tailscale/net/dns/manager_test.go
Brad Fitzpatrick 58abae1f83 net/dns/{publicdns,resolver}: add NextDNS DoH support
NextDNS is unique in that users create accounts and then get
user-specific DNS IPs & DoH URLs.

For DoH, the customer ID is in the URL path.

For IPv6, the IP address includes the customer ID in the lower bits.

For IPv4, there's a fragile "IP linking" mechanism to associate your
public IPv4 with an assigned NextDNS IPv4 and that tuple maps to your
customer ID.

We don't use the IP linking mechanism.

Instead, NextDNS is DoH-only. Which means using NextDNS necessarily
shunts all DNS traffic through 100.100.100.100 (programming the OS to
use 100.100.100.100 as the global resolver) because operating systems
can't usually do DoH themselves.

Once it's in Tailscale's DoH client, we then connect out to the known
NextDNS IPv4/IPv6 anycast addresses.

If the control plane sends the client a NextDNS IPv6 address, we then
map it to the corresponding NextDNS DoH with the same client ID, and
we dial that DoH server using the combination of v4/v6 anycast IPs.

Updates #2452

Change-Id: I3439d798d21d5fc9df5a2701839910f5bef85463
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-08 12:50:32 -07:00

724 lines
20 KiB
Go

// Copyright (c) 2021 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 dns
import (
"net/netip"
"runtime"
"strings"
"testing"
"github.com/google/go-cmp/cmp"
"github.com/google/go-cmp/cmp/cmpopts"
"tailscale.com/net/dns/resolver"
"tailscale.com/net/tsdial"
"tailscale.com/types/dnstype"
"tailscale.com/util/dnsname"
)
type fakeOSConfigurator struct {
SplitDNS bool
BaseConfig OSConfig
OSConfig OSConfig
ResolverConfig resolver.Config
}
func (c *fakeOSConfigurator) SetDNS(cfg OSConfig) error {
if !c.SplitDNS && len(cfg.MatchDomains) > 0 {
panic("split DNS config passed to non-split OSConfigurator")
}
c.OSConfig = cfg
return nil
}
func (c *fakeOSConfigurator) SetResolver(cfg resolver.Config) {
c.ResolverConfig = cfg
}
func (c *fakeOSConfigurator) SupportsSplitDNS() bool {
return c.SplitDNS
}
func (c *fakeOSConfigurator) GetBaseConfig() (OSConfig, error) {
return c.BaseConfig, nil
}
func (c *fakeOSConfigurator) Close() error { return nil }
func TestCompileHostEntries(t *testing.T) {
tests := []struct {
name string
cfg Config
want []*HostEntry
}{
{
name: "empty",
},
{
name: "no-search-domains",
cfg: Config{
Hosts: map[dnsname.FQDN][]netip.Addr{
"a.b.c.": {netip.MustParseAddr("1.1.1.1")},
},
},
},
{
name: "search-domains",
cfg: Config{
Hosts: map[dnsname.FQDN][]netip.Addr{
"a.foo.ts.net.": {netip.MustParseAddr("1.1.1.1")},
"b.foo.ts.net.": {netip.MustParseAddr("1.1.1.2")},
"c.foo.ts.net.": {netip.MustParseAddr("1.1.1.3")},
"d.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.4")},
"d.foo.ts.net.": {netip.MustParseAddr("1.1.1.4")},
"e.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.5")},
"random.example.com.": {netip.MustParseAddr("1.1.1.1")},
"other.example.com.": {netip.MustParseAddr("1.1.1.2")},
"othertoo.example.com.": {netip.MustParseAddr("1.1.5.2")},
},
SearchDomains: []dnsname.FQDN{"foo.ts.net.", "foo.beta.tailscale.net."},
},
want: []*HostEntry{
{Addr: netip.MustParseAddr("1.1.1.1"), Hosts: []string{"a.foo.ts.net.", "a"}},
{Addr: netip.MustParseAddr("1.1.1.2"), Hosts: []string{"b.foo.ts.net.", "b"}},
{Addr: netip.MustParseAddr("1.1.1.3"), Hosts: []string{"c.foo.ts.net.", "c"}},
