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>
This commit is contained in:
Brad Fitzpatrick
committed by
Brad Fitzpatrick
Brad Fitzpatrick
parent
cab5c46481
commit
cced414c7d
@ -6,16 +6,22 @@ package resolver
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import (
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"bytes"
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"context"
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"encoding/hex"
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"encoding/json"
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"errors"
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"fmt"
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"math/rand"
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"net"
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"reflect"
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"runtime"
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"strconv"
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"strings"
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"testing"
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"time"
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miekdns "github.com/miekg/dns"
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"golang.org/x/net/dns/dnsmessage"
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dns "golang.org/x/net/dns/dnsmessage"
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"inet.af/netaddr"
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"tailscale.com/net/tsdial"
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@ -43,6 +49,8 @@ var dnsCfg = Config{
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const noEdns = 0
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const dnsHeaderLen = 12
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func dnspacket(domain dnsname.FQDN, tp dns.Type, ednsSize uint16) []byte {
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var dnsHeader dns.Header
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question := dns.Question{
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@ -1093,3 +1101,383 @@ func TestForwardLinkSelection(t *testing.T) {
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type linkSelFunc func(ip netaddr.IP) string
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func (f linkSelFunc) PickLink(ip netaddr.IP) string { return f(ip) }
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func TestHandleExitNodeDNSQueryWithNetPkg(t *testing.T) {
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if runtime.GOOS == "windows" {
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t.Skip("skipping test on Windows; waiting for golang.org/issue/33097")
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}
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records := []interface{}{
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"no-records.test.",
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dnsHandler(),
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"one-a.test.",
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dnsHandler(netaddr.MustParseIP("1.2.3.4")),
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"two-a.test.",
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dnsHandler(netaddr.MustParseIP("1.2.3.4"), netaddr.MustParseIP("5.6.7.8")),
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"one-aaaa.test.",
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dnsHandler(netaddr.MustParseIP("1::2")),
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"two-aaaa.test.",
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dnsHandler(netaddr.MustParseIP("1::2"), netaddr.MustParseIP("3::4")),
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"nx-domain.test.",
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resolveToNXDOMAIN,
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"4.3.2.1.in-addr.arpa.",
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dnsHandler(miekdns.PTR{Ptr: "foo.com."}),
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"cname.test.",
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weirdoGoCNAMEHandler("the-target.foo."),
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"txt.test.",
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dnsHandler(
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miekdns.TXT{Txt: []string{"txt1=one"}},
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miekdns.TXT{Txt: []string{"txt2=two"}},
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miekdns.TXT{Txt: []string{"txt3=three"}},
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),
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"srv.test.",
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dnsHandler(
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miekdns.SRV{
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Priority: 1,
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Weight: 2,
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Port: 3,
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Target: "foo.com.",
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},
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miekdns.SRV{
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Priority: 4,
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Weight: 5,
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Port: 6,
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Target: "bar.com.",
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},
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),
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"ns.test.",
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dnsHandler(miekdns.NS{Ns: "ns1.foo."}, miekdns.NS{Ns: "ns2.bar."}),
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}
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v4server := serveDNS(t, "127.0.0.1:0", records...)
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defer v4server.Shutdown()
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// backendResolver is the resolver between
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// handleExitNodeDNSQueryWithNetPkg and its upstream resolver,
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// which in this test's case is the miekg/dns test DNS server
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// (v4server).
