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>
pull/4410/head
phirework 3 years ago committed by GitHub
parent 8de7f9bff7
commit 83c734a6e0
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

@ -204,6 +204,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
tailscale.com/logtail/filch from tailscale.com/logpolicy
💣 tailscale.com/metrics from tailscale.com/derp+
tailscale.com/net/dns from tailscale.com/cmd/tailscaled+
tailscale.com/net/dns/publicdns from tailscale.com/net/dns/resolver
tailscale.com/net/dns/resolvconffile from tailscale.com/net/dns+
tailscale.com/net/dns/resolver from tailscale.com/ipn/ipnlocal+
tailscale.com/net/dnscache from tailscale.com/control/controlclient+

@ -0,0 +1,98 @@
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package publicdns contains mapping and helpers for working with
// public DNS providers.
package publicdns
import (
"sync"
"inet.af/netaddr"
)
var knownDoH = map[netaddr.IP]string{} // 8.8.8.8 => "https://..."
var dohIPsOfBase = map[string][]netaddr.IP{}
var populateOnce sync.Once
// KnownDoH returns a map of well-known public DNS IPs to their DoH URL.
// The returned map should not be modified.
func KnownDoH() map[netaddr.IP]string {
populateOnce.Do(populate)
return knownDoH
}
// DoHIPsOfBase returns a map of DNS server IP addresses keyed
// by their DoH URL. It is the inverse of KnownDoH.
func DoHIPsOfBase() map[string][]netaddr.IP {
populateOnce.Do(populate)
return dohIPsOfBase
}
// DoHV6 returns the first IPv6 DNS address from a given public DNS provider
// if found, along with a boolean indicating success.
func DoHV6(base string) (ip netaddr.IP, ok bool) {
for _, ip := range dohIPsOfBase[base] {
if ip.Is6() {
return ip, true
}
}
return ip, false
}
// addDoH parses a given well-formed ip string into a netaddr.IP type and
// adds it to both knownDoH and dohIPsOFBase maps.
func addDoH(ipStr, base string) {
ip := netaddr.MustParseIP(ipStr)
knownDoH[ip] = base
dohIPsOfBase[base] = append(dohIPsOfBase[base], ip)
}
// populate is called once to initialize the knownDoH and dohIPsOfBase maps.
func populate() {
// Cloudflare
addDoH("1.1.1.1", "https://cloudflare-dns.com/dns-query")
addDoH("1.0.0.1", "https://cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1111", "https://cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1001", "https://cloudflare-dns.com/dns-query")
// Cloudflare -Malware
addDoH("1.1.1.2", "https://security.cloudflare-dns.com/dns-query")
addDoH("1.0.0.2", "https://security.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1112", "https://security.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1002", "https://security.cloudflare-dns.com/dns-query")
// Cloudflare -Malware -Adult
addDoH("1.1.1.3", "https://family.cloudflare-dns.com/dns-query")
addDoH("1.0.0.3", "https://family.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1113", "https://family.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1003", "https://family.cloudflare-dns.com/dns-query")
// Google
addDoH("8.8.8.8", "https://dns.google/dns-query")
addDoH("8.8.4.4", "https://dns.google/dns-query")
addDoH("2001:4860:4860::8888", "https://dns.google/dns-query")
addDoH("2001:4860:4860::8844", "https://dns.google/dns-query")
// OpenDNS
// TODO(bradfitz): OpenDNS is unique amongst this current set in that
// its DoH DNS names resolve to different IPs than its normal DNS
// IPs. Support that later. For now we assume that they're the same.
// addDoH("208.67.222.222", "https://doh.opendns.com/dns-query")
// addDoH("208.67.220.220", "https://doh.opendns.com/dns-query")
// addDoH("208.67.222.123", "https://doh.familyshield.opendns.com/dns-query")
// addDoH("208.67.220.123", "https://doh.familyshield.opendns.com/dns-query")
// Quad9
addDoH("9.9.9.9", "https://dns.quad9.net/dns-query")
addDoH("149.112.112.112", "https://dns.quad9.net/dns-query")
addDoH("2620:fe::fe", "https://dns.quad9.net/dns-query")
addDoH("2620:fe::fe:9", "https://dns.quad9.net/dns-query")
// Quad9 -DNSSEC
addDoH("9.9.9.10", "https://dns10.quad9.net/dns-query")
addDoH("149.112.112.10", "https://dns10.quad9.net/dns-query")
addDoH("2620:fe::10", "https://dns10.quad9.net/dns-query")
addDoH("2620:fe::fe:10", "https://dns10.quad9.net/dns-query")
}

