Comment 20 for bug 1527902

Kamal Mostafa (kamalmostafa) wrote :

Good news, everyone! TL;DR:

Pali, I've (finally) managed to reproduce and fix this bug (IPv6 UDP DNS), with your recommendation of the program 'jdns'. For reference, here's my reproduction procedure, on a fresh install of Precise server (a slight variation on a method Pali developed):

sudo apt-get install dnsmasq
echo listen-address=::1 | sudo tee /etc/dnsmasq.d/ipv6
echo nameserver ::1 | sudo resolvconf -a lo.inet6
sudo /etc/init.d/dnsmasq restart
# fetch and build https://github.com/psi-im/iris/tree/master/src/jdns
./jdns -d -6 uni AAAA google.com ::1

    ... kernel versions >= 3.13.0-69.112~precise1 fail with "[1] Error: Timeout"

Ian, thanks very much for the pointer! Your mention of Debian bug 808293 led to this pending patch, which does fix this bug (and hopefully your tftp bug also): https://patchwork.ozlabs.org/patch/561746/ ("udp: properly support MSG_PEEK with truncated buffers")

Here's an amd64 test kernel which is 3.13.0-69.112~precise1 + a simple backport of that patch. Pali, this passes the 'jdns' test. Can you confirm that it resolves your original issue too? Ian, does it also fix your tftp problem?

http://kernel.ubuntu.com/~kamal/lp1527902/linux-image-3.13.0-69-generic_3.13.0-69.112~precise1+lp1527902_amd64.deb