Commit Graph

791 Commits (ba4e58f429029d1b8d51967aa71ccf3bf36de278)

Author SHA1 Message Date
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
Andrew Dunham e85613aa2d net/netcheck: don't use a space in the captive portal challenge
The derpers don't allow whitespace in the challenge.

Change-Id: I93a8b073b846b87854fba127b5c1d80db205f658
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2 years ago
Andrew Dunham c2d7940ec0 cmd/tailscaled, net/tstun: add build tags to omit BIRD and TAP
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I7a39f4eeeb583b73ecffaf4c5f086a38e3a53e2e
2 years ago
Brad Fitzpatrick 036334e913 net/netcheck: deflake (maybe) magicsock's TestNewConn
Updates #6207

Change-Id: I51d200d0b42b9a1ef799d0abfc8d4bd871c50cf2
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
Brad Fitzpatrick d57cba8655 net/tshttpproxy: add clientmetrics on Windows proxy lookup paths
To collect some data on how widespread this is and whether there's
any correlation between different versions of Windows, etc.

Updates #4811

Change-Id: I003041d0d7e61d2482acd8155c1a4ed413a2c5c4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick f4ff26f577 types/pad32: delete package
Use Go 1.19's new 64-bit alignment ~hidden feature instead.

Fixes #5356

Change-Id: Ifcbcb115875a7da01df3bc29e9e7feadce5bc956
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
Joe Tsai c21a3c4733
types/netlogtype: new package for network logging types (#6092)
The netlog.Message type is useful to depend on from other packages,
but doing so would transitively cause gvisor and other large packages
to be linked in.

Avoid this problem by moving all network logging types to a single package.

We also update staticcheck to take in:

	003d277bcf

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Andrew Dunham 95f3dd1346 net/interfaces: don't dereference null pointer if no destination/netmask
Fixes #6065

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I7159b8cbb8d5f47c0668cf83e59167f182f1defd
2 years ago
Andrew Dunham ba459aeef5 net/interfaces: don't call GetList in List.ForeachInterface
It looks like this was left by mistake in 4a3e2842.

Change-Id: Ie4e3d5842548cd2e8533b3552298fb1ce9ba761a
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2 years ago
Peter Cai 4597ec1037 net/dnscache: Handle 4-in-6 addresses in DNS responses
On Android, the system resolver can return IPv4 addresses as IPv6-mapped
addresses (i.e. `::ffff:a.b.c.d`). After the switch to `net/netip`
(19008a3), this case is no longer handled and a response like this will
be seen as failure to resolve any IPv4 addresses.

Handle this case by simply calling `Unmap()` on the returned IPs. Fixes #5698.

Signed-off-by: Peter Cai <peter@typeblog.net>
2 years ago
Andrew Dunham 74693793be net/netcheck, tailcfg: track whether OS supports IPv6
We had previously added this to the netcheck report in #5087 but never
copied it into the NetInfo struct. Additionally, add it to log lines so
it's visible to support.

Change-Id: Ib6266f7c6aeb2eb2a28922aeafd950fe1bf5627e
Signed-off-by: Andrew Dunham <andrew@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
Andrew Dunham 223126fe5b cmd/derper, net/netcheck: add challenge/response to generate_204 endpoint
The Lufthansa in-flight wifi generates a synthetic 204 response to the
DERP server's /generate_204 endpoint. This PR adds a basic
challenge/response to the endpoint; something sufficiently complicated
that it's unlikely to be implemented by a captive portal. We can then
check for the expected response to verify whether we're being MITM'd.

Follow-up to #5601

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I94a68c9a16a7be7290200eea6a549b64f02ff48f
2 years ago
Anton Tolchanov d499afac78 net/interfaces: improve default route detection
Instead of treating any interface with a non-ifscope route as a
potential default gateway, now verify that a given route is
actually a default route (0.0.0.0/0 or ::/0).

Fixes #5879

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2 years ago
Anton Tolchanov 9c2ad7086c net/interfaces: deduplicate route table parsing on Darwin and FreeBSD
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2 years ago
Mihai Parparita 9d04ffc782 net/wsconn: add back custom wrapper for turning a websocket.Conn into a net.Conn
We removed it in #4806 in favor of the built-in functionality from the
nhooyr.io/websocket package. However, it has an issue with deadlines
that has not been fixed yet (see nhooyr/websocket#350). Temporarily
go back to using a custom wrapper (using the fix from our fork) so that
derpers will stop closing connections too aggressively.

