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