--- /dev/null
+package dns
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "os"
+ "path/filepath"
+ "strconv"
+ "strings"
+)
+
+const maxTok = 2048 // Largest token we can return.
+
+// The maximum depth of $INCLUDE directives supported by the
+// ZoneParser API.
+const maxIncludeDepth = 7
+
+// Tokinize a RFC 1035 zone file. The tokenizer will normalize it:
+// * Add ownernames if they are left blank;
+// * Suppress sequences of spaces;
+// * Make each RR fit on one line (_NEWLINE is send as last)
+// * Handle comments: ;
+// * Handle braces - anywhere.
+const (
+ // Zonefile
+ zEOF = iota
+ zString
+ zBlank
+ zQuote
+ zNewline
+ zRrtpe
+ zOwner
+ zClass
+ zDirOrigin // $ORIGIN
+ zDirTTL // $TTL
+ zDirInclude // $INCLUDE
+ zDirGenerate // $GENERATE
+
+ // Privatekey file
+ zValue
+ zKey
+
+ zExpectOwnerDir // Ownername
+ zExpectOwnerBl // Whitespace after the ownername
+ zExpectAny // Expect rrtype, ttl or class
+ zExpectAnyNoClass // Expect rrtype or ttl
+ zExpectAnyNoClassBl // The whitespace after _EXPECT_ANY_NOCLASS
+ zExpectAnyNoTTL // Expect rrtype or class
+ zExpectAnyNoTTLBl // Whitespace after _EXPECT_ANY_NOTTL
+ zExpectRrtype // Expect rrtype
+ zExpectRrtypeBl // Whitespace BEFORE rrtype
+ zExpectRdata // The first element of the rdata
+ zExpectDirTTLBl // Space after directive $TTL
+ zExpectDirTTL // Directive $TTL
+ zExpectDirOriginBl // Space after directive $ORIGIN
+ zExpectDirOrigin // Directive $ORIGIN
+ zExpectDirIncludeBl // Space after directive $INCLUDE
+ zExpectDirInclude // Directive $INCLUDE
+ zExpectDirGenerate // Directive $GENERATE
+ zExpectDirGenerateBl // Space after directive $GENERATE
+)
+
+// ParseError is a parsing error. It contains the parse error and the location in the io.Reader
+// where the error occurred.
+type ParseError struct {
+ file string
+ err string
+ lex lex
+}
+
+func (e *ParseError) Error() (s string) {
+ if e.file != "" {
+ s = e.file + ": "
+ }
+ s += "dns: " + e.err + ": " + strconv.QuoteToASCII(e.lex.token) + " at line: " +
+ strconv.Itoa(e.lex.line) + ":" + strconv.Itoa(e.lex.column)
+ return
+}
+
+type lex struct {
+ token string // text of the token
+ err bool // when true, token text has lexer error
+ value uint8 // value: zString, _BLANK, etc.
+ torc uint16 // type or class as parsed in the lexer, we only need to look this up in the grammar
+ line int // line in the file
+ column int // column in the file
+}
+
+// Token holds the token that are returned when a zone file is parsed.
+type Token struct {
+ // The scanned resource record when error is not nil.
+ RR
+ // When an error occurred, this has the error specifics.
+ Error *ParseError
+ // A potential comment positioned after the RR and on the same line.
+ Comment string
+}
+
+// ttlState describes the state necessary to fill in an omitted RR TTL
+type ttlState struct {
+ ttl uint32 // ttl is the current default TTL
+ isByDirective bool // isByDirective indicates whether ttl was set by a $TTL directive
+}
+
+// NewRR reads the RR contained in the string s. Only the first RR is
+// returned. If s contains no records, NewRR will return nil with no
+// error.
+//
+// The class defaults to IN and TTL defaults to 3600. The full zone
+// file syntax like $TTL, $ORIGIN, etc. is supported.
+//
+// All fields of the returned RR are set, except RR.Header().Rdlength
+// which is set to 0.
+func NewRR(s string) (RR, error) {
+ if len(s) > 0 && s[len(s)-1] != '\n' { // We need a closing newline
+ return ReadRR(strings.NewReader(s+"\n"), "")
+ }
+ return ReadRR(strings.NewReader(s), "")
+}
+
+// ReadRR reads the RR contained in r.
+//
+// The string file is used in error reporting and to resolve relative
+// $INCLUDE directives.
+//
+// See NewRR for more documentation.
