Commit Graph

1095 Commits (5550a17391f1a8765f7f56831c759ee862b6b434)

Author SHA1 Message Date
Emmanuel T Odeke 0daa32943e all: add (*testing.B).ReportAllocs() to every benchmark
This ensures that we can properly track and catch allocation
slippages that could otherwise have been missed.

Fixes #2748
3 years ago
Brad Fitzpatrick 065c4ffc2c net/dns: add start of Linux newOSConfigurator tests
Only one test case so far.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 09a47ea3f1 net/dns: prep for writing manager_linux tests; pull some stuff out
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3606e68721 net/interfaces: fix default route lookup on Windows
It wasn't using the right metric. Apparently you're supposed to sum the route
metric and interface metric. Whoops.

While here, optimize a few little things too, not that this code
should be too hot.

Fixes #2707 (at least; probably dups but I'm failing to find)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Anderson b49d9bc74d net/portmapper: fix "running a test" condition.
Fixes #2686.

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
slowy07 ac0353e982 fix: typo spelling grammar
Signed-off-by: slowy07 <slowy.arfy@gmail.com>
3 years ago
David Crawshaw 0ac2130590 net/dns: resolveConfExists reading the wrong error
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Brad Fitzpatrick 36ffd509de net/dns: avoid Linux PolicyKit GUI dialog during tests
Fixes #2672

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 1f006025c2 net/tstun: fix build on arm
Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick cd426eaf4c net/portmapper: fix t.Log-after-test-done race in tests
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Matt Layher 8ab44b339e net/tstun: use unix.Ifreq type for Linux TAP interface configuration
Signed-off-by: Matt Layher <mdlayher@gmail.com>
3 years ago
Josh Bleecher Snyder a24cee0d67 all: simplify ts_macext build tags
Now that we have the easier-to-parse go:build build tags,
it is straightforward to simplify them. Yay.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 833200da6f net/tstun: don't exec uname -r on Linux in TUN failure diagnostics
Fixes https://twitter.com/zekjur/status/1425557520513486848

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick e804ab29fd net/tstun: move TUN failure diagnostics to OS-specific files
Mostly so the Linux one can use Linux-specific stuff in package
syscall and not use os/exec for uname for portability.

But also it helps deps a tiny bit on iOS.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
julianknodt b9bd7dbc5d net/portmapper: log upnp information
This logs some basic statistics for UPnP, so that tailscale can better understand what routers
are being used and how to connect to them.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
julianknodt 26b6fe7f02 net/portmapper: add PCP integration test
This adds a PCP test to the IGD test server, by hardcoding in a few observed packets from
Denton's box.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
Brad Fitzpatrick bdb93c5942 net/portmapper: actually test something in TestProbeIntegration
And use dynamic port numbers in tests, as Linux on GitHub Actions and
Windows in general have things running on these ports.

Co-Author: Julian Knodt <julianknodt@gmail.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Adrian Dewhurst 8bdf878832 net/dns/resolver: use forwarded dns txid directly
Previously, we hashed the question and combined it with the original
txid which was useful when concurrent queries were multiplexed on a
single local source port. We encountered some situations where the DNS
server canonicalizes the question in the response (uppercase converted
to lowercase in this case), which resulted in responses that we couldn't
match to the original request due to hash mismatches. This includes a
new test to cover that situation.

Fixes #2597

Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
3 years ago
Brad Fitzpatrick e6d4ab2dd6 net/portmapper: add start of self-contained portmapper integration tests
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
julianknodt 98d36ee18d net/portmapper: add hook for use with prev ip
PCP handles external IPs by allowing the client to specify them in the packet, which is more
explicit than requiring 2 packets from PMP, so allow for future changes to add it in easily.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
julianknodt 85304d7392 net/portmapper: check disable flags
Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
julianknodt 777b711d96 net/portmapper: add pcp portmapping
This adds PCP portmapping, hooking into the existing PMP portmapping.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
julianknodt 5c98b1b8d0 net/portmapper: move pcp code to separate file
This moves all the PCP code to a separate file in preparation for portmapping with PCP.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
Josh Bleecher Snyder a5da4ed981 all: gofmt with Go 1.17
This adds "//go:build" lines and tidies up existing "// +build" lines.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick a729070252 net/tstun: add start of Linux TAP support, with DHCP+ARP server
Still very much a prototype (hard-coded IPs, etc) but should be
non-invasive enough to submit at this point and iterate from here.

Updates #2589

Co-Author: David Crawshaw <crawshaw@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick fdc081c291 net/portmapper: fix UPnP probing, work against all ports
Prior to Tailscale 1.12 it detected UPnP on any port.
Starting with Tailscale 1.11.x, it stopped detecting UPnP on all ports.

Then start plumbing its discovered Location header port number to the
code that was assuming port 5000.

Fixes #2109

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Denton Gentry 260b85458c net/dns: correct log message.
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Brad Fitzpatrick 54e33b511a net/dns/resolver: add test that I forgot to git add earlier
This was meant to be part of 53a2f63658 earlier
but I guess I failed at git.

Updates #2436
Updates tailscale/corp#2250
Updates tailscale/corp#2238

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick be921d1a95 net/dns/resolver: fix skipped DoH test that bitrot
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 5a7ff2b231 net/dnsfallback: re-run go generate 3 years ago
Matt Layher effee49e45 net/interfaces: explicitly check netaddr.IP.Is6 in isUsableV6
Signed-off-by: Matt Layher <mdlayher@gmail.com>
3 years ago
Matt Layher 3ff8a55fa7 net/tsaddr: remove IsULA, replace with netaddr.IP.IsPrivate
Signed-off-by: Matt Layher <mdlayher@gmail.com>
3 years ago
Josh Bleecher Snyder c2202cc27c net/tstun: use mono.Time
There's a call to Now once per packet.
Move to mono.Now.

Though the current implementation provides high precision,
we document it to be coarse, to preserve the ability
to switch to a coarse monotonic time later.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder 881bb8bcdc net/dns/resolver: allow an extra alloc for go closure allocation
Go 1.17 switches to a register ABI on amd64 platforms.
Part of that switch is that go and defer calls use an argument-less
closure, which allocates. This means that we have an extra
alloc in some DNS work. That's unfortunate but not a showstopper,
and I don't see a clear path to fixing it.
The other performance benefits from the register ABI will all
but certainly outweigh this extra alloc.

Fixes #2545

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick b6179b9e83 net/dnsfallback: add new nodes
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Crawshaw f414a9cc01 net/dns/resolver: EDNS OPT record off-by-one
I don't know how to get access to a real packet. Basing this commit
entirely off:

       +------------+--------------+------------------------------+
       | Field Name | Field Type   | Description                  |
       +------------+--------------+------------------------------+
       | NAME       | domain name  | MUST be 0 (root domain)      |
       | TYPE       | u_int16_t    | OPT (41)                     |
       | CLASS      | u_int16_t    | requestor's UDP payload size |
       | TTL        | u_int32_t    | extended RCODE and flags     |
       | RDLEN      | u_int16_t    | length of all RDATA          |
       | RDATA      | octet stream | {attribute,value} pairs      |
       +------------+--------------+------------------------------+

From https://datatracker.ietf.org/doc/html/rfc6891#section-6.1.2

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Josh Bleecher Snyder 1034b17bc7 net/tstun: buffer outbound channel
The handoff between tstun.Wrap's Read and poll methods
is one of the per-packet hotspots. It shows up in pprof.

Making outbound buffered increases throughput.

It is hard to measure exactly how much, because the numbers
are highly variable, but I'd estimate it at about 1%,
using the best observed max throughput across three runs.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder 965dccd4fc net/tstun: buffer outbound channel
The handoff between tstun.Wrap's Read and poll methods
is one of the per-packet hotspots. It shows up in pprof.

Making outbound buffered increases throughput.

It is hard to measure exactly how much, because the numbers
are highly variable, but I'd estimate it at about 1%,
using the best observed max throughput across three runs.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 68df379a7d net/portmapper: rename ErrGatewayNotFound to ErrGatewayRange, reword text
It confused & scared people. And it was just bad.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick aaf2df7ab1 net/{dnscache,interfaces}: use netaddr.IP.IsPrivate, delete copied code
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c17d743886 net/dnscache: update a comment
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 281d503626 net/dnscache: make Dialer try all resolved IPs
Tested manually with:

$ go test -v ./net/dnscache/ -dial-test=bogusplane.dev.tailscale.com:80

Where bogusplane has three A records, only one of which works.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick e299300b48 net/dnscache: cache all IPs per hostname
Not yet used in the dialer, but plumbed around.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 53a2f63658 net/dns/resolver: race well-known resolvers less aggressively
Instead of blasting away at all upstream resolvers at the same time,
make a timing plan upon reconfiguration and have each upstream have an
associated start delay, depending on the overall forwarding config.

So now if you have two or four upstream Google or Cloudflare DNS
servers (e.g. two IPv4 and two IPv6), we now usually only send a
query, not four.

This is especially nice on iOS where we start fewer DoH queries and
thus fewer HTTP/1 requests (because we still disable HTTP/2 on iOS),
fewer sockets, fewer goroutines, and fewer associated HTTP buffers,
etc, saving overall memory burstiness.

Fixes #2436
Updates tailscale/corp#2250
Updates tailscale/corp#2238

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick e94ec448a7 net/dns/resolver: add forwardQuery type as race work prep
Add a place to hang state in a future change for #2436.
For now this just simplifies the send signature without
any functional change.

Updates #2436

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 064b916b1a net/dns/resolver: fix func used as netaddr.IP in printf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 7b295f3d21 net/portmapper: disable UPnP on iOS for now
Updates #2495

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cecfc14875 net/dns: don't build init*.go on non-windows
To remove the regexp dep on iOS, notably.

Updates tailscale/corp#2238

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 2968893add net/dns/resolver: bound DoH usage on iOS
Updates tailscale/corp#2238

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3daf27eaad net/dns/resolver: fall back to IPv6 for well-known DoH servers if v4 fails
Should help with IPv6-only environments when the tailnet admin
only specified IPv4 DNS IPs.

See https://github.com/tailscale/tailscale/issues/2447#issuecomment-884188562

Co-Author: Adrian Dewhurst <adrian@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 74eee4de1c net/dns/resolver: use correct Cloudflare DoH hostnames
We were using the wrong ones for the malware & adult content
variants. Docs:

https://developers.cloudflare.com/1.1.1.1/1.1.1.1-for-families/setup-instructions/dns-over-https

Earlier commit which added them:
236eb4d04d

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
julianknodt 3a4201e773 net/portmapper: return correct upnp port
Previously, this was incorrectly returning the internal port, and using that with the external
exposed IP when it did not use WANIPConnection2. In the case when we must provide a port, we
return it instead.

Noticed this while implementing the integration test for upnp.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
Brad Fitzpatrick e74d37d30f net/dns{,/resolver}: quiet DNS output logging
It was a huge chunk of the overall log output and made debugging
difficult. Omit and summarize the spammy *.arpa parts instead.

Fixes tailscale/corp#2066 (to which nobody had opinions, so)
3 years ago
Josh Bleecher Snyder 84a6dcd9a9 net/dnsfallback: regenerate
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 171ec9f8f4 control/{controlknobs,controlclient}: simplify knobs API, fix controlclient crash
From integration tests elsewhere:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x70 pc=0x845c9b]

goroutine 226 [running]:
tailscale.com/control/controlclient.(*Direct).sendMapRequest(0xc00053e1e0, 0x16670f0, 0xc000353780, 0xffffffffffffffff, 0xc0003e5f10, 0x0, 0x0)
   /home/runner/go/pkg/mod/tailscale.com@v1.1.1-0.20210715222212-1bb6abc604c1/control/controlclient/direct.go:803 +0x19bb
tailscale.com/control/controlclient.(*Direct).PollNetMap(...)
   /home/runner/go/pkg/mod/tailscale.com@v1.1.1-0.20210715222212-1bb6abc604c1/control/controlclient/direct.go:574
tailscale.com/control/controlclient.(*Auto).mapRoutine(0xc00052a1e0)
   /home/runner/go/pkg/mod/tailscale.com@v1.1.1-0.20210715222212-1bb6abc604c1/control/controlclient/auto.go:464 +0x571
created by tailscale.com/control/controlclient.(*Auto).Start
   /home/runner/go/pkg/mod/tailscale.com@v1.1.1-0.20210715222212-1bb6abc604c1/control/controlclient/auto.go:151 +0x65
exit status 2

Also remove types/opt.Bool API addition which is now unnecessary.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
julianknodt 1bb6abc604 net/portmapper: add upnp port mapping
Add in UPnP portmapping, using goupnp library in order to get the UPnP client and run the
portmapping functions. This rips out anywhere where UPnP used to be in portmapping, and has a
flow separate from PMP and PCP.

