package dns
import (
"bytes"
"fmt"
"net"
"strconv"
"strings"
"time"
)
type (
// Type is a DNS type.
Type uint16
// Class is a DNS class.
Class uint16
// Name is a DNS domain name.
Name string
)
// Packet formats
// Wire constants and supported types.
const (
// valid RR_Header.Rrtype and Question.qtype
TypeNone uint16 = 0
TypeA uint16 = 1
TypeNS uint16 = 2
TypeMD uint16 = 3
TypeMF uint16 = 4
TypeCNAME uint16 = 5
TypeSOA uint16 = 6
TypeMB uint16 = 7
TypeMG uint16 = 8
TypeMR uint16 = 9
TypeNULL uint16 = 10
TypePTR uint16 = 12
TypeHINFO uint16 = 13
TypeMINFO uint16 = 14
TypeMX uint16 = 15
TypeTXT uint16 = 16
TypeRP uint16 = 17
TypeAFSDB uint16 = 18
TypeX25 uint16 = 19
TypeISDN uint16 = 20
TypeRT uint16 = 21
TypeNSAPPTR uint16 = 23
TypeSIG uint16 = 24
TypeKEY uint16 = 25
TypePX uint16 = 26
TypeGPOS uint16 = 27
TypeAAAA uint16 = 28
TypeLOC uint16 = 29
TypeNXT uint16 = 30
TypeEID uint16 = 31
TypeNIMLOC uint16 = 32
TypeSRV uint16 = 33
TypeATMA uint16 = 34
TypeNAPTR uint16 = 35
TypeKX uint16 = 36
TypeCERT uint16 = 37
TypeDNAME uint16 = 39
TypeOPT uint16 = 41 // EDNS
TypeAPL uint16 = 42
TypeDS uint16 = 43
TypeSSHFP uint16 = 44
TypeRRSIG uint16 = 46
TypeNSEC uint16 = 47
TypeDNSKEY uint16 = 48
TypeDHCID uint16 = 49
TypeNSEC3 uint16 = 50
TypeNSEC3PARAM uint16 = 51
TypeTLSA uint16 = 52
TypeSMIMEA uint16 = 53
TypeHIP uint16 = 55
TypeNINFO uint16 = 56
TypeRKEY uint16 = 57
TypeTALINK uint16 = 58
TypeCDS uint16 = 59
TypeCDNSKEY uint16 = 60
TypeOPENPGPKEY uint16 = 61
TypeCSYNC uint16 = 62
TypeZONEMD uint16 = 63
TypeSVCB uint16 = 64
TypeHTTPS uint16 = 65
TypeSPF uint16 = 99
TypeUINFO uint16 = 100
TypeUID uint16 = 101
TypeGID uint16 = 102
TypeUNSPEC uint16 = 103
TypeNID uint16 = 104
TypeL32 uint16 = 105
TypeL64 uint16 = 106
TypeLP uint16 = 107
TypeEUI48 uint16 = 108
TypeEUI64 uint16 = 109
TypeURI uint16 = 256
TypeCAA uint16 = 257
TypeAVC uint16 = 258
TypeTKEY uint16 = 249
TypeTSIG uint16 = 250
// valid Question.Qtype only
TypeIXFR uint16 = 251
TypeAXFR uint16 = 252
TypeMAILB uint16 = 253
TypeMAILA uint16 = 254
TypeANY uint16 = 255
TypeTA uint16 = 32768
TypeDLV uint16 = 32769
TypeReserved uint16 = 65535
// valid Question.Qclass
ClassINET = 1
ClassCSNET = 2
ClassCHAOS = 3
ClassHESIOD = 4
ClassNONE = 254
ClassANY = 255
// Message Response Codes, see https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml
RcodeSuccess = 0 // NoError - No Error [DNS]
RcodeFormatError = 1 // FormErr - Format Error [DNS]
RcodeServerFailure = 2 // ServFail - Server Failure [DNS]
RcodeNameError = 3 // NXDomain - Non-Existent Domain [DNS]
RcodeNotImplemented = 4 // NotImp - Not Implemented [DNS]
RcodeRefused = 5 // Refused - Query Refused [DNS]
RcodeYXDomain = 6 // YXDomain - Name Exists when it should not [DNS Update]
RcodeYXRrset = 7 // YXRRSet - RR Set Exists when it should not [DNS Update]
RcodeNXRrset = 8 // NXRRSet - RR Set that should exist does not [DNS Update]
RcodeNotAuth = 9 // NotAuth - Server Not Authoritative for zone [DNS Update]
RcodeNotZone = 10 // NotZone - Name not contained in zone [DNS Update/TSIG]
RcodeBadSig = 16 // BADSIG - TSIG Signature Failure [TSIG]
RcodeBadVers = 16 // BADVERS - Bad OPT Version [EDNS0]
RcodeBadKey = 17 // BADKEY - Key not recognized [TSIG]
RcodeBadTime = 18 // BADTIME - Signature out of time window [TSIG]
RcodeBadMode = 19 // BADMODE - Bad TKEY Mode [TKEY]
RcodeBadName = 20 // BADNAME - Duplicate key name [TKEY]
RcodeBadAlg = 21 // BADALG - Algorithm not supported [TKEY]
RcodeBadTrunc = 22 // BADTRUNC - Bad Truncation [TSIG]
RcodeBadCookie = 23 // BADCOOKIE - Bad/missing Server Cookie [DNS Cookies]
// Message Opcodes. There is no 3.
