// Create a dns message from a fingerprint string and // a DNS question. The order of a string is always the same. // .,IN,NS,QUERY,NOERROR,qr,aa,tc,RD,ad,ad,z,1,0,0,1,DO,4096,nsid func (f *fingerprint) msg() *dns.Msg { m := new(dns.Msg) m.MsgHdr.Id = dns.Id() m.Question = make([]dns.Question, 1) m.Question[0] = dns.Question{f.Query.Name, f.Query.Qtype, f.Query.Qclass} m.MsgHdr.Opcode = f.Opcode m.MsgHdr.Rcode = f.Rcode m.MsgHdr.Response = f.Response m.MsgHdr.Authoritative = f.Authoritative m.MsgHdr.Truncated = f.Truncated m.MsgHdr.RecursionDesired = f.RecursionDesired m.MsgHdr.AuthenticatedData = f.AuthenticatedData m.MsgHdr.CheckingDisabled = f.CheckingDisabled m.MsgHdr.Zero = f.Zero if f.Do { // Add an OPT section. m.SetEdns0(0, true) // We have added an OPT RR, set the size. m.Extra[0].(*dns.RR_OPT).SetUDPSize(uint16(f.UDPSize)) if f.Nsid { m.Extra[0].(*dns.RR_OPT).SetNsid("") } } return m }
func newConnMsg(qname, nameserver string, attempts int, qtype, qclass uint16, aa, ad, cd, rd, dnssec, nsid bool) (*dns.Conn, *dns.Msg) { d := new(dns.Conn) d.RemoteAddr = nameserver d.Attempts = attempts m := new(dns.Msg) m.MsgHdr.Authoritative = aa m.MsgHdr.AuthenticatedData = ad m.MsgHdr.CheckingDisabled = cd m.MsgHdr.RecursionDesired = rd m.Question = make([]dns.Question, 1) if dnssec || nsid { opt := new(dns.RR_OPT) opt.SetDo() opt.SetVersion(0) opt.SetUDPSize(dns.DefaultMsgSize) if nsid { opt.SetNsid("") } m.Extra = make([]dns.RR, 1) m.Extra[0] = opt } m.Question[0] = dns.Question{qname, qtype, qclass} m.Id = dns.Id() return d, m }
func main() { if len(os.Args) != 2 { fmt.Printf("%s DOMAIN\n", os.Args[0]) os.Exit(1) } d := new(dns.Conn) c, err := dns.ClientConfigFromFile("/etc/resolv.conf") // Errorchecking d.RemoteAddr = c.Servers[0] m := new(dns.Msg) m.Id = dns.Id() m.MsgHdr.RecursionDesired = true m.Question = make([]dns.Question, 1) m.Question[0] = dns.Question{os.Args[1], dns.TypeMX, dns.ClassINET} err = d.Dial("udp") if err != nil { fmt.Printf("*** error: %s\n", err.String()) os.Exit(1) } in, err := dns.SimpleQuery("udp", d, m) if in != nil { if in.Rcode != dns.RcodeSuccess { fmt.Printf(" *** invalid answer name %s after MX query for %s\n", os.Args[1], os.Args[1]) os.Exit(1) } // Stuff must be in the answer section for _, a := range in.Answer { fmt.Printf("%v\n", a) } } else { fmt.Printf("*** error: %s\n", err.String()) } }
func main() { dnssec := flag.Bool("dnssec", false, "request DNSSEC records") query := flag.Bool("question", false, "show question") short := flag.Bool("short", false, "abbreviate long DNSSEC records") check := flag.Bool("check", false, "check internal DNSSEC consistency") six := flag.Bool("6", false, "use IPv6 only") four := flag.Bool("4", false, "use IPv4 only") anchor := flag.String("anchor", "", "use the DNSKEY in this file for interal DNSSEC consistency") tsig := flag.String("tsig", "", "request tsig with key: [hmac:]name:key") port := flag.Int("port", 53, "port number to use") aa := flag.Bool("aa", false, "set AA flag in query") ad := flag.Bool("ad", false, "set AD flag in query") cd := flag.Bool("cd", false, "set CD flag in query") rd := flag.Bool("rd", true, "set RD flag in query") fallback := flag.Bool("fallback", false, "fallback to 4096 bytes bufsize and after that TCP") tcp := flag.Bool("tcp", false, "TCP mode") nsid := flag.Bool("nsid", false, "set edns nsid option") client := flag.String("client", "", "set edns client-subnet option") flag.Usage = func() { fmt.Fprintf(os.Stderr, "Usage: %s [@server] [qtype] [qclass] [name ...]