RELNOTE=portmapper now supports UPnP mappings

Fixes #682
Updates #2109

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
Brad Fitzpatrick 236eb4d04d net/dns/resolver: upgrade forwarded MagicDNS queries to DoH when IP known
Recognize Cloudflare, Google, Quad9 which are by far the
majority of upstream DNS servers that people use.

RELNOTE=MagicDNS now uses DNS-over-HTTPS when querying popular upstream resolvers,
so DNS queries aren't sent in the clear over the Internet.

Updates #915 (might fix it?)
Updates #988 (gets us closer, if it fixes Android)
Updates #74 (not yet configurable, but progress)
Updates #2056 (not yet configurable, dup of #74?)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaditya Chaudhary 4f89fe17a2
Implemented Commandline Download Speedtest (#2064)
Added the net/speedtest package that contains code for starting up a
speedtest server and a client. The speedtest command for starting a
client takes in a duration for the speedtest as well as the host and
port of the speedtest server to connect to. The speedtest command for
starting a server takes in a host:port pair to listen on.

Signed-off-by: Aaditya Chaudhary <32117362+AadityaChaudhary@users.noreply.github.com>
3 years ago
Denton Gentry e28bc49e5f netns_linux: remove special handling for tests.
With netns handling localhost now, existing tests no longer
need special handling. The tests set up their connections to
localhost, and the connections work without fuss.

Remove the special handling for tests.

Also remove the hostinfo.TestCase support, since this was
the only use of it. It can be added back later if really
needed, but it would be better to try to make tests work
without special cases.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Denton Gentry d2480fd508 net/netns: support !CAP_NET_ADMIN
netns_linux checked whether "ip rule" could run to determine
whether to use SO_MARK for network namespacing. However in
Linux environments which lack CAP_NET_ADMIN, such as various
container runtimes, the "ip rule" command succeeds but SO_MARK
fails due to lack of permission. SO_BINDTODEVICE would work in
these environments, but isn't tried.

In addition to running "ip rule" check directly whether SO_MARK
works or not. Among others, this allows Microsoft Azure App
Service and AWS App Runner to work.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Denton Gentry 1896bf99d9 netns_linux: No namespace for localhost.
Connections to a control server or log server on localhost,
used in a number of tests, are working right now because the
calls to SO_MARK in netns fail for non-root but then we ignore
the failure when running in tests.

Unfortunately that failure in SO_MARK also affects container
environments without CAP_NET_ADMIN, breaking Tailscale
connectivity. We're about to fix netns to recognize when SO_MARK
doesn't work and use SO_BINDTODEVICE instead. Doing so makes
tests fail, as their sockets now BINDTODEVICE of the default
route and cannot connect to localhost.

Add support to skip namespacing for localhost connections,
which Darwin and Windows already do. This is not conditional
on running within a test, if you tell tailscaled to connect
to localhost it will automatically use a non-namespaced
socket to do so.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Denton Gentry 61622b18fa net/interface: add AWS App Runner /proc/net/route test
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Brad Fitzpatrick 92077ae78c wgengine/magicsock: make portmapping async
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 440566c5d2 net/interfaces: trim getPACWindows whitespace before parsing URL
Fixes #2357

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder 0ad92b89a6 net/tstun: fix data races
To remove some multi-case selects, we intentionally allowed
sends on closed channels (cc23049cd2).

However, we also introduced concurrent sends and closes,
which is a data race.

This commit fixes the data race. The mutexes here are uncontended,
and thus very cheap.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder c35a832de6 net/tstun: add inner loop to poll
This avoids re-enqueuing to t.bufferConsumed,
which makes the code a bit clearer.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder a4cc7b6d54 net/tstun: simplify code
Calculate whether the packet is injected directly,
rather than via an else branch.

Unify the exit paths. It is easier here than duplicating them.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder cc23049cd2 net/tstun: remove multi-case selects from hot code
Every TUN Read went through several multi-case selects.
We know from past experience with wireguard-go that these are slow
and cause scheduler churn.

The selects served two purposes: they separated errors from data and
gracefully handled shutdown. The first is fairly easy to replace by sending
errors and data over a single channel. The second, less so.

We considered a few approaches: Intricate webs of channels,
global condition variables. They all get ugly fast.

Instead, let's embrace the ugly and handle shutdown ungracefully.
It's horrible, but the horror is simple and localized.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
David Crawshaw 6b9f8208f4 net/dns: do not run wsl.exe as LocalSystem
It doesn't work. It needs to run as the user.

	https://github.com/microsoft/WSL/issues/4803

The mechanism for doing this was extracted from:

	https://web.archive.org/web/20101009012531/http://blogs.msdn.com/b/winsdk/archive/2009/07/14/launching-an-interactive-process-from-windows-service-in-windows-vista-and-later.aspx

While here, we also reclaculate WSL distro set on SetDNS.
This accounts for:

	1. potential inability to access wsl.exe on startup
	2. WSL being installed while Tailscale is running
	3. A new WSL distrobution being installed

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
David Crawshaw 1147c7fd4f net/dns: set WSL /etc/resolv.conf
We also have to make a one-off change to /etc/wsl.conf to stop every
invocation of wsl.exe clobbering the /etc/resolv.conf. This appears to
be a safe change to make permanently, as even though the resolv.conf is
constantly clobbered, it is always the same stable internal IP that is
set as a nameserver. (I believe the resolv.conf clobbering predates the
MS stub resolver.)

Tested on WSL2, should work for WSL1 too.

Fixes #775

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
David Crawshaw 9b063b86c3 net/dns: factor directManager out over an FS interface
This is preliminary work for using the directManager as
part of a wslManager on windows, where in addition to configuring
windows we'll use wsl.exe to edit the linux file system and modify the
system resolv.conf.

The pinholeFS is a little funky, but it's designed to work through
simple unix tools via wsl.exe without invoking bash. I would not have
thought it would stand on its own like this, but it turns out it's
useful for writing a test for the directManager.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Brad Fitzpatrick 15677d8a0e net/socks5/tssocks: add a SOCKS5 dialer type, method-ifying code
https://twitter.com/bradfitz/status/1409605220376580097

Prep for #1970, #2264, #2268

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3910c1edaf net/socks5/tssocks: add new package, move SOCKS5 glue out of tailscaled
Prep for #1970, #2264, #2268

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Crawshaw d6f4b5f5cb ipn, etc: use controlplane.tailscale.com
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
julianknodt 72a0b5f042 net/dns/resolver: fmt item
This has been bothering me for a while, but everytime I run format from the root directory
it also formats this file. I didn't want to add it to my other PRs but it's annoying to have to
revert it every time.

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
Brad Fitzpatrick 10d7c2583c net/dnsfallback: don't depend on derpmap.Prod
Move derpmap.Prod to a static JSON file (go:generate'd) instead,
to make its role explicit. And add a TODO about making dnsfallback
use an update-over-time DERP map file instead of a baked-in one.

Updates #1264

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Crawshaw 80b1308974 net/dns: remove ref to managerImpl
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Adrian Dewhurst bcaae3e074 net/dns/resolver: clamp EDNS size
This change (subject to some limitations) looks for the EDNS OPT record
in queries and responses, clamping the size field to fit within our DNS
receive buffer. If the size field is smaller than the DNS receive buffer
then it is left unchanged.

I think we will eventually need to transition to fully processing the
DNS queries to handle all situations, but this should cover the most
common case.

Mostly fixes #2066

Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
3 years ago
Brad Fitzpatrick 7b8ed1fc09 net/netns: add Android implementation, allowing registration of JNI hook
Updates #2102
Updates #1809

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 3d777c13b0 net/socks5: fix a typo
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Anderson 084d48d22d net/dns: always proxy through quad-100 on windows 8.1.
Windows 8.1 incorrectly handles search paths on an interface with no
associated resolver, so we have to provide a full primary DNS config
rather than use Windows 8.1's nascent-but-present NRPT functionality.

Fixes #2237.

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
Brad Fitzpatrick 45e64f2e1a net/dns{,/resolver}: refactor DNS forwarder, send out of right link on macOS/iOS
Fixes #2224
Fixes tailscale/corp#2045

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 733d52827b net/dns/resolver: skip test on macOS
Fixes #2229

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Denton Gentry ad288baaea net/interfaces: use IPv4 link local if nothing better
The only connectivity an AWS Lambda container has is an IPv4 link-local
169.254.x.x address using NAT:
12: vtarget_1@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500
                    qdisc noqueue state UP group default qlen 1000
     link/ether 7e:1c:3f:00:00:00 brd ff:ff:ff:ff:ff:ff link-netnsid 1
     inet 169.254.79.1/32 scope global vtarget_1
     valid_lft forever preferred_lft forever

If there are no other IPv4/v6 addresses available, and we are running
in AWS Lambda, allow IPv4 169.254.x.x addresses to be used.

----

Similarly, a Google Cloud Run container's only connectivity is
a Unique Local Address fddf:3978:feb1:d745::c001/128.
If there are no other addresses available then allow IPv6
Unique Local Addresses to be used.
We actually did this in an earlier release, but now refactor it to
work the same way as the IPv4 link-local support is being done.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
David Crawshaw 297b3d6fa4 staticcheck.conf: turn off noisy lint errors
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Brad Fitzpatrick 1ae35b6c59 net/{interfaces,netcheck}: rename some fields, funcs
Split out of Denton's #2164, to make that diff smaller to review.

This change has no behavior changes.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Anderson 9337826011 net/dns: fix inverted test for NetworkManager version.
Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson 320cc8fa21 net/dns: verify that systemd-resolved is actually in charge.
It's possible to install a configuration that passes our current checks
for systemd-resolved, without actually pointing to systemd-resolved. In
that case, we end up programming DNS in resolved, but that config never
applies to any name resolution requests on the system.

This is quite a far-out edge case, but there's a simple additional check
we can do: if the header comment names systemd-resolved, there should be
a single nameserver in resolv.conf pointing to 127.0.0.53. If not, the
configuration should be treated as an unmanaged resolv.conf.

Fixes #2136.

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson e7164425b3 net/dns: don't use NetworkManager for DNS on very old NetworkManagers.
Fixes #1945.

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
Dave Anderson 144c68b80b
net/dns: avoid using NetworkManager as much as possible. (#1945)
Addresses #1699 as best as possible.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Adrian Dewhurst 8b11937eaf net/dns/resolver: permit larger max responses, signal truncation
This raises the maximum DNS response message size from 512 to 4095. This
should be large enough for almost all situations that do not need TCP.
We still do not recognize EDNS, so we will still forward requests that
claim support for a larger response size than 4095 (that will be solved
later). For now, when a response comes back that is too large to fit in
our receive buffer, we now set the truncation flag in the DNS header,
which is an improvement from before but will prompt attempts to use TCP
which isn't supported yet.

On Windows, WSARecvFrom into a buffer that's too small returns an error
in addition to the data. On other OSes, the extra data is silently
discarded. In this case, we prefer the latter so need to catch the error
on Windows.

