Too long tunnel devices names

[Viktor Křivák]

Openvswitch neutron agent create too long names for tunnel devices.
Ports name are created like %type-%remoteip.
For example for gre type tunnel, name is gre-192.168.201.10 which exceed max length for linux network devices (15 chars).
This name pass throw openvswitch, but create failed port with ofport -1 and proceed with error like this:

2014-02-17 11:25:14.048 22908 ERROR neutron.agent.linux.ovs_lib [-] Unable to execute ['ovs-ofctl', 'add-flow', 'br-tun', 'hard_timeout=0,idle_timeout=0,priority=1,in_port=-1,actions=resubmit(,2)']. Exception:
Command: ['sudo', '/usr/bin/neutron-rootwrap', '/etc/neutron/rootwrap.conf', 'ovs-ofctl', 'add-flow', 'br-tun', 'hard_timeout=0,idle_timeout=0,priority=1,in_port=-1,actions=resubmit(,2)']
Exit code: 1
Stdout: ''
Stderr: 'ovs-ofctl: -1: negative values not supported for in_port\n'

This bug affect only devices with long ip address 10.0.0.1 will pass, but 192.168.201.10 fail.

Found in HAVANA with:
openvswitch: 1.9.3-1
linux: 3.2.54-2

But I think length limit will apply on all versions.

[Darragh O'Reilly (darragh-oreilly)]

Running this:
from neutron.agent.linux.ovs_lib import OVSBridge
br_tun = OVSBridge(br_name='br-tun', root_helper='sudo')
br_tun.add_tunnel_port('gre-100.100.100.100', '100.100.100.100',
                       '100.100.100.99', tunnel_type='gre')

on:
$ uname -a
Linux devstack 3.2.0-58-generic #88-Ubuntu SMP Tue Dec 3 17:37:58 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
$ sudo ovs-vsctl show | tail -1
    ovs_version: "1.4.0+build0"

returns '-1'
And using a port name <=15 chars is ok.

But running the same on:
$ uname -a
Linux netnode 3.8.0-32-generic #47~precise1-Ubuntu SMP Wed Oct 2 16:19:35 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
$ sudo ovs-vsctl show | tail -1
    ovs_version: "1.10.2"

returns a positive integer in a string, ie no problem.

When using the OVS plugin, 'id' is returned from the tunnel_sync rpc, and so there is no problem. But the ML2 plugin does not return an id, and so the remote ip is used:
https://github.com/openstack/neutron/blob/stable/havana/neutron/plugins/openvswitch/agent/ovs_neutron_agent.py#L1029
  tunnel_id = tunnel.get('id', tunnel['ip_address'])
  tun_name = '%s-%s' % (tunnel_type, tunnel_id)

One solution would be to use the hex of the IP address which will always be 8 chars, so even with the 'vxlan-' prefix, port_name will only be 14 chars. The port name just needs to be unique.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/74442

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/74442
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=3d8ab7964ace4e96539cfbc0587c8f04c81ac3b3
Submitter: Jenkins
Branch: master

commit 3d8ab7964ace4e96539cfbc0587c8f04c81ac3b3
Author: Darragh O'Reilly <email address hidden>
Date: Tue Feb 18 16:31:08 2014 +0000

    ovs-agent: use hexadecimal IP address in tunnel port name

    The remote IP address is used to form the tunnel port name when
    the ovs-agent is used with the ML2 plugin. With some OVS/Linux
    combinations there is a 15 character limit on port names, so a
    name like 'gre-192.168.10.10' does not work. This fix uses the
    shorter hexadecimal representation of the IP address instead.

    Change-Id: I58caf54219130159525b5a6492eaa451062c2ff5
    Closes-Bug: 1281098