Commit Graph

281 Commits (be67b8e75b9bedb28fc8502c9295fb5f4b3fbb5f)

Author SHA1 Message Date
Tom DNetto 673b3d8dbd net/dns,userspace: remove unused DNS paths, normalize query limit on iOS
With a42a594bb3, iOS uses netstack and
hence there are no longer any platforms which use the legacy MagicDNS path. As such, we remove it.

We also normalize the limit for max in-flight DNS queries on iOS (it was 64, now its 256 as per other platforms).
It was 64 for the sake of being cautious about memory, but now we have 50Mb (iOS-15 and greater) instead of 15Mb
so we have the spare headroom.

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick ea70aa3d98 net/dns/resolvconffile: fix handling of multiple search domains
Fixes #6875

Change-Id: I57eb9312c9a1c81792ce2b5a0a0f254213b05df2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Andrew Dunham 0372e14d79 net/dns: bump DNS-over-TCP size limit to 4k
We saw a few cases where we hit this limit; bumping to 4k seems
relatively uncontroversial.

Change-Id: I218fee3bc0d2fa5fde16eddc36497a73ebd7cbda
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
Andrew Dunham 3f4d51c588 net/dns: don't send on closed channel when message too large
Previously, if a DNS-over-TCP message was received while there were
existing queries in-flight, and it was over the size limit, we'd close
the 'responses' channel. This would cause those in-flight queries to
send on the closed channel and panic.

Instead, don't close the channel at all and rely on s.ctx being
canceled, which will ensure that in-flight queries don't hang.

Fixes #6725

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8267728ac37ed7ae38ddd09ce2633a5824320097
2 years ago
Brad Fitzpatrick ca08e316af util/endian: delete package; use updated josharian/native instead
See josharian/native#3

Updates golang/go#57237

Change-Id: I238c04c6654e5b9e7d9cfb81a7bbc5e1043a84a2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 99aa335923 net/dns: [linux] log and add metric for dnsMode
I couldn't find any logs that indicated which mode it was running in so adding that.
Also added a gauge metric for dnsMode.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Andrew Dunham ec790e58df net/dns: retry overwriting hosts file on Windows
Updates #5753

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I60f81bd3325d5ba5383b947c7a7aaa5b14e460f6
2 years ago
Mihai Parparita 33520920c3 all: use strs.CutPrefix and strs.CutSuffix more
Updates places where we use HasPrefix + TrimPrefix to use the combined
function.

Updates #5309

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Aaron Klotz 41e1d336cc net/dns: change windows DNS manager to use pointer receiver
This is safer given that we need to close the NRPT database.

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Brad Fitzpatrick 90bd74fc05 net/dns: add a health warning when Linux /etc/resolv.conf is overwritten
Change-Id: I925b4d904bc7ed920bc5afee11e6dcb2ffc2fbfd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 001f482aca net/dns: make "direct" mode on Linux warn on resolv.conf fights
Run an inotify goroutine and watch if another program takes over
/etc/inotify.conf. Log if so.

For now this only logs. In the future I want to wire it up into the
health system to warn (visible in "tailscale status", etc) about the
situation, with a short URL to more info about how you should really
be using systemd-resolved if you want programs to not fight over your
DNS files on Linux.

Updates #4254 etc etc

Change-Id: I86ad9125717d266d0e3822d4d847d88da6a0daaa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 66b4a363bd net/dns/resolver: add yet another 4via6 DNS form that's hopefully more robust
$ dig +short @100.100.100.100 aaaa 10-2-5-3-via-7.foo-bar.ts.net
fd7a:115c:a1e0:b1a:0:7:a02:503

$ dig +short @100.100.100.100 aaaa 10-2-5-3-via-7
fd7a:115c:a1e0:b1a:0:7:a02:503

$ ping 10-2-5-3-via-7
PING 10-2-5-3-via-7(fd7a:115c:a1e0:b1a:0:7:a02:503 (fd7a:115c:a1e0:b1a:0:7:a02:503)) 56 data bytes
...

Change-Id: Ice8f954518a6a2fca8b2c04da7f31f61d78cdec4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick da8def8e13 all: remove old +build tags
The //go:build syntax was introduced in Go 1.17:

https://go.dev/doc/go1.17#build-lines

gofmt has kept the +build and go:build lines in sync since
then, but enough time has passed. Time to remove them.

Done with:

    perl -i -npe 's,^// \+build.*\n,,' $(git grep -l -F '+build')

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Anton Tolchanov e25ab75795 net/dns: getting base DNS config is not supported on macOS
Instead of returning a custom error, use ErrGetBaseConfigNotSupported
that seems to be intended for this use case. This fixes DNS resolution
on macOS clients compiled from source.