\n", os.Args[0]) flag.PrintDefaults() } conf, _ := dns.ClientConfigFromFile("/etc/resolv.conf") nameserver := "@" + conf.Servers[0] qtype := uint16(0) qclass := uint16(dns.ClassINET) // Default qclass var qname []string flag.Parse() if *anchor != "" { f, err := os.Open(*anchor) if err != nil { fmt.Fprintf(os.Stderr, "Failure to open %s: %s\n", *anchor, err.Error()) } r, err := dns.ReadRR(f, *anchor) if err != nil { fmt.Fprintf(os.Stderr, "Failure to read an RR from %s: %s\n", *anchor, err.Error()) } if k, ok := r.(*dns.RR_DNSKEY); !ok { fmt.Fprintf(os.Stderr, "No DNSKEY read from %s\n", *anchor) } else { dnskey = k } } Flags: for i := 0; i < flag.NArg(); i++ { // If it starts with @ it is a nameserver if flag.Arg(i)[0] == '@' { nameserver = flag.Arg(i) continue Flags } // First class, then type, to make ANY queries possible // And if it looks like type, it is a type if k, ok := dns.Str_rr[strings.ToUpper(flag.Arg(i))]; ok { qtype = k switch qtype { case dns.TypeAXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return case dns.TypeIXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return } continue Flags } // If it looks like a class, it is a class if k, ok := dns.Str_class[strings.ToUpper(flag.Arg(i))]; ok { qclass = k continue Flags } // If it starts with TYPExxx it is unknown rr if strings.HasPrefix(flag.Arg(i), "TYPE") { i, e := strconv.Atoi(string([]byte(flag.Arg(i))[4:])) if e == nil { qtype = uint16(i) switch qtype { case dns.TypeAXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return case dns.TypeIXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return } continue Flags } } // Anything else is a qname qname = append(qname, flag.Arg(i)) } if len(qname) == 0 { qname = make([]string, 1) qname[0] = "." qtype = dns.TypeNS } if qtype == 0 { qtype = dns.TypeA } nameserver = string([]byte(nameserver)[1:]) // chop off @ nameserver += ":" + strconv.Itoa(*port) // We use the async query handling, just to show how it is to be used. c := new(dns.Client) if *tcp { c.Net = "tcp" if *four { c.Net = "tcp4" } if *six { c.Net = "tcp6" } } else { c.Net = "udp" if *four { c.Net = "udp4" } if *six { c.Net = "udp6" } } m := new(dns.Msg) m.MsgHdr.Authoritative = *aa m.MsgHdr.AuthenticatedData = *ad m.MsgHdr.CheckingDisabled = *cd m.MsgHdr.RecursionDesired = *rd m.Question = make([]dns.Question, 1) if *dnssec || *nsid || *client != "" { o := new(dns.RR_OPT) o.Hdr.Name = "." o.Hdr.Rrtype = dns.TypeOPT if *dnssec { o.SetDo() o.SetUDPSize(dns.DefaultMsgSize) } if *nsid { e := new(dns.EDNS0_NSID) e.Code = dns.EDNS0NSID o.Option = append(o.Option, e) // NSD will not return nsid when the udp message size is too small o.SetUDPSize(dns.DefaultMsgSize) } if *client != "" { e := new(dns.EDNS0_SUBNET) e.Code = dns.EDNS0SUBNET e.SourceScope = 0 e.Address = net.ParseIP(*client) if e.Address == nil { fmt.Fprintf(os.Stderr, "Failure to parse IP address: %s\n", *client) return } e.Family = 1 // IP4 e.SourceNetmask = net.IPv4len * 8 if e.Address.To4() == nil { e.Family = 2 // IP6 e.SourceNetmask = net.IPv6len * 8 } o.Option = append(o.Option, e) } m.Extra = append(m.Extra, o) } for i, v := range qname { m.Question[0] = dns.Question{v, qtype, qclass} m.Id = dns.Id() if *query { fmt.Printf("%s", m.String()) fmt.Printf("\n;; size: %d bytes\n\n", m.Len()) } // Add tsig if *tsig != "" { if algo, name, secret, ok := tsigKeyParse(*tsig); ok { m.SetTsig(name, algo, 300, time.Now().Unix()) c.TsigSecret = map[string]string{name: secret} } else { fmt.Fprintf(os.Stderr, "tsig key data error\n") return } } c.DoRtt(m, nameserver, nil, func(m, r *dns.Msg, rtt time.Duration, e error, data interface{}) { defer func() { if i == len(qname)-1 { os.Exit(0) } }() Redo: if r == nil { return } if r.Rcode != dns.RcodeSuccess { return } if r.Id != m.Id { fmt.Printf("Id mismatch\n") return } if r.MsgHdr.Truncated && *fallback { if c.Net != "tcp" { if !*dnssec { fmt.Printf(";; Truncated, trying %d bytes bufsize\n", dns.DefaultMsgSize) o := new(dns.RR_OPT) o.Hdr.Name = "." o.Hdr.Rrtype = dns.TypeOPT o.SetUDPSize(dns.DefaultMsgSize) m.Extra = append(m.Extra, o) r, rtt, e = c.ExchangeRtt(m, nameserver) *dnssec = true goto Redo } else { // First EDNS, then TCP fmt.Printf(";; Truncated, trying TCP\n") c.Net = "tcp" r, rtt, e = c.ExchangeRtt(m, nameserver) goto Redo } } } if r.MsgHdr.Truncated && !*fallback { fmt.Printf(";; Truncated\n") } if *check { sigCheck(r, nameserver, *tcp) nsecCheck(r) //dns.AssertDelegationSigner(r.Reply, nil) } if *short { r = shortMsg(r) } fmt.Printf("%v", r) fmt.Printf("\n;; query time: %.3d µs, server: %s(%s), size: %d bytes\n", rtt/1e3, nameserver, c.Net, r.Size) }) } select {} }
func main() { dnssec := flag.Bool("dnssec", false, "request DNSSEC records") query := flag.Bool("question", false, "show question") short := flag.Bool("short", false, "abbreviate long DNSSEC records") check := flag.Bool("check", false, "check internal DNSSEC consistency") anchor := flag.String("anchor", "", "use the DNSKEY in this file for checking consistency") port := flag.Int("port", 53, "port number to use") aa := flag.Bool("aa", false, "set AA flag in query") ad := flag.Bool("ad", false, "set AD flag in query") cd := flag.Bool("cd", false, "set CD flag in query") rd := flag.Bool("rd", true, "unset RD flag in query") tcp := flag.Bool("tcp", false, "TCP mode") nsid := flag.Bool("nsid", false, "ask for NSID") flag.Usage = func() { fmt.Fprintf(os.Stderr, "Usage: %s [@server] [qtype] [qclass] [name ...]\n", os.Args[0]) flag.PrintDefaults() } conf, _ := dns.ClientConfigFromFile("/etc/resolv.conf") nameserver := "@" + conf.Servers[0] qtype := uint16(0) qclass := uint16(dns.ClassINET) // Default qclass var qname []string flag.Parse() if *anchor != "" { f, err := os.Open(*anchor) if err != nil { fmt.Fprintf(os.Stderr, "Failure to open %s: %s\n", *anchor, err.Error()) } r, err := dns.ReadRR(f, *anchor) if err != nil { fmt.Fprintf(os.Stderr, "Failure to read an RR from %s: %s\n", *anchor, err.Error()) } if k, ok := r.