+func ReadRR(r io.Reader, file string) (RR, error) {
+ zp := NewZoneParser(r, ".", file)
+ zp.SetDefaultTTL(defaultTtl)
+ zp.SetIncludeAllowed(true)
+ rr, _ := zp.Next()
+ return rr, zp.Err()
+}
+
+// ParseZone reads a RFC 1035 style zonefile from r. It returns
+// *Tokens on the returned channel, each consisting of either a
+// parsed RR and optional comment or a nil RR and an error. The
+// channel is closed by ParseZone when the end of r is reached.
+//
+// The string file is used in error reporting and to resolve relative
+// $INCLUDE directives. The string origin is used as the initial
+// origin, as if the file would start with an $ORIGIN directive.
+//
+// The directives $INCLUDE, $ORIGIN, $TTL and $GENERATE are all
+// supported.
+//
+// Basic usage pattern when reading from a string (z) containing the
+// zone data:
+//
+// for x := range dns.ParseZone(strings.NewReader(z), "", "") {
+// if x.Error != nil {
+// // log.Println(x.Error)
+// } else {
+// // Do something with x.RR
+// }
+// }
+//
+// Comments specified after an RR (and on the same line!) are
+// returned too:
+//
+// foo. IN A 10.0.0.1 ; this is a comment
+//
+// The text "; this is comment" is returned in Token.Comment.
+// Comments inside the RR are returned concatenated along with the
+// RR. Comments on a line by themselves are discarded.
+//
+// To prevent memory leaks it is important to always fully drain the
+// returned channel. If an error occurs, it will always be the last
+// Token sent on the channel.
+//
+// Deprecated: New users should prefer the ZoneParser API.
+func ParseZone(r io.Reader, origin, file string) chan *Token {
+ t := make(chan *Token, 10000)
+ go parseZone(r, origin, file, t)
+ return t
+}
+
+func parseZone(r io.Reader, origin, file string, t chan *Token) {
+ defer close(t)
+
+ zp := NewZoneParser(r, origin, file)
+ zp.SetIncludeAllowed(true)
+
+ for rr, ok := zp.Next(); ok; rr, ok = zp.Next() {
+ t <- &Token{RR: rr, Comment: zp.Comment()}
+ }
+
+ if err := zp.Err(); err != nil {
+ pe, ok := err.(*ParseError)
+ if !ok {
+ pe = &ParseError{file: file, err: err.Error()}
+ }
+
+ t <- &Token{Error: pe}
+ }
+}
+
+// ZoneParser is a parser for an RFC 1035 style zonefile.
+//
+// Each parsed RR in the zone is returned sequentially from Next. An
+// optional comment can be retrieved with Comment.
+//
+// The directives $INCLUDE, $ORIGIN, $TTL and $GENERATE are all
+// supported. Although $INCLUDE is disabled by default.
+//
+// Basic usage pattern when reading from a string (z) containing the
+// zone data:
+//
+// zp := NewZoneParser(strings.NewReader(z), "", "")
+//
+// for rr, ok := zp.Next(); ok; rr, ok = zp.Next() {
+// // Do something with rr
+// }
+//
+// if err := zp.Err(); err != nil {
+// // log.Println(err)
+// }
+//
+// Comments specified after an RR (and on the same line!) are
+// returned too:
+//
+// foo. IN A 10.0.0.1 ; this is a comment
+//
+// The text "; this is comment" is returned from Comment. Comments inside
+// the RR are returned concatenated along with the RR. Comments on a line
+// by themselves are discarded.
+type ZoneParser struct {
+ c *zlexer
+
+ parseErr *ParseError
+
+ origin string
+ file string
+
+ defttl *ttlState
+
+ h RR_Header
+
+ // sub is used to parse $INCLUDE files and $GENERATE directives.
+ // Next, by calling subNext, forwards the resulting RRs from this
+ // sub parser to the calling code.
+ sub *ZoneParser
+ osFile *os.File
+
+ includeDepth uint8
+
+ includeAllowed bool
+}
+
+// NewZoneParser returns an RFC 1035 style zonefile parser that reads
+// from r.
+//
+// The string file is used in error reporting and to resolve relative
+// $INCLUDE directives. The string origin is used as the initial
+// origin, as if the file would start with an $ORIGIN directive.
+func NewZoneParser(r io.Reader, origin, file string) *ZoneParser {
+ var pe *ParseError
+ if origin != "" {
+ origin = Fqdn(origin)
+ if _, ok := IsDomainName(origin); !ok {
+ pe = &ParseError{file, "bad initial origin name", lex{}}
+ }
+ }
+
+ return &ZoneParser{
+ c: newZLexer(r),
+
+ parseErr: pe,
+
+ origin: origin,
+ file: file,
+ }
+}
+
+// SetDefaultTTL sets the parsers default TTL to ttl.