Updates #5921

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
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
Brad Fitzpatrick 9a264dac01 net/netcheck: fix crash in checkCaptivePortal
If netcheck happens before there's a derpmap.

This seems to only affect Headscale because it doesn't send a derpmap
as early?

Change-Id: I51e0dfca8e40623e04702bc9cc471770ca20d2c2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Joe Tsai 1b4e4cc1e8
wgengine/netlog: new package for traffic flow logging (#5864)
The Logger type managers a logtail.Logger for extracting
statistics from a tstun.Wrapper.
So long as Shutdown is called, it ensures that logtail
and statistic gathering resources are properly cleared up.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Maisem Ali ecf6cdd830 ssh/tailssh: add TestSSHAuthFlow
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Joe Tsai 84e8f25c21
net/tstun: rename statististics method (#5852)
Rename StatisticsEnable as SetStatisticsEnabled to be consistent
with other similarly named methods.

Rename StatisticsExtract as ExtractStatistics to follow
the convention where methods start with a verb.
It was originally named with Statistics as a prefix so that
statistics related methods would sort well in godoc,
but that property no longer holds.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Joe Tsai dd045a3767
net/flowtrack: add json tags to Tuple (#5849)
By convention, JSON serialization uses camelCase.
Specify such names on the Tuple type.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Joe Tsai a73c423c8a
net/tunstats: add Counts.Add (#5848)
The Counts.Add method merges two Counts together.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Joe Tsai 24ebf161e8
net/tstun: instrument Wrapper with statistics gathering (#5847)
If Wrapper.StatisticsEnable is enabled,
then per-connection counters are maintained.
If enabled, Wrapper.StatisticsExtract must be periodically called
otherwise there is unbounded memory growth.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Joe Tsai 2934c5114c
net/tunstats: new package to track per-connection counters (#5818)
High-level API:

	type Statistics struct { ... }
	type Counts struct { TxPackets, TxBytes, RxPackets, RxBytes uint64 }
	func (*Statistics) UpdateTx([]byte)
	func (*Statistics) UpdateRx([]byte)
	func (*Statistics) Extract() map[flowtrack.Tuple]Counts

The API accepts a []byte instead of a packet.Parsed so that a future
implementation can directly hash the address and port bytes,
which are contiguous in most IP packets.
This will be useful for a custom concurrent-safe hashmap implementation.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
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
Emmanuel T Odeke f981b1d9da all: fix resource leaks with missing .Close() calls
Fixes #5706

Signed-off-by: Emmanuel T Odeke <emmanuel@orijtech.com>
2 years ago
Andrew Dunham b1867457a6
doctor: add package for running in-depth healthchecks; use in bugreport (#5413)
Change-Id: Iaa4e5b021a545447f319cfe8b3da2bd3e5e5782b
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
James Tucker f7cb535693 net/speedtest: retune to meet iperf on localhost in a VM
- removed some in-flow time calls
- increase buffer size to 2MB to overcome syscall cost
- move relative time computation from record to report time

Signed-off-by: James Tucker <james@tailscale.com>
2 years ago
James Tucker 146f51ce76 net/packet: fix filtering of short IPv4 fragments
The fragment offset is an 8 byte offset rather than a byte offset, so
the short packet limit is now in fragment block size in order to compare
with the offset value.

The packet flags are in the first 3 bits of the flags/frags byte, and
so after conversion to a uint16 little endian value they are at the
start, not the end of the value - the mask for extracting "more
fragments" is adjusted to match this byte.

Extremely short fragments less than 80 bytes are dropped, but fragments
over 80 bytes are now accepted.

Fixes #5727

Signed-off-by: James Tucker <james@tailscale.com>
2 years ago
Andrew Dunham c6162c2a94
net/netcheck: add check for captive portal (#5593)
This doesn't change any behaviour for now, other than maybe running a
full netcheck more often. The intent is to start gathering data on
captive portals, and additionally, seeing this in the 'tailscale
netcheck' command should provide a bit of additional information to
users.

