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https://github.com/tailscale/tailscale.git
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8d6cf14456
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>
113 lines
2.3 KiB
Go
113 lines
2.3 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package dnscache
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import (
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"context"
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"errors"
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"flag"
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"net"
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"reflect"
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"testing"
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"time"
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"inet.af/netaddr"
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)
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var dialTest = flag.String("dial-test", "", "if non-empty, addr:port to test dial")
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func TestDialer(t *testing.T) {
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if *dialTest == "" {
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t.Skip("skipping; --dial-test is blank")
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}
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r := new(Resolver)
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var std net.Dialer
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dialer := Dialer(std.DialContext, r)
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t0 := time.Now()
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ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
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defer cancel()
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c, err := dialer(ctx, "tcp", *dialTest)
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if err != nil {
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t.Fatal(err)
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}
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t.Logf("dialed in %v", time.Since(t0))
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c.Close()
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}
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func TestDialCall_DNSWasTrustworthy(t *testing.T) {
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type step struct {
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ip netaddr.IP // IP we pretended to dial
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err error // the dial error or nil for success
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}
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mustIP := netaddr.MustParseIP
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errFail := errors.New("some connect failure")
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tests := []struct {
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name string
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steps []step
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want bool
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}{
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{
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name: "no-info",
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want: false,
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},
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{
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name: "previous-dial",
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steps: []step{
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{mustIP("2003::1"), nil},
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{mustIP("2003::1"), errFail},
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},
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want: true,
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},
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{
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name: "no-previous-dial",
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steps: []step{
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{mustIP("2003::1"), errFail},
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},
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want: false,
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},
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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d := &dialer{
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pastConnect: map[netaddr.IP]time.Time{},
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}
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dc := &dialCall{
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d: d,
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}
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for _, st := range tt.steps {
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dc.noteDialResult(st.ip, st.err)
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}
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got := dc.dnsWasTrustworthy()
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if got != tt.want {
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t.Errorf("got %v; want %v", got, tt.want)
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}
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})
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}
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}
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func TestDialCall_uniqueIPs(t *testing.T) {
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dc := &dialCall{}
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mustIP := netaddr.MustParseIP
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errFail := errors.New("some connect failure")
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dc.noteDialResult(mustIP("2003::1"), errFail)
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dc.noteDialResult(mustIP("2003::2"), errFail)
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got := dc.uniqueIPs([]netaddr.IP{
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mustIP("2003::1"),
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mustIP("2003::2"),
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mustIP("2003::2"),
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mustIP("2003::3"),
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mustIP("2003::3"),
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mustIP("2003::4"),
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mustIP("2003::4"),
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})
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want := []netaddr.IP{
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mustIP("2003::3"),
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mustIP("2003::4"),
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}
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if !reflect.DeepEqual(got, want) {
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t.Errorf("got %v; want %v", got, want)
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}
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}
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