435c0d9fc8
This PR switches the Nomad repository from using govendor to Go modules for managing dependencies. Aspects of the Nomad workflow remain pretty much the same. The usual Makefile targets should continue to work as they always did. The API submodule simply defers to the parent Nomad version on the repository, keeping the semantics of API versioning that currently exists.
1409 lines
30 KiB
Go
1409 lines
30 KiB
Go
package dns
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import (
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"bufio"
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"fmt"
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"io"
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"os"
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"path/filepath"
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"strconv"
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"strings"
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)
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const maxTok = 2048 // Largest token we can return.
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// The maximum depth of $INCLUDE directives supported by the
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// ZoneParser API.
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const maxIncludeDepth = 7
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// Tokinize a RFC 1035 zone file. The tokenizer will normalize it:
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// * Add ownernames if they are left blank;
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// * Suppress sequences of spaces;
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// * Make each RR fit on one line (_NEWLINE is send as last)
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// * Handle comments: ;
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// * Handle braces - anywhere.
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const (
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// Zonefile
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zEOF = iota
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zString
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zBlank
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zQuote
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zNewline
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zRrtpe
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zOwner
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zClass
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zDirOrigin // $ORIGIN
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zDirTTL // $TTL
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zDirInclude // $INCLUDE
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zDirGenerate // $GENERATE
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// Privatekey file
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zValue
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zKey
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zExpectOwnerDir // Ownername
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zExpectOwnerBl // Whitespace after the ownername
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zExpectAny // Expect rrtype, ttl or class
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zExpectAnyNoClass // Expect rrtype or ttl
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zExpectAnyNoClassBl // The whitespace after _EXPECT_ANY_NOCLASS
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zExpectAnyNoTTL // Expect rrtype or class
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zExpectAnyNoTTLBl // Whitespace after _EXPECT_ANY_NOTTL
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zExpectRrtype // Expect rrtype
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zExpectRrtypeBl // Whitespace BEFORE rrtype
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zExpectRdata // The first element of the rdata
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zExpectDirTTLBl // Space after directive $TTL
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zExpectDirTTL // Directive $TTL
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zExpectDirOriginBl // Space after directive $ORIGIN
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zExpectDirOrigin // Directive $ORIGIN
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zExpectDirIncludeBl // Space after directive $INCLUDE
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zExpectDirInclude // Directive $INCLUDE
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zExpectDirGenerate // Directive $GENERATE
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zExpectDirGenerateBl // Space after directive $GENERATE
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)
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// ParseError is a parsing error. It contains the parse error and the location in the io.Reader
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// where the error occurred.
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type ParseError struct {
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file string
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err string
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lex lex
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}
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func (e *ParseError) Error() (s string) {
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if e.file != "" {
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s = e.file + ": "
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}
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s += "dns: " + e.err + ": " + strconv.QuoteToASCII(e.lex.token) + " at line: " +
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strconv.Itoa(e.lex.line) + ":" + strconv.Itoa(e.lex.column)
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return
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}
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type lex struct {
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token string // text of the token
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err bool // when true, token text has lexer error
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value uint8 // value: zString, _BLANK, etc.
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torc uint16 // type or class as parsed in the lexer, we only need to look this up in the grammar
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line int // line in the file
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column int // column in the file
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}
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// Token holds the token that are returned when a zone file is parsed.
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type Token struct {
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// The scanned resource record when error is not nil.
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RR
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// When an error occurred, this has the error specifics.
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Error *ParseError
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// A potential comment positioned after the RR and on the same line.
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Comment string
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}
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// ttlState describes the state necessary to fill in an omitted RR TTL
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type ttlState struct {
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ttl uint32 // ttl is the current default TTL
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isByDirective bool // isByDirective indicates whether ttl was set by a $TTL directive
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}
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// NewRR reads the RR contained in the string s. Only the first RR is
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// returned. If s contains no records, NewRR will return nil with no
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// error.
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//
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// The class defaults to IN and TTL defaults to 3600. The full zone
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// file syntax like $TTL, $ORIGIN, etc. is supported.
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//
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// All fields of the returned RR are set, except RR.Header().Rdlength
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// which is set to 0.
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func NewRR(s string) (RR, error) {
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if len(s) > 0 && s[len(s)-1] != '\n' { // We need a closing newline
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return ReadRR(strings.NewReader(s+"\n"), "")
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}
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return ReadRR(strings.NewReader(s), "")
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}
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// ReadRR reads the RR contained in r.
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//
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// The string file is used in error reporting and to resolve relative
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// $INCLUDE directives.
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//
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// See NewRR for more documentation.
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func ReadRR(r io.Reader, file string) (RR, error) {
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zp := NewZoneParser(r, ".", file)
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zp.SetDefaultTTL(defaultTtl)
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zp.SetIncludeAllowed(true)
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rr, _ := zp.Next()
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return rr, zp.Err()
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}
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// ParseZone reads a RFC 1035 style zonefile from r. It returns
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// Tokens on the returned channel, each consisting of either a
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// parsed RR and optional comment or a nil RR and an error. The
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// channel is closed by ParseZone when the end of r is reached.
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//
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// The string file is used in error reporting and to resolve relative
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// $INCLUDE directives. The string origin is used as the initial
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// origin, as if the file would start with an $ORIGIN directive.
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//
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// The directives $INCLUDE, $ORIGIN, $TTL and $GENERATE are all
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// supported. Note that $GENERATE's range support up to a maximum of
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// of 65535 steps.
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//
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// Basic usage pattern when reading from a string (z) containing the
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// zone data:
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//
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// for x := range dns.ParseZone(strings.NewReader(z), "", "") {
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// if x.Error != nil {
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// // log.Println(x.Error)
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// } else {
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// // Do something with x.RR
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// }
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// }
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//
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// Comments specified after an RR (and on the same line!) are
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// returned too:
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//
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// foo. IN A 10.0.0.1 ; this is a comment
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//
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// The text "; this is comment" is returned in Token.Comment.
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// Comments inside the RR are returned concatenated along with the
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// RR. Comments on a line by themselves are discarded.
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//
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// To prevent memory leaks it is important to always fully drain the
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// returned channel. If an error occurs, it will always be the last
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// Token sent on the channel.
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//
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// Deprecated: New users should prefer the ZoneParser API.
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func ParseZone(r io.Reader, origin, file string) chan *Token {
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t := make(chan *Token, 10000)
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go parseZone(r, origin, file, t)
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return t
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}
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func parseZone(r io.Reader, origin, file string, t chan *Token) {
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defer close(t)
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zp := NewZoneParser(r, origin, file)
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zp.SetIncludeAllowed(true)
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for rr, ok := zp.Next(); ok; rr, ok = zp.Next() {
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t <- &Token{RR: rr, Comment: zp.Comment()}
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}
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if err := zp.Err(); err != nil {
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pe, ok := err.(*ParseError)
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if !ok {
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pe = &ParseError{file: file, err: err.Error()}
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}
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t <- &Token{Error: pe}
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}
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}
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// ZoneParser is a parser for an RFC 1035 style zonefile.
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//
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// Each parsed RR in the zone is returned sequentially from Next. An
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// optional comment can be retrieved with Comment.
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//
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// The directives $INCLUDE, $ORIGIN, $TTL and $GENERATE are all
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// supported. Although $INCLUDE is disabled by default.
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// Note that $GENERATE's range support up to a maximum of 65535 steps.
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//
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// Basic usage pattern when reading from a string (z) containing the
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// zone data:
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//
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// zp := NewZoneParser(strings.NewReader(z), "", "")
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//
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// for rr, ok := zp.Next(); ok; rr, ok = zp.Next() {
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// // Do something with rr
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// }
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//
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// if err := zp.Err(); err != nil {
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// // log.Println(err)
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// }
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//
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// Comments specified after an RR (and on the same line!) are
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// returned too:
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//
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// foo. IN A 10.0.0.1 ; this is a comment
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//
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// The text "; this is comment" is returned from Comment. Comments inside
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// the RR are returned concatenated along with the RR. Comments on a line
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// by themselves are discarded.
