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 ** Changed in: linux (Ubuntu) Assignee: Joseph Salisbury (jsalisbury) => Kamal Mostafa (kamalmostafa) ** Changed in: linux-lts-trusty (Ubuntu) Assignee: Joseph Salisbury (jsalisbury) => Kamal Mostafa (kamalmostafa) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1527902 Title: 3.13.0-71: IPv6 UDP DNS packets are not received Status in linux package in Ubuntu: In Progress Status in linux-lts-trusty package in Ubuntu: In Progress Bug description: After upgrading linux kernel from version 3.13.0-68 to 3.13.0-71 then Kopete (IM messenger) stopped working, cannot connect to any jabber server. I started debugging this problem and found out that, problem resolve when I boot back 3.13.0-68 kernel version (without touching any system files or packages). When I boot 3.13.0-71 Kopete always does not connect. Next I debugged that problem on 3.13.0-71 is just when /etc/resolv.conf contains only IPv6 addresses of DNS servers. Problem is comes down to dns resolver (jabber in Kopete has its own for SRV records) and syscall recvfrom() (on IPv6 socket) always return error -EAGAIN without any data returned. But wireshark see that DNS response was recevied. So it looks like that after 3.13.0-68 kernel was included some change which broke receiving UDP packets via IPv6 socket. IPv4 is OK. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1527902/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