+func (zp *ZoneParser) SetDefaultTTL(ttl uint32) {
+ zp.defttl = &ttlState{ttl, false}
+}
+
+// SetIncludeAllowed controls whether $INCLUDE directives are
+// allowed. $INCLUDE directives are not supported by default.
+//
+// The $INCLUDE directive will open and read from a user controlled
+// file on the system. Even if the file is not a valid zonefile, the
+// contents of the file may be revealed in error messages, such as:
+//
+// /etc/passwd: dns: not a TTL: "root:x:0:0:root:/root:/bin/bash" at line: 1:31
+// /etc/shadow: dns: not a TTL: "root:$6$<redacted>::0:99999:7:::" at line: 1:125
+func (zp *ZoneParser) SetIncludeAllowed(v bool) {
+ zp.includeAllowed = v
+}
+
+// Err returns the first non-EOF error that was encountered by the
+// ZoneParser.
+func (zp *ZoneParser) Err() error {
+ if zp.parseErr != nil {
+ return zp.parseErr
+ }
+
+ if zp.sub != nil {
+ if err := zp.sub.Err(); err != nil {
+ return err
+ }
+ }
+
+ return zp.c.Err()
+}
+
+func (zp *ZoneParser) setParseError(err string, l lex) (RR, bool) {
+ zp.parseErr = &ParseError{zp.file, err, l}
+ return nil, false
+}
+
+// Comment returns an optional text comment that occurred alongside
+// the RR.
+func (zp *ZoneParser) Comment() string {
+ if zp.parseErr != nil {
+ return ""
+ }
+
+ if zp.sub != nil {
+ return zp.sub.Comment()
+ }
+
+ return zp.c.Comment()
+}
+
+func (zp *ZoneParser) subNext() (RR, bool) {
+ if rr, ok := zp.sub.Next(); ok {
+ return rr, true
+ }
+
+ if zp.sub.osFile != nil {
+ zp.sub.osFile.Close()
+ zp.sub.osFile = nil
+ }
+
+ if zp.sub.Err() != nil {
+ // We have errors to surface.
+ return nil, false
+ }
+
+ zp.sub = nil
+ return zp.Next()
+}
+
+// Next advances the parser to the next RR in the zonefile and
+// returns the (RR, true). It will return (nil, false) when the
+// parsing stops, either by reaching the end of the input or an
+// error. After Next returns (nil, false), the Err method will return
+// any error that occurred during parsing.
+func (zp *ZoneParser) Next() (RR, bool) {
+ if zp.parseErr != nil {
+ return nil, false
+ }
+ if zp.sub != nil {
+ return zp.subNext()
+ }
+
+ // 6 possible beginnings of a line (_ is a space):
+ //
+ // 0. zRRTYPE -> all omitted until the rrtype
+ // 1. zOwner _ zRrtype -> class/ttl omitted
+ // 2. zOwner _ zString _ zRrtype -> class omitted
+ // 3. zOwner _ zString _ zClass _ zRrtype -> ttl/class
+ // 4. zOwner _ zClass _ zRrtype -> ttl omitted
+ // 5. zOwner _ zClass _ zString _ zRrtype -> class/ttl (reversed)
+ //
+ // After detecting these, we know the zRrtype so we can jump to functions
+ // handling the rdata for each of these types.