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type ZoneParser struct {
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c *zlexer
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parseErr *ParseError
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origin string
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file string
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defttl *ttlState
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h RR_Header
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// sub is used to parse $INCLUDE files and $GENERATE directives.
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// Next, by calling subNext, forwards the resulting RRs from this
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// sub parser to the calling code.
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sub *ZoneParser
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osFile *os.File
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includeDepth uint8
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includeAllowed bool
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generateDisallowed bool
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}
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// NewZoneParser returns an RFC 1035 style zonefile parser that reads
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// from r.
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//
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// The string file is used in error reporting and to resolve relative
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// $INCLUDE directives. The string origin is used as the initial
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// origin, as if the file would start with an $ORIGIN directive.
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func NewZoneParser(r io.Reader, origin, file string) *ZoneParser {
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var pe *ParseError
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if origin != "" {
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origin = Fqdn(origin)
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if _, ok := IsDomainName(origin); !ok {
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pe = &ParseError{file, "bad initial origin name", lex{}}
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}
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}
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return &ZoneParser{
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c: newZLexer(r),
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parseErr: pe,
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origin: origin,
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file: file,
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}
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}
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// SetDefaultTTL sets the parsers default TTL to ttl.
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func (zp *ZoneParser) SetDefaultTTL(ttl uint32) {
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zp.defttl = &ttlState{ttl, false}
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}
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// SetIncludeAllowed controls whether $INCLUDE directives are
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// allowed. $INCLUDE directives are not supported by default.
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//
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// The $INCLUDE directive will open and read from a user controlled
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// file on the system. Even if the file is not a valid zonefile, the
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// contents of the file may be revealed in error messages, such as:
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//
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// /etc/passwd: dns: not a TTL: "root:x:0:0:root:/root:/bin/bash" at line: 1:31
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// /etc/shadow: dns: not a TTL: "root:$6$<redacted>::0:99999:7:::" at line: 1:125
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func (zp *ZoneParser) SetIncludeAllowed(v bool) {
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zp.includeAllowed = v
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}
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// Err returns the first non-EOF error that was encountered by the
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// ZoneParser.
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func (zp *ZoneParser) Err() error {
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if zp.parseErr != nil {
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return zp.parseErr
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}
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if zp.sub != nil {
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if err := zp.sub.Err(); err != nil {
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return err
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}
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}
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return zp.c.Err()
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}
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func (zp *ZoneParser) setParseError(err string, l lex) (RR, bool) {
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zp.parseErr = &ParseError{zp.file, err, l}
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return nil, false
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}
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// Comment returns an optional text comment that occurred alongside
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// the RR.
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func (zp *ZoneParser) Comment() string {
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if zp.parseErr != nil {
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return ""
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}
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if zp.sub != nil {
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return zp.sub.Comment()
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}
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return zp.c.Comment()
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}
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func (zp *ZoneParser) subNext() (RR, bool) {
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if rr, ok := zp.sub.Next(); ok {
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return rr, true
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}
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if zp.sub.osFile != nil {
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zp.sub.osFile.Close()
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zp.sub.osFile = nil
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}
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if zp.sub.Err() != nil {
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// We have errors to surface.
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return nil, false
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}
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zp.sub = nil
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return zp.Next()
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}
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// Next advances the parser to the next RR in the zonefile and
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// returns the (RR, true). It will return (nil, false) when the
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// parsing stops, either by reaching the end of the input or an
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// error. After Next returns (nil, false), the Err method will return
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// any error that occurred during parsing.
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func (zp *ZoneParser) Next() (RR, bool) {
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if zp.parseErr != nil {
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return nil, false
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}
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if zp.sub != nil {
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return zp.subNext()
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}
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// 6 possible beginnings of a line (_ is a space):
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//
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// 0. zRRTYPE -> all omitted until the rrtype
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// 1. zOwner _ zRrtype -> class/ttl omitted
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// 2. zOwner _ zString _ zRrtype -> class omitted
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// 3. zOwner _ zString _ zClass _ zRrtype -> ttl/class
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// 4. zOwner _ zClass _ zRrtype -> ttl omitted
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// 5. zOwner _ zClass _ zString _ zRrtype -> class/ttl (reversed)
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//
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// After detecting these, we know the zRrtype so we can jump to functions
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// handling the rdata for each of these types.
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st := zExpectOwnerDir // initial state
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h := &zp.h
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for l, ok := zp.c.Next(); ok; l, ok = zp.c.Next() {
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// zlexer spotted an error already
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if l.err {
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return zp.setParseError(l.token, l)
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}
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switch st {
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case zExpectOwnerDir:
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// We can also expect a directive, like $TTL or $ORIGIN
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if zp.defttl != nil {
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h.Ttl = zp.defttl.ttl
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}
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h.Class = ClassINET
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switch l.value {
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case zNewline:
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st = zExpectOwnerDir
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case zOwner:
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name, ok := toAbsoluteName(l.token, zp.origin)
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if !ok {
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return zp.setParseError("bad owner name", l)
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}
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h.Name = name
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st = zExpectOwnerBl
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case zDirTTL:
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st = zExpectDirTTLBl
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case zDirOrigin:
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st = zExpectDirOriginBl
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case zDirInclude:
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st = zExpectDirIncludeBl
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case zDirGenerate:
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st = zExpectDirGenerateBl
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case zRrtpe:
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h.Rrtype = l.torc
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st = zExpectRdata
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case zClass:
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h.Class = l.torc
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st = zExpectAnyNoClassBl
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case zBlank:
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// Discard, can happen when there is nothing on the
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// line except the RR type
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case zString:
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ttl, ok := stringToTTL(l.token)
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if !ok {
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return zp.setParseError("not a TTL", l)
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}
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h.Ttl = ttl
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if zp.defttl == nil || !zp.defttl.isByDirective {
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zp.defttl = &ttlState{ttl, false}
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}
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st = zExpectAnyNoTTLBl
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default:
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return zp.setParseError("syntax error at beginning", l)
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}
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case zExpectDirIncludeBl:
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if l.value != zBlank {
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return zp.setParseError("no blank after $INCLUDE-directive", l)
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}
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st = zExpectDirInclude
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case zExpectDirInclude:
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if l.value != zString {
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return zp.setParseError("expecting $INCLUDE value, not this...", l)
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}
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neworigin := zp.origin // There may be optionally a new origin set after the filename, if not use current one
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switch l, _ := zp.c.Next(); l.value {
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case zBlank:
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l, _ := zp.c.Next()
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if l.value == zString {
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name, ok := toAbsoluteName(l.token, zp.origin)
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if !ok {
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return zp.setParseError("bad origin name", l)
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}
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neworigin = name
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}
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case zNewline, zEOF:
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// Ok
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default:
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return zp.setParseError("garbage after $INCLUDE", l)
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}
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if !zp.includeAllowed {
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return zp.setParseError("$INCLUDE directive not allowed", l)
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}
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if zp.includeDepth >= maxIncludeDepth {
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return zp.setParseError("too deeply nested $INCLUDE", l)
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}
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// Start with the new file
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includePath := l.token
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if !filepath.IsAbs(includePath) {
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includePath = filepath.Join(filepath.Dir(zp.file), includePath)
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}
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r1, e1 := os.Open(includePath)
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if e1 != nil {
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var as string
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if !filepath.IsAbs(l.token) {
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as = fmt.Sprintf(" as `%s'", includePath)
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}
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msg := fmt.Sprintf("failed to open `%s'%s: %v", l.token, as, e1)
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return zp.setParseError(msg, l)
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}
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zp.sub = NewZoneParser(r1, neworigin, includePath)
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zp.sub.defttl, zp.sub.includeDepth, zp.sub.osFile = zp.defttl, zp.includeDepth+1, r1
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zp.sub.SetIncludeAllowed(true)
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return zp.subNext()
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case zExpectDirTTLBl:
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if l.value != zBlank {
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return zp.setParseError("no blank after $TTL-directive", l)
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}
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st = zExpectDirTTL
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case zExpectDirTTL:
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if l.value != zString {
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return zp.setParseError("expecting $TTL value, not this...", l)
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}
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if err := slurpRemainder(zp.c); err != nil {
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return zp.setParseError(err.err, err.lex)
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}
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ttl, ok := stringToTTL(l.token)
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if !ok {
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return zp.setParseError("expecting $TTL value, not this...", l)
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}
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zp.defttl = &ttlState{ttl, true}
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st = zExpectOwnerDir
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case zExpectDirOriginBl:
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if l.value != zBlank {
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return zp.setParseError("no blank after $ORIGIN-directive", l)
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}
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st = zExpectDirOrigin
|
|
case zExpectDirOrigin:
|
|
if l.value != zString {
|
|
return zp.setParseError("expecting $ORIGIN value, not this...", l)
|
|
}
|
|
|
|
if err := slurpRemainder(zp.c); err != nil {
|
|
return zp.setParseError(err.err, err.lex)
|
|
}
|
|
|
|
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 zp.generateDisallowed {
|
|
return zp.setParseError("nested $GENERATE directive not allowed", l)
|
|
}
|
|
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:
|
|
var rr RR
|
|
if newFn, ok := TypeToRR[h.Rrtype]; ok && canParseAsRR(h.Rrtype) {
|
|
rr = newFn()
|
|
*rr.Header() = *h
|
|
} else {
|
|
rr = &RFC3597{Hdr: *h}
|
|
}
|
|
|
|
_, isPrivate := rr.(*PrivateRR)
|
|
if !isPrivate && zp.c.Peek().token == "" {
|
|
// This is a dynamic update rr.
|
|
|
|
// TODO(tmthrgd): Previously slurpRemainder was only called
|
|
// for certain RR types, which may have been important.
|
|
if err := slurpRemainder(zp.c); err != nil {
|
|
return zp.setParseError(err.err, err.lex)
|
|
}
|
|
|
|
return rr, true
|
|
} else if l.value == zNewline {
|
|
return zp.setParseError("unexpected newline", l)
|
|
}
|
|
|
|
if err := rr.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.
|
|
if err.lex == (lex{}) {
|
|
return zp.setParseError(err.err, l)
|
|
}
|
|
|
|
return zp.setParseError(err.err, err.lex)
|
|
}
|
|
|
|
return rr, 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
|
|
}
|
|
|
|
// 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
|
|
|
|
readErr error
|
|
|
|
line int
|
|
column int
|
|
|
|
comBuf string
|
|
comment string
|
|
|
|
l lex
|
|
cachedL *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) Peek() lex {
|
|
if zl.nextL {
|
|
return zl.l
|
|
}
|
|
|
|
l, ok := zl.Next()
|
|
if !ok {
|
|
return l
|
|
}
|
|
|
|
if zl.nextL {
|
|
// Cache l. Next returns zl.cachedL then zl.l.
|
|
zl.cachedL = &l
|
|
} else {
|
|
// In this case l == zl.l, so we just tell Next to return zl.l.
|
|
zl.nextL = true
|
|
}
|
|
|
|
return l
|
|
}
|
|
|
|
func (zl *zlexer) Next() (lex, bool) {
|
|
l := &zl.l
|
|
switch {
|
|
case zl.cachedL != nil:
|
|
l, zl.cachedL = zl.cachedL, nil
|
|
return *l, true
|
|
case zl.nextL:
|
|
zl.nextL = false
|
|
return *l, true
|
|
case 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++
|
|
if comi >= len(com) {
|
|
l.token = "comment length insufficient for parsing"
|
|
l.err = true
|
|
return *l, true
|
|
}
|
|
}
|
|
|
|
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) *ParseError {
|
|
l, _ := c.Next()
|
|
switch l.value {
|
|
case zBlank:
|
|
l, _ = c.Next()
|
|
if l.value != zNewline && l.value != zEOF {
|
|
return &ParseError{"", "garbage after rdata", l}
|
|
}
|
|
case zNewline:
|
|
case zEOF:
|
|
default:
|
|
return &ParseError{"", "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
|
|
}
|