@ -0,0 +1,41 @@
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package publicdns
import (
"testing"
"inet.af/netaddr"
)
func TestInit(t *testing.T) {
for baseKey, baseSet := range DoHIPsOfBase() {
for _, addr := range baseSet {
if KnownDoH()[addr] != baseKey {
t.Errorf("Expected %v to map to %s, got %s", addr, baseKey, KnownDoH()[addr])
}
}
}
}
func TestDohV6(t *testing.T) {
tests := []struct {
in string
firstIP netaddr.IP
want bool
}{
{"https://cloudflare-dns.com/dns-query", netaddr.MustParseIP("2606:4700:4700::1111"), true},
{"https://dns.google/dns-query", netaddr.MustParseIP("2001:4860:4860::8888"), true},
{"bogus", netaddr.IP{}, false},
}
for _, test := range tests {
t.Run(test.in, func(t *testing.T) {
ip, ok := DoHV6(test.in)
if ok != test.want || ip != test.firstIP {
t.Errorf("DohV6 got (%v: IPv6 %v) for %v, want (%v: IPv6 %v)", ip, ok, test.in, test.firstIP, test.want)
}
})
}
}

@ -1,4 +1,4 @@
// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
@ -11,6 +11,7 @@ import (
"testing"
"golang.org/x/net/dns/dnsmessage"
"tailscale.com/net/dns/publicdns"
)
var testDoH = flag.Bool("test-doh", false, "do real DoH tests against the network")
@ -40,7 +41,7 @@ func TestDoH(t *testing.T) {
if !*testDoH {
t.Skip("skipping manual test without --test-doh flag")
}
if len(knownDoH) == 0 {
if len(publicdns.KnownDoH()) == 0 {
t.Fatal("no known DoH")
}
@ -48,7 +49,7 @@ func TestDoH(t *testing.T) {
dohSem: make(chan struct{}, 10),
}
for ip := range knownDoH {
for ip := range publicdns.KnownDoH() {
t.Run(ip.String(), func(t *testing.T) {
urlBase, c, ok := f.getKnownDoHClient(ip)
if !ok {
@ -85,9 +86,9 @@ func TestDoH(t *testing.T) {
}
func TestDoHV6Fallback(t *testing.T) {
for ip, base := range knownDoH {
for ip, base := range publicdns.KnownDoH() {
if ip.Is4() {
ip6, ok := dohV6(base)
ip6, ok := publicdns.DoHV6(base)
if !ok {
t.Errorf("no v6 DoH known for %v", ip)
} else if !ip6.Is6() {

