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() {
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() {
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
}
}
}
}