Updates #1634

Change-Id: I6ba08f9c584dc0200619fa97f9fde1a319f25c76
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
Denton Gentry 42f1d92ae0 net/netns: implement UseSocketMark for Android.
Build fails on Android:
`../../../../go/pkg/mod/tailscale.com@v1.1.1-0.20220916223019-65c24b6334e9/wgengine/magicsock/magicsock_linux.go:133:12: undefined: netns.UseSocketMark`

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
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
Andrew Dunham cf61070e26
net/dnscache: add better logging to bootstrap DNS path (#5640)
Change-Id: I4cde3a72e06dac18df856a0cfeac10ab7e3a9108
Signed-off-by: Andrew Dunham <andrew@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
David Anderson 7c49db02a2 wgengine/magicsock: don't use BPF receive when SO_MARK doesn't work.
Fixes #5607

Signed-off-by: David Anderson <danderson@tailscale.com>
2 years ago
Brad Fitzpatrick 024257ef5a net/stun: unmap IPv4 addresses in 16 byte STUN replies
Updates #5602

Change-Id: I2276ad2bfb415b9ff52f37444f2a1d74b38543b1
Signed-off-by: Brad Fitzpatrick <bradfitz@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 81bc4992f2 net/netns: add TS_FORCE_LINUX_BIND_TO_DEVICE for Linux
For debugging a macOS-specific magicsock issue. macOS runs in
bind-to-interface mode always. This lets me force Linux into the same
mode as macOS, even if the Linux kernel supports SO_MARK, as it
usually does.

Updates #2331 etc

Change-Id: Iac9e4a7429c1781337e716ffc914443b7aa2869d
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
Andrew Dunham f52a659076
net/dnsfallback: allow setting log function (#5550)
This broke a test in corp that enforces we don't use the log package.

Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2 years ago
Andrew Dunham b8596f2a2f
net/dnsfallback: cache most recent DERP map on disk (#5545)
This is especially helpful as we launch newer DERPs over time, and older
clients have progressively out-of-date static DERP maps baked in. After
this, as long as the client has successfully connected once, it'll cache
the most recent DERP map it knows about.

Resolves an in-code comment from @bradfitz

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
Kris Brandow 19008a3023 net/dnscache: use net/netip
Removes usage of net.IP and net.IPAddr where possible from net/dnscache.

Fixes #5282

Signed-off-by: Kris Brandow <kris.brandow@gmail.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
Kris Brandow 9ae1161e85 net/dnscache: fix v4addrs to return only v4 addrs
Update the v4addrs function to filter out IPv6 addresses.

Fixes regression from 8725b14056.

Signed-off-by: Kris Brandow <kris.brandow@gmail.com>
2 years ago
Kris Brandow 8f38afbf8e net/stun: convert to use net/netip.AddrPort
Convert ParseResponse and Response to use netip.AddrPort instead of
net.IP and separate port.

Fixes #5281

Signed-off-by: Kris Brandow <kris.brandow@gmail.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
Andrew Dunham d942a2ff56
net/dnscache: try IPv6 addresses first (#5349)
Signed-off-by: Andrew Dunham <andrew@tailscale.com>

Signed-off-by: Andrew Dunham <andrew@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
Brad Fitzpatrick ec9d13bce5 hostinfo, net/netcheck: use CutPrefix
Updates #5309

Change-Id: I37e594cfd245784bf810c493de68a66d3ff20677
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 18109c63b0 net/socks5: use new Go 1.19 binary.AppendByteOrder.AppendUintX
Updates #4872

Change-Id: I43db63d2ba237324bc1cd87d4261197f14cb1088
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Andrew Dunham f0d6f173c9
net/netcheck: try ICMP if UDP is blocked (#5056)
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
Maisem Ali a9f6cd41fd all: use syncs.AtomicValue
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 4950fe60bd syncs, all: move to using Go's new atomic types instead of ours
Fixes #5185

Change-Id: I850dd532559af78c3895e2924f8237ccc328449d
Signed-off-by: Brad Fitzpatrick <bradfitz@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 5381437664 logtail, net/portmapper, wgengine/magicsock: use fmt.Appendf
Fixes #5206

Change-Id: I490bb92e774ce7c044040537e2cd864fcf1dbe5a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 5f6abcfa6f all: migrate code from netaddr.FromStdAddr to Go 1.18
With caveat https://github.com/golang/go/issues/53607#issuecomment-1203466984
that then requires a new wrapper. But a simpler one at least.

