Commit Graph

563 Commits (cf9b9a7fec46830815d61f6306408f74f2c4c2b3)

Author SHA1 Message Date
Tom DNetto c8f4dfc8c0 derp/derphttp,net/netcheck: improve netcheck behavior under MITM proxies
In cases where tailscale is operating behind a MITM proxy, we need to consider
that a lot more of the internals of our HTTP requests are visible and may be
used as part of authorization checks. As such, we need to 'behave' as closely
as possible to ideal.

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

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

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

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

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

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

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

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

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

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

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

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

Updates #4194

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

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

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

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

Then people in my tailnet can:

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

Updates #3616, etc

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

Change-Id: I9b49b6ad10410a24b5866b9fbc69d3cae1f600ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Tom 24bdcbe5c7
net/dns, net/dns/resolver, wgengine: refactor DNS request path (#4364)
* net/dns, net/dns/resolver, wgengine: refactor DNS request path

Previously, method calls into the DNS manager/resolver types handled DNS
requests rather than DNS packets. This is fine for UDP as one packet
corresponds to one request or response, however will not suit an
implementation that supports DNS over TCP.

To support PRs implementing this in the future, wgengine delegates
all handling/construction of packets to the magic DNS endpoint, to
the DNS types themselves. Handling IP packets at this level enables
future support for both UDP and TCP.

Signed-off-by: Tom DNetto <tom@tailscale.com>
3 years ago
Tom 6be7931eb4
net/dns/resolver: return symbolic PTR records for TS service IPs (#4361)
Fixes #1233

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

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

Fixes #4300

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

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

Change-Id: Ic44fa2e6661a9c046e725c04fa6b8213d3d4d2b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali b2f269d5b7 net/dnsfallback: do not attempt lookups of IPs.
Currently if the passed in host is an IP, Lookup still attempts to
resolve it with a dns server. This makes it just return the IP directly.

Updates tailscale/corp#4475

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Maisem Ali b45bb577a0 net/dnscache: do not call LookupIPFallback if the context was canceled.
When the context is canceled, dc.dialOne returns an error from line 345.
This causes the defer on line 312 to try to resolve the host again, which
triggers a dns lookup of "127.0.0.1" from derp.

Updates tailscale/corp#4475

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick b647977b33 net/netutil: move some net utils from control/controlhttp to netutil
In prep for reuse elsewhere.

Change-Id: I1b804edf76ac66b9108e6f434e77eab7a7472d69
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
James Tucker 445c04c938
wgengine: inject packetbuffers rather than bytes (#4220)
Plumb the outbound injection path to allow passing netstack
PacketBuffers down to the tun Read, where they are decref'd to enable
buffer re-use. This removes one packet alloc & copy, and reduces GC
pressure by pooling outbound injected packets.

Fixes #2741
Signed-off-by: James Tucker <james@tailscale.com>
3 years ago
Brad Fitzpatrick f2041c9088 all: use strings.Cut even more
Change-Id: I943ce72c6f339589235bddbe10d07799c4e37979
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaron Klotz 6e91f872af net/tshttpproxy: ensure we pass the correct flags to WinHttpOpen on Win7 and Win8.0
The best flag to use on Win7 and Win8.0 is deprecated in Win8.1, so we resolve
the flag depending on OS version info.

Fixes https://github.com/tailscale/tailscale/issues/4201

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
3 years ago
David Anderson 2a412ac9ee .github/workflows: work around golang/go#51629
Incidentally, simplify the go generate CI workflow, by
marking the dnsfallback update non-hermetic (so CI will
skip it) rather than manually filter it out of `go list`.

Updates #4194

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
Josh Bleecher Snyder 0868329936 all: use any instead of interface{}
My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 61ee72940c all: use Go 1.18's strings.Cut
More remain.

Change-Id: I6ec562cc1f687600758deae1c9d7dbd0d04004cb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Josh Bleecher Snyder 0ef74f37a5 net/dns/resolver: remove closure allocation explanation
As of Go 1.18, the register ABI list includes arm64, amd64,
ppc64, and ppc64le. This is a large enough percentage of the
architectures that it's not worth explaining.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick 61cdcf4082 net/interfaces: add FreeBSD default route lookup (portmapping, etc)
Updates #4101 (probably fixes)

Change-Id: I2b75ee3ced276fb7b211f17c382621cf1ef882fa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 2fb087891b net/socks5: always close client connections after serving
Customer reported an issue where the connections were not closing, and
would instead just stay open. This commit makes it so that we close out
the connection regardless of what error we see. I've verified locally
that it fixes the issue, we should add a test for this.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
Brad Fitzpatrick b493ef5b71 net/tsaddr: add func ContainsExitRoutes
Change-Id: I772441a406083e2fe0f9374b2b23d89aac18928f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 55095df644 net/interfaces: get Linux default route from netlink as fallback
If it's in a non-standard table, as it is on Unifi UDM Pro, apparently.

Updates #4038 (probably fixes, but don't have hardware to verify)

Change-Id: I2cb9a098d8bb07d1a97a6045b686aca31763a937
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Dmytro Shynkevych d9a7205be5 net/tstun: set link speed to SPEED_UNKNOWN
Fixes #3933.

Signed-off-by: Dmytro Shynkevych <dm.shynk@gmail.com>
3 years ago
Brad Fitzpatrick 7d897229d9 net/dns: ignore permission errors on Synology DSM7 for now
Updates #4017

Change-Id: Ia7fd4df47588c010dea8e63d88f397cc8eb748e5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick bb94561c96 net/netutil: fix regression where peerapi would get closed after 1st req
I introduced a bug in 8fe503057d when unifying oneConnListener
implementations.