Partially addresses #1123

Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
4 years ago
David Anderson 7fab244614 net/dns/resolver: don't spam logs on EHOSTUNREACH.
Fixes #1719.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson df8a5d09c3 net/tstun: add a debug envvar to override tun MTU.
Signed-off-by: David Anderson <dave@natulte.net>
4 years ago
Brad Fitzpatrick 713c5c9ab1 net/{interfaces,netns}: change which build tag means mac/ios Network/System Extension
We used to use "redo" for that, but it was pretty vague.

Also, fix the build tags broken in interfaces_default_route_test.go from
a9745a0b68, moving those Linux-specific
tests to interfaces_linux_test.go.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick a321c24667 go.mod: update netaddr
Involves minor IPSetBuilder.Set API change.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick ca455ac84b net/tsaddr: simplify TailscaleServiceIP
netaddr allocated at the time this was written. No longer.

name                    old time/op  new time/op  delta
TailscaleServiceAddr-4  5.46ns ± 4%  1.83ns ± 3%  -66.52%  (p=0.008 n=5+5)

A bunch of the others can probably be simplified too, but this
was the only one with just an IP and not an IPPrefix.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 1ece91cede go.mod: upgrade wireguard-windows, de-fork wireguard-go
Pull in the latest version of wireguard-windows.

Switch to upstream wireguard-go.
This requires reverting all of our import paths.

Unfortunately, this has to happen at the same time.
The wireguard-go change is very low risk,
as that commit matches our fork almost exactly.
(The only changes are import paths, CI files, and a go.mod entry.)
So if there are issues as a result of this commit,
the first place to look is wireguard-windows changes.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder 5666663370 net/packet: use netaddr AppendTo methods
This lets us remote the types/strbuilder package,
which had only a single user.
And it's faster.

name              old time/op    new time/op    delta
String/tcp4-8        175ns ± 0%      58ns ± 1%  -66.95%  (p=0.000 n=10+9)
String/tcp6-8        226ns ± 1%     136ns ± 1%  -39.85%  (p=0.000 n=10+10)
String/udp4-8        175ns ± 1%      58ns ± 1%  -67.01%  (p=0.000 n=10+9)
String/udp6-8        230ns ± 1%     140ns ± 0%  -39.32%  (p=0.000 n=10+9)
String/icmp4-8       164ns ± 0%      50ns ± 1%  -69.89%  (p=0.000 n=10+10)
String/icmp6-8       217ns ± 1%     129ns ± 0%  -40.46%  (p=0.000 n=10+10)
String/igmp-8        196ns ± 0%      56ns ± 1%  -71.32%  (p=0.000 n=10+10)
String/unknown-8    2.06ns ± 1%    2.06ns ± 2%     ~     (p=0.985 n=10+10)

name              old alloc/op   new alloc/op   delta
String/tcp4-8        32.0B ± 0%     32.0B ± 0%     ~     (all equal)
String/tcp6-8         168B ± 0%       96B ± 0%  -42.86%  (p=0.000 n=10+10)
String/udp4-8        32.0B ± 0%     32.0B ± 0%     ~     (all equal)
String/udp6-8         168B ± 0%       96B ± 0%  -42.86%  (p=0.000 n=10+10)
String/icmp4-8       32.0B ± 0%     32.0B ± 0%     ~     (all equal)
String/icmp6-8        104B ± 0%       64B ± 0%  -38.46%  (p=0.000 n=10+10)
String/igmp-8        48.0B ± 0%     48.0B ± 0%     ~     (all equal)
String/unknown-8     0.00B          0.00B          ~     (all equal)

name              old allocs/op  new allocs/op  delta
String/tcp4-8         1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/tcp6-8         3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
String/udp4-8         1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/udp6-8         3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
String/icmp4-8        1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/icmp6-8        3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
String/igmp-8         1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/unknown-8      0.00           0.00          ~     (all equal)

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder d6d1951897 net/packet: add BenchmarkString
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
David Anderson e2dcf63420 net/dns: replace AuthoritativeSuffixes with nil Route entries.
This leads to a cleaner separation of intent vs. implementation
(Routes is now the only place specifying who handles DNS requests),
and allows for cleaner expression of a configuration that creates
MagicDNS records without serving them to the OS.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 6690f86ef4 net/dns: always offer MagicDNS records at 100.100.100.100.
Fixes #1886.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Josh Bleecher Snyder 25df067dd0 all: adapt to opaque netaddr types
This commit is a mishmash of automated edits using gofmt:

gofmt -r 'netaddr.IPPort{IP: a, Port: b} -> netaddr.IPPortFrom(a, b)' -w .
gofmt -r 'netaddr.IPPrefix{IP: a, Port: b} -> netaddr.IPPrefixFrom(a, b)' -w .

gofmt -r 'a.IP.Is4 -> a.IP().Is4' -w .
gofmt -r 'a.IP.As16 -> a.IP().As16' -w .
gofmt -r 'a.IP.Is6 -> a.IP().Is6' -w .
gofmt -r 'a.IP.As4 -> a.IP().As4' -w .
gofmt -r 'a.IP.String -> a.IP().String' -w .

And regexps:

\w*(.*)\.Port = (.*)  ->  $1 = $1.WithPort($2)
\w*(.*)\.IP = (.*)  ->  $1 = $1.WithIP($2)

And lots of manual fixups.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
David Anderson cfde997699 net/dns: don't use interfaces.Tailscale to find the tailscale interface index.
interfaces.Tailscale only returns an interface if it has at least one Tailscale
IP assigned to it. In the resolved DNS manager, when we're called upon to tear
down DNS config, the interface no longer has IPs.

Instead, look up the interface index on construction and reuse it throughout
the daemon lifecycle.

Fixes #1892.

Signed-off-by: David Anderson <dave@natulte.net>
4 years ago
Brad Fitzpatrick 3173c5a65c net/interface: remove darwin fetchRoutingTable workaround
Fixed upstream. Bump dep.

Updates #1345

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 3c8e230ee1 Revert "net/dns: set IPv4 auto mode in NM, so it lets us set DNS."
This reverts commit 7d16c8228b.

I have no idea how I ended up here. The bug I was fixing with this change
fails to reproduce on Ubuntu 18.04 now, and this change definitely does
break 20.04, 20.10, and Debian Buster. So, until we can reliably reproduce
the problem this was meant to fix, reverting.

Part of #1875

Signed-off-by: David Anderson <dave@natulte.net>
4 years ago
David Anderson 5bd38b10b4 net/dns: log the correct error when NM Reapply fails.
Found while debugging #1870.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 7d16c8228b net/dns: set IPv4 auto mode in NM, so it lets us set DNS.
Part of #1870.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 77e2375501 net/dns: don't try to configure LLMNR or mdns in NetworkManager.
Fixes #1870.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 7f2eb1d87a net/tstun: fix TUN log spam when ACLs drop a packet
Whenever we dropped a packet due to ACLs, wireguard-go was logging:

Failed to write packet to TUN device: packet dropped by filter

Instead, just lie to wireguard-go and pretend everything is okay.

Fixes #1229

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 7629cd6120 net/tsaddr: add NewContainsIPFunc (move from wgengine)
I want to use this from netstack but it's not exported.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 42c8b9ad53 net/tstun: remove unnecessary break statement
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
Brad Fitzpatrick 3237e140c4 tstest/integration: add testNode.AwaitListening, DERP+STUN, improve proxy trap
Updates #1840
4 years ago
Josh Bleecher Snyder 20e04418ff net/dns: add GOOS build tags
Fixes #1786

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
David Anderson bf9ef1ca27 net/dns: stop NetworkManager breaking v6 connectivity when setting DNS.
Tentative fix for #1699

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 72b6d98298 net/interfaces: return all Tailscale addresses from Tailscale().
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 44c2b7dc79 net/dns: on windows, skip site-local v6 resolvers.
Further refinement for tailscale/corp#1662.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Josh Bleecher Snyder 99705aa6b7 net/tstun: split TUN events channel into up/down and MTU
We had a long-standing bug in which our TUN events channel
was being received from simultaneously in two places.

The first is wireguard-go.

At wgengine/userspace.go:366, we pass e.tundev to wireguard-go,
which starts a goroutine (RoutineTUNEventReader)
that receives from that channel and uses events to adjust the MTU
and bring the device up/down.

At wgengine/userspace.go:374, we launch a goroutine that
receives from e.tundev, logs MTU changes, and triggers
state updates when up/down changes occur.

Events were getting delivered haphazardly between the two of them.

We don't really want wireguard-go to receive the up/down events;
we control the state of the device explicitly by calling device.Up.
And the userspace.go loop MTU logging duplicates logging that
wireguard-go does when it received MTU updates.

So this change splits the single TUN events channel into up/down
and other (aka MTU), and sends them to the parties that ought
to receive them.

I'm actually a bit surprised that this hasn't caused more visible trouble.
If a down event went to wireguard-go but the subsequent up event
went to userspace.go, we could end up with the wireguard-go device disappearing.

I believe that this may also (somewhat accidentally) be a fix for #1790.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
David Anderson 97d2fa2f56 net/dns: work around WSL DNS implementation flaws.
Fixes tailscale/corp#1662

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Avery Pennarun a92b9647c5 wgengine/bench: speed test for channels, sockets, and wireguard-go.
This tries to generate traffic at a rate that will saturate the
receiver, without overdoing it, even in the event of packet loss. It's
unrealistically more aggressive than TCP (which will back off quickly
in case of packet loss) but less silly than a blind test that just
generates packets as fast as it can (which can cause all the CPU to be
absorbed by the transmitter, giving an incorrect impression of how much
capacity the total system has).

Initial indications are that a syscall about every 10 packets (TCP bulk
delivery) is roughly the same speed as sending every packet through a
channel. A syscall per packet is about 5x-10x slower than that.

The whole tailscale wireguard-go + magicsock + packet filter
combination is about 4x slower again, which is better than I thought
we'd do, but probably has room for improvement.

Note that in "full" tailscale, there is also a tundev read/write for
every packet, effectively doubling the syscall overhead per packet.

Given these numbers, it seems like read/write syscalls are only 25-40%
of the total CPU time used in tailscale proper, so we do have
significant non-syscall optimization work to do too.

Sample output:

$ GOMAXPROCS=2 go test -bench . -benchtime 5s ./cmd/tailbench
goos: linux
goarch: amd64
pkg: tailscale.com/cmd/tailbench
cpu: Intel(R) Core(TM) i7-4785T CPU @ 2.20GHz
BenchmarkTrivialNoAlloc/32-2         	56340248	        93.85 ns/op	 340.98 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTrivialNoAlloc/124-2        	57527490	        99.27 ns/op	1249.10 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTrivialNoAlloc/1024-2       	52537773	       111.3 ns/op	9200.39 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTrivial/32-2                	41878063	       135.6 ns/op	 236.04 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTrivial/124-2               	41270439	       138.4 ns/op	 896.02 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTrivial/1024-2              	36337252	       154.3 ns/op	6635.30 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkBlockingChannel/32-2           12171654	       494.3 ns/op	  64.74 MB/s	         0 %lost	    1791 B/op	       0 allocs/op
BenchmarkBlockingChannel/124-2          12149956	       507.8 ns/op	 244.17 MB/s	         0 %lost	    1792 B/op	       1 allocs/op
BenchmarkBlockingChannel/1024-2         11034754	       528.8 ns/op	1936.42 MB/s	         0 %lost	    1792 B/op	       1 allocs/op
BenchmarkNonlockingChannel/32-2          8960622	      2195 ns/op	  14.58 MB/s	         8.825 %lost	    1792 B/op	       1 allocs/op
BenchmarkNonlockingChannel/124-2         3014614	      2224 ns/op	  55.75 MB/s	        11.18 %lost	    1792 B/op	       1 allocs/op
BenchmarkNonlockingChannel/1024-2        3234915	      1688 ns/op	 606.53 MB/s	         3.765 %lost	    1792 B/op	       1 allocs/op
BenchmarkDoubleChannel/32-2          	 8457559	       764.1 ns/op	  41.88 MB/s	         5.945 %lost	    1792 B/op	       1 allocs/op
BenchmarkDoubleChannel/124-2         	 5497726	      1030 ns/op	 120.38 MB/s	        12.14 %lost	    1792 B/op	       1 allocs/op
BenchmarkDoubleChannel/1024-2        	 7985656	      1360 ns/op	 752.86 MB/s	        13.57 %lost	    1792 B/op	       1 allocs/op
BenchmarkUDP/32-2                    	 1652134	      3695 ns/op	   8.66 MB/s	         0 %lost	     176 B/op	       3 allocs/op
BenchmarkUDP/124-2                   	 1621024	      3765 ns/op	  32.94 MB/s	         0 %lost	     176 B/op	       3 allocs/op
BenchmarkUDP/1024-2                  	 1553750	      3825 ns/op	 267.72 MB/s	         0 %lost	     176 B/op	       3 allocs/op
BenchmarkTCP/32-2                    	11056336	       503.2 ns/op	  63.60 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTCP/124-2                   	11074869	       533.7 ns/op	 232.32 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkTCP/1024-2                  	 8934968	       671.4 ns/op	1525.20 MB/s	         0 %lost	       0 B/op	       0 allocs/op
BenchmarkWireGuardTest/32-2          	 1403702	      4547 ns/op	   7.04 MB/s	        14.37 %lost	     467 B/op	       3 allocs/op
BenchmarkWireGuardTest/124-2         	  780645	      7927 ns/op	  15.64 MB/s	         1.537 %lost	     420 B/op	       3 allocs/op
BenchmarkWireGuardTest/1024-2        	  512671	     11791 ns/op	  86.85 MB/s	         0.5206 %lost	     411 B/op	       3 allocs/op
PASS
ok  	tailscale.com/wgengine/bench	195.724s

