openwrt-packages-dist/net/openvswitch/README.md

Which packages to install

Install openvswitch if you need OpenFlow virtual switch function. It contains ovs-vswitchd, ovsdb-server and helper utilities such as ovs-vsctl, ovs-ofctl, ovs-ctl etc.

Linux kernel datapath module openvswitch.ko will also be installed along with package openvswitch. Tunnel encap support for gre, geneve, vxlan can be included by installing kmod-openvswitch-{gre,geneve,vxlan} respectively

For OVN deployment

• Install openvswitch-ovn-north for ovs-northd, ovsdb-server, ovn helper utitlies
• Install openvswitch-ovn-host for ovn-controller and openvswitch

How to use them

Open vSwitch provides a few very useful helper script in /usr/share/openvswitch/scripts/. A simple initscript is provided. It's mainly a wrapper around ovs-ctl and ovn-ctl with simple knobs from /etc/config/openvswitch. Procd is not used here.

/etc/init.d/openvswitch start
/etc/init.d/openvswitch stop
/etc/init.d/openvswitch stop north
/etc/init.d/openvswitch restart ovs
/etc/init.d/openvswitch status

Use ovs-ctl and ovn-ctl directly for more functionalities

Open vSwitch in-tree Linux datapath modules

The Open vSwitch build system uses regexp and conditional-compilation heuristics to support building the shipped kernel module source code against a wide range of kernels, as of openvswitch-2.10, the list is supposed to include vanilla linux 3.10 to 4.15, plus a few distro kernels.

It may NOT work

• Sometimes the code does not compile
• Sometimes the code compiles but insmod will fail
• Sometimes modules are loaded okay but actually does not function right

For these reasons, the in-tree datapath modules are NOT visible/enabled by default.

Building and using in-tree datapath modules requires some level of devel abilities to proceed. You are expected to configure build options and build the code on your own

E.g. pair openvswitch userspace with in-tree datapath module

CONFIG_DEVEL=y
CONFIG_PACKAGE_openvswitch=y
# CONFIG_PACKAGE_kmod-openvswitch is not set
CONFIG_PACKAGE_kmod-openvswitch-intree=y

E.g. replace in-tree datapath module with upstream version

opkg remove --force-depends kmod-openvswitch-intree
opkg install kmod-openvswitch
ovs-ctl force-reload-kmod

UCI configuration options

There are 5 config section types in package openvswitch: ovs ovn_northd, ovn_controller & ovs_bridge.

Each of these supports a disabled option, which should be set to 0 to launch the respective daemons.

The ovs section section also supports the options below, to configure a set of SSL CA, certificate and private key. After adding these to Open vSwitch, you may specify ssl: connection methods for e.g. the OpenFlow controller. Note that Open vSwitch only reads these files during startup, so it needs to be restarted after adding or changing these options.

Name	Type	Required	Default	Description
disabled	boolean	no	0	If set to 1, do not configure SSL
ca	string	no	(none)	Path to CA certificate
cert	string	no	(none)	Path to certificate
key	string	no	(none)	Path to private key

The ovs_bridge section also supports the options below, for initialising a virtual bridge with an OpenFlow controller.

Name	Type	Required	Default	Description
disabled	boolean	no	0	If set to true, disable initialisation of the named bridge
name	string	no	Inherits UCI config block name	The name of the switch in the OVS daemon
controller	string	no	(none)	The endpoint of an OpenFlow controller for this bridge
datapath_id	string	no	(none)	The OpenFlow datapath ID for this bridge
datapath_desc	string	no	(none)	The OpenFlow datapath description for this bridge
fail_mode	string	no	standalone	The bridge failure mode

The ovs_port section can be used to add ports to a bridge. It supports the options below.

Name	Type	Required	Default	Description
disabled	boolean	no	0	If set to 1, do not add the port to the bridge
bridge	string	yes	(none)	Name of the bridge to add the port to
port	string	yes	(none)	Name of the port to add to the bridge
ofport	integer	no	(none)	OpenFlow port number to be used by the port
tag	integer	no	(none)	802.1Q VLAN tag to set on the port
type	string	no	(none)	Port type, e.g. internal, erspan, type, ...