The neutron_fwaas.services.firewall.drivers.fwaas_base_v2 Module

class neutron_fwaas.services.firewall.drivers.fwaas_base_v2.FwaasDriverBase

Bases: object

Firewall as a Service Driver base class.

Using FwaasDriver Class, an instance of L3 perimeter Firewall can be created. The firewall co-exists with the L3 agent.

One instance is created for each tenant. One firewall policy is associated with each tenant (in the Havana release).

The Firewall can be visualized as having two zones (in Havana release), trusted and untrusted.

All the ‘internal’ interfaces of Neutron Router is treated as trusted. The interface connected to ‘external network’ is treated as untrusted.

The policy is applied on traffic ingressing/egressing interfaces on the trusted zone. This implies that policy will be applied for traffic passing from

  • trusted to untrusted zones
  • untrusted to trusted zones
  • trusted to trusted zones

Policy WILL NOT be applied for traffic from untrusted to untrusted zones. This is not a problem in Havana release as there is only one interface connected to external network.

Since the policy is applied on the internal interfaces, the traffic will be not be NATed to floating IP. For incoming traffic, the traffic will get NATed to internal IP address before it hits the firewall rules. So, while writing the rules, care should be taken if using rules based on floating IP.

The firewall rule addition/deletion/insertion/update are done by the management console. When the policy is sent to the driver, the complete policy is sent and the whole policy has to be applied atomically. The firewall rules will not get updated individually. This is to avoid problems related to out-of-order notifications or inconsistent behaviour by partial application of rules. Argument agent_mode indicates the l3 agent in DVR or DVR_SNAT or LEGACY mode.

apply_default_policy(agent_mode, apply_list, firewall)

Apply the default policy on all trusted interfaces.

Remove current policy and apply the default policy on all trusted interfaces.

create_firewall_group(agent_mode, apply_list, firewall)

Create the Firewall with default (drop all) policy.

The default policy will be applied on all the interfaces of trusted zone.

delete_firewall_group(agent_mode, apply_list, firewall)

Delete firewall.

Removes all policies created by this instance and frees up all the resources.

update_firewall_group(agent_mode, apply_list, firewall)

Apply the policy on all trusted interfaces.

Remove previous policy and apply the new policy on all trusted interfaces.