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2 years ago
Andrew Dunham e966f024b0 net/dns: print systemd-resolved ResolvConfMode
The ResolvConfMode property is documented to return how systemd-resolved
is currently managing /etc/resolv.conf. Include that information in the
debug line, when available, to assist in debugging DNS issues.

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1ae3a257df1d318d0193a8c7f135c458ec45093e
2 years ago
Maisem Ali 3555a49518 net/dns: always attempt to read the OS config on macOS/iOS
Also reconfigure DNS on iOS/macOS on link changes.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Mihai Parparita 8343b243e7 all: consistently initialize Logf when creating tsdial.Dialers
Most visible when using tsnet.Server, but could have resulted in dropped
messages in a few other places too.

Fixes #5743

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Josh Soref d4811f11a0 all: fix spelling mistakes
Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>
2 years ago
Brad Fitzpatrick bb7be74756 net/dns/publicdns: permit more NextDNS profile bits in its IPv6 suffix
I brain-o'ed the math earlier. The NextDNS prefix is /32 (actually
/33, but will guarantee last bit is 0), so we have 128-32 = 96 bits
(12 bytes) of config/profile ID that we can extract. NextDNS doesn't
currently use all those, but might.

Updates #2452

Change-Id: I249bd28500c781e45425fd00fd3f46893ae226a2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Andrew Dunham a5fab23e8f
net/dns: format OSConfig correctly with no pointers (#5766)
Fixes tailscale/tailscale#5669

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
Eng Zer Jun f0347e841f refactor: move from io/ioutil to io and os packages
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.

Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
2 years ago
Brad Fitzpatrick 74674b110d envknob: support changing envknobs post-init
Updates #5114

Change-Id: Ia423fc7486e1b3f3180a26308278be0086fae49b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Mihai Parparita 82e82d9b7a net/dns/resolver: remove unused responseTimeout constant
Timeout is now enforced elsewhere, see discussion in https://github.com/tailscale/tailscale/pull/4408#discussion_r970092333.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
nyghtowl 0f16640546 net/dns: fix fmt error on Revert print
Fixes #5619

Signed-off-by: nyghtowl <warrick@tailscale.com>
2 years ago
Brad Fitzpatrick 708b7bff3d net/dns/publicdns: also support NextDNS DoH query parameters
The plan has changed. Doing query parameters rather than path +
heades. NextDNS added support for query parameters.

Updates #2452

Change-Id: I4783c0a06d6af90756d9c80a7512644ba702388c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick e7376aca25 net/dns/resolver: set DNS-over-HTTPS Accept and User-Agent header on requests
Change-Id: I14b821771681e70405a507f43229c694159265ff
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick c14361e70e net/dns/publicdns: support NextDNS DoH URLs with path parameters
Updates #2452

Change-Id: I0f1c34cc1672e87e7efd0adfe4088724dd0de3ed
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 2aade349fc net/dns, types/dnstypes: update some comments, tests for DoH
Clarify & verify that some DoH URLs can be sent over tailcfg
in some limited cases.

Updates #2452

Change-Id: Ibb25db77788629c315dc26285a1059a763989e24
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 58abae1f83 net/dns/{publicdns,resolver}: add NextDNS DoH support
NextDNS is unique in that users create accounts and then get
user-specific DNS IPs & DoH URLs.

For DoH, the customer ID is in the URL path.

For IPv6, the IP address includes the customer ID in the lower bits.

For IPv4, there's a fragile "IP linking" mechanism to associate your
public IPv4 with an assigned NextDNS IPv4 and that tuple maps to your
customer ID.

We don't use the IP linking mechanism.

Instead, NextDNS is DoH-only. Which means using NextDNS necessarily
shunts all DNS traffic through 100.100.100.100 (programming the OS to
use 100.100.100.100 as the global resolver) because operating systems
can't usually do DoH themselves.

Once it's in Tailscale's DoH client, we then connect out to the known
NextDNS IPv4/IPv6 anycast addresses.

If the control plane sends the client a NextDNS IPv6 address, we then
map it to the corresponding NextDNS DoH with the same client ID, and
we dial that DoH server using the combination of v4/v6 anycast IPs.

Updates #2452

Change-Id: I3439d798d21d5fc9df5a2701839910f5bef85463
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 9bd9f37d29 go.mod: bump wireguard/windows, which moves to using net/netip
Updates #5162

Change-Id: If99a3f0000bce0c01bdf44da1d513f236fd7cdf8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 9f6c8517e0 net/dns: set OS DNS to 100.100.100.100 for route-less ExtraRecords [cap 41]
If ExtraRecords (Hosts) are specified without a corresponding split
DNS route and global DNS is specified, then program the host OS DNS to
use 100.100.100.100 so it can blend in those ExtraRecords.

