[Bug 1665394] Re: DNS resolution of irc.freenode.net or chat.freenode.net fails

[Pirouette Cacahuète]

It is likely to be an upstream problem. Given a zone with A/AAAA records
with enough addresses, I can reproduce the problem.

Hacking in systemd source code, I could find those STR:
 - disable "resolve" in nsswitch.conf
 - add a resolution against a record with a lot of addresses in src/libsystemd/sd-resolve/test-resolve.c
 - build test-resolve tool
 - run ./test-resolve

e.g.:
> r = sd_resolve_getaddrinfo(resolve, &q2, "test.neteffmon.eu", NULL, &hints, getaddrinfo_handler, NULL);

Running this results in:
> Assertion '*length <= maxlength' failed at src/libsystemd/sd-resolve/sd-resolve.c:203, function serialize_addrinfo(). Aborting.

Changing BUFSIZE in src/libsystemd/sd-resolve/sd-resolve.c to something
bigger (e.g. 65536U), rebuild and restart ./test-resolve, the resolution
succeeds.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1665394

Title:
  DNS resolution of irc.freenode.net or chat.freenode.net fails

Status in systemd package in Ubuntu:
  Confirmed

Bug description:
  I am running Ubuntu 16.10 (from a base install upgraded several
  times), with proposed-updates enabled. Recently, I started having
  problems where I am unable to resolve irc.freenode.net.

  This is unrelated to the networks. I have been able to confirm that
  systemd-resolved is able to perform the name resolution. Yet,
  getaddrinfo() call returns -EAI_AGAIN error.

  This can be reproduced using getent:
  > $ getent ahosts irc.freenode.net
  > $

  While testing v4 or v6 directly returns something valid:
  > $ getent ahostsv4 irc.freenode.net
  > 38.229.70.22    STREAM chat.freenode.net
  > 38.229.70.22    DGRAM  
  > 38.229.70.22    RAW    
  > 130.239.18.119  STREAM 
  > 130.239.18.119  DGRAM  
  > 130.239.18.119  RAW    
  [...]
  > $

  > $ getent ahostsv6 irc.freenode.net
  > 2001:5a0:3604:1:64:86:243:181 STREAM chat.freenode.net
  > 2001:5a0:3604:1:64:86:243:181 DGRAM  
  > 2001:5a0:3604:1:64:86:243:181 RAW    
  > 2001:6b0:e:2a18::118 STREAM 
  > 2001:6b0:e:2a18::118 DGRAM  
  > 2001:6b0:e:2a18::118 RAW    
  [...]
  > $

  dpkg.log shows there has been some upgrade of systemd recently, though
  I cannot tell for sure if that directly relates to the problem, I do
  use suspend-to-ram a lot and reboot not that often.

  > $ lsb_release -a
  > LSB Version:	core-9.20160110ubuntu5-amd64:core-9.20160110ubuntu5-noarch:printing-9.20160110ubuntu5-amd64:printing-9.20160110ubuntu5-noarch:security-9.20160110ubuntu5-amd64:security-9.20160110ubuntu5-noarch
  > Distributor ID:	Ubuntu
  > Description:	Ubuntu 16.10
  > Release:	16.10
  > Codename:	yakkety

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1665394/+subscriptions