go1.16 (#14783)

vendor/github.com/miekg/dns/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}
 			}
@@ -600,13 +613,18 @@ 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)
 				}
@@ -614,6 +632,13 @@ func (zp *ZoneParser) Next() (RR, bool) {
 				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
 
@@ -1210,11 +1223,29 @@ func stringToCm(token string) (e, m uint8, ok bool) {
 		if cmeters, err = strconv.Atoi(s[1]); err != nil {
 			return
 		}
+		// There's no point in having more than 2 digits in this part, and would rather make the implementation complicated ('123' should be treated as '12').
+		// So we simply reject it.
+		// We also make sure the first character is a digit to reject '+-' signs.
+		if len(s[1]) > 2 || s[1][0] < '0' || s[1][0] > '9' {
+			return
+		}
+		if len(s[1]) == 1 {
+			// 'nn.1' must be treated as 'nn-meters and 10cm, not 1cm.
+			cmeters *= 10
+		}
+		if len(s[0]) == 0 {
+			// This will allow omitting the 'meter' part, like .01 (meaning 0.01m = 1cm).
+			break
+		}
 		fallthrough
 	case 1:
 		if meters, err = strconv.Atoi(s[0]); err != nil {
 			return
 		}
+		// RFC1876 states the max value is 90000000.00.  The latter two conditions enforce it.
+		if s[0][0] < '0' || s[0][0] > '9' || meters > 90000000 || (meters == 90000000 && cmeters != 0) {
+			return
+		}
 	case 0:
 		// huh?
 		return 0, 0, false
@@ -1227,13 +1258,10 @@ func stringToCm(token string) (e, m uint8, ok bool) {
 		e = 0
 		val = cmeters
 	}
-	for val > 10 {
+	for val >= 10 {
 		e++
 		val /= 10
 	}
-	if e > 9 {
-		ok = false
-	}
 	m = uint8(val)
 	return
 }
@@ -1275,6 +1303,9 @@ func appendOrigin(name, origin string) string {
 
 // LOC record helper function
 func locCheckNorth(token string, latitude uint32) (uint32, bool) {
+	if latitude > 90*1000*60*60 {
+		return latitude, false
+	}
 	switch token {
 	case "n", "N":
 		return LOC_EQUATOR + latitude, true
@@ -1286,6 +1317,9 @@ 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 {
+		return longitude, false
+	}
 	switch token {
 	case "e", "E":
 		return LOC_EQUATOR + longitude, true