Merge branch 'master' of github.com:miekg/dns

dns.go

@@ -1,6 +1,9 @@
 package dns
 
-import "strconv"
+import (
+	"encoding/hex"
+	"strconv"
+)
 
 const (
 	year68     = 1 << 31 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
@@ -111,7 +114,7 @@ func (h *RR_Header) parse(c *zlexer, origin string) *ParseError {
 
 // ToRFC3597 converts a known RR to the unknown RR representation from RFC 3597.
 func (rr *RFC3597) ToRFC3597(r RR) error {
-	buf := make([]byte, Len(r)*2)
+	buf := make([]byte, Len(r))
 	headerEnd, off, err := packRR(r, buf, 0, compressionMap{}, false)
 	if err != nil {
 		return err
@@ -126,9 +129,25 @@ func (rr *RFC3597) ToRFC3597(r RR) error {
 	}
 
 	_, err = rr.unpack(buf, headerEnd)
+	return err
+}
+
+// fromRFC3597 converts an unknown RR representation from RFC 3597 to the known RR type.
+func (rr *RFC3597) fromRFC3597(r RR) error {
+	*r.Header() = rr.Hdr
+
+	if len(rr.Rdata) == 0 {
+		// Dynamic update.
+		return nil
+	}
+
+	// rr.pack requires an extra allocation and a copy so we just decode Rdata
+	// manually, it's simpler anyway.
+	msg, err := hex.DecodeString(rr.Rdata)
 	if err != nil {
 		return err
 	}
 
-	return nil
+	_, err = r.unpack(msg, 0)
+	return err
 }

edns.go

@@ -88,8 +88,8 @@ func (rr *OPT) len(off int, compression map[string]struct{}) int {
 	return l
 }
 
-func (rr *OPT) parse(c *zlexer, origin string) *ParseError {
-	panic("dns: internal error: parse should never be called on OPT")
+func (*OPT) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "OPT records do not have a presentation format"}
 }
 
 func (r1 *OPT) isDuplicate(r2 RR) bool { return false }

parse_test.go

@@ -1208,8 +1208,8 @@ func TestTypeXXXX(t *testing.T) {
 		t.Errorf("this should not work, for TYPE655341")
 	}
 	_, err = NewRR("example.com IN TYPE1 \\# 4 0a000001")
-	if err == nil {
-		t.Errorf("this should not work")
+	if err != nil {
+		t.Errorf("failed to parse TYPE1 RR: %v", err)
 	}
 }
 

scan.go

@@ -577,10 +577,23 @@ func (zp *ZoneParser) Next() (RR, bool) {
 
 			st = zExpectRdata
 		case zExpectRdata:
-			var rr RR
-			if newFn, ok := TypeToRR[h.Rrtype]; ok && canParseAsRR(h.Rrtype) {
+			var (
+				rr             RR
+				parseAsRFC3597 bool
+			)
+			if newFn, ok := TypeToRR[h.Rrtype]; ok {
 				rr = newFn()
 				*rr.Header() = *h
+
+				// We may be parsing a known RR type using the RFC3597 format.
+				// If so, we handle that here in a generic way.
+				//
+				// This is also true for PrivateRR types which will have the
+				// RFC3597 parsing done for them and the Unpack method called
+				// to populate the RR instead of simply deferring to Parse.
+				if zp.c.Peek().token == "\\#" {
+					parseAsRFC3597 = true
+				}
 			} else {
 				rr = &RFC3597{Hdr: *h}
 			}
@@ -600,20 +613,32 @@ func (zp *ZoneParser) Next() (RR, bool) {
 				return zp.setParseError("unexpected newline", l)
 			}
 
-			if err := rr.parse(zp.c, zp.origin); err != nil {
+			parseAsRR := rr
+			if parseAsRFC3597 {
+				parseAsRR = &RFC3597{Hdr: *h}
+			}
+
+			if err := parseAsRR.parse(zp.c, zp.origin); err != nil {
 				// err is a concrete *ParseError without the file field set.
 				// The setParseError call below will construct a new
 				// *ParseError with file set to zp.file.
 
-				// If err.lex is nil than we have encounter an unknown RR type
-				// in that case we substitute our current lex token.
+				// err.lex may be nil in which case we substitute our current
+				// lex token.
 				if err.lex == (lex{}) {
 					return zp.setParseError(err.err, l)
 				}
 
 				return zp.setParseError(err.err, err.lex)
 			}
 
+			if parseAsRFC3597 {
+				err := parseAsRR.(*RFC3597).fromRFC3597(rr)
+				if err != nil {
+					return zp.setParseError(err.Error(), l)
+				}
+			}
+
 			return rr, true
 		}
 	}
@@ -623,18 +648,6 @@ func (zp *ZoneParser) Next() (RR, bool) {
 	return nil, false
 }
 
-// canParseAsRR returns true if the record type can be parsed as a
-// concrete RR. It blacklists certain record types that must be parsed
-// according to RFC 3597 because they lack a presentation format.
-func canParseAsRR(rrtype uint16) bool {
-	switch rrtype {
-	case TypeANY, TypeNULL, TypeOPT, TypeTSIG:
-		return false
-	default:
-		return true
-	}
-}
-
 type zlexer struct {
 	br io.ByteReader
 
@@ -1290,7 +1303,7 @@ func appendOrigin(name, origin string) string {
 
 // LOC record helper function
 func locCheckNorth(token string, latitude uint32) (uint32, bool) {
-	if latitude > 90 * 1000 * 60 * 60 {
+	if latitude > 90*1000*60*60 {
 		return latitude, false
 	}
 	switch token {
@@ -1304,7 +1317,7 @@ func locCheckNorth(token string, latitude uint32) (uint32, bool) {
 