Updates #5162

Change-Id: I0a5265065bfcd7f21e8dd65b2bd74cae90d76090
Signed-off-by: Brad Fitzpatrick <bradfitz@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
Aaron Klotz 4dbdb19c26 net/tshttpproxy: fix incorrect type in Windows implementation, switch to mkwinsyscall, fix memory leak
The definition of winHTTPProxyInfo was using the wrong type (uint16 vs uint32)
for its first field. I fixed that type.

Furthermore, any UTF16 strings returned in that structure must be explicitly
freed. I added code to do this.

Finally, since this is the second time I've seen type safety errors in this code,
I switched the native API calls over to use wrappers generated by mkwinsyscall.
I know that would not have helped prevent the previous two problems, but every
bit helps IMHO.

Updates https://github.com/tailscale/tailscale/issues/4811

Signed-off-by: Aaron Klotz <aaron@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
Maisem Ali 9514ed33d2 go.mod: bump gvisor.dev/gvisor
Pick up https://github.com/google/gvisor/pull/7787

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
David Anderson c1cb3efbba net/netcheck: test for OS IPv6 support as well as connectivity.
This lets us distinguish "no IPv6 because the device's ISP doesn't
offer IPv6" from "IPv6 is unavailable/disabled in the OS".

Signed-off-by: David Anderson <danderson@tailscale.com>
2 years ago
Brad Fitzpatrick 0d52674a84 net/tstun: diagnose /dev/net/tun fd leak, give better failure message
Updates #5029

Change-Id: Ibee5e0c9076fe764eb5d856d5ef8b09f4d0e2921
Signed-off-by: Brad Fitzpatrick <bradfitz@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
Tom DNetto d6817d0f22 net/dns/resolver: respond with SERVFAIL if all upstreams fail
Fixes #4722

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Mihai Parparita ec649e707f ipn/ipnlocal: prefer to use one CGNAT route on the Mac
Together with 06aa141632 this minimizes
the number of NEPacketTunnelNetworkSettings updates that we have to do,
and thus avoids Chrome interrupting outstanding requests due to
(perceived) network changes.

Updates #3102

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Brad Fitzpatrick aa37aece9c ipn/ipnlocal, net/dns*, util/cloudenv: add AWS DNS support
And remove the GCP special-casing from ipn/ipnlocal; do it only in the
forwarder for *.internal.

Fixes #4980
Fixes #4981

Change-Id: I5c481e96d91f3d51d274a80fbd37c38f16dfa5cb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 88c2afd1e3 ipn/ipnlocal, net/dns*, util/cloudenv: specialize DNS config on Google Cloud
This does three things:

* If you're on GCP, it adds a *.internal DNS split route to the
  metadata server, so we never break GCP DNS names. This lets people
  have some Tailscale nodes on GCP and some not (e.g. laptops at home)
  without having to add a Tailnet-wide *.internal DNS route.
  If you already have such a route, though, it won't overwrite it.

* If the 100.100.100.100 DNS forwarder has nowhere to forward to,
  it forwards it to the GCP metadata IP, which forwards to 8.8.8.8.
  This means there are never errNoUpstreams ("upstream nameservers not set")
  errors on GCP due to e.g. mangled /etc/resolv.conf (GCP default VMs
  don't have systemd-resolved, so it's likely a DNS supremacy fight)

* makes the DNS fallback mechanism use the GCP metadata IP as a
  fallback before our hosted HTTP-based fallbacks

I created a default GCP VM from their web wizard. It has no
systemd-resolved.

I then made its /etc/resolv.conf be empty and deleted its GCP
hostnames in /etc/hosts.

I then logged in to a tailnet with no global DNS settings.

With this, tailscaled writes /etc/resolv.conf (direct mode, as no
systemd-resolved) and sets it to 100.100.100.100, which then has
regular DNS via the metadata IP and *.internal DNS via the metadata IP
as well. If the tailnet configures explicit DNS servers, those are used
instead, except for *.internal.

This also adds a new util/cloudenv package based on version/distro
where the cloud type is only detected once. We'll likely expand it in
the future for other clouds, doing variants of this change for other
popular cloud environments.

Fixes #4911

RELNOTES=Google Cloud DNS improvements

Change-Id: I19f3c2075983669b2b2c0f29a548da8de373c7cf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Denton Gentry d7f452c0a1 net/portmapper: send discovery packet for IGD specifically.
There appear to be devices out there which send only their
first descriptor in response to a discovery packet for
`ssdp:all`, for example the Sagemcom FAST3890V3 only sends
urn:schemas-wifialliance-org:device:WFADevice:1

Send both ssdp:all and a discovery frame for
InternetGatewayDevice specifically.

Updates https://github.com/tailscale/tailscale/issues/3557

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2 years ago
Denton Gentry 09eaba91ad net/portmap: add a test for Sagemcom FAST3890V3.
Updates https://github.com/tailscale/tailscale/issues/3557

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2 years ago
Denton Gentry b5553c6ad2 net/portmap: run go fmt
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2 years ago
Denton Gentry de4c635e54 net/portmapper: make pcpCodeNotAuthorized log more descriptive
If PCP is present but disabled, turning it on might help
get direct connections.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2 years ago
Aaron Klotz 4baf34cf25 net/dns: set appropriate Windows registry values to prevent it from sending DNS changes concerning our interface to AD domain controllers.
We do this unconditionally inside SetDNS such that the values are always set
before we make any other changes to DNS configurations.

It should not be harmful for the settings to remain even when other DNS
settings are cleared out (since they only affect our network interface).

See https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/configure-dns-dynamic-updates-windows-server-2003 for details about the registry value.

Fixes https://github.com/tailscale/tailscale/issues/4829

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Aaron Klotz 8cdfd12977 net/dns: update Windows split DNS settings to work alongside other NRPT entries set by group policy.
When there are group policy entries for the NRPT that do not belong to Tailscale,
we recognize that we need to add ourselves to group policy and use that registry
key instead of the local one. We also refresh the group policy settings as
necessary to ensure that our changes take effect immediately.

Fixes https://github.com/tailscale/tailscale/issues/4607

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Brad Fitzpatrick 13d0b8e6a4 control/controlclient, net/dnscache: use typed singleflight fork
Change-Id: I12be4c5a91ae3a812fe88d9b2d15526fdbb5a921
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Denton Gentry 1392a93445 socks5: add a simple test
Start up a backend service, put a SOCKS5 server in front
of it, and verify that we can get data from the backend via
SOCKS5.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2 years ago
Denton Gentry 7fffddce8e net/portmapper: enable for iOS
In the 1.27 unstable releases we set the min-version to iOS15,
which means we have 50 MBytes of RAM in the Network Extension.
https://tailscale.com/blog/go-linker/

Include the UPnP/NAT-PMP/PCP portmapper support now that there
is memory for it.

Fixes https://github.com/tailscale/tailscale/issues/2495
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2 years ago
Mihai Parparita edc90ebc61 net/wsconn: remove homegrown wrapper for turning a websocket.Conn into a net.Conn
The one from the nhooyr/websocket package seems to work equally well.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Mihai Parparita 27a1ad6a70
wasm: exclude code that's not used on iOS for Wasm too
It has similar size constraints. Saves ~1.9MB from the Wasm build.

Updates #3157

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
3 years ago
Mihai Parparita a9f32656f5 control/controlhttp: allow client and server to communicate over WebSockets
We can't do Noise-over-HTTP in Wasm/JS (because we don't have bidirectional
communication), but we should be able to do it over WebSockets. Reuses
derp WebSocket support that allows us to turn a WebSocket connection
into a net.Conn.

Updates #3157

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
3 years ago
Maisem Ali 80157f3f37 net/dns/resolver: add support for <IPv4>.via-<site-id>
Currently we only support "via-<site-id>.<IPv4>", however that does not
work with Google Chrome which parses `http://via-1.10.0.0.1` as a search
string and not as a URL. This commit introduces "<IPv4>.via-<site-id>"
(`http://10.0.0.1.via-1`) which is parsed correctly by Chrome.

Updates #3616

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick 1336fb740b wgengine/netstack: make netstack MTU be 1280 also
Updates #3878

Change-Id: I1850085b32c8a40d85607b4ad433622c97d96a8d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaron Klotz b005b79236 net/dns, paths, util/winutil: change net/dns/windowsManager NRPT management to support more than 50 domains.
AFAICT this isn't documented on MSDN, but based on the issue referenced below,
NRPT rules are not working when a rule specifies > 50 domains.

This patch modifies our NRPT rule generator to split the list of domains
into chunks as necessary, and write a separate rule for each chunk.

For compatibility reasons, we continue to use the hard-coded rule ID, but
as additional rules are required, we generate new GUIDs. Those GUIDs are
stored under the Tailscale registry path so that we know which rules are ours.

I made some changes to winutils to add additional helper functions in support
of both the code and its test: I added additional registry accessors, and also
moved some token accessors from paths to util/winutil.

Fixes https://github.com/tailscale/coral/issues/63

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
3 years ago
Tom acfe5bd33b
net/dns{., resolver}: time out DNS queries after 10 seconds (#4690)
Fixes https://github.com/tailscale/corp/issues/5198

The upstream forwarder will block indefinitely on `udpconn.ReadFrom` if no
reply is recieved, due to the lack of deadline on the connection object.

There still isn't a deadline on the connection object, but the automatic closing
of the context on deadline expiry will close the connection via `closeOnCtxDone`,
unblocking the read and resulting in a normal teardown.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Mihai Parparita 86069874c9 net/tstun, wgengine: use correct type for counter metrics
We were marking them as gauges, but they are only ever incremented,
thus counter is more appropriate.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
3 years ago
Maisem Ali fd99c54e10 tailcfg,all: change structs to []*dnstype.Resolver
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Tom d1d6ab068e
net/dns, wgengine: implement DNS over TCP (#4598)
* net/dns, wgengine: implement DNS over TCP

Signed-off-by: Tom DNetto <tom@tailscale.com>

* wgengine/netstack: intercept only relevant port/protocols to quad-100

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
James Tucker f9e86e64b7 *: use WireGuard where logged, printed or named
Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
James Tucker ae483d3446 wgengine, net/packet, cmd/tailscale: add ICMP echo
Updates tailscale/corp#754

Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Tom DNetto 2a0b5c21d2 net/dns/{., resolver}, wgengine: fix goroutine leak on shutdown
Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Tom DNetto 7f45734663 assorted: documentation and readability fixes
This were intended to be pushed to #4408, but in my excitement I
forgot to git push :/ better late than never.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Tom DNetto 9e77660931 net/tstun,wgengine/{.,netstack}: handle UDP magicDNS traffic in netstack
This change wires netstack with a hook for traffic coming from the host
into the tun, allowing interception and handling of traffic to quad-100.

With this hook wired, magicDNS queries over UDP are now handled within
netstack. The existing logic in wgengine to handle magicDNS remains for now,
but its hook operates after the netstack hook so the netstack implementation
takes precedence. This is done in case we need to support platforms with
netstack longer than expected.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Tom DNetto dc71d3559f net/tstun,wgengine: split PreFilterOut into multiple hooks
A subsequent commit implements handling of magicDNS traffic via netstack.
Implementing this requires a hook for traffic originating from the host and
hitting the tun, so we make another hook to support this.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Tom DNetto 5b85f848dd net/dns,net/dns/resolver: refactor channels/magicDNS out of Resolver
Moves magicDNS-specific handling out of Resolver & into dns.Manager. This
greatly simplifies the Resolver to solely issuing queries and returning
responses, without channels.

Enforcement of max number of in-flight magicDNS queries, assembly of
synthetic UDP datagrams, and integration with wgengine for
recieving/responding to magicDNS traffic is now entirely in Manager.
This path is being kept around, but ultimately aims to be deleted and
replaced with a netstack-based path.

This commit is part of a series to implement magicDNS using netstack.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Brad Fitzpatrick 6bed781259 all: gofmt all
Well, goimports actually (which adds the normal import grouping order we do)

Change-Id: I0ce1b1c03185f3741aad67c14a7ec91a838de389
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
James Tucker 96fec4b969 net/tshttpproxy: synology: pick proxy by scheme
This updates the fix from #4562 to pick the proxy based on the request
scheme.

Updates #4395, #2605, #4562
Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Maisem Ali eff6a404a6 net/tshttpproxy: use http as the scheme for proxies
Currently we try to use `https://` when we see `https_host`, however
that doesn't work and results in errors like `Received error: fetch
control key: Get "https://controlplane.tailscale.com/key?v=32":
proxyconnect tcp: tls: first record does not look like a TLS handshake`

This indiciates that we are trying to do a HTTPS request to a HTTP
server. Googling suggests that the standard is to use `http` regardless
of `https` or `http` proxy

Updates #4395, #2605

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali 5a1ef1bbb9 net/tsdial: add SystemDial as a wrapper on netns.Dial
The connections returned from SystemDial are automatically closed when
there is a major link change.

Also plumb through the dialer to the noise client so that connections
are auto-reset when moving from cellular to WiFi etc.