Updates #1543

Change-Id: If49014a5ecc8e38978ff26e54d1f74fe8dbbb9bc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 68d9d161f4 net/dns: [win] fix regression in disableDynamicUpdate
Somehow I accidentally set the wrong registry value here.
It should be DisableDynamicUpdate=1 and not EnableDNSUpdate=0.

This is a regression from 545639e.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Nahum Shalman 214242ff62 net/dns/publicdns: Add Mullvad DoH
See https://mullvad.net/en/help/dns-over-https-and-dns-over-tls/

The Mullvad DoH servers appear to only speak HTTP/2 and
the use of a non-nil DialContext in the http.Transport
means that ForceAttemptHTTP2 must be set to true to be
able to use them.

Signed-off-by: Nahum Shalman <nahamu@gmail.com>
2 years ago
Maisem Ali 9197dd14cc net/dns: [win] add MagicDNS entries to etc/hosts
This works around the 2.3s delay in short name lookups when SNR is
enabled.
C:\Windows\System32\drivers\etc\hosts file. We only add known hosts that
match the search domains, and we populate the list in order of
Search Domains so that our matching algorithm mimics what Windows would
otherwise do itself if SNR was off.

Updates #1659

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 25865f81ee net/dns: disable NetBIOS on Tailscale interfaces
Like LLMNR, NetBIOS also adds resolution delays and we don't support it
anyway so just disable it on the interface.

Updates #1659

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 545639ee44 util/winutil: consolidate interface specific registry keys
Code movement to allow reuse in a follow up PR.

Updates #1659

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 1cff719015 net/dns: [win] respond with SERVFAIL queries when no resolvers
Currently we forward unmatched queries to the default resolver on
Windows. This results in duplicate queries being issued to the same
resolver which is just wasted.

Updates #1659

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 3bb57504af net/dns/resolver: add comments clarifying nil error returns
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 4497bb0b81 net/dns/resolver: return SERVFAIL when no upstream resolvers set
Otherwise we just keep looping over the same thing again and again.

```
dns udp query: upstream nameservers not set
dns udp query: upstream nameservers not set
dns udp query: upstream nameservers not set
```

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali a9f6cd41fd all: use syncs.AtomicValue
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 9bb5a038e5 all: use atomic.Pointer
Also add some missing docs.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 8725b14056 all: migrate more code code to net/netip directly
Instead of going through the tailscale.com/net/netaddr transitional
wrappers.

Updates #5162

Change-Id: I3dafd1c2effa1a6caa9b7151ecf6edd1a3fda3dd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 116f55ff66 all: gofmt for Go 1.19
Updates #5210

Change-Id: Ib02cd5e43d0a8db60c1f09755a8ac7b140b670be
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
nyghtowl e6e1976c3a net/dns: remove systemd-resolved ping
Ping only needed to ensure system awak otherwise utilizing resolvConf to set dns mode.

Signed-off-by: nyghtowl <warrick@tailscale.com>
2 years ago
Brad Fitzpatrick a12aad6b47 all: convert more code to use net/netip directly
perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.)
    perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. )
    goimports -w .

Then delete some stuff from the net/netaddr shim package which is no
longer neeed.

Updates #5162

Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 6a396731eb all: use various net/netip parse funcs directly
Mechanical change with perl+goimports.

Changed {Must,}Parse{IP,IPPrefix,IPPort} to their netip variants, then
goimports -d .

Finally, removed the net/netaddr wrappers, to prevent future use.

Updates #5162

Change-Id: I59c0e38b5fbca5a935d701645789cddf3d7863ad
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 7eaf5e509f net/netaddr: start migrating to net/netip via new netaddr adapter package
Updates #5162

Change-Id: Id7bdec303b25471f69d542f8ce43805328d56c12
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Aaron Klotz 1cae618b03 net/dns: add Windows group policy notifications to the NRPT rule manager
As discussed in previous PRs, we can register for notifications when group
policies are updated and act accordingly.

This patch changes nrptRuleDatabase to receive notifications that group policy
has changed and automatically move our NRPT rules between the local and
group policy subkeys as needed.

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Melanie Warrick f17873e0f4
net/dns: handle D-Bus restarts in resolved manager (#5026)
When dbus restarts it can cause the tailscaled to crash because the nil
signal was not handled in resolved.Fixing so the nil signal leads to a
connection reset and tailscaled stays connected to systemd when dbus restarted.

Fixes #4645

Co-authored-by: James Tucker <james@tailscale.com>
Signed-off-by: nyghtowl <warrick@tailscale.com>

Co-authored-by: James Tucker <james@tailscale.com>
2 years ago
Andrew Dunham c7993d2b88
net/dns/resolver: add fuzz/unit test for #2533 (#5018)
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago