DNS Server - panic: runtime error: index out of range

[miekg]

DNS Server - panic: runtime error: index out of range

[miekg]

[ Quoting <reply+i-4392099-43bc40389> in "[dns] DNS Server - panic: runtime e..." ]

I'm running Go 1.0.1.

When run the "reflect" example and them I run a nmap UDP port scan (nmap -sU localhost), the following error success (complete output log):

panic: runtime error: index out of range

Thanks for your report. I believe this is fixed in the latest Git version of
dns.

grtz Miek

[h2non]

Thanks Miek for your fast support!

In other context, I'm looking for an easy example for implement a DNS server parsing zones files, so I'm newbie with Go and I don't know how to use some functionalities and the API.

You can provide another easy example about how to make this?
Thanks a lot again!

[miekg]

[ Quoting <reply+i-4392099-43bc40389> in "Re: [dns] DNS Server - panic: runti..." ]

Thanks Miek for your fast support!

In other context, I'm looking for an easy example for implement a DNS server
parsing zones files, so I'm newbie with Go and I don't know how to use some
functionalities and the API.

You'll need a simple server that reads and parses a single zonefile? I can make
a example for that. A more complete nameserver is more difficult as Go dns does
not has a zone structure -- I might add that, but I'm still looking for a fast
tree structure for that.

For reading zone files you can use: ParseZone and of course
ex/reflect/reflect.go is a simple nameserver in itself.

Regards,

Miek Gieben

[h2non]

A basic example helps a lot!

So, I just need to insert the next code into reflec.go for implement the zone parsing?

zone := `$ORIGIN .
$TTL 3600       ; 1 hour
name                    IN SOA  a6.nstld.com. hostmaster.nic.name. (
                                203362132  ; serial
                                300        ; refresh (5 minutes)
                                300        ; retry (5 minutes)
                                1209600    ; expire (2 weeks)
                                300        ; minimum (5 minutes)
                                )
$TTL 10800      ; 3 hours
@   10800   IN  NS  @
               IN       NS      g6.nstld.com.
               7200     NS      h6.nstld.com.
             3600 IN    NS      j6.nstld.com.
             IN 3600    NS      k6.nstld.com.
                        NS      l6.nstld.com.
                        NS      a6.nstld.com.
                        NS      c6.nstld.com.
                        NS      d6.nstld.com.
                        NS      f6.nstld.com.
                        NS      m6.nstld.com.
$ORIGIN name.
0-0onlus                NS      ns7.ehiweb.it.
                        NS      ns8.ehiweb.it.
0-g                     MX      10 mx01.nic
                        MX      10 mx02.nic
                        MX      10 mx03.nic
                        MX      10 mx04.nic
                        TXT     "10 mx\"04.nic"
$ORIGIN 0-g.name
moutamassey             NS      ns01.yahoodomains.jp.
                        NS      ns02.yahoodomains.jp.
`
to := ParseZone(strings.NewReader(zone), "", "testzone")

[miekg]

[ Quoting <reply+i-4392099-43bc40389> in "Re: [dns] DNS Server - panic: runti..." ]

A basic example helps a lot!

So, I just need to insert the next code into reflec.go for implement the zone parsing?

almost.

         zone := `$ORIGIN .
$TTL 3600       ; 1 hour
name                    IN SOA  a6.nstld.com. hostmaster.nic.name. (
                                203362132  ; serial
                                300        ; refresh (5 minutes)
                                300        ; retry (5 minutes)
                                1209600    ; expire (2 weeks)
                                300        ; minimum (5 minutes)
                                )
$TTL 10800      ; 3 hours
@ 10800   IN  NS  @
               IN       NS      g6.nstld.com.
               7200     NS      h6.nstld.com.
             3600 IN    NS      j6.nstld.com.
             IN 3600    NS      k6.nstld.com.
                        NS      l6.nstld.com.
                        NS      a6.nstld.com.
                        NS      c6.nstld.com.
                        NS      d6.nstld.com.
                        NS      f6.nstld.com.
                        NS      m6.nstld.com.
$ORIGIN name.
0-0onlus                NS      ns7.ehiweb.it.
                        NS      ns8.ehiweb.it.
0-g                     MX      10 mx01.nic
                        MX      10 mx02.nic
                        MX      10 mx03.nic
                        MX      10 mx04.nic
                        TXT     "10 mx\"04.nic"
$ORIGIN 0-g.name
moutamassey             NS      ns01.yahoodomains.jp.
                        NS      ns02.yahoodomains.jp.
`
  to := ParseZone(strings.NewReader(zone), "", "testzone")

(also see parse_test the ExampleZone() function.

You'll need to add:

// Get the RRs from the zone being read
for x := range to {
if x.Error == nil {
// Print is for now
fmt.Printf("%s\n", x.RR)
} else {
// Error occured, just continue?
}
}

Resource record lookups and combining RRs to RRsets is not implemented. This is
sorta on the TODO.

Regards,

Miek Gieben

[h2non]

Thanks a lot again!

I added the above code,to the reflec example and then I try to compile it, but fails with the following error:

./reflect.go:113: undefined: ParseZone

I just want to load a zone to serve via the DNS server instance, so I'm newbie with Go and I don't understand the library API.
Please, you can provide an example about how to create a simple DNS server parsing zones from variables or files?

I think, at least for Go not experimented users, a well API documentation and some more examples will be really helpful.

Thanks a lot for your time and patience :)

[miekg]

[ Quoting <reply+i-4392099-43bc40389> in "Re: [dns] DNS Server - panic: runti..." ]

Thanks a lot again!

I added the above code,to the reflec example and then I try to compile it, but fail with the following error:

./reflect.go:113: undefined: ParseZone

dns.ParseZone

you need to prefix the funcion with the package name, in this case "dns".

I just want to load a zone the serve via the DNS server instance, so I'm newbie with Go and I don't understand the library API.
Please, you can provide an example about how to create a simple DNS server parsing zones from variables or files?

This is on my TODO, but I'm strapped for time, so I don't know when this will
happen.

I think, at least for Go not experimented users, a well API documentation and some more examples will be really helpful.

There is a lot of documentation there, and also in the ex/ directory you'll find
more (client)side examples. Learning Go and learning DNS at the same time may
not be the most efficient way to learn Go :)

Are you aware of miek.nl/files/go with copies of "Learning Go"?

What documentation do you need, besides a complete nameserver :) ?

Regards,

Miek Gieben

[h2non]

Thanks a lot Miek :)

I will take a look to your book for learning the bases of Go, a then I try again to use your library.

Congratulations for your book and code, is really amazing :)
Cheers!