Commit Graph

531 Commits (53998e26a6ce13de0f2a4b8b747206823f217e86)

Author SHA1 Message Date
Brad Fitzpatrick 2ff481ff10 net/dns: add health check for particular broken-ish Linux DNS config
Updates #3937 (need to write docs before closing)

Change-Id: I1df7244cfbb0303481e2621ee750d21358bd67c6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c988bd6ed1 net/dns/resolvconffile: unify three /etc/resolv.conf parsers into new package
Change-Id: I2120893ca802d12f1bd0407d49077d3672627d33
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8d6cf14456 net/dnscache: don't do bootstrap DNS lookup after most failed dials
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>
3 years ago
Brad Fitzpatrick 903988b392 net/dnscache: refactor from func-y closure-y state to types & methods
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>
3 years ago
Brad Fitzpatrick 8267ea0f80 net/tstun: remove TODO that's done
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>
3 years ago
Brad Fitzpatrick 8fe503057d net/netutil: unify two oneConnListeners into a new package
I was about to add a third copy, so unify them now instead.

Change-Id: I3b93896aa1249b1250a6b1df4829d57717f2311a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 21358cf2f5 net/dns: slightly optimize dbusPing for non-dbus case [Linux]
Avoid some work when D-Bus isn't running.

Change-Id: I6f89bb75fdb24c13f61be9b400610772756db1ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 37e7a387ff net/dns: remove some unused code for detecting systemd-resolved [Linux]
Change-Id: I19c5fd2cdacfb9e5b688ccd9b4336ae4edffc445
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 15599323a1 net/dns: fix systemd-resolved detection race at boot
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>
3 years ago
Denton Gentry dbea8217ac net/dns: add NetworkManager regression test
Use the exact /etc/resolv.conf file from a user report.
Updates https://github.com/tailscale/tailscale/issues/3531

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Brad Fitzpatrick 2a67beaacf net/interfaces: bound Linux /proc/net/route parsing
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>
3 years ago
Aaron Bieber e5cd765e00 net/dns/resolvd: properly handle not having "search" entries
This prevents adding an empty "search" line when no search domains are set.

Signed-off-by: Aaron Bieber <aaron@bolddaemon.com>
3 years ago
Brad Fitzpatrick 1af26222b6 go.mod: bump netstack, switch to upstream netstack
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>
3 years ago
Brad Fitzpatrick 41fd4eab5c envknob: add new package for all the strconv.ParseBool(os.Getenv(..))
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>
3 years ago
Brad Fitzpatrick 6feb8f4c51 net/dns: log why resolved does not look like it's on use [Linux]
Updates #3742
Updates #3531

Change-Id: I9fc7fa0f4bcab1cf8001ba92408c660a5b25f105
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaron Bieber 411c6c316c net/dns/resolvd: store nameservers
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>
3 years ago
Brad Fitzpatrick c64af5e676 wgengine/netstack: clear TCP ECN bits before giving to gvisor
Updates #2642

Change-Id: Ic219442a2656dd9dc99ae1dd91e907fd3d924987
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 390490e7b1 net/packet: fix typo in comment
Change-Id: Ia666609fde18db44bf38d4e656f490fc372ac3b6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Anderson 463b3e8f62 net/dnscache: use tls.Conn.HandshakeContext.
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>
3 years ago
David Anderson a9da6b73a8 net/dnscache: don't cancel the TLS context before writing to the result channel.
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>
3 years ago
Brad Fitzpatrick 24a04d07d1 net/dns/resolver: handle tabs as whitespace when ExitDNS parses resolv.conf
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>
3 years ago
Brad Fitzpatrick 51bc9a6d9d net/netns: remove a useless probe of the "ip" command
We stopped using it in 1.18.

Change-Id: If5adf1d99275286a89e2a05f0bce5193d9f6e5e3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8df3fa4638 net/dns: make WSL network configuration opt-in for now
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>
3 years ago
Aaron Bieber 189f359609
net/dns: teach OpenBSD's manager to talk to resolvd(8). (#2789)
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>
3 years ago
Brad Fitzpatrick 8d0ed1c9ba net/dns/resolver: on Android, make ExitDNS use net package for DNS
Like Windows.

Updates #1738

Change-Id: I9f26bc58ce7e760c749786fbe5d9952c99eeb91c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 506c727e30 ipnlocal, net/{dns,tsaddr,tstun}, wgengine: support MagicDNS on IPv6
Fixes #3660

RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled.

Change-Id: I001e983df5feeb65289abe5012dedd177b841b45
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 2513d2d728 net/{neterror,dns/resolver}: move PacketWasTruncated to neterror from DNS code
And delete the unused code in net/dns/resolver/neterr_*.go.

Change-Id: Ibe62c486bacce2733eb9968c96a98cbbdb2758bd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 7d9b1de3aa netcheck,portmapper,magicsock: ignore some UDP write errors on Linux
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>
3 years ago
Brad Fitzpatrick 2c94e3c4ad wgengine/magicsock: don't unconditionally close DERP connections on rebind
Only if the source address isn't on the currently active interface or
a ping of the DERP server fails.