+
+ st := zExpectOwnerDir // initial state
+ h := &zp.h
+
+ for l, ok := zp.c.Next(); ok; l, ok = zp.c.Next() {
+ // zlexer spotted an error already
+ if l.err {
+ return zp.setParseError(l.token, l)
+ }
+
+ switch st {
+ case zExpectOwnerDir:
+ // We can also expect a directive, like $TTL or $ORIGIN
+ if zp.defttl != nil {
+ h.Ttl = zp.defttl.ttl
+ }
+
+ h.Class = ClassINET
+
+ switch l.value {
+ case zNewline:
+ st = zExpectOwnerDir
+ case zOwner:
+ name, ok := toAbsoluteName(l.token, zp.origin)
+ if !ok {
+ return zp.setParseError("bad owner name", l)
+ }
+
+ h.Name = name
+
+ st = zExpectOwnerBl
+ case zDirTTL:
+ st = zExpectDirTTLBl
+ case zDirOrigin:
+ st = zExpectDirOriginBl
+ case zDirInclude:
+ st = zExpectDirIncludeBl
+ case zDirGenerate:
+ st = zExpectDirGenerateBl
+ case zRrtpe:
+ h.Rrtype = l.torc
+
+ st = zExpectRdata
+ case zClass:
+ h.Class = l.torc
+
+ st = zExpectAnyNoClassBl
+ case zBlank:
+ // Discard, can happen when there is nothing on the
+ // line except the RR type
+ case zString:
+ ttl, ok := stringToTTL(l.token)
+ if !ok {
+ return zp.setParseError("not a TTL", l)
+ }
+
+ h.Ttl = ttl
+
+ if zp.defttl == nil || !zp.defttl.isByDirective {
+ zp.defttl = &ttlState{ttl, false}
+ }
+
+ st = zExpectAnyNoTTLBl
+ default:
+ return zp.setParseError("syntax error at beginning", l)
+ }
+ case zExpectDirIncludeBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank after $INCLUDE-directive", l)
+ }
+
+ st = zExpectDirInclude
+ case zExpectDirInclude:
+ if l.value != zString {
+ return zp.setParseError("expecting $INCLUDE value, not this...", l)
+ }
+
+ neworigin := zp.origin // There may be optionally a new origin set after the filename, if not use current one
+ switch l, _ := zp.c.Next(); l.value {
+ case zBlank:
+ l, _ := zp.c.Next()
+ if l.value == zString {
+ name, ok := toAbsoluteName(l.token, zp.origin)
+ if !ok {
+ return zp.setParseError("bad origin name", l)
+ }
+
+ neworigin = name
+ }
+ case zNewline, zEOF:
+ // Ok
+ default:
+ return zp.setParseError("garbage after $INCLUDE", l)
+ }
+
+ if !zp.includeAllowed {
+ return zp.setParseError("$INCLUDE directive not allowed", l)
+ }
+ if zp.includeDepth >= maxIncludeDepth {
+ return zp.setParseError("too deeply nested $INCLUDE", l)
+ }
+
+ // Start with the new file
+ includePath := l.token
+ if !filepath.IsAbs(includePath) {
+ includePath = filepath.Join(filepath.Dir(zp.file), includePath)
+ }
+
+ r1, e1 := os.Open(includePath)
+ if e1 != nil {
+ var as string
+ if !filepath.IsAbs(l.token) {
+ as = fmt.Sprintf(" as `%s'", includePath)
+ }
+
+ msg := fmt.Sprintf("failed to open `%s'%s: %v", l.token, as, e1)
+ return zp.setParseError(msg, l)
+ }
+
+ zp.sub = NewZoneParser(r1, neworigin, includePath)
+ zp.sub.defttl, zp.sub.includeDepth, zp.sub.osFile = zp.defttl, zp.includeDepth+1, r1
+ zp.sub.SetIncludeAllowed(true)
+ return zp.subNext()
+ case zExpectDirTTLBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank after $TTL-directive", l)
+ }
+
+ st = zExpectDirTTL
+ case zExpectDirTTL:
+ if l.value != zString {
+ return zp.setParseError("expecting $TTL value, not this...", l)
+ }
+
+ if e := slurpRemainder(zp.c, zp.file); e != nil {
+ zp.parseErr = e
+ return nil, false
+ }
+
+ ttl, ok := stringToTTL(l.token)
+ if !ok {
+ return zp.setParseError("expecting $TTL value, not this...", l)
+ }
+
+ zp.defttl = &ttlState{ttl, true}
+
+ st = zExpectOwnerDir
+ case zExpectDirOriginBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank after $ORIGIN-directive", l)
+ }
+
+ st = zExpectDirOrigin
+ case zExpectDirOrigin:
+ if l.value != zString {
+ return zp.setParseError("expecting $ORIGIN value, not this...", l)
+ }
+
+ if e := slurpRemainder(zp.c, zp.file); e != nil {
+ zp.parseErr = e
+ return nil, false
+ }
+
+ name, ok := toAbsoluteName(l.token, zp.origin)
+ if !ok {
+ return zp.setParseError("bad origin name", l)
+ }
+
+ zp.origin = name
+
+ st = zExpectOwnerDir