(*dns.RR_DNSKEY); !ok { fmt.Fprintf(os.Stderr, "No DNSKEY read from %s\n", *anchor) } else { dnskey = k } } Flags: for i := 0; i < flag.NArg(); i++ { // If it starts with @ it is a nameserver if flag.Arg(i)[0] == '@' { nameserver = flag.Arg(i) continue Flags } // First class, then type, to make ANY queries possible // And if it looks like type, it is a type if k, ok := dns.Str_rr[strings.ToUpper(flag.Arg(i))]; ok { qtype = k continue Flags } // If it looks like a class, it is a class if k, ok := dns.Str_class[strings.ToUpper(flag.Arg(i))]; ok { qclass = k continue Flags } // If it starts with TYPExxx it is unknown rr if strings.HasPrefix(flag.Arg(i), "TYPE") { i, e := strconv.Atoi(string([]byte(flag.Arg(i))[4:])) if e == nil { qtype = uint16(i) continue Flags } } // Anything else is a qname qname = append(qname, flag.Arg(i)) } if len(qname) == 0 { qname = make([]string, 1) qname[0] = "." qtype = dns.TypeNS } if qtype == 0 { qtype = dns.TypeA } nameserver = string([]byte(nameserver)[1:]) // chop off @ nameserver += ":" + strconv.Itoa(*port) // ipv6 todo // We use the async query handling, just to show how // it is to be used. dns.HandleQueryFunc(".", q) dns.ListenAndQuery(nil, nil) c := dns.NewClient() if *tcp { c.Net = "tcp" } m := new(dns.Msg) m.MsgHdr.Authoritative = *aa m.MsgHdr.AuthenticatedData = *ad m.MsgHdr.CheckingDisabled = *cd m.MsgHdr.RecursionDesired = *rd m.Question = make([]dns.Question, 1) if *dnssec || *nsid { o := new(dns.RR_OPT) o.Hdr.Name = "." o.Hdr.Rrtype = dns.TypeOPT if *dnssec { o.SetDo() o.SetUDPSize(dns.DefaultMsgSize) } if *nsid { o.SetNsid("") } m.Extra = append(m.Extra, o) } for _, v := range qname { m.Question[0] = dns.Question{v, qtype, qclass} m.Id = dns.Id() if *query { fmt.Printf("%s\n", m.String()) } c.Do(m, nameserver) } i := 0 forever: for { select { case r := <-dns.DefaultReplyChan: if r.Reply != nil { if r.Reply.Rcode == dns.RcodeSuccess { if r.Request.Id != r.Reply.Id { fmt.Printf("Id mismatch\n") } } if *check { sigCheck(r.Reply, nameserver, *tcp) nsecCheck(r.Reply) } if *short { r.Reply = shortMsg(r.Reply) } fmt.Printf("%v", r.Reply) } i++ if i == len(qname) { break forever } } } }
func main() { var dnssec *bool = flag.Bool("dnssec", false, "request DNSSEC records") var query *bool = flag.Bool("question", false, "show question") var short *bool = flag.Bool("short", false, "abbriate long DNSKEY and RRSIG RRs") var aa *bool = flag.Bool("aa", false, "set AA flag in query") var ad *bool = flag.Bool("ad", false, "set AD flag in query") var cd *bool = flag.Bool("cd", false, "set CD flag in query") var rd *bool = flag.Bool("rd", true, "unset RD flag in query") var tcp *bool = flag.Bool("tcp", false, "TCP mode") var nsid *bool = flag.Bool("nsid", false, "ask for NSID") flag.Usage = func() { fmt.Fprintf(os.Stderr, "Usage: %s [@server(:port)] [qtype] [qclass] [name ...]\n", os.Args[0]) flag.PrintDefaults() } // Need to think about it... Config conf, _ := dns.ClientConfigFromFile("/etc/resolv.conf") nameserver := "@" + conf.Servers[0] qtype := uint16(0) qclass := uint16(dns.ClassINET) // Default qclass var qname []string flag.Parse() Flags: for i := 0; i < flag.NArg(); i++ { // If it starts with @ it is a nameserver if flag.Arg(i)[0] == '@' { nameserver = flag.Arg(i) continue Flags } // First class, then type, to make ANY queries possible // And if it looks like type, it is a type for k, v := range dns.Rr_str { if v == strings.ToUpper(flag.Arg(i)) { qtype = k continue Flags } } // If it looks like a class, it is a class for k, v := range dns.Class_str { if v == strings.ToUpper(flag.Arg(i)) { qclass = k continue Flags } } // If it starts with TYPExxx it is unknown rr if strings.HasPrefix(flag.Arg(i), "TYPE") { i, e := strconv.Atoi(string([]byte(flag.Arg(i))[4:])) if e == nil { qtype = uint16(i) continue Flags } } // Anything else is a qname qname = append(qname, flag.Arg(i)) } if len(qname) == 0 { qname = make([]string, 1) qname[0] = "." qtype = dns.TypeNS } if qtype == 0 { qtype = dns.TypeA } nameserver = string([]byte(nameserver)[1:]) // chop off @ if !strings.HasSuffix(nameserver, ":53") { nameserver += ":53" } // ipv6 todo // We use the async query handling, just to show how // it is to be used. dns.HandleQueryFunc(".", q) dns.ListenAndQuery(nil, nil) c := dns.NewClient() if *tcp { c.Net = "tcp" } m := new(dns.Msg) m.MsgHdr.Authoritative = *aa m.MsgHdr.AuthenticatedData = *ad m.MsgHdr.CheckingDisabled = *cd m.MsgHdr.RecursionDesired = *rd m.Question = make([]dns.Question, 1) if *dnssec || *nsid { opt := dns.NewRR(dns.TypeOPT).(*dns.RR_OPT) opt.Hdr.Rrtype = 0 opt.SetDo() opt.SetVersion(0) opt.SetUDPSize(dns.DefaultMsgSize) if *nsid { opt.SetNsid("") } m.Extra = make([]dns.RR, 1) m.Extra[0] = opt } for _, v := range qname { m.Question[0] = dns.Question{v, qtype, qclass} m.Id = dns.Id() if *query { fmt.Printf("%s\n", m.String()) } c.Do(m, nameserver) } i := 0 forever: for { select { case r := <-dns.DefaultReplyChan: if r[1] != nil { if r[0].Id != r[1].Id { fmt.Printf("Id mismatch\n") } if *short { r[1] = shortMsg(r[1]) } fmt.Printf("%v", r[1]) } i++ if i == len(qname) { break forever } } } }
func main() { dnssec := flag.Bool("dnssec", false, "request DNSSEC records") query := flag.Bool("question", false, "show question") short := flag.Bool("short", false, "abbreviate long DNSSEC records") check := flag.Bool("check", false, "check internal DNSSEC consistency") six := flag.Bool("6", false, "use IPv6 only") four := flag.Bool("4", false, "use IPv4 only") anchor := flag.String("anchor", "", "use the DNSKEY in this file for interal DNSSEC consistency") tsig := flag.String("tsig", "", "request tsig with key: [hmac:]name:key") port := flag.Int("port", 53, "port number to use") aa := flag.Bool("aa", false, "set AA flag in query") ad := flag.Bool("ad", false, "set AD flag in query") cd := flag.Bool("cd", false, "set CD flag in query") rd := flag.Bool("rd", true, "set RD flag in query") fallback := flag.Bool("fallback", false, "fallback to 4096 bytes bufsize and after that TCP") tcp := flag.Bool("tcp", false, "TCP mode") nsid := flag.Bool("nsid", false, "ask for NSID") flag.Usage = func() { fmt.Fprintf(os.Stderr, "Usage: %s [@server] [qtype] [qclass] [name ...]\n", os.Args[0]) flag.PrintDefaults() } conf, _ := dns.ClientConfigFromFile("/etc/resolv.conf") nameserver := "@" + conf.Servers[0] qtype := uint16(0) qclass := uint16(dns.ClassINET) // Default qclass var qname []string flag.Parse() if *anchor != "" { f, err := os.Open(*anchor) if err != nil { fmt.Fprintf(os.Stderr, "Failure to open %s: %s\n", *anchor, err.Error()) } r, err := dns.ReadRR(f, *anchor) if err != nil { fmt.Fprintf(os.Stderr, "Failure to read an RR from %s: %s\n", *anchor, err.Error()) } if k, ok := r.