From 9d6888a24ac7a03997b1ab543801f461bf1eabf8 Mon Sep 17 00:00:00 2001
From: ptillemans <pti@snamellit.com>
Date: Thu, 21 Sep 2023 23:58:08 +0200
Subject: [PATCH] initial commit

---
 go.mod  | 12 ++++++++++++
 go.sum  | 12 ++++++++++++
 main.go | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 go.mod
 create mode 100644 go.sum
 create mode 100644 main.go

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..92f3825
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,12 @@
+module gitea.snamellit.com/pti/godns
+
+go 1.21.1
+
+require github.com/miekg/dns v1.1.56
+
+require (
+	golang.org/x/mod v0.12.0 // indirect
+	golang.org/x/net v0.15.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+	golang.org/x/tools v0.13.0 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..92d0efe
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,12 @@
+github.com/miekg/dns v1.1.56 h1:5imZaSeoRNvpM9SzWNhEcP9QliKiz20/dA2QabIGVnE=
+github.com/miekg/dns v1.1.56/go.mod h1:cRm6Oo2C8TY9ZS/TqsSrseAcncm74lfK5G+ikN2SWWY=
+golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
+golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/net v0.15.0 h1:ugBLEUaxABaB5AJqW9enI0ACdci2RUd4eP51NTBvuJ8=
+golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
+golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
+golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.13.0 h1:Iey4qkscZuv0VvIt8E0neZjtPVQFSc870HQ448QgEmQ=
+golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..d9cb343
--- /dev/null
+++ b/main.go
@@ -0,0 +1,47 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/miekg/dns"
+)
+
+
+type DnsTest struct {
+  server net.IP
+  testHost string
+  rtt time.Duration
+  answer net.IP 
+}
+
+func RunTest(srv net.IP, host string) (*DnsTest, error) {
+  m := new(dns.Msg)
+  m.SetQuestion(host, dns.TypeA)
+  c := new(dns.Client)
+  in, rtt, err := c.Exchange(m, fmt.Sprintf("%s:53", srv))
+  if err != nil {
+    return nil, err
+  }
+  for _, answer := range in.Answer {
+    if t, ok := answer.(*dns.A); ok {
+      return &DnsTest{server: srv, testHost: host, rtt: rtt, answer: t.A}, nil
+    }
+  }
+  return nil, errors.New("No answer found")
+}
+
+
+func main() {
+  testHosts := []string{ "gitea.snamellit.com", "www.snamellit.com", "home.snamellit.com", "nas.snamellit.com" , "gitlab.melexis.com", "dsl.melexis.com", "cvs.tess.elex.be", "cvs.sofia.elex.be", "cvs.sensors.elex.be", "cvs.erfurt.elex.be", "www.google.com" }
+  for _, host := range testHosts {
+    t, err := RunTest(net.ParseIP("192.168.1.1"), host + ".")
+      if err != nil {
+      fmt.Println("Error for ", host, ":",  err.Error())
+        continue
+      }
+      fmt.Println("Answer ", t.server, t.testHost, t.answer, t.rtt)
+  }
+}