Implements NSID (option -nsid). Closes #11

bortzmeyer · Apr 16, 2018 · f960fbf · f960fbf
1 parent a12a813
commit f960fbf
Showing 1 changed file with 50 additions and 3 deletions.
diff --git a/check-soa.go b/check-soa.go
@@ -6,6 +6,7 @@
 package main
 
 import (
+ "encoding/hex"
  "errors"
  "flag"
  "fmt"
@@ -42,11 +43,13 @@ type SOAreply struct {
  retrieved bool
  msg string
  rtt time.Duration
+ nsid string
 }
 
 type nameServer struct {
  name string
  ips []string
+ fnsid []string
  globalErrMsg string
  success []bool
  errMsg []string
@@ -67,6 +70,7 @@ var (
  version *bool
  quiet *bool
  noedns *bool
+ nsid *bool
  bufsize *int
  tcp *bool
  nodnssec *bool
@@ -149,6 +153,17 @@ func soaQuery(mychan chan SOAreply, zone string, name string, server string) {
  if !*noedns {
  m.SetEdns0(uint16(*bufsize), !*nodnssec)
  }
+ if *nsid {
+ o := new(dns.OPT)
+ o.Hdr.Name = "." // MUST be the root zone, per definition.
+ o.Hdr.Rrtype = dns.TypeOPT
+ e := new(dns.EDNS0_NSID)
+ e.Code = dns.EDNS0NSID
+ e.Nsid = ""
+ o.Option = append(o.Option, e)
+ m.Extra = make([]dns.RR, 1)
+ m.Extra[0] = o
+ }
  m.Id = dns.Id()
  if *recursion {
  m.RecursionDesired = true
@@ -174,6 +189,18 @@ func soaQuery(mychan chan SOAreply, zone string, name string, server string) {
  result.msg = fmt.Sprintf("%s", err.Error())
  } else {
  result.rtt = rtt
+ if *nsid {
+ for n := range soa.Extra {
+ if soa.Extra[n].Header().Rrtype == dns.TypeOPT {
+ for m := range soa.Extra[n].(*dns.OPT).Option {
+ switch e := soa.Extra[n].(*dns.OPT).Option[m].(type) {
+ case *dns.EDNS0_NSID:
+ result.nsid = e.Nsid
+ }
+ }
+ }
+ }
+ }
  if soa.Rcode != dns.RcodeSuccess {
  result.msg = dns.RcodeToString[soa.Rcode]
  break
@@ -288,29 +315,40 @@ func masterTask(zone string, nameservers map[string]nameServer) (uint, uint, boo
  }
  soaResult := <-soaChannel
  _, present := results[soaResult.name]
+ fnsid := make([]byte, 0)
+ if *nsid {
+ fnsid = make([]byte, hex.DecodedLen(len(soaResult.nsid)))
+ n, err := hex.Decode(fnsid, []byte(soaResult.nsid))
+ if err != nil || n != hex.DecodedLen(len(soaResult.nsid)) {
+ fnsid = []byte("ERROR IN DECODING")
+ }
+ }
  if !present {
  results[soaResult.name] = nameServer{name: soaResult.name,
  ips: make([]string, 0),
  success: make([]bool, 0),
  errMsg: make([]string, 0),
  serial: make([]uint32, 0),
- rtts: make([]time.Duration, 0)}
+ rtts: make([]time.Duration, 0),
+ fnsid: make([]string, 0)}
  }
  if !soaResult.retrieved {
  results[soaResult.name] = nameServer{name: soaResult.name,
  ips: append(results[soaResult.name].ips, soaResult.address),
  success: append(results[soaResult.name].success, false),
  errMsg: append(results[soaResult.name].errMsg, fmt.Sprintf("%s", soaResult.msg)),
  serial: append(results[soaResult.name].serial, 0),
- rtts: append(results[soaResult.name].rtts, soaResult.rtt)}
+ rtts: append(results[soaResult.name].rtts, soaResult.rtt),
+ fnsid: append(results[soaResult.name].fnsid, string(fnsid))}
  success = false
  } else {
  results[soaResult.name] = nameServer{name: soaResult.name,
  ips: append(results[soaResult.name].ips, soaResult.address),
  success: append(results[soaResult.name].success, true),
  errMsg: append(results[soaResult.name].errMsg, ""),
  serial: append(results[soaResult.name].serial, soaResult.serial),
- rtts: append(results[soaResult.name].rtts, soaResult.rtt)}
+ rtts: append(results[soaResult.name].rtts, soaResult.rtt),
+ fnsid: append(results[soaResult.name].fnsid, string(fnsid))}
  }
  }
  for name := range nameservers {
@@ -338,6 +376,7 @@ func main() {
  version = flag.Bool("v", false, "Displays version of the code")
  quiet = flag.Bool("q", false, "Quiet mode, display only errors")
  noedns = flag.Bool("r", false, "Disable EDNS format")
+ nsid = flag.Bool("nsid", false, "Enable NSID option")
  bufsize = flag.Int("b", int(EDNSBUFFERSIZE), "EDNS buffer size")
  tcp = flag.Bool("tcp", false, "Use TCP")
  // DNSSEC DO is on by default, to detect firewall or
@@ -359,6 +398,11 @@ func main() {
  flag.Usage()
  os.Exit(1)
  }
+ if *noedns && *nsid {
+ fmt.Fprintf(os.Stderr, "NSID requires EDNS\n")
+ flag.Usage()
+ os.Exit(1)
+ }
  if *v4only && *v6only {
  fmt.Fprintf(os.Stderr, "v4-only or v6-only but not both\n")
  flag.Usage()
@@ -477,6 +521,9 @@ func main() {
  if *times && result.rtts[i] != 0 {
  msg = msg + fmt.Sprintf(" (%d ms)", int(float64(result.rtts[i])/1e6))
  }
+ if *nsid && result.fnsid[i] != "" {
+ msg = msg + fmt.Sprintf(" (NSID %s)", result.fnsid[i])
+ }
  if !*quiet || !result.success[i] {
  fmt.Printf("\t%s: %s: %s\n", result.ips[i], code, msg)
  }