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backResolver := &net.Resolver{
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PreferGo: true,
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Dial: func(ctx context.Context, network, addr string) (net.Conn, error) {
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var d net.Dialer
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return d.DialContext(ctx, "udp", v4server.PacketConn.LocalAddr().String())
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},
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}
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t.Run("no_such_host", func(t *testing.T) {
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res, err := handleExitNodeDNSQueryWithNetPkg(context.Background(), backResolver, &response{
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Header: dnsmessage.Header{
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ID: 123,
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Response: true,
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OpCode: 0, // query
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},
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Question: dnsmessage.Question{
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Name: dnsmessage.MustNewName("nx-domain.test."),
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Type: dnsmessage.TypeA,
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Class: dnsmessage.ClassINET,
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},
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})
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if err != nil {
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t.Fatal(err)
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}
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if len(res) < dnsHeaderLen {
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t.Fatal("short reply")
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}
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rcode := dns.RCode(res[3] & 0x0f)
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if rcode != dns.RCodeNameError {
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t.Errorf("RCode = %v; want dns.RCodeNameError", rcode)
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t.Logf("Response was: %q", res)
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}
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})
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matchPacked := func(want string) func(t testing.TB, got []byte) {
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return func(t testing.TB, got []byte) {
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if string(got) == want {
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return
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}
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t.Errorf("unexpected reply.\n got: %q\nwant: %q\n", got, want)
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t.Errorf("\nin hex:\n got: % 2x\nwant: % 2x\n", got, want)
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}
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}
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tests := []struct {
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Type dnsmessage.Type
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Name string
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Check func(t testing.TB, got []byte)
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}{
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{
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Type: dnsmessage.TypeA,
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Name: "one-a.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x01\x00\x00\x00\x00\x05one-a\x04test\x00\x00\x01\x00\x01\x05one-a\x04test\x00\x00\x01\x00\x01\x00\x00\x02X\x00\x04\x01\x02\x03\x04"),
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},
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{
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Type: dnsmessage.TypeA,
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Name: "two-a.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x02\x00\x00\x00\x00\x05two-a\x04test\x00\x00\x01\x00\x01\xc0\f\x00\x01\x00\x01\x00\x00\x02X\x00\x04\x01\x02\x03\x04\xc0\f\x00\x01\x00\x01\x00\x00\x02X\x00\x04\x05\x06\a\b"),
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},
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{
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Type: dnsmessage.TypeAAAA,
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Name: "one-aaaa.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x01\x00\x00\x00\x00\bone-aaaa\x04test\x00\x00\x1c\x00\x01\bone-aaaa\x04test\x00\x00\x1c\x00\x01\x00\x00\x02X\x00\x10\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02"),
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},
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{
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Type: dnsmessage.TypeAAAA,
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Name: "two-aaaa.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x02\x00\x00\x00\x00\btwo-aaaa\x04test\x00\x00\x1c\x00\x01\xc0\f\x00\x1c\x00\x01\x00\x00\x02X\x00\x10\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\xc0\f\x00\x1c\x00\x01\x00\x00\x02X\x00\x10\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04"),
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},
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{
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Type: dnsmessage.TypePTR,
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Name: "4.3.2.1.in-addr.arpa.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x01\x00\x00\x00\x00\x014\x013\x012\x011\ain-addr\x04arpa\x00\x00\f\x00\x01\x014\x013\x012\x011\ain-addr\x04arpa\x00\x00\f\x00\x01\x00\x00\x02X\x00\t\x03foo\x03com\x00"),
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},
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{
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Type: dnsmessage.TypeCNAME,
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Name: "cname.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x01\x00\x00\x00\x00\x05cname\x04test\x00\x00\x05\x00\x01\x05cname\x04test\x00\x00\x05\x00\x01\x00\x00\x02X\x00\x10\nthe-target\x03foo\x00"),
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},
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// No records of various types
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{
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Type: dnsmessage.TypeA,
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Name: "no-records.test.",
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Check: matchPacked("\x00{\x84\x03\x00\x01\x00\x00\x00\x00\x00\x00\nno-records\x04test\x00\x00\x01\x00\x01"),
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},
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{
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Type: dnsmessage.TypeAAAA,
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Name: "no-records.test.",
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Check: matchPacked("\x00{\x84\x03\x00\x01\x00\x00\x00\x00\x00\x00\nno-records\x04test\x00\x00\x1c\x00\x01"),
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},
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{
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Type: dnsmessage.TypeCNAME,
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Name: "no-records.test.",
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Check: matchPacked("\x00{\x84\x03\x00\x01\x00\x00\x00\x00\x00\x00\nno-records\x04test\x00\x00\x05\x00\x01"),
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},
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{
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Type: dnsmessage.TypeSRV,
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Name: "no-records.test.",
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Check: matchPacked("\x00{\x84\x03\x00\x01\x00\x00\x00\x00\x00\x00\nno-records\x04test\x00\x00!\x00\x01"),