Updates #414.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
4 years ago
David Anderson f6b7d08aea net/dns: work around new NetworkManager in other selection paths.
Further bits of #1788

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 25ce9885a2 net/dns: don't use NM+resolved for NM >=1.26.6.
NetworkManager fixed the bug that forced us to use NetworkManager
if it's programming systemd-resolved, and in the same release also
made NetworkManager ignore DNS settings provided for unmanaged
interfaces... Which breaks what we used to do. So, with versions
1.26.6 and above, we MUST NOT use NetworkManager to indirectly
program systemd-resolved, but thankfully we can talk to resolved
directly and get the right outcome.

Fixes #1788

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick e41075dd4a net/interfaces: work around race fetching routing table
Fixes #1345
Updates golang/go#45736

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 30f5d706a1 net/dns/resolver: remove unnecessary/racy WaitGroup.
Fixes #1663

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 89c81c26c5 net/dns: fix resolved match domains when no nameservers are provided.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 4be26b269f net/dns: correctly capture all traffic in non-split configs.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson ca283ac899 net/dns: remove config in openresolv when given an empty DNS config.
Part of #1720.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 53213114ec net/dns: make debian_resolvconf correctly clear DNS configs.
More of #1720.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 3b1ab78954 net/dns: restore resolv.conf when given an empty config in directManager.
Fixes #1720.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 158328ba24 net/dns: remove ForceSplitDNSForTesting.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Naman Sood 71b7e48547
net/tsaddr: expand ephemeral nodes range to /64
Signed-off-by: Naman Sood <mail@nsood.in>
4 years ago
Naman Sood b85d80b37f
net/tsaddr: add new IP range for ephemeral nodes in Tailscale ULA (#1715)
Signed-off-by: Naman Sood <mail@nsood.in>
4 years ago
David Anderson bb0710d51d net/dns: add debugging traces to DNS manager selection on linux.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 4b70c7b717 net/dns: fix inverted test for NetworkManager.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 4849a4d3c8 net/dns: error out on linux if /etc/resolv.conf can't be read.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 1f9b73a531 net/dns: fix freebsd DNS manager selection.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
AdamKorcz 2243bb48c2 stun fuzzer: Small fix
Signed-off-by: AdamKorcz <adam@adalogics.com>
4 years ago
Brad Fitzpatrick c2ca2ac8c4 net/dns: fix FreeBSD build
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 84bd50329a net/dns: fix staticheck.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson d6bb11b5bf net/dns: implement correct manager detection on linux.
Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9ef932517b net/dns: fix NM's GetBaseConfig when no configs exist.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson fe3b1ab747 net/dns: refactor dbus connection setup in resolved manager.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 854d5d36a1 net/dns: return error from NewOSManager, use it to initialize NM.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9aa33b43e6 net/dns: support split and unsplit DNS in NetworkManager.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 87eb8384f5 net/dns: fix up NetworkManager configurator a bit.
Clear LLMNR and mdns flags, update reasoning for our settings,
and set our override priority harder than before when we want
to be primary resolver.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 3d81e6260b net/dns: set resolved DefaultRoute setting according to split-dns mode.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson cca230cc23 net/dns: fix staticcheck errors.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 4b47393e0c net/dns: pacify staticcheck for now
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson a7340c2015 net/dns: support split DNS in systemd-resolved.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 84430cdfa1 net/dns: improve NetworkManager detection, using more DBus.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9a48bac8ad net/dns: rename resolvconf.go to debian_resolvconf.go.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9831f1b183 net/dns: also include 'tail' and 'base' files when fixing up resolv.conf.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson e43afe9140 net/dns: implement prior config reading for debian resolvconf.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 143e5dd087 net/dns: rename script variable.
Debian resolvconf is not legacy, it's alive and well,
just historically before the other implementations.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 55b39fa945 net/dns: add documentation to openresolv's config fetch.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 61b361bac0 net/dns: teach the openresolv manager to read DNS config.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 58760f7b82 net/dns: split resolvconfManager into a debian and an openresolv manager.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 5480189313 net/dns: implement a DNS override workaround for legacy resolvconf.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 1a371b93be util/dnsname: add FQDN type, use throughout codebase.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
AdamKorcz 7a1813fd24 Added 2 fuzzers
Signed-off-by: AdamKorcz <adam@adalogics.com>
4 years ago
David Anderson e638a4d86b net/dns: make directManager support split DNS, and work in sandboxes.
Fixes #1495, #683.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 2685260ba1 net/dns: add temporary fallback to quad-9 resolver for split-DNS testing.
This allows split-DNS configurations to not break clients on OSes that
haven't yet been ported to understand split DNS, by falling back to quad-9
as a global resolver when handed an "impossible to implement"
split-DNS config.

Part of #953. Needs to be removed before shipping 1.8.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson b9e194c14b net/dns: add missing FQDN qualification.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson b74a8994ca net/dns: make FQDN dot style consistent in more places.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 6def647514 net/dns/resolver: don't avoid tailscale routes for DNS forwarding.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 4a64d2a603 net/dns: some post-review cleanups.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 720c1ad0f0 net/dns: insert OS base config when emulating split DNS.
Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson e560be6443 net/dns: sort matchDomains to avoid test flake.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 68f76e9aa1 net/dns: add GetBaseConfig to OSConfigurator interface.
Part of #953, required to make split DNS work on more basic
platforms.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson fe9cd61d71 net/dns: add tests for DNS config generation.
Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 0ba6d03768 net/dns/resolver: add a test helper to get at the resolver config.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson da4cc8bbb4 net/dns: handle all possible translations of high-level DNS config.
With this change, all OSes can sort-of do split DNS, except that the
default upstream is hardcoded to 8.8.8.8 pending further plumbing.
Additionally, Windows 8-10 can do split DNS fully correctly, without
the 8.8.8.8 hack.

Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 939861773d net/tstun: accept peerapi connections through the filter
Fixes tailscale/corp#1545

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Maisem Ali 57756ef673 net/nettest: make nettest.NewConn pass x/net/nettest.TestConn.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
4 years ago
David Anderson e0e677a8f6 net/dns: split out search domains and match domains in OSConfig.
It seems that all the setups that support split DNS understand
this distinction, and it's an important one when translating
high-level configuration.

Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson a8dcda9c9a net/dns: start of compat hacks for Windows 7.
Correctly reports that Win7 cannot do split DNS, and has a helper to
discover the "base" resolvers for the system.

Part of #953

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 3e915ac783 net/dns: implement OS-level split DNS for Windows.
Part of #953.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson c16a926bf2 net/dns: set OSConfig.Primary.
OS implementations are going to support split DNS soon.
Until they're all in place, hardcode Primary=true to get
the old behavior.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson bc4381447f net/tstun: return the real interface name at device creation.
This is usually the same as the requested interface, but on some
unixes can vary based on device number allocation, and on Windows
it's the GUID instead of the pretty name, since everything relating
to configuration wants the GUID.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson de6dc4c510 net/dns: add a Primary field to OSConfig.
Currently ignored.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson b2a597b288 net/dns: rename Set to SetDNS in OSConfigurator.
wgengine/router.CallbackRouter needs to support both the Router
and OSConfigurator interfaces, so the setters can't both be called
Set.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 7d84ee6c98 net/dns: unify the OS manager and internal resolver.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 1bf91c8123 net/dns/resolver: remove unused err return value.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 6a206fd0fb net/dns: rename impl to os.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson c4530971db net/dns/resolver: remove leftover debug print.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 4c61ebacf4 wgengine: move DNS configuration out of wgengine/router.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 748670f1e9 net/dns: fix typo in docstring.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson a39d2403bc net/dns: disable NetworkManager and resolved configurators temporarily.
They need some rework to do the right thing, in the meantime the direct
and resolvconf managers will work out.

The resolved implementation was never selected due to control-side settings.
The networkmanager implementation mostly doesn't get selected due to
unforeseen interactions with `resolvconf` on many platforms.
Both implementations also need rework to support the various routing modes
they're capable of.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson befd8e4e68 net/dns: replace managerImpl with OSConfigurator in code.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 077d4dc8c7 net/dns: add an OSConfigurator interface.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 6ad44f9fdf wgengine: take in dns.Config, split out to resolver.Config and dns.OSConfig.
Stepping stone towards having the DNS package handle the config splitting.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 2edb57dbf1 net/dns: add new Config that captures tailscale+OS DNS config.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 8af9d770cf net/dns: rename Config to OSConfig.
Making way for a new higher level config struct.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson fcfc0d3a08 net/dns: remove ManagerConfig, pass relevant args directly.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 0ca04f1e01 net/dns: put noop.go back, limit with build tags for staticcheck.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 95470c3448 net/dns: remove Cleanup manager parameter.
It's only use to skip some optional initialization during cleanup,
but that work is very minor anyway, and about to change drastically.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson cf361bb9b1 net/dns: remove PerDomain from Config.
It's currently unused, and no longer makes sense with the upcoming
DNS infrastructure. Keep it in tailcfg for now, since we need protocol
compat for a bit longer.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson f77ba75d6c wgengine/router: move DNS cleanup into the DNS package.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9f105d3968 net/dns/resolver: teach the forwarder to do per-domain routing.
Given a DNS route map, the forwarder selects the right set of
upstreams for a given name.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 90f82b6946 net/dns/resolver: add live reconfig, plumb through to ipnlocal.
The resolver still only supports a single upstream config, and
ipn/wgengine still have to split up the DNS config, but this moves
closer to unifying the DNS configs.

As a handy side-effect of the refactor, IPv6 MagicDNS records exist
now.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson caeafc4a32 net/dns/resolver: fix package docstring.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson dbe4f6f42d net/dns/resolver: unexport Resolve and ResolveReverse.
They're only used internally and in tests, and have surprising
semantics in that they only resolve MagicDNS names, not upstream
resolver queries.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson cdeb8d6816 net/dns/resolver: fix staticcheck error.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson f185d62dc8 net/dns/resolver: unexport Packet, only use it internally.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 5fb9e00ecf net/dns/resolver: remove Start method, fully spin up in New instead.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 075fb93e69 net/dns/resolver: remove the Config struct.
In preparation for reintroducing a runtime reconfig Config struct.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson bc81dd4690 net/dns/resolver: rename ResolverConfig to just Config.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson d99f5b1596 net/dns/resolver: factor the resolver out into a sub-package.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Denton Gentry 09148c07ba interfaces: check correct error /proc/net/route
wrap io.EOF if we hit https://github.com/google/gvisor/issues/5732
Check for the correct err.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Denton Gentry a9745a0b68 interfaces: try larger read from /proc/net/route
Work around https://github.com/google/gvisor/issues/5732
by trying to read /proc/net/route with a larger bufsize if
it fails the first time.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Denton Gentry 54ba6194f7 interfaces: allow IPv6 ULA as a valid address.
IPv6 Unique Local Addresses are sometimes used with Network
Prefix Translation to reach the Internet. In that respect
their use is similar to the private IPv4 address ranges
10/8, 172.16/12, and 192.168/16.