{Addr: netip.MustParseAddr("1.1.1.4"), Hosts: []string{"d.foo.beta.tailscale.net."}},
{Addr: netip.MustParseAddr("1.1.1.4"), Hosts: []string{"d.foo.ts.net.", "d"}},
{Addr: netip.MustParseAddr("1.1.1.5"), Hosts: []string{"e.foo.beta.tailscale.net.", "e"}},
},
},
{
name: "only-exact-subdomain-match",
cfg: Config{
Hosts: map[dnsname.FQDN][]netip.Addr{
"e.foo.ts.net.": {netip.MustParseAddr("1.1.1.5")},
"e.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.5")},
"e.ignored.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.6")},
},
SearchDomains: []dnsname.FQDN{"foo.ts.net.", "foo.beta.tailscale.net."},
},
want: []*HostEntry{
{Addr: netip.MustParseAddr("1.1.1.5"), Hosts: []string{"e.foo.beta.tailscale.net."}},
{Addr: netip.MustParseAddr("1.1.1.5"), Hosts: []string{"e.foo.ts.net.", "e"}},
},
},
{
name: "unmatched-domains",
cfg: Config{
Hosts: map[dnsname.FQDN][]netip.Addr{
"d.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.4")},
"d.foo.ts.net.": {netip.MustParseAddr("1.1.1.4")},
"random.example.com.": {netip.MustParseAddr("1.1.1.1")},
"other.example.com.": {netip.MustParseAddr("1.1.1.2")},
"othertoo.example.com.": {netip.MustParseAddr("1.1.5.2")},
},
SearchDomains: []dnsname.FQDN{"foo.ts.net.", "foo.beta.tailscale.net."},
},
want: []*HostEntry{
{Addr: netip.MustParseAddr("1.1.1.4"), Hosts: []string{"d.foo.beta.tailscale.net."}},
{Addr: netip.MustParseAddr("1.1.1.4"), Hosts: []string{"d.foo.ts.net.", "d"}},
},
},
{
name: "overlaps",
cfg: Config{
Hosts: map[dnsname.FQDN][]netip.Addr{
"h1.foo.ts.net.": {netip.MustParseAddr("1.1.1.3")},
"h1.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.2")},
"h2.foo.ts.net.": {netip.MustParseAddr("1.1.1.1")},
"h2.foo.beta.tailscale.net.": {netip.MustParseAddr("1.1.1.1")},
"example.com": {netip.MustParseAddr("1.1.1.1")},
},
SearchDomains: []dnsname.FQDN{"foo.ts.net.", "foo.beta.tailscale.net."},
},
want: []*HostEntry{
{Addr: netip.MustParseAddr("1.1.1.2"), Hosts: []string{"h1.foo.beta.tailscale.net."}},
{Addr: netip.MustParseAddr("1.1.1.3"), Hosts: []string{"h1.foo.ts.net.", "h1"}},
{Addr: netip.MustParseAddr("1.1.1.1"), Hosts: []string{"h2.foo.beta.tailscale.net."}},
{Addr: netip.MustParseAddr("1.1.1.1"), Hosts: []string{"h2.foo.ts.net.", "h2"}},
},
},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
got := compileHostEntries(tc.cfg)
if diff := cmp.Diff(tc.want, got, cmp.Comparer(func(a, b netip.Addr) bool {
return a == b
})); diff != "" {
t.Errorf("mismatch (-want +got):\n%s", diff)
}
})
}
}
func TestManager(t *testing.T) {
if runtime.GOOS == "windows" {
t.Skipf("test's assumptions break because of https://github.com/tailscale/corp/issues/1662")
}
// Note: these tests assume that it's safe to switch the
// OSConfigurator's split-dns support on and off between Set
// calls. Empirically this is currently true, because we reprobe
// the support every time we generate configs. It would be
// reasonable to make this unsupported as well, in which case
// these tests will need tweaking.
tests := []struct {
name string
in Config
split bool
bs OSConfig
os OSConfig
rs resolver.Config
}{
{
name: "empty",
},
{
name: "search-only",
in: Config{
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
os: OSConfig{
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
},
{
// Regression test for https://github.com/tailscale/tailscale/issues/1886
name: "hosts-only",
in: Config{
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
},
rs: resolver.Config{
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
},
},
{
// If Hosts are specified (i.e. ExtraRecords) that aren't a split
// DNS route and a global resolver is specified, then make
// everything go via 100.100.100.100.
name: "hosts-with-global-dns-uses-quad100",
split: true,
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
Hosts: hosts(
"foo.tld.", "1.2.3.4",
"bar.tld.", "2.3.4.5"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
},
rs: resolver.Config{
Hosts: hosts(
"foo.tld.", "1.2.3.4",
"bar.tld.", "2.3.4.5"),
Routes: upstreams(".", "1.1.1.1", "9.9.9.9"),
},
},
{
// This is the above hosts-with-global-dns-uses-quad100 test but
// verifying that if global DNS servers aren't set (the 1.1.1.1 and
// 9.9.9.9 above), then we don't configure 100.100.100.100 as the
// resolver.
name: "hosts-without-global-dns-not-use-quad100",
split: true,
in: Config{
Hosts: hosts(
"foo.tld.", "1.2.3.4",
"bar.tld.", "2.3.4.5"),
},
os: OSConfig{},
rs: resolver.Config{
Hosts: hosts(
"foo.tld.", "1.2.3.4",
"bar.tld.", "2.3.4.5"),
},
},
{
// This tests that ExtraRecords (foo.tld and bar.tld here) don't trigger forcing
// traffic through 100.100.100.100 if there's Split DNS support and the extra
// records are part of a split DNS route.
name: "hosts-with-extrarecord-hosts-with-routes-no-quad100",
split: true,
in: Config{
Routes: upstreams(
"tld.", "4.4.4.4",
),
Hosts: hosts(
"foo.tld.", "1.2.3.4",
"bar.tld.", "2.3.4.5"),
},
os: OSConfig{
Nameservers: mustIPs("4.4.4.4"),
MatchDomains: fqdns("tld."),
},
rs: resolver.Config{
Hosts: hosts(
"foo.tld.", "1.2.3.4",
"bar.tld.", "2.3.4.5"),
},
},
{
name: "corp",
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
os: OSConfig{
Nameservers: mustIPs("1.1.1.1", "9.9.9.9"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
},
{
name: "corp-split",
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("1.1.1.1", "9.9.9.9"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
},
{
name: "corp-magic",
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
Routes: upstreams("ts.com", ""),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
rs: resolver.Config{
Routes: upstreams(".", "1.1.1.1", "9.9.9.9"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
LocalDomains: fqdns("ts.com."),
},
},
{
name: "corp-magic-split",
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
Routes: upstreams("ts.com", ""),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
rs: resolver.Config{
Routes: upstreams(".", "1.1.1.1", "9.9.9.9"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
LocalDomains: fqdns("ts.com."),
},
},
{
name: "corp-routes",
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
Routes: upstreams("corp.com", "2.2.2.2"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
rs: resolver.Config{
Routes: upstreams(
".", "1.1.1.1", "9.9.9.9",
"corp.com.", "2.2.2.2"),
},
},
{
name: "corp-routes-split",
in: Config{
DefaultResolvers: mustRes("1.1.1.1", "9.9.9.9"),
Routes: upstreams("corp.com", "2.2.2.2"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
rs: resolver.Config{
Routes: upstreams(
".", "1.1.1.1", "9.9.9.9",
"corp.com.", "2.2.2.2"),
},
},
{
name: "routes",
in: Config{
Routes: upstreams("corp.com", "2.2.2.2"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
bs: OSConfig{
Nameservers: mustIPs("8.8.8.8"),