+ case zExpectDirGenerateBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank after $GENERATE-directive", l)
+ }
+
+ st = zExpectDirGenerate
+ case zExpectDirGenerate:
+ if l.value != zString {
+ return zp.setParseError("expecting $GENERATE value, not this...", l)
+ }
+
+ return zp.generate(l)
+ case zExpectOwnerBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank after owner", l)
+ }
+
+ st = zExpectAny
+ case zExpectAny:
+ switch l.value {
+ case zRrtpe:
+ if zp.defttl == nil {
+ return zp.setParseError("missing TTL with no previous value", l)
+ }
+
+ h.Rrtype = l.torc
+
+ st = zExpectRdata
+ case zClass:
+ h.Class = l.torc
+
+ st = zExpectAnyNoClassBl
+ case zString:
+ ttl, ok := stringToTTL(l.token)
+ if !ok {
+ return zp.setParseError("not a TTL", l)
+ }
+
+ h.Ttl = ttl
+
+ if zp.defttl == nil || !zp.defttl.isByDirective {
+ zp.defttl = &ttlState{ttl, false}
+ }
+
+ st = zExpectAnyNoTTLBl
+ default:
+ return zp.setParseError("expecting RR type, TTL or class, not this...", l)
+ }
+ case zExpectAnyNoClassBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank before class", l)
+ }
+
+ st = zExpectAnyNoClass
+ case zExpectAnyNoTTLBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank before TTL", l)
+ }
+
+ st = zExpectAnyNoTTL
+ case zExpectAnyNoTTL:
+ switch l.value {
+ case zClass:
+ h.Class = l.torc
+
+ st = zExpectRrtypeBl
+ case zRrtpe:
+ h.Rrtype = l.torc
+
+ st = zExpectRdata
+ default:
+ return zp.setParseError("expecting RR type or class, not this...", l)
+ }
+ case zExpectAnyNoClass:
+ switch l.value {
+ case zString:
+ ttl, ok := stringToTTL(l.token)
+ if !ok {
+ return zp.setParseError("not a TTL", l)
+ }
+
+ h.Ttl = ttl
+
+ if zp.defttl == nil || !zp.defttl.isByDirective {
+ zp.defttl = &ttlState{ttl, false}
+ }
+
+ st = zExpectRrtypeBl
+ case zRrtpe:
+ h.Rrtype = l.torc
+
+ st = zExpectRdata
+ default:
+ return zp.setParseError("expecting RR type or TTL, not this...", l)
+ }
+ case zExpectRrtypeBl:
+ if l.value != zBlank {
+ return zp.setParseError("no blank before RR type", l)
+ }
+
+ st = zExpectRrtype
+ case zExpectRrtype:
+ if l.value != zRrtpe {
+ return zp.setParseError("unknown RR type", l)
+ }
+
+ h.Rrtype = l.torc
+
+ st = zExpectRdata
+ case zExpectRdata:
+ r, e := setRR(*h, zp.c, zp.origin, zp.file)
+ if e != nil {
+ // If e.lex is nil than we have encounter a unknown RR type
+ // in that case we substitute our current lex token
+ if e.lex.token == "" && e.lex.value == 0 {
+ e.lex = l // Uh, dirty
+ }
+
+ zp.parseErr = e
+ return nil, false
+ }
+
+ return r, true
+ }
+ }
+
+ // If we get here, we and the h.Rrtype is still zero, we haven't parsed anything, this
+ // is not an error, because an empty zone file is still a zone file.
+ return nil, false
+}
+
+type zlexer struct {
+ br io.ByteReader
+
+ readErr error
+
+ line int
+ column int
+
+ comBuf string
+ comment string
+
+ l lex
+
+ brace int
+ quote bool
+ space bool
+ commt bool
+ rrtype bool
+ owner bool
+
+ nextL bool
+
+ eol bool // end-of-line
+}
+
+func newZLexer(r io.Reader) *zlexer {
+ br, ok := r.(io.ByteReader)
+ if !ok {
+ br = bufio.NewReaderSize(r, 1024)
+ }
+
+ return &zlexer{
+ br: br,
+
+ line: 1,
+
+ owner: true,
+ }
+}
+
+func (zl *zlexer) Err() error {
+ if zl.readErr == io.EOF {
+ return nil
+ }
+
+ return zl.readErr
+}
+
+// readByte returns the next byte from the input
+func (zl *zlexer) readByte() (byte, bool) {
+ if zl.readErr != nil {
+ return 0, false
+ }
+
+ c, err := zl.br.ReadByte()
+ if err != nil {
+ zl.readErr = err
+ return 0, false
+ }
+
+ // delay the newline handling until the next token is delivered,
+ // fixes off-by-one errors when reporting a parse error.
+ if zl.eol {
+ zl.line++
+ zl.column = 0
+ zl.eol = false
+ }
+
+ if c == '\n' {
+ zl.eol = true
+ } else {
+ zl.column++
+ }
+
+ return c, true
+}
+
+func (zl *zlexer) Next() (lex, bool) {
+ l := &zl.l
+ if zl.nextL {
+ zl.nextL = false
+ return *l, true
+ }
+ if l.err {
+ // Parsing errors should be sticky.
+ return lex{value: zEOF}, false
+ }
+
+ var (
+ str [maxTok]byte // Hold string text
+ com [maxTok]byte // Hold comment text
+
+ stri int // Offset in str (0 means empty)
+ comi int // Offset in com (0 means empty)
+
+ escape bool
+ )
+
+ if zl.comBuf != "" {
+ comi = copy(com[:], zl.comBuf)
+ zl.comBuf = ""
+ }
+
+ zl.comment = ""
+
+ for x, ok := zl.readByte(); ok; x, ok = zl.readByte() {
+ l.line, l.column = zl.line, zl.column
+
+ if stri >= len(str) {
+ l.token = "token length insufficient for parsing"
+ l.err = true
+ return *l, true
+ }
+ if comi >= len(com) {
+ l.token = "comment length insufficient for parsing"
+ l.err = true
+ return *l, true
+ }
+
+ switch x {
+ case ' ', '\t':
+ if escape || zl.quote {
+ // Inside quotes or escaped this is legal.
+ str[stri] = x
+ stri++
+
+ escape = false
+ break
+ }
+
+ if zl.commt {
+ com[comi] = x
+ comi++
+ break
+ }
+
+ var retL lex
+ if stri == 0 {
+ // Space directly in the beginning, handled in the grammar
+ } else if zl.owner {
+ // If we have a string and its the first, make it an owner
+ l.value = zOwner
+ l.token = string(str[:stri])
+
+ // escape $... start with a \ not a $, so this will work
+ switch strings.ToUpper(l.token) {
+ case "$TTL":
+ l.value = zDirTTL
+ case "$ORIGIN":
+ l.value = zDirOrigin
+ case "$INCLUDE":
+ l.value = zDirInclude
+ case "$GENERATE":
+ l.value = zDirGenerate
+ }
+
+ retL = *l
+ } else {
+ l.value = zString
+ l.token = string(str[:stri])
+
+ if !zl.rrtype {
+ tokenUpper := strings.ToUpper(l.token)
+ if t, ok := StringToType[tokenUpper]; ok {
+ l.value = zRrtpe
+ l.torc = t
+
+ zl.rrtype = true
+ } else if strings.HasPrefix(tokenUpper, "TYPE") {
+ t, ok := typeToInt(l.token)
+ if !ok {
+ l.token = "unknown RR type"
+ l.err = true
+ return *l, true
+ }
+
+ l.value = zRrtpe
+ l.torc = t
+
+ zl.rrtype = true
+ }
+
+ if t, ok := StringToClass[tokenUpper]; ok {
+ l.value = zClass
+ l.torc = t
+ } else if strings.HasPrefix(tokenUpper, "CLASS") {
+ t, ok := classToInt(l.token)
+ if !ok {
+ l.token = "unknown class"
+ l.err = true
+ return *l, true
+ }
+
+ l.value = zClass
+ l.torc = t
+ }
+ }
+
+ retL = *l
+ }
+
+ zl.owner = false
+
+ if !zl.space {
+ zl.space = true
+
+ l.value = zBlank
+ l.token = " "
+
+ if retL == (lex{}) {
+ return *l, true
+ }
+
+ zl.nextL = true
+ }
+
+ if retL != (lex{}) {
+ return retL, true
+ }
+ case ';':
+ if escape || zl.quote {
+ // Inside quotes or escaped this is legal.
+ str[stri] = x
+ stri++
+
+ escape = false
+ break
+ }
+
+ zl.commt = true
+ zl.comBuf = ""
+
+ if comi > 1 {
+ // A newline was previously seen inside a comment that
+ // was inside braces and we delayed adding it until now.