OpcodeQuery = 0
OpcodeIQuery = 1
OpcodeStatus = 2
OpcodeNotify = 4
OpcodeUpdate = 5
)
// Used in ZONEMD https://tools.ietf.org/html/rfc8976
const (
// ZoneMD Accepted Schemes
ZoneMDSchemeSimple = 1
// ZoneMD Hash Algorithms
ZoneMDHashAlgSHA384 = 1
ZoneMDHashAlgSHA512 = 2
)
// Header is the wire format for the DNS packet header.
type Header struct {
Id uint16
Bits uint16
Qdcount, Ancount, Nscount, Arcount uint16
}
const (
headerSize = 12
// Header.Bits
_QR = 1 << 15 // query/response (response=1)
_AA = 1 << 10 // authoritative
_TC = 1 << 9 // truncated
_RD = 1 << 8 // recursion desired
_RA = 1 << 7 // recursion available
_Z = 1 << 6 // Z
_AD = 1 << 5 // authenticated data
_CD = 1 << 4 // checking disabled
)
// Various constants used in the LOC RR. See RFC 1887.
const (
LOC_EQUATOR = 1 << 31 // RFC 1876, Section 2.
LOC_PRIMEMERIDIAN = 1 << 31 // RFC 1876, Section 2.
LOC_HOURS = 60 * 1000
LOC_DEGREES = 60 * LOC_HOURS
LOC_ALTITUDEBASE = 100000
)
// Different Certificate Types, see RFC 4398, Section 2.1
const (
CertPKIX = 1 + iota
CertSPKI
CertPGP
CertIPIX
CertISPKI
CertIPGP
CertACPKIX
CertIACPKIX
CertURI = 253
CertOID = 254
)
// CertTypeToString converts the Cert Type to its string representation.
// See RFC 4398 and RFC 6944.
var CertTypeToString = map[uint16]string{
CertPKIX: "PKIX",
CertSPKI: "SPKI",
CertPGP: "PGP",
CertIPIX: "IPIX",
CertISPKI: "ISPKI",
CertIPGP: "IPGP",
CertACPKIX: "ACPKIX",
CertIACPKIX: "IACPKIX",
CertURI: "URI",
CertOID: "OID",
}
//go:generate go run types_generate.go
// Question holds a DNS question. Usually there is just one. While the
// original DNS RFCs allow multiple questions in the question section of a
// message, in practice it never works. Because most DNS servers see multiple
// questions as an error, it is recommended to only have one question per
// message.
type Question struct {
Name string `dns:"cdomain-name"` // "cdomain-name" specifies encoding (and may be compressed)
Qtype uint16
Qclass uint16
}
func (q *Question) len(off int, compression map[string]struct{}) int {
l := domainNameLen(q.Name, off, compression, true)
l += 2 + 2
return l
}
func (q *Question) String() (s string) {
// prefix with ; (as in dig)
s = ";" + sprintName(q.Name) + "\t"
s += Class(q.Qclass).String() + "\t"
s += " " + Type(q.Qtype).String()
return s
}
// ANY is a wild card record. See RFC 1035, Section 3.2.3. ANY
// is named "*" there.
type ANY struct {
Hdr RR_Header
// Does not have any rdata
}
func (rr *ANY) String() string { return rr.Hdr.String() }
func (*ANY) parse(c *zlexer, origin string) *ParseError {
return &ParseError{err: "ANY records do not have a presentation format"}
}
// NULL RR. See RFC 1035.
type NULL struct {
Hdr RR_Header
Data string `dns:"any"`
}
func (rr *NULL) String() string {
// There is no presentation format; prefix string with a comment.
return ";" + rr.Hdr.String() + rr.Data
}
func (*NULL) parse(c *zlexer, origin string) *ParseError {
return &ParseError{err: "NULL records do not have a presentation format"}
}
// CNAME RR. See RFC 1034.
type CNAME struct {
Hdr RR_Header
Target string `dns:"cdomain-name"`
}
func (rr *CNAME) String() string { return rr.Hdr.String() + sprintName(rr.Target) }
// HINFO RR. See RFC 1034.
type HINFO struct {
Hdr RR_Header
Cpu string
Os string
}
func (rr *HINFO) String() string {
return rr.Hdr.String() + sprintTxt([]string{rr.Cpu, rr.Os})
}
// MB RR. See RFC 1035.
type MB struct {
Hdr RR_Header
Mb string `dns:"cdomain-name"`
}
func (rr *MB) String() string { return rr.Hdr.String() + sprintName(rr.Mb) }
// MG RR. See RFC 1035.
type MG struct {
Hdr RR_Header
Mg string `dns:"cdomain-name"`
}
func (rr *MG) String() string { return rr.Hdr.String() + sprintName(rr.Mg) }
// MINFO RR. See RFC 1035.
type MINFO struct {
Hdr RR_Header
Rmail string `dns:"cdomain-name"`
Email string `dns:"cdomain-name"`
}
func (rr *MINFO) String() string {
return rr.Hdr.String() + sprintName(rr.Rmail) + " " + sprintName(rr.Email)
}
// MR RR. See RFC 1035.
type MR struct {
Hdr RR_Header
Mr string `dns:"cdomain-name"`
}
func (rr *MR) String() string {
return rr.Hdr.String() + sprintName(rr.Mr)
}
// MF RR. See RFC 1035.
type MF struct {
Hdr RR_Header
Mf string `dns:"cdomain-name"`
}
func (rr *MF) String() string {
return rr.Hdr.String() + sprintName(rr.Mf)
}
// MD RR. See RFC 1035.
type MD struct {
Hdr RR_Header
Md string `dns:"cdomain-name"`
}
func (rr *MD) String() string {
return rr.Hdr.String() + sprintName(rr.Md)
}
// MX RR. See RFC 1035.
type MX struct {
Hdr RR_Header
Preference uint16
Mx string `dns:"cdomain-name"`
}
func (rr *MX) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference)) + " " + sprintName(rr.Mx)
}
// AFSDB RR. See RFC 1183.
type AFSDB struct {
Hdr RR_Header
Subtype uint16
Hostname string `dns:"domain-name"`
}
func (rr *AFSDB) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Subtype)) + " " + sprintName(rr.Hostname)
}
// X25 RR. See RFC 1183, Section 3.1.
type X25 struct {
Hdr RR_Header
PSDNAddress string
}
func (rr *X25) String() string {
return rr.Hdr.String() + rr.PSDNAddress
}
// RT RR. See RFC 1183, Section 3.3.
type RT struct {
Hdr RR_Header
Preference uint16
Host string `dns:"domain-name"` // RFC 3597 prohibits compressing records not defined in RFC 1035.
