[Bug 1619896] Re: linux-user missing cmsg IP_PKTINFO support ("Unsupported ancillary data: 0/8")

[Peter Maydell]

cmsg level/type 0/8 is SOL_IP / IP_PKTINFO. QEMU's handling of
sendmsg/recvmsg control messages needs specific support for each type of
message, and we currently do not have any support for most of them.

NB: given the description of the way client 1 at least is successful,
the guest program may be successfully coping with the missing support,
in which case the other failures would be somewhere else. It would be
worth retrying with a recent version of QEMU if you still care about
this guest program.


** Summary changed:

- Unsupported ancillary data: 0/8
+ linux-user missing cmsg IP_PKTINFO support ("Unsupported ancillary data: 0/8")

** Changed in: qemu
       Status: New => Confirmed

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1619896

Title:
  linux-user missing cmsg IP_PKTINFO support ("Unsupported ancillary
  data: 0/8")

Status in QEMU:
  Confirmed

Bug description:
  Hello,

  I have the following issue when launching the Teamspeak Server x86
  binary on an arm host.

  Host:
   Linux 4.6.2 (vanilla)
   Ubuntu 14.04.5 LTS
   HW: Cubietruck board, armv7l

  
  Used SW: Release archive qemu-2.7.0.tar.bz2 and git commit 
1dc33ed90bf1fe1c2014dffa0d9e863c520d953a
  Configure options:
    ../configure --target-list=i386-linux-user 
  I attached the output of the configure script as configure.log

  Testcase:

  1. Download and extract TeamSpeak 3 Server 3.0.13.3 (x86)
    Souce: 
http://dl.4players.de/ts/releases/3.0.13.3/teamspeak3-server_linux_x86-3.0.13.3.tar.bz2

  2. Modifiy ts3server_minimal_runscript.sh for ease of use
    - ./ts3server $@
    + /usr/local/bin/qemu-i386 ./ts3server $@

  3. Execute ./ts3server_minimal_runscript.sh

  Wait for 6 Minutes until teamspeak server started. QEMU saturates the
  cpu while Teamspeak is precomputing a puzzle. (Whatever that means)

  After that Teamspeak settles with the following output:
    2016-09-03 10:50:59.555582|INFO    |Query         |   |listening on 
0.0.0.0:10011, :::10011

  The Qemu process is now idling with ~2% cpu load. This is actually the
  first time for me that QEMU is able to successfully launch the
  Teamspeak server. Kudos!

  4. Connect client 1

  TS Clients can connect, but the following line is printed pretty often:
    Unsupported ancillary data: 0/8

  The line seems to come from qemu (linux-user/syscall.c)

  
  5. Connect client 2
  When a second client is connected the audio transmission is successful for a 
few seconds, but the server drops the connection after that and refuses to take 
new connections.

  Please let me know, if you need more information. I'll gladly provide
  strace or valgrind logs.

  Best regards,
  Tobias

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1619896/+subscriptions