+ com[comi] = ' ' // convert newline to space
+ comi++
+ }
+
+ com[comi] = ';'
+ comi++
+
+ if stri > 0 {
+ zl.comBuf = string(com[:comi])
+
+ l.value = zString
+ l.token = string(str[:stri])
+ return *l, true
+ }
+ case '\r':
+ escape = false
+
+ if zl.quote {
+ str[stri] = x
+ stri++
+ }
+
+ // discard if outside of quotes
+ case '\n':
+ escape = false
+
+ // Escaped newline
+ if zl.quote {
+ str[stri] = x
+ stri++
+ break
+ }
+
+ if zl.commt {
+ // Reset a comment
+ zl.commt = false
+ zl.rrtype = false
+
+ // If not in a brace this ends the comment AND the RR
+ if zl.brace == 0 {
+ zl.owner = true
+
+ l.value = zNewline
+ l.token = "\n"
+ zl.comment = string(com[:comi])
+ return *l, true
+ }
+
+ zl.comBuf = string(com[:comi])
+ break
+ }
+
+ if zl.brace == 0 {
+ // If there is previous text, we should output it here
+ var retL lex
+ if stri != 0 {
+ l.value = zString
+ l.token = string(str[:stri])
+
+ if !zl.rrtype {
+ tokenUpper := strings.ToUpper(l.token)
+ if t, ok := StringToType[tokenUpper]; ok {
+ zl.rrtype = true
+
+ l.value = zRrtpe
+ l.torc = t
+ }
+ }
+
+ retL = *l
+ }
+
+ l.value = zNewline
+ l.token = "\n"
+
+ zl.comment = zl.comBuf
+ zl.comBuf = ""
+ zl.rrtype = false
+ zl.owner = true
+
+ if retL != (lex{}) {
+ zl.nextL = true
+ return retL, true
+ }
+
+ return *l, true
+ }
+ case '\\':
+ // comments do not get escaped chars, everything is copied
+ if zl.commt {
+ com[comi] = x
+ comi++
+ break
+ }
+
+ // something already escaped must be in string
+ if escape {
+ str[stri] = x
+ stri++
+
+ escape = false
+ break
+ }
+
+ // something escaped outside of string gets added to string
+ str[stri] = x
+ stri++
+
+ escape = true
+ case '"':
+ if zl.commt {
+ com[comi] = x
+ comi++
+ break
+ }
+
+ if escape {
+ str[stri] = x
+ stri++
+
+ escape = false
+ break
+ }
+
+ zl.space = false
+
+ // send previous gathered text and the quote
+ var retL lex
+ if stri != 0 {
+ l.value = zString
+ l.token = string(str[:stri])
+
+ retL = *l
+ }
+
+ // send quote itself as separate token
+ l.value = zQuote
+ l.token = "\""
+
+ zl.quote = !zl.quote
+
+ if retL != (lex{}) {
+ zl.nextL = true
+ return retL, true
+ }
+
+ return *l, true
+ case '(', ')':
+ if zl.commt {
+ com[comi] = x
+ comi++
+ break
+ }
+
+ if escape || zl.quote {
+ // Inside quotes or escaped this is legal.
+ str[stri] = x
+ stri++
+
+ escape = false
+ break
+ }
+
+ switch x {
+ case ')':
+ zl.brace--
+
+ if zl.brace < 0 {
+ l.token = "extra closing brace"
+ l.err = true
+ return *l, true
+ }
+ case '(':
+ zl.brace++
+ }
+ default:
+ escape = false
+
+ if zl.commt {
+ com[comi] = x
+ comi++
+ break
+ }
+
+ str[stri] = x
+ stri++
+
+ zl.space = false
+ }
+ }
+
+ if zl.readErr != nil && zl.readErr != io.EOF {
+ // Don't return any tokens after a read error occurs.
+ return lex{value: zEOF}, false
+ }
+
+ var retL lex
+ if stri > 0 {
+ // Send remainder of str
+ l.value = zString
+ l.token = string(str[:stri])
+ retL = *l
+
+ if comi <= 0 {
+ return retL, true
+ }
+ }
+
+ if comi > 0 {
+ // Send remainder of com
+ l.value = zNewline
+ l.token = "\n"
+ zl.comment = string(com[:comi])
+
+ if retL != (lex{}) {
+ zl.nextL = true
+ return retL, true
+ }
+
+ return *l, true
+ }
+
+ if zl.brace != 0 {
+ l.token = "unbalanced brace"
+ l.err = true
+ return *l, true
+ }
+
+ return lex{value: zEOF}, false
+}
+
+func (zl *zlexer) Comment() string {
+ if zl.l.err {
+ return ""
+ }
+
+ return zl.comment
+}
+
+// Extract the class number from CLASSxx
+func classToInt(token string) (uint16, bool) {
+ offset := 5
+ if len(token) < offset+1 {
+ return 0, false
+ }
+ class, err := strconv.ParseUint(token[offset:], 10, 16)
+ if err != nil {
+ return 0, false
+ }
+ return uint16(class), true
+}
+
+// Extract the rr number from TYPExxx
+func typeToInt(token string) (uint16, bool) {
+ offset := 4
+ if len(token) < offset+1 {
+ return 0, false
+ }
+ typ, err := strconv.ParseUint(token[offset:], 10, 16)
+ if err != nil {
+ return 0, false
+ }
+ return uint16(typ), true
+}
+
+// stringToTTL parses things like 2w, 2m, etc, and returns the time in seconds.
