Commit Graph

36 Commits (e3a49525277b4ea40780e6d120d17d60a30925d8)

Author SHA1 Message Date
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
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
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 24a04d07d1 net/dns/resolver: handle tabs as whitespace when ExitDNS parses resolv.conf
On Synology, the /etc/resolv.conf has tabs in it, which this
resolv.conf parser (we have two, sigh) didn't handle.

Updates #3710

Change-Id: I86f8e09ad1867ee32fa211e85c382a27191418ea
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 8d0ed1c9ba net/dns/resolver: on Android, make ExitDNS use net package for DNS
Like Windows.

Updates #1738

Change-Id: I9f26bc58ce7e760c749786fbe5d9952c99eeb91c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 506c727e30 ipnlocal, net/{dns,tsaddr,tstun}, wgengine: support MagicDNS on IPv6
Fixes #3660

RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled.

Change-Id: I001e983df5feeb65289abe5012dedd177b841b45
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 0848b36dd2 net/dns/resolver: add metrics to PTR lookup misses
Updates tailscale/corp#3326

Change-Id: I58077d889a3b58ef0633267c92ffb265686ce152
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick cced414c7d net/dns/resolver: add Windows ExitDNS service support, using net package
Updates #1713
Updates #835

Change-Id: Ia71e96d0632c2d617b401695ad68301b07c1c2ec
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick c37af58ea4 net/tsdial: move more weirdo dialing into new tsdial package, plumb
Not done yet, but this move more of the outbound dial special casing
from random packages into tsdial, which aspires to be the one unified
place for all outbound dialing shenanigans.

Then this plumbs it all around, so everybody is ultimately
holding on to the same dialer.

As of this commit, macOS/iOS using an exit node should be able to
reach to the exit node's DoH DNS proxy over peerapi, doing the sockopt
to stay within the Network Extension.

A number of steps remain, including but limited to:

* move a bunch more random dialing stuff

* make netstack-mode tailscaled be able to use exit node's DNS proxy,
  teaching tsdial's resolver to use it when an exit node is in use.

Updates #1713

Change-Id: I1e8ee378f125421c2b816f47bc2c6d913ddcd2f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 135580a5a8 tailcfg, ipn/ipnlocal, net/dns: forward exit node DNS on Unix to system DNS
Updates #1713

Change-Id: I4c073fec0992d9e01a9a4ce97087d5af0efdc68d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 78b0bd2957 net/dns/resolver: add clientmetrics for DNS
Fixes tailscale/corp#1811

Change-Id: I864d11e0332a177e8c5ff403591bff6fec548f5a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 25525b7754 net/dns/resolver, ipn/ipnlocal: wire up peerapi DoH server to DNS forwarder
Updates #1713

Change-Id: Ia4ed9d8c9cef0e70aa6d30f2852eaab80f5f695a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 676fb458c3 net/dns/resolver: make hasRDNSBonjourPrefix match shorter queries too
Fixes tailscale/corp#2886
Updates tailscale/corp#2820
Updates #2442

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 47044f3af7 net/dns/resolver: fix log prefix
The passed in logf already has a "dns: " prefix so they were
doubled up.
3 years ago
David Crawshaw 9502b515f1 net/dns: replace resolver IPs with type for DoH
We currently plumb full URLs for DNS resolvers from the control server
down to the client. But when we pass the values into the net/dns
package, we throw away any URL that isn't a bare IP. This commit
continues the plumbing, and gets the URL all the way to the built in
forwarder. (It stops before plumbing URLs into the OS configurations
that can handle them.)

For #2596

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
David Anderson 39748e9562 net/dns/resolver: authoritatively return NXDOMAIN for reverse zones we own.
Fixes #2774

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
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 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
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
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>
3 years ago
David Anderson 1a371b93be util/dnsname: add FQDN type, use throughout codebase.
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 1bf91c8123 net/dns/resolver: remove unused err return value.
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