Implements vlans, bridges, and iptables rules using linux utilities.
Bases: object
Wrapper for iptables
See IptablesTable for some usage docs
A number of chains are set up to begin with.
First, nova-filter-top. It’s added at the top of FORWARD and OUTPUT. Its name is not wrapped, so it’s shared between the various nova workers. It’s intended for rules that need to live at the top of the FORWARD and OUTPUT chains. It’s in both the ipv4 and ipv6 set of tables.
For ipv4 and ipv6, the builtin INPUT, OUTPUT, and FORWARD filter chains are wrapped, meaning that the “real” INPUT chain has a rule that jumps to the wrapped INPUT chain, etc. Additionally, there’s a wrapped chain named “local” which is jumped to from nova-filter-top.
For ipv4, the builtin PREROUTING, OUTPUT, and POSTROUTING nat chains are wrapped in the same was as the builtin filter chains. Additionally, there’s a snat chain that is applied after the POSTROUTING chain.
Apply the current in-memory set of iptables rules
This will blow away any rules left over from previous runs of the same component of Nova, and replace them with our current set of rules. This happens atomically, thanks to iptables-restore.
Bases: object
An iptables rule
You shouldn’t need to use this class directly, it’s only used by IptablesManager
Bases: object
An iptables table
Adds a named chain to the table
The chain name is wrapped to be unique for the component creating it, so different components of Nova can safely create identically named chains without interfering with one another.
At the moment, its wrapped name is <binary name>-<chain name>, so if nova-compute creates a chain named “OUTPUT”, it’ll actually end up named “nova-compute-OUTPUT”.
Add a rule to the table
This is just like what you’d feed to iptables, just without the “-A <chain name>” bit at the start.
However, if you need to jump to one of your wrapped chains, prepend its name with a ‘$’ which will ensure the wrapping is applied correctly.
Remove named chain
This removal “cascades”. All rule in the chain are removed, as are all rules in other chains that jump to it.
If the chain is not found, this is merely logged.
Remove a rule from a chain
Note: The rule must be exactly identical to the one that was added. You cannot switch arguments around like you can with the iptables CLI tool.
Bind ip to public interface
Create a bridge unless it already exists.
Parameters: |
|
---|
If net_attrs is set, it will add the net_attrs[‘gateway’] to the bridge using net_attrs[‘broadcast’] and net_attrs[‘cidr’]. It will also add the ip_v6 address specified in net_attrs[‘cidr_v6’] if use_ipv6 is set.
The code will attempt to move any ips that already exist on the interface onto the bridge and reset the default gateway if necessary.
Ensure floating ip forwarding rule
Sets up local metadata ip
Create a vlan unless it already exists
Create a vlan and bridge unless they already exist
Sets up forwarding rules for vlan
Get a string containing a network’s hosts config in dhcp-host format
Return a network’s hosts config in dnsmasq leasefile format
Basic networking setup goes here
Create forwarding rule for metadata
Remove forwarding for floating ip
Unbind a public ip from public interface
(Re)starts a dnsmasq server for a given network
if a dnsmasq instance is already running then send a HUP signal causing it to reload, otherwise spawn a new instance