SearchDomains: fqdns("coffee.shop"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf", "coffee.shop"),
},
rs: resolver.Config{
Routes: upstreams(
".", "8.8.8.8",
"corp.com.", "2.2.2.2"),
},
},
{
name: "routes-split",
in: Config{
Routes: upstreams("corp.com", "2.2.2.2"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("2.2.2.2"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
MatchDomains: fqdns("corp.com"),
},
},
{
name: "routes-multi",
in: Config{
Routes: upstreams(
"corp.com", "2.2.2.2",
"bigco.net", "3.3.3.3"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
bs: OSConfig{
Nameservers: mustIPs("8.8.8.8"),
SearchDomains: fqdns("coffee.shop"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf", "coffee.shop"),
},
rs: resolver.Config{
Routes: upstreams(
".", "8.8.8.8",
"corp.com.", "2.2.2.2",
"bigco.net.", "3.3.3.3"),
},
},
{
name: "routes-multi-split",
in: Config{
Routes: upstreams(
"corp.com", "2.2.2.2",
"bigco.net", "3.3.3.3"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
MatchDomains: fqdns("bigco.net", "corp.com"),
},
rs: resolver.Config{
Routes: upstreams(
"corp.com.", "2.2.2.2",
"bigco.net.", "3.3.3.3"),
},
},
{
name: "magic",
in: Config{
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
Routes: upstreams("ts.com", ""),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
bs: OSConfig{
Nameservers: mustIPs("8.8.8.8"),
SearchDomains: fqdns("coffee.shop"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf", "coffee.shop"),
},
rs: resolver.Config{
Routes: upstreams(".", "8.8.8.8"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
LocalDomains: fqdns("ts.com."),
},
},
{
name: "magic-split",
in: Config{
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
Routes: upstreams("ts.com", ""),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
MatchDomains: fqdns("ts.com"),
},
rs: resolver.Config{
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
LocalDomains: fqdns("ts.com."),
},
},
{
name: "routes-magic",
in: Config{
Routes: upstreams("corp.com", "2.2.2.2", "ts.com", ""),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
bs: OSConfig{
Nameservers: mustIPs("8.8.8.8"),
SearchDomains: fqdns("coffee.shop"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf", "coffee.shop"),
},
rs: resolver.Config{
Routes: upstreams(
"corp.com.", "2.2.2.2",
".", "8.8.8.8"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
LocalDomains: fqdns("ts.com."),
},
},
{
name: "routes-magic-split",
in: Config{
Routes: upstreams(
"corp.com", "2.2.2.2",
"ts.com", ""),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
split: true,
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
MatchDomains: fqdns("corp.com", "ts.com"),
},
rs: resolver.Config{
Routes: upstreams("corp.com.", "2.2.2.2"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
LocalDomains: fqdns("ts.com."),
},
},
{
name: "exit-node-forward",
in: Config{
DefaultResolvers: mustRes("http://[fd7a:115c:a1e0:ab12:4843:cd96:6245:7a66]:2982/doh"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
SearchDomains: fqdns("tailscale.com", "universe.tf"),
},
rs: resolver.Config{
Routes: upstreams(".", "http://[fd7a:115c:a1e0:ab12:4843:cd96:6245:7a66]:2982/doh"),
Hosts: hosts(
"dave.ts.com.", "1.2.3.4",
"bradfitz.ts.com.", "2.3.4.5"),
},
},
{
name: "corp-v6",
in: Config{
DefaultResolvers: mustRes("1::1"),
},
os: OSConfig{
Nameservers: mustIPs("1::1"),
},
},
{
