Murphy,

Exactly as you suggested. 3 changes did the trick.

* Added at Line 244 packet.dns:
    elif r.qtype == 28:
      assert isinstance(r.rddata, IPAddr6)
      return s + r.rddata.toRaw()

* Changed Line 435 packet.dns:
  return IPAddr6.from_raw(l[beg_index : beg_index + dlen])

* Added at line 521 (semi-arbitrary) addresses.py:
  def toRaw (self):
    return self.raw

Thanks for the help!

—Curtis
On Mar 11, 2014, at 11:13 PM, Murphy McCauley <murphy.mccau...@gmail.com> wrote:

> On Mar 11, 2014, at 7:35 PM, Curtis Taylor <yamahabo...@gmail.com> wrote:
> 
>> Hi,
>> 
>> I’m trying to parse and alter AAAA (IPv6) DNS responses with POX, but I get 
>> the following error:
>> ��B�)'packet:(dns) parsing answers: Bad address format
>> 
>> The error stems from around line 398 in addresses.py. At that point in the 
>> execution, my IPv6 address (converted to hex from binary) is 
>> 20010db8000000000000ff0000428329, which is correct. However, it appears that 
>> POX is attempting to split, based on colons, but these shouldn’t be in the 
>> binary representation of the IP -- (isinstance(addr, bytes) and not raw) is 
>> True.
> 
> I don't know what "binary representation" means in this context.  Is this a 
> string containing 32 hex characters?  Or is it 16 raw bytes?
> 
> The latter one (16 raw bytes) should be supported by IPAddr6 if it's passed 
> into the constructor with raw=True (or using the from_raw() factory).  The 
> former isn't supported -- it needs to be a properly formatted IPv6 address 
> (e.g., as per rfc5952), which contains colons.
> 
> It seems like packet.dns maybe has a bug here where line 432 should use the 
> from_raw() factory but doesn't.  If you make that fix does that help?
> 
>> I’ve attempted to alter addresses.py change addr from bytes to a IPv6 string 
>> separated by colons (2001:0db8:0000:0000:0000:ff00:0042:8329), but I only 
>> break things later down the line (dns.py for me). I also see nothing 
>> irregular with the OpenFlow traffic to the controller.
> 
> Can you elaborate on what breaks and how it breaks?  Does it break in the dns 
> class's hdr() method?  If so, a quick guess is that putData() needs an if 
> clause for qtype == 28 which is much like the one for qtype == 1.
> 
>> My current setup:
>> POX - 0.2.0 (carp) - l3_learning (also shows parsing error as above)
>> Mininet with custom topology
>> BIND9 - the entry in question looks like "server1    IN      AAAA    
>> 2001:db8::ff00:42:8329”. Wireshark shows nothing wrong with the DNS 
>> request/response.
>> 
>> Any help would be appreciated. 
>> 
>> Cheers,
>> Curtis
> 

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