Treat them as sufficient for AnyInterfaceUp(), but specifically
exclude Tailscale's own IPv6 ULA prefix to avoid mistakenly
trying to bootstrap Tailscale using Tailscale.

This helps in supporting Google Cloud Run, where the addresses
are 169.254.8.1/32 and fddf:3978:feb1:d745::c001/128 on eth1.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Denton Gentry ecf310be3c net/tsaddr: IsUla() for IPv6 Unique Local Address
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Brad Fitzpatrick 41e4e02e57 net/{packet,tstun}: send peerapi port in TSMP pongs
For discovery when an explicit hostname/IP is known. We'll still
also send it via control for finding peers by a list.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 25e0bb0a4e net/tstun: rename wrap_windows.go to tun_windows.go.
The code has nothing to do with wrapping, it's windows-specific
driver initialization code.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 22d53fe784 net/tstun: document exported function.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 016de16b2e net/tstun: rename TUN to Wrapper.
The tstun packagen contains both constructors for generic tun
Devices, and a wrapper that provides additional functionality.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 82ab7972f4 net/tstun: rename NewFakeTUN to NewFake.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 588b70f468 net/tstun: merge in wgengine/tstun.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 018200aeba net/tstun: rename from net/tun.
We depend on wireguard-go/tun, identical leaf packages can be
confusing in code.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 44d9929208 wgengine: remove Config.TUNName, require caller to create device.
Also factors out device creation and associated OS workarounds to
net/tun.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 7f174e84e6 net/interfaces: remove mutating methods, add EqualFiltered instead
Now callers (wgengine/monitor) don't need to mutate the state to remove
boring interfaces before calling State.Equal. Instead, the methods
to remove boring interfaces from the State are removed, as is
the reflect-using Equal method itself, and in their place is
a new EqualFiltered method that takes a func predicate to match
interfaces to compare.

And then the FilterInteresting predicate is added for use
with EqualFiltered to do the job that that wgengine/monitor
previously wanted.

Now wgengine/monitor can keep the full interface state around,
including the "boring" interfaces, which we'll need for peerapi on
macOS/iOS to bind to the interface index of the utunN device.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 7dc88e4c1e net/interfaces: track more interface metadata in State
We have it already but threw it away. But macOS/iOS code will
be needing the interface index, so hang on to it.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 6521f02ff6 Move DNS flush logic to net/dns.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9f7f2af008 wgengine/router/dns: move to net/dns.
Preparation for merging the APIs and whatnot.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 8432999835 Move wgengine/tsdns to net/dns.
Straight move+fixup, no other changes. In prep for merging with
wgengine/router/dns.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 2384c112c9 net/packet, wgengine/{filter,tstun}: add TSMP ping
Fixes #1467

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick e2b3d9aa5f all: s/Magic DNS/MagicDNS/ for consistency
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 1eb95c7e32 net/packet, wgengine{,/filter}: remove net/packet IPProto forwarding consts
Only use the ones in types/ipproto now.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 01b90df2fa net/packet, wgengine/filter: support SCTP
Add proto to flowtrack.Tuple.

Add types/ipproto leaf package to break a cycle.

Server-side ACL work remains.

Updates #1516

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Aleksandar Pesic 7b57310966 net/interfaces: use windows API to get the default route instead of parsing `route print` output
Fixes: #1470

Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
4 years ago
David Anderson 6fb5d4080c net/portmapper: silently handle PCP NOT_AUTHORIZED responses.
Fixes #1525.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick d5fd373f09 net/interfaces: skip IPv6 link-local interfaces like we do for IPv4
We strip them control-side anyway, and we already strip IPv4 link
local, so there's no point uploading them.  And iOS has a ton of them,
which results in somewhat silly amount of traffic in the MapRequest.

We'll be doing same-LAN-inter-tailscaled link-local traffic a
different way, with same-LAN discovery.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 44ab0acbdb net/portmapper, wgengine/monitor: cache gateway IP info until link changes
Cuts down allocs & CPU in steady state (on regular STUN probes) when network
is unchanging.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 974be2ec5c net/interfaces: rewrite the darwin likelyHomeRouterIP from C to Go
We basically already had the RIB-parsing Go code for this in both
net/interfaces and wgengine/monitor, for other reasons.

Fixes #1426
Fixes #1471

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick c6358f2247 net/netcheck: add a few more STUN retries for prior DERP home
For #1310, maybe.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 0a84359d2d tailcfg, net/netcheck: let control mark "Avoid" bit on DERP regions
So a region can be used if needed, but won't be STUN-probed or used as
its home.

This gives us another possible debugging mechanism for #1310, or can
be used as a short-term measure against DERP flip-flops for people
equidistant between regions if our hysteresis still isn't good enough.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson d79a2f3809 wgengine/filter: only log packets to/from non-default routes.
Fixes tailscale/corp#1429.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick ef7bac2895 tailcfg, net/portmapper, wgengine/magicsock: add NetInfo.HavePortMap
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick fee74e7ea7 net/interfaces, wgengine/monitor: fix false positives link changes
interfaces.State.String tries to print a concise summary of the
network state, removing any interfaces that don't have any or any
interesting IP addresses. On macOS and iOS, for instance, there are a
ton of misc things.

But the link monitor based its are-there-changes decision on
interfaces.State.Equal, which just used reflect.DeepEqual, including
comparing all the boring interfaces. On macOS, when turning wifi on or off, there
are a ton of misc boring interface changes, resulting in hitting an earlier
check I'd added on suspicion this was happening:

    [unexpected] network state changed, but stringification didn't

This fixes that by instead adding a new
interfaces.State.RemoveUninterestingInterfacesAndAddresses method that
does, uh, that. Then use that in the monitor. So then when Equal is
used later, it's DeepEqualing the already-cleaned version with only
interesting interfaces.

This makes cmd/tailscaled debug --monitor much less noisy.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick b14ea68754 net/interfaces: log why when we failed to look up gateway on macOS
Not beautiful, but I'm debugging connectivity problems on
NEProvider.sleep+wake and need more clues.

Updates #1426
Updates tailscale/corp#1289

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick d37b3b02cd net/dnsfallback: fix infinite loop and limit number of candidates
Updates #1455 (fixes the DNS spin part, but other things aren't ideal there)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 829eb8363a net/interfaces: sort returned addresses from LocalAddresses
Also change the type to netaddr.IP while here, because it made sorting
easier.

Updates tailscale/corp#1397

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 10f48087f4 net/tshttpproxy: call winhttp calls from a fixed OS thread
We often see things in logs like:

2021-03-02 17:52:45.2456258 +0800 +0800: winhttp: Open: The parameter is incorrect.
2021-03-02 17:52:45.2506261 +0800 +0800: tshttpproxy: winhttp: GetProxyForURL("https://log.tailscale.io/c/tailnode.log.tailscale.io/5037bb42f4bc330e2d6143e191a7ff7e837c6be538139231de69a439536e0d68"): ERROR_INVALID_PARAMETER [unexpected]

I have a hunch that WinHTTP has thread-local state. If so, this would fix it.
If not, this is pretty harmless.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 8a55d463c8 net/interfaces: merge darwin files for DefaultRouteInterface in sandbox
DefaultRouteInterface was previously guarded by build tags such that
it was only accessible to tailscaled-on-macos, but there was no reason
for that. It runs fine in the sandbox and gives better default info,
so merge its file into interfaces_darwin.go.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 8d77dfdacb wgengine/router: add a dummy IPv6 address if needed for default routing.
Fixes #1339

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 63ed4dd6c9 net/portmapper: fix typo
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson f647e3daaf ipn/ipnlocal: transform default routes into "all but LAN" routes.
Fixes #1177.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 9df4185c94 control/controlclient, net/{dnscache,dnsfallback}: add DNS fallback mechanism
Updates #1405
Updates #1403

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 38dc6fe758 cmd/tailscaled, wgengine: remove --fake, replace with netstack
And add a --socks5-server flag.

And fix a race in SOCKS5 replies where the response header was written
concurrently with the copy from the backend.

Co-authored with Naman Sood.

Updates #707
Updates #504

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Naman Sood fe16ef6812 net/socks5: create SOCKS5 package for proxy server in userspace networking
Updates #707
Updates #504

Signed-off-by: Naman Sood <mail@nsood.in>
4 years ago
Brad Fitzpatrick 000b80de9d net/interfaces: go idle on macOS when wifi/etc is down, ignore utun* interfaces
Updates tailscale/corp#1289
Updates tailscale/corp#1367
Updates tailscale/corp#1378
Updates tailscale/felicity#4
4 years ago
Brad Fitzpatrick c64bd587ae net/portmapper: add NAT-PMP client, move port mapping service probing
* move probing out of netcheck into new net/portmapper package
* use PCP ANNOUNCE op codes for PCP discovery, rather than causing
  short-lived (sub-second) side effects with a 1-second-expiring map +
  delete.
* track when we heard things from the router so we can be less wasteful
  in querying the router's port mapping services in the future
* use portmapper from magicsock to map a public port

Fixes #1298
Fixes #1080
Fixes #1001
Updates #864

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 6a2c6541da net/tshttpproxy: support HTTP proxy environment credentials on Windows too
and some minor style nits.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Christine Dodrill 3e5c3e932c
net/tshttpproxy: support basic auth when available (#1354)
This allows proxy URLs such as:

    http://azurediamond:hunter2@192.168.122.154:38274

to be used in order to dial out to control, logs or derp servers.

Signed-off-by: Christine Dodrill <xe@tailscale.com>
4 years ago
Brad Fitzpatrick f4ae745b0b net/{interfaces,netns}: add some new tests, missed from prior commit
I meant for these to be part of 52e24aa966.
4 years ago
Brad Fitzpatrick e923639feb net/interfaces: fix staticcheck error on darwin 4 years ago
Brad Fitzpatrick 52e24aa966 net/{interfaces,ns}: add tailscaled-mode darwin routing looping prevention
Fixes #1331

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 20e66c5b92 net/interfaces: reconcile interface filtering with address printing in logs
The interface.State logging tried to only log interfaces which had
interesting IPs, but the what-is-interesting checks differed between
the code that gathered the interface names to print and the printing
of their addresses.
4 years ago
Josh Bleecher Snyder 138055dd70 tstest/natlab: use net.ErrClosed instead of a new error
Upstream wireguard-go decided to use errors.Is(err, net.ErrClosed)
instead of checking the error string.

It also provided an unsafe linknamed version of net.ErrClosed
for clients running Go 1.15. Switch to that.

This reduces the time required for the wgengine/magicsock tests
on my machine from ~35s back to the ~13s it was before
456cf8a376.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick d37058af72 net/packet: add some more TSMP packet reject reasons and MaybeBroken bit
Unused for now, but I want to backport this commit to 1.4 so 1.6 can
start sending these and then at least 1.4 logs will stringify nicely.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Crawshaw d139fa9c92 net/interfaces: use a uint32_t for ipv4 address
The code was using a C "int", which is a signed 32-bit integer.
That means some valid IP addresses were negative numbers.
(In particular, the default router address handed out by AT&T
fiber: 192.168.1.254. No I don't know why they do that.)
A negative number is < 255, and so was treated by the Go code
as an error.