 // LOC record helper function
 func locCheckEast(token string, longitude uint32) (uint32, bool) {
-	if longitude > 180 * 1000 * 60 * 60 {
+	if longitude > 180*1000*60*60 {
 		return longitude, false
 	}
 	switch token {

scan_test.go

@@ -145,10 +145,10 @@ func TestZoneParserAddressAAAA(t *testing.T) {
 		}
 		aaaa, ok := got.(*AAAA)
 		if !ok {
-			t.Fatalf("expected *AAAA RR, but got %T", aaaa)
+			t.Fatalf("expected *AAAA RR, but got %T", got)
 		}
-		if g, w := aaaa.AAAA, tc.want.AAAA; !g.Equal(w) {
-			t.Fatalf("expected AAAA with IP %v, but got %v", g, w)
+		if !aaaa.AAAA.Equal(tc.want.AAAA) {
+			t.Fatalf("expected AAAA with IP %v, but got %v", tc.want.AAAA, aaaa.AAAA)
 		}
 	}
 }
@@ -229,6 +229,48 @@ example.com. 60 PX (
 	}
 }
 
+func TestParseKnownRRAsRFC3597(t *testing.T) {
+	t.Run("with RDATA", func(t *testing.T) {
+		rr, err := NewRR("example. 3600 CLASS1 TYPE1 \\# 4 7f000001")
+		if err != nil {
+			t.Fatalf("failed to parse RFC3579 format: %v", err)
+		}
+
+		if rr.Header().Rrtype != TypeA {
+			t.Errorf("expected TypeA (1) Rrtype, but got %v", rr.Header().Rrtype)
+		}
+
+		a, ok := rr.(*A)
+		if !ok {
+			t.Fatalf("expected *A RR, but got %T", rr)
+		}
+
+		localhost := net.IPv4(127, 0, 0, 1)
+		if !a.A.Equal(localhost) {
+			t.Fatalf("expected A with IP %v, but got %v", localhost, a.A)
+		}
+	})
+	t.Run("without RDATA", func(t *testing.T) {
+		rr, err := NewRR("example. 3600 CLASS1 TYPE1 \\# 0")
+		if err != nil {
+			t.Fatalf("failed to parse RFC3579 format: %v", err)
+		}
+
+		if rr.Header().Rrtype != TypeA {
+			t.Errorf("expected TypeA (1) Rrtype, but got %v", rr.Header().Rrtype)
+		}
+
+		a, ok := rr.(*A)
+		if !ok {
+			t.Fatalf("expected *A RR, but got %T", rr)
+		}
+
+		if len(a.A) != 0 {
+			t.Fatalf("expected A with empty IP, but got %v", a.A)
+		}
+	})
+}
+
 func BenchmarkNewRR(b *testing.B) {
 	const name1 = "12345678901234567890123456789012345.12345678.123."
 	const s = name1 + " 3600 IN MX 10 " + name1

tsig.go

@@ -106,8 +106,8 @@ func (rr *TSIG) String() string {
 	return s
 }
 
-func (rr *TSIG) parse(c *zlexer, origin string) *ParseError {
-	panic("dns: internal error: parse should never be called on TSIG")
+func (*TSIG) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "TSIG records do not have a presentation format"}
 }
 
 // The following values must be put in wireformat, so that the MAC can be calculated.

types.go

@@ -245,8 +245,8 @@ type ANY struct {
 
 func (rr *ANY) String() string { return rr.Hdr.String() }
 
-func (rr *ANY) parse(c *zlexer, origin string) *ParseError {
-	panic("dns: internal error: parse should never be called on ANY")
+func (*ANY) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "ANY records do not have a presentation format"}
 }
 
 // NULL RR. See RFC 1035.
@@ -260,8 +260,8 @@ func (rr *NULL) String() string {
 	return ";" + rr.Hdr.String() + rr.Data
 }
 
-func (rr *NULL) parse(c *zlexer, origin string) *ParseError {
-	panic("dns: internal error: parse should never be called on NULL")
+func (*NULL) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "NULL records do not have a presentation format"}
 }
 
 // CNAME RR. See RFC 1034.

update_test.go

@@ -6,15 +6,28 @@ import (
 )
 
 func TestDynamicUpdateParsing(t *testing.T) {
-	prefix := "example.com. IN "
-	for _, typ := range TypeToString {
-		if typ == "OPT" || typ == "AXFR" || typ == "IXFR" || typ == "ANY" || typ == "TKEY" ||
-			typ == "TSIG" || typ == "ISDN" || typ == "UNSPEC" || typ == "NULL" || typ == "ATMA" ||
-			typ == "Reserved" || typ == "None" || typ == "NXT" || typ == "MAILB" || typ == "MAILA" {
+	const prefix = "example.com. IN "
+
+	for typ, name := range TypeToString {
+		switch typ {
+		case TypeNone, TypeReserved:
+			continue
+		case TypeANY:
+			// ANY is ambiguous here and ends up parsed as a CLASS.
+			//
+			// TODO(tmthrgd): Using TYPE255 here doesn't seem to work and also
+			//   seems to fail for some other record types. Investigate.
 			continue
 		}
-		if _, err := NewRR(prefix + typ); err != nil {
-			t.Errorf("failure to parse: %s %s: %v", prefix, typ, err)
+
+		s := prefix + name
+		if _, err := NewRR(s); err != nil {
+			t.Errorf("failure to parse: %s: %v", s, err)
+		}
+
+		s += " \\# 0"
+		if _, err := NewRR(s); err != nil {
+			t.Errorf("failure to parse: %s: %v", s, err)
 		}
 	}
 }