Fixes https://github.com/tailscale/corp/issues/5198
The upstream forwarder will block indefinitely on `udpconn.ReadFrom` if no
reply is recieved, due to the lack of deadline on the connection object.
There still isn't a deadline on the connection object, but the automatic closing
of the context on deadline expiry will close the connection via `closeOnCtxDone`,
unblocking the read and resulting in a normal teardown.
Signed-off-by: Tom DNetto <tom@tailscale.com>
We were marking them as gauges, but they are only ever incremented,
thus counter is more appropriate.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
* net/dns, wgengine: implement DNS over TCP
Signed-off-by: Tom DNetto <tom@tailscale.com>
* wgengine/netstack: intercept only relevant port/protocols to quad-100
Signed-off-by: Tom DNetto <tom@tailscale.com>
This were intended to be pushed to #4408, but in my excitement I
forgot to git push :/ better late than never.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This change wires netstack with a hook for traffic coming from the host
into the tun, allowing interception and handling of traffic to quad-100.
With this hook wired, magicDNS queries over UDP are now handled within
netstack. The existing logic in wgengine to handle magicDNS remains for now,
but its hook operates after the netstack hook so the netstack implementation
takes precedence. This is done in case we need to support platforms with
netstack longer than expected.
Signed-off-by: Tom DNetto <tom@tailscale.com>
A subsequent commit implements handling of magicDNS traffic via netstack.
Implementing this requires a hook for traffic originating from the host and
hitting the tun, so we make another hook to support this.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Moves magicDNS-specific handling out of Resolver & into dns.Manager. This
greatly simplifies the Resolver to solely issuing queries and returning
responses, without channels.
Enforcement of max number of in-flight magicDNS queries, assembly of
synthetic UDP datagrams, and integration with wgengine for
recieving/responding to magicDNS traffic is now entirely in Manager.
This path is being kept around, but ultimately aims to be deleted and
replaced with a netstack-based path.
This commit is part of a series to implement magicDNS using netstack.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Well, goimports actually (which adds the normal import grouping order we do)
Change-Id: I0ce1b1c03185f3741aad67c14a7ec91a838de389
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This updates the fix from #4562 to pick the proxy based on the request
scheme.
Updates #4395, #2605, #4562
Signed-off-by: James Tucker <james@tailscale.com>
Currently we try to use `https://` when we see `https_host`, however
that doesn't work and results in errors like `Received error: fetch
control key: Get "https://controlplane.tailscale.com/key?v=32":
proxyconnect tcp: tls: first record does not look like a TLS handshake`
This indiciates that we are trying to do a HTTPS request to a HTTP
server. Googling suggests that the standard is to use `http` regardless
of `https` or `http` proxy
Updates #4395, #2605
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The connections returned from SystemDial are automatically closed when
there is a major link change.
Also plumb through the dialer to the noise client so that connections
are auto-reset when moving from cellular to WiFi etc.
Updates #3363
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Updates #2067
This should help us determine if more robust control of edns parameters
+ implementing answer truncation is warranted, given its likely complexity.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This populates DNS suffixes ("ts.net", etc) in /etc/resolver/* files
to point to 100.100.100.100 so MagicDNS works.
It also sets search domains.
Updates #4276
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
$ tailscale debug via 0xb 10.2.0.0/16
fd7a:115c:a1e0:b1a:0🅱️a02:0/112
$ tailscale debug via fd7a:115c:a1e0:b1a:0🅱️a02:0/112
site 11 (0xb), 10.2.0.0/16
Previously: 3ae701f0eb
This adds a little debug tool to do CIDR math to make converting between
those ranges easier for now.
Updates #3616
Change-Id: I98302e95d17765bfaced3ecbb71cbd43e84bff46
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
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>
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>
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>
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>
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>
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>
* 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>
Combine the code between `LocalBackend.CheckIPForwarding` and
`controlclient.ipForwardingBroken`.
Fixes#4300
Signed-off-by: Maisem Ali <maisem@tailscale.com>
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>
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>
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>
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>
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>
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>
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>