}
func (rr *RT) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference)) + " " + sprintName(rr.Host)
}
// NS RR. See RFC 1035.
type NS struct {
Hdr RR_Header
Ns string `dns:"cdomain-name"`
}
func (rr *NS) String() string {
return rr.Hdr.String() + sprintName(rr.Ns)
}
// PTR RR. See RFC 1035.
type PTR struct {
Hdr RR_Header
Ptr string `dns:"cdomain-name"`
}
func (rr *PTR) String() string {
return rr.Hdr.String() + sprintName(rr.Ptr)
}
// RP RR. See RFC 1138, Section 2.2.
type RP struct {
Hdr RR_Header
Mbox string `dns:"domain-name"`
Txt string `dns:"domain-name"`
}
func (rr *RP) String() string {
return rr.Hdr.String() + sprintName(rr.Mbox) + " " + sprintName(rr.Txt)
}
// SOA RR. See RFC 1035.
type SOA struct {
Hdr RR_Header
Ns string `dns:"cdomain-name"`
Mbox string `dns:"cdomain-name"`
Serial uint32
Refresh uint32
Retry uint32
Expire uint32
Minttl uint32
}
func (rr *SOA) String() string {
return rr.Hdr.String() + sprintName(rr.Ns) + " " + sprintName(rr.Mbox) +
" " + strconv.FormatInt(int64(rr.Serial), 10) +
" " + strconv.FormatInt(int64(rr.Refresh), 10) +
" " + strconv.FormatInt(int64(rr.Retry), 10) +
" " + strconv.FormatInt(int64(rr.Expire), 10) +
" " + strconv.FormatInt(int64(rr.Minttl), 10)
}
// TXT RR. See RFC 1035.
type TXT struct {
Hdr RR_Header
Txt []string `dns:"txt"`
}
func (rr *TXT) String() string { return rr.Hdr.String() + sprintTxt(rr.Txt) }
func sprintName(s string) string {
var dst strings.Builder
for i := 0; i < len(s); {
if s[i] == '.' {
if dst.Len() != 0 {
dst.WriteByte('.')
}
i++
continue
}
b, n := nextByte(s, i)
if n == 0 {
// Drop "dangling" incomplete escapes.
if dst.Len() == 0 {
return s[:i]
}
break
}
if isDomainNameLabelSpecial(b) {
if dst.Len() == 0 {
dst.Grow(len(s) * 2)
dst.WriteString(s[:i])
}
dst.WriteByte('\\')
dst.WriteByte(b)
} else if b < ' ' || b > '~' { // unprintable, use \DDD
if dst.Len() == 0 {
dst.Grow(len(s) * 2)
dst.WriteString(s[:i])
}
dst.WriteString(escapeByte(b))
} else {
if dst.Len() != 0 {
dst.WriteByte(b)
}
}
i += n
}
if dst.Len() == 0 {
return s
}
return dst.String()
}
func sprintTxtOctet(s string) string {
var dst strings.Builder
dst.Grow(2 + len(s))
dst.WriteByte('"')
for i := 0; i < len(s); {
if i+1 < len(s) && s[i] == '\\' && s[i+1] == '.' {
dst.WriteString(s[i : i+2])
i += 2
continue
}
b, n := nextByte(s, i)
if n == 0 {
i++ // dangling back slash
} else {
writeTXTStringByte(&dst, b)
}
i += n
}
dst.WriteByte('"')
return dst.String()
}
func sprintTxt(txt []string) string {
var out strings.Builder
for i, s := range txt {
out.Grow(3 + len(s))
if i > 0 {
out.WriteString(` "`)
} else {
out.WriteByte('"')
}
for j := 0; j < len(s); {
b, n := nextByte(s, j)
if n == 0 {
break
}
writeTXTStringByte(&out, b)
j += n
}
out.WriteByte('"')
}
return out.String()
}
func writeTXTStringByte(s *strings.Builder, b byte) {
switch {
case b == '"' || b == '\\':
s.WriteByte('\\')
s.WriteByte(b)
case b < ' ' || b > '~':
s.WriteString(escapeByte(b))
default:
s.WriteByte(b)
}
}
const (
escapedByteSmall = "" +
`\000\001\002\003\004\005\006\007\008\009` +
`\010\011\012\013\014\015\016\017\018\019` +
`\020\021\022\023\024\025\026\027\028\029` +
`\030\031`
escapedByteLarge = `\127\128\129` +
`\130\131\132\133\134\135\136\137\138\139` +
`\140\141\142\143\144\145\146\147\148\149` +
`\150\151\152\153\154\155\156\157\158\159` +
`\160\161\162\163\164\165\166\167\168\169` +
`\170\171\172\173\174\175\176\177\178\179` +
`\180\181\182\183\184\185\186\187\188\189` +
`\190\191\192\193\194\195\196\197\198\199` +
`\200\201\202\203\204\205\206\207\208\209` +
`\210\211\212\213\214\215\216\217\218\219` +
`\220\221\222\223\224\225\226\227\228\229` +
`\230\231\232\233\234\235\236\237\238\239` +
`\240\241\242\243\244\245\246\247\248\249` +
`\250\251\252\253\254\255`
)
// escapeByte returns the \DDD escaping of b which must
// satisfy b < ' ' || b > '~'.
func escapeByte(b byte) string {
if b < ' ' {
return escapedByteSmall[b*4 : b*4+4]
}
b -= '~' + 1
// The cast here is needed as b*4 may overflow byte.
return escapedByteLarge[int(b)*4 : int(b)*4+4]
}
// isDomainNameLabelSpecial returns true if
// a domain name label byte should be prefixed
// with an escaping backslash.
func isDomainNameLabelSpecial(b byte) bool {
switch b {
case '.', ' ', '\'', '@', ';', '(', ')', '"', '\\':
return true
}
return false
}
func nextByte(s string, offset int) (byte, int) {
if offset >= len(s) {
return 0, 0
}
if s[offset] != '\\' {
// not an escape sequence
return s[offset], 1
}
switch len(s) - offset {
case 1: // dangling escape
return 0, 0
case 2, 3: // too short to be \ddd
default: // maybe \ddd
if isDigit(s[offset+1]) && isDigit(s[offset+2]) && isDigit(s[offset+3]) {
return dddStringToByte(s[offset+1:]), 4
}
}
// not \ddd, just an RFC 1035 "quoted" character
return s[offset+1], 2
}
// SPF RR. See RFC 4408, Section 3.1.1.
type SPF struct {
Hdr RR_Header
Txt []string `dns:"txt"`
}
func (rr *SPF) String() string { return rr.Hdr.String() + sprintTxt(rr.Txt) }
// AVC RR. See https://www.iana.org/assignments/dns-parameters/AVC/avc-completed-template.
type AVC struct {
Hdr RR_Header
Txt []string `dns:"txt"`
}
func (rr *AVC) String() string { return rr.Hdr.String() + sprintTxt(rr.Txt) }
// SRV RR. See RFC 2782.
type SRV struct {
Hdr RR_Header
Priority uint16
Weight uint16
Port uint16
Target string `dns:"domain-name"`
}
func (rr *SRV) String() string {
return rr.Hdr.String() +
strconv.Itoa(int(rr.Priority)) + " " +
strconv.Itoa(int(rr.Weight)) + " " +
strconv.Itoa(int(rr.Port)) + " " + sprintName(rr.Target)
}
// NAPTR RR. See RFC 2915.
type NAPTR struct {
Hdr RR_Header
Order uint16
Preference uint16
Flags string
Service string
Regexp string
Replacement string `dns:"domain-name"`
}
func (rr *NAPTR) String() string {
return rr.Hdr.String() +
strconv.Itoa(int(rr.Order)) + " " +
strconv.Itoa(int(rr.Preference)) + " " +
"\"" + rr.Flags + "\" " +
"\"" + rr.Service + "\" " +
"\"" + rr.Regexp + "\" " +
rr.Replacement
}
// CERT RR. See RFC 4398.
type CERT struct {
Hdr RR_Header
Type uint16
KeyTag uint16
Algorithm uint8
Certificate string `dns:"base64"`
}
func (rr *CERT) String() string {
var (
ok bool
certtype, algorithm string
)
if certtype, ok = CertTypeToString[rr.Type]; !ok {
certtype = strconv.Itoa(int(rr.Type))
}
if algorithm, ok = AlgorithmToString[rr.Algorithm]; !ok {
algorithm = strconv.Itoa(int(rr.Algorithm))
}
return rr.Hdr.String() + certtype +
" " + strconv.Itoa(int(rr.KeyTag)) +
" " + algorithm +
" " + rr.Certificate
}
// DNAME RR. See RFC 2672.
type DNAME struct {
Hdr RR_Header
Target string `dns:"domain-name"`
}
func (rr *DNAME) String() string {
return rr.Hdr.String() + sprintName(rr.Target)
}
// A RR. See RFC 1035.
type A struct {
Hdr RR_Header
A net.IP `dns:"a"`
}
func (rr *A) String() string {
if rr.A == nil {
return rr.Hdr.String()
}
return rr.Hdr.String() + rr.A.String()
}
// AAAA RR. See RFC 3596.
type AAAA struct {
Hdr RR_Header
AAAA net.IP `dns:"aaaa"`
}
func (rr *AAAA) String() string {
if rr.AAAA == nil {
return rr.Hdr.String()
}
return rr.Hdr.String() + rr.AAAA.String()
}
// PX RR. See RFC 2163.
type PX struct {
Hdr RR_Header
Preference uint16
Map822 string `dns:"domain-name"`
Mapx400 string `dns:"domain-name"`
}
func (rr *PX) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference)) + " " + sprintName(rr.Map822) + " " + sprintName(rr.Mapx400)
}
// GPOS RR. See RFC 1712.
type GPOS struct {
Hdr RR_Header
Longitude string
Latitude string
Altitude string
}
func (rr *GPOS) String() string {
return rr.Hdr.String() + rr.Longitude + " " + rr.Latitude + " " + rr.Altitude
}
// LOC RR. See RFC RFC 1876.
type LOC struct {
Hdr RR_Header
Version uint8
Size uint8
HorizPre uint8
VertPre uint8
Latitude uint32
Longitude uint32
Altitude uint32
}
// cmToM takes a cm value expressed in RFC 1876 SIZE mantissa/exponent
// format and returns a string in m (two decimals for the cm).
func cmToM(m, e uint8) string {
if e < 2 {
if e == 1 {
m *= 10
}
return fmt.Sprintf("0.%02d", m)
}
s := fmt.Sprintf("%d", m)
for e > 2 {
s += "0"
e--
}
return s
}
func (rr *LOC) String() string {
s := rr.Hdr.String()
lat := rr.Latitude
ns := "N"
if lat > LOC_EQUATOR {
lat = lat - LOC_EQUATOR
} else {
ns = "S"
lat = LOC_EQUATOR - lat
}
h := lat / LOC_DEGREES
lat = lat % LOC_DEGREES
m := lat / LOC_HOURS
lat = lat % LOC_HOURS
s += fmt.Sprintf("%02d %02d %0.3f %s ", h, m, float64(lat)/1000, ns)
lon := rr.Longitude
ew := "E"
if lon > LOC_PRIMEMERIDIAN {
lon = lon - LOC_PRIMEMERIDIAN
} else {
ew = "W"
lon = LOC_PRIMEMERIDIAN - lon
}
h = lon / LOC_DEGREES
lon = lon % LOC_DEGREES
m = lon / LOC_HOURS
lon = lon % LOC_HOURS
s += fmt.Sprintf("%02d %02d %0.3f %s ", h, m, float64(lon)/1000, ew)
var alt = float64(rr.Altitude) / 100
alt -= LOC_ALTITUDEBASE
if rr.Altitude%100 != 0 {
s += fmt.Sprintf("%.2fm ", alt)
} else {
s += fmt.Sprintf("%.0fm ", alt)
}
s += cmToM(rr.Size&0xf0>>4, rr.Size&0x0f) + "m "
s += cmToM(rr.HorizPre&0xf0>>4, rr.HorizPre&0x0f) + "m "
s += cmToM(rr.VertPre&0xf0>>4, rr.VertPre&0x0f) + "m"
return s
}
// SIG RR. See RFC 2535. The SIG RR is identical to RRSIG and nowadays only used for SIG(0), See RFC 2931.
type SIG struct {
RRSIG
}
// RRSIG RR. See RFC 4034 and RFC 3755.
type RRSIG struct {
Hdr RR_Header
TypeCovered uint16
Algorithm uint8
Labels uint8
OrigTtl uint32
Expiration uint32
Inception uint32
KeyTag uint16
SignerName string `dns:"domain-name"`
Signature string `dns:"base64"`
}
func (rr *RRSIG) String() string {
s := rr.Hdr.String()
s += Type(rr.TypeCovered).String()
s += " " + strconv.Itoa(int(rr.Algorithm)) +
" " + strconv.Itoa(int(rr.Labels)) +
" " + strconv.FormatInt(int64(rr.OrigTtl), 10) +
" " + TimeToString(rr.Expiration) +
" " + TimeToString(rr.Inception) +
" " + strconv.Itoa(int(rr.KeyTag)) +
" " + sprintName(rr.SignerName) +
" " + rr.Signature
return s
}
// NSEC RR. See RFC 4034 and RFC 3755.
type NSEC struct {
Hdr RR_Header
NextDomain string `dns:"domain-name"`
TypeBitMap []uint16 `dns:"nsec"`
}
func (rr *NSEC) String() string {
s := rr.Hdr.String() + sprintName(rr.NextDomain)
for _, t := range rr.TypeBitMap {
s += " " + Type(t).String()
}
return s
}
func (rr *NSEC) len(off int, compression map[string]struct{}) int {
l := rr.Hdr.len(off, compression)
l += domainNameLen(rr.NextDomain, off+l, compression, false)
l += typeBitMapLen(rr.TypeBitMap)
return l
}
// DLV RR. See RFC 4431.
type DLV struct{ DS }
// CDS RR. See RFC 7344.
type CDS struct{ DS }
// DS RR. See RFC 4034 and RFC 3658.
type DS struct {
Hdr RR_Header
KeyTag uint16
Algorithm uint8
DigestType uint8
Digest string `dns:"hex"`
}
func (rr *DS) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.KeyTag)) +
" " + strconv.Itoa(int(rr.Algorithm)) +
" " + strconv.Itoa(int(rr.DigestType)) +
" " + strings.ToUpper(rr.Digest)
}
// KX RR. See RFC 2230.
type KX struct {
Hdr RR_Header
Preference uint16
Exchanger string `dns:"domain-name"`
}
func (rr *KX) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference)) +
" " + sprintName(rr.Exchanger)
}
// TA RR. See http://www.watson.org/~weiler/INI1999-19.pdf.
type TA struct {
Hdr RR_Header
KeyTag uint16
Algorithm uint8
DigestType uint8
Digest string `dns:"hex"`
}
func (rr *TA) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.KeyTag)) +
" " + strconv.Itoa(int(rr.Algorithm)) +
" " + strconv.Itoa(int(rr.DigestType)) +
" " + strings.ToUpper(rr.Digest)
}
// TALINK RR. See https://www.iana.org/assignments/dns-parameters/TALINK/talink-completed-template.
type TALINK struct {
Hdr RR_Header
PreviousName string `dns:"domain-name"`
NextName string `dns:"domain-name"`
}
func (rr *TALINK) String() string {
return rr.Hdr.String() +
sprintName(rr.PreviousName) + " " + sprintName(rr.NextName)
}
// SSHFP RR. See RFC RFC 4255.
type SSHFP struct {
Hdr RR_Header
Algorithm uint8
Type uint8
FingerPrint string `dns:"hex"`
}
func (rr *SSHFP) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Algorithm)) +
" " + strconv.Itoa(int(rr.Type)) +
" " + strings.ToUpper(rr.FingerPrint)
}
// KEY RR. See RFC RFC 2535.
type KEY struct {
DNSKEY
}
// CDNSKEY RR. See RFC 7344.
type CDNSKEY struct {
DNSKEY
}
// DNSKEY RR. See RFC 4034 and RFC 3755.
type DNSKEY struct {
Hdr RR_Header
Flags uint16
Protocol uint8
Algorithm uint8
PublicKey string `dns:"base64"`
}
func (rr *DNSKEY) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Flags)) +
" " + strconv.Itoa(int(rr.Protocol)) +
" " + strconv.Itoa(int(rr.Algorithm)) +
" " + rr.PublicKey
}
// RKEY RR. See https://www.iana.org/assignments/dns-parameters/RKEY/rkey-completed-template.
type RKEY struct {
Hdr RR_Header
Flags uint16
Protocol uint8
Algorithm uint8
PublicKey string `dns:"base64"`
}
func (rr *RKEY) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Flags)) +
" " + strconv.Itoa(int(rr.Protocol)) +
" " + strconv.Itoa(int(rr.Algorithm)) +
" " + rr.PublicKey
}
// NSAPPTR RR. See RFC 1348.
type NSAPPTR struct {
Hdr RR_Header
Ptr string `dns:"domain-name"`
}
func (rr *NSAPPTR) String() string { return rr.Hdr.String() + sprintName(rr.Ptr) }
// NSEC3 RR. See RFC 5155.
type NSEC3 struct {
Hdr RR_Header
Hash uint8
Flags uint8
Iterations uint16
SaltLength uint8
Salt string `dns:"size-hex:SaltLength"`
HashLength uint8
NextDomain string `dns:"size-base32:HashLength"`
TypeBitMap []uint16 `dns:"nsec"`
}
func (rr *NSEC3) String() string {
s := rr.Hdr.String()
s += strconv.Itoa(int(rr.Hash)) +
" " + strconv.Itoa(int(rr.Flags)) +
" " + strconv.Itoa(int(rr.Iterations)) +
" " + saltToString(rr.Salt) +
" " + rr.NextDomain
for _, t := range rr.TypeBitMap {
s += " " + Type(t).String()
}
return s
}
func (rr *NSEC3) len(off int, compression map[string]struct{}) int {
l := rr.Hdr.len(off, compression)
l += 6 + len(rr.Salt)/2 + 1 + len(rr.NextDomain) + 1
l += typeBitMapLen(rr.TypeBitMap)
return l
}
// NSEC3PARAM RR. See RFC 5155.
type NSEC3PARAM struct {
Hdr RR_Header
Hash uint8
Flags uint8
Iterations uint16
SaltLength uint8
Salt string `dns:"size-hex:SaltLength"`
}
func (rr *NSEC3PARAM) String() string {
s := rr.Hdr.String()
s += strconv.Itoa(int(rr.Hash)) +
" " + strconv.Itoa(int(rr.Flags)) +
" " + strconv.Itoa(int(rr.Iterations)) +
" " + saltToString(rr.Salt)
return s
}
// TKEY RR. See RFC 2930.
type TKEY struct {
Hdr RR_Header
Algorithm string `dns:"domain-name"`
Inception uint32
Expiration uint32
Mode uint16
Error uint16
KeySize uint16
Key string `dns:"size-hex:KeySize"`
OtherLen uint16
OtherData string `dns:"size-hex:OtherLen"`
}
// TKEY has no official presentation format, but this will suffice.
func (rr *TKEY) String() string {
s := ";" + rr.Hdr.String() +
" " + rr.Algorithm +
" " + TimeToString(rr.Inception) +
" " + TimeToString(rr.Expiration) +
" " + strconv.Itoa(int(rr.Mode)) +
" " + strconv.Itoa(int(rr.Error)) +
" " + strconv.Itoa(int(rr.KeySize)) +
" " + rr.Key +
" " + strconv.Itoa(int(rr.OtherLen)) +
" " + rr.OtherData
return s
}
// RFC3597 represents an unknown/generic RR. See RFC 3597.
type RFC3597 struct {
Hdr RR_Header
Rdata string `dns:"hex"`
}
func (rr *RFC3597) String() string {
// Let's call it a hack
s := rfc3597Header(rr.Hdr)
s += "\\# " + strconv.Itoa(len(rr.Rdata)/2) + " " + rr.Rdata
return s
}
func rfc3597Header(h RR_Header) string {
var s string
s += sprintName(h.Name) + "\t"
s += strconv.FormatInt(int64(h.Ttl), 10) + "\t"
s += "CLASS" + strconv.Itoa(int(h.Class)) + "\t"
s += "TYPE" + strconv.Itoa(int(h.Rrtype)) + "\t"
return s
}
// URI RR. See RFC 7553.
type URI struct {
Hdr RR_Header
Priority uint16
Weight uint16
Target string `dns:"octet"`
}
// rr.Target to be parsed as a sequence of character encoded octets according to RFC 3986
func (rr *URI) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Priority)) +
" " + strconv.Itoa(int(rr.Weight)) + " " + sprintTxtOctet(rr.Target)
}
// DHCID RR. See RFC 4701.
type DHCID struct {
Hdr RR_Header
Digest string `dns:"base64"`
}
func (rr *DHCID) String() string { return rr.Hdr.String() + rr.Digest }
// TLSA RR. See RFC 6698.
type TLSA struct {
Hdr RR_Header
Usage uint8
Selector uint8
MatchingType uint8
Certificate string `dns:"hex"`
}
func (rr *TLSA) String() string {
return rr.Hdr.String() +
strconv.Itoa(int(rr.Usage)) +
" " + strconv.Itoa(int(rr.Selector)) +
" " + strconv.Itoa(int(rr.MatchingType)) +
" " + rr.Certificate
}
// SMIMEA RR. See RFC 8162.
type SMIMEA struct {
Hdr RR_Header
Usage uint8
Selector uint8
MatchingType uint8
Certificate string `dns:"hex"`
}
func (rr *SMIMEA) String() string {
s := rr.Hdr.String() +
strconv.Itoa(int(rr.Usage)) +
" " + strconv.Itoa(int(rr.Selector)) +
" " + strconv.Itoa(int(rr.MatchingType))
// Every Nth char needs a space on this output. If we output
// this as one giant line, we can't read it can in because in some cases
// the cert length overflows scan.maxTok (2048).
sx := splitN(rr.Certificate, 1024) // conservative value here
s += " " + strings.Join(sx, " ")
return s
}
// HIP RR. See RFC 8005.
type HIP struct {
Hdr RR_Header
HitLength uint8
PublicKeyAlgorithm uint8
PublicKeyLength uint16
Hit string `dns:"size-hex:HitLength"`
PublicKey string `dns:"size-base64:PublicKeyLength"`
RendezvousServers []string `dns:"domain-name"`
}
func (rr *HIP) String() string {
s := rr.Hdr.String() +
strconv.Itoa(int(rr.PublicKeyAlgorithm)) +
" " + rr.Hit +
" " + rr.PublicKey
for _, d := range rr.RendezvousServers {
s += " " + sprintName(d)
}
return s
}
// NINFO RR. See https://www.iana.org/assignments/dns-parameters/NINFO/ninfo-completed-template.
type NINFO struct {
Hdr RR_Header
ZSData []string `dns:"txt"`
}
func (rr *NINFO) String() string { return rr.Hdr.String() + sprintTxt(rr.ZSData) }
// NID RR. See RFC RFC 6742.
type NID struct {
Hdr RR_Header
Preference uint16
NodeID uint64
}
func (rr *NID) String() string {
s := rr.Hdr.String() + strconv.Itoa(int(rr.Preference))
node := fmt.Sprintf("%0.16x", rr.NodeID)
s += " " + node[0:4] + ":" + node[4:8] + ":" + node[8:12] + ":" + node[12:16]
return s
}
// L32 RR, See RFC 6742.
type L32 struct {
Hdr RR_Header
Preference uint16
Locator32 net.IP `dns:"a"`
}
func (rr *L32) String() string {
if rr.Locator32 == nil {
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference))
}
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference)) +
" " + rr.Locator32.String()
}
// L64 RR, See RFC 6742.
type L64 struct {
Hdr RR_Header
Preference uint16
Locator64 uint64
}
func (rr *L64) String() string {
s := rr.Hdr.String() + strconv.Itoa(int(rr.Preference))
node := fmt.Sprintf("%0.16X", rr.Locator64)
s += " " + node[0:4] + ":" + node[4:8] + ":" + node[8:12] + ":" + node[12:16]
return s
}
// LP RR. See RFC 6742.
type LP struct {
Hdr RR_Header
Preference uint16
Fqdn string `dns:"domain-name"`
}
func (rr *LP) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Preference)) + " " + sprintName(rr.Fqdn)
}
// EUI48 RR. See RFC 7043.
type EUI48 struct {
Hdr RR_Header
Address uint64 `dns:"uint48"`
}
func (rr *EUI48) String() string { return rr.Hdr.String() + euiToString(rr.Address, 48) }
// EUI64 RR. See RFC 7043.
type EUI64 struct {
Hdr RR_Header
Address uint64
}
func (rr *EUI64) String() string { return rr.Hdr.String() + euiToString(rr.Address, 64) }
// CAA RR. See RFC 6844.
type CAA struct {
Hdr RR_Header
Flag uint8
Tag string
Value string `dns:"octet"`
}
// rr.Value Is the character-string encoding of the value field as specified in RFC 1035, Section 5.1.
func (rr *CAA) String() string {
return rr.Hdr.String() + strconv.Itoa(int(rr.Flag)) + " " + rr.Tag + " " + sprintTxtOctet(rr.Value)
}
// UID RR. Deprecated, IANA-Reserved.
type UID struct {
Hdr RR_Header
Uid uint32
}
func (rr *UID) String() string { return rr.Hdr.String() + strconv.FormatInt(int64(rr.Uid), 10) }
// GID RR. Deprecated, IANA-Reserved.
type GID struct {
Hdr RR_Header
Gid uint32
}
func (rr *GID) String() string { return rr.Hdr.String() + strconv.FormatInt(int64(rr.Gid), 10) }
// UINFO RR. Deprecated, IANA-Reserved.
type UINFO struct {
Hdr RR_Header
Uinfo string
}
func (rr *UINFO) String() string { return rr.Hdr.String() + sprintTxt([]string{rr.Uinfo}) }
// EID RR. See http://ana-3.lcs.mit.edu/~jnc/nimrod/dns.txt.
type EID struct {
Hdr RR_Header
Endpoint string `dns:"hex"`
}
func (rr *EID) String() string { return rr.Hdr.String() + strings.ToUpper(rr.Endpoint) }
// NIMLOC RR. See http://ana-3.lcs.mit.edu/~jnc/nimrod/dns.txt.
type NIMLOC struct {
Hdr RR_Header
Locator string `dns:"hex"`
}
func (rr *NIMLOC) String() string { return rr.Hdr.String() + strings.ToUpper(rr.Locator) }
// OPENPGPKEY RR. See RFC 7929.
type OPENPGPKEY struct {
Hdr RR_Header
PublicKey string `dns:"base64"`
}
func (rr *OPENPGPKEY) String() string { return rr.Hdr.String() + rr.PublicKey }
// CSYNC RR. See RFC 7477.
type CSYNC struct {
Hdr RR_Header
Serial uint32
Flags uint16
TypeBitMap []uint16 `dns:"nsec"`
}
func (rr *CSYNC) String() string {
s := rr.Hdr.String() + strconv.FormatInt(int64(rr.Serial), 10) + " " + strconv.Itoa(int(rr.Flags))
for _, t := range rr.TypeBitMap {
s += " " + Type(t).String()
}
return s
}
func (rr *CSYNC) len(off int, compression map[string]struct{}) int {
l := rr.Hdr.len(off, compression)
l += 4 + 2
l += typeBitMapLen(rr.TypeBitMap)
return l
}
// ZONEMD RR, from draft-ietf-dnsop-dns-zone-digest
type ZONEMD struct {
Hdr RR_Header
Serial uint32
Scheme uint8
Hash uint8
Digest string `dns:"hex"`
}
func (rr *ZONEMD) String() string {
return rr.Hdr.String() +
strconv.Itoa(int(rr.Serial)) +
" " + strconv.Itoa(int(rr.Scheme)) +
" " + strconv.Itoa(int(rr.Hash)) +
" " + rr.Digest
}
// APL RR. See RFC 3123.
type APL struct {
Hdr RR_Header
Prefixes []APLPrefix `dns:"apl"`
}
// APLPrefix is an address prefix hold by an APL record.
type APLPrefix struct {
Negation bool
Network net.IPNet
}
// String returns presentation form of the APL record.
func (rr *APL) String() string {
var sb strings.Builder
sb.WriteString(rr.Hdr.String())
for i, p := range rr.Prefixes {
if i > 0 {
sb.WriteByte(' ')
}
sb.WriteString(p.str())
}
return sb.String()
}
// str returns presentation form of the APL prefix.
func (p *APLPrefix) str() string {
var sb strings.Builder
if p.Negation {
sb.WriteByte('!')
}
switch len(p.Network.IP) {
case net.IPv4len:
sb.WriteByte('1')
case net.IPv6len:
sb.WriteByte('2')
}
sb.WriteByte(':')
switch len(p.Network.IP) {
case net.IPv4len:
sb.WriteString(p.Network.IP.String())
case net.IPv6len:
// add prefix for IPv4-mapped IPv6
if v4 := p.Network.IP.To4(); v4 != nil {
sb.WriteString("::ffff:")
}
sb.WriteString(p.Network.IP.String())
}
sb.WriteByte('/')
prefix, _ := p.Network.Mask.Size()
sb.WriteString(strconv.Itoa(prefix))
return sb.String()
}
// equals reports whether two APL prefixes are identical.
func (a *APLPrefix) equals(b *APLPrefix) bool {
return a.Negation == b.Negation &&
bytes.Equal(a.Network.IP, b.Network.IP) &&
bytes.Equal(a.Network.Mask, b.Network.Mask)
}
// copy returns a copy of the APL prefix.
func (p *APLPrefix) copy() APLPrefix {
return APLPrefix{
Negation: p.Negation,
Network: copyNet(p.Network),
}
}
// len returns size of the prefix in wire format.
func (p *APLPrefix) len() int {
// 4-byte header and the network address prefix (see Section 4 of RFC 3123)
prefix, _ := p.Network.Mask.Size()
return 4 + (prefix+7)/8
}
// TimeToString translates the RRSIG's incep. and expir. times to the
// string representation used when printing the record.
// It takes serial arithmetic (RFC 1982) into account.
func TimeToString(t uint32) string {
mod := (int64(t)-time.Now().Unix())/year68 - 1
if mod < 0 {
mod = 0
}
ti := time.Unix(int64(t)-mod*year68, 0).UTC()
return ti.Format("20060102150405")
}
// StringToTime translates the RRSIG's incep. and expir. times from
// string values like "20110403154150" to an 32 bit integer.
// It takes serial arithmetic (RFC 1982) into account.
func StringToTime(s string) (uint32, error) {
t, err := time.Parse("20060102150405", s)
if err != nil {
return 0, err
}
mod := t.Unix()/year68 - 1
if mod < 0 {
mod = 0
}
return uint32(t.Unix() - mod*year68), nil
}
// saltToString converts a NSECX salt to uppercase and returns "-" when it is empty.
func saltToString(s string) string {
if s == "" {
return "-"
}
return strings.ToUpper(s)
}
func euiToString(eui uint64, bits int) (hex string) {
switch bits {
case 64:
hex = fmt.Sprintf("%16.16x", eui)
hex = hex[0:2] + "-" + hex[2:4] + "-" + hex[4:6] + "-" + hex[6:8] +
"-" + hex[8:10] + "-" + hex[10:12] + "-" + hex[12:14] + "-" + hex[14:16]
case 48:
hex = fmt.Sprintf("%12.12x", eui)
hex = hex[0:2] + "-" + hex[2:4] + "-" + hex[4:6] + "-" + hex[6:8] +
"-" + hex[8:10] + "-" + hex[10:12]
}
return
}
// copyIP returns a copy of ip.
func copyIP(ip net.IP) net.IP {
p := make(net.IP, len(ip))
copy(p, ip)
return p
}
// copyNet returns a copy of a subnet.
func copyNet(n net.IPNet) net.IPNet {
m := make(net.IPMask, len(n.Mask))
copy(m, n.Mask)
return net.IPNet{
IP: copyIP(n.IP),
Mask: m,
}
}
// SplitN splits a string into N sized string chunks.
// This might become an exported function once.
func splitN(s string, n int) []string {
if len(s) < n {
return []string{s}
}
sx := []string{}
p, i := 0, n
for {
if i <= len(s) {
sx = append(sx, s[p:i])
} else {
sx = append(sx, s[p:])
break
}
p, i = p+n, i+n
}
return sx
}