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},
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{
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Type: dnsmessage.TypeTXT,
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Name: "txt.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x03\x00\x00\x00\x00\x03txt\x04test\x00\x00\x10\x00\x01\x03txt\x04test\x00\x00\x10\x00\x01\x00\x00\x02X\x00\t\btxt1=one\x03txt\x04test\x00\x00\x10\x00\x01\x00\x00\x02X\x00\t\btxt2=two\x03txt\x04test\x00\x00\x10\x00\x01\x00\x00\x02X\x00\v\ntxt3=three"),
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},
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{
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Type: dnsmessage.TypeSRV,
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Name: "srv.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x02\x00\x00\x00\x00\x03srv\x04test\x00\x00!\x00\x01\x03srv\x04test\x00\x00!\x00\x01\x00\x00\x02X\x00\x0f\x00\x01\x00\x02\x00\x03\x03foo\x03com\x00\x03srv\x04test\x00\x00!\x00\x01\x00\x00\x02X\x00\x0f\x00\x04\x00\x05\x00\x06\x03bar\x03com\x00"),
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},
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{
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Type: dnsmessage.TypeNS,
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Name: "ns.test.",
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Check: matchPacked("\x00{\x84\x00\x00\x01\x00\x02\x00\x00\x00\x00\x02ns\x04test\x00\x00\x02\x00\x01\x02ns\x04test\x00\x00\x02\x00\x01\x00\x00\x02X\x00\t\x03ns1\x03foo\x00\x02ns\x04test\x00\x00\x02\x00\x01\x00\x00\x02X\x00\t\x03ns2\x03bar\x00"),
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},
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}
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for _, tt := range tests {
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t.Run(fmt.Sprintf("%v_%v", tt.Type, strings.Trim(tt.Name, ".")), func(t *testing.T) {
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got, err := handleExitNodeDNSQueryWithNetPkg(context.Background(), backResolver, &response{
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Header: dnsmessage.Header{
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ID: 123,
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Response: true,
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OpCode: 0, // query
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},
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Question: dnsmessage.Question{
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Name: dnsmessage.MustNewName(tt.Name),
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Type: tt.Type,
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Class: dnsmessage.ClassINET,
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},
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})
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if err != nil {
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t.Fatal(err)
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}
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if len(got) < dnsHeaderLen {
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t.Errorf("short record")
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}
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if tt.Check != nil {
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tt.Check(t, got)
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if t.Failed() {
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t.Errorf("Got: %q\nIn hex: % 02x", got, got)
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}
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}
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})
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}
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wrapRes := newWrapResolver(backResolver)
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ctx := context.Background()
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t.Run("wrap_ip_a", func(t *testing.T) {
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ips, err := wrapRes.LookupIP(ctx, "ip", "two-a.test.")
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if err != nil {
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t.Fatal(err)
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}
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if got, want := ips, []net.IP{
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net.ParseIP("1.2.3.4").To4(),
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net.ParseIP("5.6.7.8").To4(),
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}; !reflect.DeepEqual(got, want) {
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t.Errorf("LookupIP = %v; want %v", got, want)
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}
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})
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t.Run("wrap_ip_aaaa", func(t *testing.T) {
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ips, err := wrapRes.LookupIP(ctx, "ip", "two-aaaa.test.")
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if err != nil {
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t.Fatal(err)
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}
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if got, want := ips, []net.IP{
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net.ParseIP("1::2"),
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net.ParseIP("3::4"),
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}; !reflect.DeepEqual(got, want) {
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t.Errorf("LookupIP(v6) = %v; want %v", got, want)
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}
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})
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t.Run("wrap_ip_nx", func(t *testing.T) {
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ips, err := wrapRes.LookupIP(ctx, "ip", "nx-domain.test.")
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if !isGoNoSuchHostError(err) {
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t.Errorf("no NX domain = (%v, %v); want no host error", ips, err)
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}
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})
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t.Run("wrap_srv", func(t *testing.T) {
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_, srvs, err := wrapRes.LookupSRV(ctx, "", "", "srv.test.")
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if err != nil {
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t.Fatal(err)
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}
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if got, want := srvs, []*net.SRV{
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{
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Target: "foo.com.",
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Priority: 1,
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Weight: 2,
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Port: 3,
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},
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{
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Target: "bar.com.",
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Priority: 4,
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Weight: 5,
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Port: 6,
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},
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}; !reflect.DeepEqual(got, want) {
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jgot, _ := json.Marshal(got)
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jwant, _ := json.Marshal(want)
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t.Errorf("SRV = %s; want %s", jgot, jwant)
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}
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})
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t.Run("wrap_txt", func(t *testing.T) {
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txts, err := wrapRes.LookupTXT(ctx, "txt.test.")
