diff options
-rw-r--r-- | src/net/dnsclient_unix.go | 8 | ||||
-rw-r--r-- | src/net/dnsclient_unix_test.go | 47 |
2 files changed, 55 insertions, 0 deletions
diff --git a/src/net/dnsclient_unix.go b/src/net/dnsclient_unix.go index 86ce92dc43..7f335eba9f 100644 --- a/src/net/dnsclient_unix.go +++ b/src/net/dnsclient_unix.go @@ -738,6 +738,14 @@ func (r *Resolver) goLookupPTR(ctx context.Context, addr string) ([]string, erro } } if h.Type != dnsmessage.TypePTR { + err := p.SkipAnswer() + if err != nil { + return nil, &DNSError{ + Err: "cannot marshal DNS message", + Name: addr, + Server: server, + } + } continue } ptr, err := p.PTRResource() diff --git a/src/net/dnsclient_unix_test.go b/src/net/dnsclient_unix_test.go index be04a44c14..f5e7992f30 100644 --- a/src/net/dnsclient_unix_test.go +++ b/src/net/dnsclient_unix_test.go @@ -1621,3 +1621,50 @@ func TestTXTRecordTwoStrings(t *testing.T) { t.Errorf("txt[1], got %q, want %q", txt[1], want) } } + +// Issue 34660: PTR response with non-PTR answers should ignore non-PTR +func TestPTRandNonPTR(t *testing.T) { + fake := fakeDNSServer{ + rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) { + r := dnsmessage.Message{ + Header: dnsmessage.Header{ + ID: q.Header.ID, + Response: true, + RCode: dnsmessage.RCodeSuccess, + }, + Questions: q.Questions, + Answers: []dnsmessage.Resource{ + { + Header: dnsmessage.ResourceHeader{ + Name: q.Questions[0].Name, + Type: dnsmessage.TypePTR, + Class: dnsmessage.ClassINET, + }, + Body: &dnsmessage.PTRResource{ + PTR: mustNewName("golang.org."), + }, + }, + { + Header: dnsmessage.ResourceHeader{ + Name: q.Questions[0].Name, + Type: dnsmessage.TypeTXT, + Class: dnsmessage.ClassINET, + }, + Body: &dnsmessage.TXTResource{ + TXT: []string{"PTR 8 6 60 ..."}, // fake RRSIG + }, + }, + }, + } + return r, nil + }, + } + r := Resolver{PreferGo: true, Dial: fake.DialContext} + names, err := r.lookupAddr(context.Background(), "192.0.2.123") + if err != nil { + t.Fatalf("LookupAddr: %v", err) + } + if want := []string{"golang.org."}; !reflect.DeepEqual(names, want) { + t.Errorf("names = %q; want %q", names, want) + } +} |