@ -25,6 +25,7 @@ import (
dns "golang.org/x/net/dns/dnsmessage"
"inet.af/netaddr"
"tailscale.com/hostinfo"
"tailscale.com/net/dns/publicdns"
"tailscale.com/net/neterror"
"tailscale.com/net/netns"
"tailscale.com/net/tsdial"
@ -242,7 +243,7 @@ func resolversWithDelays(resolvers []dnstype.Resolver) []resolverAndDelay {
rr := make([]resolverAndDelay, len(resolvers))
for _, r := range resolvers {
if ip, err := netaddr.ParseIP(r.Addr); err == nil {
if host, ok := knownDoH[ip]; ok {
if host, ok := publicdns.KnownDoH()[ip]; ok {
total[hostAndFam{host, ip.BitLen()}]++
}
}
@ -252,7 +253,7 @@ func resolversWithDelays(resolvers []dnstype.Resolver) []resolverAndDelay {
for i, r := range resolvers {
var startDelay time.Duration
if ip, err := netaddr.ParseIP(r.Addr); err == nil {
if host, ok := knownDoH[ip]; ok {
if host, ok := publicdns.KnownDoH()[ip]; ok {
key4 := hostAndFam{host, 32}
key6 := hostAndFam{host, 128}
switch {
@ -332,7 +333,7 @@ func (f *forwarder) packetListener(ip netaddr.IP) (packetListener, error) {
}
func (f *forwarder) getKnownDoHClient(ip netaddr.IP) (urlBase string, c *http.Client, ok bool) {
urlBase, ok = knownDoH[ip]
urlBase, ok = publicdns.KnownDoH()[ip]
if !ok {
return
}
@ -356,7 +357,7 @@ func (f *forwarder) getKnownDoHClient(ip netaddr.IP) (urlBase string, c *http.Cl
c, err := nsDialer.DialContext(ctx, "tcp", net.JoinHostPort(ip.String(), "443"))
// If v4 failed, try an equivalent v6 also in the time remaining.
if err != nil && ctx.Err() == nil {
if ip6, ok := dohV6(urlBase); ok && ip.Is4() {
if ip6, ok := publicdns.DoHV6(urlBase); ok && ip.Is4() {
if c6, err := nsDialer.DialContext(ctx, "tcp", net.JoinHostPort(ip6.String(), "443")); err == nil {
return c6, nil
}
@ -776,69 +777,3 @@ func (p *closePool) Close() error {
}
return nil
}
var knownDoH = map[netaddr.IP]string{} // 8.8.8.8 => "https://..."
var dohIPsOfBase = map[string][]netaddr.IP{}
func addDoH(ipStr, base string) {
ip := netaddr.MustParseIP(ipStr)
knownDoH[ip] = base
dohIPsOfBase[base] = append(dohIPsOfBase[base], ip)
}
func dohV6(base string) (ip netaddr.IP, ok bool) {
for _, ip := range dohIPsOfBase[base] {
if ip.Is6() {
return ip, true
}
}
return ip, false
}
func init() {
// Cloudflare
addDoH("1.1.1.1", "https://cloudflare-dns.com/dns-query")
addDoH("1.0.0.1", "https://cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1111", "https://cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1001", "https://cloudflare-dns.com/dns-query")
// Cloudflare -Malware
addDoH("1.1.1.2", "https://security.cloudflare-dns.com/dns-query")
addDoH("1.0.0.2", "https://security.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1112", "https://security.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1002", "https://security.cloudflare-dns.com/dns-query")
// Cloudflare -Malware -Adult
addDoH("1.1.1.3", "https://family.cloudflare-dns.com/dns-query")
addDoH("1.0.0.3", "https://family.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1113", "https://family.cloudflare-dns.com/dns-query")
addDoH("2606:4700:4700::1003", "https://family.cloudflare-dns.com/dns-query")
// Google
addDoH("8.8.8.8", "https://dns.google/dns-query")
addDoH("8.8.4.4", "https://dns.google/dns-query")
addDoH("2001:4860:4860::8888", "https://dns.google/dns-query")
addDoH("2001:4860:4860::8844", "https://dns.google/dns-query")
// OpenDNS
// TODO(bradfitz): OpenDNS is unique amongst this current set in that
// its DoH DNS names resolve to different IPs than its normal DNS
// IPs. Support that later. For now we assume that they're the same.
// addDoH("208.67.222.222", "https://doh.opendns.com/dns-query")
// addDoH("208.67.220.220", "https://doh.opendns.com/dns-query")
// addDoH("208.67.222.123", "https://doh.familyshield.opendns.com/dns-query")
// addDoH("208.67.220.123", "https://doh.familyshield.opendns.com/dns-query")
// Quad9
addDoH("9.9.9.9", "https://dns.quad9.net/dns-query")
addDoH("149.112.112.112", "https://dns.quad9.net/dns-query")
addDoH("2620:fe::fe", "https://dns.quad9.net/dns-query")
addDoH("2620:fe::fe:9", "https://dns.quad9.net/dns-query")
// Quad9 -DNSSEC
addDoH("9.9.9.10", "https://dns10.quad9.net/dns-query")
addDoH("149.112.112.10", "https://dns10.quad9.net/dns-query")
addDoH("2620:fe::10", "https://dns10.quad9.net/dns-query")
addDoH("2620:fe::fe:10", "https://dns10.quad9.net/dns-query")
}

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