(*dns.RR_DNSKEY); !ok { fmt.Fprintf(os.Stderr, "No DNSKEY read from %s\n", *anchor) } else { dnskey = k } } Flags: for i := 0; i < flag.NArg(); i++ { // If it starts with @ it is a nameserver if flag.Arg(i)[0] == '@' { nameserver = flag.Arg(i) continue Flags } // First class, then type, to make ANY queries possible // And if it looks like type, it is a type if k, ok := dns.Str_rr[strings.ToUpper(flag.Arg(i))]; ok { qtype = k switch qtype { case dns.TypeAXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return case dns.TypeIXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return } continue Flags } // If it looks like a class, it is a class if k, ok := dns.Str_class[strings.ToUpper(flag.Arg(i))]; ok { qclass = k continue Flags } // If it starts with TYPExxx it is unknown rr if strings.HasPrefix(flag.Arg(i), "TYPE") { i, e := strconv.Atoi(string([]byte(flag.Arg(i))[4:])) if e == nil { qtype = uint16(i) switch qtype { case dns.TypeAXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return case dns.TypeIXFR: fmt.Fprintf(os.Stderr, "AXFR not supported\n") return } continue Flags } } // Anything else is a qname qname = append(qname, flag.Arg(i)) } if len(qname) == 0 { qname = make([]string, 1) qname[0] = "." qtype = dns.TypeNS } if qtype == 0 { qtype = dns.TypeA } nameserver = string([]byte(nameserver)[1:]) // chop off @ nameserver += ":" + strconv.Itoa(*port) // We use the async query handling, just to show how it is to be used. dns.HandleQuery(".", q) dns.ListenAndQuery(nil) c := new(dns.Client) if *tcp { c.Net = "tcp" if *four { c.Net = "tcp4" } if *six { c.Net = "tcp6" } } else { c.Net = "udp" if *four { c.Net = "udp4" } if *six { c.Net = "udp6" } } m := new(dns.Msg) m.MsgHdr.Authoritative = *aa m.MsgHdr.AuthenticatedData = *ad m.MsgHdr.CheckingDisabled = *cd m.MsgHdr.RecursionDesired = *rd m.Question = make([]dns.Question, 1) if *dnssec || *nsid { o := new(dns.RR_OPT) o.Hdr.Name = "." o.Hdr.Rrtype = dns.TypeOPT if *dnssec { o.SetDo() o.SetUDPSize(dns.DefaultMsgSize) } if *nsid { o.SetNsid("") } m.Extra = append(m.Extra, o) } for _, v := range qname { m.Question[0] = dns.Question{v, qtype, qclass} m.Id = dns.Id() if *query { fmt.Printf("%s\n", m.String()) } // Add tsig if *tsig != "" { if algo, name, secret, ok := tsigKeyParse(*tsig); ok { m.SetTsig(name, algo, 300, time.Now().Unix()) c.TsigSecret = map[string]string{name: secret} } else { fmt.Fprintf(os.Stderr, "tsig key data error\n") return } } c.Do(m, nameserver) } i := 0 forever: for { select { case r := <-c.Reply: if r.Reply != nil { if r.Reply.Rcode == dns.RcodeSuccess { if r.Request.Id != r.Reply.Id { fmt.Printf("Id mismatch\n") } } if r.Reply.MsgHdr.Truncated && *fallback { if c.Net != "tcp" { if !*dnssec { fmt.Printf(";; Truncated, trying %d bytes bufsize\n", dns.DefaultMsgSize) o := new(dns.RR_OPT) o.Hdr.Name = "." o.Hdr.Rrtype = dns.TypeOPT o.SetUDPSize(dns.DefaultMsgSize) m.Extra = append(m.Extra, o) *dnssec = true c.Do(m, nameserver) break } else { // First EDNS, then TCP fmt.Printf(";; Truncated, trying TCP\n") c.Net = "tcp" c.Do(m, nameserver) break } } } if r.Reply.MsgHdr.Truncated && !*fallback { fmt.Printf(";; Truncated\n") } if *check { sigCheck(r.Reply, nameserver, *tcp) nsecCheck(r.Reply) } if *short { r.Reply = shortMsg(r.Reply) } fmt.Printf("%v", r.Reply) fmt.Printf("\n;; query time: %.3d µs, server: %s(%s)\n", r.Rtt/1e3, r.RemoteAddr, r.RemoteAddr.Network()) // Server maybe } i++ if i == len(qname) { break forever } } } }