// This one's structurally the same as the previous one (corp-v6), but
// instead of 1::1 as the IPv6 address, it uses a NextDNS IPv6 address which
// is specially recognized.
name: "corp-v6-nextdns",
in: Config{
DefaultResolvers: mustRes("2a07:a8c0::c3:a884"),
},
os: OSConfig{
Nameservers: mustIPs("100.100.100.100"),
},
rs: resolver.Config{
Routes: upstreams(".", "2a07:a8c0::c3:a884"),
},
},
}
trIP := cmp.Transformer("ipStr", func(ip netip.Addr) string { return ip.String() })
trIPPort := cmp.Transformer("ippStr", func(ipp netip.AddrPort) string {
if ipp.Port() == 53 {
return ipp.Addr().String()
}
return ipp.String()
})
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
f := fakeOSConfigurator{
SplitDNS: test.split,
BaseConfig: test.bs,
}
m := NewManager(t.Logf, &f, nil, new(tsdial.Dialer), nil)
m.resolver.TestOnlySetHook(f.SetResolver)
if err := m.Set(test.in); err != nil {
t.Fatalf("m.Set: %v", err)
}
if diff := cmp.Diff(f.OSConfig, test.os, trIP, trIPPort, cmpopts.EquateEmpty()); diff != "" {
t.Errorf("wrong OSConfig (-got+want)\n%s", diff)
}
if diff := cmp.Diff(f.ResolverConfig, test.rs, trIP, trIPPort, cmpopts.EquateEmpty()); diff != "" {
t.Errorf("wrong resolver.Config (-got+want)\n%s", diff)
}
})
}
}
func mustIPs(strs ...string) (ret []netip.Addr) {
for _, s := range strs {
ret = append(ret, netip.MustParseAddr(s))
}
return ret
}
func mustIPPs(strs ...string) (ret []netip.AddrPort) {
for _, s := range strs {
ret = append(ret, netip.MustParseAddrPort(s))
}
return ret
}
func mustRes(strs ...string) (ret []*dnstype.Resolver) {
for _, s := range strs {
ret = append(ret, &dnstype.Resolver{Addr: s})
}
return ret
}
func fqdns(strs ...string) (ret []dnsname.FQDN) {
for _, s := range strs {
fqdn, err := dnsname.ToFQDN(s)
if err != nil {
panic(err)
}
ret = append(ret, fqdn)
}
return ret
}
func hosts(strs ...string) (ret map[dnsname.FQDN][]netip.Addr) {
var key dnsname.FQDN
ret = map[dnsname.FQDN][]netip.Addr{}
for _, s := range strs {
if ip, err := netip.ParseAddr(s); err == nil {
if key == "" {
panic("IP provided before name")
}
ret[key] = append(ret[key], ip)
} else {
fqdn, err := dnsname.ToFQDN(s)
if err != nil {
panic(err)
}
key = fqdn
}
}
return ret
}
func hostsR(strs ...string) (ret map[dnsname.FQDN][]dnstype.Resolver) {
var key dnsname.FQDN
ret = map[dnsname.FQDN][]dnstype.Resolver{}
for _, s := range strs {
if ip, err := netip.ParseAddr(s); err == nil {
if key == "" {
panic("IP provided before name")
}
ret[key] = append(ret[key], dnstype.Resolver{Addr: ip.String()})
} else {
fqdn, err := dnsname.ToFQDN(s)
if err != nil {
panic(err)
}
key = fqdn
}
}
return ret
}
func upstreams(strs ...string) (ret map[dnsname.FQDN][]*dnstype.Resolver) {
var key dnsname.FQDN
ret = map[dnsname.FQDN][]*dnstype.Resolver{}
for _, s := range strs {
if s == "" {
if key == "" {
panic("IPPort provided before suffix")
}
ret[key] = nil
} else if ipp, err := netip.ParseAddrPort(s); err == nil {
if key == "" {
panic("IPPort provided before suffix")
}
ret[key] = append(ret[key], &dnstype.Resolver{Addr: ipp.String()})
} else if _, err := netip.ParseAddr(s); err == nil {
if key == "" {
panic("IPPort provided before suffix")
}
ret[key] = append(ret[key], &dnstype.Resolver{Addr: s})
} else if strings.HasPrefix(s, "http") {
ret[key] = append(ret[key], &dnstype.Resolver{Addr: s})
} else {
fqdn, err := dnsname.ToFQDN(s)
if err != nil {
panic(err)
}
key = fqdn
}
}
return ret
}