Updates #3363

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick c6c752cf64 net/tshttpproxy: fix typo
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Tom DNetto 5fb8e01a8b net/dns/resolver: add metric for number of truncated dns packets
Updates #2067

This should help us determine if more robust control of edns parameters
+ implementing answer truncation is warranted, given its likely complexity.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Brad Fitzpatrick e97209c6bf net/dns: add tailscaled-on-macOS DNS OSConfigurator
This populates DNS suffixes ("ts.net", etc) in /etc/resolver/* files
to point to 100.100.100.100 so MagicDNS works.

It also sets search domains.

Updates #4276

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Tom DNetto 78fededaa5 net/dns/resolver: support magic resolution of via-<siteid>.<ip4> domains
Updates #3616

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
James Tucker 700bd37730 tshttpproxy: support synology proxy configuration
Fixes #4395
Fixes #2605

Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Tom DNetto df26c63793 net/dns/resolver, net/tsaddr: fix reverse lookups in 4to6 IP range
Fixes #4439

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Brad Fitzpatrick d413850bd7 cmd/tailscale: add "debug via" subcommand to do CIDR math for via ranges
$ tailscale debug via 0xb 10.2.0.0/16
fd7a:115c:a1e0:b1a:0🅱️a02:0/112
$ tailscale debug via fd7a:115c:a1e0:b1a:0🅱️a02:0/112
site 11 (0xb), 10.2.0.0/16

Previously: 3ae701f0eb

This adds a little debug tool to do CIDR math to make converting between
those ranges easier for now.

Updates #3616

Change-Id: I98302e95d17765bfaced3ecbb71cbd43e84bff46
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Tom DNetto c8f4dfc8c0 derp/derphttp,net/netcheck: improve netcheck behavior under MITM proxies
In cases where tailscale is operating behind a MITM proxy, we need to consider
that a lot more of the internals of our HTTP requests are visible and may be
used as part of authorization checks. As such, we need to 'behave' as closely
as possible to ideal.

 - Some proxies do authorization or consistency checks based the on Host header
   or HTTP URI, instead of just the IP/hostname/SNI. As such, we need to
   construct a `*http.Request` with a valid URI everytime HTTP is going to be
   used on the wire, even if its over TLS.
   Aside from the singular instance in net/netcheck, I couldn't find anywhere
   else a http.Request was constructed incorrectly.

 - Some proxies may deny requests, typically by returning a 403 status code. We
   should not consider these requests as a valid latency check, so netcheck
   semantics have been updated to consider >299 status codes as a failed probe.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Brad Fitzpatrick cc575fe4d6 net/dns: schedule DoH upgrade explicitly, fix Resolver.Addr confusion
Two changes in one:

* make DoH upgrades an explicitly scheduled send earlier, when we come
  up with the resolvers-and-delay send plan. Previously we were
  getting e.g.  four Google DNS IPs and then spreading them out in
  time (for back when we only did UDP) but then later we added DoH
  upgrading at the UDP packet layer, which resulted in sometimes
  multiple DoH queries to the same provider running (each doing happy
  eyeballs dialing to 4x IPs themselves) for each of the 4 source IPs.
  Instead, take those 4 Google/Cloudflare IPs and schedule 5 things:
  first the DoH query (which can use all 4 IPs), and then each of the
  4 IPs as UDP later.

* clean up the dnstype.Resolver.Addr confusion; half the code was
  using it as an IP string (as documented) as half was using it as
  an IP:port (from some prior type we used), primarily for tests.
  Instead, document it was being primarily an IP string but also
  accepting an IP:port for tests, then add an accessor method on it
  to get the IPPort and use that consistently everywhere.

Change-Id: Ifdd72b9e45433a5b9c029194d50db2b9f9217b53
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick e3a4952527 net/dns/resolver: count errors when racing DNS queries, fail earlier
If all N queries failed, we waited until context timeout (in 5
seconds) to return.

This makes (*forwarder).forward fail fast when the network's
unavailable.

Change-Id: Ibbb3efea7ed34acd3f3b29b5fee00ba8c7492569
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick d9efbd97cb net/dns: remove an unused function
Change-Id: I7c920c76223ffac37954ef2a18754afc52177598
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick ecea6cb994 net/dns/resolver: make DoH dialer use existing dnscache happy eyeball dialer
Simplify the ability to reason about the DoH dialing code by reusing the
dnscache's dialer we already have.

Also, reduce the scope of the "ip" variable we don't want to close over.

This necessarily adds a new field to dnscache.Resolver:
SingleHostStaticResult, for when the caller already knows the IPs to be
returned.

Change-Id: I9f2aef7926f649137a5a3e63eebad6a3fffa48c0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick f4f76eb275 net/dnsfallback: update from 'go generate'
Change-Id: I93e0e6d9a4a471953c1ffef07f32605c5724aed8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
phirework 52d32c94d8
net/dns/publicdns: add missing call to sync.Once.Do (#4410)
Signed-off-by: Jenny Zhang <jz@tailscale.com>
3 years ago
phirework 83c734a6e0
net/dns, util/publicdns: extract public DNS mapping into own package (#4405)
This extracts DOH mapping of known public DNS providers in
forwarder.go into its own package, to be consumed by other repos

Signed-off-by: Jenny Zhang <jz@tailscale.com>
3 years ago
Brad Fitzpatrick a49d8d5200 Revert ".github/workflows: work around golang/go#51629"
This reverts commit 2a412ac9ee.

Updates #4194

Change-Id: I0098b66b71d20bea301ca79058c1cdd201237dd0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3ae701f0eb net/tsaddr, wgengine/netstack: add IPv6 range that forwards to site-relative IPv4
This defines a new magic IPv6 prefix, fd7a:115c:a1e0:b1a::/64, a
subset of our existing /48, where the final 32 bits are an IPv4
address, and the middle 32 bits are a user-chosen "site ID". (which
must currently be 0000:00xx; the top 3 bytes must be zero for now)

e.g., I can say my home LAN's "site ID" is "0000:00bb" and then
advertise its 10.2.0.0/16 IPv4 range via IPv6, like:

    tailscale up --advertise-routes=fd7a:115c:a1e0:b1a::bb:10.2.0.0/112

(112 being /128 minuse the /96 v6 prefix length)

Then people in my tailnet can:

     $ curl '[fd7a:115c:a1e0:b1a::bb:10.2.0.230]'
     <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ....

Updates #3616, etc

RELNOTE=initial support for TS IPv6 addresses to route v4 "via" specific nodes

Change-Id: I9b49b6ad10410a24b5866b9fbc69d3cae1f600ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Tom 24bdcbe5c7
net/dns, net/dns/resolver, wgengine: refactor DNS request path (#4364)
* 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>
3 years ago
Tom 6be7931eb4
net/dns/resolver: return symbolic PTR records for TS service IPs (#4361)
Fixes #1233

Signed-off-by: Tom DNetto <tom@tailscale.com>

Co-authored-by: Tom DNetto <tom@tailscale.com>
3 years ago
Maisem Ali 309ddef852
net/netutil: add CheckIPForwardingLinux (#4301)
Combine the code between `LocalBackend.CheckIPForwarding` and
`controlclient.ipForwardingBroken`.

Fixes #4300

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick e4d8d5e78b net/packet, wgengine/netstack: remove workaround for old gvisor ECN bug
Fixes #2642

Change-Id: Ic02251d24a4109679645d1c8336e0f961d0cce13
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 753f1bfad4 cmd/tailscale: write fewer known_hosts, resolve ssh host to FQDN early
Updates #3802

Change-Id: Ic44fa2e6661a9c046e725c04fa6b8213d3d4d2b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali b2f269d5b7 net/dnsfallback: do not attempt lookups of IPs.
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>
3 years ago
Maisem Ali b45bb577a0 net/dnscache: do not call LookupIPFallback if the context was canceled.
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>
3 years ago
Brad Fitzpatrick b647977b33 net/netutil: move some net utils from control/controlhttp to netutil
In prep for reuse elsewhere.

Change-Id: I1b804edf76ac66b9108e6f434e77eab7a7472d69
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
James Tucker 445c04c938
wgengine: inject packetbuffers rather than bytes (#4220)
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>
3 years ago
Brad Fitzpatrick f2041c9088 all: use strings.Cut even more
Change-Id: I943ce72c6f339589235bddbe10d07799c4e37979
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaron Klotz 6e91f872af net/tshttpproxy: ensure we pass the correct flags to WinHttpOpen on Win7 and Win8.0
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>
3 years ago
David Anderson 2a412ac9ee .github/workflows: work around golang/go#51629
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>
3 years ago