This fixes the unit test failure:

	$ go test -v -run=TestLikelyHomeRouterIPSyscallExec ./net/interfaces
	=== RUN   TestLikelyHomeRouterIPSyscallExec
	    interfaces_darwin_cgo_test.go:15: syscall() = invalid IP, false, netstat = 192.168.1.254, true
	--- FAIL: TestLikelyHomeRouterIPSyscallExec (0.00s)

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
4 years ago
Brad Fitzpatrick 35e10c78fc net/interfaces: don't send over zt* interfaces
Fixes #1208

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 692a011b54 net/interfaces: remove IsTailscaleIP, make callers use tsaddr.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Josh Bleecher Snyder 7c1a9e8616 net/nettest: de-flake tests on Windows
Windows has a low resolution timer.
Some of the tests assumed that unblock takes effect immediately.

Consider:

t := time.Now()
elapsed := time.Now().After(t)

It seems plausible that elapsed should always be true.
However, with a low resolution timer, that might fail.

Change time.Now().After to !time.Now().Before,
so that unblocking always takes effect immediately.

Fixes #873.
4 years ago
Josh Bleecher Snyder a64d06f15c net/nettest: remove pointless checks in tests
If err == nil, then !errors.Is(err, anything).
4 years ago
Josh Bleecher Snyder 503db5540f net/nettest: add missing check at end of TestLimit
This appears to have been an oversight.
4 years ago
Brad Fitzpatrick b560386c1a net/packet, wgengine, tstun: add inter-node TSMP protocol for connect errors
This adds a new IP Protocol type, TSMP on protocol number 99 for
sending inter-tailscale messages over WireGuard, currently just for
why a peer rejects TCP SYNs (ACL rejection, shields up, and in the
future: nothing listening, something listening on that port but wrong
interface, etc)

Updates #1094
Updates tailscale/corp#1185

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Denton Gentry ac42757cd7 netcheck: use reflect in sortRegions test.
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Denton Gentry 43e060b0e5 netcheck: test sortRegions
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Brad Fitzpatrick 5eeaea9ef9 net/packet: add TCPFlag type and some more constants
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick ad3fb6125d net/flowtrack: add Tuple.String method
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 676b5b7946 net/netcheck: improve the preferred DERP hysteresis
Users in Amsterdam (as one example) were flipping back and forth
between equidistant London & Frankfurt relays too much.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 4d15e954bd net/flowtrack: add new package to specialize groupcache/lru key type
Reduces allocs.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 66be052a70 net/dnscache: work on IPv6-only hosts (again)
This fixes the regression where we had stopped working on IPv6-only
hosts.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 1e88050403 net/tsaddr: add ChromeOS contains tests
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
David Anderson cb96b14bf4 net/packet: remove the custom IP4/IP6 types in favor of netaddr.IP.
Upstream netaddr has a change that makes it alloc-free, so it's safe to
use in hot codepaths. This gets rid of one of the many IP types in our
codebase.

Performance is currently worse across the board. This is likely due in
part to netaddr.IP being a larger value type (4b -> 24b for IPv4,
16b -> 24b for IPv6), and in other part due to missing low-hanging fruit
optimizations in netaddr. However, the regression is less bad than
it looks at first glance, because we'd micro-optimized packet.IP* in
the past few weeks. This change drops us back to roughly where we
were at the 1.2 release, but with the benefit of a significant
code and architectural simplification.

name                   old time/op    new time/op    delta
pkg:tailscale.com/net/packet goos:linux goarch:amd64
Decode/tcp4-8            12.2ns ± 5%    29.7ns ± 2%  +142.32%  (p=0.008 n=5+5)
Decode/tcp6-8            12.6ns ± 3%    65.1ns ± 2%  +418.47%  (p=0.008 n=5+5)
Decode/udp4-8            11.8ns ± 3%    30.5ns ± 2%  +157.94%  (p=0.008 n=5+5)
Decode/udp6-8            27.1ns ± 1%    65.7ns ± 2%  +142.36%  (p=0.016 n=4+5)
Decode/icmp4-8           24.6ns ± 2%    30.5ns ± 2%   +23.65%  (p=0.016 n=4+5)
Decode/icmp6-8           22.9ns ±51%    65.5ns ± 2%  +186.19%  (p=0.008 n=5+5)
Decode/igmp-8            18.1ns ±44%    30.2ns ± 1%   +66.89%  (p=0.008 n=5+5)
Decode/unknown-8         20.8ns ± 1%    10.6ns ± 9%   -49.11%  (p=0.016 n=4+5)
pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64
Filter/icmp4-8           30.5ns ± 1%    77.9ns ± 3%  +155.01%  (p=0.008 n=5+5)
Filter/tcp4_syn_in-8     43.7ns ± 3%   123.0ns ± 3%  +181.72%  (p=0.008 n=5+5)
Filter/tcp4_syn_out-8    24.5ns ± 2%    45.7ns ± 6%   +86.22%  (p=0.008 n=5+5)
Filter/udp4_in-8         64.8ns ± 1%   210.0ns ± 2%  +223.87%  (p=0.008 n=5+5)
Filter/udp4_out-8         119ns ± 0%     278ns ± 0%  +133.78%  (p=0.016 n=4+5)
Filter/icmp6-8           40.3ns ± 2%   204.4ns ± 4%  +407.70%  (p=0.008 n=5+5)
Filter/tcp6_syn_in-8     35.3ns ± 3%   199.2ns ± 2%  +464.95%  (p=0.008 n=5+5)
Filter/tcp6_syn_out-8    32.8ns ± 2%    81.0ns ± 2%  +147.10%  (p=0.008 n=5+5)
Filter/udp6_in-8          106ns ± 2%     290ns ± 2%  +174.48%  (p=0.008 n=5+5)
Filter/udp6_out-8         184ns ± 2%     314ns ± 3%   +70.43%  (p=0.016 n=4+5)
pkg:tailscale.com/wgengine/tstun goos:linux goarch:amd64
Write-8                  9.02ns ± 3%    8.92ns ± 1%      ~     (p=0.421 n=5+5)

name                   old alloc/op   new alloc/op   delta
pkg:tailscale.com/net/packet goos:linux goarch:amd64
Decode/tcp4-8             0.00B          0.00B           ~     (all equal)
Decode/tcp6-8             0.00B          0.00B           ~     (all equal)
Decode/udp4-8             0.00B          0.00B           ~     (all equal)
Decode/udp6-8             0.00B          0.00B           ~     (all equal)
Decode/icmp4-8            0.00B          0.00B           ~     (all equal)
Decode/icmp6-8            0.00B          0.00B           ~     (all equal)
Decode/igmp-8             0.00B          0.00B           ~     (all equal)
Decode/unknown-8          0.00B          0.00B           ~     (all equal)
pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64
Filter/icmp4-8            0.00B          0.00B           ~     (all equal)
Filter/tcp4_syn_in-8      0.00B          0.00B           ~     (all equal)
Filter/tcp4_syn_out-8     0.00B          0.00B           ~     (all equal)
Filter/udp4_in-8          0.00B          0.00B           ~     (all equal)
Filter/udp4_out-8         16.0B ± 0%     64.0B ± 0%  +300.00%  (p=0.008 n=5+5)
Filter/icmp6-8            0.00B          0.00B           ~     (all equal)
Filter/tcp6_syn_in-8      0.00B          0.00B           ~     (all equal)
Filter/tcp6_syn_out-8     0.00B          0.00B           ~     (all equal)
Filter/udp6_in-8          0.00B          0.00B           ~     (all equal)
Filter/udp6_out-8         48.0B ± 0%     64.0B ± 0%   +33.33%  (p=0.008 n=5+5)

name                   old allocs/op  new allocs/op  delta
pkg:tailscale.com/net/packet goos:linux goarch:amd64
Decode/tcp4-8              0.00           0.00           ~     (all equal)
Decode/tcp6-8              0.00           0.00           ~     (all equal)
Decode/udp4-8              0.00           0.00           ~     (all equal)
Decode/udp6-8              0.00           0.00           ~     (all equal)
Decode/icmp4-8             0.00           0.00           ~     (all equal)
Decode/icmp6-8             0.00           0.00           ~     (all equal)
Decode/igmp-8              0.00           0.00           ~     (all equal)
Decode/unknown-8           0.00           0.00           ~     (all equal)
pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64
Filter/icmp4-8             0.00           0.00           ~     (all equal)
Filter/tcp4_syn_in-8       0.00           0.00           ~     (all equal)
Filter/tcp4_syn_out-8      0.00           0.00           ~     (all equal)
Filter/udp4_in-8           0.00           0.00           ~     (all equal)
Filter/udp4_out-8          1.00 ± 0%      1.00 ± 0%      ~     (all equal)
Filter/icmp6-8             0.00           0.00           ~     (all equal)
Filter/tcp6_syn_in-8       0.00           0.00           ~     (all equal)
Filter/tcp6_syn_out-8      0.00           0.00           ~     (all equal)
Filter/udp6_in-8           0.00           0.00           ~     (all equal)
Filter/udp6_out-8          1.00 ± 0%      1.00 ± 0%      ~     (all equal)

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick d0baece5fa go.mod: bump inet.af/netaddr to non-allocating version 4 years ago
Brad Fitzpatrick 053a1d1340 all: annotate log verbosity levels on most egregiously spammy log prints
Fixes #924
Fixes #282

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson baa7937998 net/interfaces: return IPv6 addresses from LocalAddresses.
In practice, we already provide IPv6 endpoint addresses via netcheck,
and that address is likely to match a local address anyway (i.e. no NAT66).
The comment at that piece of the code mentions needing to figure out a
good priority ordering, but that only applies to non-active-discovery
clients, who already don't do anything with IPv6 addresses.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson aa353b8d0f net/packet: add an IP6 constructor from a raw byte array.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Josh Bleecher Snyder a6cad71fb2 go.mod: upgrade staticcheck to 0.1.0
Also run go.mod and fix some staticcheck warnings.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick 08f94b3b50 net/netcheck: fix offset of unspecified address in PCP request packet
Fixes #810
4 years ago
Brad Fitzpatrick 05e5233e07 net/netcheck: don't send flood of PCP unmap requests to router
Updates #810
4 years ago
Josh Bleecher Snyder 1ebbaaaebb net/interfaces: make syscall and netstat agree when multiple gateways are present
likelyHomeRouterIPDarwinSyscall iterates through the list of routes,
looking for a private gateway, returning the first one it finds.

likelyHomeRouterIPDarwinExec does the same thing,
except that it returns the last one it finds.

As a result, when there are multiple gateways,
TestLikelyHomeRouterIPSyscallExec fails.
(At least, I think that that is what is happening;
I am going inferring from observed behavior.)

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick 5d96ecd5e6 net/netstat: remove a bit more unsafe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 3c508a58cc wgengine/filter: don't filter GCP DNS.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 7a01cd27ca net/netstat: remove some unsafe
Just removing any unnecessary unsafe while auditing unsafe usage for #921.
4 years ago
Brad Fitzpatrick 45d96788b5 net/netns: remove use of unsafe on Windows
Found while auditing unsafe for #921 via the list at:

https://github.com/tailscale/tailscale/issues/921#issuecomment-727365383

No need for unsafe here, so remove it.
4 years ago
Josh Bleecher Snyder b0526e8284 net/packet: remove unnecessary mark
There's no need to mask out the bottom four bits
of b[0] if we are about to shift them away.
4 years ago
Josh Bleecher Snyder efad55cf86 net/packet: speed up packet decoding
The compiler is failing to draw the connection between
slice cap and slice len, so is missing some obvious BCE opportunities.
Give it a hint by making the cap equal to the length.
The generated code is smaller and cleaner, and a bit faster.

name              old time/op    new time/op    delta
Decode/tcp4-8       12.2ns ± 1%    11.6ns ± 3%  -5.31%  (p=0.000 n=28+29)
Decode/tcp6-8       12.5ns ± 2%    11.9ns ± 2%  -4.84%  (p=0.000 n=30+30)
Decode/udp4-8       11.5ns ± 1%    11.1ns ± 1%  -3.11%  (p=0.000 n=25+24)
Decode/udp6-8       11.8ns ± 3%    11.4ns ± 1%  -3.08%  (p=0.000 n=30+26)
Decode/icmp4-8      11.0ns ± 3%    10.6ns ± 1%  -3.38%  (p=0.000 n=25+30)
Decode/icmp6-8      11.4ns ± 1%    11.1ns ± 2%  -2.29%  (p=0.000 n=27+30)
Decode/igmp-8       10.3ns ± 0%    10.0ns ± 1%  -3.26%  (p=0.000 n=19+23)
Decode/unknown-8    8.68ns ± 1%    8.38ns ± 1%  -3.55%  (p=0.000 n=28+29)
4 years ago
David Anderson 2d604b3791 net/packet: represent IP6 as two uint64s.
For the operations we perform on these types (mostly net6.Contains),
this encoding is much faster.

