ic260f8e34ae2f64f34819d4a56e38bee8d8ac5ce
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This TODO was both added and fixed in 506c727e3.
As I recall, I wasn't originally going to do it because it seemed
annoying, so I wrote the TODO, but then I felt bad about it and just
did it, but forgot to remove the TODO.
Change-Id: I8f3514809ad69b447c62bfeb0a703678c1aec9a3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I was about to add a third copy, so unify them now instead.
Change-Id: I3b93896aa1249b1250a6b1df4829d57717f2311a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Avoid some work when D-Bus isn't running.
Change-Id: I6f89bb75fdb24c13f61be9b400610772756db1ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If systemd-resolved is enabled but not running (or not yet running,
such as early boot) and resolv.conf is old/dangling, we weren't
detecting systemd-resolved.
This moves its ping earlier, which will trigger it to start up and
write its file.
Updates #3362 (likely fixes)
Updates #3531 (likely fixes)
Change-Id: I6392944ac59f600571c43b8f7a677df224f2beed
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
tailscaled was using 100% CPU on a machine with ~1M lines, 100MB+
of /proc/net/route data.
Two problems: in likelyHomeRouterIPLinux, we didn't stop reading the
file once we found the default route (which is on the first non-header
line when present). Which meant it was finding the answer and then
parsing 100MB over 1M lines unnecessarily. Second was that if the
default route isn't present, it'd read to the end of the file looking
for it. If it's not in the first 1,000 lines, it ain't coming, or at
least isn't worth having. (it's only used for discovering a potential
UPnP/PMP/PCP server, which is very unlikely to be present in the
environment of a machine with a ton of routes)
Change-Id: I2c4a291ab7f26aedc13885d79237b8f05c2fd8e4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Now that Go 1.17 has module graph pruning
(https://go.dev/doc/go1.17#go-command), we should be able to use
upstream netstack without breaking our private repo's build
that then depends on the tailscale.com Go module.
This is that experiment.
Updates #1518 (the original bug to break out netstack to own module)
Updates #2642 (this updates netstack, but doesn't remove workaround)
Change-Id: I27a252c74a517053462e5250db09f379de8ac8ff
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.
Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Currently only search domains are stored. This was an oversight
(under?) on my part.
As things are now, when MagicDNS is on and "Override local DNS" is
off, the dns forwarder has to timeout before names resolve. This
introduces a pretty annoying lang that makes everything feel
extremely slow. You will also see an error: "upstream nameservers
not set".
I tested with "Override local DNS" on and off. In both situations
things seem to function as expected (and quickly).
Signed-off-by: Aaron Bieber <aaron@bolddaemon.com>
Go 1.17 added a HandshakeContext func to take care of timeouts during
TLS handshaking, so switch from our homegrown goroutine implementation
to the standard way.
Signed-off-by: David Anderson <danderson@tailscale.com>
Cancelling the context makes the timeout goroutine race with the write that
reports a successful TLS handshake, so you can end up with a successful TLS
handshake that mysteriously reports that it timed out after ~0s in flight.
The context is always canceled and cleaned up as the function exits, which
happens mere microseconds later, so just let function exit clean up and
thereby avoid races.
Signed-off-by: David Anderson <danderson@tailscale.com>
On Synology, the /etc/resolv.conf has tabs in it, which this
resolv.conf parser (we have two, sigh) didn't handle.
Updates #3710
Change-Id: I86f8e09ad1867ee32fa211e85c382a27191418ea
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Tailscale seems to be breaking WSL configurations lately. Until we
understand what changed, turn off Tailscale's involvement by default
and make it opt-in.
Updates #2815
Change-Id: I9977801f8debec7d489d97761f74000a4a33f71b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
OpenBSD 6.9 and up has a daemon which handles nameserver configuration. This PR
teaches the OpenBSD dns manager to check if resolvd is being used. If it is, it
will use the route(8) command to tell resolvd to add the Tailscale dns entries
to resolv.conf
Signed-off-by: Aaron Bieber <aaron@bolddaemon.com>
Fixes#3660
RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled.
Change-Id: I001e983df5feeb65289abe5012dedd177b841b45
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And delete the unused code in net/dns/resolver/neterr_*.go.
Change-Id: Ibe62c486bacce2733eb9968c96a98cbbdb2758bd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Treat UDP send EPERM errors as a lost UDP packet, not something super
fatal. That's just the Linux firewall preventing it from going out.
And add a leaf package net/neterror for that (and future) policy that
all three packages can share, with tests.
Updates #3619
Change-Id: Ibdb838c43ee9efe70f4f25f7fc7fdf4607ba9c1d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