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if err != nil {
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t.Fatal(err)
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}
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if got, want := txts, []string{"txt1=one", "txt2=two", "txt3=three"}; !reflect.DeepEqual(got, want) {
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t.Errorf("TXT = %q; want %q", got, want)
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}
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})
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t.Run("wrap_ns", func(t *testing.T) {
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nss, err := wrapRes.LookupNS(ctx, "ns.test.")
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if err != nil {
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t.Fatal(err)
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}
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if got, want := nss, []*net.NS{
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{Host: "ns1.foo."},
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{Host: "ns2.bar."},
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}; !reflect.DeepEqual(got, want) {
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jgot, _ := json.Marshal(got)
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jwant, _ := json.Marshal(want)
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t.Errorf("NS = %s; want %s", jgot, jwant)
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}
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})
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}
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// newWrapResolver returns a resolver that uses r (via handleExitNodeDNSQueryWithNetPkg)
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// to make DNS requests.
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func newWrapResolver(r *net.Resolver) *net.Resolver {
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if runtime.GOOS == "windows" {
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panic("doesn't work on Windows") // golang.org/issue/33097
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}
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return &net.Resolver{
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PreferGo: true,
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Dial: func(ctx context.Context, network, addr string) (net.Conn, error) {
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return &wrapResolverConn{ctx: ctx, r: r}, nil
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},
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}
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}
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type wrapResolverConn struct {
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ctx context.Context
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r *net.Resolver
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buf bytes.Buffer
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}
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var _ net.PacketConn = (*wrapResolverConn)(nil)
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func (*wrapResolverConn) Close() error { return nil }
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func (*wrapResolverConn) LocalAddr() net.Addr { return fakeAddr{} }
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func (*wrapResolverConn) RemoteAddr() net.Addr { return fakeAddr{} }
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func (*wrapResolverConn) SetDeadline(t time.Time) error { return nil }
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func (*wrapResolverConn) SetReadDeadline(t time.Time) error { return nil }
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func (*wrapResolverConn) SetWriteDeadline(t time.Time) error { return nil }
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func (a *wrapResolverConn) Read(p []byte) (n int, err error) {
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n, _, err = a.ReadFrom(p)
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return
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}
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func (a *wrapResolverConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
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n, err = a.buf.Read(p)
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return n, fakeAddr{}, err
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}
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func (a *wrapResolverConn) Write(packet []byte) (n int, err error) {
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return a.WriteTo(packet, fakeAddr{})
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}
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func (a *wrapResolverConn) WriteTo(q []byte, _ net.Addr) (n int, err error) {
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resp := parseExitNodeQuery(q)
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if resp == nil {
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return 0, errors.New("bad query")
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}
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res, err := handleExitNodeDNSQueryWithNetPkg(context.Background(), a.r, resp)
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if err != nil {
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return 0, err
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}
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a.buf.Write(res)
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return len(q), nil
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}
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||||
|
||||
type fakeAddr struct{}
|
||||
|
||||
func (fakeAddr) Network() string { return "unused" }
|
||||
func (fakeAddr) String() string { return "unused-todoAddr" }
|
||||
|
||||
func TestUnARPA(t *testing.T) {
|
||||
tests := []struct {
|
||||
in, want string
|
||||
}{
|
||||
{"", ""},
|
||||
{"bad", ""},
|
||||
{"4.4.8.8.in-addr.arpa.", "8.8.4.4"},
|
||||
{".in-addr.arpa.", ""},
|
||||
{"e.0.0.2.0.0.0.0.0.0.0.0.0.0.0.0.b.0.8.0.a.0.0.4.0.b.8.f.7.0.6.2.ip6.arpa.", "2607:f8b0:400a:80b::200e"},
|
||||
{".ip6.arpa.", ""},
|
||||
}
|
||||
for _, tt := range tests {
|
||||
got, ok := unARPA(tt.in)
|
||||
if ok != (got != "") {
|
||||
t.Errorf("inconsistent results for %q: (%q, %v)", tt.in, got, ok)
|
||||
}
|
||||
if got != tt.want {
|
||||
t.Errorf("unARPA(%q) = %q; want %q", tt.in, got, tt.want)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user