Method and apparatus for distributing firewall rules
Some embodiments of the invention provide a novel method for specifying firewall rules. In some embodiments, the method provides the ability to specify for a particular firewall rule, a set of network nodes (also called a set of enforcement points below) at which the particular firewall should be enforced. To provide this ability, the method of some embodiments adds an extra tuple (referred to below as the AppliedTo tuple) to a firewall rule. This added AppliedTo tuple lists the set of enforcement points at which the firewall rule has to be applied (i.e., enforced).
1. A method of distributing firewall rules, the method comprising:
defining a firewall rule to include (i) a set of fields for matching a set of attributes of a flow to determine whether the flow matches the firewall rule, (ii) an action field to identify an action to perform on the flow when the flow matches the firewall rule, and (iii) a group identifier field that identifies a group of one or more enforcement devices at which the firewall rule should be enforced;
distributing the firewall rule to each enforcement device in the group of enforcement devices;
modifying the group of enforcement devices; and
in response to the modification, communicating with at least one enforcement device in the group of enforcement devices to account for the modification;
wherein modifying the group of enforcement devices comprises removing a particular enforcement node from the group of enforcement nodes of the first enforcement device; and
wherein communicating comprises directing the first enforcement device to remove the particular enforcement node from the group of enforcement nodes.
2. The method of claim 1 , wherein modifying the group of enforcement devices comprises adding an enforcement device to the group; and
communicating comprises distributing the firewall rule to the added enforcement device.
3. The method of claim 1 , wherein
modifying the group of enforcement devices comprises removing an enforcement device from the group; and
communicating comprises directing the removed enforcement device to remove the firewall rule.
4. The method of claim 1 , wherein
the group identifier field identifies a set of enforcement nodes at which the firewall rule should be enforced by the group of enforcement devices; and
at least a first enforcement device in the group of enforcement devices enforces the firewall rule for at least a group of two enforcement nodes.
5. The method of claim 4 , wherein the first enforcement device is a host computing device on which a plurality of virtual machines (VMs) are executing, wherein the enforcement nodes in the group of enforcement nodes are VMs executing on the host.
6. The method of claim 5 , wherein each enforcement node in the group of enforcement nodes is specified in terms of an identifier for a virtual network interface card (VNIC) of a VM.
7. The method of claim 1 , wherein the group identifier field is separate from the set of fields for matching.
8. A non-transitory machine readable medium storing a program for distributing firewall rules, the program comprising sets of instructions for:
defining a firewall rule to include a group identifier that identifies a set of enforcement devices at which the firewall rule should be enforced; and
distributing the firewall rule to each enforcement device in the set of enforcement devices of the group;
modifying the set of enforcement devices identified by the group;
in response to the modification, communicating with at least one enforcement device in the set of enforcement devices to account for the modification;
wherein the set of instructions for modifying the set of enforcement devices comprises a set of instructions for removing a particular enforcement node from the group of enforcement nodes of the first enforcement device; and
wherein the set of instructions for communicating comprises a set of instructions for directing the first enforcement device to remove the particular enforcement node from the group of enforcement nodes.
9. The non-transitory machine readable medium of claim 8 , wherein
the set of instructions for modifying the set of enforcement devices comprises a set of instructions for adding an enforcement device to the set; and
the set of instructions for communicating comprises a set of instructions for distributing the firewall rule to the added enforcement device.
10. The non-transitory machine readable medium of claim 8 , wherein
the set of instructions for modifying the set of enforcement devices comprises a set of instructions for removing an enforcement device from the set; and
the set of instructions for communicating comprises a set of instructions for directing the removed enforcement device to remove the firewall rule.
11. The non-transitory machine readable medium of claim 8 , wherein
the group identifier identifies a set of enforcement nodes at which the firewall rule should be enforced by the set of enforcement devices; and
at least a first enforcement device in the set of enforcement devices enforces the firewall rule for at least a group of two enforcement nodes.
12. The non-transitory machine readable medium of claim 11 , wherein the first enforcement device is a host computing device on which a plurality of virtual machines (VMs) are executing, wherein the enforcement nodes in the group of enforcement nodes are VMs executing on the host.
13. The non-transitory machine readable medium of claim 12 , wherein each enforcement node in the group of enforcement nodes is specified in terms of an identifier for a virtual network interface card (VNIC) of a VM.
14. A method of specifying firewall rules, the method comprising:
specifying a plurality of firewall rules that each includes at least one enforcement-node identifier that identifies a set of enforcement nodes in a network where the firewall rule has to be enforced, at least one enforcement-node identifier being a group identifier that includes a modifiable set of members; and
based on the enforcement-node identifiers of the specified firewall rules, distributing at least first and second firewall rules respectively to first and second enforcement devices;
in response to a modification to the members of the group identifier, identifying at least the first firewall rule as a rule that uses the group identifier as an enforcement-node identifier, wherein the modification comprises removing a particular enforcement node from the set of enforcement nodes of the first enforcement device; and
distributing an update to the first enforcement device to update the set of enforcement nodes to which the first enforcement device applies the first firewall rule by directing the first enforcement device to remove the particular enforcement node from the set of enforcement nodes.
15. The method of claim 14 , wherein the update removes an enforcement node from the set of enforcement nodes to which the first enforcement device applies the first firewall rule.
16. The method of claim 14 , wherein the update adds an enforcement node to the set of enforcement nodes to which the first enforcement device applies the first firewall rule.
17. The method of claim 14 , further comprising distributing the identified firewall rule to a third enforcement device after identifying the firewall rule.