Part of #19.

name                   old time/op    new time/op    delta
Filter/icmp4-8           27.5ns ± 1%    28.0ns ± 2%   +1.89%  (p=0.016 n=5+5)
Filter/tcp4_syn_in-8     38.8ns ± 2%    38.3ns ± 1%   -1.24%  (p=0.024 n=5+5)
Filter/tcp4_syn_out-8    27.6ns ±12%    24.6ns ± 1%     ~     (p=0.063 n=5+5)
Filter/udp4_in-8         71.5ns ± 5%    65.9ns ± 1%   -7.94%  (p=0.008 n=5+5)
Filter/udp4_out-8         132ns ±13%     119ns ± 1%  -10.29%  (p=0.008 n=5+5)
Filter/icmp6-8            169ns ±10%      54ns ± 1%  -68.35%  (p=0.008 n=5+5)
Filter/tcp6_syn_in-8      149ns ± 6%      43ns ± 1%  -71.11%  (p=0.008 n=5+5)
Filter/tcp6_syn_out-8    37.7ns ± 4%    24.3ns ± 3%  -35.51%  (p=0.008 n=5+5)
Filter/udp6_in-8          179ns ± 5%     103ns ± 1%  -42.75%  (p=0.008 n=5+5)
Filter/udp6_out-8         156ns ± 3%     191ns ± 1%  +22.54%  (p=0.008 n=5+5)

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 04ff3c91ee wgengine/filter: add full IPv6 support.
Part of #19.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick a2d78b4d3e net/dnscache, control/controlclient: use DNS cache when dialing control
Cache DNS results of earlier login.tailscale.com control dials, and use
them for future dials if DNS is slow or broken.

Fixes various issues with trickier setups with the domain's DNS server
behind a subnet router.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 97e82c6cc0 net/netcheck: remove unused DNSCache from netcheck
It's easy to add back later if/when the TODO is implemented.
4 years ago
Brad Fitzpatrick 19b0cfe89e all: prepare for GOOS=ios in Go 1.16
Work with either way for now on iOS (darwin/arm64 vs ios/arm64).

In February when Go 1.16 comes out we'll have a universal binary for
darwin/arm64 (macOS) and will drop support for Go 1.15 and its
darwin/amd64 meaning iOS. (it'll mean macOS).

Context:

* https://tip.golang.org/doc/go1.16#darwin
* https://github.com/golang/go/issues/38485
* https://github.com/golang/go/issues/42100
4 years ago
David Anderson a38e28da07 net/packet: documentation pass.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson c2cc3acbaf net/packet: remove NewIP, offer only a netaddr constructor.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson d7ee3096dd net/packet: documentation cleanups.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9ef39af2f2 net/packet: fix panic on invalid IHL field.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 22bf48f37c net/packet: remove {get,put}{16,32} indirection to encoding/binary.
name              old time/op    new time/op    delta
Decode/tcp4-8       28.8ns ± 2%    13.1ns ± 4%  -54.44%  (p=0.008 n=5+5)
Decode/tcp6-8       20.6ns ± 1%    12.6ns ± 2%  -38.72%  (p=0.008 n=5+5)
Decode/udp4-8       28.2ns ± 1%    12.1ns ± 4%  -57.01%  (p=0.008 n=5+5)
Decode/udp6-8       20.0ns ± 6%    12.1ns ± 2%  -39.38%  (p=0.008 n=5+5)
Decode/icmp4-8      21.7ns ± 2%    11.5ns ± 1%  -47.01%  (p=0.008 n=5+5)
Decode/icmp6-8      14.1ns ± 2%    11.8ns ± 4%  -16.60%  (p=0.008 n=5+5)
Decode/unknown-8    9.43ns ± 2%    9.30ns ± 3%     ~     (p=0.222 n=5+5)

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 55b1221db2 net/packet: support full IPv6 decoding.
The packet filter still rejects all IPv6, but decodes enough from v6
packets to do something smarter in a followup.

name              time/op
Decode/tcp4-8     28.8ns ± 2%
Decode/tcp6-8     20.6ns ± 1%
Decode/udp4-8     28.2ns ± 1%
Decode/udp6-8     20.0ns ± 6%
Decode/icmp4-8    21.7ns ± 2%
Decode/icmp6-8    14.1ns ± 2%
Decode/unknown-8  9.43ns ± 2%

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 89894c6930 net/packet: add IPv6 source and destination IPs to Parsed.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick d192bd0f86 net/interfaces: ignore bogus proxy URLs from winhttp [windows]
Updates tailscale/corp#853
4 years ago
David Anderson 6e52633c53 net/packet: record allocations in benchmark. 4 years ago
David Anderson 093431f5dd net/packet: s/ParsedPacket/Parsed/ to avoid package stuttering.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 427bf2134f net/packet: rename from wgengine/packet.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 1036f51a56 net/tshttpproxy: aggressively rate-limit error logs in Transport.Proxy path
Otherwise log upload HTTP requests generate proxy errrors which
generate logs which generate HTTP requests which generate proxy
errors which generate more logs, etc.

Fixes #879
4 years ago
Brad Fitzpatrick 7ac91c15bd net/netcheck: fix tests on Windows
Updates #50
4 years ago
Brad Fitzpatrick fd2a30cd32 wgengine/magicsock: make test pass on Windows and without firewall dialog box
Updates #50
4 years ago
David Anderson 5c35c35e7f tsaddr: add helpers for the Tailscale IPv6 range, and 4to6 conversion.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 551e1e99e9 net/netns: don't bind to device for localhost connections
Fixes derphttp test failures on Windows (for #50).
4 years ago
Alex Brainman f2ce64f0c6 wgengine/router: unfork winipcfg-go package, use upstream
Use golang.zx2c4.com/wireguard/windows/tunnel/winipcfg
instead of github.com/tailscale/winipcfg-go package.

Updates #760

Signed-off-by: Alex Brainman <alex.brainman@gmail.com>
4 years ago
Brad Fitzpatrick 6ee219a25d ipn, wgengine, magicsock, tsdns: be quieter and less aggressive when offline
If no interfaces are up, calm down and stop spamming so much. It was
noticed as especially bad on Windows, but probably was bad
everywhere. I just have the best network conditions testing on a
Windows VM.

Updates #604
4 years ago
Brad Fitzpatrick 587bdc4280 ipn, wgengine: disable subnet routes if network has PAC configuration
Not configurable yet.

Updates tailscale/corp#653

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick ed5d5f920f net/interfaces: add interfaces.State.String method 4 years ago
Brad Fitzpatrick cab3eb995f net/interfaces: quiet PAC detection logging in no-PAC case, add benchmark 4 years ago
Brad Fitzpatrick 8051ecff55 net/interfaces: add State.PAC field, populate it on Windows
Not used for anything yet (except logging), but populate the current
proxy autoconfig PAC URL in Interfaces.State.

A future change will do things based on it.
4 years ago
Brad Fitzpatrick 8893c2ee78 net/interfaces, net/netns: move default route interface code to interfaces
To populate interfaces.State.DefaultRouteInterface.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick fda9dc8815 net/netns: document Windows socket binding a bit more
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 963b927d5b net/tshttpproxy: appease staticcheck 4 years ago
Brad Fitzpatrick 5bcac4eaac net/tshttpproxy: add GetProxyForURL negative cache
Otherwise when PAC server is down, we log, and each log entry is a new
HTTP request (from logtail) and a new GetProxyForURL call, which again
logs, non-stop. This is also nicer to the WinHTTP service.

Then also hook up link change notifications to the cache to reset it
if there's a chance the network might work sooner.
4 years ago
David Anderson 8f5b52e571 net/netns: add windows support.
Also remove rebinding logic from the windows router. Magicsock will
instead rebind based on link change signals.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 40e12c17ec net/netcheck: remove mistaken double Mutex.Unlock in error path
Thanks to @dotaheor for noticing.

Fixes #751
4 years ago
Brad Fitzpatrick f65eb4e5c1 net/netstat: start of new netstat package, with Windows for now
This will be used in a future change to do localhost connection
authentication. This lets us quickly map a localhost TCP connection to
a PID. (A future change will then map a pid to a user)

TODO: pull portlist's netstat code into this package. Then portlist
will be fast on Windows without requiring shelling out to netstat.exe.
4 years ago
Brad Fitzpatrick 9c25968b63 net/tshttpproxy: fix typo in Windows code added at least second
I ran tests & vet & staticcheck, but for Linux, not Windows.
(#728 would be nice)
4 years ago
Brad Fitzpatrick b026a638c7 net/tshttpproxy: if winhttp.GetProxyForURL blocks too long, use previous value
We currently have a chickend-and-egg situation in some environments
where we can set up routes that WinHTTP's WPAD/PAC resolution service
needs to download the PAC file to evaluate GetProxyForURL, but the PAC
file is behind a route for which we need to call GetProxyForURL to
e.g. dial a DERP server.

As a short-term fix, just assume that the most recently returned proxy
is good enough for such situations.
4 years ago
Brad Fitzpatrick 74ee374667 net/tshttpproxy: add more winhttp logging
Notably around duration of calls.
4 years ago
Brad Fitzpatrick 1e0be5a458 tshttp, derphttp: send Proxy-Authorization, not Authorization, to proxies
Whoops. But weirdly, sending Authorization sometimes worked?
4 years ago
Brad Fitzpatrick 2bac125cad net/tshttpproxy: move the TS_DEBUG_FAKE_PROXY_AUTH knob up a level 4 years ago
Brad Fitzpatrick 28f9cd06f5 tshttpproxy, controlclient, derphttp, logpolicy: send Negotiate auth to proxies
For Windows only, and only when built with Tailscale's Go tree.

Updates tailscale/corp#583
4 years ago
Brad Fitzpatrick f915ab6552 net/tshttpproxy: add start of Kerberos Negotiate auth to proxies on Windows
For now only used by a new cmd/tailscale debug --get-url
subcommand. Not yet wired up to the places making HTTP requests.

Updates tailscale/corp#583
4 years ago
renthraysk 10cad39abd
net/stun: Fix STUN attribute padding (#710)
net/stun: fix STUN attribute padding

Signed-off-by: RenThraysk <renthraysk@gmail.com>
4 years ago
Brad Fitzpatrick 9be1917c5b net/tshttpproxy: discard secondary Windows proxies for now 4 years ago
Brad Fitzpatrick 1e562886f5 net/netcheck: in verbose mode, probe all regions
So 'tailscale netcheck --verbose' shows all regions' latencies.
4 years ago
Brad Fitzpatrick c5eb57f4d6 net/tshttpproxy: new package, support WPAD/PAC proxies on Windows
Updates tailscale/corp#553

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick dbb4c246fa wgengine/monitor: add Windows linkchange monitor
Updates tailscale/corp#553

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick b97aac1718 net/interfaces: include DefaultRouteInterface in interfaces.State
And log it in wgengine on change. Changing bug in #643.

Updates #643
4 years ago
Josh Bleecher Snyder a9b1e3f9e8 net/interfaces: remove old debug old
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick 25b021388b net/netns, net/interfaces: move defaultRouteInterface, add Android fallback
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder a16a793605 net/interfaces: use syscalls to find private gateway IP address
iOS doesn't let you run subprocesses,
which means we can't use netstat to get routing information.
Instead, use syscalls and grub around in the results.
We keep the old netstat version around,
both for use in non-cgo builds,
and for use testing the syscall-based version.