Updates #3619

Change-Id: I6bf06503cff4d781f518b437c8744ac29577acc8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 04c2c5bd80 net/interfaces: define DefaultRouteInterface and State.DefaultRouteInterface
It was pretty ill-defined before and mostly for logging. But I wanted
to start depending on it, so define what it is and make Windows match
the other operating systems, without losing the log output we had
before. (and add tests for that)

Change-Id: I0fbbba1cfc67a265d09dd6cb738b73f0f6005247
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick eb26c081b1 net/dns: bound time we wait on restarting systemd-resolved in another place
Fixes #3629
Updates #3537

Change-Id: I5d4b6acfcfdf0e3efcf6eb49c5e6cf4521e4baed
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 0aa4c6f147 net/dns/resolver: add debug HTML handler to see what DNS traffic was forwarded
Change-Id: I6b790e92dcc608515ac8b178f2271adc9fd98f78
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 0848b36dd2 net/dns/resolver: add metrics to PTR lookup misses
Updates tailscale/corp#3326

Change-Id: I58077d889a3b58ef0633267c92ffb265686ce152
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 39f22a357d net/dns/resolver: send NXDOMAIN to iOS DNS-SD/Bonjour queries
Don't just ignore them. See if this makes them calm down.

Updates #3363

Change-Id: Id1d66308e26660d26719b2538b577522a1e36b63
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 394c9de02b net/dns/resolver: add nameFromQuery benchmark
To convince me it's not as alloc-y as it looks.

Change-Id: I503a0cc267268a23d2973dfde9833c420be4e868
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c7052154d5 net/dns/resolver: fix the subject in a func comment
Change-Id: I519268c20dbd2c2da92da565839d3c1c84612dcc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 486059589b all: gofmt -w -s (simplify) tests
And it updates the build tag style on a couple files.

Change-Id: I84478d822c8de3f84b56fa1176c99d2ea5083237
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cced414c7d net/dns/resolver: add Windows ExitDNS service support, using net package
Updates #1713
Updates #835

Change-Id: Ia71e96d0632c2d617b401695ad68301b07c1c2ec
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cab5c46481 net/dns: bound how long we block looking for, restarting systemd-resolved
Fixes #3537

Change-Id: Iba6a3cde75983490d4072b5341f48dbfa2f997c0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 39ffa16853 net/dnscache, net/tsdial: add DNS caching to tsdial UserDial
This is enough to handle the DNS queries as generated by Go's
net package (which our HTTP/SOCKS client uses), and the responses
generated by the ExitDNS DoH server.

This isn't yet suitable for putting on 100.100.100.100 where a number
of different DNS clients would hit it, as this doesn't yet do
EDNS0. It might work, but it's untested and likely incomplete.

Likewise, this doesn't handle anything about truncation, as the
exchanges are entirely in memory between Go or DoH. That would also
need to be handled later, if/when it's hooked up to 100.100.100.100.

Updates #3507

Change-Id: I1736b0ad31eea85ea853b310c52c5e6bf65c6e2a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 21741e111b net/packet: add ICMP6Header, like ICMP4Header
So we can generate IPv6 ping replies.

Change-Id: I79a9a38d8aa242e5dfca4cd15dfaffaea6cb1aee
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick affc4530a2 net/packet: don't make IP6Header.marshalPseudo assume UDP
It will be used for ICMPv6 next, so pass in the proto.

Also, use the ipproto constants rather than hardcoding the mysterious
number.

Change-Id: I57b68bdd2d39fff75f82affe955aff9245de246b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 485bcdc951 net/packet: fix doc copy/paste-o
Change-Id: I0aca490b3ccb0c124192afb362a10b19a15a3e2b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 9c5c9d0a50 ipn/ipnlocal, net/tsdial: make SOCKS/HTTP dials use ExitDNS
And simplify, unexport some tsdial/netstack stuff in the the process.

Fixes #3475

Change-Id: I186a5a5cbd8958e25c075b4676f7f6e70f3ff76e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick adc5997592 net/tsdial: give netstack a Dialer, start refactoring name resolution
This starts to refactor tsdial.Dialer's name resolution to have
different stages: in-memory MagicDNS vs system resolution. A future
change will plug in ExitDNS resolution.

This also plumbs a Dialer into netstack and unexports the dnsMap
internals.

And it removes some of the async AddNetworkMapCallback usage and
replaces it with synchronous updates of the Dialer's netmap
from LocalBackend, since the LocalBackend has the Dialer too.

Updates #3475

Change-Id: Idcb7b1169878c74f0522f5151031ccbc49fe4cb4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8775c646be net/tsdial: make dialing to peerapi work in netstack mode
With this, I'm able to send a Taildrop file (using "tailscale file cp")
from a Linux machine running --tun=userspace-networking.

Updates #2179

Change-Id: I4e7a4fb0fbda393e4fb483adb06b74054a02cfd0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick ad3d6e31f0 net/tsdial: move macOS/iOS peerapi sockopt logic from LocalBackend
Change-Id: I812cae027c40c70cdc701427b1a1850cd9bcd60c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c7fb26acdb net/tsdial: also plumb TUN name and monitor into tsdial.Dialer
In prep for moving stuff out of LocalBackend.

Change-Id: I9725aa9c3ebc7275f8c40e040b326483c0340127
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c37af58ea4 net/tsdial: move more weirdo dialing into new tsdial package, plumb
Not done yet, but this move more of the outbound dial special casing
from random packages into tsdial, which aspires to be the one unified
place for all outbound dialing shenanigans.

Then this plumbs it all around, so everybody is ultimately
holding on to the same dialer.

As of this commit, macOS/iOS using an exit node should be able to
reach to the exit node's DoH DNS proxy over peerapi, doing the sockopt
to stay within the Network Extension.

A number of steps remain, including but limited to:

* move a bunch more random dialing stuff

* make netstack-mode tailscaled be able to use exit node's DNS proxy,
  teaching tsdial's resolver to use it when an exit node is in use.

Updates #1713

Change-Id: I1e8ee378f125421c2b816f47bc2c6d913ddcd2f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder 2075c39fd7 net/portmapper: deflake TestPCPIntegration
Logging in goroutines after the test completed
caused data races and panics. Prevent that.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago