ae9d1160bd
Setting up rules to allow DHCPv6, DHCP, and RAs from specific IP addresses based on Neutron resources has a few issues: 1. It violates separation of concerns. We are implementing logic to calculate where an IPv6 RA advertisement or DHCP advertisement should be coming from in the security group code. This code should not be trying to guess IPv6 LLAs, know about subnet modes, DHCP server implementations, or the type of L3 plugin being used. Currently all of these assumptions are baked into code that should only be filtering, which makes it very rigid and brittle when it comes to other implementations for DHCP and/or RAs. 2. It has scaling issues on large networks. Every time one of these provider rules is updated, it triggers every L2 agent to refresh all of the security group rules for ports in that network, which puts significant load on the server. 3. It's main purpose: preventing spoofing of RA[1,2] and DHCP packets, has long been superceded by preventing VMs from acting as DHCP/RA servers[3][4]. This patch completely removes all of this logic and just returns static provider rules to the agents that allow all DHCP server and RA traffic ingress to the client. This addresses the issues highlighted above since the code is significantly simplified and the provider rules don't require refreshes on the agents. Now that the provider rules never change, the RPC notification listener on the agent-side for 'notify_provider_updated' is now just a NOOP that doesn't trigger any refreshes. The notification was left in place on the server side for older version agents that have stale IP-specific provider rules. The entire notification can be removed in the future. The one open concern with this approach is that VMs will now be able to receive DHCP offers from other DHCP servers on the same network that aren't being filtered (e.g. a VM with port security disabled or another device on a provider network). In order to address this for DHCP, this patch adds two rules that only allow DHCP offers targeted to either the broadcast or the correct client IP. This prevents incorrect offers from ever reaching the client. For RAs, this patch just allows all RAs so we may pick up advertisements from other v6 routers attached to a network; however, the instance won't actually be allowed to use bad addresses. 1. https://bugs.launchpad.net/neutron/+bug/1262759 2. I1d5c7aaa8e4cf057204eb746c0faab2c70409a94 3. Ice1c9dd349864da28806c5053e38ef86f43b7771 4. https://git.openstack.org/cgit/openstack/neutron/tree/ neutron/agent/linux/iptables_firewall.py ?h=521b1074f17574a5234843bce68f3810995e0e1d#n475 Closes-Bug: #1653830 Closes-Bug: #1663077 Change-Id: Ibfbf011284cbde396f74db9d982993f994082731 |
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| bin | ||
| devstack | ||
| doc | ||
| etc | ||
| neutron | ||
| rally-jobs | ||
| releasenotes | ||
| tools | ||
| .coveragerc | ||
| .gitignore | ||
| .gitreview | ||
| .mailmap | ||
| .pylintrc | ||
| .testr.conf | ||
| CONTRIBUTING.rst | ||
| HACKING.rst | ||
| LICENSE | ||
| README.rst | ||
| TESTING.rst | ||
| babel.cfg | ||
| bindep.txt | ||
| requirements.txt | ||
| run_tests.sh | ||
| setup.cfg | ||
| setup.py | ||
| test-requirements.txt | ||
| tox.ini | ||
README.rst
Team and repository tags
Welcome!
To learn more about neutron:
- Documentation: http://docs.openstack.org
- Features: http://specs.openstack.org/openstack/neutron-specs
- Defects: http://launchpad.net/neutron
Get in touch via email. Use [Neutron] in your subject.
To learn how to contribute:
CONTRIBUTING.rst