Note that iOS doesn't ship route.h,
so we include a copy here from the macOS 10.15 SDK
(which is itself unchanged from the 10.14 SDK).

I have tested manually that this yields the correct
gateway IP address on my own macOS and iOS devices.
More coverage would be most welcome.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
Dmytro Shynkevych 28e52a0492
all: dns refactor, add Proxied and PerDomain flags from control (#615)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick c253d4f948 net/interfaces: don't try to fork on iOS in likelyHomeRouterIPDarwin
No subprocesses allowed on iOS. Will need to do this differently later.
4 years ago
Brad Fitzpatrick 33a748bec1 net/interfaces: fix likelyHomeRouterIP on Android 4 years ago
David Anderson a2b4ad839b net/netcheck: lower the hairpin check timeout to 100ms.
This single check is the long pole for netcheck, and significantly slows down magicsock
tests.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 25288567ec net/netcheck: centralize all clock values in one place.
This makes it easier to see how long a netcheck might take, and what
the slow bits might be.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson d60917c0f1 wgengine/router: switch packet marks to avoid conflict with Weave Net.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 10ac066013 all: fix vet warnings 4 years ago
Brad Fitzpatrick 723b9eecb0 net/interfaces: set SysProcAttr.HideWindow to prevent cmd.exe flash on Windows 4 years ago
Brad Fitzpatrick 6c74065053 wgengine/magicsock, tstest/natlab: start hooking up natlab to magicsock
Also adds ephemeral port support to natlab.

Work in progress.

Pairing with @danderson.
4 years ago
Brad Fitzpatrick ecf5d69c7c net/netcheck: add missing comment asked for in earlier code review 4 years ago
Brad Fitzpatrick 742b8b44a8 net/tsaddr: new package to hold Tailscale-specific IPs/ranges
And update existing callers with (near) duplicated cases.
4 years ago
Brad Fitzpatrick 5c6d8e3053 netcheck, tailcfg, interfaces, magicsock: survey UPnP, NAT-PMP, PCP
Don't do anything with UPnP, NAT-PMP, PCP yet, but see how common they
are in the wild.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 32156330a8 net/interfaces: add func LikelyHomeRouterIP
For discovering where we might direct NAT-PMP/PCP/UPnP queries at in
the future.
4 years ago
Brad Fitzpatrick cf74e9039e net/netcheck: add an informative payload in the netcheck UDP helper packets
Per comment from @normanr:
0a5ab533c1 (r40401954)

Updates #188
4 years ago
Brad Fitzpatrick 0a5ab533c1 net/netcheck: send dummy packet out to help airport extreme in hairpin check
At least the Apple Airport Extreme doesn't allow hairpin
sends from a private socket until it's seen traffic from
that src IP:port to something else out on the internet.

See https://github.com/tailscale/tailscale/issues/188#issuecomment-600728643

And it seems that even sending to a likely-filtered RFC 5737
documentation-only IPv4 range is enough to set up the mapping.
So do that for now. In the future we might want to classify networks
that do and don't require this separately. But for now help it.

I've confirmed that this is enough to fix the hairpin check on Avery's
home network, even using the RFC 5737 IP.

Fixes #188
4 years ago
Brad Fitzpatrick 2d6e84e19e net/netcheck, wgengine/magicsock: replace more UDPAddr with netaddr.IPPort 4 years ago
Quoc-Viet Nguyen 15a23ce65f net/stun: Remove unreachable code
- Reuse IP length constants from net package.
- Remove beu16 to make endianness functions consistent.

Signed-off-by: Quoc-Viet Nguyen <afelion@gmail.com>
5 years ago
Brad Fitzpatrick deb113838e net/netcheck: use logger.ArgWriter in logConciseReport, fix comma bug, add tests 5 years ago
Brad Fitzpatrick 24009241bf net/netns: move SOCKS dialing to netns for now
This lets control & logs also use SOCKS dials.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
Brad Fitzpatrick cf0d19f0ab net/tlsdial, derp/derphttp: finish DERPNode.CertName validation 5 years ago
Brad Fitzpatrick a5d6c9d616 net/netns: optimize defaultRouteInterface a bit
It'll be called a bunch, so worth a bit of effort. Could go further, but not yet.
(really, should hook into wgengine/monitor and only re-read on netlink changes?)

name                     old time/op    new time/op    delta
DefaultRouteInterface-8    60.8µs ±11%    44.6µs ± 5%  -26.65%  (p=0.000 n=20+19)

name                     old alloc/op   new alloc/op   delta
DefaultRouteInterface-8    3.29kB ± 0%    0.55kB ± 0%  -83.21%  (p=0.000 n=20+20)

name                     old allocs/op  new allocs/op  delta
DefaultRouteInterface-8      9.00 ± 0%      6.00 ± 0%  -33.33%  (p=0.000 n=20+20)
5 years ago
Brad Fitzpatrick becce82246 net/netns, misc tests: remove TestOnlySkipPrivilegedOps, argv checks
The netns UID check is sufficient for now. We can do something else
later if/when needed.
5 years ago
Brad Fitzpatrick 7a410f9236 net/netns: unindent, refactor to remove some redunant code
Also:
* always error on Control failing. That's very unexpected.
* pull out sockopt funcs into their own funcs for easier future testing
5 years ago
Brad Fitzpatrick 45b139d338 net/netns: remove redundant build tag
Filename is sufficient.
5 years ago
Brad Fitzpatrick dcd7a118d3 net/netns: add a test that tailscaleBypassMark stays in sync between packages 5 years ago
Brad Fitzpatrick 1e837b8e81 net/netns: refactor the sync.Once usage a bit 5 years ago
Avery Pennarun e7ae6a2e06 net/netns, wgengine/router: support Linux machines that don't have 'ip rule'.
We'll use SO_BINDTODEVICE instead of fancy policy routing. This has
some limitations: for example, we will route all traffic through the
interface that has the main "default" (0.0.0.0/0) route, so machines
that have multiple physical interfaces might have to go through DERP to
get to some peers. But machines with multiple physical interfaces are
very likely to have policy routing (ip rule) support anyway.

So far, the only OS I know of that needs this feature is ChromeOS
(crostini). Fixes #245.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Brad Fitzpatrick 765695eaa2 net/netns: also don't err on tailscaled -fake as a regular user
That's one of my dev workflows.
5 years ago
Brad Fitzpatrick 7f68e097dd net/netcheck: fix HTTPS fallback bug from earlier today
My earlier 3fa58303d0 tried to implement
the net/http.Tranhsport.DialTLSContext hook, but I didn't return a
*tls.Conn, so we ended up sending a plaintext HTTP request to an HTTPS
port. The response ended up being Go telling as such, not the
/derp/latency-check handler's response (which is currently still a
404). But we didn't even get the 404.

This happened to work well enough because Go's built-in error response
was still a valid HTTP response that we can measure for timing
purposes, but it's not a great answer. Notably, it means we wouldn't
be able to get a future handler to run server-side and count those
latency requests.
5 years ago
Brad Fitzpatrick 1407540b52 net/netns: don't return an error if we're not root and running the tailscale binary
tailscale netcheck was broken otherwise.

We can fix this a better way later; I'm just fixing a regression in
some way because I'm trying to work on netcheck at the moment.
5 years ago
David Anderson 5114df415e net/netns: set the bypass socket mark on linux.
This allows tailscaled's own traffic to bypass Tailscale-managed routes,
so that things like tailscale-provided default routes don't break
tailscaled itself.

Progress on #144.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
Brad Fitzpatrick 3fa58303d0 netcheck: address some HTTP fallback measurement TODOs 5 years ago
Brad Fitzpatrick 7247e896b5 net/netcheck: add Report.IPv4 and another TODO 5 years ago
David Anderson e9f7d01b91 derp/derphttp: make DERP client use netns for dial-outs. 5 years ago
Brad Fitzpatrick 9e3ad4f79f net/netns: add package for start of network namespace support
And plumb in netcheck STUN packets.

TODO: derphttp, logs, control.

Updates #144

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
Brad Fitzpatrick 0245bbe97b Make netcheck handle v6-only interfaces better, faster.
Also:

* add -verbose flag to cmd/tailscale netcheck
* remove some API from the interfaces package
* convert some of the interfaces package to netaddr.IP
* don't even send IPv4 probes on machines with no IPv4 (or only v4
  loopback)
* and once three regions have replied, stop waiting for other probes
  at 2x the slowest duration.

Updates #376
5 years ago
Avery Pennarun 7cd9ff3dde net/netcheck: fix race condition initializting RegionLatency maps.
Under some conditions, code would try to look things up in the maps
before the first call to updateLatency. I don't see any reason to delay
initialization of the maps, so let's just init them right away when
creating the Report instance.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Brad Fitzpatrick b0c10fa610 stun, netcheck: move under net 5 years ago
David Anderson 657f331e8b net/dnscache: remove unnecessary lint warning. 5 years ago
Elias Naur ad0795efc2 net/dnscache: don't use the Go resolver on Android
The local resolver is not available for apps on Android.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
5 years ago
Brad Fitzpatrick 2244cca5ff net/tlsdial: update package doc to say it's now somewhat useless 5 years ago
Brad Fitzpatrick 172d72a060 Revert "net/tlsdial: add memory-optimized TLS cert verification path for iOS"
This reverts commit 6fcbd4c4d4.

Decided to put it in tailscale/go's crypto/x509 instead.
5 years ago
Brad Fitzpatrick 6fcbd4c4d4 net/tlsdial: add memory-optimized TLS cert verification path for iOS
Behind a build tag for now.
5 years ago
Brad Fitzpatrick b6fa5a69be net/tlsdial: add package for TLS dials, and make DERP & controlclient use it
This will do the iOS-optimized cert checking in a following change.
5 years ago
Brad Fitzpatrick c0697e1feb net/interfaces: add IsExpensive and up state to State
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
Brad Fitzpatrick a4ef345737 cmd/tailscale: add status subcommand
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
David Anderson 315a5e5355 scripts: add a license header checker.
Signed-off-by: David Anderson <dave@natulte.net>
5 years ago
David Crawshaw 41ac4a79d6 net/nettest: new package with net-like testing primitives
This is a lot like wiring up a local UDP socket, read and write
deadlines work. The big difference is the Block feature, which
lets you stop the packet flow without breaking the connection.
This lets you emulate broken sockets and test timeouts actually
work.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
5 years ago
Brad Fitzpatrick 023df9239e Move linkstate boring change filtering to magicsock
So we can at least re-STUN on boring updates.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
Brad Fitzpatrick 5c1e443d34 wgengine/monitor: don't call LinkChange when interfaces look unchanged
Basically, don't trust the OS-level link monitor to only tell you
interesting things. Sanity check it.

Also, move the interfaces package into the net directory now that we
have it.
5 years ago
Brad Fitzpatrick bd0e20f351 net/dnscache: ignore annoying staticcheck check 5 years ago
Brad Fitzpatrick d44325295e net/dnscache: initialize the single Resolver more directly 5 years ago
David Crawshaw cac68fe102 net/dnscache: do not PreferGo on macOS/iOS
With this commit my iPhone can now DERP.
5 years ago
Brad Fitzpatrick 8f0fd01efd net/dnscache: add copyright header to test 5 years ago
David Crawshaw 5a1ce4adae net/dnscache: parse passed CIDR
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
5 years ago
Brad Fitzpatrick 2cff9016e4 net/dnscache: add overly simplistic DNS cache package for selective use
I started to write a full DNS caching resolver and I realized it was
overkill and wouldn't work on Windows even in Go 1.14 yet, so I'm
doing this tiny one instead for now, just for all our netcheck STUN
derp lookups, and connections to DERP servers. (This will be caching a
exactly 8 DNS entries, all ours.)

Fixes #145 (can be better later, of course)
5 years ago