<div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Mar 24, 2017 at 7:27 PM, Brian Haley <span dir="ltr"><<a href="mailto:haleyb.dev@gmail.com" target="_blank">haleyb.dev@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><span class="gmail-">On 03/24/2017 06:41 AM, Ghanshyam Mann wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Hi All,<br>
<br>
Tempest is testing SG rule creation and pinging scenario tests with<br>
ethertype='IPv6' and protocol='icmp' [0].<br>
In case of ethertype='IPv6', currently neutron accept protocol type<br>
as 'icmp', 'icmpv6' and 'ipv6-icmp' which again seems like duplication<br>
of SG rules bug on neutron side but not sure [1]<br>
<br>
But it seems like some driver does not work with 'icmp' on IPv6, at<br>
least ODL as mentioned in bug [2]. Where few others like ML2/OVS<br>
iptables driver convert 'icmp' to 'icmpv6' when ethertype='IPv6' and had<br>
no issue with 'icmp'.<br>
<br>
IMO neutron should keep accepting 'icmp' for IPv6 for backward<br>
compatibility and legacy usage and tempest should test 'icmp' also along<br>
with other protocol type.<br>
But we need more feedback on that what is right way (as per backward<br>
compatibility pov) and recommended way for having best behaviour for SG<br>
rules on IPv6. What best can work for all plugins also?<br>
</blockquote>
<br></span>
Thanks for raising this issue. Let me just restate it a little so it's clear.<br>
<br>
1. One can create an IPv6 rule using protocol value "icmp" today, and the base security group code does the right thing changing the rule to be correct for the underlying implementation, for example, "ipv6-icmp" for iptables. It doesn't look like all other drivers handle this properly.<br>
<br></blockquote><div><div class="gmail_default" style="font-family:tahoma,sans-serif">Well, let the Neutron API accept multiple values like "icmp/icmpv6/ipv6-icmp", but IMO it should store a single Security Group rule in the DB and raise "Duplicate error when similar rule is configured once again".</div><div class="gmail_default" style="font-family:tahoma,sans-serif">Currently, Neutron treats each of them as a different Security Group rule and stores them as separate entries in the DB.</div><div class="gmail_default" style="font-family:tahoma,sans-serif">However, IPtables Firewall driver in Neutron is converting[1] the "ethertype=IPv6 and protocol=icmp" as a request to ICMPv6 and applying the necessary ip-table rule.</div><div class="gmail_default"><font face="tahoma, sans-serif"><a href="https://github.com/openstack/neutron/blob/stable/newton/neutron/agent/linux/iptables_firewall.py#L373">https://github.com/openstack/neutron/blob/stable/newton/neutron/agent/linux/iptables_firewall.py#L373</a></font><br></div><div class="gmail_default"><font face="tahoma, sans-serif"><br></font></div><div class="gmail_default" style="font-family:tahoma,sans-serif">Since this is not a documented behavior, other firewall drivers (which I guess could be an issue even with OVS firewall driver) may be missing this info.</div></div><div> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
2. The neutron API will accept multiple values - "icmp", "ipv6-icmp" and "icmpv6" for an IPv6 rule, but it will create unique database entries for each (I just verified that). While that shouldn't create multiple entries in the base iptables code, it will probably generate a warning in the logs about a duplicate being suppressed.<br>
<br>
<br>
So there are a few things that could be done:<br>
<br>
1. Drivers need to accept "icmp" in order to be backwards-compatible with the current code.<br>
<br>
2. Duplicates should be detected and generate 409 (?) errors.<br>
<br>
3. We should add a migration (IMO) where any duplicates are squashed.<br>
<br></blockquote><div class="gmail_default" style="font-family:tahoma,sans-serif">Agree with your points.</div><div class="gmail_default" style="font-family:tahoma,sans-serif"></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
The open question is, do we want to change the DB to have a different value here, like "icmpv6" ? We could obviously add a migration where we update the value. The problem is that flag day could pose a problem if out-of-tree drivers don't support the new value. I think we should leave it "icmp" for that reason, thoughts from others?<br>
<br></blockquote><div><div class="gmail_default" style="font-family:tahoma,sans-serif">IMO, the out-of-tree drivers should be supporting the icmpv6 protocol rule properly. There is a possibility that they may hit this issue[<a href="https://bugs.launchpad.net/tempest/+bug/1671366">https://bugs.launchpad.net/tempest/+bug/1671366</a>] for not being aware that a request for "Ethertype=IPv6 and protocol=icmp" should be treated as ICMPv6 SG rule.</div><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif">Please see the DB entries for the two SG rules - <a href="http://paste.openstack.org/show/604190/">http://paste.openstack.org/show/604190/</a></div><br></div><div><div class="gmail_default" style="font-family:tahoma,sans-serif"><br></div></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
-Brian<br>
<br>
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