+func stringToTTL(token string) (uint32, bool) {
+ var s, i uint32
+ for _, c := range token {
+ switch c {
+ case 's', 'S':
+ s += i
+ i = 0
+ case 'm', 'M':
+ s += i * 60
+ i = 0
+ case 'h', 'H':
+ s += i * 60 * 60
+ i = 0
+ case 'd', 'D':
+ s += i * 60 * 60 * 24
+ i = 0
+ case 'w', 'W':
+ s += i * 60 * 60 * 24 * 7
+ i = 0
+ case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+ i *= 10
+ i += uint32(c) - '0'
+ default:
+ return 0, false
+ }
+ }
+ return s + i, true
+}
+
+// Parse LOC records' <digits>[.<digits>][mM] into a
+// mantissa exponent format. Token should contain the entire
+// string (i.e. no spaces allowed)
+func stringToCm(token string) (e, m uint8, ok bool) {
+ if token[len(token)-1] == 'M' || token[len(token)-1] == 'm' {
+ token = token[0 : len(token)-1]
+ }
+ s := strings.SplitN(token, ".", 2)
+ var meters, cmeters, val int
+ var err error
+ switch len(s) {
+ case 2:
+ if cmeters, err = strconv.Atoi(s[1]); err != nil {
+ return
+ }
+ fallthrough
+ case 1:
+ if meters, err = strconv.Atoi(s[0]); err != nil {
+ return
+ }
+ case 0:
+ // huh?
+ return 0, 0, false
+ }
+ ok = true
+ if meters > 0 {
+ e = 2
+ val = meters
+ } else {
+ e = 0
+ val = cmeters
+ }
+ for val > 10 {
+ e++
+ val /= 10
+ }
+ if e > 9 {
+ ok = false
+ }
+ m = uint8(val)
+ return
+}
+
+func toAbsoluteName(name, origin string) (absolute string, ok bool) {
+ // check for an explicit origin reference
+ if name == "@" {
+ // require a nonempty origin
+ if origin == "" {
+ return "", false
+ }
+ return origin, true
+ }
+
+ // require a valid domain name
+ _, ok = IsDomainName(name)
+ if !ok || name == "" {
+ return "", false
+ }
+
+ // check if name is already absolute
+ if IsFqdn(name) {
+ return name, true
+ }
+
+ // require a nonempty origin
+ if origin == "" {
+ return "", false
+ }
+ return appendOrigin(name, origin), true
+}
+
+func appendOrigin(name, origin string) string {
+ if origin == "." {
+ return name + origin
+ }
+ return name + "." + origin
+}
+
+// LOC record helper function
+func locCheckNorth(token string, latitude uint32) (uint32, bool) {
+ switch token {
+ case "n", "N":
+ return LOC_EQUATOR + latitude, true
+ case "s", "S":
+ return LOC_EQUATOR - latitude, true
+ }
+ return latitude, false
+}
+
+// LOC record helper function
+func locCheckEast(token string, longitude uint32) (uint32, bool) {
+ switch token {
+ case "e", "E":
+ return LOC_EQUATOR + longitude, true
+ case "w", "W":
+ return LOC_EQUATOR - longitude, true
+ }
+ return longitude, false
+}
+
+// "Eat" the rest of the "line"
+func slurpRemainder(c *zlexer, f string) *ParseError {
+ l, _ := c.Next()
+ switch l.value {
+ case zBlank:
+ l, _ = c.Next()
+ if l.value != zNewline && l.value != zEOF {
+ return &ParseError{f, "garbage after rdata", l}
+ }
+ case zNewline:
+ case zEOF:
+ default:
+ return &ParseError{f, "garbage after rdata", l}
+ }
+ return nil
+}
+
+// Parse a 64 bit-like ipv6 address: "0014:4fff:ff20:ee64"
+// Used for NID and L64 record.
+func stringToNodeID(l lex) (uint64, *ParseError) {
+ if len(l.token) < 19 {
+ return 0, &ParseError{l.token, "bad NID/L64 NodeID/Locator64", l}
+ }
+ // There must be three colons at fixes postitions, if not its a parse error
+ if l.token[4] != ':' && l.token[9] != ':' && l.token[14] != ':' {
+ return 0, &ParseError{l.token, "bad NID/L64 NodeID/Locator64", l}
+ }
+ s := l.token[0:4] + l.token[5:9] + l.token[10:14] + l.token[15:19]
+ u, err := strconv.ParseUint(s, 16, 64)
+ if err != nil {
+ return 0, &ParseError{l.token, "bad NID/L64 NodeID/Locator64", l}
+ }
+ return u, nil
+}
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