The NewOneConnListenerFrom API was easy to misuse (its Close method
closes the underlying Listener), and we did (via http.Serve, which
closes the listener after use, which meant we were close the peerapi's
listener, even though we only wanted its Addr)

Instead, combine those two constructors into one and pass in the Addr
explicitly, without delegating through to any Listener.

Change-Id: I061d7e5f842e0cada416e7b2dd62100d4f987125
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 2ff481ff10 net/dns: add health check for particular broken-ish Linux DNS config
Updates #3937 (need to write docs before closing)

Change-Id: I1df7244cfbb0303481e2621ee750d21358bd67c6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c988bd6ed1 net/dns/resolvconffile: unify three /etc/resolv.conf parsers into new package
Change-Id: I2120893ca802d12f1bd0407d49077d3672627d33
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8d6cf14456 net/dnscache: don't do bootstrap DNS lookup after most failed dials
If we've already connected to a certain name's IP in the past, don't
assume the problem was DNS related. That just puts unnecessarily load
on our bootstrap DNS servers during regular restarts of Tailscale
infrastructure components.

Also, if we do do a bootstrap DNS lookup and it gives the same IP(s)
that we already tried, don't try them again.

Change-Id: I743e8991a7f957381b8e4c1508b8e9d0df1782fe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 903988b392 net/dnscache: refactor from func-y closure-y state to types & methods
No behavior changes (intended, at least).

This is in prep for future changes to this package, which would get
too complicated in the current style.

Change-Id: Ic260f8e34ae2f64f34819d4a56e38bee8d8ac5ce
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8267ea0f80 net/tstun: remove TODO that's done
This TODO was both added and fixed in 506c727e3.

As I recall, I wasn't originally going to do it because it seemed
annoying, so I wrote the TODO, but then I felt bad about it and just
did it, but forgot to remove the TODO.

Change-Id: I8f3514809ad69b447c62bfeb0a703678c1aec9a3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8fe503057d net/netutil: unify two oneConnListeners into a new package
I was about to add a third copy, so unify them now instead.

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

Change-Id: I6f89bb75fdb24c13f61be9b400610772756db1ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 37e7a387ff net/dns: remove some unused code for detecting systemd-resolved [Linux]
Change-Id: I19c5fd2cdacfb9e5b688ccd9b4336ae4edffc445
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 15599323a1 net/dns: fix systemd-resolved detection race at boot
If systemd-resolved is enabled but not running (or not yet running,
such as early boot) and resolv.conf is old/dangling, we weren't
detecting systemd-resolved.

This moves its ping earlier, which will trigger it to start up and
write its file.

Updates #3362 (likely fixes)
Updates #3531 (likely fixes)

Change-Id: I6392944ac59f600571c43b8f7a677df224f2beed
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Denton Gentry dbea8217ac net/dns: add NetworkManager regression test
Use the exact /etc/resolv.conf file from a user report.
Updates https://github.com/tailscale/tailscale/issues/3531

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
3 years ago
Brad Fitzpatrick 2a67beaacf net/interfaces: bound Linux /proc/net/route parsing
tailscaled was using 100% CPU on a machine with ~1M lines, 100MB+
of /proc/net/route data.

Two problems: in likelyHomeRouterIPLinux, we didn't stop reading the
file once we found the default route (which is on the first non-header
line when present). Which meant it was finding the answer and then
parsing 100MB over 1M lines unnecessarily. Second was that if the
default route isn't present, it'd read to the end of the file looking
for it. If it's not in the first 1,000 lines, it ain't coming, or at
least isn't worth having. (it's only used for discovering a potential
UPnP/PMP/PCP server, which is very unlikely to be present in the
environment of a machine with a ton of routes)

Change-Id: I2c4a291ab7f26aedc13885d79237b8f05c2fd8e4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaron Bieber e5cd765e00 net/dns/resolvd: properly handle not having "search" entries
This prevents adding an empty "search" line when no search domains are set.

Signed-off-by: Aaron Bieber <aaron@bolddaemon.com>
3 years ago
Brad Fitzpatrick 1af26222b6 go.mod: bump netstack, switch to upstream netstack
Now that Go 1.17 has module graph pruning
(https://go.dev/doc/go1.17#go-command), we should be able to use
upstream netstack without breaking our private repo's build
that then depends on the tailscale.com Go module.

This is that experiment.

Updates #1518 (the original bug to break out netstack to own module)
Updates #2642 (this updates netstack, but doesn't remove workaround)

Change-Id: I27a252c74a517053462e5250db09f379de8ac8ff
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 41fd4eab5c envknob: add new package for all the strconv.ParseBool(os.Getenv(..))
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.

Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 6feb8f4c51 net/dns: log why resolved does not look like it's on use [Linux]
Updates #3742
Updates #3531

Change-Id: I9fc7fa0f4bcab1cf8001ba92408c660a5b25f105
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Aaron Bieber 411c6c316c net/dns/resolvd: store nameservers
Currently only search domains are stored. This was an oversight
(under?) on my part.

As things are now, when MagicDNS is on and "Override local DNS" is
off, the dns forwarder has to timeout before names resolve. This
introduces a pretty annoying lang that makes everything feel
extremely slow. You will also see an error: "upstream nameservers
not set".

I tested with "Override local DNS" on and off. In both situations
things seem to function as expected (and quickly).

Signed-off-by: Aaron Bieber <aaron@bolddaemon.com>
3 years ago
Brad Fitzpatrick c64af5e676 wgengine/netstack: clear TCP ECN bits before giving to gvisor
Updates #2642

Change-Id: Ic219442a2656dd9dc99ae1dd91e907fd3d924987
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 390490e7b1 net/packet: fix typo in comment
Change-Id: Ia666609fde18db44bf38d4e656f490fc372ac3b6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago