574 lines
11 KiB
Go
574 lines
11 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Extended and bugfixes by Miek Gieben
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// Basic usage pattern for creating new Resource Record:
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//
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// r := new(RR_TXT)
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// r.TXT = "This is the content of the TXT record"
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// r.Hdr = RR_Header{Name: "a.miek.nl", Rrtype: TypeTXT, Class: ClassINET, Ttl: 3600}
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//
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package dns
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import (
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"net"
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"strconv"
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"strings"
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"time"
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)
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// Packet formats
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// Wire constants.
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const (
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// valid RR_Header.Rrtype and Question.qtype
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TypeA = 1
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TypeNS = 2
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TypeMD = 3
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TypeMF = 4
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TypeCNAME = 5
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TypeSOA = 6
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TypeMB = 7
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TypeMG = 8
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TypeMR = 9
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TypeNULL = 10
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TypeWKS = 11
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TypePTR = 12
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TypeHINFO = 13
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TypeMINFO = 14
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TypeMX = 15
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TypeTXT = 16
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TypeAAAA = 28
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TypeLOC = 29
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TypeSRV = 33
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TypeNAPTR = 35
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// EDNS
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TypeOPT = 41
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// Old DNSSEC
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TypeSIG = 24
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TypeKEY = 25
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TypeNXT = 30
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// DNSSEC
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TypeDS = 43
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TypeRRSIG = 46
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TypeNSEC = 47
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TypeDNSKEY = 48
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TypeNSEC3 = 50
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TypeNSEC3PARAM = 51
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TypeTKEY = 249
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TypeTSIG = 250
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// valid Question.qtype only
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TypeIXFR = 251
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TypeAXFR = 252
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TypeMAILB = 253
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TypeMAILA = 254
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TypeALL = 255
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// valid Question.qclass
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ClassINET = 1
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ClassCSNET = 2
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ClassCHAOS = 3
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ClassHESIOD = 4
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ClassANY = 255
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// Msg.rcode
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RcodeSuccess = 0
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RcodeFormatError = 1
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RcodeServerFailure = 2
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RcodeNameError = 3
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RcodeNotImplemented = 4
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RcodeRefused = 5
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RcodeYXDomain = 6
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RcodeYXRrset = 7
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RcodeNXRrset = 8
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RcodeNotAuth = 9
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RcodeNotZone = 10
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// Tsig errors
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TsigBadSig = 16
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TsigBadKey = 17
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TsigBadTime = 18
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// Tkey errors
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TkeyBadMode = 19
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TkeyBadName = 20
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TKeyBadAlg = 21
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// Opcode
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OpcodeQuery = 0
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OpcodeIQuery = 1
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OpcodeStatus = 2
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// There is no 3
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OpcodeNotify = 4
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OpcodeUpdate = 5
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)
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// The wire format for the DNS packet header.
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type Header struct {
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Id uint16
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Bits uint16
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Qdcount, Ancount, Nscount, Arcount uint16
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}
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const (
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// Header.Bits
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_QR = 1 << 15 // query/response (response=1)
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_AA = 1 << 10 // authoritative
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_TC = 1 << 9 // truncated
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_RD = 1 << 8 // recursion desired
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_RA = 1 << 7 // recursion available
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_Z = 1 << 6 // Z
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_AD = 1 << 5 // authticated data
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_CD = 1 << 4 // checking disabled
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)
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// DNS queries.
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type Question struct {
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Name string "domain-name" // "domain-name" specifies encoding; see packers below
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Qtype uint16
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Qclass uint16
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}
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func (q *Question) String() string {
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// prefix with ; (as in dig)
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s := ";" + q.Name + "\t"
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s = s + Class_str[q.Qclass] + "\t"
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s = s + Rr_str[q.Qtype]
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return s
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}
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type RR_CNAME struct {
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Hdr RR_Header
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Cname string "domain-name"
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}
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func (rr *RR_CNAME) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_CNAME) String() string {
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return rr.Hdr.String() + rr.Cname
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}
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type RR_HINFO struct {
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Hdr RR_Header
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Cpu string
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Os string
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}
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func (rr *RR_HINFO) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_HINFO) String() string {
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return rr.Hdr.String() + rr.Cpu + " " + rr.Os
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}
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type RR_MB struct {
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Hdr RR_Header
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Mb string "domain-name"
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}
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func (rr *RR_MB) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_MB) String() string {
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return rr.Hdr.String() + rr.Mb
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}
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type RR_MG struct {
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Hdr RR_Header
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Mg string "domain-name"
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}
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func (rr *RR_MG) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_MG) String() string {
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return rr.Hdr.String() + rr.Mg
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}
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type RR_MINFO struct {
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Hdr RR_Header
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Rmail string "domain-name"
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Email string "domain-name"
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}
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func (rr *RR_MINFO) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_MINFO) String() string {
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return rr.Hdr.String() + rr.Rmail + " " + rr.Email
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}
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type RR_MR struct {
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Hdr RR_Header
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Mr string "domain-name"
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}
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func (rr *RR_MR) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_MR) String() string {
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return rr.Hdr.String() + rr.Mr
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}
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type RR_MX struct {
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Hdr RR_Header
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Pref uint16
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Mx string "domain-name"
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}
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func (rr *RR_MX) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_MX) String() string {
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return rr.Hdr.String() + strconv.Itoa(int(rr.Pref)) + " " + rr.Mx
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}
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type RR_NS struct {
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Hdr RR_Header
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Ns string "domain-name"
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}
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func (rr *RR_NS) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_NS) String() string {
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return rr.Hdr.String() + rr.Ns
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}
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type RR_PTR struct {
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Hdr RR_Header
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Ptr string "domain-name"
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}
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func (rr *RR_PTR) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_PTR) String() string {
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return rr.Hdr.String() + rr.Ptr
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}
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type RR_SOA struct {
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Hdr RR_Header
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Ns string "domain-name"
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Mbox string "domain-name"
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Serial uint32
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Refresh uint32
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Retry uint32
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Expire uint32
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Minttl uint32
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}
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func (rr *RR_SOA) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_SOA) String() string {
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return rr.Hdr.String() + rr.Ns + " " + rr.Mbox +
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" " + strconv.Itoa(int(rr.Serial)) +
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" " + strconv.Itoa(int(rr.Refresh)) +
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" " + strconv.Itoa(int(rr.Retry)) +
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" " + strconv.Itoa(int(rr.Expire)) +
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" " + strconv.Itoa(int(rr.Minttl))
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}
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type RR_TXT struct {
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Hdr RR_Header
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Txt string // not domain name
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}
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func (rr *RR_TXT) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_TXT) String() string {
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return rr.Hdr.String() + "\"" + rr.Txt + "\""
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}
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type RR_SRV struct {
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Hdr RR_Header
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Priority uint16
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Weight uint16
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Port uint16
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Target string "domain-name"
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}
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func (rr *RR_SRV) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_SRV) String() string {
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return rr.Hdr.String() +
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strconv.Itoa(int(rr.Priority)) + " " +
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strconv.Itoa(int(rr.Weight)) + " " +
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strconv.Itoa(int(rr.Port)) + " " + rr.Target
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}
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type RR_NAPTR struct {
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Hdr RR_Header
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Order uint16
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Preference uint16
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Flags string
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Service string
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Regexp string
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Replacement string
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}
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func (rr *RR_NAPTR) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_NAPTR) String() string {
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return rr.Hdr.String() + "TODO"
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}
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type RR_A struct {
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Hdr RR_Header
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A net.IP "A"
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}
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func (rr *RR_A) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_A) String() string {
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return rr.Hdr.String() + rr.A.String()
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}
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type RR_AAAA struct {
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Hdr RR_Header
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AAAA net.IP "AAAA"
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}
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func (rr *RR_AAAA) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_AAAA) String() string {
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return rr.Hdr.String() + rr.AAAA.String()
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}
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type RR_LOC struct {
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Hdr RR_Header
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Version uint8
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Size uint8
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HorizPre uint8
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VertPre uint8
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Latitude uint32
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Longitude uint32
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Altitude uint32
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}
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func (rr *RR_LOC) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_LOC) String() string {
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return rr.Hdr.String() + "TODO"
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}
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// DNSSEC types
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type RR_RRSIG struct {
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Hdr RR_Header
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TypeCovered uint16
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Algorithm uint8
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Labels uint8
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OrigTtl uint32
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Expiration uint32
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Inception uint32
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KeyTag uint16
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SignerName string "domain-name"
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Signature string "base64"
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}
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func (rr *RR_RRSIG) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_RRSIG) String() string {
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return rr.Hdr.String() +
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" " + Rr_str[rr.TypeCovered] +
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" " + strconv.Itoa(int(rr.Algorithm)) +
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" " + strconv.Itoa(int(rr.Labels)) +
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" " + strconv.Itoa(int(rr.OrigTtl)) +
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" " + timeToDate(rr.Expiration) +
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" " + timeToDate(rr.Inception) +
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" " + strconv.Itoa(int(rr.KeyTag)) +
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" " + rr.SignerName +
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" " + rr.Signature
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}
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type RR_NSEC struct {
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Hdr RR_Header
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NextDomain string "domain-name"
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TypeBitMap []int "NSEC"
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}
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func (rr *RR_NSEC) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_NSEC) String() string {
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return rr.Hdr.String() + "NSEC BLAH"
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}
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type RR_DS struct {
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Hdr RR_Header
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KeyTag uint16
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Algorithm uint8
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DigestType uint8
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Digest string "hex"
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}
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func (rr *RR_DS) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_DS) String() string {
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return rr.Hdr.String() +
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" " + strconv.Itoa(int(rr.KeyTag)) +
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" " + strconv.Itoa(int(rr.Algorithm)) +
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" " + strconv.Itoa(int(rr.DigestType)) +
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" " + strings.ToUpper(rr.Digest)
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}
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type RR_DNSKEY struct {
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Hdr RR_Header
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Flags uint16
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Protocol uint8
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Algorithm uint8
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PubKey string "base64"
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}
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func (rr *RR_DNSKEY) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_DNSKEY) String() string {
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return rr.Hdr.String() +
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" " + strconv.Itoa(int(rr.Flags)) +
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" " + strconv.Itoa(int(rr.Protocol)) +
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" " + strconv.Itoa(int(rr.Algorithm)) +
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" " + rr.PubKey
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}
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type RR_NSEC3 struct {
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Hdr RR_Header
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Hash uint8
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Flags uint8
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Iterations uint16
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SaltLength uint8
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Salt string "hex"
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HashLength uint8
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NextDomain string "domain-name"
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TypeBitMap []int "NSEC3" // &{TypeSOA,TypeDS,etc}
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}
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func (rr *RR_NSEC3) Header() *RR_Header {
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return &rr.Hdr
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// Salt with strings.ToUpper()
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}
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func (rr *RR_NSEC3) String() string {
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return rr.Hdr.String() + "BLAH"
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}
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type RR_NSEC3PARAM struct {
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Hdr RR_Header
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Hash uint8
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Flags uint8
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Iterations uint16
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SaltLength uint8
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Salt string "hex"
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}
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func (rr *RR_NSEC3PARAM) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_NSEC3PARAM) String() string {
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return rr.Hdr.String() + "BLAH"
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// Salt with strings.ToUpper()
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}
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type RR_TKEY struct {
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Hdr RR_Header
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Algorithm string "domain-name"
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Inception uint32
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Expiration uint32
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Mode uint16
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Error uint16
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KeySize uint16
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Key string
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Otherlen uint16
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OtherData string
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}
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func (rr *RR_TKEY) Header() *RR_Header {
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return &rr.Hdr
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}
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func (rr *RR_TKEY) String() string {
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// It has no presentation format
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return ""
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}
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// Translate the RRSIG's incep. and expir. time to the correct date.
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// Taking into account serial arithmetic (RFC 1982)
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func timeToDate(t uint32) string {
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utc := time.UTC().Seconds()
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mod := (int64(t) - utc) / Year68
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// If needed assume wrap around(s)
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ti := time.SecondsToUTC(int64(t) + (mod * Year68)) // abs()? TODO
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return ti.Format("20060102030405")
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}
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// Translate the TSIG time signed into a date. There is no
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// need for RFC1982 calculations as this date is 48 bits
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func tsigTimeToDate(t uint64) string {
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// only use the lower 48 bits, TODO(mg), check for 48 bit size
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ti := time.SecondsToUTC(int64(t))
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return ti.Format("20060102030405")
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}
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// Map of constructors for each RR wire type.
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var rr_mk = map[int]func() RR{
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TypeCNAME: func() RR { return new(RR_CNAME) },
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TypeHINFO: func() RR { return new(RR_HINFO) },
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TypeMB: func() RR { return new(RR_MB) },
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TypeMG: func() RR { return new(RR_MG) },
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TypeMINFO: func() RR { return new(RR_MINFO) },
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TypeMR: func() RR { return new(RR_MR) },
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TypeMX: func() RR { return new(RR_MX) },
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TypeNS: func() RR { return new(RR_NS) },
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TypePTR: func() RR { return new(RR_PTR) },
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TypeSOA: func() RR { return new(RR_SOA) },
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TypeTXT: func() RR { return new(RR_TXT) },
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TypeSRV: func() RR { return new(RR_SRV) },
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TypeNAPTR: func() RR { return new(RR_NAPTR) },
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TypeA: func() RR { return new(RR_A) },
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TypeAAAA: func() RR { return new(RR_AAAA) },
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TypeLOC: func() RR { return new(RR_LOC) },
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TypeOPT: func() RR { return new(RR_OPT) },
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TypeDS: func() RR { return new(RR_DS) },
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TypeRRSIG: func() RR { return new(RR_RRSIG) },
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TypeNSEC: func() RR { return new(RR_NSEC) },
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TypeDNSKEY: func() RR { return new(RR_DNSKEY) },
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TypeNSEC3: func() RR { return new(RR_NSEC3) },
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TypeNSEC3PARAM: func() RR { return new(RR_NSEC3PARAM) },
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TypeTKEY: func() RR { return new(RR_TKEY) },
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TypeTSIG: func() RR { return new(RR_TSIG) },
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}
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